Apparatus and method for preparing multi-scale distribution energetic composite microspheres

Abstract

This invention belongs to the field of energetic materials technology and discloses an apparatus and method for preparing multi-scale distributed energetic composite microspheres based on the droplet method. This invention combines microchannel extrusion technology with water suspension, overcoming the shortcomings of traditional granulation processes, such as difficulty in achieving continuous production and irregular shapes. Simultaneously, during the solidification and molding of microdroplets, by providing a force field generated by high-speed stirring, the microdroplets are effectively modified, which helps to improve the complete coating of the energetic composite microspheres, thereby significantly enhancing the safety and reliability of single-element explosives. This invention achieves efficient and continuous preparation of multi-scale energetic composite microspheres with a median particle size ranging from 30 μm to 800 μm, with the advantages of high sphericity and narrow particle size distribution.

Description

Technical Field

[0001] This invention belongs to the field of energetic materials technology, and particularly relates to an apparatus and method for the efficient and continuous preparation of multi-scale distributed energetic composite microspheres based on the droplet method. Background Technology

[0002] Energetic compounds such as RDX (cyclotrimethylenetrinitramine), HNS (hexanitrozimine), HMX (cyclotetramethylenetetranitramine), and CL-20 (hexanitrohexaazaisowulzane) are widely used in gun and solid rocket propellants due to their excellent energy release characteristics. Their safety and reliability directly affect their practical application performance; therefore, improving the safety and reliability of single-element explosives is key to optimizing their performance and achieving safe and efficient applications. Currently, spheroidization coating technology has shown significant effectiveness in improving the safety of single-element explosives. The preparation of energetic composite microspheres depends on the interfacial reaction between the single-element explosive and the binder. By coating single-element explosives with a binder, the resulting energetic composite microspheres significantly improve the safety and reliability of the explosives. Furthermore, effective regulation of coating completeness is of great significance in further improving the safety and reliability of explosives.

[0003] With the development of coating technology, various techniques such as water suspension, emulsion, spray drying, and microfluidics have achieved significant results in improving the coating effect of explosive particles, reducing mechanical sensitivity, and optimizing molding performance. However, these methods are mostly intermittent processes, resulting in poor product consistency and low production efficiency. In contrast, continuous coating technology has advantages in efficiency and repeatability, attracting widespread attention in recent years. The droplet method is an economical and efficient microsphere preparation technology. By controlling the formation conditions and solidification process of microdroplets, the morphology and size of microspheres can be controlled. However, existing droplet methods still face problems such as low particle size control precision, uneven particle size distribution, and low production efficiency, making it difficult to meet the needs of mass production of high-performance energetic materials. Therefore, there is an urgent need for an energetic composite microsphere preparation technology that can achieve efficient continuous production and multi-scale particle size distribution to further improve the coating completeness, morphology control, and safety and reliability of microspheres, providing innovative solutions for the field of energetic materials. Summary of the Invention

[0004] The technical problem to be solved by this invention is that traditional granulation processes are difficult to achieve continuous production and have the defect of irregular microsphere shapes.

[0005] To solve the above-mentioned technical problems, the specific technical solution of the present invention is as follows: The present invention provides an apparatus for preparing multi-scale distributed energetic composite microspheres based on the droplet method, comprising a droplet generation system 1, a microdroplet solidification system 2, a microsphere collection system 3, a circulating liquid storage system 4, and a circulating pipeline system 5; The droplet generation system 1 includes a dispersed phase solution receiver, a pump, a magnetic stirrer, a rotor, and an extension tube needle. The dispersed phase solution is placed inside the dispersed phase solution receiver, the rotor is located inside the dispersed phase solution receiver, and the dispersed phase solution receiver is placed above the magnetic stirrer. The extension tube needle is connected to the pump, with one end of its liquid-conducting end located inside the dispersed phase solution receiver and the other end of the needle located in the glass reactor of the microdroplet solidification system 2. The microdroplet solidification system 2 includes a stirrer, a stirring paddle, and a glass reaction vessel. The stirrer is connected to the stirring paddle, and the stirring paddle is placed inside the glass reaction vessel. The pipes and peristaltic pump in the circulation pipeline system 5 transport the composite microspheres prepared by the microdroplet solidification system 2 to the microsphere collection system 3. The microsphere collection system 3 includes a glass reactor II and a filter tank. The glass reactor II is used for the storage and circulation of the continuous phase solution. The filter tank is located in the glass reactor II and collects the composite microspheres and filters out the continuous phase solution. The pipes and peristaltic pump in the circulation pipeline system 5 connect the microsphere collection system 3 and the circulating liquid storage system 4. The circulating liquid storage system 4 includes a glass reactor and a continuous phase solution. The glass reactor is used for storing, circulating, and replacing the continuous phase solution. The upper inlet of the glass reactor is used for injecting the continuous phase solution, and the lower outlet is used for discharging the continuous phase solution. The pipes and peristaltic pump in the circulating pipeline system 5 connect the microdroplet solidification system 2 and the circulating liquid storage system 4 to realize the circulating flow of the continuous phase solution.

