Symposium Organizers
Laura Espinal, National Institute of Standards and Technology
Enrico Traversa, University of Rome Tor Vergata
Samuel S. Mao, Lawrence Berkeley National Laboratory
Marie-Isabelle Baraton, Centre Europeen de la Ceramique
Symposium Support
National Institute of Standards and Technology
G3: Materials Sustainability in Research Policy
Session Chairs
Marie-Isabelle Baraton
Sam Mao
Monday PM, November 26, 2012
Hynes, Level 3, Room 306
2:30 AM - *G3.01
The Sustainable Chemistry, Engineering and Materials Initiative at the National Science Foundation
Ian Robertson 2 1
1University of Illinois Urbana USA2National Science Foundation Arlington USA
Show AbstractSustainability has become an area of emphasis for the National Science Foundation, NSF, as evidenced by the many programs within the portfolio of the Science, Engineering, and Education for Sustainability (SEES) initiative. A new effort under the SEES initiative, and one outlined in the FY13 Budget Request, is the Sustainable Chemistry, Engineering, and Materials (SusChEM) initiative. The Sustainable Materials effort seeks to support and encourage research projects targeting the discovery of new materials or make materials more sustainable through improved synthesis, enhanced applications, and/or advances in lifecycle management. These efforts as well as those in other participating divisions will be described.
3:00 AM - *G3.02
Sustainability in Materials Research in the EU: From FP7 to Horizon 2020
Renzo Tomellini 1 Johan Veiga Benesch 1
1European Commission Brussels Belgium
Show AbstractEnvironmental issues are steadily getting more and more attention at EU policy level. This can for example be seen in the Raw Materials Initiative by DG Enterprise and Resource Efficient Europe by DG Environment which goes back to the theme of a sustainable economy as expressed by the Europe 2020 growth strategy. DG Research and Innovation supports related research activities. The Nanotechnology, Materials & Production (NMP) Theme in the FP7 Cooperation scheme has taken stock of this, by for example by including aspects such as substitution, life cycle assessment, improved resource efficiency and better performance materials in the NMP calls for proposals. This is done with the aim to achieve a more green economy and fostering more sustainable consumption and production patterns. Research on better performing and sustainable materials will more than ever be a pre-condition to meeting such challenges. Progress will come through the development of intelligent materials that embed and transfer knowledge into products and processes or perform certain tasks, when in use or during manufacturing. Already, some 70 percent of all technical innovations hinge directly or indirectly on the properties of the materials employed. We have passed from the perception "materials are in the drawer" to the perception "materials are the bottleneck". The next step can be "materials are the solution". At least 60 % of the total proposed Horizon 2020 budget will be related to sustainable development, the vast majority of this expenditure contributing to mutually reinforcing climate and environmental objectives. In a resource-scarce Europe, new products must have low material / energy resource needs and high knowledge content. As stated in the Europe 2020 strategy endorsed by EU leaders: “Europe must promote technologies and production methods that reduce natural resource use, and increase investment in the EU's existing natural assets”. Materials can have a large environmental impact in many of its stages, from sourcing, extraction, processing, auxiliary materials and processes, use and end of life fate. The choice or design of material solutions can thus have a great impact on the technologies in which they are used. Implying that a material could be an integral part of the solution to a problem created by the use of a specific technology. Such solutions could require entirely new materials either to replace a material or be part of a new technology based on better performing materials and ecodesigned products.
GF2: Sustainability Forum: Successful Interdisciplinary Sustainable Development Research
Session Chairs
John Abelson
Ashley White
Martin Green
Frank DiSalvo
Monday PM, November 26, 2012
Hynes, Level 3, Room 306
4:15 AM - *GF2.01
Sustainable Materials: With Both Eyes Open
Julian Allwood 1
1University of Cambridge Cambridge United Kingdom
Show AbstractOne third of the world's carbon emissions are emitted by industry. Most industrial emissions relate to producing materials, and steel and cement are by far the most important contributors. The industries that make materials are energy-intensive, so have always been motivated to be efficient, and have now reached a fantastic level of performance. However the world's demand for materials is growing, and likely to double by 2050. So, by default, industrial emissions will also double, unless we do something differently. This talk sets out an agenda for making a big difference to global emissions, by requiring less new material. Based on a five-year project, with eight researchers and a consortium of 20 large industrial partners, we have gathered evidence on six “material efficiency” options which allow us to provide the same final services (such as housing or transport) with significantly less material. The talk will present a series of case studies to demonstrate how these strategies can be applied in practice, and explore the actions by government, businesses, and consumers that would bring them about.
4:45 AM - *GF2.02
Empowering and Engaging Engineering Students through Immersion and Discourse in Sustainable Development for the 21st Century
Diran Apelian 1
1Worcester Polytechnic Institute Worcester USA
Show AbstractSustainability is a hot topic nowadays, and seems to be quite the popular issue; and it is about time! Rachel Carson&’s seminal book “Silent Spring” was published in 1962 and ten years later, in 1972, DDT was banned. Sustainable development is and must be part of the engineering curriculum. Societal issues facing the 21st century spanning from energy, food and water, transportation, housing, materials, and health require engineering solutions that are sustainable. But how does one teach this? Where does it fit in our packed curricula? How does one teach the basic concepts that natural systems are closed loop, use few elements, are cyclic, and where the indicator of well-being is equilibrium? At WPI, we have decided to start this journey early on, and in fact the first day the student sets foot on campus. In this presentation, the Great Problem Seminars (GPS) course will be described and discussed, and in particular, the course titled: “Sustainable Development for the 21st Century”, a course developed by D. Apelian and S. Nikitina (from Humanities and Arts). The course is different than any structured engineering course. It is interdisciplinary, it is writing intensive, and requires a Socratic approach to “learning” (not teaching) and an immersion in an eight week long project in teams of five students. In brief, the course implants in the students&’ mind from day one that we can make a difference in the world through engineering, and through elegant solutions that are sustainable.
G4: Poster Session: Materials Sustainability
Session Chairs
Laura Espinal Thielen
Enrico Traversa
Monday PM, November 26, 2012
Hynes, Level 2, Hall D
9:00 AM - G4.01
Clay-chitosan Nanobrick Walls: Completely Renewable Gas Barrier and Flame Retardant Nanocoatings
Galina Laufer 1 Jaime C. Grunlan 1 2 3
1Texas Aamp;M University College Station USA2Texas Aamp;M University College Station USA3Texas Aamp;M University College Station USA
Show AbstractThin films prepared via layer-by-layer (LbL) assembly of renewable materials exhibit exceptional oxygen barrier and flame retardant properties. Positively- charged chitosan (CH), at two different pH levels (3 and 6), was paired with anionic montmorillonite (MMT) clay nanoplatelets. Thin film assemblies prepared with CH at high pH are thicker due to low polymer charge density. A 30 bilayer (CH pH 6-MMT) nanocoating (~100 nm thick) reduces the oxygen permeability of a 0.5 mm thick polylactic acid film by four orders of magnitude. This same coating system completely stops the melting of a flexible polyurethane foam, when exposed to direct flame from a butane torch, with just 10 bilayers (~ 30 nm thick). Cone calorimetry confirms that this coated foam exhibited a reduced peak heat release rate, by as much as 52%, relative to the uncoated control. These sustainable nanocoatings could prove beneficial for new types of food packaging or a replacement for environmentally persistent antiflammable compounds.
9:00 AM - G4.03
Tangible Plasticization Effects of Sodium Salts of Dimer Acids Prepared by Recycling of Waste Cooking Oil on the Mechanical Properties of Styrene Ionomers
Kwang-Hwan Ko 1 Hye Ryeon Park 2 Joon-Seop Kim 1 Young-Wun Kim 3
1Chosun University Gwangju Republic of Korea2Chosun University Gwangju Republic of Korea3KRICT Daejeon Republic of Korea
Show AbstractThese days, the environmental regulations on industrial consumption have been tightened up, leading to an urgent need for the development of new eco-friendly materials. Thus, natural products, non-toxic and environmental-friendly products, have gained much attention in regard to the development of “green chemicals”. During the last five years, we have undertaken research on the preparation and modification of bio-based monomers. In course of our project, a number of “dimer acids” have been prepared by recycling of waste cooking oil, e.g. waste vegetable and animal oils. In general, vegetable oil contains unsaturated fatty acids such as oleic acid and linoleic acid, and, thus, various dimer acids, e.g. monocyclic, bicyclic, acyclic dimer acids can be prepared via the synthesis process using fatty acids as raw materials. In the present work, we investigated the effects of the presence of dimer acid (DA) molecules in the Na-sulfonated polystyrene (PSSNa) and poly(styrene-co Na-methacrylate) (PSMANa) ionomers on the ionomer properties dynamic mechanically. We found that the presence of DA molecules in the PSSNa ionomer decreased the matrix and cluster Tgs of the ionomer strongly without changing the ionic modulus of the ionomer. Thus, we proposed that the DA molecules resided in the matrix and cluster regions of the PSSNa ionomer and acted mainly as effective plasticizer. In the case of the PSMANa ionomers, the presence of the DA molecules decreased the cluster Tg of the ionomer, without chaining the matrix Tg, and increased the ionic modulus of the ionomer. Thus, we suggested that the monocyclic and bicyclic DA molecules in the PSMANa ionomer also acted as plasticizer, but the acyclic DA molecules were phase-separated to form filler particles that increased the ionic modulus of the PSMANa ionomer. We also observed that the positions of X-ray peak of PSSNa ionomers containing DA did not change with DA amounts, but those of PSMANa ionomers shifted to higher angles. This X-ray result was also supportive for the proposed roles of Na molecules in PSSNa and PSMANa ionomers. In conclusion, we found that the NA can be used as very effective “green” plasticizer [This study was supported by the R&D Center for Valuable Recycling (Global-Top Environmental Technology Development Program) funded by the Ministry of Environment, Korea (Project No.:11-D27-OD)].
9:00 AM - G4.05
Investigation of Castor Oil-based Polyurethane Reinforced by Nanocellulose
Seong Hun Kim 1 Sang Ho Park 1 Kyung Wha Oh 2
1Hanyang University Seoul Republic of Korea2Chung-Ang University Seoul Republic of Korea
Show AbstractPolyurethane (PU) is one of the most frequently used for various applications such as insulation, automotive parts and seating materials. However, these materials were strongly depended on petroleum as feedstock and this fact became problematic because of steadily going up of petroleum oil price and environmental aspect as well as sustainability. Therefore the development of bio-renewable feedstocks for PU such as plant oil-based materials became highly desirable in industrial field. In this research, the bio-based PU was synthesized by reaction between isocyanate and castor oil. The castor oil was used as polyol among various plant oils because it was excellent polyol candidate because of its low toxicity, availability, and low cost. In addition, the castor oil could be used for polyol directly to react with isocyanate groups without chemical modification because it had already hydroxyl groups. The nanocellulose of eco friendly nanofillers was prepared in order to reinforce the castor oil-based polyurethane. Nano size cellulose fiber and whisker have a great interest as new excellent reinforcements because it was biodegradable and had remarkable mechanical properties and lightness than those of natural fiber or glass fiber. The nanocellulose whiskers were prepared by chemical and mechanical treatments. The castor oil-based PU (CPU) was reinforced by nanocellulose with two different methods, which the CPU was physically bonded with nanocellulose (CPU/nanocellulose) by solution casting and chemically bonded with nanocellulose (CPU-nanocellulose) to improve interfacial adhesion. The covalent bonding formation between hydroxyl group of nanocellulose and isocyanate was confirmed by FTIR. The nanocellulose covalently bonded with CPU increased storage modulus and complex viscosity of CPU as measured by rheological analysis. This was due to improvement of cross-link density of the elastomer network because of nanocellulose-PU molecular interaction. The mechanical properties of CPU reinforced by nanocellulose composites were investigated. Tensile test revealed that CPU-nanocellulose composites had highest tensile strength and modulus because of improvement of interfacial adhesion and nanoreinforcing effect of nanocellulose with high aspect ratio. The effect of nanocellulose on thermal stability of CPU was also investigated. This research was supported by National Research Foundation of Korea. (Project No. 2011-0028966)
9:00 AM - G4.06
Distributed Recycling of Post-consumer Plastic Waste in Rural Areas
M. Kreiger 1 G. C. Anzalone 2 M. L. Mulder 1 A. Glover 1 J. M. Pearce 1 3
1Michigan Technological University Houghton USA2Michigan Technological University Houghton USA3Michigan Technological University Houghton USA
Show AbstractAlthough the environmental benefits of recycling plastics are well established and most geographic locations within the U.S. offer some plastic recycling, recycling rates are often low. Low recycling rates are often observed in conventional centralized recycling plants due to the challenge of collection and transportation for high-volume low-weight polymers. The recycling rates decline further when low population density, rural and relatively isolated communities are investigated because of the distance to recycling centers makes recycling difficult and both economically and energetically inefficient. The recent development of a class of open source hardware tools (e.g. RecycleBots) able to convert post-consumer plastic waste to polymer filament for 3-D printing offer a means to increase recycling rates by enabling distributed recycling. In addition, to reducing the amount of plastic disposed of in landfills, distributed recycling may also provide low-income families a means to supplement their income with domestic production of small plastic goods. This study investigates the environmental impacts of polymer recycling. A life-cycle analysis (LCA) for centralized plastic recycling is compared to the implementation of distributed recycling in rural areas. Environmental impact of both recycling scenarios is quantified in terms of both emissions and energy use per unit mass of recycled plastic. A sensitivity analysis is used to determine the environmental impacts of both systems as a function of distance to recycling centers. The results of this LCA are discussed and conclusions are drawn about the viability of distributed recycling from an ecological perspective and trajectories of future research in open source hardware for recycling plastics are established.
9:00 AM - G4.08
Microwave Assisted In situ Synthesis of Proton Conducting Titanate Nanotubes into Nafion
Bruno R Matos 1 Elisabete I Santiago 1 Andre S Ferlauto 2 Fabio C Fonseca 1
1IPEN Sao Paulo Brazil2UFMG Belo Horizonte Brazil
Show AbstractThe in situ synthesis of inorganic nanoparticles such as titania and silica by using the sol-gel method has been successfully reported previously in organic-inorganic hybrids. Such a technique takes advantage of the hydrophobic-hydrophilic phase-separated structure of ionomers as a template for in situ grow of finely dispersed inorganic particles. However, one disadvantage of the sol-gel method is the restriction for producing nanoparticles with new architectures such as nanotubes . In the present study, spherical titania nanoparticles incorporated in a ionomer-matrix composite were converted in situ to titanate nanotubes aiming at enhanced properties at high temperature (~130°C). Nafion-titania (anatase) hybrids produced by in situ sol-gel, with high inorganic phase content (~25 wt.%) and titania average particle size of ~5 nm, were used as a precursor. Hybrid membranes were immersed in a concentrated basic solution and a microwave-assisted hydrothermal treatment was carried out in a microwave oven at 150 °C for 180 min. Both the precursor and the modified composite membranes were characterized by X-ray diffraction (XRD), Raman spectroscopy (RS), small angle X-ray scattering (SAXS), and transmission electron microscopy (TEM). The experimental results revealed that the anatase precursor phase was successfully converted into the proton conducting titanate phase, as confirmed from XRD, RS , and TEM results. The composite membranes based on Nafion containing proton conducting fillers are envisioned as good candidates for the application as electrolytes in proton exchange membrane fuel cells operating at high temperature.
9:00 AM - G4.10
SnP2O7 Dispersed Proton/electron Mixed Conducting Glass-ceramics
Satoshi Yamanishi 1 Yusuke Daiko 1 Atsushi Mineshige 1 Tetsuo Yazawa 1
1University of Hyogo Himeji Japan
Show AbstractIntroduction Inorganic electrolytes with high proton conductivity in temperatures ranging from approximately 300 to 500°C have attracted much attention owing to their various applications such as fuel cells, sensors, electrolyzers, and solid catalysts. An anhydrous proton conductor, M3+-doped SnP2O7 (M = In or Al ), shows high proton conductivities ( > 10-1 S cm-1) and good fuel cell performance between 150 and 350°C under dry conditions [1,2]. However, pure SnP2O7 has some serious problems including chemical durability and sinterability for practical applications. We have studied a new type of proton conducting glass-electrolyte prepared utilizing a conventional melting method. Recently, we successfully prepared a glass electrolyte with 100 % proton transport (proton transport number, tH=1) at 400-500 °C [3]. In this study, crystallization behavior of tin-phosphosilicate glasses and those electrical conductivity under the intermediate temperature (300 - 700 °C) were investigated. Experiments Regent grade of SnO2, Al2O3 (or In2O3), P2O5, SiO2 and B2O3 were melted in an alumina crucible at 1600°C, and the obtained glasses were heat-treated at 900°C for the crystallization. X-ray diffraction (XRD), differential scanning calorimeter (DSC), alternate current (AC) and direct current (DC) conductivities, open-circuit voltage (OCV) under H2/O2 fuel cell conditions and proton transport number (tH) measurements were performed under the intermediate temperature region. Results Glasses with different Sn/P ratio (Sn/P = 0.15~1.53) were prepared, and all the as-deposited glasses obtained were x-ray amorphous. It was found that only SnP2O7 crystal was precipitated in the glass with Sn/P = 0.52 after the crystallization at 900°C. Proton/electron conductivities and the results of proton transport number measurement revealed that the glass with Sn/P = 0.52 shows pure proton conduction (tH=1 meaning no electron conductivity). On the other hand, in the samples with Sn/P > 0.90, both the SnP2O7 and Sn2.5P3O12 crystalline phases were precipitated. Interestingly, these samples show not only proton conductivity but also electron conductivity. Effect of the trivalent cation dopant into the tin-phosphosilicate is also discussed in relation to the proton/electron conductivity. Reference [1] M. Nagao et al., J. Electrochem. Soc., 153, A1604(2006). [2] A. Tomita et al., J. Electrochem. Soc., 154, B1265 (2007). [3] Y. Daiko et al., J. Electrochem. Solid State Lett., 14, B63 (2011).
9:00 AM - G4.13
Up-cycling of Solid Polymer Wastes and Biomass Residues to Carbon Nanomaterials
Chuanwei Zhuo 1 Joner Alves 1 2 4 Jorge Tenorio 2 Henning Richter 3 Yiannis Levendis 1
1Northeastern University Boston USA2University of Sao Paulo Sao Paulo Brazil3Nano-C, Inc. Westwood USA4Aperam South America Timamp;#243;teo Brazil
Show AbstractThis work addresses the up-cycling of common solid wastes by utilizing them as carbon sources for the synthesis of carbon nanomaterials (CNMs). Agricultural sugar cane bagasse and corn residues, scrap tire chips, and postconsumer polyethylene terephthalate (PET) and polyethylene (PE) bottle shreddings were either thermally treated by sole pyrolysis, or by sequential pyrolysis and partial oxidation. The resulting gaseous carbon-bearing effluents were then channeled into a heated reactor. CNMs, including carbon nanotubes, were catalytically synthesized therein on stainless steel meshes. These feedstocks could supersede the use of costly and often toxic or highly flammable chemicals, such as hydrocarbon gases, carbon monoxide, and hydrogen, which are commonly used as feedstocks in current nanomanufacturing processes for CNMs. This work revealed that the structure of the resulting CNMs is determined by the feedstock type, through the disparate mixtures of carbon-bearing gases generated when different feedstocks are pyrolyzed. CNM characterization was conducted by scanning and transmission electron microscopy, as well as by Raman spectroscopy and by thermogravimetric analysis. Gas chromatography was used to characterize the gases in the synthesis chamber. This work demonstrated an alternative method for efficient manufacturing of CNMs using both biodegradable and nonbiodegradable agricultural and municipal carbonaceous wastes.
9:00 AM - G4.14
Chemically Synthesized ZnSb Alloy Nanoparticles towards Thermoelectric Applications
Mai Thanh Nguyen 1 Derrick Michael Mott 1 Higashimine Koichi 1 Maenosono Shinya 1
1Japan Advanced Institute of Science and Technology Nomi Japan
Show AbstractRecently thermoelectric (TE) materials are becoming a very attractive field of research toward applications in micro cooling devices, energy conversion and waste heat recovery. For this purpose, these materials should have high thermoelectric figure of merit arising from high Seebeck coefficient, high electrical conductivity and low thermal conductivity. From bulk materials, it is challenging to achieve a high value for TE efficiency because of the close inverse relation between electrical and thermal conductivity. On the other hand, low dimensional materials offer a host of advantages to address this challenge based on electron transmission and phonon blocking at the particle grain boundary which helps maintain the electrical conductivity while reducing the thermal conductivity or the increase of the Seebeck coefficient due to the quantum confinement effect or energy filtering. Therefore, TE research now focuses on nano-structured materials. Among many TE materials, ZnSb systems consist of relatively abundant elements and exhibit excellent TE performance (especially β-Zn4Sb3 phase) because of the remarkably low thermal conductivity (κ) arising from their disordered local structure. Nanostructured Zn-Sb, therefore, is expected to have extremely low κ due to the multiplier effect of intrinsic disordered structure and nanograin boundaries which makes it a promising material for energy harvesting purposes. To achieve this, we have developed a synthetic method towards Zn-Sb alloy nanoparticles (NPs) via a sequential reduction of metal precursors and subsequent alloying. Sb cores were first synthesized followed by the growth of Zn shell onto the cores and subsequent alloying. Resulting NPs collected after the synthesis were characterized by various methods including TEM, Scanning TEM, XRD, TEM-EDS, XPS and EDS mapping. It is found that the NPs are nearly spherical in shape with a mean size of 21.1±3.4 nm and are composed of both Zn and Sb. The XRD and XPS analysis of ZnSb containing NPs indicate alloy phases with higher oxidation stability compared to monoelemental Zn or Sb NPs. EDS mapping furthermore illustrates the alloy structure with a composition gradient along the NP radius in which the core is Sb rich and the shell is Zn rich. Primary results in processing and characterizing the thermoelectric properties of thin film made from these NPs show the ability to use these chemically-synthesized ZnSb NPs as building blocks for efficient nanostructured thermoelectric materials.
9:00 AM - G4.15
Stable, Single-layer MX2 Transition-metal Oxides and Dichalcogenides in a Honeycomb-like Structure
Can Ataca 1 2 4 Hasan Sahin 3 4 5 Salim Ciraci 2 3 4
1Massachusetts Institute of Technology Cambridge USA2Bilkent University Ankara Turkey3Bilkent University Ankara Turkey4Bilkent University Ankara Turkey5University of Antwerp Antwerpen Belgium
Show AbstractRecent studies have revealed that single-layer transition-metal oxides and dichalcogenides (MX2) might offer properties superior to those of graphene. So far, only very few MX2 compounds have been synthesized as suspended single layers, and some of them have been exfoliated as thin sheets. Using first-principles structure optimization and phonon calculations based on density functional theory, we predict that, out of 88 different combinations of MX2 compounds, several of them can be stable in free-standing, single-layer honeycomb-like structures. These materials have two-dimensional hexagonal lattices and have top-view appearances as if they consisted of either honeycombs or centered honeycombs. However, their bonding is different from that of graphene; they can be viewed as a positively charged plane of transition-metal atoms sandwiched between two planes of negatively charged oxygen or chalcogen atoms. Electron correlation in transition-metal oxides was treated by including Coulomb repulsion through LDA + U calculations. Our analysis of stability was extended to include in-plane stiffness, as well as ab initio, finite-temperature molecular dynamics calculations. Some of these single-layer structures are direct- or indirect-band-gap semiconductors, only one compound is half-metal, and the rest are either ferromagnetic or nonmagnetic metals. Because of their surface polarity, band gap, high in-plane stiffness, and suitability for functionalization by adatoms or vacancies, these single-layer structures can be utilized in a wide range of technological applications, especially as nanoscale coatings for surfaces contributing crucial functionalities. In particular, the manifold WX2 heralds exceptional properties promising future nanoscale applications. This work is published at J. Phys. Chem. C 116, 8983 (2012).
