Boron nitride hollow microsphere aerogel, preparation method and application thereof

Abstract

The present invention discloses a boron nitride hollow microsphere aerogel, a preparation method and an application thereof. The boron nitride hollow microsphere aerogel is assembled from boron nitride hollow microspheres as building units, and the boron nitride hollow microspheres are overlapped and assembled to form a three-dimensional porous network structure, and the boron nitride hollow microsphere aerogel has a fluorescence phenomenon under ultraviolet irradiation. The preparation method comprises: providing a melamine-borate-based aerogel material, which includes melamine, boric acid and a small molecule regulator; in a selected gas atmosphere, the melamine-borate-based aerogel material is subjected to instantaneous high-temperature treatment by laser direct writing technology to obtain a boron nitride hollow microsphere aerogel. The boron nitride hollow microsphere aerogel of the present invention has a fluorescence phenomenon and can be processed into different patterns during the synthesis process. The preparation process is simple, the preparation cycle is short, it is green and pollution-free, and fast and accurate patterned design and synthesis can be achieved.

Description

Technical Field

[0001] The present invention relates to a boron nitride aerogel, in particular to a boron nitride hollow microsphere aerogel and a preparation method and application thereof, belonging to the field of nano energy technology. Background Art

[0002] Aerogels are low-density solid materials with a continuous three-dimensional porous network structure, dispersed in a gas medium. Since 1932, when American chemist Samuel Stephens Kistler first used supercritical fluid drying technology to prepare "solid smoke"—silica aerogel—aerogel has attracted considerable attention and research as a new member of the aerogel family. Over the past century, a wide range of aerogels with diverse materials, structures, and properties have been synthesized, including various alkoxysilane-derived silica aerogels, metal oxide aerogels (such as TiO2, Al2O3, and ZrO2), metal aerogels (such as gold), polymer aerogels (such as polyaniline, polypyrrole, and polyimide), carbon aerogels and novel nanocarbon aerogels (such as graphene and carbon nanotubes), semiconductor sulfide aerogels, carbide aerogels (such as silicon carbide and titanium aluminum carbide), natural polymer aerogels (i.e., cellulose and other polysaccharides, various proteins, and DNA), and boron nitride aerogels. These have greatly enriched the aerogel family and expanded the research and application areas of aerogels. However, current aerogel sol-gel transitions are mostly macroscopic bulk reactions, and the reaction system is relatively uniform, resulting in a material with only a simple structural morphology. Furthermore, the inherent brittleness of aerogels makes them difficult to pattern and engrave through post-processing. Consequently, the current aerogel material preparation process and macroscopic structural morphology are relatively simple.

[0003] In view of the urgent need for aerogels in catalysis, thermal insulation, patterning-informatization applications, etc., a process method with simple process, short production cycle, low cost and customizable design is developed, and patterned aerogel materials with optical properties and information management functions are developed to give full play to the advantages of aerogels and push the application of aerogels to a new level, thereby meeting the social development demand for new functional integrated materials. Summary of the Invention

[0004] The main purpose of the present invention is to provide a boron nitride hollow microsphere aerogel and a preparation method and application thereof, so as to overcome the deficiencies in the prior art.

[0005] To achieve the aforementioned object of the invention, the technical solutions adopted by the present invention include:

[0006] An embodiment of the present invention provides a boron nitride hollow microsphere aerogel, which is assembled from boron nitride hollow microspheres as building units, and the boron nitride hollow microspheres are overlapped and assembled to form a three-dimensional porous network structure. The boron nitride hollow microsphere aerogel exhibits fluorescence under ultraviolet irradiation.

[0007] The present invention also provides a method for preparing a hollow boron nitride microsphere aerogel, which comprises:

[0008] Providing a melamine-borate-based aerogel material, wherein the melamine-borate-based aerogel material comprises melamine, boric acid, and a small molecule regulator;

[0009] In a selected gas atmosphere, the melamine-borate-based aerogel material is subjected to instantaneous high-temperature treatment by laser direct writing technology to obtain a boron nitride hollow microsphere aerogel.

