The effect of amine functionalization of CuO and ZnO nanoparticles used as additives on the morphology and the permeation properties of polyethersulfone ultrafiltration nanocomposite membranes

New polyethersulfone (PES) ultrafiltration blended membranes were prepared by doping them with different amine-functionalized CuO (FCN) and ZnO (FZN) nanostructures added at different concentrations (0-2 wt%). 3-(aminopropyl) trimetoxysilane was used as an amine precursor in a simple method for the amino-functionalization of the nanoparticles. Physicochemical properties of the synthesized nanoparticles before and after amino-functionalization were characterized by X-ray diffraction, SEM and FTIR techniques to confirm the correct synthesis. SEM, EDAX, AFM, and pore size distribution were utilized as the applied techniques to know more about the membrane morphology. Water contact angle measurement was used to determine the hydrophilicity of the membranes. All of the doped membranes showed a significant increase in porosity and hydrophilicity, resulted leading to considerable improvement in the pure water flux, as compared with the bare PES membrane. Comparison of FCN and FZN showed that the NH2CuO nanoparticles participation in the PES polymeric matrix had a more remarkable positive effect on permeability, reaching to 886.6 kg/m2h (0.5 wt% FCN/PES), as compared with the bare one (554.2 kg/m2h). By the addition of the nanoparticles in specific amounts, AFM results showed the remarkable reduction in the determined roughness. Moreover, the obtained results were in a good agreement with the antifouling modification of the amino-functionalized blended membranes. More roughness of the bare PES membrane, as compared to the mixed one, increased the possibility of fouling. The FRR of the blended membranes was improved. AFM and FRR results showed that the more roughness of the membrane surface increased the possibility of fouling.