Mischungsverhalten von binären Flüssigkeiten: Kritisches Verhalten in dünnen Filmen

• Applicant: Professor Dr. Werner Press
• Subject Area: Experimental Condensed Matter Physics
• Term: from 1998 to 2003
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5106740

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.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1052: Benetzung und Strukturbildung an Grenzflächen
• Participating Person: Professor Dr. Metin Tolan