A novel hydrophilic treatment of polyvinylidene fluoride membrane based on layer-by-layer assembly

Abstract

TiO2 nanoparticles with diameter of approximately 20 nm were successfully assembled on polyvinylidene fluoride (PVDF) membranes layer-by-layer so as to improve the hydrophilicity of the PVDF membranes. SEM and droplet imaging system were used to determine microstructure and hydrophilicity of PVDF membranes. The effect of the TiO2 assembling layers on the contact angle (CA) of PVDF membranes was explored. As the number of the assembling layers were 2 and 3, the CAs of the modified PVDF membranes slightly increased at initial frozen time whilst decreased obviously after 1 min. For the modified PVDF membrane with assembling 5 layers TiO2 nanoparticles, the initial CA significantly decreased to 72.1° by approximately 30%. This novel method can be used to develop high performance hydrophilic PVDF membranes with high dispersion of TiO2 in filtration and separation applications.