Preparation of an ion imprinted chitosan-based porous film with an interpenetrating network structure for efficient selective adsorption of Gd(iii)

The separation and recovery of gadolinium ions [Gd(iii)] from aqueous solution has received considerable attention because of the growing supply-demand gap of high-purity Gd in high-tech devices. In this work, for the first time, a new Gd(iii) ion imprinted chitosan-based porous film (II-CPF) with an interpenetrating network structure was successfully fabricated using a simple polymerization-evaporation method for the selective adsorption of Gd(iii) from aqueous solution. The interpenetrating network structure was formed by the simultaneous polymerization of chitosan (complexing monomer) and para aminobenzoic acid (monomer) with glutaraldehyde (crosslinker). The as-obtained II-CPF was characterized via multiple physicochemical techniques, and the adsorption experimental results indicated that the saturation adsorption capacity of II-CPF for Gd(iii) reached was up to 58.70 mg g(-1) at 298 K at the optimal pH of 7.0. The adsorption kinetics and isotherms revealed that the pseudo-second-order kinetic model and the Langmuir model could well describe Gd(iii) adsorption on II-CPF. Moreover, the selective adsorption tests showed that the as-formed II-CPF had a remarkable selectivity towards Gd(iii) against other competing ions. The reusability tests also proved that the II-CPF had good recyclability and favored the fast retrieval from water due to its film structure. Our work provides a straightforward synthetic strategy to prepare a low-cost and highly selective chitosan-based adsorbent for the adsorption of Gd(iii) from aqueous solution.