8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

P7.84Thu 811:10-14:00Anisotropic pair correlations of confined hard-spherefluids, an experimental and theoretical studyKim Nygard, 1 Roland Kjellander, 2 Sten Sarman, 3 Johan Buitenhuis, 4 and J. Frisovan der Veen 51 European Synchrotron Radiation Facility, 6 Rue Jules Horowitz, BP 220 38043, Grenoble,France2 University of Gothenburg, Gothenburg, Sweden3 Stockholm University, Stockholm, Sweden4 Forschungszentrum Jülich, Jülich, Germany5 Paul Scherrer Institut, Viligen, SwitzerlandThe structure and properties of simple liquids are governed by their pair correlations, which areisotropic in the bulk phase. In the case of confined fluids, it has for a long time been knowntheoretically that the pair correlations are anisotropic and they have also been explicitly calculated[1]. However, to date no quantitative experimental verification of these predictions have beenreported. Here, we address this problem by combining x-ray scattering experiments on hardspherecolloidal fluids confined in diffraction gratings [2] and inhomogeneous liquid-state theorywithin the anisotropic Percus-Yevick approximation. We find the experiment and theory to be inexcellent agreement at the pair correlation level. The description of confined fluids on this levelgives important insights for the mechanisms of interparticle interactions in dense fluids.[1] R. Kjellander and S. Sarman, J. Chem. Soc. Faraday Trans. 87, 1869 (1991).[2] K. Nygård et al. , EPL 86, 66001 (2009).84