巨大コロイド単結晶の成長過程

抄録

Single crystals of giant size in colloidal distribution are observed with the naked eyes, for the first time, for the completely deionized and diluted suspensions. In this review article, shapes, colors and sizes of single crystals are discussed. The largest single crystals are observed in the suspensions at sphere concentrations slightly higher than the critical concentration of melting which results in a liquid-like structure. The size of single crystals decreases very sharply as the sphere concentration increases. Two kinds of single crystals form in the bulk phase of suspension and on the surface of the cell wall via homogeneous and heterogeneous nucleation mechanisms, respectively. Crystal structures of face-centered cubic and body-centered cubic lattices appear in the colloidal suspensions. The important role of the electrical double layers are pro-posed under the influence of purely electrostatic repulsive forces in the effective hard-sphere model. Asymmetric colloidal crystals, alloy structures are observed. Phase diagram, structural relaxation time, static and dynamic elastic moduli, and viscosity of the colloidal crystals are reviewed. Furthermore, this article discusses the influence of the external fields such as gravitational, centrifugal, electrical and shearing force fields on colloidal crystals.