巨电流变液分散相界面结构及工作过程的原位SHINERS研究

The interfacial structure and behaviors of the dielectric particles has been found to be one of the key parameters which cause the giant electrorheological (GER) effect. In order to understand the GER mechanism, the research shall be directed toward investigation of the interfacial physics and chemistry of the dielectric particles on the molecular scale. However, the lack of chemical resolution of surface analytical technique is inhibited broad the related research. In this project, we will apply shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) in the colloids system. We design a 3D plasmonic superstructure microsphere containing of many shell isolated nanoparticles (SHINs), which carries abundant plasmon coupling in high density. By aid of SHINERS,the in situ Raman spectra can be obtained from the dielectric particle surface.Subsequently, the molecular configuration, conformation, charge transmission , the key relationship variation are analyzed, further, the relationship between the interfacial structure, component and dielectric properties , rheological behavior of GER fluids is explored. It is expected that our research can provide scientific guidance for the design and development of efficient, stable ER materials, and promote the application of SHINERS technique in colloid interface research field.

从分子水平观测巨电流变液分散相界面结构和工作过程是探索巨电流变效应机理的有效方法。具有化学分辨能力的光谱能够为界面问题研究提供重要信息，但灵敏度、基底导电等因素制约了常用光谱技术的应用。本项目将壳层隔绝纳米粒子增强拉曼光谱（SHINERS）引入胶体体系，以壳层隔绝纳米粒子为功能单元，自组装构建携带高密度“热点”的三维等离激元超结构颗粒，提高检测灵敏度；建立适用于介电颗粒表/界面研究的SHINERS技术方案，实现对表面组成及发生在界面上的物理化学事件的原位观测。本研究不仅开拓了SHINERS技术在胶体界面领域的应用，而且为深入认识巨电流变效应的微观机制提供有效的技术手段。

壳层隔绝纳米粒子增强拉曼光谱（SHINERS）是一种新型拉曼技术，它在金属纳米粒子表面包覆上超薄壳层，利用内层金属纳米粒子的强电磁场的长程效应增强拉曼信号。然而壳层隔离纳米粒子的增强能力较弱，特别在溶液中的检测灵敏度仍比较低。本项目发展和完善以Au/Ag为核，包覆超薄碳层的壳层隔绝纳米粒子（SHINs）的可控制备方法，然后以SHINs为基本单元通过静电作用、连接剂构造具有分级等离激元耦合的超结构颗粒。经过对壳层厚度、耦合颗粒缝隙的间距、SHINs粒径尺寸、堆积密度等参数的优化，这种材料表现出优异的拉曼增强能力，与SHINs相比，其拉曼信号强度提高2个数量级；在此基础上，利用外加电/磁场作用，诱导超结构颗粒发生自组装排列，实时形成SERS热点聚集体，将其用于介电材料表面和胶体体系原位实时观测，成功实现多环芳烃、农药残留物等的超灵敏原位检测。项目的成果不仅拓展SHINERS 技术的应用范围，而且能够为巨电流变液机理研究提供有效的技术手段，将给电流变液中的界面科学问题研究带来新的契机。