Eric Amis, United Technologies Research Center
David Cahen, Weizmann Institute of Science
Martin L. Green, National Institute of Standards and Technology
Alan J. Hurd, Los Alamos National Laboratory and the Santa Fe Institute
Symposium Support United Technologies Research Center
K2: Materials for Sustainable Transportation, Buildings and Infrastructure
Thursday PM, April 04, 2013
Moscone West, Level 2, Room 2020
2:30 AM - *K2.01
Activating Small Abundant Molecules Such as Water, Carbon Dioxide and Oxygen: Efforts to Create ``Greenrdquo; Chemical Processes and Renewable Energy Resources
Ronny Neumann 1
1Weizmann Institute of Science Rehovot IsraelShow Abstract
Polyoxometalates are soluble, inorganic metal oxide clusters of discrete structure that can be used as electron acceptors and donors, and oxygen transfer agents. These properties along with their intrinsic stability make them excellent candidates for “green” transformations such as the oxygenation of hydrocarbons with molecular oxygen, photoreduction of carbon dioxide and water splitting catalysts.
In the lecture we will describe our efforts in these fields concentrating on the approach that mechanistic understanding will enable desirable catalytic processes.
The H5PV2Mo10O40 polyoxometalate was shown to be able to cleave carbon-carbon bonds of vicinal and primary alcohols. Spectroscopic and kinetic studies supported by DFT calculations reveal that the reaction proceeds by an electron-transfer oxygen transfer mechanism. This understanding is leading to the development of a catalytic process where carbohydrates ranging from simple sugar to cellulose and hemicellulose can be transformed to a petrochemical feedstock.
The formation of a hybrid material consisting of a polyoxometalate as an electron reservoir and a rhenium-based photocatalyst for carbon dioxide reduction will be shown to be effective for the formation of carbon monoxide as a chemical feedstock using hydrogen or water as reducing agent.
Cobalt catalysts have been shown to be of the most effective for the oxidation of water to molecular oxygen. We will present our results on the isolation of the active species for this reaction. Mechanistic and computational studies will try to differentiate between Co(IV) and Co(III)-oxo cation radicals as active species.
3:00 AM - K2.02
Development of a ``Green" Supercapacitor Based Entirely on Disposable, Environmentally Benign Materials
Boris Dyatkin 1 Volker Presser 1 2 Min Heon 1 Majid Beidaghi 1 Yury Gogotsi 1
1Drexel University Philadelphia USA2INM - Leibniz-Institut fur Neue Materialien gGmbH Saarbrucken GermanyShow Abstract
Due to recent advances in power and energy densities, high efficiency, and an almost unlimited lifetime, electrical double layer capacitors (supercapacitors) are likely to be integrated into a wide range of applications, either as standalone energy storage/harvesting devices or as complements to a hybrid battery/capacitor configuration. While novel materials for the electrode and electrolyte have brought forth these performance advantages, many such device components pose significant environmental hazards once disposed: they often contain fluorine, sulfur, and cyanide groups, which are harmful if discarded using conventional trash methods, and are constructed using multiple metallic parts, which result in a high ash content upon incineration. We present a design for a fully operational supercapacitor that incorporates materials that are completely safe to dispose and produce negligible ash content upon incineration. The key device design and general structure is the same as that in existing supercapacitor modules, and the active material is composed of reliable, inexpensive, and environmentally benign activated carbon. The components, which include novel material alternatives for electrolyte, current collector, separator, binder, and packaging, are all mutually compatible, with most of them exhibiting better performance than currently accepted materials. We selected graphite foil, sodium acetate, a nitrocellulose and acetate cellulose ester porous membrane, and polyvinyl alcohol-based polymers as, respectively, the optimal current collector, electrolyte, separator, and particle binder. For several device components, multiple additional alternative materials are presented as viable options, making them suitable for a larger number of supercapacitor and battery configurations. The presented materials all originate from source compounds that are simple and inexpensive to produce, decreasing environmental damage and the carbon footprint of their manufacture and making them more viable for integration into commercial devices for large scale stationary and transportation energy storage application.
3:15 AM - K2.03
Direct Synthesis of Carbon Nanotubes from Stainless Steel Meshes for High Performance Microbial Fuel Cells
Woongchul Choi 1 Xiong Pu 1 Celal Erbay 2 Mi-Jin Choi 2 Arum Han 2 Choongho Yu 1 3
1Texas Aamp;M College Station USA2Texas Aamp;M College Station USA3Texas Aamp;M College Station USAShow Abstract
Electrodes in microbial fuel cells (MFCs) determine the effectiveness of charge transport from microbes, which has great impact on improving the performance. In particular, it is necessary to have highly electrically conductive with large surfaces that microbes can interact with. Here we used three dimensional carbon nanotube (CNT) networks as an anode since CNTs can provide excellent electron conduits and huge surface areas. CNTs in our novel electrodes play a role in getting microbes like tentacle, and CNTs directly grown from stainless steel meshes (physically connected) greatly minimize electron loss. The CNTs were synthesized using a chemical vapor deposition method with C2H4 and H2O with Ar carrier gas. Surface morphology of the CNT electrodes was characterized by scanning electron microscopy and high-resolution transmission electron microscopy. The electrode characteristics were also evaluated by using cyclic voltammetry and linear sweep voltammetry. The power output from the fuel cell with our novel electrodes has been increased up to ~1200 times, compared to those with bare stainless steel meshes and carbon cloths.
3:30 AM - K2.04
Synthesis and Characterization of Block Copolymers and Their Use in Nanomaterial Removal from Water
Ziyauddin Qureshi 1 Suresh Valiyaveettil 1
1National University of Singapore Singapore SingaporeShow Abstract
The field of nanotechnology has showed interesting opportunities in various fields, which led to many commercial products and new technologies. This also led to contamination of environment with nanoparticles. Since these ultra-small particles may have potential risks for human and animals,1-3 it is importnat to consider methods for their removal from polluted water. Nevertheless, the direct separation would be difficult due to their small size, high reactivity and large surface area. In this work, we have synthesized and characterized block copolymer of poly(N-(2-aminoethyl)methacrylamide-b-styrene using atom transfer radical polymerization. This functionalized polymer showed good adsorption capacity for the removal of citrate capped gold and silver nanoparticles from water at moderate pH range, with lower adsorbent concentrations.
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 no. R-706-002-013-290, R-143-000-458-750, R-143-000-458-731) for the financial support of the work.
1. Y. Teow, P. V. Asharani, M. P. Hande and S. Valiyaveettil, Chem. Commun. 47 (25), 7025 (2011)
2. N. Khlebtsov and L. Dykman, Chem. Soc. Rev. 40 (3), 1647 (2011)
3. J. S. Teodoro, A. M. Simotilde;es, F. V. Duarte, A. P. Rolo, R. C. Murdoch, S. M. Hussain and C. M. Palmeira, Toxicol. in Vitro 25 (3), 664 (2011)
3:45 AM - K2.05
Synthesis and Characterization of Nd2NiO4+delta; via Sol-gel as Cathode Application to Solid Oxide Fuel Cell (SOFC)
Rene Fabian Cienfuegos 1 2 Marco Antonio Garza-Navarro 1 2 Domingo I. Garcia-Gutierrez 1 2 Leonardo Chavez-Guerrero 1 2 Ivan Eleazar Moreno-Cortez 1 2 Moises Hinojosa-Rivera 1 2
1Facultad de Ingenieramp;#237;a Mecamp;#225;nica y Elamp;#233;ctrica San Nicolas de los Garza Mexico2Centro de Innovaciamp;#243;n, Investigaciamp;#243;n y Desarrollo en Ingenieramp;#237;a y Tecnologamp;#237;a (CIIDIT) Apodaca MexicoShow Abstract
Nd2NiO4+δ was investigated as SOFC cathode material. The innovation of this research is in two ways first use a low cost technique and rapid polymeric way, using metallic salts (MS) and complexing agent (CA) to elaborate the material and second the precursor reagent optimization that mean change the index “R=CA/MS”, from 1 to 6 in order to know the ratio to get the material. The powders attained were calcined at 1000 °C with a constant period of 2 hours, and obtained a nanoscale crystalline structure. Characterization of material was made for analyze thermic TG-DTA, scanning electron microscope (SEM) and x-ray diffraction. This result presents the viability to elaborate the material with this technique and put in evidence the crystallized material for the index 1 and 2
4:30 AM - *K2.06
Cement: a Multi-scale Porous Material Under the Nanoscope
Roland J-M Pellenq 1
1MIT Cambridge USAShow Abstract
Setting up the stage, one can list important engineering problems such as hydrogen storage for transportation applications, electric energy storage in batteries, CO2 sequestration in used coal mines, earthquake mechanisms, durability of nuclear fuels, stability of soils and sediment and cement and concrete cohesive properties in the context of sustainability.Tthese are basically the challenging engineering problems of the coming century that address energy, environment and natural hazards.
Behind all those problems are complex multi-scale porous materials that have a confined fluid in their pore void: water in the case cement and clays, an electrolyte in the case of batteries , weakly interacting molecular fluids in the case of gas-shale (CH4) and nuclear fuel bars (Xe)...
So what do we mean by “under the nanoscope” ? The nanoscope does not exist as a single experimental technique able of assessing the 3D texture of complex multiscale material. Obviously techniques such as TEM are part of the answer but are not the “nanoscope” in itself. In our idea, the “nanoscope” is more than a technique producing images. It is rather a concept that links a suite of modeling techniques coupled with experiments (electron and X-rays microscopies, tomography, nanoindentation, nanoscratching...). If properly defined, the nanoscope should allow accessing material texture, chemistry, mechanical behavior, and adsorption/condensation behavior at all scales starting from the nanoscale upwards in a bottom-up fashion. The toolbox of the simulation aspect of the "nanoscope" is akin to a statistical physics description of material texture and properties including the thermodynamics and dynamics of the fluids confined to their pore voids as a means to linking atomic scale properties to macroscopic properties and behaviors. The “Art of simulation” includes the description of realistic multiscale porous materials samples at atomic scales, the set up and the validity checking of transferable interatomic/intermolecular/interparticle potentials, Grand canonical Monte Carlo and Molecular Dynamics simulation techniques with the goal of probing mechanical, adsorption and transport properties.
By contrast, the engineering toolbox consists in continuum or discrete models, which are either based on continuum theories that usually neglect thermal fluctuations and are assumed to a obey equilibrium thermodynamics at least in a macroscopic formulation based on adjusting variables on limiting simpler cases. Both routes aim at predicting material properties. Ideally, the “dream” would be to have a unified engineering/ physical approach consistent from the scale of atoms to the scale of continuum theories, to tackle the challenging problems evoked here above. In this talk, I will specifically address the case of cement hydrate (CSH), the glue that gives concrete its remarkable mechanics properties by putting "CSH under the nanoscope".
