Nanoparticle-loaded composite material and preparation method thereof

Abstract

The invention discloses a nanoparticle-loaded composite material and a preparation method thereof. The preparation method comprises the following steps: providing a substrate material; adding a precursor solution for preparing nanoparticles on the substrate material, and drying to obtain a precursor material; loading a protective layer on the precursor material, and performing laser processing on the protective layer to obtain a nano-particle loaded composite material; wherein the in-plane heat conductivity coefficient of the protective layer is more than or equal to 200W / (m.K), and the out-plane heat conductivity coefficient of the protective layer is less than or equal to 20W / (m.K). According to the preparation method, the in-plane high-heat-conduction and out-plane high-heat-insulation protective layer is introduced, so that the global transmission efficiency of laser pulse energy in the laser processing process is remarkably improved, the phenomena of local heat damage and stress concentration are reduced, the problem of uneven heat energy distribution is effectively solved, and the service life of the laser is prolonged. Therefore, the structural damage of the substrate material and the non-uniform size and distribution of the precipitated material caused by the laser processing process are avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of material processing, and particularly relates to a composite material loaded with nanoparticles and a preparation method thereof. Background Art

[0002] At present, there are various schemes for preparing or loading nano / micron-scale materials, such as hydrothermal method, electrochemical deposition method, etc. The hydrothermal method usually uses water as the reaction medium and is a method for synthesizing nanoparticles in a closed autoclave with a high-temperature and high-pressure reaction environment. In this special environment, poorly soluble or insoluble precursors become easily soluble, and high temperature and high pressure enable the completion of the reaction and synthesis. The characteristic of this method is to provide a special physical and chemical environment that cannot be obtained under normal pressure conditions, enabling the precursors to be fully dissolved in the reaction system and finally nucleating and crystallizing. Recrystallization can also occur during the reaction process to obtain the product. Finally, through processes such as filtration, washing, and drying, various materials with high purity and small particle size are obtained. However, the hydrothermal method currently has disadvantages such as an unintuitive reaction process, uncontrollable reaction area, and long reaction time, making it difficult to efficiently and batchwise manufacture target products controllably.

[0003] The electrochemical deposition method is a preparation method in which metal ions in an electrolyte solution undergo a reduction reaction on the surface of an electrode by applying a voltage or current on the electrode surface, thereby depositing into metal nanoparticles. Through this method, target substances can be grown on the surface of large-area or complex parts, and it is easy to prepare pure metals, alloys, and composite nanocrystals. Its advantage is that alloys can be formed at room temperature. However, during the electrochemical deposition process, part of the current may be used for the decomposition of the electrolyte or the generation of by-products, rather than all being used for the reduction and deposition of metal ions. This results in a low electro-deposition current efficiency and a long deposition time is required to obtain the desired material thickness. At the same time, due to its relatively complex preparation process and the need for precise control, it is difficult to achieve large-scale and uniform production of nanoparticles. This limits the application of the electrochemical deposition method in industry.

[0004] In recent years, laser processing methods have shone brightly in nanostructure engineering, such as applications in fields such as precisely adjusting the shape, structure, and composition of materials. Compared with wet synthesis methods such as the hydrothermal method and the electrochemical deposition method, the preparation process of laser-induced generation of nano / micron materials is simpler and more environmentally friendly. In addition, increasing the laser power and pulse oscillation rate can effectively improve production efficiency, thereby achieving large-scale industrial manufacturing. For example, a composite EMI shielding film with a structure of Fe3O4 nanoparticles loaded on LIG (LIG@Fe3O4) can be obtained by laser processing a composite film of a metal salt precursor and a polymer resin. Compared with other methods, laser processing has the advantages of high efficiency, controllable synthesis area, and large-scale production.

[0005] However, during the laser processing, the laser pulses have strong thermal shock and thermal accumulation effects, which can damage the structure of the synthesized material, reduce the effective load of the nano / micro materials generated during the processing, and at the same time cause uneven distribution and different sizes of the prepared materials, further exacerbating the stress concentration phenomenon in the structure, such as Figure 1 shown in the traditional laser processing scheme without a protective layer in Figure 1 . The temperature field and stress field in the processing system are extremely unevenly distributed, resulting in the collapse of the structure of the prepared material, which is then ejected from the material system, greatly reducing the synthesis efficiency and the uniformity of the size of the prepared material.

