Abrasion-resistant polyethersulfone/Al2O3 membranes with excellent permeability: Fabrication, evaluation, and molecular dynamics simulation

Abstract

Extending the membrane lifespan against abrasion and improving the membrane filtering performance in an economical and widely applicable manner remain urgent demand. Herein, by employing a one-step spray-sediment method, we prepared an abrasive-resistant polyethersulfone (PES)/Al₂O₃ hybrid membrane with excellent permeability, assisted by the Al₂O₃ nanoparticles, which are concentratedly embedded in the top surface. The water flux and BSA solution flux of the PES/Al₂O₃ hybrid membranes were increased by as high as ~80 % and ~27.0 %, respectively, at the Al₂O₃ loading ratio of merely 0.5–0.6 wt%, while the BSA rejection rate kept at a high level (~88 %). The flux recovery rate was increased from 63.3 % to 70.5 % at the loading ratio of 0.8 wt%. Remarkably, the PES/Al₂O₃ hybrid membrane possessed excellent enhancement of abrasion resistance against the grinding of silicon carbide sandpaper, possessing a reduction of weight loss as high as 75.6 % in the initial 50 abrasion cycles. Molecular dynamics simulations revealed that the improved permeability can be attributed to the porous area of the particle-polymer bound layer formed by the nanoparticles embedded in the membrane's skin layer. Our findings highlight a simple and cost-effective one-step spray-sediment method suitable for the large-scale industrial fabrication of abrasive-resistant membranes with high performance, as well as provide physical insights into the improved membrane permeability.