5:00 AM - K2.07
Influences of Hydrogen on the Fracture Behavior of Weld Heat Affected Zones in Pipeline Steel
Jung-A Lee 1 Dong-Hyun Lee 1 Moo-Young Seok 1 Un Bong Baek 2 Yun-Hee Lee 2 Seung Hoon Nahm 2 Jae-il Jang 1
1Hanyang University Seoul Republic of Korea2Korea Research Institute of Standards and Science Daejeon Republic of KoreaShow Abstract
For preparing the upcoming ‘hydrogen economy&’ era, the use of existing natural gas pipeline is considered to be the most cost-effective way for hydrogen delivery (i.e., hydrogen pipeline). Since it is well known that hydrogen can lead to mechanical degradation, much research has been performed on the possible hydrogen effects in pipeline steels. However, little study has been reported for weld heat-affected zone (HAZ), although the HAZ is obviously the weakest region in the pipeline due to the complex thermal cycles during welding. With this in mind, here we explore the hydrogen effect on the fracture behavior of the HAZs in pipeline steel. Various simulated HAZ samples were prepared for electrochemical charging of hydrogen. Charpy impact tests were carried out on both the hydrogen charged and hydrogen-free samples. The results were systematically analyzed based on the correlation between microstructural features and hydrogen effects. * This work was supported by the Korea Research Council of Fundamental Science and Technology (KRCF) through National Agenda Project.
5:15 AM - K2.08
Hydrogen Sintering of Titanium; Reducing Energy of Production and Fuel Consumption in the Transportation Sector
Mark Koopman 1 Z. Zak Fang 1 Pei Sun 1 James Paramore 1 Lu Yang 1
1Univ. of Utah Salt Lake City USAShow Abstract
Titanium (Ti) is among the Earth&’s most abundant metals and has an exceptional combination of positive attributes: low density, high strength, excellent corrosion resistance and for many alloys, biocompatibility. Due to its high reactivity, however, it is also difficult to refine and to form into final components, having one of the highest embodied energies of commercially produced materials; 6.1e8 - 7.45e8 J/kg and a carbon footprint of ~40 - 45 kg of CO2 per kg of Ti. Because of high energy use in the production of Ti and Ti components, the associated cost of these materials has deterred their use in many applications, including the auto industry.
A novel method for powder metallurgy (PM) forming of Ti and Ti alloys has been introduced, termed hydrogen sintering and phase transformation (HSPT), which promises energy savings of approximately 30% for total forming operations. By using near-net-shape PM processing, machining costs are also dramatically reduced. Further, the HSPT process achieves very low porosity, equaling that of cast ingot/wrought materials, without the energy intensive thermo-mechanical processes necessary to close porosity by hot isostatic pressing and forging methods. Early testing indicates that yield and tensile strengths, 943 MPa and 1,036 MPa, respectively, are comparable or superior to wrought processed materials while maintaining good ductility. Successful fatigue testing will place HSPT Ti in a position to replace steels for a number of vehicle components. Additionally, work by other authors has shown that the corrosion resistance of Ti would nearly double the service life of components such as exhaust systems. The lowered cost of component production combined with the high specific mechanical properties of Ti will encourage substantial weight savings for automobiles and trucks, thus reducing total mass and significantly lowering fuel consumption over the life of the vehicles. Details of the HSPT process will be presented, as well as energy savings for Ti component production and for the transportation sector.
K1: Materials for Sustainable Energy
Thursday AM, April 04, 2013
Moscone West, Level 2, Room 2020
9:00 AM - *K1.01
Gallium Nitride: A Key Material for Sustainable Development
Colin John Humphreys 1
1University of Cambridge Cambridge United KingdomShow Abstract
A recent US Department of Energy Report stated that “No other consumer of electricity has such a large energy-savings potential as LED lighting”. Electricity generation is the main source of energy-related greenhouse gas emissions. Lighting uses one-fifth of its output. LEDs are poised to reduce this figure by 50-75%. Lighting will then use only 5-10% of all electricity. This will save up to 15% of electricity use and save up to 15% of carbon emissions from power stations, if these are fossil fuelled. However, although GaN-based LEDs are widely used for displays, traffic lights, LCD backlighting in TVs, computer screens, etc, they are not yet widely used in our homes and offices, which is where the major electricity savings will be made. The main reason for this is the cost. A 75 Watt-equivalent LED of good quality from a reputable manufacturer costs $40. The public is not prepared to pay such a high initial cost, even though over the lifetime of the LED lamp significant savings will be made because of the reduction in electricity consumed. All commercial GaN-based LEDs are grown on either sapphire or silicon carbide substrates. However, if these LEDs are grown on large-area silicon substrates (of 6-inch diameter or greater) then substantial cost savings result, of at least a factor of 5. This should enable the widespread adoption of GaN LED lighting in our homes and offices, thus saving up to 15% of our electricity use and up to 15% of carbon emissions from power stations. It is also worth noting that GaN-based power electronics has the potential to make significant contributions to low-energy electronics because such devices are substantially more efficient than power electronic devices based on silicon. GaN power electronics has potential to save up to 40% of the energy used by silicon power electronics. Hence GaN is a key material for sustainable development, both for lighting and for electronics.
K3: Poster Session
Martin L. Green
Thursday PM, April 04, 2013
Marriott Marquis, Yerba Buena Level, Salons 7-8-9
9:00 AM - K3.01
Noble Photoactive Antibacterial Cotton Treated by Benzophenone Derivative in Deep Eutectic Solvent
Kyung Wha Oh 1 Hyung-Min Choi 2
1Chung-Ang University Seoul Republic of Korea2Soongsil University Seoul Republic of KoreaShow Abstract
Cotton fabrics were treated by 3,3'4,4'-benzophenone tetracarboxylic dianhydride (BPTCD) in a combined process of immersion and pad-drying-cure. Environmentally-benign deep eutectic solvents (DES) and water were examined as treatment media. Among various treatment media, urea-choline chloride DES and ethylene glycol-choline chloride DES were effective. Especially, cotton fabrics treated with BPTCD in urea-choline chloride DES showed a strong ester carbonyl peak in FTIR analysis, indicating the presence of ester formation between BPTCD and cotton cellulose. Antibacterial testing revealed high level of antibacterial characteristics before and after UV exposure of the treated fabrics. The treated fabrics were also evaluated by SEM, TGA, strength, wicking test, contact angle measurement, and methylene blue dye staining technique. Use of DES provided environmentally acceptable and economically feasible treatment process for preparation of novel antibacterial cotton.
This research was supported by the National Research Foundation of Korea(Project No. 2012-0002165).
9:00 AM - K3.03
Mechanical Properties of Nanocellulose Reinforced Polylactide Films
Seong Hun Kim 1 Kyung Wha Oh 2 Joo Hyung Lee 1
1Hanyang University Seoul Republic of Korea2Chung Ang University Seoul Republic of KoreaShow Abstract
Development of biodegradable polymers and the reinforced composites with natural fibers have received great attentions. The polylactide (PLA) is a bio-degradable polyester which can be derived from renewable resources such as starch. The PLA is being used in many applications, such as biomedical, food packaging, and automotives, because it has excellent mechanical properties, good processability. The PLA is considered a good alternative to the petroleum based polymers. Recently, considerable research has been carried out on a natural fiber reinforced polymer composites as an alternative to pure polymer or glass fiber reinforced polymer composites. Among the natural fiber reinforcement, the cellulose, which can be derived from renewable biomass, has an advantage as a natural reinforcement due to its excellent reinforcing effect. Nanocellulose is considered as a more effective reinforcement for biocomposite due to its excellent mechanical properties with high flexural strength and high stiffness. When using cellulose nanofibers, due to their polar surface, it is difficult to disperse uniformly in a non-polar polymer matrix. In this study, the cellulose nano-whiskers (CNW) were separated from microcrystalline cellulose, by sulfuric acid treatment and ultrasonication methods. The resulted CNW was introduced to the PLA matrix by using a solution casting method with a ratio of 0.1 and 0.5 wt%. By the TEM images, an isolation of nanocellulose was confirmed. The reinforcement effect of the CNW contents on the PLA composites was investigated in terms of mechanical, thermal, and rheological properties. To improve dispersability of the CNW, the surface modification of the CNW was carried out by acetylation reaction with excess acetic anhydride. And then, the resulted acetylated cellulose nanowhiskers were introduced to the PLA matrix by solution casting method. The acetylation reaction of the CNW was carried out, successfully, and confirmed by FT-IR and 13C-NMR spectroscopies. The acetylated cellulose nanowhiskers was introduced to the PLA matrix, and the biocomposite films were characterized in terms of thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and universal testing machine (UTM). This research was supported by the National Research Foundation of Korea (Project No. 2012-0001597).
9:00 AM - K3.04
UCST and LCST Phase Behavior of a Renewably Sourced Poly(trimethylene ether) Glycol in Water
Hau-Nan Lee 1 Brad Rosen 1 Gyorgyi Fenyvesi 1 Hari Sunkara 1
1DuPont Wilmington USAShow Abstract
A bacterial fermentation process was developed to produce 1,3-propanediol (Bio-PDOtrade;) directly from natural glucose, and, through the acid catalyzed polycondensation of Bio-PDOtrade;, a route to a 100% renewably sourced poly(trimethylene ether) glycol (Cerenol® or PO3G) was developed. In this presentation, we describe the initial studies of the complex aqueous phase behavior of a renewably sourced poly(trimethylene ether) glycol. Cloud point measurement revealed that a low molecular weight PO3G exhibits both lower critical solution temperature (LCST) and upper critical solution temperature (UCST) in water in the temperature range between 30 °C and 80 °C. At low concentrations of PO3G, the polymer solutions exhibit LCST-type phase behavior. In the intermediate concentration ranges, PO3G and water are immiscible. However, at higher concentrations of PO3G, the solutions show UCST-type phase behavior. In addition, both the LCSTs and UCSTs can be easily tuned over a wide range by varying the amount of alcohol co-solvents. These findings have potential applications in the design of personal care applications and in the development of thermosensitive “smart” materials.
9:00 AM - K3.05
Zr Studies for Sustainable Energy Applications
Shao-Ping Chen 1
1Los Alamos National Laboratory Los Alamos USAShow Abstract
Zr metal is an important material for the Sustainable energy (in particular nuclear energy) industries. It is used in the cladding environment for the nuclear reactor as well as other high temperature and corossive resistant environment. Ability to extend the temperature and stress ranges of applications of this material will have a great impact in the sustainable energy applications. We have generated a new angular embedded atom method potential for Zr. The results of the calculations of relevant point defects, diffusion, deformation behaviors will be presented.
