Green high-energy high-temperature-resistant energetic metal organic framework material and preparation method thereof

Abstract

The invention relates to a green high-energy high-temperature-resistant energetic metal organic framework material and a preparation method thereof, the energetic metal organic framework material comprises: the structural formula of the energetic metal organic framework material is [Cu2L2] n, the energetic metal organic framework material is a three-dimensional metal organic framework compound constructed by binuclear copper (I) and mu4-L ligands, and the ligand L comprises 5-[4-(1 imidazolyl) phenyl]-2H-tetrazole. The energetic metal organic framework material has abundant supramolecular actions such as strong coordination bonds and strong pi-pi accumulation, has higher decomposition temperature and higher thermal stability, has equivalent detonation velocity and detonation pressure, higher decomposition temperature and detonation heat and lower friction sensitivity and impact sensitivity compared with traditional TNT, RDX and HMX, is not sensitive to external stimulation, and can be used for preparing a high-energy-density metal organic framework material. Explosive products are free of pollution, the energy-containing material is a novel green high-energy high-temperature-resistant energy-containing material, and the limitation of a traditional energy-containing compound on balance of energy, safety and environmental protection is broken through.

Description

Technical Field

[0001] This invention belongs to the field of energetic materials technology, specifically relating to a green, high-energy, high-temperature resistant energetic metal-organic framework material and its preparation method. Background Technology

[0002] Energetic materials, as the core carriers for energy release and power propulsion, directly determine the efficiency and safety of related equipment. Although traditional energetic compounds (such as TNT, RDX, and HMX) have achieved industrial applications, they have revealed irreconcilable technical pain points in long-term practice, and there is an urgent need for new energetic systems to break through performance bottlenecks.

[0003] Traditional energetic compounds mostly rely on intramolecular energetic groups such as nitro groups (-NO2) to store energy and release detonation energy through the breaking of chemical bonds. However, these compounds have three major drawbacks: First, it is difficult to balance energy and safety: to improve detonation performance such as detonation velocity and detonation pressure, it is necessary to increase the number of nitro groups or optimize molecular density, but this will significantly increase the sensitivity of the material to external stimuli such as friction and impact. For example, the impact sensitivity of RDX is 8J, which can easily cause accidental explosions during transportation and use. Second, insufficient thermal stability: most traditional energetic compounds have a decomposition temperature below 300℃ (such as the decomposition temperature of TNT, which is about 240℃). They are prone to thermal decomposition in high-temperature environments (such as engine compartments and high-temperature battlefields), resulting in premature energy release or structural failure. Third, poor environmental compatibility: some detonators (such as lead azide and lead stethonitrile) will produce pollutants such as lead ions and nitrophenol after detonation. Long-term accumulation will damage the soil and water ecology, and the highly toxic raw materials used in the synthesis process (such as azides) pose serious safety hazards.

[0004] Therefore, how to overcome the limitations of traditional energetic compounds in balancing energy, safety, and environmental protection to meet the needs of next-generation equipment for high-performance energetic materials has become an urgent problem to be solved. Summary of the Invention

[0005] To address the aforementioned problems in the existing technology, this invention provides a green, high-energy, high-temperature resistant energetic metal-organic framework material, its preparation method, and its applications. The technical problem to be solved by this invention is achieved through the following technical solution: This invention provides a green, high-energy, high-temperature resistant energetic metal-organic framework material, comprising: the energetic metal-organic framework material having the structural formula: [Cu2L2] n A three-dimensional metal-organic framework compound is formed by constructing a binuclear copper (I) unit and a μ4-L ligand, wherein the L ligand includes 5-[4-(1-imidazolyl)phenyl]-2H-tetrazole.

[0006] In one embodiment of the present invention, the energetic metal-organic framework material belongs to the monoclinic crystal system with space group P21 / c The unit cell parameters are a= 19.2760 Å, b = 10.4530 Å, c = 9.4213 Å, α = 90°, β = 93.981°, γ = 90°, crystal size is 0.22 × 0.18 × 0.17 mm. 3 The unit cell volume is 1893.74 Å. 3 The number of molecules in the unit cell is 4.

[0007] In one embodiment of the present invention, the minimum repeating unit in the energetic metal-organic framework material structure contains 2 Cu(I) and 2 ligands L; Each Cu(I) center is bonded to N atoms from four different ligands L, forming an approximately tetrahedral coordination geometry. The bond length of the Cu-N bond and the N-Cu-N bond angle vary from 1.990 Å to 2.171 Å and 98.67° to 124.62°, respectively.

[0008] In one embodiment of the present invention, in the metal-organic framework material structure, the ligand L exhibits the same μ4 bridging mode to connect four Cu(I) units, and the binuclear Cu(I) units are interconnected to form a strip structure; when Cu(I) and L ligand are regarded as 3-connection nodes and 4-connection nodes respectively, the strip structure extends to form a two-dimensional layered structure parallel to the b-axis; Adjacent Cu(I) extend in four directions through bridging, forming a three-dimensional network structure.

[0009] In one embodiment of the present invention, in the three-dimensional network structure, all Cu(I) and ligand L are regarded as 4-connection nodes, and the three-dimensional network structure is simplified to a topology with topology symbol 4².6³.8 and topology type SrAl2.

[0010] Another embodiment of the present invention provides a method for preparing a green, high-energy, high-temperature resistant energetic metal-organic framework material, used to prepare the green, high-energy, high-temperature resistant energetic metal-organic framework material described in the above embodiment, comprising the following steps: Weigh out ligand 5-[4-1(1-imidazolyl)phenyl]-2H-tetrazole and Cu(NO3)2·3H2O and add them to the reaction vessel. Use N,N-dimethylformamide as solvent and HCl solution as pH adjuster. Stir at room temperature for a period of time, then transfer the reaction vessel to an environment with a preset temperature and react for a preset time. After the reaction is complete, the reaction product is cooled at a preset rate until it reaches room temperature to obtain an energetic material.

[0011] In one embodiment of the present invention, the molar ratio of the ligand 5-[4-1(1-imidazolyl)phenyl]-2H-tetrazole to Cu(NO3)2·3H2O is 1:(2~3); The volume ratio of N,N-dimethylformamide to HCl solution is 40:3.

[0012] In one embodiment of the present invention, the HCl solution comprises 0.1 mol·L⁻¹ -1 HCl solution.

