Boron-based composite energetic material assembled with sodium molybdate and oxidizer and preparation method thereof

Abstract

This invention provides a boron-based composite energetic material with sodium molybdate assembled with an oxidant and its preparation method. The material includes a boron matrix, an energetic oxidant assembled on the boron matrix, and sodium molybdate dispersed within the energetic oxidant. The boron matrix is ​​boron powder, mono-modified boron powder, or binary modified boron powder. The energetic oxidant is ammonium perchlorate, ammonium nitrate, or potassium perchlorate. The morphology of the boron-based composite energetic material is rough-surfaced spherical particles. The ignition delay time of the boron-based composite energetic material with sodium molybdate assembled with an oxidant prepared by spray drying is 37-30 ms, which is half that of boron powder or surface-modified boron powder; the oxidation peak temperature of this composite energetic material is 560-533℃, which is more than 100℃ lower than that of boron powder or surface-modified boron powder.

Description

Technical Field

[0001] This invention belongs to the field of energetic materials technology, and relates to boron-based energetic materials, specifically to a boron-based composite energetic material composed of sodium molybdate assembled with an oxidant and its preparation method. Background Technology

[0002] Boron possesses extremely high calorific value (approximately 58.5 kJ / g) and volumetric calorific value, making it one of the highest energy density materials among known metallic fuels. However, boron particles are typically coated with an oxide layer (B₂O₃), which has a boiling point as high as 1860 °C. This oxide layer significantly inhibits the ignition reaction of boron during combustion, thereby reducing its combustion efficiency. Techniques such as nano-sizing, surface coating modification, or combination with energetic oxidants can effectively improve the ignition performance and combustion characteristics of boron.

[0003] Energetic materials formed by combining boron with energetic oxidizers are a class of metastable energetic systems prepared by combining high-energy fuel boron powder with strong energetic oxidizers. These materials combine the advantages of boron's high volumetric calorific value (approximately 136 kJ / cm³) with the high oxygen content and excellent decomposition characteristics of energetic oxidizers, showing significant application potential in defense and industrial fields such as propellants, explosives, and ignition agents. However, due to the constraints of the aforementioned oxide layer, the ignition process of boron particles exhibits a relatively long "ignition delay period," during which heating, melting, and ultimately breaking through the surface oxide layer barrier occur. This directly leads to a significant increase in the ignition delay time of boron / energetic oxidizer composite materials, making it difficult to meet the stringent requirements of applications such as igniters and initiating elements that demand rapid response. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a boron-based composite energetic material composed of sodium molybdate with an oxidant and its preparation method, thereby solving the technical problem that the ability of boron-based composite energetic materials to reduce the oxidation temperature of boron powder needs to be further improved.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution.

[0006] A boron-based composite energetic material with sodium molybdate assembled with an oxidant includes a boron matrix, an energetic oxidant assembled on the boron matrix, and sodium molybdate dispersed within the energetic oxidant.

[0007] The boron matrix is ​​boron powder, mono-modified boron powder, or binary modified boron powder.

[0008] The energetic oxidant is ammonium perchlorate (AP, NH4ClO4), ammonium nitrate (AN, NH4NO3) or potassium perchlorate (PP, KClO4).

[0009] The morphology of the boron-based composite energetic material is rough-surfaced spherical particles.

[0010] The present invention also has the following technical features.

[0011] Preferably, the diameter of the spherical particles is 2 to 25 μm.

[0012] Preferably, the energetic oxidant accounts for 10 wt% to 20 wt% of the boron-based composite energetic material in which sodium molybdate is assembled with the oxidant; and the sodium molybdate accounts for 20 wt% to 30 wt% of the boron-based composite energetic material in which sodium molybdate is assembled with the oxidant.

[0013] More preferably, the energetic oxidant accounts for 12.5 wt% of the boron-based composite energetic material in which sodium molybdate is assembled with oxidant; and the sodium molybdate accounts for 25 wt% of the boron-based composite energetic material in which sodium molybdate is assembled with oxidant.

[0014] Preferably, the unary modified boron powder is prepared by depositing metal oxides on the surface of boron powder using atomic layer deposition; the binary modified boron powder is prepared by depositing metal oxides and molybdenum metal on the surface of boron powder using atomic layer deposition.

[0015] Preferably, the metal oxide is Nb2O5.

[0016] Preferably, the boron matrix is ​​boron powder B, mono-modified boron powder B@Nb2O5, or binary modified boron powder B@W@Nb2O5.