9:00 AM - G4.16
Towards a Factory for Infinity
Raymond Oliver 1 Alexander Louis Bone 1 Oliver Poyntz 1
1Northumbria University London United Kingdom
Show AbstractTo be competitive in the 21st Century on a global basis, manufacturing technologies have to demonstrate low cost, low inventory, high functionality, high added value product flexibility and be amendable and agile enough to work in both societal (concerns driven) and commercial (opportunities driven) environments. This paper focuses on the rate at which we consume and waste material and how therefore we can use lean manufacturing to create the lowest possible energy-materials cycles. We examine additive technologies, rapid prototyping and 3D printing/extrusion, self assembly materials (SAMs) and directed assembly materials (DAMs) as well as ambient processing on a local scale, going against the 20th Century view of ‘heat, beat and treat&’ where we overwhelm materials with energy until the materials succumb to our designs. The Factory for Infinity is the foundation for future factories, supporting an ideal system for consumption of products. Using only 100% recyclable (no ‘downcycling&’) or truly biodegradable materials, we have designed a system of low energy, small scale manufacturing processes that require old products to make new ones, allowing materials to be recycled infinitely in a local, closed loop cycle. This project led to the coining of the term ‘Disassembly is Manufacture&’ , a phrase which epitomises the ethos and ideals of this vision. The pursuit of this ideal vision lead the research team to the repurposing of techniques used within the extractive sector to enable new recycling systems and technologies. In practical terms experiments were conducted in two major sectors - zero waste, low energy metals remanufacture; by taking waste metals, dissolving them into an acid solution then precisely printing specific metals out of solution directly into new product; and rapid growth bio-materials; where microbials assist in new bio composites. The outcomes of this research were 3 sample products which exemplify current consumption. The Copper Bottle Filling discarded, one-use plastic bottles with frozen water; we melted forms that people would keep for much longer. We used electroforming from copper e-waste and lined the inside of the bottle with an antibacterial film of silver. The Glass keyboard The keyboard was selected as it is considered to be a device with a limited life expectancy, soon to be made obsolete by a variety of new types of input device. Having a short life expectancy it seemed an excellent product to display the qualities of the factory for infinities methodology. The Lamp Mycelium bond together local crop waste to form a light, fire-retardant, fully compostable material. The material is grown around the electronic components. A hazel neck and recycled glass printed with copper from e-waste complete the circuit.
9:00 AM - G4.18
Energy Efficient and Multi-functional Liquid Infused Nanostructured Coatings on Aluminum Surfaces
Philseok Kim 1 2 Michael J Kreder 1 Jack Alvarenga 1 Joanna Aizenberg 1 2 3
1Harvard University Cambridge USA2Harvard University Cambridge USA3Harvard University Cambridge USA
Show AbstractLiquid interfaces typically provide ultrasmooth, defect-free, and chemically homogeneous characteristics. If a layer of liquid film is locked in place on a porous solid surface, the surface can also present similar properties. Our group has recently developed this novel concept of surface, SLIPS (Slippery Liquid Infused Porous Substrates, Nature 477 443, 2011) that exhibits extremely low friction and adhesion to a wide range of materials with extreme temperature and pressure stability. SLIPS-coated surfaces thus present extreme repellent properties to almost any type of materials and have been proven to prevent ice and frost formation and to show about an order of magnitude lower adhesion to ice than other known materials (ACS Nano ASAP 2012). We will discuss recent advances in materials and methods to allow SLIPS coatings on aluminum to improve the energy efficiency and sustainability of many infrastructures, for example, as energy-efficient frost-free refrigeration coils and as drag reducing coatings in fluid transport pipeline systems. Preliminary results show that our new approach combining microtexturing and nanotexturing methods exhibits a wide range of applicability of SLIPS coating as well as improved long term performance of maintaining low friction and adhesion than previously reported approaches based on electrodeposited nanostructured polypyrrole coating. Characterizations of surface micro/nanostructures, contact angles and hysteresis, adhesion properties, and the robustness of SLIPS performance under high shear conditions will be presented. These studies will provide basic understanding for the mechanisms associated with the topography of textured substrates and their SLIPS performances. We envision that further development of materials and methods based on these design principles will lead to universal and general coating methods to create SLIPS on a wide range of substrates including metals, glass, plastics, ceramics, fabrics, etc.
G1: Materials for Sustainable Development and Technologies
Session Chairs
Laura Espinal Thielen
Enrico Traversa
Monday AM, November 26, 2012
Hynes, Level 3, Room 306
9:30 AM - *G1.01
Materials for Sustainable Development
Martin L Green 1
1NIST Gaithersburg USA
Show AbstractEvery human endeavor should be informed by sustainable development, because none of our material resources are infinite and only a few sources of energy are sustainable. The most common definition of sustainable development comes from the 1987 Brundtland report, “Our Common Future”, and states that “Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs.” However, this is not a scientific definition, and essentially refers to economic development. Further, it requires that we know, or at least accurately estimate, what the needs of future generations will be. In this talk I will address the meaning and definition of sustainable development, and explore the space at its intersection with materials science. Materials have always served the role of technology enablers, and will continue to do so for sustainable development. The immediate and direct connections between sustainable development and materials science include efficient use of materials (conservation, substitution, reuse, repurposing, recycling), materials life cycle assessment, replacement materials (scarcity, resource availability, materials flow analysis and economics), energy (materials to support alternative energy technologies, to mitigate problems with fossil-fuel technologies, and to increase energy efficiency), mitigation of undesirable impacts on environment and human health from technology and economic growth (corrosion, pollution, toxic waste), and water purification. In this talk I will further highlight a few examples of materials for sustainable development in research programs at NIST, such as materials for carbon capture, thermoelectric devices, and standards for bio-derived products.
10:00 AM - G1.02
Environmental Impacts of Distributed Manufacturing from 3-D Printing of Polymer Components and Products
M. Kreiger 1 J. M. Pearce 1 2
1Michigan Technological University Houghton USA2Michigan Technological University Houghton USA
Show AbstractAlthough additive layer manufacturing is well established for rapid prototyping the low throughput and historic costs have prevented mass-scale adoption. The recent development of the RepRap, an open source self-replicating rapid prototyper, has made low-cost 3-D printers readily available to the public at reasonable prices (<$1,000). The RepRap (Prusa Mendell variant) currently prints 3-D objects in a 200x200x200 square millimeters build envelope from acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA). ABS, a rigid thermoplastic, can be injection molded to manufacture polymer objects that need strength and durability. PLA, which can also be injection molded is a plant-based thermoplastic that can be recycled and composted. The melting temperature of ABS and PLA enable use in low-cost 3-D printers, as these temperature are low enough to use in melt extrusion in the home, while high enough for prints to retain their shape at average use temperatures. Using 3-D printers to manufacture provides the ability to both change the fill composition by printing voids and fabricate shapes that are impossible to make using tradition methods like injection molding. This allows more complicated shapes to be created while using less material, which could reduce environmental impact. As the open source 3-D printers continue to evolve and improve in both cost and performance, the potential for economically-viable distributed manufacturing of products increases. Thus, products and components could be customized and printed on-site by individual consumers as needed, reversing the historical trend towards centrally mass-manufactured and shipped products. Distributed manufacturing reduces embodied transportation energy from the distribution of conventional centralized manufacturing, but questions remain concerning the potential for increases in the overall embodied energy of the manufacturing due to reduction in scale. In order to quantify the environmental impact of distributed manufacturing using 3-D printers, a life cycle analysis was performed on three plastic products. The energy consumed and emissions produced from conventional large-scale production overseas are compared to experimental measurements on a RepRap producing identical products with ABS and PLA. The results of this LCA are discussed in relation to the environmental impact of distributed manufacturing with 3-D printers and polymer selection for 3-D printing to reduce this impact. Conclusions are drawn about the viability of distributed manufacturing from an ecological perspective and trajectories of future research in open source 3-D manufacturing are established.
10:15 AM - G1.03
Sustainable Semiconducting Copper Zinc Sulfide Nanoparticles
Derrick Mott 1 Shinya Maenosono 1
1Japan Advanced Institute of Science and Technology Nomi Japan
Show AbstractOne of the primary drawbacks of nanotechnology today is the limited abundance of the elements used to create the most enhanced materials. Nanoparticles composed of precious and rare metals such as gold, platinum, palladium, antimony, tellurium, etc. have been demonstrated in fundamental studies to possess novel properties that can be used in advanced applications such as sensors, catalysis, thermoelectrics, solar cells, as well as many others. The advances in these areas are exciting, but there are few cases of these fundamental studies moving on to widespread development and overall adoption of the new technology by society. The advancement of these materials has been restricted by the non-sustainability of the technology, namely the limited availability and resulting cost of the raw materials needed to create the nanoparticles is too high. In response, studies are needed that focus on the synthesis and characterization of new nanoparticle systems that utilize abundant and non-toxic elements. In this study, we have developed a synthetic technique towards copper zinc sulfide nanoparticles, which are highly attractive because of the high abundance and low toxicity of these elements. These chalcogenide type nanoparticles are semiconducting in nature which is advantageous for use in a wide variety of applications including thermoelectrics, solar cells and solar catalysis. The particles are also highly intriguing from a fundamental perspective because the relative composition of copper and zinc in the particles can be tuned, resulting in the ability to manipulate the electronic or band gap properties for the desired application. The synthetic technique and compositional/structural nanoparticle characterization are discussed using techniques such as XRD, XPS, HAADF-STEM, elemental mapping and others. An assessment of the thermoelectric and electronic properties for these materials will also be presented.
10:30 AM - *G1.04
Engineering Atoms in Silicon: Building Qubits for the Quantum Internet of the Mid-21st C
David Jamieson 1
1University of Melbourne Parkville Australia
Show AbstractNew technologies based on the applications of fundamental quantum mechanical principles promise revolutionary applications for information gathering, storage, processing and transmission. The emerging field of quantum technologies has been identified as a research priority area by the 2001 report from the Board on Physics and Astronomy, National Research Council, USA. Deployment of these technologies could lead to the quantum internet of the mid-21st C which could be part of the smart grid to securely manage the complex distributed power systems characteristic of intermittent sustainable power generators based on wind or solar that could help mitigate our present high carbon emissions. The development of next-generation materials for quantum technologies presents a significant challenge. We address this challenge and aim to exploit quantum superposition and entanglement in nanoscale quantum devices engineered with just a single atom that could sustain the extraordinary progress in the ever expanding capabilities of silicon nano-scale Complementary Metal-Oxide-Semiconductor (CMOS) field effect transistors. Present generation devices are now so small that the channel length in the transistors (~20 nm) is comparable in size to the Bohr orbit of the donor electrons (~1.22 nm for Si:P). The devices are sensitive to the variation in the position of the donor atoms and, when cooled, also to the quantum state of single donors. The position variability issue is flagged in the International semiconductor roadmap for 2011. We have exploited these issues to engineer silicon CMOS devices with a single phosphorous atom implanted with a deterministic doping method that is cited by the 2011 roadmap. Our devices, fabricated in natural silicon, have now proved the ability to perform single shot readout of a single donor electron spin. We use electron spin resonance to drive Rabi oscillations to show a coherence time (T2) exceeding 200 µs suggesting a single electron spin can be used as a long-lived quantum bit. Further, the same device has allowed us to perform nuclear magnetic resonance on the single 31P nuclear spin by coupling the electron and nuclear spins and hence providing access to an even longer-lived nuclear qubit. Future devices, built from enriched 28Si, described as a “semiconductor vacuum” because of the absence of nuclear spin, offer longer coherence times. This presentation reviews the remaining challenges of building a large scale silicon quantum device for computation and communication especially if we are to securely control dispersed, low emission technologies that may be adopted by the mid-21st C.
G2: Materials for Transportation
Session Chairs
Laura Espinal Thielen
Enrico Traversa
Monday AM, November 26, 2012
Hynes, Level 3, Room 306
11:30 AM - *G2.01
Materials for Energy and Environmental Sustainability: Aviation Materials Advancements
Linda Cadwell Stancin 1 Robin Bennett 1 William Carberry 1 Peter Thompson 1 Jeannie Yu 1
1Boeing Seattle USA
Show AbstractTo ensure a balance between the social and economic benefits of commercial aviation and it's energy and environmental impacts, the industry is working on improvements across the entire life cycle of its products and services. Opportunities for environmental improvement reside in advanced materials and manufacturing technologies, improved aerodynamics systems and engine efficiency, alternative fuels, increased fleet operational efficiency, and aircraft recycling. The design of aircraft is highly dependent on materials and technologies that can meet the stringent performance requirements established by manufacturers and aviation authorities to ensure safe flight. Additionally, aircraft manufacturers focus on materials technologies that can improve fuel efficiency, thereby lessening the impact on the environment. Some technologies modify the airplane itself and other technologies improve operational systems, helping aircraft fly the most efficient routes. In addition to fuel conservation, technologies are also focused on the fuel itself and sustainable alternatives. Sustainable fuels based on renewable resources provide long term viability and can reduce environmental impact. At the end of service, the aircraft-recycling industry is capturing high value materials found in aircraft for processing reuse by other industries. Ideally the goal is a closed loop material cycle that optimizes material resource utilization, minimizes both the energy required for processing and the environmental impacts over the entire life cycle of an aircraft. This presentation describes the research and development work being conducted on materials and processes to advance aviation industry sustainability.
12:00 PM - G2.02
Thermal and Rheological Investigation of Surface Interactions in Poly(butylene succinate) Nanocomposites
Margaret Sobkowicz 1 JeongIn Gug 1 Xun Chen 1
1University of Massachusetts Lowell Lowell USA
Show AbstractFossil resources are becoming increasingly expensive and difficult to extract, which puts pressure on the market for conventional polymers. Polymers from renewable resources have the potential to perform as well or better than materials in use today. The same lightweight, high-strength properties of petroleum-based polymers and composites are required for renewable materials, and a better understanding of processing properties will improve their ability to compete with existing materials. In this work, a promising polyester made from renewable starting materials, poly(butylene succinate), is melt-mixed with silica to create nanocomposites. The surface of the silica nanofiller is modified to explore the effects of surface chemistry on filler dispersion and mixing energy. Rheological and thermal measurements are used to probe the interactions between filler and polymer, and to provide guidance for improved nanocomposite preparation. The demonstrated mechanical property improvements over neat polymer enable a broader range of applications.
12:15 PM - G2.03
Novel Protection Solutions against Environmental Attack for Light Weight High Temperature Materials
Alexander Donchev 1 Michael Schuetze 1
1DFI Frankfurt/Main Germany
Show AbstractThe use of light weight structural materials such as titanium in transport systems such as aero planes leads to significant reduction in fuel consumption. However, titanium and its alloys cannot be used at elevated temperature above 500°C for several reasons. Today aero engine compressors are made of a mixture of light Ti- and heavy Ni-alloys. The improvement of Ti-alloys to withstand the conditions in the high pressure compressor i.e. temperatures above 500°C would enable the manufacturing of a compressor from titanium as a whole with all its associated benefits. Intermetallic TiAl-alloys are another class of light weight materials for several high temperature applications. The use of TiAl as low pressure turbine (LPT) blades in the last sections of a large jet engine could save up to 150 kg which would be beneficial for fuel consumption. In the last sections of the LPTS the temperature is quite moderate (max. 650°C). The improvement of the high temperature capability of TiAl would allow the use in hotter sections of the engine with higher weight reduction. Similarly, the response performance of TiAl-turbocharger rotors in an automotive engine would be 120% compared to the heavy Ni-based alloys used today. Furthermore higher rotation speeds are possible. Due to the novel so called fluorine effect the oxidation mechanism of TiAl is changed. Fluorine treated TiAl-components are protected by an alumina layer formed during high temperature exposure in oxidizing environments. This effect can be transferred to Ti-base materials if they are enriched with aluminum in a thin surface zone. The concepts and the results of high temperature exposure experiments of treated Ti- and TiAl-specimens are presented in this paper. They are discussed in the view of a use for real components.
12:30 PM - *G2.04
Materials in Use in Mobile Emissions after Treatment Systems
Chris Heckle 1
1Corning Incorporated Corning USA
Show AbstractAs global concern for air quality intensifies, emissions control technologies play an increasing role in designing materials for transportation. Innovative diesel and gasoline emissions control technologies that help prevent harmful pollutants from entering the air rely on sophisticated materials understanding and product design. Substrates are extruded honeycomb monoliths containing thousands of parallel channels. The channel walls are coated with precious metal catalysts that convert noxious emissions into less harmful gases and water vapor. Filters are used in diesel-powered passenger cars, tractor trailers, buses, agriculture and construction equipment. Diesel particulate filters remove particulate matter (soot) and reduce harmful gases from diesel emissions. Both product families rely on high surface area, excellent thermomechanical performance and low pressure drop. The materials aspects of these products will be reviewed, especially as they pertain to tightening air quality regulations around the world.
Symposium Organizers
Laura Espinal, National Institute of Standards and Technology
Enrico Traversa, University of Rome Tor Vergata
Samuel S. Mao, Lawrence Berkeley National Laboratory
Marie-Isabelle Baraton, Centre Europeen de la Ceramique
Symposium Support
National Institute of Standards and Technology
G6/D5: Joint Session: Materials Availability
Session Chairs
Tuesday PM, November 27, 2012
Hynes, Level 3, Room 306
2:30 AM - *G6.01/D5.01
Energy Limitations on Materials Availability
Igor Lubomirsky 1 David Cahen 1
1Weizmann Institute of Science Rehovot Israel
Show AbstractRapidly occurring changes in energy availability lead to the question if energy and materials sustainability are equivalent. The answer is not straightforward because of two reasons: a) the amount of energy or of major materials types that can be diverted from one to the other to allow changes to new energy sources, without disrupting our daily life, is restricted to at most a few percent of the total energy production; b) if the transition to new energy sources requires large quantities of materials that are byproducts of large scale production cycles, this may pose a problem that has no obvious solution at present. The reason is that any increase in the production of a byproduct requires an almost proportional increase in the production of the primary product. Increased production of the primary product may require materials and energy expenditures, which are too large to be practical. Both theses lead to a number of issues that are critical in considering materials-energy interdependence: a) there is very little flexibility in the ability to divert energy resources to new technologies; b) production of those materials that are by-products cannot be increased rapidly, something that imposes severe restrictions on the rate of technology change and c) recycling can provide only a partial relief of the demand for energy to produce materials, because many items with high energy consumption cannot be recycled. d) although production becomes less and less materials- and energy-intensive, because of the introduction of more and more efficient processes, energy expenditure for production of materials may strongly deviate from this trend for a number of reasons, the most obvious of which is depletion of rich ores and increased hauling distances.
3:00 AM - G6.02/D5.02
Cellulose Nanomaterials: Imaging, Characterization and Applications
Jeffrey William Gilman 1
1NIST Gaithersburg USA
Show AbstractCellulose is the most abundant organic polymer on Earth, found in plants (cotton, hemp, wood), marine animals (Tunicate), algae (Valonia) bacteria (Acetobacter xylium) and even amoeba (Dictyostelium discoideum). Critical features of the structural performance of cellulose in these diverse settings are the large aspect ratio and high strength properties of the cellulose nanocrystals (CNC) and cellulose nanofibers (CNF), which provides nano-scale reinforcement. Acid hydrolysis of the native cellulose is the predominant method used to prepare pure CNC and CNF. Depending on the source of the cellulose and the chemical treatment the resulting material can vary in crystalline type, surface chemistry, dimensions, and aspect ratio. This new class of materials is gaining increased importance due to their novel properties (high strength, low thermal expansion, rich surface chemistry and optical transparency). Primary drivers for their use include their renewability and proven low toxicity. Consequently, several pilot plants and a number of commercial scale CNC manufacturing facilities have recently gone online worldwide utilizing wood as raw material. The applications envisioned range from transportation to biomedical. The use of CNC/CNF to enhance the properties of polymers originated with Marchessault&’s research in1959.1 Recently, this approach has become the focus of international research efforts.2 The development of measurement method which can characterize the structure and morphology of cellulose nanocomposites over many length scales are needed to enable successful manufacturing and product development of cellulose nanomaterials. Our application of laser scanning confocal microscope (LSCM) imaging combined with Forster resonance energy transfer (FRET)3 has enabled multi-scale characterization of the dispersion of nanofibrillated cellulose fibers in a polymer matrix. The LCSM-FRET method has supplied detailed nano-scale interface information, which has been used to inform more detailed structure property force-indentation studies of CNF nanocomposites. The results of these efforts will be presented, along with our recent efforts to characterize the different surface chemistry and morphologies of the CNC/CNF from various sources. 1. R. H. Marchessault, F.F. Morehead, N. M. Walter, Nature 1959, 184, 632. 2. Y. Habibi, L.A. Lucian, O. Rojas, Cellulose nanocrystals: chemistry, self-assembly and applications. Chem. Rev. 2011, 110, 3479-3500. 3. M. Zammarano, P. Maupin, L.P. Sung, J. W. Gilman, D. M. Fox, "Revealing the Interphase in Polymer Nanocomposites" ACS Nano, 2011, 3391-3399.
3:15 AM - G6.03/D5.03
Glass: An Old Material for the Future of Manufacturing
Susanne Klein 1 Steven J Simske 2
1HP Labs Bristol United Kingdom2HP Labs Ft. Collins USA
Show AbstractTraditional assembly line manufacturing is speculative, costly and environmentally unsustainable. It is speculative because it commits substantial resources—energy, materials, shipping, handling, stocking and displaying—without a guaranteed sale. It is costly because each of these resources—material, process, people and place—involves expense not encountered when a product is manufactured at the time of sale. It is environmentally unsustainable because, no matter how much recycling is done, not using the resources unless actually needed is always a better path. As part of the Ragnarok (Research on Advancing Glass & Nonorganic Applications to Recreate Objects & Kinetics) project in HP Labs, we identified glass as a promising candidate for additive manufacturing based on 3-D printing methods. Glass is a silica-based material. With 90% of the earth&’s crust composed of silicate minerals, there will be no shortage of silica resources. Glass is easy to recycle and is environmentally friendly. Only when glass dust is inhaled can ill health effects be associated with glass. Glass is inexpensive but looks precious, is pleasant to the touch and is so familiar that customers will not be disappointed by its fragility—under certain conditions. Glass is versatile. Glass is ubiquitous in time and space—the ancient Egyptians valued glass as precious jewellery, and energy saving light bulbs are still made of glass. Look around in your environment and you will suddenly realize how widely glass is used. But it can also be used in other high tech applications like: Printed electronics Electronic codes (readable by smartphones, tablets or touchscreens) Security printing (color effects, coatings) Functional surfaces for part assembly Tactile surfaces for touchscreen applications Tactile surfaces on objects replacing classic methods; e.g. veneer. Industrial surfaces—sandpaper, polishing surfaces, abrasive surfaces, friction surfaces, etc. Protective films and coatings The basis of all applications is ‘glass ink&’ for 3D printing. To achieve a sustainable, environmental friendly and ‘carefree&’ technology we concentrate on water-based inks. Glass will suspend in water when the particles are small enough but a glass and water mixture alone is not printable. Under pressure the water is expelled from the mixture and jamming occurs. A binder is needed to trap the water between the glass particles. Traditionally polysaccharides are used for glass, see for example http://www.washington.edu/news/archive/id/52160. In small amounts, the sugar will simply burn off during firing: when it is trapped inside the glass object, it will lead to discolouration. We will present alternative approaches leading to transparent glass objects.
3:30 AM - *G6.04/D5.04
Will Metal Scarcity Impede Routine Industrial Use?
Thomas Graedel 1
1Yale University New Haven USA
Show AbstractMaterials scientists today employ essentially the entire periodic table in creating modern technology. In an age of sharply increasing usage, it is reasonable to wonder about the supplies of these elemental building blocks. This talk will present a recent history of resource use trends, emphasizing the rapid recent growth in the use of scarce “specialty metals”. A methodology for assessing relative metal criticality is discussed, and illustrated with a sampling of results for a variety of metals. The implications of criticality and its evolution provide food for thought with respect to the widespread use of metals based solely on their physical and chemical properties, with little or no consideration given to long term availability.
4:30 AM - *G6.05/D5.05
Project Phoenix: Making More Clean Energy-critical Materials Available
John L. Burba 1 Andy Davis 1
1Molycorp, Inc. Greenwood Village USA
Show AbstractOne way to reduce the criticality of materials is to increase their production and recycling on a local basis. This talk will focus on Molycorp&’s Project Phoenix at Mountain Pass, CA, a major expansion, renovation, and restarting of rare earth production in the U.S. after a decade-long hiatus. Molycorp is expected achieve a Phase 1 rate of production of 19,050 tonnes/year in the fourth quarter of 2012, and is expected to expand its production capacity in mid-2013 to as much as 40,000 tonnes/year. Coupled with its additional processing facilities around the world, the Company will produce a wide variety of high-purity, custom engineered, light and heavy rare earths. Molycorp's production will go a long way to reducing the criticality of such key elements as neodymium, europium, dysprosium, terbium and others.
