Liquid metal-aerogel composite material with Janus structure as well as preparation method and application of liquid metal-aerogel composite material

Abstract

The invention relates to a liquid metal-aerogel composite material with a Janus structure and a preparation method and application of the liquid metal-aerogel composite material with the Janus structure, and the liquid metal-aerogel composite material with the Janus structure comprises aerogel and a liquid metal layer arranged in a preset area on the surface of the aerogel, and at the contact interface of the aerogel and the liquid metal layer, liquid metal infiltrates into the aerogel to form an infiltration layer. According to the invention, the liquid metal layer is arranged in the preset area on the surface of the aerogel, and the liquid metal is infiltrated into the aerogel to form the infiltration layer, so that the liquid metal and the aerogel can be compounded to form a Janus structure, and the conductive characteristic of the liquid metal and the light / heat insulation property of the aerogel are integrated; therefore, the composite material has conductivity, light weight and heat insulation performance.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic materials, in particular to a liquid metal-aerogel composite material with a Janus structure, a preparation method and an application thereof. Background Art

[0002] Silicon-based, carbon-based, ceramic-based, 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 insulating 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, a preparation method thereof, and an application thereof are provided. The liquid metal-aerogel composite material with a Janus structure has electrical conductivity, light weight, and thermal insulation properties.

[0004] A liquid metal-aerogel composite material with a Janus structure, comprising an aerogel and a liquid metal layer arranged in a preset area on the surface of the aerogel, wherein the liquid metal infiltrates into the interior of the aerogel at the contact interface between the aerogel and the liquid metal layer to form an infiltration layer.

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

[0006] And / or, the thickness of the wetting layer is within 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 aerogel, carbon-based aerogel, ceramic-based aerogel, and polymer-based aerogel.

[0011] A method for preparing the liquid metal-aerogel composite material having a Janus structure comprises the following steps:

[0012] Preparing a dispersion of liquid metal nanoparticles, wherein the liquid metal nanoparticles have a particle size of less than 600 nm and a surface oxide shell thickness of 3 nm to 10 nm;

[0013] Using the dispersion to prepare a liquid metal nanoparticle layer with a thickness of 1 μm to 20 μm on a transparent substrate;

[0014] placing an aerogel on the surface of the liquid metal nanoparticle layer facing away from the transparent substrate;

[0015] A laser with a wavelength of 532 nm or more is used to make the laser incident from the surface of the transparent substrate away from the liquid metal nanoparticle layer and focus on the interface between the liquid metal nanoparticle layer and the transparent substrate. Then, the laser is scanned according to a preset pattern. After the scanning is completed, a liquid metal-aerogel composite material with a Janus structure is obtained. The energy density of the laser is 40 J / cm 2 Up to 60J / cm 2 .

[0016] In one embodiment, the particle size of the liquid metal nanoparticles is 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 40J / cm 2 Up to 55J / cm 2 .

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

[0020] And / or, the energy density of the laser is 40J / cm 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 distance is 1 μm to 50 μm, and the pulse interval distance 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 a sapphire substrate and a quartz substrate.

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

[0024] The present invention arranges a liquid metal layer in a preset area on the surface of the aerogel and allows the liquid metal to infiltrate the interior of the aerogel to form an infiltration layer, so that the liquid metal and the aerogel can be composited to form a Janus structure, thereby integrating the conductive properties of the liquid metal with the lightweight and thermal insulation properties of the aerogel, so that the composite material has conductive, lightweight and thermal insulation properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

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

[0027] Figure 2 Schematic diagram of the process of preparing the liquid metal-aerogel composite material having a Janus structure of the present invention;

[0028] Figure 3 This is a sample 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 picture 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 DESCRIPTION

[0031] To facilitate understanding of the present invention, the present invention 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. On the contrary, the purpose of providing these embodiments or examples is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the technical field of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments or embodiments and are not intended to limit the present invention. The optional scope of the term "and / or" used herein includes any one of two or more related listed items, and also includes any and all combinations of related listed items, including any two related listed items, any more related listed items, or the combination of all related listed items.

[0033] In the present invention, when referring to numerical ranges, 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 such minimum and maximum values. Furthermore, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe a feature or characteristic, the ranges can be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges subsumed therein.

[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 from the aerogel.

[0035] For this reason, Figure 1 As shown, the liquid metal-aerogel composite material with a Janus structure provided by the present invention includes an aerogel 30 and a liquid metal layer 21 arranged in a preset area on the surface of the aerogel, and at the contact interface between the aerogel 30 and the liquid metal layer 21, the liquid metal infiltrates into the interior of the aerogel 30 to form an infiltration layer 31.

