Robust graphene oxide hybrid membrane for high-efficiency emulsion separation in high-salt brine systems

Abstract

Exploring robust membrane with special wettability is of great significance for efficient emulsion separation under harsh environment. Herein, the multifunctional GO@PDA@Ag/PES membrane with rough structure was successfully constructed, which exhibited remarkable emulsion separation and mechanochemical performances in high-salt brine systems. Results showed the separation efficiency for surfactant stabled TBP-in-brine emulsion and actual solvent extraction emulsion can reach up to 99.6 % and 95.2 %, respectively. The GO@PDA@Ag/PES membrane displayed excellent structural stability, which could maintain the superwettability and superhigh separation efficiency even corrosion in acid, alkali and salt environment for 14 days. Surprisingly, the GO@PDA@Ag/PES membrane can withstand 2000 times folds, 100 times abrasion, and 20 times cycles without separation performances reduced. The robust mechanochemical properties can be ascribed to the covalent bond bridged structure crosslinked by polydopamine, and the non-covalent interactions between GO and PES. Importantly, Ag nanoparticles on the surface and embedded in membrane were investigated by XPS, which indicated the different chemical speciation. The hybrid membrane with excellent oil-in-brine emulsion separation performance, corrosion resistance and mechanical stability will have broad prospects in the field of high-salt lake industry.