A ni3ga c 0.5 Ni3ga5 / nigal5 / nicomposite microsphere wave-absorbing material, preparation method and application

Abstract

Ni3GaC 0.5 / Ni3Ga5 / Ni composite microsphere wave-absorbing material, preparation method and application, (1) Ga (NO3) 3 x H2O is dispersed into deionized water, after stirring uniformly, NH3 H2O is slowly added dropwise by using a rubber head dropper, liquid A is obtained; (2) liquid A is placed into a circulating water filter for filtration, and is placed in a vacuum drying box for drying, GaOOH is obtained; (3) the filtered and dried GaOOH is added into C3H6N6 and Ni (OH) 2 and is uniformly mixed, Ni3GaC 0.5 precursor; (4) the Ni3GaC 0.5 precursor obtained in step (3) is calcined under hydrogen atmosphere, after natural cooling to room temperature, Ni3GaC 0.5 / Ni3Ga5 / Ni composite microsphere wave-absorbing material is obtained. The present application has the advantages of simple process, stable raw materials, strong controllability of structure and suitability for large-scale preparation.

Description

Technical Field

[0001] This invention relates to the field of microwave absorbing materials technology, and particularly to a Ni3GaC... 0.5 / Ni3Ga5 / Ni composite microsphere microwave absorbing material, preparation method and application. Background Technology

[0002] In recent years, metal carbide composites with multiple physical loss mechanisms (such as dielectric loss, magnetic loss, interfacial polarization, and conductive network loss) have attracted widespread attention due to their excellent structural controllability, good chemical stability, and low density. In particular, non-stoichiometric bimetallic carbides (such as Ni3ZnC) have gained significant attention. 0.7 Ni3ZnC possesses advantages such as precise composition control, low synthesis cost, and easier defect formation, thus showing great potential for development in the field of microwave absorption. Against this backdrop, some researchers have attempted to synthesize Ni3ZnC... 0.7 Excellent results have been achieved by combining carbon nanotubes, graphene, conductive polymers and other carbon-based materials to further enhance dielectric properties, impedance matching and microwave absorption.

[0003] Ni3GaC 0.5 With Ni3ZnC 0.7 It has many similarities and possesses properties similar to Ni3ZnC. 0.7 It has a similar crystal structure, but its raw materials are more stable. The covalent properties and thermal stability of metallic Ga and Ni are better. In addition, Ga atoms are more likely to form defect control centers in the crystal lattice, which is expected to enhance the synergistic effect of polarization loss and conductivity loss of the material, providing a new candidate system for the development of novel lightweight broadband microwave absorbing materials.

[0004] Currently, Ni3GaC 0.5 The intrinsic electromagnetic parameters and absorption performance of Ni3GaC have not yet been reported. Publicly available literature mainly describes its preparation using an acetylene atmosphere heat treatment method (DOI: 10.1016 / j.cclet.2024.109525; 10.1039 / d2ta02216h). This method has significant drawbacks: it is complex and energy-intensive, requiring high-temperature reduction (>800°C) to synthesize Ni3Ga alloy, followed by acetylene treatment (300°C) to embed carbon atoms, resulting in a lengthy and energy-intensive process; and it demands strict condition control, with a high risk of carbon deposition during acetylene treatment, easily leading to amorphous carbon contamination. Therefore, a simpler method for preparing Ni3GaC is needed. 0.5 The synthesis method of basic composite absorbing materials is an important foundation for in-depth research on their absorbing performance. Summary of the Invention

[0005] To overcome the above technical problems, the purpose of this invention is to provide a Ni3GaC 0.5The application discloses a kind of Ni3GaC 0.5 / Ni3Ga5 / Ni composite microsphere wave-absorbing materials and preparation method and application, the method has the advantages of simple process, raw material stability, strong structure controllability and being suitable for large-scale preparation, and the material prepared is applied to wave-absorbing material field for the first time and exhibits excellent microwave absorption performance in 2-18GHz frequency band.

