Double-defence design for super-antifouling membranes in emulsion separation

Abstract

The development of super-antifouling membranes is paramount for efficient and sustainable emulsion separation in various industrial applications. This study presents a double-defence design strategy aimed at enhancing the antifouling properties of membranes used in emulsion separation processes. The primary defence mechanism involves the integration of waste-derived oxidized graphene into polysulfone, which significantly enhances flux and antifouling properties. The inclusion of oxidized graphene within the polysulfone membrane resulted in 1.3-fold increase in hydrophilicity with water contact angle of 61 ± 2° and 1.6-fold improvement in separation efficiency. The secondary defence employs a layer of graphene-based foam at the top of the membrane, designed to manage sudden loadings and serve as a protective barrier for the membrane surface. This dual-defence configuration has resulted in 3.7-fold reduction in fouling even after the 10^th cycle, ensuring prolonged membrane lifespan and consistent separation performance. The effectiveness of this double-defence design is evidenced by its superior antifouling performance and efficient resource recovery from graphene-based foam in crude and motor oil emulsions. This innovative approach paves the way for the development of next-generation antifouling membranes, offering a robust solution to the long-lasting challenge of membrane fouling.