Conductive type infrared emission composite material and preparation method thereof

Abstract

This invention relates to the field of infrared emitting composite materials, specifically to a conductive infrared emitting composite material and its preparation method. The preparation method is as follows: AB2O is prepared. 4‑δ Spinel material; the prepared AB2O 4‑δ Spinel material, carbonaceous material, and ceramic material are mixed and then sandwiched together with carbonaceous material to form a pressed tablet. Microwave plasma discharge treatment is used to activate the infrared emission performance of the plasma elements and excite the conductivity channels, resulting in a conductive composite material with high infrared emissivity. This composite material solves the technical problems of limited infrared emission capability, single excitation method, and complex preparation method of existing composite ceramic materials, and has broad application prospects in the field of tunable photoelectric synergistic excitation of infrared radiation.

Description

Technical Field

[0001] This invention belongs to the field of infrared emitting composite materials, and more specifically, relates to a conductive infrared emitting composite material and its preparation method. Background Technology

[0002] With the widespread application of infrared heating technology, infrared emitting materials have experienced rapid development. Based on the principle of "spectral matching resonance," infrared radiation in the 5-12μm band is close in size to human cells, water molecule clusters, and protein molecules. After being absorbed by the human body, it resonates with human cell molecules, energizing cells, strengthening tissue metabolism, enhancing tissue regeneration, and improving the body's immunity, thus showing broad application prospects in the medical and healthcare fields. Furthermore, infrared emitting materials, due to their non-toxicity and ability to achieve upconversion luminescence, also have wide applications in lighting and display equipment, temperature sensing, solar cells, chemical analysis, biological imaging, modern fiber optic communication, and night vision surveillance. Summary of the Invention

[0003] The present invention aims to provide a conductive infrared emitting composite material and its preparation method, so as to solve the technical problems of limited infrared emission capability, single excitation mode and complex preparation method of existing infrared emitting materials.

[0004] To achieve the above objectives, the present invention provides a method for preparing a conductive infrared emitting composite material, which can adopt the following technical solution:

[0005] Step 1, Preparation of AB2O 4-δ Type spinel material, where 0≤δ<1, A and B represent transition metals and A and B are of different types.

[0006] Step 2: Hybrid ceramic materials are used to form cluster molecules with high infrared emissivity. Simultaneously, carbonaceous materials are mixed to form a doped structure to enhance the infrared emission capability of the cluster molecules. At the same time, conductive channels are initially constructed, and infrared emission plasma units are formed based on the stable structure of carbonaceous materials to obtain infrared emission precursor materials.

[0007] Step 3: Construct a composite structure of a first infrared emission precursor material, a carbonaceous material, and a second infrared emission precursor material in sequence. Use microwave plasma discharge treatment to activate the infrared emission performance of the plasma element and excite the conductivity channel to obtain a conductive infrared emission composite material. The spinel material, ceramic material, and carbonaceous material contained in the first infrared emission precursor material and the second infrared emission precursor material may be the same or different.

[0008] Furthermore, AB2O 4-δThe spinel material is a carbon-doped spinel material, wherein the carbon material is one or more of graphene oxide, graphene, carbon nanotubes, carbon fibers, or carbon nanowires. The carbon material replaces oxygen in the AB₂O₄ type spinel material to form AB₂O₄. 4-δ The form is defined as 0 ≤ δ < 1. Doping with carbon materials can increase the conductivity of infrared emitting composite materials, enabling them to have more efficient electroexcitation.

[0009] Furthermore, a conductive matrix may be disposed between the first infrared emitting precursor material and the second infrared emitting precursor material. The conductive matrix may include a metal mesh, a conductive fiber mesh, or a carbon plate. For example, a mesh-like conductive matrix may be coated onto the surface of the intermediate carbonaceous material. The addition of the conductive matrix can further optimize the conductivity of the infrared emitting composite material, enabling the composite material to have more efficient electroexcitation. The conductive matrix material may include foamed metal (copper, nickel, iron, etc.), metal mesh, conductive fibers, or carbon plates, etc.

[0010] Furthermore, both the first and second infrared emission precursor materials can be obtained through step 2. Since the types and contents of transition metals, ceramic materials, and carbonaceous materials contained in the spinel material, as well as the ratios between these materials, can vary, infrared emission precursor materials with different component types and ratios can be obtained. By adjusting the types and contents of each component in the first and second infrared emission precursor materials, the infrared emission band of the conductive infrared emission composite material can be tunable in the range of 2-14 μm.

[0011] Furthermore, the transition metal is selected from copper, iron, cobalt, manganese, nickel, magnesium, zinc, or chromium. Preferably, B can represent Fe, AB₂O. 4-δ The spinel material is a ferrite spinel material.

