Polyelectrolyte complex composite gel membranes based on two cationic polymers for the separation of methyl tert-butyl ether and methanol mixtures

For the separation of methyl tert-butyl ether (MTBE) and methanol mixtures, the pervaporation performance of polyelectrolyte complex (PEC) composite gel membranes based on two cationic polymers has been investigated. The composite gel membranes were prepared by complexation into a protonated chitosan solution after doping blend solutions of polyacrylic acid (PAA) and sodium alginate (SA) on a porous polysulfone supporting membrane. The pervaporation experiments were carried out under various preparation and operating conditions. The results showed that the selectivity and permeation flux of the membranes were dependent on the blend ratio of cationic polymers. Especially, the pervaporation performance of the membrane prepared at a blend ratio having low PAA content was better than that of a previous PIC membrane complexed with SA and chitosan and moreover, the performance of the membrane was enhanced significantly in proportion to an increase of operating temperature. Finally, these membranes had fluxes of 0.5653–2.4473 kg/m2 h and MTBE concentrations in the permeate of 0–0.6% up to 15% PAA blend ratio at 55 °C.