CN116283452A - Preparation method of explosive/HNS core-shell structure spherical composite based on pickering emulsion method - Google Patents

Abstract

The invention discloses a method for preparing an explosive/HNS core-shell structure spherical compound based on a pickering emulsion method, which comprises the following steps: carrying out interface modification or modification on the nano HNS, and regulating the HLB value of the nano HNS to obtain modified nano HNS; adding the simple substance explosive into the solvent A, adding the modified nano HNS after dissolving, adding the non-solvent B after stirring, forming emulsion under the auxiliary effect of ultrasonic waves, and drying to obtain the spherical composite with the explosive/HNS core-shell structure. According to the invention, the nano HNS surface is modified and modified, and the HLB value of the nano HNS can be changed, so that the nano HNS is used as a surfactant of a pickering emulsion, and finally the spherical explosive/HNS compound with a shell-core structure is obtained. On one hand, the sensitivity of the explosive is reduced through the spherical structure of the compound, on the other hand, the nano HNS attached to the surface of the compound can better exert the heat-resistant insensitive performance of the nano HNS while repairing the surface defect of the compound, so that the sensitivity of the compound is reduced more effectively, and the stability of the explosive is improved.

Description

Preparation of explosive/HNS core-shell spherical composites based on pickering emulsion method method

technical field

The invention belongs to material composite technology, specifically a method for preparing explosive/HNS core-shell structure spherical composite based on a pickering emulsion method.

Background technique

With the continuous development of science and technology, people's requirements for weapons and explosives are not only high energy performance during use, but also green production process and stable storage. Energetic compound, the most basic energy unit of energetic material, is the main factor affecting the strength of the warhead of a weapon, thus affecting the upgrading of weapons and equipment. American scientist Nielsen first synthesized hexanitrohexaazaisowurtzitane (CL-20) in 1987, which attracted the attention of scientists from all over the world. Compared with the second-generation energetic material tetranitrotetraazaisooctane (HMX), the density of CL-20 is increased by 8%, the detonation velocity is increased by 6%, the detonation pressure is increased by 8%, and the energy density is increased by 10%. However, CL-20 is highly sensitive to mechanical stimulation, electrostatic stimulation, etc., has poor thermal stability such as easy crystal form transformation, and low thermal decomposition temperature. These defects greatly limit the use of CL-20.

Hexanitrostilbene (HNS) is widely used in aerospace, modified additives for casting explosives and military and civilian durability due to its stable physical and chemical properties, low impact sensitivity, insensitivity to static sparks, and high thermal stability. Thermal equipment and other fields. Surface modification of nano-HNS is used in pickering emulsion containing CL-20, so that it can be attached to the surface of the spherical compound and form a core-shell structure, which can effectively reduce the sensitivity of the compound and expand the CL-20. The range of use increases its security.

At present, the desensitization technology for CL-20 is mainly concentrated in two aspects: the inside of the crystal and the outside of the crystal: the desensitization technology inside the crystal is mainly CL-20/energetic component passivation eutectic, CL-20/non-energetic component Component eutectic, etc.; the desensitization technology outside the crystal is mainly the control of CL-20 crystal form, the ultra-fine of CL-20, the spheroidization of CL-20, the surface coating of CL-20, etc. Liang Li et al. (Liang Li, Chang Zhipeng, Zhang Zhengjin, et al. Controllable batch preparation and desensitization technology of ultrafine CL-20[J]. Shanghai Aerospace (Chinese and English), 2020,37(04):148- 154.) Using HLG-05 crushing equipment, using 0.8mm and 0.3mm zirconia balls as the medium, prepared micron-sized and sub-micron-sized smooth surface, spherical-like superfine particles with an average particle size of 3.43μm and 320nm CL-20, through characterization analysis, it is found that the mechanical sensitivity and friction sensitivity are effectively reduced, but its thermal stability is reduced, and the electrostatic spark sensitivity is increased. Yao Jian (Yao J, Li B, Xie L. Preparation and Properties of Spherical CL-20 Composites. [J]. ACS omega, 2022, 7(42).) Prepared CL-20/F2604 and CL-20 by electrostatic spraying method /DOS and CL-20/PVB spherical composites, through characterization analysis, found that compared with the raw material CL-20, the mechanical sensitivity is effectively reduced, but the thermal stability is reduced, and the explosive energy is greatly reduced. Wang Xinquan, et al. Nitroguanidine (NQ) was coated on the surface of refined CL-20 by spray crystallization process to form a CL-20/NQ composite. After characterization analysis, it was found that the impact sensitivity was effectively reduced and the thermal stability was effectively increased. However, the experiment Too many process steps and high particle size requirements for CL-20. Hang Guiyun et al. (Hang Guiyun, Yu Wenli, Wang Tao, et al. Preparation and performance test of CL-20/RDX eutectic explosive [J]. Journal of Explosives and Explosives, 2021,44(04):484-488.) Prepared by spray drying method The CL-20/RDX eutectic explosive with a molar ratio of 1:1 was obtained. The characterization analysis found that the energy of the explosive was well preserved, and the impact sensitivity and friction sensitivity were reduced to a certain extent, but the thermal stability was reduced to a certain extent. .

