The effect of electric field-assisted non-solvent induced phase separation method on PVDF membrane morphologies and performances

Abstract

ABSTRACT Achieving specific functions in polyvinylidene fluoride (PVDF) membranes requires precise control over their crystalline and morphological structure. In this study, we introduce an innovative method involving the application of an electric field as a preliminary treatment step before immersing PVDF in water during the fabrication of non-solvent induced phase separation (NIPS) membranes. Our study reveals that even a brief exposure to an electric field result in a more organized and aligned molecular structure and significantly altered the crystallinity of polyvinylidene fluoride (PVDF). This structural transformation leads to notable improvements in membrane morphology, characterized by reduced macrovoids and enhanced uniformity. Additionally, membranes produced through this method exhibit markedly enhanced ionic conductivity, a pivotal attribute for optimal performance in electrochemical devices. This innovative approach presents an effective alternative for enhancing PVDF membrane properties, with promising implications for high-performance electrochemical devices and separation membranes. Future research endeavors are necessary to elucidate the underlying mechanisms responsible for these enhancements and to assess the long-term stability and practical applicability of the pretreated membranes.