Preparation and characterisation of the novel hydrophobic FAS/α-Al2O3 composite membrane for membrane distillation

The ceramic support with pore gradient structure was modified by the chloroform solution of 1 H, 1 H, 2 H, 2 H-perfluorodecytriethoxysilane (FAS) to prepare hydrophobic FAS/α-Al2O3 composite membrane. The effects of FAS solution concentration, reaction time and number of surface modification on the contact angle were investigated by the orthogonal experiments. The physical and chemical properties of the modified ceramic membrane and the unmodified one were characterised by the SEM analysis, FT-IR analysis, pore size and its distribution measurements. The salt rejection and the permeate flux of the membranes were investigated by air gap membrane distillation (AGMD). Results showed that the contact angles were all above 130° and up to 156.2° and the hydrophobicity of the membrane was quite obvious. Under the experimental conditions, the salt rejection of the composite membrane was 98.5% and the permeate flux was 12.68 kg·m−2·h−1. © 2021 Informa UK Limited, trading as Taylor & Francis Group.