[0006] Therefore, the existing technology still needs to be improved and developed. Summary of the Invention

[0007] In view of the above deficiencies of the prior art, the purpose of the present invention is to provide a composite material loaded with nanoparticles and a preparation method thereof, aiming to solve the problem that the structure of the material is damaged due to thermal damage and stress concentration during the process of preparing the composite material loaded with nanoparticles by laser processing.

[0008] The technical solution of the present invention is as follows:

[0009] In the first aspect, a preparation method of a composite material loaded with nanoparticles is provided, including the steps of:

[0010] Providing a substrate material;

[0011] Adding a precursor solution for preparing nanoparticles on the substrate material, and drying to obtain a precursor material;

[0012] Loading a protective layer on the precursor material, and performing laser processing on the protective layer to obtain a composite material loaded with nanoparticles;

[0013] Wherein, the in-plane thermal conductivity of the protective layer ≥ 200 W / (m·K), and the out-of-plane thermal conductivity of the protective layer ≤ 20 W / (m·K).

[0014] In a preferred technical solution, the material composition of the protective layer is one or more of graphene oxide, graphene, reduced graphene oxide, molybdenum disulfide, and boron nitride.

[0015] In a preferred technical solution, the thickness of the protective layer is 0.1 - 20 μm.

[0016] In a preferred technical solution, the parameters of the laser processing include: the laser scanning speed is 100 - 500 mm / s, the scanning pitch is 0.05 - 2 mm, the laser pulse frequency is 100 - 500 kHz, and the pulse width is 0.5 - 2 μs.

[0017] Preferred technical solution: The drying conditions include: drying temperature of 40 - 80°C and drying time of 0.5 - 3 h.

[0018] Preferred technical solution: The substrate material is a two-dimensional planar structure or a three-dimensional three-dimensional structure.

[0019] Preferred technical solution: The substrate material is one or more of laser-induced graphene, carbon fiber cloth, nickel mesh, nickel foil, copper mesh, and copper foil.

[0020] Preferred technical solution: The method for preparing the laser-induced graphene includes the steps of:

[0021] Providing a polyimide film;

[0022] Using an ultraviolet laser to perform laser induction on the polyimide film to obtain the laser-induced graphene.

[0023] Preferred technical solution: The parameters of the laser induction include: laser scanning speed of 100 - 500 mm / s, scanning pitch of 0.05 - 2 mm, laser pulse frequency of 100 - 500 kHz, and pulse width of 0.5 - 2 μs.

[0024] Preferred technical solution: The nanoparticles are cobalt ferrite nanoparticles.

[0025] Preferred technical solution: The precursor solution is an aqueous cobalt chloride solution and an aqueous iron nitrate solution.

[0026] Preferred technical solution: The concentration of the aqueous cobalt chloride solution is 0.1 - 1 mol / L, and the concentration of the aqueous iron nitrate solution is 0.1 - 1 mol / L.

[0027] In a second aspect, a composite material loaded with nanoparticles is provided, which is prepared by using the preparation method described in the first aspect.

[0028] Beneficial effects: The present invention provides a method for preparing a composite material loaded with nanoparticles. By introducing a protective layer with high in-plane thermal conductivity and high out-of-plane thermal insulation, the global transmission efficiency of laser pulse energy during the laser processing is significantly improved, and the phenomena of local thermal damage and stress concentration are alleviated. This method effectively solves the problem of uneven thermal energy distribution commonly encountered in the preparation of composite materials loaded with nanoparticles by laser processing, thereby avoiding the structural damage of the substrate material and the non-uniformity of the size and distribution of the precipitated particles caused by the laser processing. Due to the more uniform distribution of laser thermal energy, in the composite material loaded with nanoparticles prepared by this method, the nanoparticles exhibit high crystallinity and size consistency, and are uniformly distributed. Description of the Drawings

[0029] Figure 1Schematic diagram of the temperature field and stress field distribution during laser processing of the preparation method without a protective layer.