[0010] The embodiments of the present invention further provide applications of the aforementioned boron nitride hollow microsphere aerogel in fields such as fluorescent labeling, high-efficiency thermal insulation, or information management.

[0011] Compared with the prior art, the advantages of the present invention are at least:

[0012] 1) The basic structural unit of the boron nitride hollow microsphere aerogel provided by the present invention is mainly boron nitride hollow microspheres, which exhibit obvious fluorescence phenomenon;

[0013] 2) The boron nitride hollow microsphere aerogel provided by the present invention is based on melamine-borate aerogel material and is prepared by laser direct writing, which can accurately and quickly realize the pattern design and synthesis of aerogel materials; moreover, the preparation process is simple, the production cycle is short, the operation is easy, the energy consumption is low, the cost is low, it is green and pollution-free, and large-scale continuous production can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 This is a scanning electron microscope (SEM) photograph of the boron nitride hollow microsphere aerogel obtained in Example 1 of the present invention.

[0016] Figure 2 This is a fluorescent optical photograph of the boron nitride hollow microsphere aerogel obtained in Example 1 of the present invention.

[0017] Figure 3This is a scanning electron microscope (SEM) photograph of the boron nitride hollow microsphere aerogel obtained in Example 2 of the present invention.

[0018] Figure 4 This is an optical photograph of the boron nitride hollow microsphere aerogel obtained in Example 2 of the present invention.

[0019] Figure 5 This is a scanning electron microscope (SEM) photograph of the nitrided hollow microsphere aerogel obtained in Example 3 of the present invention.

[0020] Figure 6 This is a fluorescent optical photograph of the boron nitride hollow microsphere aerogel obtained in Example 3 of the present invention.

[0021] Figure 7 This is a scanning electron microscope (SEM) photograph of the boron nitride hollow microsphere aerogel obtained in Example 4 of the present invention.

[0022] Figure 8 This is a fluorescent optical photograph of the boron nitride hollow microsphere aerogel obtained in Example 4 of the present invention.

[0023] Figure 9 This is a scanning electron microscope (SEM) photograph of the boron nitride hollow microsphere aerogel obtained in Example 5 of the present invention.

[0024] Figure 10 This is a fluorescent optical photograph of the boron nitride hollow microsphere aerogel obtained in Example 5 of the present invention.

[0025] Figure 11 This is a scanning electron microscope (SEM) photograph of the boron nitride hollow microsphere aerogel obtained in Example 6 of the present invention.

[0026] Figure 12 This is a fluorescent optical photograph of the boron nitride hollow microsphere aerogel obtained in Example 6 of the present invention.

[0027] Figure 13 This is a scanning electron microscope (SEM) photograph of the boron nitride hollow microsphere aerogel obtained in Example 7 of the present invention.

[0028] Figure 14 This is a fluorescent optical photograph of the boron nitride hollow microsphere aerogel obtained in Example 7 of the present invention.

[0029] Figure 15 This is a scanning electron microscope (SEM) photograph of the boron nitride hollow microsphere aerogel obtained in Example 8 of the present invention.

[0030] Figure 16 This is a fluorescent optical photograph of the boron nitride hollow microsphere aerogel obtained in Example 8 of the present invention.

[0031] Figure 17This is a scanning electron microscope (SEM) photograph of the boron nitride hollow microsphere aerogel obtained in Example 9 of the present invention.

[0032] Figure 18 This is a fluorescent optical photograph of the boron nitride hollow microsphere aerogel obtained in Example 9 of the present invention.

[0033] Figure 19 This is a transmission electron microscope (TEM) photograph of the nitrided hollow microsphere aerogel obtained in Example 1 of the present invention.

[0034] Figure 20 This is a distribution diagram of the outer diameter of the boron nitride hollow microsphere aerogel obtained in Example 1 of the present invention.

