Stepwise UV crosslinking in solvent: A novel method to enhance the solvent resistance of poly(aryl ether ketone) membranes

Abstract

In this contribution, the viability of using UV to give separation membranes a high crosslinking degree and broad-spectrum solvent resistance was investigated. A series of poly(aryl ether ketone) polymers suitable for UV crosslinking were first designed. And a unique photocrosslinking method, stepwise UV crosslinking in solvent, was developed by understanding photochemical reactions and molecular dynamics. This method does not require the introduction of additional photoinitiators and crosslinking agents, and the membrane preparation is a green and efficient process with a theoretical 100% atomic utilization rate. Combining this method with the special polymer structure design, a solvent-resistant nanofiltration membrane that can withstand strong polar aprotic solvents can be obtained. The molecular weight cut off of the membrane in N,N-dimethylformamide was 300 g/mol, and the permeance was 1.154 L m−2 h−1 bar−1. This separation effect even exceeded that of most composite membranes. After testing, the membranes prepared using this method had the ability to maintain functional stability at 80 °C in N,N-dimethylformamide for one month. The excellence of membrane performance and the flexibility of regulatory methods both reveal the enormous potential of this method.