Immobilized metal ion affinity hollow-fibre membranes obtained by the direct grafting technique

An immobilized metal ion affinity hollow fibre was prepared by radiation-induced direct grafting of glycidylmethacrylate (GMA) on hydrophilized polyethylene membranes. The epoxy group was converted into an iminodiacetate by iminodiacetic acid treatment. The effect of the radiation dose, salt inhibitors, methanol and GMA concentration, on the grafting degree vas studied. The degree of grafting was closely related to the GMA concentration. Salt inhibitors failed in the production of a differential effect on the grafting and homopolymerization processes. Between 30 and 35% of methanol, there is a maximum yield, and no grafting was obtained with a methanol concentration above 50%. Water flux dropped exponentially with the increase in the grafting degree. Scanning-electron microscopy showed that the graft branches are formed on the pores. The pectinesterase adsorption capacity of the membranes was of the same order as of the commercial chelating soft gels. (C) 1999 Elsevier Science Ltd. All rights reserved.