Tuning of solvent evaporation to prepare PEBA membrane with high separation performance for the pervaporation of phenol aqueous solution

Phenol is an important chemical that is widely used as a raw material in various industries. However, its high toxicity necessitates effective treatment of phenol-containing wastewater. In this study, membrane-based separation of a phenol/water solution was investigated. A simple and feasible method for tuning the solvent evaporation was developed to fabricate poly(ether-block-amide) copolymer (PEBA) membranes with enhanced separation performance. The solvent evaporation rates and temperatures of three different PEBAs were systematically regulated. PEBA1074, as a promising candidate, was studied using different characterization techniques, such as differential scanning calorimetry and scanning electron microscopy, to reveal changes in crystallinity and membrane structure under different solvent evaporation conditions. The results showed that a low solvent evaporation rate and high temperature favored the formation of a uniform membrane with an increased number of amorphous domains. A separation factor of 78 and a flux of 1.5 kg/(m2⸱h) were obtained at 80 °C for the separation of 1.5 wt% phenol/water solution. This separation performance is superior to those of previously reported PEBA membranes. This work provides a new and easy method to fabricate PEBA membranes with enhanced separation performance, which can promote the industrial application of pervaporative separation of phenol from wastewater.