Efficient method for continuous synthesis and recrystallization of energetic complex based on flow chemistry
Through the continuous synthesis and recrystallization system of energy-containing complexes based on flow chemistry technology, the problems of low yield, high risk and inconsistent product quality in traditional methods are solved, and nano-energy-containing complexes with specific morphology and particle size are efficiently and safely prepared.
Patent Information
- Application Number
- CN202411777807.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-05
- Publication Date
- 2025-03-11
AI Technical Summary
Traditional energy-containing complex preparation methods have problems such as low yield, high risk and poor product quality consistency, making it difficult to achieve morphological regulation, narrow particle size distribution and precise particle size regulation.
The continuous synthesis and recrystallization system of energy-containing complexes based on flow chemistry technology is adopted to achieve rapid mixing and reaction of ligands and metal ion salts through a dual-channel syringe pump and a Y-type reaction pipeline, and the particle size and morphology are precisely controlled by combining recrystallization units.
It is possible to efficiently and safely prepare energy-containing complexes with spherical nano micromorphology and consistent particle size, which improves yield and product purity and reduces the risk of the production process.
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Figure CN119588271A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of energetic materials, and in particular to an efficient method for realizing continuous synthesis and recrystallization of energetic complexes by utilizing flow chemistry technology. Background Art
[0002] Energetic complexes are complexes formed by the coordination of central metal ions, nitrogen-rich ligands and external anions. Their structures contain functional groups such as nitro, hydrazine and amino groups that can release a large amount of energy. Thanks to their high design flexibility and diverse assembly methods, energetic complexes have the advantages of high explosion heat and high thermal stability. They have become one of the hot research directions in the field of energetic materials. The performance and structure of energetic complexes mainly depend on the selected metal ions and functionalized organic ligands. Their design and synthesis aim to achieve high thermal stability, low mechanical sensitivity and excellent energy performance.
[0003] Traditional methods for preparing energetic complexes, such as solution method and solvent / hydrothermal method, are suitable for single crystal preparation and structure determination, but they have problems such as low yield, high risk and poor product quality consistency. In particular, it is difficult to achieve morphology control, narrow particle size distribution and precise particle size control of energetic materials.
[0004] In contrast, flow chemistry technology is gradually gaining attention in the field of energetic materials due to its high-efficiency mixing, rapid heat and mass transfer, low reagent consumption, and precise control. The technology involves low instantaneous holding of materials, which reduces the retention of toxic or explosive substances, enhances heat exchange efficiency, avoids the formation of hot spots, and effectively suppresses the risk of explosion. In addition, flow chemistry technology can precisely control local reaction conditions, improve product yields, and break through the limitations of traditional batch synthesis, providing a safer and more efficient method for the synthesis of energetic complexes. Summary of the invention
[0005] The present invention aims to provide an efficient method for continuous synthesis and recrystallization of energetic complexes based on flow chemistry, which can prepare energetic complexes with spherical nano-microscopic morphology and uniform particle size. The method of the present invention is simple to operate, can realize continuous synthesis and recrystallization of energetic complexes, solve the problems of low reaction efficiency and low product purity in traditional methods, and improve the safety of energetic material synthesis and preparation. The method is particularly suitable for the preparation of carbohydrazide energetic complexes.
[0006] The technical solution of the present invention is to build a continuous synthesis and recrystallization system for energetic complexes based on flow chemistry technology, which includes a synthesis unit and a recrystallization unit. The synthesis unit is connected by a dual-channel injection pump with a ligand solution syringe and a metal ion salt solution syringe through a Y-shaped reaction pipeline, and the reaction pipeline is arranged in a water bath in the form of a coil. The recrystallization unit is connected to a non-solvent syringe by a single-channel injection pump, and is further connected to the reaction tube of the synthesis unit through a Y-shaped recrystallization pipeline; the recrystallization pipeline is placed in a water bath in the form of a coil. The ligand solution and the metal ion salt solution are simultaneously introduced into the synthesis unit for mixed reaction, and the reaction solution then flows into the recrystallization unit together with the non-solvent. After the reaction solution is collected, it is centrifuged, washed and dried to obtain a nano energetic complex.
[0007] The efficient method for continuous synthesis and recrystallization of energetic complexes based on flow chemistry of the present invention is achieved by the following steps: step 1, respectively loading the ligand solution and the metal ion salt solution into the syringe of the dual-channel injection pump and preparing them; step 2, starting the dual-channel injection pump, and respectively passing the ligand solution and the metal ion salt solution into the synthesis unit at a set flow rate; step 3, in the synthesis unit, the ligand solution and the metal ion salt solution are mixed in the microchannel and a coordination reaction occurs to form a reaction solution; step 4, introducing the reaction solution into the recrystallization unit through a pipeline, and simultaneously introducing a non-solvent, and realizing the recrystallization process of the complex by adjusting conditions such as the flow rate and temperature; step 5, collecting the obtained nano suspension from the pipeline outlet of the recrystallization unit; step 6, washing, centrifuging and drying the collected nano suspension to obtain a nano energetic complex.
