Facilitated transport membranes based on the solid polymer electrolytes of poly(vinyl alcohol)-Co2+ (PVA-CO2+) blends were prepared. The membrane morphology was analyzed with X-ray scattering and DSC. The sorption behavior of cyclohexene, cyclohexane in the membranes were measured and the separation performance of the membrane were investigated for cyclohexene/cyclohexane mixtures. The result showed that Co2+ salts were highly soluble in PVA and disrupted the crystallinity of PVA. Compared with pure PVA, the cyclohexene saturated sorption capacity in the solid polymer electrolytes was improved a lot and reached 60 mg (cyclohexene)/g (dry membrane), while the cyclohexane saturated sorption capacity in the solid polymer electrolytes had little differences and was only 15 mg (cyclohexane)/g (dry membrane). Permeability flux of the membrane was 150 g/(m(2)h) and a cyclohexene/cyclohexane separation factor was 60 when at 40 degrees C and the optimal carrier content of the membrane ([Co2+]/[-OH]) was 0.75 (mol/mol) and cyclohexene mass fraction in the feed was 0.5. (C) 2005 Elsevier B.V. All rights reserved.