The Research Of Thethermo-responsive And Light-responsive Photonic Composite Film Based On Liquid Crystalline Polymer Network

Photonic crystals(PCs)are composed of spatially ordered dielectrics with lattice parameters.PCs with tunable photonic band gaps(PBGs)have attracted great interests because of their important applications in many fields such as tunable laser,color displays and chemical sensor and so on.Liquid crystals(LCs)are the ideal choice to be used to achieve the change of PBGs due to that the LCs’ orientation and effective refractive can be easily changed upon the environment stimuli,such as temperature,electricity,pressure,solution and so on.Herein,we fabricate a series of photonic composite film based on the PCs and LC material.In the case of thermoresponsive LC photonic film,thermal-induced deformation accompanied by shape and optical memories could be realized.Furthermore,photoresponsive LC photonic film with selective bending and self-oscillating was fabricated.Firstly,we fabricated the photonic composite film by introducing liquid crystal network(LCN)precursor into silica opal PC template,then irradiating by UV light and finally removing silica.The photonic composite film in this study was found to spontaneously form the bending shape without any external mechanical force,and the temporary bending shape can be fixed by mechanical constraint.Meanwhile,the bending deformation led to a blue-shift of the photonic composite film.Secondly,we developed a light photoresponsive LC photonic actuator based on LCN as a thermal—mechanical component and graphene oxide(GO)as photothermal-conversion component.Furthermore,the selective bending and self-oscillation of the film can be realized by preparing periodic nematic phase and isotropic phase region on a single film.Finally,as a concept-proofing-demonstration,a phototriggered generator by combining the self-oscillation behavior with piezoelectric of PVDF film was constructed,which can effectively convert light energy to electricity energy.The photoelectric converting device produced the voltage and current of 24 mV and 0.51 nA respectively.In summary,we developed the thermal-responsive and light-responsive LC composite photonic films.The photonic composite film will have potential applications in color-changing sensors and actuators.This also may provide new direction of the polymer actuators for applications in automated systems and energy-converting fields.