[0008] In the technical solution of the above-mentioned efficient method for continuous synthesis and recrystallization of energetic complexes based on flow chemistry, the pipe material of the synthesis unit and the recrystallization unit is a chemically corrosion-resistant material selected from polytetrafluoroethylene; the outer diameter of the reaction pipe is 1.6 to 2 mm, the inner diameter is 0.5 to 1.0 mm, and the length is 2 to 10 m; the outer diameter of the recrystallization pipe is 1.6 to 2 mm, the inner diameter is 0.5 to 1.0 mm, and the length is 0.5 to 2 m.
[0009] In the technical scheme of the above-mentioned efficient method for continuous synthesis and recrystallization of energetic complexes based on flow chemistry, the concentration range of the ligand dissolved in the solvent is 0.1 to 1 mol / L, the concentration range of the metal ion salt dissolved in the solvent is 0.1 to 1 mol / L, the flow rate of the ligand and the metal ion salt is consistent, the flow rate range is 100 to 1000 μL / min, the synthesis temperature range is 25 to 60°C, the non-solvent flow range is 1 to 20 mL / min, and the recrystallization temperature range is 0 to 40°C.
[0010] Furthermore, in the technical solution of the above-mentioned efficient method for continuous synthesis and recrystallization of energetic complexes based on flow chemistry, the ligand is a five-membered heterocyclic carbohydrazide, the metal ion salt is copper perchlorate, the solvent is dimethyl sulfoxide, and the non-solvent is ethanol.
[0011] In the technical solution of the efficient method for continuous synthesis and recrystallization of energetic complexes based on flow chemistry, the particle size of the synthesized nano energetic complex can be flexibly adjusted by adjusting the injection pump flow rate or the water bath temperature. Generally, the particle size of the nano energetic complex synthesized by the above technical solution is between 20 and 200 nanometers.
[0012] The present invention is a flow chemistry technology based on chemical reactions in a continuously flowing fluid, which allows the ligand and the metal ion salt to react quickly, and can solve the problems of low yield, high risk and poor consistency of product quality of existing energetic complexes, and realize efficient, highly controllable and highly safe synthesis of energetic complexes. At the same time, the composition and construction process of the flow chemistry system relied on by the method of the present invention are simple, and there is no need to master the professional operation skills of complex fluid flow.
[0013] The beneficial effects of the present invention include:
[0014] 1. The flow chemistry-based continuous synthesis and recrystallization system for energetic complexes used in the present invention has high modularity, integrates the synthesis unit and the recrystallization unit, reduces human operation errors, improves experimental stability and repeatability, and realizes the continuous progress of multi-step reactions. The entire system can automatically adjust the flow rate and reaction time.
[0015] 2. Compared with the traditional method, the flow channel of the present invention has a small diameter, which creates laminar flow conditions, and the diffusion mixing is fast and efficient. The key reaction parameters such as reaction mixing, heating and residence time are more accurately controlled, which increases product yield and reduces impurity content, and obtains high-purity and high-stability nano energetic complexes. The preparation time is shortened from several days to minutes, which greatly improves the production efficiency of energetic complexes, realizes precise control of crystal morphology and particle size, and provides a new technical approach for the synthesis of energetic materials.
[0016] 3. The present invention can handle reactions that are too dangerous to be carried out in an intermittent manner. In a flow reaction, explosive products and reactants exist in liquid form in a micro-scale pipe, and the reaction liquid holding volume is small, which reduces the possibility of dangerous reactions and significantly improves the safety of the energetic complex production process. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is the main component and connection of an efficient method for continuous synthesis and recrystallization of energetic complexes based on flow chemistry.
[0018] Figure 2This is the crystal morphology of the 1H-pyrazole-4-carboxyhydrazide copper perchlorate complex obtained in the examples of the present application.
[0019] Figure 3 This is the particle size distribution of the 1H-pyrazole-4-carboxyhydrazide copper perchlorate complex obtained in the examples of the present application.
[0020] Figure 4 This is a total spectrum of the distribution diagram of the 1H-pyrazole-4-carboxyhydrazide copper perchlorate complex obtained in the examples of the present application.
[0021] Figure 5 This is the crystal morphology of the copper perchlorate complex of 4-amino-1,2,5-oxadiazole-3-carboxylic acid hydrazide obtained in the examples of the present application.