[0017] This invention also protects a method for preparing a boron-based composite energetic material of sodium molybdate assembled with an oxidant as described above, wherein the method employs a spray drying method to prepare the boron-based composite energetic material of sodium molybdate assembled with an oxidant.

[0018] The method includes the following steps.

[0019] Step 1: Add water to sodium molybdate and stir with a magnetic stirrer until the sodium molybdate is completely dissolved; then add an energetic oxidizing agent and stir until the energetic oxidizing agent is completely dissolved.

[0020] Step 2: Add the boron matrix to the solution prepared in Step 1 and stir continuously for 30 minutes to obtain a liquid. Then, continuously sonicate the liquid and insert the spray drying feed pipe into the liquid.

[0021] Step 3: The atmosphere of the spray dryer is high-purity nitrogen. Set the reaction temperature, feed rate and spray pressure of the spray dryer. After the reaction temperature of the spray dryer reaches the preset value, start the peristaltic pump.

[0022] Step 4: After the liquid material has completely entered the spray dryer, turn off the peristaltic pump and the spray dryer. After the temperature drops to room temperature, open the material collector and collect the sample to obtain the boron-based composite energetic material of sodium molybdate assembled with oxidant.

[0023] Preferably, in step 2, the material concentration of the liquid is 6 wt% to 48 wt%.

[0024] Preferably, in step 3, the reaction temperature is 120°C to 180°C, the feed rate is 5 r / min to 15 r / min, and the spray pressure is 0.05 MPa to 0.2 MPa.

[0025] Compared with the prior art, the present invention has the following technical effects.

[0026] (I) The ignition delay time of the boron-based composite energetic material with sodium molybdate assembled by the spray drying method prepared in this invention is 37-30ms, which is half that of boron powder or surface-modified boron powder; the boron-based composite energetic material is a boron-based metastable composite energetic material, and the oxidation peak temperature of the boron-based composite energetic material is 560-533℃, which is more than 100℃ lower than that of boron powder or surface-modified boron powder.

[0027] (II) In this invention, NH4ClO4, with the addition of Na2MoO4, can decompose at a lower temperature to generate intermediate products with stronger oxidizing activity, such as HClO4 and ClO2. This provides a more active reaction environment and a more sufficient gaseous energetic oxidant for the early oxidation of boron, thereby significantly shortening the ignition delay time of the entire composite system and greatly advancing the oxidation temperature of boron powder. Furthermore, the addition of (NH4)6Mo7O 24 and (NH4)2Mo4O 13 Neither AP nor Na2MoO4 has a significant effect on shortening ignition delay time or advancing oxidation temperature. AP and Na2MoO4 have a very significant synergistic effect on reducing the oxidation temperature of boron powder.

[0028] (III) The three metastable composite energetic materials B / AP / Na2MoO4, B@Nb2O5 / AP / Na2MoO4, and B@W@Nb2O5 / AP / Na2MoO4 prepared in this invention have short ignition delay times. It was found that Nb2O5 and Na2MoO4 have a synergistic effect in reducing the ignition delay time of boron powder, while other species such as Fe2O3 and CeO2 have no synergistic effect with Na2MoO4 in reducing the ignition delay time of boron powder.

[0029] (IV) The preparation method of this invention is simple, efficient, reproducible, and low in cost. The preparation method adopted in this invention has high control precision, is easy to industrialize, and shows good application prospects in the field of high-energy solid fuel modification. Attached Figure Description

[0030] Figure 1 SEM image of B / AP / Na2MoO4.

[0031] Figure 2 The images show the elemental distribution mapping of B / AP / Na2MoO4, where B1 is a combined image of the electron image and the measured elements, and B2-B7 are the elemental distribution images of B, N, Cl, Na, Mo, and O, respectively.

[0032] Figure 3 The image shows the elemental distribution mapping of B@Nb2O5 / AP / Na2MoO4, where C1 is the combined image of the electron image and the measured elements, and C2-C6 are the elemental distribution images of B, Na, Mo, Nb, and Cl, respectively.

[0033] Figure 4 The images show SEM images and elemental distribution mapping images of B@W@Nb2O5 / AP / Na2MoO4, where D1 is the SEM image and D2-D7 are the elemental distribution images of B, Cl, Mo, W, Nb, and O, respectively.

[0034] Figure 5 The graphs show the DSC data for B, B / AP, and B / AP / Na2MoO4. Where a represents B, b represents B / AP, and c represents B / AP / Na2MoO4.

