Colloidal crystal

A colloidal crystal is an ordered array of colloidal particles and fine grained materials analogous to a standard crystal whose repeating subunits are atoms or molecules.[1] A natural example of this phenomenon can be found in the gem opal, where spheres of silica assume a close-packed locally periodic structure under moderate compression.[2][3] Bulk properties of a colloidal crystal depend on composition, particle size, packing arrangement, and degree of regularity. Applications include photonics, materials processing, and the study of self-assembly and phase transitions.

A collection of small 2D colloidal crystals with grain boundaries between them. Spherical glass particles (10 μm diameter) in water.
The connectivity of the crystals in the colloidal crystals above. Connections in white indicate that particle has six equally spaced neighbours and therefore forms part of a crystalline domain.
IUPAC definition

Assembly of colloid particles with a periodic structure that
conforms to symmetries familiar from molecular or atomic crystals.

Note: Colloidal crystals may be formed in a liquid medium or during
drying of particle suspension.[4]

  1. ^ Pieranski, Pawel (1983). "Colloidal crystals". Contemporary Physics. 24: 25–73. Bibcode:1983ConPh..24...25P. doi:10.1080/00107518308227471.
  2. ^ Jones, J. B.; Sanders, J. V.; Segnit, E. R. (1964). "Structure of Opal". Nature. 204 (4962): 990. Bibcode:1964Natur.204..990J. doi:10.1038/204990a0. S2CID 4191566.
  3. ^ Darragh, P.J., et al., Opal, Scientific American, Vol. 234, p. 84, (1976)
  4. ^ Slomkowski, Stanislaw; Alemán, José V; Gilbert, Robert G; Hess, Michael; Horie, Kazuyuki; Jones, Richard G; Kubisa, Przemyslaw; Meisel, Ingrid; Mormann, Werner; Penczek, Stanisław; Stepto, Robert F. T (2011). "Terminology of polymers and polymerization processes in dispersed systems (IUPAC Recommendations 2011)" (PDF). Pure and Applied Chemistry. 83 (12): 2229–2259. doi:10.1351/PAC-REC-10-06-03. S2CID 96812603. Archived from the original (PDF) on 2022-10-09. Retrieved 2013-07-17.