[0030] Figure 2 Schematic diagram of the temperature field and stress field distribution during laser processing of the preparation method with a protective layer.

[0031] Figure 3 SEM image of the LIG prepared in Example 1.

[0032] Figure 4 Magnified SEM image of the LIG prepared in Example 1.

[0033] Figure 5 SEM image of the composite material after laser processing in Example 1.

[0034] Figure 6 Magnified SEM image of the composite material after laser processing in Example 1.

[0035] Figure 7 SEM image of the composite material after laser processing in Example 2 (left) and the LIG prepared in Example 1 (right).

[0036] Figure 8 SEM image of the composite material after laser processing in Example 3.

[0037] Figure 9 Theoretical model diagram of the composite materials in Examples 2 and 3.

[0038] Figure 10 Temperature change curve graph under the preparation methods with and without a protective layer.

[0039] Figure 11 Stress change curve graph under the preparation methods with and without a protective layer.

[0040] Figure 12 Temperature change curve graph of different preparation methods under single and multiple pulse processing conditions.

[0041] Figure 13 Stress change curve graph of different preparation methods under single and multiple pulse processing conditions. Detailed implementation manner

[0042] The present invention provides a composite material loaded with nanoparticles and a preparation method thereof. To make the purpose, technical solution and effects of the present invention clearer and more definite, the present invention is further described in detail below.

[0043] The embodiment of the present invention provides a preparation method of a composite material loaded with nanoparticles, including the steps of:

[0044] Providing a substrate material;

[0045] Add a precursor solution for preparing nanoparticles on the substrate material, and dry it to obtain a precursor material;

[0046] Load a protective layer on the precursor material, and perform laser processing on the protective layer to obtain a composite material loaded with nanoparticles;

[0047] Wherein, the in-plane thermal conductivity of the protective layer ≥ 200 W / (m·K), and the out-of-plane thermal conductivity of the protective layer ≤ 20 W / (m·K).

[0048] Specifically, in the current process of preparing a composite material loaded with nanoparticles by laser processing, there are significant problems such as thermal damage, stress concentration, and damage to the substrate material structure. In the embodiments of the present invention, by adding a protective layer with high in-plane thermal conductivity (thermal conductivity ≥ 200 W / (m·K)) and high out-of-plane thermal insulation (thermal conductivity ≤ 20 W / (m·K)) on the substrate material, it is possible to effectively suppress quality loss and structural damage caused by local transient heat accumulation and high temperature during laser processing( Figure 2 ), making the product distribution more uniform, the particle size of the generated nanoparticles more stable, and at the same time alleviating the stress concentration phenomenon during laser processing. In the composite material loaded with nanoparticles prepared by this method, the nanoparticle sizes are uniform and the distribution is homogeneous.

[0049] In one embodiment, the material composition of the protective layer is one or more of graphene oxide, graphene, reduced graphene oxide, molybdenum disulfide, boron nitride, but not limited thereto.

[0050] In one embodiment, the thickness of the protective layer is 0.1 - 20 μm; preferably, the thickness of the protective layer is 1 - μm; further preferably, the protective layer is a single layer of graphene oxide with a thickness of 1 μm; but not limited thereto. The thickness of the protective layer can be adjusted according to the power during laser processing. In the future, if the laser light source breaks through the limit, it may be necessary to further increase the thickness to play a protective role.

[0051] In one embodiment, the parameters of the laser processing include: the laser scanning speed is 100 - 500 mm / s, the scanning pitch is 0.05 - 2 mm, the laser pulse frequency is 100 - 500 kHz, and the pulse width is 0.5 - 2 μs, but not limited thereto. Appropriate laser processing parameters can be selected according to specific needs.

[0052] In one embodiment, the drying conditions include: the drying temperature is 40 - 80 °C, and the drying time is 0.5 - 3 h, but not limited thereto. Appropriate drying conditions can be selected according to specific needs.

