title: Direct imaging of dynamical heterogeneities near the colloid-gel transition.
abstract: We observe the microscopic dynamics of a suspension of colloids with attractive interaction by confocal fluorescence microscopy to provide a deeper understanding of the relationship between local structure and dynamics near the gel transition. We study the distinct and self-parts of the van Hove density-density correlation function applied to our experimental data. Separable fast and slow populations emerge in the self-part, while the distinct part shows a pronounced signature of dynamic heterogeneities close to the gel transition, dominated by the fast particles. The slow population close to the gel transition shares features with an attraction-driven colloidal glass, including a plateau in the mean squared displacement that provides an estimate for the dynamical localization length.
authors.affiliation: Department of Physics, McGill University, Montréal, Canada H3A 2T8.
authors.forename: Y
authors.initials: Y
authors.lastname: Gao
authors.forename: M L
authors.initials: ML
authors.lastname: Kilfoil