Photo-Response Properties of Inverse Opal Infiltrated with Push-Pull Type Azobenzene Functionalized Polymer Liquid Crystals

Abstract

Azo-containing polymers, poly(DR1Mc), poly(Dc2AzMc) and their copolymers, having push-pull type of azo-group were prepared and their photo-orientation behaviors were investigated. They were infiltrated into silica inverse opal, and reversible Bragg reflection shift was induced by irradiation of light in a range of 500 nm to 600 nm. With linearly polarized light irradiation, Bragg reflection of inverse opal was shifted to longer wavelength region, because azobenzene compounds oriented perpendicular to the axis of incident polarized light and the refractive index contrast was changed. On the other hand, with unpolarized light, Bragg reflection was shifted to shorter wavelength region. This blue shift was due to the molecular orientation preferring parallel to the incident light direction.

Inkless Rewritable Photonic Crystals Paper Enabled by a Light-Driven Azobenzene Mesogen Switch

“…There are two mechanisms for the change of the refractive index of azobenzene mesogens induced by UV/vis irradiation. One is reversible transformation between anisotropic and random molecular orientations of azobenzene mesogens. ,, For example, the refractive index increased in the case of the uniaxial in-plane orientation of the azobenzene parallel to the plane of the film surface under the linearly polarized light irradiation. On the contrary, the out-of-plane orientation along the propagation direction of light results in a decreased refractive index under unpolarized light.…”

Synthesis and Electrooptical Properties of Side-Chain Polymethacrylates and Polycomplexes Containing Azobenzene Moieties with Different Length Spacers

“…Many potential applications have been proposed for these polymers, such as optical data storage, liquid crystal displays, molecular switches, nonlinear optical devices, and photomechanical systems. So far, a great number of azo-containing polymers have been developed for different purposes, including side-chain liquid crystalline polymers with azo mesogens as side groups [9][10][11][12][13][14], photoresponsive polymers with azo units located in the main chains, [15,16] and photoresponsive polymers networks [17][18][19][20]. One of the main focuses in this rapidly developing area is the rational design and efficient synthesis of novel azo-containing side-chain polymers in order to provide advanced functional materials with potential applications in desired areas.…”