【摘要】 以聚乙烯醇修饰的多壁碳纳米管(MWCNTs)为基材,熊果酸(UA)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(EGDMA)为交联剂,采用表面印迹技术在碳纳米管表面合成对熊果酸具有良好选择性的分子印迹聚合物(MWCNTs-MIPs).讨论了不同摩尔比例的功能单体与模板分子合成印迹聚合物的效果,得出最佳的摩尔比为4∶1.采用红外光谱、扫描电镜对该印迹聚合物进行表面形态表征,结果表明在碳纳米管表面接枝一层稳定、均匀、20～25 nm厚的印迹材料.采用静态吸附和吸附动力学实验研究其吸附性能,结果表明MWCNTs-MIPs对熊果酸具有特异吸附性,其最大吸附量为53.1μmol/g,在60 min时达到吸附平衡.优化固相萃取条件,结果表明采用100%甲醇溶液淋洗和10%乙酸甲醇溶液洗脱效果最好.将该印迹聚合物装填于固相萃取柱中,可将熊果酸与其结构类似物齐墩果酸进行分离.更多还原

【Abstract】 A novel surface molecularly imprinted polymer was synthesized using poly(vinyl alcohol) modified multi-walled carbon nanotubes(MWCNTs) as supporting matrix,ursolic acid(UA) as the template molecule,methacrylic acid(MAA) as the functional monomer and ethylene glycol dimethacrylate(EGDMA) as the cross-linking agent.Effect of different molar ratios of the functional monomer to the template on the performance of the synthesized MWCNTs-MIPs was discussed and the results showed that the optimum ratio was 4∶1.The multi-walled carbon nanotubes-molecularly imprinted polymers(MWCNTs-MIPs) were characterized by Fourier transform infrared spectroscopy(FTIR) and scanning electron microscopy(SEM).The results showed that a stable imprinted layer was grafted on the MWCNTs surface successfully.The adsorption properties were demonstrated by static adsorption and adsorption kinetic experiments.The results demonstrated that the MWCNTs-MIPs had specific selectivity for UA,yielding a maximum adsorption capacity of 53.1 μmol/g and the equilibrium time took about 60 min.Solid phase extraction condition was optimized,and the optimal condition was washing with 100% methanol and eluting with 10% acetic acid methanol solution.The solid-phase extraction column packed with MWCNTs-MIPs could be applied to separate ursolic acid(UA) from similar structure oleanolic acid(OA).更多还原