Computer simulation of formation of polymeric ultrafiltration membrane via immersion precipitation

▶ Polymeric ultrafiltration membrane formed via immersion precipitation is simulated using polymeric bond fluctuation lattice model. ▶ The exchange algorithm using probability density is proposed to simulate the open and wide diffusion layer in coagulation bath. ▶ The quantitative information about the diffusion of solvent and nonsolvent coupling with the aggregation of polymer is achieved. ▶ Solvent diffusion obeys Fick's law and the apparent diffusion coefficient of nonsolvent has exponential relationship with the concentration of polymer solution and operation temperature. ▶ The asymmetrical structure from island-like phase to continuous phase is found.