화학공학소재연구정보센터
Journal of Membrane Science, Vol.370, No.1-2, 166-174, 2011
Using co-solvents and high throughput to maximize protein resistance for poly(ethylene glycol)-grafted poly(ether sulfone) UF membranes
The surface of poly(ether sulfone) (PES) membranes were modified to reduce protein fouling by grafting poly(ethylene glycol) methyl ether methacrylate (PEG) onto the membrane. Photo-induced graft polymerization (PGP) was used with a recently developed high throughput platform (HTP). To optimize and improve PEG protein resistance, four different co-solvent additives (dimethyl chloride (DCM), dimethylene formamide (DMF), dimethylene sulfoxide (DMSO) and N-methyl-2-pyrrolidone (NMP)) were mixed with aqueous PEG solution in order to examine co-solvent effects on grafting and filtration performance of PES-g-PEG surfaces. Bovine serum albumin (BSA, 1 mg mL(-1)) was used as model "foulant" protein and DI water and PBS filtration resistance and protein sieving were measured. The intensity of fouling was quantified by a fouling index (R) and correlated with the degree of grafting (DG) using FTIR-ATR spectra. Lower R values were observed for grafting PEG in the presence of co-solvents than in their absence. The lowest fouling index (R = 0.03 +/- 0.04) was with a 0.2 mol L(-1) PEG and 0.15 mol L(-1) DCM mixture, where the DG was 0.05 +/- 0.005. As differences in Hansen solubility parameters reflect, the high affinity of co-solvent with PEG and with PES appears to result in lower fouling. Also, weak affinity between co-solvent and water helps maximize the fouling index suppression. The results reported here are significant because they demonstrate that co-solvents can increase the anti-fouling properties of PEG-grafted PES membranes beyond that possible with PEG alone (up to 86% decrease in R) and far better than that with commercial PES membranes (up to 97% decrease in R). Of the four PEG-solvent pairs used to modify the PES membranes, PEG-DMF and PEG-DCM exhibited lower fouling than the others and the control (PEG alone) at the expense of lower permeation flux, while PEG-DCM was the best compromise with respect to anti-fouling properties, permeability, and protein permeation, i.e. maximizing protein capture in the permeate. (C) 2011 Elsevier B.V. All rights reserved.