Color changing materials arranged in slow particle coloration materials

Abstract

Articles comprises iron oxide colloidal nanocrystals arranged within chains, wherein the chains of nanocrystals are embedded within a material used to form the article or a transfer medium used to transfer a color to the article are described. The material or transfer medium includes elastic properties that allow the nanocrystals to display a temporary color determined by the strength of an external force applied to the article, and the material or transfer medium includes memory properties that cause the displayed temporary color to dissipate when the external force is removed, wherein the dissipation of the displayed temporary color is sufficiently slow as to be visually observable by an average observer's unaided eye.