[0013] In one embodiment of the present invention, the volume of the HCl solution is 0.9 mL, and the volume of the N,N-dimethylformamide is 12 mL.

[0014] In one embodiment of the present invention, the preset temperature includes 120°C, and the preset time includes 48 hours; The preset rate includes 5℃·h -1 .

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The energetic metal-organic framework material of the present invention is a three-dimensional metal-organic framework compound constructed from binuclear copper (I) units and μ4-L. The three-dimensional metal-organic framework contains abundant strong coordination bonds and strong π-π stacking supramolecular interactions, resulting in a high decomposition temperature and high thermal stability. Compared with traditional TNT, RDX, and HMX, it has comparable detonation velocity and detonation pressure, higher decomposition temperature and detonation heat, lower friction sensitivity and impact sensitivity, is insensitive to external stimuli, and produces no pollution from explosion products. It is a novel green, high-energy, high-temperature resistant energetic material that breaks through the limitations of traditional energetic compounds in terms of energy, safety, and environmental protection balance. 2. The synthesis method of the energetic metal-organic framework material of the present invention is simple, with high synthesis yield, and the post-processing only requires filtration, without recrystallization and complicated purification processes, making it easy to industrialize. Attached Figure Description

[0016] Figure 1 A schematic diagram of the smallest repeating unit of the green, high-energy, high-temperature resistant energetic metal-organic framework (EMOF) material provided in the embodiments of the present invention; Figure 2 Coordination environment diagram of Cu(I) in the green, high-energy, high-temperature resistant energetic metal-organic framework material provided in the embodiments of the present invention; Figure 3 A one-dimensional structural diagram of the green, high-energy, high-temperature resistant energetic metal-organic framework material provided in the embodiments of the present invention; Figure 4 A two-dimensional layered structure diagram of the green, high-energy, high-temperature resistant energetic metal-organic framework material provided in the embodiments of the present invention; Figure 5 A three-dimensional framework structure diagram of the green, high-energy, high-temperature resistant energetic metal-organic framework material provided in the embodiments of the present invention; Figure 6 The topological structure diagram of the green, high-energy, high-temperature resistant energetic metal-organic framework material provided in the embodiments of the present invention; Figure 7 The PXRD spectra of energetic metal-organic framework materials are shown. The PXRD spectra are compared with those obtained from EMOF experimental samples and single-crystal structure simulations. Figure 8 XPS spectra of energetic metal-organic framework materials; Figure 9 The thermal stability analysis curves for EMOF are shown. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0018] Example 1 Please see Figures 1-6 , Figure 1 This is a schematic diagram of the smallest repeating unit of the green, high-energy, high-temperature resistant energetic metal-organic framework (EMOF) material provided in an embodiment of the present invention. Figure 2 This is a coordination environment diagram of Cu(I) in the green, high-energy, high-temperature resistant energetic metal-organic framework material provided in the embodiments of the present invention. Figure 3 This is a one-dimensional structural diagram of the green, high-energy, high-temperature resistant energetic metal-organic framework material provided in the embodiments of the present invention. Figure 4 This is a two-dimensional layered structure diagram of the green, high-energy, high-temperature resistant energetic metal-organic framework material provided in the embodiments of the present invention. Figure 5 This is a three-dimensional framework structure diagram of the green, high-energy, high-temperature resistant energetic metal-organic framework material provided in an embodiment of the present invention. Figure 6 The diagram shows the topological structure of the green, high-energy, high-temperature resistant, energetic metal-organic framework material provided in the embodiments of the present invention, wherein gray represents μ4-L ligands, bright blue represents Cu(I), and blue represents N atoms.

[0019] The structural formula of the green, high-energy, high-temperature resistant energetic metal-organic framework material provided in this invention embodiment is: [Cu2L2] n A three-dimensional metal-organic framework (MOF) compound is formed by constructing a binuclear copper (I) and a μ4-L ligand, wherein the L ligand includes 5-[4-(1-imidazolyl)phenyl]-2H-tetrazole.

[0020] Please combine Figures 1-6 Tables 1, 2, and 3 are provided. Table 1 is a table of crystallographic parameters of energetic metal-organic framework materials, Table 2 is a table of partial bond lengths of energetic metal-organic framework materials, and Table 3 is a table of partial bond angles of energetic metal-organic framework materials.

[0021] Specifically, X-ray single-crystal diffraction analysis revealed that the energetic metal-organic framework material belongs to the monoclinic crystal system, with space group P 21 / c The unit cell parameters are a= 19.2760 Å, b=10.4530 Å, c=9.4213 Å, α=90°, β=93.981°, γ=90°, crystal size is 0.22×0.18×0.17 mm. 3 The unit cell volume is 1893.74 Å. 3 The number of molecules per unit cell is 4, as shown in Table 1.

[0022] The smallest repeating unit in the structure of energetic metal-organic frameworks contains two Cu(I) atoms (Cu1 and Cu2) and two ligands L. Each Cu(I) center is bonded to N atoms from four different ligands L, forming an approximately tetrahedral coordination geometry, such as... Figure 2 As shown in Table 2, the bond length of Cu-N bond and the N-Cu-N bond angle vary from 1.990(2) to 2.171(2) Å and 98.67(12)° to 124.62(10)°, respectively.

[0023] The L ligand exhibits the same μ4 bridging mode to connect the four Cu(I) units, which differs from previous literature descriptions of L ligands exhibiting only monodentate or bidentate bridging coordination modes. The binuclear Cu(I) units interconnect to form a banded structure, such as... Figure 3 As shown. When Cu(I) and L ligands are considered as 3-connecting nodes and 4-connecting nodes, respectively, the banded structure further extends to form a two-dimensional layered structure parallel to the b-axis, as shown. Figure 4 As shown, adjacent Cu(I) atoms extend in four directions through bridging, forming a three-dimensional network structure, as illustrated. Figure 5 As shown. In topological analysis, all Cu(I) centers and L ligands are considered as four-connected nodes, and the 3D framework of EMOF can be simplified to a topology of four-connected SrAl2, with the topological notation 4. 2 0.6 3 0.8, such as Figure 6 As shown.

