TMBZ-TXBQ eutectic material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of eutectic materials, and discloses a TMBZ-TXBQ eutectic material as well as a preparation method and application thereof. The TMBZ-TXBQ eutectic material comprises an electron donor and an electron acceptor, the electron donor is N, N, N, N-tetramethyl benzidine, and the electron acceptor is a 1, 2, 4, 5-tetrahalogen p-benzoquinone compound. The TMBZ-TXBQ eutectic material disclosed by the invention can be triggered by 808nm laser with the power density of 330mW. Cm <-2 >, a large amount of heat can be quickly released, and a high temperature exceeding 400 DEG C can be provided, so that the requirement on the laser can be obviously reduced, and the cost of a trigger system can be reduced and the miniaturization of the trigger system is facilitated; the device can be very sensitively controlled by laser, and the higher critical temperature ensures the safety of the device. Meanwhile, heat release of the TMBZ-TXBQ eutectic material can be remotely controlled, and after the TMBZ-TXBQ eutectic material is wrapped by a packaging material, the TMBZ-TXBQ eutectic material can still be triggered by laser irradiated from the outside to release heat.

Description

Technical Field

[0001] The present invention belongs to the technical field of eutectic materials, and particularly relates to a TMBZ-TXBQ eutectic material, a preparation method thereof, and an application thereof. Background Art

[0002] Laser ignition results in the explosion of energetic materials. The explosion of energetic materials can be divided into a deflagration-detonation mechanism and a shock wave triggering mechanism. Therefore, two different laser ignition systems have been designed. The laser ignition system using the deflagration-detonation mechanism is also called a laser thermal initiation system. It mainly uses high-energy laser to irradiate the surface of energetic materials. The laser energy is absorbed by the energetic materials, increasing the kinetic energy of its molecules, thereby raising the temperature of the agent. When the ignition temperature is reached, deflagration occurs, and finally explosion occurs. The laser ignition system using the shock wave triggering mechanism is called a laser shock initiation system. It mainly irradiates a metal film on the surface of a transparent substrate with high-power pulsed laser to generate a plasma with high temperature, high pressure and high density, and finally expands to generate a shock wave, driving the flyer plate to strongly impact and detonate the energetic materials. Therefore, it is also called a laser-driven flyer plate ignition system.

[0003] The design of laser-driven flyer plate devices is complex, with high requirements for process manufacturing, and still requires complex lasers to provide high-energy pulsed lasers. Therefore, it is difficult to popularize this advanced ignition system. The laser thermal initiation system is the earliest proposed laser initiation method. The mechanism of laser thermal initiation is clear, the device is simple, and continuous laser triggering can be achieved. Therefore, it is more advantageous in applications. The core of laser thermal initiation lies in materials with laser response. The defect of the previous laser thermal initiation system is exactly that the energetic materials have poor response to laser, heat up slowly under laser, and therefore require high-power lasers. Although experiments have been carried out to develop energetic materials with better near-infrared light (the laser wavelength required for laser ignition) response, or to incorporate carbon black, carbon nanotubes, and nano-metal powders with strong light absorption to improve the thermal response of the materials to laser, the experimental results are not ideal. Therefore, there is an urgent need to develop a new type of material that not only needs to effectively absorb and utilize near-infrared laser, but also needs to quickly provide high temperature under low-power laser irradiation to ignite energetic materials.

[0004] Currently, a series of materials that can be triggered by lasers and applied to laser ignition have been reported. They mainly include metal coordination compounds, such as Fe(II)-tetrazine complexes (J. Am. Chem. Soc., 2016, 138, 4685-4692), and nano-metal particles, such as aluminum and copper nanoparticles encapsulated with organic dyes (J. Ind. Eng. Chem., 2020, 82, 50-56.), aluminum-magnesium alloy nanoparticles (Propellants Explos. Pyrotech. 2020, 45, 1745-1754.), etc. Some composite materials have also been reported, such as potassium nitrate / carbon nanotube composite materials (Initiators & Pyrotechnics, 2020, (1), 29-33) or surface-porous pentaerythritol tetranitrate explosives doped with nano-metals (Patent Application No. 201810073978.9). The core-shell structured carbon nanotubes encapsulated with potassium nitrate or the nano-metals doped in pentaerythritol tetranitrate explosives can efficiently absorb infrared light for photothermal conversion, provide high temperature for the combustion or explosion of energetic materials, and significantly reduce the near-infrared laser initiation energy of energetic materials.