[0035] Figure 6 The image shows the laser ignition delay time data for samples B, B / AP, and B / AP / Na2MoO4, where a1 represents B, a2 represents B / AP, a3 represents B / AP / Na2MoO4, a4 ​​represents B@Nb2O5 / AP / Na2MoO4, a5 represents B@W@Nb2O5 / AP / Na2MoO4, a6 represents B@CeO2 / AP / Na2MoO4, a7 represents B@Fe2O3 / AP / Na2MoO4, and a8 represents Na2MoO4 / B.

[0036] The specific content of the present invention will be further explained in detail below with reference to the embodiments. Detailed Implementation

[0037] It should be noted that, unless otherwise specified, all materials and devices used in this invention are those known in the art.

[0038] To overcome the technical bottlenecks described in the background section, adding sodium molybdate is a highly efficient catalytic promotion strategy. Sodium molybdate can significantly lower the high-temperature decomposition temperature of energetic oxidants and promote the formation of more reactive intermediates such as HClO4 and ClO2, providing a more active reaction environment and a more sufficient amount of gaseous energetic oxidants for the early oxidation of boron, thereby significantly shortening the ignition delay time of the entire composite system. By accelerating the ignition process and optimizing the combustion reaction path, the introduction of sodium molybdate ensures that more boron particles are fully oxidized in a shorter time, which not only improves the energy release rate but also enhances the combustion efficiency of boron, ultimately significantly strengthening the actual energy release performance of the composite material.

[0039] In this invention, boron powder can also be referred to as boron particles or boron fuel; all three are the same concept. The boron powder is amorphous boron fuel and / or crystalline boron fuel, with a particle size distribution ranging from micrometers to nanometers. Preferably, the particle size of the boron powder is 100 nm to 5 μm.

[0040] In this invention, the boron powder is boron raw material that has not been modified by atomic layer deposition. The mono-modified boron powder is boron powder on which a modification layer such as B@Nb2O5 is deposited by atomic layer deposition technology. The binary modified boron powder is boron powder on which two modification layers such as B@W@Nb2O5 are deposited by atomic layer deposition technology.

[0041] The oxidant assembly of the present invention, which is a boron-based composite energetic material of sodium molybdate, is used as a boron-based fuel in the field of explosives.

[0042] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments. All equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0043] Example 1:

[0044] This embodiment provides a method for preparing a boron-based composite energetic material composed of sodium molybdate assembled with an oxidant, which includes the following steps.

[0045] Step 1: Weigh 2g of Na₂MoO₄ and pour it into an Erlenmeyer flask. Measure 25ml of deionized water using a graduated cylinder and pour it into the Erlenmeyer flask. Add a magnetic stir bar and stir until the Na₂MoO₄ is completely dissolved. Then weigh 1g of NH₄ClO₄ and pour it into the Erlenmeyer flask, and stir until the NH₄ClO₄ is completely dissolved.

[0046] Step 2: Weigh 5g of boron powder and pour it into the solution prepared in Step 1 and stir continuously for 30 minutes to obtain a liquid. Then, continuously sonicate the liquid and insert the spray drying feed tube into the liquid.

[0047] Step 3: The atmosphere of the spray dryer is high-purity nitrogen. Set the spray dryer parameters to 180℃ reaction temperature, 15r / min feed rate, and 0.1MPa spray pressure. After the reaction temperature reaches the preset value, start the peristaltic pump.

[0048] Step 4: After the liquid material has completely entered the spray dryer, turn off the peristaltic pump and the spray dryer. After the temperature drops to room temperature, open the material collector and collect the sample to obtain the boron-based composite energetic material B / AP / Na2MoO4 with sodium molybdate assembled with oxidant.

[0049] In the B / AP / Na2MoO4 material obtained in this embodiment, the AP content is 12.5wt% and the Na2MoO4 content is 25wt%.

[0050] Figure 1 The image shows a SEM image of B / AP / Na2MoO4. Under low magnification, the sample morphology appears as rough, spherical particles with a size ranging from 2 to 25 μm. Further magnification reveals that these spherical particles are composed of many irregular small particles.

[0051] Figure 2 The images show the elemental distribution mapping of B / AP / Na2MoO4, where B1 is a combined image of the electron image and the measured elements, and B2-B7 are the elemental distribution images of B, N, Cl, Na, Mo, and O, respectively. The elemental distribution maps show that the distribution areas and trends of B, N, Cl, Na, Mo, and O are almost identical, indicating that the components of the B / AP / Na2MoO4 material prepared using spray drying technology are uniformly distributed.

[0052] Example 2: This embodiment provides a method for preparing a boron-based composite energetic material composed of sodium molybdate assembled with an oxidant, which includes the following steps.

