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Repeatably erasable photonic crystal structure color-based anti-counterfeiting film and preparation method and application thereof

A technology of photonic crystals and structural colors, applied in optics, optical components, instruments, etc., can solve the problem that photonic crystals cannot realize the target pattern invisible and can be visualized and reproduced, repeated erasing and reusing, single luminous light color, and easy to be oxidized and deactivated and other problems, to achieve good visual presentation effect, simple process, and clear pattern information

Active Publication Date: 2020-04-21
SUN YAT SEN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this method uses the cellulose nanocrystal suspension and the polymer precursor solution to be mixed in advance and co-assembled while polymerizing, which requires high types of polymers, and the structures that can be formed are relatively limited, and the formed photonic crystals cannot be realized. The invisible and visible reproduction of the target pattern and the function of reusing after repeated erasing limit its application range
[0006] In summary, how to solve the problems of low sensitivity, weak concealment, single luminous light color, and easy to be oxidized and deactivated in the existing anti-counterfeiting materials, and prepare a high-sensitivity, reversible erasable and hidden function, and have a certain mechanical High-strength photonic crystal anti-counterfeiting materials are still a direction worth exploring

Method used

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  • Repeatably erasable photonic crystal structure color-based anti-counterfeiting film and preparation method and application thereof
  • Repeatably erasable photonic crystal structure color-based anti-counterfeiting film and preparation method and application thereof
  • Repeatably erasable photonic crystal structure color-based anti-counterfeiting film and preparation method and application thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0054] (1) Preparation of photonic crystal thin films of cellulose nanocrystals

[0055] Get 20g paper pulp and wash with 8% sodium hydroxide solution alkali, then wash with 8L deionized water to neutrality, and then dry to constant weight at 120°C; get 5g of the product after alkali washing, and wash it in 50mL sulfuric acid (64wt) at 45°C %) in acid wash for 1h, then stop the reaction with 500mL 4°C deionized water; then centrifuge 3 times, each time for 15min, at a speed of 10000rpm, at a temperature of 4°C, and take the third centrifugation upper layer suspension for dialysis (molecular weight cut-off 14000 ) to a pH of 3, take 4 mL of the dialyzed product, dry and concentrate to 800 μL, drop and spread it on a petri dish for evaporation-induced self-assembly; after drying, a photonic crystal film of cellulose nanocrystals can be obtained.

[0056] (2) Preparation of rewritable anti-counterfeiting films based on photonic crystal structural colors loaded with ionic liquids ...

Embodiment 3

[0073] Other preparation conditions and test conditions are identical with embodiment 1, and difference is only: the NaPF in embodiment 1 6 Replaced by NaTf 2 N, PF 6 - Ions are replaced by Tf 2 N - ion.

Embodiment 4

[0075] Other preparation conditions and test conditions are identical with embodiment 1, and difference is only: the NaPF in embodiment 1 6 Replaced with NaClO 4 , PF 6 - Ions are replaced by ClO 4 - ion.

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Abstract

The invention discloses a repeatably erasable photonic crystal structure color-based anti-counterfeiting film and a preparation method and application thereof. The method comprises the following steps: soaking a photonic crystal film of cellulose nanocrystalline in a mixed solution of an ionic liquid methacryloyloxyethyltrimethyl ammonium chloride, a cross-linking agent, an initiator and absoluteethyl alcohol, after illumination polymerization, covering an anti-counterfeiting film with a hollow patterned polyester film, dropwise adding a solution containing at least one hydrophobic anion of ClO4<->, Tf2N<-> or PF6<-> to obtain a structural color anti-counterfeiting film loaded with hidden patterns in a natural state, responding to obtain complete corresponding pattern information under water stimulation, and soaking the anti-counterfeiting film in a soluble chlorine salt solution so that the hidden patterns can be wiped off. According to the invention, hydrophobic ions and hydrophilicions are exchanged to prepare the anti-counterfeiting film which has high sensitivity, reversible erasing, writing, displaying and hiding functions and certain mechanical strength, so that wiping andrecoding of information are realized.

Description

technical field [0001] The invention belongs to the technical field of preparation of photonic crystals and structural color anti-counterfeiting materials. More specifically, it relates to a rewritable anti-counterfeiting film based on photonic crystal structural color and its preparation method and application. Background technique [0002] In today's information society, the security and reliability of the information transmission process is an important content of the information society, which depends on effective information anti-counterfeiting technology, and with the popularization of large-scale computers, there is a risk of information being cracked, especially in Counterfeiting and counterfeiting crimes such as currency and pharmaceuticals are on the rise, causing enormous property losses. At present, the value of counterfeit and infringing goods in the world exceeds the trillion-dollar mark, which seriously inhibits people's innovative spirit and causes problems ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08J7/18C08J5/18C08F251/02C08F220/34C08F222/20C08F2/50G02B1/00C08L1/02
CPCC08F2/50C08F251/02C08J5/18C08J7/18C08J2301/02G02B1/005C08F220/34
Inventor 洪炜陈锐炼陈旭东
Owner SUN YAT SEN UNIV
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