CAREER: Orientational Dynamics in Flows of Thermotropic Polymers

University Of Connecticut, Storrs CT

Investigators

Abstract

Abstract CTS-0093880 P. Mather, University of Connecticut This proposal presents new experimental approaches, combined with carefully prepared model polymers, whose aim is to definitively answer outstanding questions of orientational stability for flows of thermotropic polymers. A third-generation controlled environment microheometer will be designed and assembled to allow direct measurements of both first normal stress differences and various measures of local and global orientation (birefringence, UV dichroism, IR dichroism, and wide-angle x-ray scattering) for the series of model materials is proposed. By examining the influence of TLCP chain flexibility on the linear Leslie-Ericksen tumbling parameter, and the evolution of microscopic (orientational defects) and macroscopic (birefringence) orientations in shear transients, we will significantly improve the understanding of TLCP dynamics, enabling both quantitative comparison with present polydomain models and further molecular modeling developments. An education plan is proposed to combine outreach to local teachers in Connecticut with the development of a new undergraduate chemical engineering elective, "Our World of Complex Fluids." In particular, the planned outreach efforts will feature the development of a pilot summer internship program for high school teachers. Polymer Links, in which high school teachers are teamed with chemical engineering faculty to conduct hands-on science projects (4-6 weeks) designed specifically to develop laboratory experiments in polymers and other complex fluids for use in the high school classroom. The complementary undergraduate course will first introduce students to a wide range of industrially relevant complex fluids, including foodstuffs, pharmaceuticals, and plastics along with biological fluids, including synovial fluid and cartilage. Then, this elective will expose students to underlying physical properties, microstructures, and quantitative descriptions of substances ranging from polymeric fluids to colloidal suspensions and from surfactant solutions to glasses.