Lu J.,Technova Corporation
Applied Biochemistry and Biotechnology | Year: 2011
Diminishing fossil fuel reserve and increasing cost of fossil hydrocarbon products have rekindled worldwide effort on conversion of lignocellloloses (plant biomass) to renewable fuel. Inedible plant materials such as grass, agricultural, and logging residues are abundant renewable natural resources that can be converted to biofuel. In an effort to mimic natural cellulolytic- xylanolytic microbial community in bioprocessing of lignocelluloses, we enriched cellulolytic-xylanolytic microorganisms, purified 19 monocultures and evaluated their cellulolytic-xylanolytic potential. Five selected isolates (DB1, DB2, DB7, DB8, and DB13) were used to compose a defined consortium and characterized by 16S ribosomal RNA gene sequence analysis. Nucleotide sequence blast analysis revealed that DB1, DB2, DB7, DB8, and DB13 were respectively similar to Pseudoxanthomonas byssovorax (99%), Microbacterium oxydans (99%), Bacillus sp. (99%), Ochrobactrum anthropi (98%), and Klebsiella trevisanii (99%). The isolates produced an array of cellulolytic-xylanolytic enzymes (filter paper cellulase, β-glucosidase, xylanase, and β-xylosidase), and significant activities were recorded in 30 min. Isolates DB1 and DB2 displayed the highest filter paper cellulase: 27.83 and 31.22 U mg-1, respectively. The highest β-glucosidase activity (18.07 U mg-1) was detected in the culture of isolate DB1. Isolate DB2 produced the highest xylanase activity (103.05 U mg-1), while the highest β-xylosidase activity (7.72 U mg-1) was observed with DB13. Use of microbial consortium in bioprocessing of lignocelluloses could reduce problems such as incomplete synergistic enzymes, end-product inhibition, adsorption, and requirement for high amounts of enzymes in direct use of enzymes. © 2010 Springer Science+Business Media, LLC.
Agency: Department of Defense | Branch: Navy | Program: STTR | Phase: Phase I | Award Amount: 149.99K | Year: 2011
Shipboard structures can benefit from the relatively high performance-to-weight ratio, fatigue life, durability, processability and multi-functionality of polymer composites (versus metals). The fire, smoke and toxicity (FST) performance and the initial economics of composites, however, cannot match those of metals. Efforts to replace metals with composites in shipboard structures have emphasized the use of brominated vinyl esters as fire-retardant polymers in composites. Despite their relatively low cost and ease of fabrication, such halogenated polymers are toxic and potentially carcinogenic, and their compatibility with carbon fiber is less than desirable. There is thus a need for environmentally friendly and affordable polymers which offer desired FST behavior, processability, structural performance and compatibility with carbon fiber. We propose to meet this challenge by developing a tailored polymer chemistry which embodies synergistic and affordable features of organic-inorganic hybrids with nano-scale inorganic constituents and benzoxazines with phosphorus- or silicon-based chemistry. The proposed Phase I project will: (i) synthesize and screen refined epoxy resins incorporating selected elements of the new molecular structure; (ii) thoroughly characterize selected refined epoxies, and identify the system with a preferred balance of performance, cost and sustainability for use in composite topside structures; and (iii) verify the competitive technical, economic and sustainability merits of the refined epoxy system versus brominated vinyl esters and standard phenolic resins. The follow-up Phase I Option will optimize the refined epoxy chemistry embodying organic-inorganic hybrids and phosphorus-/silicon-containing benzoxazines.
Agency: Department of Defense | Branch: Navy | Program: STTR | Phase: Phase II | Award Amount: 500.00K | Year: 2012
Efforts to replace metals with composites in shipboard applications have emphasized the use of brominated vinyl esters as fire-retardant polymers. Despite their relatively low cost and ease of fabrication, such halogenated polymers produce toxic and potentially carcinogenic gases; their compatibility with carbon fibers is also less than desirable. There is thus a need for environmentally friendly and affordable polymers that offer desired fire resistance, processability, structural performance and compatibility with carbon fibers. This challenge is addressed in the project by developing a modified epoxy chemistry which employs the organic-inorganic hybridization principle. Chemical integration of phosphorus- and silicon-based compounds into selected epoxy systems yielded a single, inherently flame-retardant polymer structure with a desired balance of fire, smoke and toxicity behavior, compatibility with the resin-infusion approach to room-temperature processing of composites, thermo-mechanical performance, bonding characteristics, and economics. The Phase II project will optimize this modified epoxy chemistry, and will undertake laboratory investigations and scale-up efforts towards qualification of the new polymer composite for use in shipboard structures. The proposed project will be implemented in a base (Phase II) and two option steps, and will be guided by the experience gained in successful qualification of composites for use in Naval surface combatants.
