Deformation behavior of polymeric colloidal photonic crystals induced by UV irradiation

The deformation behavior of polymeric colloidal photonic crystals (CPCs) during UV irradiation was investigated. A CPC grown from a polystyrene (PS) colloidal suspension was prepared and exposed to UV light. The UV irradiation resulted in photochemical reactions that induced morphological changes in the surfaces of CPC, including deformations in the sizes, shapes, and packing structures of the PS particles. The crystal morphology evolution resulting from UV irradiation differed significantly from the photoaging behavior observed during exposure to a light source that mimicked natural sunlight. The structural deformations destroyed the optical properties (by deteriorating the photonic bandgap). The UV irradiation induced photooxidation processes that altered the composition of the polymer material surface.