Fur the practical applications of facilitated olefin transport membranes, long-term stability, high selectivity for propylene/propane, and high permeance are required. Previous results obtained for membranes consisting of poly(2-ethyl-2-oxazoline) (POZ), AgBF4, and Al(NO3)(3) showed relatively low mixed-gas permeance, i.e., 4.8 gas permeance units (GPO), even though these membranes have excellent long-term stability. In this study, poly(ethylene oxide) (FED) was suggested as a new polymer matrix for enhanced separation performance. When PEO was utilized as the polymer matrix, the membrane showed long-term stability and the mixed-gas permeance increased to 20 GPO. This enhanced permeance was attributed to the stabilization of silver ions in the permeable polymer matrix. The coordinative interactions in PEO/AgBF4/Al(NO3)(3) were investigated by FT-IR. FT-Raman, and X-ray photoelectron spectroscopy analyses. (C) 2014 Elsevier B.V. All rights reserved.