High-performance self-healing composite ultrafiltration membrane based on multiple molecular dynamic interactions

The inevitable membrane damage during the use of separation membrane seriously affects the separation and purification effects. Herein, we first synthesized a novel poly(aryl ether sulfone) material containing boronic acid groups (PES-H2BO2) through molecular design, then PES-H2BO2 ultrafiltration membrane was prepared via nonsolvent induced phase inversion method. Further, the PES-H2BO2 ultrafiltration membrane and polyvinyl alcohol (PVA) hydrogel were composited by hydrogen bonds and reversible boronate ester bonds between the two to fabricate a series of novel PVA hydrogel/PES-H2BO2 composite ultrafiltration membranes. Through the ultrafiltration experiment of polyacrylamide (PAM) solution, the flux and retention rate changes of the composite ultrafiltration membrane in the initial stage, damage stage, self-healing stage, and stabilization stage were tested and analyzed. The results confirmed that the composite membrane has the ability to rapidly restore the flux and retention rate to the pre-breakage levels through a self-healing effect within 15 min after being damaged, demonstrating their outstanding self-healing characteristics. The design strategy of fabricating composite ultrafiltration membrane with excellent self-healing performance by forming hydrogen bond and reversible boronate ester bond between hydrogel and membrane matrix in this study provides a convenient and feasible way for the design and preparation of high-performance self-healing separation membranes.