Preparation and adsorption properties of crosslinked polystyrene-supported low-generation diethanolamine-typed dendrimer for metal ions

Two novel chelating resins, polystyrene supported G1.0 diethanolamine-typed dendrimer (PS-DEA) and G2.0 diethanolamine-typed dendrimer (PS-(DEA)2), were prepared by anchoring low-generations diethanolamine-typed dendrimer into crosslinked polystyrene in this paper. Fourier transform-infrared spectra (FTIR), scanning electron microscopy (SEM) and elemental analysis were employed to character their structures. The results of adsorption for metal ions showed that the resins had good adsorption capacities for Cu2+, Ag+ and Hg2+, especially PS-DEA for Cu2+. The adsorption kinetics and adsorption isotherms of PS-DEA for Cu2+ and PS-(DEA)2 for Hg2+ were studied. The results showed that the adsorption kinetics of the two resins can be modeled by pseudo second-order rate equation wonderfully and Langmuir and Freundlich equations could well interpret the adsorption of PS-(DEA)2 for Hg2+ and PS-DEA for Cu2+, respectively. The adsorption mechanism of the resins for Cu2+ was confirmed by X-ray photoelectron spectroscopy (XPS).