Wideband radar-absorbing energetic cloud damage materials, their preparation methods and applications

Abstract

This invention discloses a broadband radar-absorbing energetic cloud destructive material, its preparation method, and its applications. CoNi alloy nanoparticles are prepared using a hydrothermal method and loaded onto expanded graphite to obtain an electromagnetically coupled absorbing material. Subsequently, nitramine explosive RDX is intercalated into the CoNi / expanded graphite using a solvent-antisolvent method to form a sandwich-structured composite energetic material. The energetic composite material obtained by this invention detonates within the target's effective range, forming a broadband electromagnetic wave absorbing cloud with a long loiter time. By absorbing and attenuating the target's electromagnetic wave signals, it paralyzes enemy command, disrupts communications, and renders the enemy incapable of combat. The electromagnetic wave absorbing cloud obtained by this invention exhibits a reflection loss of less than -50 dB, an absorption band width of less than -10 dB greater than 4 GHz, and a loiter time of more than 40 s per 100 grams of explosive, demonstrating excellent broadband electromagnetic cloud destructive effects and showing promising application prospects for non-lethal destruction of mobile targets.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic damage materials technology, and relates to a broadband radar absorbing energetic cloud damage material, its preparation method and application. Background Technology

[0002] Modern electronic reconnaissance equipment covers almost all available electromagnetic bands. The rapid development of detection technology and early warning systems has made the development of asymmetric and disruptive soft-damage technologies an important research direction in military equipment systems. Electromagnetic countermeasures, as an important means of modern information warfare, can not only suppress and destroy enemy weapons and equipment, but also reduce the detection rate of our own equipment to improve our own survivability. Among many detection technologies, radar detection is one of the most effective and widespread. The shielding and blocking of its electromagnetic signals requires materials to strongly absorb electromagnetic waves within a certain frequency range (such as 2-18 GHz), that is, to have low reflection and high emission characteristics.

[0003] Transition metals nickel and cobalt, as two typical magnetic materials, possess excellent physical, chemical, and mechanical properties. CoNi alloy is a high-performance magnetic absorbing material that integrates multiple excellent properties such as wear resistance, corrosion resistance, and oxidation resistance, exhibiting good absorption effects for low-frequency electromagnetic waves. Expanded graphite, a carbon material with abundant porosity and good conductivity, provides a site for electromagnetic wave absorption and multiple reflection attenuation due to its large porosity, demonstrating good absorption effects for high-frequency electromagnetic waves. Combining magnetic CoNi with conductive expanded graphite not only achieves effective absorption of both low-frequency and high-frequency electromagnetic waves but also significantly improves the impedance matching characteristics of the composite material, allowing incident electromagnetic waves to penetrate the material interior and be attenuated as much as possible.

[0004] There are no publicly reported examples of using high-energy explosives to directionally detonate composite materials with broadband wave absorption capabilities, forming a large-scale, uniformly dispersed electromagnetic interference cloud to achieve efficient absorption and attenuation of radar signals, thus achieving large-scale, long-term, and low-cost cloud damage to targets. Summary of the Invention

[0005] This invention relates to broadband radar-absorbing energetic cloud destruction materials, their preparation methods, and applications. It obtains a magnetoelectric coupled broadband CoNi / expanded graphite composite absorbing material, then intercalates high-energy explosive RDX into the CoNi / expanded graphite to obtain the composite energetic material, and detonates it directionally to disperse the absorbing material over a large area uniformly, forming an electromagnetic interference cloud. This achieves large-scale, long-term, and low-cost electromagnetic cloud destruction of target radar signals, and will be applied in the field of information attack and defense, primarily based on radar detection.

[0006] The present invention is achieved through the following technical solution.

[0007] This invention provides a broadband radar-absorbing energetic cloud destruction material, the raw materials of which include the following components by weight percentage: 30-40% expanded graphite, 20-30% CoNi nanoparticles and 30-50% 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX), wherein CoNi nanoparticles are loaded onto expanded graphite and RDX is intercalated into CoNi / expanded graphite to form a sandwich-structured composite energetic material.

