Comparing the effect of incorporation of various nanoparticulate on the performance and antifouling properties of polyethersulfone nanocomposite membranes

We have prepared polyethersulfone (PES) nanocomposite membranes comprising of cloisite 30B clay, SiO₂, TiO₂, hydroxyl-functionalized multi-walled carbon nanotubes (MWCNTs-OH), and carboxyl-functionalized multi-walled carbon nanotubes (MWCNTs-COOH). The nanoparticulate at five different concentrations were added into the polymeric dope solutions including 15 or 18 wt% of PES, N,N-dimethylacetamide (DMAc) or 1-methyl-2-pyrrolidone (NMP) as solvents, and 1 wt% of pore forming agent. These nanoparticulate may improve porosity, hydrophilicity, and open the channels up for improved water transport. Although many nanoparticulate with various properties and functionalities have been used for the same aims, the efforts have been made to choose the best nanomaterial and its loading among these five famous nanofillers for modifying PES ultrafiltration membrane. The nanocomposite membranes showed better antifouling characteristics and water permeability as compared with the pristine PES membrane because of the porosity and hydrophilicity improvements. However, further increasing nanoparticulate loading led to a possible agglomeration and diminished the water flux and fouling resistance. The effect of polymer concentration and solvent showed that membranes fabricated using 15 wt% of PES concentration possessed greater fouling resistance and water flux compared to those of fabricated using 18 wt% of PES concentration. Also, membranes fabricated using DMAc exhibited a more porous structure with considerably greater water flux as compared with those of fabricated using NMP as the solvent. Based on the results, 1 wt% of TiO₂ is recommended as the best nanoparticulate for the PES ultrafiltration membrane modification since it exhibited the superlative performance with a 320% water flux enhancement, nearly 98% BSA rejection, and 130% FRR improvement.