Preparation method of g-c3n4-based composite energetic material

Abstract

This invention discloses a method for preparing g-C3N4-based composite energetic materials. The method employs simple physical grinding, in-situ reduction, and electrostatic self-assembly. First, g-C3N4 and explosive are physically ground at a specific mass ratio to obtain composite material 1. Then, ultrasonically treated g-C3N4 and GO are coated onto the surface of the explosive crystals through in-situ reduction to obtain composite material 2. Finally, the highly cationic properties of polyethyleneimine are used to modify the surface of ammonium nitrate explosives, and composite material 3 is obtained through electrostatic self-assembly. This invention combines g-C3N4 and GO to desensitize ammonium nitrate explosive crystals, resulting in an ammonium nitrate explosive composite material that simultaneously possesses desensitization and high energy performance. The high stability, high thermal conductivity, and lubricity of g-C3N4 and GO are utilized to passivate the mechanical sensitivity of the energetic material.

Description

Technical Field

[0001] This invention belongs to the field of energetic material composite technology, specifically relating to the preparation method of g-C3N4-based composite energetic materials. Background Technology

[0002] In modern warfare, to meet the high-performance military requirements of modern weaponry, weapon systems place higher demands on the comprehensive performance of single-element energetic materials. There is an urgent need to develop energetic materials with low sensitivity and high safety. Besides considering the impact of the mechanical sensitivity and electric spark sensitivity of energetic materials on their safety, the energy properties of these materials should also be taken into account to ensure their high-energy characteristics. Therefore, how to prepare high-energy, low-sensitivity energetic composite materials is one of the most pressing research topics in the field of single-element explosive modification.

[0003] Common modification methods for highly sensitive elemental materials mainly include eutectic modification and coating. Compared to the crystal transformation problem that is prone to occur in eutectic modification, effectively coating the surface of sensitive explosives is a more preferable way to reduce their mechanical sensitivity. Traditional coating techniques generally suffer from drawbacks such as uneven explosive surface, weak bonding force between the coating material and the elemental explosive, and energy loss. Based on this, developing and preparing energetic composite materials that combine high energy performance and high safety, enabling their better application in military systems, will be of great significance to the practical application and development of energetic materials.

[0004] Carbon materials, due to their diverse size structures and unique microstructures, possess excellent electrical, magnetic, mechanical, and optical properties. Among them, graphene oxide, with its abundant oxygen-containing functional groups and conjugated structure, exhibits outstanding thermal conductivity and lubricity, making it suitable for surface coating modification of highly sensitive single-element explosives, attracting considerable attention and research from scholars for decades. Although surface coating with graphene materials has been proven to effectively improve the safety performance of energetic materials, the high carbon content of graphene materials can easily lead to energy loss and low coating efficiency after coating. Therefore, there is an urgent need to find new desensitizing agents that not only have a desensitizing effect but also compensate for the energy performance of energetic materials. Thus, the preparation of g-C3N4-based composite energetic materials is of great significance for improving the overall performance of highly sensitive explosives. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention proposes a method for preparing g-C3N4-based composite energetic materials, addressing the problems of poor stability, low mechanical sensitivity, and energy loss in coated explosive samples inherent in ammonium nitrate explosives. The technical solution of this invention is as follows:

[0006] A method for preparing a g-C3N4-based composite energetic material involves physical grinding, in-situ reduction, and electrostatic self-assembly. First, g-C3N4 and explosive are physically ground at a specific mass ratio to obtain composite material 1. Then, ultrasonically treated g-C3N4 and GO are coated onto the surface of the explosive crystals via in-situ reduction to obtain composite material 2. The high cationic properties of polyethyleneimine are used to modify the surface of ammonium nitrate explosives, and then composite material 3 is obtained through electrostatic self-assembly. By combining g-C3N4 and GO using the above methods to desensitize ammonium nitrate explosive crystals, an ammonium nitrate explosive composite material with both desensitization and high energy performance is obtained. Finally, the high stability, high thermal conductivity, and lubricity of g-C3N4 and GO are utilized to passivate the mechanical sensitivity of the energetic material.

