Self-assembly of nanoparticle thin films at the liquid-liquid interface

纳米粒子的自组装是当前研究的决定性课题之一。它可以在中观或宏观尺度上形成有序结构，从而将大尺度结构的优点与纳米尺度的特殊性质结合起来。在这方面，研究制备自组装同时又耐用的纳米结构材料（如内聚薄膜）的新方法是最重要的。在我们研究碳酸钙薄膜的仿生形成过程中，我们发现了一种在液-液界面制备内聚薄膜的新方法，该薄膜由表面活性剂（如硬脂酸）和纳米颗粒（如二氧化硅Ludox珠）的混合物组成。虽然膜的形成机制目前尚不清楚，但该体系提供了一种直接的方法，可以通过界面流变学和胶体和界面科学的方法来研究。因此，本研究计划的重点是研究膜生长和颗粒吸附过程中液-液界面处发生的现象。这些可以包括两相的相互渗透，局部微乳液的形成，胶束，层状相或在膜形成过程中出现的其他结构，并由有机相的组成引导。最重要的是，纳米颗粒与表面活性剂的相互作用导致薄膜的形成需要详细研究。

The self-assembly of nanoparticles is one of the decisive topics of current research. It leads to the formation of ordered structures on a meso- or macroscopic scale and thus combines the advantages of large scale structures with the special properties of the nanoscale. In this respect it is of foremost interest to investigate new ways for the preparation of self-assembled and at the same time durable nano-structured materials like cohesive thin films. During our studies of the biomimetic formation of calcium carbonate thin films we found a new method for the preparation of cohesive thin films at the liquid-liquid interface, which consist of a mixture of a surfactant (e.g. stearic acid) and nanoparticles (e.g. Silica Ludox beads). Although the mechanism of film formation is at present unknown to us, this system presents a straight-forward approach which can be studied by means of interfacial rheology and methods of colloid and interface sciences. Accordingly the focus of the proposed research plan lies in the investigation of the phenomena that occur at the liquid-liquid interface during film growth and the adsorption of particles. These can include the mutual permeation of both phases, the formation of local microemulsions, micelles, lamellar phases or other structures that emerge during film formation and that are guided by the composition of the organic phase. Most importantly, the interaction of the nanoparticles with surfactants that leads to the film formation needs to be studied in detail.