The above results show that both coating and eutectic can effectively reduce the sensitivity of explosives, but there are certain defects in the single technical means.

Contents of the invention

The invention adopts the method of preparing the compound, organically combines various desensitization technologies such as coating, eutectic, and spheroidization, and is expected to obtain high-energy insensitivity energetic materials. In order to ensure the energy release of the energetic material, all the components of the present invention are energetic materials. However, it is still a technical problem to uniformly coat the nanometer HNS on the surface of the explosive compound. In the invention, the surface of the nanometer HNS is firstly modified and modified to change its HLB value, and then it is used as a surfactant of the pickering emulsion to finally obtain an explosive/HNS compound with a core-shell structure.

The present invention adopts the pickering emulsion method to prepare the spherical composite of explosive/HNS core-shell structure, which can not only reduce the mechanical sensitivity of simple explosives through the spherical structure of the composite, but also reduce crystal surface defects and improve Crystal morphology and surface smoothness reduce its sensitivity; on the other hand, it can give full play to the heat resistance and insensitivity performance of nano-HNS itself, and improve the stability of explosives.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide the advantages described hereinafter.

In order to realize these purposes and other advantages according to the present invention, a kind of method for preparing explosive/HNS core-shell structure spherical compound based on pickering emulsion method is provided, comprising the following steps:

Step 1, modifying or modifying the interface of the nano-HNS, adjusting its HLB value, and obtaining the modified nano-HNS;

Step 2. Add the elemental explosive to the solvent A, add the modified nano-HNS after dissolving, add the non-solvent B after stirring, make it form an emulsion under the assisted action of the ultrasonic wave, and dry it to obtain the explosive/HNS core-shell structure spherical compound .

Preferably, the method for modifying or modifying the interface of nano-HNS is: adding nano-HNS to 0.01mol/L stearic acid-ethanol, dispersing under the action of ultrasound, stirring at room temperature for 45-60min, and drying to obtain Modified nano-HNS.

Preferably, the mass volume ratio of the nano-HNS to ethanol is 1-2g:30-60mL; the mass ratio of the nano-HNS to stearic acid is 8-12g:0.3g;

Preferably, the stirring speed is 200-300r/min; the ultrasonic power is 300-1200W, and the frequency is 30-120KHZ.

Preferably, in the first step, the HLB value is between 10-15.

Preferably, the elemental explosive is hexanitrohexaazaisowurtzitane, hexogen, octogen, ammonium perchlorate, ammonium dinitramide, ammonium nitrate, 5,5'-bistetrazole- 1,1'-Dioxyhydroxyl ammonium salt, 3,3'-diamino-4,4'-azofurazan, 3,3'-diamino-4,4'-azofurazan, 1, 1-diamino-2,2-dinitroethylene, 2,4,6-trinitrotoluene, picric acid, 1,3-dinitrobenzene, 1,2-dinitrobenzene, p-nitrochloride Benzene, p-nitroaniline, p-nitrophenol, 3,5-dinitroaniline, 3,5-dinitrotoluene, 2,4-dinitrotoluene, 2,4-dinitrophenol, 3, One or more of 5-dinitrobenzoic acid and nitrocellulose.

Preferably, the single explosive is a mixture of any two explosives, and the mass ratio of the mixture of any two explosives is 0.1-1:1-10.

Preferably, the mass ratio of the modified nanometer HNS to the explosive is 0.01 to 1:1; the volume ratio of the solvent A to the non-solvent B is 0.1 to 1:1 to 20; the elemental explosive to the non-solvent B The mass volume ratio is 1.0～2.5g:5～45mL.

