Sodium alginate coating: A strategy to fabricate a membrane surface resistant against sodium alginate fouling

In this research, to reduce fouling of polyacrylonitrile (PAN) membrane, first, zinc-oxide (ZnO) nanoparticles as hydrophilic agent was utilized and PAN/ZnO membrane was synthesized, then, sodium-alginate (SA) as nanoparticle regulating agent was deposited on ZnO ([email protected]) and PAN/[email protected] membrane was synthesized. The performance of the synthesized membranes in reducing fouling of humic acid (HA), bovine serum albumin (BSA), and SA was examined. Results showed PAN/ZnO were 10.5% more porous, 27% less tortuous as well as greater negative charge density compared to PAN membranes. Also, the contact angle was reduced from 42° for PAN to 27° for PAN/ZnO membranes; meanwhile, the PAN/ZnO suffered disadvantages including larger pore size, higher molecular-weight-cut-off (MWCO), and fewer pores. The SA coating via ordered arrangement of nanoparticles caused PAN/[email protected] to have a contact angle of 24°, further, the number of its pores was about 35% greater compared to PAN membranes. These changes caused the fouling of BSA, HA, and SA by PAN/ZnO to be 2.5, 13.6, and 46.6% lower compared to PAN membranes. By contrast, because of superior structural features like more hydrophilicity, porosity, pore number; less tortuosity, lower MWCO, and fewer pore sizes; these figures were reported 5.8, 17.1, and 58.2% for PAN/[email protected] membranes.