[0035] Figure 21 This is a nitrogen adsorption-desorption curve of the boron nitride hollow microsphere aerogel obtained in Example 1 of the present invention.

[0036] Figure 22 This is a pore size distribution diagram of the nitrided hollow microsphere aerogel obtained in Example 1 of the present invention.

[0037] Figure 23 This is a scanning electron microscope (SEM) photograph of the nitrided micro-nanobelt aerogel obtained in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0038] In light of the shortcomings of the existing technology, the inventors of this case, after extensive research and extensive practice, have developed the technical solution of the present invention. This solution primarily utilizes a polymelamine-borate-based aerogel material, which is then subjected to instantaneous high-temperature treatment via laser direct writing to produce a hollow boron nitride microsphere aerogel. This technical solution, its implementation process, and its principles are further explained below.

[0039] One aspect of an embodiment of the present invention provides a boron nitride hollow microsphere aerogel assembled from boron nitride hollow microspheres as building units, and the boron nitride hollow microspheres are overlapped and assembled to form a three-dimensional porous network structure.

[0040] The boron nitride hollow microsphere aerogel appears white under natural light and exhibits obvious fluorescence under ultraviolet irradiation. Furthermore, the fluorescent color includes any one of blue, green, purple, etc.

[0041] In some embodiments, the boron nitride hollow microspheres are mainly composed of boron and nitrogen, and can further be specifically composed of boron, nitrogen, carbon, oxygen and other elements.

[0042] In some embodiments, the morphology of the hollow boron nitride microspheres includes any one or a combination of two or more of hollow spheres, hollow ellipsoidal spheres, broken hollow spheres, hollow dumbbell-shaped spheres, etc., but is not limited thereto.

[0043] In some embodiments, the outer diameter of the hollow boron nitride microspheres is 10 nm to 100 μm, preferably 100 nm to 50 μm.

[0044] Furthermore, the specific surface area of ​​the boron nitride hollow microsphere aerogel is 0.1 to 900 m 2 / g, preferably 30 to 500 m 2 / g.

[0045] Furthermore, the pore volume of the boron nitride hollow microsphere aerogel is 0.1 to 3 cm 3 / g, preferably 0.5 to 2 cm 3 / g.

[0046] Furthermore, the density of the boron nitride hollow microsphere aerogel is 5 to 200 mg / cm 3 , preferably 10 to 30 mg / cm 3 .

[0047] Furthermore, the three-dimensional porous network structure of the boron nitride hollow microsphere aerogel includes micropores with a pore size of 0.5 to 2 nm, mesopores with a pore size of 2 to 50 nm, and macropores with a pore size of 50 nm to 100 μm.

[0048] In some preferred embodiments, the macropores are formed between the boron nitride hollow microspheres, and the boron nitride hollow microspheres themselves have the mesopores and micropores.

[0049] In some preferred embodiments, the boron nitride hollow microspheres are stacked in a three-dimensional porous network structure and connected by nanofibers.

[0050] In some embodiments, the macroscopic morphology of the boron nitride hollow microsphere aerogel may include any one or a combination of two or more of three-dimensional macroscopic blocks, two-dimensional plane patterns, one-dimensional line patterns, zero-dimensional lattices, and complex patterns, but is not limited thereto.

[0051] In summary, the basic structural unit of the boron nitride hollow microsphere aerogel provided by the present invention is mainly composed of boron nitride hollow microspheres, and the hollow microspheres are overlapped and assembled to form a three-dimensional porous network structure. The boron nitride aerogel exhibits obvious fluorescence phenomenon.

[0052] Another aspect of the embodiments of the present invention further provides a method for preparing boron nitride hollow microsphere aerogel, comprising:

[0053] Providing a melamine-borate-based aerogel material, wherein the melamine-borate-based aerogel material comprises melamine, boric acid, and a small molecule regulator;

[0054] In a selected gas atmosphere, the melamine-borate-based aerogel material is subjected to instantaneous high-temperature treatment by laser direct writing technology to obtain a boron nitride hollow microsphere aerogel.