[0012] Further, AB2O was prepared. 4-δ The spinel material comprises: mixing transition metal oxides and ball milling them, with or without the addition of carbon materials, to obtain a mixed powder; pressing the mixed powder into sheets; and subjecting the sheets to microwave plasma discharge sintering to obtain AB2O. 4-δ Spinel material. Microwave sintering can be performed in an inert atmosphere or vacuum. Microwave plasma discharge sintering can reduce the spacing between metal ions, enhancing conductivity while maintaining the material's infrared emission capability, resulting in AB2O. 4-δ In spinel materials, 0 ≤ δ < 1. In some embodiments, rGO can be added to the mixed powder to prepare rGO-doped AB₂O. 4-δSpinel material. The transition metal oxide may include at least two of CuO, Fe2O3, Co2O3, MnO2, and ZnO. Before use, the transition metal oxide can be dried at 80-140℃ for 2-4 hours, and then processed according to AB2O. 4-δ The molar mass ratio of the ferrite provides the raw material for sintering. AB2O 4-δ Type ferrite spinel materials may include CuFe2O 4-δ CoFe2O 4-δ MnFe2O 4-δ and ZnFe2O 4-δ At least one of the following. In some embodiments, the ball milling process can be dry ball milling or wet ball milling, using Si3N4 milling beads of various sizes. The ball milling speed can be 300-600 r / min, the ball milling time can be 30-120 min, the ball milling air humidity can be 20%-40%, and the particle size of the mixed powder obtained after ball milling can be 0.1-20 μm; the solvent used for wet ball milling includes water and / or organic solvents; the organic solvents include alcohols and / or other organic solvents; the alcohols include at least one of ethanol, propanol, and butanol; the other organic solvents include at least one of toluene, ethyl acetate, and dichloromethane. In some embodiments, the microwave frequency in the microwave plasma discharge can be 2450 MHz ± 20 Hz, the power can be 600-1000 W, and the time can be 60-120 s.

[0013] Furthermore, the mass ratio of the infrared emission precursor material, carbonaceous material, and infrared emission precursor material in the composite structure can be 10:d:10, where 0 < d < 9. For example, the mass ratio of the infrared emission precursor material, carbonaceous material, and infrared emission precursor material can be 10:1:10, 10:2:10, 10:3:10, 10:4.5:10, 10:5.8:10, 10:7.2:10, 10:8:10, 10:8.5:10, etc.

[0014] Furthermore, the composite structure can be a "sandwich" structure or a "sandwich-like" structure, with carbonaceous material placed between two layers of infrared-emitting precursor material.

[0015] Furthermore, in the step of obtaining the infrared emission precursor material, AB2O 4-δ Spinel materials, ceramic materials, and carbonaceous materials can be mixed in a mass ratio of a:b:c, where 0 < a < 9, 0 < b < 9, and 0 < c < 9. For example, AB₂O 4-δSpinel materials, ceramic materials, and carbonaceous materials can be combined in a mass ratio of 1:(1-3):(2-4), 1:(2-5):(5-9), 1:(6-9):(1-5), or a combination thereof. For example, AB2O... 4-δ The mass ratio of spinel materials, ceramic materials and carbonaceous materials can be 1:1:1, 1:2:3, 1:2:9, 1:3:1, 1:5:2, 1:7:8, etc.

[0016] Furthermore, the ceramic material may include any one of cordierite, silicon carbide, perovskite, and mullite.

[0017] Furthermore, the carbonaceous material may include any one of reduced graphene oxide, carbon nanotubes, carbon fibers, and carbon nanowires. Preferably, the carbonaceous material may be a carbonaceous material containing oxygen-containing functional groups. The oxygen-containing functional groups contained in the carbonaceous material can coat cluster molecules with high infrared emissivity to enhance the infrared emission capability of the composite material.

[0018] Furthermore, the microwave frequency in the microwave plasma discharge is 2450MHz±20Hz, the power is 600-1000W, and the duration is 60-120s.

[0019] Furthermore, after constructing the composite structural material, a sintering aid is added, which is at least one of TiO2, Al2O3, TiC, and ZrO2. The amount of sintering aid added is 0-5% of the mass of the composite structural material. For example, the amount of sintering aid added is a combination of 1-4%, 2-3%, or more of the mass of the composite structural material.

