Self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material and preparation method thereof

Abstract

The application discloses a preparation method of a self-adhesion silicon rubber-based electromagnetic shielding and infrared stealth composite material, and comprises the following steps: step 1, synthesizing a self-adhesion silicon rubber elastomer based on multiple dynamic reversible bonds; step 2, preparing a Ti3C2T x MXene ethanol dispersion solution; step 3, preparing a Ti3C2T x / liquid metal paste according to the product obtained in step 2 and a liquid metal; step 4, coating the Ti3C2T x / liquid metal on the surface of the self-adhesion silicon rubber to obtain a self-adhesion silicon rubber-based electromagnetic shielding and infrared stealth composite material with an asymmetric structure according to the products obtained in steps 1 and 3. The application further discloses the self-adhesion silicon rubber-based electromagnetic shielding and infrared stealth composite material, and the composite material has the advantages of self-adhesion, recyclability and excellent electromagnetic shielding and infrared stealth performance, and can meet the application requirements in the fields of aerospace, electronic appliances and intelligent wearable electronic devices.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electromagnetic shielding and infrared stealth composite materials, and relates to a preparation method of a self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material. BACKGROUND

[0002] With the rapid development of modern aerospace technology, electronic appliances and smart wearable electronic devices, the high-density integration of electronic components and the widespread application of wireless communication technology, electromagnetic radiation interference problems have become an important hidden danger affecting the reliability of equipment and information security. At the same time, the power systems and electronic devices in related fields are prone to produce significant infrared characteristic signals, which are easily identified and located by modern detection systems, leading to a sharp increase in the risk of infrared exposure of key equipment. Under this background, it is urgent to develop multifunctional composite materials with high electromagnetic shielding efficiency (SE>60 dB) and wide-band infrared stealth characteristics (8~14 μ Traditional metal materials (such as aluminum, copper and silver, etc.) have high electrical conductivity and low infrared emissivity, and are widely used in electromagnetic shielding and infrared stealth fields, but have problems such as high density, poor corrosion resistance and difficult forming and processing.

[0003] Polymer elastomer-based conductive composites are widely used in flexible electromagnetic shielding due to their light weight, good flexibility, corrosion resistance and adjustable electromagnetic shielding performance. Polymer elastomer-based conductive composites are prepared by adding conductive fillers (such as metal and carbon nanofillers) in polymer elastomer matrix (such as silicone rubber, polyurethane and styrene-butadiene-styrene block copolymer, etc.). Common preparation methods include solution blending, emulsion blending and melt blending, etc. However, these methods are relatively complicated, and the polymer elastomer-based electromagnetic shielding composites prepared by these methods have the following disadvantages: (1) it is difficult to form a uniform and efficient continuous conductive network, and the conductive performance and electromagnetic shielding performance are poor, and increasing the amount of fillers will seriously affect the flexibility, mechanical properties and processability of the composite material; (2) the infrared emissivity of the polymer elastomer-based electromagnetic shielding composite material is high, and the infrared stealth performance is poor; (3) in actual application, additional adhesives or special assembly techniques are required to adhere the flexible electromagnetic shielding composite material to the protected part, greatly increasing the construction cost and process complexity.

[0004] Liquid metal is a new type of conductive alloy with the characteristics of both metal and liquid. It has good application potential in the field of electromagnetic shielding and infrared stealth due to its high electrical conductivity, low infrared emission and high flowability. Compared with rigid fillers such as metals and carbon nanomaterials, liquid metal can maintain the integrity of the conductive network under mechanical deformation such as stretching and bending. However, liquid metal usually has high surface tension, which makes it difficult to form conductive pathways in the polymer matrix. Its adhesion and ductility on the surface of the polymer matrix are also poor, making it difficult to form non-spherical large-area structures, which limits its application. Studies have shown that the introduction of SiO2 and MXene nanomaterials into liquid metal can significantly reduce the surface tension and improve its matrix compatibility and surface adhesion.

[0005] In summary, the development of self-adhesive high-efficiency electromagnetic shielding and infrared stealth polymer elastomer-based electromagnetic shielding composites is of great significance to the development of aerospace, electronic appliances and intelligent wearable electronic devices. SUMMARY

[0006] The purpose of the present application is to provide a preparation method of self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material, which solves the problems of poor electromagnetic shielding and infrared stealth performance, difficulty in achieving self-adhesion and high cost of traditional polymer elastomer-based conductive composites.

[0007] Another purpose of the present application is to provide an asymmetric structure self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material.

[0008] The first technical solution adopted by the present application is a preparation method of self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material, which specifically includes the following steps:

[0009] Step 1, synthesis of self-adhesive silicone rubber elastomer based on multiple dynamic reversible bonds;

[0010] Step 2, preparation of Ti3C2T x MXene ethanol dispersion liquid;

[0011] Step 3, preparation of Ti3C2T x / liquid metal paste from the product obtained in step 2;

[0012] Step 4, preparation of asymmetric structure self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material by blade coating method according to the products obtained in steps 1 and 3.

