Structure-induced superhydrophilicity of silica membranes through hybridization and self-assembly of different dispersed nanoparticles

Abstract Self-assembled membranes with remarkable superhydrophilicity and high optical transparency are prepared by hybridizing dispersed silica nanoparticles of mean diameters, D S and D L (D S  « D L ). It has been found out in the previous work that the hybridized silica sol consisting of two dispersed nanoparticles that differ greatly in size would help lead to a smaller water contact angle for the final membrane. Among the results, one hybridized membrane containing silica nanoparticles of 45 nm and 483 nm exhibits 8.9 ± 1° as for water contact angle and 90% as for transmittance within UV–Visible region. Morphology of the membranes shows hierarchical structure or cracky layer, while the specific architecture is still influenced by the gap in particle size. As a conclusion, the process of hybridization enhances the hydrophilicity and adjusts the transmittance of membranes as well. The new method is a feasible simplification comparing with the traditional ways in attaining superhydrophilicity and we hope it will apply for other hydrophilic materials to improve their wetting ability.