Sevim Erhan U. S. Dept. of Agriculture
Seiichiro Isobe National Food Research Institute
Manjusri Misra University of Guelph
LinShu Liu U. S. Dept. of Agriculture
Monday PM, November 30, 2009
Room 303 (Hynes)
9:30 AM - **AA1.1
Government’s Role in Supporting the Development and Use of Biobased Products.
Frank Flora 1 Show Abstract
1 ARS, USDA, Beltsville, Maryland, United States
Market drivers and projections, and policy and research challenges for non-fuel biobased products and U.S. Department of Agriculture activities supporting the development and use of these products will be reviewed, including rural development grants and loans, competitive research grants, government procurement, and relevant research activities and accomplishments by the Agricultural Research Service.
10:00 AM - **AA1.2
Winter Barley: A ``Generation 1.5” Feedstock for Sustainable Production of Fuel Ethanol and Valuable Co-products.
Kevin Hicks 1 , John Nghiem 1 , Andrew McAloon 1 , David Johnston 1 , Robert Moreau 1 Show Abstract
1 Eastern Regional Research Service, U. S. Department of Agriculture, Wyndmoor, Pennsylvania, United States
The Renewable Fuel Standard of the 2007 Energy Independence and Security Act requires the use of 36 billion gallons of renewable fuels by 2022 of which 21 billion gallons must come from non-food feedstocks. Bridging the gap from today's 1st generation corn ethanol plants to tomorrow's economically viable 2nd generation cellulosic ethanol plants is a daunting task, especially since new cellulosic ethanol plants cost 5-10 times more to build than today's corn ethanol plants. Further, the cost of producing cellulosic ethanol is estimated to be at least twice the cost of ethanol from corn starch. While there are numerous laboratory demonstrations for cellulosic ethanol production and approximately 26 demonstration/pilot plants under construction as of July 2009, no full scale (>60 million gallons per year) cellulosic ethanol plants have been built and no one has produced cellulosic ethanol at a cost that would be attractive to blenders or consumers. We are conducting research to develop a way to ease the transition to second generation biofuels by developing a "generation 1.5" ethanol process that uses winter barley (also known as "energy barley") as the feedstock. Winter barley can be grown from Pennsylvania to South Carolina as a "winter crop" that fits in well with corn and soy rotations. For instance, when corn is harvested in October of year one, winter barley can be immediately planted. This barley germinates and slowly grows through the winter. In the spring, the barley rapidly matures and can be harvested in late May or early June, allowing time for soybeans to be planted and harvested in year two. This provides a bonus crop for farmers and an ethanol feedstock that has not been produced at the expense of food or feed production. Further, since no new land (only winter fallow land) was put into production, there are no direct or indirect land use changes due to its production. Finally, growth of winter barley actually improves soil and water by acting as a winter cover crop that prevents leaching of nitrates, phosphates, and sediment into sensitive waterways, such as the Chesapeake Bay. Winter barley is therefore a win/win/win situation for farmers, ethanol producers, and the environment. Barley had not been used extensively in the US as an ethanol feedstock because of several negative issues: 1) lower starch content than corn which led to lower ethanol yields; 2) the presence of viscous beta-glucans in barley made its processing into ethanol technically difficu< and 3) the presence of beta-glucans in the ethanol coproduct, DDGS, made it unsuitable for poultry and swine diets. In this presentation, we will describe the research accomplishments of our team and key collaborators, Virginia Tech and Genencor, that have solved the problems associated with using barley as an ethanol feedstock: 1) the development of superior barley varieties and 2) the development of a new barley EDGE (Enhanced Dry Grind Ethanol) production process. Due to these efforts and to the pioneering development by Osage Bio Energy, the first new generation winter barley ethanol plant will begin production in summer of 2010. It is intended that the ethanol produced will qualify as an "advanced biofuel" with a significantly improved carbon footprint compared to gasoline. Research efforts now are being directed to producing value added food and feed coproducts from this unique feedstock which would result in a true barley biorefinery. The migration of cellulosic feedstocks into this refinery will complete the development of an environmentally and economically sustainable system for the production of biofuels and valuable coproducts. This system of using generation 1.5 feedstocks is proposed as a model that can be repeated in many other regions of the country with regionally appropriate crops.
10:30 AM - **AA1.3
Green Engineered Materials for the Renewable Energy Infrastructure.
R. Wool 1 , M. Zhan 1 , E. Senoz 1 , A. Campanella 1 , J. Stanzione 1 , S. Zero 1 , D. Branch 1 , S. Fita 1 , C. Vogelsang 1 , H. Shenton 1 Show Abstract
1 ACRES Program, Center for Composite Materials, University of Delaware, Newark, Delaware, United States
The objective of the ACRES (Affordable Composites from Renewable Resources) research is to address climate change by providing a sustainable supply of low-cost, bio-based materials for the materials-intensive renewable energy infrastructure. The ACRES objectives are in accord with the critical national goal to achieve a secure and abundant supply of sustainable energy. This research focuses on the development of bio-based materials in support of renewable energy (solar, wind, hydro) and related advanced materials technologies (especially for use in energy-efficient housing). The evolving green energy infrastructure is very material intensive. For example, the proposed Boone Pickens wind farm of 2,000 turbines in Texas will require 123 million lbs of petroleum-based plastics every 20 years (anticipated lifetime of turbine blades). The towers and engine cover nacelles will require a similar quantity of materials with a projected growth to 100 million turbines requiring about 10 billion tons of plastics. The nation’s first offshore wind farm approved in Delaware will require 27 tons of plastic per turbine. Similar wind farms are being explored by coastal states (MD, VA, NJ, RI and MA). Replacing traditional petroleum-based plastics with low-cost bio-based materials for these green energy projects will provide a drastically improved economic and environmental solution. A most significant impact on climate change will come from the solar-integrated energy-efficient new house design, (figure 1) which can be made with bio-based resins and natural fibers in a bio-foam core monolithic composite structure.Significant advances have been made in the development of bio-based composite resins for liquid molding, SMC, BMC, RTM and VARTM, natural fibers for composites and hydrogen storage, elastomers and pressure sensitive adhesives from genetically engineered oils, bio-foams (non-PU) and new fundamental theories of the glass transition and yield stress via the Twinkling Fractal Theory.
11:30 AM - **AA1.4
Economical Efficiency of a Non-catalytic Alcoholysis Process for Production of Biodiesel Fuel.
Hiroshi Nabetani 1 2 , Shoji Hagiwara 1 , Yasuomi Suzuki 1 2 , Tetsuya Araki 2 , Yasuyuki Sagara 2 , Yutaka Miyano 3 , Masahiro Tatara 3 , Masafumi Goto 3 Show Abstract
1 Food Engineering Division, National Food Research Institute, NARO, Tsukuba, Ibaraki, Japan, 2 Graduate School of Agricultural and Life Sciences, University of Tokyo, Bunkyo-ku, Tokyo, Japan, 3 Kajima Technical Research Institute, Kajima Corporation, Chofu, Tokyo, Japan
Production of biodiesel fuel (fatty acid methyl ester) by use of conventional method (alkaline catalyst method) requires deacidification process prior to the reaction and refining process to remove the catalyst after the reaction. These processes increase total cost required for production of biodiesel fuel. In order to solve the problem, authors recently proposed a method called superheated methanol vapor method. In a process with this method, superheated methanol vapor is continuously bubbled into the oil in the reactor vessel and reacted with triglycerides to form fatty acid methyl ester and glycerol. The fatty acid methyl ester and glycerol formed flows out of the reactor together with unreacted methanol vapor and is collected using a condenser. Reaction using the superheated methanol vapor method can be conducted at atmospheric pressure. Production of fatty acid methyl ester by use of the superheated methanol vapor method does not require refining process after the reaction because no catalyst is used in this method and fatty acid methyl ester can be separated from glycerol simply by sedimentation. The method does not require deacidification process prior to the reaction because not only triglyceride but also free fatty acid can be converted into fatty acid methyl ester by use of the method. Therefore, both initial and running costs required for biodiesel production are thought to be reduced by applying the method. In order to estimate the cost required by a process based on the superheated methanol vapor method, a demonstration plant (design productivity: 400 L/d) was constructed and its efficiency was evaluated. The plant could produce 425 L of fatty acid methyl ester in a day from used frying oil. Energy consumed in each unit of the demonstration plant was measured (electrical energy and thermal energy). Based on the energy consumption data obtained with the demonstration plant, production cost required with a practical scale plant (designed productivity: 6000 kL/y) was calculated. The cost required by the practical scale plant with the superheated methanol vapor method was estimated to be 40.2 yen/L (about 40 cent/L) while the cost required by a plant with the alkaline catalyst method was 62.5 yen/L (about 62 cent/L). The estimated cost includes depreciation cost, cost of repairing, labor cost, methanol cost and energy cost (heat and electricity). Most of the energy consumed by the plant was thermal energy and the plant could be automatically controlled. Therefore, required cost will be further decreased by installing the plant next to an incineration facility because thermal energy can be supplied from the facility and the labor cost can also be supported by the facility.
12:00 PM - **AA1.5
Bioethanol Production from Various Cellulosic Biomasses Using Novel Two-step Fermentation System.
