Pseudo-Zwitterions Self-Assembled From Polycation and Anion-Clusters Showing Exceptional Water-Cleanable Anti-Crude Oil Adhesion Property

Abstract

It is of great importance and practical value to develop a facile and operable surface treatment method of materials with excellent anti-pollution and anti-adhesion property, but still a huge challenge. In this work, a series of pseudo-zwitterions are prepared from electrostatic assembly of cationic polyethyleneimine and anionic phosphonic clusters. These pseudo-zwitterionic assemblies provide a strong hydration through electrostatic interaction with water and in turn create a barrier against oil foulants, leading to a nearly zero crude oil adhesion force. The pseudo-zwitterions decorated surfaces exhibit exceptional water-cleanable oil repellent property, even when they are completely dried and without pre-hydration before fouled by crude oil. While using these pseudo-zwitterions modified polymeric membranes for separating surfactant stabilized oil-in-water emulsion, less than 10% decline of permeating flux is observed throughout a 2 h continuous separation experiment, showing excellent emulsion separation ability and anti-pollution performance for high viscous oil.