Thermo-responsive ReO4− composite membranes with SiO2 modified: Preparation, performances and application in secondary resources

With the continuous depletion of global rhenium resources, the separation and purification of rhenium (Re) from secondary resources became very important. Herein, an imprinted composite membrane with “flexible chain” thermo-responsive imprinted separation layer structure (Re-TIICM) was prepared to achieve selective separation and recovery of Re from secondary resources with complex composition. Re-TIICM's thermo-responsive imprinted separation layer occurred sol/gel phase transition by adjusting the temperature, which effectively mitigated the trade-off between selectivity and desorption. The structure and performance of Re-TIICM under optimum process conditions were tested and evaluated. The results showed that Re-TIICM exhibited a maximum adsorption capacity of 0.1036 mmol/g at 35°C, a separation degree of 4.37 (MnO 4 − as disturbing ions), and remained good adsorption capacity and selectivity after 9 adsorption/desorption cycles. When Re-TIICM was applied in secondary resources, the purity of Re increased from 35.412% to 70.208% after one adsorption/desorption cycle, showing a great potential for industrial applications.