[0006] The circulating pipeline system 5 consists of a peristaltic pump and pipelines, which connect the microdroplet solidification system 2, the microsphere collection system 3 and the circulating liquid storage system 4.

[0007] Furthermore, the pump in the droplet generation system 1 is a peristaltic pump, a centrifugal pump, or a syringe pump.

[0008] Another aspect of the present invention provides a method for preparing multi-scale distributed energetic composite microspheres based on the droplet method. The method is implemented using the aforementioned apparatus and includes the following steps: Step 1: Preparation of the continuous phase solution and continuous circulation flow The surfactant and water-soluble polymer material in the corresponding proportions are dissolved in deionized water to prepare a continuous phase solution, which is then added to glass reactors one, two, and three of the microdroplet solidification system 2, microsphere collection system 3, and circulating liquid storage system 4, respectively. The peristaltic pump is turned on to realize the continuous circulation of the continuous phase in the device. At the same time, the stirrer in the microdroplet solidification system 2 is turned on and the stirring rate is set to make the continuous phase solution stably stirred, forming a high-speed rotating crushing force field. Step 2: Preparation of the dispersed phase of the explosive suspension The binder is dissolved in the dispersion solvent. After complete dissolution, explosive particles of the corresponding proportion are added. The explosive particles are dispersed by ultrasonic action to make them uniformly dispersed in the dispersion solvent, thus preparing a dispersion suspension solution. This solution is then added to the dispersion solution receiver of the droplet generation system 1 for later use. Step 3: Extrusion of dispersed phase droplets The dispersed phase suspension solution in the dispersed phase solution receiver is squeezed through the extension tube from the needle into the glass reactor of the microdroplet solidification system 2 using the pump in the droplet generation system 1; Step 4: Stir, solidify, and shape. After the dispersed phase droplets in the droplet generation system 1 are extruded into the microdroplet solidification system 2, the stirring rate is set by the stirrer. Under the action of high-speed stirring, the continuous phase solution shears the dispersed phase droplets into spheres. Under the action of high-speed stirring in the microdroplet solidification system 2, the dispersed phase microdroplets are suspended in the continuous phase, which accelerates the solvent exchange rate and realizes the rapid solidification of the microdroplets, thus obtaining a liquid containing the sample. Step 5: Post-processing such as collection and cleaning of composite microspheres The sample obtained in step four is transported to the filter tank of the microsphere collection system 3 through the circulation pipeline system 5. After washing the composite microspheres in the filter tank, they are dried in an oven to obtain the finished composite microsphere product.

[0009] Furthermore, in step one, by changing the concentration of the continuous phase, the shearing effect of the continuous phase on the dispersed phase is controlled, thereby further controlling the size of the composite microspheres. The lower the concentration of the continuous phase, the more likely the shearing and breaking effect of the dispersed phase droplets will generate smaller droplets.

[0010] Furthermore, in step two, the size of the composite microspheres is further controlled by changing the concentration of the dispersed phase and adjusting the size of the dispersed phase microdroplets.

