| Abstract
| - To understand the effects of protein adsorption on filtration performance, poly(2-hydroxyethylmethacrylate) (PHEMA) was grafted by the γ-ray preirradiation process onto the porous surface of apolypropylene (PP) membrane. The colloidal filtration of such membranes was discussed with respect tothe correlation between the adsorption of the bovine serum albumin (BSA) proteins and the variation ofphysical properties of the PP-graft-PHEMA (PP-g-PHEMA) membrane surface. The specific resistance (αc)of the protein layer formed during filtration was obtained by line fitting through the filtration experimentalresults, using the colloidal filtration model proposed by Carman. The existence of PHEMA gave muchfaster rates of permeation than those of the original PP membrane because of the more or less dilute BSAprotein concentration at the PHEMA layer. It was confirmed from the filtration experiment that thePHEMA layer grafted on the surface of the membrane prevented the intimate contact of BSA proteins withthe surface of the membrane, resulting in a low specific resistance because of the increase of interspacingof the protein layer composed of the BSA protein particles. Especially, αc of a 40.6 wt % PHEMA layer is0.72 × 102 (m-1 g-1), much lower than that of the unmodified original PP membrane (αc = 6.24 × 102).In addition, although the mutual repulsive interaction between BSA protein and the surface of the PP-g-PHEMA membrane was weak with the increase of the grafting degree, the low adsorption of BSA proteinswith the increase of PHEMA grafting was crucially affected by the contribution of the higher roughnessand hydrophilicity due to grafting PHEMA rather than by the contribution of repulsive interaction betweentwo species.
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