High-flux thin-film composite polyelectrolyte hydrogel membranes for ethanol dehydration by pervaporation

The pervaporation performance of the TFC membranes was studied with a 90% ethanol solution at 50 °C. The separation factor coincided with the increase in the IEC, which is attributed to the higher sorption of water molecules to the active layer. The degree of swelling had a lesser influence on the membrane performance than the IEC, but greater swelling decreased the performance for similar IEC values. The optimal membrane with a 7.5 kg m−2 h−1 flux and a separation factor of 313 was obtained at the highest IEC and a limited degree of swelling, making it one of the membranes with the highest pervaporation separation index reported to date. However, the stability of the membrane should be improved, as its high performance decreased after 24-48 h and reached a plateau after a few days of operation.