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° of original ceramic membrane to 159°, 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 °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.