Preparation and pervaporation of a palygorskite/polyacrylamide inorganic–organic hybrid membrane for separating m-/p-xylene isomers

A palygorskite/polyacrylamide (PGS/PAM) hybrid was synthesized via intercalation polymerization initiated by a redox initiator consisting of modified PGS and Ce4+, and used as a pervaporation membrane for the separation of an m-/p-xylene mixture. The effects of the PGS content in the hybrid membrane, m-xylene concentration in the m-/p-xylene mixture and operation temperature on the pervaporation performance of the hybrid membrane were investigated. It was observed that the maximum value of the separation factor αm/p = 1.399 revealed as the PGS content in the hybrid membrane was 1.92 wt%, and the permeate flux, Jm, of the hybrid membrane increased with the increasing of the PGS content for separating m-/p-xylene mixture containing 10 wt% m-xylene at 25°C. The viewpoint that the competition of the affinity caused by the secondary adsorption and the static excludability caused by the electronegative in the PGS aperture was used to interpret the results.