[0005] However, the reported materials still have the following deficiencies: (1) They cannot effectively utilize near-infrared light with relatively low energy. For example, aluminum and copper nanoparticles encapsulated with organic dyes need to release heat under the irradiation of 445 nm blue light with an intensity of 5.7 W·cm -2 . (2) They have high requirements for lasers, with a high cost for the trigger system and difficulty in miniaturization. For example, Fe(II)-tetrazine complexes and surface-porous pentaerythritol tetranitrate explosives doped with nano-metals require relatively expensive pulsed lasers to provide high-power pulsed lasers for initiation. If a relatively inexpensive near-infrared continuous laser is used, a higher laser power is required. For example, core-shell structured carbon nanotubes need to be triggered by a continuous laser with a maximum output power of 8 W. And aluminum-magnesium alloy nanoparticles need to be initiated under an energy density of 500 W·cm -2 , and the power of the laser used is 1 W. (3) The preparation process is relatively complex, with high energy consumption and high cost in preparation. Therefore, new laser ignition materials with excellent performance and simple preparation are still needed.

[0006] Organic co-crystal materials are crystalline phase materials composed of two or more organic components arranged directionally through non-covalent bond forces. Organic co-crystal materials have the advantages of simple preparation process, low cost, short cycle, etc., and the constructed co-crystals have novel properties such as non-linear optics, optoelectronic properties, photo-induced deformation, and photothermal conversion that small molecule monomers do not have or are difficult to have (Adv. Mater., 2019, 31, 1902328). Most of the reported organic photothermal co-crystals currently cannot provide the high temperature required for laser ignition and have poor thermal stability, unable to meet the requirements of laser ignition. Therefore, applying organic photothermal co-crystal materials to the field of laser ignition is still a great challenge. Summary of the Invention

[0007] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention provides a TMBZ-TXBQ eutectic material, a preparation method thereof, and an application thereof. The TMBZ-TXBQ eutectic material of the present invention can be triggered by a low-power and low-energy near-infrared laser to rapidly release a large amount of heat. Its heat release can be triggered by a commercially available inexpensive small near-infrared continuous laser, significantly reducing the requirements for the laser, effectively reducing the cost, and facilitating the miniaturization of the entire system.

[0008] In the first aspect of the present invention, a TMBZ-TXBQ eutectic material is provided. The TMBZ-TXBQ eutectic material includes an electron donor and an electron acceptor. The electron donor is N,N,N,N-tetramethylbenzidine, and the electron acceptor is a 1,2,4,5-tetrachlorobenzoquinone compound.

[0009] Specifically, the present invention creatively uses a laser to trigger a violent radical polymerization reaction between closely arranged N,N,N,N-tetramethylbenzidine (TMBZ) and 1,2,4,5-tetrachlorobenzoquinone (TXBQ) compounds in an organic eutectic, and provides high temperature to ignite an energetic material by this reaction. This strategy mainly uses the chemical energy of the TMBZ-TXBQ eutectic to provide energy for the ignition of the energetic material.

[0010] In some embodiments of the present invention, the 1,2,4,5-tetrachlorobenzoquinone (TXBQ) compound is one or a mixture of two of tetrachlorobenzoquinone (TCBQ) and tetrabromobenzoquinone (TBBQ).

[0011] In some embodiments of the present invention, the molar ratio of the electron donor to the electron acceptor is 1:1.

[0012] In some embodiments of the present invention, the TMBZ-TXBQ eutectic material is a TMBZ-TCBQ eutectic material or a TMBZ-TBBQ eutectic material.

[0013] In the second aspect of the present invention, a preparation method of the TMBZ-TXBQ eutectic material described in the first aspect of the present invention is provided, and the TMBZ-TXBQ eutectic material is prepared by a solvent evaporation method or a solid-phase method.

[0014] In some embodiments of the present invention, the solvent evaporation method includes the following steps:

[0015] Mix the N,N,N,N-tetramethylbenzidine, the 1,2,4,5-tetrachlorobenzoquinone compound and an organic solvent, ultrasonically dissolve, and volatilize and crystallize to obtain the TMBZ-TXBQ eutectic material.

[0016] In some embodiments of the present invention, the organic solvent includes toluene, acetone or dichloromethane.

[0017] In some embodiments of the present invention, the time for ultrasonic dissolution is 3 - 5 min.

