Ultrafiltration (UF) polyethersulfone (PES) membranes were prepared by wet phase inversion method. Commercial halloysite nanotubes (HNTs) in the amount of 0.5–4 wt % vs PES (15 wt %) were introduced into the casting solution containing the polymer and N,N-dimethylformamide as a solvent. The morphology, physicochemical properties and performance of the membranes were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM), zeta potential, porosity and contact angle analyses, as well as permeability measurements. Moreover, the antifouling properties of the membranes were evaluated during UF of a model solution of bovine serum albumin (BSA). The research revealed a positive influence of modification with HNTs on hydrophilicity, water permeability and antifouling properties of the PES membranes. The most significant improvement of permeability was obtained in case of the membrane containing 2 wt % of HNTs, whereas the highest fouling resistance was observed for 0.5 wt % HNTs content. It was found that a good dispersion of HNTs can be obtained only at loadings below 2 wt %. Based on the results a relation between severity of membrane fouling and surface roughness was proved. Moreover, an increase of the roughness of the modified membranes was found to be accompanied by an increase of isoelectric point values.

No abstract

No abstract

No abstract

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. density of polyethersulfone (g mL −1 ) w density of water at 20 ∘ C (g mL −1 )