[0053] Step 1: Prepare B@Nb2O5 mono-modified boron powder using atomic layer deposition technology.

[0054] Step 1.1: Spread boron powder evenly on the sample stage, then place the sample stage in the reaction chamber of the atomic layer deposition equipment. Use a mechanical pump to evacuate the reaction chamber to below 20 Pa. Set the temperature of the ALD reaction chamber to 230℃, set the temperature of the niobium ethanol storage tank to 120℃, and set the carrier gas flow rate to 105 ml / min.

[0055] Step 1.2: Niobium ethanol vapor is introduced into the reaction chamber by a carrier gas through bubbling, so that the niobium ethanol vapor molecules are adsorbed on the surface of boron powder. The introduction time is 60s. Then, the niobium ethanol physically adsorbed on the sample surface is blown off the sample surface for 60s.

[0056] Step 1.3: Inject water vapor into the reaction chamber to allow water molecules to fully react with niobium ethanol molecules chemically adsorbed on the surface of boron powder. The injection time is 60s. Then, blow away excess water molecules and byproducts from the sample surface for 60s.

[0057] Steps 1.4 and 1.2 to 1.3 constitute one cycle of Nb2O5 deposition. Repeating steps 1.2 to 1.3 can control the number of Nb2O5 deposition cycles to 10 cycles, thus obtaining B@Nb2O5 mono-modified boron powder.

[0058] Step 2: Weigh 2g of Na₂MoO₄ and pour it into an Erlenmeyer flask. Measure 25ml of deionized water using a graduated cylinder and pour it into the Erlenmeyer flask. Add a magnetic stir bar and stir until the Na₂MoO₄ is completely dissolved. Then weigh 1g of NH₄ClO₄ and pour it into the Erlenmeyer flask, and stir until the NH₄ClO₄ is completely dissolved.

[0059] Step 3: Weigh 5g of B@Nb2O5 mono-modified boron powder and pour it into the solution prepared in step 2. Stir continuously for 30 minutes to obtain a liquid. Then, continuously sonicate the liquid and insert the spray drying feed tube into the liquid.

[0060] Step 4: The atmosphere of the spray dryer is high-purity nitrogen. Set the spray dryer parameters to 180℃ reaction temperature, 15r / min feed rate, and 0.1MPa spray pressure. After the reaction temperature reaches the preset value, start the peristaltic pump.

[0061] Step 5: After the liquid material has completely entered the spray dryer, turn off the peristaltic pump and the spray dryer. After the temperature drops to room temperature, open the material collector and collect the sample to obtain the boron-based composite energetic material B@Nb2O5 / AP / Na2MoO4 with sodium molybdate assembled with oxidant.

[0062] In the B@Nb2O5 / AP / Na2MoO4 material obtained in this embodiment, the AP content is 12.5wt%, the Na2MoO4 content is 25wt%, and the Nb2O5 deposition cycle number is 10 cycles.

[0063] Figure 3 The images show SEM images and elemental distribution mapping images of B@Nb₂O₅ / AP / Na₂MoO₄, where C1 is the SEM image and C2-C6 are the elemental distribution images of B, Na, Mo, Nb, and Cl, respectively. The SEM images show that the sample morphology consists of many irregular small particles with rough surfaces, forming near-spherical particles with sizes ranging from 2-25 μm. The elemental distribution maps show that the distribution areas and trends of B, Na, Mo, Nb, and Cl are almost identical, indicating that the components of the B@Nb₂O₅ / AP / Na₂MoO₄ material prepared by spray drying technology are uniformly distributed.

[0064] Example 3: This embodiment provides a method for preparing a boron-based composite energetic material composed of sodium molybdate assembled with an oxidant, which includes the following steps.

[0065] Step 1: Prepare B@W@Nb2O5 binary modified boron powder using atomic layer deposition technology.

[0066] Step 1.1: Spread boron powder evenly on the sample stage, then place the sample stage in the reaction chamber of the atomic layer deposition equipment, use a mechanical pump to evacuate the reaction chamber to below 150 Pa, and set the temperature of the reaction chamber to 200℃.

[0067] Step 1.2: Si₂H₆ is injected into the adjustable precursor storage container. The carrier gas and the pneumatic valve of the mechanical pump are closed to bring the system to a near-static state. Then, the precursor from the storage container is injected into the reaction chamber over 30 seconds to allow for saturation adsorption of the precursor on the boron particles. After sufficient adsorption, the pneumatic valve of the mechanical pump is opened to remove excess precursor or physically adsorbed precursor from the reaction chamber over 25 seconds. Then, the carrier gas is used for purging over 25 seconds.