Sho Shindo 1 , Takanori Nishida 1 , Sayaka Tomatsu 1 , Hayato Sugimoto 1 Show Abstract
1 , Akita Research Institute of Food and Brewing, Akita Japan
Bioethanol is an ideal fuel for transportation use since it is easily transported, charged to vehicles, and carried on board. Lignocellulosic biomass sources, such as agricultural and forestry residues, the major portion of municipal solid waste, and ultimately energy crops, have the potential to act feedstock for the sustainable production of organic liquid fuels. 7.6 million ton of forest residues were generated every year in Japan. It is thus environmentally and economically significant to consider the production of ethanol using forest residues. If forest residues could be efficiently used as raw materials for the production of bioethanol, a considerable reduction in costs would be possible. Although the discovery of xylose-fermenting yeasts has enhanced interest in the microbial conversion of renewable lignocellulosic resources to ethanol, various problems occurred in the development of an efficient fermentation: the main problem is that these yeast strains exhibit low ethanol-tolerance and low ethanol productivities from xylose, compared to those obtained from D-glucose with other microorganism. We reported that the novel bioethanol production system using immobilized Saccharomyces cerevisiae and Pichia stipitis from spent grain. However, it was difficult to produce the high concentration of ethanol because of low ethanol-tolerance of Pichia stipitis. To improve the efficiency of xylose fermentation, it is necessary to remove the ethanol from fermentation broth. Recently, we isolated the novel yeast cell (SS 2-1) from decayed wood in Japanese mountain. This strain can produce the bioethanol from xylose and glucose. This strain was identified as Pichia stipits by morphological, physiological and biochemical characterisation. We developed the novel bioethanol production system using S. cerevisiae and SS2-1 from a mixture of glucose and xylose. Firstly, mixture of glucose and xylose was fermented by S. cerevisiae. When glucose was converted ethanol completely, the fermented broth was treated by gas-stripping method using CO2 gas in order to remove the bioethanol. Secondly, the treated broth was fermented by SS2-1. When two-step fermentation system was cried out using a mixture of 140g/ L of glucose and 70 g/L of xylose, 58 g/L of ethanol was produced from glucose by S. cerevisiae. In this case, theoretical yield was 82%. Furthermore, 25 g/L of ethanol was produced from xylose by SS2-1. In this case, theoretical yield was 72%. Finally, 83.5 g/ L of bioethanol was obtained from a mixture of 140 g/ L of glucose and 70 g/L of xylose. Furthermore, Salix pet-susu was investigated using this novel ethanol production system. Saccharified-liquid was obtained by anmonia-pretreatement and cellulase treatment method and this Saccharified-liquid contained 54 g/L of glucose and 17 g/L of xylose. When ethanol production was done using novel production system, 32 g/L of ethanol was produced and theoretical yield was 87%.
12:30 PM - **AA1.6
Consolidated Bioprocessing using an Edible Mushroom.
Ryoji Mizuno 1 , Hitomi Ichinose 1 , Tomoko Maehara 1 , Koji Takabatake 2 , Satoshi Kaneko 1 Show Abstract
1 Food Biotechnology Division, National Food Research Institute, Tsukuba Japan, 2 , Forest Institute, Toyama Prefectural Agricultural, Forestry and Fisheries Research, Toyama Japan
Plant cell walls are the most abundant biomass source in nature and are of increasing importance because worldwide attention has now focused on bioethanol production to combat global warming and to safeguard global energy. Because of competition between food and fuel production, lignocelluloses are expected to be utilized for future fuel ethanol production. One of the major problems in producing ethanol from lignocellulosic biomass is the expensive production cost. Consolidated bioprocessing (CBP) is gaining recognition as a potential breakthrough for low-cost biomass processing. CBP of lignocellulose to bioethanol refers to the combination of the 4 biological events required for this conversion process (production of lignocellulose-degrading enzymes, hydrolysis of polysaccharides present in pre-treated biomass and fermentation of hexose and pentose sugars) in one reactor. However, no natural microorganism exhibits all the features desired for CBP. Basidiomycetes, also known as wood-rotting fungi, can achieve the complete breakdown of lignin, and are considered primary agents of plant litter decomposition in terrestrial ecosystems. Furthermore, some basidiomycetes produce alcohol dehydrogenase, thus allowing the production of wine using a mushroom. These properties of basidiomycetes appear suitable for use in CBP. In a preliminary study, we screened some edible mushrooms for their ability to produce ethanol and found that Flammulina velutipes is a good producer of ethanol. F. velutipes is a white-rot fungus that grows from spring through late autumn on a variety of hardwood tree stubs and dead stems and is widely distributed in temperate to subarctic regions. Currently, F. velutipes is the most produced mushroom in bed cultivation in Japan, the annual production being 130,000 tons/year. Artificial cultivation of mushrooms in polypropylene bottles is popular in Japan. F. velutipes has been characterized as wide adapted strain for various kinds of substance of artificial cultivation media, thus suggesting that the strain may be useful in the conversion of a wide variety of biomass types. Because the use of basidiomycetes for bioethanol production is not common and the ethanol fermentation abilities of basidiomycetes are not well characterized, the properties of ethanol fermentation by F. velutipes to determine its suitability for CBP will be presented.
Monday PM, November 30, 2009
Room 303 (Hynes)
2:30 PM - **AA2.1
Bioethanol Production from Rice Straw in the MAFF Research Project, Japan.
Ken Tokuyasu 1 Show Abstract
1 , National Food Research Institute, NARO, Tsukuba Japan
Bioethanol industry has been rapidly growing in both developing and developed countries, in parallel with the increase in the needs of sustainable supply of energies and materials by environmentally friendly systems. In industries, lignocellulosic biomass has been regarded as an alternative source of fermentable monosaccharides to corn starch or sugarcane juice. However, no bioethanol-production systems from lignocellulosic feedstocks can run economically independently, mainly due to a high cost for monosaccharide extraction from rigid lignocellulose, a high cost for saccharification enzymes, and inefficient fermentation of pentoses such as D-xylose and L-arabinose. From Fy07, the ministry of agriculture, forestry and fisheries, Japan (MAFF) started a five year research project named “Development of biomass conversion technologies as a way of vitalizing areas.” The ministry set two kinds of agricultural waste (rice straw, wheat straw, barley straw, etc.), as well as five herbaceous energy crops (sugar beet, potato, sorghum, sweet potato, and sugarcane) as feedstock for bioethanol production. In order to develop breakthrough methods for efficient bioethanol production without competition with food/feed production, our group has been studying a synthetic method for conversion of these herbaceous feedstocks into ethanol. Rice straw is among the most abundant herbaceous biomass in Japan and other parts in Asia, and the central feedstock for bioethanol production in Japan. In MAFF project, we found that significant amounts of soft carbohydrates (SCs), defined as carbohydrates readily recoverable by mere extraction from the biomass or brief enzymatic saccharification, exist in rice straw in the form of free glucose, free fructose, sucrose, starch, and β-1,3-1,4-glucan. Also, 75% of total SCs exist in the culms of straw from the “Leaf Star” cultivar and that the total amount of SCs in the culm was about 55% of dry weight. Taking cellulose into account, the total amount of hexose in the culm reaches 72% of the dry weight. We developed a simple method for bioethanol production from the culm, by a heat treatment for sterilization and starch gelatinization, followed by simultaneous saccharification/fermentation with Saccharomyces cerevisiae. This method would offer an efficient process for bioethanol production without the aid of harsh thermo/chemical pretreatment step.
3:00 PM - **AA2.2
A Crankcase Oil Dilution Study Using Biodiesel Fuel.
Joseph Perez 1 , Andre Boehman 2 , Peng Yu 2 Show Abstract
1 Chemical Engineering Department, The Pennsylvania State University, University Park, Pennsylvania, United States, 2 , Engineering and Material Sciences, University Park, Pennsylvania, United States
Concerns reported in the literature over the effect of crankcase oil dilution when using biodiesel fuel resulted in a 1-year study of farm tractors operating on B100 and fleet vehicles operating on B20. Infrared and viscosity test methods to track the levels of crankcase fuel dilution as a result of blow-by were developed. Samples were taken at normal engine oil change periods. Low levels of dilution were found in the study. None of the units exceeded a level of 3 %. This was attributed to the fact none of the test units had the newest emission technology requiring late injection timing.
3:30 PM - AA2.3
Enhancement of Hydrocarbon Components from Anaerobic Swine Waste using an Environmental Microbial Pre-treatment.
Justin Biffinger 1 , Cherie Ziemer 2 , Lisa Fitzgerald 1 , Aleksandra Denisin 1 , Preston Fulmer 1 , Bradley Ringeisen 1 , Barry Spargo 1 , Theodor Zainal 3 , Kurt Henry 3 Show Abstract
1 Chemistry, US Naval Research Lab, Washington , District of Columbia, United States, 2 , National Soil Tilth Lab, ARS, USDA, Ames, Iowa, United States, 3 Biological Defense Research Directorate, NMRC, Silver Spring, Maryland, United States
The microbial ecology of human and animal waste is complex because of the high diversity of bacterial species and metabolic capabilities. Research into the generation of energy from these wastes has primarily focused on gas generation (especially methane). While there is some work looking at ethanol and biodiesel production from solid wastes, little effort has focused on long-chain hydrocarbon production. There are limited options to alter undigested dietary and host excreted lipids under conditions of military diets so targeting lipids associated with bacteria in the waste gives a greater number of options. Kerosene components from swine fecal waste have been generated from four natural sources: undigested dietary lipids, host lipids excreted in feces, bacterial cell walls and products of bacterial fermentation. This presentation will describe our results in increasing the amount of aviation fuel like components from the anaerobic treatment of swine waste with environmental microbes. Our results using TGA/DSC, GC/MS, and GC/TCD demonstrate that using facultative anaerobic microbes to bioremediate fecal and urine waste will increase the energetic content of the source by at least 20% and increase the percentage of valuable alkane components with carbon chain lengths between C10-C17.