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 954.51K | Year: 2010
Thermal energy storage systems balance out the discrepancies caused by the mismatch in the timing of energy supply and demand in alternative energy systems. In the case of solar space heating, for example, the intermittent supply of solar radiation requires storage of the excess daytime supply to meet the nighttime demand. Thermal energy storage benefits the energy-efficiency of buildings by controlling indoor temperature fluctuations, and by shifting the energy demand away from peak hours. The focus of the project is on development of a new thermal energy storage material which complements large latent heat capacity with desired shape-stability, thermal conductivity, heat and fire resistance, scalability, economy, sustainability, and versatility for use in diverse energy systems. The new hybrid nano-phase change materials (nano-PCMs) rely upon the molecular interactions of PCM with the enormous (functionalized) surface area of low-cost expanded graphite nanosheets as well as the support of PCM by a networked, thermally stable polymer to realize a highly desired balance of qualities favoring their broad transition to energy-efficient buildings and solar energy markets. Hybrid nano-PCMs are produced by simple intercalation of expanded graphite nanosheets, preserving the interconnected nature of nanosheets to render high levels of thermal conductivity. High thermal conductivity is key to timely mobilization of the whole volume of nano-PCMs towards latent heat storage in scaled-up building applications. The Phase I project developed simple processing techniques for production of hybrid nano-PCMs, and validated their ability to provide a distinct balance of latent heat capacity, thermal conductivity, and high-temperature stability of shape and mechanical performance. Building walls incorporating nano-PCMs were also developed, and their value towards control of indoor temperature fluctuations and shifting of thermal load in building applicaitons was demonstrated. Numerical analyses confirmed that nano-PCM building products can bring about major energy savings and thermal load shifts. The proposed Phase II project will build upon the Phase I accomplishments towards: (i) full development and thorough characterization of hybrid nano-PCMs and building products incorporating them; (ii) theoretical and experimental validation of the benefits of hybrid nano-PCMs in terms of energy-efficiency, thermal comfort and shifting of thermal load in different building systems and climatic conditions; and (iii) competitive market evaluation of the technology for identifying priority applications and viable routes to market transition. Commercial Applications and Other Benefits: Nano-PCMs offer a desired balance of performance and cost for convenient incorporation into building construction products. These products can bring about major gains in the energy-efficiency and life-cycle economy of buildings at viable initial cost. The significant energy consumption and greenhouse gas emission of buildings magnify the benefits of the technology. The near-term markets in energy-efficient building construction offer the potential to consume close to 10 million tons/yr of thermal storage materials. A 5% share of this market represents ~$200 million annual sales of nano-PCM. The diminishing resources of fossil fuels, and their environmental burdens and rising costs are key factors benefiting market acceptance of the technology.
Agency: Environmental Protection Agency | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 225.00K | Year: 2011
Production of cement (the binder in concrete) is a highly polluting and energy-intensive process, accounting for about 6% of global, anthropogenic C02 emissions and close to 2% of worldwide primary energy use. This project focuses on partial (~20%) replacement of cement in concrete with milled (mixed-color) waste glass to improve the moisture barrier qualities, durability, dimensional stability and other engineering properties of concrete. These beneficial effects would be realized as far as waste glass is milled to micro-scale particle size for accelerating its chemical reactions with cement hydrates. The landfill-bound quantities of glass are adequate to significantly impact the concrete construction practice. Waste glass is generated largely in urban areas, where the bulk of concrete production also takes place. Broad use of milled waste glass in concrete would yield significant environmental, energy, and cost benefits, and also would enable more extensive use of recycled aggregate concrete. The Phase I effort identified desired particle size and dosage of milled (mixed-color) waste glass for beneficial use as partial replacement for cement in concrete. The favorable effects of milled waste glass on the chemical composition, microstructure, and key engineering properties (including stability under potential alkali-silica reactions) of normal and recycled aggregate concrete were identified through laboratory investigations. Theoretical and numerical studies were conducted to rationalize the experimental observations and to assess practical implications of using recycled glass concrete. A successful field study also was implemented in collaboration with concrete and recycling industries. The environmental, energy and (initial and life-cycle cost) benefits associated with partial replacement of cement with milled waste glass were quantified using the outcomes of Phase I effort. The proposed Phase II project will: (i) expand the experimental database on recycled glass concrete to cover broader ranges of concrete materials and engineering properties; (ii) corroborate the statistical significance of the benefits rendered by milled waste glass and verify the statistical control over production of recycled glass concrete; (iii) identify the mechanisms through which milled waste glass benefits the engineering properties of normal and recycled aggregate concrete; (iv) thoroughly assess the gains in service life and life-cycle economy of major concrete-based infrastructure associated with the use of milled waste glass; (v) implement and monitor large-scale field projects to demonstrate the scalability, compatibility with prevalent construction practices, and practical value of recycled glass concrete; and (vi) evaluate the environmental, energy, and cost benefits of recycled glass concrete in different applications and service environments.
