Research On Photoactuating Properties Based On Optical Frequency Selectivity Of Dye-doped Liquid Crystal Elastomers

Liquid crystal elastomer?LCE?is a new kind of responsive intelligent deformation material.Because of its advantages of clean energy,simple equipment and remote control,the photoelastic liquid crystal has a wide application prospect in artificial muscle,microfluidic and micromechanical fields.At present,the band range of most LCE actuation light sources is ultraviolet and infrared light area,and there are few reports that the quasi sunlight band light source is used as the actuation light source.In addition,most multifunctional LCE brakes can only perform two functions through the actuation light sources of different light areas?ultraviolet and infrared?.Very few multifunctional LCE brakes can perform three functions,but they also need different functions A plurality of actuation light sources in the light region perform three functions respectively.Therefore,based on the photo thermal mechanical mechanism of LCE,the dye-doped liquid crystal elastomers?Dye-doped LCE?were prepared by using the visible absorber dyes of Luxottica exiton company as the photo thermal medium Materials)and its structure and performance were characterized by UV-Vis absorption spectrum,transmission electron microscope,polarized light microscope,differential scanning calorimetry,actuation light source and mechanical experiment machine Materials can effectively use quasi day-light source for photoactivation,while 594/LCE has the best photoactivation performance because its light absorption range is near the strongest emission spectrum of quasi day-light source.In addition,Dye-MOCH₃-LCE materials with non liquid crystal elements were prepared in this paper.Through the structural characterization and performance analysis of Dye-MOCH₃-LCE materials,a single light source,multi light frequency controlled switch in visible light area was designed.The main conclusions are as follows:?1?The side chain waist liquid crystal monomer 4'-acryloxybutyl 2,5-Bis?4'-butyloxyphenoxy?benzoate?4a?and4'-acryloxybutyl2,5-Bis?4'-pentylcyclohexoxycarboxyloxy?benzoate?4b?were synthesized,and the side chain tail liquid crystal monomer 2,5-Bis?formoxy-4-butyloxybenzene??MBB?and the crosslinker1,4-undecylenoxybenzene?11UB?were prepared.The side chain tail type liquid crystal elastomer is suitable for dye doping.It has large size and is suitable for device design and fabrication.?2?Dye-doped LCE materials were prepared by two-step crosslinking method and solvent exchange technology.Under the illumination of a quasi sunlight area actuation light source,the photoinduced shrinkage rate of Dye-doped LCE materials can reach about 30%.Among them,594/LCE showed the optimal photoactivation behavior in the Dye-doped LCE.?3?Dye-MOCH₃-LCE materials were prepared by two-step crosslinking method and solvent exchange technology.Compared with Dye-doped LCE materials,the phase transition temperature of Dye-MOCH₃-LCE materials decreased by 10?12?.Under the illumination of different frequencies?405nm,450nm,590nm?in the visible region,the shrinkage rate of a single Dye-MOCH₃-LCE material is about 30%,and that of the other two Dye-MOCH₃-LCE materials is less than 10%.The results show that the Dye-MOCH₃-LCE materials have wavelength-selectivity in the visible region.?4?Dye-MOCH₃-LCE materials composite was prepared by using Dye-MOCH₃-LCE materials in the upper layer and MOCH₃-LCE materials in the lower layer,which were not doped with dyes.Finally,a simple light controlled infrared sensor switch is designed,which can perform many different functions through different light frequencies in the visible light area.It has a certain application value for the development of environmental engineering,biomedical,electronic technology,artificial intelligence,micro electron mechanical and other fields.