Liquid metal-aerogel composite with Janus structure and preparation method and application thereof

Abstract

The application relates to a liquid metal-aerogel composite material with a Janus structure and a preparation method and application thereof, the liquid metal-aerogel composite material with the Janus structure comprises an aerogel and a liquid metal layer arranged in a preset region on the surface of the aerogel, and at the contact interface between the aerogel and the liquid metal layer, the liquid metal is infiltrated into the aerogel to form an infiltration layer. The application can make the liquid metal and the aerogel be combined and constructed into the Janus structure by arranging the liquid metal layer in the preset region on the surface of the aerogel and making the liquid metal be infiltrated into the aerogel to form the infiltration layer, and then the conductive property of the liquid metal and the light / heat insulation property of the aerogel are integrated, so that the composite material has the conductive, light and heat insulation properties.

Description

Technical Field

[0001] This invention relates to the field of electronic materials technology, and in particular to liquid metal-aerogel composite materials with Janus structure, their preparation methods and applications. Background Technology

[0002] Silicon-based, carbon-based, ceramic-based, and polymer-based aerogels have become ideal candidate materials for electronic devices due to their ultra-low density, high porosity, and excellent thermal insulation properties, but their inherent insulation properties limit their application in electronic devices. Summary of the Invention

[0003] Based on this, a liquid metal-aerogel composite material with a Janus structure is provided, along with its preparation method and application. The liquid metal-aerogel composite material with a Janus structure combines electrical conductivity, lightweight, and thermal insulation properties.

[0004] A liquid metal-aerogel composite material with a Janus structure, the liquid metal-aerogel composite material with a Janus structure includes an aerogel and a liquid metal layer disposed in a predetermined area on the surface of the aerogel, and at the contact interface between the aerogel and the liquid metal layer, the liquid metal wettes into the interior of the aerogel to form an impregnation layer.

[0005] In one embodiment, the thickness of the liquid metal layer is less than 500 μm;

[0006] And / or, the thickness of the wetting layer is less than 1 μm.

[0007] In one embodiment, the thickness of the liquid metal layer is 10 μm to 50 μm;

[0008] And / or, the thickness of the wetting layer is 10 nm to 50 nm.

[0009] In one embodiment, the liquid metal is selected from at least one of gallium indium alloy, gallium indium tin alloy, and bismuth indium tin zinc alloy;

[0010] And / or, the aerogel is selected from one of silicon-based aerogels, carbon-based aerogels, ceramic-based aerogels, and polymer-based aerogels.

[0011] A method for preparing the liquid metal-aerogel composite material with the Janus structure, comprising the following steps:

[0012] A dispersion of liquid metal nanoparticles is prepared, wherein the particle size of the liquid metal nanoparticles is less than 600 nm and the thickness of the surface oxide shell is 3 nm to 10 nm.

[0013] Liquid metal nanoparticle layers with a thickness of 1 μm to 20 μm were prepared on a transparent substrate using the aforementioned dispersion.

[0014] The aerogel is placed on the surface of the liquid metal nanoparticle layer facing away from the transparent substrate;

[0015] A laser with a wavelength above 532 nm was used to incident from the transparent substrate away from the surface of the liquid metal nanoparticle layer and focused at the interface between the liquid metal nanoparticle layer and the transparent substrate. Then, a scan was performed according to a preset pattern. After the scan, a liquid metal-aerogel composite material with a Janus structure was obtained, wherein the laser energy density was 40 J / cm². 2 Up to 60J / cm 2 .

[0016] In one embodiment, the liquid metal nanoparticles have a particle size of 100 nm to 500 nm;

[0017] And / or, the thickness of the liquid metal nanoparticle layer is 5 μm to 10 μm;

[0018] And / or, the energy density of the laser is 40 J / cm². 2 Up to 55J / cm 2 .

[0019] In one embodiment, the liquid metal nanoparticles have a particle size of 200 nm to 400 nm;

[0020] And / or, the energy density of the laser is 40 J / cm². 2 Up to 50J / cm 2 .

