Dissipative Particle Dynamic Mean-field Simulations of Phase Inversion Processing Polymer Thin Films with Hydrodynamic Interactions

Several important industrial processes rely on phase inversion membranes with microstructures on length scales from 10s of nm to several microns. The microstructures are typically formed during the flow of polymers and solvents, such as the formation of microstructures in phase inversion processing techniques. In the techniques, hydrodynamic effects often play a critical role in processing of polymer thin films. The thin films are cast as a polymer solution and then immersed in a bath of a non-solvent to the polymer. The hydrodynamics during the processing determine the final microscopic. However, hydrodynamic mechanisms at microscopic level that control the structures are far from fully understood and difficult to examine experimentally. In this talk, I will describe our work to develop computational tools capable of describing multiphase flows with hydrodynamic interactions. Our method is based on a dynamic mean-field theory with dissipative particle dynamics. We will present results from study of phase inversion processing of homopolymer solution thin films. Our study shows that the development of microstructures in the films depends on the hydrodynamic effects and can be manipulated by tuning factors including the polymer concentration and polymer/nonsolvent incompatibility.