[0068] Step 1.3: WF6 is injected into an adjustable precursor storage container, which precisely controls the amount of precursor entering the system. The pneumatic valves of the carrier gas and mechanical pump are closed, bringing the system to a near-static state. The precursor from the storage container is then injected into the reaction chamber over 30 seconds, allowing the WF6 to fully react with the Si2H6 adsorbed on the boron particles. After the reaction is complete, the pneumatic valve of the mechanical pump is opened to remove excess precursor or byproducts from the reaction chamber over 25 seconds. Then, the carrier gas is used for purging for 25 seconds. The carrier gas is either high-purity argon or high-purity nitrogen.

[0069] Step 1.4, steps 1.2 to 1.3 constitute one cycle of elemental W deposition. Steps 1.2 to 1.3 are repeated to control the number of deposition cycles of elemental W on boron particles to be 5 cycles.

[0070] Step 1.5: Keep the sample in situ, set the temperature of the ALD reaction chamber to 230℃, the temperature of the niobium ethanol storage tank to 120℃, and the carrier gas flow rate to 105ml / min.

[0071] Step 1.6: The vapor of niobium ethanol is introduced into the reaction chamber by a carrier gas through bubbling, so that the niobium ethanol vapor molecules are adsorbed on the surface of boron powder. The introduction time is 60s. Then, the niobium ethanol physically adsorbed on the sample surface is blown off the sample surface for 60s.

[0072] Step 1.7: Inject water vapor into the reaction chamber to allow water molecules to fully react with niobium ethanol molecules chemically adsorbed on the sample surface. The infusion time is 60s. Then, blow away excess water molecules and byproducts from the sample surface for 60s.

[0073] Steps 1.8 and 1.6 to 1.7 constitute one cycle of Nb2O5 deposition. By repeating steps 1.6 to 1.7 to control the number of Nb2O5 deposition cycles to 10 cycles, B@W@Nb2O5 binary modified boron powder can be obtained.

[0074] Step 2: Weigh 2g of Na₂MoO₄ and pour it into an Erlenmeyer flask. Measure 25ml of deionized water using a graduated cylinder and pour it into the Erlenmeyer flask. Add a magnetic stir bar and stir until the Na₂MoO₄ is completely dissolved. Then weigh 1g of NH₄ClO₄ and pour it into the Erlenmeyer flask, and stir until the NH₄ClO₄ is completely dissolved.

[0075] Step 3: Weigh 5g of B@W@Nb2O5 binary modified boron powder and pour it into the solution prepared in Step 2. Stir continuously for 30 minutes to obtain a liquid. Then, continuously sonicate the liquid and insert the spray drying feed tube into the liquid.

[0076] Step 4: The atmosphere of the spray dryer is high-purity nitrogen. Set the spray dryer parameters to 180℃ reaction temperature, 15r / min feed rate, and 0.1MPa spray pressure. After the reaction temperature reaches the preset value, start the peristaltic pump.

[0077] Step 5: After the liquid material has completely entered the spray dryer, turn off the peristaltic pump and the spray dryer. After the temperature drops to room temperature, open the material collector and collect the sample to obtain the boron-based composite energetic material B@W@Nb2O5 / AP / Na2MoO4 composed of sodium molybdate and oxidant.

[0078] In the B@W@Nb2O5 / AP / Na2MoO4 material obtained in this embodiment, the AP content is 12.5wt%, the Na2MoO4 content is 25wt%, the W deposition cycle number is 5 cycles, and the Nb2O5 deposition cycle number is 10 cycles.

[0079] Figure 4The images show SEM images and elemental distribution mapping images of B@W@Nb2O5 / AP / Na2MoO4, where D1 is the SEM image and D2-D7 are the elemental distribution images of B, Cl, Mo, W, Nb, and O, respectively. The SEM images show that the sample morphology consists of many irregular small particles with rough surfaces, forming near-spherical particles with sizes ranging from 2-25 μm. The elemental distribution maps show that the distribution areas and trends of B, Cl, Mo, W, Nb, and O are almost identical, indicating that the components of the B@W@Nb2O5 / AP / Na2MoO4 material prepared using spray drying technology are uniformly distributed.

[0080] Example 4: This embodiment provides a method for preparing a boron-based composite energetic material with sodium molybdate assembled with an oxidant. This method is basically the same as that in Example 1, except that NH4ClO4 in Example 1 is replaced with an equal amount of NH4NO3.

[0081] In the B / AN / Na2MoO4 material obtained in this embodiment, the AN content is 12.5wt% and the Na2MoO4 content is 25wt%.

