The Stability of Poly(ether sulfone) Membranes Treated in Hot Water and Hypochlorite Solution

In order to improve hydrophilic property and filtration performance, a membrane has been modified by addition of polymeric additives in polymer solution. In the practical application, it is necessary to control the stability of the modified membrane. This study discusses filtration stability and hydrophilic property of four types of polyethersulfone hollow fiber membrane prepared with and without polymeric additives. The effect of membrane treatment (soaked in hot water and hypochlorite solution) on the filtration performance and hydrophilic property was investigated. Membrane consists of original PES membrane (M1), and three types of PES modified membrane with three different additive (M2, M3, and M4). The stability investigation was designed by using single module of hollow fiber membrane filtrated with deionized water during 10 days of filtration time. The hydrophilic property change of membrane was analyzed by measuring water contact angle. It was found that hydrophilic property and ultrafiltration performance of membrane M1 does not change after treated in water at temperature of 40o C and in NaOCl solution. The treatment of membrane has also showed no impact on the hydrofilic property and ultrafiltration performance of membrane M2, M3, and M4. A significant change of filtration performance of membrane M2, M3, and M4 was obtained after membrane soaked in hypochlorite solution. Water permeability of those membrane increased up to 50% after ten days of filtration.