A super-hydrophilic and underwater super-oleophobic membrane with robust anti-fouling performance of high viscous crude oil for efficient oil/water separation

Abstract

In recent years, crude oil-spill accidents released millions of tonnes of crude oil into the environment worldwide. Oily wastewater has persistent harmful influences on the marine environment and animal health. It is essential to dispose of crude-oil contained wastewater. The high adhesion of crude oil is easy to adhere to the surface of separation materials, and traditional separation equipments always become invalidation when used for treating the oily wastewater containing crude oil. To solve this problem, we have successfully prepared super-hydrophilic chitosan hydrogel coated metal mesh (CS-SSM) via a simple coating method and the cross-linking reaction of chitosan and glutaraldehyde, which exhibits robust anti-high viscous crude oil-fouling performance. The super-hydrophilic CS-SSM showed excellent separation performance for various oil/water mixtures, and the separation efficiency and flux for the high viscous crude oil/water mixture exceed 99.99% and 12,000 L·m−2·h−1 respectively. Moreover, the molecular dynamics simulation clarified that the chitosan hydrogel coating the surface of metal mesh can dramatically decrease the interaction between crude oil molecules and metal mesh, resulting in the robust anti-high viscous crude oil-fouling performance for CS-SSM. In addition, the oil skimmer fabricated with the super-hydrophilic CS-SSM was demonstrated to effectively deal with large-area spills of crude oil.