Agency: Department of Agriculture | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 460.00K | Year: 2011
The perchlorate generated over decades has impacted our nation's waters; it is environmentally recalcitrant and potentially toxic. Perchlorate has significant effects on irrigated agriculture; it is detected in vegetables and dairy food products. Perchlorate has emerged as a significant threat to public health. Substantial efforts are devoted to perchlorate removal and also to its identification down to the lowest possible limit of detection (LoD). The US Environmental Protection Agency (EPA) has recently (in February 2011) announced its decision to set a first-ever national standard for perchlorate. Standard methods for perchlorate detection using ion chromatography or mass spectrometry are costly and time-consuming, and require professional laboratory operators. There is a strong need and opportunity to develop simple and inexpensive analytical methods for rapid field detection of perchlorate. The focus of this project is on development of an simple, inexpensive and highly sensitive nano-biosensor for rapid detection of perchlorate down to 1 ppb. This biosensor will suit field use, laboratory applications, and on-line monitoring; it facilitates cost-effective and convenient monitoring of perchlorate in groundwater, soil, drinking water, food and beverages. It will make important contributions towards improvement of public health. Three primary market segments have been identified for the technology: water quality testing, food safety evaluation, and remediation. In addition, the nano materials developed and investigated in the project for perchlorate biosensor would serve as a protocol for other species-selective bio-interfaces suiting detection of other environmental contaminates (e.g., nitrate).
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase I | Award Amount: 99.99K | Year: 2010
The main thrust of the proposed research is to develop a new class of high-performance pressure-sensitive adhesives for use with aircraft appliqué films. Our approach merges the conventional pressure-sensitive adhesives technology with recent advances towards development of dry adhesives inspired by the nano-fibrillar structure of gecko-foot. Nano-texturing of pressure-sensitive adhesives is proposed here as a means of producing conformable surfaces which can establish thorough intermolecular contacts with rough substrates under pressure without requiring a liquid-type fluidity. The merger of the two (pressure-induced) adhesion mechanisms would complement the powerful and highly versatile contact mechanics of nano-fibrillar structures with the high adhesion energy and peel resistance of pressure-sensitive adhesives associated with their cavitation/fibrillation during debonding. The conformable nano-textured surfaces would remove a major constraint (the need for liquid-type fluidity) against optimum formulation and processing of pressure-sensitive adhesives with a desirable balance of peel and shear resistance, thermal and chemical stability, and repositionability and removability for use with aircraft applique films. The proposed Phase I research will verify the benefits of nano-texturing to pressure-sensitive adhesives, and will demonstrate the potential to refine the formulations and processing conditions of nano-textured pressure-sensitive adhesives to suit aircraft appliqué film applications.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase II | Award Amount: 599.54K | Year: 2010
Appliqué coating, as paint replacement on aircraft surfaces, offers significant environmental benefits as well as performance and cost advantages. Pressure sensitive adhesives (PSAs) are critical components of appliqué coatings; improvements in the thermal stability, chemical resistance and removability of PSAs are needed before appliqué films can realize their full potential as aircraft paint-replacement coatings. PSAs require a liquid-like flow under pressure to establish contact, and a high energy dissipation capacity for peel resistance. The need to balance these two features limits the thermal stability and chemical/weathering resistance of today’s PSAs. We have employed nanostructuring and hybridization principles to overcome this obstacle. Nanostructured PSAs employ the tremendous specific surface area and the nano-scale spacing of nanomaterials to realize improvements in energy dissipation, cohesive qualities, thermal stability, barrier attributes and chemical/weathering resistance. Hybrid pressure sensitive adhesives make complementary use of different PSA constituents, which retain their distinct qualities within a stabilized hybrid system, to meet demanding performance requirements at competitive cost. The Phase I project developed a cost-competitive class of hybrid/nanostructured PSAs which are stable over a broad temperature range, provide high levels of chemical/weathering resistance, and exhibit desired removability after aging for use with appliqué coatings on exterior aircraft surfaces. The proposed Phase II (and Phase II Option) efforts will develop scaled-up processing and control capabilities for high-volume, low-cost production of hybrid/nanostructured PSAs, their transition to appliqué films, and thorough characterization of the end product for use on aircraft surfaces.