3:45 PM - AA2.4
Materials Strategy to Standardize Microbial Fuel Cell Anodes via Bacterial Cell Immobilization.
Susan Sizemore 1 3 , Heather Luckarift 1 3 , Gautum Gupta 2 , Plamen Atanassov 2 4 , Glenn Johnson 1 Show Abstract
1 Microbiology & Applied Biochemistry-Materials Research Directorate, Air Force Research Laboratory, Tyndall AFB, Florida, United States, 3 , Universal Technology Corporation, Dayton, Ohio, United States, 2 Chemical And Nuclear Engineering, University of New Mexico, Albuquerque, New Mexico, United States, 4 Center for Emerging Energy Technology, University of New Mexico, Albuquerque, New Mexico, United States
In microbial fuel cells (MFC), bacteria serve as anodic “catalysts” to yield protons and electrons from the breakdown of organic fuels. The bulk anode material serves as the electron acceptor for the bacterial anaerobic respiration. The extracellular electron transfer provides an interesting biological phenomenon as well as a key determinant for energy conversion in an MFC. The ability to interpret and predict electrochemical output from MFCs is often limited by confounding behavior of the microbes within the system. Accordingly, technology development would benefit from approaches that provide consistent catalyst loading (cell number and physiological state) and a reproducible electrochemical interface between the cells and electrodes in prototype systems. The present work aims to develop a method to encapsulate and associate bacterial cells with an electrode surface in a model MFC. The methodology is based on techniques for vapor deposition of silica for bacterial cell immobilization. The method is simple, rapid (<1 hour) and provides reproducible encapsulation of whole cells in a solid matrix that supports consistent cell loading. This approach was used to effectively encapsulate Shewanella oneidensis cells and join to a carbon cloth electrode. Encapsulated cells retained viability, evident by the metabolism of lactate and reduction of the carbon electrode when joined with the silica matrix. The open circuit potential upon startup was as high as 0.7V and the potential was sustained at approximately 0.5V under an external load for up to 5 days of continuous operation. Electrodes made in replicate experiments provided comparable electrochemical output and effectively eliminates the complications of current practices, in particular, the considerable time required for cells to establish an electrochemically active biofilm. The approach may be used to rigorously examine the effect of various materials supports and bioelectrochemical interfaces upon MFC output.
4:30 PM - AA2.5
Recyclable Biocatalysts: Enzyme Immobilization on Magnetic Nanoparticles for Cellulose Hydrolysis.
Patrick Johnson 1 , Hee Joon Park 1 , Ashley Driscoll 1 Show Abstract
1 Chemical & Petroleum Engineering, University of Wyoming, Laramie, Wyoming, United States
Cellulosic ethanol has received a lot of recent attention as an alternative transportation fuel to reduce global dependence on oil. However, due to the high cost of enzymes, the process is not currently economically feasible. Our approach is to formulate recyclable enzyme constructs by immobilizing cellulases on magnetic nanoparticles. Glucose oxidase was selected as a model enzyme to demonstrate the immobilization strategies. Three different size magnetic nanoparticles (5 nm, 25 nm and 50 nm) were fabricated to explore the effect of particle size on diffusion efficiency. Two different methods, co-precipitation and oxidation of Fe(OH)2 were used to fabricate different sizes of magnetic nanoparticles. Magnetic nanoparticles were functionalized with amine groups by 3-(amino propyl) triethoxysilane. Glutaldehyde was then used as a cross-linking agent between functionalized magnetic nanoparticles and glucose oxidase. Enzyme activity was measured by a spectrophotometer using a glucose oxidase assay kit from Megazyme. We have found that activity of glucose oxidase immobilized various size magnetic nanoparticles retained activity after more than 40 days. The analysis of transmission electron microscopy (TEM) showed that the morphology of magnetic nanoparticles was spherical and that sizes agreed with results from those of Brunauer, Emmett, Teller (BET) method analysis. The magnetic strength of nanoparticles analyzed via a Physical Properties Measurement System (PPMS) revealed that 48.5 emg g-1 (5 nm), 72.7 emu g -1 (25 nm), and 84.5 emu g-1 (50 nm) respectively. The analysis of X-ray photoelectron spectroscopy (XPS) confirmed that each step of magnetic nanoparticle surface modification and successful glucose oxidase binding. Recycling stability studies showed that only 20% of activity loss occurred during 10 consecutive recycle for large (50 nm) and medium (25 nm) size enzyme magnetic nanoparticles. We are applying the results from these model enzymes to cellulase multi-enzyme mixtures. In addition, we continue to improve the modification strategies by varying the anchor spacer arm using different lengths of biocompatible polymers such as a PEG (200, 400, 1000 MW).
4:45 PM - AA2.6
Novel Carbon MEMS Platform for Genetically Engineered Enzyme Based Implantable Biofuel Cell.
Gobind Bisht 1 , Genis Turon Teixidor 2 , Sungduk Kim 1 , Marc Madou 1 2 , Sylvia Daunert 3 Show Abstract
1 Department of Biomedical Engineering, University of California Irvine, Irvine, California, United States, 2 Department of Mechanical and Aerospace Engineering, University of California Irvine, Irvine, California, United States, 3 Department of Chemistry, University of Kentucky, Lexington, Kentucky, United States
Biofuel cells have emerged as a potential solution for powering implantable biomedical devices, but are still challenged by their low power output and short operational lifetime which is impeding their commercial adoption. The goal of our research is to integrate genetically engineered catalytic proteins .i.e., mutant enzymes, with carbon-based 3 dimensional structures based on a ubiquitous biomimetic design known as fractals. The use of biomimetic fractal structures for biofuel cell electrodes significantly increases its working surface area, thereby increasing the enzyme loading capacity, while keeping the internal resistance at a minimum. As a result, higher current densities are achieved resulting in a higher power output. The fabrication technique used is known as Carbon-MEMS and it allows for the creation of complex, high aspect-ratio geometric carbon patterns on the electrodes, with a dimensional control spanning from millimiters to nanometers. These electrodes are then derivatized with mutant enzymes (like Glucose Oxidase) that use biochemical molecules (like Glucose) found in the body as substrate. The mutant enzyme’s genetically engineered structure imparts them improved catalytic stability even under fluctuating pH and temperature conditions of a sick individual. Other advantages of mutant enzymes include higher substrate selectivity and enhanced electron exchange rates, adding to the overall improved performance of the biofuel cell. In this contribution we demonstrate that it is possible to covalently link enzymes to C-MEMS based carbon electrodes while retaining their electrochemical activity. For this purpose two approaches were used to functionalize the electrode surface and covalently bind the enzymes to it. The first approach is the activation of the carbon surface through Oxygen Plasma treatment generating hydroxyl and carboxyl motifs on the surface. These motifs provide linkage points for the enzyme molecules, through esteric and amide bonds formed between the amino acid side chains in the enzyme molecules and the motifs. The second approach is to couple the enzymes to the residual carboxylate motifs present on the electrode carbon surface through a variation of the carbodiimide reaction. Reagents namely EDC and NHS were used to activate the surface carboxylate motifs by creating an NHS ester of carboxylate, which then reacts easily with the amino acid side chains in the enzyme due to the weak nature of the NHS ester linkage. Thereafter the electrochemical activity of the covalently attached enzyme was studied through amperometry. It is found that the combination of the first and second approach for enzyme linkage yields the highest immobilization while retaining the most catalytic activity. The electron transfer efficiency of the biofuel system is then measured with free redox mediators (eg. ferrocene) and complex linked mediators. Different parameters are optimized to improve overall current density and power output.
5:00 PM - AA2.7
Molecular Simulation Evidence for Processive Motion of Trichoderma reesei Cel7A during Cellulose Depolymerization.
Xiongce Zhao 1 , Tauna Rignall 2 , Clare McCabe 2 , William Adney 3 , Michael Himmel 3 Show Abstract
1 Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States, 2 Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee, United States, 3 Chemical and Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado, United States
We present free energy calculations for the Trichoderma reesei Cel7A (cellobiohydrolase I) linker peptide from molecular dynamics simulations directed towards understanding the linker role in cellulose hydrolysis. The calculations predict an energy storage mechanism of the linker under stretching/compression that is consistent with processive depolymerization. The linker exhibits two stable states at lengths of 2.5 nm and 5.5 nm during extension/compression, with a free energy difference of 10.5 kcal/mol between the two states separated by an energy barrier. The switching between stable states supports the hypothesis that the linker peptide has the capacity to store energy in a manner similar to a spring.
Sevim Erhan U. S. Dept. of Agriculture
Seiichiro Isobe National Food Research Institute
Manjusri Misra University of Guelph
LinShu Liu U. S. Dept. of Agriculture
Tuesday AM, December 01, 2009
Room 303 (Hynes)
9:30 AM - **AA3.1
Natural Polymers in Gene Therapy Applications.