[0006] The technical scheme adopted by the application is:

[0007] A kind of Ni3GaC 0.5 / Ni3Ga5 / Ni composite microsphere wave-absorbing material has hierarchical spherical structure and is composed of micrometer spheres with a diameter of about 5-20 μm.

[0008] The petal-shaped rough morphology significantly improves the specific surface area and geometric irregularity. 0.5 The micrometer sphere body is assembled by Ni3GaC 0.5 , Ni3Ga5 and Ni particles. The multi-phase structure not only maintains the interface effect but also introduces additional multiple scattering and multiple reflection paths, thereby giving the material stronger electromagnetic wave dissipation capacity.

[0009] From the chemical composition, the main phase of the composite material is Ni3GaC 0.5 . The abundant heterojunction and grain boundary region help to form polarization loss and interface energy level traps. The rough spherical aggregates composed of particles with different sizes provide abundant multi-interface structure, effectively prolong the propagation path of electromagnetic waves in the material and enhance energy dissipation.

[0010] A preparation method of a kind of Ni3GaC 0.5 / Ni3Ga5 / Ni composite microsphere wave-absorbing material includes the following steps:

[0011] (1) Ga (NO3) 3 x H2O is dispersed into deionized water, and after stirring uniformly, NH3 H2O is slowly added dropwise by using a rubber head dropper to obtain liquid A;

[0012] (2) Liquid A is placed in a circulating water filter for filtration and dried in a vacuum drying box to obtain GaOOH;

[0013] (3) The filtered and dried GaOOH is mixed with C3H6N6 and Ni (OH) 2 to obtain Ni3GaC 0.5 precursor;

[0014] (4) The Ni3GaC 0.5The precursor was calcined under hydrogen atmosphere, and after natural cooling to room temperature, Ni3GaC was obtained 0.5 / Ni3Ga5 / Ni composite microspheres wave-absorbing material.

[0015] In step (1), Ga(NO3)3xH2O is dispersed in 40-60 ml deionized water. A stable, uniform, and controllable Ga 3+ Ion source creates good reaction conditions for subsequent precipitation reaction or coordination precursor construction, and improves structure controllability and final material performance.

[0016] In step (1), NH3H2O is added until no flocculation appears, which lays a foundation for the generation of GaOOH precipitate in subsequent step (2).

[0017] In step (1), the ratio of Ga(NO3)3xH2O and NH3H2O is 1:3 (2-4).

[0018] In step (2), the sample is dried in a vacuum drying oven at 60℃ (50-80℃) for 6 h (3-6 h).

[0019] In step (3), the molar ratio of GaOOH to Ni(OH)2 is 1:3 (2.9-3.1), which ensures the formation of Ni3GaC 0.5 Precise stoichiometric composition of main phase, promoting efficient formation of target phase, optimizing magnetic / electric composite structure and loss mechanism, thereby significantly improving the final wave-absorbing performance and material stability.

[0020] In step (3), the mass ratio of C3H6N6 to GaOOH and Ni(OH)2 is (9.5-10.5)10:1. It is beneficial to control the morphology of microspheres, construct conductive network and polarization center, significantly improve the dielectric loss, multiple scattering ability and overall wave-absorbing performance of the material, while ensuring the structural stability and repeatability.

[0021] In step (4), the sample obtained in step (3) is calcined under hydrogen atmosphere, and the temperature is increased to 600-800℃ at a rate of 5 ℃ / min and maintained for 3-5 h. Under this calcination time and temperature, the formation of Ni3GaC 0.5 The complete formation of the main phase, the induction of crystal defects and the optimization of the conductive network significantly enhance the electromagnetic wave absorption capacity and structural stability of the material.

[0022] Ni3GaC 0.5 / Ni3Ga5 / Ni composite microspheres material is applied in the field of wave-absorbing, and Ni3GaC 0.5 / Ni3Ga5 / Ni composite microspheres material through Ni (magnetic loss), Ni3Ga5, Ni3GaC0.5 The three-phase synergy of the carbide reinforced dielectric loss and stability realizes the precise matching of the magnetic permeability-dielectric constant, and solves the industry problem that high loss and high matching cannot be achieved simultaneously. Meanwhile, the composite wave-absorbing agent is applied to the wave-absorbing material field for the first time, and has obvious creativity.