[0053] In one embodiment, the substrate material is a two-dimensional planar structure or a three-dimensional solid structure, but is not limited thereto. A suitable substrate material can be selected according to specific needs.

[0054] In one embodiment, the substrate material is a porous structure, but is not limited thereto. A suitable substrate material can be selected according to specific needs.

[0055] In one embodiment, the substrate material is one or more of laser-induced graphene, carbon fiber cloth, nickel mesh, nickel foil, copper mesh, and copper foil, but is not limited thereto. A suitable substrate material can be selected according to specific needs.

[0056] In one embodiment, the method for preparing the laser-induced graphene includes the steps of:

[0057] Providing a polyimide film;

[0058] Using an ultraviolet laser to perform laser induction on the polyimide film to obtain the laser-induced graphene.

[0059] In one embodiment, the parameters of the laser induction include: the laser scanning speed is 100-500 mm / s, and the scanning spacing is 0.05-2 mm; the laser pulse frequency is 100-500 kHz, and the pulse width is 0.5-2 μs, but is not limited thereto. Suitable laser induction parameters can be selected according to specific needs.

[0060] In one embodiment, the nanoparticles are cobalt ferrite nanoparticles, but are not limited thereto. A suitable nanoparticle material can be selected according to specific needs.

[0061] In one embodiment, the precursor solution is an aqueous solution of cobalt chloride and an aqueous solution of iron nitrate, but is not limited thereto. A suitable precursor solution can be selected according to specific needs.

[0062] In one embodiment, the concentration of the aqueous solution of cobalt chloride is 0.1-1 mol / L, and the concentration of the aqueous solution of iron nitrate is 0.1-1 mol / L, but is not limited thereto. The concentration of the precursor solution can be selected according to specific needs.

[0063] In a specific embodiment, the composite material loaded with nanoparticles is an rGO / LIG@nanoparticle composite material. The method for preparing the rGO / LIG@nanoparticle composite material includes the following steps:

[0064] Using laser-induced graphene (LIG) as a substrate;

[0065] The cobalt chloride hexahydrate aqueous solution was dropped onto the laser-induced graphene, dried, and then the iron nitrate nonahydrate aqueous solution was dropped onto the laser-induced graphene containing cobalt chloride hexahydrate, followed by drying to obtain the precursor material;

[0066] A protective layer was loaded on the precursor material, dried, and laser processing was performed on the protective layer (equivalent to laser processing the precursor material through the protective layer) to obtain the rGO / LIG@nanoparticle composite material;

[0067] Among them, the protective layer is composed of graphene oxide.

[0068] Specifically, the graphene oxide protective layer converts the local transient laser pulse energy into global uniform and continuous thermal energy and confines it within the LIG, which not only protects the structural integrity of the LIG but also realizes a more uniform and controllable nanoscale size distribution of cobalt ferrite precipitated on the LIG. In addition, the graphene oxide becomes highly conductive and highly thermally conductive reduced graphene oxide after laser processing.

[0069] An embodiment of the present invention provides a composite material loaded with nanoparticles, which is prepared by the preparation method described above.

[0070] The present invention will be further described below through specific embodiments.

[0071] Example 1

[0072] In this example, laser-induced graphene (LIG) was first prepared by laser processing a polyimide film as a substrate for loading target materials. The steps are as follows: First, the polyimide film was evenly cut into small pieces of 1×1.5 cm in size, cleaned with deionized water and ethanol in sequence, and adhered to a clean glass substrate. Then, a UV laser was used to perform laser induction on it to prepare a highly conductive graphene film. The laser parameters are as follows: the scanning speed of the laser is 125 mm / s, the scanning spacing is 0.1 mm; the laser pulse frequency is 300 kHz, the pulse width is 1 μs, and the light beam is focused on the plane of the polyimide film. The obtained product is called LIG, and its structure is as Figure 3 and Figure 4 shown. It can be seen from Figure 3 and Figure 4 that the LIG has a rich vertical three-dimensional (3D) porous structure, which has high conductivity and crystallinity.