Joseph Kost 1 Show Abstract
1 Chemical Engineering, Ben-Gurion University, Beer-Sheva Israel
Gene therapy encompasses strategies to treat a disease by introducing genes into cells of an affected person. The major hurdle of these therapies is the difficulty of delivering genetic material to the nucleus of the target cell in an effective, non-toxic and non-immunogenic manner. DNA delivery systems have been classified as viral vector- mediated systems and non-viral vector-mediated systems. Non-viral systems have become increasingly desirable as such vectors should equivocate some of the problems occurring with viral vectors such as endogenous virus recombination, oncogenic effects and unexpected immune response. Although the field of non-viral gene delivery is dominated by synthetic polymeric or lipid gene carriers, natural polymers offer distinct advantages and may help advance the field of non-viral gene therapy. Most natural polymers contain reactive sites amenable for ligand conjugation, cross-linking, and other modifications that can render the polymer tailored for a range of clinical applications. Pectin for example is a structural plant polysaccharide used as a substance with a growing number of recognized pharmacological activities such as inhibition of human cancer cell growth and metastasis, and as colon-specific drug delivery system. The chemical structure of pectin contains branches, rich in galactose residues, which serve as potential ligands for membrane receptors interaction molecules. The lecture will present gene delivery systems based on quaternized polysaccharides such as starch, pectin, and chitosan which have the potential to be biocompatible, less toxic and biodegradable. The quaternization procedure, DNA complexation, as well as the main extra and intracellular transport barriers and approaches to overcome them will be discussed.
10:00 AM - **AA3.2
Renewable Resource Block Polymers.
Marc Hillmyer 1 Show Abstract
1 Chemistry, University of Minnesota, Minneapolis, Minnesota, United States
Polylactide is a renewable resource polymer currently produced on a commercial scale. The physical properties of polylactide render it attractive for a variety of packaging, biomedical, fiber and other applications. Furthermore, it is a compostable material thus enhancing its environmental appeal. However, polylactide exhibits modest impact strength, an attribute that has limited broader utilization of this thermoplastic. Several blending strategies have been reported for the generation of toughened polylactides with varying degrees of success. In this presentation I will discuss our recent efforts in developing new polylactide block and graft polymers for the purposes of increasing the toughness of this aliphatic polyester while retaining a high level of renewable content.
10:30 AM - **AA3.3
Novel Green Composites from Low Cost Filler and Lignin.
Amar Mohanty 1 2 , Saswata Sahoo 1 , Manjusri Misra 1 2 Show Abstract
1 Bioproducts Discovery and Development Center, Department of Plant Agriculture, University of Guelph, Guelph, Ontario, Canada, 2 School of Engineering, University of Guelph, Guelph, Ontario, Canada
Lignin is a byproduct/co-product produced in a huge amount from paper industries and bioethanol industries. Currently, Lignin is mainly used as fuel for boilers with a very negligible percentage utilized for chemical recovery, agriculture and value added material applications. In the present study, Green composites were fabricated from engineered lignin, switch grass fiber and a biopolymer using twin screw extruder followed by injection moulding. 1% newly discovered compatibilizer with active functionality was used to improve the performance of composites. Different formulations i.e. with varying lignin content (30%, 50%, and 65%), biomass-lignin hybridization (50% filler content) and compatibiliized composites were made to evaluate the desired material properties for specific applications. The specimens were characterized through dynamic mechanical analysis (DMA), tensile and flexural tests. Incorporation of lignin improved the tensile, flexural, thermo mechanical properties of composites. Biomass-lignin hybridization with 1 wt% compatibilizer improved the flexural strength by 165%, storage modulus by 480% and heat deflection temperature (97.5 0C) by 26 0C. Compatibilized hybrid composite achieved flexural strength of 75 MPa.
11:30 AM - **AA3.4
Challenges and Developments in Renewable Biomaterials for Food Packaging Applications.
Kit Yam 1 Show Abstract
1 SEBS-Food Science, Rutgers University, New Brunswick, New Jersey, United States
A major application for renewable biomaterials is in food packaging, since packaged foods are consumed in large quantities all over the world. First, the basic functions of the food package will be reviewed for the purpose of defining the requirements of biomaterials for food packaging materials. Next, examples of recent developments in functional packaging materials using biomaterials will be presented. Finally, the challenges of developing biomaterials that satisfy the criteria of sustainable packaging will be discussed.
12:00 PM - **AA3.5
Poly(lactic acid) and its Blends with Biobased Polymers and Nano Particles.
Xiuzhi Sun 1 Show Abstract
1 Grain Science and Industry, Kansas State University, Manhattan, Kansas, United States
Poly(lactic acid)(PLA) has been considered as one of the promising biodegradable polyesters for various applications. This paper discusses research efforts towards improvement of PLA’s brittleness and limited thermal stability by incorporating naturally occurring biopolymers (i.e., starch, protein, wood fibers) and nano particles (i.e., nano crystals). Blended with either starch or protein, PLA serves as the matrix, and biobased polymers are the filler. The thermal transition behaviors of the PLA blends are similar to that of extruded pure PLA indicating that the thermal transition of the blends mainly results from the PLA. PLA is often not compatible with these biomacromolecules, resulting in poor mechanical properties, especially at higher loading rate (i.e., 25-50%). A small amount of coupling reagents has to be used to improve compatibility of PLA and these large molecules. Nano particles at small loading levels are also used to improve PLA properties either by melt compounding or in-situ synthesis during polymerization. In this paper, particularly, functionalized magnesium oxide (CP-MgO) was used as a nanofiller by both melt compounding and condensation polymerization methods. Mechanical, thermal, and morphological properties of PLA and its blends and nanocomposites will be discussed during presentation.
Tuesday PM, December 01, 2009
Room 303 (Hynes)
2:30 PM - AA4.1
Design and Development of Biodegradable Sapling Pot with Biodegradable Polymer and Biomass.
Seiichiro Isobe 1 , Itaru Sotome 1 , Hiroshi Okatome 1 , Masaru Wakisaka 2 , Yoshinubu Ueki 2 Show Abstract
1 , National Food Research Institute, Tsukuba, Ibaraki, Japan, 2 , Nara Fruit Tree Research Center, Gojo, Nara, Japan
To make molded products from Corn Gluten Meal based agro by-products by the injection molding system was carried out jointly with Showa Sangyo Co. and The Japan Steel Works. In this process, we were able to successfully reduce costs and to obtain solid molded products for practical use by adopting the injection molding method, which has many advantages in productivity (low costs, high moldability and flexibility to make various shapes of molds). At present, we are working to assess the biodegradable molded products actually applied and to improve products for different purposes. This time, we introduce one application for Fruit tree cultivation system to use biodegradable sapling pot. We expect when the biodegradable sapling pot would be used, the farmer feed the sapling with its pot at the cultivation field. That means the steps of cultivation process may be reduced. Such application will be addressed in our talk and general situation of biodegradable products by biomass resources in Japan will be also introduced.Persimmon saplings are used as the sample of the Fruit tree sapling. At first, small size pot (pellet weight ca.30g) are made by CGM (Corn gluten meal) , rice husk flour(as filler) and starch (as plastisizer) . The effect for the plant growth is not clear, in other words, this pot is acceptable for persimmon sapling. However, the fruit tree saplings usually are kept in the pot more than half year. Those pot could not keep physical stable condition such long time. So, you made new pot using PLA (polylactic acid) or PBSA (Poly butylenes succinate adipate) instead of CGM. This pot could keep more than one year. The disadvantage for the plant growth was not founded. So, we tried to make large size pot (pellet weight ca.250g, height 180mm, diameter (top 180mm, bottom 120mm)) to test into the field using the persimmon sapling at Nara Fruit Tree Research. At first, we design new mold and then the large pots were injected with the different ingredients (PLA or PBSA, several condition of blend ration among polymer, filler (Rice husk flour) and plastisizer (starch)).The large pots were injected with PBSA 50%, Rice husk flour 30% and Starch 20%. The mold operation condition is as follows. The screw temp is 160C. And the Cycle time, feeding time, 6.5sec and Injection pressure, were set 5.4sec, 6.5sec and 120MPa respectively. Under this condition, the injection process is very stable. The Corn gluten meal based large pot was biodegraded within 3 months. And Corn Zein which was one kind of the corn maize protein contained in CGM could be used for the biodegradable material which has high mechanical properties and long stability. However, the cost of refining process of this protein is very high under current situation. So, PBSA based biodegradable pot was selected for the practical test sample.
2:45 PM - AA4.2
Hydrothermal Carbonization of Plant Material: A Route to Nanostructured Carbonaceous Materials and an Efficient Chemical Process to Treat the CO2 Problem.