[0082] Example 5: This embodiment provides a method for preparing a boron-based composite energetic material with sodium molybdate assembled with an oxidant. The method is basically the same as that in Example 1, except that NH4ClO4 in Example 2 is replaced with an equal amount of NH4NO3.

[0083] In the B@Nb2O5 / AN / Na2MoO4 material obtained in this embodiment, the AN content is 12.5 wt%, the Na2MoO4 content is 25 wt%, and the Nb2O5 deposition cycle number is 10 cycles.

[0084] Example 6: This embodiment provides a method for preparing a boron-based composite energetic material with sodium molybdate assembled with an oxidant. The method is basically the same as that in Example 1, except that NH4ClO4 in Example 3 is replaced with an equal amount of NH4NO3.

[0085] In the B@W@Nb2O5 / AN / Na2MoO4 material obtained in this embodiment, the AN content is 12.5wt%, the Na2MoO4 content is 25wt%, the W deposition cycle number is 5 cycles, and the Nb2O5 deposition cycle number is 10 cycles.

[0086] Example 7: This embodiment provides a method for preparing a boron-based composite energetic material with sodium molybdate assembled with an oxidant. This method is basically the same as that in Example 1, except that NH4ClO4 in Example 1 is replaced with an equal amount of KClO4.

[0087] In the B / PP / Na2MoO4 material obtained in this embodiment, the PP content is 12.5wt% and the Na2MoO4 content is 25wt%.

[0088] Example 8: This embodiment provides a method for preparing a boron-based composite energetic material with sodium molybdate assembled with an oxidant. The method is basically the same as that in Example 1, except that NH4ClO4 in Example 2 is replaced with an equal amount of KClO4.

[0089] In the B@Nb2O5 / PP / Na2MoO4 material obtained in this embodiment, the content of PP is 12.5wt%, the content of Na2MoO4 is 25wt%, and the number of Nb2O5 deposition cycles is 10 cycles.

[0090] Example 9: This embodiment provides a method for preparing a boron-based composite energetic material with sodium molybdate assembled with an oxidant. The method is basically the same as that in Example 1, except that NH4ClO4 in Example 3 is replaced with an equal amount of KClO4.

[0091] In the B@W@Nb2O5 / PP / Na2MoO4 material obtained in this embodiment, the PP content is 12.5wt%, the Na2MoO4 content is 25wt%, the W deposition cycle number is 5 cycles, and the Nb2O5 deposition cycle number is 10 cycles.

[0092] Comparative Example 1: This comparative example presents a method for preparing a boron-based composite energetic material B / AP assembled with an energetic oxidant. The B / AP material contains 16.7 wt% NH4ClO4 to compare the effect of sodium molybdate addition on the performance enhancement of the composite energetic material. The method includes the following steps.

[0093] Step 1: Weigh 1g of NH4ClO4 and pour it into an Erlenmeyer flask. Measure 25ml of deionized water using a graduated cylinder and pour it into the Erlenmeyer flask. Add a magnetic stir bar and stir until the NH4ClO4 is completely dissolved.

[0094] Step 2: Weigh 5g of boron powder and pour it into the solution prepared in Step 1 and stir continuously for 30 minutes to obtain a liquid. Then, continuously sonicate the liquid and insert the spray drying feed tube into the liquid.

[0095] Step 3: Set the spray dryer parameters to 180℃ reaction temperature, 15r / min feed rate, and 0.1MPa spray pressure. After the reaction temperature reaches the preset value, turn on the peristaltic pump.

[0096] Step 4: After the liquid material has completely entered the spray dryer, turn off the peristaltic pump and the spray dryer. After the temperature drops to room temperature, open the material collector and collect the sample to obtain the B / AP boron-based composite energetic material.

[0097] Comparative Example 2: This comparative example presents a boron-based composite energetic material B / AP / (NH4)6Mo7O assembled with an energetic oxidant. 24 The preparation method is based on B / AP / (NH4)6Mo7O. 24 The material contains 12.5 wt% AP and (NH4)6Mo7O. 24 The content is 25 wt%. The preparation steps of this comparative example are similar to those of Example 1, except that Na2MoO4 in Example 1 is replaced with an equal amount of ammonium heptamolybdate ((NH4)6Mo7O). 24 The other steps are all the same as in Example 1.

[0098] Comparative Example 3: This comparative example presents a boron-based composite energetic material B / AP / (NH4)2Mo4O assembled with an energetic oxidant. 13 The preparation method is based on B / AP / (NH4)2Mo4O 13 The material contains 12.5 wt% AP and (NH4)2Mo4O. 13 The content was 25 wt%. The preparation steps for this comparative example were similar to those in Example 1, except that Na₂MoO₄ in Example 1 was replaced with an equal amount of ammonium molybdate ((NH₄)₂Mo₄O₄). 13 The other steps are all the same as in Example 1.

