Charged colloidal particles are spontaneously organized into three-dimensional periodic arrays in a liquid medium. This ordered state is called a colloidal crystal and has received considerable attention with respect to its potential application, particularly, as photonic crystals. For practical use as photonic crystals, production of large single crystals is required. In this paper, we report a practical method of fabricating centimeter-sized uniform colloidal crystals with a high spectral quality by shear-induced orientation: a charge-stabilized colloidal suspension is driven by a pressure-regulated air pulse and run in a flat capillary. Above a critical pressure, a very uniform and transparent texture is attained. Optical characterization by ordinary spectroscopic methods, imaging spectroscopy, and Kossel line analysis indicate that almost all the capillary space is filled with a single-domain crystal with a fixed crystallographic orientation determined by the cell geometry. The flow-aligned sample also shows two-dimensional diffraction, from which the lattice constants can be accurately determined.
ASJC Scopus subject areas
- Chemical Engineering (miscellaneous)
- Materials Science (miscellaneous)
- Environmental Science(all)
- Polymers and Plastics