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Black magnetic fingerprint display powder using graphene-modified stearic acid and its preparation

A technology of graphene modification and stearic acid, which is applied in the fields of application, medical science, diagnosis, etc., can solve the problems of lack of lubrication, etc., and achieve the effects of good fingerprint display, easy preservation, and strong adsorption force

Active Publication Date: 2019-01-25
TONGJI UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] In the above patent, C powder is only used as a dyeing agent and has no lubricating effect. At the same time, the main powder used in the above patent is sodium stearate. The principle of its appearance is to rely on the adsorption of stearic acid and organic components in fingerprints. The BN powder used in the above-mentioned patents mainly uses physical adsorption and the characteristics of peaks and valleys of fingerprints to display

Method used

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  • Black magnetic fingerprint display powder using graphene-modified stearic acid and its preparation
  • Black magnetic fingerprint display powder using graphene-modified stearic acid and its preparation
  • Black magnetic fingerprint display powder using graphene-modified stearic acid and its preparation

Examples

Experimental program
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Effect test

Embodiment 1

[0036] Magnetic powder Fe 3 o 4 Powder (the mesh number is controlled between 800-5000 mesh), stearic acid powder and graphene (the mesh number is controlled between 6000-10000 mesh) are mixed according to the ratio of 32:16:1 by weight, and ball milled. The parameters of the ball milling process are: the ratio of ball to material is 3:1, the speed is 120 rpm, and the time is 30 minutes. The powder obtained after ball milling was sieved with a 100-mesh sieve to obtain the desired powder, and dried in an oven at 50° C. for 2 hours.

[0037] The resulting black magnetic fingerprint display powder on the iron plate covered with blue paint shows the effect of fingerprint display on fresh fingerprints. figure 1 shown.

[0038] The resulting black magnetic fingerprint display powder on the glass surface for fingerprint display of fresh fingerprints is shown in the figure figure 2 shown.

[0039] The resulting black magnetic fingerprint display powder on the black electrostatic...

Embodiment 2

[0044] Magnetic powder Fe 3 o 4 Powder (the mesh number is controlled between 800-5000 mesh), stearic acid powder and graphene (the mesh number is controlled between 6000-10000 mesh) are mixed according to the weight ratio of 40:15:2, and then ball milled. Ball milling process The parameters are: the ratio of ball to material is 6:1, the speed is 250 rpm, and the time is 20 minutes. The powder obtained after ball milling was sieved with a 100-mesh sieve to obtain the desired powder, and dried in an oven at 50° C. for 2 hours.

[0045] The black magnetic fingerprint display powder obtained in this example has a clear display effect and is easy to preserve.

Embodiment 3

[0047] Magnetic powder Fe 3 o 4 Powder (the mesh number is controlled between 800-5000 mesh), stearic acid powder and graphene (the mesh number is controlled between 6000-10000 mesh) are mixed at a weight ratio of 60:25:5, and then ball milled. Ball milling process The parameters are: the ratio of ball to material is 4:1, the speed is 150 rpm, and the time is 25 minutes. The powder obtained after ball milling was sieved with a 100-mesh sieve to obtain the desired powder, and dried in an oven at 50° C. for 2 hours.

[0048] The black magnetic fingerprint display powder obtained in this example has a clear display effect and is easy to preserve.

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Abstract

The invention relates to black magnetic fingerprint showing powder adopting graphene modified stearic acid and a preparation method of the black magnetic fingerprint showing powder. The black magnetic fingerprint showing powder is prepared from, by weight, 40-60 parts of magnetic powder, 15-25 parts of fingerprint showing powder and 2-5 parts of graphene and prepared through ball milling after the magnetic powder, the fingerprint showing powder and the graphene are mixed in proportion, and according to the ball milling process parameters, the ball material ratio is 3:1 to 6:1, the rotating speed ranges from 120 r / min to 250 r / min, and the time ranges from 20 min to 30 min. Compared with the prior art, the lubricating powder-graphene is added into the magnetic powder and stearic acid powder so as to guarantee that original fingerprint characteristics cannot be damaged, and the accuracy of showing the fingerprint characteristics is guaranteed. Meanwhile, ferroferric oxide (Fe3O4) is adopted as the magnetic powder, and the color of shown fingerprints is darkened. In practice, the powder prepared through the method has a good showing effect.

Description

technical field [0001] The invention belongs to the technical field of fingerprint identification, and in particular relates to a black magnetic fingerprint display powder using graphene-modified stearic acid and its preparation. Background technique [0002] Fingerprints are unique and invariable, so fingerprints are an important identification tool in criminal investigation. Through the contact between the finger and the object, many secretions on the finger will remain on the surface of the object. The identification of fingerprints is very important in criminal investigation. The identified fingerprints can be used as strong evidence of whether a person is present. [0003] Under certain circumstances, hands that have touched colored dyes, blood, or ink can leave clear fingerprint images on surfaces. However, in most cases, fingerprints cannot be clearly seen, which are called "latent fingerprints". These fingerprints need to be clearly revealed through some means. At ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): A61B5/1172
CPCA61B5/1172
Inventor 陆伟王韬磊夏卡达牛俊超
Owner TONGJI UNIV
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