[0011] Furthermore, in step three, the flow rate of the dispersed phase is adjusted by using a pump. By changing the extrusion rate of the dispersed phase, the size of the dispersed phase microdroplets is controlled, thereby further controlling the size of the composite microspheres. When the shearing effect of the continuous phase on the dispersed phase is the same, the higher the extrusion rate, the larger the particle size of the prepared microspheres.

[0012] Furthermore, in step four, the size of the composite microspheres is further controlled by changing the stirring rate to regulate the shear force of the continuous relative dispersed phase droplets; the higher the stirring rate, the smaller the particle size of the prepared microspheres.

[0013] The present invention has the following advantages: (1) This invention combines microchannel extrusion technology with water suspension method to achieve the preparation of energetic composite microspheres with simple process operation, high efficiency, high sphericity and uniform particle size. At the same time, by adjusting the process parameters, it is possible to prepare multi-scale shaped powder microsphere particles from micrometer to millimeter scale.

[0014] (2) The continuous droplet device designed in this invention can precisely control key process parameters such as the extrusion rate of the dispersed phase droplets and the stirring rate of the continuous phase solution, effectively ensuring the monodispersity of the microdroplets and the environmental consistency of the assembly and molding process. The energetic composite microspheres prepared in this way have significant advantages such as high sphericity, narrow particle size distribution and excellent uniformity.

[0015] (3) The present invention introduces high-speed stirring during the solidification process of microdroplets after shearing and forming to form a specific force field, which is conducive to fine modification and processing of microdroplets, thereby significantly improving the sphericity and coating completeness of energetic composite microspheres and realizing the efficient preparation of high-quality energetic composite microspheres. Attached Figure Description

[0016] Figure 1 A device for the efficient and continuous preparation of multi-scale distributed energetic composite microspheres based on the droplet method; Figure 2 Here is a schematic diagram of the SEM image of HNS-Ⅳ@NC microspheres; Figure 3 The particle size distribution of HNS-Ⅳ@NC microspheres is shown. Figure 4 Here is a schematic diagram of the SEM image of HMX@F2602 microspheres; Figure 5 The particle size distribution of HMX@F2602 microspheres is shown. Figure 6 Here is a schematic diagram of the SEM image of CL-20@ACM microspheres; Figure 7 The particle size distribution of CL-20@ACM microspheres is shown. Figure 8 Here is a schematic diagram of a SEM image of TATB@PMMA microspheres. Figure 9 The particle size distribution of CL-20@ACM microspheres is shown. The markings in the diagram are as follows: 1-Droplet generation system, 2-Microdroplet solidification system, 3-Microsphere collection system, 4-Circulating liquid storage system, 5-Circulating pipeline system, 01-Dispersed phase solution receiver, 02-Rotor, 03-Magnetic stirrer, 04-Pump, 05-Extension tube needle, 06-Stirrer, 07-Stirring paddle, 08-Glass reactor, 09-Peristaltic pump, 010-Filter screen. Detailed Implementation

[0017] To better understand the purpose, structure, and function of this invention, the invention will be described in further detail below with reference to the accompanying drawings.

[0018] Example 1 like Figure 1 As shown, an efficient and continuous device for preparing multi-scale distributed energetic composite microspheres based on the droplet method includes a droplet generation system (1), a microdroplet solidification system (2), a microsphere collection system (3), a circulating liquid storage system (4), and a circulating pipeline system (5).

[0019] The droplet generation system (1) includes a dispersed phase solution receiver, a pump, a magnetic stirrer, a rotor, and an extension tube needle. The dispersed phase solution receiver is used to hold the dispersed phase solution. The magnetic stirrer and rotor are used to ensure the uniform distribution of components inside the dispersed phase suspension. The pump, by adjusting the extrusion rate, stably extrudes the dispersed phase suspension, thereby achieving precise control over the preparation of microdroplets. At the same time, the cooperation between the pump and the dispersed phase solution receiver allows for the continuous addition of the dispersed phase suspension during the preparation process, achieving continuous liquid supply and ensuring the continuity and stability of the preparation process. The extension tube needle is assembled from a liquid guide tube, a Luer connector, and a needle. During the assembly process, the dispersed phase solution and the rotor are placed inside the dispersed phase solution receiver, which is placed on top of the magnetic stirrer to ensure the uniformity of the dispersed phase solution. The extension tube needle is connected to the pump, the end of the liquid guide tube is placed in the dispersed phase, and the needle is placed in the glass reactor of the microdroplet solidification system (2) to ensure that the dispersed phase is extruded into the microdroplet solidification system.

