Effects of Polyvinylpyrrolidone on the Permeation and Fouling-Resistance Properties of Polyetherimide Ultrafiltration Membranes

In this study, polyetherimide (PEI) ultrafiltration (UF) membranes were fabricated by incorporating different amounts of hydrophilic polyvinylpyrrolidone (PVP) via the phase inversion technique. The PEI/PVP blended membrane showed the highest pure water flux (147.1 L m(-2) h(-1)), water content (70.2%), and surface energy (112.1 mN/m) when the 8 wt % of PVP was blended into the base polymer PEI. This particular membrane,,designated as PVP 8, also showed the lowest contact angle (56.1 degrees)) hydraulic resistance (2.2 kPa/(L m(-2) h(-1))), and shrinkage ratio (4.3%). The addition of PVP has reduced the tensile strength of the PEI membrane because of the decrease in, rigidity. The UF experiments with the following proteins, bovine serum albumin (BSA), egg albumin (EA)) pepsin, and trypsin, had experienced a decrease in protein rejection whereas permeate flux increased by increasing PVP loading. The BSA adsorption experiment revealed that the adsorbed amount of BSA on the surface of the membrane was notably decreased from 0.17 mg cm(-2) of neat PEI membrane to 0.08 mg cm(-2) of PVP 8. The flux recovery ratio (FRR) experiment also showed that the fouling resistance property of the membrane was enhanced with the increment of PVP.