Study Of Polystyrene-based Chelating Adsorbents With Different Hydrophilic Chain Structure

Four series of crosslinked polystyrene-based chelating adsorbents were synthesized in this thesis, which used S, N-containing heterocyclic compound via line-shaped polyethylene glycol, tree-shaped and network-shaped poly(diethanolamine) or poly(amido amine)'dendrimer-like'hyperbranched molecule, and ring-shaped glucosamine as hydrophilic chain structure in functional groups, respectively. Fourier transform-infrared spectra, elemental analysis, scanning electron microscopy, aperture analysis and X-ray photoelectron spectroscopy were employed to characterize their structures. The adsorption capabilities and mechanism for common heavy metal ions of the adsorbents were studied. The conception"Micro-environmental Structure Part"was first present in the thesis and the effects of it especially the hydrophilic chain structure in it on the adsorption behaviors of the adsorbents were also researched.The heterocyclic compounds such as 2-amion-pyridine, 2-amino-5-methylthio-1,3,4-thiadizole, 2-amino-5-ethyl- 1,3,4-thiadizole and 2-mercaptobenzothiazole were used in the preparations. The adsorbents with different hydrophilicity were obtained by anchoring those heterocyclic compounds into PS matrix via hydrophilic chain structure. The results showed that the introduction of the hydrophilic chain structure can increase the hydrophilicity of the adsorbents. Accordingly, the adsorption capacities of the adsorbents towards metal ions increased compared with those having no hydrophilic chain structure.The PS supported'dendrimer-like'hyperbranched molecule chelating adsorbents having tree-shaped hydrophilic chain structure were synthesized by anchoring poly(diethanolamine) and poly(amido amine) into PS matrix using divergent method. The adsorption for metal ions was studied and the results showed that this series of adsorbents could adsorb Hg2+,Ag+ and Cu2+ effectively, especially the adsorbents that have S-containing spacer. But the adsorption capability of the network-shaped adsorbents which were obtained by the increase of the generation of hyperbranched molecule was inferior to that of tree-shaped group.The adsorbent having ring-shaped hydrophilic chain structure was prepared by the reaction of chloromethylated polystyrene with glucosamine hydrochlorate. The adsorption results showed that the adsorbent had good adsorption and enrichment capacities for Au3+. Moreover, redox reaction occurred during the adsorption and Au3+ was reduced into Au particles.