[0020] The microdroplet solidification system (2) mainly consists of a stirrer, a stirring paddle, and a glass reactor. After the droplet generation system generates microdroplets, the microdroplets are sheared into spheres by stirring. During the solidification process of the microdroplets (the droplets exchange solvent from the outside to the inside to ensure stable precipitation of the binder and uniform coating on the surface of the explosive particles), the microdroplets are effectively modified by providing a force field formed by high-speed stirring, thus achieving complete sphericity coating of the energetic composite microspheres. During the construction process, the stirrer and the stirring paddle are connected, and the stirring paddle is placed in the glass reactor. At the same time, the pipes and peristaltic pump in the circulation pipeline system (5) transport the composite microspheres prepared by the microdroplet solidification system (2) to the microsphere collection system (3).

[0021] The microsphere collection system (3) mainly consists of a glass reactor and a filter tank. The glass reactor is used for the storage and circulation of the continuous phase solution. The composite microspheres are collected in the filter tank, and the continuous phase solution is filtered out. The filter screen has a pore size of 1400 mesh, which can effectively collect the prepared composite microspheres. At the same time, the filter tank can be removed. The pipes and peristaltic pump in the circulation pipeline system (5) connect the microsphere collection system (3) and the circulating liquid storage system (4).

[0022] The circulating liquid storage system (4) mainly consists of a glass reactor and a continuous phase solution. The glass reactor is used for the storage, circulation, and replacement of the continuous phase solution. The upper inlet of the glass reactor is used for the injection of the continuous phase solution, and the lower outlet is used for the discharge of the continuous phase solution. The pipes and peristaltic pump in the circulating pipeline system (5) connect the microdroplet solidification system (2) and the circulating liquid storage system (4) to realize the circulation flow of the continuous phase solution.

[0023] The circulating pipeline system (5) mainly consists of a peristaltic pump and pipelines. The pipelines include silicone tubes and polytetrafluoroethylene tubes, etc. The peristaltic pump circulates the continuous phase solution in the pipelines and glass reactor. The pipelines connect the microdroplet solidification system (2), the microsphere collection system (3), and the circulating liquid storage system (4). The peristaltic pump circulates and transports the continuous phase solution through the pipelines.

[0024] Example 2 An efficient and continuous preparation method for energetic composite microspheres based on the device of Example 1 is disclosed, which prepares hexanitrozines (HNS)-based energetic composite microspheres with the following mass percentages: nitrocellulose (NC) 3% and HNS 97% (HNS-Ⅳ) (median particle size of 80 nm).

[0025] Step 1: Preparation and continuous circulation of the continuous phase solution. Dissolve 90 ml of Tween-80 and 60 g of PVA (1788) in 2850 ml of deionized water to prepare a continuous phase solution. Add the solution to the glass reactors of the microdroplet solidification system (2), the microsphere collection system (3), and the circulating liquid storage system (4), respectively. Turn on the peristaltic pump in the circulation pipeline system (5) to pre-circulate the continuous phase solution in the circulation pipeline system.

[0026] Step 2: Preparation of the dispersed phase of the explosive suspension. Dissolve 0.15g of NC in 25g of ethyl acetate. After complete dissolution, add 4.85g of HNS-Ⅳ. Under ultrasonic conditions, the explosive particles are uniformly dispersed. Under stirring conditions, the explosive suspension is placed in the dispersed phase solution receiver of the droplet generation system (1) for later use.

[0027] Step 3: Extrusion of dispersed phase droplets. Using the pump in the droplet generation system (1), the dispersed phase suspension in the dispersed phase solution receiver is extruded through the extension tube from the needle into the glass reactor of the microdroplet solidification system (2). At the same time, the flow rate of the dispersed phase is adjusted using a peristaltic pump and set to 0.5 ml / min.