[0007] The specific steps of this method are as follows:

[0008] Step 1: Using urea as raw material, place the crucible in a muffle furnace and calcine it at a high temperature of 550℃ to obtain light yellow powder g-C3N4;

[0009] Step 2: Mix the explosive raw materials and the g-C3N4 material from Step 1 in a mass ratio of 99 / 1, 98 / 2, and 97 / 3, grind them evenly in a mortar, and obtain the physically ground composite material 1.

[0010] Step 3: Disperse graphene oxide (GO) and the g-C3N4 material from Step 1 in deionized water, and after ultrasonic dispersion, obtain a suspension of GO and g-C3N4.

[0011] Step 4: Add appropriate amounts of ammonium nitrate explosive to the suspension from Step 3 according to different mass ratios of ammonium nitrate explosive: g-C3N4: GO. After ultrasonic dispersion treatment, a mixture containing ammonium nitrate explosive, g-C3N4 and GO suspension is obtained. The mass ratio of ammonium nitrate explosive, g-C3N4 and GO in the mixture is 97 / 3 / 0, 97 / 0 / 3, and 97 / 2 / 1.

[0012] Step 5: Add hydrazine hydrate to the mixture obtained in Step 4, wherein the mass fraction of hydrazine hydrate is 80%, stir at 400 r / min for 2 hours in an oil bath at 100℃, cool to room temperature and filter, wash several times with room temperature deionized water, and dry in a vacuum drying oven to obtain ammonium nitrate explosive composite energetic material 2 with g-C3N4 and GO as desensitizing agents;

[0013] Step 6: Disperse ammonium nitrate explosive and g-C3N4 in deionized water by ultrasonication, add polyethyleneimine aqueous solution dropwise, and stir at 400 r / min for 2 h at room temperature to obtain a mixture containing ammonium nitrate explosive, g-C3N4 and PEI.

[0014] Step 7: Add GO dispersion dropwise to the mixture from Step 6, and stir at 400 r / min for 2 h at room temperature to obtain a mixture containing ammonium nitrate explosive, g-C3N4, PEI and GO, wherein the mass ratio of ammonium nitrate explosive, g-C3N4 and GO is 97 / 3 / 0, 97 / 0 / 3, 97 / 2 / 1.

[0015] Step 8: Add hydrazine hydrate to the mixture from Step 7, wherein the mass fraction of hydrazine hydrate is 80%, and react at 400 r / min for 2 h in an oil bath at 100 °C. After cooling to room temperature, filter the mixture, rinse it several times with room temperature deionized water, and dry it in a vacuum drying oven to obtain ammonium nitrate explosive composite energetic material 3, which uses PEI as the explosive surface modifier and g-C3N4 and GO as desensitizing agents.

[0016] The ammonium nitrate explosives include, but are not limited to: cyclotetramethylenetetranitramine (HMX), bicyclooctogen (BCHMX), cyclotrimethylenetrinitramine (RDX), or hexanitrohexaazaisowurtzite (CL-20).

[0017] The polyethyleneimine includes, but is not limited to, polyethyleneimine with a molecular weight of 600, 1800, or 10000.

[0018] The concentration of the graphene oxide material suspension is 0.5 mg / ml.

[0019] The concentration of the polyethyleneimine suspension is 0.5 mg / ml.

[0020] The ultrasonic treatment in step three lasts for 50 to 55 minutes.

[0021] Step four involves ultrasonic treatment for 60–65 minutes.

[0022] Step six involves ultrasonic treatment for 90–100 minutes.

[0023] The beneficial effects of this invention compared to existing technologies are:

[0024] 1. This invention patent enhances the thermal stability and safety of energetic materials by adding GO and g-C3N4 as composite desensitizers, and effectively compensates for the energy loss of energetic materials after coating, thereby improving the overall performance of energetic materials.

