Superhydrophobic Surface Modification of Carbon Nanotubes for Polymer Membrane in Direct Contact Membrane Distillation

Abstract

Direct contact membrane distillation (DCMD) is a promising method for water purification and membrane is the key component governing the performance of the membrane distillation (MD) process which need the high porosity, thin thickness, narrow pore distribution and enough pore size. However, the commercial PVDF membrane still have a very low MD efficiency which block the industrial application. In this study, fluorosilanization and silanization modification methods were applied to modify the carbon nanotubes (CNTs) respectively and the combination of these methods were also employed. The polyvinylidene fluoride (PVDF) membranes with different surface modification of CNTs were prepared by electrospun method and employed in MD process. The effect of different methods of surface modification on membrane morphology, dispersion hydrophilicity, porosity and DCMD performance were investigated. These results should demonstrate that whether the modified CNTs is a promising material for PVDF membrane in DCMD application or not. Finally, the possible mechanism of functioned CNTs in PVDF membrane was explained.