TixO2x-1 multi-shell hollow sphere wave-absorbing coating as well as preparation method and application thereof

Abstract

The invention discloses a TixO2x-1 multi-shell hollow sphere wave-absorbing coating as well as a preparation method and application thereof, and relates to the technical field of wave-absorbing materials. The preparation method of the absorbent comprises the following steps: preparing a TiO2 precursor mixture; adding ammonia water containing CTAB (Cetyltrimethyl Ammonium Bromide) into the TiO2 precursor mixture, and hydrolyzing for 4-8 hours to obtain TiO2 multi-shell hollow spheres; in a hydrogen atmosphere, the TiO2 multi-shell hollow spheres are subjected to heat preservation for 4-8 h at the temperature of 850-950 DEG C, and the TixO2x-1 multi-shell hollow sphere wave-absorbing agent is obtained. According to the invention, the number of shell layers, sphericity and porosity of the TiO2 multi-shell hollow sphere can be designed by adjusting hydrolysis conditions, and then the components and oxygen vacancy concentration of the TixO2x-1 multi-shell hollow sphere are adjusted by a high-temperature calcination method, so that the wave-absorbing performance of the wave-absorbing agent is optimized.

Description

Technical Field

[0001] The present invention relates to the technical field of wave absorbing materials, and in particular to a Ti x O 2x-1 Multi-shell hollow sphere wave-absorbing coating, preparation method and application thereof. Background Art

[0002] With the rapid development of 5G technology, electromagnetic waves have been widely used in military facilities, medical equipment, aerospace, and electronic communications. However, the resulting electromagnetic pollution (electromagnetic radiation and interference) will not only affect the normal operation of the equipment, but also threaten human health. At present, electromagnetic shielding technology or absorbing materials are often used to reduce or eliminate electromagnetic pollution. Traditional electromagnetic shielding technology mainly uses the surface of the shielding body to reflect electromagnetic waves. However, the secondary reflected waves generated will cause secondary pollution and cannot completely eliminate electromagnetic pollution, thus affecting the normal use of the equipment. In contrast, absorbing materials absorb electromagnetic waves and convert them into heat energy for dissipation, thereby reducing or weakening electromagnetic radiation and electromagnetic interference. It is the most effective way to eliminate electromagnetic pollution and has become one of the current research and application hotspots.

[0003] There are many types of absorbing materials currently being studied. They are mainly classified by loss type into dielectric loss type, conductive loss type and magnetic loss type absorbing materials. The attenuation loss of electromagnetic waves by magnetic loss type absorbing materials mainly comes from the natural resonance, eddy current loss and hysteresis loss of magnetic materials. Conductive loss type absorbing materials attenuate electromagnetic waves through the interaction between carriers and electric fields. Dielectric loss type absorbing materials consume and transform electromagnetic waves through polarization effects (including electronic polarization, dipole polarization, ionic polarization, and interface polarization). The speed of electronic polarization and ionic polarization is very fast (10 3 -10 6 GHz) and is basically elastic, with negligible energy consumption, mainly contributed by dipole polarization and interface polarization. Dipole polarization is usually caused by the dipole formed by defects in the material or the doping of heteroatoms acting as a polarization center in the external electromagnetic field. Interface polarization refers to the polarization caused by the different dielectric constants and conductivity of the two materials in contact at the heterogeneous interface, resulting in different current densities. Dielectric lossy absorbing materials are mainly ZnO, TiO 2 , Fe 2 O 3 、ZrO 2 、CoO、WO 3 、In 2 O 3 、Al 2 O 3 and Fe 3 O 4 Oxide ceramics are representative, and their advantages are low density, oxidation resistance, and high temperature resistance, but their absorption intensity is usually low.

