A ternary boron nanosphere, its preparation method, and its application

Abstract

This invention discloses a ternary boron nanosphere particle, its preparation method, and its application. A mixed suspension of boron and titanium nanoparticles is sprayed into a nitrocellulose suspension, heated and stirred to allow the boron and titanium nanoparticles to enter the nitrocellulose, forming a mixed solution. An organic solvent is added to the mixture, and the mixture is heated and stirred to dissolve the nitrocellulose with ethyl acetate and coat the boron and titanium nanoparticles, forming a ternary aggregate. A gelatin aqueous solution is then added, and the mixture is heated and stirred, filtered, and dried to obtain the ternary boron nanosphere particles. The high-energy composite material prepared by this invention uses NC as a carrier and binder. The prepared spherical particles have a dense structure and uniform size; they simultaneously possess both a metallic combustion accelerant and a metallic fuel, enabling a sustained and vigorous reaction that releases enormous energy. They can be used as a raw material for boron-rich solid propellants, achieving stable combustion of solid propellants under low pressure and improving combustion efficiency. The synthesis method of this invention is green, safe, and easy to industrialize.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of nano energetic materials, and particularly relates to a ternary nano boron spherical particle and a preparation method and application thereof. BACKGROUND

[0002] The theoretical specific impulse of boron-containing fuel-rich propellant is very high, but since the melting point and boiling point of boron are relatively high, i.e. 2347K and 2823K respectively, the ignition process is slow, and the surface oxidation process generates B2O3, and the melting point of B2O3 is 723K and the boiling point is 1973K, so the continuous combustion of boron needs to be higher than 1973K, which is difficult to achieve in a one-time combustion gas generator, so that boron particles coated with viscous liquid coagulate into blocks when colliding with each other in the gas flow, and the increased particles will be retained in the gas generator, reducing the ejection efficiency [1-3], thereby leading to insufficient combustion efficiency of boron-containing fuel-rich propellant.

[0003] A. Maˇceic, J.M. Semple, Combustion of boron particles at atmospheric pressure, Combust. Sci. Technol. 1 (3) (1969) 181-191.

[0004] M.K. King, Ignition and combustion of boron particles and clouds, J. Spacecraft Rockets 19 (4) (1982) 294-306.

[0005] S.C. Li, F.A. Williams, Ignition and combustion of boron particles, Int. J. Energ. Mater. Ch. 2 (1993) 248-271. SUMMARY

[0006] In order to overcome the problems in the prior art, the purpose of the present application is to provide a ternary nano boron spherical particle and a preparation method and application thereof, which has good dispersibility, high density and high combustion efficiency, and can improve the combustion efficiency of boron-containing propellant, thereby providing a possibility for stable combustion at low pressure.

[0007] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0008] A preparation method of a ternary nano boron spherical particle, comprising the following steps:

[0009] The mixed suspension of nano-boron and nano-titanium is sprayed into the nitrocellulose suspension, heated and stirred to make the nano-boron and nano-titanium enter the nitrocellulose to form a mixed solution;

[0010] The organic solvent is added into the mixed solution, heated and stirred to make the ethyl acetate dissolve the nitrocellulose and coat the nano-boron and nano-titanium to form a three-component agglomerate, then the gelatin aqueous solution is added, heated and stirred, filtered, dried to obtain the ternary nano-boron spherical particles.

[0011] Further, the nitrocellulose suspension is prepared by the following process: the nitrocellulose is placed in water at 87-93℃, heated and stirred to form the nitrocellulose suspension; wherein the nitrogen content of the nitrocellulose is 12.1%.

[0012] Further, the mixed suspension of nano-boron and nano-titanium is prepared by the following process:

[0013] The nano-boron and nano-titanium are added into water, mixed uniformly under ultrasonic oscillation to obtain the mixed suspension of nano-boron and nano-titanium.

[0014] Further, the particle size of the nano-boron is 100-200nm, and the particle size of the nano-titanium is 50-100nm.

[0015] Further, the amount of the gelatin is 5-8wt% of the total mass of the nitrocellulose, nano-titanium and nano-boron.

[0016] Further, the amount of the nano-titanium is 1-10wt% of the ternary nano-boron spherical particles, the amount of the nano-boron is 71-83wt% of the ternary nano-boron spherical particles, and the amount of the nitrocellulose is 15-19wt% of the ternary nano-boron spherical particles.

[0017] Further, the organic solvent is ethyl acetate, and the amount ratio of the nitrocellulose to the ethyl acetate is 1g:3-5mL.

[0018] Further, the stabilizer is a gelatin solution.

[0019] A ternary nano-boron spherical particle, the particle size of which is 50-500μm.

[0020] The application of the ternary nano-boron spherical particle in preparing a boron-containing fuel-rich solid propellant.

