Chromium oxide activated boron fuel and preparation method thereof

Abstract

The invention provides a chromium oxide activated boron fuel and a preparation method thereof, the method takes a boron fuel as a carrier, and the method adopts a microwave precipitation method to load chromium oxide particles on the surface of the boron fuel to prepare the chromium oxide activated boron fuel. According to the microwave precipitation method, chromium trichloride and ammonia water are used as raw materials, and the chromium trichloride and the ammonia water react in a microwave synthesis instrument to generate chromium oxide precipitate. The reaction temperature of the microwave precipitation method is 80 DEG C, and the reaction time is 60 minutes. And the particle size of the chromium oxide particles is 1-10nm. The temperature corresponding to the oxidation peak of the chromium oxide activated boron fuel is 624-625 DEG C; the ignition delay time ranges from 36 ms to 38 ms. According to the Cr2O3 / B activated fuel prepared by the invention, Cr2O3 is particles on the surface of the boron fuel, Cr2O3 is highly dispersed on the surface of the B fuel and is uniformly loaded on the surface of the boron fuel, and the loading capacity is accurate and adjustable.

Description

Technical Field

[0001] The invention belongs to the technical field of high-energy fuels and relates to boron fuel, in particular to a chromium oxide activated boron fuel and a preparation method thereof. Background Art

[0002] Boron powder (B) as a fuel has a series of outstanding properties. Its volume calorific value reaches 1310MJ / m 3 , and its mass calorific value is 58.3MJ / kg. More importantly, its combustion products are clean and environmentally friendly. In view of these characteristics, the development of green and environmentally friendly boron-based propellants has become a highly-anticipated research direction. However, the high melting point and high boiling point of B create obstacles to its melting and vaporization process. During the combustion process of boron, an oxide layer is formed on its surface. The melting point of this oxide layer is lower than that of boron, but its boiling point is higher than that of boron. Compared with metals that evaporate easily, the combustion characteristics of B make its ignition delay time and burning time relatively long. In a system with limited volume, B can only release a small part of its theoretical calorific value.

[0003] To reduce the processing difficulty of B, effectively address its ignition and combustion issues, and simultaneously increase the mass ratio of B and ultrafine oxidizer in the propellant, adding oxides is an effective strategy. Research has found that adding metal oxides can significantly improve the combustion performance of B. Chromium oxide has a wide range of applications in fuels, catalysts, and refractory materials.

[0004] Titanium and vanadium are adjacent to chromium in the same period. Their oxides, titanium dioxide and vanadium pentoxide, play an important role in the surface modification of boron powder. Previous patent research has shown that depositing a small amount of titanium dioxide or vanadium pentoxide on the surface of boron powder can significantly reduce the peak temperature of the boron powder's oxidation exotherm and significantly shorten the ignition delay time. This suggests that chromium, as an adjacent element in the same period, and its oxide, chromium oxide, are likely to be effective in improving the combustion properties of boron powder.

[0005] Currently, the literature records a variety of chromium oxide production processes, such as the chromium hydroxide method and the direct thermal decomposition method of chromic anhydride. However, the above methods cannot produce uniformly loaded particles. Therefore, it is very important to develop a method for preparing nanoparticles. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a chromium oxide activated boron fuel and a preparation method thereof, so as to solve the technical problem in the existing technology that the uniformity of chromium oxide loading needs to be further improved while ensuring the combustion performance of the boron fuel.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] A method for preparing chromium oxide activated boron fuel uses the boron fuel as a carrier and adopts a microwave precipitation method to load chromium oxide particles on the surface of the boron fuel to prepare the chromium oxide activated boron fuel.

[0009] The present invention also has the following technical features:

[0010] Specifically, the microwave precipitation method uses chromium trichloride (CrCl3) and ammonia water (NH3·H2O) as raw materials, and the chromium trichloride and ammonia water react in a microwave synthesis instrument to generate chromium oxide (Cr2O3) precipitate.

[0011] Preferably, the reaction temperature of the microwave precipitation method is 80° C. and the reaction time is 60 min.

[0012] Specifically, the method includes the following steps:

[0013] Step 1: Pour the boron fuel into a microwave digestion tank, add water, perform ultrasound, and magnetic stirring; measure the chromium trichloride solution and add it into the microwave digestion tank and perform magnetic stirring.