[0099] Comparative Example 4: This comparative example provides a method for preparing a Na2MoO4 / B material, in which the Na2MoO4 content is 25 wt%. The preparation steps of this comparative example are similar to those of Example 1, except that NH4ClO4 in Example 1 is removed; all other steps are identical to those of Example 1.

[0100] Comparative Example 5: This comparative example provides a method for preparing a B@CeO2 / AP / Na2MoO4 material. In the B@CeO2 / AP / Na2MoO4 material, the NH4ClO4 content is 12.5 wt%, the Na2MoO4 content is 25 wt%, and the CeO2 deposition cycle number is 10 cycles. The preparation steps of this comparative example are similar to those of Example 2, except that the B@Nb2O5 mono-modified boron powder in Example 2 is replaced with an equal amount of B@CeO2 mono-modified boron powder, and the niobium ethanol in the steps is replaced with tris(isopropylcyclopentadienyl)cerium. Other steps and experimental temperatures are consistent with those of Example 2.

[0101] Comparative Example 6: This comparative example provides a B@Fe2O3 / AP / Na2MoO 4材料 The preparation method involves using B@Fe2O3 / AP / Na2MoO4 material with an NH4ClO4 content of 12.5 wt%, a Na2MoO4 content of 25 wt%, and 10 Fe2O3 deposition cycles. The preparation steps for this comparative example are similar to those in Example 2, except that the B@Nb2O5 mono-modified boron powder in Example 2 is replaced with B@Fe2O3 mono-modified boron powder, and the niobium ethanol in the steps is replaced with ferrocene. Other steps and experimental temperatures are consistent with Example 2.

[0102] Performance testing: First, DSC testing of boron-based energetic materials.

[0103] Weigh the boron-based energetic material into an alumina crucible and place it in a DSC testing device. Set the instrument's heating rate to 10℃ / min, the test temperature range to room temperature - 900℃, and the atmosphere to air to obtain the DSC curve of the boron-based composite energetic material.

[0104] Figure 5 The figures show DSC data for B, B / AP, and B / AP / Na2MoO4. Where a represents B, b represents B / AP, and c represents B / AP / Na2MoO4. The oxidation peak temperature of the boron feedstock is 677℃, and that of B / AP is 668℃. The addition of AP (NH4ClO4) alone did not significantly reduce the oxidation temperature of B, while the oxidation peak temperature of B / AP / Na2MoO4 was 533℃. This demonstrates that the addition of Na2MoO4 significantly advances the oxidation temperature of B.

[0105] In Example 1, Na2MoO4 was replaced with (NH4)6Mo7O. 24 and (NH4)2Mo4O 13 The obtained B / AP / (NH4)6Mo7O 24 and B / AP / (NH4)2Mo4O 13 The oxidation peak temperature data of the material are shown in Table 1. They are not significantly different from those of the boron raw material and B / AP, indicating that the addition of (NH4)6Mo7O... 24 and (NH4)2Mo4O 13Neither of these methods significantly reduced the oxidation temperature of boron (B). The oxidation peak temperature of 25% Na₂MoO₄ / B was 639℃, indicating that Na₂MoO₄ has some effect on lowering the oxidation temperature of boron in the absence of AP, but the effect is limited, reducing it by less than 40℃. However, in the presence of AP, Na₂MoO₄ can reduce the oxidation peak temperature of boron by more than 140℃. This is because AP, when combined with Na₂MoO₄, can decompose at a lower temperature to generate intermediate products with stronger oxidizing activity, such as HClO₄ and ClO₂. This provides a more active reaction environment and a more sufficient gaseous energetic oxidant for the early oxidation of boron, thus significantly advancing the oxidation temperature of boron powder. This also demonstrates that AP and Na₂MoO₄ have a very significant synergistic effect in reducing the oxidation temperature of boron powder.

[0106] Table 1. DSC peak temperatures of boron-based energetic materials

[0107] Second, the laser ignition delay time test of boron-based energetic materials.

[0108] Weigh a certain amount of boron-based energetic material into an alumina crucible, place the crucible in the sample slot of a laser ignition instrument, and set the instrument parameters as follows: frequency Hz: 1000; duty cycle (1-40%): 3; number of pulses: 300; pulse train output.