[0013] The first technical solution of the present application is also characterized in that:

[0014] The specific process of step 1 is as follows: first, the aminopropyl-terminated polydimethylsiloxane and isophorone diisocyanate are added to tetrahydrofuran and reacted at room temperature under a nitrogen atmosphere for 12-24 hours; then, 2, 6-pyridine dicarboxaldehyde is dissolved in N, N-dimethylformamide and added to the reaction system for continuous reaction for 12-24 hours; the metal ion compound is dissolved in a methanol solution, added to the reaction system and continuously reacted for 6-12 hours, after the reaction is completed, the obtained solution is poured into deionized water, and constant stirring is carried out to promote the product to be precipitated in the form of flocculation, and the product is washed repeatedly with deionized water; finally, the product is placed in a vacuum oven at 45-60°C for drying to obtain a self-adhesive silicone elastomer based on multiple dynamic reversible bonds of hydrogen bonds, imine bonds and metal coordination bonds.

[0015] In step 1, the sum of the molar amounts of isophorone diisocyanate and 2, 6-pyridine dicarboxaldehyde is equal to the molar amount of the aminopropyl-terminated polydimethylsiloxane.

[0016] In step 1, the metal ion compound is any one of cobalt chloride, iron chloride, zinc chloride, copper chloride, magnesium chloride, calcium chloride and nickel chloride, and the molar ratio of 2, 6-pyridine dicarboxaldehyde to metal ion is 4:1-4:3.

[0017] The specific process of step 2 is as follows: Ti3AlC2 ceramic powder is added to a mixed solution of hydrochloric acid and lithium fluoride, and stirred at 50°C for 24-48 hours to obtain a black dispersion liquid, so that the aluminum layer in Ti3AlC2 is completely etched; deionized water is added to the black dispersion liquid, and after centrifugation, the supernatant is discarded, and repeated washing is carried out until the supernatant pH is ≥6, and then the Ti3C2T x MXene aqueous dispersion liquid is prepared by centrifugation and oscillation stripping. x MXene. x The solvent in the Ti3C2T

[0018] In step 2, the size of the Ti3AlC2 ceramic powder is 200-400 mesh, and the ratio of Ti3AlC2, lithium fluoride and hydrochloric acid is 1-2 g: 1-2 g: 20-40 mL, and the size of the Ti3C2T x MXene sheet layer is 0.1-5 μ m.

[0019] The specific process of step 3 is as follows: the Ti3C2T x MXene ethanol dispersion liquid and liquid metal are added to a polytetrafluoroethylene beaker, and the Ti3C2T x MXene is mixed with the liquid metal until the ethanol is completely volatilized, and after vacuum drying, the Ti3C2T xLiquid metal paste.

[0020] In step 3, Ti3C2T x In the liquid metal paste, Ti3C2T x The mass fraction of MXene is 1-3 wt%, and the liquid metal is a gallium-indium-tin alloy.

[0021] The specific process of step 4 is as follows: the self-adhesive silicone rubber elastomer obtained in step 1 is dissolved in tetrahydrofuran solvent, poured into a polytetrafluoroethylene mold and dried to obtain a self-adhesive silicone rubber elastomer film; Ti3C2T x The liquid metal paste is uniformly coated on the upper surface of the self-adhesive silicone rubber film to obtain an asymmetric structure self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material.

[0022] The second technical solution adopted by the present application is a self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material prepared by the preparation method of the self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material.

[0023] The present application has the advantages that the self-adhesive silicone rubber elastomer based on multiple dynamic reversible chemical networks is synthesized, and Ti3C2T x MXene significantly reduces its surface tension and improves the adhesion of the matrix, and further coats MXene / liquid metal on the surface of the self-adhesive silicone rubber elastomer by the scraping method to form a high-efficiency continuous conductive layer, thereby obtaining a high electromagnetic shielding efficiency and self-adhesive asymmetric structure silicone rubber elastomer-based electromagnetic shielding and infrared stealth composite material. The synthesized silicone rubber elastomer contains rich hydrogen bonds, imine bonds and metal coordination bonds multiple dynamic reversible bonds, which have excellent self-adhesion properties to metals, ceramics, glass, polymers and wood. Ti3C2T x During the mixing of MXene and liquid metal, ethanol and trace residual water are used to reduce the surface tension of Ti3C2T x The uniform dispersion of MXene creates an environment rich in hydrogen bonds, while reducing the surface tension of the liquid metal. The obtained Ti3C2T x The liquid metal paste has good matrix adhesion and ductility. Therefore, Ti3C2T x The liquid metal paste is uniformly coated on the surface of the silicone rubber elastomer to form a high-efficiency continuous conductive layer, thereby obtaining an asymmetric structure self-adhesive silicone rubber elastomer-based electromagnetic shielding and infrared stealth composite material. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a structural schematic diagram of the self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material of the present application;

[0025] Figure 2is a digital photo of the composite material obtained from example 5 of the preparation method of the self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material of the present application;

[0026] Figure 3 is a scanning electron microscope photo of the cross section of the composite material obtained from example 5 of the preparation method of the self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material of the present application;

[0027] Figure 4 is a digital photo of the silicone rubber adhering to the surface of stainless steel and lifting the weight obtained from example 5 of the preparation method of the self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material of the present application. DETAILED DESCRIPTION

[0028] The present application will be described in detail below in combination with the drawings and specific embodiments.

