Enhanced hydrophilicity and mechanical robustness of polysulfone nanofiber membranes by addition of polyethyleneimine and Al2O3 nanoparticles

A novel hydrophilic and mechanically robust polysulfone (PSF) nanofiber membrane (NFM) was prepared by electrospinning of a PSF solution blended with polyethyleneimine (PEI) and Al2O3 nanoparticles. The influence of PEI and Al2O3 nanoparticles concentration on the NFM characteristics was studied using scanning electron microscopy (SEM), Fourier transform infrared FT-IR spectroscopy, porosity, water contact angle measurement, and tensile strength test. Filtration performance of the nanofiber membranes (NFMs) were evaluated by the measurement of pure water flux (PWF) and bovine serum albumin (BSA) rejection tests. According to the results, blending PSF solution with 2 wt.% PEI and 0.05 wt.% Al2O3 nanoparticles resulted in formation of NFMs with high porosity and increased mechanical strength, which exhibited a low water contact angle of 23.5° and high water flux of 28,456 L/m2 h. On the other hand, incorporation of nanoparticles and PEI in the PSF membrane matrix led to increasing of tensile strength that it was changed from 0.15 to 0.69 for pure PSF and PSF/PEI/Al2O3, respectively. A-24 and 48% BSA rejection performances were obtained by nanoparticle incorporated PSF membranes. In conclusion, the studies strongly suggest that blending with hydrophilic additives of NFMs can enhance the hydrophilicity and mechanical strength of PSF membranes and these NFMs can be effectively used in water based membrane systems.