液-液界面介导的贵金属纳米粒子自组装：和频振动光谱研究

将纳米粒子组装成有序的二维或三维阵列对其应用具有重要的意义。液-液界面介导的自组装是制备纳米粒子二维有序薄膜的重要方法。人们已经研究证实此类自组装过程与纳米粒子与液-液界面的接触角密切相关，但对影响该接触角的关键因素还缺乏深入的了解。本项目拟采用具有高界面选择性的和频振动光谱技术研究贵金属纳米粒子在水-油界面上的自组装机制，通过考察液-液界面的分子组成、分子取向与构象等性质以及纳米粒子自组装过程对这些性质造成的影响，在分子水平上揭示液体对纳米粒子表面浸润现象的本质和关键影响因素，进一步通过改变溶剂种类或添加其他试剂，探索有目的性调控液-液界面性质的方法，拓展液-液界面介导纳米粒子自组装方法的应用范围。

The assembly of nanoparticles into two- or three-dimensional ordered arrays is crucial for their applications. One of important approches to prepare ordered 2D films of nanoparticles is via liquid-liquid interface mediated self-assembly (LLIMSA). It has been proved that such self-assembly procedure is essentially determined by the contact angle between the nanoparticles and the liquid-liquid interface. However, the key factors affecting the contact angle has not yet been well understood. In this project, we propose to use sum frequency generation vibrational spectroscopy, a spectroscopic tool having high interface selectivity, to study the self-assembly mechanism of noble metal nanoparticles at water-oil interfaces. By investigating the interfacial properties such as chemical composition, molecular configurations and orientations, and how these properties are impacted during nanoparticle assembly, one can gain novel insights into the nature of wetting effect of liquids on nanosurfaces. Based on the gained knowledge, the liquid-liquid interfacial properties will be rationally tunned by selecting proper oil or adding proper reagent into the liquids.This study will broaden the application range of LLIMSA in fabricating well-ordered assemblies of nanoparticles.