9:00 AM - K3.06
Os/Ir-based Materials and Their Application as Electrocatalysts for Oxygen Reduction and Hydrogen Oxidation
Jorge Uribe-Godinez 1 Veronica Garcia-Montalvo 2 Omar Jimenez-Sandoval 1
1Centro de Investigaciamp;#243;n y de Estudios Avanzados del Instituto Politamp;#233;cnico Nacional, Unidad Queramp;#233;taro Queramp;#233;taro Mexico2Instituto de Quamp;#237;mica de la Universidad Nacional Autamp;#243;noma de Mamp;#233;xico Distrito Federal MexicoShow Abstract
In this work, we have prepared two Os/Ir-based materials by pyrolysis of the triosmium dodecacarbonyl and tetrairidium dodecacarbonyl precursors in different atmospheres (nitrogen and hydrogen) as electrocatalysts for the Oxygen Reduction Reaction (ORR) and the Hydrogen Oxidation Reaction (HOR) in the absence and presence of carbon monoxide (100 ppm); these materials were structurally characterized by different analytical techniques, such as FTIR, SEM, XRD and EDS, and electrochemically by rotating disk electrode measurements in acid media.
In general, both catalysts exhibit an acceptable catalytic activity for ORR in the absence of methanol; however, the material synthesized in hydrogen showed an open circuit potential higher than that obtained in nitrogen, therefore proving that the atmosphere plays an important role on the catalytic properties of these materials.
In the case of HOR, both materials have a good catalytic activity even when the reaction is performed in the presence of 100 ppm CO.
The kinetic parameters of the novel bimetallic catalysts, such as Tafel slope (b), exchange current density (jo), charge transfer coefficient (α) and reaction order (m) were calculated for both reactions and they do not change significantly in the case of HOR in the presence of carbon monoxide.
9:00 AM - K3.07
Performance of Bimetallic Electrocatalysts for Oxygen Reduction and Hydrogen Oxidation, in the Presence of Fuel Cell Contaminants
Jorge Uribe-Godinez 1 2 Veronica Garcia-Montalvo 2 Omar Jimenez-Sandoval 1
1Centro de Investigaciamp;#243;n y de Estudios Avanzados del Instituto Politamp;#233;cnico Nacional, Unidad Queramp;#233;taro Queramp;#233;taro Mexico2Instituto de Quamp;#237;mica de la Universidad Nacional Autamp;#243;noma de Mamp;#233;xico Distrito Federal MexicoShow Abstract
Novel bimetallic electrocatalysts were synthesized by pyrolysis of hexarhodium hexadecacarbonyl/triosmium dodecacarbonyl and hexarhodium hexadecacarbonyl/triruthenium dodecacarbonyl mixtures in an inert (nitrogen) atmosphere. The materials were structurally characterized by infrared spectroscopy, X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. All the materials synthesized not only show carbonyl stretching vibration bands, but also show carbonyl bridge vibration bands. These materials were evaluated as electrocatalysts for the oxygen reduction (ORR) and hydrogen oxidation reaction (HOR), in the presence of common fuel cell contaminants, such as methanol and carbon monoxide, respectively, (both of them in different concentrations).
The electrochemical characterization was performed by the rotating disk electrode (RDE) technique in a 0.5 M sulfuric acid electrolyte. The two bimetallic materials can perform the ORR, even in the presence of methanol (2 M). Also, the new materials are capable to carry out the hydrogen oxidation reaction even in the presence of carbon monoxide in different concentrations (100 ppm and 0.5% in mixtures with hydrogen). These results contrast those of platinum commercial fuel cell catalysts, which become easily deactivated by CO levels of a few ppm.
The kinetic parameters of the novel catalysts, such as Tafel slope (b), exchange current density (jo) and charge transfer coefficient (α), are reported as well.
The results show that the new materials are good potential candidates to be used as both cathodes and anodes in polymer electrolyte fuel cells.
9:00 AM - K3.08
A Facile Recovery of Silicon Nanoparticles from Waste Silicon Sludge Using Sonication and Centrifugation
HeeDong Jang 1 Hyekyoung Kim 1 Dae Sup Kil 1 Hankwon Chang 1
1Korea Institute of Geoscience amp; Mineral Resources Daejeon Republic of KoreaShow Abstract
As the semiconductor and photovoltaic industry undergo rapid growth, a large amount of silicon sludge is generated from the cutting process of silicon ingots. However, it is not effectively recycled. Recovery of silicon powder from the sludge has become an important concern because the silicon sludge contains valuable resources including high purity silicon. In the present study, we investigated the recovery of silicon particles from waste silicon sludge. The waste silicon sludge also contained surfactant, silicon carbide particles and metallic fragments. After removal of the surfactant by distillation, silicon particles were recovered by applying ultrasonic waves and centrifugation in series. Metallic impurities in the recovered silicon particles were purified by HCl leaching. The overall maximum yield and purity of the recovered silicon powder were about 80% and 99.7%, respectively.
9:00 AM - K3.09
First-principles Study on Native Defects in alpha;-Fe2O3; Implication to Efficiency of Water Splitting
Joohee Lee 1 Kye Yeop Kim 1 Gijae Gang 1 Seungwu Han 1
1Seoul National University Seoul Republic of KoreaShow Abstract
Hematite (α-Fe2O3) is a promising candidate for the water splitting application owing to several advantages such as stability in water, abundance in earth crust, and proper band gap for light absorption. While extensive experimental studies have been carried out, theoretical investigations, particularly at the first-principles level, are scarce. Furthermore, there are few studies on the point defects although the material property critically depends on the presence of native defects.
In this presentation, we carry out GGA+U calculations to investigate point defects in hematite. In particular, we consider vacancy and interstitial defects of oxygen and iron and determine relative stability by computing formation energies. The cell-size dependence of charged defects is carefully tested. The defect levels associated with each defect is also examined and explained on the basis of bulk electronic structure. In addition, we consider electron and hole polarons on defect-free structures. The transition level of charged states is then computed and defect densities and Fermi level positions are determined by the charge neutrality condition. It is found that the intrinsic defects generally lead to n-type condition and this is mainly driven by Fe interstitials. This is consistent with the fact that the hematite is used as photoanode in water splitting. Interestingly, we find that the Fermi level in n-type condition is pinned to 0.7 eV below the conduction band minimum by the formation of electron polaron.
9:00 AM - K3.10
Magnesium-Poly(methyl methacrylate) Nanocomposites for High Gravimetric Capacity, Reversible Solid-state Hydrogen Storage
Alyssa Brand 1 Anne Ruminski 1 Rizia Bardhan 1 Jeffrey Urban 1
1Lawrence Berkeley National Lab Berkeley USAShow Abstract
Hydrogen is widely recognized as an ideal alternative fuel source which has higher energy density than either gasoline or methane and produces no carbon emissions upon combustion. The two main barriers to hydrogen&’s use as a practical fuel source are the production of hydrogen gas from water and its storage once produced. This poster will concern the challenges of hydrogen storage, focusing on magnesium hydride as a model system for improving current hydrogen storage technologies. Through the designed synthesis of an air-stable nanocomposite of < 5nm magnesium metal nanoparticles in a matrix of gas selective polymer, we have begun to study the hydrogen absorption and desorption properties of metal hydride nanomaterials for safe, high gravimetric capacity, reversible hydrogen storage. Nanosizing of magnesium confers the benefit of enhanced kinetics. Meanwhile, embedding the magnesium nanocrystals in a gas-selective polymer matrix allows the composites to withstand atmospheric oxygen without formation of a passivating oxide layer usually associated with metal nanoparticles, which can act as a barrier to hydrogen diffusion into the metal interior. These composites show hydrogen absorption up to 7 wt. % in magnesium, as compared to its theoretical capacity of 7.6%. Surprisingly, the air stability of the composites was actually found to improve by increasing the loading of the magnesium to up to 65% by total composite weight, and the hydrogen absorption and desorption properties of the composite also improve as magnesium loading is increased. Furthermore, we can improve the kinetics of the absorption and desorption processes, as well as the temperature at which absorption and desorption occur, through doping with titanium and nickel.
9:00 AM - K3.11
Photothermal Isomerization of Dimetallic Fulvalene Complexes as an Approach to Capturing and Storing Solar Energy
Michael Harpham 6 Son Nguyen 1 Zongrui Hou 1 Jeffrey Grossman 4 Charles Harris 1 Michael Mara 5 Andrew Stickrath 6 Yosuke Kanai 3 Alexie Kolpak 4 Donghwa Lee 3 Di-Jia Liu 6 Justin Lomont 1 Kasper Moth-Poulsen 2 Nikolai Vinokurov 1 Lin Chen 6 5 Peter Vollhardt 1
1UC-Berkeley Berkeley USA2Chalmers University of Technology Gothenburg Sweden3University of North Carolina at Chapel Hill Chapel Hill USA4Massachusetts Institute of Technology Cambridge USA5Northwestern University Evanston USA6Argonne National Laboratory Lemont USAShow Abstract
Amid the ongoing efforts to develop methods for capturing and storing solar energy, thermochemical batteries capable of storing energy in reversible chemical reactions are receiving significant attention. Here we report on the current state of our ongoing investigation into the use of photochromic dimetallic fulvalene complexes as a potential target for use as a solar energy storage complex. Light from the solar spectrum readily induces photoisomerization of these complexes, storing over 20 kcal/mol of energy, which can then be rapidly released in the presence of an appropriate catalyst. In addition to summarizing recent literature reports on investigations into ruthenium based complexes, we report our new results on investigations into the more cost-viable iron analogues. In this collaborative project, diverse research groups have combined their efforts using synthetic organometallic chemistry, ultrafast infrared and X-ray spectroscopies, computational chemistry, and chemical engineering to develop and scrutinize the viability of this approach to efficiently capturing and storing solar energy.
9:00 AM - K3.12
Facilitated Transport Porous Polybenzoxazine Membrane for Flue Gas Separation
Nicharat Manmuanpom 1 2 Sujitra Wongkasemjit 1 2 Thanyalak Chaisuwan 1 2
1The Petroleum and Petrochemical College Bangkok Thailand2The Center of Excellence on Petrochemical and Materials Technology Bangkok ThailandShow Abstract
The emission of CO2 which is a greenhouse gas has resulted in the increase of the world temperature and environmental disasters. Gas separation is an attractive approach to enable the utilization of CO2 emitted from petrochemical and power plants for other applications. Polymeric membranes with excellent stability and separation performance appear to be a promising candidate for flue gas separation. In this study, porous polybenzoxazine (PBZX), prepared via sol-gel and ambient drying processes, was used as the membrane matrix. Silver ions were incorporated into the membrane in order to enhance the membrane separation performance. The effect of silver ion loading content was investigated. SEM and BET measurement were used to characterize the morphology of porous PBZX membrane. Thermal properties were characterized by DSC and TGA. The CO2, CH4 and N2 permeability was determined by using the single gas measurement.