[0024] Table 1 Crystallographic parameters of energetic metal-organic framework materials

[0025] In Table 1, aα, β, and γ are the core parameters describing the geometry of the unit cell; α, β, and γ are the angles between crystal axes; V is the unit cell volume; Z is the number of chemical units in the unit cell; ρ is the density; F(000) is the structure factor; and μ is the linear absorption coefficient. h, k, and l are crystal plane indices, a set of integers used to uniquely identify a family of parallel crystal planes in a crystal, and are key parameters describing the crystal microstructure and diffraction phenomena. "Reflections collected / unique" refers to the total number of diffraction points collected / the number of unique diffraction points. The former is the total number of diffraction signals actually recorded in the experiment, and the latter is the number of unique diffraction points after removing redundancy. Both reflect the completeness and quality of the diffraction data. R int. The consistency factor, representing the integral intensity of diffraction points, is used to evaluate the degree of agreement between repeated measurements of intensity from the same family of crystal planes (equivalent diffraction points). It is one of the key indicators for judging the quality of diffraction data. Data / Restraints / Parameters refers to data points / constraints / refinement parameters, which are three core indicators. They collectively reflect the rationality and reliability of structural refinement, and the quantitative relationship among them directly affects the credibility of the refinement results. GOF on F 2 Goodness of fit is a key indicator that measures the degree of agreement between the calculated crystal structure model and the experimental diffraction data (based on F², i.e., the square of the diffraction intensity), and directly reflects the reliability of the refinement results. The value of GOF on F² should be close to 1.0 (usually between 0.8 and 1.2), which indicates that the calculated model fits the experimental data very well and the structural analysis results are reliable.

[0026] R1[I>2σ(I)] is the R1 factor for observed intensity greater than twice the standard deviation. Specifically, it refers to the residual factor calculated only for strong diffraction points where the observed intensity I is greater than twice the standard deviation σ(I). R1[I>2σ(I)] is a core indicator for evaluating refinement quality. The smaller the value, the better the calculated value of the strong diffraction point matches the experimental value. Generally, a high-quality structure should have a value ≤0.05 (5%). wR2 [I>2σ(I)] is a weighted R2 factor for observed intensity greater than 2 standard deviations. It is also based on strong diffraction points with "[I>2σ(I)]", but introduces a residual factor with a weighting factor (related to diffraction intensity error), which focuses more on the fitting quality of weak diffraction points. The value should be ≤0.15 (15%). It works together with R1 to reflect the overall fitting effect of strong diffraction points.

[0027] R1 (all data) is the R1 factor for all data, which includes the residual factor calculated from all collected independent diffraction points (regardless of intensity or whether I>2σ(I)). Because it includes weak diffraction points (with larger errors), its value is usually greater than R1[I>2σ(I)], used to comprehensively evaluate the fit of all data and avoid missing information from weak diffraction points.

[0028] wR2 (all data) is the weighted R2 factor for all data. It is a weighted residual factor calculated based on all independent diffraction points, and also introduces a weight factor. The value is generally greater than wR2 [I>2σ(I)], which can more comprehensively reflect the fit between all diffraction data (including weak diffraction points) and the structural model. It is an important indicator for supplementing the evaluation of refinement quality.

[0029] Among them, R1 and wR of [I>2σ(I)] are the core evaluation indicators, and we should first check whether these two values ​​are within a reasonable range. R1 and wR2 of (all data) are used for auxiliary judgment. If they differ too much from the value of [I>2σ(I)], it may indicate that the data quality of weak diffraction points is poor and needs to be optimized.

[0030] The largest diff. peak and hole reflect local electron density anomalies in the crystal electron density map that are not explained by the model. They are important auxiliary indicators for evaluating the integrity of structural refinement and the rationality of the model.

[0031] Table 2. Partial bond lengths of energetic metal-organic framework materials

[0032] Table 3. Partial Bond Angle Table of Energetic Metal-Organic Frameworks

[0033] In Table 3, the following symbols represent the symmetry transformations used to generate equivalent atoms: #1 -x+2,-y+1,-z+2; #2 -x+2,y-1 / 2,-z+3 / 2; #3 -x+1,y+1 / 2,-z+1 / 2; #4 -x+1,-y+1,-z; #5 -x+2,y+1 / 2,-z+3 / 2; #6 -x+1,y-1 / 2,-z+1 / 2.

[0034] Example 2 Based on Example 1, this example provides a method for preparing a green, high-energy, high-temperature resistant energetic metal-organic framework material, which is used to prepare the energetic metal-organic framework material of Example 1.

[0035] The preparation method of the green, high-energy, high-temperature resistant energetic metal-organic framework material in this embodiment includes the following steps: The ligand 5-[4-1(1-imidazolyl)phenyl]-2H-tetrazole and Cu(NO3)2·3H2O were weighed and added to a reaction vessel. N,N-dimethylformamide was used as the solvent and HCl solution was used as the pH adjuster. After stirring at room temperature for a period of time, the reaction vessel was transferred to an environment with a preset temperature and reacted for a preset time. After the reaction was completed, the reaction product was cooled at a preset rate until it cooled to room temperature to obtain the energetic material.

[0036] Specifically, the molar ratio of ligand 5-[4-1(1-imidazolyl)phenyl]-2H-tetrazole to Cu(NO3)2·3H2O is 1:(2~3); the volume ratio of N,N-dimethylformamide to HCl solution is 40:3.

[0037] For example, the HCl solution comprises 0.1 mol·L⁻¹ -1 The HCl solution has a volume of 0.9 mL; the N,N-dimethylformamide has a volume of 12 mL; the preset temperature includes 120 °C; the preset time includes 48 h; and the preset rate includes 5 °C·h. -1 .

[0038] To facilitate understanding of the present invention, examples and comparative examples are provided below. Those skilled in the art should understand that these examples are merely illustrative and should not be construed as limiting the scope of the invention.

[0039] Example 1 A highly stable energetic metal-organic framework (EMOF) material was synthesized using a solvothermal method. The specific steps are as follows: using 5-[4-1(1-imidazolyl)phenyl]-2H-tetrazole as a ligand (HL), according to... n HL : n Cu(NO3)2·3H2O Accurately weigh HL (0.0361 g, 0.17 mmol) and Cu(NO3)2·3H2O (0.1230 g, 0.51 mmol) in a 1:3 ratio and add them to a 25 mL polytetrafluoroethylene reactor. Then, add 12 mL of N,N-dimethylformamide (DMF) and 0.9 mL of 0.1 mol·L⁻¹. -1 Using HCl solution as a solvent, the mixture was stirred at room temperature for 1 hour, then the reactor was transferred to an oven at 120°C for 48 hours. After the reaction was completed, the temperature was increased by 5°C per hour. -1 The cooling rate was adjusted to allow the crystals to cool to room temperature, resulting in gray blocky crystals with a yield of 85%.