[0021] In one embodiment, a laser with a wavelength of 1064 nm is used. During scanning, the repetition frequency is 2 kHz to 300 kHz, the scanning speed is 50 mm / s to 1000 mm / s, the scanning line spacing is 1 μm to 50 μm, and the pulse interval is 10 μm to 200 μm.

[0022] In one embodiment, the thickness of the transparent substrate is 0.5 mm to 1.5 mm, and the transparent substrate is selected from sapphire substrate and quartz substrate.

[0023] Application of the aforementioned liquid metal-aerogel composite material with a Janus structure in electronic devices.

[0024] This invention sets a liquid metal layer in a predetermined area on the surface of an aerogel and allows the liquid metal to impregnate into the interior of the aerogel to form an impregnation layer. This allows the liquid metal to be combined with the aerogel and constructed into a Janus structure, thereby integrating the conductive properties of the liquid metal with the lightweight / thermal insulation properties of the aerogel, so that the composite material has the properties of conductivity, lightweight and thermal insulation. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the liquid metal-aerogel composite material with Janus structure of the present invention;

[0027] Figure 2 This is a schematic diagram of the preparation method of the liquid metal-aerogel composite material with Janus structure according to the present invention;

[0028] Figure 3 This is a sample image of the liquid metal-aerogel composite material with a Janus structure prepared in Example 1 of the present invention;

[0029] Figure 4 This is a sample image of the liquid metal-aerogel composite material prepared in Comparative Example 1 of the present invention.

[0030] In the figure: 10, transparent substrate; 20, liquid metal nanoparticle layer; 21, liquid metal layer; 30, aerogel; 31, wetting layer; 40, laser. Detailed Implementation

[0031] To facilitate understanding of the present invention, it will be described in more detail below. However, it should be understood that the present invention can be implemented in many different forms and is not limited to the embodiments or examples described herein. Rather, these embodiments or examples are provided to make the disclosure of the present invention more thorough and complete.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments or examples only and is not intended to limit the invention. The optional scope of the term "and / or" as used herein includes any one of two or more of the related listed items, as well as any and all combinations of the related listed items, including any two related listed items, any more related listed items, or a combination of all related listed items.

[0033] In this invention, numerical ranges are involved. Unless otherwise specified, the numerical ranges are considered continuous and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe features or characteristics, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are included.

[0034] Liquid metal, with its unique fluidity and high conductivity, is an ideal material for constructing high-precision conductive patterns on aerogel surfaces. However, when liquid metal is placed on an aerogel surface, it easily shrinks, forming two separate materials with the aerogel.

[0035] Therefore, such as Figure 1 As shown, the liquid metal-aerogel composite material with Janus structure provided by the present invention includes an aerogel 30 and a liquid metal layer 21 disposed in a predetermined area on the surface of the aerogel. At the contact interface between the aerogel 30 and the liquid metal layer 21, the liquid metal is impregnated into the interior of the aerogel 30 to form an impregnation layer 31.

[0036] Therefore, by setting a liquid metal layer 21 in a predetermined area on the surface of the aerogel 30 and allowing the liquid metal to impregnate into the interior of the aerogel 30 to form an impregnation layer 31, the liquid metal can be combined with the aerogel 30 to form a Janus structure, thereby integrating the conductive properties of the liquid metal with the lightweight / thermal insulation properties of the aerogel 30, so that the composite material has both conductive, lightweight and thermal insulation properties.

[0037] It is understandable that the preset areas on the surface of aerogel 30 can be constructed according to the desired conductive pattern.

[0038] Optionally, the thickness of the liquid metal layer 21 is less than 500 μm, and the thickness of the wetting layer 31 is less than 1 μm; further, the thickness of the liquid metal layer 21 is 10 μm to 50 μm, and the thickness of the wetting layer 31 is 10 nm to 50 nm.

[0039] Optionally, the liquid metal is selected from at least one of gallium indium alloy, gallium indium tin alloy, and bismuth indium tin zinc alloy, and the aerogel is selected from one of silicon-based aerogel, carbon-based aerogel, ceramic-based aerogel, and polymer-based aerogel.