[0018] In some embodiments of the present invention, the solid-phase method includes the following steps:

[0019] Mix the N,N,N,N-tetramethylbenzidine and 1,2,4,5-tetrachloro-p-benzoquinone compound, and grind to obtain the TMBZ-TXBQ eutectic material.

[0020] In some embodiments of the present invention, the grinding time is 10 - 20 min.

[0021] In the third aspect of the present invention, there is provided the use of the TMBZ-TXBQ eutectic material described in the first aspect of the present invention in laser ignition.

[0022] Specifically, the TMBZ-TXBQ eutectic material is used as a light-controlled detonator in the laser ignition of energetic materials.

[0023] Specifically, the TMBZ-TXBQ eutectic material provided by the present invention can be triggered by a near-infrared laser with a low power density (330 mW·cm -2 ), and rapidly release a large amount of heat, providing a high temperature of more than 400 °C. Its use as a light-controlled detonator in the laser ignition of energetic materials is determined by the following factors:

[0024] (1) It can effectively utilize light in the near-infrared band. The present invention uses N,N,N,N-tetramethylbenzidine (TMBZ) as an electron donor, and the sp 3 hybridized N is a strong electron-donating group, so the benzene ring is electron-rich (i.e., the electrostatic potential is negative). On the other hand, 1,2,4,5-tetrachloro-p-benzoquinone (TXBQ) compounds containing strong electron-withdrawing groups are preferably used as electron acceptors, including tetrachloro-p-benzoquinone (TCBQ) and tetrabromo-p-benzoquinone (TBBQ), and their benzene rings are electron-deficient (electrostatic potential is positive). When the above electron donor and electron acceptor are combined, electrons can delocalize from the donor to the acceptor. The two form a charge transfer (CT) state, which broadens the absorption spectrum of the whole system, enabling it to effectively absorb near-infrared light that cannot be utilized by the two monomer components.

[0025] (2) It can effectively perform photothermal conversion. Since there is a strong interaction force between the components forming the eutectic in pairs, after forming the TMBZ-TXBQ eutectic (including the TMBZ-TCBQ and TMBZ-TBBQ eutectics), the stacking pattern of the eutectic is a relatively tight mixed stacking pattern in which TMBZ and the corresponding TXBQ compounds are stacked face to face alternately. When the formed CT complex is oriented and arranged to form a eutectic through intermolecular non-covalent bond forces, it can mainly release the absorbed light energy in the form of non-radiative transitions such as vibrational relaxation, that is, it can effectively perform photothermal conversion and make the crystal heat up efficiently.

[0026] (3) It can undergo an exothermic reaction after heating. In the formed eutectic, charge transfers from TMBZ to the corresponding TXBQ, so both the TXBQ compound and TMBZ exhibit the characteristics of corresponding cationic and anionic free radicals. Both TMBZ and the benzoquinone free radicals have relatively long lifetimes and high reaction activities. In addition, due to the strong intermolecular interaction force between the two components, the TMBZ-TXBQ eutectic has a tight stacking pattern in which TMBZ and TXBQ are stacked face to face alternately, and the distance between TMBZ and TXBQ is relatively short. The formed TMBZ+· and TXBQ-· free radicals can react with each other on the premise of obtaining sufficient energy. Therefore, under the initiation of a laser with a certain power, the TMBZ-TXBQ eutectic material can undergo a rapid and intense free radical coupling polymerization reaction, releasing a large amount of heat energy. Also due to the strong intermolecular interaction force between TMBZ and TXBQ, the electron donor TMBZ and the TXBQ acceptor component tend to self-assemble, so the TMBZ-TXBQ eutectic material can also be easily prepared by a very simple and inexpensive solvent evaporation method or solid phase method.

[0027] It should be noted here that the exothermic process of the TMBZ-TXBQ eutectic material induced by laser involves two processes. First, the eutectic absorbs light energy and undergoes photothermal conversion to generate heat energy, and the temperature of the material itself rises. Then, when the temperature reaches the reaction critical value, a free radical polymerization reaction occurs, and this reaction will release a large amount of heat, which can meet the requirements of laser ignition. Single photothermal conversion cannot provide enough heat energy to ignite energetic materials. At present, most of the reported photothermal eutectics can only perform photothermal conversion and cannot undergo an exothermic reaction, so they cannot be used as initiators for laser ignition.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] The TMBZ-TXBQ eutectic material of the present invention can be irradiated by a laser with a power density of 330 mW·cm -2Triggered by 808nm laser, it can rapidly release a large amount of heat, providing a high temperature exceeding 400°C, thus significantly reducing the requirements for the laser, facilitating the reduction of the cost and miniaturization of the triggering system; it can be very sensitively controlled by the laser, and the relatively high critical temperature ensures its safety. Meanwhile, the exothermic reaction of the TMBZ-TXBQ eutectic material of the present invention can be remotely controlled. After being wrapped by the packaging material, it can still be triggered to release heat by the laser irradiated from the outside. Description of the Drawings