[0040] Example 2 according to n HL : n Cu(NO3)2·3H2OWeigh HL (0.0361 g, 0.17 mmol) and Cu(NO3)2·3H2O (0.0825 g, 0.34 mmol) in a ratio of 1:2. Under the same conditions as in Example 1, the product was prepared.

[0041] Comparative Example 1 Adjust the ratio of ligand to copper salt in Example 1: Accurately weigh two portions of HL (0.0361 g, 0.17 mmol each), add them separately to two 25 mL PTFE reactors, and then proceed as follows: n HL : n Cu(NO3)2·3H2O Weigh out Cu(NO3)2·3H2O (0.1648 g, 0.68 mmol) in a ratio of 1:4, and then... n HL : n Cu(NO3)2·3H2O Weigh out Cu(NO3)2·3H2O (0.2050 g, 0.85 mmol) in a ratio of 1:5 and add it to two separate reaction vessels. Add 12 mL of N,N-dimethylformamide (DMF), 0.9 mL of 0.1 mol·L⁻¹, and 0.9 mL of 0.1 mol·L⁻¹. - 1 Using HCl solution as a solvent, the mixture was stirred at room temperature for 1 hour, then the reactor was transferred to an oven at 120°C for 48 hours. After the reaction was completed, the temperature was increased by 5°C per hour. -1 The cooling rate is adjusted to cool the product to room temperature.

[0042] Through Examples 1-2 and Comparative Example 1, it was found that: when the molar ratio of ligand HL to Cu(NO3)2·3H2O was 1:2, a small amount of fine gray blocky crystals were obtained, with a yield of 20%; when the molar ratio of ligand HL to Cu(NO3)2·3H2O was 1:3, a larger amount of gray blocky crystals were obtained, and the quality of the crystals was relatively high and the crystals were relatively regular, with a yield of 85%; when the molar ratio of ligand HL to Cu(NO3)2·3H2O was 1:4-5, a large amount of grayish-white solid powder was obtained, and no crystals were observed. Therefore, it can be seen that... n HL : n Cu(NO3)2·3H2O EMOFs can be prepared when the ratio is 1:(2~3), preferably... n HL : n Cu(NO3)2·3H2O The yield is highest and the quality is better when the ratio is 1:3.

[0043] Comparative Example 2 Adjust the ratio of ligand to different copper salts in Example 1: Accurately weigh two portions of HL (0.0361 g, 0.17 mmol each) and add them to two 25 mL polytetrafluoroethylene reaction vessels. Weigh different copper salts: CuCl2 (0.0687 g, 0.51 mmol) and Cu(CH3COO)2 (0.0928 g, 0.51 mmol). Add these to the two reaction vessels separately, using 12 mL of N,N-dimethylformamide (DMF), 0.9 mL of 0.1 mol·L⁻¹, and 0.1 mol·L⁻¹. -1 Using HCl solution as a solvent, the mixture was stirred at room temperature for 1 hour, then the reactor was transferred to an oven at 120°C for 48 hours. After the reaction was completed, the temperature was increased by 5°C per hour. -1 The cooling rate is adjusted to cool the product to room temperature.

[0044] Through Example 1 and Comparative Example 2, it was found that after HL reacts with CuCl2 under these conditions, no crystals are formed, and the solution remains a clear green solution. However, after HL reacts with Cu(CH3COO)2 under these conditions, a small amount of blue powder is formed, and no crystals are formed. Therefore, the optimal choice for the copper salt is Cu(NO3)2·3H2O.

[0045] Comparative Example 3 Adjust the type of pH adjuster acid in Example 1: Accurately weigh two portions of HL (0.0361 g, 0.17 mmol each) and Cu(NO3)2·3H2O (0.1230 g, 0.51 mmol) and add them separately to two 25 mL polytetrafluoroethylene reaction vessels. Then, add 12 mL of N,N-dimethylformamide (DMF) to each reaction vessel, followed by 0.9 mL of 0.1 mol·L⁻¹ solution. -1 HNO3, 0.1 mol·L -1 HCOOH was added to two separate reaction vessels, and the mixture was stirred at room temperature for 1 hour. The reaction vessels were then transferred to an oven at 120°C and reacted for 48 hours. After the reaction was complete, the mixture was dried at 5°C per hour. -1 The cooling rate is adjusted to cool the product to room temperature.

[0046] Example 1 and Comparative Example 3 show that using 0.9 mL of 0.1 mol·L⁻¹ -1 When the acidity of the reaction system was adjusted with HCl, the yield of grayish-white blocky crystals was 85%, and no powder was formed; using 0.9 mL of 0.1 mol·L⁻¹ HCl… -1 When HNO3 was used to adjust the acidity of the reaction system, a small amount of white powder appeared in the solution, with no crystals; 0.9 mL of 0.1 mol·L⁻¹ HNO₃ was used. - 1 When HCOOH is used to adjust the acidity of the reaction system, no crystals are formed, and the solution is a clear, light blue color. Therefore, 0.9 mL of 0.1 mol·L⁻¹ solution...-1 HCl is the optimal reaction condition.

[0047] Comparative Example 4 Adjust the amount of pH adjuster HCl in Example 1: Accurately weigh four portions of HL (0.0361 g, 0.17 mmol each) and Cu(NO3)2·3H2O (0.1230 g, 0.51 mmol) and add them to four separate 25 mL polytetrafluoroethylene reaction vessels. Add 12 mL of N,N-dimethylformamide (DMF) to the reaction vessel, and then add 0.3 mL, 0.6 mL, 1.2 mL, and 1.5 mol·L⁻¹ of HCl respectively. -1 HCl was added to four reaction vessels, and the mixture was stirred at room temperature for 1 hour. The reaction vessels were then transferred to an oven at 120°C and reacted for 48 hours. After the reaction was completed, the mixture was dried at 5°C per hour. -1 The cooling rate is adjusted to cool the product to room temperature.