[0029] The self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material of the present application comprises a multiple dynamic reversible bond self-adhesive silicone rubber elastomer, Ti3C2T x MXene and liquid metal; the self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material has a double-layer asymmetric structure, wherein the multiple dynamic reversible bond silicone rubber elastomer is a self-adhesive layer, Ti3C2T x / liquid metal is a high-conductive layer; the self-adhesive silicone rubber elastomer layer contains rich multiple dynamic reversible bonds of hydrogen bonds, imine bonds and metal coordination bonds, and has excellent self-adhesive properties to metals, ceramics, glass, polymers and wood, etc.; the metal ion compound is any one of cobalt chloride, iron chloride, zinc chloride, copper chloride, magnesium chloride, calcium chloride and nickel chloride, preferably cobalt chloride. Ti3C2T x / liquid metal coating layer, the mass fraction of Ti3C2T x MXene is 1-3wt%, and the liquid metal is gallium-indium-tin alloy; the thickness of the Ti3C2T x / liquid metal coating layer in the self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material is 2.5-25 μ m; Ti3C2T x MXene is prepared by chemical etching and peeling from 200-400 mesh Ti3AlC2 ceramic powder, Ti3C2T x The size of the MXene sheet layer is 0.1-5 μ m.

[0030] The preparation method of the self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material of the present application specifically comprises the following steps:

[0031] Step 1: First, aminopropyl-terminated polydimethylsiloxane and isophorone diisocyanate were added to tetrahydrofuran and reacted at room temperature under a nitrogen atmosphere for 12-24 hours. Then, 2,6-pyridinedicarboxaldehyde was dissolved in N,N-dimethylformamide and added to the reaction system, and the reaction continued for another 12-24 hours. Further, a certain amount of a metal ion compound was dissolved in methanol solution, added to the reaction system, and the reaction continued for 6-12 hours. After the reaction was complete, the resulting solution was poured into deionized water, and the mixture was continuously stirred to promote flocculent precipitation of the product. The product was repeatedly washed with deionized water. Finally, the product was dried in a vacuum oven at 45-60°C to obtain a self-adhesive silicone rubber elastomer based on multiple dynamic reversible bonds of hydrogen bonds, imine bonds, and metal coordination bonds.

[0032] In step 1, the sum of the molar amounts of isophorone diisocyanate and 2,6-pyridinedicarboxaldehyde is equal to the molar amount of aminopropyl-terminated polydimethylsiloxane.

[0033] In step 1, the metal ion compound is any one of cobalt chloride, ferric chloride, zinc chloride, copper chloride, magnesium chloride, calcium chloride, and nickel chloride, with cobalt chloride being preferred.

[0034] In step 1, the molar ratio of 2,6-pyridinedicarboxaldehyde to metal ions is 4:1 to 4:3.

[0035] Step 2: Add Ti3AlC2 (MAX phase) ceramic powder to a hydrochloric acid / lithium fluoride mixed solution and stir at 50°C for 48 h to obtain a black dispersion, thus completely etching the aluminum layer in Ti3AlC2. Add deionized water to the dispersion at 3500 r·min. -1 After centrifugation for 5-10 minutes, discard the supernatant and wash repeatedly until the pH of the supernatant is ≥6, then stop centrifugation. Then, prepare Ti3C2T by centrifugation and oscillation exfoliation. x MXene aqueous dispersion. Finally, Ti3C2T was separated by centrifugation. x The solvent in the MXene aqueous dispersion was replaced with anhydrous ethanol to obtain Ti3C2T with a concentration of 5-20 mg / mL. x MXene ethanol dispersion.

[0036] In step 2, the Ti3AlC2 ceramic powder has a size of 200-400 mesh, and the ratio of Ti3AlC2, lithium fluoride, and hydrochloric acid is 1-2g: 1-2g: 20-40mL. x The size of MXene sheets ranges from 0.1 to 5. μ m.

[0037] Step 3, Ti3C2T xMXene ethanol dispersion and liquid metal were added to a polytetrafluoroethylene (PTFE) beaker, and Ti3C2T was stirred magnetically. x MXene was mixed with liquid metal until the ethanol was completely evaporated, and then vacuum dried to obtain Ti3C2T. x / Liquid metal paste.

[0038] In step 3, Ti3C2T x / Ti3C2T in liquid metal paste x The mass fraction of MXene is 1~3 wt%.

[0039] In step 3, the liquid metal is a gallium indium tin alloy.

[0040] Step 4: Dissolve the self-adhesive silicone rubber elastomer obtained in Step 1 in tetrahydrofuran solvent, pour it into a polytetrafluoroethylene mold, and dry it to obtain a self-adhesive silicone rubber elastomer film. Apply Ti3C2T using a blade coating method. x A self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material with an asymmetric structure is prepared by uniformly coating a liquid metal paste onto the surface of a self-adhesive silicone rubber film.

[0041] In step 4, the coating thickness of the asymmetric self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material is 2.5~25 mm. μ m.

