Colloidal Crystallization by Centrifugation

Abstract

Columnar-shaped colloidal crystals (width and length of the columns —0.1-1.0 mm and 10 mm, respectively) have been grown by centrifugation of the dispersion of polystyrene particles. The crystals were re-dispersed reversibly. Close-packed colloidal crystals were obtained by drying the columnar crystals gently. The dried crystals contained no macroscopic cracks over several mm³. Some stacking disorders were observed on the cross sections of the dried crystals. The average grain size of the columnar crystals increased with decreasing centrifugal acceleration. Too fast centrifugation caused the sedimentation of randomly oriented small grains in front of the growth interfaces.