[0048] Examples 1 and 4 show that using 0.3 mL and 0.6 mL of 0.1 mol·L⁻¹ -1 When the acidity in the reaction system is adjusted with HCl, a small amount of white powder is generated, accompanied by a very small amount of fine crystals, which are difficult to separate; using 0.9 mL of 0.1 mol·L⁻¹... -1 The yield of grayish-white blocky crystals formed in HCl was 85%, with no powder formation; 1.2 mL and 1.5 mL of 0.1 mol·L⁻¹ -1 After HCl is added to the system, the product after the reaction is complete is a small amount of white powder, with no crystals formed. Therefore, 0.9 mL of 0.1 mol·L⁻¹ solution... -1 HCl is the best choice.

[0049] Comparative Example 5 Adjust the solvent types in Example 1: Accurately weigh three portions of HL (0.0361 g, 0.17 mmol each) and Cu(NO3)2·3H2O (0.1230 g, 0.51 mmol) and add them to three 25 mL polytetrafluoroethylene reaction vessels respectively. Then, add 12 mL of acetonitrile (CH3CN), water (H2O), and N,N-dimethylformamide (DMA) to the three reaction vessels in sequence. Finally, add 0.9 mL of 0.1 mol·L⁻¹ solution to each reaction vessel. -1 HCl was added and stirred at room temperature for 1 hour, then the reactor was transferred to an oven at 120°C and reacted for 48 hours. After the reaction was completed, the temperature was increased by 5°C per hour. -1 The cooling rate is adjusted to cool the product to room temperature.

[0050] Based on Example 1 and Comparative Example 5, we found that: when using acetonitrile as a solvent, a small amount of white powder appeared in the system, with no crystals formed; when using water as a solvent, due to the solubility of HL in water, the reaction initially presented as a suspension, but after the reaction, a large amount of white powder was formed in the solution, with no crystals formed; when using DMF as a solvent, the product was grayish-white blocky crystals, with no powder formation, and the yield was 85%; when using DMA as a solvent, the reaction resulted in a light blue transparent solution, with no crystalline product formed. Therefore, DMF is the optimal solvent.

[0051] Comparative Example 6 Adjust the reaction temperature in Example 1: Accurately weigh 3 portions of HL (0.0361 g, 0.17 mmol each) and Cu(NO3)2·3H2O (0.1230 g, 0.51 mmol) into a 25 mL polytetrafluoroethylene reactor, and add 12 mL of N,N-dimethylformamide (DMF) and 0.9 mL of 0.1 mol·L⁻¹ -1 Using HCl solution as a solvent, the mixture was stirred at room temperature for 1 hour, and then the reaction vessel was transferred to ovens at 100, 140, and 160°C for 48 hours respectively. After the reaction was completed, the mixture was dried at 5°C / h. -1 The cooling rate is adjusted to cool the product to room temperature.

[0052] Based on Example 1 and Comparative Example 6, it was found that: after HL reacts with Cu(NO3)2·3H2O at 100℃, no crystals are formed, and the solution remains a clear yellow solution; after HL reacts with Cu(NO3)2·3H2O at 120℃, the crystal yield is 85%, and no powder is formed; after HL reacts with Cu(NO3)2·3H2O at 140℃, a small amount of crystals are formed, but the crystal quality is poor, twins appear, and a large amount of white powder is also produced; after HL reacts with Cu(NO3)2·3H2O at 160℃, a large amount of white powder is formed, and no crystals are formed; therefore, 120℃ is the optimal temperature.

[0053] Furthermore, the EMOF prepared in Example 1 was tested and characterized.

[0054] EMOF was characterized by PXRD powder diffraction, with 2θ = 5–60°. The characterization results can be found in [reference needed]. Figure 7 , Figure 7 The PXRD pattern of the energetic metal-organic framework material is shown. Comparing the PXRD patterns of the experimental EMOF sample and the simulated single-crystal structure, the positions of the main diffraction peaks (2...) are... θThe values ​​(19.39, 23.33, 21.28, 21.84, 25.44, 28.27, 29.02, 29.97, 30.82, 31.87, 33.38, 34.04) are basically consistent, indicating that the experimental EMOF sample has good purity and is in a single crystal orientation.

[0055] Please see Figure 8 , Figure 8 The image shows the XPS spectrum of an energetic metal-organic framework material, where... Figure 8 In this context, 'a' represents the XPS full spectrum, and 'b' represents C1. s Fine spectrum, c is N 1 s Fine spectrum, d represents Cu 2 p Detailed spectrum.

[0056] X-ray photoelectron spectroscopy (XPS) analysis was performed on EMOF to investigate the valence state and related chemical environment of copper. The XPS full-spectrum analysis of EMOF showed seven characteristic signal peaks within the binding energy range of 0-1200 eV, with the following specific binding energies and their corresponding assignments: 75.5 eV (Cu 3p), 122.4 eV (Cu 3s), 284.8 eV (C 1s), 399.0 eV (N 1s), 561.0 eV (Cu Auger), 932.0 eV (Cu 2p3 / 2), and 952.2 eV (Cu 2p1 / 2). All these signal peaks originated from the constituent elements C, N, and Cu of EMOF, and no interference peaks from impurity elements were found, indicating that EMOF has high purity. Figure 8 As shown in 'a'.

[0057] Peak fitting was performed on the high-resolution C 1s spectrum of EMOF, and the results are as follows: the signal peaks at binding energies of 284.8 eV, 285.5 eV, and 286.1 eV correspond to C=C / CC in the benzene ring structure, NC=C in the imidazole ring, and C=NC in the tetrazolium ring, respectively. Figure 8 As shown in b, after peak fitting of the N 1s high-resolution spectrum, the chemical environment of nitrogen can be clearly identified: the signal peak at a binding energy of 399.0 eV corresponds to the NN / N=N bond in the tetrazolium ring; the signal peak at 400.3 eV can be attributed to the NC in the imidazolium cation or the N-Cu bond in the coordination environment, because the binding energies of these two bonds are relatively close and there is no completely strict distinction; the peak at 401.8 eV is mainly attributed to the C=N in the imidazolium / tetrazolium ring. + This is because after N-Cu coordination, a charged onium salt form is formed, such as... Figure 8 As shown in c in the figure. The high-resolution Cu 2p spectrum of EMOF shows two sets of characteristic main peaks, corresponding to Cu 2p. 3 / 2(932.03 eV) and Cu 2p 1 / 2 The spin-orbit splitting signal at (951.79 eV) can be used to determine the oxidation state and chemical bonding environment of copper. The two sets of peaks are narrow with no significant broadening. Combined with their characteristic binding energy values, it can be determined that the valence state of copper in EMOF is +1. This result is consistent with the conclusions obtained from X-ray single-crystal diffraction analysis. Figure 8 As shown in d.