[0055] In a specific embodiment, the preparation method of the boron nitride hollow microsphere aerogel specifically comprises the following steps:

[0056] 1) providing a melamine-borate-based aerogel material, wherein the melamine-borate-based aerogel material comprises melamine, boric acid, and a small molecule regulator;

[0057] 2) The melamine-borate-based aerogel material is placed in a specific atmosphere and subjected to instantaneous high-temperature treatment by laser direct writing technology to obtain a boron nitride hollow microsphere aerogel.

[0058] In some preferred embodiments, in step 1), the mass ratio of melamine to boric acid is 1:20 to 20:1, preferably 1:10 to 10:1.

[0059] Furthermore, the small molecule regulator includes any one or a combination of two or more of urea, cyanuric acid, sodium borate, boric anhydride, biuret, metal salt, etc., but is not limited thereto.

[0060] Furthermore, the mass fraction of the small molecule regulator in the melamine-borate based aerogel material is 0 to 50 wt%.

[0061] In some preferred embodiments, in step 2), the laser used in the laser direct writing technology is obtained by excitation of a laser, and the laser includes any one of a continuous laser, a quasi-continuous laser, a pulsed laser, and the like.

[0062] Furthermore, the modes of the laser direct writing technology include any one or a combination of two or more of laser scanning, laser drilling, laser cutting, etc., but are not limited thereto.

[0063] Furthermore, the laser wavelength used in the laser direct writing technology is any one of the wavelengths of ultraviolet light, visible light, infrared light, etc.

[0064] Furthermore, the power used in the laser direct writing technology is 0.1W to 10000W, preferably 5W to 600W.

[0065] Furthermore, the speed adopted by the laser direct writing technology is 0 to 1000 mm / s, preferably 0 to 100 mm / s.

[0066] In some preferred embodiments, in step 2), the temperature of the instantaneous high temperature treatment is 300-3000° C., and the time is 1 ms-1 min.

[0067] Furthermore, in step 2), the gas used in the selected gas atmosphere includes any one or a combination of two or more of air, nitrogen, argon, helium, etc., but is not limited thereto.

[0068] In summary, the boron nitride hollow microsphere aerogel provided by the present invention is based on melamine-borate aerogel materials and is prepared by laser direct writing. This allows for precise patterning of the aerogel material and allows for processing into different patterns during the synthesis process. Furthermore, the preparation process is simple, with a short production cycle, ease of operation, low energy consumption, low cost, and environmentally friendly, pollution-free production, enabling large-scale continuous production.

[0069] Another aspect of the embodiments of the present invention further provides a boron nitride hollow microsphere aerogel prepared by the aforementioned preparation method.

[0070] Another aspect of the embodiments of the present invention further provides applications of the boron nitride hollow microsphere aerogel in the fields of fluorescent labeling, high-efficiency thermal insulation, information management, etc.

[0071] The present invention will be more fully understood through the following detailed description, which should be read in conjunction with the accompanying drawings. Detailed embodiments of the present invention are disclosed herein; however, it should be understood that the disclosed embodiments are merely exemplary of the present invention, which can be embodied in various forms. Therefore, the specific functional details disclosed herein should not be construed as limiting, but rather as a basis for the claims and as a representative basis for teaching those skilled in the art to employ the present invention in various ways in virtually any appropriately detailed embodiment.

[0072] Example 1

[0073] (1) A melamine borate-based material having a mass ratio of boric acid to melamine of 2:1 and a cyanuric acid content of 0.5 wt% was selected.