5:00 AM - *G6.06/D5.06
Critical Elements and New Energy Technologies
Robert L Jaffe 1
1MIT Cambridge USA
Show AbstractThe twin pressures of growing demand for energy and increasing concern about anthropogenic climate change have stimulated research into new sources of energy and novel ways to harvest, transmit, store, transform or conserve it. At the same time, advances in physics, chemistry, and material science have enabled researchers to identify chemical elements with properties that can be finely tuned to their specific needs and to employ them in new energy-related technologies. Elements that were once laboratory curiosities, like neodymium, tellurium, and terbium, now figure centrally when novel energy systems are discussed. Many of these elements are not at present mined, refined, or traded in large quantities. New technologies can only impact our energy needs, however, if they can be scaled from laboratory, to demonstration, to massive implementation. As a result, some previously unfamiliar elements will be needed in great quantities. Although every element has its unique story, these Energy Critical Elements have many features in common. I will describe the shared characteristics of these elements, their roles in emerging technologies, potential constraints on their availability, and government actions that can help avoid disruptive shortages. As an example, I will focus especially on elements that are required for photovoltaic technologies.
5:30 AM - G6.07/D5.07
Microbial Approaches to the Extraction and Recovery of Scarce Metals
William Bonificio 1 David Clarke 1
1Harvard University Cambridge USA
Show AbstractBiologically mediated extractive metallurgy promises to be a sustainable and environmentally low impact approach to the production of critical energy materials. Our work focuses on the role microbes may have in the recovery of tellurium and rare earth elements (REEs). The microbes used in our studies are three strains of extremophilic microbes from the East Pacific Rise hydrothermal vent fields: pseudoalteromonas sp., alcanivorax sp., and acinetobacter sp., two copper mine drainage microbes: acidithiobacillus thiooxidans and leptospirillum ferrodiazotrophum, and the dissimilatory metal reducer shewanella oneidensis. These microbes, specifically pseudoalteromonas sp., have shown an unusually high resistance to both tellurium and the REEs with a minimum inhibitory concentration (MIC) of ~0.1mM for both. Pseudoalteromonas sp. has the ability to reduce tellurite (TeO32-) to metallic tellurium (Te0) and methylate it forming dimethyl telluride (Te(CH3)2). Our investigations into these exact mechanism has demonstrated the direct conversion of various other tellurium compounds, such as tellurium dioxide (TeO2), and telluric acid (Te(OH)6) to Te0, paralleling that already occurs during standard, chemical tellurium production. Furthermore we have demonstrated the recovery of Te0 from cadmium telluride, which lends itself to CdTe solar cell recycling, and recovery from autoclave leach slime, the effluent from copper production. We are currently exploring the role of reactive oxygen species (ROS) in these tellurium transformations and will describe our findings. These microbes also appear to biosorp REEs from solution. When incubated with 100 ppb of the rare earth chlorides they have demonstrated enhanced uptake, extracting >95% of REEs from their medium. During this extraction the microbes fractionate individual REEs resulting in separation factors for neighboring REEs of ~1.2, comparable to current industrial solvent-extraction methods. Finally, we will discuss our research on the interaction between these strains and bastnasite concentrate and how it applies to microbially-aided rare earth production.
5:45 AM - G6.08/D5.08
Thermochemistry of Indium Recovery in the Pyrometallurgical Recyling Technology
Joo Hyun Park 1 Kyu-yeol Ko 1
1University of Ulsan Ulsan Republic of Korea
Show AbstractIndium (In) is usually produced as a minor by-product of lead and zinc smelting and refining processes, and is used in flat panel display (ITO) and thin film solar cell (CuInSe2, CuInGaSe2), etc. Recently, the pyrometallurgical recycling of In-containing materials has been issued in view of 'Urban Mining' due to very high cost and scarceness of indium. However, the solubility of indium into the molten flux has not been fully understood yet. Therefore, in the present study, the solubility of indium at 1773 K in molten CaO-SiO2-Al2O3 flux was measured under reducing atmosphere. The pure indium (99.99%) contained in a graphite crucible was equilibrated with a purified CO(+Ar) gas mixture in the mullite reaction tube which was heated by MoSi2 heating element. The oxygen potential was controlled by C/(CO+Ar) equilibrium. After equilibrating, the samples were quenched by dipping the crucible into brine and crushed for chemical analysis. The content of indium was analyzed by ICP-AES and that of slag components was analyzed by XRF spectroscopy. In high silica region, the solubility of indium increases with increasing oxygen potential and decreases with increasing content CaO, which is in proportion to the basicity. Also, the effect of flux composition and temperature on the solubility of indium is discussed. The solubility of indium was measured in the low silica melts to ensure the applicability of the established reaction mechanism. The solubility of indium follows different mechanism at low silica region. The solubility of indium at low silica region decreases with increasing oxygen potential and increases with increasing CaO content. Consequently, the optimized flux composition was designed to increase the recovery of indium in the pyrometallurgical treatment of In-containing materials.
G7: Poster Session: Materials for Sustainable Technologies
Session Chairs
Laura Espinal Thielen
Sam Mao
Tuesday PM, November 27, 2012
Hynes, Level 2, Hall D
9:00 AM - G7.01
Nano Lift-off Method for Fabricating GaN Thin Films
Yuefeng Wang 1 5 Liang Tang 2 5 Gary J Cheng 3 5 Michael J Manfra 1 2 5 Timothy D Sands 1 4 5
1Purdue University West Lafayette USA2Purdue University West Lafayette USA3Purdue University West Lafayette USA4Purdue University West Lafayette USA5Purdue University West Lafayette USA
Show AbstractGaN is one of the most widely used semiconductor materials in optoelectronic devices, high speed transistors, high power electronics, spintronics and biocompatible devices. Compared to GaN on sapphire or SiC substrate, free-standing GaN films have multiple exclusive benefits such as strain relieve, light extraction, defect reduction and potential flexibility. While the traditional Laser lift-off (LLO) was developed to separate GaN from sapphire substrates, the technique has limitations of only being able to lift off GaN film with a thickness of several um and leaving degraded surfaces. In this work, we present a novel method able to fabricate thin film GaN suitable for electronics device application with a thickness greater than tens of nm. Starting from GaN on sapphire substrate, MBE or MOCVD can be used to fabricate an epitaxial superlattice sacrificial layer and the GaN epilayer to be lifted off. The average In composition in the sacrificial layer is critical for effective laser absorption, which is examined by XRD and EDS. By manipulating growth parameters, the In composition can be control from 0% to over 50%. The sacrificial layer is lattice matched to the GaN substrate, enabling high quality GaN epilayer growth to an arbitrary thickness. After growth, photoluminescence and ellipsometer were used to determine the effective bandgap of the sacrificial layer. Pulsed laser with photon energy of ~2.3eV and fluencies ranging from 50mJ/cm2 to 300mJ/cm2 was irradiated onto the sample which leads to the controlled decomposition of sacrificial midlayer and easy separation of the top GaN film from the substructure by adhesive transfer. This technique can be used to fabricate GaN films with low defects and a wide range of thickness, especially sub-um level. TEM, AFM and FESEM were used to characterize the crystallinity and surface morphology of the freestanding film. A numerical laser-solid interaction model was developed to optimize the lift-off process. Lamellar structures were demonstrated for the possibility of multiple-film nano lift-offs on single substrate, which substantially reduced the cost and improved the crystal quality of freestanding GaN film. LED devices were integrated on a GaN epilayer to confirm the preservation and enhancement of device performance. Overall, the recently developed nano lift-off process is a promising pathway to nanoscale GaN freestanding devices and high quality GaN substrates.
9:00 AM - G7.02
Flame-made Nanostructured Ca/Fe Oxides for Nutritional Supplements
Jesper T.N. Knijnenburg 1 Florentine M. Hilty 2 Michael B. Zimmermann 2 Sotiris E. Pratsinis 1
1ETH Zurich Zurich Switzerland2ETH Zurich Zurich Switzerland
Show AbstractCalcium and iron are essential for humans, but inadequate intakes are common and adversely affect health. Dietary intakes of these minerals can be improved by supplementation, typically with element-specific but also with multivitamin/multimineral supplements. Since recently, nanostructured iron compounds emerged as promising materials against iron deficiency [1,2] The large surface area of these iron oxides and phosphates enhances their dissolution in the stomach. Very recently we have shown that the incorporation of calcium into nanostructured iron oxide increases iron solubility even further [3] and potentially also bioavailability [2] compared to pure iron oxide. For high dopant contents the solubility was comparable to the “gold standard” FeSO4. The increase in iron solubility is a result of the formation of a solid solution, decreasing the average bond energy of the crystal. Calcium-containing supplements are the most commonly consumed mineral supplements worldwide. Their high solubility and bioavailability makes them attractive as carrier matrix for trace minerals such as iron. Here, nanostructured calcium oxide-based supplements are developed as carriers for iron supplementation. Calcium oxide doped with nutritionally relevant amounts of iron was produced in one step by flame spray pyrolysis. Inexpensive precursors (nitrates) and solvents (ethanol-based) were used to minimize synthesis costs. Large amounts of calcium resulted in matrix encapsulation of iron, preventing the formation of low-solubility oxides, but forming Ca/Fe oxide solid solutions instead. Solubility measurements i.d.a. demonstrated rapid and complete dissolution of all elements, suggesting they would have high in vivo bioavailability. This rapid, simple one-step synthesis process allows tunable composition of multimineral supplements with high mineral solubility, making them promising for nutritional applications. [1] Miller DD. New leverage against iron deficiency, Nature Nanotechnology (2010), 5, 318-319. [2] Hilty FM, Arnold M, Hilbe M, Teleki A, Knijnenburg JTN, Ehrensperger F, Hurrell RF, Pratsinis SE, Langhans W & Zimmermann MB. Iron from nanocompounds containing iron and zinc is highly bioavailable in rats without tissue accumulation, Nature Nanotechnology (2010), 5, 374-380. [3] Hilty FM, Knijnenburg JTN, Teleki A, Krumeich F, Hurrell RF, Pratsinis SE & Zimmermann MB. Incorporation of Mg and Ca into Nanostructured Fe2O3 Improves Fe Solubility in Dilute Acid and Sensory Characteristics in Foods, Journal of Food Science (2010), 76, N2-N10.
9:00 AM - G7.03
Solvent-mediated H2-release from Ammonia Borane
Chang Won Yoon 1 Yong Min Kim 1 Suk Woo Nam 1
1Korea Institute of Science and Technology Seoul Republic of Korea
Show AbstractAmmonia borane (AB) and its related amine boranes have widely been studied as promising hydrogen storage materials. We found that the rate and extent of H2-release from AB were increased at 85 oC in the presence of various types of polyetheral solvents. These enhanced effects were pronounced particularly with tetraetraethylene glycol (T4EG) and tetraethylene glycol dimethyl ether (T4EGDE). Spent-fuels produced by the thermolyses of AB with either T4EG or T4EGDE at 85 oC were found to be polyaminoborane (PAB) and diammoniate of diborane (DADB), as evidenced by 11B NMR spectroscopy. In situ infrared spectroscopy indicated the formation of B-(cyclodiborazanyl)amino-borohydride (BCBD) and borazine as gaseous byproducts. Density functional theory (DFT) methods were employed to understand the influence of the solvents on the enhancement of rate and extent of H2-release from AB.
9:00 AM - G7.04
Forward Voltage Reduction and Light Extraction Enhancement of InGaN/GaN MQW LEDs Using ALD-grown Ga-doped Transparent Conductive Layers
Kuo-Yi Yen 1 Chien-Hua Chiu 1 Chien-Hua Chou 1 Tzu-Pei Chen 1 Tai-Yuan Lin 2 Jyh-Rong Gong 1
1National Chung Hsing University Taichung Taiwan2National Taiwan Ocean University Keelung Taiwan
Show AbstractGa-doped zinc oxide (GZO) transparent conducting layers (TCLs) were deposited at 300oC by atomic layer deposition (ALD) on the InGaN/GaN multiple quantum well (MQW) light emitting diode (LED) structures. The GZO-coated InGaN/GaN MQW LED structures were then annealed at 400, 500, 600, 700, 800oC for 5 min under N2 ambient prior to LED chip fabrication. It was found that reduced forward voltage and enhanced light extraction were achieved in certain annealed GZO-coated InGaN/GaN MQW LED structures. A forward voltage of 3.1 V at 20mA was found for an LED with annealed GZO TCL at 400oC with the GZO on p-GaN contact showing a specific contact resistance of 4.1×10-3Omega;-cm2. The ohmic nature between GZO and p-GaN is attributed to the very high electron background of 1.5×1021cm-3 in the 400oC-annealed GZO, which supports electron tunneling through the GZO/p-GaN heterointerface. An increment of light output power by 15% at 20mA for an InGaN/GaN MQW LED having 400oC-annealed GZO TCL compared with the same InGaN/GaN LED structure having an ITO TCL was observed. It is believed that the enhanced light extraction of the GZO TCL-coated InGaN/GaN MQW LED is mainly the consequence of higher refractive index of GZO than that of ITO.
9:00 AM - G7.05
Carbon Dioxide Separation of Ultrathin Multilayers Prepared Using Layer-by-layer Self-assembly Technique
Tatsuya Funaoka 1 Yusuke Daiko 1 Atsushi Mineshige 1 Tetsuo Yazawa 1
1University of Hyogo Himeji Japan
Show AbstractIntroduction Greenhouse effect is becoming an urgent environmental problem, and removal or separation of carbon dioxide from flue gases are considered to be a promising technology for greenhouse-gas emission control. One technology for carbon dioxide separation is based on an adsorption process using liquid amines. Compared with adsorption method, membrane separation method has advantages such as low cost and rapid recovery. For practical application, membranes with both a high gas permiability and high carbon dioxide selectivity are required. However, there is a trade-off relationship between them. The thinner membrane shows better gas permeability whereas shows lower carbon dioxide selectivity. We have focused on the preparation of ultrathin coatings with a good carbon dioxide affinity utilizing layer-by-layer (LbL) self-assembly. We anticipate that a separation membrane with both a good gas permeability and selectivity would be obtained by controlling the thickness and polarity (affinity) for carbon dioxide. In this study, various cationic polymers with amino groups were deposited, and carbon dioxide separation and its relation to the LbL structure were investigated. Experimental A porous alumina tube with the pore diameter of 0.1 mu;m was used as a support. At first, a commercial silica colloid and then silica/PEG hybrid membrane were coated on the alumina support by dip coating. Finally, cationic primary ammonium salt of poly(allylamine hydrochloride) (PAH) or quaternary ammonium of poly(diallyl dimethylammonium)choloride (PDDA) were deposited on the silica coating via LbL technique. Result and discussion Pore structure was measured by using nitrogen gas absorption/desorption method. The pore diameter of alumina substrate with silica coatings was estimated to be 2 nm. After the deposition of polycation thin film, carbon dioxide adsorption on the film was measured utilizing quartz crystal microbalance (QCM). The QCM results revealed that the amount of carbon dioxide adsorption increased clearly after the deposition of PAH or PDDA. Interestingly, carbon dioxide separation factor was also increased after the LbL deposition.
9:00 AM - G7.06
Self-separating Catalyst Using Magnetic Nanoparticles Combined with Thermoresponsive Polymers
Martin Zeltner 1 Alexander Schaetz 1 Max Leo Hefti 1 Wendelin Jan Stark 1
1ETH Zurich Zurich Switzerland
Show AbstractCatalysis is among the most important applications within the field of nanoscience [1]. The large surface area of nanoparticles qualifies them naturally to act either as heterogeneous promoters for catalytic reactions or as a support for homogeneous catalysts. Especially magnetic nanoparticles are meant to overcome the most tantalizing drawback in homogeneous catalysis, i.e. reliable separation and recycling of often toxic and expensive transition metal complexes for more sustainability in catalysis. Thus, they simultaneously comply with economical and ecological requirements[2]. We have synthesized highly ferromagnetic, thermoresponsive nanomagnets with a graphene coated cobalt metal core to which amphiphilic N-isopropylacrylamide polymer branches were covalently attached. [3] This novel hybrid material could be further modified with a Pd-phosphine complex to catalyze Suzuki-Miyaura cross-coupling reactions. The heterogenized metal-complex acted as a ‘self-separating&’ catalyst. Thermally triggered switching of poly-NIPAM coated C/Co-nanoparticles in typical biphasic water/toluene reaction systems allowed for a temperature- controlled shift of the catalyst from the organic to water phase and vice versa. This enabled the catalyst to switch in the organic layer at reaction temperature and to return into the aqueous layer once the reaction mixture was cooled (ambient temperature; magnetic removal and reuse of the catalyst). Thus, the product phase was isolated via simple extraction/decantation. Moreover, the supported catalyst was recycled from the aqueous phase by taking advantage of the magnetic cores and reused over ten times. [1] A. Schaetz, O. Reiser, W.J. Stark, Chem. Eur. J., 2010, 16, 8950. [2] R. N. Grass, E. K. Athanassiou, W. J. Stark, Angew. Chem., 2007, 119, 4996. [3] M. Zeltner, A. Schaetz, M.L. Hefti, W.J. Stark, J. Mater. Chem., 2011, 21, 2991.
9:00 AM - G7.07
Photocatalytic Properties of TiO2/WO3/FTO Multi-layer Structures Prepared by Spray Pyrolysis Deposition
Masahiko Maeda 1 Takahiro Horikawa 1
1Kanazawa Institute of Technology Ishikawa Japan
Show AbstractIn recent years, titanium dioxide (TiO2) with super-hydrophilic and photocatalytic characteristics has received a great deal of attention. In environmental fields, particularly, such materials are important because of their ability to detoxify environmental pollutants. When the TiO2 is irradiated with ultraviolet-light (UV-light), organic compounds are decomposed on their surface and water spreads evenly to their super-hydrophilic surface, as a result, surface self-cleaning can be easily realized. Because the bandgap energy of TiO2 is 3.2 eV, UV-light of wavelength of 380 nm or less is necessary to fulfill their photocatalytic properties. Even in outdoors during daytime, the intensity of UV-light is only about 1 mW/cm2. Under these circumstances, the demand for the photocatalytic materials that can respond to visible-light has strengthened day by day. Visible-light photocatalytic materials have been intensively investigated. For development of visible-light response of TiO2 photocatalytic materials, novel metal oxides with narrow bandgap and doping of transition metals or non-metallic elements into the TiO2 have been intensively investigated until now. The other approach for improvement of TiO2 photocatalytic activity, it has been reported that bilayer structures of TiO2 and other metal oxide films with appropriate conduction band and valence band edges are effective. In these structures, charge separation of photogenerated electron/hole pairs takes place effectively. In this study, we investigated on the visible-light response of photocatalysis for TiO2/WO3/FTO multi-layer structures prepared by spray pyrolysis deposition. The effect of fluorine concentration in SnO2 under layer on photocatalytic activity was investigated. The precursor solutions used for preparation of the TiO2/WO3/FTO multi-layer structures were ethanol solution dissolved titanyl(IV) acetylacetonate, ammonia solution dissolved WO3, and ethanol solution dissolved tin(IV) chloride and ammonium fluoride, respectively. Each film was continuously deposited on the substrate by spraying the precursor solution through the spray nozzle. The visible-light response of photocatalysis was successively observed in these structures and its activity increases with increasing fluorine concentration in the SnO2 films. Because the bandgap energies of TiO2, WO3, and SnO2 films were 3.2, 2.5, and 3.6 eV, respectively, the visible-light absorption takes place in WO3 layer. The generated electrons and holes diffuse to SnO2 conduction band and TiO2 covalent band, respectively, due to difference of band edges. The conductivity of FTO films increases with increasing the fluorine concentration, therefore, the electron diffusion takes place effectively from WO3 to FTO. As a result, higher photocatalytic activity is observed in order to enhancement of hole diffusion from WO3 to TiO2.
9:00 AM - G7.10
Iron Phosphate Nanoparticles for Food Fortification by Combustion of Sprays
Thomas Rudin 1 Sotiris E. Pratsinis 1
1ETH Zurich Zurich Switzerland
Show AbstractIron deficiency is still a major global public health issue that can be addressed by food fortification, an effective way to improve iron intake. Low-cost synthesis of iron phosphate nanostructured powders is attractive for large scale fortification of basic foods (rice, bread etc.). This is achieved here by flame-assisted and flame spray pyrolysis of inexpensive precursors (iron nitrate, phosphate), solvents (ethanol) and support gases (acetylene and methane). The iron phosphate powders produced here were mostly amorphous and exhibited excellent solubility in dilute acid, an indicator of relative iron bioavailability. The amorphous and crystalline fractions of such powders were determined by X-ray diffraction (XRD) and their cumulative size distribution by X-ray disc centrifuge. Fine and coarse size fractions were obtained also by sedimentation and characterized by microscopy and XRD. The coarse size fraction contained maghemite Fe2O3 while the fine was amorphous iron phosphate. Furthermore, the effect of increased production rate (up to 11 g/h) on product morphology and solubility was explored. Using increased acetylene/methane flow rates for the flames and inexpensive powder precursors resulted in homogeneous iron phosphate nanoparticles with excellent iron solubility in dilute acid, independent on the production rates investigated here.
9:00 AM - G7.11
Carbonyl-based Organics as Novel Cathodes for Lithium Ion Batteries
Kenneth Hernandez-Burgos 1 Stephen Edwards Burkhardt 1 Hector Abruna 1
1Cornell University Ithaca USA
Show AbstractAn important challenge for enabling the wide-spread utilization of renewable energy sources, such as solar and wind, consists in developing high efficiency, low cost, high energy density, safe and environmentally benign batteries. Lithium ion batteries (LIBs) represent an attractive alternative as energy storage devices because they exhibit a higher voltage, and higher energy density compared to traditional batteries. Organic compounds are an attractive alternative for use as cathodes in LIBs. The building blocks of Carbonyl based organic molecules (C-bOMs) (i.e. carbon, hydrogen, nitrogen, oxygen and sulfur) are abundant and inexpensive and shows rapid and chemically reversible electrochemical behavior and their reduced forms (enolates) display a strong ionic interaction with lithium cations. Furthermore, a wide range of chemical variations/modifications can be performed on C-bOM structures to predictably modify their electrochemical behavior, e.g. to maximize the interaction of the material with lithium, maximize the number of electrons transferred while minimizing the molecular weight of the compound, thus maximizing energy density. Is our plan to present the developing of high performance electrical energy storage devices for application in LIBs by identifying/designing new low molecular weight and high voltage C-bOMs, which will overcome the high cost, low gravimetric capacities and energy densities, slow charge discharge rates, typical of the currently employed inorganic (especially oxides) materials. The studies consist of three steps: computational screening and designing of new molecules, electrochemical characterization, and practical testing using “coin cells”. Computational chemistry was used to predict the formal potentials of the new materials (E= 2.5-3.0 V) and identify the most promising candidates. Also was studied the influence in the formal potential of the addition of electro-withdrawing groups. Finally, for the electrochemical characterization cyclic voltammetry (CV) was employed to characterize the molecules that were identified from the computational screening. In the electrochemical characterization we were able to study the influence of alkali metals base electrolytes in aprotic organic solvents, which shows how from a two one electrons waves were found a conjoining of the two waves into one two electrons wave. After all the studies we were able to design and characterize new C-bOMs molecules, which represent new alternatives as cathodes materials for LIBs.
