乳液聚合法制备红霉素分子印迹聚合物微球及其吸附性能

摘要

以大环内酯类抗生素红霉素(EM)为模板分子,甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EDMA)为交联剂,十二烷基苯磺酸钠(SBS)为乳化剂,采用乳液聚合法制备了粒径均匀的分子印迹聚合物微球(EM-MIPMs).通过核磁共振氢谱(1H NMR)、紫外光谱和傅里叶变换红外(FTIR)光谱对模板分子和功能单体形成的复合物进行了研究,结果表明EM与MAA之间的相互作用力为氢键作用.利用扫描电镜(SEM)、热重分析(TGA)仪对EM-MIPMs的形貌和热稳定性进行表征,结果显示EM-MIPMs为均匀规整的球型,平均粒径为4.24μm,且有良好的热稳定性.同时采用动力学,平衡吸附和选择性吸附实验对其吸附性能进行研究.动力学研究结果表明, EM-MIPMs的吸附速率符合准二级动力学方程.利用Langmuir和Freundlich吸附等温方程分别分析了EM-MIPMs的平衡吸附数据,结果表明, EM-MIPMs对红霉素有良好的结合性能,其吸附过程符合Langmuir吸附模型,饱和吸附量为0.242 mmol∙g-1. EM-MIPMs的选择识别性能利用固相萃取法来考察,研究表明EM-MIPMs有着良好的特异识别选择性.%Uniform molecularly imprinted polymeric microspheres (EM-MIPMs) were prepared by emulsion polymerization using erythromycin as the template molecule, methacrylic acid (MAA) as the functional monomer, and ethylene glycol dimethacrylate (EDMA) and sodium dodecylbenzene sulfonate (SBS) as the cross-linker and emulsifier, respectively. The obtained erythromycin-MAA complexes were characterized using ultraviolet (UV) absorption spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, and 1H nuclear magnetic resonance (NMR) spectroscopy. The results showed that erythromycin-MAA complexes were obtained by cooperative hydrogen-bonding interactions. The surface features and thermal stability of the EM-MIPMs were investigated using scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA). The average diameter of the EM-MIPMs was 4.24μm, larger than non-imprinted polymeric microspheres. They exhibited excellent thermal stability. Kinetic, equilibrium adsorption, and selectivity adsorption experiments (solid-phase extraction) were used to evaluate the binding properties and molecule recognition characteristics of EM-MIPMs for erythromycin. The experimental kinetic data were wel described by a pseudo-second-order kinetic model. Erythromycin binding was examined using the Langmuir and Freundlich isotherm models. The EM-MIPMs had an excellent affinity for erythromycin. The equilibrium experimental data for the EM-MIPMs fitted the Langmuir isotherm wel , and the binding amount reached 0.242 mmol∙g- 1. Furthermore, solid-phase extraction experiments demonstrated that the EM-MIPMs had a higher affinity for the target molecules than for roxithromycin and erythromycin ethylsuccinate.