Superhydrophilic/underwater superoleophobic oil-in-water emulsion separation membrane modified by the co-deposition of polydopamine and chitosan-tripolyphosphate nanoparticles

Abstract

Environmentally friendly separation materials are essential for separating emulsified oil-water mixtures. The nylon membrane has been facilely converted into highly hydrophilic and underwater superoleophobic via a simple one-step co-deposition of polydopamine and chitosan-tripolyphosphate (CS-TPP) nanoparticles, wherein the CS-TPP particles were prepared by the ion gel method. The modified membrane exhibited excellent antifouling performance with the underwater oil contact Angle (UOCA) at 179.6°. The prepared environmental CS-TPP@PDA@nylon membrane was characterized by SEM, EDS, FTIR, and XPS. The membrane could separate various oil-in-water emulsions in a wide range of average particle sizes (50.9–1832.0 nm). In addition, the CS-TPP@PDA@nylon membrane demonstrated high permeation flux (221.0–1770.5 L m−2 h−1) and good regeneration ability. The flux could still maintain more than 89% even after fifteen cycles. The degradable modification materials and simple preparation process would highlight the potential of modified membranes in large-scale production and green oily wastewater treatment.