尼莫地平分子印迹聚合物的制备及热力学性能研究

Preparation and Thermodynamic Study of Nimodipine Molecularly Imprinted Polymer

采用本体聚合法,以甲基丙烯酸(MAA)为功能单体、三羟甲基丙烷三丙烯酸酯(TMPTA)为交联剂、尼莫地平为模板分子,制备了分子印迹聚合物。运用平衡结合实验,研究了印迹聚合物对尼莫地平、尼群地平、非洛地平药物分子的选择性识别能力。3种药物的静态吸附分配系数KD值分别为0.221 4、0.197 2、0.051 4。结果表明分子印迹聚合物对尼莫地平有较高的选择性。测定了不同温度下印迹聚合物的吸附等温曲线,表明吸附等温线为Ⅰ型吸附等温线,且随着温度的升高吸附量降低,说明吸附过程是放热过程。为了进一步研究印迹聚合物的吸附机理,进行了热力学性质的研究,测定了不同温度下吸附过程的熵变、焓变和吉布斯自由能变化,实验结果表明吸附是焓控制过程。

A molecularly imprinted polymer（MIP） for nimodipine was prepared by bulk polymerization method,utilizing methacrylic acid（MAA） as functional monomer,trimethylol propane triacrylate（TMPTA） as cross-linking agent.The selective recognition characteristics of MIP for nimodipine,nitrendipine and felodipine drug molecules were studied in equilibrium binding experiment.The static adsorption distribution coefficient（KD） values of the three drugs were 0.221 4,0.197 2 and 0.051 4,respectively.The results showed that MIP had a high affinity and selectivity to nimodipine.Type I adsorption isotherm was obtained by determining the adsorptive capacity at different temperatures,and an exothermic process was confirmed by the change of adsorption capacity with temperature.To further study the adsorption mechanism of the imprinted polymer and its thermodynamic properties,the changes of entropy,enthalpy and Gibbs free energy were estimated in the adsorption process at different temperature.The results showed that the adsorption process of imprinted polymer was controlled by enthalpy.