Abstract Proposal No: 9713322 Proposal Type: Investigator Initiated Principal Investigator: William B. Krantz Affiliation: University of Colorado at Boulder This grant is awarded through the Separations and Purification Program sub-element of the Interfacial, Transport and Separations Program of the Chemical and Transport Systems Division. The principal investigator is Dr. William Krantz of the University of Colorado. The research involves fundamental studies of the thermally induced phase separation process (TIPS) for membrane formation. The process involves cooling a polymer solution to effect phase separation and the formation of a dense polymer phase which is then recovered and becomes the membrane. The investigators propose to conduct their studies on fluorinated polymers due to the potentially wide applicability of these membranes and the lack of fundamental knowledge on optimal membrane fabrication. A novel aspect of the research is the use of acoustic time-domain reflectometry (ATDR) to characterize the thermally induced phase transitions and obtain polymer phase thickness as a function of time. ATDR can also provide information on membrane microstructure and is complementary to information obtained through electron micrography. Finally, the investigators seek to use analogies to alloy solidification theories to model the TIPS process. The research will provide a better understanding of membranes formed through thermally induced phase separation processes. This should have a direct impact on membrane design and casting procedures to fine-tune pore distributions and membrane thickness. Application lie in a variety of membrane separation technologies adapted to the chemical, petroleum and pharmaceutical industries.
