Multi-functional zwitterionic compounds as new membrane materials for separating oletin-paraffin mixtures

Abstract

Various types of multi-functional zwitterionic compounds containing both ester and sulfonate groups were prepared and their silver nitrate salts were tested as carriers for facilitated olefin transport membranes in the separation of ethylene-ethane and propylene-propane mixtures. Ester group-containing multi-functional zwitterionic silver compounds exhibited Much higher performances in comparison with methyl group-containing zwitterionic compounds. A FT-IR study showed that ester-containing zwitterionic compounds interact with silver ions through both sulfonate and ester functional groups.