Magdalena Titirici 1 , Jelena Popovic 1 , Fernando Perez 1 , Markus Antonietti 1 Show Abstract
1 Colloids, Max-Planck Institute for Colloids and Interfaces, Potsdam Germany
The search for meaningful ways to transfer biomass into useful materials, more efficient energy carriers, and/or carbon storage deposits is a key question of our days. Transfer of biomass toward carbon-rich materials with potential large scale application is an option to sequester carbon from plant material, taking it out of the short-term carbon cycle and therefore binding CO2 efficiently and in a useful way. Carbonaceous materials can be produced using hydrothermal carbonization, which is now already a well-established method to create hydrophilic carbon materials starting from water soluble carbohydrates. Since nature produces the vast amount of 170 billion tons of biomass per year by photosynthesis, 75% of which can be assigned to the class of carbohydrates, this can be easily converted into a coal-like materials using hydrothermal carbonization. Hydrothermal carbonization is therefore an alternative and simple option to use wet, low-value biomass, leading to hard carbonaceous products, with the majority of original carbon being sequestered in the solid. A key feature is not only the occurrence of carbonization in itself but also the appearance as useful nanostructures with an appropriate surface chemistry. References:M.M Titirici, A.Thomas, M Antonietti, New J. Chem., 2007, 31, 787–789 M.M. Titirici, A. Thomas, S.H Yu, J.O. Muller, M. Antonietti, Chem. Mater. 2007, 19, 4205-4212
3:00 PM - AA4.3
Carbon Nanospheres Fabricated by Pyrolysis of Micelles formed in Pectin Gels.
Peter Wong 1 , Brendan O'Brien 1 , Bruce Panilaitis 2 Show Abstract
1 Mechanical Engineering, Tufts University, Medford, Massachusetts, United States, 2 Biomedical Engineering, Tufts University, Medfors, Massachusetts, United States
Since the discovery of carbon nanotubes in 1991, there is an ongoing race towards more cost effective and reliable means of its production. The formation of nanospheres is typically relegated to two costly methods. Chemical vapor deposition produces uniform spheres safely anchored to a substrate but at the cost of being slow and expensive to run. Arc discharge of a carbon target produces soot containing a low density of random spheres that must be laboriously sorted. An alternative approach is to fabricate carbon nanospheres through the pyrolysis of micelles, an arrangement of molecules comprised of a hydrophobic tail and a hydrophilic head that coalesce as spheres in aqueous solutions. Other researchers show pyrolysis on core cross-linked diblock copolymer micelles. In this case polyethylene oxide (hydrophilic) is cross-linked to polyethynylstyrene (hydrophobic) and put in water.Our research focuses on fabricating carbon nanospheres by pyrolysis of micelles in polysaccharide gels. The polysaccharide gel, commonly known as fruit jelly, is formed through the activation of gel-formation process with pectin, acidic aqueous solution (e.g., fruit juice), and sucrose (or dextrose). Pectin reaches its optimal gelling ability at pH values between 2.8 and 3.6. We propose that micelles form in the gels, and the sucrose and dextrose act as the hydrophilic heads and the pectin becomes weakly hydrophobic tails of micelles. These micelles in the gel can be pyrolysized into carbon nanospheres. Pyrolysis conditions are an inert atmosphere of nitrogen at 5000C for 2 hours. SEM images of the surface of the processed materials consistently show spheres in the range of 30 to 80 nm. The research focuses on augmenting micelle production via the introduction of lipids, naturally hydrophobic molecules. Test runs with concentrations of peanut oil at 0.5 %wt, 1 %wt, and 2 %wt show that the ensuing nanostructures are not spherical or uniform. Mineral oil tests do not show improvements as well. Also, trace amounts of lipids that naturally occur in fruit juice are found to have an insubstantial effect on the presence of nanospheres. This was established by creating gels made from sucrose and water that is pH corrected through the use of acetic or ascorbic acid are able to recreate the same nanospheres. Thus, formation of pectin-sucrose structures into micelles appears to be the main source for spherical shapes in the gel. Studies are on-going to pinpoint the mechanism for the nanosphere formation. B.J. Kim, J.Y. Chang, Macromolec. 39, 90 (2006).
3:15 PM - AA4.4
Multi-functional, Biopolymer and Biocomposite Foams Manufactured by Freeze-casting.
Amalie Oroho 1 , Philipp Hunger 1 , Ulrike G. Wegst 1 , Lars Berglund 2 Show Abstract
1 , Drexel University, Philadelphia, Pennsylvania, United States, 2 , Royal Institute of Technology, Stockhom Sweden
Trees are a city’s lungs: they absorb carbon dioxide and produce oxygen. While doing so, they also reduce urban heat island effects, serve as noise barriers, reduce stormwater, and create local “third places,” neither home nor work, encouraging street life that is even believed to lower inner city crime. However, densely populated areas lack the physical space for urban forestry. Here, the introduction of green roofs and green walls, or vertical gardens, can achieve the same effect, both out- and indoors. To construct such green spaces, porous multifunctional materials are needed that ideally act as substrates for plants and as systems for rainwater filtration and retention. One process with which it is possible to manufacture such multifunctional materials from widely abundant, renewable resources such as biopolymers and natural fibers is freeze-casting. It utilizes the intricate process of ice formation to create hybrid materials with complex structures. These constructs can be functionalized and optimized to achieve desired features and unique combinations of mechanical properties, which derive from an architectural design that spans from nanoscale to macroscopic dimensions. First results show that both strength and toughness of freeze-cast biopolymer and biopolymer-based hybrid materials increase in a non-additive manner that goes well beyond the simple “rule of mixture” for composites, allowing for high porosity (>90%) and surface area to be created while ensuring structural integrity. Using sustainable materials such as chitin, chitosan, and cellulose as raw materials and an environmentally-benign processing technique (water-based freeze-casting), we are able to minimize the environmental impact of a construction material that can be used for green-roof and vertical garden fabrication. This construction material will further contribute to sustainability by reducing the energy consumption of a building. Year round, the multifunctional, biopolymer-based green skin of the building will enhance thermal insulation, improve air quality, lower noise pollution, and provide a calming environment with the aesthetic appeal of a garden, or even sculpted artwork.
4:00 PM - AA4.5
Hydrothermal Carbon from Biomass: Recent Advances in Synthesis, One Pot Functionalization and Fine Structure Resolution by 13C Solid State NMR.
Niki Baccile 1 , Florence Babonneau 1 , Guillaume Laurent 1 , Magdalena Titirici 2 , Markus Antonietti 2 Show Abstract
1 LCMCP, CNRS-UPMC, Paris France, 2 Colloid and Interfaces, Max-Planck Institut, Golm Germany
Carbon-based materials have been used so far for a number of applications ranging from adsorbents to catalyst supports or electrode materials according to their structural features (amorphous, graphitic), surface areas and surface functionalities. Costs of production, though, may be important due to the methods employed; for instance, in the case of activated carbon, high temperatures are needed while when ordered mesopority is the final goal, back-copy of classical silica SBA-15 structure is the main approach. Although obtaining a long-range structured porous network is of primary importance, we estimate that knowledge over the synthesis procedure, functionalization and refinement of the structure of amorphous carbon itself is of primary importance, as well.In this study we show how the synthesis of carbon material can be performed under mild conditions (T= 180°C in water) using biomass (mono and polysaccharides) as starting material[1,2]. This process being known, our contribution went much further both in the one-pot introduction of chemical functions (-COOH, -NHx (x=0-2), CHO) and using naturally functionalized biomass like chitosan or proteins, reduction from micron to nm-sized particles, and in the understanding of the bulk carbon structure by mean of advanced 13C solid-state NMR techniques using isotopic enrichment as a preferred tool to gain in detection sensitivity. An advanced 13C NMR study goes through a first step of peak attribution (1 to 6) and finally the use of pulse sequences based on through-space dipolar coupling and double quantum excitation/reconversion steps . This allows a clear identification of carbon-carbon proximities below 3Å in spatial range. The possibility of direct carbon functionalization and the knowledge of its fine structure should open new possibilities in controlling the structure/properties balance.1 M.-M. Titirici, A. Thomas, S.-H. Yu, J.-O. Muller, M. Antonietti, Chem. Mater. 2007, 19, 42052 M.-M. Titirici, M. Antonietti, N. Baccile, Green Chem., 2008, 11,12042 N. Baccile, G. Laurent, F. Babonneau, F. Fayon, M.-M. Titirici, M. Antonietti J. Phys. Chem. C, 2009, 113, 9644
4:15 PM - AA4.6
X-ray Tomographic Characterization of Natural Polymer Nanocomposites and Correlation of Bulk Mechanical Properties.
Anahita Pakzad 1 , Paul Mainwaring 2 , Patricia Heiden 3 , John Simonsen 4 , Reza Shahbazian Yassar 1 Show Abstract
1 Mechanical Engineering- Engineering Mechanics, Michigan Technological University, Houghton, Michigan, United States, 2 , Gatan Inc, Pleasanton, California, United States, 3 Chemistry Department, Michigan Technological University, Houghton, Michigan, United States, 4 College of Forestry, Oregon State University, Corvallis, Oregon, United States
Mechanical properties of nanocomposites are directly affected by the formation of a continuous 3D network of nanostructures. Along with high specific area, cellulose nanocrystals (CNXL) possess hydroxyl groups on their surface which make their uniform dispersion in polymer matrices even more challenging. Thus, improvements in the characterization of their dispersion will ultimately lead to improved mechanical properties. This research used, for the first time, a new technique involving X-ray ultramicroscopy (XuM) and tomography in the scanning electron microscope. This allows imaging of the 3D internal structure of composites. In this study the mechanical properties of cellulose-polymer nanocomposites are evaluated using nanoindentation and a one-to-one correlation with their 3D internal structure can be made. The XuM technique used in this study is a new tool in the polymer scientist’s toolbox which allows the imaging of materials in bulk rather than on the surface or in small volumes, and leads to better understanding of their material behavior.
