Efficient Oil/Water Separation by Zwitterionic Poly(sulfobetaine methacrylate)@Cu(OH)₂ Nanoneedle Array-Coated Copper Meshes with Superwetting and Antifouling Properties

Abstract

Efficiently separating oil and water has become a globally challenging problem. Herein, we report a novel graft-polymerization method to synthesize poly(sulfobetaine methacrylate)@Cu(OH)2 nanoneedle array (PSBMA@CHNNA)-coated copper meshes with superwetting and antifouling abilities to efficiently separate oil and water. The zwitterionic PSBMA@CHNNA-coated membranes were synthesized by the combination of chemical oxidation and a surface-initiated free-radical polymerization method. The as-synthesized mesh membranes showed a highly efficient separation capability toward different oil/water mixtures, oilfield wastewater, and oilfield produced fluids with a chemical oxygen demand (COD) in the filtrated water less than 30 ppm. The water fluxes of the as-synthesized meshes were as high as about 80 kL·h–1·m–2 for different oil/water mixtures and more than 10 kL·h–1·m–2 for the oil/water emulsion of oilfield wastewater. Moreover, the as-synthesized membranes exhibited excellent antifouling ability to ensure easy cleaning, good stability, and durability for recycle use. With the inherent advantages of high efficiency, easy scale-up, and reusability, the current membrane fabrication strategy may offer an alternative promising approach to developing a new-generation membrane for practical oil/water separation.