CN-121990861-A - Carbon dot-based photosensitive composite energetic micro unit and preparation method thereof

Abstract

The invention relates to the field of preparation of composite energetic materials, and particularly discloses a carbon-point-based photosensitive composite energetic micro unit and a preparation method thereof; the composite energetic micro unit takes Carbon Dots (CD) as photosensitive materials, nano high explosive as energetic components and water-soluble polymer materials/sodium alginate aqueous solution as a liquid phase carrier, and the photosensitive materials and the energetic components are dispersed into the liquid phase carrier to prepare a precursor with fluidity. Then, by combining a sol-gel method and a ball dropping process, the precursor is dropped into an aqueous solution with an ion replacement material through a needle, and the photosensitive composite energetic micro-unit is obtained through ion replacement, pre-freezing and freeze drying. The photosensitive composite energetic micro-unit components prepared by the method are uniformly distributed, can be reliably ignited under the irradiation of multi-angle incident laser, are beneficial to improving the reliability of laser ignition high explosive, and have important practical application values in micro ignition and micro initiation.

Inventors

• XU CHUANHAO
• HU SHENGLIANG
• ZHANG HONGXIA
• AN CHONGWEI
• WANG JIECHAO
• GAO LEI
• WANG YUTONG
• WANG ZHILONG
• SUN JINDONG
• SHI CHAO
• LIU LEI
• FAN XIANGQIAN

Assignees

• 中北大学

Dates

Publication Date

20260508

Application Date

20260205

Claims (10)

1. 1. The preparation method of the carbon dot-based photosensitive composite energetic micro unit is characterized by comprising the following steps of: Step one, taking an aqueous solution of a water-soluble high polymer and sodium alginate as a liquid phase carrier, taking a nano high explosive as a solid phase component and taking a water-soluble carbon point as a photosensitive material, and mixing the solid phase component and the photosensitive material into the liquid phase carrier in an ultrasonic dispersion and physical stirring mode to form a precursor; Step two, dropwise adding the precursor into an aqueous solution dissolved with transition metal ion salt through an injector, and forming gel through ion crosslinking reaction between transition metal ions and sodium alginate in the precursor so as to preliminarily mold the photosensitive composite energetic micro-unit; And thirdly, pre-freezing and freeze-drying the preliminarily formed photosensitive composite energetic micro unit to finally obtain the photosensitive composite energetic micro unit.
2. 2. The method for preparing a carbon-point-based photosensitive composite energetic micro unit according to claim 1, wherein the water-soluble high molecular polymer in the first step is at least one of polyvinyl alcohol, hydroxypropyl methylcellulose, carboxymethyl chitosan and hydroxyethyl cellulose.
3. 3. The method for preparing the carbon-dot-based photosensitive composite energetic micro unit according to claim 1, wherein the water-soluble carbon dot in the first step is at least one of a coal tar pitch carbon dot, a grapheme carbon dot and a carbonized polymer carbon dot, and the particle size is 4-20nm, and the mass percentage range is 0.5% -10%.
4. 4. The method for preparing the carbon-point-based photosensitive composite energetic micro-unit according to claim 1, wherein the nano high explosive obtained in the step (a) is CL-20, HMX or RDX.
5. 5. The preparation method of the carbon dot matrix photosensitive composite energetic micro unit according to claim 1 is characterized in that in the first step, a liquid phase carrier is formed by mixing a high polymer aqueous solution with the mass concentration of 0.5% -1.5% and a sodium alginate aqueous solution with the mass concentration of 1% according to the mass ratio of 1-2:1-4, and the mass ratio of the liquid phase carrier to the water-soluble carbon dot to the nano high explosive is 63-71:1-2.6:27.5-34.4.
6. 6. The method for preparing the carbon-point-based photosensitive composite energetic micro unit according to claim 1, wherein the diameter of the injection needle of the injector in the second step is 0.1mm-1.6mm.
7. 7. The preparation method of the carbon-point-based photosensitive composite energetic micro unit is characterized in that the transition metal ion salt in the second step is at least one of copper chloride, copper sulfate, ferrous chloride, ferric chloride, cobalt chloride, nickel chloride and aluminum chloride, and the mass concentration of the aqueous solution of the transition metal ion salt is 1% -5%.
8. 8. The method for preparing the carbon-point-based photosensitive composite energetic micro unit according to claim 1, wherein the mass ratio of the precursor to the aqueous solution of the transition metal ion salt in the second step is 1:10-30.
9. 9. The method for preparing the carbon-point-based photosensitive composite energetic micro unit according to claim 1, wherein the pre-freezing in the step three adopts refrigeration equipment, the temperature is maintained at-10 ℃ to-30 ℃, the freezing time is 6h to 24h, and the freezing drying time is 9h to 12h.
10. 10. A carbon-dot based photoactive composite energetic micro-unit obtained by the method of any one of claims 1-9.

