Enhanced propylene/propane separation in facilitated transport membranes containing multisilver complex

Abstract

Abstract Facilitated transport membrane containing a zero complex Ag 4 tz 4 and 6FDA‐TMPDA was fabricated via a solution‐casting method and their separation performance toward C 3 H 6 /C 3 H 8 was investigated. Ag 4 tz 4 complexes were well dispersed in the polymeric matrix owing to the weak hydrogen bond between Ag 4 tz 4 and 6FDA‐TMPDA which can efficiently improve their interface compatibility. The reversible π complexation between C 3 H 6 and Ag + facilitates the C 3 H 6 transport in membranes, which is beneficial to achieve high C 3 H 6 /C 3 H 8 permselectivity according to the density functional theory calculation. Remarkably, the best separation performance was achieved by the 10 wt% Ag 4 tz 4 membrane, for which the C 3 H 6 permeability is 22 Barrer and the C 3 H 6 /C 3 H 8 selectivity reaches up to 43, surpassing the Robeson upper bound. In addition, the membranes also exhibit great long‐term stability (>120 h). The excellent separation performance together with the long‐term stability render the membrane to be an interesting candidate for C 3 H 6 /C 3 H 8 separation.