[0058] This embodiment utilizes a solvothermal method to synthesize energetic metal-organic framework materials. The synthesis method is simple, the synthesis yield is high, and the post-processing only requires filtration, without the need for recrystallization and complicated purification processes, making it easy to industrialize.

[0059] Example 3 Based on Examples 1 and 2, this example analyzes and studies the thermal stability, non-isothermal thermal analysis kinetics, thermal explosion critical temperature, standard molar enthalpy of formation, detonation performance, and explosion performance of energetic metal-organic framework (EMOF) materials.

[0060] 1) Thermal stability analysis of EMOF Please see Figure 9 , Figure 9 The thermal stability analysis curves for EMOF are shown. Figure 9 In the figure, a is the TG curve of EMOF, b is the DSC curve of EMOF, and c is the TG curve of HL.

[0061] Thermal stability is an important evaluation indicator for energetic materials. The thermal stability at 10 °C·min under a nitrogen atmosphere was investigated using TG-DSC technology. -1 The thermal decomposition behavior of EMOF with heating rate in the range of 30-800℃, such as Figure 8 As shown in a, the solvent-free EMOF remained stable up to 350.1℃. Within a short temperature range of 351.0℃ to 402.0℃, it underwent a rapid decomposition process with a weight loss rate as high as 51.4%, indicating that EMOF possesses excellent thermal stability and the potential to be an energetic material. This rapid weight loss is mainly attributed to the decomposition of organic ligands and the collapse of the overall framework. A sharp exothermic peak appeared on the DSC curve of EMOF between 383.1℃ and 408.7℃, with the decomposition peak temperature (T0) being the highest. d The temperature reached 399.7℃, indicating a rapid release of energy from the high-energy components within the EMOF, a phenomenon consistent with the results obtained from the TG curve. In contrast, the ligand HL underwent a relatively slow decomposition process between 298.4 and 465.7℃, and the T... d =298.5℃ Figure 9(c) EMOF exhibits high thermal stability, possibly due to its solvent-free nature, abundant strong coordination bonds, and supramolecular interactions such as strong π-π stacking within the 3D framework. Comparing the thermal stability of ligand HL and EMOF, EMOF shows a rapid weight loss plateau in a relatively small region, with a weight loss rate of 54%. Combined with the DSC curve of EMOF, a significant exothermic peak can be seen in the weight loss region. Generally, energetic materials must have the characteristic of concentrated exothermic release and sudden energy release. HL, on the other hand, loses weight relatively slowly over a wider range and does not have the characteristic of rapid energy release, thus indicating that it does not possess the rapid exothermic characteristic of energetic materials.

[0062] 2) Non-isothermal thermal analysis kinetics of EMOF The thermodynamic parameters during EMOF decomposition can be calculated using the Kissinger and Ozawa-Doyle methods. The Kissinger and Ozawa-Doyle equations are shown below: (1) (2) In the above formula, E Apparent activation energy (kJ·mol) -1 ), β heating rate (K·min) -1 ), T P To decompose the peak temperature (K). A Pre-exponential factor (s) -1 ), R The gas constant is 8.314 J·mol⁻¹. -1 ·K -1 ), C The constant is used. According to the Kissinger method, using 2℃·min -1 5℃·min -1 8℃·min -1 10℃·min -1 Decomposition peak temperature at different heating rates T P The thermodynamic parameters of the EMOF decomposition process, including the apparent activation energy, were obtained. E k and E o Pre-exponential factors A k and linear correlation coefficient R k and R o Specific data are shown in Table 4. Decomposition peak temperature T PThe apparent activation energy increases with increasing temperature, and the results calculated by both methods are essentially consistent, both within the acceptable range of normal deviation. The Arrhenius equation can utilize the obtained activation energy. E a ( E k and E o (average) and lg A The value is expressed as lg. k = 15.91 - 228.85 × 10 3 / (2.303 RT This is used to evaluate the rate constant during the EMOF decomposition process.

[0063] Table 4 Relevant thermodynamic parameters in the exothermic decomposition reaction of EMOF

[0064] Activation enthalpy during the exothermic decomposition reaction of EMOF ( H ≠ ) and activation entropy ( S ≠ ), activated Gibbs free energy ( G ≠ Important thermodynamic parameters such as ( ) can be obtained through the following reaction equations: S ≠ = R [ln A -ln( k B T p0 / h (3) H ≠ = Ea – RT p0 (4) G ≠ = H ≠ – T p0 S ≠ (5) In the formula, k B Boltzmann's constant,h Let be Planck's constant. E a = E k and A = A k , T p0 The peak temperature point when the heating rate approaches 0, Δ G ≠ >0, and Δ H ≠ The value >0 indicates that the thermal decomposition reaction of EMOF is a non-spontaneously enthalpy-driven process.

[0065] 3) Critical temperature of thermal explosion thermal explosion critical temperature ( T b ) and self-accelerating decomposition temperature ( T SADT Thermal safety is a crucial indicator of the thermal safety of high-energy materials during storage and operation. Therefore, according to... β →0 corresponds to the initial temperature value ( T e0 and T p0 EMOF was further determined using equations (6), (7), and (8). T b and T SADT value: (6) (7) (8) In the formula, a , b , c For coefficients, T e0 and T p0 They represent β →0, extrapolating the initial and peak temperatures, we can derive the following from the above equations: T SADT =338.1℃, T b =382.4℃, which indicates that solvent-free EMOF has better thermal safety than some common explosives, such as HMX, CL-20 and FOX-7. Specific parameters are shown in Table 5.

