Patternable liquid crystal film based on spiropyran derivative molecular switch and preparation method and application of liquid crystal film

A technology of spiropyran derivatives and molecular switches, applied in chemical instruments and methods, liquid crystal materials, luminescent materials, etc., can solve problems such as easy oxidation and decomposition, fast aging, general patterning effect, etc., to improve stability and use Longevity, improved overall effect, good patterning effect

Active Publication Date: 2021-06-29
PEKING UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The small-molecule spiropyran molecule can be used directly as a color-changing material, or it can be used as a color-changing material after simple compounding with other materials, but these two color-changing materials have disadvantages such as poor fatigue resistance, easy oxidative decomposition, and fast aging.
Spiropyran and its derivatives can be mixed with liquid crystal materials to form liquid crystal films, which can increase the service life of materials. However, at present, liquid crystal films made of color-changing materials containing spiropyran molecules can only achieve color changes, and cannot have both color and fluorescence. And the change of liquid crystallinity, the patterning effect is general, and the coexistence of non-erasable patterns and erasable patterns cannot be realized, which limits the scope of use of this type of liquid crystal film

Method used

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  • Patternable liquid crystal film based on spiropyran derivative molecular switch and preparation method and application of liquid crystal film
  • Patternable liquid crystal film based on spiropyran derivative molecular switch and preparation method and application of liquid crystal film
  • Patternable liquid crystal film based on spiropyran derivative molecular switch and preparation method and application of liquid crystal film

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1～7

[0046] The preparation method of embodiment 1~7 spiropyran derivative

[0047] Examples 1 to 7 are respectively a preparation method of a spiropyran derivative. The spiropyran derivative is obtained by taking 10 mol of 1',3',3'-trimethyl-6-nitrospiro[benzo Pyran-2,2'-indoline]-5',8-diol (referred to as compound 1) and 20mol of benzoic acid (referred to as compound 2) substituted with alkoxy groups and derivatives thereof at the para-position 20mol of dicyclohexylcarbodiimide is used as a dehydrating agent, and 1mol of 4-dimethylaminopyridine is used as a catalyst for the esterification reaction. The chemical reaction formula of the specific esterification reaction is as follows:

[0048]

[0049] Among them, R is n is an integer among 2-18.

[0050] The difference in the preparation methods of the spiropyran derivatives in Examples 1 to 7 is only that the difference in compound 2 and the adjustment of reaction parameters such as the esterification reaction time known to ...

Embodiment 8～14

[0059] Examples 8-14 Preparation method of patternable liquid crystal film based on spiropyran derivative molecular switch

[0060] Examples 8 to 14 are respectively a method for preparing a patternable liquid crystal film based on a molecular switch of a spiropyran derivative. ) and the photoinitiator are heated to 80-100°C to melt, stir and mix well, add to the liquid crystal cell, raise the temperature to the clearing point, observe the phase change of the liquid crystal with a polarizing microscope, determine the crystallization point of the liquid crystal mixture, and cool down to the crystallization point +2℃~clearing point -2℃, keep warm, then place it at 5~100mW / cm 2 Irradiate under visible light to make it polymerized and solidified for 1-5 hours. After the polymerization and solidification is completed, the liquid crystal cell is removed, and the corresponding patternable liquid crystal film based on the molecular switch of the spiropyran derivative is obtained, whic...

Embodiment 15

[0069] Example 15 A patterning method of a patternable liquid crystal film based on a spiropyran derivative molecular switch

[0070] This embodiment is a method for patterning a patternable liquid crystal film based on a molecular switch of a spiropyran derivative. Heat the initiator to 90°C to melt, stir and mix well, add it to the liquid crystal cell, raise the temperature to the clearing point of 70°C, observe the phase change of the liquid crystal with a polarizing microscope, and confirm that the crystallization point of the liquid crystal mixture is 43°C, and cool down to 48°C Insulation, the optical mask with the initial pattern (i.e. the mask of the smiley face pattern) is covered on the upper surface of the liquid crystal cell after insulation, and the temperature is controlled by 10mW / cm 2 365nm photopolymerization curing (first time) for 1.5h, remove the optical mask with the initial pattern, and then 10mW / cm 2 520nm visible light polymerization curing (second t...

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Abstract

The invention belongs to the technical field of photochromic and thermochromic film materials, and discloses a patternable liquid crystal film based on a spiropyrane derivative molecular switch and a preparation method and application of the liquid crystal film. The liquid crystal film is prepared by the following steps: heating a spiropyran derivative, a liquid crystal polymerizable monomer and a photoinitiator to a molten state, conducting uniform mixing, adding the obtained mixture into a liquid crystal box, successively carrying out heating, cooling and heat preservation, and perofrming polymerizing and curing through visible light irradiation. The patternable liquid crystal film based on the spiropyrane derivative molecular switch can be changed in color, fluorescence and liquid crystal property after being excited, is good in stability and patterning effect, has various patterning methods, and is suitable for being used as a multiple anti-counterfeiting material capable of selectively retaining and erasing stored information.

Description

technical field [0001] The invention belongs to the technical field of light and thermochromic thin film materials, and relates to a patternable liquid crystal film and its preparation method and application, in particular to a patternable liquid crystal film based on a spiropyran derivative molecular switch and its preparation method and apply. Background technique [0002] Spiropyran and its derivatives are widely studied organic switch molecules with reversible discoloration properties, which can change the structure of this compound under various external stimuli such as heat, light, force and electricity. Thereby achieving discoloration. Spiropyran and its derivatives are not only used in the field of analytical chemistry as sensors, but also widely used in the field of optoelectronic materials as molecular devices. [0003] Photo and thermochromic film is a film containing photo and thermochromic materials, which will change color after being excited, and has good se...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09K19/38C09K11/06
CPCC09K19/3852C09K11/06C09K2211/1475C09K2211/1425C09K2211/1433
Inventor 杨槐胡威孙畅任云霄秦晟煜黄隽怡
Owner PEKING UNIV
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