[0040] Combination Figure 2 As shown, the present invention also provides a method for preparing a liquid metal-aerogel composite material with a Janus structure, comprising the following steps:

[0041] S1, a dispersion for preparing liquid metal nanoparticles;

[0042] S2, a liquid metal nanoparticle layer 20 is prepared on a transparent substrate 10 using the dispersion;

[0043] S3, place the aerogel 30 on the surface of the liquid metal nanoparticle layer 20 away from the transparent substrate 10;

[0044] S4, the laser 40 is incident from the transparent substrate 10 away from the surface of the liquid metal nanoparticle layer 20 and focused at the interface between the liquid metal nanoparticle layer 20 and the transparent substrate 10, and then scanned according to a preset pattern. After the scan is completed, a liquid metal-aerogel composite material with a Janus structure is obtained.

[0045] In the preparation method of the present invention, liquid metal is first prepared into nanoparticles, and a liquid metal nanoparticle layer 20 is prepared on a transparent substrate 10. Then, aerogel 30 is placed on the surface of the liquid metal nanoparticle layer 20 away from the transparent substrate 10. When the laser 40 is focused on the interface between the liquid metal nanoparticle layer 20 and the transparent substrate 10 for scanning, the liquid metal nanoparticles at the interface can be rapidly heated and transformed from liquid phase to gas phase vapor. The gas phase vapor will rapidly expand outward, manifested as high-speed jet. According to the law of conservation of momentum, when the gas phase vapor is jetted at high speed, the unvaporized liquid metal nanoparticles in the scanning area will be subjected to a recoil pressure opposite to the direction of gas phase vapor jetting. This causes the liquid metal nanoparticles in the scanning area to break and fuse with each other while being pushed onto the aerogel 30, forming a predetermined liquid metal layer 21 on the aerogel 30. The liquid metal nanoparticles that are not processed by the laser remain on the transparent substrate 10.

[0046] However, this method does not necessarily enable the liquid metal layer 21 and aerogel 30 to form a Janus structure. Further research revealed that the liquid metal nanoparticles consist of a liquid core and a surface oxide shell. The thickness of the surface oxide shell affects the effectiveness of liquid metal vapor permeation and cooling on the aerogel 30 as a seed layer to promote liquid metal wetting of the aerogel 30. Liquid metal nanoparticles of different sizes have different specific surface areas, resulting in different evaporation rates at the interface during laser scanning. Different laser energy densities during laser scanning result in different energy levels for the liquid metal nanoparticles at the interface. Furthermore, different thicknesses of the liquid metal nanoparticle layer result in different recoil pressures required to propel the liquid metal nanoparticles into the aerogel 30.

[0047] Based on the above findings, this invention controls the particle size of liquid metal nanoparticles to below 600 nm, the thickness of the surface oxide shell to between 3 nm and 10 nm, the thickness of the liquid metal nanoparticle layer 20 to between 1 μm and 20 μm, and the laser energy density to 40 J / cm². 2 Up to 60J / cm 2 This allows liquid metal to impregnate aerogel 30, forming an impregnation layer 31, which in turn allows the liquid metal layer 21 to combine with aerogel 30 and form a Janus structure. Simultaneously, it does not damage aerogel 30.

[0048] Furthermore, when the particle size of the liquid metal nanoparticles and the thickness of the liquid metal nanoparticle layer 20 are equal, the conductivity of the formed liquid metal layer 21 will further increase with the increase of laser energy density. However, when the energy density is too high, the liquid metal will oxidize, and the conductivity of the formed liquid metal layer 21 will decrease. Similarly, when the laser energy density is the same, the conductivity of the liquid metal layer 21 will also differ depending on the particle size of the liquid metal nanoparticles and the thickness of the liquid metal nanoparticle layer 20. Therefore, the particle size of the liquid metal nanoparticles is further preferably 100 nm to 500 nm, the thickness of the liquid metal nanoparticle layer 20 is further preferably 5 μm to 10 μm, and the laser energy density is further preferably 40 J / cm². 2 Up to 55J / cm 2 Alternatively, the particle size of the liquid metal nanoparticles is more preferably 200 nm to 400 nm, and the energy density of the laser is more preferably 40 J / cm². 2 Up to 50J / cm 2 At this time, composite materials with better electrical conductivity can be formed.