[0020] Furthermore, in some embodiments, obtaining a conductive infrared emitting composite material may include: using AB2O 4-δSpinel material, ceramic material, and carbonaceous material are mixed in a mass ratio of a:b:c, where 0 < a < 9, 0 < b < 9, and 0 < c < 9. After adding a sintering aid, the mixture is ball-milled and then aged to obtain a mixed powder, which is the infrared emission precursor material. The mixed powder, carbonaceous material, and another mixed powder are then stacked sequentially from bottom to top and pressed into sheets. The sheets are then microwave-sintered to obtain a conductive graphene-reinforced composite material with high infrared emissivity. In some embodiments, the ball milling process can be dry or wet, using Si3N4 grinding beads of various sizes. The ball milling speed can be 300-600 r / min, the ball milling time can be 30-120 min, the ball milling air humidity can be 20%-40%, and the particle size of the mixed powder obtained after ball milling can be 0.1-20 μm. The solvent used for wet ball milling includes water and / or organic solvents; the organic solvents include alcohols and / or other organic solvents; the alcohols include at least one of ethanol, propanol, and butanol; the other organic solvents include at least one of toluene, ethyl acetate, and dichloromethane. In some embodiments, the aging treatment time can be 4-9 h.

[0021] Another aspect of the present invention provides a conductive infrared emitting composite material, which is composed of a first infrared emitting precursor material, a carbonaceous material, and a second infrared emitting precursor material sequentially assembled, wherein both the first infrared emitting precursor material and the second infrared emitting precursor material contain AB2O. 4-δ Spinel materials, ceramic materials, and carbonaceous materials; the spinel materials, ceramic materials, and carbonaceous materials contained in the first infrared emission precursor material and the second infrared emission precursor material may be the same or different; 0≤δ<1, A and B represent transition metals and A and B are of different types.

[0022] Furthermore, in the electro-excitation of conductive infrared emitting composite materials, the applied current can be 0 < I ≤ 5 A. For example, the applied current can be a combination of 1 ≤ I ≤ 4 A, 2 ≤ I ≤ 3 A, or higher. The electrode material used for electro-excitation is graphite, tungsten, platinum, molybdenum, or nickel. Stable and efficient electro-excited infrared emission can be achieved under the above-mentioned applied current of 0 < I ≤ 5 A.

[0023] Furthermore, the infrared emission band of the conductive infrared emitting composite material can be tunable within the range of 2-14 μm, which can be controlled by changing the proportion and type of the composite material's components. The resulting conductive infrared emitting composite material can utilize optical fields, electric fields, or synergistic optical and electric fields to synchronously control infrared emission, i.e., it can achieve electro-excitation, optical excitation, or photoelectric synergistic excitation. For example, the infrared emission band can be tunable within the ranges of 2-4 μm, 4-8 μm, and 8-14 μm.

[0024] Another aspect of the present invention provides an application of a conductive infrared emitting composite material. This conductive infrared emitting composite material can be applied in fields such as textiles, infrared stealth, temperature sensing, solar cells, chemical analysis, biological imaging, fiber optic communication, and night vision surveillance.

[0025] Specifically, in the preparation process of the conductive infrared emitting composite material of the present invention, carbonaceous materials are used in both the steps of obtaining the infrared emitting precursor material and obtaining the composite material, giving them two uses. In the preparation process of the infrared emitting precursor material, carbonaceous materials are used to select the emission band and adjust AB2O. 4-δ The increased oxygen content in the spinel reduces the inter-ion spacing, allowing for the formation of conduction bands and the adsorption of molecules to form clusters, thus imparting conductivity to the composite material. During composite material preparation, a "sandwich structure" is constructed to form infrared-emitting plasma units and stable conductive channels. Therefore, the composite material obtained by this invention possesses excellent conductivity.

[0026] On the other hand, the present invention will use AB2O 4-δ By combining spinel, cordierite, and other ceramic materials with reduced graphene oxide (rGO) and other carbonaceous materials, a conductive infrared-emitting composite material with a low coefficient of thermal expansion, a high lattice distortion coefficient, and high infrared emissivity in the 2-14 μm wavelength band can be obtained. The infrared emission properties of the composite material are conferred by the cluster molecules formed through internal ion transfer and exchange during processing of the spinel and cordierite ceramic materials. Furthermore, the addition of reduced graphene oxide (rGO) and other carbonaceous materials with internal oxygen-containing functional groups allows for the reaction of the spinel and ceramic materials. The excellent conductivity (high conductivity) of the carbonaceous materials provides free electrons and alters the conduction band energy level, thereby forming free electron channels (conductive channels) in the infrared-emitting material. This achieves a combination of laser excitation and electrical excitation, solving the problem of a single excitation method. In addition, the large specific surface area of ​​carbonaceous materials such as reduced graphene oxide (rGO) can adsorb other materials to promote solid-phase reactions, and its high surface activity allows for strong interactions with other compounds. Furthermore, infrared emitting materials typically require high-temperature environments, while carbonaceous materials possess high chemical and thermal stability, which can improve the stability and durability of the material. Preferably, the carbonaceous material is reduced graphene oxide (rGO), which exhibits a unique resonance effect due to its π-electron band structure, and it resonates with ceramic materials and spinel-type ferrites (AB₂O₃). 4-δ By combining AB₂O₂ with π electrons, metal ions can resonate with π electrons to form new band structures and electronic states, thereby affecting the conductivity and optical properties of the composite material and further improving the infrared emission capability of the infrared emitting material. 4-δThe composite material, consisting of spinel, ceramic, and carbonaceous materials, exhibits a synergistic effect, overcoming the limitations of using only AB2O. 4-δ This method overcomes the problems of limited infrared emission methods and insufficient infrared emission efficiency in spinel and ceramic materials, while also addressing the technical issue of low infrared emissivity in single-phase ceramic materials.