[0021] Compared with the prior art, the present application has the following beneficial effects:

[0022] The present application uses nano-boron, nitrocellulose and nano-titanium as raw materials. -3 ~10 -1 μm of the capillary tube, and the specific surface area is 2300-3200cm 2With a price between [value missing] g and [value missing], and in a swollen state, nitrocellulose can serve as a carrier for nanoparticles, effectively dispersing them and reducing slurry viscosity, improving leveling, and enhancing the bonding strength between components. Nitrocellulose can also act as a dispersant and binder for ternary boron nanospheres. During combustion, it releases gas, ejecting the encapsulated nano-metal particles into the air, allowing them to come into contact with more oxygen and thus improving combustion efficiency. In this invention, the introduction of high-volume calorific value active nano-titanium (n-Ti) powder improves the ignition and combustion performance of the system and increases the density of agglomerates. Under the action of a stabilizer, nitrocellulose can effectively combine with nB and n-Ti, effectively inhibiting the automatic agglomeration of a large number of small spheres when stirring stops, improving dispersibility, and contributing to the stability of the ternary boron nanospheres. The synthesis method of this invention is simple, safe, and effective, and is environmentally friendly and easy to industrialize. This method significantly differs from traditional physical mixing methods, effectively solving the problem that the addition of large amounts of nano-boron leads to difficulty in uniform dispersion in the propellant slurry during the preparation of boron-rich solid propellants, resulting in increased slurry viscosity and poor rheological properties. This invention transforms small-particle boron powder into large-particle agglomerated boron, thereby improving the process and increasing the boron content in the boron-rich solid propellant, greatly enhancing the dispersibility and combustion efficiency of the prepared ternary nano-boron spherical particles. The ternary nano-boron spherical particles prepared by this invention exhibit superior ignition and combustion performance compared to binary components NC and nB, and significantly better than elemental nB, achieving rapid steady-state combustion of boron-rich propellants under low pressure and improving combustion efficiency.

[0023] The ternary boron nanospheres prepared by this invention simultaneously contain the metallic combustion promoter n-Ti and the metallic fuel nB, which can undergo a violent reaction, release huge energy, and promote the complete combustion of nB.

[0024] Compared to micron-sized boron, the nano-sized boron spherical particles prepared in this invention burn more completely, which is expected to completely solve the problem of insufficient combustion efficiency and can be used as a raw material for preparing boron-rich solid propellants. Attached Figure Description

[0025] Figure 1 The images show SEM images of the ternary spherical particles and their cross-sections from Example 1; where (a) is an SEM image of the ternary spherical particles, (b) is an SEM image of the cross-sections, and (c) is an enlarged view of the area within the box in Figure (b).

[0026] Figure 2 This is a particle size distribution diagram of the ternary spherical particles in Example 2;

[0027] Figure 3SEM images of the combustion products of Example 3 and Comparative Example 1 are shown below; where (a) is the SEM image of the combustion product of Example 3 and (b) is the SEM image of the combustion product of Comparative Example 1.

[0028] Figure 4 The XRD patterns of the combustion products of Example 4 and Comparative Example 1 are shown below.

[0029] Figure 5 The combustion flame diagrams are for Example 5 and Comparative Example 1;

[0030] Figure 6 SEM image of the ternary spherical particles in Example 10;

[0031] Figure 7 This is a SEM image of the ternary spherical particles from Example 11. Detailed Implementation

[0032] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0033] The present invention discloses a five-step method for preparing high-energy composite ternary boron nanospheres using swelling-adsorption-dissolution-spheroidization-drying, comprising the following steps:

[0034] A ternary boron nanosphere particle, comprising the following steps:

[0035] Nitrocellulose (NC) was placed in hot water at a temperature of 90±3℃ with a water-to-nitrocellulose mass ratio of 10:1. The mixture was heated and stirred for 30 minutes to form suspension A. The nitrogen content (mass content) of NC was approximately 12.1%.

[0036] Nano-boron (nB) and nano-titanium (n-Ti) were added to water and mixed uniformly under ultrasonic vibration. The mass ratio of water to the total mass of nano-boron (nB) and nano-titanium (n-Ti) was 12-20:1, resulting in a mixed suspension of nano-boron and nano-titanium. The particle size of nB was 100-200 nm, and the particle size of n-Ti was 50-100 nm. The mixed suspension of nano-boron and nano-titanium was sprayed into suspension A using an injector. Under constant temperature and stirring conditions, the uniform metal powder gradually entered NC, meaning that nano-boron and nano-titanium were adsorbed by NC, forming mixed solution B. The adsorption time, stirring speed, and temperature all affected the adsorption process. The temperature was controlled at 90±3℃, the stirring speed at 700 rpm, and the time was 16 hours. The amount of n-Ti is 1-10 wt% of the ternary boron nanoparticles, the amount of nB is 71-83 wt% of the ternary boron nanoparticles, and the amount of NC is 15-19 wt% of the ternary boron nanoparticles.

[0037] Add ethyl acetate to mixture B, with NC:ethyl acetate = 1g: 3-5mL, and stir at 60±3℃ (stirring speed 500-800rpm) for 30min. This allows the ethyl acetate to dissolve and coat nB and n-Ti in mixture B, while also preventing solvent evaporation and the formation of ternary aggregates.