9:00 AM - G7.12
Testing the Trigger Theory: The Effect of Different Nutrients on the Lipid Content in Tetraselmis suecica
Tanay Lathia 1 Ajay Bhargava 2 Deborah Day 1
1Amity High School Woodbridge USA2NEBA Hamden USA
Show AbstractThe world today consumes an enormous amount of unsustainable energy; thus, scientists are trying to identify an alternate, renewable fuel source. One possible fuel source is algal biodiesel, which is made from algal lipids. This study aims to maximize the lipid content in the green microalgae, Tetraselmis suecica, through the deprivation of nutrients. It is hypothesized that as the amount of nutrients, sodium nitrate (NaNO3) and sodium glycerophosphate (C3H7Na2O6P), is decreased in the medium, the lipid content of the Tetraselmis suecica will increase. This hypothesis is based on the trigger theory established in a study completed in 1998 by the National Renewable Energy Laboratory, which stated that as algae are deprived of nutrients they compensate by producing more lipids. To test the trigger theory, different batches of algae were grown with varying concentrations of sodium nitrate. The control group contained 100% of all nutrients as dictated by the UTEX Enriched Seawater Medium. The experimental batches had 75% and 50% of the recommended sodium nitrate content, respectively. These trials were repeated using the same protocol except the sodium nitrate was replaced with sodium glycerophosphate. After two weeks of incubation under 12 hour light/dark cycles and constant shaking, the algae were harvested using a centrifuge. The samples were transported on dry ice to a second laboratory in preparation for the lipid analysis. The total biomass of each sample was measured, followed by a chemical extraction. The chemical extraction consisted of covering the algae in various chemicals, such as methanol and then dichloromethanol. The chemicals caused the algae to split into its various components, such as the carbohydrate portion, the lipid portion, etc. The lipid fraction of each trial was massed and compared to its total biomass. The algae grown in the media with 100% of nutrients consisted of 32% by mass of lipids. Furthermore, when the amount of sodium nitrate in the media was cut in half, the algae were 56% by mass of lipids. A similar result occurred with the media that had 50% of the recommended sodium glycerophosphate; the Tetraselmis suecica was 48% by mass of lipids. These results showed an inverse trend between the amount of a specific nutrient in the medium and the lipid yield of the Tetraselmis suecica, supporting the Trigger Theory. After gathering results, statistical tests were done to analyze the significance of the data. The sodium nitrate results yielded a p-value of 0.0312, while the sodium glycerophosphate results had a p-value of 0.0459. Both of these values are less than 0.05, showing the significance of the data. The results obtained in this study can be utilized to optimize the lipid content and fuel output of algae.
9:00 AM - G7.13
Photocatalytic TiO2 Macroscopic Fiber Obtained through Integrative Chemistry
Natacha Kinadjian 1 2 Mickael Le Bechec 3 Thierry Pigot 3 Fabien Dufour 4 Olivier Durupthy 4 Ahmed Bentaleb 1 Eric Prouzet 2 Sylvie Lacombe 3 Renal Backov 1
1Universitamp;#233; de Bordeaux 1 Bordeaux France2University of Waterloo Waterloo Canada3Universitamp;#233; de Pau et des Pays de lamp;#8217;Adour Pau France4Collamp;#232;ge de France Paris France
Show AbstractWith the apparition of the “environmentally friendly production” concept, air purification by photocatalysis became one of the major concerns for industries. Photocatalytic properties of titanium oxide (TiO2) depend, not only on its electronic property, but also on the material size and shape, which can favor a higher interaction between reactants and catalyst. In order to make such architectures, we used the concept of integrative Chemistry [1]. In our study, we used a new process to obtain macroscopic TiO2/polyvinylalcohol(PVA) fibers nanocomposite fibers which was developed in the last years for carbon/PVA fibers or again vanadium oxide/PVA fibers. [2] We studied five different sets of TiO2/PVA nanocomposite, which were synthesized by varying the TiO2 nanoparticles synthesis and the TiO2 nanoparticles concentration in the solution used for the fibers synthesis process (co-axial flux extrusion).[3] All the sets presents a high specific surface area as there are in the range of 100 to 700 m2.g-1 compared to 50 m2.g-1 for the P25 Evonik reference material. Moreover, we demonstrated that the surface roughness and the specific surface area decrease as the particles concentration increases. These parameters combined with the particles shapes gave us specific design for each set. This design have been combined with material 1D processing and orientation, and it has been demonstrated that the photocatalytic properties are f avored, especially mineralization, when the material hierarchical 1D orientation is combined with unidirectional gas flow. These sets of materials have been characterized and tested for the photocatalytic degradation and mineralization (conversion into CO2) of acetone, and compared with commercial catalysts. Our study reveals that a suitable combination of multiscale design and optimized matching between material orientation and gas flow, can favor high mineralization yield. [1] N. Brun, S. Ungureanu, H. Deleuze and R. Backov. Chem. Soc. Rev., 2011, 40, 771 [2] L. Biette, F. Carn, M. Maugey, M.-F. Achard, J. Maquet, N. Steunou, J. Livage, H. Serier, R. Backov, Adv. Mater. 2005, 17, 2970 [3] N. Kinadjian, M. Le Bechec, T. Pigot, F. Dufour, O. Durupthy, A. Bentaleb, E. Prouzet, S. Lacombe and R. Backov Eur. J. Inorg. Chem. (under submission)
9:00 AM - G7.14
Optimal Design of Ca-modified Ni/Al2O3 Catalyst for Low Temperature Ethanol Steam Reforming
Catherine Kai Shin Choong 1 2 Ziyi Zhong 1 Lin Huang 1 Jianyi Lin 1 Liang Hong 2 Luwei Chen 1
1Institute of Chemical and Engineering Sciences Singapore Singapore2National University of Singapore Singapore Singapore
Show AbstractHydrogen is an important energy carrier which can be utilized as a fuel for fuel cell applications. Amid the variety of new technologies available for hydrogen production, catalytic ethanol steam reforming (ESR, C2H5OH + 3H2O -> 2CO2 + 6H2) is a promising reaction and has generated extensive interest in the past decade. The low toxicity and high energy density of ethanol present itself as an attractive precursor. In addition, the production of ethanol from lignocellulosic biomass such as wood chips and grasses is garnering maturity in the technology and hence portrays a positive outlook towards net-zero carbon emission. Nickel catalysts have demonstrated promising results for ESR, mainly because of its excellent C-C bond breaking activity. However, the use of Ni catalyst to perform ESR without coke deposition at low temperature range (T < 400oC) is a challenge in this process. In this study, catalysts comprised of Ni particles were impregnated over Ca-modified Al2O3 (Ca loading = 3-7 wt%). The catalysts were characterized using XRD, XPS, TEM, H2-TPR and TPD of different probe molecules such as NH3, CO2, H2O and C2H5OH. Deactivation study was conducted using a tapered element oscillating microbalance (TEOM). The catalytic properties were studied for ESR using a 5 channels micro-reactor at 400oC. Results showed that catalyst with 3 wt% of Ca remains stable at 400oC for at least 24 hr, while 0 wt% and 7 wt% Ca modified catalysts deactivate easily. The introduction of Ca greatly reduces the acidity of Al2O3, depressing ethanol dehydration and ethylene formation. It brings about positive attributes such as increasing water adsorption, providing Ni catalyst the proximity and abundance of adsorbed OH groups. The involvement of OH groups in the reactions in turn enhances the ethanol adsorption, stabilizes its adsorbate intermediates for further conversions to H2, CH4 and CO2 at relatively low temperatures. In the meantime, the addition of Ca increases the particle size of active Ni which promotes the formation of un-reactive and encapsulating carbons, undermining the stability of highly loaded (7 wt%) Ca-modified Ni catalyst. XPS valence band shows that the presence of Ca increases the density of Ni 3d band valence electrons which helps in dissociation of methane and deactivates the catalysts, as in the case of nickel catalysts supported on 7 wt% of Ca on Al2O3. Excellent catalytic performance of 10Ni/3Ca-Al2O3 is due to the effective coke removal and the amorphous nature of coke deposition. Optimized Ca loading was found to play a critical role in coke removal, through its effect on Ni particle size, valence band of catalyst and steam gasification of coke.
9:00 AM - G7.15
Theoretical Study on Porphyrin Based Covalent Organic Polyhedra as a Hydrogen Storage
Dae jin Kim 1 2 Hyein Guk 1 Dong Hyun Jung 1 Kihang Choi 2 Seung-Hoon Choi 1
1Insilicotech Seongnam-Si, Gyeonggi-Do Republic of Korea2Korea University Seoul Republic of Korea
Show AbstractAs potential candidate materials for hydrogen storage, COFs (covalent-organic frameworks) are appealing because they can take up and release hydrogen reversibly with fast kinetics. And COFs may have an advantage in increasing gravimetric hydrogen storage capacity because their frameworks are light. Porous organic molecules display some striking differences in comparison with porous networks such as COFs, both in terms of processability and physical properties. Much effort has been devoted to discovering new COPs (covalent organic polyhedra) as porous molecules for applications such as gas separation, energy storage and catalysis. Here, we introduce new COP containing porphyrinyl groups. Porphyrin COP can be synthesized by the [6+8] condensation which means that 6 tetraaldehyde molecules with 8 triamine molecules make 24 imine bonds. During the reversible process of imine bond formation and break, the reaction is driven toward the most stable product, and this process is called dynamic covalent bond. Porphyrinyl group is good for metallation which can make coordination with ligands such as bipyridine. This ligand-coordinated metal play an important role in connecting porphyrin COP molecules and creating extrinsic porosity in the crystal in addition to the intrinsic porosity of porphyrin COP molecule. For the modeling of the crystalline structure, polymorphs of molecular crystal are predicted by the simulated annealing Monte Carlo simulation method. Grand canonical Monte Carlo simulations predict the hydrogen uptakes of these polymorphs of porphyrin COP and the values are from 99 to 262 mg g-1 for gravimetric uptake and from 46 to 51 kg m-3 for volumetric uptake at 77 K. Hydrogen uptake of porphyrin COPs is comparable to the best records of MOFs (164.1 mg g-1 for NU-100 and 166.9 mg g-1 for MOF-210 at 77 K). In this work, we suggest new porous organic cage molecules called COPs with large surface area, high hydrogen capacity and these molecules can have a variety of polymorphs. Hence, porphyrin based COPs are expected to be applied to various applications including hydrogen storage, CO2 storage or separation, catalyst supports, and so on by modifying the crystal structure.
9:00 AM - G7.16
A Feasibility Study of Cerium Doped NaSICON for Use as a Trivalent Ion Sensor
Ryan Steven Eriksen 1 Srikanth Gopalan 1
1Boston University Brookline USA
Show AbstractAs the need for specific elemental selection increases in order to meet the demand of modern electronics, the need to improve refining techniques is growing especially, for rare earth metals. Better monitoring of these processes can reduce the time and cost of these techniques. Potentiometric sensors output a potential difference when exposed to concentration differences and can be calibrated to determine an unknown concentration. One of the key components of any potentiometric sensor is the electrolyte, which must be conductive to the species being measured. NaSICON has been shown to be one of the few materials capable of conducting trivalent rare earth elements such as cerium, giving cerium doped NaSICON, (Ce.1Zr.8)40/39Nb(PO4)3 the theoretical basis to function as an electrolyte in a cerium ion sensor. Pellets were manufactured by powder processing and sintering to produce a dense NaSICON disc, which was then used in a concentration cell with aqueous cerium nitrate. A definitive response was observed when the cell was exposed to varying concentration differences, indicating that the disc was behaving as a sensor. Similar results were also obtained when the tests were conducted with cerium nitrate solution in two molar nitric acid; however some characteristics of the sensor were changed. The work presented here indicates that cerium doped NaSICON is a viable candidate for a trivalent cerium ion sensor.
9:00 AM - G7.17
Novel Halogen-free Phenol Based Polymeric Flame Retardant Additives
Ruchi Bakshi 1 2 4 Sethumadhavan Ravichandran 3 1 Weeradech Kiratitanavit 2 1 Jayant Kumar 1 4 Ramaswamy Nagarajan 2
1Umass Lowell Lowell USA2Umass Lowell Lowell USA3Umass Lowell Lowell USA4Umass Lowell Lowell USA
Show AbstractIncreasing awareness of toxicity of halogenated flame retardants (FR) has resulted in stringent regulations that require elimination of their use in most commodity plastics like polyolefins. Consequently, there is considerable interest in developing new varieties of high performance FR. In addition to being non-toxic, new types of FR additives should be designed in such a way that they are also compatible with the matrix polymer. We report a new class of polymeric FR that have the potential to offer the best combination of FR performance and blend compatibility. These FR additives are based on polyphenols and the polymerization reaction is catalyzed by a biomimetic catalyst namely Iron Salen (Iron-N,N&’-ethylenebis(salicylideneamine). These FR exhibit the combination of radical scavenging and char-forming capabilities. Thermal characterization of the polyphenols using thermogravimetric analysis and pyrolysis combustion flow calorimetry indicated that these polymers have very low heat release capacity and also produce significant amount of carbonaceous char upon combustion. These polyphenols can also be blended into polyolefins and are envisioned to be potential replacements to toxic halogenated flame retardants.
9:00 AM - G7.18
Broad-spectrum Anti-fouling Performance of Betaine-modified Surfaces as Sustainable Underwater Coatings
Zheng Zhang 1 Laura Rushford 1 Michael Ashman 1 Roger Smith 1 Aaron Berkenwald 1 Christopher Loose 1
1Semprus BioSciences Cambridge USA
Show AbstractTo reduce the impact of marine coatings on the environment, various “inert&’ polymers have been applied to reduce fresh water and marine fouling. This research project compares the anti-fouling performance of hydrophobic silicone coatings and hydrophilic betaine-modified silicone coatings. The anti-fouling performance was assessed for long-term applications across a broad-spectrum of common pathogens. Two hydrophobic coatings, a non-leaching silicone formulation and a fouling-release marine coating were compared to respective betaine-modified formulations. The surface of the hydrophobic coatings were modified with sulfobetaine homopolymer to improve the hydrophilicity. The surfaces were then evaluated by ATR-FTIR, contact angle, optical and electron microscopy methodologies. The comparative evaluations included protein adsorption, the surface attachment of three common bacteria, Staphylococcus aureus (Gram positive), Escherichia coli (Gram negative), and Cellulophaga lytica (a marine bacteria), as well as barnacle attachment. The betaine-modified surfaces compared favorable across the range of evaluations when compared with the two silicone formulations. For example, a comparative fibrinogen reduction of 91% was achieved on both betaine-modified coatings. For E coli, S. aureus, and C. lytica, respective reductions of 97.0%, 99.6%, and 99.5% were obtained using the modified non-leaching formulations, whereas 90.7%, 88.5%, and 93.4% reductions were obtained on the modified marine formulations. The attachment of barnacle cyprids was also significantly reduced on the betaine-modified formulations. Finally, when the samples were evaluated for long-term two month durability, a comprehensive foulant reduction was obtained on the betaine-modified samples. Biocompatibility, hydrolytic stability and oxidative stability were also evaluated and supported long-term application. In conclusion, the results show that the hydrophilic betaine surface modification yielded a consistent high resistance to protein adsorption, bacterial attachment, and barnacle settlement for long duration applications. This technology is promising as a sustainable underwater coating for marine and hydrokinetic devices.
9:00 AM - G7.19
Surface Modified Magnetite Sorbents for Water Purification Technologies
Daniela S. Tavares 1 2 Ana Luisa Daniel da Silva 1 Claudia B. Lopes 2 Eduarda Pereira 2 Tito Trindade 1
1University of Aveiro Aveiro Portugal2University of Aveiro Aveiro Portugal
Show AbstractWater pollution by trace metals is a serious environmental issue that has attracted attention for the development of more effective sorbents.[1] Among trace metals there has been great concern about mercury pollution, which is due to its toxicity, persistent character in the environment and bioaccumulation along the food chain. Although a variety of sorbents for aqueous mercury are available, there is need of more effective materials that allows the removal of these species when present at very low concentration. This communication presents a new class of sorbents for water purification that are based on surface modified magnetite particles. The main aims of this research are the development of sorbents that can be collected by low-field magnetic separation and that are efficient in water remediation processes in realistic working conditions, namely in terms of vestigial amounts of the pollutant and the salinity of water. Cubic shaped magnetite (Fe3O4) particles were prepared by hydrolysis of FeSO4 in alkaline medium. Chelating moieties with high affinity for mercury were grafted at the materials surfaces by investigating two routes based on dithiocarbamate chemistry. In a first strategy, Fe3O4 particles were modified with amorphous silica shells using a sol-gel method that were then functionalized with dithiocarbamate groups by insertion of CS2 into aminopropyltriethoxysilane (APTS) grafted at the particles surfaces. A second route involved the one step hydrolysis of tetraethylorthosilicate (TEOS) in the presence of the dithiocarbamate derivative of APTS leading to higher content of sulfur containing chelating moieties. The effectiveness of the two types of sorbents as cleanup agents for contaminated waters was then assessed by taking into account their chemical composition, specific surface area and morphological characteristics. Batch stirred tank experiments were carried out by contacting a volume of solution with known amounts of functionalized particles, aiming to investigate the effect of sorbent dose and salinity, and the kinetics and the equilibrium of this unit operation. Typically, complete magnetic Hg (II) removal (ca. 99.8%) was attained with 6 mg/L of sorbents for an initial metal concentration of 50 µg/L. Highly complex matrices, such as seawater (ca. 99%) and river water (ca. 97%), did not affect the removal capacity of the functionalized magnetic particles. The solid loadings measured in this essay surmount the majority of the values found in literature for other type of sorbents.[2] The high efficiency displayed by these samples for the magnetic uptake of cationic mercury in water is ascribed to the presence of dithiocarbamate groups whose affinity for mercury ions is well known. [1] E. H. Borai et al., Adsorption 2007, 13, 95. [2] P. Figueira et al., Water Res. 2011, 45, 5773. Acknowledgements:The authors acknowledge FCT (Project PTDC/CTM-NAN/120668/2010) for funding.
9:00 AM - G7.20
Group III-nitride Based Electronic and Optoelectronic Integrated Circuits for Smart Lighting Applications
J. Justice 1 D. Korakakis 1
1West Virginia University Morgantown USA
Show AbstractWith general lighting applications being responsible for over 20% of the energy consumption in the United States, advances in solid state lighting have the potential for considerable energy and cost savings [1]. The United States Department of Energy predicts that the increased use of solid state lighting will result in a 46% lighting consumption energy savings by the year 2030 [2]. Smart lighting systems also have the potential for reducing energy costs [3] while providing a means for short distance data transmission via free space optics [4,5]. The group III-nitride (III-N) family of materials, including aluminum nitride (AlN), gallium nitride (GaN), indium nitride (InN), their ternary and quaternary alloys, are uniquely situated to provide light emitting diodes (LEDs) across the full visible spectrum, photodetectors (PDs) and high power, high speed transistors [6]. In this work, aluminum gallium nitride (AlGaN)/GaN high electron mobility transistors (HEMTs) are fabricated and characterized for the purpose of III-N integrated circuits. HEMTs are also integrated with indium gallium nitride (InGaN) based LEDs and PDs on a single chip. [1]I. L. Azevedo, M. G. Morgan and F. Morgan, Proc. IEEE, 97(3) (2009) 481-510. [2]Navigant Consulting, Inc., “Energy Savings Potential of Solid-State Lighting in General Illumination Applications”, Prepared for: Solid-State Lighting Program, U.S. DOE, (2012). [3]R. F. Hughes, P. Eng. and S. S. Dhannu, IEEE Elec. Power & Energy Conf., 978-1-4244-2895-3/08 (2008). [4]H. Willebrand and B. Ghuman, “Free Space Optics: Enabling Optical Connectivity in Today's Networks”, 1st ed., (Sams, 2001). [5]S. Deng and Z. R. Huang, Conference on Lasers and Electro-Optics (CLEO), JWA92 (2011). [6]S. N. Mohammad, A. A. Salvador and H. Morkoc, Proc. IEEE, 83(10) (1995) 1306-1355.
9:00 AM - G7.21
Preparation of Anatase Nanoparticles for Heavy Metal Ions Adsorption from Aqueous Solution
Zuleyha Ozlem Kocabas Atakli 1 Yuda Yurum 1
1Sabanci University Istanbul Turkey
Show AbstractAnatase nanoparticles (ANPs) were used successfully in removing heavy metals from aqueous solution. The nanoparticles were obtained by sol-gel method varying the water/alcohol molar ratios and pH values of solution. Characterization techniques indicated the nanoparticles with a primary particle size between 5 and 30 nm and the main (101) peak of anatase at 2theta; values of 25.4o. The effect of contact time, initial metal ions concentration, and solution of pH on the adsorption of Pb(II), Cu(II) and As(III) by ANPs were investigated and optimized. According to kinetic sorption data, the higher regression coefficients (R2) were obtained after the application of pseudo-second order to the experimental data of heavy metal initial concentrations. In terms of adsorption mechanisms, the initial stage of adsorption of the heavy metals onto ANPs was mainly governed by external diffusion mechanism. The maximum removal percentages of Pb(II), Cu(II), and As(III) were 97.82%, 99.35%, and 66.7%, respectively. The equilibrium data were modeled with the help of Langmuir and Freundlich equations. Overall, the data are well fitted with both the models, with a slight advantage for Langmuir model. The ability of ANPs for removing Pb(II), Cu(II) and As(III) is remarkable when considered in terms of the amount of metal adsorbed per unit mass (39.35 mg/g for Pb(II), 44.07 mg/g for Cu(II) and 18.75 mg/g for As(III). ANPs are a good nano-adsorbent candidate, with high efficiency for heavy metal treatment, commercial availability, and low cost.
9:00 AM - G7.22
Development of Multichannel Packed-bed Microreactor with Temperature Sensor for Safely Hydrogen Peroxide Production
Jiro Adachi 1 Kenichirou Ootaki 1 Ming Lu 1 Sunao Murakami 2 Sohei Matsumoto 1 Tomoya Inoue 1
1National Institute of Advanced Industrial Science and Technology Tsukuba, Ibaraki Japan2National Institute of Advanced Industrial Science and Technology Iiduka, Fukuoka Japan
Show AbstractHydrogen peroxide (H2O2) is a basic chemical having various kinds of application. Industrial production of H2O2 is mainly based on the indirect process called as anthraquinone process. This process is complicated and energy consuming process, thus the commercialization of direct synthesis of hydrogen peroxide from hydrogen and oxygen has been strongly required as an alternative process. Since the last decade, microreactor technology has offered an alternative opportunity to handle chemical processes safely, enabling safe handling of hydrogen - oxygen mixture during the reaction. We had performed the gas-liquid reaction in 600 mu;m-wide channels packed with catalytic microparticles, and achieved the safe synthesis of hydrogen peroxide without the explosive reaction even when the explosive gas content was used [1]. As the next step, high-throughput operations with high stability are also required to achieve the practical production of the chemicals. We designed and fabricated 4 and 8-channel microfluidic device for the scale-up of multiphase chemical reactions in catalytic packed-beds. In the parallelization of the packed-bed channels for multiphase reactions, it is so important to avoid the significant maldistribution of the flow and heat heterogeneity among the channels [3]. We additionally embedded microstructure generating large pressure drop at the upstream of the microchannel to suppress the maldistribution of the flow of a reaction solution among the microchannels which derived from the intrinsic high flow resistance and the pressure fluctuation. The flow maldistribution of paralleled channels will causes heterogeneity of reactions among the channels and leads to explosive reaction in some cases. To detect the abnormal reaction temperature, we introduced gold/chromium thin film resistance temperature sensor on the substrate with additional process. The microchannels were separately fabricated on three glass substrates by chemical etching with HF solution and micro drilling. After the inlet and outlet holes were fabricated with micro drilling, the glass substrates were thermally bonded. Catalytic microparticles were additionally loaded into the microchannels as slurry to prepare catalytic packed-beds. Gold and chromium were sputtered to the microchannels and the pattern of the sensors were defined by photolithography, followed by wet etching. We developed the temperature sensor mounted multichannel packed-bed microreactor. Our effort on temperature sensing and numbering up will be presentated on site. References [1] T. Inoue, Y. Kikutani, S. Hamakawa, K. Mawatari, F. Mizukami and T. Kitamori, Chem. Eng. J., 160 (2010), pp. 909-914. [2] N. de Mas, A. Gunther, T. Kraus, M. A. Schmidt and K. F. Jensen, Ind. Eng. Chem. Res., 44 (2005), pp. 8997-9013. [3] M. Mendorf, H. Nachtrodt, A. Mescher, A. Ghaini and D. W. Agar, Ind. Eng. Chem. Res., 49 (2010), pp. 10908-10916.