[0027] Furthermore, this invention utilizes microwave plasma discharge sintering technology to obtain AB2O. 4-δ Microwave plasma allows transition metals such as Cu, Fe, and Co atoms and their oxides to easily reach chemical reaction conditions, enabling self-propagating diffusion sintering solid-state reactions to produce composite ferrite microcrystals such as CuFe2O4, FeFe2O4, and CoFe2O4. These microcrystals can then be effectively combined with ceramic and carbonaceous materials, and microwave plasma discharge sintering technology can be used to obtain composite materials with high infrared emissivity. Under microwave sintering, the Cu atoms inside the material... 2+ Fe 3+ Al 3+ Mg 2+ Elements such as C effectively absorb microwave energy, which can trigger multi-step cascade reactions and energy transfer, thereby inducing the mixed raw materials to undergo high-temperature solid-state reactions, generating the desired carbonaceous reinforcing materials, and simultaneously activating the electrically excited infrared emission channel.

[0028] The main benefits of this technical solution are:

[0029] (1) The obtained composite material has the advantages of low thermal expansion coefficient, large lattice distortion coefficient, high thermal stability, and high infrared emissivity in the 2-14μm band. The infrared emission band is adjustable in the 2-14μm range and can be widely used in food preservation, medical care, military confrontation and other fields.

[0030] (2) The composite material prepared by the present invention has the advantages of simple preparation technology, strong repeatability, high production efficiency, low energy consumption and low raw material cost, and can be applied to industrial production.

[0031] (3) The composite material prepared by the present invention has multiple ways to excite infrared radiation, and the infrared emission of the material can be controlled by using light field, electric field or synergistic light field and electric field.

[0032] (4) The composite material prepared by the present invention has high conductivity and strong absorption peaks for some wavelengths of laser light, which can further increase infrared emission efficiency through photoelectric synergistic excitation. Attached Figure Description

[0033] Figure 1This is a schematic diagram of the preparation method of the conductive infrared emitting composite material of the present invention, and a schematic diagram of the infrared emission principle of the photoelectric synergistic excitation composite material.

[0034] Figure 2 This is a schematic diagram of the sandwich structure of the conductive infrared emitting composite material of the present invention.

[0035] Figure 3 This is a schematic diagram of the portable optoelectronic co-excitation infrared emitting device used in the embodiment.

[0036] Figure 4 Comparison of Raman and Fourier transform infrared absorption (FTIR) spectra of the conductive infrared emitting composite materials prepared in Examples 1-5.

[0037] Figure 5 The current-voltage characteristic curves are those of the conductive infrared emitting composite materials prepared in Examples 1-5.

[0038] Figure 6 The infrared emission spectra are those of the conductive infrared emitting composite materials prepared in Examples 1 to 5.

[0039] Figure 7 Single-phase AB2O under 10W laser power irradiation 4-δ Infrared images of single-phase rGO, single-phase cordierite, and the conductive high infrared emissivity graphene-reinforced composite material prepared in Example 2 in the 5-12 μm band.

[0040] Figure 8 The infrared emission spectra of the conductive infrared emitting composite material prepared in Example 4 are shown under laser excitation and electrical excitation, respectively.

[0041] Figure 9 The infrared emission spectra of the conductive infrared emitting composite materials prepared in Comparative Examples 1-4 are compared with those of the conductive infrared emitting composite material prepared in Example 5.

[0042] Figure 10 This is a comparison graph showing the current-voltage characteristic curves of the conductive infrared emitting composite materials prepared in Comparative Examples 1, 3, and 4 of this scheme with the current-voltage characteristic curves of the conductive infrared emitting composite materials prepared in Example 5. Detailed Implementation

[0043] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto. Unless otherwise specified, the technical means used in the following embodiments and experimental examples are conventional means well known to those skilled in the art, and the materials and reagents used can all be obtained commercially.

