Study On The Properties Of Photodeformable Liquid Crystal And Its Application

Photodeformable liquid crystal is a kind of light-responsive intelligent material which can change its properties under the stimulation of external illumination conditions.The material is safe,secure,and highly controlled,and has a vast application space.The chiral material with photosensitive azo phenyl group is introduced into the liquid crystal matrix,and the liquid crystal materials can be obtained with the light responsiveness,thus giving the traditional materials special new performance.Based on azo-type deformation caused by liquid crystal light as the research object,and theoretically analyzes the cholesteric phase liquid crystal optical properties,azo compound of isomerization and light orientation and its effect on liquid crystal.The research contents include the study of the basic properties of azo-type photodeformable liquid crystals,the test of electro-optical characteristics and optical-optical characteristics of azo-type liquid crystal display units,and their applications in liquid crystal grating and liquid crystal optical information storage.First,the azo compound was doped into the cholesteric liquid crystal to be configured into a mixed liquid crystal material,and the photosensitive properties of the material were verified.The electro-optical properties of azo-type photodeformable liquid crystal display devices were studied.The electric field is applied to the device.With the increase of the electric field intensity,the device will enter the scattering state from the initial semi-transparent state,and finally become transparent at high pressure.The overall change trend of the electric field is consistent with the cholesteric liquid crystal devices,but the threshold voltage and other parameters decrease with the increase of azo compound concentration,and the scattering effect is better.Secondly,the ultraviolet light stability of the liquid crystal subject is verified,and the effect of the box thickness on the optical properties of the device is eliminated.On the basis of this,the light-optical properties of azo-type photodeformable liquid crystal display devices are studied.Azo-benzene molecules usually exist as rod-like trans-isomers,and in ultraviolet light,isomerization becomes curved cis-isomer,which in turn affects the arrangement of liquid crystal molecules.The experiment shows that the spectral transmittance of the device is concentrated in 300~450nm band under low intensity ultraviolet light(seconds).The spectral transmittance of the components in the range of 530~780nm is more obvious under the high intensity uv irradiation(minutes).Since azo-benzene molecules can naturally relax into trans-isomers,the components of uv irradiation can slowly recover to the initial state.Using 480 nm laser irradiation devices,azo-benzene molecules rapidly changed from cis to trans-isomer,so the device quickly recovered to its initial state.The experiment further verifies the reversible transformation of the device in ultraviolet and visible light,and has good repeatability.The reflective properties of azo-type photodeformable liquid crystals are determined by chiral agents and azo compounds,study the effect of each composition concentration reflection characteristics to the device,to determine the azo compound optimization of doping concentration between 3% and 12%.Finally,we explore the application of azo-type photodeformable liquid crystal.The crystal grating is prepared by the amplitude mask method,and the diffraction effect of the grating is verified.Was prepared to realize the light with the light erase information storage,information can be stable in a dark state environment storage more than 12 hours,light erasing process can be completed within 10 seconds,write and erase process can be repeated many times.