[0066] Table 5 Thermal safety parameters of EMOF

[0067] 4) Standard molar enthalpy of formation The standard molar enthalpy of formation of a compound is one of the key indicators for evaluating the detonation performance of energetic materials. Using an IKAC5000 oxygen bomb calorimeter, the detonation performance of a compound was determined by comparing it with the reference material benzoic acid (purity ≥99.999%, enthalpy of combustion: -26434±3 J·g). -1 Mixed tablets are used to test the heat of combustion of compounds. c U (The experiment was conducted in a 3MPa high-purity oxygen atmosphere, with six parallel trials performed and the average value taken.) The standard molar enthalpy of formation of the material was calculated based on Hess's law. The experimentally measured isochoric heat of combustion of EMOF c U It is -10367.25 ± 1.47 J·g -1 The isobaric heat of combustion of EMOF, i.e. the standard molar enthalpy of combustion at 298.15 K and 100 kPa, was calculated according to formulas (9) and (10). (kJ·mol -1 The value is -5693.43 ± 1.53 kJ·mol⁻¹ -1 The combustion reaction equation for the ideal combustion of compound 1 is derived from the following equation (11). The standard molar enthalpy of formation of the corresponding substance can be obtained from relevant literature data: (CuO, s) = -157.3 kJ·mol -1 , (CO2, g)=-393.51±0.13kJ·mol -1 , (H2O, l)=-258.83±0.04kJ·mol -1 Finally, the standard molar enthalpy of formation of EMOF is calculated using equation (12) to be -4474.09 ± 1.45 kJ·mol⁻¹. -1 .

[0068] (9) n = n g,P - n g,R (10) In the formula, M It is the molar mass of the substance, g·mol -1 ; n g,R It is the total molar amount of gas in the reactants, expressed in mol. n g,P It is the total molar amount of gas in the product, in mol;R It is the gas constant, J -1 ·mol -1 ·K -1 ; T It is 298.15K.

[0069] C 20 H 14 Cu2N 12 + O2→2CuO + 20CO2+ 7H2O + 6N2 (11) =2 +20 +7 - (12) 5) Detonation performance Based on the maximum exothermic principle proposed by Kamlet-Jacobs, the detonation performance of metal-containing explosives was studied using an empirical method. In such metal explosive systems, the formation of the most stable products of the detonation reaction is limited by the stoichiometric availability of oxygen. Based on this, for EMOFs, nitrogen, carbon, and ammonia are considered to be the final products of the decomposition of their organic skeleton, while the formation of metals is attributed to oxygen deficiency. The complete characteristics of the detonation reaction can be evaluated through calculations using equations (14)-(16).

[0070] Based on crystal density and heat of formation, the detonation performance parameters of the compound EMOF, heat of detonation (Q, kJ·g), were calculated using the Kamel-Jacobs equations (14) and (17). -1 ), explosion velocity (D, km·s -1 The explosion pressure (P, GPa) and burst pressure values ​​were 7.55 kJ·g. -1 8.77 km·s -1 The values ​​of 35.45 GPa, compared to other parameters of traditional catalysts, as well as literature values ​​of TNT, HMX, and RDX, are listed in Table 6.

[0071] C 20 H 14 Cu2N 12 →2Cu + 20C + H2O + N2 (13) (14) (15) (16) (17) In the formula D Detonation velocity (km·s)-1 ), P The detonation pressure is GPa. N The number of moles of detonation gas per gram of explosive. M The average molecular mass of the gas. Q The heat of detonation (kcal·g) -1 ), ρ Density of explosive (g·cm) -3 The enthalpy of formation can be determined based on the known enthalpy of formation, where NH3(g) (-46 kJ·mol⁻¹) -1 H2O(g) (-242kJ·mol) -1 Cu2C 20 H 14 N 12 (s) (-4474.09kJ·mol -1 The detonation heat of EMOF can be calculated to be 1.852 kcal·g. -1 Based on equations (14)-(17), the detonation velocity and detonation pressure can be further calculated, and the specific values ​​are shown in Table 5. From the above results, it can be concluded that EMOF-1 exhibits excellent detonation performance: its detonation pressure and detonation velocity are comparable to those of conventional explosives, while its detonation heat is not only higher than that of conventional explosives, but also superior to some reported copper-based EMOF materials.

[0072] Table 6 Physicochemical properties of EMOF and some energetic materials

[0073] 6) Sensitivity testing Impact sensitivity tests were conducted on EMOF using a drop hammer apparatus. 20 mg of EMOF was compressed into coin-shaped samples under a pressure of 39.2 MPa, and then impacted with a 2 kg drop hammer. h 50% The calculated value represents the drop height when the impact initiation probability is 50%. Test results show that EMOF at a drop height of 200cm (i.e., h 50% No ignition occurred at the highest point (corresponding to an impact energy of 40 J); this indicates that the impact sensitivity of EMOF is much lower than that of HMX (which has an impact energy of 7.4 J), as detailed in Table 5. Simultaneously, the tribological sensitivity of EMOF was measured using a 20 mg sample on a Julius Peter tribometer, and the results showed that no tribological initiation was observed in EMOF below a pressure of 360 N. In summary, these results indicate that EMOF is insensitive to external stimuli, a characteristic likely attributed to the rigid framework in its molecular structure.

[0074] In summary, the green, high-energy, high-temperature resistant energetic metal-organic framework (EMOF) material in this embodiment has a crystal density of 1.928 g·cm³. -3 The decomposition temperature is 399.7℃, and the detonation velocity is 8.775 km / s. -1 The detonation pressure was 35.45 GPa, and the detonation heat was 1.852 kcal·g. -1 Impact sensitivity > 40J, friction sensitivity > 360N.

[0075] This embodiment features a three-dimensional porous framework structure constructed by the energetic ligand 5-[4-(1-imidazolyl)phenyl]-2H-tetrazole and metal ions through coordination bonds. It has the advantages of high energy regulation flexibility, significantly improved thermal stability and safety, and excellent environmental compatibility.

[0076] High flexibility in energy regulation: The EMOF of this invention is a three-dimensional metal-organic framework compound constructed from binuclear copper (I) units and μ4-L ligands. Its energy source benefits from both the energetic groups within the ligand molecules and the metal-ligand coordination bonds. Specifically, the energetic ligand 5-[4-(1-imidazolyl)phenyl]-2H-tetrazole stores energy through high-energy chemical bonds such as N=N and CN, while the metal ion Cu(I) stabilizes the framework structure through strong coordination bonds. Therefore, the energy density can be precisely controlled by adjusting the nitrogen content of the ligands and the type of metal ion. This EMOF can achieve a detonation velocity exceeding 8000 m / s, comparable to HMX, and the high sensitivity problem caused by excessive energy concentration can be avoided by adjusting the framework porosity, demonstrating high flexibility in energy regulation.

