High performance PVDF-TiO2 membranes for water treatment

In order to obtain low-fouling membranes, TiO2 nanoparticles were entrapped in PVDF membranes prepared by the NIPS wet-process. Typical asymmetric membrane structure was obtained. Membrane structure, hydrophilic properties and permeability were improved in comparison with PVDF neat membrane when increasing TiO2 concentration up to an optimum concentration of 25%wt. Maximum permeate flux of 150 L/h/m2 was successfully obtained. For TiO2 content beyond 25%wt, TiO2 particles agglomeration prevents the improvement of hydrophilic properties and permeability. Under UV irradiation, phenomena of super-hydrophilicity due to presence of TiO2 in the composite membrane permits to suppress pure water permeate flux decline and reach higher fluxes. Fouled composite membranes after BSA filtration were successfully cleaned using water and UV irradiation. Permeate flux was totally recovered after this cleaning.