[0022] Figure 6 4-amino-1,2,5-oxadiazole-3-carboxylic acid hydrazide copper perchlorate complex obtained in the examples of the present application.
[0023] Figure 7 This is a total spectrum of the distribution diagram of the copper perchlorate complex of 4-amino-1,2,5-oxadiazole-3-carboxylic acid hydrazide obtained in the examples of the present application.
[0024] Description of the accompanying drawings: 1-dual-channel injection pump, 2-ligand solution syringe, 3-metal ion salt solution syringe, 4-Y-type synthesis reaction channel, 5-synthesis reaction tube, 6-water bath, 7-Y-type recrystallization channel, 8-recrystallization reaction tube, 9-non-solvent syringe, 10-single-channel injection pump, 11-water bath, 12-collection container DETAILED DESCRIPTION
[0025] The following examples further illustrate the efficient method for continuous synthesis and recrystallization of energetic complexes based on flow chemistry provided by the present invention. It is necessary to point out that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention according to the above invention content and implement them specifically, which still belongs to the scope of protection of the present invention.
[0026] Example 1 Preparation of 1H-pyrazole-4-carboxyhydrazide copper perchlorate complex
[0027] In this embodiment, the process of preparing 1H-pyrazole-4-carboxylic acid hydrazide copper perchlorate complex by continuous synthesis and recrystallization system based on flow chemistry, dimethyl sulfoxide was selected as solvent and anhydrous ethanol was used as non-solvent in the experiment. 1H-pyrazole-4-carboxylic acid hydrazide was dissolved in dimethyl sulfoxide to prepare a 0.5 mol / L ligand solution; similarly, copper perchlorate was also dissolved in dimethyl sulfoxide to prepare a 0.5 mol / L metal ion salt solution. The ligand solution and the metal ion salt solution were respectively loaded into syringes, driven by a dual-channel injection pump, and the flow rate was set to 500 μL / min. The length of the synthesis reaction pipeline was set to 5m, and the coil was placed in a water bath at 25°C. Anhydrous ethanol was driven by a single-channel injection pump, and the flow rate was set to 5mL / min. The length of the recrystallization pipeline was set to 1m, and the coil was placed in a water bath at 10°C to promote the formation and growth of crystals. At the beginning of the experimental operation, first turn on the dual-channel syringe pump to allow the 1H-pyrazole-4-carboxyhydrazide solution and the copper perchlorate solution to meet and quickly mix in the first Y-shaped channel, and then flow to the recrystallization unit after a coordination reaction in the synthesis reaction pipeline. Subsequently, turn on the single-channel syringe pump, mix the reaction solution with anhydrous ethanol in the second Y-shaped channel, and recrystallize in the recrystallization pipeline to form a suspension containing blue nano 1H-pyrazole-4-carboxyhydrazide copper perchlorate particles. The resulting nanosuspension is collected in a beaker, and subsequent washing, centrifugation and drying treatments are performed to obtain nano 1H-pyrazole-4-carboxyhydrazide copper perchlorate particles. The crystal morphology and particle size distribution of the resulting nano 1H-pyrazole-4-carboxyhydrazide copper perchlorate are shown in Figure 2. Figure 2 and Figure 3 As shown, the total number spectrum of the 1H-pyrazole-4-carboxyhydrazide copper perchlorate distribution diagram is shown in 4.
[0028] Example 2 Preparation of 4-amino-1,2,5-oxadiazole-3-carboxylic acid hydrazide copper perchlorate complex
[0029] In this embodiment, in the experiment of preparing 4-amino-1,2,5-oxadiazole-3-carboxylic acid hydrazide copper perchlorate complex using a continuous synthesis and recrystallization system based on flow chemistry, dimethyl sulfoxide was used as a solvent and anhydrous ethanol was used as a non-solvent. 4-amino-1,2,5-oxadiazole-3-carboxylic acid hydrazide was dissolved in dimethyl sulfoxide to prepare a 0.5 mol / L ligand solution; similarly, copper perchlorate was also dissolved in dimethyl sulfoxide to prepare a 0.5 mol / L metal ion salt solution. The ligand solution and the metal ion salt solution were respectively loaded into syringes, driven by a dual-channel injection pump, and the flow rate was set to 500 μL / min. The length of the synthesis reaction tube was set to 5m, and the coil was placed in a water bath at 60°C to promote the reaction. Anhydrous ethanol was driven by a single-channel injection pump, and the flow rate was set to 10mL / min. The length of the recrystallization pipeline was set to 1m, and the coil was placed in a water bath at 10°C to promote the formation and growth of crystals. At the beginning of the experimental operation, first turn on the dual-channel syringe pump to allow the 4-amino-1,2,5-oxadiazole-3-carboxylic hydrazide solution and the copper perchlorate solution to meet and mix quickly in the first Y-shaped channel, and then flow to the recrystallization unit after coordination reaction in the reaction pipeline. Subsequently, turn on the single-channel syringe pump, mix the reaction solution with anhydrous ethanol in the second Y-shaped channel, and recrystallize in the recrystallization pipeline to form a suspension containing blue nano 4-amino-1,2,5-oxadiazole-3-carboxylic hydrazide copper perchlorate particles. The resulting nanosuspension is collected in a beaker, and subsequent washing, centrifugation and drying treatments are performed to obtain nano 4-amino-1,2,5-oxadiazole-3-carboxylic hydrazide copper perchlorate particles. The crystal morphology and particle size distribution of the obtained nano 4-amino-1,2,5-oxadiazole-3-carboxylic hydrazide copper perchlorate are shown in Figure 2. Figure 5 and Figure 6 As shown, the total number spectrum of 4-amino-1,2,5-oxadiazole-3-carboxylic acid hydrazide copper perchlorate distribution diagram is shown in 7. Combined with Example 1, it is proved that carbohydrazide energetic complexes can be continuously synthesized and efficiently prepared by recrystallization through this system, which provides a safer and more efficient method for the synthesis of energetic complexes.
