Professor Robijn Bruinsma
Department of Physics
University of California at Los Angeles
Los Angeles, California

Informal

Wednesday, February 2, 2000
3:00 pm (CT)
3169 Beckman Institute

Abstract

Actin protein filaments have already provided us with a model system that allowed fundamental tests of polymer physics at a single-molecule basis, which led to a renaissance of the theory of polymer physics. Recent synchrotron x-ray studies of Actin solutions indicate that Actin holds further surprises: cross-linked Actin networks appear to be liquid crystal gels with unfamiliar properties. The talk will discuss why the application of classical Onsager theory to Actin liquid crystals leads to the conclusion that they should belong to a novel class of liquid crystals, such as the "cubatic" phase, which has been encountered so far only in numerical simulations. Actin gels coexist with dense bundles ("stress fibers") producing a rich phase behavior with a surprising structural flexibility.

Tea and coffee will be served in R3151 Beckman Institute at 2:15pm.