Improving the filtration performance of ZrO₂ membrane in non-polar organic solvents by surface hydrophobic modification

Recently, ceramic membranes have been used increasingly in the treatment of non-polar organic solvents, such as oil purifying. The presence of water in organic solvents leads to membrane fouling, because of the hydrophilic property of ceramic membranes. To improve the filtration performance, surface hydrophobic modification was conducted in this study. ZrO₂ membranes with a mean pore size of 0.2μm were modified with a self-assembled monolayer of hexadecyltrimethoxysilane (HDTMS). The modified membranes were characterized with FTIR, TGA, SEM, contact angle measurements, and gas permeation tests. The filtration performance of the modified membranes was experimentally studied in the treatment of water-in-oil (W/O) emulsions. All of the characterizations showed that HDTMS was successfully grafted onto the membrane surface and surface modification had little influence on the membrane morphology and pore structure. The filtration results showed that a higher permeate flux and water rejection was obtained with the modified membranes. As a result, surface hydrophobic modification was effective to mitigate membrane fouling. The presented method is important for developing robust membranes with a low level of membrane fouling in the filtration of non-polar organic solvents.