Silicon quantum dot-based fluorescent invisible ink and its preparation method and use

A silicon quantum dot, invisible ink technology, applied in the field of ultraviolet fluorescent invisible ink, can solve the problems of low environmental protection index, adverse effects on human body, toxicity and so on

Inactive Publication Date: 2015-11-25
ZHEJIANG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] At present, there are certain research results on fluorescent invisible inks at home and abroad, but organic fluorescent dyes or organic rare earth metal fluorescent complexes are mostly used as fluorescent luminescent agents, which generally have certain toxicity and low environmental protection index, which will have adverse effects on the human body.

Method used

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  • Silicon quantum dot-based fluorescent invisible ink and its preparation method and use
  • Silicon quantum dot-based fluorescent invisible ink and its preparation method and use
  • Silicon quantum dot-based fluorescent invisible ink and its preparation method and use

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Example 1: Surface lipophilic modification of silicon quantum dots

[0032] Silicon quantum dots with a size of 5nm were prepared by the plasma preparation system of silicon quantum dots, and the surface oxide layer was naturally formed in the air. Use hydrofluoric acid to etch silicon quantum dots with an oxide layer on the surface, add 5ml of hydrofluoric acid with a concentration of 40wt% to 50mg of silicon quantum dots, stir at room temperature for 5min, and centrifuge to obtain silicon quantum dots whose surface is passivated by hydrogen point. Under the protection of an argon atmosphere, the above-mentioned hydrogen-passivated silicon quantum dots were added to a mixed solution of 15 ml of n-dodecene and 40 ml of trimethylbenzene, and the reaction was stirred at 165° C. for 1 hour. The excess reagents were removed by rotary evaporation to obtain dodecyl-passivated silicon quantum dots.

Embodiment 2

[0033] Example 2: Hydrophilic modification of the surface of silicon quantum dots

[0034] The silicon quantum dots whose surface has been modified by lipophilicity in Example 1 were dispersed in toluene to prepare a 1 mg / ml silicon quantum dot toluene solution. Take 0.5 ml of the toluene solution of silicon quantum dots, add it to 5 ml of the aqueous solution (10 mg / ml) of Pluronic block copolymer F127, and stir in the air until the solvent evaporates completely. After adding 5 ml of deionized water and ultrasonicating for 15 min, filter with a 0.45 μm filter membrane to obtain a 1 mg / ml aqueous solution of silicon quantum dots.

Embodiment 3

[0035] Example 3: Hydrophilic modification of the surface of silicon quantum dots

[0036] The silicon quantum dots whose surface has been modified by lipophilicity in Example 1 were dispersed in toluene to prepare a 1 mg / ml silicon quantum dot toluene solution. Take 0.5ml of the toluene solution of silicon quantum dots, add to 5ml of Pluronic block copolymer F127 aqueous solution (0.2mg / ml), and stir in the air until the solvent evaporates completely. After adding 5 ml of deionized water and ultrasonicating for 15 min, filter with a 0.45 μm filter membrane to obtain a 1 mg / ml aqueous solution of silicon quantum dots.

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Abstract

The invention discloses silicon quantum dot-based fluorescent invisible ink. The silicon quantum dot-based fluorescent invisible ink is suitable for writing, ink-jet printing and stamp-type engraving. According to demands, the silicon quantum dot surface is subjected to lipophilic or hydrophilic modification and is used for preparation of solvent-type fluorescent invisible ink and aqueous fluorescent invisible ink, and the solvent-type fluorescent invisible ink and aqueous fluorescent invisible ink can be matched with different types of printing ink or ink. The silicon quantum dot-based fluorescent invisible ink is colorless under natural light and can give out orange or red visible light under the action of UV.

Description

technical field [0001] The invention relates to a colorless fluorescent invisible ink, in particular to an ultraviolet fluorescent invisible ink based on luminescent silicon quantum dots. The ink can be used as anti-counterfeiting material. Background technique [0002] In order to effectively prevent counterfeit and shoddy products from disrupting the market and deceiving consumers, more and more anti-counterfeiting methods have been developed. With the rapid development of science and technology, some traditional anti-counterfeiting technologies can no longer effectively play an anti-counterfeiting effect. The new fluorescent invisible ink has the characteristics of simple implementation process, low cost, good concealment, strong reproducibility, and easy detection. It has been widely used as one of the important anti-counterfeiting marks in banknotes, bills, stamps and other fields. [0003] At present, there are certain research results on fluorescent invisible inks a...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09D11/50
Inventor 皮孝东杨歆逸杨德仁
Owner ZHEJIANG UNIV
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