Figure 1: Metastable colloidal crystallites adrift in a colloidal fluid after 10 minutes melting. The scale bar denotes in a field of view.
Figure 2: (a) Video micrograph of the surface plane of a faceted colloidal crystal in contact with a dilute colloidal fluid. The dashed line demarks a (110) facet of the crystallite, while the arrow points out a sphere about to attach to the surface. (b) Trajectories of the spheres in (a) taken over 15 seconds. Dark trajectories are part of the crystal and light are in the fluid.
Figure 3: Metastable cluster of 10 spheres against a glass wall. The appearance of clusters such as this and the lack of smaller clusters suggest that the maximum unstable radius is . (a) The initial 10 sphere cluster highlighted by a green circle. The arrow indicates the direction in which a sphere will eventually leave the surface. (b) The same cluster 6 seconds later when one sphere detaches. The crystallite has drifted in the interval. The next two spheres to detach are indicated by arrows. (c) After another 2 seconds, the cluster is down to 7 spheres (d) One second later, the crystal has completely dissipated.
Figure 4: Interaction potential as a function of center-to-center separation for a pair of 0.65 diameter polystyrene sulfate spheres near a charged glass surface. The experimental geometry is represented schematically in the inset. The upper curve was measured a distance from the nearest wall and has been offset by vertically for clarity. The dashed line is a fit to Eq. (1). The lower curve was acquired at and has an attractive minimum roughly deep for spheres separated by more than five diameters.