Revelation of facilitated olefin transport through silver-polymer complex membranes using anion complexation

Abstract

Polymer complex membranes containing AgNO3 dissolved in a polymeric solvent do not exhibit facilitated olefin transport in the solid state due to strong interaction between the silver ion and its counteranion. However, we successfully made AgNO3 as an active olefin carrier upon incorporation of positively charged polypyrrole (PPy) into a polymer solvent such as poly(N-vinylpyrrolidone) (PVP) or poly(2-ethyl-2-oxazoline) (POZ). Upon addition of positively charged PPy into polymer/AgNO3 complex membranes, the interaction of the silver cation with the nitrate anion was weakened because of nitrate anion complexation by positively charged PPy. This was confirmed by FT-IR and X-ray photoelectron spectroscopy. The enhanced carrier activity of AgNO3 in PVP or POZ with PPy is attributable to complexation of NO3 with positively charged PPy, which led to a weak interaction between Ag+ and NO3-