[0023] The beneficial effects of the present application are as follows:

[0024] The present application has the following prominent and substantial features: for the first time, a solid-phase reaction strategy is adopted, Ga(NO3)3xH2O, Ni(OH)2 and C3H6N6 are used as raw materials, and the target phase is constructed in one step through uniform mixing, pyrolysis and hydrogen reduction. C3H6N6 has dual functions of carbon source and dispersant, and its solid powder can fill the gap between Ga(NO3)3xH2O and Ni(OH)2 particles during mixing, and further promote the uniform dispersion of the raw materials through mechanical force. NH3 is released and amorphous carbon is generated during pyrolysis, which not only provides carbon source for the target phase Ni3GaC 0.5 The gas generated by the decomposition of the carbon source can also inhibit particle agglomeration, and the NH3 atmosphere can adjust the reducibility of the reaction system, creating a synergistic environment for subsequent hydrogen reduction. The solid-phase reaction avoids complex solvent conditions and multi-step processing, and does not need to rely on organic solvents to dissolve raw materials like liquid-phase methods, avoiding environmental pollution and subsequent washing, drying and other complex processing steps. The mixing process only needs mechanical action, and the energy consumption is reduced by more than 40%. Pyrolysis and reduction are continuously carried out in the same reaction device, without the need to transfer intermediates, realizing the integration of the three steps of mixing-pyrolysis-reduction. The traditional method needs multiple device transfers and step processing, while the present application compresses the process into one-step solid-phase reaction, and the time is shortened by 60%. The overall synthesis process is simple, environmentally friendly and low in cost, and is suitable for large-scale production.

[0025] Ni3GaC 0.5 The intrinsic electromagnetic parameters and wave-absorbing performance of Ni3GaC 0.5 Under the condition of m(Ni3GaC 0.5 The minimum reflection loss of Ni3GaC 0.5 Ni3GaC

[0026] The excellent wave-absorbing performance is mainly due to the following aspects:

[0027] First, the prepared Ni3GaC 0.5 / Ni3Ga5 / Ni particles self-assemble into spherical microspheres at high temperatures, with an outer layer of carbon formed by pyrolysis. There is a significant difference in electrical conductivity between the metal carbide core and the carbon shell, forming a large number of interfacial polarization sites.

[0028] Second, interfaces, gaps, and rough structures of different scales help guide electromagnetic waves to be reflected, scattered, and attenuated.

[0029] Third, Ni3GaC 0.5 The Ni element in / Ni3Ga5 / Ni possesses excellent magnetic response characteristics, and the presence of Ni3Ga5 alloy forms a multiphase interface, enhancing interface polarization loss. It can participate in mechanisms such as hysteresis loss, natural resonance, and eddy current loss in multiple frequency bands, which is beneficial for impedance matching optimization. Attached Figure Description

[0030] Figure 1 The Ni3GaC obtained in Example 1 0.5 X-ray diffraction pattern of the / Ni3Ga5 / Ni composite microsphere absorbing material.

[0031] Figure 2 The Ni3GaC obtained in Example 1 0.5 Scanning electron microscope image of / Ni3Ga5 / Ni material.

[0032] Figure 3 In Example 2, when m(Ni3GaC) 0.5 When / Ni3Ga5 / Ni):m(paraffin) = 40%, Ni3GaC 0.5 Performance diagram of / Ni3Ga5 / Ni material.

[0033] Figure 4 In Example 3, when m(Ni3GaC) 0.5 When / Ni3Ga5 / Ni):m(paraffin) = 50%, Ni3GaC 0.5 Performance diagram of / Ni3Ga5 / Ni material.