[0038] Take 5-8 wt% of the total mass of NC, n-Ti and nB gelatin, place it in a large amount of water, and stir at 800-1300 rpm at a temperature of 75±3℃ until the gelatin particles are completely dissolved to form a gelatin aqueous solution.

[0039] A prepared gelatin aqueous solution as a stabilizer was added to the ternary agglomerate. After addition, the mixture was continuously stirred at a temperature of 40-70℃ (stirring speed of 300-1500 rpm) to allow the particles to spherize under surface tension. A protective film was formed on the surface of the spheres, keeping them stable. After filtration, the spherical particles were dried in a vacuum drying oven to obtain ternary boron nanospheres. By controlling the temperature to 40-70℃ and the stirring speed to 300-1500 rpm, ternary boron nanospheres with good sphericity were achieved, and their particle size was adjustable within the range of 50μm-500μm.

[0040] Ethyl acetate is used as the solvent because it can dissolve NC and is insoluble in water.

[0041] Gelatin is used as a stabilizer because it is soluble in water but insoluble in organic solvents.

[0042] A ternary boron nanosphere with a particle size of 50μm-500μm was prepared according to the method described above, and the particle size is controllable.

[0043] In this invention, the components are fully ultrasonically dispersed and stirred in a solvent to form a uniform and stable mixture. Then, through the action of dissolving and stabilizing agents, the mixture is prepared into a suspension containing ternary boron nanospheres.

[0044] In this invention, nB is used as a high-energy combustion agent, n-Ti is used as a combustion improver, and NC is used as a carrier and coating agent for n-Ti and nB. The prepared spherical structure is dense, the particle size is uniform, n-Ti and nB are well dispersed in it, and the combustion efficiency is high. As an important component of solid propellant, it can burn stably under low pressure.

[0045] Example 1

[0046] (1) Disperse 1.5g NC in 15mL of water, heat to 90℃, stir at 800rpm for 30min to obtain a suspension of swollen NC; disperse 0.6g n-Ti and 7.9g nB in 127.5mL of water, sonicate for 30min, and then stir at 500rpm for 30min to obtain a mixed suspension of nB and n-Ti;

[0047] (2) The mixed suspension of nB and n-Ti was sprayed into the swollen NC suspension using an injector. The mixture was kept at 90°C and 700 rpm for 16 hours to obtain the NC mixture that adsorbs nB and n-Ti.

[0048] (3) Add 4.5 mL of ethyl acetate as a solvent to dissolve NC to the NC mixture that adsorbs nB and n-Ti. The rotation speed is still 700 rpm, but in order to prevent solvent evaporation, the temperature should be reduced to 60℃. After stirring for 30 min, a suspension of ternary aggregates is formed.

[0049] (4) Place 0.5g of gelatin in 300mL of water, and stir at 800rpm at a temperature of 75℃ until the gelatin particles are completely dissolved to form a gelatin aqueous solution.

[0050] (5) Use gelatin aqueous solution as a stabilizer, add it to the suspension of the ternary agglomerates, increase the rotation speed to 1300 rpm, keep the temperature at 60℃, and disperse it into small balls under the action of surface tension to keep the balls stable.

[0051] (6) The prepared spheres were placed in a vacuum drying oven and dried at 35°C to obtain thoroughly dried ternary boron nanospheres.

[0052] Depend on Figure 1 It can be seen that the ternary boron nanospheres prepared under these conditions have high sphericity and uniform size, and the cross-section shows that the nB and n-Ti particles are densely distributed.

[0053] Example 2

[0054] (1) Disperse 1.7g NC in 17mL of water, heat to 90℃, stir at 800rpm for 30min to obtain a suspension of swollen NC; disperse 0.6g n-Ti and 7.7g nB in 124.5mL of water, sonicate for 30min to obtain a mixed suspension of nB and n-Ti.

[0055] (2) The mixed suspension of nB and n-Ti was sprayed into the swollen NC suspension using an injector. The mixture was kept at 90°C and 700 rpm for 16 hours to obtain the NC mixture that adsorbs nB and n-Ti.

[0056] (3) Add 5.1 mL of ethyl acetate as a solvent to dissolve NC to the NC mixture that adsorbs nB and n-Ti. The rotation speed is still 700 rpm, but in order to prevent solvent evaporation, the temperature should be reduced to 60℃. After stirring for 30 min, a suspension of ternary aggregates is formed.

[0057] (4) Place 0.5g of gelatin in 300mL of water, and stir at 800rpm at a temperature of 75℃ until the gelatin particles are completely dissolved to form a gelatin aqueous solution.

[0058] (5) Use gelatin aqueous solution as a stabilizer, add it to the suspension of the ternary agglomerates, increase the rotation speed to 1300 rpm, keep the temperature at 60℃, and disperse it into small balls under the action of surface tension to keep the balls stable.

[0059] (6) The prepared spheres were placed in a vacuum drying oven and dried at 35°C to obtain thoroughly dried ternary boron nanospheres.