[0014] Step 2: Measure ammonia water, add it into a microwave digestion tank and stir it thoroughly.

[0015] Step 3: Place the microwave digestion tank into a microwave synthesizer to carry out a microwave precipitation reaction.

[0016] Step 4: After the reaction is completed and the temperature drops to room temperature, the microwave digestion tank is taken out and the product is collected by filtration. The product is washed and filtered with water until no chloride ions are detected; the washed product is dried to obtain chromium oxide-activated boron fuel.

[0017] Preferably, the method comprises the following steps:

[0018] Step 1: Weigh 1g of boron fuel and pour it into a 25ml microwave digestion tank, then add 10ml of deionized water, ultrasonicate for 5min, and magnetically stir for 10min. Measure 0.05mol / L CrCl3 solution and add it into the microwave digestion tank and magnetically stir.

[0019] Step 2: Measure 0.1 mol / L ammonia water, add it into a microwave digestion tank and stir it thoroughly.

[0020] Step 3: Place the microwave digestion tank into a microwave synthesizer, set the temperature to 80° C., set the time to 60 min, and perform a microwave precipitation reaction.

[0021] Step 4: After the reaction is completed and the temperature drops to room temperature, the microwave digestion tank is taken out and the product is collected by filtration. The product is washed with deionized water and filtered until no chloride ions are detected; the washed product is placed in an oven at 80°C for drying to obtain chromium oxide-activated boron fuel.

[0022] The present invention also protects a chromium oxide activated boron fuel, which is prepared by the above-mentioned preparation method of the chromium oxide activated boron fuel.

[0023] The particle size of the chromium oxide particles is 1 to 10 nm.

[0024] Preferably, the content of the chromium oxide particles is 1.0 wt% to 7.0 wt%.

[0025] Preferably, the temperature corresponding to the oxidation peak of the chromium oxide activated boron fuel is 624° C. to 625° C.; and the ignition delay time of the chromium oxide activated boron fuel is 36 ms to 38 ms.

[0026] Compared with the prior art, the present invention has the following technical effects:

[0027] (I) In the Cr2O3 / B activated fuel prepared by the present invention, Cr2O3 is in the form of particles on the surface of the boron fuel. Cr2O3 is highly dispersed on the surface of the B fuel and is uniformly loaded on the surface of the boron fuel. The loading amount is precisely adjustable.

[0028] (II) The role of chromium oxide (Cr2O3) in the present invention is to activate the surface of the boron fuel and improve the ignition and combustion performance of the boron fuel. The Cr2O3 / B activated fuel prepared by the present invention has a lower oxidation temperature and a shorter ignition delay time. The temperature corresponding to the oxidation peak of the Cr2O3 / B activated fuel is 624°C to 625°C. Compared with the B fuel that has not been activated with Cr2O3, it is reduced by 52°C to 53°C. The ignition delay time of the Cr2O3 / B activated fuel is 36ms to 38ms. Compared with the B fuel that has not been activated with Cr2O3, it is reduced by 14ms to 12ms.

[0029] (III) The preparation method of the present invention is simple, efficient, reproducible and low-cost.

[0030] (IV) The preparation method adopted by the present invention has high control precision, is easy to industrialize, and shows good application prospects in the field of high-energy solid fuel modification. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is the SEM image of unmodified fuel B.

[0032] Figure 2 SEM and element distribution mapping images of 7.0wt% Cr2O3 / B activated fuel.

[0033] Figure 3 XPS Cr 2p, B 1s and O1s spectra of 7.0wt% Cr2O3 / B activated fuel.

[0034] Figure 4 XRD data of Cr2O3 / B activated fuel: a0 is unmodified B fuel, a1 is 1.0wt%-Cr2O3 / B, and a2 is 7.0wt%-Cr2O3 / B.

[0035] Figure 5 DSC data of Cr2O3 / B activated fuel: a0 is unmodified B fuel, a1 is 1.0wt%-Cr2O3 / B, and a2 is 7.0wt%-Cr2O3 / B.

[0036] Figure 6 TG data of Cr2O3 / B activated fuel: a0 is unmodified B fuel, a1 is 1.0wt%-Cr2O3 / B, and a2 is 7.0wt%-Cr2O3 / B.