[0074] (2) The boric acid-melamine salt-based aerogel material in step (1) is placed in an argon atmosphere, and a pulsed laser in the infrared band (wavelength 1053 nm) with a power of 0.1 W is used to scan the surface of the melamine-borate salt-based aerogel material at a moving speed of 350 mm / s. The temperature of the instantaneous high-temperature treatment is 300°C and the time is 1 min. By adjusting the laser scanning trajectory, a boron nitride hollow microsphere aerogel with a two-dimensional planar pattern is obtained.

[0075] The structure and performance characterization data of the aerogel obtained in this example are as follows: According to the BET test, the specific surface area of ​​the boron nitride hollow microsphere aerogel is 189m 2 / g, pore size distribution is 0.5-50nm, and its SEM structure is as follows Figure 1 , fluorescent images such as Figure 2 As shown, its TEM image is Figure 19 The size distribution of the hollow boron nitride microspheres is as follows Figure 20 , and its nitrogen adsorption and desorption curve is as follows Figure 21 , pore size distribution as Figure 22 The relevant physical properties of the aerogel obtained in this example are shown in Table 1.

[0076] Example 2

[0077] (1) Select a melamine borate-based material with a mass ratio of boric acid to melamine of 1:1.

[0078] (2) The boric acid / melamine aerogel in step (1) is placed in an argon atmosphere, and a pulsed laser with a power of 100 W in the visible light band (wavelength 532 nm) is used to perform laser cutting on the surface of the melamine-borate-based aerogel material at a moving speed of 100 mm / s. The temperature of the instantaneous high-temperature treatment is 2000° C. and the time is 1 ms. By adjusting the laser cutting trajectory, a three-dimensional block of boron nitride hollow microsphere aerogel is obtained.

[0079] The scanning electron microscope (SEM) photograph of the boron nitride hollow microsphere aerogel obtained in this example is as follows: Figure 3 As shown, the fluorescence images are Figure 4 The relevant physical properties are shown in Table 1.

[0080] Example 3

[0081] (1) A melamine-borate-based material with a mass ratio of boric acid to melamine of 10:1 and a mass fraction of the small molecule additive biuret of 30 wt% was selected.

[0082] (2) The boric acid-melamine salt-based aerogel material in step (1) is placed in an air atmosphere, and laser scanning is performed at a moving speed of 1000 mm / s by a continuous laser in the visible light band (wavelength 638 nm) with a power of 1 W. The temperature of the instantaneous high temperature treatment is 1000°C and the time is 0.5 min. By regulating the laser scanning trajectory, a boron nitride hollow microsphere aerogel with a complex planar pattern is obtained.

[0083] The scanning electron microscope (SEM) photograph of the boron nitride hollow microsphere aerogel obtained in this example is as follows: Figure 5 As shown, the fluorescence images are Figure 6 The relevant physical properties are shown in Table 1.

[0084] Example 4

[0085] (1) A melamine-borate-based material with a mass ratio of boric acid to melamine of 20:1 and a urea content of 10 wt% was selected.

[0086] (2) The boric acid-melamine salt-based aerogel material in step (1) is placed in a nitrogen atmosphere, and a continuous laser in the infrared band (wavelength 10600nm) with a power of 10000W is used to scan the surface of the melamine-borate salt-based aerogel material at a moving speed of 500mm / s. The temperature of the instantaneous high temperature treatment is 3000℃ and the time is 1ms. By adjusting the laser scanning trajectory, a boron nitride hollow microsphere aerogel with a two-dimensional planar pattern is obtained.

[0087] The scanning electron microscope (SEM) photograph of the boron nitride hollow microsphere aerogel obtained in this example is as follows: Figure 7 As shown, the fluorescence images are Figure 8 The relevant physical properties are shown in Table 1.

[0088] Example 5

[0089] (1) A melamine borate-based material having a mass ratio of boric acid to melamine of 5:1 and a metal salt (nickel chloride) content of 50 wt% was selected.

