Reversal of wettability of carbon cloth by microwave-assisted modification technology for efficient oil-water separation application

Abstract

A modified layer of ZnO coating with the thickness of about 0.57 μm has been uniformly deposited on carbon cloth by microwave-assisted modification technology for reversing the wettability of carbon cloth, resulting in the fabrication of ZnO/CC Mem. The inherent properties of carbon fibers absorbing microwave radiation and converting it into volumetric heating contribute to the uniform deposition of ZnO modified coating on carbon cloth. After modification, the WCA of as-prepared ZnO/CC Mem is 0° while the corresponding UWOCA is up to 158.4 ± 1.1°, exhibiting the excellent superhydrophilicity/underwater superoleophobicity. In the process of gravity driven oil-water separation, a high filtrate flux about 18,625 ± 100 L/(m 2 h), is found in the separation of oil-water mixture, and the corresponding separation efficiency is 99.9%; While for the treatment of simulated kitchen oily wastewater, a bilayer ZnO/CC Mem is used. The corresponding filtrate flux and separation efficiency are 15,880 ± 100 L/(m 2 h) and 99.8%, respectively. In addition, the fouled ZnO/CC Mem could restore the virgin performance by a simple cleaning process. • A modified layer of ZnO coating had been uniformly deposited on carbon cloth by microwave-assisted modification technology for efficient oil-water separation. • The underwater oil contact angle of ZnO/CC Mem was up to 158.4 ± 1.1°, exhibiting the excellent superhydrophily/underwater superoleophobicity. • A high filtrate flux and excellent separation efficiency were found in the separation of simulated kitchen oily wastewater by ZnO/CC Mem.