Date/Time
Date(s) - 09/02/2011
3:20 pm - 4:20 pm

Title: Dynamics of Microstructural Transitions in Block Copolymer Melts

Speaker: Dr. Rob Wickham, Univ of Guelph

Institute: University of Guelph

Location: ABB 102

Description:

In block copolymer melts, competing interactions of entropic and energetic origin cause macromolecules to assemble into intricate domain structures at nanometer scales. The resulting rich structural phase diagram makes these materials attractive candidates for applications ranging from nanolithographic templates to optical crystals. Slow structural relaxation arising from collective molecular motion means, however, that block copolymer melts are often found out of equilibrium. Important questions then arise, such as: Which dynamical pathway is taken as one structure transforms into another? What is the nature of long-lived, intermediate structures, if present? These issues influence material properties, and must be understood when processing block copolymers. I will discuss analytical calculations and dynamical simulations that address this problem in the context of the nucleation of one microstructured phase out of another.