Nano titanium dioxide fluorescent powder and preparation method thereof

A nano-titanium dioxide and fluorescent powder technology, applied in chemical instruments and methods, luminescent materials, medical science and other directions, can solve the problems of light metal powders easily floating in the air, low sensitivity of old fingerprints, and pollution of fluorescent powders. Delicate, overcoming inconspicuous contrast, clear handprint lines

CN104388084BInactive Publication Date: 2016-05-11CHINESE PEOPLE'S PUBLIC SECURITY UNIVERSITY
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2016-05-11
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention relates to a nanometer titanium dioxide fluorescent powder, and the fluorescent powder is perylene diimide-coated nanometer titanium dioxide. The disclosed nanometer titanium dioxide fluorescent powder is a light-pink particle under natural light, is fine in powder, and can be selectively adsorbed on a fingerprint when being used to develop the potential fingerprint through brushing, phenomena of powder adhering to or retained on background are less, and the developed fingerprint shows clear and coherent lines. When being observed under natural light, the fingerprint lines show light pink, and under excitation of blue-green light, the fluorescent powder is excited and emits high-intensity fluorescent light, the fingerprint lines show orange red when being observed through an orange filter lens, good contrast can be obtained on various objects, and the problem is overcome that the contrast is not obvious when a white titanium dioxide powder is used to develop a light-color object.
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Description

technical field

[0001] The invention belongs to the technical field of criminal investigation technology, and more specifically, the invention relates to a nano-titanium dioxide fluorescent powder for displaying fingerprints and a preparation method thereof. Background technique

[0002] Fingerprints refer to the imprints left when the palm of a person touches a tangible object. The skin patterns on the palm of the hand, including mastoid lines, flexor folds, wrinkles, scars, peeling, etc. on the entire palm are collectively referred to as palm prints, including fingerprints, knuckle lines and palm prints. Since the mastoid pattern structure of fingerprints is the most complex and the rate of on-site legacy is also the highest, fingerprints are usually referred to as handprints. Due to the characteristic that each person is different and remains unchanged throughout life, fingerprints can provide clues for investigation and provide evidence for solving, prosecuting and adju...

Examples

Embodiment 1

[0039] as attached figure 1 As shown, in the nano-titanium dioxide fluorescent powder material described in this embodiment, the nano-titanium dioxide particles used are circular, the particle size is 100-200nm, the dispersion is good, and there is only slight agglomeration; Toxic, tasteless, non-irritating nano-titanium dioxide as the matrix, and nano-titanium dioxide particles are coated with perylene diimide materials to prepare nano-titanium dioxide fluorescent powder. Strong fluorescence enhances the contrast between the handprint and the background. The preparation process of the nano-titanium dioxide fluorescent powder is simple and low in price. The finished product is easy to carry and easy to operate, and can be used in on-site survey work without causing harm to the operator's body. It is helpful for the discovery and extraction of on-site fingerprints, can effectively improve the extraction rate of on-site fingerprints, and provides more valuable clues for invest...

Embodiment 2

[0051] In order to further improve coverage and increase the intensity of fluorescence, the perylene diimide can be modified, and the specific method is as follows:

[0052] a) adding perylene diimide to dichloromethane and stirring and mixing for 10 minutes to obtain a perylene diimide premixed solution, wherein the mass of the perylene diimide is 3 to 5 times that of the perylene diimide;

[0053] b) adding a modifier whose mass is 10-15% of the perylene diimide mass to the premixed solution obtained in step a), and stirring for 60 minutes to obtain a perylene diimide solution;

[0054] Wherein, the modifying agent used in step b) is a compound with general formula (I) structure:

[0055]

[0056] In general formula (I), m and n are integers, and 5≤m≤10, 1≤n≤5.

[0057] The substance with the structure of general formula (I) can be prepared by ring-opening ethylene oxide by the reaction product of nonylphenol and formaldehyde, and can be obtained by controlling the molar...