[0036] Thus, by providing a liquid metal layer 21 in a preset area on the surface of the aerogel 30 and allowing the liquid metal to infiltrate the interior of the aerogel 30 to form an infiltration layer 31, the liquid metal and the aerogel 30 can be compounded and constructed into 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 conductive, lightweight and thermal insulation properties.

[0037] It is understood that the predetermined area on the surface of the aerogel 30 can be constructed according to the desired conductive pattern.

[0038] Optionally, the thickness of the liquid metal layer 21 is within 500 μm, and the thickness of the wetting layer 31 is within 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] Combine Figure 2 As shown, the present invention also provides a method for preparing a liquid metal-aerogel composite material having a Janus structure, comprising the following steps:

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

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

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

[0044] S4, make the laser 40 incident from the surface of the transparent substrate 10 away from the liquid metal nanoparticle layer 20 and focus on the interface between the liquid metal nanoparticle layer 20 and the transparent substrate 10, and then scan according to the preset pattern. After the scanning 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, an aerogel 30 is placed on the surface of the liquid metal nanoparticle layer 20 facing away from the transparent substrate 10. Then, when a laser 40 is focused on the interface between the liquid metal nanoparticle layer 20 and the transparent substrate 10 and scanned, the liquid metal nanoparticles at the interface can be rapidly heated, transforming from a liquid phase to a gas phase vapor. The gas phase vapor will rapidly expand outward, manifesting as a high-speed jet. According to the law of conservation of momentum, when the gas phase vapor is ejected at high speed, the unvaporized liquid metal nanoparticles in the scanning area will experience a recoil pressure opposite to the direction of the gas phase vapor ejection, causing the liquid metal nanoparticles in the scanning area to break and fuse with each other while being propelled onto the aerogel 30, forming a predetermined liquid metal layer 21 on the aerogel 30, while the liquid metal nanoparticles not processed by the laser remain on the transparent substrate 10.

[0046] However, this approach does not necessarily allow the liquid metal layer 21 and the 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 permeation of liquid metal vapor and its cooling on the aerogel 30, acting as a seed layer to promote the infiltration of liquid metal into the aerogel 30. Liquid metal nanoparticles of different particle sizes have different specific surface areas, resulting in different evaporation rates of the liquid metal nanoparticles at the interface during laser scanning. The energy density of the laser during laser scanning varies, resulting in different energies obtained by the liquid metal nanoparticles at the interface. The thickness of the liquid metal nanoparticle layer varies, resulting in different recoil pressures required to propel the liquid metal nanoparticles into the aerogel 30.

[0047] In combination with the above findings, the present invention controls the particle size of liquid metal nanoparticles to below 600nm, the thickness of the surface oxide shell to 3nm to 10nm, the thickness of the liquid metal nanoparticle layer 20 to 1μm to 20μm, and the energy density of the laser to 40J / cm 2 Up to 60J / cm 2 , the liquid metal can infiltrate the aerogel 30 to form an infiltration layer 31, and then the liquid metal layer 21 and the aerogel 30 are composited to form a Janus structure. At the same time, the aerogel 30 will not be damaged.

[0048] Furthermore, when the particle size of the liquid metal nanoparticles and the thickness of the liquid metal nanoparticle layer 20 are equal, as the energy density of the laser increases, the conductivity of the formed liquid metal layer 21 will further increase. However, when the energy density is too large, the liquid metal will oxidize, and the conductivity of the formed liquid metal layer 21 will decrease. Similarly, when the energy density of the laser is the same, the conductivity of the liquid metal layer 21 obtained by liquid metal nanoparticles of different particle sizes and liquid metal nanoparticle layers 20 of different thicknesses will also be different. Therefore, the particle size of the liquid metal nanoparticles is further preferably 100nm to 500nm, the thickness of the liquid metal nanoparticle layer 20 is further preferably 5μm to 10μm, and the energy density of the laser is further preferably 40J / cm 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 / cm 2 Up to 50J / cm 2 When the conductivity of the composite material is better, it can form a composite material with better electrical conductivity.

[0049] Therefore, the preparation method of the present invention can not only obtain a liquid metal-aerogel composite material with a Janus structure, but also will not damage the aerogel 30 during the preparation process, and there is no specific restriction on the material of the aerogel 30. Silicon-based, carbon-based, ceramic-based, polymer-based aerogels can all be applied, and it is 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 arbitrarily changed through software, so that the pattern of the liquid metal layer 21 has great flexibility in selection.