[0077] Significantly improved thermal stability and safety: The three-dimensional coordination framework of this invention contains abundant strong coordination bonds and supramolecular interactions such as π-π stacking. These interactions effectively suppress molecular thermal motion and increase the decomposition temperature; the decomposition temperature of this EMOF reaches 399.7℃, far exceeding that of traditional TNT (240℃) and RDX (230℃). Simultaneously, the porosity of the framework structure buffers detonation shock waves, reducing the impact of external stimuli on the internal energetic groups. This EMOF has a friction sensitivity greater than 360N and an impact sensitivity greater than 40J, meeting the safety requirements for use in harsh environments.

[0078] Excellent environmental compatibility: The energetic ligand of the EMOF of this invention is the nitrogen-rich heterocyclic compound 5-[4-(1-imidazolyl)phenyl]-2H-tetrazole. The explosion products are mainly N2, CO2, and H2O, with no release of heavy metal ions or toxic organic matter. Moreover, the synthesis process does not require the use of highly toxic raw materials and can be prepared in a green manner through a solvothermal method. The atom utilization rate is over 95%, which is in line with the development trend of "green and low pollution" of modern energetic materials.

[0079] Therefore, the EMOF of this embodiment, compared with traditional TNT, RDX, and HMX, has comparable detonation velocity and detonation pressure, but higher decomposition temperature and heat of explosion than traditional energetic materials. It has lower friction and impact sensitivity, is insensitive to external stimuli, and produces no pollution from explosion products. It is a novel green, high-energy, and high-temperature resistant energetic material. Moreover, the synthesis method of this material is simple, the synthesis yield is high, and the post-processing only requires filtration, without the need for recrystallization and complicated purification processes. It is easy to industrialize and breaks through the limitations of traditional energetic compounds in energy-safety-environmental balance. It is of great significance for promoting technological innovation in the field of energetic materials.

[0080] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A green high-energy high-temperature tolerant energetic metal-organic framework material, characterized in that, Comprise: The energetic metal-organic framework material has a structural formula of: [Cu2L2] n A three-dimensional metal-organic framework compound is constructed from dinuclear copper(I) and a μ4-L ligand, the ligand L including 5-[4-(1 imidazolyl)phenyl]-2H-tetrazole.

2. The green high-energy tolerant high-temperature energetic metal-organic framework material of claim 1, wherein, The energetic metal-organic framework material belongs to a monoclinic system, and a space group is P 21 / c , a unit cell parameter is a= 19.2760Å, b=10.4530Å, c=9.4213Å, α=90°, β=93.981°, γ=90°, and a crystal size is 0.22x0.18x0.17mm 3 , a unit cell volume is 1893.74Å 3 , and a unit cell molecule number is 4.

3. The green high-energy tolerant high-temperature energetic metal-organic framework material of claim 1, wherein, 2 Cu(I) and 2 ligands L in the smallest repeating unit in the energetic metal-organic framework structure; Each Cu(I) center is bonded to N atoms from four different ligands L, forming an approximately tetrahedral coordination geometry, wherein the Cu-N bond lengths and N-Cu-N bond angles range from 1.990-2.171 Å and 98.67°-124.62°, respectively.

4. The green high-energy tolerant high-temperature energetic metal-organic framework material of claim 3, wherein, The ligands L in the metal-organic framework structure exhibit the same μ4 bridging mode to connect four Cu(I), and the dinuclear Cu(I) units are connected to each other to form a strip structure; When the Cu(I) and L ligand are regarded as 3-connected nodes and 4-connected nodes, respectively, the strip structure extends to form a two-dimensional layered structure parallel to the b-axis; The adjacent Cu(I) extends in four directions through bridging to form a three-dimensional network structure.

5. The green high-energy tolerant high-temperature energetic metal-organic framework material of claim 4, wherein, In the three-dimensional network structure, all Cu(I) centers and ligands L are regarded as 4-connected nodes, and the three-dimensional network structure is simplified to a topology with a topology symbol of 4².6³.8 and a topology type of SrAl2.

6. A method for preparing a green high-energy high-temperature tolerant energetic metal-organic framework material, characterized in that, A method for preparing a green high-energy high-temperature-resistant energetic metal-organic framework material according to any one of claims 1-5, comprising the steps of: Weighing the ligand 5-[4-1(1-imidazolyl)phenyl]-2H-tetrazole and Cu(NO3)2·3H2O into a reaction kettle, using N,N-dimethylformamide as a solvent, using HCl solution as a PH regulator, stirring at room temperature for a period of time, then transferring the reaction kettle to an environment with a preset temperature for a preset time; After the reaction is completed, the reaction product is cooled at a preset rate until it cools to room temperature to obtain an energetic material.

7. The method of claim 6, wherein the green high-energy tolerant high-temperature energetic metal-organic framework material is prepared by the steps of: providing a mixture of a metal-organic framework material and a binder; and heating the mixture to a temperature of 300 °C to 400 °C for 1 hour to 3 hours. The molar ratio of the ligand 5-[4-1(1-imidazolyl)phenyl]-2H-tetrazole to the Cu(NO3)2·3H2O is 1:(2~3); The volume ratio of the N,N-dimethylformamide and the HCl solution is 40:

3.

8. The method of claim 7, wherein the green high-energy tolerant high-temperature energetic metal-organic framework material is prepared by the steps of: providing a mixture of a metal-organic framework material and a binder; and heating the mixture to a temperature of 300 °C to 400 °C for 1 hour to 3 hours. The HCI solution comprises 0.1 mol L -1 HCl solution.

9. The method of claim 8, wherein the green high-energy tolerant high-temperature energetic metal-organic framework material is prepared by the steps of: providing a mixture of a metal-organic framework material and a binder; and heating the mixture to a temperature of about 100 °C to about 200 °C for about 1 hour to about 24 hours. The volume of the HCl solution is 0.9 mL, and the volume of the N,N-dimethylformamide is 12 mL.

10. The method of claim 6, wherein the green high-energy tolerant high-temperature energetic metal-organic framework material is prepared by the method comprising: providing a mixture of a metal-organic framework material precursor and a binder; and heating the mixture to a temperature of 300 °C to 400 °C for 1 hour to 3 hours. The preset temperature includes 120℃, and the preset time includes 48h; The preset rate includes 5℃·h -1 .

Images