[0034] Figure 5 In Example 4, when m(Ni3GaC) 0.5 When / Ni3Ga5 / Ni):m(paraffin) = 60%, Ni3GaC 0.5 Performance diagram of / Ni3Ga5 / Ni material. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0036] (1) Disperse 1.25 g Ga(NO3)3·xH2O into 30 mL of deionized water, stir well, and slowly add NH3·H2O with a dropper until no more white flocculent matter appears, and then obtain liquid A.

[0037] (2) Liquid A was placed in a circulating water filter and filtered. The sample obtained by filtration was placed in a vacuum drying oven at 60°C and dried for 6 h to obtain GaOOH.

[0038] (3) Mix 0.008 mol GaOOH with 0.024 mol Ni(OH)2 and add 30 g C3H6N6 (10 times the total mass of GaOOH and Ni(OH)2).

[0039] (4) Take the sample obtained in step (3), heat it to 700 ℃ at a heating rate of 5 ℃ / min under hydrogen atmosphere and hold it for 4 h. After natural cooling to room temperature, Ni3GaC is obtained. 0.5 / Ni3Ga5 / Ni.

[0040] To further analyze the phase structure and morphology of the prepared material, the synthesized Ni3GaC was subjected to further analysis. 0.5 The / Ni3Ga5 / Ni material was characterized by X-ray diffraction, such as... Figure 1 As shown, multiple diffraction peaks can be clearly observed in the XRD pattern within the 2θ range of 10–90°. Among them, the characteristic diffraction peaks located at 2θ = 43.54°, 50.72°, and 74.56° correspond to Ni3GaC. 0.5 The final product contains three main phases: the target phase Ni3GaC (PDF#29-0625). Furthermore, at approximately 44.5°, 51.84°, and 76.37°, diffraction peaks corresponding to the (111), (200), and (220) crystal planes of Ni (PDF#04-0850) are observed, and several characteristic peaks can be attributed to the Ni3Ga5 phase (PDF#43-1376). Therefore, the final product mainly contains three phases: the target phase Ni3GaC. 0.5 Metallic Ni and Ni3Ga5 secondary phases. Due to insufficient carbon source, some Ni did not react completely, or some Ga was in excess and formed Ni3Ga5. For example... Figure 2 As shown, for Ni3GaC 0.5The SEM morphology analysis of the / Ni3Ga5 / Ni material shows that it mainly has a spherical particle structure. The average diameter of the spherical particles is about 5-20 μm, the overall surface is relatively rough, but the particle size distribution is relatively uniform. Combined with the XRD and SEM analysis results, it is shown that the synthesized Ni3GaC 0.5 / Ni3Ga5 / Ni sample has good crystallinity and structural integrity, although there is a small amount of secondary phase, but the overall morphology is uniform, and has good microwave absorption structure basis. Example

[0041] Synthesis of Ni3GaC 0.5 / Ni3Ga5 / Ni material and prepare a paraffin filling ratio of 40% test ring. The specific steps are as follows:

[0042] (1) Disperse 1.25 g Ga(NO3)3·xH2O into 30 mL deionized water, stir uniformly, and slowly add NH3·H2O with a rubber dropper until no white flocculent appears. Then liquid A is obtained.

[0043] (2) Put liquid A into a circulating water filter for filtration. The sample obtained by filtration is placed in a 60°C vacuum drying oven for drying for 6 h to obtain GaOOH.

[0044] (3) Mix 0.008 mol GaOOH with 0.024 mol nickel hydroxide, and add 30 g C3H6N6 (10 times the total mass of GaOOH and Ni(OH)2).

[0045] (4) Take the sample obtained in step (3), and heat to 700°C at a heating rate of 5°C / min under hydrogen atmosphere for 4 h. After natural cooling to room temperature, Ni3GaC 0.5 / Ni3Ga5 / Ni is obtained.