9:00 AM - K3.13
Preparation of Porous Hybrid Composite from Calcium Sand
Vararat Swatdiponphallop 1 2 Sujitra Wongkasemjit 1 2 Thanyalak Chaisuwan 1 2
1The Petroleum and Petrochemical College Bangkok Thailand2Center of Excellence on Petrochemical and Materials Technology Bangkok ThailandShow Abstract
In this study, Koh samed sand which is a calcium carbonate compound was chosen to prepared porous hybrid composite. This sand is different from general sand in Thailand. It has mostly been created over the past half billion years by various forms of life-like corals and shellfish. Sand was chosen because it is cheap, non toxic, etc. and high molecular weight of poly vinyl alcohol (PVA) as a polymeric phase. Boric acid was used as a crosslinking agent to improve the mechanical properties. The porous hybrid composite materials were prepared via cheap and short process. They were characterized by XRD, SEM-EDX, and Autosorp-1 MP and then the potential application as a new high performance material with light weight is further investigated.
9:00 AM - K3.14
Nanoporous Carbon Membrane Prepared from Aromatic Benzoxazine Precursor for CO2/CH4 Separation
Kanokporn Wongthai 1 2 Sujitra Wongkasemjit 1 2 Thanyalak Chaisuwan 1 2
1The Petroleum and Petrochemical College Bangkok Thailand2The Center of Excellence on Petrochemical and Materials Technology Bangkok ThailandShow Abstract
The separation of CO2 from CH4 is an important process in natural gas processing and biogas purification since acidic CO2 gas can cause pipeline corrosion. Membrane separation is an excellent method to separate CO2 from CH2 due to low energy consumption, membrane design flexibity, easy installation and low maintenance required. In this study, polybenzoxazine, a high performance thermosetting resin, was used to prepare nanoporous carbon membrane via sol-gel process. Aromatic diamine-based benzoxazine precursor was prepared by using 4,4&’-diaminodiphenylmethane, formaldehyde, and bisphenol-A. Polybenzoxazine membrane was pyrolysed at 800 °C. The selectivity and permeability of CO2 and CH4 by using polybenzoxazine-derived carbon membrane were studied to determine the separation performance. The permeability of CO2 and CH2 was determined by using the single gas measurement.
9:00 AM - K3.15
Synthesis and Electrochemical Characterization of Co Based Catalyst for Fischer Tropsch Process
Battsengel Baatar 1 Munkshur Myekhlai 1 Bolormaa Gendensuren 1 Ganbaatar Gansukh 1
1National University of Mongolia Ulaanbaatar MongoliaShow Abstract
The present research focused on the preparation of cobalt based catalysts with different support materials and impregnation solutions. Co catalyst for Fischer-Tropsch processes was synthesized by the pore volume impregnation method. Cobalt was deposited on SiO2 and CNT support materials. By the preparation of Co/SiO2 catalysts three types solution such as isopropanol, ethanol and acetic acid were used for the pore building. Surface and structure of catalysts were characterized by XRD method, Particle distribution analysis and Scanning Electron Microscopy. According to the particle distribution analysis, there was no observable influence of solution on particle size building of catalyst. The activity of catalysts Co/SiO2 and Co/CNT was tested in Fischer Tropsch reactor. The high CO conversion grade has been shown on Co/SiO2 catalyst prepared by isopropanol impregnation method. The catalysts activity has been determined also by the electrochemical method- cyclic voltammetry using screen printed carbon electrode.
9:00 AM - K3.17
Colloidal Growth, Characterization and Optoelectronic Study of Strong Light Absorber Inexpensive Iron Pyrite Nanomaterials by Using Amine Ligands for Photovoltaics Application
Mahmood Alam Khan 1 Omar Manasreh 1 Scott A Little 1 Yahia Makableh 1 Scott Mangham 1 Seunyong Lee 1
1University of Arkansas Fayetteville USAShow Abstract
By converting the sun&’s energy into electrical energy, photovoltaic (PV) devices are widely viewed as a viable, sustainable means of meeting growing global energy needs while minimizing detrimental effect on the environment. Today global energy consumption mostly relies on environment damaging combustible fuels such as oil, gas and coals. So, it is clearly desirable that low-cost, nontoxic, highly absorbent and abundant materials that could create much less expensive solar cells to meet long-term local and global sustainability challenges. Iron pyrite (commonly referred as “fool&’s gold”) seen as a potential promising candidate for photovoltaic application owing to its very suitable band gap (Eg=0.95eV), very strong light absorption (α >105) capacity, long minority carrier diffusion length (100-1000nm) most abundant having theoretical efficiency of 31% estimated by Shockley-Queisser. We prepared pure iron pyrites (FeS2) cubic phased nanocrystals of diameter ~ 90nm by colloidal method using several amines as coordinating ligands and optimized the best synthetic conditions when using octylamine as a ligand at 230C for 2h reaction condition in an inert atmosphere. The XRD measurement shows cubic iron pyrite crystal structure without detectable marcasite, pyrrotite, greigyte and other impurity structures. The UV-Vis spectra depict clear absorption onset at 1100 nm with estimated bandgap of ~1.2 eV. We have further compared and elucidated details of synthetic condition at temperature 175C, 215, 230, 240, and 260C. Similarly FeS2 nanocrystals purity and structure were also explored using other amines at the optimized temperature of 230C such as Hexadecylamine, hexamethylamine, ethylenediamine, diaethanolamine and compared with the best observed results. These high pure and nanostructures based iron pyrite processed from solution route may offer excellent manufacturing scalability at very low cost since it can be used as inks for large scale fabrication. For the photovoltaic application p-n junction, hybrid solar cells are prepared using FeS2/CdSe active layer and efficiency was evaluated. The morphological and optical characterizations are carried out by using XRD, UV.Vis, SEM, TEM, Raman spectra, PL, IV curve and quantum efficiency techniques.
9:00 AM - K3.18
The Effect of Hydrogen Embrittlement on the Fatigue Properties of Austenitic Stainless Steel
Adam Nekimken 1 Patrick Ferro 1
1Gonzaga University Spokane USAShow Abstract
Hydrogen can be used as an environmentally friendly fuel to power vehicles, electric devices, and spacecraft with water vapor as the only emission. One associated challenge is the development of safe hydrogen storage systems. Hydrogen tanks and other hydrogen infrastructure elements are exposed to both high-pressure hydrogen and cyclic stresses due to pressure changes. As a result, it is desirable to understand how hydrogen embrittlement, a well-documented phenomenon, affects the fatigue of structural metals. In our work, austenitic stainless steel specimens were exposed to different hydrogen conditions and fatigued to failure. The fatigue behavior of specimens subjected to no hydrogen, moderate hydrogen pressures (200 psi), and high hydrogen pressure (20,000 psi at elevated temperature) is then compared. Because of the expense and danger of in situ hydrogen testing, samples are pre-charged with hydrogen and tested in air. A mathematical hydrogen diffusion model was solved for the geometry of the fatigue specimens to enable the approximation of the concentration of hydrogen still present in the specimen during fatigue testing. Previous work has shown that exposure to high pressure hydrogen reduces the fatigue life of simple bending fatigue specimens from 75,070 (Sx=27840, N=15) cycles to 9460 (Sx=1960, N=5) cycles at a maximum stress level of 183 MPa, a factor of approximately 8. Statistically significant changes in fatigue life for specimens subjected to 1 atmosphere of hydrogen pressure have not been found. Current research is focused on corroborating these results using rotational bending fatigue tests of specimens exposed to the same hydrogen conditions. Performing rotational bending fatigue tests instead of simple bending fatigue allows for the control of the maximum bending stress and reduces the time consumed by each test. This enables the generation of S-N curves and leads to an improvement in statistics of the results by increasing the sample size. The next research milestone is the generation of S-N curves with enhanced statistical significance for specimens exposed to different hydrogen conditions.
9:00 AM - K3.19
Crystallization Kinetics of Thermoelectric Bi2Se3 Crystals in Ge-Se-Bi Chalcogenide Glasses
Yinyao Liu 1 Jing Ren 1 Guorong Chen 1 2 Stefania Baccaro 2 Alessia Cemmi 2
1East China University of Science and Technology Shanghai China2ENEA Rome ItalyShow Abstract
Nowadays human beings around the world are facing increasingly alarming problems of energy shortage and the environmental impact of global climate change, which is causing a dramatic escalation of social and political unrest. Hence, it is important to find ways towards the realization of the recycle of waste heat and clean energy generation. Thermoelectric (TE) materials have been catching much attention due to the potential of converting waste heat directly to electricity. In the past decades it has been a thrust to enhance the TE performance of materials to achieve higher figure of merit (ZT=σS2T/κ). One of the most significant approaches to the design of improved TE materials is believed to realize materials conducting electricity like crystals but diffusing heat like glasses, namely “electron crystals-phonon glasses (ECPG)”. It is thus supposed that glass with the controlled precipitation of specific TE crystals might be a promising way of developing new TE materials with the higher ZT value.
Bismuth chalcogenides (Bi2Se3/Bi2Te3) gained much research interest due to their good TE properties and high ZT values at room temperature. There are also a wide variety of synthesis techniques to prepare various nanostructures of Bi2Se3. We previously proposed novel glass ceramic materials based on Ge-Se-Bi ternary glasses and embedded with nano/micro scaled TE Bi2Se3 crystals. To estimate the possibility of the precipitation of pure, uniformly distributed and nano/micro scaled Bi2Se3 TE crystals, it is crucial to study the crystallization kinetics of the crystals in the glass system. Therefore, in this paper we investigated the crystallization activation energy (Ec) and the Avrami exponent (n) by DSC curves through four commonly used methods. The calculated Ec by different methods matches well with each other. The average Avrami exponent (nave) obtained from Augis-Bennett approximation and Matusita-Sakka theory is over 4 for the Ge20Se70Bi10 (B10) sample and close to 4 for the Ge20Se68Bi12 (B12) sample, indicating an overall nucleation and three-dimensional growth of crystals, respectively. The TE Bi2Se3 crystal phase has been precipitated from the three bismuth containing glass samples after annealing at different temperature for various time. The sample B10 (Ge20Se70Bi10) is considered to be the promising one due to availability of pure TE Bi2Se3 crystals under proper annealing conditions. These results indicate that Ge-Se-Bi chalcogenide glass system has great potential to the preparation of novel TE glass-ceramic materials.