9:00 AM - G7.24
Process Temperature Dependence on Moisture Permeation Barrier Characteristics of Al2O3 Films Deposited by Remote Plasma Atomic Layer Deposition
Hagyoung Choi 1 Seokyoon Shin 1 Joohyun Park 1 Sanghun Lee 1 Hyunsoo Jung 1 Hyeongtag Jeon 1
1Hanyang University Seoul Republic of Korea
Show AbstractRecently, Organic electronic devices have emerged as attractive alternatives for lighting and power generation. Making these devices on flexible polymers provides a portable, lighter weight. However, the high permeability of polymer to atmospheric gases such as O2 and H2O can corrode the cathodes in organic light emitting diode (OLED) displays. An important goal for realization of flexible OLED is to deposit moisture permeation barrier on polymers at low temperature. These moisture permeation barriers can also be used in many modern high precision applications, such as automotive and aerospace for corrosion protection. Atomic Layer Deposition (ALD) is well-known process that grows dens, highly conformal, pinhole-free thin films needed for superior permeation barriers. Also Plasma Enhanced ALD (PEALD) has been widely used to enhance chemical reactivity between metal-organic precursors and reactant gas. However, the introduction of plasma in the ALD process can result in plasma-induced substrate and film damages. In this respect, Remote Plasma ALD (RPALD) was developed to minimize the plasma damage by generating the plasma remotely outside of chamber and the generated radicals and ions enter into the chamber by a downstream flow. The moisture permeation barrier properties of Al2O3 films deposited by RPALD at various process temperatures between 50°C and 200°C using Trimethylaluminum [TMA, Al(CH3)3] as source and O2 gas as reactant is presented in this study. Also we carried out several analyses such as field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), X-ray auger electron spectroscopy (AES), Fourier transform infrared spectroscopy, and the X-ray reflectometry (XRR) to investigate physical and chemical properties of the deposited films. Finally moisture barrier performances of films were characterized using the calcium degradation test by monitoring the change in ohmic behavior of the thin film of Ca covered with moisture barrier film. The Al2O3 films deposited by RPALD having a thickness of 100 nm were grown at each process temperature of 50, 100, 150 and 200°C. The mass density increases from 2.5 to 2.8 g/cm3 with increasing the process temperature. XPS analysis of O1s peak show that the OH ratio decreases with process temperature from 38% at 50°C to 25% at 200°C. The electrical Ca degradation test indicates that the 100nm Al2O3 film on PES, side sealed with UV-cured resin, enhance the moisture barrier performance with increasing the process temperature at 40°C and 40% relative humidity (RH) test condition.
9:00 AM - G7.25
Additional Hydrogen Uptake in Nano-porous Materials Due to a Strong Remanent Crystalline Field after the Surface Adsorption: Observation by In-situ Neutron Scattering
Heeju Lee 1 Yong Nam Choi 1 Sang Beom Choi 2 Jaheon Kim 2 Kyung Byung Yoon 3 Daejin Kim 4 Dong Hyen Chung 4
1Korea Atomic Energy Research Institute Daejeon Republic of Korea2Soongsil University Seoul Republic of Korea3Sogang University Seoul Republic of Korea4Insilicotech Seongnam Republic of Korea
Show AbstractRecently, physisorption has attracted more attention because the adsorption is reversible and thus the adsorbent can be recycled. Moreover, physisorption offers the possibility of high hydrogen storage capacity and quick hydrogen desorption. The mechanism of adsorption in porous materials is that hydrogen molecules are forced into the pores under pressure and low temperature. Porous materials, which have large internal surface area, have recently attracted much attention and increasing interest due to their promising use in hydrogen storage [1,2]. Among many kinds of candidates for hydrogen storage, we have considered zeolite (Na-X) and Metal-Organic Frameworks (MOFs : HKUST-1 and MOF-205) which have various surface area and adsorption enthalpy [surface area: MOF-205>HKUST-1>Na-X, H2 adsorption enthalpy: MOF-205
9:00 AM - G7.26
Development of Renewable Surfactants from Bio-based Waste Using Principles of Green Chemistry and Engineering
Zarif Farhana Mohd Aris 1 Ryan Bouldin 2 Vishal Bavishi 1 Natalia Muniz Rivera 3 Ramaswamy Nagarajan 1
1University of Massachusetts Lowell Lowell USA2College of the Atlantic Lowell USA3University of Puerto Rico Mayaguez Puerto Rico
Show AbstractSurfactants based on renewable starting materials and ‘greener&’ synthetic routes have become a major focus of researchers worldwide. Although the surfactant industry uses the term `natural surfactant' to indicate the presence of bio-based ingredients in their product lines, the industry as a whole still heavily relies on petrochemical feedstock and harsh chemical synthesis for the manufacture of surfactants. In addition, after use, most commercially available surfactants are either non-biodegradable or degrade to produce more toxic products as in the case of Nonylphenol ethoxylates (NPEs). Therefore, there is a need for developing non-toxic, bio-based, and biodegradable surfactants using ‘safer&’ materials and methods. In an attempt to promote the use of renewable feedstock and eliminate the use of toxic materials, we have demonstrated the possibility of converting a fruit waste product (i.e. fruit peels) and algae obtained from renewable resources into efficient non-toxic and biodegradable surfactants. The hydrophilic modification of water insoluble polysaccharides in non-toxic solvents will be described. The structural characterization, surface activity and cleaning efficiency of these polysaccharide-based surfactants will also be presented. Our work establishes a general methodology for the modification of natural polysaccharides, opening new possibilities for the synthesis of novel amphiphilic, non-toxic and bio-based emulsifiers and surfactants.
9:00 AM - G7.27
Ecodesign Concept
Tarja Mirjam Johanna Laitinen 1 Erja Turunen 2 Mona Arnold 2 Ulla-Maija Mroueh 2
1VTT Technical Research Centre of Finland Tampere Finland2VTT Technical Research Centre of Finland Espoo Finland
Show AbstractEnergy efficiency is an established, global megatrend throughout the industries in order to secure energy supply, cut costs and mitigate greenhouse gas emissions. Resource efficiency is becoming the demand of industrial activity in sectors like construction, chemicals, automotive, aerospace, machinery or commodities. The alternatives to tackle the raw materials scarcity are either new primary (arctic, seabed) or secondary sources (reuse, recycling) or substitution. Current amount of metals (e.g. Cu, Zn, Ni and Al) that can be directed to recycling from their present use is inadequate compared with the market need. Substitution can be used to develop alternative materials in certain applications or to replace those applications by an equivalent technology that does not rely on the key raw materials. The typical material life cycle starts from primary production, mining. The ore is converted into metallic form, alloyed with other elements and semi-fabricated in a form of, e.g., powder, sheet or forging for manufacturing the final product. Once the product has served for its purpose, it is either recycled or wasted. The resulting carbon and water footprints are large and solutions are looked for from new technology breakthroughs including new material design concepts, additive manufacturing methods and new recycling and recovery technologies. The future society is based on sustainable development, where the re-use is of central importance. Materials reuse, efficient use of secondary flows as well as more efficient recovery technologies provide the basis for the sustainable exploitation of natural resources. VTT has implemented the demand of energy and resource efficiency in the framework of Ecodesign concept covering the whole material life cycle from material sources to material design and manufacturing, component life time optimisation and finally recycling concepts. The vision of the virtually supported Ecodesign concept is to create optimized and efficient machine and device components regarding their whole lifecycle by evolving multiscale modelling. In this presentation we will introduce our development work within our Ecodesign concept by giving two case examples including copper flow in electrical vehicle and nickel flow in combustion boiler. First we will discuss new design methods, copper flow in electrical motor and introduce new bio-chemical recovery technologies. In the latter we will discuss multiscale modelling starting from raw materials and new design criteria regarding performance, life time, maintenance strategies and finally energy efficiency in system level operation.
9:00 AM - G7.28
Dilution Effect of Contiguous Ti Sites on Photocatalytic Synthesis of Oxygenated Hydrocarbons from Diesel Fuel for Mobile DeNOx Application
Jae Yul Kim 1 Sun Hee Choi 2 Jae Sung Lee 1
1Pohang University of Science and Technology (POSTECH) Pohang Republic of Korea2Pohang University of Science and Technology (POSTECH) Pohang Republic of Korea
Show AbstractDiesel engine vehicles are the major source of harmful NOx emission on the road threatening urban ecosystem. NOx SCR method is one of the most prevalent technologies to convert NOx contaminants into neutral N2 in transport sector. Currently, urea-SCR is considered the most promising reductant for NOx SCR because it generates NH3, the strong reductant of NOx at low temperatures and has been selected by European vehicle makers. Yet, this technology has several drawbacks that ammonia is toxic and carrying a urea tank on board is not safe and needs charge stations. Diesel fuel itself can be directly used as a convenient reductant, but it is not reactive enough at the diesel exhaust temperatures under lean conditions. From this circumstance, we propose a new scheme of nitrogen oxides (NOx) after-treatment system of diesel engine vehicle exhaust line involving a new photocatalytic reaction. Thus, on-board photocatalytic partial oxidation of a small amount of diesel fuel produces oxygenated hydrocarbons (OHC, mainly C1-C6 aldehydes) as an effective NOx reductant. The TiO2-SiO2 mixed oxide photocatalysts showed higher selectivity and yield to OHC than commercial TiO2 under UV irradiation by diluting contiguous Ti sites to suppress complete oxidation to CO2.[1] To achieve further enhanced OHC selectivity and yield, we synthesized TS-1 and Ti incorporated mesoporous materials, so called atomic scale dispersed photocatalysts.[2] Improvement in OHC selectivity was obvious that it was 100% and 61.2% in case of TS-1 and Ti-SBA-15 respectively. Due to small ratio of Ti/Si=0.04, conversion of dodecane was not drastically higher than commercial TiO2. Scientifically, the reaction is a rare example of photocatalytic partial oxidation for cracking and functionalizing a long chain organic alkane into smaller OHC molecules. References [1] Green Chemistry submitted, 18-May-2012, Manuscript ID: GC-ART-05-2012-035763. [2] M. Anpo, T.H. Kim, M. Matsuoka, Catal. Today. 142 (2009) 114-124.
9:00 AM - G7.29
High Temperature Sustainability of a New Material Made of Atomized Co:Ni Alloy Composited with Multiwalled Carbon Nanotubes
Xu Chen 1 Kalathur S Santhanam 1 2
1Rochester Institute of Technology Rochester USA2Rochester Institute of Technology Rochester USA
Show AbstractThere has been an enormous interest in ferromagnetic metals and their alloys that will have stability in high temperature applications (1). They tend to get oxidized at high temperatures in air and hence currently attempts are being made to develop materials that would have long lasting sustainability. We wish to report here an alloy of atomized Co and Ni that is synthesized and composited with multiwalled carbon nanotubes (diameter 60-100 nm, length 5-40 mu;m ) having thermal stabilty. The composite was annealed at 500 C and examined for its thermal, spectral and catalytic properties. The thermogravimetric (TGA) curves have been recorded in the presence of oxygen supply and it showed the following features; no weight gain in the temperature range from 25-700 C. Beyond 700 C, there is a steady weight loss up to 800C. The weight loss stops beyond this temperature. Analysis of the sample after treatment at 800 C by Fourier Transform Infra red spectroscopy showed the features of nickel oxide suggesting the alloy had a preferential bonding to oxygen through Ni atom. Additional support is provided by the XRD data of the samples. The new material showed two theta reflections corresponding to (220) and (111) planes of Co and (220) plane of Ni. This new material shows high temperature sustainability up to 700 C. This is in contrast to the poor sustainability of Ni or Co or the alloy; Atomized Ni and Co show the formation of oxides at temperatures of 520 C and 250 C respectively. The composited alloy shows thermal stability up to 700 C. This new material exhibits electrocatalytic production of hydrogen. The Tafel plot showed a slope of 13.6 mV/decade that is comparable to platinum with an exchange current density of 2.5 X 10-4 A/cm2. The results obtained show a preferential binding of carbon nanotubes to Ni atom in the composite. ________________________________________________________________________ 1. K.S.V. Santhanam and G. Lein, Encyclopedia of Nanoscience and Nanotechnology, Vol. 24, p.249, (2011).(American Scientific Publishers)
9:00 AM - G7.30
Reusable Si-Thiol Supported Pd for Active Pharmaceutical Ingredients
Chang Liu 1 Fei Deng 1 Jinsheng Li 1 ZuoGang Huang 1 Huiying Harry Li 1 Chaoying Ni 1
1University of Delaware Newark USA
Show AbstractTransition metal catalyzed coupling reactions have been widely used in modern synthetic practices. However, use of transition metals for the synthesis of active pharmaceutical ingredients (APIs) necessitates the removal of the metal-containing impurities in the isolated products. The post-reaction removal is a challenging task for the process chemistry in pharmaceutical industry, and the associated cost and environmental implications are nontrivial. To meet strict limit for heavy metal residues in APIs, one such post-reaction process includes the adsorption of the remaining transition metals to an appropriate solid scaffold followed by the removal of the scaffold absorbent from the process stream by filtration. Palladium catalyst supported by Si-Thiol, a commercially available mercaptopropyl-modified and TMS-passivated amorphous silica, was investigated as a replacement of conventional homogeneous catalysts for coupling reactions. The outcomes of the Suzuki reaction were found to be greatly affected by the choice of solvents. Reactions in alcohols gave optimal results, and the Pd/Si-Thiol was demonstrated to be reusable over multiple times without noticeable loss of activity, to simplify the post-reaction procedure, and to save the cost.
G5: Reducing Impact on Environment
Session Chairs
Thomas Graedel
Linda Gaines
Tuesday AM, November 27, 2012
Hynes, Level 3, Room 306
9:30 AM - *G5.01
Meeting the Materials Challenges to Enable Clean Fossil Energy Technologies
Bryan Morreale 1
1US DOE National Energy Technology Laboratory Pittsburgh USA
Show AbstractRealization that the environmental impact of energy production must be reduced on a global scale, combined with an increased national desire to reduce dependence on foreign energy, is driving significant change in the energy outlook of the United States. While renewable energy resources will continue to grow in importance, environmentally responsible fossil energy production will be necessary to provide a bridge to the next energy revolution. This drive to increase process efficiencies and reduce the environmental impact in fossil-based energy production will require processes with increased operating temperatures and pressures, and increasingly aggressive operating environments. The practical result is a requirement for affordable and reliable high-performance materials and materials systems to enable these next-generation fossil energy systems. This talk will focus on the role and importance of fossil energy into our future, the challenges towards sustainability, and the research being performed within the Department of Energy&’s Fossil Energy Program to meet the requirement for high performance yet affordable materials.
10:00 AM - G5.02
Living Hybrid Materials for Sustainable Energy Technologies and a Greener Environment
Bao-Lian Su 1
1University of Namur, 61 rue de Bruxelles Namur Belgium
Show AbstractThe world today is different from which it has been. The deficit in fossil fuel resources and the global warming calamity, due at least in part to the increased emission of CO2, are two current existential problems facing Humanity. The entire planet is at risk; these are our crises. As Mankind is the cause, Mankind should find the solution. Solving these two problems is thus a top priority. The effects of global warming and the energy crisis have spurred a multitude of research projects focused on reducing CO2 emissions and on finding and producing clean energy. Unfortunately solutions to the energy crisis are often at the expense of the environment. This presentation describes the sustainable design and processing of photobiochemical leaf-like materials capable of the energy conversion as the principal component of a photobioreactor [1-10] and a biofuel cell [11, 12]. The photosynthetic activity shows that the material was able to produce oxygen for over a month. The photochemical material was also able to reduce CO2 into carbohydrates. A part of these photosynthates were excreted into the aqueous phase contained within the pores of silica. By a simple extraction method, these products could be recovered. The molecules excreted by the material were mainly polysaccharides composed of rhamnose, galactose, glucose, xylose and mannose units. Considering that the quantity of sugars increased as a function of time, this photosynthetic material holds much promise in the development of new, green chemical processes. For instance, atmospheric CO2 could be strategically exploited via this kind of artificial leaf-like materials, as a source of carbon to produce valuable compounds or biofuels while the active biomass is continuously reused. These results constitute a significant advance towards the final goal, long-lasting semi-artificial photobioreactors and biofuel cells that can advantageously exploit solar radiation to convert polluting carbon dioxide into useful biofuels, sugars or medical metabolites [1-10] and electricity [11, 12]. ____ [1] B. L. Su et al, J. Mater. Chem., 2008, 18, 2833. [2] B. L. Su et al, J. Mater. Chem., 2008, 18, 1333. [3] B. L. Su et al, J. Mater. Chem., 2009, 19, 4131. [4] B. L. Su et al, J. Mater. Chem., 2009, 19, 1505. [5] B. L. Su et al, J. Mater. Chem., 2010, 20, 929. [6] B. L. Su et al, Energy Environ. Sci., 2010, 3, 370. [7] B. L. Su et al, Chem. Commun. 2010, 46, 3843 [8] B. L. Su et al, ChemSusChem, 2011, 4, 1327 [9] B. L. Su et al, B. L. Su et al, Chem. Soc. Rev., 2011, 40, 860 [10] B. L. Su et al, ChemSusChem, 2011, 4, 1249 [11] B. L. Su et al, ChemCatChem, 2011, 3, 476 [12] B. L. Su et al, Energy Environ. Sci., 2012, 5, 5540
10:15 AM - G5.03
Molecular Modeling of Zeolites for Carbon Dioxide Sequestration
Jennifer C. Crabtree 1 2 Stephen C. Parker 2 Semali Perera 3 John A. Purton 4
1University of Bath Bath United Kingdom2University of Bath Bath United Kingdom3University of Bath Bath United Kingdom4STFC Daresbury Laboratory Daresbury United Kingdom
Show AbstractThe emission of greenhouse gases is contributing to global warming and climate change. Carbon dioxide represents 77% of the total anthropogenic greenhouse gases in the atmosphere, therefore the adsorption and separation of CO2 from waste gas streams is a key area of research. Silicate materials such as zeolites have been shown to be good candidates for CO2 adsorption. Zeolites are microporous crystalline solids that exhibit a wide range of framework structures. Many zeolites occur naturally while others are synthetically produced. This work aims to accurately model the adsorption of CO2 in a selection of zeolites to find the most suitable candidates for sequestration. The initial work focuses on zeolites FAU and MFI, but once the procedure is optimized it can be extended to other zeolite structures. Our computational approach uses interatomic potentials to describe the interactions between atoms. Energy minimization is used to find the most stable configuration of the zeolite structure and molecular dynamics (MD) is used to study the diffusion of CO2 in the zeolites. Grand canonical Monte Carlo (GCMC) simulations are used to generate adsorption isotherms showing the amount of CO2 that can be adsorbed as a function of pressure, which can in turn be used to calculate the heats of adsorption. In order to find trends in the isotherm characteristics we present adsorption isotherms for a range of zeolite structures, Si:Al ratios, counter-cations and temperatures. The transport mechanisms are then explored using MD simulations, considering the effect of bulk and interfacial properties. Results are also presented for a range of interfaces, clearly showing the impact that they can have on the transport properties. Through GCMC simulation results we show that our potential model can accurately reproduce experimental isotherms for siliceous zeolites. This is extended to cover aluminosilicate zeolites, with a range of counter-cations including Na+, K+ and Ca2+. Our model can now be used to predict and identify potential candidates for CO2 adsorption materials.
10:30 AM - G5.04
Exceptional CO2 Adsorption by Covalent Organic Polymers (COPs)
Hasmukh A Patel 1 Ferdi Karadas 2 Ali Canlier 1 Joonho Park 1 Erhan Deniz 2 Yousung Jung 1 Mert Atilhan 2 Cafer T Yavuz 1
1KAIST Daejeon Republic of Korea2Qatar University Doha Qatar
Show AbstractEfficient CO2 scrubbing without a significant energy penalty remains an outstanding challenge for fossil fuel-burning industry where aqueous amine solutions are still widely used. Porous materials have long been evaluated for next generation CO2 adsorbents. Porous polymers, robust and inexpensive, show promise as feasible materials for the capture of CO2 from warm exhaust fumes. We report the syntheses of porous covalent organic polymers (COPs) with CO2 adsorption capacities of up to 5616 mg/g (a world record - measured at high pressures, i.e. 200 bar) and industrially relevant temperatures (as warm as 65 oC). COPs are stable in boiling water for at least one week and near infinite CO2/H2 selectivity is observed. Theoretical calculations refer to an amorphous extended framework as density is likely the main reason for exceptional CO2 capacities. COPs 1-2 feature basic nitrogen sites that show chemospecific affinity towards acidic gases such as CO2. COP-3 has reasonably high surface area (418 m2/g), effective for low pressure operations. Post combustion carbon capture from fossil fuel power plants demands pressures of up to 6 bar and a minimum temperature of 40 oC. By tuning their architecture, we show that COPs reach to 3 mmol CO2/g sorbent at 6 bar and 45 oC. High and low pressure capacities make these porous polymer structures viable alternatives to amine scrubbers.
10:45 AM - G5.05
Novel Flame Retardants Based on Polyphenol-metal Oxide Complex
Weeradech Kiratitanavit 1 Sethumadhavan Ravichandran 2 Ruchi Bakshi 4 Timothy Ponrathnam 1 Jayant Kumar 3 4 Ramaswamy Nagarajan 1 4
1University of Massachusetts Lowell Lowell USA2University of Massachusetts Lowell Lowell USA3University of Massachusetts Lowell Lowell USA4University of Massachusetts Lowell Lowell USA
Show AbstractMost commodity polymers are quite flammable and in order to ensure fire safety, additives known as Flame Retardants (FR) are often compounded into the base polymer. FR additives decrease the rate of flame propagation and polymer decomposition. Halogenated (bromine and chlorine) compounds are one of the most commonly used of FR additives for polyolefins. However, some of these halogenated FR are toxic, environmentally persistent and harmful impact to humans and others forms of biological life. Several countries have already banned the production and use of some types of halogenated FR. There is a dire need for non-halogenated FR alternatives that are safer and effective. We have recently reported that polymers of phenols can be used as FR additives. The mechanism of action of these polyphenols is predominantly radical scavenging and char formation. In an attempt to improve the effectiveness of these FR, polyphenols have been complexed with metal oxides. Here we report the polymerization of an acid-functionalized phenol (4-hydroxyphenylacetic acid - HPA) using enzyme catalysis; followed by electrostatic binding of the polymer onto titania (TiO2) nanoparticles to produce polyphenol-titania complex. The polymer was characterized using spectroscopic techniques (UV-Visible spectroscopy, FTIR-ATR) and Gel permeation chromatography. Thermal characterization of the complex using TGA (Thermogravimetric analysis) and PCFC (Pyrolysis Combustion Flow Calorimetry) revealed the presence of 10% by weight polyphenol bound to the titania. The complex also exhibited high char formation (about 40% at 750oC) and low heat release capacity [HRC] (less than 100 J/gK). The polyphenol-titania complex was blended into polypropylene (at 1%, 5% and 10% by weight) using a brabender plasticorder. The thermal stability, heat release capacity and char yield of these blends were also determined. HRC of polypropylene decreased more than 25% as compared to the virgin polypropylene. This decrease is similar to some of commercially used halogenated FR like hexabromocyclododecane. The detailed synthesis and characterization of this new class of FR additives will be presented.