[0060] Depend on Figure 2 It can be seen that the particle size of the ternary boron nanospheres prepared under these conditions is mainly 200-300 μm.

[0061] Example 3

[0062] (1) Disperse 1.9g NC in 19mL of water, heat to 90℃, stir at 800rpm for 30min to obtain a suspension of swollen NC; disperse 0.6g n-Ti and 7.5g nB in 121.5mL of water, sonicate for 30min to obtain a mixed suspension of nB and n-Ti.

[0063] (2) The mixed suspension of nB and n-Ti was sprayed into the swollen NC suspension using an injector. The mixture was kept at 90°C and 700 rpm for 16 hours to obtain the NC mixture that adsorbs nB and n-Ti.

[0064] (3) Add 5.7 mL of ethyl acetate as a solvent to dissolve NC to the NC mixture that adsorbs nB and n-Ti. The rotation speed is still 700 rpm, but in order to prevent solvent evaporation, the temperature should be reduced to 60℃. After stirring for 30 min, a suspension of ternary aggregates is formed.

[0065] (4) Place 0.5g of gelatin in 300mL of water, and stir at 800rpm at a temperature of 75℃ until the gelatin particles are completely dissolved to form a gelatin aqueous solution.

[0066] (5) Use gelatin aqueous solution as a stabilizer, add it to the suspension of the ternary agglomerates, increase the rotation speed to 1300 rpm, keep the temperature at 60℃, and disperse it into small balls under the action of surface tension to keep the balls stable.

[0067] (6) The prepared spheres were placed in a vacuum drying oven and dried at 35°C to obtain thoroughly dried ternary boron nanospheres.

[0068] Depend on Figure 3 It can be seen that when the ternary boron nanospheres prepared under these conditions are directly ignited by a laser in atmospheric pressure air, the product is white after combustion.

[0069] Example 4

[0070] (1) Disperse 1.5g NC in 15mL of water, heat to 90℃, stir at 800rpm for 30min to obtain a suspension of swollen NC; disperse 0.8g n-Ti and 7.7g nB in 127.5mL of water, sonicate for 30min to obtain a mixed suspension of nB and n-Ti.

[0071] (2) The mixed suspension of nB and n-Ti was sprayed into the swollen NC suspension using an injector. The mixture was kept at 90°C and 700 rpm for 16 hours to obtain the NC mixture that adsorbs nB and n-Ti.

[0072] (3) Add 4.5 mL of ethyl acetate as a solvent to dissolve NC to the NC mixture that adsorbs nB and n-Ti. The rotation speed is still 700 rpm, but in order to prevent solvent evaporation, the temperature should be reduced to 60℃. After stirring for 30 min, a suspension of ternary aggregates is formed.

[0073] (4) Place 0.5g of gelatin in 300mL of water, and stir at 800rpm at a temperature of 75℃ until the gelatin particles are completely dissolved to form a gelatin aqueous solution.

[0074] (5) Use gelatin aqueous solution as a stabilizer, add it to the suspension of the ternary agglomerates, increase the rotation speed to 1300 rpm, keep the temperature at 60℃, and disperse it into small balls under the action of surface tension to keep the balls stable.

[0075] (6) The prepared spheres were placed in a vacuum drying oven and dried at 35°C to obtain thoroughly dried ternary boron nanospheres.

[0076] Example 5

[0077] (1) Disperse 1.7g NC in 15mL of water, heat to 90℃, stir at 800rpm for 30min to obtain a suspension of swollen NC; disperse 0.8g n-Ti and 7.5g nB in 124.5mL of water, sonicate for 30min to obtain a mixed suspension of nB and n-Ti.

[0078] (2) The mixed suspension of nB and n-Ti was sprayed into the swollen NC suspension using an injector. The mixture was kept at 90°C and 700 rpm for 16 hours to obtain the NC mixture that adsorbs nB and n-Ti.

[0079] (3) Add 5.1 mL of ethyl acetate as a solvent to dissolve NC to the NC mixture that adsorbs nB and n-Ti. The rotation speed is still 700 rpm, but in order to prevent solvent evaporation, the temperature should be reduced to 60℃. After stirring for 30 min, a suspension of ternary aggregates is formed.

[0080] (4) Place 0.5g of gelatin in 300mL of water, and stir at 800rpm at a temperature of 75℃ until the gelatin particles are completely dissolved to form a gelatin aqueous solution.

[0081] (5) Use gelatin aqueous solution as a stabilizer, add it to the suspension of the ternary agglomerates, increase the rotation speed to 1300 rpm, keep the temperature at 60℃, and disperse it into small balls under the action of surface tension to keep the balls stable.

[0082] (6) The prepared spheres were placed in a vacuum drying oven and dried at 35°C to obtain thoroughly dried ternary boron nanospheres.

[0083] Example 6

[0084] (1) Disperse 1.9g NC in 19mL of water, heat to 90℃, stir at 800rpm for 30min to obtain a suspension of swollen NC; disperse 0.8g n-Ti and 7.3g nB in 121.5mL of water, sonicate for 30min to obtain a mixed suspension of nB and n-Ti.

