Preparation and characterization of modified ultrafiltration nylon 6 membrane modified by poly (acrylamide-co-maleic anhydride)

In attempt to prepare modified ultrafiltration (UF) Nylon 6 membrane and improve its hydrophilicity and anti-fouling performance, poly (acrylamide-co-maleic anhydride)(AM-MA) was utilized as hydrophilic copolymer additive in the dope solution. The UF Nylon 6/AM-MA membranes were synthesized through blending Nylon 6 with poly(AM-MA) using a phase inversion process. Characterization of the prepared membranes for morphological studies and thermal behavior was carried out by SEM and DSC instruments respectively. The SEM photos demonstrated that by increasing the copolymer density in the dope solution, the morphology was changed from spongy to bi-continuous, composed of small interlocked and stick-like crystallites. FTIR/ATR and water contact angle data also confirmed the existence of AM-MA copolymer on the blend membranes surface. Furthermore, the effect of different molecular weights and concentration of hydrophilic copolymer on filtration performance and antifouling properties were experimentally studied. The results exhibited that the blend UF membranes possessed better water flux permeability than pure Nylon 6 membrane due to the increased surface hydrophilicity and porosity. Fouling resistance experiments revealed that the surface anti-fouling ability of the blend membranes was improved via the addition of AM-MA copolymer with lower MW (co1) to the cast solution, while this parameter was weakened in higher MW of copolymer (co2).