Porous carboxymethyl cellulose nanocrystalline imprinted composite aerogels for selective adsorption of gadolinium

Abstract

Gadolinium is widely applied in medical and high-tech materials because of special magnetic properties. Recovery of gadolinium from waste rare earth products has both economic and environmental value. In this experiment, honeycomb porous composite aerogels were constructed using sericin and sodium alginate mixed with functionally modified carboxymethylated cellulose nanocrystals for the adsorption and separation of gadolinium ions. There were large numbers of carboxyl groups as well as hydroxyl groups on the surface of sodium alginate and filamentous protein, which provided more sites for the adsorption of gadolinium ions. Besides, a stable honeycomb structure appeared on the surface of composite aerogels when the mixture of filamentous protein and sodium alginate was 1:1, which increased the specific surface area of materials to 140.65 m2 g−1. Additionally, the imprinted composite aerogels Ic-CNC/SSA were prepared by virtue of the imprinting technology, enhancing the adsorption selectivity of composite aerogels for gadolinium. The adsorption experiments revealed that the maximum adsorption capacity of Ic-CNC/SSA reached 93.41 mg g−1 at pH 7.0, indicating good selective adsorption of gadolinium ions. In summary, such composite aerogels provide great potential and reference value for the selective adsorption of gadolinium ions in industry.