Preparation method of cellulose nanocrystal cholesteric liquid crystal texture anti-counterfeiting mark

A cholesteric liquid crystal and nano-crystal technology, applied in stamps, instruments, identification devices, etc., can solve the problems of no packaging texture research, etc., and achieve the effect of size balance, good stability, and clear lines

Inactive Publication Date: 2015-12-30
NANJING FORESTRY UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

At present, there is no research on its application in the field of packaging texture anti-counterfeiting

Method used

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  • Preparation method of cellulose nanocrystal cholesteric liquid crystal texture anti-counterfeiting mark
  • Preparation method of cellulose nanocrystal cholesteric liquid crystal texture anti-counterfeiting mark
  • Preparation method of cellulose nanocrystal cholesteric liquid crystal texture anti-counterfeiting mark

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preparation example Construction

[0021] A preparation method of a cellulose nanocrystal cholesteric liquid crystal texture anti-counterfeiting mark, comprising the following process steps:

[0022] The microcrystalline cellulose described in step a) prepares the nanocrystal suspension, and its specific method steps include:

[0023] (1) Weigh 1-10g of microcrystalline cellulose and add it to 50-100ml of 50-65wt% sulfuric acid, and carry out acidic hydrolysis for 30-120min under magnetic stirring at 40-55°C;

[0024] (2) Add deionized water to terminate the above reaction, and the obtained solution is centrifuged several times and then transferred to a dialysis bag for dialysis for 1 to 2 days to obtain a nanocrystal suspension, which is filtered and stored for later use;

[0025] Step b) Observing the cholesteric liquid crystal texture pattern with a polarizing microscope, the specific method steps include:

[0026] (1) Take 10-25ml of the above-mentioned nanocrystal suspension, conduct ultrasonic treatment ...

Embodiment 1

[0036] Microcrystalline cellulose to prepare nanocrystalline suspension: (1) Weigh 5g of microcrystalline cellulose and add it to 80ml of 64wt% sulfuric acid, and carry out acidic hydrolysis for 80min under constant temperature water bath at 45°C. (2) Add deionized water to terminate the above reaction, After the obtained solution was left to stand, centrifuge at a speed of 5000rpm / m for 10min with a centrifuge, then wash the precipitate, centrifuge again, and repeat several times until no obvious precipitate appears, then transfer the solution to a dialysis bag for dialysis for 2 days, after filtration Save for future use, the pH value of the nanocrystal suspension thus obtained is 5.5, and the concentration is 0.8wt%.

[0037] Observing the texture pattern of cholesteric liquid crystal with a polarizing microscope: (1) Measure 20ml of the above-mentioned nanocrystal suspension with a graduated cylinder, and ultrasonically treat it in an ice-water bath for 5 minutes (ultrasoni...

Embodiment 2

[0039] Microcrystalline cellulose to prepare nanocrystalline suspension: (1) Weigh 5g of microcrystalline cellulose and add it to 80ml of 64wt% sulfuric acid, and carry out acidic hydrolysis for 80min under constant temperature water bath at 45°C. (2) Add deionized water to terminate the above reaction, After the obtained solution was left to stand, centrifuge at a speed of 5000rpm / m for 10min with a centrifuge, then wash the precipitate, centrifuge again, and repeat several times until no obvious precipitate appears, then transfer the solution to a dialysis bag for dialysis for 2 days, after filtration Save for future use, the pH value of the nanocrystal suspension thus obtained is 5.5, and the concentration is 0.8wt%.

[0040] Observing the texture pattern of cholesteric liquid crystal with a polarizing microscope: (1) Take 0.2 ml of the above-mentioned nanocrystal suspension and drop it on a glass slide with a plastic dropper. (2) After the suspension is dried, observe it u...

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Abstract

The invention relates to a preparation method of a cellulose nanocrystal cholesteric liquid crystal texture anti-counterfeiting mark. The preparation method comprises the following processing steps: a) preparing nanocrystal suspension with microcrystalline cellulose; b) observing a cholesteric liquid crystal texture pattern through a polarizing microscope; c) preparing a texture anti-counterfeiting mark. The prepared cholesteric liquid crystal texture anti-counterfeiting mark has clear lines and unduplicatedness and has application value in the package anti-counterfeiting field.

Description

technical field [0001] The invention relates to a method for preparing an anti-counterfeiting mark of cellulose nanocrystal cholesteric liquid crystal texture. It belongs to the field of anti-counterfeiting of biomass materials. Background technique [0002] Cellulose is the most abundant natural polymer in nature and an inexhaustible natural renewable resource. Microcrystalline cellulose is a kind of partially depolymerized cellulose, which is a crystalline powder composed of porous particles. In general plant fibers, microcrystalline cellulose accounts for about 73%. Nanocrystalline cellulose prepared by hydrolysis of sulfuric acid will form negatively charged sulfate radical groups on the surface. The special anisotropic morphology and surface charge enable it to form lyotropic cholesteric liquid crystals in water, because of its unique The texture structure and optical properties of sintered have attracted much attention in recent years. [0003] Most of the studies o...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08L1/04G09F3/02
Inventor 李大纲张亚运
Owner NANJING FORESTRY UNIV
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