[0049] Therefore, the preparation method of the present invention can not only obtain liquid metal-aerogel composite material with Janus structure, but also does not damage aerogel 30 during the preparation process, and has no specific restrictions on the material of aerogel 30. Silicon-based, carbon-based, ceramic-based, polymer-based and other aerogels are all applicable. It can be compatible with aerogels of various materials such as flexible, elastic and brittle materials, and has strong applicability.

[0050] In addition, the present invention utilizes laser to selectively sinter liquid metal nanoparticles, and the processing pattern can be changed at will by software, which makes the pattern of the liquid metal layer 21 highly flexible in selection.

[0051] Step S1, the step of preparing the dispersion of liquid metal nanoparticles, includes: ultrasonically treating the liquid metal in an organic solvent to obtain the dispersion of the liquid metal nanoparticles. Further, it is preferable to mix the liquid metal, dispersant, and organic solvent and then ultrasonically treat them to obtain the dispersion of liquid metal nanoparticles, which helps to obtain a stable dispersion. The choice of dispersant is not specific, as long as it can disperse the liquid metal in the solvent; specifically, it can be selected from at least one of 3-mercapto-N-nonylpropionamide, polyacrylamide, sodium dodecyl sulfate, and polyethylene glycol fatty acid esters. The choice of liquid metal is not specific, but can be selected from at least one of gallium indium alloy, gallium indium tin alloy, and bismuth indium tin zinc alloy. The choice of organic solvent is not specific, but can be selected from anhydrous ethanol, isopropanol, glycerol, dimethyl sulfoxide, etc.

[0052] Furthermore, the mass ratio of the liquid metal to the surfactant is preferably 160:1 to 90:1, the ratio of the liquid metal to the organic solvent is preferably 250mg:4mL to 450mg:4mL, and the ultrasonic treatment time is 2h to 5h, which is beneficial to obtaining liquid metal nanoparticles with uniform and controllable particle size.

[0053] In step S2, the liquid metal nanoparticle layer 20 can be prepared on the transparent substrate 10 by means of spraying, coating, etc., and the liquid metal nanoparticle layer 20 can be obtained after drying.

[0054] The thickness of the transparent substrate 10 is preferably 0.5 mm to 1.5 mm, and the transparent substrate 10 is selected from sapphire substrate and quartz substrate.

[0055] Since the method of the present invention does not damage the aerogel 30 and there are no specific limitations on the material of the aerogel 30, the selection of the aerogel 30 in step S3 is not limited, and it can be selected from one of silicon-based aerogel, carbon-based aerogel, ceramic-based aerogel, and polymer-based aerogel.

[0056] In order for the laser 40 to be incident from the transparent substrate 10 away from the surface of the liquid metal nanoparticle layer 20 and focused at the interface between the liquid metal nanoparticle layer 20 and the transparent substrate 10, the laser 40 needs to pass through the transparent substrate 10. At the same time, considering the absorption range of the liquid metal nanoparticles for the laser wavelength, a laser with a wavelength of 532 nm or higher is used in step S4 of the present invention.

[0057] Specifically, lasers with wavelengths above 532nm mainly include lasers with wavelengths of 589nm, 635nm, 650nm, 660nm, 670nm, 671nm, 808nm, 914nm, 946nm, 980nm, 1047nm, 1053nm, 1064nm, 1320nm, 1342nm, and 1650nm, with lasers with wavelengths of 1064nm being the preferred choice.

[0058] When using a laser for scanning, the repetition frequency and scanning speed of the laser determine the size of the laser pulse interval, and the scanning line spacing affects the distance between two lines of pulse scanning lines. All of these factors affect the formation effect of the liquid metal layer 21 and need to be adjusted according to the specific wavelength of the laser.

