2019 Volume 127 Issue 1 Pages 35-43
Inorganic surface modification was performed using a SiO2 sol–gel technique to mitigate the fouling of alumina microfiltration membranes. A positively charged alumina membrane was coated with SiO2 to generate a negative charge, and as a result, electrostatic repulsion prevented the serious adsorption (or deposition) of model foulants on the membrane. Upon the formation of the SiO2 layer, small changes in the surface morphology, pore size, and surface roughness were detected. In particular, as the pore size decreased, the pure water permeability gradually decreased. When the membrane fouling was accelerated with model foulants, the highest normalized flux level and the lowest flux decline ratio (%) were observed in the smallest SiO2-coated microfiltration membrane (0.1 M SiO2). In summary, the SiO2 coating contributed to the optimization of the antifouling properties of the ceramic membranes, although the pore size was reduced.