Study of antifouling and decolorization effect in polyethersulfone membranes improved with dendrimer-modified metal–organic frameworks

The Mil-125(Ti) metal–organic framework nanoparticles were modified with different compounds i.e. polyamidoamine dendrimer (Mil-Den), chitosan (Mil-CS) and Mil-CS-Den to prepare functional and hydrophilic nanocomposites. These nanocomposites were characterized and applied for modification of polyethersulfone (PES) membrane by blending them in the dope solutions. The mixed matrix PES membranes were manufactured by the nonsolvent-induced phase inversion method. The introduction of the nanocomposites into the membrane structure led to positive alterations such as the improvement of hydrophilicity and morphology causing the development of permeability and antifouling properties. The bare PES membrane contact angle was decreased from 60° to 34.5° by adding 0.5 wt% of Mil-CS-Den nanocomposite. Applications of novel structures with special absorption in 0.5 wt% of Mil-CS-Den membrane, caused an increment of porosity, mean pore size and reduction of surface roughness. The permeability was enhanced from 4.2 to 21.43 L/m² h bar, while fouling was reduced from 48.5% to 13.5% which indicates the strengthening of the antifouling feature of the hydrophobic PES membrane. Also, the flux recovery ratio was enhanced from 66.7% to 89.3% by blending 0.5 wt% of Mil-CS-Den. The modified membranes showed an excellent dye separation performance. The attachment of dendrimer and chitosan to the Mil-125(Ti) surface increased the efficiency of Mil-125(Ti) in the modification of the PES membrane. The utilization of nanomaterial features can reduce the limitation of membrane processes and reach desirable outcomes. The results of this work indicate the high potential of the modified MOF for the removal of dye contaminants as well as provide a suitable perspective for water purification with the help of membrane processes.