Design and fabrication of fouling resistant cross-linked polyamide thin film composite nanofiltration membrane consisting of an aliphatic triamine and terephthaloyl chloride for water desalting applications

Although a lot of polyamide thin film composite nanofiltration (TFC-NF) membranes have been developed but organic and biofouling are affecting the performance and lifespan of such membranes. Hence, the development of new and efficient polyamide membrane with a great potential against fouling is desperately needed. A new polyamide TFC-NF membrane was fabricated by reacting a linear aliphatic diethylene triamine (DETA) and linear cross-linker terephthaloyl chloride (TPC) through interfacial polymerization on ultrafiltration porous support. The resulting membrane namely Polyamide@PSf/PET was further treated with 15% hydrofluoric acid (HF) for 1 week. Membranes were extensively characterized by XPS, AFM, Zeta-potential, FESEM, FTIR, EDX, Elemental mapping and Contact angle. The HF treated Polyamide@PSf/PET showed superior performance in terms of pure water flux and rejection of tested salts and flux recovery. The highest observed water flux was 48 LMH at 24 bars while the rejection of MgSO₄ reached to > 95%. HF treated Polyamide@PSf/PET membrane showed greater flux recovery of 86.4% compared to Polyamide@PSf/PET which showed a flux recovery of 84.5%. The HF treated membrane showed lower tendency towards biofouling. The bacteriostatic studies revealed that the HF treated Polyamide@PSf/PET membrane inhibited S. aureus growth by 70.7%.