[0042] Example 1

[0043] Self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite materials, including multi-dynamic reversible bond self-adhesive silicone rubber elastomers and Ti3C2T... x MXene and liquid metal, a self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material, has a double-layer asymmetric structure, in which a multi-dynamically reversible bonded silicone rubber elastomer serves as the self-adhesive layer, Ti3C2T x The liquid metal layer is highly conductive; the composite material thickness is 0.5 mm; the self-adhesive silicone rubber elastomer layer contains multiple dynamic reversible bonds, including hydrogen bonds, imine bonds, and metal coordination bonds; the metal ion compound is zinc chloride, and the molar ratio of 2,6-pyridinedicarboxaldehyde to zinc ions is 4:1; Ti3C2T x / Ti3C2T in liquid metal coating x The mass fraction of MXene is 2 wt%, and the liquid metal is a gallium indium tin alloy.

[0044] A method for preparing a self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material includes the following steps: 2 mmol of aminopropyl-terminated polydimethylsiloxane and 1.6 mmol of isophorone diisocyanate are added to 40 mL of tetrahydrofuran and reacted at room temperature under a nitrogen atmosphere for 12 h. 0.4 mmol of 2,6-pyridinedicarboxaldehyde is dissolved in 8 mL of N,N-dimethylformamide and added to the reaction system, and the reaction continues for 24 h. 0.1 mmol of zinc chloride is dissolved in 4 mL of methanol solution and added to the reaction system, and the reaction continues for 12 h. After the reaction is complete, the resulting solution is washed in 500 mL of deionized water to precipitate the product. The product is dried in a vacuum oven at 60 °C, dissolved in tetrahydrofuran solvent, poured into a polytetrafluoroethylene mold, and dried to obtain a self-adhesive silicone rubber elastomer film. 1 g of Ti3AlC2 ceramic powder is added to 20 mL of a 50 mg / mL hydrochloric acid / lithium fluoride mixed solution and stirred at 50 °C for 24 h to obtain a black dispersion. Ti3C2T was prepared by centrifugation and oscillatory exfoliation. x MXene aqueous dispersion, and Ti3C2T x The solvent in the MXene aqueous dispersion was replaced with anhydrous ethanol to obtain Ti3C2T with a concentration of 5 mg / mL. x MXene ethanol dispersion. Ti3C2T x MXene ethanol dispersion and liquid metal were added to a polytetrafluoroethylene (PTFE) beaker, and Ti3C2T was stirred magnetically. x MXene was mixed with liquid metal until the ethanol was completely evaporated, and then vacuum dried to obtain Ti3C2T. x / Liquid metal paste, containing Ti3C2T x The mass fraction of MXene is 1 wt%. Ti3C2T is applied via a blade coating method. x A liquid metal paste was uniformly coated onto the surface of a self-adhesive silicone rubber film, resulting in a coating thickness of 2.5 mm. μ An asymmetric self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material with a thickness of 0.5 mm was developed. The adhesion strength of the self-adhesive silicone rubber on stainless steel sheets after 16 hours at 35℃ and 70℃ were 389.5 and 753.6 kPa, respectively. The conductivity of the self-adhesive silicone rubber-based composite material was 34.2 S / cm, and the electromagnetic shielding effectiveness in the X-band (8.2-12.4 GHz) was 17.1 dB. Furthermore, it could reduce the radiation temperature of a 100℃ infrared target to 42.2℃.

[0045] Example 2

[0046] Self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite materials, including multi-dynamic reversible bond self-adhesive silicone rubber elastomers and Ti3C2T... xMXene and liquid metal, a self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material, has a double-layer asymmetric structure, in which a multi-dynamically reversible bonded silicone rubber elastomer serves as the self-adhesive layer, Ti3C2T x The liquid metal layer is highly conductive; the composite material thickness is 0.5 mm; the self-adhesive silicone rubber elastomer layer contains multiple dynamic reversible bonds, including hydrogen bonds, imine bonds, and metal coordination bonds; the metal ion compound is cobalt chloride, and the molar ratio of 2,6-pyridinedicarboxaldehyde to cobalt ions is 4:3; Ti3C2T x / Ti3C2T in liquid metal coating x The mass fraction of MXene is 3 wt%, and the liquid metal is a gallium indium tin alloy.

[0047] A method for preparing a self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material includes the following steps: 2 mmol of aminopropyl-terminated polydimethylsiloxane and 1.6 mmol of isophorone diisocyanate are added to 40 mL of tetrahydrofuran and reacted at room temperature under a nitrogen atmosphere for 24 h. 0.4 mmol of 2,6-pyridinedicarboxaldehyde is dissolved in 8 mL of N,N-dimethylformamide and added to the reaction system, and the reaction continues for 24 h. 0.3 mmol of cobalt chloride is dissolved in 12 mL of methanol solution and added to the reaction system, and the reaction continues for 12 h. After the reaction, the resulting solution is washed in 600 mL of deionized water to precipitate the product. The product is dried in a vacuum oven at 45 °C, dissolved in tetrahydrofuran solvent, poured into a polytetrafluoroethylene mold, and dried to obtain a self-adhesive silicone rubber elastomer film. 1 g of Ti3AlC2 ceramic powder is added to 20 mL of a 50 mg / mL hydrochloric acid / lithium fluoride mixed solution and stirred at 50 °C for 24 h to obtain a black dispersion. Ti3C2T was prepared by centrifugation and oscillatory exfoliation. x MXene aqueous dispersion, and Ti3C2T x The solvent in the MXene aqueous dispersion was replaced with anhydrous ethanol to obtain Ti3C2T with a concentration of 10 mg / mL. x MXene ethanol dispersion. Ti3C2T x MXene ethanol dispersion and liquid metal were added to a polytetrafluoroethylene (PTFE) beaker, and Ti3C2T was stirred magnetically. x MXene was mixed with liquid metal until the ethanol was completely evaporated, and then vacuum dried to obtain Ti3C2T. x / Liquid metal paste, containing Ti3C2T x The mass fraction of MXene is 2 wt%. Ti3C2T is applied via a blade coating method. x A liquid metal paste was uniformly coated onto the surface of a self-adhesive silicone rubber film to obtain a coating thickness of 5 mm. μAn asymmetric self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material with a thickness of 0.5 mm was developed. The adhesion strength of the self-adhesive silicone rubber on stainless steel sheets after 16 hours at 35℃ and 70℃ were 406.2 and 805.4 kPa, respectively. The conductivity of the self-adhesive silicone rubber-based composite material was 95.6 S / cm, and the electromagnetic shielding effectiveness in the X-band (8.2-12.4 GHz) was 61.1 dB. Furthermore, it could reduce the radiation temperature of a 100℃ infrared target to 39.2℃.

