Mischungsverhalten von binären Flüssigkeiten: Kritisches Verhalten in dünnen Filmen

两种或两种以上液体的混合行为是近20年来备受关注的一个令人兴奋的问题。但目前的研究多为理论工作，定量实验较少。在我们的项目中，我们建议测量x射线和中子反射率和漫射散射，以获得密度剖面和关于靠近衬底及其近表面区域的二元混合物的横向波动的信息。该项目的第一部分涉及通过x射线反射率确定密度剖面。在过去和以前的项目中已经表明，x射线反射率非常适合在埃尺度上确定液体膜的密度分布。首先，非常有希望的实验已经进行了。在第二部分中，我们计划将重点放在“临界吸附”的特殊主题上，在接近系统临界点的地方，一种物质相对于另一种物质在壁上的富集是预期的。详细的计算密度分布存在于文献中，将通过x射线和中子反射率测量进行测试。

The mixing behavior of two or more liquids is an exciting problem which has attracted great attention within the past 20 years. However, most of the studies are theoretical works and only a few quantitative experiments have been carried out so far. We propose in our project x-ray and neutron reflectivity and diffuse scattering measurements to obtain density profiles and information about lateral fluctuations of binary mixtures next to a substrate and in their near surface regions. The first part of the project deals with the determination of density profiles by x-ray reflectivity. It has been shown in the past and the previous project that x-ray reflectivity is very well suited to determine density profiles of liquid films on an angstrom scale. First very promising experiments have already been carried out.In the second part we plan to focus on the special topic of "critical adsorption" where close to the critical point of the system an enrichment of one species with respect to the other next to a wall is expected. Detailed calculated density profiles exist in the literature which will be tested by x-ray and neutron reflectivity measurements.