[0025] 2. This invention patent enhances the interaction between the energetic material and the desensitizing agent by adding a certain amount of polyethyleneimine to the energetic material, thereby increasing the crystallization temperature and effectively improving the desensitization effect of the energetic material.

[0026] 3. The preparation method of the present invention uses water as a reaction solvent, the reaction is mild, no organic reagents are introduced, and it is environmentally friendly.

[0027] 4. The preparation method of the present invention is applicable to energetic material particles that are insoluble in water, and has strong versatility and good prospects for practical application. Attached Figure Description

[0028] Figure 1 SEM images of g-C3N4 after ultrasound

[0029] Figure 2 SEM images of HMX / g-C3N4(97 / 3) composite material after ultrasonication

[0030] Figure 3 SEM images of the HMX / g-C3N4 / rGO (97 / 1 / 2) composite material after ultrasonication.

[0031] Figure 4 DSC curves of HMX / g-C3N4 / rGO (97 / 1 / 2) composite material and raw material HMX

[0032] Figure 5 SEM images of the HMX / g-C3N4 / rGO (97 / 2 / 1) composite material after ultrasonication.

[0033] Figure 6 DSC curves of HMX / g-C3N4 / rGO (97 / 2 / 1) composite material and raw material HMX

[0034] Figure 7 SEM images of the HMX-PEI / g-C3N4 / rGO (97 / 1 / 2) composite material after ultrasonication.

[0035] Figure 8 DSC curves of HMX-PEI / g-C3N4 / rGO (97 / 1 / 2) composite material and raw material HMX

[0036] Figure 9 SEM images of the HMX-PEI / g-C3N4 / rGO (97 / 1.5 / 1.5) composite material after ultrasonication.

[0037] Figure 10 DSC curves of HMX-PEI / g-C3N4 / rGO (97 / 1.5 / 1.5) composite material and raw material HMX

[0038] Figure 11 XRD patterns of HMX-PEI / g-C3N4 / rGO (97 / 2 / 1) composite material and raw material HMX.

[0039] Figure 12 XPS-N1s fitting spectra of HMX, rGO, g-C3N4 and HMX-PEI / g-C3N4 / rGO (97 / 2 / 1) composites Detailed Implementation

[0040] The present invention will now be further described in conjunction with the embodiments and accompanying drawings:

[0041] The preparation method of g-C3N4-based composite energetic materials includes the following steps:

[0042] S1. Using urea as raw material, a crucible is placed in a muffle furnace and calcined at 550℃ to obtain light yellow powder g-C3N4.

[0043] S2. Mix ammonium nitrate explosive (using HMX as an example) and g-C3N4 material in a certain mass ratio, grind them evenly in a mortar, and obtain the physically ground HMX composite material 1;

[0044] S3. Graphene oxide (GO) and g-C3N4 materials were dispersed in deionized water and ultrasonically dispersed for 50 min to obtain a suspension of GO and g-C3N4.

[0045] S4. Add appropriate amounts of ammonium nitrate explosive to the suspension of GO and g-C3N4 according to different mass ratios of ammonium nitrate explosive: g-C3N4: GO, and ultrasonically disperse for 60 min to obtain a mixture containing HMX, g-C3N4 and GO suspension;

[0046] S5. Add hydrazine hydrate to the mixture obtained in S4, wherein the mass fraction of hydrazine hydrate is 80%, stir at 400 r / min for 2 h in an oil bath at 100 °C, cool to room temperature and filter, wash several times with room temperature deionized water, and dry in a vacuum drying oven to obtain HMX composite energetic material 2 with g-C3N4 and GO as desensitizers.

[0047] S6. Disperse HMX and g-C3N4 in deionized water by ultrasonication. After ultrasonication for 90 min, add polyethyleneimine aqueous solution dropwise. Stir at 400 r / min for 2 h at room temperature to obtain a mixture containing HMX, g-C3N4 and PEI.

