Preparation and characterization of PFTS grafted alumina supported zirconia (ASZ) membrane for removal of phenol from aqueous solution

Asymmetric alumina supported zirconia (ASZ) grafted 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFTS) membranes were successfully prepared. The structure, micromorphology, surface elements, roughness and hydrophobicity of the ASZ membrane before and after grafting were evaluated by XRD, SEM, EDS, AFM and contact angle, respectively. The effects of PFTS concentration, different solvents and alkali pretreatment on the hydrophobicity of the membrane surface were investigated systematically. The surface roughness and contact angle increased while the SFE decreased as the pH of the alkali pretreatment increased. The results show that the hydrophobicity of the PFTS grafted membrane depends on the roughness of the modified membrane surface and the low surface energy of the CF₂ and CF₃ bonds in the PFTS molecule on the membrane surface. The grafting mechanism of ASZ membrane with PFTS was studied by various analytical methods such as XPS, FTIR and TG-DSC, and the grafting process was verified. According to obtained results, PFTS chains were grafted onto the ASZ surface successfully. The PFTS grafted ASZ ceramic membrane is suitable for pervaporation to remove phenol from aqueous solutions, the phenol removal increased from 29.1 mg/L to 138.73 mg/L as the pH of the pretreatment increased from 7 to 11.