[0004] In view of the excellent electromagnetic absorption properties of dielectric lossy materials, previous scholars have conducted a lot of research, by compounding dielectric lossy materials with other lossy materials, or doping dielectric lossy materials to obtain absorbing materials with better performance. However, the dielectric loss capacity of such materials is generally not strong, and a large filling rate is required to achieve ideal absorbing performance, which is not conducive to reducing the density of absorbing materials. In summary, studying a low-density absorbing material with good impedance matching, interface polarization, and strong dielectric loss capacity is a key scientific challenge faced in the development of new absorbing materials. Summary of the invention

[0005] In view of the shortcomings of the above background technology, the present invention mainly addresses the problems of low conductivity, poor impedance matching, weak electromagnetic loss capability, etc. of the current single dielectric loss material. The present invention provides a Ti x O 2x-1 Multi-shell hollow sphere wave absorbing coating and its preparation method and application. The present invention studies titanium dioxide, a semiconductor material with low dielectric constant and high dielectric loss, and provides a method for enhancing Ti x O 2x-1 The method for preparing the absorbing coating with interface polarization and conductivity loss is relatively simple. x O 2x-1 The absorber does not need to be doped, has a low density and has excellent conductivity loss and dielectric loss. The present invention adopts a precursor hydrolysis method to prepare TiO 2 Multi-shell hollow sphere (TiO 2 HSS), TiO can be designed by adjusting the hydrolysis conditions 2 The number of shells, sphericity, and porosity of HSS were then adjusted by high-temperature calcination. x O 2x-1 Multi-shell hollow sphere (Ti x O 2x-1 The composition of HSS particles and the concentration of oxygen vacancies can be optimized to optimize the absorbing performance of the absorber. Among them, HSS is a multi-shell hollow sphere.

[0006] The first object of the present invention is to provide a Ti x O 2x-1 The preparation method of the multi-shell hollow sphere absorber is characterized by comprising the following steps: Preparation of TiO 2 Precursor mixture; TiO 2 Ammonia containing CTAB was added to the precursor mixture and hydrolyzed for 4-8 hours to obtain TiO 2 Multi-shell hollow sphere; In a hydrogen atmosphere, TiO2 The multi-shell hollow spheres were kept at 850~950℃ for 4~8h to obtain Ti x O 2x-1 Multi-shell hollow sphere absorber.

[0007] Preferably, the mass content of CTAB in ammonia water is 1-20%; wherein the pH of the ammonia water is 12; The temperature during hydrolysis is 20~30℃.

[0008] Preferably TiO 2 The precursor mixture is prepared according to the following steps: At room temperature, N 2 as carrier gas, and TiCl 4 and NH 3 The reaction was carried out in a fluidized bed reactor to obtain TiO 2 Precursor mixture.

[0009] Preferably, when the fluidized bed reactor is reacting, the reaction temperature is 20-30° C. and the reaction time is 20-40 min.

[0010] Preferably, N 2 、TiCl 4 and NH 3 The mixture was introduced into the fluidized bed reactor at a flow rate of 5.12 g / min and reacted for 20 to 40 minutes.

[0011] After hydrolysis, the hydrolyzate is centrifuged at 1000-3000 rpm, and the centrifuged product is dried at 40-80° C. for 4-8 h.

[0012] Preferably, in a hydrogen atmosphere, the heating rate is 5-10°C / min.

[0013] The second object of the present invention is to provide a Ti x O 2x-1 Multi-shell hollow sphere absorber.

[0014] The present invention includes Ti x O 2x-1 Multi-shell hollow sphere absorber.

[0015] The fourth object of the present invention is to provide a Ti x O 2x-1 Application of multi-shell hollow sphere absorbing coating in electromagnetic absorption.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a TixO2x-1 multi-shell hollow sphere wave absorbing coating and a preparation method and application thereof. x O2x-1 The raw materials of HSS absorber are cheap and the preparation process is simple. 2 In HSS, the TiO 2 The number of shells of HSS. The multi-shell Ti prepared by the present invention x O 2x-1 Absorber, relative to solid TiO 2 The product prepared by the present invention has excellent performance, strong interface polarization and conductivity loss, excellent wave absorbing performance in the X-band range, and stable product performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 1 is a reflection loss curve diagram of Example 1 and Comparative Example 1; Figure 2 It is a reflection loss curve diagram of Example 2 and Comparative Example 1; Figure 3 It is a reflection loss curve diagram of Example 3 and Comparative Example 1; Figure 4 A scanning electron microscope image of the multilayer core-shell structure TiO2HSS provided in Example 2; Figure 5 This is a scanning electron microscope image of the multilayer core-shell structure TiO2HSS provided in Example 3. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand and implement the technical solution of the present invention, the present invention is further described below in conjunction with specific embodiments and drawings, but the embodiments are not intended to limit the present invention.

