Preparation and characterization of hydrophobic ceramic hollow fibre membrane

Alumina hollow fibre membranes were prepared by spinning alumina/binder suspensions to hollow fibre precursors, which were then sintered at elevated temperatures. The obtained membranes are hydrophilic in nature and their outer surfaces were then modified to be hydrophobic by grafting with 0.01 mol/l of 1H, 1H, 2H, 2H-perfluorooctylethoxysilane (FAS) solution. The results from membrane characterization experiments revealed that the membrane surfaces were successfully changed from hydrophilic to hydrophobic, as reflected by the contact angles, which were increased from less than 80° to more than 100°. The gas permeation results indicated a slight decrease in gas permeability of the membranes due to the additional resistance from a FAS layer on the membrane surface. The membranes were found to be thermally stable up to 250 °C and showed no changes in their hydrophobicity after in contact with hexane for 96 h.