[0028] Step 4: Stirring and solidification. After the dispersed phase droplets in the droplet generation system (1) are extruded into the microdroplet solidification system (2), the stirring speed is set to 400 rpm by the stirrer. Under the action of high-speed stirring, the continuous phase solution shears the dispersed phase droplets into spheres. Under the high-speed stirring action of the microdroplet solidification system (2), the dispersed phase microdroplets are suspended in the continuous phase, which accelerates the solvent exchange rate and realizes the rapid solidification of the microdroplets. Through the solvent exchange mechanism of the microdroplets from the outside to the inside, it is ensured that the binder can be stably precipitated and uniformly coated on the surface of the explosive particles. At the same time, the force field formed by the high-speed stirring action is used to modify and process the microdroplets, thereby significantly improving the sphericity and coating completeness of the energetic composite microspheres and realizing the preparation of high-quality microspheres.

[0029] Step 5: Post-processing such as collection and cleaning of composite microspheres. The sample obtained in Step 4 is transported to the filter tank of the microsphere collection system (3) through the circulation pipeline system (5). After washing the composite microspheres in the filter tank, they are dried in an oven to obtain the finished HNS-Ⅳ@NC composite microspheres.

[0030] As attached Figure 2 , 3 The prepared HNS-Ⅳ@NC composite microspheres have a particle size distribution between 500.93μm and 564.42μm, exhibiting a single-peak distribution with a particle size span of 0.12 and good flowability.

[0031] Example 3 An efficient and continuous preparation method for energetic composite microspheres based on the device of Example 1 is disclosed, which prepares octogen (HMX)-based energetic composite microspheres with the following mass percentages: fluororubber (F2602) 5% and HMX 95% (median particle size of 200 nm).

[0032] Step 1: Preparation and continuous circulation of the continuous phase solution. Dissolve 90 ml of Tween-80 and 60 g of PVA (1788) in 2850 ml of deionized water to prepare a continuous phase solution. Add the solution to the glass reactors of the microdroplet solidification system (2), the microsphere collection system (3), and the circulating liquid storage system (4), respectively. Turn on the peristaltic pump in the circulation pipeline system (5) to pre-circulate the continuous phase solution in the circulation pipeline system.

[0033] Step 2: Preparation of the dispersed phase of the explosive suspension. Dissolve 0.10g F2602 in 20g ethyl acetate. After complete dissolution, add 4.90g HMX. Under ultrasonic conditions, the explosive particles are evenly dispersed. Under stirring conditions, the explosive suspension is placed in the dispersed phase solution receiver of the droplet generation system (1) for later use.

[0034] Step 3: Extrusion of dispersed phase droplets. Using the pump in the droplet generation system (1), the dispersed phase suspension in the dispersed phase solution receiver is extruded through the extension tube from the needle into the glass reactor of the microdroplet solidification system (2). At the same time, the flow rate of the dispersed phase is adjusted using a peristaltic pump and set to 0.1 ml / min.

[0035] Step 4: Stirring and solidification. After the dispersed phase droplets in the droplet generation system (1) are extruded into the microdroplet solidification system (2), the stirring speed is set to 300 rpm by the stirrer. Under the action of high-speed stirring, the continuous phase solution shears the dispersed phase droplets into spheres. Under the action of high-speed stirring in the microdroplet solidification system (2), the dispersed phase microdroplets are suspended in the continuous phase, which accelerates the solvent exchange rate and realizes the rapid solidification of the microdroplets. Through the solvent exchange mechanism of the microdroplets from the outside to the inside, it is ensured that the binder can be stably precipitated and uniformly coated on the surface of the explosive particles. At the same time, the force field formed by the high-speed stirring is used to modify and process the microdroplets, thereby significantly improving the sphericity and coating completeness of the energetic composite microspheres and realizing the preparation of high-quality microspheres.

[0036] Step 5: Post-processing such as collection and cleaning of composite microspheres. The sample obtained in Step 4 is transported to the filter tank of the microsphere collection system (3) through the circulation pipeline system (5). After washing the composite microspheres in the filter tank, they are dried in an oven to obtain the finished HMX@F2602 composite microspheres.

