Long & Medium-Term Research: Transport of Fluid and Macro- molecules in Polymeric Gels. This award recommendation is made under the Program for Long & Medium-Term Research at Foreign Centers of Excellence. The program seeks to enable U.S. scientists and engineers to conduct long-term research abroad at research institutions of proven excellence. Awards provide opportunities for the conduct of joint research, and the use of unique or comple- mentary facilities, expertise and experimental conditions in foreign countries. This award will support a twelve-month visit by Dr. Laurence T. Baxter to India to work with Dr. Ramesh A. Mashelkar, Director of the National Chemical Laboratory ?NCL! at Pune on "Transport of Fluid and Macromolecules in Polymeric Gels." Recently, the NCL has developed super-absorbent polymers, i.e., polymers capable of absorbing several hundred times their own weight of water or other liquids. NCL designed one such polymer, Jalshakti, to improve the ability of plants to obtain water in arid climates. NCL's polymers have potential uses in many areas, such as agriculture, medical and personal hygiene products, controlled-release drug delivery, and separations. The researchers plan to model the transport of fluid and macromolecules in polymer gels, incorporating hydrodynamic and steric effects, as well as the thermodynamic properties of the gel. They will use this model to predict macroscopic transport properties, such as diffusivity or hydraulic conductivity, as well as concentration and pressure profiles, from microscopic properties. Their goal is to relate structure to function, to take thermodynamic parameters and incorporate them into a framework to analyze dynamic transport effects. The will test the mathematical model experimentally, by measuring effective diffusivity, perme- ability, and macromolecular concentration profiles, through standard techniques available at NCL. The investigators hope that insight into transport within gels obtained from a verifiable model will yield a rational basis for polymer design, and for optimization of system parameters for effective drug release or water absorption, or both. The award recommendation provides funds to cover, as appropriate, international travel, local travel abroad, stipend, dependents' allowance if applicable, and a flat administrative allowance of $250 for the U.S. home institution.
