DESIGN AND DEVELOPMENT OF POLYIMIDE BASED COMPOSITE MEMBERANES FOR ORGANIC SOLVENT NANOFILTRATION

Abstract

Crosslinked polyimide membranes are among the most promising options for molecular separation in organic solvents due to their reasonable stability, ease of processing, and low cost. However, crosslinked polymeric membranes still face challenges: poor stability in harsh solvents and a trade-off between selectivity and permeability.

This work will cover different fabrication and modification methods of four polyimide based composite membranes with enhanced chemical stability and durable mechanical flexibility, as well as improved permeability and selectivity for organic solvent nanofiltration. Plasma-grafted high-density polyethylene glycols, nano-size amine-functionalized UiO-66 particles, a series of amine vapor-phase crosslinking reagents, and covalent organic frameworks are used to modify crosslinked Matrimid® substrates and directly converted ultrafiltration substrates to nanofiltration membranes. The physicochemical properties and separation performance of membranes are investigated systematically. This work may provide insights into designing sustainable and scalable strategies for developing next-generation polymeric organic solvent nanofiltration membranes.