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Bistable liquid crystal device with optical writing or optical erasing function and preparation method thereof

A bistable liquid crystal, optical writing technology, applied in instruments, optics, nonlinear optics, etc., can solve problems such as difficult control and complex process, and achieve the effects of simple processing, simple synthesis, and precise control

Active Publication Date: 2017-11-03
PEKING UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Through a simple process, a cholesteric liquid crystal device that can smoothly switch between the planar texture and the focal conic texture under the condition of remote non-contact light radiation is prepared, which overcomes the complicated and difficult process. Controlled Orientation Technical Disadvantages

Method used

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  • Bistable liquid crystal device with optical writing or optical erasing function and preparation method thereof
  • Bistable liquid crystal device with optical writing or optical erasing function and preparation method thereof
  • Bistable liquid crystal device with optical writing or optical erasing function and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0048] Example 1: Electrical writing, optical erasing

[0049] The composite system of chiral spiroene compound (right-handed) / R811 (right-handed) / nematic liquid crystal SLC1717 is blended according to the ratio of 1.00 / 5.30 / 93.70 to modulate the light-responsive cholesteric liquid crystal composite system. Such as image 3 As shown, in the excitation light (365nm, 10.0mW / cm 2 ) Under irradiation, the pitch of the light-responsive cholesteric liquid crystal is from p 0 = 1.1μm becomes p 1 =7.8μm; when the excitation light is turned off, the pitch changes from p 1 =7.8μm back to p 0 = 1.1 μm. First, the liquid crystal composite system is poured into a liquid crystal cell with a cell thickness of 20μm. The liquid crystal is in a planar texture, showing a transparent selective reflection state, and the visible light transmittance is about 95% ( Pic 4-1 ). Applying an electric field to the circular area where information needs to be written, the arrangement of the liquid crystal mol...

Embodiment 2

[0052] Example 2: Electrical writing, optical erasing

[0053] The chiral spiro ene compound (left-handed) / S811 (left-handed) / nanoparticle NaYF 4 The composite system of Yb,Er / nematic liquid crystal E7 is blended according to the ratio of 1.60 / 4.80 / 0.90 / 92.70 to modulate the light-responsive cholesteric liquid crystal composite system. In the excitation light (975nm, 200.0W / cm 2 ) Under irradiation, nanoparticle NaYF 4 : Yb, Er will emit in-situ excited ultraviolet light, and the light response of the cholesteric liquid crystal has a pitch from p 0 =0.7μm becomes p 1 =3.7μm; when the excitation light is turned off, the pitch changes from p 1 =3.7μm back to p 0 =0.7μm. First, the liquid crystal composite system is poured into a liquid crystal cell with a cell thickness of 70 μm. The liquid crystal is in a planar texture, showing a transparent selective reflection state, and the visible light transmittance is about 94%. An electric field is applied to the circular area where inform...

Embodiment 3

[0056] Example 3: Optical writing, electrical erasing

[0057] The composite system of chiral spiroene compound (right-handed) / R811 (right-handed) / nematic liquid crystal SLC1717 was blended according to the ratio of 1.40 / 5.10 / 93.50 to modulate the light-responsive cholesteric liquid crystal composite system. In the excitation light (400nm, 30.0mW / cm 2 ) Under irradiation, the pitch of the light-responsive cholesteric liquid crystal is from p 0 =1.0μm becomes p 1 =9.4μm; when the excitation light is turned off, the pitch changes from p 1 =9.4μm back to p 0 =1.0μm. The liquid crystal composite system is first poured into a liquid crystal cell with a cell thickness of 2μm, and then an electric field is applied to the liquid crystal cell to make the liquid crystal molecules arranged into a focal conic state, showing a light scattering state, with a transmittance of about 12% ( Figure 6-1 ). Then use excitation light (400nm, 30.0mW / cm 2 ) Irradiate the triangular area where informati...

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Abstract

The invention discloses a bistable liquid crystal device with an optical writing or optical erasing function and a preparation method thereof. The bistable liquid crystal device comprises a liquid crystal box or liquid crystal film with the thickness of 2-200 micrometers, and a photoresponsive cholesteric liquid crystal composite system is poured into the liquid crystal box or the liquid crystal film; the photoresponsive cholesteric liquid crystal composite system is prepared from, by mass, 60.0 wt%-97.0 wt% of main micro-molecular liquid crystal materials, 0.5 wt%-15.0 wt% of chiral helicene compounds and 0.2 wt%-30.0 wt% chiral compounds; the initial pitch of the photoresponsive cholesteric liquid crystal composite system is p0, and the pitch rises to p1 or decreases to p2 under the irradiation of excitation light. Through a simple process, the cholesteric liquid crystal device capable of stably switching between a planar texture state and a focal conic texture state under the condition of remote non-contact illumination radiation is prepared.

Description

Technical field [0001] The present invention belongs to the field of bistable liquid crystal materials and devices. Specifically, the present invention provides a bistable liquid crystal device with optical writing or optical erasing function and a preparation method thereof. The prepared liquid crystal device can be remotely contactless Under the light irradiation conditions of the formula, the planar texture and the focal conic texture of the cholesteric liquid crystal can be adjusted and switched to achieve the characteristics of optical writing or optical erasing in different display modes. This kind of liquid crystal device can be widely used in the research of liquid crystal display, information storage, electronic writing board, smart glass, adjustable grating and related fields. Background technique [0002] Since its discovery in 1888, liquid crystals have been developing vigorously in the past 20 years. From the beginning of the popular electronic watch to the current ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G02F1/1333G02F1/137G02F1/139
CPCG02F1/1333G02F1/13718G02F1/1391
Inventor 杨槐孙健兰若尘张兰英
Owner PEKING UNIV
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