Preferably, the duration of the ultrasound is 10-30 minutes, the power of the ultrasound is 300-1200W, and the frequency is 30-120kHz.

Preferably, the solvent A and the non-solvent B are distilled water, methanol, ethanol, acetic acid, ethyl acetate, butyl acetate, isoamyl acetate, acetone, n-butyl ketone, methyl isobutyl ketone, cyclohexane Alkanes, n-butane, cyclohexanone, toluene cyclohexanone, methyl butanone, chlorobenzene, dichlorobenzene, methylene chloride, chloroform, carbon tetrachloride, benzene, toluene, xylene, dimethyl sulfoxide , N,N dimethylformamide, diethyl ether, petroleum ether, propylene oxide, glycol ether, acetonitrile; and when the solvent A chooses to dissolve elemental explosives, the non-solvent B chooses not to Solvent for dissolving elemental explosives.

The present invention at least includes the following beneficial effects: the present invention modifies and modifies the surface of nano-HNS, can change its HLB value, make it a surfactant of pickering emulsion, and finally obtain explosive/HNS spherical composite with shell-core structure. On the one hand, the spherical structure of the composite reduces the sensitivity of explosives. On the other hand, the nano-HNS attached to the surface of the composite can better exert its heat resistance and insensitivity performance while repairing the surface defects of the composite, and more effectively reduce The sensitivity of the compound improves the stability of explosives. In the impact sensitivity test of pure CL-20, CL-20/DNB/HNS mechanical mixing (comparative example 1) and the spherical compound of the present invention, the H50 of the spherical compound is obviously improved, the exothermic peak is shifted backward, and the heat release It has been greatly improved, and the invention fully achieves the maximum guarantee of explosive energy while reducing its sensitivity and improving safety.

Other advantages, objectives and features of the present invention will partly be embodied through the following descriptions, and partly will be understood by those skilled in the art through the research and practice of the present invention.

Description of drawings:

Fig. 1 is scanning electron microscope (SEM) picture of the present invention, wherein (a), (b), (c) are raw material CL-20, raw material DNB, raw material HNS successively; Fig. (d) is modified HNS; Fig. (e ) is the mechanical mixture of CL-20/DNB/HNS; Figure (f) is the spherical complex of CL-20/DNB/HNS core-shell structure and its enlarged view;

Fig. 2 is the infrared spectrogram (FT-IR) of modified HNS of the present invention and its raw material;

Fig. 3 is the X-ray diffraction spectrum (XRD) of the present invention, wherein (a) is four crystal forms α, β, ε, γ of raw material CL-20; (b) is raw material CL-20, raw material DNB, modified HNS, CL-20/DNB/HNS mechanical mixture and CL-20/DNB/HNS core-shell structure spherical complex;

Fig. 4 is the DSC diagram of raw material CL-20, raw material DNB, modified HNS, CL-20/DNB/HNS mechanical mixture and CL-20/DNB/HNS core-shell structure spherical composite of the present invention;

Fig. 5 is a diagram of the mechanical sensitivity test results of raw material CL-20, raw material DNB, CL-20/DNB/HNS mechanical mixture and CL-20/DNB/HNS core-shell structure spherical composite of the present invention.

Detailed ways:

The present invention will be further described in detail below in conjunction with the accompanying drawings, so that those skilled in the art can implement it with reference to the description.

It should be understood that terms such as "having", "comprising" and "including" as used herein do not entail the presence or addition of one or more other elements or combinations thereof.

Example 1:

A method for preparing explosives/HNS core-shell structure spherical composite based on pickering emulsion method, comprising the following steps:

Step 1. Add 1g of nano-HNS to 30mL of the prepared 0.01mol/L stearic acid-ethanol solution, disperse it by ultrasonic, put it on a magnetic stirrer and stir for 1h, then put it in a constant temperature water bath oven at 35°C for drying. Obtain stearic acid-modified nano-HNS, HLB value is 14.2; ultrasonic power is 300W, frequency is 45kHz; the speed of the stirring is 200r/min;

Step 2. Dissolve 2 g of CL-20/DNB (1,3-dinitrobenzene) mixture at a molar ratio of 1:1 in 20 mL of ethyl acetate, and then add 0.3 g of stearic acid-ethanol modified nano HNS, add 100mL deionized water after 10min, sonicate to obtain emulsion, and obtain CL-20/DNB/HNS spherical complex after freeze-drying; the ultrasonic time is 15min, the ultrasonic power is 300-1200W, and the frequency is 30- 120kHz.