[0090] (2) The boric acid-melamine salt-based aerogel material in step (1) is placed in an argon atmosphere, and a continuous laser with a visible light band (wavelength of 532 nm) with a power of 50 W is used to perform laser cutting on the surface of the melamine-borate salt-based aerogel material at a moving speed of 100 mm / s. The temperature of the instantaneous high-temperature treatment is 800°C and the time is 1 s. By adjusting the laser cutting trajectory, a boron nitride hollow microsphere aerogel with a one-dimensional linear pattern is obtained.

[0091] The scanning electron microscope (SEM) photograph of the boron nitride hollow microsphere aerogel obtained in this example is as follows: Figure 9 As shown, the fluorescence images are Figure 10 The relevant physical properties are shown in Table 1.

[0092] Example 6

[0093] (1) A melamine borate-based material with a mass ratio of boric acid to melamine of 1:10 and a sodium borate content of 0.1 wt% was selected.

[0094] (2) The boric acid-melamine salt-based aerogel material in step (1) is placed in a helium atmosphere, and a mid-infrared band (wavelength 10600nm) continuous laser with a power of 600W is used to scan the surface of the melamine-borate salt-based aerogel material at a moving speed of 300mm / s. The temperature of the instantaneous high temperature treatment is 1500℃, and the time is 0.1min. By adjusting the laser scanning trajectory, a boron nitride hollow microsphere aerogel with a two-dimensional planar pattern is obtained.

[0095] The scanning electron microscope (SEM) photograph of the boron nitride hollow microsphere aerogel obtained in this example is as follows: Figure 11 As shown, the fluorescence images are Figure 12 The relevant physical properties are shown in Table 1.

[0096] Example 7

[0097] (1) A melamine borate-based material with a mass ratio of boric acid to melamine of 1:20 and a boric anhydride content of 5 wt% was selected.

[0098] (2) The boric acid-melamine salt-based aerogel material in step (1) is placed in an air atmosphere, and a pulsed laser with a power of 5000 W in the infrared band (wavelength 1064 nm) is used to scan the surface of the melamine-borate salt-based aerogel material at a moving speed of 5 mm / s. The temperature of the instantaneous high temperature treatment is 2500° C. and the time is 10 ms. By adjusting the laser drilling trajectory, a boron nitride hollow microsphere aerogel with a lattice pattern is obtained.

[0099] The scanning electron microscope (SEM) photograph of the boron nitride hollow microsphere aerogel obtained in this example is as follows: Figure 13 As shown, the fluorescence images are Figure 14 The relevant physical properties are shown in Table 1.

[0100] Example 8

[0101] (1) A melamine borate-based material with a mass ratio of boric acid to melamine of 2:1 and a biuret content of 1 wt% was selected.

[0102] (2) The boric acid-melamine salt-based aerogel material in step (1) is placed in an air atmosphere, and a continuous laser in the ultraviolet band (wavelength 315-400 nm) with a power of 10 W is used to perform laser drilling on the surface of the melamine-borate salt-based aerogel material at a moving speed of 0 mm / s. The temperature of the instantaneous high-temperature treatment is 600° C. and the time is 500 ms. By adjusting the laser drilling trajectory, a boron nitride hollow microsphere aerogel with a lattice pattern is obtained.

[0103] The scanning electron microscope (SEM) photograph of the boron nitride hollow microsphere aerogel obtained in this example is as follows: Figure 15 As shown, the fluorescence images are Figure 16 The relevant physical properties are shown in Table 1.

[0104] Example 9

[0105] (1) A melamine borate-based material having a mass ratio of boric acid to melamine of 1:5 and a metal salt (calcium phosphate) content of 25 wt% was selected.

[0106] (2) The boric acid-melamine salt-based aerogel material in step (1) is placed in a nitrogen atmosphere, and a continuous laser with a visible light band (wavelength of 660 nm) with a power of 5 W is used to scan the surface of the melamine-borate salt-based aerogel material at a moving speed of 50 mm / s. The temperature of the instantaneous high temperature treatment is 900°C and the time is 800 ms. By adjusting the laser scanning trajectory, a boron nitride hollow microsphere aerogel with a two-dimensional planar pattern is obtained.