[0030] Figure 1 are the PXRD patterns of TZCQ (a) prepared in Example 1 and TZBQ (b) prepared in Example 2;

[0031] Figure 2 are the comparison of the absorption spectra of TMBZ-TCBQ eutectic with monomers TMBZ and TCBQ (a), and the comparison of the absorption spectra of TMBZ-TBBQ eutectic with monomers TMBZ and TBBQ (b);

[0032] Figure 3 are the crystal structure stacking modes of TMBZ-TCBQ (a) and TMBZ-TBBQ (b); the π-π interaction force between the donor and acceptor of TMBZ-TCBQ (c) and TMBZ-TBBQ (d); the hydrogen bond interaction between the donor and acceptor of TMBZ-TCBQ (e) and TMBZ-TBBQ (f);

[0033] Figure 4 are the temperature changes and pictures of the eutectics after reaction when TZCQ (a) and TZBQ (b) are continuously irradiated by 808nm lasers with three different power densities; the images of the maximum temperatures of TZCQ (c) and TZBQ (d) at different times under continuous irradiation by an 808nm laser with a rated power of 2W;

[0034] Figure 5 are the thermogravimetric (TGA) curves of TMBZ-TCBQ (a) and TMBZ-TBBQ (b) eutectic materials;

[0035] Figure 6 are the molecular structures and pictures of various eutectic materials, where (a) are TMB, TCBQ and TCQ; (b) are TMB, TBBQ and TBQ; the images of the maximum temperatures of TCQ (c) and TBQ (d) at different times under continuous irradiation by an 808nm laser; the morphology diagrams of TZCQ (e), TZBQ (f), TCQ (g) and TBQ (h) after continuous irradiation by an 808nm laser. Detailed Embodiments

[0036] The content of the present invention will be further described in detail through specific embodiments below. Unless otherwise specified, the raw materials, reagents or devices used in the embodiments can be obtained from conventional commercial channels or can be obtained by existing technical methods. Unless otherwise specified, the test or testing methods are all conventional methods in the art.

[0037] Example 1

[0038] The detailed steps for preparing the TMBZ-TCBQ eutectic material by the solvent evaporation method are as follows:

[0039] (1) Mix N,N,N',N'-tetramethylbenzidine (12.0 mg) and tetrachlorobenzoquinone (12.3 mg) and place them in a 20 mL sample bottle.

[0040] (2) Add 14 mL of toluene solvent to the sample bottle and ultrasonically dissolve the mixed sample for 4 minutes at room temperature.

[0041] (3) Seal the sample bottle with a sealing film, then pierce several small holes in the film, and then place the sample bottle in a cool, dry and ventilated place to slowly evaporate and crystallize.

[0042] (4) After the solvent has evaporated for some time, crystals will precipitate on the bottle wall and bottom, and finally a black TMBZ-TCBQ eutectic material can be obtained.

[0043] The detailed steps for preparing the TMBZ-TCBQ eutectic material by the solid-phase method are as follows:

[0044] (1) Mix N,N,N',N'-tetramethylbenzidine (36.0 mg) and tetrachlorobenzoquinone (36.9 mg) to obtain a mixture (in which the mutually contacting TMBZ and TCBQ start to form a dark intermolecular CT complex).

[0045] (2) Transfer the mixture to a mortar and grind it under a certain pressure for 15 min. During this period, the contact between the two components becomes more sufficient, and it promotes the ordered self-assembly of the CT complex in the lowest energy form to form a eutectic. After grinding, the TMBZ-TCBQ eutectic material in powder form can be obtained.

[0046] The TMBZ-TCBQ eutectic materials prepared by the above solvent evaporation method and solid-phase method can be abbreviated as TZCQ.

[0047] Example 2

[0048] The detailed steps for preparing the TMBZ-TBBQ eutectic material by the solvent evaporation method are as follows:

[0049] (1) Mix N,N,N',N'-tetramethylbenzidine (12.0 mg) and tetrabromobenzoquinone (21.2 mg), and place them in a 20 mL sample vial.

