Structure, adsorption and separation comparison between the thermosensitive block segment polymer modified ReO4− ion imprinted polymer and traditional ReO4− ion imprinted polymer

Abstract

A novel smart ion imprinted polymer (SIIP) introduced a thermosensitive block segment polymer, poly N, N-diethylacrylamide (PDEA), as the smart segment into ion imprinted polymer (IIP) matrix to simultaneously improve the adsorption performance and selectivity. PDEA was synthesized by a reversible addition-fragmentation chain transfer (RAFT) polymerization, and then it was introduced into the polymerization process to fabricate SIIP. Meanwhile, IIP without PDEA block segment was prepared under similar conditions. Results showed that the morphology of SIIP was composed of tiny fiber, but IIP was composed of small globule. The initiate adsorption capacity (Q) and the separation degree (R) of SIIP to ReO4− were 0.065 mmol/g and 3.25, while that of IIP were 0.06 mmol/g and 3.00. After 11 times recycling, adsorption capacity (Q) and the separation degree (R) of SIIP to ReO4− decreased to 0.043 mmol/g and 2.05, while that of IIP decreased to 0.024 mmol/g and 1.09, and the desorption rate was higher than IIP. Finally, SIIP showed a better separation effect to Re than IIP in the secondary superalloys leaching solution. After a circle of adsorption and desorption, the purity of Re was upped from 36.8413% to 62.9448%, which was higher than IIP (37.1761%).