Effects of polyvinylpyrrolidone additive on structures and properties of Poly(m-phenylene isophthalamide) hollow fiber membranes -experiment observation and computation approach

Abstract

This study systematically investigates the effect of introduction of polyvinylpyrrolidone (PVP) used as a hydrophilic additive and its molecular weight change on the morphological, mechanical properties, and membrane performances of poly(m-phenylene isophthalamide) (PMIA) hollow fiber (HF) membranes prepared by dry-jet wet spinning method. The results of the morphological and mechanical properties clearly show an increased proportion of a sponge-like pore structure and an overall improvement in the mechanical properties of the PMIA HF membranes with higher molecular weight PVP, respectively. Interestingly, molecular dynamics simulation showed that the presence of PVP within the PMIA matrix activated the overall movement of PMIA molecules, suggesting that the overall flexibility of the system, which can potentially inhibit the collapse of relatively brittle membranes, is increased by the presence of PVP. Finally, as the molecular weight of PVP increases, a typical trade-off phenomenon is observed on PMIA HF membranes, where the water permeability decreases while the rejection rate increases. Based on these results, the findings on the influence of PVP additive and its potential as a reinforcing agent observed in this study through experimental analysis and computational approaches are expected to provide new insights into the development of high-performance polymeric HF membranes.