[0008] The preparation method of expanded graphite includes the following steps:

[0009] (1) Preparation of expanded graphite: under water bath conditions, 4-16 mL of nitric acid and 5-20 mL of phosphoric acid are mixed evenly at room temperature to obtain a mixed solution;

[0010] (2) Add 5g of natural flake graphite to the mixed solution, raise the water bath temperature to 30-90℃ and add 0.1-0.6g of KMnO4 to react for 0.5-2h;

[0011] (3) Add 1-2 mL of acetic anhydride to the mixed solution obtained in step (2), react for 1-3 hours, filter to remove waste liquid, and wash with deionized water until pH > 5;

[0012] (4) The sample obtained in step (3) is dried at 60-80°C and then placed in a muffle furnace at 1000°C to expand it to obtain expanded graphite.

[0013] A method for preparing broadband radar-absorbing energetic cloud damage materials includes the following steps:

[0014] Step 1: Mix expanded graphite, CoCl2·6H2O, and NiCl2·6H2O evenly in polyethylene glycol, then add 5%–10% hydrazine hydrate and stir until homogeneous to obtain a mixed solution;

[0015] Step 2: Place the mixed solution from Step 1 in a high-pressure reactor and react at 150–190°C for 10–16 h. Wash with ethanol and deionized water 3–5 times and dry at 60–80°C to obtain expanded graphite-supported CoNi composite material.

[0016] Step 3: Prepare 100 mL of a 20%–60% RDX dimethyl sulfoxide (DMSO) solution at room temperature;

[0017] Step 4: Add expanded graphite-supported CoNi composite material to the solution obtained in Step 3, filter out the CoNi / expanded graphite composite material with DMSO solution adsorbed in the suspension, and quickly pour it into deionized water and stir for 5-10 minutes to allow it to fully crystallize, thus obtaining an aqueous suspension of RDX intercalated CoNi / expanded graphite sandwich composite energetic material.

[0018] Step 5: The product obtained in Step 4 is filtered and washed with deionized water 3 to 5 times, and then dried at 60 to 80°C to obtain the RDX intercalated CoNi / expanded graphite sandwich composite energetic material.

[0019] Preferably, the particle size of the natural flake graphite is ≤50 mesh.

[0020] Preferably, the purity of the RDX raw material is ≥98%.

[0021] The energetic RDX intercalated CoNi / expanded graphite sandwich composite material obtained by this invention has a mass scale of grams, hundreds of grams, and kilograms.

[0022] The energetic composite material obtained in this invention detonates within the target's effective range, forming a broadband electromagnetic wave absorbing cloud with a long loiter time. By absorbing and attenuating the target's electromagnetic wave signals, it paralyzes enemy command and disrupts communications, rendering the enemy incapable of combat. The electromagnetic wave absorbing cloud obtained in this invention exhibits a reflection loss of less than -50 dB, an absorption band width of less than -10 dB greater than 4 GHz, and a loiter time of more than 40 seconds per 100 grams of the agent, demonstrating excellent broadband electromagnetic cloud damage effects and showing promising application prospects for non-lethal damage to mobile targets.

[0023] The beneficial effects of this invention are:

[0024] (1) CoNi / expanded graphite composite microwave absorbing material was prepared by hydrothermal method. The obtained CoNi nanoparticles were tightly attached to the surface of expanded graphite and had a strong interaction with the graphite sheets. CoNi nanoparticles have excellent ferromagnetism and a reflection loss of less than -10dB (99%) in the range of 3.5 to 10.4 GHz, showing good low-frequency absorption characteristics. Expanded graphite has good conductivity and a reflection loss of less than -10dB in the range of 7.5 to 14.2 GHz, showing good high-frequency absorption characteristics. The expanded graphite-loaded CoNi composite material has good absorption characteristics for both low-frequency and high-frequency electromagnetic waves, with a reflection loss of less than -10dB in the range of 3.5 to 13.8 GHz, showing excellent broadband electromagnetic wave absorption performance.