[0048] Example 3

[0049] Self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite materials, including multi-dynamic reversible bond self-adhesive silicone rubber elastomers and Ti3C2T... x MXene and liquid metal, a self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material, has a double-layer asymmetric structure, in which a multi-dynamically reversible bonded silicone rubber elastomer serves as the self-adhesive layer, Ti3C2T x The liquid metal layer is highly conductive; the composite material thickness is 0.5 mm; the self-adhesive silicone rubber elastomer layer contains multiple dynamic reversible bonds, including hydrogen bonds, imine bonds, and metal coordination bonds; the metal ion compound is cobalt chloride, and the molar ratio of 2,6-pyridinedicarboxaldehyde to cobalt ions is 4:2; Ti3C2T x / Ti3C2T in liquid metal coating x The mass fraction of MXene is 1 wt%, and the liquid metal is a gallium indium tin alloy.

[0050] A method for preparing a self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material includes the following steps: 2 mmol of aminopropyl-terminated polydimethylsiloxane and 1.8 mmol of isophorone diisocyanate are added to 40 mL of tetrahydrofuran and reacted at room temperature under a nitrogen atmosphere for 12 h. 0.2 mmol of 2,6-pyridinedicarboxaldehyde is dissolved in 4 mL of N,N-dimethylformamide and added to the reaction system, and the reaction continues for 12 h. 0.1 mmol of cobalt chloride is dissolved in 4 mL of methanol solution and added to the reaction system, and the reaction continues for 6 h. After the reaction is complete, the resulting solution is washed in 800 mL of deionized water to precipitate the product. The product is dried in a vacuum oven at 45 °C, dissolved in tetrahydrofuran solvent, poured into a polytetrafluoroethylene mold, and dried to obtain a self-adhesive silicone rubber elastomer film. 1 g of Ti3AlC2 ceramic powder is added to 20 mL of a 50 mg / mL hydrochloric acid / lithium fluoride mixed solution and stirred at 50 °C for 24 h to obtain a black dispersion. Ti3C2T was prepared by centrifugation and oscillatory exfoliation. x MXene aqueous dispersion, and Ti3C2T x The solvent in the MXene aqueous dispersion was replaced with anhydrous ethanol to obtain Ti3C2T with a concentration of 20 mg / mL.x MXene ethanol dispersion. Ti3C2T x MXene ethanol dispersion and liquid metal were added to a polytetrafluoroethylene (PTFE) beaker, and Ti3C2T was stirred magnetically. x MXene was mixed with liquid metal until the ethanol was completely evaporated, and then vacuum dried to obtain Ti3C2T. x / Liquid metal paste, containing Ti3C2T x The mass fraction of MXene is 3 wt%. Ti3C2T is applied via a blade coating method. x A liquid metal paste was uniformly coated onto the surface of a self-adhesive silicone rubber film to obtain a coating thickness of 10 mm. μ A self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material with an asymmetric structure and a thickness of 0.5 mm was developed. The adhesion strength of the self-adhesive silicone rubber on stainless steel sheets after 16 hours at 35℃ and 70℃ were 415.6 and 851.7 kPa, respectively. The conductivity of the self-adhesive silicone rubber-based composite material was 102.5 S / cm, and the electromagnetic shielding effectiveness in the X-band (8.2-12.4 GHz) was 62.8 dB. Furthermore, it could reduce the radiation temperature of a 100℃ infrared target to 38.3℃.

[0051] Example 4

[0052] Self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite materials, including multi-dynamic reversible bond self-adhesive silicone rubber elastomers and Ti3C2T... x MXene and liquid metal, a self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material, has a double-layer asymmetric structure, in which a multi-dynamically reversible bonded silicone rubber elastomer serves as the self-adhesive layer, Ti3C2T x The liquid metal layer is highly conductive; the composite material thickness is 0.5 mm; the self-adhesive silicone rubber elastomer layer contains multiple dynamic reversible bonds, including hydrogen bonds, imine bonds, and metal coordination bonds; the metal ion compound is cobalt chloride, and the molar ratio of 2,6-pyridinedicarboxaldehyde to cobalt ions is 4:2; Ti3C2T x / Ti3C2T in liquid metal coating x The mass fraction of MXene is 2 wt%, and the liquid metal is a gallium indium tin alloy.