[0019] The present invention aims to provide a Ti-based material which does not require doping, has low density and has excellent conductivity loss and dielectric loss. x O 2x-1 HSS absorber preparation method, the present invention Ti x O 2x-1 The design ideas for the preparation method of HSS absorber are as follows: TiO was prepared by precursor hydrolysis at room temperature. 2 HSS precursor mixture, followed by TiO 2 The precursor mixture is hydrolyzed in ammonia water. Adding a certain amount of CTAB during hydrolysis can change the final TiO 2 The number of HSS shells. This is because CTAB acts as a merging inhibitor, [C 19 H 38 NH 4 ] + Adsorbed on TiO 2The surface of the precursor particles is positively charged, and the electrostatic pulse prevents the precursor particles from merging, thereby producing particles with a reduced diameter. As the particles become smaller, TiO 2 The number of HSS shells also decreases.

[0020] Subsequently, the hydrolyzed precursor mixture was centrifuged to collect the residual powder, which was then dried to obtain TiO 2 HSS. Prepared TiO 2 HSS has a multi-shell structure, which provides more interfaces. Electron migration and hopping at the interface can cause interface polarization. The increase in the number of interfaces can promote interface polarization and optimize the impedance matching characteristics of the material, thereby enhancing the dissipation of electromagnetic waves. 2 HSS was calcined in a tubular furnace with hydrogen atmosphere. Due to the high temperature calcination, the TiO 2 Oxygen vacancies and Ti in the lattice 3+ The high concentration of oxygen vacancies can capture the free electrons of neighboring Ti atoms, inducing the formation of Ti with lower valence 3+ , which eventually leads to Ti x O 2x-1 Abundant positively charged holes are generated in the lattice, which are unique electric dipoles with the ability to move under electromagnetic fields, causing conductivity loss, and finally preparing Ti with excellent microwave absorption performance. x O 2x-1 HSS absorber.

[0021] In order to achieve the above object, the present invention first provides a Ti x O 2x-1 The preparation method of the multi-shell hollow sphere absorber comprises the following steps: Preparation of TiO 2 Precursor mixture; TiO 2 Ammonia containing CTAB was added to the precursor mixture and hydrolyzed for 4-8 hours to obtain TiO 2 HSS; In a hydrogen atmosphere, TiO 2 HSS was heated at 850~950℃ for 4~8h to obtain Ti x O 2x-1 HSS absorber. In hydrogen atmosphere, the heating rate is 5~10℃ / min.

[0022] The content of CTAB in ammonia water is 1-20wt%; the pH of ammonia water is 12; and the temperature during hydrolysis is 20-30°C.

[0023] TiO 2The precursor mixture was prepared by the following steps: N 2 as carrier gas, and TiCl 4 and NH 3 The reaction was carried out in a fluidized bed reactor to obtain TiO 2 Precursor mixture.

[0024] When the fluidized bed reactor is reacting, the reaction temperature is 20-30°C and the reaction time is 20-40 minutes. Preferably, the reaction temperature is 25°C and the reaction time is 30 minutes.

[0025] N 2 、TiCl 4 and NH 3 The mixture was introduced into the fluidized bed reactor at a flow rate of 5.12 g / min and reacted for 20 to 40 minutes.

[0026] According to the present invention, after hydrolysis, the hydrolyzate is centrifuged at 1000-3000 rpm, and the centrifuged product is dried at 40-80° C. for 4-8 hours.

