PVDF–TiO₂ composite hollow fiber ultrafiltration membranes prepared by TiO₂ sol–gel method and blending method

Abstract

Abstract Organic–inorganic polyvinylidene fluoride (PVDF)–titanium dioxide (TiO 2 ) composite hollow fiber ultrafiltration (UF) membranes were prepared by TiO 2 sol–gel method and blending method, respectively. The membranes were characterized in terms of microstructure, hydrophilicity, permeation performance, thermal stability, and mechanical strength. The experimental results indicated that PVDF–TiO 2 composite UF membranes exhibited significant differences in surface properties and intrinsic properties because of the addition of inorganic particles. The TiO 2 particles improved the membrane strength and thermal stability of PVDF–TiO 2 composite UF membranes. In particular, hydrophilicity and permeability increased dramatically with the increase of TiO 2 , whereas the retention property of UF membranes was nearly unchanged. However, high TiO 2 concentration induced the aggregation of particles, resulting in the decline of hydrophilicity and permeability. Compared with PVDF–TiO 2 composite hollow fiber UF membranes prepared by TiO 2 blending method, PVDF–TiO 2 composite hollow fiber UF membranes prepared by TiO 2 sol–gel method formed a dispersed inorganic network, and the stronger interaction between inorganic network and polymeric chains led to TiO 2 particles being uniformly dispersed in UF membranes. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009