[0073] Secondly, using the prepared LIG as the substrate, 120 μL of an aqueous solution of cobalt chloride hexahydrate (concentration: 0.5 mol / L) was evenly dropped onto the graphene plane in the LIG substrate and dried in an oven at 60 °C for 1 h. Then, 120 μL of an aqueous solution of iron nitrate nonahydrate with the same concentration was dropped onto the dried graphene film containing cobalt chloride hexahydrate, and then placed in an oven at 60 °C for 1 hour. The dried film was processed by a UV laser, and the laser parameters were as follows: the scanning speed of the laser was 125 mm / s, the scanning pitch was 0.1 mm; the laser pulse frequency was 300 kHz, the pulse width was 1 μs, and the beam was focused on the plane of the target film. The composite material after laser processing is as Figure 5 and Figure 6 shown. It can be seen from Figure 5 that the three-dimensional structure in the LIG substrate was severely damaged, the uniformly distributed vertical three-dimensional porous structure collapsed and reorganized, and the size of the porous structure in the laser processing area changed significantly. It can be seen from Figure 6 that the size of the cobalt ferrite particles in the prepared composite material showed a distribution ranging from nanoscale to micron scale, with a large size span and uneven distribution.

[0074] Example 2

[0075] Using the LIG prepared in Example 1 as the substrate, 120 μL of an aqueous solution of cobalt chloride hexahydrate (concentration: 0.5 mol / L) was evenly dropped onto the graphene plane in the LIG substrate and dried in an oven at 60 °C for 1 h. Then, 120 μL of an aqueous solution of iron nitrate nonahydrate with the same concentration was dropped onto the dried graphene film containing cobalt chloride hexahydrate, and then placed in an oven at 60 °C for 1 hour.

[0076] 10 mg of graphene oxide (GO) was dissolved in 100 mL of ethanol in advance and ultrasonicated at a frequency of 37 kHz for 5 h. Then, using the Langmuir-Blodgett (LB) film preparation scheme, it was evenly sprayed onto the surface of the deionized aqueous solution contained in a container. Subsequently, a sponge was placed in a corner to make the GO arranged orderly on the surface closely aggregate together under the action of tension. The dried film was put into deionized water and fished up from below the GO, so that a layer of graphene oxide protective layer parallel to the film plane was loaded on its surface, and then placed in an oven at 60 °C for 1 hour. The dried film was processed by a UV laser, and the laser parameters were as follows: the scanning speed of the laser was 125 mm / s, the scanning pitch was 0.1 mm; the laser pulse frequency was 300 kHz, the pulse width was 1 μs, and the beam was focused on the plane of the target film. The composite material after processing is as Figure 7As shown, the left side is the structural diagram of the composite material at the micron scale, and the right side is the partial enlarged view of the LIG structure. By comparing the two, it can be seen that the damage of the composite material in this embodiment occurs in the protective layer, the LIG structure of the substrate remains intact, and uniformly loads cobalt ferrite nanoparticles with uniform size and small particle size.

[0077] Example 3

[0078] Using the LIG prepared in Example 1 as the substrate, 120 μL of an aqueous solution of cobalt chloride hexahydrate (concentration 0.5 mol / L) was uniformly dropped onto the graphene plane in the LIG substrate and dried in an oven at 60 °C for 1 h. Then, 120 μL of an aqueous solution of iron(III) nitrate nonahydrate with the same concentration was dropped onto the dried graphene film containing cobalt chloride hexahydrate, and then placed in an oven at 60 °C for 1 hour.

[0079] 10 mg of graphene oxide (GO) was dissolved in 100 ml of ethanol in advance and ultrasonicated at a frequency of 37 kHz for 5 h. 120 μL of the GO solution was drop-coated onto the dried LIG composite film, and then placed in an oven at 60 °C for 1 hour. The dried film was processed by an ultraviolet laser, and the laser parameters were as follows: the scanning speed of the laser was 125 mm / s, the scanning pitch was 0.1 mm; the laser pulse frequency was 300 kHz, the pulse width was 1 μs, and the light beam was focused on the plane of the target film. The processed composite material is as Figure 8 , By comparing it with the composite material prepared in Example 2, it can be seen that the particle sizes of the products obtained by loading GO on the LIG composite film by different methods are also different. The present invention can control the thickness of the protective layer by regulating the GO concentration, and can also achieve the effect of controlling the particle size of the product nanoparticles by changing the loading method of the protective layer.

