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CP: Chemische Physik
CP 17: Postersitzung Transportprozesse durch Grenzflächen und Membranen
CP 17.3: Poster
Dienstag, 18. März 1997, 18:30–21:15, FBH
Absorption and Fluorescence in the Surface Forces Apparatus — •Torsten Grünewald1, Dirk Eck1, and Christiane A. Helm2 — 1Institut für Physikalische Chemie, Johannes Gutenberg-Universität, 55099 Mainz — 2Fachrichtung Kristallographie, Universität des Saarlandes, 66041 Saarbrücken
In the classical Surface Forces Apparatus, the interaction force between surfaces of a well defined geometry is measured quantitatively as a function of distance. To measure interactions between surfaces separated by a few molecular layers, the distance is measured interferometrically with 1/10 nm-resolution using a CCD-camera connected to a high resolution spectrograph. To get further insight into the properties of the confined thin film, we developed a method to measure the absorption by using the field enhancement within an interferometer. Extensive quantitative simulations are used to quantify the dielectric constant. Also, it is possible to measure the absorption of noninteracting dye covered surfaces. Furthermore, we modify the optics so far, that we can do fluorescence measurements. Here, we already succeeded in observing the lateral movement of a 0.7 nm thin fluorescence-labeled polymer film.