[0109] Figure 6The image shows the laser ignition delay time data for samples B, B / AP, and B / AP / Na2MoO4, where a1 represents B, a2 represents B / AP, a3 represents B / AP / Na2MoO4, a4 ​​represents B@Nb2O5 / AP / Na2MoO4, a5 represents B@W@Nb2O5 / AP / Na2MoO4, a6 represents B@CeO2 / AP / Na2MoO4, a7 represents B@Fe2O3 / AP / Na2MoO4, and a8 represents Na2MoO4 / B. The ignition delay time for B is 63.8 ms, for B / AP it is 54.4 ms, for B / AP / Na2MoO4 it is 34.0 ms, for B@Nb2O5 / AP / Na2MoO4 it is 25.0 ms, for B@W@Nb2O5 / AP / Na2MoO4 it is 25.5 ms, for B@CeO2 / AP / Na2MoO4 it is 34.8 ms, and for B@Fe2O3 / AP / Na2MoO4 it is 33.9 ms. The three composite energetic materials prepared in this invention, namely B / AP / Na2MoO4, B@Nb2O5 / AP / Na2MoO4, and B@W@Nb2O5 / AP / Na2MoO4, have short ignition delay times. It was found that Nb2O5 and Na2MoO4 have a synergistic effect in reducing the ignition delay time of boron powder, while other species such as Fe2O3 and CeO2 do not have any synergistic effect with Na2MoO4 in reducing the ignition delay time of boron powder.

[0110] The laser ignition delay time of samples after replacing AP with AN was also tested, and the results are shown in Table 2. The laser ignition delay times of samples B / AN / Na2MoO4 and B / PP / Na2MoO4 are not significantly different from those of B / AP / Na2MoO4. The laser ignition delay times of samples B@Nb2O5 / AN / Na2MoO4 and B@Nb2O5 / PP / Na2MoO4 are not significantly different from those of B@Nb2O5 / AP / Na2MoO4. The laser ignition delay times of samples B@W@Nb2O5 / AN / Na2MoO4 and B@W@Nb2O5 / PP / Na2MoO4 are similar to those of B@W@Nb2O5 / AP / Na2MoO4. This indicates that the type of energetic oxidant has little effect on the laser ignition delay time of the samples.

[0111] Table 2 Ignition Delay Time of Boron-Based Energetic Materials

Claims

1. A boron-based composite energetic material composed of sodium molybdate assembled with an oxidant, comprising a boron matrix, characterized in that, An energetic oxidant is assembled on a boron matrix, and sodium molybdate is dispersed within the energetic oxidant. The boron matrix is ​​boron powder, mono-modified boron powder, or binary modified boron powder; The energetic oxidant is ammonium perchlorate, ammonium nitrate, or potassium perchlorate; The morphology of the boron-based composite energetic material is rough-surfaced spherical particles.

2. The boron-based composite energetic material of sodium molybdate assembled with an oxidant as described in claim 1, characterized in that, The diameter of the spherical particles is 2 to 25 μm.

3. The boron-based composite energetic material of sodium molybdate assembled with an oxidant as described in claim 1, characterized in that, The energetic oxidant accounts for 10 wt% to 20 wt% of the boron-based composite energetic material in which sodium molybdate is assembled with the oxidant; the sodium molybdate accounts for 20 wt% to 30 wt% of the boron-based composite energetic material in which sodium molybdate is assembled with the oxidant.

4. The boron-based composite energetic material of sodium molybdate assembled with an oxidant as described in claim 3, characterized in that, The energetic oxidant accounts for 12.5 wt% of the boron-based composite energetic material in which sodium molybdate is assembled with the oxidant; the sodium molybdate accounts for 25 wt% of the boron-based composite energetic material in which sodium molybdate is assembled with the oxidant.

5. The boron-based composite energetic material of sodium molybdate assembled with an oxidant as described in claim 1, characterized in that, The mono-modified boron powder is prepared by depositing metal oxides on the surface of boron powder using atomic layer deposition (ALD); the binary modified boron powder is prepared by depositing metal oxides and molybdenum metal on the surface of boron powder using ALD.

6. The boron-based composite energetic material of sodium molybdate assembled with an oxidant as described in claim 5, characterized in that, The metal oxide is Nb2O5; the boron matrix is ​​boron powder B, mono-modified boron powder B@Nb2O5, or binary modified boron powder B@W@Nb2O5.

7. A method for preparing a boron-based composite energetic material with sodium molybdate assembled with an oxidant as described in any one of claims 1 to 6, characterized in that, This method uses spray drying to prepare boron-based composite energetic materials with sodium molybdate assembled with oxidant.

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