[0107] The scanning electron microscope (SEM) photograph of the boron nitride hollow microsphere aerogel obtained in this example is as follows: Figure 17 As shown, the fluorescence images are Figure 18 The relevant physical properties are shown in Table 1.

[0108] Table 1 Structure and performance parameters of the boron nitride hollow microsphere aerogels prepared in Examples 1-9

[0109]

[0110]

[0111] Comparative Example 1

[0112] 1) Selecting a melamine borate-based material with a boric acid: melamine mass ratio of 2:1 and a melamine borate-based material with a cyanuric acid content of 0.5 wt %.

[0113] 2) The boric acid-melamine salt-based aerogel material in step (1) is placed in an argon atmosphere, heated to 1200°C at a heating rate of 10°C / min, and subjected to high-temperature annealing for 3 hours to obtain boron nitride aerogel. This comparative example is different from Example 1 in that a slow high-temperature annealing method is used and no laser processing is performed, and finally a boron nitride micro-nanobelt aerogel is obtained.

[0114] The SEM image of the boron nitride aerogel structure obtained in this comparative example is as follows Figure 23 shown.

[0115] In addition, the inventors of this case also used other raw materials and process conditions listed in this specification and prepared a series of boron nitride hollow microsphere aerogels in the manner described in Examples 1-9. Testing found that these boron nitride hollow microsphere aerogels also exhibited the excellent properties described in this specification.

[0116] The aforementioned examples demonstrate that the boron nitride hollow microsphere aerogel of the present invention has excellent performance, requires simple preparation equipment, can achieve continuous automated production, greatly shortens the preparation cycle and cost, and has great application prospects.

[0117] Although the present invention has been described with reference to illustrative embodiments, it will be understood by those skilled in the art that various other changes, omissions, and / or additions may be made and that substantial equivalents may be substituted for elements of the described embodiments without departing from the spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present invention without departing from the scope of the invention. Therefore, it is not intended that the present invention be limited to the specific embodiments disclosed for carrying out the invention, but rather that the invention will encompass all embodiments falling within the scope of the appended claims.

Claims

1. A method for preparing boron nitride hollow microsphere aerogel, characterized in that: include: A melamine-borate-based aerogel material is provided, wherein the melamine-borate-based aerogel material comprises melamine, boric acid, and a small molecule regulator, wherein the small molecule regulator is selected from any one or a combination of two or more of urea, cyanuric acid, boric anhydride, biuret, and metal salts; In a selected gas atmosphere, the melamine-borate-based aerogel material is subjected to instantaneous high-temperature treatment by laser direct writing technology to obtain a boron nitride hollow microsphere aerogel, wherein the gas used in the selected gas atmosphere is selected from any one of air, nitrogen, argon, and helium, or a combination of two or more thereof; The boron nitride hollow microsphere aerogel is assembled using boron nitride hollow microspheres as building units, and the boron nitride hollow microspheres are overlapped and assembled to form a three-dimensional porous network structure. The boron nitride hollow microsphere aerogel exhibits fluorescence under ultraviolet irradiation.

2. The preparation method according to claim 1, wherein: The mass ratio of melamine to boric acid is 1:20 to 20:

1.

3. The preparation method according to claim 2, wherein: The mass ratio of melamine to boric acid is 1:10 to 10:

1.

4. The preparation method according to claim 1, wherein: The mass fraction of the small molecule regulator in the melamine-borate-based aerogel material is greater than 0 and less than or equal to 50 wt %.

5. The preparation method according to claim 1, wherein: The laser used in the laser direct writing technology is obtained by exciting a laser, and the laser includes any one of a continuous laser, a quasi-continuous laser, and a pulsed laser.

6. The preparation method according to claim 1, wherein: The laser direct writing technology includes any one of laser scanning, laser drilling, and laser cutting, or a combination of two or more thereof.