[0050] (2) Add 14 mL of toluene solvent to the sample vial, and ultrasonically dissolve the mixed sample for 4 minutes at room temperature;

[0051] (3) Seal the sample vial with a sealing film, then pierce several small holes in the film, and then place the sample vial in a cool, dry, and well-ventilated place to slowly volatilize and crystallize;

[0052] (4) After the solvent has volatilized for some time, crystals will precipitate on the inner wall and bottom of the vial, and finally, a black TMBZ-TBBQ eutectic material can be obtained.

[0053] The detailed steps for preparing the TMBZ-TBBQ eutectic material by the solid-phase method are as follows:

[0054] (1) Mix N,N,N',N'-tetramethylbenzidine (36.0 mg) and tetrabromobenzoquinone (63.6 mg) to obtain a mixture (where the mutually contacting TMBZ and TBBQ start to form a dark-colored intermolecular CT complex);

[0055] (2) Transfer the mixture to a mortar and grind it under a certain pressure for 15 min. During this period, the contact between the two components becomes more sufficient, and it promotes the orderly self-assembly of the CT complex in the form with the lowest energy to form a eutectic. After grinding, the TMBZ-TBBQ eutectic material in powder form can be obtained.

[0056] The TMBZ-TBBQ eutectic materials prepared by the above solvent evaporation method and solid-phase method can be briefly denoted as TZBQ.

[0057] Performance testing

[0058] 1. X-ray powder diffraction test (PXRD)

[0059] Perform X-ray powder diffraction tests on the TZCQ prepared by the solvent evaporation method and the solid-phase method in Example 1, and the results are as Figure 1 (a) shown; perform X-ray powder diffraction tests on the TZBQ prepared by the solvent evaporation method and the solid-phase method in Example 2, and the results are as Figure 1 (b) shown. It can be seen from Figure 1 that the eutectic materials prepared by the solid-phase method all have sharp and clear X-ray diffraction peaks, indicating that the prepared eutectic materials are crystals with long-range order and anisotropy, and have good crystallinity. Moreover, the diffraction peaks of each crystal plane of the powder are in good agreement with the X-ray diffraction peak results of the eutectic single crystal obtained by the solvent evaporation method. This shows that the powder material prepared by the solid-phase method and the crystal material obtained by the solvent evaporation method are the same substance.

[0060] 2. Absorption spectrum test

[0061] The absorption spectrum of the TMBZ-TCBQ eutectic material prepared by the solvent evaporation method in Example 1 is as shown in Figure 2 (a); the absorption spectrum of the TMBZ-TBBQ eutectic material prepared by the solvent evaporation method in Example 2 is as shown in Figure 2 (b). It can be seen from Figure 2 that in the eutectic material, TMBZ shows a strong CT interaction with TCBQ or TBBQ, and electrons can easily migrate from TMBZ to TCBQ or TBBQ for charge separation. This also makes the excited state electron transition energy level of the eutectic become narrow and dense compared with the monomer, and the absorption spectrum of the eutectic broadens from the ultraviolet to the visible region of the monomer to the near-infrared region with a maximum wavelength of 2500 nm.

[0062] 3. Single crystal structure analysis

[0063] The TMBZ-TCBQ eutectic material prepared by the solvent evaporation method in Example 1 has a mixed stacking crystal structure, and the donor and acceptor are stacked face to face. The structure is as shown in Figure 3 (a); the TMBZ-TBBQ eutectic material prepared by the solvent evaporation method in Example 2 has a mixed stacking crystal structure, and the donor and acceptor are stacked face to face. The structure is as shown in Figure 3 (b). There is a donor-acceptor π-π interaction with a distance of in TMBZ-TCBQ, as shown in Figure 3 (c); there is a donor-acceptor π-π interaction with a distance of in TMBZ-TBBQ, as shown in Figure 3 (d). For TMBZ-TCBQ, there are hydrogen bonds between the donor and acceptor, where the hydrogen atom on the N,N-dimethyl of the donor TMBZ and the O atom on the carbonyl group of the acceptor have a distance of , as shown in Figure 3 (e); for TMBZ-TBBQ, there are hydrogen bonds between the donor and acceptor, where the hydrogen atom on the N,N-dimethyl of the donor TMBZ and the O atom on the carbonyl group of the acceptor have a distance of , as shown in Figure 3 (f).

