Ionic crosslinking of SO3H-group-containing graft chains helps to capture lysozyme in a permeation mode

SO3H-groupcontaining polymer chains were grafted onto a porous hollow-fiber membrane uniformly across the thickness of the membrane (about 0.9 mm) by radiation-induced graft polymerization of glycidyl methacrylate and subsequ ent reaction with sodium sulfite. The graft chains extended from the pore s urface due to their mutual electrostatic repulsion, and were crosslinked wi th bivalent ions such as Mg2+ and Ca2+, resulting in an increase in permeat ion rate of the liquid through the pores. Lysozyme was bound in multilayers to the SO3H-group-containing graft chains, which had been previously cross linked with Mg ions, and the permeation rate was increased with the progres sion of lysozyme binding based on the ion-exchange interaction with Mg ions . (C) 1999 Elsevier Science B.V. All rights reserved.