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

Thu 811:10-14:00P8.23Confocal microscopy of colloidal hard sphere andcharged sphere fluids and crystalsAchim Lederer 1 and Hans Joachim Schöpe 11 University of Mainz, Staudinger Weg 7, 55128, Mainz, GermanyMonodisperse suspensions of colloidal spheres with known interaction are a terrific model systemfor testing predictions by statistical physics. Their typical length scales are accessible via opticalmethods like light scattering in reciprocal and microscopy in real space. Light scattering leadsto ensemble averaged observables like structure factors in reciprocal space with a high statisticalaccuracy, while information about the local order and the local dynamic are very difficult to get.A state-of-the-art technique to gain information about the local parameters of a colloidal system isthe Laser Scanning Confocal Microscope (LSCM) which takes 3D-videos from a sample. By thismethod, the structure and dynamics of a colloidal suspension can be observed on a single particlescale ([1], [2]). In this work we investigate colloidal model systems with hard sphere and chargedsphere interaction in the fluid and crystalline regime using LSCM showing significant differencesin dynamic and structure as function of particle interaction.[1] V. Prasad et al. , J. Phys. : Condens. Matter 19, 113102 (2007).[2] A. D. Dinsmore et al. , Appl. Opt. 40, 4152 (2001)23