Comparative example 1:

A method for preparing explosives/HNS core-shell structure spherical composite based on the pickering emulsion method, comprising the following steps:

Step 1. Add 1g of nano-HNS to 30mL of the prepared 0.01mol/L stearic acid-ethanol solution, disperse it by ultrasonic, put it on a magnetic stirrer and stir for 1h, then put it in a constant temperature water bath oven at 35°C for drying. Obtain stearic acid-modified nano-HNS, HLB value is 14.2; ultrasonic power is 300W, frequency is 45kHz; the speed of the stirring is 200r/min;

Step 2: 2 g of CL-20/DNB mixture mixed at a molar ratio of 1:1 and 0.3 g of stearic acid-modified nano-HNS were mechanically mixed and stirred to obtain a CL-20/DNB/HNS complex.

Figure 1(a), (b), (c), (d), (e), and (f) are the raw materials CL-20, raw material DNB, raw material HNS, modified HNS, CL-20 obtained by scanning electron microscope respectively /DNB/HNS mechanical mixture and CL-20/DNB/HNS core-shell spherical complex and its enlarged view. From Figure 1(a), (b), (c) and (d), it can be seen that most of the particles of the raw material CL-20 are octahedral bipyramids, and the particle size is about 20-60 μm; the raw material DNB particles are Irregular long rod shape, the particle size is about 100-400μm; the raw material HNS is mostly spherical crystals with a size of 100nm, including a small part of irregular crystals and rod-shaped crystals. After modification, the rod-shaped crystals disappear, and the crystals tend to be spherical and uniform in size; It can be seen from Figure 1(e) that the particle size of CL-20/DNB/HNS mechanical mixture is reduced to a certain extent compared with the raw material due to the grinding effect during the mixing process, but it is not difficult to see several components in the scanning electron microscope picture It is simply mixed together, and there is no specific substantive change; in Figure 1(f), the individual raw material components cannot be seen, and several energetic materials form a new type of compound, which can be clearly observed from the figure The particle size is mainly distributed in the regular spherical structure of 1-3 μm and some core-shell structures; the reason for the formation is that the modified HNS has hydrophilic and lipophilic properties, making the whole system into an oil-in-water structure. Under the action, the oil phase with a spherical structure changes into a smaller spherical shape. After adding deionized water, the ethyl acetate in the oil phase gradually decreases, which makes the interaction force between different components of explosive molecules stronger and gradually precipitates. At this time The modified HNS was attached to the surface of tiny droplets and precipitated together. After drying, due to the reduction of ethyl acetate, the shell strength of some spherical structures was not enough, forming a core-shell structure.

Figure 2 compares the FT-IR spectra of raw HNS and modified HNS. The peak at 3097.5cm ^-1 is related to the stretching vibration of -CH=; the peak at 1602.9cm ^-1 is related to the stretching vibration of the C=C bond in the benzene ring; the peak at 1539.1cm ^-1 is the stretching vibration of the -NO ₂ group Antisymmetric stretching vibration, 1348.1cm ^-1 is the symmetrical stretching vibration of -NO ₂ group, the peak in the modified HNS is consistent with that of the raw material, indicating that the modification has not changed the chemical properties of HNS. What is inconsistent with the raw material HNS is that the modified HNS has a peak at 3617.7~3877.2cm ^-1 , which is the stretching vibration peak of the hydroxyl group in stearic acid, and the peak at 1550.7cm ^-1 is the difference of ^COO- The symmetrical stretching vibration peaks indicate that the modification is successful, stearic acid has been successfully modified on HNS, and the interface modification of HNS can make it act as a surfactant in the pickering emulsion, which is conducive to the formation of a stable pickering emulsion;