[0048] S7. Add GO dispersion dropwise to the mixture in S6, and stir at 400 r / min for 2 h at room temperature to obtain a mixture containing HMX, g-C3N4, PEI and GO;

[0049] S8. Add hydrazine hydrate to the mixture of S7, wherein the mass fraction of hydrazine hydrate is 80%, react at 400 r / min for 2 h in an oil bath at 100 °C, cool to room temperature and filter, wash several times with room temperature deionized water, and dry in a vacuum drying oven to obtain HMX composite energetic material 3 with PEI as explosive surface modifier and g-C3N4 and GO as desensitizers;

[0050] Examples 1-6 illustrate the use of polyethyleneimine-reinforced graphene to passivate nitramine-based energetic materials. The specific steps are as follows:

[0051] Example 1:

[0052] The preparation method of g-C3N4-based HMX composite energetic materials includes the following process steps:

[0053] Preparation of g-C3N4 powder:

[0054] After grinding 20 g of urea raw material evenly, it was placed in a crucible and heated to 500℃ at a heating rate of 2K / min. After holding at this temperature for 4 hours and cooling to room temperature, it was taken out and ground evenly to obtain g-C3N4 powder.

[0055] According to the mass ratio of HMX:g-C3N4 of 97 / 3, 30mg g-C3N4 and 970mg HMX were added to a mortar and ground until the whole mixture was uniform to obtain HMX / g-C3N4 (97 / 3) composite material. Its impact sensitivity was 5.0J (3.6J for raw material HMX) and its friction sensitivity was 128N (96N for raw material HMX).

[0056] The g-C3N4 powder and HMX / g-C3N4 (97 / 3) composite material prepared in Example 1 were analyzed by scanning electron microscopy, and their crystal morphology is as follows: Figure 1 and Figure 2 As shown, the g-C3N4 powder prepared in Example 1 has fewer layered structures and smaller, more uniform size. In the HMX / g-C3N4 (97 / 3) composite crystal, g-C3N4 sheets are stacked and distributed on the surface of HMX.

[0057] Example 2:

[0058] Preparation of g-C3N4 and GO suspension:

[0059] Weigh 20 mg g-C3N4 and 10 mg GO respectively and add them to 60 mL of deionized water. Disperse by sonication for 50 min to obtain g-C3N4 and GO suspension (concentration of 0.5 mg / mL).

[0060] The mixture was doped with HMX:g-C3N4:GO in a mass ratio of 97 / 2 / 1. 970 mg of HMX explosive was added to the above g-C3N4 and GO suspension. After ultrasonic treatment for 60 min, a mixture containing HMX, g-C3N4 and GO suspension was obtained. 64 μL of hydrazine hydrate (mass fraction of 80%) was added, and the mixture was stirred at 400 r / min for 2 h in an oil bath at 100 °C. After cooling to room temperature, the mixture was filtered, washed several times with room temperature deionized water, and dried in a vacuum drying oven to obtain HMX / g-C3N4 / rGO (97 / 1 / 2) composite material with g-C3N4 and GO as desensitizers. Its impact sensitivity was 12 J (3.6 J for raw material HMX) and its friction sensitivity was 128 N (96 N for raw material HMX).

[0061] The HMX / g-C3N4 / rGO (97 / 1 / 2) composite material prepared in Example 2 was analyzed by scanning electron microscopy, and its crystal morphology is as follows: Figure 3 As shown, the surface of the HMX / g-C3N4 / rGO (97 / 1 / 2) composite material prepared in Example 2 is more characterized by wrinkled rGO and accompanied by a small amount of layered g-C3N4, which may be due to the difference in the amount of g-C3N4 and rGO added.

