An ion imprinted macroporous chitosan membrane for efficiently selective adsorption of dysprosium

A novel Dy3+ ion-imprinted membrane material (II-MAC) with interconnected 3D macroporous structure was firstly prepared by a simple immersion-precipitation-evaporation method for the selective solid liquid extraction of Dy3+. The morphology and chemical structure of II-MAC were characterized using multiple physicochemical techniques, such as SEM, nitrogen adsorption/desorption, FTIR, and element analysis. Adsorption experiments shown that the maximum adsorption capacity of II-MAC to Dy3+ was 23.3 mg g(-1) in the optimal pH (7.0) at 25 degrees C, and the value of imprint factor at pH = 7.0 was the highest. The distribution coefficient for Dy3+ in the presence of the competitive rare earth metal ions was 494.88 mL g(-1), which was remarkably higher than that of other ions. Moreover, II-MAC could be easily retrieved due to the membrane structure, which could tactfully avoid the complex centrifugation and greatly decrease the operation time. The reusability tests demonstrated that II-MAC could be repeatedly used without significant loss even after the fifth runs. This work not only provides a more straightforward and high-efficiency means in selective extraction of Dy3+, but also promotes the development of green and sustainable material. (c) 2017 Published by Elsevier B.V.