[0037] As attached Figure 4 , 5 The prepared HMX@F2602 composite microspheres exhibited a unimodal particle size distribution ranging from 755.47 μm to 948.52 μm, with a particle size span of 0.22, and good flowability.

[0038] Example 4 An efficient and continuous preparation method for energetic composite microspheres based on the apparatus of Example 1 is disclosed, which prepares hexanitrohexaazaisowulzane (CL-20) based energetic composite microspheres with the following mass percentages: polyacrylate rubber (ACM) 5%, CL-20 95% (median particle size of 200 nm).

[0039] Step 1: Preparation and continuous circulation of the continuous phase solution. Dissolve 30 ml of Tween-80 and 60 g of PVA (1788) in 2910 ml of deionized water to prepare a continuous phase solution. Add the solution to the glass reactors of the microdroplet solidification system (2), the microsphere collection system (3), and the circulating liquid storage system (4), respectively. Turn on the peristaltic pump in the circulation pipeline system (5) to pre-circulate the continuous phase solution in the circulation pipeline system.

[0040] Step 2: Preparation of the dispersed phase of the explosive suspension. Dissolve 0.25g of ACM in 30g of dichloromethane. After complete dissolution, add 4.75g of CL-20. Under ultrasonic conditions, the explosive particles are evenly dispersed. Under stirring conditions, the explosive suspension is placed in the dispersed phase solution receiver of the droplet generation system (1) for later use.

[0041] Step 3: Extrusion of dispersed phase droplets. Using the pump in the droplet generation system (1), the dispersed phase suspension solution in the dispersed phase solution receiver is extruded through the extension tube from the needle into the glass reactor of the microdroplet solidification system (2). At the same time, the flow rate of the dispersed phase is adjusted using a peristaltic pump and set to 10 ml / min.

[0042] Step 4: Stirring and solidification. After the dispersed phase droplets in the droplet generation system (1) are extruded into the microdroplet solidification system (2), the stirring speed is set to 700 rpm by the stirrer. Under the action of high-speed stirring, the continuous phase solution shears the dispersed phase droplets into spheres. Under the high-speed stirring action of the microdroplet solidification system (2), the dispersed phase microdroplets are suspended in the continuous phase, which accelerates the solvent exchange rate and realizes the rapid solidification of the microdroplets. Through the solvent exchange mechanism of the microdroplets from the outside to the inside, it is ensured that the binder can be stably precipitated and uniformly coated on the surface of the explosive particles. At the same time, the force field formed by the high-speed stirring action is used to modify and process the microdroplets, thereby significantly improving the sphericity and coating completeness of the energetic composite microspheres and realizing the preparation of high-quality microspheres.

[0043] Step 5: Post-processing such as collection and cleaning of composite microspheres. The sample obtained in Step 4 is transported to the filter tank of the microsphere collection system (3) through the circulation pipeline system (5). After washing the composite microspheres in the filter tank, they are dried in an oven to obtain the finished CL-20@ACM composite microspheres.

[0044] As attached Figure 6 , 7 The obtained CL-20@ACM composite microspheres have a particle size distribution between 86.89 μm and 106.26 μm, exhibiting a unimodal distribution with a particle size span of 0.20 and good flowability.

[0045] Example 5 An efficient and continuous preparation method for energetic composite microspheres based on the apparatus of Example 1 is disclosed, which prepares 1,3,5-triamino-2,4,6-trinitrobenzene (TATB)-based energetic composite microspheres with the following mass percentages: polymethyl methacrylate (PMMA) 3% and TATB 97% (median particle size of 200 nm).

[0046] Step 1: Preparation and continuous circulation of the continuous phase solution. Dissolve 60 ml of Tween-80 and 30 g of PVA (1788) in 2910 ml of deionized water to prepare a continuous phase solution. Add the solution to the glass reactors of the microdroplet solidification system (2), the microsphere collection system (3), and the circulating liquid storage system (4). Turn on the peristaltic pump in the circulation pipeline system (5) to pre-circulate the continuous phase solution in the circulation pipeline system.