[0085] (2) The mixed suspension of nB and n-Ti was sprayed into the swollen NC suspension using an injector. The mixture was kept at 90°C and 700 rpm for 16 hours to obtain the NC mixture that adsorbs nB and n-Ti.

[0086] (3) Add 5.7 mL of ethyl acetate as a solvent to dissolve NC to the NC mixture that adsorbs nB and n-Ti. The rotation speed is still 700 rpm, but in order to prevent solvent evaporation, the temperature should be reduced to 60℃. After stirring for 30 min, a suspension of ternary aggregates is formed.

[0087] (4) Place 0.5g of gelatin in 300mL of water, and stir at 800rpm at a temperature of 75℃ until the gelatin particles are completely dissolved to form a gelatin aqueous solution.

[0088] (5) Use gelatin aqueous solution as a stabilizer, add it to the suspension of the ternary agglomerates, increase the rotation speed to 1300 rpm, keep the temperature at 60℃, and disperse it into small balls under the action of surface tension to keep the balls stable.

[0089] (6) The prepared spheres were placed in a vacuum drying oven and dried at 35°C to obtain thoroughly dried ternary boron nanospheres.

[0090] Example 7

[0091] (1) Disperse 1.5g NC in 15mL of water, heat to 90℃, stir at 800rpm for 30min to obtain a suspension of swollen NC; disperse 1.0g n-Ti and 7.5g nB in 127.5mL of water, sonicate for 30min to obtain a mixed suspension of nB and n-Ti.

[0092] (2) The mixed suspension of nB and n-Ti was sprayed into the swollen NC suspension using an injector. The mixture was kept at 90°C and 700 rpm for 16 hours to obtain the NC mixture that adsorbs nB and n-Ti.

[0093] (3) Add 4.5 mL of ethyl acetate as a solvent to dissolve NC to the NC mixture that adsorbs nB and n-Ti. The rotation speed is still 700 rpm, but in order to prevent solvent evaporation, the temperature should be reduced to 60℃. After stirring for 30 min, a suspension of ternary aggregates is formed.

[0094] (4) Place 0.5g of gelatin in 300mL of water, and stir at 800rpm at a temperature of 75℃ until the gelatin particles are completely dissolved to form a gelatin aqueous solution.

[0095] (5) Use gelatin aqueous solution as a stabilizer, add it to the suspension of the ternary agglomerates, increase the rotation speed to 1300 rpm, keep the temperature at 60℃, and disperse it into small balls under the action of surface tension to keep the balls stable.

[0096] (6) The prepared spheres were placed in a vacuum drying oven and dried at 35°C to obtain thoroughly dried ternary boron nanospheres.

[0097] Example 8

[0098] (1) Disperse 1.7g NC in 17mL of water, heat to 90℃, stir at 800rpm for 30min to obtain a suspension of swollen NC; disperse 1.0g n-Ti and 7.3g nB in 124.5mL of water, sonicate for 30min to obtain a mixed suspension of nB and n-Ti.

[0099] (2) The mixed suspension of nB and n-Ti was sprayed into the swollen NC suspension using an injector. The mixture was kept at 90°C and 700 rpm for 16 hours to obtain the NC mixture that adsorbs nB and n-Ti.

[0100] (3) Add 5.1 mL of ethyl acetate as a solvent to dissolve NC to the NC mixture that adsorbs nB and n-Ti. The rotation speed is still 700 rpm, but in order to prevent solvent evaporation, the temperature should be reduced to 60℃. After stirring for 30 min, a suspension of ternary aggregates is formed.

[0101] (4) Place 0.5g of gelatin in 300mL of water, and stir at 800rpm at a temperature of 75℃ until the gelatin particles are completely dissolved to form a gelatin aqueous solution.

[0102] (5) Use gelatin aqueous solution as a stabilizer, add it to the suspension of the ternary agglomerates, increase the rotation speed to 1300 rpm, keep the temperature at 60℃, and disperse it into small balls under the action of surface tension to keep the balls stable.

[0103] (6) The prepared spheres were placed in a vacuum drying oven and dried at 35°C to obtain thoroughly dried ternary boron nanospheres.

[0104] Example 9

[0105] (1) Disperse 1.9g NC in 19mL of water, heat to 90℃, stir at 800rpm for 30min to obtain a suspension of swollen NC; disperse 1.0g n-Ti and 7.1g nB in 121.5mL of water, sonicate for 30min to obtain a mixed suspension of nB and n-Ti.

[0106] (2) The mixed suspension of nB and n-Ti was sprayed into the swollen NC suspension using an injector. The mixture was kept at 90°C and 700 rpm for 16 hours to obtain the NC mixture that adsorbs nB and n-Ti.

[0107] (3) Add 5.7 mL of ethyl acetate as a solvent to dissolve NC to the NC mixture that adsorbs nB and n-Ti. The rotation speed is still 700 rpm, but in order to prevent solvent evaporation, the temperature should be reduced to 60℃. After stirring for 30 min, a suspension of ternary aggregates is formed.

