建立了一种新的离子表面印迹(IIP)方法. 使用偶联剂γ-氨丙基三甲氧基硅烷(AMPS)对微米级硅胶微粒进行表面改性, 制得表面含有氨基的改性硅胶AMPS-SiO₂. 凭借离子交换作用, 阳离子单体甲基丙烯酰氧乙基三甲基氯化铵(DMC)结合在模板离子磷酸根周围; 改性硅胶AMPS-SiO₂表面的氨基与溶液中的过硫酸盐构成氧化还原引发体系, 使DMC及交联剂N,N'-亚甲基双丙烯酰胺(MBA)在硅胶微粒表面发生接枝交联聚合, 从而实现了磷酸根离子的表面印迹, 制得了阴离子表面印迹材料IIP-PDMC/SiO₂. 采用静态与动态两种方法, 考察研究了IIP-PDMC/SiO₂对PO₄^3-离子的识别特性与结合性能. 研究结果表明, 离子表面印迹材料IIP-PDMC/SiO₂对PO₄^3-离子具有特异的识别选择性与优良的结合亲和性, 相对于对比离子高锰酸根离子, IIP-PDMC/SiO₂对PO₄^3-离子的识别选择性系数为9.58.

The molecularly imprinted polymers (MIPs) synthesized by conventional bulky imprinting methods suffer from several limitations, such as time-consuming preparation process, poor site accessibility to the target molecules and the lower binding capacity for the target molecules. To overcome these problems in bulking imprinting, in this work, a novel surface-ion imprinting method that not only is simple but also highly effective, is put forward and found. The coupling agent γ-aminopropyltrimethoxysilane (AMPS) was bond onto the surface of silica gel particles, and amino groups were introduced onto the surfaces of silica gel particles, obtaining the modified particles AMPS-SiO₂. In aqueous solution, the molecules of the cationic monomer methacryloxyethyltrimethyl ammonium chloride (DMC) were first combined around the template ion, phosphate ion, by right of ion exchange action. A redox initiating system was constructed by the amino groups on AMPS-SiO₂ and ammonium persulphate in the solution, and free radicals were produced on the surfaces of silica gel particles. These free radicals initiated the monomer DMC and the crosslinker N,N'-methylene bisacrylamide (MBA) to be graft-copolymerized and crosslinked, and the surface-imprinting of phosphate ion was realized. After removing the template ions, PO₄^3- ion surface-imprinted material IIP-PDMC/SiO₂ was obtained. Both permanganate ion, MnO₄^- ion, and PO₄^3- ion are isoelectronic bodies. Their chemical structures are similar and their configurations are the same, but their sizes are different. In this work, MnO₄^- ion was used as contrast ion, and both static and dynamic methods were adopted to study the binding properties and ion recognition character of IIP-PDMC/SiO₂ for PO₄^3- ion. The experiment results show that IIP-PDMC/SiO₂ have specific recognition selectivity and excellent binding affinity for PO₄^3- ion, and its selectivity selectivity coefficients for PO₄^3- ion with respect of MnO₄^- ion is 9.58. Besides, IIP-PDMC/SiO₂ has excellent elution property, with NaCl solution as eluent, the desorption ratio of PO₄^3- ion reach 99.53% in 20 BV.