SYNTHESIS OF ORGANIC-INORGANIC COMPOSITE MEMBRANE BY SOL-GEL PROCESS

Silica was succesfully incorporated into cation exchange polymer membr anes, CL-25T and Nafion 417, utilizing sol-gel process. As dipping tim e increased, increase in silica uptake in membrane was observed. In Na fion 417 membrane, no relationship was found between the silica uptake and the change in ion exchange capacity. But CL-25T which has larger pores than Nafion 417 shows proportional decrease in ion exchange capa city with increasing silica uptake. It suggests that the pore structur e of membrane and the size control of silica sol are important to modi fy the structure of composite membranes. In CL-25T membranes modified by silica, the transport rate of IPA (isopropyl alcohol) increased wit h increasing OH- concentration on the pore surface.