Influence of MgO nanoparticles on the physiochemical, transport, and antimicrobial properties of polyethersulfone membranes

摘要

In this study the influence of the addition of MgO nanoparticles (NPs) on physiochemical, transport, separation, and antimicrobial properties of polyethersulfone (PES) membranes was investigated. The MgO NPs with the agglomerate size of ca. 139 nm and the isoelectric point of 12.4 were obtained by the sol-gel technique. The unmodified membrane (A1, 15 wt.% PES) and membranes modified with different concentrations of MgO NPs (0.1-5 wt.% in relation to PES) were obtained by the wet phase inversion method using water as a nonsolvent and N, N-dimethylformamide as a solvent. The highest permeability values (209 dm(3)/m(2)h bar) were noted for a membrane containing 5 wt.% of MgO NPs (A6). A decrease of porosity from 75% (A1) to 70% (A6) and contact angle values from 59.2 degrees (A1) to 46.6 degrees (A6) with the increasing concentration of MgO NPs was observed. The isoelectric point was higher for the modified membranes (pH(I) = 3.4-3.6) compared with the unmodified one (2.8). Atomic force microscopy analysis revealed a significant difference between the surface roughness of the unmodified (1.75 nm) and modified membranes (2.84-2.60 nm). The highest inhibition of Escherichia coli growth was observed for the membrane modified with 5 wt.% MgO NPs, in case of which the bacterial cell viability was reduced by ca. 50%.