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

Thu 811:10-14:00P7.83Pair correlations at fluid interfaces probed by x-rayscatteringKim Nygard 1 and Oleg Konovalov 11 European Synchrotron Radiation Facility, 6 Rue Jules Horowitz, BP 220 38043, Grenoble,FranceFluids are known to order into distinct layers normal to an interface, the amplitude of which decaywith increasing distance from the interface. Liquid-state theory predicts that in the asymptoticlimit, this ordering is governed by the fluid’s bulk pair correlations. Interestingly, recent surfaceforceexperiments imply that this prediction holds already for fluid films as thin as a few particlediameters. Here we pose the question, to which extent the ordering at fluid interfaces is governedby the fluids’ bulk pair correlations. For this purpose, we have studied a dense charge-stabilizedcolloidal suspension at the fluid-air interface and at two different solid-fluid interfaces by x-rayreflectivity and grazing-incidence small-angle x-ray scattering.83