Polypropylene microfiltration membranes modified with TiO2 nanoparticles for surface wettability and antifouling property

TiO 2 nanoparticles have attracted much attention in the surface modification of polymer membranes for antifouling purpose due to their excellent hydrophilicity. In this work, a polydopamine/polyethyleneimine (PDA/PEI) intermediate layer was fabricated on the polypropylene microfiltration membrane via a co-deposition method and then TiO 2 nanoparticles (NPs) were modified on the membrane surfaces through a sol–gel process. TiO 2 -modified membranes with various Ti/C ratios were prepared and their surface structures and properties are compared with those of the nascent and PDA/PEI-deposited ones. Results indicate that the TiO 2 NPs modification increases both the surface wettability and the water permeation flux of the membranes remarkably. TiO 2 NPs also endow the membranes with promoted protein resistance properties. The relative flux reduction and flux recovery ratio are 31±3% and 82±5% for bovine serum albumin solution, while 26±4% and 86±3% for lysozyme solution. The TiO 2 NPs are also stable on the membrane surfaces under a wide range of pH value.