Study on fouling of ultrafiltration membrane by electron spin resonance

Electron spin resonance (ESR) spectroscopy has been used as a method to stu dy membrane fouling during ultrafiltration (UF). Bovine serum albumin (BSA) and polyethylene oxide (PEO), with and without TEMPO (spin probe), solutio ns in water were used as the feed in the UF experiments. Asymmetric membran es were prepared by phase inversion technique using casting solutions of po lyethersulfone (PES) in n-methyl pyrrolidone (NMP). Polyvinyl pyrrolidone ( PVP) was added as a nonsolvent additive. The fouling of the membrane was de pendent on the size and shape of the macromolecular solute and the operatin g feed pressure. Tt was also observed that the mobility of the deposited ma cromolecular solute in the membrane pore became the least in a certain rang e of pore size of UF membranes and this minimum mobility was also dependent on the operating pressure. (C) 2000 Elsevier Science B.V. All rights reser ved.