Copolymer Particles with Incorporated Gold and Silver Nanoparticles to Absorb Short-Wavelength Scattering in Full-Color Photonic Glasses

Abstract

Photonic glasses (PGs) have fascinated researchers because the structural colors that are reflected from PGs are angle independent. However, low color saturation, especially for colors at longer wavelengths, is an obstacle for realizing full-color PGs. It is reported that the form-factor-(FF)-derived reflections that degrade the color saturation of PGs can be removed by embedding Ag and Au nanoparticles (NPs) into copolymers. Styrene and 4-vinylpyridne copolymer particles are prepared and used as nanotemplates to synthesize AgNPs and AuNPs. The wavelength of the FF-derived reflections in relation to the diameter of the particles is estimated. NPs with an absorption spectrum corresponding to the calculated values are then selectively embedded in the copolymer particles. PGs fabricated with AgNP- and AuNP-embedded copolymer particles exhibit fewer FF-derived reflections owing to the surface-plasmon-resonance-induced absorption of the embedded NPs. Using these FF-reduced PGs, angle-independent full-color PG pigments are realized.