4:30 PM - AA4.7
Three-Dimensional Molecular Imaging of Lignocellulosic Materials by Confocal Raman Microscopy.
Liqiang Chu 1 2 , Rachel Masyuko 1 2 , Jonathan Sweedler 3 4 , Paul Bohn 1 2 Show Abstract
1 Department of Chemical and Biomolecular Engineering , University of Notre Dame, Notre Dame, Indiana, United States, 2 Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, United States, 3 Department of Chemistry , University of Illinois at Urbana-Champaign, Urbana, Illinois, United States, 4 Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States
The ability to efficiency use lignocellulosic materials (LCMs) to feed the biorefinery of the future depends on high-efficiency pre-enzymatic processing to render lignin separable from cellulose/hemicelluloses.[1, 2] The complex 3-D network structure and chemical characteristics of LCMs pose daunting challenges for imaging and molecular characterization: (1) they are opaque and highly scattering; (2) their chemical composition is a spatially variegated mixture of heteropolymers; (3) the nature of the matrix evolves in time during processing. Presently, there are few in situ characterization tools that can be applied to materials with these characteristics, especially during processing—yet acquiring this information is of paramount importance. Here we present the use of confocal Raman microscopy to investigate the structural and chemical changes upon NaOH treatment in a model LCM, Miscanthus x giganteus, a tall perennial grass and a potential energy crop for conversion to either fuel or chemicals. Longitudinal and transversal-section images of raw miscanthus samples reveal that lignin and cellulose are collocated in the cell wall and that a globular structure, composed predominantly of hemicellulose and lignin is associated with the interior cell wall. NaOH treatment results in the complete removal of lignin at long processing times, but does not disturb the cellulose as shown by the lack of conversion from type I to type II cellulose. Depth profiling images of partially processed (short time) parenchyma cells reveals that lignin is removed preferentially from the interior surface of the cell wall as indicated by the spatially anisotropic distribution of lignin and cellulose across the cell wall. Besides the parenchyma cells, we are currently investigating other types of plant cells, and we are correlating these confocal Raman results with mass spectrometric imaging. Together these studies promise to provide a much more complete picture of the effects of alkaline treatment on miscanthus. References1.Hendriks, A.; Zeeman, G., Bioresource Technology 2009, 100, (1), 10-18.2.Mosier, N.; Wyman, C.; Dale, B.; Elander, R.; Lee, Y. Y.; Holtzapple, M.; Ladisch, M., Bioresource Technology 2005, 96, (6), 673-686.3.Michel, R.; Mischler, N.; Azambre, B.; Finqueneisel, G.; Machnikowski, J.; Rutkowski, P.; Zimny, T.; Weber, J. V., Environmental Chemistry Letters 2006, 4, (4), 185-189.
4:45 PM - AA4.8
Potential Energy Surface Calculations of Alanine Dipeptide using BVWN Density Functional Approach and 6-311G Basis Set.
Subhash Singh 2 , Jyoti Singh 1 , Ashish Khare 1 Show Abstract
2 Physics, Laser Spectroscopy & Nanoamterials Lab, University of Allahabad, , Allahabad India, 1 Computer Science, J.K. Institute of Applied Physics and Technology, University of Allahabad, , Allahabad India
Proteins consist of amino acids whose number may vary in the range from hundreds up to tens of thousands. Small fragments of proteins are usually called polypeptide chains or polypeptides. This work is devoted to a study of the conformational properties of alanine dipeptide. We have studied potential energy surfaces of alanine dipeptide molecule using density functional theoretical approach using 6-311G basis set. For this purpose potential energies of this molecule are calculated as a function of Ramachandran angles phi (φ) and shi(ψ), which are important factors for the characterizations of polypeptide chains. These degrees of freedoms phi (φ) and shi(ψ) are important for the characterization of protein folding systems. Stable conformations, energy barriers and reaction coordinates of this important dipeptide molecule are calculated. Energy required for the transition of one conformation into other are calculated. The obtained results are compared with the results obtained from other theoretical and experimental methods. Vibrational frequencies, mulliken charges, dipole moments etc. for these conformations are also extracted.
Sevim Erhan U. S. Dept. of Agriculture
Seiichiro Isobe National Food Research Institute
Manjusri Misra University of Guelph
LinShu Liu U. S. Dept. of Agriculture
Wednesday AM, December 02, 2009
Room 303 (Hynes)
9:30 AM - **AA5.1
Synthesis of Rosin-based Epoxies and Curing Agents and Properties of the Cured Resin Systems.
Jinwen Zhang 1 Show Abstract
1 Composite Materials and Engineering Center, Washington State University, Pullman, Washington, United States
In recent years, we have conducted a series of investigations using the fused ring structure of rosin acids as a rigid building block in the syntheses of epoxies and curing agents and achieved fruitful results on design of molecular structure, synthesis methods, curing kinetics and properties of the cured resins. Rosin is an abundantly available natural product from either the exudate of pines and conifers or the byproduct of the Kraft pulp process. Rosin is a mixture of acidic (ca. 90%) and neutral (ca. 10%) compounds. The acidic components, generally named rosin acids, are also a mixture consisting mainly of isomeric abietic-type acids (40 – 60%) and pimaric-type acids. The characteristic hydrogenated phenanthrene nucleus of rosin acids is analogous to that of petroleum-based aromatic and cycloaliphatic compounds in rigidity. In our study, rosin acid derivatives were used in the places of aromatic or cycloalipahtic monomers for the synthesis of epoxies and curing agents. The curing reactions, curing behavior of rosin-based epoxies and curatives were assessed and compared with that of commercial epoxy systems. Mechanical, dynamic mechanical properties and thermal stability of the cured epoxies were also investigated. By manipulating the molecular rigidity of the epoxies or curing agents with the introduction of soft spacer segments or rigid imide groups, the cured epoxy resins exhibited a broad spectrum of mechanical properties ranging from flexible to rigid. The results suggest that rosin derivatives can be important alternatives to current aromatic and cycloaliphatic monomers in the synthesis of epoxies and curatives.
10:00 AM - **AA5.2
Degradation of Plant Cell Wall Protopectin with Acid Catalyst.
Juraboy Khalikov 1 , Zayniddin Muhidinov 1 Show Abstract
1 , Chemistry Institute, Dushnabe, Dushnabe, Tajikistan
Results of studies on protopectin (PP) acid hydrolysis of an apple, an orange and the sunflower head residue are generalized in concept of network polymer degradation, as the sets of parallel and consecutive chemical reactions occurring in heterogeneous system. The obtained products by traditionally hydrolysis methods and at flash extractor were identified by means of centrifugation refer as microgel (MG), alcohol insoluble materials as pectin substances (PS) and alcohol soluble materials as oligosaccharides (OS). The key parameters of pectin macromolecules: anhydro galacturonic acid (AGA) content, degree of methyl esterification and calcium ions contents were studied. It is observed that these parameters and calcium ions content were changed extremely in the MG during hydrolysis time. A distinguishing feature of this process is the peak in the change of MG content in the hydrolysate. It can also be seen that the contents of PS and OS gradually increase with increasing hydrolysis time whereas the cellular PP decreases to zero. The results can be explained by assuming that the monosaccharide units from chains of PP and its decomposition products redistribute after hydrolysis into the observed fractions according to the reaction sequence. Considering this sequence, the data were processed using equations derived for describing the kinetics of a sequential first-order reaction at the maximal content of monosaccharide in MG, and reaction time at which the monosaccharide in MG reaches a maximum, and at the initial monosaccharide content in the PP. A value of r that satisfies that equations was selected using experimental values of wmax, tmax, by computer software. These processes cause the GA content in the MG to be stabilized and reach >80% if the process is carried out for about one hour. The degree of GA esterification also remains unchanged, up to 52-57%. It is shown, that calcium ions may play an important role in stabilization of MG structure in the cell wall. The elimination of these ions from a polymer network by preliminary processing, using solutions of a hydrochloric acid, sodium hexamethphospahe, sodium chloride lead to essentially change both in structure, and quality of PP degradation products. Obtained data show, that during preliminary processing a MG matrix produce a number of polysaccharide with less branched and linear structure.For the improvement of PS extraction from hydrolyzate solution there a dia-ultrafiltration methods of polymer purification and concentration were applied to produce a highly quality and low cost pectin.
10:30 AM - **AA5.3
Influence of Hydrolysis Time on the Quality of Pectin Obtained by Flash Extraction.