[0044] This invention utilizes microwave plasma discharge sintering technology, and its basic sintering process and reaction principle are as follows: Figure 1 As shown. Microwave sintering is performed in two steps: the first step involves preparing AB2O. 4-δ In the first step, appropriate proportions of CuO, Fe2O3, and Co2O3 metal oxides are mixed, pressed into sheets, and microwave sintered. In the second step, the AB2O obtained in the first step is ball-milled and mixed. 4-δ Spinel, reduced graphene oxide, and a suitable amount of cordierite are then combined with rGO to construct a sandwich structure (such as...). Figure 2 As shown, the material includes a middle layer of graphene oxide and two sides of infrared-emitting precursor materials, which are then pressed into a sheet and sintered using microwave plasma discharge. Figure 1 It can be seen that Cu in the material 2+ Fe 3+ Al 3+ Mg 2+ Elements such as C effectively absorb microwave energy, with Mg being particularly effective. 2+ Al 3+ It is easily replaced by other ions, reducing the symmetry of the structure and thus enhancing the anharmonic effect, promoting the increase of infrared emissivity. Secondly, metal ions can resonate with the π electrons of graphene to form new band structures and electronic states, thereby affecting the conductivity and optical properties of the composite material, improving the infrared emission capability of the infrared emitting material, and then transferring energy to other elements. In the oscillation, the raw material components organically combine to form a conductive composite material with high infrared emissivity. Figure 4 and Figure 5 ).

[0045] The CuO, Fe2O3, and Co2O3 raw material powders used in this invention all have a purity higher than 98 wt.% and a particle size of 200-300 mesh. The cordierite raw material powder has an industrial grade purity and a particle size of less than 300 mesh. The reduced graphene oxide raw material powder has a purity higher than 97 wt.% and a particle size of 200-300 mesh.

[0046] Example 1

[0047] Step 1: Using CuO, Fe2O3, and Co2O3 metal oxides as raw materials (the oxides were dried in an oven at 120℃ for 4 hours before use), they were ball-milled at a mass ratio of 2.7:5.4:1. During ball milling, a certain amount of Si3N4 grinding beads of varying sizes were added, with a ball-to-material ratio of 10:1. The ball diameters were 10mm and 5mm, and the ratio of large to small beads was 1:1. The ball milling speed was 500r / min, and the milling time was 30-120min. The air humidity during ball milling was 20%. After ball milling, the material was dried in an oven at 120℃ for 2 hours. The obtained powder had a particle size between 8-20μm, and was then compacted into tablets with a thickness of 0.5mm (first tablet). During the compaction process, the above raw materials were subjected to isostatic pressing using a hydraulic method. The pressure during isostatic pressing was 10MPa, and the pressing time was 90s. Subsequently, a Ni metal mesh was placed at the bottom of the alumina crucible, and the pressed sheet was placed on the Ni metal mesh. The crucible was then covered and placed in a microwave oven. The microwave power was adjusted to 600W and the microwave time was 90s at a working frequency of 2450MHz±20Hz to induce a high-temperature solid-phase reaction in the raw material mixture, yielding AB2O. 4-δ Type ferrite spinel material. The microwave sintering process is carried out in air, and during the sintering process, a certain thickness of aluminum silicate fiber insulation material is placed at the bottom of the microwave oven.

[0048] Step 2: Prepare the AB2O 4-δ Ferrite spinel material, reduced graphene oxide (rGO), and cordierite powder were mixed at a mass ratio of 2.5:1:5, and a sintering aid (nucleating agent) of 1% by mass was added. The mixture was then ball-milled until homogeneous. The ball-milling parameters were the same as those used in the first step of AB2O. 4-δ The ball milling conditions in the preparation of the ferrite spinel material are consistent. After ball milling and mixing, the mixture is aged for 4 hours, and then dried at 120°C for 2 hours to obtain the infrared emitting precursor materials (AB2O doped with rGO and cordierite) on both sides of the sandwich-structured composite material of this scheme. 4-δ The infrared emitting precursor material is combined with rGO material to form a sandwich structure, with the three layers (infrared emitting precursor material: rGO material: infrared emitting precursor material) assembled in a mass ratio of 10:1:10, and compacted into a 0.5mm thick sheet (the parameters for the pressing process are the same as those in the first pressing step). Then, a Ni metal mesh is placed at the bottom of an alumina crucible, the sheet is placed on the Ni metal mesh, the crucible is covered, and the crucible is placed in a microwave oven. At a microwave operating frequency of 2450MHz±20Hz, the microwave power is adjusted to 600W and the microwave time to 60s to allow the sheet material to fully sinter. High-temperature sintering of the sheet is then performed using microwave plasma discharge technology, ultimately obtaining a conductive high-infrared emissivity graphene-reinforced composite material (conductive infrared emitting composite material).