[0059] Taking a laser with a wavelength of 1064nm as an example, during scanning, the repetition frequency is 2kHz to 300kHz, the scanning speed is 50mm / s to 1000mm / s, the scanning line spacing is 1μm to 50μm, and the pulse interval is 10μm to 200μm.

[0060] The present invention also provides an application of the liquid metal-aerogel composite material with Janus structure described above in electronic devices.

[0061] The following specific embodiments will further illustrate the liquid metal-aerogel composite material with Janus structure, its preparation method, and its application.

[0062] Example 1

[0063] 252 mg of eutectic gallium-indium alloy (comprising 75% Ga and 25% In by mass fraction) and 2.8 mg of 3-mercapto-N-nonylpropionamide were added to 4 mL of anhydrous ethanol and then sonicated for 3 h to obtain a dispersion of liquid metal nanoparticles with a particle size of 300 nm and a surface oxide layer thickness of 5 nm. After sonication, the mixture was diluted to 40 mL with anhydrous ethanol.

[0064] The above-obtained dispersion of liquid metal nanoparticles was sprayed onto a sapphire substrate with a thickness of 0.5 mm and a size of 2 inches using a spray gun. After the anhydrous ethanol evaporated, a liquid metal nanoparticle layer with a thickness of 5 μm was obtained on the surface of the sapphire substrate.

[0065] Silica aerogel is placed on the surface of the liquid metal nanoparticle layer facing away from the sapphire substrate.

[0066] A laser with a wavelength of 1064nm is used to direct the laser from the surface of the sapphire substrate away from the liquid metal nanoparticle layer. The displacement stage is controlled to adjust the focal length so that the laser is focused at the interface between the liquid metal nanoparticle layer and the sapphire substrate.

[0067] In the control software, a 5mm square is drawn as the processing pattern. Scan lines are then filled into the pattern, and the laser scanning is initiated. The laser's optical parameters are set as follows: wavelength 1064nm, pulse interval 10μm, repetition frequency 2kHz, scanning speed 50mm / s, and laser scanning power 50% (corresponding to a laser energy density of 40J / cm²). 2 The laser scanning line spacing was 1 μm, and the scanning path uniformly filled the interior of the processed pattern. After scanning, the sapphire substrate was removed, yielding a liquid metal-silica aerogel composite material with a Janus structure. The sample is shown below. Figure 3 As shown.

[0068] from Figure 3 It can be seen that the liquid metal forms a conductive pattern on the silica aerogel that is consistent with the preset pattern, proving that the method of the present invention has high fidelity. At the same time, the conductive pattern has no cracks, forming a conductive path. In addition, silica aerogel is a very fragile and sensitive material. Figure 2 The silica aerogel remained intact without any cracks, proving that the method of the present invention does not damage the aerogel.

[0069] Example 2

[0070] The only difference between Example 2 and Example 1 is that the relative power of the laser scanning is 60% (corresponding to a laser energy density of 50 J / cm²). 2 ).

[0071] Example 3

[0072] The only difference between Example 3 and Example 1 is that the relative power of the laser scanning is 70% (corresponding to a laser energy density of 60 J / cm²). 2 ).

[0073] Comparative Example 1

[0074] A liquid metal-aerogel composite material was obtained by directly coating a eutectic gallium-indium alloy onto the surface of silica aerogel, as shown in the sample. Figure 4 As shown. By Figure 4 It can be seen that liquid metal and aerogel are two independent materials, and no liquid metal-aerogel composite material with Janus structure is formed.

[0075] Comparative Example 2

[0076] The only difference between Comparative Example 2 and Example 1 is that the relative power of the laser scanning is 20% (corresponding to a laser energy density of 10 J / cm²). 2 ).

[0077] Comparative Example 3

[0078] The only difference between Comparative Example 3 and Example 1 is that the relative power of the laser scanning is 30% (corresponding to a laser energy density of 20 J / cm²). 2 ).