11:30 AM - *G5.06
Modelling Chemo-mechanical Properties of Materials for Energy Saving
Alessandro De Vita 1 2
1King's College London London United Kingdom2Universita' di Trieste Trieste Italy
Show AbstractModelling many complex materials processes of high social and economic impact requires a non-uniform-precision, multi-scale treatment. An example of this is crashing and grinding of mineral ores for metal extraction, on its own responsible for ~5% of the total industrial energy consumption worldwide. Here, catastrophic or stress-corrosive brittle fracture and failure result from a coupling between dynamical large-scale stress concentration effects and detailed local chemical processes occurring at the advancing crack tip. This class of chemo-mechanical phenomena can be described at the atomic scale by “Learn On The Fly” schemes, which are quantum-based hybrid multi-scale simulations [1], often based on machine learning paradigms [2] and typically carried out in conjunction with fracture experiments [3]. The approach offers an inexpensive, quantum-accurate and completely risk-free discovery tool for testing/optimizing new materials and properties [4-5]. Research partnerships between the Thomas Young Centre of London[6] and, e.g., UK-based[7] and EU[8] industries provide an indication that hybrid methods can be useful to investigate a number of problems of direct industrial relevance for the commodity and renewable energy sectors. References> [1] G..Csanyi, T.Albaret, M.C.Payne and A.De Vita, Phys. Rev. Lett. 93, 175503/1-4 (2004). [2] A.P.Bartok, M.C.Payne, R.Kondor, and G.Csanyi, Phys. Rev. Lett. 104, 136403 (2010). [3] J.R.Kermode, T.Albaret, D. Sherman, N. Bernstein, P.Gumbsch, M.C.Payne, G.Csanyi and A.De Vita, Nature 455, 1224-U41 (2008). [4]D.Fernandez-Torre, T. Albaret and A.De Vita, Phys. Rev. Lett. 105, 185502 (2010). [5]G.Moras, L. Colombi Ciacchi, C.Elsaesser, P.Gumbsch and A.De Vita, Phys. Rev. Lett. 105, 075502 (2010), featured in Physical Review Focus (Vol. 26, Story 7, 13 August 2010). [6] The London Centre for Theory and Simulation of Materials (Imperial College, University College, King&’s College and Queen Mary University, http://www.thomasyoungcentre.org/ ) [7] Cf. e.g., the Rio Tinto Advanced Mineral Recovery Centre at the Royal School of Mines, Imperial College http://www.riotinto.com/ourapproach/17203_mine_of_the_future_17280.asp [8] Cf. e.g., the EU-FP7-“ADGLASS project, involving Schott AG, on adhesion and cohesion interfaces in high performance glassy systems, http://lib.bioinfo.pl/projects/view/6117
12:00 PM - G5.07
Modeling Organic Adsorption and Transport at Clay Mineral-water Interfaces
Thomas V. Shapley 1 Stephen C. Parker 1
1University of Bath Bath United Kingdom
Show AbstractThe remediation of pollutants from the environment can be an expensive process. Fortunately, clay minerals represent one promising candidate for cheap and sustainable pollutant remediation. Bentonite has been shown experimentally to adsorb both heavy metal ions and organic pollutants. Here we model the adsorption of a range of organic compounds (OCs) on the {001} surface of the clay mineral montmorillonite, a dioctahedral smectite and the main constituent of bentonite. We consider sodium-montmorillonite and organo-montmorillonite as well as pyrophyllite, a structurally related but hydrophobic clay mineral, for comparison. The CLAYFF and GAFF force fields are applied to the clay minerals and organic molecules, while AMBER TIP3P is used for water. These Lennard-Jones 12-6 force fields allow the new potential parameters describing the interactions between the three models to be derived using Lorentz-Berthelot mixing rules. The new potentials are validated using DFT calculations including dispersion corrections, using the DFT-D2 and vdw-DF2 methods. These potentials are then applied in a series of free energy of adsorption simulations using a constraints method to evaluate the effect of surface composition and solvent on the adsorption energy. We find that the adsorption energies of OCs on dry surfaces from the derived interatomic potentials are in good agreement with dispersion corrected DFT calculations. The free energy calculations show that replacing the sodium cation with a small organic cation (tetramethylammonium) improves that adsorption of the OCs to montmorillonite. Moreover, the addition of a large organic cation (hexadecyltrimethylammonium) further increases the energies of adsorption to a magnitude comparable to that of pyrophyllite, a fully hydrophobic surface. In calculations containing polyhalogenated compounds it is observed that the adsorption becomes more favorable with increasing chlorine content. The diffusion of the OCs at the surface is lower for systems with organic cations.
12:15 PM - G5.08
Binding and Diffusion of Small Molecules in MOF-74-Mg
Pieremanuele Canepa 1 Nour Nijem 2 Yves Chabal 2 Timo Thonhauser 1
1Wake Forest University Winston-Salem USA2University of Texas at Dallas Richardson USA
Show AbstractDistressing scenarios of fossil fuel shortages and increasing green-house effects have intensified scientific efforts to find innovative materials capable of efficient/effective hydrogen storage and gas separation. Metal organic frameworks (MOF) are a broad class of novel porous materials that exhibit the necessary prerequisites for feasible hydrogen storage and gas separation. For example, MOFs have large surface areas, high porosity, high thermal stability, high structural flexibility, and easily tunable chemical and physical properties.1, 2 , 3 A great deal of experimental effort has been made in synthesizing MOFs and tailoring their chemical properties, but insight into the physisorption phenomena that govern MOF macroscopic properties is best obtained through a combination of experiment and theory. We will present promising results from such a combined study, focusing on theoretical DFT simulations of the adsorption and diffusion of small, non-polar molecules such as H2, CO2, and N2 throughout the MOF scaffold. Standard exchange-correlation functionals are not capable of describing weak van der Waals interactions responsible for binding these molecules inside MOFs; however, we will show that the truly non-local functional vdW-DF4, 5 gives results -for a variety of properties of MOFs -in remarkable agreement with our experiments.
12:30 PM - G5.09
Formation of Mullite from Al2O3/SiO2 and Al2O3/SiC Composites for the Processing of Porous Radiant Burners
Daphiny Pottmaier 1 Jefferson Jean Rosario 1 Gisele Hammes 2 Orestes Alarcon 1 Marcio Celso Fredel 1
1Federal University of Santa Catarina (UFSC) Florianopolis Brazil2Federal University of Santa Catarina (UFSC) Florianopolis Brazil
Show AbstractCombustion using radiant ceramic burners combined with natural gas is and optimum alternative to enhance energy efficiency with lower emission of product gases per generated power. Materials properties required for the operation of such burners are mainly thermal shock and chemical resistance. Porous or cellular ceramics attend these properties as a function of porosity percentage and morphology, porous distribution and type. However, these characteristics may vary depending on the constituent materials (i.e. pure, mixture, composite) and their processing (e.g. replication, foaming, gelation among others). Mullite was already identified as an optimum choice for this application by advanced modeling of fluid flow, heat generation from chemical reactions, and coupled heat transfer inside the burner, however, its potential is not yet commercially well explored. Even though mullite can be prepared by synthesis of different compounds following different routes, control of reactive sintering from alumina and silica precursors is still complicated depending on the crystallinity, particles size, and impurity of the starting materials. Other than the thermodynamic constraints imposed by temperature and chemical potential, mechanism governing mullitization are related from activation energy to mass transport, grain boundary diffusion and sintering rate which are controlled by the presence or not of a liquid phase. In one degree or another all of these are influenced by powder characteristics, heat treatment, and Al2O3/SiO2 ratio. Using a more technological approach, mullite was processed in different ratios of Al2O3/SiO2/SiC by the replication method widely used for cellular ceramics, in this case radiant porous burners. Rheological studies together with Zeta potential of the suspensions were conducted for the Al2O3/SiO2/SiC composites and optimum additive content varied between 1.0 - 0.25 wt.%, while water to solid content was kept in 80/20 for the coating of the polyurethane sponges of 7 to 10 pores per inch and density of 0.03 g/cm3. After varying sintering temperatures and isotherm times of a maximum of 1600 and 12 hours, respectively, product materials were characterized mainly by X-ray diffraction for the identification of mullite and other phases. Results have shown a range from 26 to 82 wt.% of mullite with residual Al2O3, SiO2, SiC. Except for amorphous silica, the other phases were not expected to introduce thermal stresses to the composite but instead release crack propagation as a second minor phase and that is suggested by Scanning Electron Microscopy analysis after thermal shock rapture of the burners. Dilatometry and thermogravimetry have also supported the observation by a variation in their contraction profiles from 2 to 20 % depending on the composite. In addition, porous burners are also being processed and characterized with the incorporation of fly ashes from coal combustion to these composite materials.
12:45 PM - G5.10
Photocatalytic Synthesis of Oxygenated Hydrocarbons from Diesel Fuel for Mobile DeNOx Application
Jae Yul Kim 1 Yeon Ho Kim 1 Suenghoon Han 1 Sun Hee Choi 2 Jae Sung Lee 1
1Pohang University of Science and Technology (POSTECH) Pohang Republic of Korea2Pohang University of Science and Technology (POSTECH) Pohang Republic of Korea
Show AbstractDiesel engine vehicles are the major source of harmful NOx emission on the road. NOx SCR method is one of the best technologies to reduce NOx into neutral N2. Currently, urea is considered the most promising reductant for NOx SCR because it generates NH3, the strong reductant of NOx at low temperatures. Yet, ammonia is toxic and carrying a urea tank on board is not safe. Diesel fuel itself can be directly used as a convenient reductant, but it is not reactive enough at the diesel exhaust temperatures under lean conditions. From this circumstance, we propose a new scheme of nitrogen oxides (NOx) after-treatment system of diesel engine vehicle exhaust line involving a new photocatalytic reaction. Thus, on-board photocatalytic partial oxidation of a small amount of diesel fuel produces oxygenated hydrocarbons (OHC, mainly C1-C6 aldehydes) as an effective NOx reductant. The TiO2-SiO2 mixed oxide photocatalysts show higher selectivity and yield to OHC than commercial TiO2 under UV irradiation by diluting contiguous Ti sites to suppress complete oxidation to CO2. The effects of reaction variables have been studied in detail. Scientifically, the reaction has never been studied before, and is a rare example of photocatalytic partial oxidation for cracking and functionalizing a long chain organic alkane into smaller OHC molecules. In the process, the reactivity of TiO2, widely recognized as a total mineralization photocatalyst, can be controlled by dispersing it in an inactive oxide matrix. The proposed scheme is more environment-friendly than the reduction by urea, currently considered the most promising technology.[1] Reference [1] Green Chemistry submitted, 18-May-2012, Manuscript ID: GC-ART-05-2012-035763.
Symposium Organizers
Laura Espinal, National Institute of Standards and Technology
Enrico Traversa, University of Rome Tor Vergata
Samuel S. Mao, Lawrence Berkeley National Laboratory
Marie-Isabelle Baraton, Centre Europeen de la Ceramique
Symposium Support
National Institute of Standards and Technology
G9: Water Sustainability
Session Chairs
Wednesday PM, November 28, 2012
Hynes, Level 3, Room 306
2:30 AM - *G9.01
The Energy-water Nexus: Water Use Trends in Sustainable Energy and Opportunities for Materials R&D
Anthony Ku 1 Andrew Shapiro 1
1General Electric Niskayuna USA
Show AbstractOver the next few decades, the challenge of water scarcity is expected to grow more acute as water demand from power generation, agriculture, industrial and municipal sectors all increase. Energy production requires copious amounts of water and the volume of water used by power generation ranks second only that used for agriculture. This presentation will discuss how materials R&D can help manage the water requirements associated with power generation. Although the effect of both existing and emerging power generation modes on water use trends will be explored, the primary focus will be on thermal systems which account for the majority of existing capacity. The presentation will be divided into three parts. The first part will review power generation and water use trends, and introduce a metric that can be used to compare different technology approaches. The next section will address water use in power plants, and explore ways that materials innovation can reduce water demand. These include improving the efficiency of gas and steam turbines through the development of next generation superalloys, high temperature materials such as ceramic matrix composites, and hydrophobic condenser surfaces. Since cooling accounts for the majority of water use in thermal systems, lower cost heat transfer materials can improve the economic competitiveness of air-cooled condensers and other low water demand cooling options. The final section focuses on ways materials R&D can help to expand the supply of water for power generation use. Non-traditional water sources such as brackish aquifers and produced water have a higher tendency to foul equipment, and materials advances such as biofilm resistance coatings and membranes have the potential to enable the use of these water resources for cooling.
3:00 AM - G9.02
Magnetic Separation: An Energy Efficient Separation Method to Treat Diluted Contaminated Water Streams
Michael Rossier 1 Robert N Grass 1 Detlef Gunther 1 Wendelin J Stark 1
1ETH Zurich Zurich Switzerland
Show AbstractPure water is a key issue for the future. Unfortunately large amount of water is currently still polluted by heavy metals. The existing water purification methods lack of efficiency to treat large amount of water containing minute but toxic concentration of pollutants. Magnetic filtration promises an efficient way to control large liquid volumes with a specific reagent and a low energy input. At present, the lack of sufficiently magnetic nanoparticles has limited the magnetic separation to small volume and low flows (diagnostic). The recently developed highly magnetic metallic nanoparticles meet the requirements to apply this separation method in large water volumes. In this presentation, the advantages of the metallic nanoparticles versus the commonly used iron oxide micro- or nanoparticles will be shortly presented. Following this, two case-study will be used to demonstrate the efficiency of the magnetic separation. The low energy consumption of the magnetic separation in regard of other commonly used separation method (chromatography) will be shown with the example of a contaminated retention basin. After the adsorption of the contaminant by the nanomagnets, the recycling avoids the loss of particles. This recycling process of the nanomagnets consume minute amount of chemical as shown in the arsenate adsorption case study where the recycling of the nanomagnets use to treat 3000 m3 of contaminated water required only 2L HCl and 0.2 kg NaOH. To fully demonstrate the applicability of the magnetic separation to continuously treat large water volumes a prototype able to treat up to 1 m3 water per hour has been developed [1, 2, 3, 4,5]. [1] M. Rossier et al., Sep. Purif. Technol., 2012, 96, 68. [2] M. Rossier et al., J. Mater. Chem., 2009, 19, 8239. [3] F.M. Koehler et al., Magnetic, Chem. Commun., 2009 , 32, 4862. [4] M. Rossier et al., Ind. Eng. Chem. Res., 2010 49, 9355. [5] M. Rossier et al., Chem. Eng. J., 2011 175, 244.
3:15 AM - G9.03
Magnetic Catch & Release: Reversible Organic Contaminant Adsorption and Enrichment from Water
Roland Fuhrer 1 Inge K. Herrmann 1 Evagelos K. Athanassiou 1 Robert N. Grass 1 Wendelin J. Stark 1
1Institute for Chemical and Bioengineering Zurich Switzerland
Show AbstractThere is an increasing need for fast and efficient extraction methods to remove low concentrated (ppb levels) organic compounds from water with high adsorbent recyclability. Surface-modified magnetic nanoparticles can be used in extraction processes as they readily disperse in common solvents and combine high saturation magnetization with excellent accessibility. Reversible and recyclable adsorption and desorption through solvent changes and magnetic separation provide technically attractive alternatives to classical solvent extraction. Carbon-coated cobalt nanoparticles with a thin polymer layer were tagged with β-cyclodextrin [1]. The resulting material reversibly adsorbed organic contaminants in water within minutes. Isolation of the immobilized inclusion complex was easily carried out within seconds by magnetic separation due to the strong magnetization of the nanomagnets (metal core). The trapped molecules were fully and rapidly recovered by filling the cyclodextrin cavity with a microbiologically well accepted substitute, e.g. benzyl alcohol. Phenolphthalein was used as a model compound for organic contaminants such as polychlorinated dibenzodioxins (PCDDs) or bisphenol A (BPA). The nanomagnets could be regenerated under mild conditions and reused in the next cycle at full efficiency (16 recycles tested). Tagging cyclodextrins with magnetic, stable nanoparticles (carbon shell, polymer layer) makes them magnetoresponsive and may lead to a new generation of adsorbents in separation, contaminant enrichment or drug delivery. Experiments at ultralow concentrations (160 ppb) underline the high potential of cyclodextrin modified nanomagnets as a fast, recyclable extraction method for organic contaminants in large water streams [2]. Cyclodextrin modified magnetic nanoparticles are therefore suited as a sustainable tool in water cleaning. Reference: 1) R. Fuhrer, I.K. Herrmann, E.K. Athanassiou, R.N. Grass, W.J. Stark, Langmuir, 2011, 27(5), 1924-9 2) M. Rossier, M. Schreier, U. Krebs, B. Aeschlimann, R. Fuhrer, M. Zeltner, R.N. Grass, D. Günther, W.J. Stark, Separation and Purification Technology, 2012, 96, 68-74
3:30 AM - G9.04
Efficient Removal of Anionic Pollutants by ZrO2 Loaded Biomembrane
Ramakrishna Mallampati 1 Suresh Valiyaveettil 1
1National University of Singapore Singapore Singapore
Show AbstractPresence of anions such as chromate, arsenate and arsenite is of environmental concern due to their high toxicity and carcinogenicity. Removal of these anions from water using low cost biomass is an efficient and affordable treatment process. Biomembranes loaded with zirconium(IV) oxide have been used to extract As(V), As(III) and Cr(VI) oxide anions from an aquatic environment. Immobilization of zirconium onto the membrane surface created a good efficiency for extraction of anionic pollutants. Adsorbent was characterized using SEM, EDS and FT-IR. Removal efficiency was estimated by batch adsorption studies. Adsorption kinetics for all pollutants at different concentrations are described in terms of pseudo-second-order rate equation with respect to adsorption capacity and correlation coefficients. Arsenate and chromium were strongly adsorbed in the pH range from 2 to 6, while arsenite was strongly adsorbed between pH 9 and 10. Acknowledgement: The authors thank the Environment and Water Industry Programme Office (EWI) under the National Research Foundation of Singapore (PUBPP 21100/36/2, NUS WBS R-706-002-013-290, R-143-000-458-750, R-143-000-458-731) for the financial support of the work. RM also thanks the National University of Singapore for a scholarship for graduate studies.
3:45 AM - G9.05
Highly Efficient Catalytic Reduction of Bromate in Water over a Quasi-monodispersed Superparamagnetic Pd/Fe3O4 Catalyst
Wuzhu Sun 1 2 Qi Li 1 Shian Gao 1 Jian Ku Shang 1 3
1Institute of Metal Research, Chinese Academy of Sciences Shenyang China2University of Science and Technology of China Hefei China3University of Illinois at Urbana-Champaign Urbana USA
Show AbstractBromate is a by-product of ozonation disinfection of drinking water, which is identified as a 2B substance by the International Agency for Research on Cancer. There are three ways to removal bromate in drinking water, including the removal of bromate precursors, the minimization of bromate formation during the ozonation process, and the removal of bromate after its formation. However, the removal of bromate precursors, for example, bromide, is difficult in the water treatment practice, while the minimization of bromate formation in the ozonation process may cause slower disinfection/degradation or introducing ammonia. Thus, the removal of bromate from the drinking water after the ozonation process is more practical. Various post-treatment technologies have been proposed to remove bromate in drinking water after the ozonation disinfection. Compared with other technologies, the catalytic hydrogenation could be conducted under mild conditions without the production of contaminated disposals. Thus, the catalytic hydrogenation may be a promising technology for water treatment. The reported effective catalyst systems for the catalytic bromate reduction currently are limited to only Ru-Adams, Ru/cabon nanotube, and Pd/Al2O3 catalysts. It would be of interest to develop other high efficient catalyst systems for the catalytic bromate reduction in water treatment. In this study, a quasi-monodispersed superparamagnetic Pd/Fe3O4 nanocatalyst was synthesized, and its high catalytic efficiency in the reduction of bromate was demonstrated for the first time. It demonstrated a superior bromate reduction performance than previously reported Pd catalysts supported on Al2O3, and could effectively reduce bromate in drinking water samples containing various coexisting ions with high concentrations. Due to its superparamagnetic nature, no magnetic attraction existed when there was no external magnetic field, which enhanced its dispersion and contact with bromate in water and subsequently ensured its high reaction activity under mild reaction conditions. After the water treatment, however, its high saturation magnetization ensured an easy magnetic separation from water when an external magnetic field was present. It could be easily recycled and reused without the loss of efficiency, further enhancing its application potential.
G10: Materials for Improving Healthcare and Quality of Life
Session Chairs
Wednesday PM, November 28, 2012
Hynes, Level 3, Room 306
4:30 AM - *G10.01
The Shape of Cardiac Reparation to Come
Paolo Di Nardo 1
1Universitamp;#224; di Roma Tor Vergata Roma Italy
Show AbstractPharmacological treatments, although very sophisticated, are not able to definitively cure cardiac diseases, the major cause of death worldwide. Heart transplantation, although effective, is unsustainable because of donor shortage and high costs of surgery and patient follow up. Finally, cell therapy applied to the injured myocardium is inadequate to integrate efficient contractile cells into the cardiac architecture. Considering the further increment of cardiac diseases related to the extension of longevity, it is urgent to formulate safe and cost-effective novel strategies to treat cardiac patients, without further economic and social burden on public and private insurances as well as on families. Among others, the “selective repair” of the damaged region of a organ appears as the most reliable approach in the near future. Indeed, adult progenitor cells can be used to fabricate ex vivo engineered cardiac tissue to be implanted into the injured myocardium. In this respect, novel materials and procedures are necessary to cope with the peculiar heart microenvironment and functional characteristics. In principle, engineered tissues can be fabricated using biocompatible polymeric scaffolds that remain embedded in the engineered tissue or, alternatively, the scaffold can be stuck on the petri dish bottom and the new tissue fabricated on, and not around, it. In the latter, the engineered tissue will be scaffoldless. The current limitation of both technologies is that the scaffold is intended as a mere cell support. Instead, the scaffold must be active part in the array of biological signals governing the formation of a new tissue. This issue is very crucial in the specific case of engineered cardiac tissues that must repeat the native architecture and function. Indeed, preliminary results have shown that specifically manipulated biomaterials can be used to fabricate scaffolds able to deliver signals independent of embedded growth factors and sensed as “biologically relevant” by cells. The manipulation of the scaffold topology and nanostructure or the use of appropriate composite materials can allow to differentiate stem cells towards the cardiac phenotype in an architectural context very similar to the native one. This new class of scaffolds has been dubbed “Inherently Bio-Active Scaffolds” (IBAS) and are very potent in addressing the cell phenotype when fine tuned in respect to the culture medium. An alternative strategy could be to fabricate scaffoldless tissue sheets made of human progenitor cells, possibly isolated from the heart of the same patient candidate to receive the cell treatment. The results so far obtained have demonstrated that, when leant on the heart surface used as a scaffold, the progenitor cells embedded into the scaffoldless sheets easily migrated into the myocardium differentiating in cardiomyocytes and integrating in the tissue architecture, as demonstrated by the proper connections established between the graft and host cells.
5:00 AM - G10.02
Pharmacological Potential of Cerium Oxide Nanoparticles: Protection against Oxidative Stress of Cardiac Progenitor Cells
Francesca Pagliari 3 Paolo Di Nardo 3 Enrico Traversa 1 2
1University of Rome Tor Vergata Roma Italy2Xi'an Jiaotong University Xi'an China3University of Rome Tor Vergata Roma Italy
Show AbstractOver the last few years, medicine is taking massive advantage of nanotechnology. The extensive use of nanoparticles, standing alone for targeted therapy, such as drug delivery and magnetic-induced hyperthermia, and diagnostics, such as imaging, or as fillers of polymeric scaffolds for tissue engineering, has disclosed a new generation of nano-biomaterials for medical applications. Consequently, studying how cells interact with the novel nano-biomaterials is crucial for tailoring reproducible and promising bioactive properties. The trend is towards the development of bioactive rather than bio-inert materials, with materials directly triggering or participating to cellular reaction pathways. Among these nano-biomaterials, cerium oxide nanoparticles (nanoceria) have been recently reported to show outstanding biomedical activity, acting as well tolerated anti-age and anti-inflammatory agents, and potential pharmacological applications due to redox changes in the Ce oxidation state (Ce4+/Ce3+) that trigger the abatement of intracellular reactive oxygen species (ROS), hindering the oxidative stress cytotoxic effects. This is especially important, since the etiology or development of many serious diseases imply oxidative stress, and the search of reliable and effective antioxidant therapy is a focus of current pharmacological research. Nanoceria are redox-active owing to the co-existence of Ce3+ and Ce4+ oxidation states and to the fact that Ce3+ defects, and the compensating oxygen vacancies, are more abundant at the surface. Here we will present the response of cardiac progenitor cells (CPCs) in terms of cyto-compatibility, cell morphology and phenotype, and cell differentiation and multipotency to ceria nanoparticle exposure. In particular, we investigated the possibility that nanoceria could protect CPCs from oxidative stress resulting by ROS production. The study showed that 24 hour exposure to 10, 25, and 50 mu;g/mL of nanoceria did not affect CPC survival and function. On the contrary, all concentrations were effective in protecting CPCs from water peroxide insults even after 7 days from the nanoceria exposure (without being in contact with nanoceria), which could be ascribed to the efficient antioxidant mechanism elicited by ceria nanoparticles. These results unravel enormous possibilities for the use of nanoceria in cardiac tissue regeneration therapies.
