SBA-15表面咖啡因分子印迹聚合物的制备及性能研究

Preparation and characterization of mesoporous silica SBA-15-supported molecularly caffeine-imprinted polymers by surface molecularly imprinting technique

目的:探讨咖啡因表面分子印迹聚合物的吸附性能,分析该印迹聚合物用于提取茶叶中咖啡因的可行性。方法:以咖啡因(caffeine)为模板分子,功能化的介孔分子筛SBA-15为载体材料,合成咖啡因表面分子印迹聚合物。采用扫描电镜对其表面进行表征,利用吸附平衡实验研究聚合物对咖啡因的吸附性能;用该印迹聚合物提取茶叶中的咖啡因。结果:在最佳吸附pH为7.0的条件下,印迹聚合物吸附速度快,吸附容量大,对咖啡因的吸附平衡和动力学数据分别符合Freundlich等温线模型和Pseudo-second-order动力学模型。提取实验表明印迹聚合物能有效地从茶叶粗提物中分离咖啡因。结论:分子印迹技术为茶叶中有效成分的提取分离提供了新思路。

Objective： The adsorption behavior of the caffeine molecularly imprinted polymer for caffeine was investigated.Moreover,the imprinted polymer was applied for selective extraction of caffeine from tea.Methods： A novel molecularly imprinted polymer was prepared with caffeine as template and modified ordered mesoporous silica SBA-15 as carrier based on surface molecularly imprinting technique.The prepared polymer was characterized by the scanning electron microscopy.The adsorption behavior of the adsorbent for caffeine was investigated using batch experiments.In addition,these imprinted polymers were applied for selective extraction of caffeine from tea.Results： The optimum acidity was around pH 7.0 and the imprinted polymer exhibited fast kinetics and high adsorption capacity for caffeine.Caffeine adsorption process onto MIPs followed the Freundlich adsorption isotherm and the Pseudo-second-order kinetic model.Furthermore,these imprinted polymers could extract caffeine from tea effectively.Conclusion： MIT looks forward to be used as the materials for extraction of caffeine from tea.