[0047] Step 2: Preparation of the dispersed phase of the explosive suspension. Dissolve 0.25g PMMA in 45g ethyl acetate. After complete dissolution, add 4.75g TATB. Under ultrasonic conditions, the explosive particles are uniformly dispersed. Under stirring conditions, the explosive suspension is placed in the dispersed phase solution receiver of the droplet generation system (1) for later use.

[0048] Step 3: Extrusion of dispersed phase droplets. The dispersed phase suspension in the dispersed phase solution receiver is extruded through an extension tube from the needle into the glass reactor of the microdroplet solidification system (2) using the pump in the droplet generation system (1). Simultaneously, a peristaltic pump is used to adjust the dispersed phase flow rate, setting it to 10 ml / min.

[0049] Step 4: Stirring and solidification. After the dispersed phase droplets in the droplet generation system (1) are extruded into the microdroplet solidification system (2), the stirring speed is set to 1000 rpm by the stirrer. Under the action of high-speed stirring, the continuous phase solution shears the dispersed phase droplets into spheres. Under the action of high-speed stirring in the microdroplet solidification system (2), the dispersed phase microdroplets are suspended in the continuous phase, which accelerates the solvent exchange rate and realizes the rapid solidification of the microdroplets. Through the solvent exchange mechanism of the microdroplets from the outside to the inside, it is ensured that the binder can be stably precipitated and uniformly coated on the surface of the explosive particles. At the same time, the force field formed by the high-speed stirring is used to modify and process the microdroplets, thereby significantly improving the sphericity and coating completeness of the energetic composite microspheres and realizing the preparation of high-quality microspheres.

[0050] Step 5: Post-processing such as collection and cleaning of composite microspheres. The sample obtained in Step 4 is transported to the filter tank of the microsphere collection system (3) through the circulation pipeline system (5). After washing the composite microspheres in the filter tank, they are dried in an oven to obtain the finished TATB@PMMA composite microspheres.

[0051] As attached Figure 8 , 9 The obtained TATB@PMMA composite microspheres have a particle size distribution between 13.53 μm and 45.70 μm, exhibiting a unimodal distribution with a particle size span of 1.10, and good flowability.

[0052] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art will be able to make various modifications and improvements without departing from the principles of the present invention, and these modifications and improvements should also be considered to fall within the scope of protection of the present invention.

Claims

1. A device for preparing multi-scale distributed energetic composite microspheres based on the droplet method, characterized in that, It includes a droplet generation system (1), a microdroplet solidification system (2), a microsphere collection system (3), a circulating liquid storage system (4), and a circulating pipeline system (5). The droplet generation system (1) includes a dispersed phase solution receiver, a pump, a magnetic stirrer, a rotor, and an extension tube needle; the dispersed phase solution is placed inside the dispersed phase solution receiver, the rotor is placed inside the dispersed phase solution receiver, and the dispersed phase solution receiver is placed above the magnetic stirrer; the extension tube needle is connected to the pump, one end of which is placed inside the dispersed phase solution receiver, and the other end of the needle is placed in the glass reactor of the microdroplet solidification system (2); The microdroplet solidification system (2) includes a stirrer, a stirring paddle, and a glass reactor. The stirrer is connected to the stirring paddle, and the stirring paddle is placed inside the glass reactor. The pipes and peristaltic pump in the circulation pipeline system (5) transport the composite microspheres prepared by the microdroplet solidification system (2) to the microsphere collection system (3). The microsphere collection system (3) includes a glass reactor II and a filter tank. The glass reactor II is used for the storage and circulation of the continuous phase solution. The filter tank is installed in the glass reactor II to collect the composite microspheres and filter out the continuous phase solution. The pipes and peristaltic pump in the circulation pipeline system (5) connect the microsphere collection system (3) and the circulating liquid storage system (4). The circulating liquid storage system (4) includes a glass reactor and a continuous phase solution. The glass reactor is used for the storage, circulation, and replacement of the continuous phase solution. The upper inlet of the glass reactor is used for the injection of the continuous phase solution, and the lower outlet is used for the discharge of the continuous phase solution. The pipes and peristaltic pump in the circulating pipeline system (5) connect the microdroplet solidification system (2) and the circulating liquid storage system (4) to realize the circulation flow of the continuous phase solution. The circulating pipeline system (5) consists of a peristaltic pump and pipelines, which connect the microdroplet solidification system (2), the microsphere collection system (3) and the circulating liquid storage system (4).

