酚酞分子印迹聚合物的制备及特异吸附性能

以泻药酚酞为模板分子，4-乙烯基吡啶为功能单体制备了模板分子和功能单体不同比例的一系列酚酞分子印迹聚合物。利用扫描电镜对聚合物进行了表面形态分析，采用静态平衡实验法研究了聚合物对模板分子及其类似物的吸附行为和选择性识别能力。实验结果表明，所制备的分子印迹聚合物，吸附 3 h 后基本接近最大吸附量，其中模板分子、4-乙烯基吡啶和交联剂的摩尔比为 1∶6∶20的MIP2的印迹因子为 2.30，效果最佳。Scatchard 分析表明, 在所研究的浓度范围内,吸附过程存在两类结合位点，一类高亲和力结合位点的离解常数为Kd1= 0.63 mmol/L，最大表观结合量 Qmax1 = 25.4 umol/g，另一类低亲和力结合位点的离解常数为 Kd2 =3.5 mmol/L,最大表观结合量 Qmax2 = 61.9 umol/g，通过与酚酞类似物质在酚酞分子印迹聚合物上的吸附行为比较，表明对酚酞具有很好的选择性吸附。

Preparation and Specific Absorption performance of Molecularly Imprinting Polymers for Phenolphthalein

A series of molecularly imprinting polymers (MIPs) at different ratios of template and functional monomer were prepared using phenolphthalein as template and 4-vinylpyridine as functional monomer. The surface features of the polymers were analyzed by scan electron micrographs. The static equilibrium binding experiments were performed to investigate the adsorption property and selective recognition of the MIPs for phenolphthalein and its analogues. It was shown that saturated adsorption was achieved in 3 hours. The best imprinting effect was observed when the molar ratio of the template molecules, functional monomer and crosslinker is 1∶6∶20. Scatchard analysis showed that two classes of binding sites were formed in the imprinted polymers in the concentrations range studied. The calculated dissociation constant Kd1 and apparent maximum binding capacities Qmax1for the high affinity sites are 0.63 mmol/L and 25.4 μmol/g, while Kd2 and Qmax2 for the low affinity sites are 3.5 mmol/L and 61.9 umol/g, respectively. The molecularly imprinting polymers displayed higher selectivity for phenolphthalein compared with the analogues of phenolphthalein.