Prevention of Lattice Disproportionation of Electrostatic Interactional Silica Colloidal Crystals Grown via Heterogenous Nucleation by Cationic Groups of Substrate Surfaces

The effect of introducing a cationic group to the substate on the crystallization process of electrostatic interactional silica colloidal crystals formed via heterogeneous nucleation was investigated by measuring the reflection spectrum and Kikuchi-Kossel diffraction patterns of the colloidal crystals on two types of substrate: one charged negatively by silanol groups and one with introduced amino groups. On the negatively charged substrate, the colloidal crystals formed a body centered cubic (bcc) structure and a face centered cubic (fcc) structure. On the other hand, on the substrate introduced amino groups, the colloidal crystals formed only bcc structure. The decrease in the close packing trend of the colloidal crystallin lattice was derived from the decrease in the particle mobility on the substrate with introduced cationic groups through the interaction between the negatively charged silica particles and the substrates, which resulted in the prevention of the crystalline lattice disproportionation.