界面诱导胶体纳米颗粒自组装

The self-assembly of colloidal nano-particles based on the minimization of the system's free energy is a significant technique to manufacturing next-generation nanomaterials. Colloidal crystals self-assembled by colloidal nano-particles have many unique properties and important potential applications in sensors, micro-nanofabrication templates and functional surfaces. The properties of the colloidal crystals depend on the properties and crystal structures of the nano-particles. At present, it has been developed a variety of nano-particles having excellent characteristics. Therefore, the bottleneck of colloidal crystals preparation is the ordered self-assembly of colloidal nano-particles. Interface induction is one of the most important methods of self-assembly of colloidal nano-particles, and the two-phase interface induction method overcomes the shortcomings of the traditional methods which is also able to realize large-area preparation of colloidal crystal films. This study mainly aims to discover the theory of self-assembly of colloidal nano-particles induced by the two-phase interface and obtain associated control technology. On the base of fluid/fluid interface induced self-assembly of colloidal nano-particles, the method of fluid/solid interface induced self-assembly of colloidal nano-particles will be proposed. The main content to be completed of this study include: 1) the interactions between colloidal nano-particles and interactions between colloidal nano-particles and the two-phase interface; 2) the wetting and thermodynamic processes of the colloidal particles penetrating fluid/fluid interface; 3) the control of colloidal nano-particles self-assembly at the two-phase interface; 4) the preparation of large-area functional surface like superhydrophobic, etc.

基于系统自由能最小化的胶体纳米颗粒自组装是实现下一代纳米材料制备的重要手段。由胶体纳米颗粒自组装而来的胶体晶体具有独特特性，其在传感器、微纳加工模板和功能表面等方面具有重要的应用前景。胶体晶体的特性取决于纳米颗粒的特性和晶体结构。目前，人们已开发了各种具有优异特性的纳米颗粒。因此，胶体晶体制备的瓶颈是胶体纳米颗粒的有序化自组装。界面诱导法是胶体纳米颗粒自组装的最重要方法之一，其中两相界面诱导法克服了传统方法的缺点，可实现大面积的胶体晶体薄膜制备。研究以探明两相界面诱导胶体自组装的机理，并获得相关控制技术为主要研究目标，在流/流界面诱导胶体颗粒自组装的基础上，提出液/固界面诱导胶体自组装的方法。拟主要完成的研究内容包括：1）胶体纳米颗粒间及其与两相界面间的相互作用；2）胶体颗粒穿透流/流界面的润湿和热力学过程；3）胶体颗粒在两相界面上的自组装控制；4）大面积的超疏水等功能表面制备。

胶体纳米颗粒自组装是实现下一代纳米材料制备的重要手段。自组装结构表现出构成单元所不具备的独特的整体性质，其在光伏、生物医学、传感器、催化等领域有广泛的应用前景。项目以研究胶体颗粒间及其与界面间的相互作用为主线，以实现界面附近胶体颗粒的行为控制为目标，通过仿真和实验相结合的方式，研究了胶体颗粒趋近界面及其在界面上实现组装的动力学过程，获得了以下关键研究进展：.1）静电力自组装研究中，发现了基于长程引力的二维微孔结构的纳米胶体颗粒自组装过程，提出了一种基于静电斥力的胶体颗粒自组装方法。.2）提出并实现了基于张力梯度的胶体纳米颗粒自组装新方法，并初步探索了其组装机理。.3）固壁表面纳米颗粒加热过程的分子自组装研究中，发现了纳米金在远低于熔点温度下的聚并现象，探明其表面热力学波动和原子间范德华力作用机理；发现了加热引起的PTFE纳米颗粒的纳米纤维化现象，其影响因素及影响规律被探明。.4）探索了水中胶体微油滴间的相互作用，及其在微结构表面上的润湿特性等，获得了水下油滴在结构表面上不同润湿状态，发展了基于润湿的油水分离技术。.5）基于发展的纳米胶体自组装方法，实现了超疏水自清洁、防腐、除甲醛等功能表面涂层的制备，部分技术已产业化。