[0037] The specific contents of the present invention are further explained in detail below with reference to the embodiments. DETAILED DESCRIPTION

[0038] It should be noted that, unless otherwise specified, all materials and equipment in the present invention are those known in the art.

[0039] In the present invention, boron fuel refers to boron powder, which can also be referred to as boron particles or elemental boron; all four are synonymous. The boron fuel can be amorphous and / or crystalline, with a particle size distribution ranging from micrometers to nanometers. Preferably, the particle size of the boron fuel is 100 nm to 5 μm.

[0040] The chromium oxide activated boron fuel of the present invention is used as a boron-based fuel in the field of explosives.

[0041] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent modifications made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0042] Example:

[0043] This embodiment provides a method for preparing a chromium oxide activated boron fuel, which comprises the following steps:

[0044] Step 1: Weigh 1g of boron fuel and pour it into a 25ml microwave digestion tank, then add 10ml of deionized water, ultrasonicate for 5min, and magnetically stir for 10min. Measure 0.05mol / L CrCl3 solution and add it into the microwave digestion tank and magnetically stir.

[0045] Step 2: Measure 0.1 mol / L ammonia water, add it into a microwave digestion tank and stir it thoroughly.

[0046] Step 3: Place the microwave digestion tank into a microwave synthesizer, set the temperature to 80° C., set the time to 60 min, and perform a microwave precipitation reaction.

[0047] Step 4: After the reaction is completed and the temperature drops to room temperature, the microwave digestion tank is removed and the product is collected by filtration. The product is washed with deionized water and filtered until no chloride ions are detected; the washed product is placed in an oven at 80°C and dried to obtain chromium oxide-activated boron fuel (i.e., Cr2O3 / B activated fuel).

[0048] In this embodiment, the amounts of chromium trichloride (CrCl 3 ) and ammonia (NH 3 ·H 2 O) are calculated based on the loading amount of chromium oxide (Cr 2 O 3 ) particles.

[0049] Figure 1 This is a SEM image of unmodified B fuel. Scanning electron microscopy revealed that the boron particles have a complete structure and no specific morphology.

[0050] Figure 2 SEM and element distribution mapping images of 7.0wt% Cr2O3 / B activated fuel. Figure 1 From the SEM images, we can see that the morphology of fuel B does not change after Cr2O3 activation modification, that is, Cr2O3 activation modification does not affect the morphology of fuel B. At the same time, the element distribution mapping image shows that the distribution of Cr, O and B is completely consistent, indicating that Cr2O3 is highly dispersed on the surface of fuel B. Figure 2 It can also be seen that the particle size of Cr2O3 particles in the 7.0wt% Cr2O3 / B activated fuel is 1-10nm.

[0051] Figure 3 The XPS Cr 2p, B 1s and O1s spectra of 7.0wt% Cr2O3 / B activated fuel. The B1s spectrum at 187.6eV is assigned to B 0 The peak at 192.5 eV is attributed to B 3+ The peak of Cr 2p spectrum is attributed to Cr. 3+ It can be seen that the microwave precipitation method produces Cr2O3 species.

[0052] Figure 4 XRD data for Cr2O3 / B activated fuel: a0 represents unmodified B fuel, a1 represents 1.0 wt% Cr2O3 / B, and a2 represents 7.0 wt% Cr2O3 / B. These three samples have nearly identical spectra, demonstrating that microwave precipitation-induced Cr2O3 activation of the boron fuel surface does not alter the B crystal structure.

[0053] TG-DSC test of Cr2O3 / B activated fuel:

[0054] The Cr2O3 / B activated fuel was placed in an alumina crucible, which was placed on the sample stage of the TG-DSC instrument. The sample mass was input and the heating rate of the instrument was set to 10K / min. The test temperature range was room temperature-900°C, and the test atmosphere was air. In this way, the TG and DSC curves of the Cr2O3 / B activated fuel were obtained.

[0055] Figure 5 DSC data for Cr2O3 / B activated fuel: a0 represents fuel B without Cr2O3 activation, a1 represents 1.0wt% Cr2O3 / B, and a2 represents 7.0wt% Cr2O3 / B. The oxidation peak of fuel B without Cr2O3 activation corresponds to 677°C, while the peak for 1.0wt% Cr2O3 / B is 624°C, and the peak for 7.0wt% Cr2O3 / B is 625°C. Cr2O3 activation significantly reduces the oxidation temperature of fuel B, maintaining a constant level of Cr2O3 loading. Only 1.0wt% is needed to achieve a significant reduction in the oxidation temperature.

