Application of nanosized TiO2 in membrane technology

Membranes can be produced either from inorganic or polymeric materials. Although inorganic membranes offer some advantages, such as high chemical, thermal and mechanical resistance, their preparation is often very costly. On the other hand, polymeric membranes, both as flat sheets and hollow fibers, can be easily manufactured via the phase inversion technique, which is, indeed, the most versatile and widespread process for membrane preparation. Recently, the introduction of different nano materials into polymeric membranes, for producing the so-called mixed matrix membranes (MMMs), has been proposed as a viable strategy to combine the typical advantages of inorganic materials with the ease of preparation of polymeric membranes. Titanium dioxide (TiO2), in particular, is among the most investigated materials, because it can endow membranes with excellent photocatalytic, antibacterial, anti-fouling and UV-cleaning properties. In this chapter, the most recent advances regarding the preparation and application of TiO2 membranes are presented.We show how the combination of the most commonly used polymeric materials, such as poly(vinylidene fluoride) (PVDF) and poly(ether sulfone) (PES),with TiO2 nanoparticles (NPs) enables the preparation of membranes with superior performance coupled to outstanding fouling resistance. The application of TiO2 membranes to water and wastewater treatment will be discussed as one of the most interesting applications of this technology.