[0046] (5) Weigh 0.04 g Ni3GaC 0.5 / Ni3Ga5 / Ni powder and 0.06 g paraffin (m(Ni3GaC 0.5 / Ni3Ga5 / Ni):m(paraffin)=40%) and mix. Put the mixture into a container and melt the paraffin using the heating function of the constant temperature magnetic stirrer. After stirring gently with a medicine spoon until uniform, place it in a mold and apply pressure to prepare a paraffin filling ratio of 40% Ni3GaC 0.5 / Ni3Ga5 / Ni test ring with an outer diameter of 7 mm and an inner diameter of 3.04 mm.

[0047] The vector network analyzer (3656D) is used to test the wave absorption performance of the paraffin filling ratio of 40% Ni3GaC 0.5 test ring prepared in Example 2. As shown inFigure 3 The results show that the minimum reflection loss of Ni3GaC 0.5 is -22.93 dB, and the effective absorption bandwidth is 2.55 GHz. Embodiment

[0048] Synthesis of Ni3GaC 0.5 / Ni3Ga5 / Ni material and preparation of a paraffin-filled test ring with a paraffin filling ratio of 50% are as follows:

[0049] (1) 1.25 g of Ga(NO3)3xH2O was dispersed into 30 mL of deionized water, stirred uniformly, and NH3H2O was slowly added by means of a rubber bulb dropper until no white flocculent appeared, and then liquid A was obtained.

[0050] (2) Liquid A was placed into a circulating water filter for filtration, and the sample obtained by filtration was placed into a vacuum drying oven at 60°C for drying for 6 h to obtain GaOOH.

[0051] (3) 0.008 mol of GaOOH was mixed with 0.024 mol of Ni(OH)2, and 30 g of C3H6N6 (10 times the total mass of GaOOH and Ni(OH)2) was added.

[0052] (4) The sample obtained in step (3) was heated to 700°C at a heating rate of 5°C / min under a hydrogen atmosphere and kept for 4 h, and after natural cooling to room temperature, Ni3GaC 0.5 / Ni3Ga5 / Ni was obtained.

[0053] (5) 0.05 g of Ni3GaC 0.5 / Ni3Ga5 / Ni powder and 0.05 g of paraffin (m(Ni3GaC 0.5 / Ni3Ga5 / Ni):m(paraffin)=50%) were weighed and mixed, and the mixture was placed in a container, and the heating function of a constant-temperature magnetic stirrer was used to melt the paraffin. After gentle stirring with a medicine spoon until the mixture was uniformly mixed, it was placed in a mold, and pressure was applied to prepare a paraffin-filled Ni3GaC 0.5 / Ni3Ga5 / Ni test ring with an outer diameter of 7 mm and an inner diameter of 3.04 mm and a paraffin filling ratio of 50%.

[0054] The paraffin-filled Ni3GaC 0.5 test ring prepared in Embodiment 3 was subjected to wave absorption performance testing by means of a vector network analyzer (3656D). As Figure 4 shown, the minimum reflection loss of Ni3GaC 0.5 / Ni3Ga5 / Ni is -40.2 dB, and the effective absorption bandwidth is 5.91 GHz. Embodiment

[0055] Synthesis of Ni3GaC 0.5 / Ni3Ga5 / Ni material and preparing a paraffin filling ratio 60% test ring. The specific steps are as follows:

[0056] (1) 1.25 g Ga(NO3)3xH2O was dispersed into 30 mL deionized water, stirred uniformly, and NH3H2O was slowly added by using a rubber dropper until no white flocculent appeared. Then liquid A was obtained.

[0057] (2) Liquid A was placed in a circulating water filter for filtration. The sample obtained by filtration was placed in a 60°C vacuum drying oven for drying for 6 h to obtain GaOOH.

[0058] (3) 0.008 mol GaOOH was mixed with 0.024 mol Ni(OH)2, and 30 g C3H6N6 (10 times the total mass of GaOOH and Ni(OH)2) was added.

[0059] (4) The sample obtained in step (3) was heated to 700°C at a heating rate of 5°C / min under a hydrogen atmosphere for 4 h, and then naturally cooled to room temperature to obtain Ni3GaC 0.5 / Ni3Ga5 / Ni.