2. The method for preparing multi-scale distributed energetic composite microspheres based on the droplet method according to claim 1, characterized in that, The pumps in the droplet generation system (1) are peristaltic pumps, centrifugal pumps or syringe pumps.

3. A method for preparing multi-scale distributed energetic composite microspheres based on the droplet method, characterized in that, The method is implemented based on the apparatus of claim 1 and includes the following steps: Step 1: Preparation of the continuous phase solution and continuous circulation flow The surfactant and water-soluble polymer material in the corresponding proportions are dissolved in deionized water to prepare a continuous phase solution, which is then added to the glass reactors one, two, and three of the microdroplet solidification system (2), microsphere collection system (3), and circulating liquid storage system (4), respectively. The peristaltic pump is turned on to realize the continuous circulation of the continuous phase in the device. At the same time, the stirrer in the microdroplet solidification system (2) is turned on and the stirring rate is set to make the continuous phase solution stably stirred and form a high-speed rotating crushing force field. Step 2: Preparation of the dispersed phase of the explosive suspension The binder is dissolved in the dispersed phase solvent. After complete dissolution, explosive particles of the corresponding proportion are added. The explosive particles are dispersed by ultrasonic action so that they are evenly dispersed in the dispersed phase solvent to prepare a dispersed phase suspension solution. This solution is then added to the dispersed phase solution receiver of the droplet generation system (1) for later use. Step 3: Extrusion of dispersed phase droplets The dispersed phase suspension solution in the dispersed phase solution receiver is squeezed from the needle through the extension tube using the pump in the droplet generation system (1) into the glass reactor of the microdroplet solidification system (2); Step 4: Stir, solidify, and shape. After the dispersed phase droplets in the droplet generation system (1) are extruded into the microdroplet solidification system (2), the stirring rate is set by the stirrer, and the continuous phase solution shears the dispersed phase droplets into spheres under the action of high-speed stirring; under the action of high-speed stirring of the microdroplet solidification system (2), the dispersed phase microdroplets are suspended in the continuous phase, which accelerates the solvent exchange rate and realizes the rapid solidification of the microdroplets, thus obtaining a liquid containing the sample; Step 5: Post-processing such as collection and cleaning of composite microspheres The sample obtained in step four is transported to the filter tank of the microsphere collection system (3) through the circulation pipeline system (5). After washing the composite microspheres in the filter tank, they are dried in an oven to obtain the finished composite microspheres.

4. The method for preparing multi-scale distributed energetic composite microspheres based on the droplet method according to claim 3, characterized in that, In step one, by changing the concentration of the continuous phase, the shearing effect of the continuous phase on the dispersed phase is controlled, and the size of the composite microspheres is further controlled. The lower the concentration of the continuous phase, the more likely the shearing and breaking effect of the dispersed phase droplets will generate smaller droplets.

5. The method for preparing multi-scale distributed energetic composite microspheres based on the dropping method according to claim 3, characterized in that, In step two, the size of the composite microspheres is further controlled by changing the concentration of the dispersed phase and adjusting the size of the dispersed phase microdroplets.

6. The method for preparing multi-scale distributed energetic composite microspheres based on the droplet method according to claim 3, characterized in that, In step three, the flow rate of the dispersed phase is adjusted by a pump. By changing the extrusion rate of the dispersed phase, the size of the dispersed phase microdroplets is controlled, and the size of the composite microspheres is further controlled. When the shearing effect of the continuous phase on the dispersed phase is the same, the higher the extrusion rate, the larger the particle size of the prepared microspheres.

7. The method for preparing multi-scale distributed energetic composite microspheres based on the droplet method according to claim 3, characterized in that, In step four, the size of the composite microspheres is further controlled by adjusting the stirring rate and regulating the shear force of the continuous relative dispersed phase droplets; the higher the stirring rate, the smaller the particle size of the prepared microspheres.

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