Saodat Khalikova 1 , Raisa Gorshkova 1 , Zayniddin Muhidinov 1 Show Abstract
1 , Chemistry Institute, Dushnabe, Dushnabe, Tajikistan
To obtain high quality pectin we have applied method of flash extraction in the autoclave. Raw swelled apple pomace and sunflower head residue in acidic solution (1:20 w/w) was undergo hydrolysis in the flash extractor at the 120oC, 1,5 bar (30 psi) for the 3, 5, 7 and 10 min. The pressure was controlled automatically by steam generator (MBA 20D, USA). The pectin solution was cooled by ice containing plastic bottles, was centrifuged and isolated from hydrolisate solution by alcohol precipitation. For each hydrolysis time (3, 5, 7, 10 minutes) pectin main characteristics- AGA content, DE and molecular parameters were determined. Resulted data shows that during the hydrolysis time from 3 to 10 min quantity of MG fraction markedly decreased, while pectin and oligosaccharides fraction increased. The AGA of isolated pectins increased from 68 to 74% with increasing hydrolysis duration, while pectin’s DE reduced negligible from 54.3 to 50.5%. Those facts: enhance of AGS and yield of pure pectins indicating that neutral sugar side chains of apple pectin more labile then sunflower pectins due to structural configuration of these polysaccharides and removed from pectin main chain by acidic treatments. The molecular masses and molecular weight distribution (MWD) of pectins were analyzed by the HPSEC method with the aid of a Waters HPSEC delivery system coupled with a ViscoStar detector. Values of molar mass were obtained using universal calibration. The specific viscosity versus eluted volume chromatograms for the 3-7 min hydrolysis time observed as monomodal and very broad distribution of molecular weight. Flash method of hydrolysis allows isolating native and high molecular (1600-4200KD) pectins at low hydrolysis time in comparison with traditionally method, but the samples were polydispers (Mw/Mn=57-102). In comparison with sunflower raw materials the apple cell walls have less resistance to pressure and temperature treatment, where pectin extracted easily. The increasing of hydrolysis time to 10 min lead to the degradation of highly branched pectin molecules in hydrolisate solution and molecular chain became monomodal with narrow distribution (Mw/Mn=1,5-7,3). Thus the optimum time for hydrolysis for both apple and sunflower pectins have been established 7-10 min. The flash extraction method shows a number of advantages against traditionally hydrolysis methods. Moreover, as our experience shows, the optimization for the condition of hydrolysis for pectin contain raw material depend also on many different parameters like ripeness of fruits, location of grows, duration of juice making process and the conditions for raw material storage, which need to take into consideration at pectin production.
11:30 AM - **AA5.4
Development of Biodegradable Materials from Food By-products.
Tomoyuki Yoshino 1 , Seiichiro Isobe 2 Show Abstract
1 , Prefectural University of Hiroshima, Shobara, Hiroshima, Japan, 2 , National Food Research Institute, Tsukuba, Ibaraki, Japan
Biodegradable materials made of natural resources have attracted worldwide interest and a desire to expand their non-food use, partially due to their low cost. Therefore, zein or water insoluble corn prolamin provides an alternative to a production of biodegradable materials. This natural protein is contained in gluten meal, and is produced as a by-product of the wet-milling starch making process. In this study, we produced the zein film, and used a variety of controlled drying conditions and production methods. Then, some physical mechanical properties, the tensile strength, the contact angle and gas permeability were measured, and an atomic force microscope was used to obtain an image of the surface structure of the zein film. One gram of purified zein powder was dissolved in 10 mL of 80% ethanol or 70% acetone and heated at 50 degrees celsius for 10 minutes. The film was cast by pouring the 10 mL of the zein solution onto a level 200 square centimeter smooth polyethylene sheet using an auto casting machine, and allowed to dry for 5 hours at temperatures ranging from 30 to 45 degrees celsius and between 5 and 90% relative humidity in an controlled environmental chamber. The resultant film could be peeled intact from the casting surface. After drying, the films were kept at the same relative humidity used during the film preparation and at room temperature. The tensile strength of the zein film was between 7 and 30 MPa. We found a correlation between the surface structure and the contact angle of the zein film. The surface morphology was found to depend upon the drying conditions. The films with projections smaller than 200 nm in base diameter on the surface had a high contact angle (>70 °). Thermal elongation temperature of the films was between 167.0 and 172.7 degrees celsius. Oxygen and carbon dioxide permeability of the zein film have a selective gas permeability that depends on drying conditions, especially relative humidity. By finding relationships between the mechanism of gas permeability and the drying conditions, the zein film may be formed with advantageous physical properties. According to the results of this study, the relationship between the physical mechanical properties and preparation methods of the zein film are as follows. The transparent zein films were made from zein in organic solutions. We found that the physical mechanical properties of the zein film depended on the drying rate during preparation. Our hypothesis is that the difference in physical mechanical properties of the different zein film was caused by a variation in the internal microstructure of the zein film. We expect that it will be possible to make zein film with various useful physical mechanical properties by using controlled drying conditions.
12:00 PM - AA5.5
Hybrid Composite from Wood Fiber, Talc and Polyhydroxybutyrate-co-valerate (PHBV) Bioplastic: A New Opportunity for the Green Materials World.
Manjusri Misra 1 2 , Sanjeev Singh 2 , Amar Mohanty 1 2 Show Abstract
1 School of Engineering, University of Guelph, Guelph, Ontario, Canada, 2 Bioproducts Discovery and Development Centre, Department of Plan Agriculture, University of Guelph, Guelph, Ontario, Canada
This research describes the development of hybrid composites from wood fiber, talc and a bioplastic i.e., polyhydroxybutyrate-co-valerate (PHBV) using the extrusion-injection molding technique. Significant improvements in the mechanical characteristics of the composites were obtained with the reinforcement of micro sized talc. The hybrid green composites depicted a manifest leap of more than 200% in flexural modulus with the dual reinforcement of 20 wt% of talc and 20 wt% of wood fiber in PHBV matrix, and 270% in talc filled PHBV. A theoretical reasoning, based on the surface energy parameters of the interacting components in the composite, is elaborated to explain the reinforcing effect of talc and wood fiber. The Morphological analysis of the hybrid composite was carried out using the scanning electron microscopy (SEM) to study the interfacial interactions among the different components in the hybrid composite. The Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) for the 2008 Alternative Renewable Fuels Research and Development Fund Project ARF24 and USDA-CSREES under the McIntire-Stennis program for the financial supports.
Wednesday PM, December 02, 2009
Room 303 (Hynes)
2:30 PM - **AA6.1
Coextrusion of Poly(lactic acid) and Nisaplin® in the Presence of Plasticizers: Preparation, Physical Characterization and Evaluation of Microbial Activity.
LinShu Liu 1 , Tony Jin 1 , David Coffin 1 , Kevin Hicks 1 Show Abstract
1 , USDA-ARS-ERRC, Wyndmoor, Pennsylvania, United States
Nisin, a natural antimicrobial polypeptide, is frequently used in food and food packaging. It is deactivated above 120oC. Poly(lactic acid) (PLA) is a biodegradable thermoplastic with great potential for food packaging applications. The high melt temperature of PLA (>150oC) could make it difficult to incorporate nisin. However, successful incorporation of nisin is possible using plasticizers such as lactic acid, lactide, or glycerol triacetate and careful control of extrusion conditions.Nisin, in the form of Nisaplin®, was blended into PLA by co-extrusion using a bench top micro extruder. PLA and most of the plasticizer were blended together and introduced into the extruder barrel with the temperature set to 160oC and the unit in recycle mode. After the PLA was melted the temperature was set to 120oC. When this temperature was reached, Nisaplin® and the remaining plasticizer were added. Mixing in recycle mode continued for a designated time, and the blend was extruded in the form of ribbons and collected. In some samples pore forming reagents such as salt, sugar, or vitamin C were added with the PLA and plasticizer.Molecular weight of PLA in the extrudates was determined by gel permeation chromatography. Values for thermal transitions were determined using DSC, and the mechanical properties were determined using a tensile tester. Morphology of the materials was investigated using SEM. An agar diffusion assay was used to determine the capability of the Nisaplin® containing materials to inhibit the growth of the pathogenic bacteria L. monocytogenes Scott A 724. The plasticized blends could be extruded at a barrel temperature of 120oC, although there was a limited time window where this was possible. The samples showed a small decrease in molecular weight after extrusion, particularly with lactic acid as the plasticizer. Melting and glass transition temperatures for the blends were lowered relative to pure PLA. Incorporation of lactic acid or lactide tended to reduce tensile strength and modulus, but had little effect on elongation, as did glycerol triacetate. Pore forming reagents also had an effect. PLA/plasticizer blends showed a smooth, homogeneous morphology. Use of pore-forming reagents led to a heterogeneous craggy morphology on the fracture surfaces, and a pore structure was clearly visible. No antimicrobial activity was seen with neat PLA or with a PLA/Nisaplin® blend extruded at 160oC . However the blends containing Nisaplin® which were extruded at 120oC all showed significant antimicrobial activity, and they prevented bacterial recovery after culture for 24 and 48 hours. These results show that membranes of PLA and Nisaplin® were prepared by co-extrusion at 120oC without losing bioactivity. The resulting membranes have mechanical properties comparable to petroleum based thermoplastics. Inclusion of pore forming reagents accelerates biocide release, and improves antimicrobial activity.
3:00 PM - AA6.2
Viscoelastic Creep from Interfacial Effects in Bio-based Composites.