[0025] (2) The loose and porous structure of expanded graphite is an ideal carrier for nano-alloy particles and energetic materials. In this invention, the solvent-antisolvent method is used to insert RDX into the internal cavity of CoNi / expanded graphite, constructing a novel three-dimensional host-guest microstructure composite energetic material. The surface of the expanded graphite cavity contains a variety of oxygen-containing groups, which form hydrogen bonds and other host-guest interactions with RDX, promoting the stable adhesion of the explosive. By adjusting the preparation process, the crystal form, content and particle size of the intercalated explosive can be controlled. The RDX intercalated CoNi / expanded graphite composite energetic material has a higher thermal decomposition temperature, activation energy and thermal explosion critical temperature, further improving the thermal stability of RDX and significantly reducing the sensitivity of RDX.

[0026] (3) RDX, a high-energy explosive intercalated into a composite energetic material formed by CoNi / expanded graphite, can form a large-scale, uniformly distributed electromagnetic interference cloud after directional detonation, exhibiting excellent absorption and attenuation effects on broadband electromagnetic waves. A hundred grams of the composite energetic material has an effective loiter time exceeding 40 seconds and a kill radius exceeding 6 meters. By shielding and attenuating the target's electromagnetic wave signals, it disrupts the enemy's weapon and equipment communications, rendering them combat ineffective, thus achieving cloud-based damage to the target's signals. Attached Figure Description

[0027] Figure 1 This is a SEM image of expanded graphite loaded with CoNi prepared based on Example 1.

[0028] Figure 2 This is a SEM image of the RDX intercalated CoNi / expanded graphite energetic composite material prepared based on Example 1.

[0029] Figure 3 These are the absorption performance parameters of the electromagnetic interference cloud obtained in Example 3.

[0030] Figure 4 This is a digital photograph of the RDX intercalated CoNi / expanded graphite energetic composite material obtained in Example 4. Detailed Implementation

[0031] To provide a clearer understanding of the technical features of the present invention, the technical solution of the present invention will now be described in detail below, but this should not be construed as limiting the scope of implementation of the present invention.

[0032] Example 1

[0033] (1) Mix 5 mL of nitric acid and 10 mL of phosphoric acid at room temperature to obtain a mixed solution. Add 5 g of natural flake graphite to the mixed solution, raise the water bath temperature to 70 °C and add 0.4 g of KMnO4 to react for 1 h. Add 1.5 mL of acetic anhydride to the obtained mixed solution and react for 2 h. Filter to remove waste liquid and wash with deionized water until pH = 6. Dry the obtained sample at 80 °C and place it in a muffle furnace at 1000 °C to expand it to obtain expanded graphite.

[0034] (2) 5g of expanded graphite, 2mol of CoCl2·6H2O and 2mol of NiCl2·6H2O were uniformly mixed in 100mL of polyethylene glycol and 3mL of hydrazine hydrate was added and stirred evenly to obtain a mixed solution. The resulting mixed solution was placed in a high-pressure reactor and reacted at 170℃ for 12h. After washing with ethanol and deionized water, it was dried at 60℃ to obtain expanded graphite-supported CoNi composite material.

[0035] (3) Prepare 100 mL of DMSO solution of 30% RDX at room temperature, add 5 g of expanded graphite-supported CoNi composite material and stir evenly. Filter the expanded graphite-supported CoNi composite material with DMSO solution adsorbed in the suspension and quickly pour it into deionized water and stir for 6 min to allow it to fully crystallize. Filter, wash and dry the obtained product at 60℃ to obtain RDX intercalated CoNi / expanded graphite sandwich composite energetic material.

[0036] (4) The 5g of RDX intercalated CoNi / expanded graphite energetic composite material was directionally detonated, so that the CoNi / expanded graphite composite material was uniformly diffused over a large area, achieving efficient absorption and attenuation of broadband electromagnetic wave signals.