[0051] In step S1, the step of preparing a dispersion of liquid metal nanoparticles includes: ultrasonically treating the liquid metal in an organic solvent to obtain a dispersion of the liquid metal nanoparticles. Furthermore, it is preferred that the liquid metal, a dispersant and an organic solvent are mixed and ultrasonically treated to obtain a dispersion of liquid metal nanoparticles, which helps to obtain a stably dispersed dispersion. There is no specific restriction on the selection of the dispersant, as long as the liquid metal can be dispersed in the solvent. Specifically, it can be selected from at least one of 3-mercapto-N-nonylpropionamide, polyacrylamide, sodium lauryl sulfate, and fatty acid polyethylene glycol esters. There is no specific restriction on the selection of the liquid metal, and it can be selected from at least one of gallium-indium alloy, gallium-indium-tin alloy, and bismuth-indium-tin-zinc alloy. There is no specific restriction on the selection of the organic solvent, and it can be selected from anhydrous ethanol, isopropyl alcohol, 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 250 mg:4 mL to 450 mg:4 mL, and the ultrasonic treatment time is 2 h to 5 h, which is conducive to obtaining liquid metal nanoparticles with uniform and controllable particle size.

[0053] In step S2 , the liquid metal nanoparticle layer 20 is prepared on the transparent substrate 10 by using the dispersion liquid by spraying, coating, etc., and the liquid metal nanoparticle layer 20 is 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 a sapphire substrate and a quartz substrate.

[0055] Since the method of the present invention does not damage the aerogel 30 and has no specific restrictions on the material of the aerogel 30, in step S3, the selection of the aerogel 30 is not limited, and specifically 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 surface of the transparent substrate 10 away from 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 transmit the transparent substrate 10. At the same time, considering the absorption range of the liquid metal nanoparticles to the laser wavelength, a laser with a wavelength above 532 nm is used in step S4 of the present invention.

[0057] Specifically, the lasers with a wavelength of more than 532nm mainly include a laser with a wavelength of 589nm, a laser with a wavelength of 635nm, a laser with a wavelength of 650nm, a laser with a wavelength of 660nm, a laser with a wavelength of 670nm, a laser with a wavelength of 671nm, a laser with a wavelength of 808nm, a laser with a wavelength of 914nm, a laser with a wavelength of 946nm, a laser with a wavelength of 980nm, a laser with a wavelength of 1047nm, a laser with a wavelength of 1053nm, a laser with a wavelength of 1064nm, a laser with a wavelength of 1320nm, a laser with a wavelength of 1342nm, a laser with a wavelength of 1650nm, etc., and a laser with a wavelength of 1064nm is preferably adopted.

[0058] When using laser scanning, the repetition frequency and scanning speed of the laser will determine the size of the laser pulse interval distance, and the scanning line distance will affect the distance between two rows of pulse scanning lines. These will 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 distance is 1μm to 50μm, and the pulse interval distance is 10μm to 200μm.

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

[0061] Hereinafter, the liquid metal-aerogel composite material having a Janus structure, its preparation method and application will be further described through the following specific examples.

[0062] Example 1

[0063] 252 mg of eutectic gallium-indium alloy (75% Ga and 25% In by mass) and 2.8 mg of 3-mercapto-N-nonylpropionamide were added to 4 mL of anhydrous ethanol, and then ultrasonicated for 3 hours 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 ultrasonic treatment, the dispersion was diluted to 40 mL with anhydrous ethanol.

[0064] The dispersion of liquid metal nanoparticles obtained above was sprayed onto the surface of 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] The 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 make the laser incident from the surface of the sapphire substrate away from the liquid metal nanoparticle layer. The control stage is used to adjust the focal length so that the laser is focused on the interface between the liquid metal nanoparticle layer and the sapphire substrate.

[0067] In the control software, a square with a side length of 5 mm was drawn for processing. Then, the scanning lines were filled into the pattern and the laser was turned on to start scanning. The optical parameters of the laser were set as follows: wavelength of 1064 nm, pulse interval of 10 μm, repetition frequency of 2 kHz, scanning speed of 50 mm / s, and laser scanning power of 50% (corresponding to a laser energy density of 40 J / cm 2 ), the laser scanning line pitch is 1μm, and the scanning path is evenly filled in the processing pattern. After the scanning is completed, the sapphire substrate is removed to obtain a liquid metal-silica aerogel composite material with a Janus structure. The sample is as follows Figure 3 shown.

[0068] from Figure 3 It can be seen that the liquid metal formed a conductive pattern on the silica aerogel that was consistent with the preset pattern, proving that the method of the present invention has high fidelity. At the same time, the conductive pattern had no cracks and formed a conductive path. In addition, silica aerogel is a very fragile and sensitive material. Figure 2 The silica aerogel is intact without any cracks, which proves 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 / cm 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 / cm 2 ).

