Abstract: Ordered colloids are rapidly formed by dialysis and exhibit unusual levels of shock resistance. Ordered colloids may be used to form a “fingerprint” optical diffraction pattern for security marking, and may also be used for freshness dating by controlling the timing of the formation or loss of order. The ordered colloids may be biocompatible, and may be directly incorporated into foods, drugs, or other ingestible substances, or they may be incorporated into distinctive packaging.

Abstract: Ionic colloidal crystals (ordered multicomponent colloids formed by attractive electrostatic interactions) may be produced by controlling the surface potential and relative size of multiple populations of colloidal particles in suspension. Such suspensions are dried or otherwise caused to precipitate out the particles in ordered arrays. The crystal structure of the arrays may be controlled by appropriate choices of particle materials, sizes, and charge ratios.