[0037] like Figure 1 This is a SEM image of expanded graphite loaded with CoNi prepared based on Example 1. Figure 2 The images show SEM images of the RDX-intercalated CoNi / expanded graphite energetic composite material prepared in Example 1. The resulting electromagnetic interference cloud exhibits a reflection loss of less than -10 dB in the 4–8.2 GHz range, with a minimum reflection loss of -21 dB and an effective loiter time of 15 s.

[0038] Example 2

[0039] (1) Mix 5 mL of nitric acid and 10 mL of phosphoric acid at room temperature to obtain a mixed solution. Add 5 g of natural flake graphite to the mixed solution, raise the water bath temperature to 70 °C and add 0.4 g of KMnO4 to react for 1 h. Add 1.5 mL of acetic anhydride to the obtained mixed solution and react for 2 h. Filter to remove waste liquid and wash with deionized water until pH = 6. Dry the obtained sample at 80 °C and place it in a muffle furnace at 1000 °C to expand it to obtain expanded graphite.

[0040] (2) 5g of expanded graphite, 3mol of CoCl2·6H2O, and 3mol of NiCl2·6H2O were uniformly mixed in 100mL of polyethylene glycol and 3mL of hydrazine hydrate was added and stirred evenly to obtain a mixed solution. The resulting mixed solution was placed in a high-pressure reactor and reacted at 170℃ for 12h. After washing with ethanol and deionized water, it was dried at 60℃ to obtain expanded graphite-supported CoNi composite material.

[0041] (3) Prepare 100 mL of DMSO solution of 30% RDX at room temperature, add 5 g of expanded graphite-supported CoNi composite material and stir evenly. Filter the expanded graphite-supported CoNi composite material with DMSO solution adsorbed in the suspension and quickly pour it into deionized water and stir for 6 min to allow it to fully crystallize. Filter, wash and dry the obtained product at 60℃ to obtain RDX intercalated CoNi / expanded graphite sandwich composite energetic material.

[0042] (4) The 5g of RDX intercalated CoNi / expanded graphite energetic composite material was directionally detonated, so that the CoNi / expanded graphite composite material was uniformly diffused over a large area, achieving efficient absorption and attenuation of broadband electromagnetic wave signals.

[0043] The resulting electromagnetic interference cloud exhibits a reflection loss of less than -10dB in the 3.5–9.3GHz range, with a minimum reflection loss of -24dB and an effective loiter time of 16s.

[0044] Example 3

[0045] (1) Mix 5 mL of nitric acid and 10 mL of phosphoric acid at room temperature to obtain a mixed solution. Add 5 g of natural flake graphite to the mixed solution, raise the water bath temperature to 70 °C and add 0.4 g of KMnO4 to react for 1 h. Add 1.5 mL of acetic anhydride to the obtained mixed solution and react for 2 h. Filter to remove waste liquid and wash with deionized water until pH = 6. Dry the obtained sample at 80 °C and place it in a muffle furnace at 1000 °C to expand it to obtain expanded graphite.

[0046] (2) 10g of expanded graphite, 3mol CoCl2·6H2O, and 3mol NiCl2·6H2O were uniformly mixed in 100mL of polyethylene glycol and 3mL of hydrazine hydrate was added and stirred evenly to obtain a mixed solution. The resulting mixed solution was placed in a high-pressure reactor and reacted at 170℃ for 12h. After washing with ethanol and deionized water, it was dried at 60℃ to obtain expanded graphite-supported CoNi composite material.

[0047] (3) Prepare 100 mL of DMSO solution of 30% RDX at room temperature, add 5 g of expanded graphite-supported CoNi composite material and stir evenly. Filter the expanded graphite-supported CoNi composite material with DMSO solution adsorbed in the suspension and quickly pour it into deionized water and stir for 6 min to allow it to fully crystallize. Filter, wash and dry the obtained product at 60℃ to obtain RDX intercalated CoNi / expanded graphite sandwich composite energetic material.