The raw materials and products of Example 1 and Comparative Example 1 were characterized by X-ray diffraction (XRD), as shown in Figure 3(a)(b). In Figure 3(b), the raw material CL-20 has diffraction peaks at 2θ of 12.0°, 13.6°, 20.1°, 24.9°, 27.9° and 28.8°, etc. These diffraction peaks are similar to those of α- The consistency of CL-20 indicates that the crystal form of the raw material CL-20 is pure α crystal form; the raw material DNB has diffraction peaks at 2θ of 9.2°, 13.3°, 14.7°, 18.3°, 21.1° and 23.2°; the raw material HNS There are diffraction peaks at 2θ of 8.3°, 14.7°, 18.0°, 20.0° and 23.7°. The above-mentioned diffraction peaks are all reflected in the mechanical mixture (Phys.mixing), but these strong characteristic peaks are not fully reflected in the CL-20/DNB/HNS core-shell spherical composite. On the contrary, the CL-20/DNB/HNS core-shell spherical complex has strong diffraction peaks at 5.4° and 10.5° that do not appear in the diffraction patterns of the raw material components and mechanical mixing, and are consistent with the CL-20 reported in the literature. /DNB eutectic peaks are consistent. It shows that in the process of preparing the complex, it is not a simple mechanical mixing, but a new phase is produced to form a CL-20/DNB/HNS complex.

Using DSC to characterize and analyze the thermal decomposition performance of raw materials CL-20, DNB, modified HNS, CL-20/DNB/HNS mechanical mixture (Phys.mixing) and CL-20/DNB/HNS core-shell structure spherical composite, The result is shown in Figure 4. It can be seen from Figure 4 that the raw material CL-20 has a crystallization peak at 178.3°C and a decomposition exothermic peak at 239.8°C; raw material DNB has an endothermic peak due to melting at 91.5°C and an endothermic peak at 219.8°C. An endothermic peak generated by evaporation; the raw material HNS has a melting endothermic peak at 321.6°C, and an exothermic peak generated by decomposition at 351.2°C; it can be seen from the curve of the CL-20/DNB/HNS mechanical mixture It can be seen that all the peaks of each raw material component can basically be reflected in it. Due to the small content of modified HNS, its exothermic peak is not obvious, resulting in only one obvious exothermic peak at 246.6 ° C, which is different from that of pure CL-20 Compared with the delay of 6.8 ℃, it shows that in the process of mechanical mixing, the components have a certain synergistic effect; and the thermal decomposition curve of the CL-20/DNB/HNS core-shell structure spherical compound is larger than that of the raw material The difference is that there is only an endothermic peak at 127.5°C and an exothermic peak at 247.7°C. Except for a CL-20 crystallization peak in the raw material, all other peaks disappear, forming a new and unique thermal decomposition performance. Composite The exothermic peak of the thermal decomposition of the compound is 7.9 °C higher than that of the raw material, which is consistent with the thermal decomposition performance of the CL-20/DNB eutectic reported in the literature, so it can also be shown here that several energetic components are not simply mechanical Mixing, but forming a new phase.

The test of mechanical sensitivity is shown in Figure 5. It can be seen from Figure 5 that the characteristic drop height (H ₅₀ ) of the raw material CL-20 is 13cm, that of the raw material DNB is greater than 100cm, that of the CL-20/DNB/HNS mechanical mixture is 21cm, and that the core-shell structure of CL-20/DNB/HNS The spherical complex is 43 cm. The H ₅₀ of the compound is 30cm higher than that of the raw material, and 22cm higher than that of the mechanical mixture, indicating that although there is a certain synergistic effect when CL-20 is mechanically mixed with DNB and HNS, the reduction effect on the sensitivity of CL-20 is limited , and after being prepared into a composite, the sensitivity can be greatly reduced. The reason for this result may be: on the one hand, the particle size and particle morphology of the composite are obviously different from the mechanical mixture. The particle size of the composite is smaller, more uniform, closer to spherical, and has a larger specific surface area. It can better prevent the generation of hot spots and reduce its sensitivity; on the other hand, CL-20 and DNB exist in the form of eutectic in the complex, forming a new phase, which is more stable and safer than raw materials Better; finally, nano-HNS modified the surface of CL-20/DNB molecule, so that the complex has fewer defects, and due to the heat-resistant insensitivity of HNS itself, the sensitivity is greatly reduced.

Although the embodiment of the present invention has been disclosed as above, it is not limited to the use listed in the specification and implementation, it can be applied to various fields suitable for the present invention, and it can be easily understood by those skilled in the art Therefore, the invention is not limited to the specific details and examples shown and described herein without departing from the general concept defined by the claims and their equivalents.

