Facilitated transport of oxygen in poly(dimethylsiloxane-co-styrene-co-4- vinyl pyridine) terpolymer membrane containing cobalt Schiff base carrier

Abstract

A facilitated transport membrane was prepared by incorporating a cobalt Schiff base, Co(salen), as an oxygen carrier into a terpolymer membrane of poly(dimethylsiloxane-co-styrene-co-4-vinyl pyridine). A reversible oxygen binding of the carrier was investigated with UV-visible spectroscopy. The terpolymer membrane with carrier showed that the permeability of oxygen was increased from 275 to 405 barrer due to a facilitation action of Co(salen) carriers. Upon incorporating Co(salen) into the membrane, the free volume is expected to be increased due to the bulkiness of Co(salen). The increased free volume resulted in the enhanced permeabilities of both oxygen and nitrogen. Therefore, the oxygen selectivity over nitrogen through the terpolymer membrane with Co(salen) was only marginally increased. The effects of the temperature and carrier concentration on the diffusivity and solubility were also investigated.