[0080] The theoretical model of the embodiment is as Figure 9 shown. Taking the presence or absence of a protective layer above the material as the difference, theoretical calculations were carried out for two cases of "relatively continuous laser processing process" and "transient pulse laser processing process" during the processing.

[0081] In continuous laser processing, assuming that the composite material is under the action of a 2.4 W laser and undergoes laser processing for a duration of 1 s. Compared with the LIG@nanoparticle composite material (without a protective layer), the rGO / LIG@nanoparticle composite material (with a protective layer) exhibits a relatively low temperature level, as Figure 10As shown, without the protective layer, the temperature difference between the highest and lowest temperatures in the processing area exceeded 1000 K. With the protective layer, the temperature difference significantly shrank to within 300 K, and the uniformity of the temperature field was greatly improved. This difference can be attributed to the protective effect of the rGO layer. Its out-of-plane thermal insulation effectively protects the underlying materials, while its in-plane excellent thermal conductivity quickly converts the local heat source of laser processing into a global heat source under the coverage area of the protective layer, reducing the temperature and stress concentration in the underlying layer.

[0082] Figure 11 Shows the maximum stress generated by the composite material under two laser processing conditions with and without the protection of the rGO layer. After adding the protective layer, the maximum stress level borne by the material structure is about 60% of that of the non-protective layer scheme, greatly improving the integrity of the prepared composite material structure. Combining Figure 10 and Figure 11 It can be seen that without the protection of the rGO layer, the thermal stress of the composite material is close to its theoretical strength limit, which will inevitably cause structural defects in the material, such as flaws or cracks. Some cracks will merge to form continuous cracks, severely collapsing the structure of the processed material and causing quality loss.

[0083] For the transient pulsed laser processing process, as Figure 12 shown, under the action of the pulsed laser, the temperature of the LIG@nanoparticle composite material (without the protective layer) will rise sharply to the highest point and then gradually decrease. In the rGO / LIG@nanoparticle composite material (with the protective layer), due to the excellent in-plane heat transfer efficiency of the rGO layer, the transient laser heat will first be stored in the rGO layer, and then the heat in the layer will continuously and stably transfer heat to the underlying materials as a continuous heat source, with the temperature rising slowly and finally maintaining at a relatively low level. Compared with the LIG@nanoparticle composite material without the protective layer, the temperature rise process of the composite material with the rGO layer protection is more controlled and smoother, which helps to alleviate the thermal effect phenomenon that damages the material structure during the laser processing. At the same time, the present invention studied the situation of whether there is pre-precipitated material to determine the difference between single-pulse laser processing (without pre-precipitated material) and multi-pulse processing (with pre-precipitated material).

[0084] Figure 12 The green and orange curves in show that when there is an rGO protective layer, even though there are differences in pre-precipitated materials between single-pulse laser processing and multi-pulse processing, the difference in the temperature rise rate of the composite material is not significant. The alleviation of the laser thermal effect mainly benefits from the introduction of a protective layer with high in-plane thermal conductivity and high out-of-plane thermal insulation above the composite material. The pre-precipitated materials formed during the previous laser processing in multi-pulse processing have little effect on the temperature field of the system.

[0085] Figure 13 It shows the difference in the maximum stress generated by the composite material in two cases with and without the rGO layer protection. It can be seen from the figure that the green and orange curves are nearly coincident, indicating that when the protective layer exists, the pre-precipitated material formed by multiple pulsed laser processing has almost no effect on the thermal stress generated by the material. At the same time, the maximum stress level borne by the material structure in the processing scheme with the protective layer drops to about 50% of that in the scheme without the protective layer, ensuring the integrity of the composite material structure.

