PEG-modified GO nanosheets, a desired additive to increase the rejection and antifouling characteristics of polyamide thin layer membranes

In this study, polyethylene glycol-modified graphene oxide (PEG/GO) nanosheets were utilized to enhance and improve the characteristics of polyamide (PA) thin layer membranes. UV irradiation was employed to study the effects of irradiation on the membranes properties. The modified thin layers were fabricated with addition of different concentrations of PEG/GO (0.5, 1.0 and 1.5 wt.%) in aqueous phase. SEM and AFM images clearly illustrated the formation of compressed and dense thin layers. The rejection capability of the modified membranes against NaCl and Na2SO4 was increased from 18.5% and 63.5% to 51% and 93%, respectively. The contact angle results showed a notable increase in surface hydrophilicity of the thin layers at the presence of PEG/GO. The flux recovery ratio, which refers to the antifouling properties of the thin layers, increased from 62% to approximately 90%. SPM software showed that the surface pore sizes and roughness parameters of the in-house fabricated membranes decreased obviously. The pure water flux was significantly improved when the surface was exposed to UV radiation. A commercial membrane (NF2, Sepro) was employed to compare the characteristics of the prepared thin layers.