[0073] Comparative Example 1

[0074] The eutectic gallium-indium alloy is directly coated on the surface of silica aerogel to obtain liquid metal-aerogel composite materials. Figure 4 As shown. Figure 4 It can be seen that the liquid metal and the aerogel are two independent materials, and no liquid metal-aerogel composite material with a Janus structure is formed.

[0075] Comparative Example 2

[0076] The only difference between Comparative Example 2 and Example 1 is that the laser scanning relative power is 20% (corresponding to a laser energy density of 10 J / cm 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 / cm 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 / cm 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 / cm 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 can be seen from Table 1, if the energy density of the laser 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, and thus a liquid metal-silica aerogel composite material with a Janus structure cannot be obtained. If the energy density of the laser is too high, not only will the liquid metal be oxidized and the conductivity reduced, but the aerogel will also be damaged.

[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 particle size of the liquid metal nanoparticles is 100 nm.

[0095] Example 8

[0096] The only difference between Example 8 and Example 2 is that the particle size of the liquid metal nanoparticles is 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 particle size of the liquid metal nanoparticles is 400 nm.

[0101] Example 11

[0102] The only difference between Example 11 and Example 2 is that the particle size of the liquid metal nanoparticles is 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 can be seen from Table 2, the thickness of the liquid metal nanoparticle layer and the particle size of the liquid metal nanoparticles will affect the electrical 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 electrical 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, and the liquid metal-Al2O3 aerogel composite material has 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, and the liquid metal-ZrO2 aerogel composite material has 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 to obtain 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, and the liquid metal-reduced graphene oxide aerogel composite material has 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 to form 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 to provide 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, and the liquid metal-carbon nanofiber aerogel composite material has 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-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned 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 above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A liquid metal-aerogel composite material with a Janus structure, characterized in that: The liquid metal-aerogel composite material with a Janus structure includes an aerogel and a liquid metal layer arranged in a preset area on the surface of the aerogel, and at the contact interface between the aerogel and the liquid metal layer, the liquid metal infiltrates into the interior of the aerogel to form an infiltration layer.

2. The liquid metal-aerogel composite material having a Janus structure according to claim 1, characterized in that: The thickness of the liquid metal layer is within 500 μm; And / or, the thickness of the wetting layer is within 1 μm.

3. The liquid metal-aerogel composite material having a Janus structure according to claim 2, 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.

4. The liquid metal-aerogel composite material having a Janus structure according to any one of claims 1 to 3, 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 aerogel, carbon-based aerogel, ceramic-based aerogel, and polymer-based aerogel.

5. A method for preparing a liquid metal-aerogel composite material having a Janus structure according to any one of claims 1 to 4, characterized in that: The following steps are involved: Preparing a dispersion of liquid metal nanoparticles, wherein the liquid metal nanoparticles have a particle size of less than 600 nm and a surface oxide shell thickness of 3 nm to 10 nm; Using the dispersion to prepare a liquid metal nanoparticle layer with a thickness of 1 μm to 20 μm on a transparent substrate; placing an aerogel on the surface of the liquid metal nanoparticle layer facing away from the transparent substrate; A laser with a wavelength of 532 nm or more is used to make the laser incident from the surface of the transparent substrate away from the liquid metal nanoparticle layer and focus on the interface between the liquid metal nanoparticle layer and the transparent substrate. Then, the laser is scanned according to a preset pattern. After the scanning is completed, a liquid metal-aerogel composite material with a Janus structure is obtained. The energy density of the laser is 40 J / cm 2 Up to 60J / cm 2 .

6. The method for preparing a liquid metal-aerogel composite material having a Janus structure according to claim 5, characterized in that: The particle size of the liquid metal nanoparticles is 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 40J / cm 2 Up to 55J / cm 2 .

7. The method for preparing a liquid metal-aerogel composite material having a Janus structure according to claim 6, characterized in that: The particle size of the liquid metal nanoparticles is 200 nm to 400 nm; And / or, the energy density of the laser is 40J / cm 2 Up to 50J / cm 2 .

8. The method for preparing a liquid metal-aerogel composite material having a Janus structure according to any one of claims 5 to 7, characterized in that: A laser with a wavelength of 1064nm is used. When scanning, the repetition frequency is 2kHz to 300kHz, the scanning speed is 50mm / s to 1000mm / s, the scanning line distance is 1μm to 50μm, and the pulse interval distance is 10μm to 200μm.

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

10. Use of the liquid metal-aerogel composite material having a Janus structure according to any one of claims 1 to 4 in an electronic device.

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