9:00 AM - K3.20
A Novel Method for the Preparation of Bi12TiO20 Selenite for Environmental Applications
Andre Esteves Nogueira 1 Emerson Rodrigues Camargo 1
1Federal University of Samp;#227;o Carlos Samp;#227;o Carlos BrazilShow Abstract
Ternary bismuth oxide semiconductors, such as Bi2WO6 , BiVO4 , Bi12TiO20  have been widely studied as a class of promising photocatalyst which can respond under visible light. Several authors have reported the synthesis of Bi12TiO20 materials using numerous techniques, including solid-state reaction, sol-gel, polymeric precursor and hydrothermal methods. However, these methods still have some drawbacks as the appearance of secondary phases, non-stoichiometric composition and impurities . A recent study describing the oxidant-peroxo method (OPM) synthesis, showed advantages in terms of purity, reactivity, control of particle size and free of contaminants such as chloride ions and organic compounds that could interfere in the properties and photocatalytic process of TiO2 nanocrysta. In this technique the hydrogen peroxide is replaced by an inorganic peroxo complex, such as peroxytitanate [Ti(OH)3O2]-. The reaction with bismuth ions occurs in the presence of peroxo-complex with the formation of a non-crystalline yellow precipitate, which was posteriorly calcined between 400 and 800 °C/1 h to obtain crystalline Bi12TiO20. The morphology and microstructure of the catalyst were characterized using X-ray diffractometry (XRD), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS-UVvis), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and nitrogen adsorption measurements. In addition, the photocatalytic activity of synthesized Bi12TiO20 powders was evaluated by studying the degradation of 10 mg.L-1 aqueous rodamine B (RhB) dye under ultraviolet radiation. X-ray diffraction and Raman spectroscopy show that the samples were in pure cubic phase after calcinations with temperature above 400 °C. The band gap energies of the material showed a shift of the absorption edge to longer wavelengths with increasing calcination temperatures, which correspond to the decrease in the band gap energy. The efficient photocatalytic activity of the materials calcined at 400 and 500 °C was confirmed by the complete degradation of RhB solution (10 mg.L-1) under ultraviolet litht irradiation for three hours. However, the photocatalytic activity of powders calcined at 700 and 800 °C decreased drastically The lower activity of these materials can be related to the formation of larger crystallites induced by the calcinations processes, which present smaller surface area and reduce the charge transport efficiency from the bulk to the material surface. This description is speculative but probably is correct in general and more studies are needed to uncover particular mechanisms.
Work supported by FAPESP, CMDMC/Cepid, CNPq and CAPES.
 S. Zhang, et al. J. Solid State Chem. 179, 62 (2006).
 J. Yu, et al. J. Solid State Chem. 182, 223 (2009).
 H. Zang, et al. Surf. Coat. Technol. 202, 4930 (2008).
 R. Camargo; M. Kakihana Chem. Mater. 13, 1181 (2001).
9:00 AM - K3.21
High Porous Material from Poly (Styrene/Ethylene Glycol Dimethacrylate)HIPE for Agriculture Application
Supakorn Jindacharin 1 2 Manit Nithitanakul 1 2 Pornsri Pekayangkoon 3
1The Petroleum and Petrochemical college Bkk Thailand2The Center of Excellence on Petrochemical and Materials Technology Bkk Thailand3King Mongkut's University of Technology North Bangkok Bangkok ThailandShow Abstract
Lacking of water in soil is still a very serious problem for semi-arid or arid agriculture area. In this study, a novel porous polymer, polyHIPE (high internal phase emulsion), synthesized through the emulsion templating technique, and will be used as a soil additive in agriculture application. The outstanding characteristics of polyHIPEs are controllable size, interconnected porous microstructure, manageable rigidity and especially good water adsorption capacity. However, due to its rigid structure, this resulting in a limited water uptake of the material. This problem can be solved by varying the synthesis conditions such as changing the type of stabilizer salt or increasing in percentage of aqueous phase to generate more spongy form. Furthermore, supplementation of hydrophilicity with ethylene glycol dimethacrylate (EGDMA) as a crosslinking monomer will be employed to improve the water adsorption ability of the material. The pore size and surface area will be characterized by SEM and Autosorp-1MP.
9:00 AM - K3.22
Designing Microstructure of Nanoporous Carbon as a Catalyst Support for Biodiesel Production
Juta Jaroonkiattikhun 1 2 Sujitra Wongkasemjit 1 2 Thanyalak Chaisuwan 1 2
1The Petroleum and Petrochemical College Bangkok Thailand2The Center of Excellence on Petrochemical and Materials Technology Bangkok ThailandShow Abstract
In this study, nanoporous carbon materials prepared from polybenzoxazine precursor have been used as catalyst supports for the biodiesel upgrading. Polybenzoxazine was synthesized from 1,6-hexamethylene diamine, bisphenol-A and formaldehyde while silica particles were used as the templates to achieve the controllable mesoporous carbons. The SEM micrographs revealed that the obtained carbons consisted of the interconnected 3D particles. For the biodiesel upgrading, the conversion of methyl linoleate (C 18:2) to methyl oleate (C 18:1) or partial hydrogenation reaction by using PdNO3 supported on carbon materials (Pd/porous carbon) is investigated. The effects of carbon microstructure and silica particle content (acidity) on the upgrading performances will be further discussed.
9:00 AM - K3.24
Electrical Percolation Behavior of Epoxy/Silver Nanowire Composites Mixed with Silica Nanoparticles: Experiment and Simulation
Heesuk Kim 1 Seungwoong Nam 1 Hyun Woo Cho 2 Bong June Sung 2
1Korea Institute of Science and Technology Seoul Republic of Korea2Sogang University Seoul Republic of KoreaShow Abstract
Isotropic conductive adhesives (ICAs) have drawn much attention in recent years due to their potential applications in environmentally friendly microelectronic packaging such as ball grid arrays and flip chip technologies. ICAs have numerous advantages over traditional Sn/Pb solder because ICAs require fewer processing steps and a lower processing temperature. One can prepare heat-sensitive and low-cost chip carriers with fine pitch capabilities. However, the high electrical resistivity and poor mechanical properties of ICAs have been stumbling blocks to their development. One may decrease the electrical resistivity by increasing the volume fraction of conductive fillers in ICAs beyond a percolation threshold volume fraction. But, too high filler loading would cause the mechanical integrity of adhesive joints to deteriorate. Finding an optimal condition to achieve both a high electrical conductivity and desired mechanical properties, therefore, should be of significant importance.
One-dimensional conductive fillers such as silver nanowires and carbon nanotubes are used to reduce the contact resistance, thereby decreasing the electrical percolation threshold concentration. However, more than 10 vol% of silver nanowires are necessary for a low enough electrical percolation threshold concentration. The electrical percolation threshold concentration can be reduced with carbon nanotubes due to their high aspect ratio but the electrical conductivity of these nanocomposites is only 10^2 S/cm. In this study, we illustrate a novel but facile strategy to obtain high electrical conductivity for epoxy nanocomposites with a small amount of silver nanowires by introducing non-conductive silica nanoparticles. Using our strategy, one can decrease the concentration of silver nanowires down to only 2 vol% and still obtain the electrical conductivity of 10^4 S/cm. The minimum content of silver nanoparticles or nanowires required for electrical conductivity of 10^4 S/cm was known to be 10 ~ 25 vol%. We also perform extensive molecular simulations to elucidate how one can obtain such a good electrical conductivity by mixing silica nanoparticles.
9:00 AM - K3.26
Enhancement of Aluminum Thin Film Properties by Titanium Carbide Addition
Felipe Sampaio Alencastro 1 Emanuel Santos 1 Oleksii Kuznetsov 2 Renata Antoun Simao 1
1COPPE/UFRJ Rio de Janeiro Brazil2INMETRO Xerem BrazilShow Abstract
Aluminum films have been widely used as high performance reflective coatings for optical devices and as an alternative to cadmium- and chromium-based films due to its high corrosion resistance. However, aluminum-based films often present low hardness and elastic modulus. This study reports on the effect of TiC addition to aluminum films as a way of increasing its mechanical properties.
Films were made via magnetron sputtering with aluminum and titanium carbide targets, with different deposition powers applied to each target, where both components were deposited concomitantly on the substrates.
The films were analyzed by scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, atomic force microscopy, contact perfilometry, Berkovich nanohardness and grazing-angle X-ray diffraction. Results suggest that the addition of TiC to aluminum films forms a fine dispersion of crystalline grains over an amorphous matrix, increasing its hardness and elastic modulus.
9:00 AM - K3.27
Effects of Carbon Dioxide on Methane Adsorption on Activated Carbon in a Packed Bed Column
Chompunick Sitthirawiphong 1 2 Pramoch Rangsunvigit 1 2 Santi Kulprathipanja 3
1The Petroleum and Petrochemical College Bangkok Thailand2The Center of Excellence on Petrochemical and Materials Technology Bangkok Thailand3A Honeywell Company Des Plaines USAShow Abstract
Effects of carbon dioxide on the methane adsorption on activated carbons derived from coconut shell were investigated in a packed bed column. The experiments were operated at atmospheric pressure and room temperature. The kinetics adsorption of methane and carbon dioxide was examined. SEM and BET measurements were used to characterize the adsorbents. The binary mixtures of methane and carbon dioxide (1, 3, 5, 10, 15, 20, 30, and 35% by volume of CO2) was used to study the effect of carbon dioxide on methane adsorption. In the procedure, pure methane and binary mixtures will pass through and be adsorbed in the packed bed column. Carbon dioxide has significantly affect the adsorption capacity of methane. The amount of adsorbed methane decreases with the presence of carbon dioxide.