5:30 AM - G10.04
Binding Polymer Particles with Encapsulated Antibacterial Cinnamaldehyde to Thin-film Composite Membranes
Katherine Zodrow 1 Marissa Tousley 1 Menachem Elimelech 1
1Yale University New Haven USA
Show AbstractBiofouling continues to be a major challenge for membrane processes. Several methods have been proposed to curtail biofouling, including membrane surface modification with hydrophilic and antimicrobial polymers and nanomaterials. We present here the binding of biodegradable, slow-release poly(lactic-co-glycolic acid) particles with cinnamaldehyde, a natural antimicrobial compound, to a thin-film composite polyamide membrane surface for biofouling prevention. Cinnamaldehyde is an extract of cinnamon that exhibits both antimicrobial and anti-quorum sensing activity. PLGA particles are coated with poly(ethylene-alt-maleic acid), which contains carboxyl groups that can be covalently bound to the carboxyl groups present on the polyamide surface using ethylcarbodiimide hydrochloride. These particles allow the slow-release of natural antimicrobial compounds, curtailing microbial growth and preventing biofilm formation. Because these compounds are derived from edible plants, adverse effects to human populations are limited, and the compounds, if released, can be readily degraded in the environment.
G8: Energy Sustainability
Session Chairs
Igor Lubormirsky
Bryan Morreale
Wednesday AM, November 28, 2012
Hynes, Level 3, Room 306
9:30 AM - *G8.01
Three Dimensional Design of Crystalline Silicon Based Thin-film Solar Cells: Opportunities and Challenges
Bernd Rech 1 Tobias Sontheimer 1 Daniel Lockau 1 4 Daniel Amkreutz 1 Christiane Becker 1 Lars Korte 1 Matthias Bockmeyer 2 Eveline Rudigier-Voigt 2 Frank Schmidt 4 Sebastian Schmitt 3 Silke H Christiansen 3
1Helmholtz-Zentrum Berlin Berlin Germany2Schott AG Mainz Germany3Max-Planck-Institute for the Science of Light Erlangen Germany4Zuse Institute Berlin Berlin Germany
Show AbstractToday, the world production of solar modules relies on crystalline silicon wafer technology yielding conversion efficiencies as high as 25 % for laboratory cells and efficiencies approaching 20 % for solar modules. Certainly, silicon as a non-toxic and highly abundant raw material fulfills most requirements for sustainability in an ideal way. One constraint within the classical crystalline Si based wafer technology is the relatively high amount of energy required for the fabrication of the rather thick (150-200 µm) silicon wafers. Thin-film silicon solar cells bare the potential to significantly reduce the production costs for PV modules and promise significant energy savings during fabrication. However, todays most advanced thin film-silicon technology based on amorphous silicon (a-Si:H) and micro-crystalline silicon (µc-Si:H) yields module efficiencies around 10 %. In the long run it is of key importance to increase efficiencies towards 20 % for thin-film Si while maintaining the advantages of low-cost, large area processing. This efficiency goal requires fundamental progress in the materials research of thin-film silicon. The realization of perfect electronic properties of the silicon absorber material, carefully optimized interfaces and the design of the solar cell as an extremely efficient light trapping architecture are necessary prerequisites. This contribution reviews latest results achieved in our labs on the design of nanoµ-structured Si films. The approach comprises electron-beam evaporation and adapted crystallization techniques on glass substrates on the one hand and relies on perfect interface passivation by a-Si:H/c-Si hetero junctions on the other hand. In a joint approach of SCHOTT AG and HZB, we developed a low-cost and easily scalable fabrication process for the design of periodic arrays of Si crystals on large areas permitting the precise control over feature size of the crystals. These 3-dimensional structures provide excellent light trapping as monitored by absorption measurements. First principle optical simulations reveal a light path enhancement factor of more than 100 for long wavelength light. A complementary approach towards 3-dim silicon nano-architectures is pursued in close cooperation between the Max-Planck-Institute for the Science of Light and HZB. In this case, the approach relies on silicon nanowires which were realised by nano-structuring based on wet or dry etching of large grained electron beam crystallised silicon films on glass substrates. These nanostructured films show very promising structural and electronic properties for photovoltaic applications. Finally, we will discuss the opportunities and challenges of the presented 3-dim silicon based thin-film solar cell concepts.
10:00 AM - G8.02
Old-new Silicon Technology: Photovoltaic and Hydrogen Production Based on Silicon Nanostructures
Vladimir Sivakov 1 Marina Kulmas 1 Florian Talkenberg 1 Arne Bochmann 1 Silke Christiansen 2 1
1Institute of Photonic Technology Jena Germany2Max Planck Institute for the Science of Light Erlangen Germany
Show AbstractThe silicon based technologies are certainly favored because of material abundance and non-toxicity at a high level of materials control and understanding together with a huge industrial infrastructure to account for low production/processing costs and high production yields. This article comprises a comprehensive review of new observation in silicon material grown by top-down or bottom-up technologies (more favored) which can be useful for the future optoelectronic applications, especially in energy sector. Bottom-up created Silicon Nanowire (SiNW) Arrays with different morphology and microstructure can be easily observed using metal assisted wet chemical etching (MAE) of single or multi-crystalline silicon material. The nature and evolution of room temperature light emission and optical properties in such nanostructures and possible application in hydrogen production and photovoltaic will be discussed. Our photovoltaic concept is based on quantum-mechanical limitation in semiconductor material. The sub-nano layer of high k-material (thickness about 5-10 monolayers, about 8-12 Å) between two semiconductor materials can be deposited using atomic layer deposition technique. The influence of high k-material to device efficiency will be presented and discussed in details. The minimizing of leaking current can be a key for the increasing of device efficiency as it well known from microelectronic praxis. The energy conversation degree in semiconductor-high k material-semiconductor device of about 10% can be reached to-time. MAE SiNWs can be effectively (approx. 18-20%) used in the hydrogen production as possible source for the fuel cell.
10:15 AM - G8.03
The Measured Efficiency of a ZnO Nanostructured Diode Energy Harvesting Device
Joe Briscoe 1 Steve Dunn 1
1Queen Mary University of London London United Kingdom
Show AbstractThere has been a growing interest in the use of nanostructures for energy harvesting applications. The interest ranges from the modification of traditional semiconductor systems where size can have dramatic influences on the behaviour of a material to the development of functional materials for photocatalysis and energy conversion devices. One area that is being increasingly well studied is using the piezoelectric effect of ZnO nanostructures to convert stray kinetic energy in the form of vibrations or movement into electrical energy. A variety of structures have been tested and developed that include Schottky barrier type structures and in recent developments a solid state p-n junction has been proven to be a suitable and interesting structure for energy conversion. The p-n structure has the benefit of scalability with readily available and cost-effective components. We use controlled bending of a ZnO/PEDOT:PSS diode using an Instron mechanical test machine to measure the efficiency of a p-n diode based energy harvesting device in converting the applied mechanical into an output of electrical energy. By subtracting the work required to bend a complete device from that required to bend a blank substrates we measure the mechanical energy input into the nanostructured diode. The electrical energy output can be calculated from the short circuit current and open circuit voltage so enabling a measured external energy conversion efficiency of the device to be 0.0067%. As the fundamental limit to the efficiency is fixed by the electromechanical couple coefficient, accepted as 3% for ZnO, then the material limited efficiency is 0.22%. We discuss the efficiency of the device in terms of losses in the structure and the fundamental limitations imposed by the electromechanical coupling coefficient of a piezo electric material. Additionally we show that increased strain rate increases the energy conversion efficiency, through an increase in output electrical energy. However, we propose that the electromechanical coupling coefficient can never be exceeded due to material limitations and that such devices will be limited in external efficiency to a value of 0.1 to 1%.
10:30 AM - G8.04
Alkaline Salt Additives for Improved Light Emitting Electrochemical Cells (LEECs)
Yulong Shen 1 Daniel Kuddes 1 Bradley Holliday 2 Jason Slinker 1
1The University of Texas at Dallas Richardson USA2The University of Texas at Austin Austin USA
Show AbstractLight Emitting Electrochemical Cells (LEECs) from ionic transition metal complexes (iTMCs) may serve as a new lighting technology candidate. These simple, cost effective devices are solution processable and compatible with low-temperature assembly and reel-to-reel fabrication under ambient conditions. However, these devices have yet to achieve the stringent operational benchmarks required for lighting. We used the archetypal iridium iTMC as the emissive material in LEECs and blended in alkaline additives to control ionic space charge effects and substantially improve performance. For lithium additives, turn-on time was reduced, the maximum luminance and quantum efficiency were both increased, and the lifetime was not negatively affected. We have also studied other alkaline salts and justified their relative impact on device performance in view of double layer charging. These observations suggest that iTMCs from LEECs have the potential to serve as bright, long-lasting light sources.
10:45 AM - G8.05
Theoretical Aspects of Gas Storage in Clathrate Hydrates for Realization Sustainable Future
Rodion Belosludov 1 Oleg Subbotin 2 Hiroshi Mizuseki 1 Vladimir Belosludov 2 Yoshiyuki Kawazoe 1
1Tohoku University Sendai Japan2SB RAS Novosibirsk Russian Federation
Show AbstractIn parallel with experimental efforts, computer-aided materials design is also an important factor in the fabrication of novel materials, to be applied in driving engineering innovations and urgent technological needs for achieving a sustainable society. Here, an original approach has been demonstrated that allows us to construct a p-T phase diagrams of various gas hydrates, three-dimensional hydrogen-bonded water structures in which water molecules arrange themselves in a cage-like structure around guest molecules, with complex gas compositions [1]. In order to evaluate the parameters of weak interactions, a time-dependent density-functional formalism and local density technique entirely in real space have been implemented for calculations of vdW dispersion coefficients for atoms within the all-electron mixed-basis approach. The combination of both methods enables one to calculate thermodynamic properties of gas hydrates without recourse to any empirical parameter fitting. It is possible not only confirm existing experimental data but also predict the unknown region of thermodynamic stability of clathrate hydrates. The interest in gas hydrates as potential hydrogen storage materials has risen after a report that the CS-II hydrate can store around 4.96 wt%. [2]. However, the extreme pressure required to stabilize the hydrogen hydrate makes it impractical. Using proposed approach, the phase diagram of the hydrogen CS-II hydrate has been constructed [3]. The calculations also showed that the formation pressure of hydrogen hydrates was significantly reduced in the presence of propane as second component. At small concentration of propane in gas phase, the amount of hydrogen around 4 wt% can be stored at 270 K [3]. It has been estimated that the pure hydrogen CS-I hydrate can store more hydrogen but this structure is thermodynamically unstable as comparable with CS-II one [4].The stabilization of the CS-I hydrate can be realized for the hydrogen-ethane-water system with a small concentration of ethane. The amount of storage depends on the ethane concentration in the gas phase [4]. Thus, it is important to accurately determine the optimal balance between storage capacity and formation conditions for the practical feasibility of the binary hydrates. Thermodynamic stability of ozone hydrates has been studied in a wide range of temperatures and pressures. It has been found that pure ozone can form CS-I hydrate. At temperature 273 K the formation pressure for ozone hydrate was found to be 0.4 MPa. The formation pressure is reduced at lower temperature. Stabilization of ozone in clathrate hydrates is useful for enrichment and long time storage of ozone without usage of carbon chlorines or fluorides. REFERENCES [1] V.R. Belosludov et al., Mat. Trans. 48 (2007) 704. [2] V.V. Struzhkin et al., Chem. Rev. 107 (2007) 4133-4151. [3] R.V. Belosludov et al., J. Chem. Phys. 131 (2009) 244510. [4] R.V. Belosludov et al., Mol. Simul. 38 (2012) in press.
11:30 AM - *G8.06
Nanomaterial and Nanotechnologies for New Energy Applications
Bertrand Fillon 1
1CEA Grenoble France
Show AbstractToday, more and more nanotechnologies are used to produce PV cells, batteries, printed batteries, fuel cells. The process is many times based on deposition techniques (printed or vacuum deposition) with a goal of tracking the best performances and reliability. This presentation will introduce the benefits to be expected from the development of nanotechnologies for new energy applications. The goal is to produce cheap energy component where multi-components are requested and the core components (eg: silicon for solar cell) is not necessary. Recent advances in the production of silicon, thin film and thrid generation solar cells will be discussed and compared.
12:00 PM - G8.07
Notable Doping Effects in the Thermoelectric Properties of Boron Cluster Compounds
Takao Mori 1 2 3 Anastasiia Prytuliak 1 Satofumi Maruyama 1 4 Oksana Sologub 1 David Berthebaud 1 Yuichi Michiue 1 Yuzuru Miyazaki 4 Tsuyoshi Kajitani 4 Kei Hayashi 4 Akiko Nomura 4 Toetsu Shishido 4
1National Institute for Materials Science (NIMS) Tsukuba Japan2Hiroshima University Higashi Hiroshima Japan3University of Tsukuba Tsukuba Japan4Tohoku University Sendai Japan
Show AbstractApproximately two thirds of all primary energy (fossil fuels, etc.) being consumed in the world, sadly turns out to be unutilized, with much of it being waste heat. The useful and direct conversion of waste heat to electricity is a large incentive to find viable thermoelectric (TE) materials. One need exists to develop materials which can function at high temperature, T. Boron cluster compounds are attractive materials for their stability, exhibiting melting points above 2200 K. Furthermore, they have been found to possess low thermal conductivity, κ, even for single crystals, which is an inherent advantage for TE application. The main constituent element, boron, is also relatively abundant and nontoxic, whereas, traditional TE materials have tended to be mainly composed of elements like Bi, Te, Pb, Ag. We have found some notable doping effects in borides. Small amounts of third elements like C, N, and Si can function as bridging sites and result in the formation of novel and varied boron cluster structures [1]. As a result, new borides promising for TE were found. REB44Si2 exhibit Seebeck coefficients, α, greater than 200 mu;V/K at high T and unlike most compounds, the figure of merit, ZT, shows a steep increase at T>1000 K [2]. A series of homologous RE-B-C(N) compounds; REB17CN, REB22C2N, and REB28.5C4, was discovered to be the long awaited n-type counterpart to p-type boron carbide [3], which is one of the few TE materials with a history of commercialization. Further doping into the voids and framework of boron cluster compounds revealed striking effects. For example, through transition metal doping into the voids, the Seebeck coefficient of REB22C2N could be increased by 180% while electrical resistivity was simultaneously reduced by more than 100 times. Carbon substitution into the framework significantly increased the power factor. In a recent striking development, we have also been able to vary excellent (#9474;α#9474;> 200 mu;V/K) p-type or n-type characteristics in a boride with a single crystal structure and composed of the exact same abundant elements, which is optimum for sustainability in the case of mass application. [1] T. Mori, in Handbook on the Physics and Chemistry of Rare Earths, Vol. 38, (North-Holland, Amsterdam, 2008) pp. 105-173 (2008), in: Modules, Systems, and Applications in Thermoelectrics, (Taylor and Francis, London), 14, 1-18 (2012). [2] T. Mori et al., J. Appl. Phys. 97, 093703 (2005), Dalton Trans. 39, 1027 (2010) Hot Article. [3] T. Mori et al., J. Solid State Chem. 179, 2908 (2006), J. Appl. Phys. 101, 093714 (2007), A. Prytuliak et al., J. Electron. Mat. 40, 920 (2011).
12:15 PM - G8.08
Identifying Optimal Properties of Large-scale Energy Storage Systems
William A. Braff 2 Jessika E. Trancik 1
1MIT Cambridge USA2MIT Cambridge USA
Show AbstractThe adoption of renewable energy technologies such as photovoltaic panels and wind turbines impacts the electrical grid in several important ways. Recent investigations have shown that the intermittent generation profile of these technologies can create considerable stress on transmission and distribution systems. Past work has discussed how energy storage can be used in conjunction with intermittent energy sources to provide baseline power and frequency regulation, or simply to increase the value of existing generation technologies. Recent research has also considered the strengths and weakness of existing energy storage technologies for providing those services. However, there is no general agreement on an optimal set of properties for energy storage. Here we investigate the desired properties of a large-scale energy storage system, in order to guide materials and technology design. In particular, we study the tradeoff between peak power capability (e.g. super capacitors and flywheels), and energy capacity (e.g. flow batteries and compressed air energy storage). This work provides quantitative insight into the optimal design of a hybrid renewable generation and energy storage plant. We find that the optimal combination of properties depends on the frequencies and amplitudes of fluctuations in the energy resource availability and the price of electricity. By analyzing the performance of an energy storage system coupled to either a photovoltaics or a wind turbine plant in several locations, we determine an optimal trade-off between power and energy density. This relationship is independent of the generation technology employed, as well as geographic location, and suggests a generally applicable framework with which to make technology development decisions. These results have important implications for the design of materials and technologies for energy storage.
12:30 PM - G8.09
Core-corona Structured Bifunctional Catalyst for Rechargeable Zinc-air Battery Application
Aiping Yu 1 Zhongwei Chen 1
1University of Waterloo Waterloo Canada
Show AbstractWe demonstrate here that a new class of coreminus;corona structured bifunctional catalyst (CCBC) consisting of lanthanum nickelate centers supporting nitrogen-doped carbon nanotubes (NCNT) has been developed for rechargeable Znicminus;air battery application. The nanostructured design of the catalyst allows the core and corona to catalyze the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), respectively. CCBC are presented as a novel, inexpensive catalyst component for the cathode of rechargeable metalminus;air batteries. Moreover, after full-range degradation testing (FDT) CCBC retained excellent activity, retaining 3 and 13 times greater ORR and OER current upon comparison to state of the art Pt/C. Zincminus;air battery performances of CCBC is in good agreement with the half-cell experiments with this bifunctional electrocatalyst displaying high activity and stability during battery discharge, charge, and cycling processes. Owing to its outstanding performance toward both the OER and ORR, comparable with the highest performing commercial catalysts to date for each of the respective reaction, coupled with high stability and rechargeability, CCBC is presented as a novel class of bifunctional catalyst material that is very applicable to future generation rechargeable metalminus;air batteries
12:45 PM - G8.10
Gas Shale as a Tool for Sustainability
Ange-Therese Akono 1 Amer Deirieh 1 Franz-Josef Ulm 1
1Massachusetts Institute of Technology Cambridge USA
Show AbstractA lot of focus has been given to organic-rich shale for its major role in sustainability. In fact, over the last decade, gas shale production has dramatically soared in the United States and it is expected to reach half of the country&’s total gas supply by 2035. Therefore the characterization and prediction of the elastic and fracture properties of shale is of crucial importance. The main challenge in this endeavor is the complexity of shale that is viscoelastic, anisotropic and highly heterogeneous. The aim of this work is to predict and characterize the intrinsic fracture properties of shale using scratch tests at different velocities and with different loading rates. To this end, a Linear Viscoelastic Fracture Mechanics framework is developed to describe the internal viscous dissipation and its influence on the measured fracture properties. A coupling is found between the intrinsic fracture energy and the viscoelastic properties, that leads to the rate-dependence of the apparent fracture toughness. An experimental scheme is then implemented that combines scratch test with indentation in order to separate creep from fracture and predict the intrinsic fracture toughness. This scheme, applied to four gas shale materials, enables to analyze the influence of microstructure on the intrinsic fracture behavior. As such our method for the assessment of intrinsic fracture properties in rate-dependent materials represents an important development in the field of mechanical microcharacterization.
Symposium Organizers
Laura Espinal, National Institute of Standards and Technology
Enrico Traversa, University of Rome Tor Vergata
Samuel S. Mao, Lawrence Berkeley National Laboratory
Marie-Isabelle Baraton, Centre Europeen de la Ceramique
Symposium Support
National Institute of Standards and Technology
G12: Recycling, Reuse, Repurposing
Session Chairs
Marie-Isabelle Baraton
Sam Mao
Thursday PM, November 29, 2012
Hynes, Level 3, Room 306
2:30 AM - *G12.01
The Material Energy Nexus and Design Decisions for Product Life Cycle Sustainability
Gregory A. Keoleian 1 2
1University of Michigan Ann Arbor USA2University of Michigan Ann Arbor USA
Show AbstractMaterials influence the life cycle sustainability performance of a product system throughout materials production, manufacturing, use and end-of-life management stages. Material choices represent a key opportunity for enhancing product system sustainability. The impact of these choices, however, is highly dependent on the energy resource inputs across each life cycle stage. The paper will demonstrate the role of the material energy nexus in material design decisions. The material production stage is highly dependent on the characteristics of input fuels and carriers such as carbon intensity which can vary geographically. Material sustainability profiles will vary accordingly and energy system transformation with renewables can dramatically shift material sustainability. In the use phase, a wide range of material design and substitution strategies can improve sustainability. For example, vehicle lightweighting and increasing the R value for a building envelope can reduce operational energy for these systems. The specific vehicle lightweighting (LW) benefits which are driven by vehicle efficiency gains, however, will be highly dependent on propulsion fuels. LW of an electric vehicle that is charged by renewable electricity will result in much lower improvements than the same vehicle that is charged with electricity from a coal fired power plant. Adding insulation material to a building will create material production impacts but will lower building operation energy consumption. The net benefits will depend on the material production energy inputs and the energy characteristics of the heating and cooling systems. The sustainability performance of end of life management options for products and materials are also strongly influenced energy systems. Tradeoffs also often exist between material and energy recovery schemes. Enhancing the material durability that extends service life of a product is generally expected to enhance sustainability performance. Life extension may not be optimal, however, if older technology can be replaced with more energy efficient technology that controls use phase impacts. This paper will identify material classes that are more strongly influenced by the material energy nexus and also summarize the implications of the material energy nexus for product design and policy decisions.
3:00 AM - *G12.02
To Recycle or Not To Recycle, That Is the Question: Insights from Life-Cycle Analysis
Linda Gaines 1
1Argonne National Laboratory Argonne USA
Show AbstractEveryone has heard the slogan “Reduce, Reuse, Recycle” used by people who want to preserve the environment. But does observing this hierarchy really minimize negative impacts? It seems clear that if we use less of something, we cause less impact. And if we reuse a material or product, we reduce the impact per use, but we must take into account resource use to restore the item to a usable condition. For recycling, the picture varies by material and may involve trade-offs among impacts. Life-cycle analysis enables comparison among options for the disposition of something that has fulfilled its original purpose. Recycling is not always the best option. For example, recycling office paper reduces the cutting of timber, but it does not save fossil fuel, and combustion of waste paper — a very clean fuel — can displace coal in power plants. On the other hand, the recycling of metals is a big win. This presentation starts with simple examples of consumer products and then provides more in-depth discussion of considerations involved in recycling of batteries for electric vehicles. Other factors, such as economics and technological uncertainties, are seen to enter into real-world decisions.
3:30 AM - *G12.03
Tackling the Challenge - How Could Electronics Recycling Move to the Next Level?
Christina Meskers 1
1Umicore Precious Metals Refining Hoboken Belgium
Show AbstractElectronic products are highly complex, highly coveted fast moving consumer goods. As a result devices move all over the world, going from one owner to the other, and becoming End-of-Life devices in large amounts. The recycling chain is complex and involves many actors. Its organisation, efficiency, the recycling technologies used, the resources recovered and environmental impacts generated vary strongly between different countries and parts of the world. What can be done to transition to ``sustainable" recycling chains around the world? Is there a single solution that is applicable to every circumstance, or is fundamental change required with tailor-made solutions taking into account local circumstances? This talk explores the possibilities from among others a technology, policy, societal and environmental point of view.