[0062] Thermal analysis was performed on the HMX / g-C3N4 / rGO (97 / 1 / 2) composite material prepared in Example 2 and the raw material HMX. The analysis results are as follows: Figure 4 As shown, compared with the raw material HMX, the transcrystallization endothermic peak temperature and decomposition exothermic peak temperature of the HMX / g-C3N4 / rGO (97 / 1 / 2) composite material were slightly improved. The decomposition exothermic peak temperature was 557.60K, which was about 1K higher than that of pure HMX (556.96K). Moreover, the difference in decomposition peak temperature was less than 2K, indicating that the coating material and the explosive raw material have good compatibility. The thermal stability of the explosive composite material can be improved by in-situ reduction coating.

[0063] Example 3:

[0064] Preparation of g-C3N4 and GO suspension:

[0065] Weigh 10 mg g-C3N4 and 20 mg GO respectively and add them to 60 mL of deionized water. Disperse by sonication for 50 min to obtain g-C3N4 and GO suspension (concentration of 0.5 mg / mL).

[0066] The mixture was doped with HMX:g-C3N4:GO at a mass ratio of 97 / 2 / 1. 970 mg of HMX explosive was added to the suspension of g-C3N4 and GO. After ultrasonic treatment for 60 min, a mixture containing the suspension of HMX, g-C3N4 and GO was obtained. 64 μL of hydrazine hydrate (mass fraction of 80%) was added, and the mixture was stirred at 400 r / min for 2 h in an oil bath at 100 °C. After cooling to room temperature, the mixture was filtered, washed several times with room temperature deionized water, and dried in a vacuum drying oven to obtain the HMX / g-C3N4 / rGO (97 / 2 / 1) composite material with g-C3N4 and GO as desensitizers. Its impact sensitivity was 18 J (3.6 J for raw material HMX) and its friction sensitivity was 144 N (96 N for raw material HMX).

[0067] The HMX / g-C3N4 / rGO (97 / 2 / 1) composite material prepared in Example 3 was analyzed by scanning electron microscopy, and its crystal morphology is as follows: Figure 5 As shown, the surface of the HMX / g-C3N4 / rGO composite material prepared in Example 3 has both layered g-C3N4 and wrinkled rGO. Since GO has a large specific surface area, it can completely coat the HMX crystal, which intuitively shows the coating of HMX explosive crystal by g-C3N4 and rGO.

[0068] Thermal analysis was performed on the HMX / g-C3N4 / rGO (97 / 2 / 1) composite material prepared in Example 3 and the raw material HMX. The analysis results are as follows: Figure 6 As shown, compared with the raw material HMX, the decomposition exothermic peak temperature of the HMX / g-C3N4 / rGO (97 / 2 / 1) composite material is slightly increased to 557.73K, which is about 1K higher than that of pure HMX (556.96K). Moreover, the difference in decomposition peak temperature is less than 2K, indicating that the coating material and the explosive raw material have good compatibility. The thermal stability of HMX can be improved by coating the surface of g-C3N4 and rGO.

[0069] Example 4:

[0070] Preparation of graphene oxide suspension: Weigh 20 mg of graphene oxide and add it to 40 mL of water. Disperse the mixture by ultrasonication for 60 min to obtain a graphene oxide suspension (concentration of 0.5 mg / mL).

[0071] Preparation of g-C3N4 and GO suspension: Weigh 970 mg HMX and 10 mg g-C3N4 respectively and add them to 30 mL of deionized water. After ultrasonic dispersion for 90 min, add 5 mL of polyethyleneimine aqueous solution (concentration of 0.5 mg / mL). Stir at 400 r / min for 2 h at room temperature to obtain a mixture containing HMX, g-C3N4 and PEI.

[0072] A pre-prepared 40 mL GO suspension was slowly added dropwise to the above mixture while stirring. After adding 96 μL of hydrazine hydrate, the mixture was reacted at 400 r / min for 2 h in an oil bath at 100 °C. After cooling to room temperature, the mixture was filtered, rinsed several times with room temperature deionized water, and dried in a vacuum drying oven to obtain the HMX-PEI / g-C3N4 / rGO (97 / 1 / 2) composite material, which uses PEI as the explosive surface modifier and g-C3N4 and GO as desensitizing agents. Its impact sensitivity was 18 J (3.6 J for raw material HMX) and its friction sensitivity was 144 N (96 N for raw material HMX).