9:00 AM - K3.28
Synthesis of Pt-CeOx Electrocatalysts for the Oxygen Reduction Reaction in Absence and Presence of Methanol in 0.1 M KOH
Alejandro Altamirano Gutierrez 1 A. M. Fernandez 1 F. J. Rodriguez Varela 2
1Universidad Nacional Autamp;#243;noma de Mamp;#233;xico Mexico Mexico2Cinvestav Unidad Saltillo Saltillo MexicoShow Abstract
In this work, we report the synthesis and the structural, morphology and electrochemical characterization of novel Pt-CeOx electrocatalysts, as a candidate cathode for DAFCs (Direct Alcohol Fuel Cells). The electrocatalytic materials have been prepared by two methods a) chemical reduction of H2PtCl6#9679;6H2O and Ce(NO3)3#9679;6H2O precursors with sodium borohydride and b) pyrolysis of the same precursors at temperatures between 300 and 600 °C, under an (H2/N2 50:50) atmosphere for 5 h. This was done to evaluate the effect of the medium of synthesis on the structure and electrocatalytic properties of the materials for the oxygen reduction reaction (ORR) in absence and presence of methanol in 0.1 M KOH. The materials were structurally characterized by XRD and were subjected to chemical analysis by EDS. From theses analyses we estimated the particle size, the structural phases and the atomic composition of the materials. The electrochemical characterization consisted of rotating disk electrode (RDE) measurement at room temperature in 0.1 M KOH, using cyclic and linear sweep voltammetry (CV and LSV) techniques. The crystal size obtained from XDR analysis was from 8 to 22 nm depending on the synthesis condition. The Pt-CeO2 nanostructures showed a high catalytic activity for the ORR in alkaline solution. Moreover, these materials demonstrated tolerance to the presence of methanol. These features make the Pt-CeO2 electrocatalysts cathode candidates for Alkaline Direct Methanol Fuel Cells.
9:00 AM - K3.29
A New LiPON Solid State Electrolyte: Synthesis, Properties, and Electronic Structure
Abdou Lachgar 1 2 Natalie A. W. Holzwarth 3 2 Keerthi Senevirathne 1 2 Michael Gross 4 2
1Wake Forest University Winston Salem USA2Wake Forest University Winston Salem USA3Wake Forest University Winston Salem USA4Bucknell University Lewisburg USAShow Abstract
The new crystalline compound, Li2PO2N, was synthesized using high temperature solid state methods starting with a stoichiometric mixture of Li2O, P2O5, and P3N5. Its crystal structure was determined ab initio from powder X-ray diffraction. The compound crystallizes in the orthorhombic space group Cmc21 (# 36) with lattice constants a=9.0692(4) Å, b=5.3999(2) Å, and c=4.6856(2) Å. The crystal structure of SD-Li2PO2N consists of parallel arrangements of anionic chains formed of corner sharing (PO2N2) tetrahedra. The chains are held together by Li+ cations. The structure of the synthesized material is similar to that predicted by Du and Holzwarth on the basis of first principles calculations (Phys. Rev. B 81, 184106 (2010)). The compound is chemically and structurally stable in air up to 650 C and in vacuum up to 1050 C. The energy band gap was estimated to be larger than 6 eV. The minimum activation energies for Li ion vacancy and interstitial migrations are computed to be 0.4 eV and 0.8 eV respectively. Th eactivation energy of SD-Li2PO2N was determined to be 0.6 eV by Impedance measurements, comparable to that of the glassy electrolyte LiPON developed at Oak Ridge National Laboratory.
9:00 AM - K3.30
Development of Bimetallic Electrocatalysts Based on Rhodium and Various Non-noble Transition Metals for the Oxygen Reduction and Hydrogen Oxidation Reactions
Maria Lizbeth Barrios-Reyna 1 Jorge Uribe-Godinez 1 2 Omar Jimenez-Sandoval 1
1Cinvestav Queramp;#233;taro Mexico2UNAM Mexico MexicoShow Abstract
In this work we report the synthesis and characterization of novel bimetallic electrocatalysts for oxygen reduction and hydrogen oxidation, which are based on rhodium and different non-noble transition metals: Cu, Ni, Fe, Mn. This kind of materials is a novelty in a field dominated by catalysts based on platinum group metals and their alloys. The syntheses were carried out by thermolysis in dimethylsulfoxide. The new materials were characterized structurally and morphologically by analytical techniques such as: FTIR, micro-Raman spectroscopy, XRD, SEM and EDS. The materials synthesized show catalytic activity towards the oxygen reduction reaction (ORR) and hydrogen oxidation reaction (HOR), thus exhibiting a dual catalytic behavior. Furthermore, most of the materials developed in this work, have good resistance to methanol concentrations of 2 mol L-1 and CO concentrations of 0.5% in H2 mixtures. This is a very important property with respect to platinum catalysts, since the latter are easily deactivated with low concentrations of such contaminants. In general, according to the electrochemical analysis performed, the material which showed better values of exchange current density (jo) Tafel slope (b), and charge transfer coefficient (α) for the ORR in the absence and presence of methanol was RhxCuy(CO)n, while for the HOR, even in the presence of CO, was RhxMny(CO)n.
The authors acknowledge M. A. Hernández-Landaverde and R.A. Mauricio-Sánchez (CINVESTAV-Querétaro) for their support in some experiments.
Presenting author&’s e-mail: email@example.com
9:00 AM - K3.31
Ir-Mn and Rh-Mn Bimetallic Electrocatalysts for Oxygen Reduction and Hydrogen Oxidation in Acid Media
Maria Lizbeth Barrios-Reyna 1 Jorge Uribe-Godinez 1 2 Omar Jimenez-Sandoval 1
1Cinvestav Queramp;#233;taro Mexico2UNAM Mexico MexicoShow Abstract
New catalytic materials were synthesized using metal carbonyl clusters and a manganese(II) salt as precursors [Rh6(CO)16, Ir4(CO)12 and MnCl2.4H2O], by thermolysis reactions in organic solvents. The compounds obtained were characterized structurally and morphologically by the following techniques: FT-IR and micro-Raman spectroscopy, XRD, SEM and EDS. The electrochemical characterization was performed by rotating disk electrode (RDE) studies at room temperature. The novel materials have dual electrocatalytic behavior, i.e. they are capable of carrying out both the oxygen reduction reaction (ORR) and hydrogen oxidation reaction (HOR), and are also resistant to poisoning by methanol (2 mol L-1) and carbon monoxide in different concentrations (100 ppm and 0.5%). This property is a major advantage over traditional platinum-based catalysts, since the latter are easily deactivated by CO concentrations of a few ppm. Although other bimetallic electrocatalysts for these reactions have been prepared and their properties proved to be potentiated by the bonding between both metals, they are based solely on platinum group elements. The catalysts reported in this work combine Rh and Ir with a non-noble metal, Mn, and their potential as PEM fuel cell electrodes is addressed.
The authors are thankful to M. A. Hernández-Landaverde and R. A. Mauricio-Sánchez (CINVESTAV-Querétaro) for their assistance in some experiments.
Presenting author's e-mail: firstname.lastname@example.org
9:00 AM - K3.33
Thermodynamics of Cellulose Solvation in Novel Solvent Mixtures
Ritankar Das 1 Jhih-Wei Chu 1
1UC Berkeley Albany USAShow Abstract
Biomass contains abundant amounts of cellulose as crystalline microfibrils. A limiting step to using cellulose as an alternative energy source, however, is the hydrolysis of the biomass and subsequent transformation into fuels. Cellulose is insoluble in most solvents including organic solvents and water, but it is soluble in some ionic liquids like BMIM-Cl. This project aims to find alternative solvents that are less expensive and are more environmentally benign than the ionic liquids.
All-atom molecular dynamics simulations were performed on dissociated glucan chains separated by multiple (4-5) solvation shells, in the presence of several novel solvents and solvent mixtures. The solubility of the chains in each solvent was indicated by contacts calculations after the equilibration of the molecular dynamics. It was discovered that pyridine and imidazole acted as the best solvents because their aromatic electronic structure was able to effectively disrupt the inter-sheet interactions among the glucan chains in the axial direction, and because perturbation of the solvent interactions in the presence of glucan chains was minimal.
9:00 AM - K3.34
Effect of Glycerol on Miscibility of Thermoplastic Starch/Poly(ethylene-co-vinyl alcohol) Blends
Jitrawee Suk-em 1 Ranumas Thipmanee 1 Rangrong Yoksan 1 2 Amporn Sane 1 2
1Kasetsart University Bangkok Thailand2Kasetsart University Bangkok ThailandShow Abstract
The interest of using thermoplastic starch (TPS) for packaging application originates from renewability, biodegradability, low cost and processability with conventional equipment used for processing synthetic polymers. However, TPS has not been widely used in packaging because of its limitations in moisture resistance and mechanical properties. Blending with a flexible hydrophobic polymer can improve the limitations of TPS. Among hydrophobic polymers, poly(lactic acid) (PLA) is commonly blended with TPS to improve the moisture barrier of TPS; however, the obtained blend is not flexible due to the rigidity and brittleness of PLA. Poly(ethylene-co-vinyl alcohol) (EVOH), a flexible copolymer with excellent oxygen barrier, consists of hydroxyl groups that potentially enhance the miscibility of TPS/EVOH blend. Therefore, the objective of this work was to investigate the effect of glycerol concentration on mechanical, morphological and thermal properties of TPS/EVOH blend films. Glycerol concentrations used during TPS extrusion were 25, 30 and 35 parts per hundred starch (PHS). The prepared TPS was melt blended with EVOH to obtain a TPS/EVOH blend containing 40 % of TPS and 60 % of EVOH. Then, the TPS/EVOH blend pellets were converted into films by a blown film extrusion line. Morphological, thermal and mechanical properties of the obtained films were characterized by scanning electron microscope (SEM), differential scanning calorimeter (DSC), and Instron universal tester. It was found that the miscibility of TPS/EVOH blend increased with increasing glycerol contents from 25 to 35 PHS. This was also confirmed by the decrease in temperature difference between Tms of TPS and EVOH (~7 °C). Hence, the results indicate that glycerol does not function only as a plasticizer for TPS but also a compatibilizer for TPS/EVOH blend. Furthermore, increasing glycerol concentration from 25 to 35 PHS resulted in increased elongation at break while decreased tensile strength and Young&’s modulus.
9:00 AM - K3.35
Mechanical Metamaterials Manufactured from Additive Manufacturing
Xiaoyu Zheng 1 Josh Deotte 1 Chris Spadaccini 1
1Lawrence Livermore National Laboratory Livermore USAShow Abstract
Recent developments have enabled generation of mimicking nature cellular materials such as honey combs, foams, light weight structural panels etc. These types of porous structures have displayed high porosity and strong stiffness as compared to random porous materials in nature. No current technology is able to rapidly and sustainably produce structures with optimized three-dimensional architectures at the meso- and micro-scales while also being flexible enough to vary the geometry and constituent materials. This paper reports construction of low density high stiffness cellular materials through Projection Microstereolithography, an additive, high throughput manufacturing technique capable of generating complex three-dimensional structures. The resulting microstructural materials have mechanical stiffness that is two-orders of magnitude higher than conventional cellular materials given the same density.