Peter Johnson 1 , Christopher Stafford 1 Show Abstract
1 Polymers Division, National Institute of Standards and Technology, Gaithersburg, Maryland, United States
The long-term performance and stability of biocomposites made from renewable feedstocks will be largely dependent on the inherent viscoelastic relaxation processes of the material. When the biomaterial is reinforcing the matrix, surface treatments are used to enhance interfacial adhesion and the overall properties of the composite, but the level of enhancement from a surface treatment is difficult to predict. These relaxations are controlled not only by the polymer network structure but also the local dynamics of the material that occur over a wide spectrum of time scales. While we can probe the dynamics of bulk materials, it is difficult to measure the contributions from buried interfaces, as found in composites. As the particle/fiber size becomes smaller and the loading increases, the interfacial contributions begin to dominate the viscoelastic material response. Furthermore, the role of these interfaces becomes even more important as the material degrades or is recycled.In this work, we create model (confined) material systems with controlled chemical interfaces and then use a high-throughput indentation technique to measure viscoelastic responses. While the viscoelastic relaxations of the confined polymer film are equivalent to the bulk response, the local dynamics at the interface alter the stress relaxations underneath the indenter and resulting deformation profile over time. Viscoelastic indentation measurements of confined films with different chemical interfaces were compared to slip and no-slip adhesion conditions to determine overall efficacy of the chemically modified interface and were also compared with an unmodified interface. Composite polymer systems with equivalent chemical interfaces were developed using modified nanoparticles, and these viscoelastic responses were measured at different particle loads, temperatures, and degradation environments to begin to correlate the viscoelastic response from the confined interface to bulk viscoelastic measurements of a composite material.
3:15 PM - AA6.3
Polyhydroxyalkanoate Nanocomposites with Optimal Mechanical Properties.
Yvonne Akpalu 1 , Isao Noda 2 , Dale Schaefer 1 Show Abstract
1 Chemical & Materials Engineering, University of Cincinnati, Cincinnati, Ohio, United States, 2 Materials Science & Technology/Corporate R&D, Procter & Gamble , West Chester, Ohio, United States
The progressive dwindling of fossil resources, coupled with increasing public preference for environmentally friendly plastics, have increased academic and industrial interest in biodegradable polymers prepared from renewable sources. A family of promising polyhydroxyalkanoate (PHA) polyesters called Nodax™ class PHA copolymers, consisting of 3-hydroxyalkanoate comonomer units with medium size chain side groups and 3-hydroxybutyrate, have the potential to replace the 300 billion pounds of petroleum-based amorphous and semicrystalline polymers used of a wide range of applications. The bio-based biodegradable plastics made from renewable resources will be commercially available from Meredian, Inc. Because of the unique design of molecular structure, the Nodax™ class PHA copolymers have a set of useful attributes, including polyolefin-like thermo-mechanical properties, polyester-like physico-chemical properties and interesting biological properties. Therefore, broad ranges of industrial and consumer product applications are anticipated. Molecular level structure-property relationships of the new PHA copolymers and their application for the sustainable manufacture of PHA nanocomposites with optimal mechanical properties is presented.
3:30 PM - AA6.4
Properties of PLA and Cellulose Based Composite Materials.
Mihir Oka 1 , Yonathan Thio 1 Show Abstract
1 School of Polymer, Textile and Fiber Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
We studied PLA-microcrystalline cellulose composites, focusing on the effects of processing, particle size distribution, and surface modification. The thermal and mechanical properties of these PLA based composites were studied and the effect of cellulose addition on PLA degradation was analyzed. Composites were prepared using solution processing and melt mixing methods. The processing methods influenced the polymer’s ability to crystallize affecting the mechanical properties. Isothermal crystallization studies carried out to study the kinetics of crystallization showed melt processed samples to have lower half time for crystallization and higher value for the Avrami exponent. Influence of filler surface modification and filler size on the composite properties was studied via grafting of lactic acid to cellulose particles and hydrolysis of microcrystalline cellulose particles respectively. A simple esterification reaction that required no external catalyst was used for surface modification of cellulose particles. Tuning of the interfacial interactions through surface modification of the cellulose particles was found to affect both static and dynamic mechanical properties of the composite.
4:15 PM - AA6.5
Heavy Metal Removal from Electroplating Wastewater Using Acacia Cellulose Based Polymeric Chelating Ligand.
Lutfor Rahman 1 , Simon Wen 1 Show Abstract
1 School of Science and Technology, University Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia
A simple process has been used for removing heavy metals from industrial wastewaters, which is a major concern about the discharge of effluents from metal plating industries. Therefore, a polymeric chelating ligand containing hydroxamic acid and amidoxime functional groups were prepared from acacia cellulose and this ligand was introduced for heavy metals removal. The heavy metals binding property with this ligand is good up to 3.00 mmol g-1 sorbent and the rate of exchange of some metals was very fast i.e. t½ = 5 min (average). Two types of wastewater from electroplating plants used in this study those containing chromium, zinc, nickel, copper and iron etc. Before removing heavy metals from wastewater, pH was adjusted to 4 and various metal concentrations were used for finding the extraction capability of the ligand. It was found that the metals recovery was highly efficient up to 97.5% of several heavy metals were removed from electroplating wastewater. Therefore, the proposed polymeric chelating ligands could be used to the removal of several heavy metals from industrial wastewater and as well as effective ligand for environment protection.
4:30 PM - AA6.6
Characterization of Algae Fiber Reinforced Biocomposites.
Seong Ok Han 1 , Yoon Jong You 1 , Hee Yeon Kim 1 Show Abstract
1 Nano Materials Research Center, Korea Institute of Energy Research, Daejeon Korea (the Republic of)
The red algae (Gelidium Elegance) fiber was examined as a reinforcement of biocomposite. The extracting and bleaching process of the fiber from red algae were optimized and the thermal properties and crystallinity of algae fiber were compared to cellulose fibers. The bleached red algae fiber(BRAF) showed similar crystallinity to the cellulose and also higher thermal stability with the maximum thermal decomposition temperature of 359.3oC. Biodegradable polymers are actively applying to many areas in order to replace the petroleum based polymers. The combination of algae fiber reinforcement and a biodegradable polymer matrix can be the most promising biocomposite in terms of developing a completely biodegradable biocomposite as an environmentally friendly material. The objective of this study is to investigate the properties of BRAF reinforced poly(lactic acid) (PLA), poly(butylene succinate) biocomposites and to compare to BRAF reinforced polypropylene biocomposites. Biocomposites reinforced with BRAF have been fabricated with varying BRAF contents by a compression molding method and their mechanical and thermal properties have been studied. The storage modulus of polymer matrix and the thermomechanical stability are markedly improved with increasing the BRAF content, showing a maximum value of storage modulus and the least coefficient of thermal expansion value at 50w% of fiber loading. The performances of biocomposites are compared and it is found that the storage modulus and dimensional stability of BRAF/PLA biocomposites improved much higher than those of BRAF/PP biocomposites with the fiber loading. As a result, we conclude that the biocomposites made of BRAF and a biodegradable polymer can be used as alternatives of biocomposites of the plant fiber and petroleum based polymer as a completely biodegradable biocomposite.
4:45 PM - AA6.7
Development of Bentonite-Alginate Films for Enhancement in Cd(II) Removal.
WahTzu Teoh 1 , Takuma Tsuritani 1 , Kazunori Sato 1 Show Abstract
1 Environmental Engineering, Nagaoka University of Technology, Nagaoka, Niigata, Japan
The objective of this work is to investigate the Cd(II) adsorption kinetics and adsorption isotherms of conventionally prepared bentonite-alginate beads and the novel bentonite-alginate films. Bentonite, a mineral clay, has been found to be capable of removing heavy metals in wastewater through adsorption process. The abundance of bentonite and inexpensive cost make it a strong candidate as an adsorbent. However the use of bentonite in powder form introduces practical problems since separation of bentonite from the wastewater will be difficult. Powder immobilization is a method used to fix and retain the bentonite on a suitable polymer support for continuous operations. Natural polysaccharide such as alginate is one of the good alternatives to synthetic polymers. Alginate is a biopolymer extracted mainly from brown seaweed that is known to have good affinity for heavy metals. Immobilizing bentonite powder with alginate has synergy effect for heavy metal adsorption. To investigate the Cd(II) adsorption kinetics, similar weight of bentonite-alginate beads and film were place in contact with 30 ml of Cd(II) solution (100 mg/l) at room temperature under stirring condition. The pH of Cd(II) solution is 5.0. Samples (3 ml) were removed at different time (30, 60, 120, 180, 360, 1440 min). The Cd(II) concentrations were determined by Inductively Coupled Plasma Atomic Emission Spectroscopy (Shimadzu, ICP-7510). The adsorption data were described using different kinetics models, namely pseudo-first-order, pseudo-second-order, and intraparticle diffusion model. The adsorption isotherms were obtained using similar method as the kinetics experiment. Different initial concentrations were used: 10, 20, 40, 60, 80 mg/l.The isotherms adsorption tests were run for 1440 min, provide enough time for the system to reach equilibrium. The adsorption data were plotted to fit the Langmuir isotherm and Freundlich isotherm. The kinetics of Cd(II) adsorption by bentonite-alginate film and beads fitted better to the pseudo-second-order kinetics. The bentonite- alginate film showed higher adsorption capacity, rate constant as well as initial adsorption rate, attributed to the larger surface area which is exposed to the Cd(II) solution. The intraparticle diffusion model suggested that intraparticle diffusion may not be the only rate controlling step. The adsorption isotherms data fitted with both the Langmuir and Freundlich models with regression coefficients above 0.97, suggesting that both models closely fitted the experimental results. However, the regression coefficients indicate that the Langmuir model fitted better than Freundlich model. Based on the Langmuir model, the saturation adsorption capacity for bentonite-alginate films (59.9 mg/g) is higher than the beads form (17.9 mg/g). Both of the kinetics and isotherm models suggested that the bentonite-alginate films has better performance in Cd(II) removal as compared to beads.