[0108] (4) Place 0.5g of gelatin in 300mL of water, and stir at 800rpm at a temperature of 75℃ until the gelatin particles are completely dissolved to form a gelatin aqueous solution.

[0109] (5) Use gelatin aqueous solution as a stabilizer, add it to the suspension of the ternary agglomerates, increase the rotation speed to 1300 rpm, keep the temperature at 60℃, and disperse it into small balls under the action of surface tension to keep the balls stable.

[0110] (6) The prepared spheres were placed in a vacuum drying oven and dried at 35°C to obtain thoroughly dried ternary boron nanospheres.

[0111] The SEM images of the ternary boron nanospheres prepared in Examples 2-9 are similar to those of the ternary spheres and their cross-sections.

[0112] Example 10

[0113] (1) Disperse 1.9g NC in 15mL of water, heat to 87℃, stir at 800rpm for 30min to obtain a suspension of swollen NC; disperse 1g n-Ti and 7.1g nB in 86.4mL of water, sonicate for 30min to obtain a mixed suspension of nB and n-Ti.

[0114] (2) The mixed suspension of nB and n-Ti was sprayed into the swollen NC suspension using an injector. The mixture was kept at 90°C and 700 rpm for 16 hours to obtain the NC mixture that adsorbs nB and n-Ti.

[0115] (3) Add 4.5 mL of ethyl acetate as a solvent to dissolve NC to the NC mixture that adsorbs nB and n-Ti. Reduce the speed to 600 rpm, but in order to prevent solvent evaporation, the temperature should be reduced to 57°C. Stir for 30 min to form a suspension of ternary aggregates.

[0116] (4) Place 0.8g of gelatin in 300mL of water, and stir at 1300rpm at a temperature of 72℃ until the gelatin particles are completely dissolved to form a gelatin aqueous solution.

[0117] (5) Use gelatin aqueous solution as a stabilizer, add it to the suspension of the ternary agglomerates, increase the rotation speed to 1500 rpm, keep the temperature at 50°C, and disperse it into small balls under the action of surface tension to keep the balls stable.

[0118] (6) The prepared spheres were placed in a vacuum drying oven and dried at 35°C to obtain thoroughly dried ternary boron nanospheres.

[0119] Depend on Figure 6 It can be seen that the ternary boron nanospheres prepared under these conditions have high sphericity and a particle size of about 50 μm.

[0120] Example 11

[0121] (1) Disperse 1.5g NC in 15mL of water, heat to 93℃, stir at 800rpm for 30min to obtain a suspension of swollen NC; disperse 0.2g n-Ti and 8.3g nB in 170mL of water, sonicate for 30min to obtain a mixed suspension of nB and n-Ti.

[0122] (2) The mixed suspension of nB and n-Ti was sprayed into the swollen NC suspension using an injector. The mixture was kept at 87°C and 700 rpm for 16 hours to obtain the NC mixture that adsorbs nB and n-Ti.

[0123] (3) Add 6 mL of ethyl acetate as a solvent to the NC mixture that adsorbs nB and n-Ti, reduce the speed to 500 rpm, but in order to prevent solvent evaporation, the temperature should be reduced to 63℃. After stirring for 30 min, a suspension of ternary aggregates is formed.

[0124] (4) Place 0.6g of gelatin in 300mL of water, and stir at 800rpm at a temperature of 75℃ until the gelatin particles are completely dissolved to form a gelatin aqueous solution.

[0125] (5) Use gelatin aqueous solution as a stabilizer, add it to the suspension of the ternary agglomerates, increase the rotation speed to 300 rpm, keep the temperature at 40°C, and disperse it into small balls under the action of surface tension to keep the balls stable.

[0126] (6) The prepared spheres were placed in a vacuum drying oven and dried at 35°C to obtain thoroughly dried ternary boron nanospheres.

[0127] Depend on Figure 7It can be seen that the ternary boron nanospheres prepared under these conditions have high sphericity and a particle size of about 500 μm.

[0128] Example 12

[0129] (1) Disperse 1.9g NC in 15mL of water, heat to 87℃, stir at 800rpm for 30min to obtain a suspension of swollen NC; disperse 1g n-Ti and 7.1g nB in 86.4mL of water, sonicate for 30min to obtain a mixed suspension of nB and n-Ti.

[0130] (2) The mixed suspension of nB and n-Ti was sprayed into the swollen NC suspension using an injector. The mixture was kept at 90°C and 700 rpm for 16 hours to obtain the NC mixture that adsorbs nB and n-Ti.

[0131] (3) Add 4.5 mL of ethyl acetate as a solvent to dissolve NC to the NC mixture that adsorbs nB and n-Ti. Reduce the speed to 600 rpm, but in order to prevent solvent evaporation, the temperature should be reduced to 57°C. Stir for 30 min to form a suspension of ternary aggregates.

[0132] (4) Place 0.8g of gelatin in 300mL of water, and stir at 1300rpm at a temperature of 72℃ until the gelatin particles are completely dissolved to form a gelatin aqueous solution.