7. The preparation method according to claim 1, wherein: The laser wavelength used in the laser direct writing technology is any one of the ultraviolet light, visible light, and infrared light bands, the power used in the laser direct writing technology is 0.1 W~10000 W, and the speed used in the laser direct writing technology is 0~1000 mm / s.

8. The preparation method according to claim 7, wherein: The power used in the laser direct writing technology is 5 W to 600 W, and the speed used in the laser direct writing technology is 0 to 100 mm / s.

9. The preparation method according to claim 1, wherein: The temperature of the instantaneous high temperature treatment is 300-3000°C, and the time is 1ms-1min.

10. A boron nitride hollow microsphere aerogel prepared by the preparation method according to any one of claims 1 to 9, wherein the boron nitride hollow microsphere aerogel is assembled from boron nitride hollow microspheres as building blocks, and the boron nitride hollow microspheres are overlapped and assembled to form a three-dimensional porous network structure, and the boron nitride hollow microsphere aerogel exhibits fluorescence under ultraviolet irradiation.

11. The boron nitride hollow microsphere aerogel according to claim 10, characterized in that: The boron nitride hollow microspheres are composed of boron, nitrogen, carbon and oxygen elements.

12. The boron nitride hollow microsphere aerogel according to claim 10, characterized in that: The shape of the hollow boron nitride microspheres includes any one of hollow spheres, hollow elliptical spheres, broken hollow spheres, and hollow dumbbell-shaped spheres, or a combination of two or more thereof.

13. The boron nitride hollow microsphere aerogel according to claim 10, wherein: The outer diameter of the boron nitride hollow microspheres is 10 nm to 100 μm.

14. The boron nitride hollow microsphere aerogel according to claim 13, wherein: The outer diameter of the boron nitride hollow microspheres is 100 nm to 50 μm.

15. The boron nitride hollow microsphere aerogel according to claim 10, wherein: The specific surface area of ​​the boron nitride hollow microsphere aerogel is 0.1~900 m 2 / g.

16. The boron nitride hollow microsphere aerogel according to claim 15, wherein: The specific surface area of ​​the boron nitride hollow microsphere aerogel is 30~500 m 2 / g.

17. The boron nitride hollow microsphere aerogel according to claim 10, wherein: The pore volume of the boron nitride hollow microsphere aerogel is 0.1~3 cm 3 / g.

18. The boron nitride hollow microsphere aerogel according to claim 17, wherein: The pore volume of the boron nitride hollow microsphere aerogel is 0.5~2 cm 3 / g.

19. The boron nitride hollow microsphere aerogel according to claim 10, wherein: The density of the boron nitride hollow microsphere aerogel is 5-200 mg / cm 3 .

20. The boron nitride hollow microsphere aerogel according to claim 19, wherein: The density of the boron nitride hollow microsphere aerogel is 10-30 mg / cm 3 .

21. The boron nitride hollow microsphere aerogel according to claim 10, wherein: The three-dimensional porous network structure of the boron nitride hollow microsphere aerogel includes micropores with a pore size of 0.5-2 nm, mesopores with a pore size of 2-50 nm, and macropores with a pore size of 50 nm-100 μm.

22. The boron nitride hollow microsphere aerogel according to claim 10, characterized in that: The macroscopic morphology of the boron nitride hollow microsphere aerogel includes any one of a three-dimensional macroscopic block, a two-dimensional plane pattern, a one-dimensional line pattern, and a zero-dimensional lattice, or a combination of two or more thereof.

23. The boron nitride hollow microsphere aerogel according to claim 10, characterized in that: The fluorescent color exhibited by the boron nitride hollow microsphere aerogel includes any one of blue, green and purple.

24. Use of the boron nitride hollow microsphere aerogel according to any one of claims 10 to 23 in the fields of fluorescent labeling, high-efficiency thermal insulation or information management.

Images