STUDY FOR BASIS OF THERMAL OPERATED SMART WINDOWS USING TEMPERATURE DEPENDENT CHOLESTERIC LIQUID CRYSTALS

Abstract

A thermally tunable light filter modulated in near-infrared region by using temperature dependent cholesteric liquid crystals as a reflective type of optical device is proposed for an advanced thermo-driven light controller to realize the efficient control of solar-rays. The selective transmittance spectra of cholesteric liquid crystals are controlled by using the composites of various chiral dopants with different temperature dependence. The position and band width of selective reflective wavelength based on the helical structure formed in cholesteric liquid crystals are investigated by the mixture of chiral dopants with different temperature dependence. The optical properties and internal structure for polymer stabilized cholesteric liquid crystal are also investigated by the spectroscopic measurements and a polarizing optical microscope. The optical performance as the basis of thermal operated smart windows formed by the combination of cholesteric liquid crystal cells is demonstrated as a reflective thermal operated solar-ray controller.