Dissipative structures formed in the course of drying the colloidal crystals of monodispersed polystyrene spheres on a cover glass

Abstract.

Macroscopic and microscopic dissipative structural patterns formed in the course of drying the deionized aqueous colloidal crystal suspensions of monodispersed polystyrene spheres (diameter: 88 nm) on a cover glass have been observed. Spoke-like and ring-like crack patterns are formed in the macroscopic scale. The broad ring patterns of the hill accumulated with spheres are also formed around the outside edge. The pattern area, drying time, neighbored inter-spoke angle, thickness of the film, and other morphological parameters have been discussed as a function of sphere concentration and concentration of sodium chloride. Fractal patterns of the sphere association are observed at the microscopic scale. Capillary forces between spheres at the air-liquid surface and the relative rates of water flow at the drying front and the convection flow of water accompanying the movement of spheres are important for the pattern formation.