아조 화합물을 함유한 고분자 분산 액정의 전기·광학적 특성 연구

Abstract

To investigate the effects of Azo compound on the electro-optical properties of Polymer Dispersed liquid crystal(PDLC), 4-Hexyloxy-4-methoxy-azobenzene(Azo-S) was synthesized. The Azo-S synthesized in this investigation were identified using FTIR, NMR, and estimated with elemental analysis. The photo-isomerization of the Azo-S was studied with Ultraviolet–visible(UV–vis) spectroscopy. And, The variation in the phase-transition temperature of liquid crystal after UV irradiation was investigated by Differetial Scanning Calorimeter(DSC) The effects of Azo-S and curing intensity on the photopolymerization behavior, the phase separation process, the electro-optical properties, and the morphology have been analyzed by Photo-DSC, Relative conductivity, Visible Spectrometer and Scanning Electron Microscopy. The results show that Azo-S and curing intensity are important parameters which influence the final electro-optical properties and the morphology of PDLC. The PDLC containing Azo-S with an decrease in the curing Intensity resulted in the larger droplet size due to gradual phase separation during for photo Polymerization. Variation of Transmittance of PDLC film was increased by Photo isomerization of Azo-S after 365nm irradiation. Therefore PDLC contained Azo-S shows better transmittance with an decrease in the applied voltage than PDLC which doesn't contain Azo-S.