核壳双亲水性超支化共聚物稳定化金属纳米材料的构筑与性能研究

Au/Ag nanoclusters or Au/Ag nanoparticles tend to aggregate and form larger particles during their synthesis and sensing application, which leads to a loss of applied value. Our research found core-shell hyperbranched polymers hold great promise as templates for metal nanomaterials because of their highly branched, double-hydrophilic core-shell architectures, spheroid-like cavity and plenty of functional groups allowing them to increase the stability of these metal nanomaterials. Compared with the ordinary hyperbranched polymers core-shell ones can be better for stabilizing metal nanoparticles, more suitable for application in sensing. Therefore, in this project we shall design and synthesize a series of double-hydrophilic hyperbranched copolymer with a hyperbranched polyethyleneimine core and many hyperbranched polyglycidol shells. The Au/Ag nanoclusters or Au/Ag nanoparticles supported and stabilized by double-hydrophilic core-shell architectures will be used as sensors for metal ion detecting. The carboxyl group will also be further grafted selectively as needed in order to increae sensitivity. The core-shell architectures and carboxyl group influence on the stability of metal nanomaterials and sensing performance will be investigated so as to provide theoretical basis for practical application. The sensitivity and selectivity will be improved by introduction of shell and carboxyl when the stablized metal nanomaterials is used as sensors. After the color change, the metal nanomaterials will not aggregate futher and can keep stable for a long time. Therefore, it is convenient to record, detection, observation and it will achieve more favorable applications for sensing.

金、银纳米团簇或金、银纳米粒子在制备和传感应用过程中易发生聚集而失去应用价值。本课题组研究发现具有类球型结构微空腔和大量官能团的核壳均为支化结构均亲水的超支化聚合物为模板或稳定剂可以提高这些金属纳米材料在制备和传感应用中的稳定性，相对于普通的超支化聚合物能更好地稳定金属纳米材料，更适合在传感中应用。因此，本项目将以亲水性超支化聚乙烯亚胺为核，亲水性聚缩水甘油为壳制备一系列核壳均为支化结构的功能性亲水共聚物，以其为模板或稳定剂制备高稳定性金、银纳米团簇或金、银纳米粒子，使其有效地应用于金属离子传感检测。同时，根据传感响应灵敏度需要选择性进行羧基修饰，并详细研究核壳结构、羧基与金属纳米材料稳定性、传感检测性能之间的关系。借助壳结构及羧基的协同作用使其作为传感器具有更高的灵敏度、选择性，尤其是颜色变化后能长久保持稳定，不会进一步聚集沉淀，便于记录、检测和观察，更好的实现其在传感方面的应用。

超支化聚合物因其具有紧密类球型结构，多官能度，粘度低，端基改性后具有核壳结构等特性而在基础和应用研究方面受到广泛关注。在国家自然科学基金的资助下，课题组构建制备了不同核壳结构的超支化聚合物，以其为模板或稳定剂提高了金、银纳米粒子在制备和传感应用中的稳定性，更适合在传感、分离等过程中应用。项目实施过程发展了对于不同重金属离子的比色传感检测、分离等方法，具有较高的灵敏度、选择性和吸附能力。采用红外、核磁、扫描、粒度仪、透射电镜、X射线衍射等技术分析和表征了材料的结构及检测和分离机理。系统研究了超支化聚合物结构、纳米粒子尺寸、组成等因素对重金属离子检测、吸附分离、染料负载等性能的影响，对超支化聚合物的结构与性能间的构效关系有了深入了解。因此，项目构建的核壳超支化聚合物稳定化或改性的材料不仅能实现对客体污染物的高灵敏、高选择性检测，而且还能有效分离和去除目标物，从而可有效防止和控制对环境的污染，实现了高效制备、检测、分离的有机结合，为节能、环保、可持续发展服务，也为多功能纳米材料的进一步发展提供了依据。部分工作已正式发表在Chemical Engineering Journal（1篇），Sensors and Actuators B: Chemical（2篇），Analyst（1篇）， Polymers （1篇），Analytical Methods（1篇），RSC Advances（1篇），Catalysts（1篇）等期刊上。