[0073] The HMX-PEI / g-C3N4 / rGO (97 / 1 / 2) composite material prepared in Example 4 was analyzed by scanning electron microscopy, and its crystal morphology is as follows: Figure 7 As shown, the surface of the HMX / g-C3N4 / rGO composite material prepared in Example 4 exhibits wrinkled rGO and layered g-C3N4, indicating that g-C3N4 and rGO can successfully encapsulate HMX to form a composite material.

[0074] Thermal analysis was performed on the HMX-PEI / g-C3N4 / rGO (97 / 1 / 2) composite material prepared in Example 4 and the raw material HMX. The analysis results are as follows: Figure 8 As shown, compared with the raw material HMX, the decomposition deheating peak temperature of the HMX-PEI / g-C3N4 / rGO (97 / 1 / 2) composite material is slightly increased to 557.90K, which is about 1K higher than that of pure HMX (556.96K). This indicates that the thermal stability of the HMX-PEI / g-C3N4 / rGO (97 / 1 / 2) composite material, which uses PEI as the explosive surface modifier and g-C3N4 and GO as desensitizers, can be improved.

[0075] Example 5:

[0076] Preparation of graphene oxide suspension: Weigh 15 mg of graphene oxide and add it to 30 mL of water. Disperse the mixture by ultrasonication for 60 min to obtain a graphene oxide suspension (concentration of 0.5 mg / mL).

[0077] Preparation of g-C3N4 and GO suspension: Weigh 970 mg HMX and 15 mg g-C3N4 respectively and add them to 30 mL of deionized water. After ultrasonic dispersion for 90 min, add 5 mL of polyethyleneimine aqueous solution (concentration of 0.5 mg / mL). Stir at 400 r / min for 2 h at room temperature to obtain a mixture containing HMX, g-C3N4 and PEI.

[0078] The pre-prepared 30 mL GO suspension was slowly added dropwise to the above mixture while stirring. After adding 96 μL of hydrazine hydrate, the mixture was reacted at 400 r / min for 2 h in an oil bath at 100 °C. After cooling to room temperature, the mixture was filtered, rinsed several times with room temperature deionized water, and dried in a vacuum drying oven to obtain the HMX-PEI / g-C3N4 / rGO (97 / 1.5 / 1.5) composite material, which uses PEI as the explosive surface modifier and g-C3N4 and GO as desensitizers. Its impact sensitivity is 26 J (3.6 J for raw material HMX) and its friction sensitivity is 160 N (96 N for raw material HMX).

[0079] The HMX-PEI / g-C3N4 / rGO (97 / 1.5 / 1.5) composite material prepared in Example 5 was analyzed by scanning electron microscopy, and its crystal morphology is as follows: Figure 9 As shown, the surface of the HMX / g-C3N4 / rGO composite material prepared in Example 5 exhibits wrinkled rGO with layered g-C3N4, resulting in a more prominent overall coating effect. This may be due to the addition of PEI enhancing the interfacial bonding between the explosive crystals and the coating material.

[0080] Thermal analysis was performed on the HMX-PEI / g-C3N4 / rGO (97 / 1.5 / 1.5) composite material prepared in Example 5 and the raw material HMX. The analysis results are as follows: Figure 10 As shown, the decomposition peak temperature of raw material HMX is 556.96K. Compared with raw material HMX, the decomposition exothermic peak temperature of HMX-PEI / g-C3N4 / rGO (97 / 2 / 1) composite material is increased by 1.31K, indicating that the thermal stability of HMX-PEI / g-C3N4 / rGO (97 / 1.5 / 1.5) composite material is improved.

[0081] Example 6:

[0082] Preparation of graphene oxide suspension: Weigh 10 mg of graphene oxide and add it to 20 mL of water. Disperse the mixture by ultrasonication for 60 min to obtain a graphene oxide suspension (concentration of 0.5 mg / mL).