[0053] A method for preparing a self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material includes the following steps: 2 mmol of aminopropyl-terminated polydimethylsiloxane and 1.8 mmol of isophorone diisocyanate are added to 40 mL of tetrahydrofuran and reacted at room temperature under a nitrogen atmosphere for 24 h. 0.2 mmol of 2,6-pyridinedicarboxaldehyde is dissolved in 4 mL of N,N-dimethylformamide and added to the reaction system, and the reaction continues for 24 h. 0.1 mmol of cobalt chloride is dissolved in 4 mL of methanol solution and added to the reaction system, and the reaction continues for 24 h. After the reaction is complete, the resulting solution is washed in 800 mL of deionized water to precipitate the product. The product is dried in a vacuum oven at 45 °C, dissolved in tetrahydrofuran solvent, poured into a polytetrafluoroethylene mold, and dried to obtain a self-adhesive silicone rubber elastomer film. 2 g of Ti3AlC2 ceramic powder is added to 40 mL of a 50 mg / mL hydrochloric acid / lithium fluoride mixed solution and stirred at 50 °C for 24 h to obtain a black dispersion. Ti3C2T was prepared by centrifugation and oscillatory exfoliation. x MXene aqueous dispersion, and Ti3C2T x The solvent in the MXene aqueous dispersion was replaced with anhydrous ethanol to obtain Ti3C2T with a concentration of 20 mg / mL. x MXene ethanol dispersion. Ti3C2T x MXene ethanol dispersion and liquid metal were added to a polytetrafluoroethylene (PTFE) beaker, and Ti3C2T was stirred magnetically. x MXene was mixed with liquid metal until the ethanol was completely evaporated, and then vacuum dried to obtain Ti3C2T. x / Liquid metal paste, containing Ti3C2T x The mass fraction of MXene is 2 wt%. Ti3C2T is applied via a blade coating method. x A liquid metal paste was uniformly coated onto the surface of a self-adhesive silicone rubber film to obtain a coating thickness of 15 mm. μ A self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material with an asymmetric structure and a thickness of 0.5 mm was developed. The adhesion strength of the self-adhesive silicone rubber on stainless steel sheets after 16 hours at 35℃ and 70℃ were 431.1 kPa and 937.3 kPa, respectively. The self-adhesive silicone rubber-based composite material had an electrical conductivity of 107.9 S / cm, an infrared emissivity of only 0.098, and an X-band (8.2-12.4 GHz) electromagnetic shielding effectiveness of 65.3 dB. Furthermore, it could reduce the radiation temperature of a 100℃ infrared target to 37.6℃.

[0054] Example 5

[0055] Self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite materials, including multi-dynamic reversible bond self-adhesive silicone rubber elastomers and Ti3C2T...x MXene and liquid metal, a self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material, has a double-layer asymmetric structure, in which a multi-dynamically reversible bonded silicone rubber elastomer serves as the self-adhesive layer, Ti3C2T x The liquid metal layer is highly conductive; the composite material thickness is 0.5 mm; the self-adhesive silicone rubber elastomer layer contains multiple dynamic reversible bonds, including hydrogen bonds, imine bonds, and metal coordination bonds; the metal ion compound is cobalt chloride, and the molar ratio of 2,6-pyridinedicarboxaldehyde to cobalt ions is 4:2; Ti3C2T x / Ti3C2T in liquid metal coating x The mass fraction of MXene is 2 wt%, and the liquid metal is a gallium indium tin alloy.

[0056] A method for preparing a self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material includes the following steps: 2 mmol of aminopropyl-terminated polydimethylsiloxane and 1.8 mmol of isophorone diisocyanate are added to 40 mL of tetrahydrofuran and reacted at room temperature under a nitrogen atmosphere for 24 h. 0.2 mmol of 2,6-pyridinedicarboxaldehyde is dissolved in 4 mL of N,N-dimethylformamide and added to the reaction system, and the reaction continues for 24 h. 0.1 mmol of cobalt chloride is dissolved in 4 mL of methanol solution and added to the reaction system, and the reaction continues for 24 h. After the reaction is complete, the resulting solution is washed in 800 mL of deionized water to precipitate the product. The product is dried in a vacuum oven at 45 °C, dissolved in tetrahydrofuran solvent, poured into a polytetrafluoroethylene mold, and dried to obtain a self-adhesive silicone rubber elastomer film. 2 g of Ti3AlC2 ceramic powder is added to 40 mL of a 50 mg / mL hydrochloric acid / lithium fluoride mixed solution and stirred at 50 °C for 24 h to obtain a black dispersion. Ti3C2T was prepared by centrifugation and oscillatory exfoliation. x MXene aqueous dispersion, and Ti3C2T x The solvent in the MXene aqueous dispersion was replaced with anhydrous ethanol to obtain Ti3C2T with a concentration of 20 mg / mL. x MXene ethanol dispersion. Ti3C2T x MXene ethanol dispersion and liquid metal were added to a polytetrafluoroethylene (PTFE) beaker, and Ti3C2T was stirred magnetically. x MXene was mixed with liquid metal until the ethanol was completely evaporated, and then vacuum dried to obtain Ti3C2T. x / Liquid metal paste, containing Ti3C2T x The mass fraction of MXene is 2 wt%. Ti3C2T is applied via a blade coating method. x A liquid metal paste was uniformly coated onto the surface of a self-adhesive silicone rubber film to obtain a coating thickness of 20 mm. μAn asymmetric self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material with a thickness of 0.5 mm was developed. The adhesion strength of the self-adhesive silicone rubber on stainless steel sheets after 16 hours at 35℃ and 70℃ were 431.1 kPa and 937.3 kPa, respectively. The self-adhesive silicone rubber-based composite material had an electrical conductivity of 108.3 S / cm, an infrared emissivity of only 0.098, and an X-band (8.2-12.4 GHz) electromagnetic shielding effectiveness of 69.7 dB. Furthermore, it could reduce the radiation temperature of a 100℃ infrared target to 37.2℃.

