Superhydrophobic modification of ceramic membranes for vacuum membrane distillation

The hydrophobically modified ceramic membranes have great potential for energy-efficient membrane distillation. In this work, flat-sheet ceramic membranes with a superhydrophobic surface were fabricated by grafting 1H, 1H, 2H, 2H-perfluorooctyltrichlorosilane or 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane and followed by ultraviolet irradiation. The surface water contact angle was improved from 46 degrees of original ceramic membrane to 159 degrees, which exhibited a stable and excellent superhydrophobic effect. The modified membranes showed a high flux of 27.28 kg.m(-2).h(-1) and simultaneously maintained an excellent retention rate of 99.99%, when used in vacuum membrane distillation process for treatment of a 1 wt% NaCl (75 degrees C) aqueous solution. These results suggested that superhydrophobic modification of ceramic surface is a facile and cost-effective way to achieve higher membrane distillation performance. The superhydrophobically-modified ceramic membrane with an excellent desalination capacity would show considerable potential in practical membrane distillation utilizations. (C) 2017 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.