[0083] Preparation of g-C3N4 and GO suspension: Weigh 970 mg HMX and 20 mg g-C3N4 respectively and add them to 40 mL of deionized water. After ultrasonic dispersion for 90 min, add 5 mL of polyethyleneimine aqueous solution (concentration of 0.5 mg / mL). Stir at 400 r / min for 2 h at room temperature to obtain a mixture containing HMX, g-C3N4 and PEI.

[0084] A pre-prepared 20 mL GO suspension was slowly added dropwise to the above mixture while stirring. After adding 64 μL of hydrazine hydrate, the mixture was reacted at 400 r / min for 2 h in an oil bath at 100 °C. After cooling to room temperature, the mixture was filtered, rinsed several times with room temperature deionized water, and dried in a vacuum drying oven to obtain the HMX-PEI / g-C3N4 / rGO (97 / 2 / 1) composite material, which uses PEI as the explosive surface modifier and g-C3N4 and GO as desensitizers. Its impact sensitivity is 40 J (3.6 J for raw material HMX) and its friction sensitivity is 192 N (96 N for raw material HMX).

[0085] The HMX-PEI / g-C3N4 / rGO (97 / 2 / 1) composite material prepared in Example 6 and the raw material HMX were subjected to XRD crystal form analysis. The analysis results are as follows: Figure 11 As shown, the diffraction peaks of HMX and the HMX-PEI / g-C3N4 / rGO (97 / 2 / 1) composite material match well with the XRD spectrum of theoretical β-HMX (JCPDS NO.45-0893). This is reflected in the fact that the three characteristic peaks of β-type HMX at 15.9°, 20.4°, and 31.8° correspond to the (-1 1 1), (-1 0 2), and (1- 3 2) lattice planes, respectively. Furthermore, compared to the raw material HMX, the composite material exhibits relatively weaker characteristic absorption peaks, which also reflects the coating of g-C3N4 and rGO on the HMX surface.

[0086] XPS chemical bond analysis was performed on the HMX-PEI / g-C3N4 / rGO (97 / 2 / 1) composite material prepared in Example 6 and the raw material HMX. The analysis results are as follows: Figure 12 As shown, the atomic structure environment of g-C3N4, HMX, rGO, and the HMX-PEI / g-C3N4 / rGO (97 / 2 / 1) composite material was obtained by high-resolution C1s spectroscopy. In C3N4, carbon atoms can be divided into three characteristic peaks at 284.4, 285.7, and 288.0 eV, originating from CC, C=N, and CN groups, respectively. HMX has two peaks in the C1 region, corresponding to CC (284.9 eV) and NCN (287.7 eV). For rGO, the C1s component consists of four peaks, namely C=C, CO, C=O, and OC=O. Compared with the raw material HMX, the basic C1s distribution at 284.9 eV (CC / C=C type) in the HMX-PEI / g-C3N4 / rGO (97 / 2 / 1) composite material is significantly reduced. Meanwhile, two new peaks appeared in rGO and C3N4, which were attributed to the CO / C=N (285.4 eV) and OC=O / CN (288.2 eV) groups of rGO and g-C3N4, respectively, indicating the presence of each coating material in the composite material.