[0086] From the above analysis, it can be seen that whether to introduce a protective layer with high in-plane thermal conductivity and high out-of-plane thermal insulation has a great impact on the temperature field and stress field of the system, and the differences in the thermal distribution and stress distribution in the processing area directly affect the nucleation and growth processes of nanoparticles and the integrity of the material.

[0087] In laser processing, the influence of laser power on particle size can refer to the formula: D = K(P / V) a (where D is the grain size, K and a are constants related to the metal salt solution precursor, P is the laser power, and v is the laser scanning speed). Without introducing a protective layer, the energy of the transient high-energy laser directly leads to non-uniform thermal distribution in the LIG, and this significant temperature gradient will cause obvious differences in the sizes of the generated nanoparticles. The increase in the sintering temperature during the processing will increase the energy level of the metal particles themselves, thereby enhancing the thermal motion of atoms or ions and resulting in a higher diffusion rate. The concentrated high temperature will cause the rate of particle coalescence and growth to be too fast, making the particle size of the metal particles loaded on the composite material larger and unevenly distributed.

[0088] In the present invention, the protective layer with high in-plane thermal conductivity and high out-of-plane thermal insulation will convert the local transient laser pulse energy into global uniform and continuous thermal energy and confine it within the LIG structure, which not only protects the integrity of the structure but also realizes a more uniform and controllable nano-scale size distribution of the precipitated substances on the substrate.

[0089] It should be understood that the application of the present invention is not limited to the above examples. For those of ordinary skill in the art, improvements or transformations can be made according to the above description, and all such improvements and transformations should fall within the protection scope of the appended claims of the present invention.

Claims

1. A method for preparing a composite material loaded with nanoparticles, characterized in that, Including the steps of: Providing a substrate material; Adding a precursor solution for preparing nanoparticles on the substrate material, and drying to obtain a precursor material; Loading a protective layer on the precursor material, and performing laser processing on the protective layer to obtain a composite material loaded with nanoparticles; Wherein, the in-plane thermal conductivity of the protective layer is ≥200 W / (m·K), and the out-of-plane thermal conductivity of the protective layer is ≤20 W / (m·K).

2. The preparation method according to claim 1, characterized in that, The material composition of the protective layer is one or more of graphene oxide, graphene, reduced graphene oxide, molybdenum disulfide, and boron nitride; And / or, the thickness of the protective layer is 0.1 - 20 μm.

3. The preparation method according to claim 1, characterized in that, The parameters of the laser processing include: the laser scanning speed is 100 - 500 mm / s, the scanning pitch is 0.05 - 2 mm, the laser pulse frequency is 100 - 500 kHz, and the pulse width is 0.5 - 2 μs; The conditions of the drying include: the drying temperature is 40 - 80 °C, and the drying time is 0.5 - 3 h.

4. The preparation method according to claim 1, wherein The substrate material is a two-dimensional planar structure or a three-dimensional stereoscopic structure.

5. The preparation method according to claim 1, wherein, The substrate material is one or more of laser-induced graphene, carbon fiber cloth, nickel mesh, nickel foil, copper mesh, and copper foil.

6. The preparation method according to claim 5, characterized in that, The preparation method of the laser-induced graphene includes the steps of: Providing a polyimide film; Using an ultraviolet laser to perform laser induction on the polyimide film to obtain the laser-induced graphene.

7. The preparation method according to claim 6, characterized in that, The parameters of the laser induction include: the laser scanning speed is 100 - 500 mm / s, the scanning pitch is 0.05 - 2 mm, the laser pulse frequency is 100 - 500 kHz, and the pulse width is 0.5 - 2 μs.

8. The preparation method according to claim 1, wherein, The nanoparticles are cobalt ferrite nanoparticles; the precursor solution is an aqueous cobalt chloride solution and an aqueous iron nitrate solution.

9. The preparation method according to claim 8, characterized in that, The concentration of the aqueous cobalt chloride solution is 0.1 - 1 mol / L, and the concentration of the aqueous iron nitrate solution is 0.1 - 1 mol / L.

10. A composite material loaded with nanoparticles, characterized in that, Prepared by using the preparation method according to any one of claims 1 - 9.

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