分子印迹-金属有机骨架复合材料的可控构建及其对环境激素和抗生素的分离富集

Molecularly imprinted polymers have the ability of strong selective recognition. However, due to the limitation of “specific binding”, the adsorption capacities of most molecularly imprinted polymers are lower and the equilibrium time is longer, which is not conducive to the practical application. The metal organic frameworks have the characteristics of large surface area, controllable pore and easy modification. Therefore, the aim of this work is to prepare a series of molecularly imprinted polymers by using the mesoporous/macroporous metal organic frameworks with groups of -NH2, -COOH and -C=C on its inner and outer surfaces as the supporter. The composites can selectively recognize targets with higher adsorption capacities and shorter equilibrium time in aqueous media. The specific adsorption performance of the composites synthesized by different metal organic frameworks is tested by the adsorption isotherms, kinetic curve, and selective adsorption experiments. The inherent relationship between the material structure and adsorption performance is also discussed. The adsorption mechanism will be analyzed from the study of spectroscopy. Based on these results, the prepared molecularly imprinted polymer and metal-organic frameworks composites are used as solid phase extractant, and the parameters such as the binding capacity, equilibrium time and its regeneration and recyclability will be investigated to value the performance of selective separation. Thereafter, combined with the chromatography determinations, the new methods for high capacity, rapid and green separation of trace environmental hormones and antibiotics will be established. It is helpful to improve the application of imprinted polymers in the field of environment.

分子印迹聚合物是一类特异识别能力强的高分子材料。但是，由于“特异识别位点”数量有限，绝大多数印迹材料的吸附容量低，平衡时间长，难以实际应用。本项目拟利用金属有机骨架比表面积大、孔径可控、骨架易修饰的特点，设计合成一系列内、外表面-NH2、-COOH、-C=C等功能基团含量丰富的介孔/大孔型金属有机骨架载体，采用表面印迹技术，制备在水相介质特异识别能力强、吸附容量大、传质速率快的新型分子印迹-金属有机骨架复合材料；通过对不同结构类型复合材料的选择性识别能力、吸附热力学和动力学特征考察，认识新型复合材料结构与吸附性能之间的关系，结合光谱学研究，阐明分离机制；在此基础上，将新型复合材料用于固相萃取预处理，考察其吸附容量、平衡时间、稳定性及再生性等参数，并与色谱技术联用，建立环境中痕量激素和抗生素类污染物的高容量、快速、绿色分离分析新方法，为高效、绿色的印迹材料在环境领域的应用提供理论和技术支持。

本项目通过设计、合成比表面积大、孔径可调控、骨架易修饰的ZIF-67、UIO-66、MIL-100(Fe)、UIO-66-NH2、MIL-53(Fe)、MIL-101(Cr)、HKUST-1等金属有机骨架载体材料，在水和乙醇介质中制备出10种对痕量环境激素和抗生素特异识别能力强、吸附容量大、传质速率快的新型分子印迹-金属有机骨架复合材料；研究了不同类型、不同孔径大小金属有机骨架载体与印迹聚合物的复合规律，考察了不同结构类型复合印迹材料的选择性识别能力、吸附热力学和动力学等参数，明确了影响新型复合材料萃取性能的主要因素，并阐明了识别分离机制。研究结果表明，基于比表面积较大的金属有机骨架载体制备的复合印迹材料，形成了数量更加丰富的“特异识别位点”，协同印迹孔穴、静电引力和氢键等作用力，对环境中双酚类环境激素和痕量非甾体类、磺胺类、喹诺酮类、氯霉素类抗生素、消炎类药物等污染物表现出更优异的特异识别性能，其吸附容量在25.8-71.36 mg g-1之间，在5-30 min之内即可达到吸附平衡，经过多次再生循环使用，对复杂环境中双酚类环境激素和痕量抗生素等污染物的回收率仍在70%以上，显著提升了印迹聚合物材料的吸附容量、缩短了吸附平衡时间，且本项目研发的印迹材料均在纯水和乙醇等绿色介质中制备和应用，极大增强了印迹聚合物材料的固相萃取实用性；此外，对金属有机骨架材料的孔径进行调控，发现在一定范围内增大孔径，可以实现载体骨架表层和孔道内部多空间印迹位点的形成，能够明显改善吸附容量和印迹因子；将金属有机骨架材料作为载体制备的复合分子印迹材料用作固相萃取吸附剂，实现了对环境中痕量双酚类激素和抗生素类污染物的高容量、快速、绿色分离，为高效、绿色的印迹材料在环境领域的应用提供了技术支持。