[0064] 4. Test of heat release during the reaction under 808 nm laser irradiation

[0065] Two TMBZ-TXBQ eutectic materials (TZCQ and TZBQ eutectic) obtained by the solvent evaporation method in Example 1 and Example 2 were tested. When the TMBZ-TXBQ eutectic is irradiated with a near-infrared laser, TMBZ-TXBQ first undergoes photothermal conversion, efficiently converting near-infrared light energy into thermal energy to heat the crystal. After the crystal reaches the critical temperature, a rapid exothermic reaction occurs, releasing heat violently. 310 mW·cm -2 、320mW·cm -2 and 330mW·cm -2 The TMBZ-TXBQ eutectic was irradiated with 808 nm laser and found that the -2 、320mW·cm -2 No thermal polymerization reaction occurred under the laser power of 330 mW·cm -2 When the temperature of TZCQ and TZBQ reached 114℃ and 125℃ respectively after 1 minute of laser irradiation, a dramatic temperature rise process occurred, and the substances formed after the reaction expanded relative to the eutectic. The temperature change of this process was measured using an infrared thermal imaging camera, and a time-temperature curve was drawn based on it, as shown in the figure. Figure 4 (a) and Figure 4 (b) As shown; it can be seen from the figure that the heat release of both eutectics is very rapid and can reach a high temperature of more than 250°C, especially the TZBQ eutectic, with a maximum temperature of more than 300°C.

[0066] In order to explore the highest temperature generated by the thermal polymerization of TZCQ and TZBQ, a laser with a rated power of 2W was used to directly irradiate the sample. It was found that the temperature of the TZCQ eutectic reached more than 400°C within 2 seconds, exceeding the detection temperature of the infrared camera, while the TZBQ eutectic exceeded 400°C in about 5 seconds. The results are as follows Figure 4 (c) and Figure 4 As shown in (d), this result indicates that the TMBZ-TXBQ eutectic material has unique thermal polymerization properties.

[0067] 5. Thermogravimetric (TGA) curve

[0068] Example 1 Thermogravimetric analysis of TMBZ-TCBQ eutectic material prepared by solvent evaporation method Figure 5 (a) As shown; Thermogravimetric analysis of TMBZ-TBBQ eutectic material prepared by solvent evaporation method in Example 2 is as shown Figure 5 (b) as shown; Figure 5 It can be seen that the critical temperatures for thermal decomposition are 117°C and 136°C, which basically correspond to the lowest temperature of its thermal polymerization reaction. This is also the safety threshold for heat release of this type of eutectic, that is, only when the temperature of the crystal reaches or exceeds this critical temperature can the rapid heat release of TMBZ-TXBQ eutectic be triggered.

[0069] 6. Feasibility of Laser Ignition Application

[0070] From Figure 4 It can be seen that since the TMBZ-TXBQ reaction is initiated by heating up and releases a large amount of heat during the reaction, the reaction of a small part of the eutectic can trigger the reaction of the surrounding samples, that is, the reaction has the property of self-propagation. Since the near-infrared laser only needs to heat up a small part of the material to the reaction critical temperature, and thanks to the excellent near-infrared photothermal conversion performance of the TMBZ-TXBQ eutectic, the exothermic reaction of the TMBZ-TXBQ eutectic can be triggered with low-power laser at extremely low input energy. Therefore, the use of low-power laser can significantly reduce the cost of the laser light source and its corresponding power supply, is conducive to the miniaturization of the overall system, and significantly improves the performance-price ratio and portability of the laser ignition system.

[0071] Since the exothermic processes of the two TMBZ-TXBQ eutectic materials (TMBZ-TCBQ and TMBZ-TBBQ eutectics) can be triggered by low-power, low-energy near-infrared lasers, the controllable heat release of such eutectics can be triggered very sensitively. At the same time, the critical temperatures of the exothermic reactions of TMBZ-TCBQ and TMBZ-TBBQ eutectics need to reach 114 °C and 125 °C respectively, so the thermal stability is good. If a single-point propagation laser is used, two TMBZ-TXBQ eutectics can be remotely detonated at a distance. In addition, under the initiation of low-power laser, the heat release of the TMBZ-TXBQ eutectic can also reach above 250 °C. Especially for the TMBZ-TBBQ eutectic, the heat release can reach above 300 °C, which basically meets the thermal detonation conditions of the common energetic materials listed in Table 1 below. Therefore, TMBZ-TXBQ is very promising to be used as a photo-controlled detonator in the laser ignition of energetic materials.