[0027] For example, a Ti x O 2x-1 The method for preparing the HSS absorber comprises: Precursor preparation: At room temperature, N 2 As carrier gas, TiCl 4 and NH 3 After passing through the fluidized bed reactor for a period of time, TiO 2 Precursor mixture. It has an irregular shape similar to dendritic cells.

[0028] Hydrolysis: The obtained TiO 2 The precursor mixture was added into a hydrolysis reactor containing a certain amount of CTAB and ammonia water, and TiO 2 The precursor mixture is hydrolyzed.

[0029] Centrifugation: The hydrolyzed TiO 2 The precursor mixture was centrifuged to collect the residual powder, and dried at 40-80°C for 4-8 hours.

[0030] Calcination: The prepared TiO 2 HSS was placed in a tube furnace and hydrogen was introduced as a protective gas. The temperature was raised to 900°C at a heating rate of 10°C / min and kept at this temperature for 6 hours. After the end of the heat preservation, the furnace was cooled. Ti x O 2x-1 HSS absorber.

[0031] In the precursor preparation step, TiCl4 The concentration is 99.5%, NH 3 The concentration is 99.999%, N 2 The concentration is 99.999%.

[0032] The TiCl 4 and NH 3 The flow rate is 5.12 g / min, and the gas introduction time is 30 min.

[0033] The pH of the ammonia water used for hydrolysis is 12, the content of the CTAB in the ammonia water is 1%-20wt%, the stirring speed during the hydrolysis is 100r / min, the temperature during the hydrolysis is 25°C, and the hydrolysis time is 4-8h.

[0034] In the centrifugation step, the centrifugal speed is 2000 rpm and the drying temperature is 60°C.

[0035] In the calcination step, the heating rate is 10°C / min, and the suitable temperature is 900°C.

[0036] It should be noted that compared with conventional TiO 2 Compared with the materials, after calcination, Ti x O 2x-1 HSS material absorbent has excellent microwave absorption capacity. This is because the hydrogenation temperature regulates the TiO 2 Oxygen vacancies and Ti in the lattice 3+ The high concentration of oxygen vacancies can capture the free electrons of neighboring Ti atoms, inducing the formation of Ti with lower valence 3+ , which eventually leads to Ti x O 2x-1 Abundant positive charge holes are generated in the material, which are unique electric dipoles that can move under electromagnetic fields, causing conductivity loss. In addition, the multi-shell structure of titanium dioxide provides more interfaces, where electron migration and hopping can cause interface polarization. The increase in the number of interfaces can promote interface polarization and optimize the impedance matching characteristics of the material, thereby enhancing the dissipation of electromagnetic waves.

[0037] A second aspect of the present invention provides a Ti x O 2x-1 Multi-shell hollow sphere absorber.

[0038] The third aspect of the present invention provides a Ti x O 2x-1 Multi-shell hollow sphere absorbing coating, including Ti x O 2x-1 Multi-shell hollow sphere absorber.

[0039] A fourth aspect of the present invention provides a Ti x O2x-1 Application of multi-shell hollow sphere absorbing coating in electromagnetic absorption.

[0040] It should be noted that the experimental methods used in the present invention are all conventional methods unless otherwise specified; the reagents and materials used are all commercially available unless otherwise specified.

[0041] Example 1 Step 1: Preparation of TiO by precursor hydrolysis 2 HSS At room temperature, N with a purity of 99.99% 2 As carrier gas, 99.5% pure TiCl 4 and 99.99%NH 3 The gas was introduced into the fluidized bed reactor at a flow rate of 5.12 g / min. After reacting in the fluidized bed reactor for 30 min, the gas introduction was stopped to prepare TiO 2 The precursor mixture was used to obtain an irregularly shaped product similar to dendritic cells. 2 The precursor mixture and ammonia water with a CTAB content of 3wt% and a pH of 12 were placed in a hydrolysis reactor with a rotation speed of 100r / min for hydrolysis at a hydrolysis temperature of 25°C. After hydrolysis for 4h, the mixture was placed in a centrifuge and centrifuged at a speed of 2000rpm to collect the residual powder, which was then dried at 60°C for 5 hours to finally obtain TiO with a shell number of 4. 2 HSS.