Claims

1. A method for preparing a g-C3N4-based composite energetic material, characterized in that, The g-C3N4 and explosives are physically ground to obtain a composite material 1 in a certain mass ratio by physical grinding, the g-C3N4 after ultrasonic is coated on the surface of the GO to obtain a composite material 2 by in-situ reduction, the surface of the ammonium nitrate explosive is modified by the high cationic property of the polyethylene imine, and then the composite material 3 is obtained by the electrostatic self-assembly method; the g-C3N4 and the GO are combined to reduce the sensitivity of the ammonium nitrate explosive crystal by the above method, and the ammonium nitrate explosive composite material with the functions of reducing the sensitivity and high energy is obtained; the g-C3N4 and the GO have high stability, high thermal conductivity and lubricity, so that the mechanical sensitivity of the energetic material is passivated; the specific steps of the method are as follows: Step one: taking urea as a raw material, a crucible is placed in a muffle furnace, and a light yellow powder g-C3N4 is obtained after calcination at 550 DEG C; Step two: the explosive raw material and the g-C3N4 material in step one are mixed in a mass ratio of 99 / 1, 98 / 2 and 97 / 3, and are uniformly ground in a mortar to obtain a physically ground composite material 1; Step three: the graphene oxide GO and the g-C3N4 material in step one are dispersed in deionized water, and a suspension of GO and g-C3N4 is obtained after ultrasonic dispersion; Step four: a certain amount of ammonium nitrate is added to the suspension in step three according to different mass ratios of ammonium nitrate, g-C3N4 and GO, and a mixed solution containing ammonium nitrate, g-C3N4 and GO is obtained after ultrasonic dispersion treatment, wherein the mass ratio of ammonium nitrate, g-C3N4 and GO in the mixed solution is 97 / 2 / 1; Step five: hydrazine hydrate is added to the mixed solution obtained in step four, the mass fraction of the hydrazine hydrate is 80%, and the stirring speed is 400 r / min at 100 DEG C in an oil bath for 2 h, then the mixture is cooled to room temperature, filtered, washed with deionized water at room temperature for several times, and dried in a vacuum drying box to obtain an ammonium nitrate composite energetic material 2 with g-C3N4 and GO as a sensitivity reducer; Step six: the ammonium nitrate and g-C3N4 are ultrasonically dispersed in deionized water, and a polyethylene imine aqueous solution is added dropwise, and the stirring speed is 400 r / min at room temperature for 2 h to obtain a mixed solution containing ammonium nitrate, g-C3N4 and PEI; Step seven: the GO dispersion liquid is added dropwise to the mixed solution in step six, and the stirring speed is 400 r / min at room temperature for 2 h to obtain a mixed solution containing ammonium nitrate, g-C3N4, PEI and GO, wherein the mass ratio of ammonium nitrate, g-C3N4 and GO is 97 / 2 / 1; Step eight: hydrazine hydrate is added to the mixed solution in step seven, the mass fraction of the hydrazine hydrate is 80%, and the stirring speed is 400 r / min at 100 DEG C in an oil bath for 2 h, then the mixture is cooled to room temperature, filtered, washed with deionized water at room temperature for several times, and dried in a vacuum drying box to obtain an ammonium nitrate composite energetic material 3 with PEI as a surface modifier of the explosive and g-C3N4 and GO as a sensitivity reducer.

2. The method of claim 1, wherein the g-C3N4-based composite energetic material is prepared by: The ammonium nitrate explosives include, but are not limited to, cyclotetramethylene tetranitramine HMX, bicyclooctanamine BCHMX, cyclotrimethylene trinitramine RDX, or hexanitrohexaazaisowurtzitane CL-20.

3. The method of claim 1, wherein the g-C3N4-based composite energetic material is prepared by: The polyethyleneimine includes, but is not limited to, polyethyleneimine with a molecular weight of 600, 1800, or 10000.

4. The method of claim 1, wherein the g-C3N4-based composite energetic material is prepared by: The concentration of the graphene oxide material suspension is 0.5 mg / ml.

5. The method of claim 1, wherein the g-C3N4-based composite energetic material is prepared by: The concentration of the polyethyleneimine suspension is 0.5 mg / ml.

6. The method of claim 1, wherein the g-C3N4-based composite energetic material is prepared by: The step three ultrasonic treatment is 50-55 min.

7. The method of claim 1, wherein the g-C3N4-based composite energetic material is prepared by: The step four ultrasonic treatment is 60-65 min.

8. The method of claim 1, wherein the g-C3N4-based composite energetic material is prepared by: The step six ultrasonic treatment is 90-100 min.

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