Claims (10)

1. The method for preparing the spherical composite with the explosive/HNS core-shell structure based on the pickering emulsion method is characterized by comprising the following steps of:

step one, carrying out interface modification or modification on nano HNS, and regulating the HLB value of the nano HNS to obtain modified nano HNS;

and step two, adding the simple substance explosive into the solvent A, adding the modified nano HNS after dissolution, adding the non-solvent B after stirring, forming emulsion under the auxiliary effect of ultrasonic waves, and drying to obtain the spherical composite with the explosive/HNS core-shell structure.

2. The method for preparing the spherical composite with the explosive/HNS core-shell structure based on the pickering emulsion method as set forth in claim 1, wherein the method for carrying out interface modification or modification on the nano HNS is as follows: adding nano HNS into 0.01mol/L stearic acid-ethanol, dispersing under the action of ultrasound, stirring at room temperature for 45-60 min, and drying to obtain the modified nano HNS.

3. The method for preparing the spherical composite with the explosive/HNS core-shell structure based on the pickering emulsion method as claimed in claim 2, wherein the mass volume ratio of the nano HNS to the ethanol is 1-2 g:30-60 mL; the mass ratio of the nano HNS to the stearic acid is 8-12 g/0.3 g.

4. The method for preparing the spherical composite with the explosive/HNS core-shell structure based on the Pickering emulsion method as recited in claim 2, wherein the stirring speed is 200-300 r/min; the ultrasonic power is 300-1200W, and the frequency is 30-120 KHZ.

5. The method for preparing the spherical composite with the explosive/HNS core-shell structure based on the Pickering emulsion method as recited in claim 1, wherein in the first step, the HLB value is between 10 and 15.

6. The method for preparing the spherical composite with the explosive/HNS core-shell structure based on the pickering emulsion method according to claim 1, wherein the elementary explosive is one or more of hexanitrohexaazaisowurtzitane, hexogen, octogen, ammonium perchlorate, ammonium dinitrate, ammonium nitrate, 5 '-bitetrazole-1, 1' -dioxyhydroxylammonium salt, 3 '-diamino-4, 4' -azofurazan, 3 '-diamino-4, 4' -azofurazan, 1-diamino-2, 2-dinitroethylene, 2,4, 6-trinitrotoluene, picric acid, 1, 3-dinitrobenzene, 1, 2-dinitrobenzene, p-nitrochlorobenzene, p-nitroaniline, p-nitrophenol, 3, 5-dinitroaniline, 3, 5-dinitrotoluene, 2, 4-dinitrophenol, 3, 5-dinitrobenzoic acid and nitrocellulose.

7. The method for preparing the spherical composite with the explosive/HNS core-shell structure based on the pickering emulsion method as recited in claim 6, wherein the single explosive is a mixture of any two explosives, and the mass ratio of the mixture of any two explosives is 0.1-1:1-10.

8. The method for preparing the spherical composite with the explosive/HNS core-shell structure based on the pickering emulsion method as recited in claim 1, wherein the mass ratio of the modified nano HNS to the explosive is 0.01-1:1; the volume ratio of the solvent A to the non-solvent B is 0.1-1:1-20; the mass volume ratio of the simple substance explosive to the non-solvent B is 1.0-2.5 g:5-45 mL.

9. The method for preparing the spherical composite of the explosive/HNS core-shell structure based on the Pickering emulsion method as recited in claim 1, wherein the ultrasonic time is 10-30 min, the ultrasonic power is 300-1200W, and the frequency is 30-120 kHz.

10. The method for preparing the spherical composite with the explosive/HNS core-shell structure based on the pickering emulsion method according to claim 1, wherein the solvent a and the non-solvent B are one or more of distilled water, methanol, ethanol, acetic acid, ethyl acetate, butyl acetate, isoamyl acetate, acetone, N-butanone, methyl isobutyl ketone, cyclohexane, N-butane, cyclohexanone, toluene cyclohexanone, methyl butanone, chlorobenzene, dichlorobenzene, dichloromethane, chloroform, carbon tetrachloride, benzene, toluene, xylene, dimethyl sulfoxide, N dimethylformamide, diethyl ether, petroleum ether, propylene oxide, glycol ether and acetonitrile; and when solvent a selects a solvent that dissolves the elemental explosive, non-solvent B selects a solvent that does not dissolve the elemental explosive.

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