Magnetic Th(IV)-ion imprinted polymers with salophen schiff base for separation and recognition of Th(IV)

Abstract

A new complex of N,N′-bis(3-allyl salicylidene)o-phenylenediamine and thorium(IV) (Th(IV)) was synthesized and used as the functional monomer for a novel Th(IV) magnetic ion-imprinted polymer; this polymer was synthesized using a surface imprinting technique that included the modified magnetic Fe3O4 particle and used tetraethyl orthosilicate, 3-Aminopropyltriethoxysilane and maleic anhydride in the process. The magnetic polymer was characterized using FT-IR, and powder- and single crystal-XRD. The behavior of Th(IV) was investigated using batch experiments. At pH 4.5, the uptake capacity of this adsorbent and that of the non-imprinted polymer was 42.54 and 14.10 mg g−1, respectively, and the relative selectivity coefficient values of the synthesized adsorbent for Th(IV)/La(III), Th(IV)/Ce(III), Th(IV)/Nd(III), and Th(IV)/U(VI) were 82.2, 93.1, 21.0 and 62.4 times greater than that of the non-imprinted matrix, respectively. In addition, the Th(IV) adsorption process using Fe3O4@SiO2-IIP follows pseudo-second-order reaction kinetics and the Langmuir adsorption isotherm. The thermodynamic parameters also suggest that the adsorption of Th(IV) onto Fe3O4@SiO2-IIPs was a spontaneous and endothermic process.