[0049] Example 2

[0050] This embodiment is basically the same as Embodiment 1, except that in the infrared emitting material, AB2O 4-δ The mass ratio of the ferrite spinel material, reduced graphene oxide (rGO), and cordierite powder is 5:1:5.

[0051] Example 3

[0052] This embodiment is basically the same as Embodiment 1, except that in the infrared emitting material, AB2O 4-δ The mass ratio of the ferrite spinel material, reduced graphene oxide (rGO), and cordierite powder is 5:1:2.5.

[0053] Example 4

[0054] This embodiment is basically the same as Embodiment 1, except that in the infrared emitting material, AB2O 4-δ The mass ratio of the ferrite spinel material, reduced graphene oxide (rGO), and cordierite powder is 10:1:2.5.

[0055] Example 5

[0056] This embodiment is basically the same as Embodiment 1, except that in the infrared emitting material, AB2O 4-δ The mass ratio of the ferrite spinel material, reduced graphene oxide (rGO), and cordierite powder is 10:1:5.

[0057] Figure 4 and Figure 5 This is a comparison of the Raman spectra, FTIR, and voltammetric characteristic curves of Examples 1-5. Using... Figure 3 A portable photoelectric co-excitation infrared emission device was used to test the performance of the prepared conductive graphene-reinforced composite material with high infrared emissivity. The comparison results of the infrared emission spectra of Examples 1-5 are as follows: Figure 6 As shown, only laser excitation was used here, with a wavelength of 980 nm and a power of 2 W. From the comparative results, Examples 5 and 3 showed better infrared emissivity in the 5-12 μm infrared band, while Examples 1 and 2 had finer spectral lines. Among these, with AB2O... 4-δ Increasing the proportion of ferrite spinel leads to a more stable material structure. However, considering the linear correlation between conductivity and current-voltage characteristic curves, Example 5 achieves higher electro-excitation efficiency while maintaining linearity. Therefore, by combining the proportions of Examples 1-5, and rationally selecting the material ratio based on electro-induced excitation efficiency and infrared emissivity, the optimal application can be achieved.

[0058] Figure 7 Demonstrated single-phase AB2O under 10W laser power irradiation 4-δ Infrared images of single-phase rGO, single-phase cordierite, and the conductive high-infrared-emissivity graphene-reinforced composite material prepared by the method of the present invention in Example 2, in the 5-12 μm band. Among them, single-phase AB2O... 4-δ Single-phase rGO and single-phase cordierite were all processed into pressed sheets according to the method in Example 1, forming sheets with a thickness of 0.5 mm (maintaining consistent shape for all four types of pressed sheets). As seen in the images, under 10W laser power irradiation, the conductive high-infrared emissivity graphene-reinforced composite material prepared in this invention exhibits stronger infrared emission in the 5-12 μm band. Under 10W laser power irradiation, the four test materials, single-phase AB2O... 4-δ The highest temperatures achievable by single-phase rGO, single-phase cordierite, and conductive high-infrared emissivity graphene-reinforced composites were 133.79℃, 60.94℃, 70.75℃, and 191.32℃, respectively. These temperature data also indicate that the conductive high-infrared emissivity graphene-reinforced composite has a higher temperature and a stronger ability to radiate infrared radiation in the 5-12μm band. The addition of single-phase rGO was intended to increase the material's conductivity, making electro-excitation possible. Although the infrared radiation effect of single-phase rGO under laser excitation is not ideal, combining single-phase rGO with single-phase AB₂O... 4-δ By mixing with single-phase cordierite, a composite material was prepared, which enhanced the material's ability to emit infrared radiation in the 5-12μm band under laser excitation, showing superior performance compared to any single-phase material. The inventors analyzed that the reason is that metal ions can resonate with the π electrons of graphene to form new band structures and electronic states, thereby affecting the conductivity and optical properties of the composite material, improving the infrared emission capability of the infrared emitting material, and producing a synergistic effect.

[0059] Figure 8 The conductive high infrared emissivity graphene-reinforced composite material prepared in Example 4 is shown, with infrared emission spectra under 3A and 6W electrical excitation and 980nm and 2W laser excitation, respectively. This demonstrates the electrical excitation characteristics of the composite material of the present invention, providing a material basis for electric field-tuned excitation of infrared emission.