K1: Materials for Sustainable Energy
Thursday AM, April 04, 2013
Moscone West, Level 2, Room 2020
9:30 AM - K1.02
Aqueous Self-assembly of an Electroluminescent Double-helical Metallo-polymer
Demet Asil 1 Xavier Hatten 2 Richard H. Friend 1 Jonathan R Nitschke 2
1University of Cambridge Cambridge United Kingdom2University of Cambridge Cambridge United KingdomShow Abstract
A novel water soluble metallo-polymer containing copper has been designed and synthesized using sub-component self-assembly technique (1). The imine bond formation between triethylene-glycol-functionalized 1,2-phenylenediamine and 2,9-diformylphenanthroline lead to a double helical ligand strands around a linear array of copper ions. The model compounds have also been formulated to control and compare the results. The polymer has been fully characterized by variety of analytical methods. It has been shown that it forms aggregates in the shape of nano bow ties and macrocyles, which has been proved by several imaging techniques. The polymer has been shown to be undergoing reversible and stable oxidation and reduction in solution whereas the model compounds suffer from instability. Electrochemical reversibility and stability of the metallo-polymer compared to model compounds has been attributed to the steric protection of the metal centres from the surroundings. The conjugated double helical ligands around the copper (I) ions also lead to promising photo physical properties. In spite of having a weak photo-luminescence in the solid phase, the simple single layer light emitting diodes with the polymer gave promising results. The devices emitted white-blue light with CIE coordinates of (0.337, 0.359). Formation of well-defined superstructures and light emitting properties of the novel metallo-polymer demonstrates the use of the technique of subcomponent self-assembly for the design of straightforward and smart materials.
(1) Xavier De Hatten , Demet Asil , Richard H. Friend , Jonathan R. Nitschke, J. Am. Chem. Soc., Just Accepted Manuscript, DOI: 10.1021/ja308055s
9:45 AM - K1.03
Thin Films of Solar Absorber Cu2ZnSnS4 Deposited from Nanocrystal Dispersions in Polar Solvents
B.Selin Tosun 1 Boris Chernomordik 1 Aloysius Gunawan 1 K.Andre Mkhoyan 1 Eray S. Aydil 1
1University of Minnesota Minneapolis USAShow Abstract
Thin-film copper zinc tin sulfide (Cu2ZnSnS4 or CZTS) and selenide (Cu2ZnSnSe4 or CZTSe) solar cells have reached 7-10% power conversion efficiencies during the last few years. This rapid advance attests to the remarkable potential of this material as a light absorber comprised of earth-abundant and nontoxic elements. Thin CZTS films have been synthesized using a variety of vacuum deposition methods including coevaporation from elemental sources in vacuum. Coating from colloidal nanocrystal dispersions (inks) is emerging as an alternative method to vacuum deposition because it has the potential to be less expensive than vacuum processing. Recently, several methods for synthesizing CZTS nanocrystals have been reported. However, all methods produce nanocrystal dispersions in organic solvents where the nanocrystals are sterically stabilized by long alkyl ligands on their surfaces. Deposition of thin films from these nanocrystal dispersions necessitates the handling of large volumes of organic solvents undermining the presumed cost advantage of making solar cells from nanocrystal inks. Aqueous dispersions of CZTS are preferred. In this talk, we will describe a simple method for extracting CZTS nanocrystals from organic solvents into polar solvents and ultimately forming aqueous dispersions. Specifically, we use an aqueous solution of K2S in formamide to extract the CZTS nanoparticles into formamide. The CZTS nanoparticles are dispersed in aqueous phase by electrostatic stabilization after cleaning the excess K2S from the ligand exchange reaction. The ligand coverage on the nanocrystal surfaces was quantified using attenuated total reflection Fourier transform spectroscopy. Quantification of the ligand coverage on the CZTS nanocrystals revealed that the magnitude of the C-H stretching absorbance on as synthesized nanocrystals corresponds to ~5×1013 to 1.5×1014 ligand molecules/cm2. Extraction into the polar solvent is achieved by reducing the oleylamine and oleic acid ligands and covering the surface sites with S2- ions. A small amount of alkyl ligands remain but appear inconsequential to their dispersion in polar solvents. The extraction of CZTS nanocrystals into formamide and their subsequent dispersion in water does not change their structure, size and optical properties. However, we observe the formation of zinc hydroxystannate (ZnSn(OH)6) and significant changes in the CZTS nanocrystals when high concentrations of K2S was present in aqueous dispersions. These aqueous dispersions of the CZTS nanocrystals were used for depositing absorber layers for solar cells. The nanocrystal films were annealed under nitrogen, sulfur or selenium vapor to form large grain CZTS and CZTSe films for solar cells. Films synthesized from aqueous and organic dispersions under different annealing conditions will be compared.
10:00 AM - K1.04
Enhancing Light Harvesting Efficiency of Hematite Nanorods Using Squaraine Dye in Photo-electrochemical Solar Cell
Hemant Kumar Mulmudi 1 2 Nripan Mathews 1 2 Subodh Mhaisalkar 1 2 Yeng Ming Lam 1
1Nanyang Technological University Singapore Singapore2Energy Research Institute@NTU Singapore SingaporeShow Abstract
Hematite( α-Fe2O3), an allotrope of iron oxide, is an interesting material for photovoltaic application as it has a narrow bandgap of 2.2 eV. A maximum of 12-13 mAcm-2 of current can be drawn out from hematite photoanodes when used in a photo-electrochemical solar cell configuration. But bulk recombination has been a major problem and to address this issue nanostructuring has been adopted.
Another approach to increase the light harvesting of these photoanodes is to use squaraine dye which absorbs in the wavelength range of 600-700 nm. A thorough investigation of these devices has been done using impedance analysis to understand the root causes of recombination and limitations in such cells.
10:15 AM - K1.05
Picosecond IR Spectroscopy of Fulvalene(Tetracarbonyl)Dimetal: A Solar Storage and Thermal Release Molecule
Son C. Nguyen 1 Zongrui Hou 1 Justin P. Lomont 1 Charles B. Harris 1 Peter C. Vollhardt 1
1Chemistry Dept., UC, Berkeley Berkeley USAShow Abstract
Storing solar energy in chemical bonds and releasing that energy “on demand” provides a good solution for the inherent intermittency of solar sources. Recent studies have shown that the (Fulvalene)tetracarbonyldiruthenium (Ru-Fuv) complex has this capacity. This robust molecule Ru-Fuv absorbs sunlight, converting to a stable photoisomer which can easily release the energy in form of heat via catalyzed the thermal reversal. Thus understanding the isomerization mechanism of the Ru-Fuv is necessary to develop a cheaper and more efficient rechargeable solar thermal battery. We used picosecond time-resolved infrared spectroscopy to study the dynamics of the Ru-Fuv following photoexcitation. In combination with DFT calculations, we found that after the Ru-Ru bond cleavage, the photoproducts exist in both singlet and triplet syn biradicals. The singlet biradical rapidly geminates to return to the parent molecule with a time constant of 30 ps. The syn triplet state has lifetime up to nanoseconds, proceeds to photoisomer product via a triplet-singlet crossing point. These results show the important role of triplet biradicals in making photoisomerization possible, furthering development of analogous Fe system.
10:30 AM - K1.06
Modifying Atomic Layer Deposition with Low Temperature Growth of Ruthenium Oxide on Special Electrode Substrates for Energy Storage Applications
Xianbin Wang 1 Wei Chen 2 Liang Li 1 Zhihong Wang 1 Elhadj M Diallo 1 Weisheng Yue 1 Xiaoming Yang 1 Ahad Syed 1 Xixiang Zhang 1 Husam N Alshareef 2
1King Abdullah University of Science and Technology Thuwal Saudi Arabia2King Abdullah University of Science and Technology Thuwal Saudi ArabiaShow Abstract
Ruthenium oxide (RuO2), a representative member of the transitional metal dioxides family, has been considered for a wide variety of applications as a potential candidate for the applications in electrodes in capacitors, optoelectronic devices and electrochemical devices owing to its semi-transparency, extremely low resistivity, excellent chemical and thermal stability and high catalytic activity [1-2]. Recently, atomic layer deposition (ALD) has been intensively explored as one of most favorable techniques for RuO2 deposition. ALD is a chemical vapor deposition technique based on sequential introduction of gaseous precursors and selective chemistry. It has demonstrated the capability to achieve accurate thickness control with highly consistent conformability even if on extremely high aspect ratio patterns or three dimensional structures. However, RuO2 thin film with good quality is highly sensitive to the ALD process temperature and only available when the temperature is as high as about 300 °C. In this talk, we will present our development work in a modified plasma assisted ALD process which combined a continuous flow of diluted oxygen gas in all the conventional sequential steps of precursor-purge-oxygen plasma-purge with an insertion of additional soaking step after precursor pulse. By investigating the process responses to the ALD parameters of pulse time of precursor, oxygen plasma exposure time and soaking duration the deposition temperature is reduced to below 200 °C, a temperature range which can be withstandable for some of potential electrode supporting substrates such as some of conductive fabrics and flexible materials. In addition, the modified ALD RuO2 samples has been examined by spectroscopic ellipsometry, X-ay diffraction (XRD), micro-Raman spectroscopy and atomic force microscope (AFM) in terms of thin film growth rate, refraction index, crystalline structure and gap-filling conformability. Our attempts in the demonstration of this modified ALD process on selected electrode supporting substrates for energy storage will also be presented.
 L. J. Chou, Y. L. Chueh, C. H. Hsieh, M. T. Chang, C. S. Lao, J. H. Song, J. Y. Gan and Z. L. Wang, Adv. Mater., 2007, 19, 143-149
 Z. G. Zou, J. H. Ye, K. Sayama and H. Arakawa, Nature, 2001, 414, 625-627
10:45 AM - K1.07
Optimization of the Spectral Selectivity of Alpha-SiC Foams Used in Open Volumetric Solar Absorbers
Benoit Rousseau 1 Simon Guevelou 1 Gilberto Domingues 1 Jerome Vicente 2 Cyril Caliot 3 Gilles Flamant 3
1LTN UMR CNRS 6607 Nantes France2IUTSI UMR CNRS 7343 Marseille France3PROMES UPR CNRS 8521 Odeillo FranceShow Abstract
The interest for alpha-SiC foams is growing substantially since they can be advantageously applied as volumetric absorbers in solar thermal and solar thermochemical processes. Such an interest for these foams relies on their large specific surface area, high permeability and resistance to thermal stress. Indeed in central solar power plants, volumetric solar absorbers receive high and unsteady heat flux (up to 1200 kW/m^2) and operate at high temperatures up to 1500 K. So, SiC reputes to be a refractory material well adapted to operate under severe conditions. According to the thermal cycling under air, a thin layer of silica (SiO2) (amorphous or polycrystalline) can grow to passively protect the SiC sample. This thermal oxidation occurs for temperatures around 900-1200°C and chemical mechanisms (grow rate, final thickness and effect of gaseous environment) had been intensively studied in particular for microelectronic applications. From an thermal radiative viewpoint, the thin layer of SiO2 must have a weak impact for thicknesses lower than 50 nm on the radiative behavior of a SiC foam.