[0042] Step 2: Preparation of Ti by calcination x O 2x-1 HSS absorber The prepared TiO 2 HSS was placed in a tube furnace and hydrogen was introduced as a protective gas. The temperature was raised to 900°C at a rate of 10°C / min, kept at that temperature for 6 hours, and then cooled with the furnace to obtain Ti x O 2x-1 HSS absorber is four layers of HSS.

[0043] The Ti obtained in step 2 x O 2x-1 After the HSS powder is configured into a coating, a reflection loss test is performed. The obtained reflection loss data is plotted against the reflection loss data of the coating configured with solid HSS powder to form a comparative image. Figure 1 shown.

[0044] Example 2 Step 1: Preparation of TiO by precursor hydrolysis 2 HSS At room temperature, N with a purity of 99.99% 2As carrier gas, 99.5% pure TiCl 4 and 99.99%NH 3 The gas was introduced into the fluidized bed reactor at a flow rate of 5.12 g / min. After reacting in the fluidized bed reactor for 30 min, the gas introduction was stopped to prepare TiO 2 The precursor mixture was used to obtain an irregularly shaped product similar to dendritic cells. 2 The precursor mixture and ammonia water with a CTAB content of 8% and a pH of 12 were placed in a hydrolysis reactor with a rotation speed of 100 r / min for hydrolysis at a hydrolysis temperature of 25°C. After hydrolysis for 4 hours, the mixture was placed in a centrifuge and centrifuged at a speed of 2000 rpm to collect the residual powder, which was then dried at 60°C for 5 hours to finally obtain TiO with a shell number of 2. 2 HSS.

[0045] Step 2: Preparation of Ti by calcination x O 2x-1 HSS absorber The prepared TiO 2 HSS was placed in a tube furnace and hydrogen was introduced as a protective gas. The temperature was raised to 900°C at a rate of 10°C / min, kept at that temperature for 6 hours, and then cooled with the furnace to obtain Ti x O 2x-1 HSS absorber. That is, two layers of HSS.

[0046] The Ti obtained in step 2 x O 2x-1 The reflection loss data of HSS powder was compared with that of solid TiO 2 The reflection loss data of the coating made of HSS powder is plotted into a comparative image. Figure 2 shown.

[0047] Example 3 Step 1: Preparation of TiO by precursor hydrolysis 2 HSS At room temperature, N with a purity of 99.99% 2 As carrier gas, 99.5% pure TiCl 4 and 99.99%NH 3 The gas was introduced into the fluidized bed reactor at a flow rate of 5.12 g / min. After reacting in the fluidized bed reactor for 30 min, the gas introduction was stopped to prepare TiO 2 The precursor mixture was used to obtain an irregularly shaped product similar to dendritic cells. 2The precursor mixture and ammonia water with a CTAB content of 15% and a pH of 12 were placed in a hydrolysis reactor with a rotation speed of 100 r / min for hydrolysis at a hydrolysis temperature of 25°C. After hydrolysis for 4 hours, the mixture was placed in a centrifuge and centrifuged at a speed of 2000 rpm to collect the residual powder, which was then dried at 60°C for 5 hours to finally obtain TiO with a shell number of 1. 2 HSS.

[0048] Step 2: Preparation of Ti by calcination x O 2x-1 HSS absorber The prepared TiO 2 HSS was placed in a tube furnace and hydrogen was introduced as a protective gas. The temperature was raised to 900°C at a rate of 10°C / min, kept at that temperature for 6 hours, and then cooled with the furnace to obtain Ti x O 2x-1 HSS absorber. It is a layer of HSS.

[0049] The Ti obtained in step 2 x O 2x-1 The reflection loss data of HSS powder was compared with that of solid TiO 2 The reflection loss data of the coating made of HSS powder is plotted into a comparative image. Figure 3 shown.

