Effect of incorporating graphene oxide and surface imprinting on polysulfone membranes on flux, hydrophilicity and rejection of salt and polycyclic aromatic hydrocarbons from water

We report a significant enhancement of hydrophillity of polysulfone (Psf) membranes after modification with graphene oxide (GO) as a filler followed by surface imprinting on the surface of GO/Psf composite imprinted membranes (CIMs). The surface imprinting on the GO-Psf membrane was employed in order to enhance its selectivity towards polycyclic aromatic hydrocarbons (PAHs) in water. The CIMs were prepared through a process of phase inversion of a mixture of graphene oxide and polysulfone (Psf) in N-methylpyrrolidone (NMP). Fourier-transform spectroscopy (FT-IR) of the imprinted showed new peaks at 935 cm⁻¹ and 1638 cm⁻¹ indicating success in surface imprinting on the GO-Psf membrane. The CIM also showed improvement in flux from 8.56 LM⁻² h⁻¹ of unmodified polysulfone membrane to 15.3 LM⁻² h⁻¹ in the CIM, salt rejection increased from 57.2 ± 4.2% of polysulfone membrane to 76 ± 4.5%. The results obtained from the contact angle measurements showed a decrease with increase in GO content from 72 ± 2.7% of neat polysulfone membrane to 62.3 ± 2.1% of CIM indicating an improvement in surface hydrophilicity. The results from this study shows that, it is possible to improve the hydrophilicity of the membranes without affecting the performance of the membranes.