Polyethersulfone Ultrafiltration Membranes Modified With Hybrid Ag/Titanate Nanotubes: Physicochemical Characteristics, Antimicrobial Properties, And Fouling Resistance

The influence of the addition of Ag-modified titanate nanotubes (Ag/TNTs) on transport, antifouling and antibacterial properties of polyethersulfone (PES) ultrafiltration membranes is presented and discussed. The membranes were prepared by the wet phase inversion method using blending of casting dope with Ag/TNTs of various Ag content (2.83 (Ag/TNT_2.5)-23.21 wt% (Ag/TNT_100)). The nanocomposites exhibited good stability in aqueous medium with less than 0.82% of the initial Ag content released during 7 d. The presence of the Ag/TNTs contributed to changes of the surface properties of the membranes evaluated on a basis of zeta potential measurement and atomic force microscopy analysis. Moreover, the modified membranes exhibited higher hydrophilicity than the unmodified (M1) membrane. The addition of Ag/TNTs containing 11.44 or 23.21 wt% Ag contributed to an increase of pure water flux compared with the one measured for M1 membrane, by 15% and 30%, respectively. The applied modification also resulted in an improvement of fouling resistance of the membranes as evaluated on a basis of ultrafiltration of bovine serum albumin solution. Moreover, an improved inhibition of Escherichia coli growth with increasing concentration of Ag in Ag/TNTs applied for membrane modification was also observed.