[0060] Comparative Example 1:

[0061] This comparative example is basically the same as Example 5, except that in the second step, microwave treatment is not performed, and the infrared emitting precursor material (AB2O doped with rGO and cordierite) is directly applied. 4-δ The ferrite spinel material is pressed into a 0.5mm thick sheet.

[0062] Comparative Example 2:

[0063] This comparative example is basically the same as Example 5, except that in the second step, the infrared emitting precursor material is not doped with rGO, but instead contains cordierite and AB2O. 4-δ The mixed ferrite spinel material is ball-milled to form an infrared emission precursor material. Then, it is pressed into a 0.5 mm thick tablet in the order of infrared emission precursor material + rGO + infrared emission precursor material.

[0064] Comparative Example 3:

[0065] This comparative example is basically the same as Example 5, except that in the second step, instead of preparing a sandwich structure, the infrared emitting precursor material (AB2O doped with rGO and cordierite) is directly applied. 4-δ The ferrite spinel material is pressed into a 0.5mm thick sheet.

[0066] Comparative Example 4:

[0067] This comparative example is basically the same as Example 5, except that it uses AB2O doped with rGO. 4-δ Type ferrite spinel materials (infrared emission precursor materials): Reduced graphene oxide (rGO): AB2O doped with rGO 4-δ The mass ratio of the ferrite spinel material (infrared emission precursor material) is 10:2:10, with a relatively large amount of reduced graphene oxide added in the middle.

[0068] The infrared emission effect and electrical properties of the material can be respectively determined by... Figure 9 and Figure 10 Among them, Figure 9 The excitation conditions for (a), (c), and (d) are simultaneous 1A, 4W electrical excitation and 980nm, 6W laser excitation. Figure 9 (b) Since the material in Comparative Example 2 is non-conductive, a 980nm, 8W laser excitation method was chosen. For Comparative Example 1, from... Figure 9 (a) It can be seen that the infrared emission capability was improved by about 20% after microwave treatment. Figure 10 Furthermore, the electrical properties will tend to be more linearly correlated, making it easier to regulate the excitation of the electric field. For Comparative Example 2, Figure 9 (b) The infrared emission capability shows that AB2O 4-δ The infrared emission capability of rGO-doped ferrite spinel materials decreases to some extent, but considering that undoped rGO materials are non-conductive, rGO doping is necessary. The appropriate doping ratio is determined by examples 1-5. For comparative examples 3 and 4, Figure 9 As can be seen from (c) and (d), the ratio of sandwich structures to other sandwich structures has little effect on the infrared emission capability of the material. However, from Figure 10The electrical performance results show that the sandwich structure in Example 5 improves the linear correlation of the current-voltage characteristic curve, making electrical excitation easier to control. Furthermore, a higher proportion of the sandwich structure improves the material's conductivity but reduces the linear correlation of the current-voltage characteristic curve (correlation coefficient R). 2 (Value). Meanwhile, considering the density of rGO, a large amount of rGO incorporation would result in an excessively large material volume and thickness. Therefore, in practice, the proportion of the sandwich structure components can be selected based on the results of Comparative Example 4.

[0069] In summary, this technical solution aims to increase the excitation methods of composite materials by using cordierite and AB2O. 4-δ The addition of rGO to the ferrite spinel material is a key focus of this research. Ensuring the ideal properties of the resulting composite material after rGO addition is crucial. The inventors initially experimented with combining rGO, cordierite, and AB2O. 4-δ The ferrite spinel materials were mixed and directly pressed into tablets to form the final composite material (Comparative Example 1). However, the infrared emission capability of the product obtained in Comparative Example 1 was significantly reduced. The infrared emission capability of rGO itself is not ideal. To integrate rGO into the composite material while ensuring both electrical and infrared radiation properties, it is necessary to further refine the composition of rGO, cordierite, and AB2O. 4-δ A mixture of ferrite spinel materials was microwave sintered to ensure that metal ions could resonate with graphene π electrons to form new band structures and electronic states. rGO was added to cordierite and AB2O. 4-δ There are many ways to add ferrite spinel materials, such as in Comparative Example 2, where cordierite and AB2O are added. 4-δ The infrared emitting material formed by the ferrite spinel material forms a sandwich shape with the rGO in the middle, thus achieving the addition of rGO. However, the addition method in Comparative Example 2 results in the composite material lacking electrical conductivity, failing to achieve the purpose of electro-excitation. In this technical solution, the infrared emitting material containing rGO and rGO form a sandwich-like assembly. The inventors also tried directly using the infrared emitting material containing rGO for pressing and sintering, and found that whether or not a sandwich-like assembly method is used has little impact on the infrared emission capability, but the sandwich structure can improve the linear correlation of the current-voltage characteristic curve, making electro-excitation easier to control. However, adding too much rGO to the sandwich structure leads to a decrease in linear correlation (Comparative Example 3 and Comparative Example 4).