[0133] (5) Use gelatin aqueous solution as a stabilizer, add it to the suspension of the ternary agglomerates, increase the rotation speed to 300 rpm, keep the temperature at 40°C, and disperse it into small balls under the action of surface tension to keep the balls stable.

[0134] (6) The prepared spheres were placed in a vacuum drying oven and dried at 35°C to obtain thoroughly dried ternary boron nanospheres.

[0135] Example 13

[0136] (1) Disperse 1.5g NC in 15mL of water, heat to 93℃, stir at 800rpm for 30min to obtain a suspension of swollen NC; disperse 0.2g n-Ti and 8.3g nB in 170mL of water, sonicate for 30min to obtain a mixed suspension of nB and n-Ti.

[0137] (2) The mixed suspension of nB and n-Ti was sprayed into the swollen NC suspension using an injector. The mixture was kept at 87°C and 700 rpm for 16 hours to obtain the NC mixture that adsorbs nB and n-Ti.

[0138] (3) Add 6 mL of ethyl acetate as a solvent to the NC mixture that adsorbs nB and n-Ti, reduce the speed to 500 rpm, but in order to prevent solvent evaporation, the temperature should be reduced to 63℃. After stirring for 30 min, a suspension of ternary aggregates is formed.

[0139] (4) Place 0.6g of gelatin in 300mL of water, and stir at 800rpm at a temperature of 75℃ until the gelatin particles are completely dissolved to form a gelatin aqueous solution.

[0140] (5) Use gelatin aqueous solution as a stabilizer, add it to the suspension of the ternary agglomerates, increase the rotation speed to 800 rpm, keep the temperature at 50°C, and disperse it into small balls under the action of surface tension to keep the balls stable.

[0141] (6) The prepared spheres were placed in a vacuum drying oven and dried at 35°C to obtain thoroughly dried ternary boron nanospheres.

[0142] Example 14

[0143] (1) Disperse 1.6g NC in 15mL of water, heat to 90℃, stir at 800rpm for 30min to obtain a suspension of swollen NC; disperse 1g n-Ti and 8.3g nB in 146mL of water, sonicate for 30min to obtain a mixed suspension of nB and n-Ti.

[0144] (2) The mixed suspension of nB and n-Ti was sprayed into the swollen NC suspension using an injector. The mixture was kept at a temperature of 93°C and a stirring speed of 700 rpm for 16 hours to obtain the NC mixture that adsorbs nB and n-Ti.

[0145] (3) Add 8 mL of ethyl acetate as a solvent to dissolve NC in the NC mixture that adsorbs nB and n-Ti, increase the speed to 800 rpm, but in order to prevent solvent evaporation, the temperature should be reduced to 60℃. After stirring for 30 min, a suspension of ternary aggregates is formed.

[0146] (4) Place 0.5g of gelatin in 300mL of water and stir at 1000rpm at a temperature of 78℃ until the gelatin particles are completely dissolved to form a gelatin aqueous solution.

[0147] (5) Use gelatin aqueous solution as a stabilizer, add it to the suspension of the ternary agglomerates, increase the rotation speed to 1500 rpm, keep the temperature at 70°C, and disperse it into small balls under the action of surface tension to keep the balls stable.

[0148] (6) The prepared spheres were placed in a vacuum drying oven and dried at 35°C to obtain thoroughly dried ternary boron nanospheres.

[0149] Comparative Example 1 does not contain titanium

[0150] (1) Disperse 1.7g NC in 17mL of water, heat to 90℃, stir at 800rpm for 30min to obtain a suspension of swollen NC; disperse 8.3g nB in 124.5mL of water, sonicate for 30min to obtain a suspension of nB.

[0151] (2) The nB suspension was sprayed into the swollen NC suspension using an injector. The mixture was kept at 90°C and 700 rpm for 16 hours to obtain an NC mixture that adsorbs nB and n-Ti.

[0152] (3) Add 5.1 mL of ethyl acetate as a solvent to dissolve NC to the NC mixture that adsorbs nB. The rotation speed is still 700 rpm, but in order to prevent solvent evaporation, the temperature should be reduced to 60℃. After stirring for 30 min, a suspension of binary agglomerates is formed.

[0153] (4) Place 0.5g of gelatin in 300mL of water, and stir at 800rpm at a temperature of 75℃ until the gelatin particles are completely dissolved to form a gelatin aqueous solution.

[0154] (5) Use gelatin aqueous solution as a stabilizer, add it to the suspension of the ternary agglomerates, increase the rotation speed to 1300 rpm, keep the temperature at 60℃, and disperse it into small balls under the action of surface tension to keep the balls stable.

[0155] (6) The prepared spherical particles were placed in a vacuum drying oven and dried at 35°C to obtain thoroughly dried binary boron nanosphere aggregate particles.