[0079] Comparative Example 4

[0080] The only difference between Comparative Example 4 and Example 1 is that the relative power of the laser scanning is 40% (corresponding to a laser energy density of 30 J / cm²). 2 ).

[0081] Comparative Example 5

[0082] The only difference between Comparative Example 5 and Example 1 is that the relative power of the laser scanning is 80% (corresponding to a laser energy density of 70 J / cm²). 2 ).

[0083] The results of Examples 1 to 3 and Comparative Examples 2 to 5 are shown in Table 1.

[0084] Table 1

[0085]

[0086] As shown in Table 1, if the laser energy density is too low, the liquid metal cannot be transferred to the aerogel, or even if it is transferred, a liquid metal layer cannot be formed, thus making it impossible to obtain a liquid metal-silica aerogel composite material with a Janus structure. If the laser energy density is too high, it will not only oxidize the liquid metal and reduce its conductivity, but also damage the aerogel.

[0087] Example 4

[0088] The only difference between Example 4 and Example 2 is that the thickness of the liquid metal nanoparticle layer is 3 μm.

[0089] Example 5

[0090] The only difference between Example 5 and Example 2 is that the thickness of the liquid metal nanoparticle layer is 10 μm.

[0091] Example 6

[0092] The only difference between Example 6 and Example 2 is that the thickness of the liquid metal nanoparticle layer is 15 μm.

[0093] Example 7

[0094] The only difference between Example 7 and Example 2 is that the liquid metal nanoparticles have a particle size of 100 nm.

[0095] Example 8

[0096] The only difference between Example 8 and Example 2 is that the liquid metal nanoparticles have a particle size of 200 nm.

[0097] Example 9

[0098] The only difference between Example 9 and Example 2 is that the particle size of the liquid metal nanoparticles is 200 nm and the thickness of the liquid metal nanoparticle layer is 10 μm.

[0099] Example 10

[0100] The only difference between Example 10 and Example 2 is that the liquid metal nanoparticles have a particle size of 400 nm.

[0101] Example 11

[0102] The only difference between Example 11 and Example 2 is that the liquid metal nanoparticles have a particle size of 500 nm.

[0103] The results of the liquid metal-silica aerogel composite materials with Janus structure obtained in Examples 4 to 11 are shown in Table 2.

[0104] Table 2

[0105]

[0106] As shown in Table 2, the thickness of the liquid metal nanoparticle layer and the particle size of the liquid metal nanoparticles both affect the conductivity. By optimizing the thickness of the liquid metal nanoparticle layer, the particle size of the liquid metal nanoparticles, and the energy density of the laser, the conductivity can be further improved.

[0107] Example 12

[0108] The only difference between Example 12 and Example 2 is that Al2O3 aerogel is used instead of SiO2 aerogel, resulting in a liquid metal-Al2O3 aerogel composite material with a Janus structure.

[0109] Example 13

[0110] The only difference between Example 13 and Example 2 is that ZrO2 aerogel is used instead of SiO2 aerogel, resulting in a liquid metal-ZrO2 aerogel composite material with a Janus structure.

[0111] Example 14

[0112] The only difference between Example 14 and Example 2 is that resorcinol formaldehyde aerogel is used instead of SiO2 aerogel, resulting in a liquid metal-resorcinol formaldehyde aerogel composite material with a Janus structure.

[0113] Example 15

[0114] The only difference between Example 15 and Example 2 is that reduced graphene oxide aerogel is used instead of SiO2 aerogel, resulting in a liquid metal-reduced graphene oxide aerogel composite material with a Janus structure.

[0115] Example 16

[0116] The only difference between Example 16 and Example 2 is that cellulose aerogel is used instead of SiO2 aerogel, resulting in a liquid metal-cellulose aerogel composite material with a Janus structure.

[0117] Example 17

[0118] The only difference between Example 17 and Example 2 is that aramid fiber aerogel is used instead of SiO2 aerogel, resulting in a liquid metal-aramid fiber aerogel composite material with a Janus structure.