[0050] At this point, all embodiments of the present invention are completed. x O 2x-1 The advancement and superiority of HSS absorber are illustrated by a comparative example.

[0051] Comparative Example 1 Step 1: With tetrabutyl titanate as the titanium source and methanol as the solvent, 2.5 ml of tetrabutyl titanate was dropped into a mixed solution of 80 ml of methanol and water (the molar ratio of water to tetrabutyl titanate was 3.75:1) under a nitrogen atmosphere as the protective atmosphere, and stirred for 60 minutes under a magnetic stirrer. The solution was then transferred to the inner liner of a 100 ml reactor.

[0052] Step 2: Heat the reactor to 130°C at a rate of 5°C / min and keep it warm for 24 hours to promote the TiO 2 After the reaction was completed, the solution was cooled to room temperature and centrifuged at 5000 rpm to obtain TiO 2 Colloidal microspheres. The separated TiO 2 The colloidal microspheres were washed three times with deionized water and anhydrous methanol respectively, and finally dried under vacuum and low temperature to obtain amorphous TiO 2 The obtained amorphous TiO 2The colloidal microspheres were calcined at 600 °C for 2 h to obtain solid TiO 2 Microspheres.

[0053] In order to illustrate the electromagnetic wave absorption efficiency of the material prepared by the present invention, the TixO2x-1HSS absorber prepared in Examples 1 to 3 and Comparative Example 1 was prepared into a coating, wherein the coating preparation process includes: 1. Clean the mold and evenly apply the release agent polydimethylsiloxane on the surface of the polytetrafluoroethylene mold, put it in an 80℃ oven, and after 10 minutes, apply another layer of release agent. Repeat three times to ensure that the release agent is evenly spread on the surface of the mold.

[0054] 2. Weigh 19g E51 epoxy resin and 1g C12-14 alkyl glycidyl ether into a 25ml beaker, stir at 300rpm for 30min at 35°C to dilute the epoxy resin.

[0055] 3. Add 1 g of the absorber provided in Examples 1 to 3 or Comparative Example 1 and continue stirring for 30 min.

[0056] 4. After 30 minutes, place the mixture into a vacuum pump and use negative pressure to remove bubbles for 10 minutes.

[0057] 5. Add 4 g of curing agent into a beaker, stir at 250 rpm for 10 min, degas under negative pressure for 10 min, pour into the prepared mold, set the curing temperature to 100 ° C / 2h, and obtain the TixO2x-1 / epoxy resin absorbing coating after curing.

[0058] The electromagnetic parameters of the coating in the x-band were tested using a vector network analyzer (ROHDE&SCHWARZ ZNB 20). The reflection losses of the four samples are shown in Figure 1 , Figure 2 , Figure 3 As shown, from Figures 1 to 3 It can be seen that the reflection losses of the samples prepared in Examples 1 to 3 are improved to varying degrees compared with Comparative Example 1, indicating that the prepared TixO2x-1HSS absorber has excellent absorbing performance in the X-band.

[0059] Figure 4 The scanning electron microscope image of the multilayer core-shell structure TiO2HSS provided in Example 2; Figure 4 It can be seen that in TiO 2 When the precursor mixture is hydrolyzed, as the content of CTAB added reaches 15%, TiO 2 The number of shell layers of HSS is reduced to one layer, and the overall structure is an outer spherical shell that wraps the inner core, with a clear structural hierarchy.

[0060] Figure 5The scanning electron microscope image of the multilayer core-shell structure TiO2HSS provided in Example 3; Figure 5 It can be seen that as the CTAB content decreases to 8%, the number of shell layers of the sample increases to two layers. This is mainly because CTAB plays the role of a merging inhibitor when the TiO2 precursor mixture is hydrolyzed. The cations generated by its hydrolysis are adsorbed on the TiO2 precursor particle liquid film to make it positively charged. The positively charged particles show mutual repulsation, which effectively prevents the merging of the precursor particles, thereby producing particles with reduced diameters. Since the shell of HSS is formed by an expanded liquid film, when the thickness of the liquid film is constant, the larger the diameter of the precursor particle, the more shells there are. Therefore, as the CTAB content decreases from 15% to 8%, the diameter of the precursor particle increases, and the number of shell layers increases to two layers. The core-shell structure consists of two hollow spherical shells and a spherical core. The diameter of the outer core-shell structure is smaller than the diameter of the inner core-shell structure. The structural hierarchy is clear and controllable.