Description

Carbon dot-based photosensitive composite energetic micro unit and preparation method thereof Technical Field The invention relates to the field of preparation of composite energetic materials, in particular to a carbon dot-based photosensitive composite energetic micro unit and a preparation method thereof. Background The laser ignition high explosive is an ignition mode for triggering the chemical reaction of the high explosive by utilizing laser energy, has good electromagnetic interference resistance, and is an important means for realizing energy control release in the fields of weapon systems and aerospace. It should be noted, however, that despite the advantages of laser-ignited explosives, they tend to require loading of a laser of a specific wavelength and higher energy during ignition due to their poor light absorption characteristics, which is disadvantageous for accomplishing a laser ignition action. To address this problem, photosensitive materials are often introduced into high explosives to form a composite energetic system to reduce laser ignition energy and improve ignition reliability. However, since the high explosive is an organic material and the photosensitive material is mostly an inorganic material or a metal material, a strong force is difficult to form in the mixing/compounding process due to different material properties, so that uneven distribution of the photosensitive material in the compound energetic system is easy to be caused, and a uniform light absorption and light-heat conversion interface is difficult to form in the compound energetic system. To solve the above problems, researchers introduce low-dimensional materials rich in active groups into a composite energetic system, such as graphene oxide rich in hydroxyl groups (Small, 2019, 1900338), modified carbon nanotubes, etc., or prepare a photothermal conversion material into a photothermal conversion film to realize laser ignition (CN 113353924B). However, it is not negligible that Graphene Oxide (GO) and Carbon Nanotubes (CNT) belong to two-dimensional and one-dimensional materials, respectively, and such materials inevitably face the problem of orientation of laser light irradiation during light absorption, for example, graphene oxide can exert the maximum effect only when laser light vertically irradiates the surface thereof, which is disadvantageous for the ignition mode of laser light with high directional selectivity. On the other hand, although the photo-thermal conversion film can solve the problem of orientation of laser irradiation through a prefabricated structure, the problem of potential interface combination between the photo-thermal conversion film and the explosive material must be considered. Furthermore, from the presently disclosed data, the study of carbon dots as photosensitive materials for laser-ignition energetic materials has not been reported. Disclosure of Invention The invention provides a preparation method of a carbon-point-based photosensitive composite energetic micro unit, which aims to solve the problems that a relatively uniform light absorption and light-heat conversion interface is difficult to form in a composite energetic system and the orientation of laser absorption of the energy-containing composite system is difficult to form due to the uneven distribution phenomenon of a photosensitive material in the composite energetic system at present. According to the invention, a Carbon Dot (CD) which has the characteristics of zero dimension, contains active groups on a surface interface, has stable properties and has photo-thermal conversion capability is selected as a photosensitive material, a sol-gel method is adopted to construct a carbon dot-based photosensitive composite energetic micro-unit, the problem of uneven distribution of the photosensitive material in the composite energetic micro-unit and heat transfer of a photo-thermal heterogeneous interface is solved through the hydrogen bond effect formed between-OH and-COOH functional groups rich in the carbon dot surface interface and a high polymer material, and meanwhile, the zero dimension attribute of the CD can also avoid the problem of orientation of the one-dimensional or two-dimensional photosensitive material to laser absorption, thereby being beneficial to realizing homogenization response under multi-angle laser irradiation. In order to solve the technical problems, the technical scheme adopted by the invention is that the preparation method of the carbon dot-based photosensitive composite energetic micro-unit comprises the following steps: Step one, taking an aqueous solution of a water-soluble high polymer and sodium alginate as a liquid phase carrier, taking a nano high explosive as a solid phase component and taking a water-soluble carbon point as a photosensitive material, and mixing the solid phase component and the photosensitive material into the liquid phase carrier in an ultrasonic dispersion and physical st