Claims
1. An efficient method for continuous synthesis and recrystallization of energetic complexes based on flow chemistry technology, characterized in that: Build a continuous synthesis and recrystallization system for energetic complexes based on flow chemistry technology, including: synthesis unit and recrystallization unit. The synthesis unit is used to mix the ligand solution and the metal ion salt solution for reaction; The recrystallization unit is used to receive the reaction solution and non-solvent of the synthesis unit for recrystallization.
2. The system according to claim 1, characterized in that The synthesis unit comprises: the unit comprises a dual-channel injection pump, the pump is connected to a ligand solution injector and a metal ion salt solution injector, and is connected to a reaction pipeline through a Y-shaped pipeline; the reaction pipeline is arranged in a water bath in the form of a coil.
3. The system according to claim 1, wherein the recrystallization unit is characterized in that: the unit includes a single-channel injection pump, which is connected to a non-solvent injector and is further connected to a reaction pipe of the synthesis unit according to claim 3 through a Y-shaped recrystallization pipe; the recrystallization pipe is placed in a water bath in the form of a coil.
4. The synthesis unit and the recrystallization unit according to claim 2 and claim 3, characterized in that: The pipeline material of the synthesis unit and the recrystallization unit is a chemically corrosion-resistant material selected from polytetrafluoroethylene; the reaction pipeline has an outer diameter of 1.6 to 2 mm, an inner diameter of 0.5 to 1.0 mm, and a length of 2 to 10 m; the recrystallization pipeline has an outer diameter of 1.6 to 2 mm, an inner diameter of 0.5 to 1.0 mm, and a length of 0.5 to 2 m.
5. The method according to claim 1, characterized in that The steps include: Step 1, loading the ligand solution and the metal ion salt solution into the syringe of the dual-channel syringe pump respectively; Step 2, turning on the dual-channel injection pump to pass the ligand solution and the metal ion salt solution into the synthesis unit at set flow rates respectively; Step 3, in the synthesis unit, the ligand solution and the metal ion salt solution are mixed in the microchannel and undergo a coordination reaction to form a reaction solution; Step 4, introducing the reaction solution into a recrystallization unit through a pipeline, and simultaneously introducing a non-solvent, and realizing the recrystallization process of the complex by adjusting conditions such as flow rate and temperature; Step 5, collecting the obtained nano suspension from the pipeline outlet of the recrystallization unit; Step six, washing, centrifuging and drying the collected nano suspension to obtain a nano energetic complex.
6. The method according to claim 5, characterized in that: The concentration range of the ligand dissolved in the solvent is 0.1-1 mol / L, the concentration range of the metal ion salt dissolved in the solvent is 0.1-1 mol / L, the flow rate of the ligand and the metal ion salt is consistent, the flow rate range is 100-1000 μL / min, the synthesis temperature range is 25-60°C, the non-solvent flow range is 1-20 mL / min, and the recrystallization temperature range is 0-60°C.
7. The method according to claim 5, characterized in that: The ligand is a five-membered heterocyclic carbohydrazide, the metal ion salt is copper perchlorate, the solvent is dimethyl sulfoxide, and the non-solvent is ethanol.
8. The system or method according to any one of claims 1 to 7, wherein the particle size of the nano energetic complex is between 20 and 200 nanometers, and has good dispersibility and stability.
9. The system or method according to any one of claims 1 to 8, wherein the obtained nano energetic complex is suitable for use in detonating explosives.