[0061] The TiO prepared by the present invention 2 HSS compared to TiO 2 The solid sphere has a multi-shell structure, which provides more interfaces. The electron migration and jumping at the interface can cause interface polarization. The increase in the number of interfaces can promote interface polarization and optimize the impedance matching characteristics of the material, thereby enhancing the dissipation of electromagnetic waves. 2 After HSS was calcined in a tubular furnace with hydrogen atmosphere, the high temperature calcination adjusted the TiO 2 Oxygen vacancies and Ti in the lattice 3+ The high concentration of oxygen vacancies can capture the free electrons of neighboring Ti atoms, inducing the formation of Ti with lower valence 3+ , which eventually leads to Ti x O 2x-1 Abundant positively charged holes are generated in the lattice, which are unique electric dipoles that have the ability to move under electromagnetic fields, causing conductivity losses, and finally preparing Ti with excellent microwave absorption performance. x O 2x-1 HSS absorber.

[0062] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A Ti x O 2x-1 The method for preparing a multi-shell hollow sphere absorber is characterized in that: The following steps are involved: preparing a TiO2 precursor mixture; Adding ammonia water containing CTAB to the TiO2 precursor mixture and hydrolyzing for 4 to 8 hours to obtain TiO2 multi-shell hollow spheres; In a hydrogen atmosphere, TiO2 multi-shell hollow spheres were heated at 850-950℃ for 4-8h to obtain Ti x O 2x-1 Multi-shell hollow sphere absorber.

2. Ti according to claim 1 x O 2x-1 The method for preparing a multi-shell hollow sphere absorbing coating is characterized in that: The mass content of CTAB in ammonia water is 1-20%; wherein the pH of the ammonia water is 12; The temperature during hydrolysis is 20~30℃.

3. Ti according to claim 1 x O 2x-1 The method for preparing a multi-shell hollow sphere absorbing coating is characterized in that: The TiO2 precursor mixture was prepared according to the following steps: At room temperature, N2 is used as a carrier gas, and TiCl4 and NH3 are introduced into a fluidized bed reactor for reaction to obtain a TiO2 precursor mixture.

4. Ti according to claim 3 x O 2x-1 The method for preparing a multi-shell hollow sphere absorbing coating is characterized in that: When the fluidized bed reactor is reacting, the reaction temperature is 20-30° C. and the reaction time is 20-40 min.

5. Ti according to claim 3 x O 2x-1 The method for preparing a multi-shell hollow sphere absorbing coating is characterized in that: N2, TiCl4 and NH3 were introduced into the fluidized bed reactor at a flow rate of 5.12 g / min and reacted for 20 to 40 minutes.

6. Ti according to claim 1 x O 2x-1 The method for preparing a multi-shell hollow sphere absorbing coating is characterized in that: After hydrolysis, the hydrolyzate is centrifuged at 1000-3000 rpm, and the centrifuged product is dried at 40-80° C. for 4-8 h.

7. Ti according to claim 1 x O 2x-1 The method for preparing a multi-shell hollow sphere absorbing coating is characterized in that: In a hydrogen atmosphere, the heating rate is 5~10℃ / min.

8. Ti prepared by the method according to any one of claims 1 to 7 x O 2x-1 Multi-shell hollow sphere absorber.

9. A Ti x O 2x-1 The multi-shell hollow sphere absorbing coating is characterized by: The Ti according to claim 8 x O 2x-1 Multi-shell hollow sphere absorber.

10. Ti according to claim 9 x O 2x-1 Application of multi-shell hollow sphere absorbing coating in electromagnetic absorption.

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