以Pb^2+为模板,壳聚糖为单体,硅胶为载体,γ-(2,3环氧丙氧)丙基三甲氧基硅烷(KH-560)为偶联剂,利用表面分子印迹技术和溶胶-凝胶法制备了Pb^2+印迹聚合物。采用傅立叶变换红外光谱法(FT—IR)、紫外光谱法、扫描电镜对Pb^2+印迹和非印迹聚合物的表面形貌和结构进行表征;并用电感耦合等离子体原子发射光谱法考察了吸附酸度、吸附剂用量、静置时间等对聚合物吸附性能的影响;研究了印迹聚合物在混合溶液中对Pb^2+的选择性,比较了印迹和非印迹聚合物的吸附容量;并提出了印迹聚合物的印迹吸附机理。在最佳吸附酸度pH=4.5时,0.3g吸附剂吸附5h达到平衡,Pb^2+印迹聚合物对模板离子具有较高的选择性,其饱和吸附容量是非印迹聚合物的2倍。
Pb^2+ -imprinted polymer particles were prepared by surface moleeular imprinting technique and solgel process with Pb^2+ ion as the template, ehitosan as the functional monomer, silica gel as the carrier, and KH-560 as the cross-linking agent. Both the imprinted and non-imprinted polymer particles were characterized by FT-IR, UV-spectra, and scanning electron microscopy. The effect of adsorption acidity, sorbent dosage and resting time on adsorption rate was investigated by inductively coupled plasma atomic emission spectrometry. Selectivity for Pb^2+ ions of the prepared polymer was also studied in mixed aqueous solution. Adsorption eapaeity of Pb^2+-imprinted polymer was compared with that of non-imprinted polymer. Finally, imprint and adsorption mechanism was also put forward. The optimum acidity for quantitative enrichment was around pH 4.5 and the adsorption equilibrium could be reached in five hours. Pb^2+ -imprinted polymer exhibited high selectivity for Pb^2+ ions, and its adsorption capacity was two times higher than that of non-imprinted polymer.