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 150.00K | Year: 2010
Air conditioning of building accounts for a major fraction of the U.S. primary energy consumption. Air conditioning is also a major contributor to electric utility peak loads, which incur high generation costs and generally use inefficient and polluting generation turbines. Peak loads are also a major factor in poor grid reliability. The proposed project focuses on shifting of thermal loads to lower the high utility peak loads, and also on enhancing the passive use of solar energy. Thermal load shifting will be realized through development of an innovative phase change material (nano-PCM), which is highly conductive for enhanced thermal storage and energy distribution, and is shape-stable for convenient incorporation into lightweight building components. This approach intimately associates the phase change material molecules with the large and compatibly functionalized surface area of exfoliated graphite nanoplatelets. Binding of the phase change molecules upon the nanoplatelet surfaces mitigates bulk liquefaction of nano-PCM upon phase change (providing for shape-stability). The percolated network of highly conductive graphite nanoplatelets provides nano-PCM with high thermal conductivity. Commercial Applications and Other Benefits: The technology enables effective, convenient and economical use of latent heat thermal energy storage in buildings for achieving the following advantages: (i) the ability to narrow the gap between the peak and off-peak loads of electricity demand; (ii) the ability to save operative fees by shifting the electrical consumption from peak periods to off-peak periods since the cost of electricity at night is 1/3-1/5 of that during the day; (iii) the ability to utilize solar energy continuously, storing solar energy during the day, and releasing it at night, particularly for space heating in winter by reducing diurnal temperature fluctuations thus improving the degree of thermal comfort; (iv) the ability to store the natural cooling by ventilation at night in summer and to release it to decrease the room temperature during the day, thus reducing the cooling load of air conditioning.
Agency: Department of Defense | Branch: Office for Chemical and Biological Defense | Program: SBIR | Phase: Phase II | Award Amount: 749.24K | Year: 2010
A new generation of bio-inspired adhesives is under development for controlling the face-seal leakage in respirator masks. While conventional pressure-sensitive adhesives rely on liquid-like fluidity under pressure to adapt to surface roughness, biological adhesion mechanisms employed by gecko, spider and insects rely upon the compliance of a fibrillar array to accommodate surface roughness for magnifying molecular-scale contacts. The fibrillar nature of biological adhesives distinguishes them from conventional pressure-sensitive adhesives in terms of adhesion to wet surfaces via capillary action, self-cleaning, stability under repeated use and in severe conditions, the ability to accommodate facial hair, dirt and skin irregularities, and removability. Bio-inspired adhesives, however, cannot match some key qualities of pressure-sensitive adhesives, including ductility and energy absorption capacity (reliability and immunity to excess size effect), density of the interface (sealing qualities), and accommodation of local (sub-micron-scale) roughness (adhesion capacity). Our approach makes complementary use of patterned bio-inspired adhesives and highly stable variations of pressure-sensitive adhesives to combine their corresponding advantages in a new generation of bio-inspired adhesives. The integrated theoretical/experimental work of Phase I project verified the balanced qualities and the commercial promise of the new bio-inspired adhesives. The proposed Phase II project will build upon the Phase I accomplishments towards full development and optimization of the new bio-inspired adhesives, their integration into the peripheral seal of full-facepiece respirator masks, thorough evaluation of the corresponding benefits to the face-seal leak resistance of respirators, and assessment of the commercial potential of the technology in application to respirator masks and also in other fields of application.