[0156] Depend on Figure 4 XRD analysis of the combustion products showed that, under these conditions, the combustion products of the ternary boron nanospheres did not contain elemental boron, while the elemental boron and binary products still contained elemental boron nanospheres. This indicates that the particles prepared by this method can burn completely and have a higher combustion efficiency than the binary products and elemental boron. This is because n-Ti promotes the combustion of agglomerates.

[0157] Depend on Figure 5It can be seen that the ternary boron nanospheres prepared under these conditions, from the appearance of sparks to the flame turning into a dazzling white, then gradually turning into a bright green, and then further weakening to a dark green, until the flame at the bottom completely disappears, show that the ternary boron nanospheres have a shorter burning time and burn more intensely, while the binary mixture burns poorly. This is because n-Ti has a low ignition point and burns quickly under the heating effect of laser, releasing a large amount of heat, which is quickly transferred to the nB gathered around it, promoting the combustion of nB.

[0158] The ternary boron nanospheres prepared by the present invention using a five-step method of swelling-adsorption-dissolution-spheroidization-drying can be used as raw materials for boron-rich fuel solid propellants, or as high-energy spherical nano-metal agglomerates for solid powder ramjet engines.

[0159] To address the problem of low combustion efficiency of boron powder, this invention employs a five-step method of swelling, adsorption, dissolution, spheroidization, and drying to obtain ternary boron nanospheres with high combustion efficiency.

[0160] Because nanoparticles are too small, they tend to stick together. The method of this invention allows nanoparticles to remain dispersed in a nanoscale state during combustion, thus avoiding their sticking and improving combustion efficiency.

[0161] This invention employs a five-step method—swelling-adsorption-dissolution-sphericalization-drying—to prepare ternary boron nanospheres. Ethyl acetate is used as the solvent, NC as the dispersion medium, n-Ti as the combustion promoter, and nB as the high-energy fuel. After ultrasonic stirring and homogenization of each component, the resulting ternary boron nanospheres are a high-energy composite material with high dispersibility and excellent combustion performance. This composite material is a mixture of a metallic combustion promoter (n-Ti) and a metallic fuel (nB), and the adsorption and dissolution of NC ensures uniform mixing of the two phases. Furthermore, the superior gas production and large specific surface area of ​​NC further enhance its catalytic combustion effect on solid propellants. This method is green, safe, and simple to operate, representing a novel and efficient method for preparing highly dispersible energetic nanocomposite materials.

[0162] The high-energy composite material prepared by this invention uses NC as a carrier and binder, resulting in dense spherical structures with uniform particle size. It simultaneously possesses both a metallic combustion accelerant and a metallic fuel, enabling a sustained and vigorous reaction that releases enormous energy. It can serve as a raw material for boron-rich solid propellants, achieving stable combustion of solid propellants under low pressure and improving combustion efficiency. The synthesis method of this invention is green, safe, simple, and effective, and is environmentally friendly and easily industrialized.

[0163] The above description is only of the preferred embodiment of the present invention and should not be construed as limiting the scope of the claims. The present invention is not limited to the above embodiments, and variations in its specific structure are permitted. All variations made within the scope of the independent claims of the present invention are also within the scope of protection of the present invention.

[0164] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

Claims

1. A method for preparing ternary nanoboron spherical particles, characterized in that, The method comprises the following steps: adding nano-boron and nano-titanium into water, mixing uniformly under ultrasonic oscillation to obtain a mixed suspension of nano-boron and nano-titanium, wherein the particle size of the nano-boron is 100-200 nm, and the particle size of the nano-titanium is 50-100 nm; placing nitrocellulose into water at 87-93 ℃, and heating and stirring to form a nitrocellulose suspension; spraying the mixed suspension into the nitrocellulose suspension, heating and stirring to make the nano-boron and nano-titanium enter the nitrocellulose to form a mixed solution; adding ethyl acetate into the mixed solution, heating and stirring to make the ethyl acetate dissolve the nitrocellulose and coat the nano-boron and nano-titanium, thereby forming a three-component agglomerate; wherein the ratio of the amount of the nitrocellulose to the amount of the ethyl acetate is 1 g: 3-5 mL; adding a gelatin aqueous solution into the three-component agglomerate, heating and stirring, filtering, and drying to obtain the ternary nano-boron spherical particles; wherein the amount of the gelatin is 5-8 wt% of the total mass of the nitrocellulose, nano-titanium and nano-boron.

2. The method for preparing ternary boron nanospheres according to claim 1, characterized in that, The nitrogen content of the nitrocellulose is 12.1%.

3. The method for preparing ternary boron nanospheres according to claim 1, characterized in that, The amount of the nano-titanium is 1-10 wt% of the ternary nano-boron spherical particles, the amount of the nano-boron is 71-83 wt% of the ternary nano-boron spherical particles, and the amount of the nitrocellulose is 15-19 wt% of the ternary nano-boron spherical particles.

4. The ternary nanoboric spherical particles prepared according to the method of any one of claims 1-3, characterized in that, The particle size is 50-500 μm.

5. Use of the ternary nano-boron spherical particles according to claim 4 in the preparation of a boron-containing fuel-rich solid propellant.

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