title: Systematic coarse graining flowing polymer melts: thermodynamically guided simulations and resulting constitutive model.
abstract: Complex fluids, such as polymers, colloids, liquid-crystals etc., show intriguing viscoelastic properties, due to the complicated interplay between flow-induced structure formation and dynamical behavior. Starting from microscopic models of complex fluids, a systematic coarse-graining method is presented that allows us to derive closed-form and thermodynamically consistent constitutive equations for such fluids. Essential ingredients of the proposed approach are thermodynamically guided simulations within a consistent coarse-graining scheme. In addition to this new type of multiscale simulations, we reconstruct the building blocks that constitute the thermodynamically consistent coarse-grained model. We illustrate the method for low-molecular polymer melts, which are subject to different imposed flow fields like planar shear and different elongational flows. The constitutive equation for general flow conditions we obtain shows rheological behavior including shear thinning, normal stress differences, and elongational viscosities in good agreement with reference results.
authors.affiliation: Institut für Polymere Eidgenössische Technische Hochschule Zürich, Wolfgang-Pauli-Strasse 10, HCI H541, CH-8093 Zürich. patrick.ilg@mat.ethz.ch
authors.forename: Patrick
authors.initials: P
authors.lastname: Iig
mesh_terms: D000465:Algorithms; D008956:Models, Chemical; D056004:Molecular Dynamics Simulation; D011108:Polymers / Q000737:chemistry*; D013816:Thermodynamics; D014783:Viscosity
chemical_list: D011108:Polymers