Optical properties caused by periodical array structure with colloidal particles and their applications

High quality opal films have been attracting much attention due to their novel properties and applications, such as smart materials with structural color, novel photonic/optical devices and three-dimensional photonic crystals. In this article, the author reported a colloidal crystal consisting of cubic closely packed (ccp) polystyrene particles and filled with polydimethylsiloxane (PDMS) elastomer. The array of ccp (111) planes diffracts light of selective wavelengths according to Bragg’s law. The PS-PDMS hybrid opal films exhibit dynamic tuning structural colors. The lattice distance of ccp (111) planes is variable by swelling PDMS elastomer with hydrophobic liquid or by applying mechanical deformation. The hybrid opal films have potential applications in wide fields, for example, in smart sensing materials, color imaging without pigments and strain mapping of plastic deformation.