Designing mechanochromic photonic materials composed of nonclose-packed colloidal arrays

Abstract

Chameleons employ the face-centered cubic structure of guanine nanocrystals rather than chemical pigments for exhibition of skin colors. Moreover, chameleons show color change in full visible range as actively regulating the interparticle spacing of lattice structures. Therefore, mimicking the periodic nanostructures of chameleon enables us to fabricate color-tunable materials. In this thesis, inspired by chameleon, we design nonclose-packed colloidal arrays by spontaneous crystallization attributed from interparticle repulsion. In addition, we manipulate the structural coloration and optical properties by controlling the colloidal arrangements by employing the bidisperse colloidal particles. Moreover, color visibility is significantly enhanced by suppressing the incoherent scattering of light through employing the light-absorbing nanoparticles. Finally, microfluidic technology is employed to produce elastic photonic microbeads and fibers. The resulting microbeads and fiber are utilized as building blocks for secondary assembly to produce mechanochromic materials with any formats. Therefore, the mechanochromic photonic materials have a potential for lots of application such as camouflage, display, and sensors.