[0057] Example 6

[0058] Self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite materials, including multi-dynamic reversible bond self-adhesive silicone rubber elastomers and Ti3C2T... x MXene and liquid metal, a self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material, has a double-layer asymmetric structure, in which a multi-dynamically reversible bonded silicone rubber elastomer serves as the self-adhesive layer, Ti3C2T x The liquid metal layer is highly conductive; the composite material thickness is 0.5 mm; the self-adhesive silicone rubber elastomer layer contains multiple dynamic reversible bonds, including hydrogen bonds, imine bonds, and metal coordination bonds; the metal ion compound is cobalt chloride, and the molar ratio of 2,6-pyridinedicarboxaldehyde to cobalt ions is 4:3; Ti3C2T x / Ti3C2T in liquid metal coating x The mass fraction of MXene is 2 wt%, and the liquid metal is a gallium indium tin alloy.

[0059] A method for preparing a self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material includes the following steps: 2 mmol of aminopropyl-terminated polydimethylsiloxane and 1.8 mmol of isophorone diisocyanate are added to 40 mL of tetrahydrofuran and reacted at room temperature under a nitrogen atmosphere for 24 h. 0.2 mmol of 2,6-pyridinedicarboxaldehyde is dissolved in 4 mL of N,N-dimethylformamide and added to the reaction system, and the reaction continues for 24 h. 0.15 mmol of cobalt chloride is dissolved in 4 mL of methanol solution and added to the reaction system, and the reaction continues for 24 h. After the reaction is complete, the resulting solution is washed in 800 mL of deionized water to precipitate the product. The product is dried in a vacuum oven at 45 °C, dissolved in tetrahydrofuran solvent, poured into a polytetrafluoroethylene mold, and dried to obtain a self-adhesive silicone rubber elastomer film. 2 g of Ti3AlC2 ceramic powder is added to 40 mL of a 50 mg / mL hydrochloric acid / lithium fluoride mixed solution and stirred at 50 °C for 24 h to obtain a black dispersion. Ti3C2T was prepared by centrifugation and oscillatory exfoliation. x MXene aqueous dispersion, and Ti3C2T xThe solvent in the MXene aqueous dispersion was replaced with anhydrous ethanol to obtain Ti3C2T with a concentration of 20 mg / mL. x MXene ethanol dispersion. Ti3C2T x MXene ethanol dispersion and liquid metal were added to a polytetrafluoroethylene (PTFE) beaker, and Ti3C2T was stirred magnetically. x MXene was mixed with liquid metal until the ethanol was completely evaporated, and then vacuum dried to obtain Ti3C2T. x / Liquid metal paste, containing Ti3C2T x The mass fraction of MXene is 2 wt%. Ti3C2T is applied via a blade coating method. x A liquid metal paste was uniformly coated onto the surface of a self-adhesive silicone rubber film to obtain a coating thickness of 25 mm. μ An asymmetric self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material with a thickness of 0.5 mm was developed. The adhesion strength of the self-adhesive silicone rubber on stainless steel sheets after 16 hours at 35℃ and 70℃ were 452.6 kPa and 963.8 kPa, respectively. The conductivity of the self-adhesive silicone rubber-based composite material was 110.5 S / cm, and the electromagnetic shielding effectiveness in the X-band (8.2-12.4 GHz) was 73.7 dB. Furthermore, it could reduce the radiation temperature of a 100℃ infrared target to 36.6℃.

[0060] Comparative Example 1

[0061] The self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material comprises a multi-dynamically reversible bond self-adhesive silicone rubber elastomer and liquid metal nanoparticles. The composite material has a homogeneous structure, with the multi-dynamically reversible bond silicone rubber elastomer serving as the polymer matrix and the liquid metal nanoparticles as the conductive filler. The composite material has a thickness of 0.5 mm. The self-adhesive silicone rubber elastomer matrix contains dynamically reversible hydrogen and imine bonds. The liquid metal is a gallium indium tin alloy with a content of 20 wt%.