[0048] (4) The 5g of RDX intercalated CoNi / expanded graphite energetic composite material was directionally detonated, so that the CoNi / expanded graphite composite material was uniformly diffused over a large area, achieving efficient absorption and attenuation of broadband electromagnetic wave signals.

[0049] like Figure 3 These are the absorption performance parameters of the electromagnetic interference cloud obtained in Example 3. The obtained electromagnetic interference cloud has a reflection loss of less than -10dB in the range of 3.5 to 11.3GHz, a minimum reflection loss of -27dB, and an effective loiter time of 18s.

[0050] Example 4

[0051] (1) Mix 5 mL of nitric acid and 10 mL of phosphoric acid at room temperature to obtain a mixed solution. Add 5 g of natural flake graphite to the mixed solution, raise the water bath temperature to 70 °C and add 0.4 g of KMnO4 to react for 1 h. Add 1.5 mL of acetic anhydride to the obtained mixed solution and react for 2 h. Filter to remove waste liquid and wash with deionized water until pH = 6. Dry the obtained sample at 80 °C and place it in a muffle furnace at 1000 °C to expand it to obtain expanded graphite.

[0052] (2) 10g of expanded graphite, 3mol CoCl2·6H2O, and 3mol NiCl2·6H2O were uniformly mixed in 100mL of polyethylene glycol and 3mL of hydrazine hydrate was added and stirred evenly to obtain a mixed solution. The resulting mixed solution was placed in a high-pressure reactor and reacted at 170℃ for 12h. After washing with ethanol and deionized water, it was dried at 60℃ to obtain expanded graphite-supported CoNi composite material.

[0053] (3) Prepare 100 mL of DMSO solution of 30% RDX at room temperature, add 5 g of expanded graphite-supported CoNi composite material and stir evenly. Filter the expanded graphite-supported CoNi composite material with DMSO solution adsorbed in the suspension and quickly pour it into deionized water and stir for 6 min to allow it to fully crystallize. Filter, wash and dry the obtained product at 60℃ to obtain RDX intercalated CoNi / expanded graphite sandwich composite energetic material.

[0054] (4) The 20g of RDX intercalated CoNi / expanded graphite energetic composite material was directionally detonated, so that the CoNi / expanded graphite composite material was uniformly diffused over a large area, achieving efficient absorption and attenuation of broadband electromagnetic wave signals.

[0055] like Figure 4 This is a digital photograph of the RDX intercalated CoNi / expanded graphite energetic composite material obtained in Example 4. The resulting electromagnetic interference cloud exhibits a reflection loss of less than -10 dB in the 3.5–12.5 GHz range, with a minimum reflection loss of -31 dB and an effective loiter time of 30 s.

[0056] Example 5

[0057] (1) Mix 5 mL of nitric acid and 10 mL of phosphoric acid at room temperature to obtain a mixed solution. Add 5 g of natural flake graphite to the mixed solution, raise the water bath temperature to 70 °C and add 0.4 g of KMnO4 to react for 1 h. Add 1.5 mL of acetic anhydride to the obtained mixed solution and react for 2 h. Filter to remove waste liquid and wash with deionized water until pH = 6. Dry the obtained sample at 80 °C and place it in a muffle furnace at 1000 °C to expand it to obtain expanded graphite.

[0058] (2) 10g of expanded graphite, 3mol CoCl2·6H2O, and 3mol NiCl2·6H2O were uniformly mixed in 100mL of polyethylene glycol and 3mL of hydrazine hydrate was added and stirred evenly to obtain a mixed solution. The resulting mixed solution was placed in a high-pressure reactor and reacted at 170℃ for 12h. After washing with ethanol and deionized water, it was dried at 60℃ to obtain expanded graphite-supported CoNi composite material.

[0059] (3) Prepare 100 mL of DMSO solution of 30% RDX at room temperature, add 5 g of expanded graphite-supported CoNi composite material and stir evenly. Filter the expanded graphite-supported CoNi composite material with DMSO solution adsorbed in the suspension and quickly pour it into deionized water and stir for 6 min to allow it to fully crystallize. Filter, wash and dry the obtained product at 60℃ to obtain RDX intercalated CoNi / expanded graphite sandwich composite energetic material.

