8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Tue 611:23-14:00P9.7A microscopic derivation of the constitutive equationdescribing the rheology of complex polymer liquidsWim Briels 1 and Jan Dhont 21 University of Twente, PO 215, 7500 AE, Enschede, Netherlands2 Forschungszentrum Juelich, Juelich, GermanyMost soft matter systems consist of particles which by themselves are too large to be simulated infull detail. In order to be able to simulate the rheological properties of such systems, only relevanttime scales must be addressed and most degrees of freedom must be eliminated from the description.The elimination process introduces memory effects in the coarse description which renderssimulations of realistic systems impossible. I will present a solution to this problem by keepingtrack of perturbations of the thermodynamic state of the eliminated variables. The resulting model,called RaPiD, is very generic and may be applied to study rheological properties of a large classof soft and composite matter. As examples of the RaPiD model I will present a few results of simulationsof dense systems containing telechelic micelles pressure sensitive adhesives. The mainpart of the presentation will be about the derivation of the constitutive model for the rheology ofthis model. Among the contributions to the stress tensor will be the so-called shear curvature termintroduced in 1999 by Jan Dhont on the basis of very general considerations. This term allows theselection of stresses in shear banding systems.7