[0070] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for preparing a conductive infrared emitting composite material, characterized in that, Includes the following steps: Preparation of AB2O 4-δ Type spinel material, wherein 0≤δ<1, A and B represent transition metals and A and B are of different types; High infrared emissivity cluster molecules are formed by hybridizing ceramic materials, while carbonaceous materials are simultaneously hybridized to form doped structures that enhance the infrared emission capability of the cluster molecules. Conductive channels are also initially constructed, and infrared emission plasma units are formed based on the stable structure of the carbonaceous materials, thus obtaining an infrared emission precursor material. In the step of obtaining the infrared emission precursor material, AB2O... 4-δ Spinel material, ceramic material and carbonaceous material are mixed in mass ratio a:b:c, where 0 < a < 9, 0 < b < 9 and 0 < c < 9. A composite structure consisting of a first infrared emission precursor material, a carbonaceous material, and a second infrared emission precursor material is constructed sequentially. Microwave plasma discharge treatment is used to activate the infrared emission performance of the plasma element and excite the conductivity channel to obtain a conductive infrared emission composite material. The spinel material, ceramic material, and carbonaceous material contained in the first infrared emission precursor material and the second infrared emission precursor material may be the same or different. In the composite structure, the mass ratio of the first infrared emission precursor material, the carbonaceous material, and the second infrared emission precursor material is 10:d:10, where 0 < d < 9.

2. The method for preparing a conductive infrared emitting composite material according to claim 1, characterized in that, AB2O 4-δ The spinel material is a carbon-doped spinel material, where the carbon material is one or more of graphene oxide, graphene, carbon nanotubes, carbon fibers, or carbon nanowires; A and B are selected from any one of copper, iron, cobalt, manganese, nickel, magnesium, zinc, and chromium.

3. A method for preparing a conductive infrared emitting composite material according to claim 1 or 2, characterized in that, It also includes setting a conductive substrate between the first infrared emitting precursor material and the second infrared emitting precursor material, wherein the conductive substrate includes a metal mesh, a conductive fiber mesh or a carbon plate.

4. A method for preparing a conductive infrared emitting composite material according to claim 1 or 2, characterized in that, The steps for obtaining infrared emission precursor materials include mixing AB2O 4-δ Microwave plasma sintering of spinel materials, ceramic materials and carbonaceous materials.

5. A method for preparing a conductive infrared emitting composite material according to claim 1 or 2, characterized in that, Ceramic materials include any one of cordierite, silicon carbide, perovskite, and mullite; carbonaceous materials include any one of reduced graphene oxide, carbon nanotubes, carbon fibers, and carbon nanowires.

6. The method for preparing a conductive infrared emitting composite material according to claim 5, characterized in that, The infrared emission band of conductive infrared emitting composite materials can be controlled by adjusting the types and / or proportions of spinel, ceramic, and carbonaceous materials.

7. A conductive infrared emitting composite material, characterized in that, It is composed of a first infrared emission precursor material, a carbonaceous material, and a second infrared emission precursor material in a mass ratio of 10:d:10, and 0 < d < 9. Both the first infrared emission precursor material and the second infrared emission precursor material include AB2O in a mass ratio of a:b:c. 4-δ Spinel materials, ceramic materials, and carbonaceous materials, and 0 < a < 9, 0 < b < 9, 0 < c < 9; where 0 ≤ δ < 1, A and B represent transition metals and A and B are of different types; the spinel materials, ceramic materials, and carbonaceous materials contained in the first infrared emission precursor material and the second infrared emission precursor material are the same or different. The conductive infrared emitting composite material is obtained by sequentially constructing a composite structure of a first infrared emitting precursor material, a carbonaceous material, and a second infrared emitting precursor material, and then using microwave plasma discharge treatment to activate the infrared emission performance of the plasma elements and excite the conductivity of the conductive channels to obtain the conductive infrared emitting composite material.

8. The conductive infrared emitting composite material according to claim 7, characterized in that, The infrared emission band of the conductive infrared emitting composite material is adjustable in the range of 2-14μm. The infrared emission of the conductive infrared emitting composite material can be controlled by light field, electric field, or a combination of light field and electric field.

9. The conductive infrared emitting composite material prepared by the method of any one of claims 1 to 6, or the conductive infrared emitting composite material of claim 7 or 8, is used in textiles, infrared stealth, temperature sensing, solar cells, chemical analysis, biological imaging, fiber optic communication, and night vision surveillance.

Images