G13: Green Synthesis, Catalysis, Photocatalysis
Session Chairs
Thursday PM, November 29, 2012
Hynes, Level 3, Room 306
4:30 AM - *G13.01
Soft Processing of Ceramics:Direct Fabrication of Ceramics Films and Patterns from Solution without Firing of Powders/Particles
Masahiro Yoshimura 1
1National Cheng Kung University Tainan Taiwan
Show AbstractAs we proposed since 1998-2000,solution processing now become popular for the fabrication of ceramics films and patterns. They, however, are mostly based upon (1) Printing of solution containing nano-particles(Colloids) or their precursors,then (2) Firing/Sintering of those patterns, that is,Nano-structured ceramics have generally been fabricated from nano-particles as building blocks via firing(sintering) after shape forming. However those processes would have serious problems in the consolidation: Shape forming and Firing/Sintering, i.e. agglomeration, loose and/or inhomogeneous packing of particles,and deformation/peeling/cracking and/or poor adhesion etc.of them during firing/sinterng due to 3D shrinkages of packed powders. Instead of those powder/particle processing, direct fabrication of nano-structured ceramics is possible if approapriate precursors and processes are selected. We have developed Soft Processing or Soft Solution Processing as a bio-inspired process. As a summary review of Soft Procassing,the presentation includes guiding principles for the selection of [I] Precursors: (a) Solution ( solute,solvent,and chelating agent,etc.),(b) Substrate(oftenly a reactant),and [II]Activated reaction(s) between them. Several examples, Film formation of BaTiO3,SrTiO3,LiCoO2,,CaWO4,SrWO4,Ferrites,and Pattern formation of CaWO4,TiO2,CeO2,BaTiO3,Carbon,etc. will be presented. Furthermore, a new concept and technology, ”Growing Integration Layer [GIL] method “ will be introduced to realize integrated multi-layers and/or coatings of ceramics on a substrate, i.e. bioactive ceramic layers on alloys and bulk metallic glasses. Those results would be discussed in the relation to Green Technology and Sustainable Society. Reference 1) Yoshimura et al.,MRS Bulletin,25[9],(2000),special issue of Soft Processing. 2) Yoshimura et al., J. Mater. Sci.,41[5],1299(2006), ibid. 43[7],2085(2008)
5:00 AM - G13.03
Microwave Irradiation Creates Unique Environments Which Promote the Selective Green Chemical Modification of Complex Molecules and Nanostructures
Giancarlo Cravotto 1 Stefano Mantegna 1 Luisa Boffa 1 Katia Martina 1
1University of Turin Turin Italy
Show AbstractSynthetic chemists are paying increasing amounts of attention to enabling technologies as they would appear to be opening a path towards the double goal of achieving high efficiency while meeting the green criteria of saving energy without using dangerous catalysts and harsh reagents. Sustainable improvement in this area aims to design cleaner, safer and highly selective synthetic protocols which are able to minimize side reactions and by-products. The scaling up of these challenging strategies will definitively involve flow-chemistry and process intensification. After more than 20 years of investigation, the use of dielectric heating to promote chemical reactions is now well established as a reliable technique which can be applied on a range of scales, from milliliters to tonnes. The availability of professional microwave (MW) reactors (batch and flow), in which all the main parameters are under control over a wide range of temperatures and pressures, makes critical conversions of even poorly reactive substrates feasible. A comparison of processes performed under classic conductive heating and under MW irradiation is not a trivial task. Most likely, we can expect both purely thermal MW action effects and effects related to the transformation of the active catalyst component because of the simultaneous action MW and the reaction medium will have on it. MW effects on catalysis activation are still not fully understood although it is clear that the irradiation of MW absorbing materials (catalysts, carriers and reaction medium) can cause rapid volumetric heating, effectively remove moisture from solids and modify surface properties. Despite the risk of electrical arching, the new frontiers of MW-assisted reactions (MAE) also include the use of metal particles even in flammable solvents which is made possible when working under pressure in an inert atmosphere (N2, Ar). The unique environments obtained under MW irradiation have enabled us to prepare star-shaped macromolecular platforms, made up of β- and γ-cyclodextrin, and highly functionalized carbon nanotubes (CNTs). In the first case the efficient synthetic protocol is based on a MW-promoted Cu-catalyzed 1,3-dipolar cycloaddition of cyclodextrin monoazides to cyclodextrin monoacetylenes. The properties of this novel dendrimeric multicarrier make it suitable for several pharmaceutical, diagnostic and theranostic applications ranging from targeted drug delivery to molecular imaging. Highly dispersible CNTs have been investigated as new carriers for diagnostic and therapeutic applications in spite of the heated debate on the cytotoxicity risk they may pose. A solvent-free, microwave-assisted 1,3-dipolar cycloaddition of carbonyl ylides, generated from a series of oxiranes, to single-walled CNTs will be discussed. We currently envisage that this versatile nano-object may play a major role in research in the near future.
5:15 AM - G13.04
ZnO-ZnGaON Core-shell Nanowire Array on a Film Structure for Efficient Photoelectrochemical Water Splitting
Miao Zhong 1 Jean-Jacques Delaunay 1
1The University of Tokyo Tokyo Japan
Show AbstractNanostructured photoanodes consisting of a dense semiconductor core-shell nanowire array on a conductive film have been proposed for efficient and stable photoelectrochemical (PEC) water splitting. In this type of photoanodes, increased light absorption, improved photo-generated carrier lifetime, enlarged surface areas and enhanced chemical stability are achieved thanks to the dense array of semiconductor core-shell nanowires with photocatalytic and anti-photocorrosive activities. Further, efficient electrical connection of the core-shell nanowires is obtained through the underneath conducting film, thus enabling an easy integration of the photoanodes into the PEC applications. Here, we report the synthesis, characterization and PEC performance of the ZnO-ZnGaON core-shell nanowires-on-a-film-structure (NFS) photoanodes. A controllable two-step chemical vapor deposition (CVD) process was developed to fabricate the ZnO-ZnGaON core-shell NFS. In the first CVD step, the ZnO NFS of dense and vertically aligned ZnO nanowires on a ZnO film was fabricated on an a-plane sapphire substrate. This process enables the growth of ZnO NFS in a single crystal domain quality (unique in-plane and out-plane orientation) over large areas. The growth mechanism of this single-domain ZnO NFS is elucidated: a single crystalline ZnAl2O4 intermediate layer is formed at the interface to support a high-quality epitaxial growth. Further, the optoelectronic quality of the ZnO NFS was evidenced by free excitonic emission. An electron density of ~ 10^17 cm^-3 of the ZnO NFS was obtained with electrochemical impedance spectroscope. The high-quality ZnO NFS was then used as a substrate for a subsequent growth of the ZnO-ZnGa2O4 core-shells NFS in the second CVD step. The single crystal quality of the core-shell NFS was examined by XRD and TEM analyses. The carrier density of the ZnO-ZnGa2O4 was increased to ~ 10^19 cm^-3, explained as the formation of conductive ZnGa2O4 shells. A stable photocurrent of ~ 1.2 mA/cm^2 was obtained with the ZnO-ZnGa2O4 core-shell NFS as a photoanode at VRHE of 1.23 V under a 300 W Xeon lamp illumination. In contrast, the reported PEC performance of ZnO nanowires easily deteriorates under continuous light illumination. Finally, nitration of the ZnO-ZnGa2O4 core-shell NFS was applied. The crystal quality, visible light absorption and electron density of the ZnO-ZnGaON core-shell NFS were analyzed in details. Very promising water splitting results with visible light illumination (wavelength > 420 nm) have been obtained. Further optimization processes for improved crystal quality with nitrogen doping and surface decoration with co-catalyst nanoparticles is ongoing to further enhance the PEC performance. We believe that the densely packed and single crystal ZnO-ZnGaON NFS photoanode can contribute efficiently to the solar water splitting applications for the conversion of solar energy into chemical energy in the form of hydrogen.
5:30 AM - G13.05
Enzyme-based Biohybrid Foams Designed for Biodiesel Production and Continuous Flow Heterogeneous Catalysis
Nicolas Brun 1 2 Herve Deleuze 2 Clement Sanchez 3 Renal Backov 1
1CNRS Pessac France2Universitamp;#233; de Bordeaux Talence France3Collamp;#232;ge de France Paris France
Show AbstractModern societies will be confronted in the near future to an increasing requirement of fuels combined with a programmed diminution of easily extractable resources of fossil origin. In this context, biodiesels, which are fatty acid methyl or ethyl esters obtained by transesterification of vegetable oils has attracted considerable attention during the last decade. Particularly, enzymatic transesterification using lipases has become an interesting alternative for biodiesel fuel production. We have first reported the integrative chemistry-based[1] rational design of the first lipase hybrid macrocellular bio-catalysts[2] where immobilization of crude enzymes is optimized while circumventing the reactants&’ low kinetic diffusion through the use of silica macroporous hosts. These new hybrid bio-catalysts depict unprecedented cycling catalysis performances. Later on we proposed the synthesis and use of enzyme-based macrocellular green catalyst in continuous flow devices[3] where reactant mass transport has been reached. Overall, the one pot-synthesis and use of monolithic biohybrid foams in a continuous flow device reported inhere presents the advantages of covalent stabilization of the enzymes, together with a low steric hindrance between proteins and substrates, an optimized mass transport due to the interconnected macroporous network and a rather simplicity in regard of the column in-situ synthetic path. Those features, concerning transesterification (biodiesel production) enzyme based catalyzed reaction, provide among the top enzymatic activity addressed with bio-hybrid catalysts bearing unprecedented endurance of continuous catalysis for a two months period of time. [1] N. Brun, S. Ungureanu, H. Deleuze and R. Backov. Chem. Soc. Rev., 2011, 40, 771 [2] N. Brun, A. Babeau-Garcia, H. Deleuze, F. Duran, C. Sanchez, V. Ostreicher and R. Backov. Chem. Mater.,2010, 22, 4555 (cover). [3] N.Brun, A.Babeau-Garcia, M.-F. Achard, C. Sanchez, F. Durand, L. Guillaume, M. Birot, H. Deleuze, and R. Backov. Energy sect; Environmental Science, 2011, 4, 2840
G11: Construction Materials
Session Chairs
Bernd Rech
Gregory Keoleian
Thursday AM, November 29, 2012
Hynes, Level 3, Room 306
9:30 AM - *G11.01
Progress in Chromogenic Materials and Devices: New Data on Electrochromics and Thermochromics
Claes G Granqvist 1
1The Angstrom Laboratory Uppsala Sweden
Show AbstractChromogenic fenestration can provide energy efficiency as well as comfort in buildings. In particular much interest has been devoted recently to windows and glass facades whose transmittance of visible light and solar energy can be regulated by electricty (electrochromics) or depends on temperature (thermochromics). The electrochromic device embodies a centrally positioned electrolyte connecting two electrochromic films (one coloring under ion insertion and the other film coloring under ion extraction), with this three-layer stack positioned between transparent electrical conductors for charge insertion and extraction. The thermochromic option is simpler, tough less versatile, and includes a single layer. This paper discusses recent progress--mainly from the author's laboratory--in these fields. Specifically, the paper treats electrochromic thin films in the tungsten-nickel oxide system, functionalized polymer electrolytes, and novel gold-based transparent conductors. Results on thermochromics include thin films and nanoparticles of vanadium dioxide based materials. Particular attention is devoted to low-cost, large-area options whose implementation could radically cut down on the buildings' energy consumption and thereby impact on energy expenditure in the built environment.
10:00 AM - G11.02
Combinatorial Survey of Thermochromism in VO2-based Thin Films for Smart Window Applications
S. C. Barron 1 M. L. Green 1
1National Institute of Standards and Technology Gaithersburg USA
Show AbstractHeating and cooling costs typically represent around 25% of the energy costs for a modern U.S. office building, illustrating a clear financial incentive for developing energy saving technologies for regulating temperature. Vanadium dioxide-based materials are a promising approach to passive smart window controls, in which the transmission of solar infrared radiation varies with ambient temperature. These attractive optical properties are caused by a low temperature phase transformation from an electrically insulating, IR transparent monoclinic structure to a metallic, IR reflective rutile structure. While the transformation temperature in pure VO2 is 68 °C, transition metal impurities such as W and Mo at atomic concentrations of 1-10 % have been found to depress the transition to the range of terrestrial ambient temperatures (approx. -5 °C to 40 °C). We describe a systematic study of the impurity concentration on the thermochromic transition, using a combinatorial materials technique. Thin film samples of VO2 and other transition metal oxides are prepared with an intentional composition gradient across the 3” sample, using pulsed laser deposition (PLD) from multiple unary oxide targets and exploiting the non-uniformity of the PLD plumes. We have custom built a high throughput infrared reflectivity measurement apparatus for the characterization of thermochromic behavior, including transition temperatures, thermal hysteresis, spectral reflectance, and changes in reflectance. By rapidly collecting reflectance spectra from hundreds of different locations on the sample, with measurement areas of less than 1 mm, we can map out the thermochromic behavior continuously as a function of chemical composition. Additionally, complementary x-ray diffraction studies on these samples reveal the low temperature solubility limits of transition metals such as W, Ta, Nb, and Mo in VO2.
10:15 AM - G11.03
Coatings Containing Bactericidal V2O5 Nanoparticles Combat Biofouling
Rute Andre 1 Filipe Natalio 1 Aloysius F. Hartog 2 Ron Wever 2 Wolfgang Tremel 1
1Johannes Gutenberg-Universitamp;#228;t Mainz Germany2University of Amsterdam Amsterdam Netherlands
Show AbstractMarine biofouling is caused by the adhesion of barnacles, macroalgae and microbial slimes. It is a worldwide problem in marine systems, costing an estimated $200 billion per annum. On ships&’ hulls, biofouling results in an increase in roughness, which in turn leads to an increase in hydrodynamic drag as the vessel moves through water. Increased fuel consumption, hull cleaning, paint removal and repainting, and associated environmental compliance measures all contribute to the costs of biofouling. New, effective, and environmentally compatible options are needed to control biofouling. An active research front is aimed at understanding how adhesives, produced by fouling organisms, interact with surfaces, so that coatings may be designed in a rational way to inhibit this process. Antifouling paints have a profound effect on the environment, and research on bioadhesives may contribute to the development of environmentally benign fouling control. Mimicking nature's defense mechanisms has provided inspiration for a new approach to swart biofouling. Certain enzymes found in brown and red algae produce halogen compounds that have a biocidal potential. Similarly, V2O5 nanoparticles have an intrinsic biomimetic bromination activity, which makes them a practical and cost-efficient alternative for conventional chemical biocides. V2O5 nanoparticles act as a catalyst in the formation of hypobromous acid from hydrogen peroxide and bromide. HBrO is highly toxic to many microorganisms and has a pronounced antibacterial effect. The required reactants are present in seawater, which contains bromide ions, while small quantities of hydrogen peroxide are formed when seawater is exposed to sunlight. We tested the possibility of applying V2O5 V-HPO mimics as a paint additive, building up a new type of antifouling paints combining the following advantages: (i) low H2O2 inhibition/deactivation, (ii) low environmental toxicity due to its complete insolubility in water, (iii) constant availability of substrates (H2O2 and Br-) required for a dynamic antibacterial activity (HOBr formation), (iv) proven intrinsic activity at substrate concentrations identical of those found in marine environments (e.g. seawater), (v) high chemical stability and (vi) low costs. The process has been demonstrated for underwater paints containing V2O5 nanoparticles under laboratory conditions and in natural seawater. It has only minimal consequences for the environment because the effect is restricted to micro-surfaces. V2O5 is much less toxic to marine life than tin- and copper-based substances, which are used in the commercially available products. ICP-MS studies of the vanadium concentration in various samples of seawater showed only slightly elevated vanadium concentrations compared to the normal level.The metallic oxide is particularly potent when present in the form of nanoparticles due to the larger surface area
10:30 AM - *G11.04
Channeling the Forces of Nature
Emile Hideki Ishida 1
1Tohoku Univ. Sendai Japan
Show AbstractThe Great East Japan Earthquake, which happened on March 11, 2011, made us aware once again that we had forgotten we were just one species within the great cycle of nature on earth, that we were allowed to survive only because of nature, and that the idea that we were somehow able to conquer the nature was simply an illusion. Now, more than ever, is the time we must confront face-to-face the change from the underground resources type of civilization to one with a new way of life and technology that embraces a sense of nature. To do so, we must learn from nature that possesses the only sustainable society on earth and create technology which embraces such a view of nature. We call technology, which cleverly revives nature&’s greatness, Nature Technology Taking a casual glance at nature, a nest of termites in the savanna region can be observed to maintain a steady temperature of 30°C despite the fact that the outside air temperature ranges from 50°C during the day to nearly 0°C at night. In the “earth” of the nest, are countless numbers of open pores just several billionths of meters thick (nanometers) and this regulates the temperature and humidity. In fact, any kind of “earth” has these pores (clay mineral with aggregated structures) and air conditioners with no power source have been created by hardening this earth while preserving its structure. A floor or wall becomes the alternative to an air conditioner. This is one example of how Nature Technology can provide a new lifestyle which is spiritually uplifting rather than just putting up with things.
11:30 AM - *G11.05
Advanced Material Technologies for Efficient and Sustainable Buildings
Eric J. Amis 1 Zissis Dardas 1
1United Technologies Research Center East Hartford USA
Show AbstractBuildings account for 39% of the primary energy consumption, equivalent to 21.2 Quads annually, and for 39% of the CO2 emissions in US (1). Residential buildings account for 21% and commercial buildings for 18% of the total consumption and emission. The Heating, Ventilation and Air Conditioning (HVAC) system accounts for 39% of the energy use for the residential and 32% for the commercial buildings for a combined total of 7.6 Quads of energy consumption annually in US. From 2006 to 2030, the US population is expected to increase by 21%, the number of households (residential buildings) by 25% and commercial space by 35% (2). Building floor space is increasing at an even faster rate in developing countries such as China and India. The need for energy reduction in buildings is one of today&’s grand challenges and materials science can impact advanced technologies to reduce the energy demand of the HVAC systems. Air conditioning (AC) systems are an integral part of the HVAC and more than 90% of systems today are based on vapor compression cycle (3). AC is used to both control the temperature (sensible load) and the humidity (latent load) in the indoor environment. In warm and humid climates, this results in a very high latent heat load (dehumidification load). This paper will discuss work currently underway on the development of advanced AC systems. One approach is a novel integration of a liquid desiccant flowing through two heat and moisture exchanging modules (an absorber and a desorber) made out of micro-porous polymer membranes. The system provides cool and dry air in the building by absorbing heat and moisture in the absorber and rejecting it to outside air in the desorber. Highlights of technology challenges are the emphasis on high performance membrane materials. Reducing the outside air ventilation in the HVAC system without compromising occupant thermal comfort or indoor air quality (IAQ) is a way of further improving system efficiency. The IAQ ventilation procedure allows airflow to be re-circulated as air is cleaned before being reintroduced to the space. This method provides a direct solution and addresses the root cause of the problem, by removing the indoor contaminants through air purification integrated with air contaminant detection. It is estimated that implementation of advanced air purification technologies in buildings combined with closed loop air contaminant detection control could result in 30% energy savings for an HVAC system. A summary of technology development for air purification and air contaminant detection will be presented. (1) U.S. DOE Office of Energy Efficiency and Renewable Energy, 2005. (2) Buildings Energy Data Book, 2009. (3) http://www.whitehouse.gov/administration/eop/nec/StrategyforAmericanInnovation/
12:00 PM - G11.06
Sweating Surfaces - A Smart Way to Passively Cool Buildings
Aline Christine Catherine Rotzetter 1 Christoph Martin Schumacher 1 Stephanie Brigitte Bubenhofer 1 Lukas Cyrill Gerber 2 Martin Zeltner 1 Wendelin Jan Stark 1
1ETH Zurich Zurich Switzerland2Harvard University Boston USA
Show AbstractOver 40% of the energy consumed in the United States is based on building maintenance, of which cooling and heating are the main contributors. Therefore, novel sustainable concepts for cooling have been proposed in the past years. Most promising solutions are based on passive systems (i.e. no electricity needed) directly integrated in the roof or the faccedil;ade of buildings. Inspired by the perspiration action of mammals, we designed a new passive cooling system for buildings based on thermoresponsive hydrogels (PNIPAM) [1]. The high water storage and the ability to change their property from hydrophilic to hydrophobic upon their lower critical solution temperature makes these materials most useful for autonomous cooling solutions. Thereby, the hydrogel can take up water during simulated rainy periods and releases it again in a sweating like manner when the surface heats up by intense solar irradiation. Comparison to conventional hydrogels such as poly-hydroxyethylmethacrylate (pHEMA) demonstrated a better cooling performance as a result of reduced diffusion resistance through dried out top layers. Furthermore, weather cycles of hot and rainy periods as well as long and intense sun irradiation showed an unchanged cooling capability, which makes the material for a future long term usage promising. [1] Thermoresponsive polymer induced sweating surfaces as an efficient way to passively cool buildings (under review).
12:15 PM - G11.07
Unraveling Conceretersquo;s Genome via Reactive Atomistic Simulation
Dieter Brommer 1 Mohammad Javad Abdolhosseini Qomi 1 Franz-Josef Ulm 1 Markus Buehler 1 Roland Pellenq 1 2
1MIT Cambridge USA2CNRS Marseille France
Show AbstractConcrete is the most widely-used man made material and the way it is produced is responsible for five to eight percent of global carbon dioxide emission. With ever-growing concerns about sustainable infrastructure engineering particularly about green-house gas emission and energy efficiency, there are still many unanswered questions about the origin of this liquid stone. One of these particular unknowns is the genome of concrete glue known as calcium-silicate-hydrate (CSH). Inspired by experimental and computational modeling, we propose that CSH paste is agglomeration of CSH polymorphs with range of chemical composition and morphology. To achieve this goal, numerous CSHs covering a wide range of calcium to silicon ratio is produced and hydrated using Grand Canonical Monte-Carlo method. The state of water in nano-scale pores is affected by the surrounding environment leading to decomposition of a portion of water molecules to hydroxyl groups, which further leads to elongation of silanol chains. This is achieved via reactive force-field modeling using ReaxFF potential specifically tuned for cement hydrates. While the chemical composition and morphology of CSHs change upon reactivity, short-range interactions represented by radial distribution function remain intact. Subsequently, the elastic properties are calculated for equilibrated models. Herein, it is asserted that while the density controls the mechanics of CSH paste, the mechanical properties of CSH polymorphs within each chemistry is both function of the density and silica chain. We believe this study will illuminate the design space of concrete, paving the path for environmentally friendly design of durable and mechanically strong concrete.
12:30 PM - G11.08
How to Minimize the Energy Consumption of a Building Starting Right from the Atomic Scale?
Mohammad Javad Abdolhosseini Qomi 1 Franz-Josef Ulm 1 Roland Pellenq 1
1MIT Cambridge USA
Show AbstractThis work presents a bottom-up hierarchical model to consistently study energy transfer in buildings from the scale of atoms, nanoseconds and nanometer, to the scale of buildings, days and meters. The heat transfer through the envelope of a structure is characterized by heat diffusion length scale, which depends on the heat capacity and heat conductivity of materials. These properties originate from atomic scales and depend on the molecular structure of materials and interatomic potential describing the energy landscape. While the heat capacity can be readily calculated using phonon density of states, the thermal conductivity is measured using Green-Kubo approach within equilibrium molecular dynamics for a wide class of materials. These materials range from perfect crystals, crystals with point defects and porosity to complex iono-covalent calcio-silicate systems with a range of chemistry that are polymorphs of one of the major construction materials. It is found that the thermal conductivity can be effectively modified by incorporating nanoscale defects which directly effects the mean free path of phonons. Having the thermal properties at nanoscale, the self-consistent micro-thermoporomechanics scheme is used to calculate the composite thermal properties at the engineering scale. These values are compared with experimental data at macroscale, which shows the robustness of upscaling scheme. In addition, it is shown that the micron-scale porosity is not as effective as nanoscale porosity mainly because mean free path of phonons is much smaller than micron length scale. To thoroughly assess the impact of nano-engineering thermal properties of building materials, an ideal-cube model is developed to measure the energy consumption of an ideal building based on heat transfer physics. It is shown that for the range of nano-engineered properties, the thermal conductivity is playing the major role while the heat capacity has a marginal effect in energy consumption.
12:45 PM - G11.09
Surface Reactivity/Stability and Hydration of Calcium Silicate Phases
Can Ataca 1 Engin Durgun 1 Hamlin Jennings 2 Jeffrey Grossman 1
1Massachusetts Institute of Technology Cambridge USA2Massachusetts Institute of Technology Cambridge USA
Show AbstractRecent studies on synthetic calcium silicate structures revealed important mechanisms to tune the reactivity of various cement phases. Interaction of water with dicalcium silicate (C2S-belite) and tricalcium silicate (C3S-alite), dominant phases in Portland Cement, are the most important and anticipated reactions. In this work, using first-principles calculations, a fundamental understanding of how water pressure affects the reactivity of C3S and C2S phases is provided. In order to understand the hydration of different phases, as a first step the surface energetics of all lower index orientations are calculated and the stability/reactivity of the surfaces are determined. Taking into account the most and least energetic surfaces of the C3S phase, detailed analyses are carried out in order to understand the induction period in alite hydration. Surface transformation from highly reactive C3S to low reactive C2S revealed that upon increasing the water pressure, the surface with C2S character becomes energetically more favorable. Reduction of the surface energy is more intense in the case of proton exchange of surface Ca atoms. Our calculations suggest that these processes are the most probable mechanisms underlying the rapid decrease in reactivity in alite hydration.