Preparation and Characterization of a Robust and Hydrophobic Ceramic Membrane via an Improved Surface Grafting Technique

Studies have shown that hydrophilic surfaces of ceramic membranes can be modified to be hydrophobic using a grafting method. In this study, a robust and hydrophobic ceramic hollow-fiber membrane was developed by introducing a pretreatment technique, followed by a grafting method. The contact angle of the grafted membranes using the pretreatment technique was approximately 140°, indicating that the hydrophilic membrane surfaces were successfully modified to be hydrophobic. The mean roughness and the root roughness of grafted membranes decreased from 41 to 27.6 nm and from 53.4 to 33.6 nm, respectively, indicating that the membrane was covered by a grafted layer. The mechanical strength of the membrane was retained after the grafting process, and the grafted membrane was found to be thermally stable up to 270 °C and chemically stable in hexane for 100 h.