Levich Institute Seminar Announcement, 02/28/2006
Steinman Hall, Room #312
(Chemical Engineering Conference Room)
Professor Charles Manke
Wayne State University
Chemical Engineering Department
"Simulation of Polymeric Liquids by Dissipative Particle Dynamics"
Dissipative Particle Dynamics (DPD) is a mesoscopic simulation technique suitable for representing polymer molecules with a wide variety of architectures in both solutions and melts. Here, we present DPD simulations of linear polymer chains in three regimes of concentration: dilute solution, semi-dilute solutions, and melts. In the dilute solution regime, the DPD simulations exhibit the correct scaling of both radius of gyration and relaxation time with chain length, indicating that excluded volume and hydrodynamic interaction effects are represented, and realistic rheological responses in steady shear flow. As the polymer concentration is increased to the semi-dilute regime, the DPD simulations are able to represent the polymer-polymer frictional interactions giving rise to non-linear dependence of viscosity on concentration, and realistic values of the Huggins coefficient are obtained. In the polymer melt regime, a segmental repulsion model is introduced to impede unphysical chain crossing events, and thereby impose topological constraints for chain motions. The DPD melt simulations show evidence of a plateau modulus in the relaxation modulus, and a transition in the scaling behavior of both viscosity and diffusion coefficient with chain length indicative of entanglement dynamics.
BRIEF ACADEMIC/EMPLOYMENT BACKGROUND:
Degrees: BS Chemical Engineering Oregon State Univ. MS∓Ph.D. Chemical Engineering University of California Berkeley Employment: Shell Development Company 1983-1988 Wayne State University, Dept. Chemical Engineering and Materials Science 1988-present; current position Professor and Department Chair
Rheology and polymer processing; Mesoscopic simulation of polymer rheology; Processing of polymers with supercritical fluids.