Anti-Fouling Ternary Zwitterionic Coating Membrane with Strong Surface Hydration and Salt Resistant for Efficient Long-Term Emulsion Separation in High Salinity Marine Environment

Abstract

Membrane separation has been acknowledged as an advanced technology to handle the oil spills. However, most of the superhydrophilic/underwater superhydrophobic membranes currently applied for oil/water separation would lose their superwettability when exposed to salty marine environments, leading to serious membrane plugging and separation performance decline. Herein, inspired by seawater fish and mussels, a simple, green, and versatile one-step co-deposition strategy is proposed for fabrication of a ternary zwitterionic coating with strong surface hydration on diverse membranes, showing excellent anti-fouling properties in high salinity environments, even in a saturated NaCl solution. Thanks to the excellent superhydrophilic and salt resistance, it is capable of separating oil from aqueous salts. Moreover, the coated microfiltration membrane achieves high-performance long-term surfactant-stabilized oil-in-seawater emulsion separation with impressive recyclability. The ternary zwitterionic coating membrane exhibits great potential in treating oily wastewater in marine.

Keywords: superhydrophilic, anti-fouling, salt resistant, oil/water emulsion separation