[0072] Table 1 Thermal Detonation Critical Temperatures of Common Energetic Materials

[0073]

[0074] 7. Uniqueness of TMBZ-TXBQ Eutectic as a Laser Ignition Material

[0075] Currently, many eutectic materials with excellent photothermal properties have been reported. However, there is no report on eutectic materials that can be triggered by low-power, low-energy near-infrared lasers and release a large amount of heat like the TMBZ-TXBQ of the present invention. This is because most photothermal eutectics cannot undergo thermal polymerization reactions, and the heat generated only by non-radiative transition is not sufficient to ignite energetic materials. The present invention selects the isomers TMB of TMBZ and TXBQ, and prepares two eutectics, TCQ and TBQ, by the solvent evaporation method respectively, as Figure 6 (a) and Figure 6(b). Similarly, 808 nm lasers with a rated power of 2 W were used to directly irradiate TCQ and TBQ. It was found that within 2 seconds, the maximum temperature that TCQ and TBQ could reach was only 150 °C, as shown in Figure 6 (c) and Figure 6 (d), which is much lower than that of TZCQ and TZBQ prepared by the present invention. The reason is that the TMB molecules and TXBQ molecules in the eutectic of TCQ and TBQ cannot undergo free radical coupling polymerization reactions, so the heat released is less than that of TZCQ and TZBQ. In addition, Figure 6 (e - h) respectively show the morphologies of TZCQ, TZBQ, TCQ, and TBQ after continuous irradiation with an 808 nm laser. After comparison, it is not difficult to find that due to the polymerization reaction occurring under laser initiation, the overall substances after the reaction of TZCQ and TZBQ show swelling, while only holes left after laser irradiation can be found locally in TCQ and TBQ, indicating that no thermal polymerization reaction has occurred in both materials.

[0076] In summary, the TMBZ - TXBQ eutectic designed by the present invention has characteristics that most photothermal eutectics do not have, that is, it can undergo a thermal polymerization reaction under laser initiation and release a large amount of heat, sufficient to ignite common energetic materials, and it is an extremely innovative laser ignition material.

[0077] The above has specifically described the preferred embodiments of the present invention, but the present invention is not limited to the described embodiments. Those skilled in the art can also make various equivalent variations or substitutions without departing from the spirit of the present invention, and these equivalent variations or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A TMBZ-TXBQ eutectic material, characterized in that, The TMBZ-TXBQ eutectic material includes an electron donor and an electron acceptor. The electron donor is N,N,N,N-tetramethylbenzidine, and the electron acceptor is a 1,2,4,5-tetrachloro-p-benzoquinone compound.

2. The TMBZ-TXBQ eutectic material according to claim 1, wherein The 1,2,4,5-tetrachloro-p-benzoquinone compound is one or a mixture of two of tetrachloro-p-benzoquinone and tetrabromo-p-benzoquinone.

3. The TMBZ-TXBQ eutectic material according to claim 1, wherein The molar ratio of the electron donor to the electron acceptor is 1:

1.

4. The preparation method of the TMBZ-TXBQ eutectic material according to any one of claims 1-3, characterized in that, The TMBZ-TXBQ eutectic material is prepared by a solvent evaporation method or a solid-phase method.

5. The preparation method according to claim 4, characterized in that, The solvent evaporation method includes the following steps: Mix the N,N,N,N-tetramethylbenzidine, the 1,2,4,5-tetrachloro-p-benzoquinone compound and an organic solvent, ultrasonically dissolve, and volatilize and crystallize to obtain the TMBZ-TXBQ eutectic material.

6. The preparation method according to claim 5, characterized in that, The organic solvent includes toluene, acetone or dichloromethane.

7. The preparation method according to claim 4, characterized in that, The solid-phase method includes the following steps: Mix the N,N,N,N-tetramethylbenzidine and the 1,2,4,5-tetrachloro-p-benzoquinone compound, and grind to obtain the TMBZ-TXBQ eutectic material.

8. The preparation method according to claim 7, characterized in that, The grinding time is 10-20 min.

9. Application of the TMBZ-TXBQ eutectic material according to any one of claims 1-3 in laser ignition.

10. The application according to claim 9, characterized in that, The TMBZ-TXBQ eutectic material is used as a light-controlled detonator in the laser ignition of energetic materials.

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