Hydrodynamics Coupled Simulation of Fingerlike Pore Formation During Nonsolvent Induced Phase Separation

The finger-like pore (FP) is one of the most important phenomena in the fabrication of membranes via nonsolvent induced phase separation (NIPS), as the performance of most functional membrane is heavily dependent on the appropriate regulation of the FPs. However, the mechanisms governing the initiation and growth of FPs are still not fully understood, and their regulation often relies on empirical knowledge and practice. This study presents the development of a hydrodynamics-coupled phase-field model that reproduces the process of FP initiation and parallel growth from the dense skin layer. The evolution process of the finger morphology and the impact of various manufacturing parameters are investigated. Optical observations are conducted and compared with simulated morphologies under different parameter conditions, revealing that the simulations mirrored the effects of these parameters, as seen in actual processes.