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Rare earth long-persistence luminescent powder, preparation method and application thereof

A technology of long-lasting luminescent powder and rare earth, which is applied in the fields of application, luminescent materials, chemical instruments and methods, etc. It can solve problems such as display problems, and achieve the effects of narrow emission wavelength range, simple preparation method, and expanded range

Inactive Publication Date: 2012-10-24
CHINA UNIV OF GEOSCIENCES (WUHAN)
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide a rare earth long-lasting luminescent powder and its preparation method and a method of using it as a latent fingerprint display reagent. The rare earth long-lasting luminescent powder can solve the problem of fingerprint display on difficult objects and complex backgrounds

Method used

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  • Rare earth long-persistence luminescent powder, preparation method and application thereof
  • Rare earth long-persistence luminescent powder, preparation method and application thereof
  • Rare earth long-persistence luminescent powder, preparation method and application thereof

Examples

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Embodiment 1

[0051] The invention provides a rare earth long-lasting luminescent powder, the general structural formula of the compound is Sr 1-x-y Al 2 o 4 :Eu x 2+ , Dy y 3+ (x=0.005, y=0.011), the particle size of the rare earth long-lasting luminescent powder is 1-3 μm. Such as figure 2 As shown, the excitation wavelength range of the rare earth long-lasting luminescent powder is 250-450nm, and the emission wavelength is 513nm, detected by a Japanese Hitachi F-4500 fluorescence instrument.

[0052] The afterglow time of the rare earth long-lasting luminescent powder is more than 20 hours. The method for measuring the afterglow time of luminescence in this embodiment is: irradiating the luminescent material under sunlight for 5 minutes, and then placing it in a dark room to observe its luminescence.

[0053] The preparation method of the above-mentioned rare earth long afterglow luminescent powder comprises the following steps:

[0054] 1) According to Al(NO 3 ) 3 9H 2 O:M(...

Embodiment 3

[0069] The method for using the rare earth long-lasting luminescent powder prepared in Example 1 as a latent fingerprint display reagent comprises the following steps:

[0070] 1) Use a 100-mesh sieve to sieve the commercially available reduced iron powder, and then mix the rare earth long-lasting luminescent powder prepared in Example 1 and the sieved iron powder evenly at a mass ratio of 1:9 to obtain a mixture ;

[0071] 2) Use the magnetic brushing method to brush the mixture obtained in step 1) to reveal the fresh sweat and latent fingerprints left on the smooth hard paper;

[0072] 3) Use white light or ultraviolet light (365nm) to irradiate the manifested fingerprints, and collect fingerprint images in two different modes: the first is to collect fingerprint fluorescence images in the light source excitation mode; the second is to remove the light source mode, in the Self-luminous handprint images collected in a darkroom environment. Sr 1-x-y Al 2 o 4 :Eu x 2+ , ...

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Abstract

The invention provides rare earth long-persistence luminescent powder, a preparation method and a method of applying the powder as a latent fingerprint revealing reagent. The structural general formula of the rare earth long-persistence luminescent powder is M1-x-yAl2O4:Eux<2+>, Dyy<3+ > (x=0.005, and y=0.011), wherein M is any one of Sr, Ca or Ba; and the grain diameter of the long-persistence luminescent powder is 1-3 microns. The rare earth long-persistence luminescent powder is prepared by a sol-gel method. The method of applying the powder as the latent fingerprint revealing reagent comprises the following steps: the rare earth long-persistence luminescent powder is mixed with reduced iron powder; then the compound is used to reveal the latent fingerprint on an object; white light or UV-light excitation is used to collect fingerprint images or self-luminous images. The preparation method of the rare earth long-persistence luminescent powder is simple; the excitation wavelength coverage of the prepared rare earth long-persistence luminescent powder is wider and the emission wavelength coverage is narrower, so that the powder is convenient to reveal the latent fingerprint in the field. The powder has the characteristics of higher fluorescent intensity and long persistence (self-luminous); and after the fingerprint is revealed, the object background interference can be effectively eliminated. The powder is non-toxic, lossless and environment-friendly.

Description

technical field [0001] The invention belongs to the fields of material science and forensic science, and in particular relates to a rare earth long-lasting luminescent powder, a preparation method thereof and a method of using it as a latent fingerprint display reagent. Background technique [0002] After hundreds of years of evolution, the latent fingerprint display technology has become increasingly mature, but there are still a series of problems to be solved in the existing display methods: First, the display methods of many fingerprints with unfavorable objective conditions have yet to be perfected, such as dust-reduced fingerprints, grease Reduced layer fingerprints, reduced layer blood fingerprints, latent fingerprints of human skin, fingerprints on textiles with thick latitude and longitude threads, and fingerprints superimposed tens of millions of times; secondly, there are still hidden dangers in the existing visualization reagents and visualization methods. The sm...

Claims

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Application Information

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IPC IPC(8): C09K11/64A61B5/117A61B5/1171
CPCY02B20/181Y02B20/00
Inventor 熊晓波袁曦明李柳张剑王永钱孙琦
Owner CHINA UNIV OF GEOSCIENCES (WUHAN)
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