[0060] (4) 100g of the obtained RDX intercalated CoNi / expanded graphite energetic composite material was directionally detonated, so that the CoNi / expanded graphite composite material was uniformly diffused over a large area, thereby achieving efficient absorption and attenuation of wide-band electromagnetic wave signals.

[0061] The resulting electromagnetic interference cloud exhibits a reflection loss of less than -10dB in the 3.5–13.8 GHz range, with a minimum reflection loss of -36dB and an effective loiter time of 41s.

Claims

1. A method for preparing broadband radar-absorbing energetic cloud damage material, characterized in that, The process includes the following steps: CoNi nanoparticles are loaded onto expanded graphite, and 1,3,5-trinitro-1,3,5-triazacyclohexane RDX is intercalated into CoNi / expanded graphite to form a sandwich-structured composite energetic material. Specifically, the steps include the following: Step 1: Mix expanded graphite, CoCl2·6H2O, and NiCl2·6H2O evenly in polyethylene glycol, then add 5%~10% hydrazine hydrate by mass and stir evenly to obtain a mixed solution; Step 2: Place the mixed solution from Step 1 in a high-pressure reactor and react at 150-190℃ for 10-16 hours. Wash with ethanol and deionized water 3-5 times and dry at 60-80℃ to obtain expanded graphite-supported CoNi composite material. Step 3: Prepare a 20-60% RDX dimethyl sulfoxide (DMSO) solution at room temperature; Step 4: Add the expanded graphite-supported CoNi composite material obtained in Step 2 to the solution obtained in Step 3, filter out the CoNi / expanded graphite composite material with DMSO solution adsorbed in the suspension, and quickly pour it into deionized water and stir for 5-10 minutes to allow it to fully crystallize, so as to obtain an aqueous suspension of RDX intercalated CoNi / expanded graphite sandwich composite energetic material. Step 5: The product obtained in Step 4 is filtered and washed with deionized water 3-5 times and dried at 60-80℃ to obtain the RDX intercalated CoNi / expanded graphite sandwich composite energetic material.

2. The method for preparing a broadband radar-absorbing energetic cloud damage material according to claim 1, characterized in that, The raw materials are in the following weight proportions: 30-40 parts expanded graphite, 20-30 parts CoNi nanoparticles and 30-50 parts RDX.

3. The method for preparing a broadband radar-absorbing energetic cloud damage material according to claim 1, characterized in that, The preparation method of expanded graphite includes the following steps: (1) Preparation of expanded graphite: The reaction was carried out under water bath conditions. 4~16 mL of nitric acid and 5~20 mL of phosphoric acid were mixed evenly at room temperature to obtain a mixed solution. (2) Add 5g of natural flake graphite to the mixed solution, raise the water bath temperature to 30~90℃ and add 0.1~0.6g of KMnO4 to react for 0.5~2h; (3) Add 1-2 mL of acetic anhydride to the mixed solution obtained in step (2), react for 1-3 h, filter to remove waste liquid, and wash with deionized water until pH > 5; (4) The sample obtained in step (3) is dried at 60~80℃ and then placed in a muffle furnace at 1000℃ to expand it to obtain expanded graphite.

4. The method for preparing the broadband radar-absorbing energetic cloud damage material according to claim 3, characterized in that, The particle size of the natural flake graphite in step (2) is ≤50 mesh.

5. A broadband radar-absorbing energetic cloud-damaging material, characterized in that, The material comprises the following: CoNi nanoparticles, expanded graphite, and 1,3,5-trinitro-1,3,5-triazacyclohexane RDX, obtained by the preparation method according to any one of claims 1 to 4.

6. The application method of the broadband radar-absorbing energetic cloud-damaging material according to claim 5, characterized in that, Used to form electromagnetic interference clouds, which cause electromagnetic cloud damage to the target radar signal.

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