Influence of Ag/titanate nanotubes on physicochemical, antifouling and antimicrobial properties of mixed‐matrix polyethersulfone ultrafiltration membranes

BACKGROUND One of the main drawbacks of membrane processes is (bio)fouling. Recent attempts to overcome these phenomena focus on incorporation of nanoparticles into polymeric membrane matrices. This paper presents an investigation of the influence of modification of polyethersulfone (PES) ultrafiltration membranes with Ag/titanate nanotubes (Ag/TNTs) on physicochemical characteristics, water permeability and antifouling and antibacterial properties. RESULTS The modified membranes were prepared via a wet phase inversion method by adding 0.1–1.5 wt% of Ag/TNTs relative to PES into the casting solution. An increase of water permeability with increasing Ag/TNTs content up to 1 wt% was found. The modification contributed to fouling mitigation during ultrafiltration of humic acids solution due to (i) improved hydrophilicity, (ii) presence of Ag/TNTs turbulence promoters and (iii) negative surface charge of the membranes. A correlation between membrane surface roughness, zeta potential and proneness to fouling is discussed. The highest inhibition of bacterial growth, reaching 99.8 and 99.3% for Escherichia coli and Staphylococcus epidermidis, respectively, was observed at the highest Ag/TNTs content. CONCLUSIONS The introduction of Ag/TNTs into PES membrane structures improved membrane permeability, fouling resistance and antibacterial properties. The most significant improvement was observed in the case of membranes containing the largest quantities of Ag/TNTs. © 2019 Society of Chemical Industry