[0119] Example 18

[0120] The only difference between Example 18 and Example 2 is that carbon nanofiber aerogel is used instead of SiO2 aerogel, resulting in a liquid metal-carbon nanofiber aerogel composite material with a Janus structure.

[0121] The results of the liquid metal-aerogel composite materials with Janus structure obtained in Examples 12 to 18 are shown in Table 3.

[0122] Table 3

[0123]

[0124] As can be seen from Table 3, the method of the present invention can be applied to any aerogel material, and has strong applicability.

[0125] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0126] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for preparing a liquid metal-aerogel composite material with a Janus structure, characterized in that, Includes the following steps: A dispersion of liquid metal nanoparticles is prepared, wherein the particle size of the liquid metal nanoparticles is less than 600 nm and the thickness of the surface oxide shell is 3 nm to 10 nm. Liquid metal nanoparticle layers with a thickness of 1 μm to 20 μm were prepared on a transparent substrate using the aforementioned dispersion. The aerogel is placed on the surface of the liquid metal nanoparticle layer facing away from the transparent substrate; A laser with a wavelength above 532 nm was used to incident from the transparent substrate away from the surface of the liquid metal nanoparticle layer and focused at the interface between the liquid metal nanoparticle layer and the transparent substrate. Then, a scan was performed according to a preset pattern. After the scan, a liquid metal-aerogel composite material with a Janus structure was obtained, wherein the laser energy density was 40 J / cm². 2 Up to 60J / cm 2 .

2. The method for preparing the liquid metal-aerogel composite material with a Janus structure according to claim 1, characterized in that, The liquid metal nanoparticles have a particle size of 100 nm to 500 nm; And / or, the thickness of the liquid metal nanoparticle layer is 5 μm to 10 μm; And / or, the energy density of the laser is 40 J / cm². 2 Up to 55J / cm 2 .

3. The method for preparing the liquid metal-aerogel composite material with a Janus structure according to claim 2, characterized in that, The liquid metal nanoparticles have a particle size of 200 nm to 400 nm; And / or, the energy density of the laser is 40 J / cm². 2 Up to 50J / cm 2 .

4. The method for preparing a liquid metal-aerogel composite material with a Janus structure according to any one of claims 1 to 3, characterized in that, A laser with a wavelength of 1064nm is used. During scanning, the repetition frequency is 2kHz to 300kHz, the scanning speed is 50mm / s to 1000mm / s, the scanning line spacing is 1μm to 50μm, and the pulse interval is 10μm to 200μm.

5. The method for preparing the liquid metal-aerogel composite material with a Janus structure according to claim 1, characterized in that, The thickness of the transparent substrate is 0.5 mm to 1.5 mm, and the transparent substrate is selected from sapphire substrate and quartz substrate.

6. A liquid metal-aerogel composite material with a Janus structure, characterized in that, The liquid metal-aerogel composite material with Janus structure is prepared by any one of claims 1 to 5. The liquid metal-aerogel composite material with Janus structure includes an aerogel and a liquid metal layer disposed in a predetermined region on the surface of the aerogel. At the contact interface between the aerogel and the liquid metal layer, the liquid metal wets into the interior of the aerogel to form an impregnation layer.

7. The liquid metal-aerogel composite material with a Janus structure according to claim 6, characterized in that, The thickness of the liquid metal layer is less than 500 μm; And / or, the thickness of the wetting layer is less than 1 μm.

8. The liquid metal-aerogel composite material with a Janus structure according to claim 7, characterized in that, The thickness of the liquid metal layer is 10 μm to 50 μm; And / or, the thickness of the wetting layer is 10 nm to 50 nm.

9. The liquid metal-aerogel composite material with a Janus structure according to any one of claims 6 to 8, characterized in that, The liquid metal is selected from at least one of gallium indium alloy, gallium indium tin alloy, and bismuth indium tin zinc alloy; And / or, the aerogel is selected from one of silicon-based aerogels, carbon-based aerogels, ceramic-based aerogels, and polymer-based aerogels.

10. The application of a liquid metal-aerogel composite material with a Janus structure as described in any one of claims 6 to 9 in electronic devices.

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