[0056] Figure 6 The TG data of Cr2O3 / B activated fuel are shown in Figure 2: a0 is unmodified B fuel, a1 is 1.0wt%-Cr2O3 / B, and a2 is 7.0wt%-Cr2O3 / B. The initial mass increase and other results in the TG data are similar to those in the Figure 5 The DSC results are consistent with those in .

[0057] The laser ignition delay time test of Cr2O3 / B activated fuel showed that the ignition delay time of Cr2O3 / B activated fuel was 36ms-38ms.

[0058] Compared with existing technologies, the Cr2O3 / B activated fuel prepared by the present invention has the advantages of good reproducibility, environmental friendliness, and high activity. The preparation process of this type of Cr2O3 / B activated fuel is simple and convenient. The microwave precipitation technology used in this experimental method is mild, and the experimental chemicals are all common laboratory drugs. The sample preparation cost is low. The Cr2O3 / B activated fuel of the present invention is easy to prepare, has good reproducibility, and is low in price, greatly reducing the preparation cost of boron-based fuels and showing great application prospects.

Claims

1. A method for preparing a chromium oxide activated boron fuel, wherein the method uses the boron fuel as a carrier, characterized in that: The method adopts microwave precipitation method to load chromium oxide particles on the surface of boron fuel to prepare chromium oxide activated boron fuel.

2. The method for preparing a chromium oxide activated boron fuel according to claim 1, wherein: The microwave precipitation method uses chromium trichloride and ammonia water as raw materials, and the chromium trichloride and ammonia water react in a microwave synthesis instrument to generate chromium oxide precipitation.

3. The method for preparing the chromium oxide activated boron fuel according to claim 2, wherein: The reaction temperature of the microwave precipitation method is 80° C. and the reaction time is 60 min.

4. The method for preparing chromium oxide activated boron fuel according to claim 1, wherein: The method comprises the following steps: Step 1: Pour the boron fuel into a microwave digestion tank, add water, perform ultrasound, and magnetic stirring, measure the chromium trichloride solution, add it into the microwave digestion tank, and perform magnetic stirring; Step 2: Measure ammonia water, add it into a microwave digestion tank and stir thoroughly; Step 3, placing the microwave digestion tank into a microwave synthesizer to perform a microwave precipitation reaction; Step 4: After the reaction is completed and the temperature drops to room temperature, the microwave digestion tank is taken out and the product is collected by filtration. The product is washed and filtered with water until no chloride ions are detected; the washed product is dried to obtain chromium oxide-activated boron fuel.

5. The method for preparing chromium oxide activated boron fuel according to claim 4, wherein: The method comprises the following steps: Step 1: Weigh 1g of boron fuel into a 25ml microwave digestion tank, add 10ml of deionized water, sonicate for 5min, and magnetically stir for 10min. Measure 0.05mol / L CrCl3 solution and add it to the microwave digestion tank and magnetically stir. Step 2: Measure 0.1 mol / L ammonia water, add it into a microwave digestion tank and stir thoroughly; Step 3: Place the microwave digestion tank into a microwave synthesizer, set the temperature to 80°C, set the time to 60 minutes, and perform a microwave precipitation reaction; Step 4: After the reaction is completed and the temperature drops to room temperature, the microwave digestion tank is taken out and the product is collected by filtration. The product is washed with deionized water and filtered until no chloride ions are detected; the washed product is placed in an oven at 80°C for drying to obtain chromium oxide-activated boron fuel.

6. A chromium oxide activated boron fuel, characterized in that: The boron fuel is prepared by the method for preparing a chromium oxide activated boron fuel as claimed in any one of claims 1 to 5; The particle size of the chromium oxide particles is 1 to 10 nm.

7. The chromium oxide activated boron fuel according to claim 6, characterized in that The content of the chromium oxide particles is 1.0wt% to 7.0wt%.

8. The chromium oxide activated boron fuel according to claim 6, wherein The temperature corresponding to the oxidation peak of the chromium oxide activated boron fuel is 624° C. to 625° C.; the ignition delay time of the chromium oxide activated boron fuel is 36 ms to 38 ms.

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