Dissipative Particle Dynamics Simulation of PVDF Membrane Formation Via Non-Solvent Induced Phase Separation Process

Polymeric membranes produced by Non-solvent Induced Phase Separation (NIPS) have been extensively used across a wide array of microfiltration and ultrafiltration processes. However, despite their broad applications, current fabrication processes are largely empirical, determined largely by trial and error. Better insights into the factors affecting membrane morphology would be of great use. To that end, Dissipative Particle Dynamics (DPD), a mesoscale simulation tool, was used to simulate membrane formation process involving PVDF in DMF with H₂O as a nonsolvent. The DPD simulations were performed for a total of several million beads and over several microseconds. The interactions between these beads are determined according to Flory-Huggins thermodynamic theory and continuum transport equation. Significant insights have been obtained on the effects of polymer concentration and polymer molecular weight on the pore size, pore size distribution and membrane morphology.