APPLICATION OF ION-BEAMS TO SYNTHESIS OF ENVIRONMENTALLY RESPONSIVE TRACK MEMBRANES

Ion beams with an energy of 10 MeV/n were used for producing porous me mbranes of poly(ethylene terephthalate) and poly(diethyleneglycol-bis- allylcarbonate films. The condition to obtain cylindrical pores was ex plained by the relation between the relative etching rate and restrict ed energy transfer from ion beams to polymer films. The porous membran es were chemically modified either by copolymerizing or by grafting su ch hydrogel monomers as N-isopropylacrylamide and acryloyl-L-proline m ethyl ester. The obtained membranes changed pore size in response to t he change in environmental conditions such as temperature. The change was followed by electron microscopy. A cyclic change in conductivity o f potassium ion through the membrane of a single pore was observed whe n the temperature of the dialysis cell containing a 0.1 M KCl solution was cycled between two temperatures. The selectivity of organic ion p assing through the membrane drastically changed at the phase transitio n temperature of the attached hydrogel layer. (C) 1997 Elsevier Scienc e B.V.