[0060] (5) 0.06 g Ni3GaC 0.5 / Ni3Ga5 / Ni powder and 0.04 g paraffin (m(Ni3GaC 0.5 ):m(paraffin)=60%) were weighed and mixed. The mixture was placed in a container, and the heating function of a constant-temperature magnetic stirrer was used to melt the paraffin. After gentle stirring with a medicine spoon until the mixture was uniformly mixed, it was placed in a mold and pressure was applied to prepare a paraffin filling ratio 60% Ni3GaC 0.5 / Ni3Ga5 / Ni test ring with an outer diameter of 7 mm and an inner diameter of 3.04 mm.

[0061] The paraffin filling ratio 60% Ni3GaC 0.5 test ring prepared in Example 3 was tested for wave absorption performance using a vector network analyzer (3656D). As Figure 5 shown, the minimum reflection loss of the Ni3GaC 0.5 / Ni3Ga5 / Ni was -7.03 dB.

[0062] In summary, the above is only an embodiment of the present application and is not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A Ni3GaC 0.5 Preparation method of a composite microsphere wave-absorbing material of Ni3GaC It comprises the following steps: (1) dispersing Ga(NO3)3xH2O into deionized water, stirring uniformly, then slowly adding NH3H2O drop by drop with a rubber head dropper to obtain liquid A; (2) filtering liquid A in a circulating water filter and drying in a vacuum drying box to obtain GaOOH; (3) The GaOOH dried by suction filtration is added into C3H6N6 and Ni(OH)2 and mixed uniformly to obtain Ni3GaC 0.5 precursor; (4) taking the Ni3GaC obtained in step (3) 0.5 The precursor is calcined under a hydrogen atmosphere, and after natural cooling to room temperature, Ni3GaC is obtained 0.5 / Ni3Ga5 / Ni composite microsphere wave-absorbing material In the step (4), the Ni3GaC obtained in the step (3) is taken 0.5 The precursor is calcined under a hydrogen atmosphere, and the temperature is raised to 600-800 ℃ at a rate of 5 ℃ / min and maintained for 3-5 h. In the step (1), NH3H2O is added until no flocculation appears; In the step (1), the ratio of Ga(NO3)3xH2O and NH3H2O is 1:3; In the step (2), the vacuum drying box is at 50-80℃ and the drying time is 3-6 hours.

2. The Ni3GaC according to claim 1 0.5 The method for preparing Ni3Ga5 / Ni composite microsphere microwave absorbing material is characterized by... In the step (1), Ga(NO3)3xH2O is dispersed into 40-60 ml deionized water.

3. The Ni3GaC composite microspheres according to claim 1. 0.5 The preparation method of the composite microspheres of Ni3GaC / Ni3Ga5 / Ni, characterized in that, In the step (3), the molar ratio of GaOOH and Ni(OH)2 is 1:

3.

4. A Ni3GaC according to claim 1 0.5 The method for preparing Ni3Ga5 / Ni composite microsphere microwave absorbing material is characterized by... In the step (3), the mass ratio of C3H6N6 to the total mass of GaOOH and Ni(OH)2 is 10:

1.

5. A Ni3GaC composite microspheres wave-absorbing material prepared according to the method of any one of claims 1-4. 0.5 The Ni3GaC / Ni3Ga5 / Ni composite microspheres wave-absorbing material is characterized in that, The composite microspheres have hierarchical spherical structure, are composed of microspheres with a diameter of 5-20 μm, have rough and irregular surface, present obvious petal-like structure, and have abundant interfaces and gaps between the particles. The composite microsphere body is assembled by Ni3GaC 0.5 , Ni3Ga5 and Ni particles; and a large number of heterogeneous interfaces are formed.

6. Ni3GaC prepared based on the method according to any one of claims 1 to 4 0.5 The application relates to the application of the composite microspheres of / Ni3Ga5 / Ni, characterized in that, Ni3GaC 0.5 The composite microspheres of / Ni3Ga5 / Ni are applied in the field of wave absorption.

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