Preparation of high performance membrane via one-step polymerization and co-deposition of polydopamine/zwitterionic monomers/poly(ethylene glycol) diacrylate

Abstract

Membrane separation is an effective method for water purification. However, conventional preparation processes for the membranes usually suffer from complicated production technology and lack versatility. Mussel-inspired chemistry has generated extensive interest in exploring a facile strategy for the preparation of polymeric membranes. In this work, a simple, green and time saving strategy is proposed for accomplishing the surface functionalization via one-step polymerization and co-deposition of dopamine/zwitterion/poly(ethylene glycol) diacrylate (PEGDA). The chain segment of the zwitterion can tightly bind water molecules upon the membrane surface, enhancing the hydrophilicity of the membrane. The chain segment of PEGDA can offer cross-linking sites during the co-deposition process, facilitating the formation of the network structure. The retention to dyes for the membranes prepared with PEGDA was higher than those membranes prepared without PEGDA. The optimized membrane exhibited high water permeance up to 25.9 L m−2 h−1 bar−1, with rejection of 99.7 % and 99.6 % for Methyl blue and Congo Red. Meanwhile, the anti-bacterial rate for the optimized membrane reaches 75.9 %, and the water flux recovery rate (FRR) is as high as 86.65 %. The results cast a light on the exploration of the PDA-based NF membranes, featuring simple production technology and versatile capabilities for the separation of various dyes.