A key challenge for volumetric solar absorber is to increase their spectral selectivity. Indeed a good solar absorber efficiently captures solar energy in the high intensity visible and in the near infrared regions while maintaining low infrared emissivity. This requirement involves the accurate control of the optical mechanisms responsible of the absorption of light for several scale of length. In turn, the obtaining of the desired spectral selectivity implies also to control the process of elaboration leading to the volumetric solar absorber. In conclusion, this task is real challenge for physicians and chemists working in the field of materials science.
In this work, both the textural and the radiative properties of a SiC foam used as volumetric solar absorber was investigated in order to deal with its spectral selectivity. X-ray µ-tomography and scanning electron microscopy were performed for describing the texture of the foam. In the other hand, infrared spectroscopy and infrared microscopy were used to probe the radiative properties for the mid-infrared spectral range. A brief overview of the optical properties of alpha-SiC is also provided so as to give the first tracks making it possible to design a SiC foam with an optimized spectral selectivity. In particular a numerical tool based on a Monte Carlo Ray Tracing code will be present to deal with this task.
11:30 AM - *K1.08
Life Cycle Greenhouse Gas Emissions from Unconventional Natural Gas and Comparison to Other Fossil Energy Sources
Corrie Clark 1
1Argonne National Laboratory Washington USAShow Abstract
Large-scale development of shale gas resources in the U.S. has generated interest in expanding the usage of natural gas (NG) in sectors such as electricity generation and transportation. This potential game-changer to the U.S. energy market has been made possible through advancements in drilling technologies, specifically through horizontal drilling and hydraulic fracturing. The environmental impacts of such rapid growth in shale gas production are not well understood. One concern is the amount methane (CH4) leakage from production activities and its impact on the life-cycle greenhouse gas (GHG) emissions of NG. Results of a life cycle analysis on shale gas as compared to conventional fossil energy sources for electricity generation and transportation will be discussed. Our base case results show that shale gas life-cycle emissions are 23% lower than gasoline and 33% lower than coal. Additionally, our results indicate that shale gas life-cycle emissions are 6% lower than those of conventional natural gas; however, there is a statistical uncertainty whether shale gas emissions are indeed lower than conventional gas.
The submitted manuscript has been created by the UChicago Argonne, LLC, Operator of Argonne National Laboratory (“Argonne”). Argonne, a U.S. Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357. The U.S. Government retains for itself, and others acting on its behalf, a paid-up, nonexclusive, irrevocable worldwide license in said article to reproduce, prepare derivative works, distribute copies to the public, and perform publicly and display publicly, by or on behalf of the Government.
12:00 PM - K1.09
Sequestration of Carbon Dioxide from Transportation Vehicles
Hal Gokturk 1
1Ecoken San Francisco USAShow Abstract
Internal combustion engine which powers most transportation vehicles emits a number of gaseous pollutants like carbon monoxide which are converted to benign gases in the catalytic converter utilizing the catalytic activity of precious metals. Unfortunately the cleaning process is not designed to remove CO2 generated during the combustion. Furthermore, unburned or partially burned carbon compounds in the exhaust are neutralized by oxidizing them to CO2. The transportation sector accounts for about 20% of the total CO2 emissions and governments concerned about global warming are imposing restrictions on vehicle emissions . There is a need for a new type of catalytic converter which reduces CO2 as well as the regulated pollutants.
CO2 does not readily interact with neutral molecules either chemically or electrically because of the double bonds and the quadrupolar charge distribution. The objective of this research is to investigate whether ions introduced into the exhaust gas would help to sequester CO2. Four types of ions are chosen for the study: Singly charged Na+, Cl- and doubly charged Mg++ and SO4--. Such ions can be dissolved in water and introduced into the exhaust as small droplets.
Interactions between the ions and CO2 are calculated by using the DFT method with B3LYP hybrid functional and Pople type basis sets augmented with polarization and diffuse functions.
CO2 cannot interact directly with an ion due to the water molecules surrounding the ion. When CO2 is located behind a layer of water molecules, energy of the interaction between the CO2 and the ion ranges from 0.1 eV to 0.5 eV, which is significantly greater than the thermal energy of the exhaust (~0.05 eV). As expected, interaction energy is higher for doubly charged ions (0.3-0.5 eV) than for singly charged ones (0.1-0.2 eV). One can infer that triply charged ions would be even more effective than the doubly charged ones in boosting the interaction energy. Overall, ions introduced into the exhaust in small droplets can facilitate the absorption of CO2 into the droplets which can be removed from the exhaust simply by condensation. This approach would be a low cost method of reducing CO2 from transportation vehicles.
 "Monitoring CO2 Emissions from New Cars in the EU," report published by European Environmental Agency, October 2012
12:15 PM - K1.10
Long-term Storage of Solar Energy with Chemical Heat Pumps
Yannick De Decker 1
1Universitamp;#233; Libre de Bruxelles Brussels BelgiumShow Abstract
Most of the energy coming from the sun reaches homes during the summer, while the highest domestic needs typically take place during the winter months. It is thus highly desirable to develop long term (inter-seasonal) strategies to store solar energy, which could then be released on demand.
In this contribution, we show how one can use reversible endothermic chemical reactions to achieve such goal, in terms of domestic heating needs. Carefully selected, harmless chemicals can be used used together with water to ensure a total energetic autarky at the level of individual housings. The dynamics of the storage/release phases proved to be a crucial point in the development of the process, so that a detailed modelling of the reactions and transport properties in the reactor bed had to be developed. I will thus here present the global project, but willespcially insist on the criteria for the choice of reactants and the relevance of the modelling for which multiscale simulations revealed mandatory.
12:30 PM - K1.11
Analytical Model for Heat Transfer in a Finite Region of Organic Phase Change Materials
Yejun Zhu 1 Baoling Huang 1 Jingshen Wu 1
1Hong Kong University of Science and Technology Hong Kong Hong KongShow Abstract
The concept of low carbon, energy saving and sustainable design has been widely accepted all over the world. As a matter of fact, large amount energy is consumed to control the indoor environment to maintain a comfortable ambience for living and working. To increase the energy utilization efficiency, phase change material (PCM), which can store and release heat through phase change, has been recognized as an excellent candidate for green building. Analytical model is of great importance to describe and predict heat transfer with phase change. Many numerical and experimental works have been done to predict the phase change process. Explicit analytical model is much faster and more efficient, compared with simulations and experiments, in describing heat transfer with phase change. The classic Stefan problem solutions are quite suitable for crystalline materials, which require the input of phase change temperature. However, many PCMs widely used, like paraffin, are semi-crystalline polymers, which have a much larger phase changing temperature range compared with small molecule crystalline materials It is important to appropriately model the phase change of semi-crystalline polymers for the application of PCM. Furthermore, in large spatial scale prediction, the widely used semi-infinite plane model is usually quite suitable to explain initial heat transfer and predict phase change time. Unfortunately, semi-infinite plane is an ideal condition that can never be reached, which leads to large deviation between predictions and experiments on the temperature profile. In this paper, by using the temperature at the end of the phase change as the equivalent melting temperature, a heat transfer model for semi-crystalline organic PCM is constructed. Meanwhile, this model concerns the phase change in a limited region, which is explained in the form of infinite series. This model can serve as a fast tool to predict the one-dimensional heat transfer with phase change in an explicit form. The model is validated by the results of simulations and experiments reported in the literature for both melting and solidification processes. To sum up, this model reveals different stages of phase change and provides an approximate solution to evaluate phase change time for organic PCM in a clearer and faster way.
12:45 PM - K1.12
Hydrothermal Synthesis of Superparamagnetic Magnesium Ferrite Nanoadsorbent and Its Effective Arsenic (III, V) Removal Performance and Easy Magnetic Separation
Wenshu Tang 1 Qi Li 1 Yu Su 1 Shian Gao 1 Jian Ku Shang 1 2
1Institute of Metal Research, Chinese Academy of Sciences Shenyang China2University of Illinois at Urbana-Champaign Urbana USAShow Abstract
Arsenic is of serious health concern due to its toxicity and carcinogenicity. In order to minimize its health risk, the World Health Organization (WHO) set a new guideline limit of 0.01 mg/L in drinking water to replace the previous 0.05 mg/L limit in 1996 for arsenic, and this new guideline limit has been adopted by many countries. Adsorption is considered to be one of the most promising technologies for arsenic removal. In recent years, synthesized metal oxide nanoadsorbents have been extensively studied for arsenic adsorption, which demonstrated superior performance because of their large surface areas from their nano-size and preferred surface properties. However, the separation of current nanoadsorbents from treated water bodies still remains as a challenge to their potential application in real water treatment practice. The inefficient separation could cause their dispersion into the aqueous environment, resulting in the operation cost increase and potential damages to both natural organisms and the environment.
Iron oxide-based materials had been extensively studied as the arsenic adsorbents because of their low costs, high stability, environmental friendliness, and strong affinity for arsenic species. In this work, a superparamagnetic ultrafine magnesium ferrite (Mg0.27Fe2.50O4) nanoadsorbent was created by doping Mg2+ into ultrafine α-Fe2O3 nanocrystallite during the hydrothermal process. The specific surface area of Mg0.27Fe2.50O4 largely increased due to the Mg-doping, subsequently enhancing its arsenic adsorption performance on both As(III) and As(V) species compared with the ultrafine α-Fe2O3 nanoadsorbent we developed before. Furthermore, a proper amount of ~ 10% Mg-doping into iron oxide crystal lattice caused a crystal structure change from the rch α-Fe2O3 phase to a single magnesium ferrite phase with cubic spinel structure, which endowed the ultrafine Mg0.27Fe2.50O4 nanoadsorbent a superparamagnetic behavior with a high saturation magnetization. Thus, no magnetic attraction existed when there was no external magnetic field applied during the water treatment, which is beneficial to its better dispersion and the subsequent better contact efficiency with arsenic species in water. After the water treatment, however, the external magnetic field applied could induce its easy magnetic separation from treated water bodies. Then, the ultrafine Mg0.27Fe2.50O4 nanoadsorbent could be easily recovered by NaOH washing and reused for arsenic removal. With further development, this novel superparamagnetic magnesium ferrite nanoadsorbent may offer a simple single step adsorption treatment option to remove arsenic contamination from water without the pre-/post-treatment requirement for current industrial practice.