[0062] A method for preparing a self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material includes the following steps: 2 mmol of aminopropyl-terminated polydimethylsiloxane and 1.8 mmol of isophorone diisocyanate are added to 40 mL of tetrahydrofuran, and the mixture is reacted at room temperature under a nitrogen atmosphere for 24 h. 0.2 mmol of 2,6-pyridinedicarboxaldehyde is dissolved in 4 mL of N,N-dimethylformamide and added to the reaction system, and the reaction continues for another 24 h. After the reaction is complete, the resulting solution is washed in 800 mL of deionized water to precipitate the material, and then dried in a vacuum oven at 45 °C to obtain a self-adhesive silicone rubber elastomer. Liquid metal is mixed with tetrahydrofuran solvent, and the mixture is ultrasonically treated in an ice bath using an ultrasonic cell grinder for 40 min to obtain a dispersion of liquid metal nanoparticles. Self-adhesive silicone rubber elastomer was dissolved in tetrahydrofuran solvent, and a liquid metal nanoparticle dispersion was added and mixed uniformly. The mixture was then poured into a polytetrafluoroethylene mold and dried to obtain a homogeneous self-adhesive silicone rubber elastomer film with a thickness of 2 mm. The liquid metal content was 20 wt%. The adhesion strength of the obtained self-adhesive silicone rubber on the surface of stainless steel sheet after 16 h at 35 and 70 °C was 215.2 kPa and 617.6 kPa, respectively. The electromagnetic shielding effectiveness of the composite material in the X-band (8.2-12.4 GHz) was 3.2 dB, and it could reduce the radiation temperature of a 100 °C infrared target to 94.5 °C.

[0063] Comparative Example 2

[0064] The self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material comprises a multi-dynamically reversible bond self-adhesive silicone rubber elastomer and liquid metal nanoparticles. The composite material has a homogeneous structure, with the multi-dynamically reversible bond silicone rubber elastomer serving as the polymer matrix and the liquid metal nanoparticles as the conductive filler. The composite material has a thickness of 0.5 mm. The self-adhesive silicone rubber elastomer matrix contains dynamically reversible hydrogen and imine bonds. The liquid metal is a gallium indium tin alloy with a content of 30 wt%.

[0065] A method for preparing a self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material includes the following steps: 2 mmol of aminopropyl-terminated polydimethylsiloxane and 1.6 mmol of isophorone diisocyanate are added to 40 mL of tetrahydrofuran, and the mixture is reacted at room temperature under a nitrogen atmosphere for 24 h. 0.4 mmol of 2,6-pyridinedicarboxaldehyde is dissolved in 16 mL of N,N-dimethylformamide and added to the reaction system, and the reaction continues for another 24 h. After the reaction is complete, the resulting solution is washed in 800 mL of deionized water to precipitate the precipitate, and then dried in a vacuum oven at 45 °C to obtain a self-adhesive silicone rubber elastomer. Liquid metal is mixed with tetrahydrofuran solvent, and the mixture is ultrasonically treated in an ice bath using an ultrasonic cell grinder for 40 min to obtain a dispersion of liquid metal nanoparticles. Self-adhesive silicone rubber elastomer was dissolved in tetrahydrofuran solvent, and a liquid metal nanoparticle dispersion was added and mixed uniformly. The mixture was then poured into a polytetrafluoroethylene mold and dried to obtain a homogeneous self-adhesive silicone rubber elastomer film with a thickness of 2 mm. The liquid metal content was 30 wt%. The adhesion strength of the obtained self-adhesive silicone rubber on the surface of stainless steel sheet at 35 and 70 °C for 16 h was 164.8 and 548.6 kPa, respectively. The electromagnetic shielding effectiveness of the composite material in the X-band (8.2-12.4 GHz) was 5.5 dB, and it could reduce the radiation temperature of an infrared target at 100 °C to 94.7 °C.

[0066] Table 1 shows the adhesion strength of the self-adhesive silicone rubber synthesized in Example 5 of the self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material after 16 hours of adhesion to various substrates including stainless steel sheets, aluminum sheets, ceramics, glass, plastics (polyethylene terephthalate), and wood at 35 and 70°C.

[0067] As shown in Table 1, the obtained self-adhesive silicone rubber exhibits high adhesion strength on various substrates including stainless steel sheets, aluminum sheets, ceramics, glass, plastics (polyethylene terephthalate), and wood. At 35℃, the adhesion strength on stainless steel sheets and wood surfaces reaches 431.1 kPa and 949 kPa, respectively. At a higher temperature of 70℃, the adhesion strength of the self-adhesive silicone rubber on stainless steel sheets and wood surfaces reaches 937.3 kPa and 1638.6 kPa, respectively.

[0068] Table 1

[0069]

[0070] Table 2 shows Examples 1-6 and Comparative Examples 1 and 2 of the preparation of self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite materials, as well as the Ti3C2T content of the prepared composite materials. x Comparison of liquid metal coating thickness and mass fraction, electromagnetic shielding performance and infrared stealth performance.

[0071] Table 2

[0072]

[0073] As shown in Table 2, Examples 1-6 used a multi-dynamically reversible bond silicone rubber elastomer as the self-adhesive layer, with Ti3C2T x A double-layer asymmetric self-adhesive silicone rubber elastomer-based electromagnetic shielding and infrared stealth composite material was prepared by a blade coating method using liquid metal as a highly conductive layer. Comparative Examples 1 and 2 were prepared by solvent blending using a multi-dynamically reversible bond silicone rubber elastomer as the matrix and liquid metal as the conductive filler to create a homogeneous silicone rubber elastomer-based composite material. In Comparative Examples 1 and 2, the liquid metal nanoparticles inside the homogeneous silicone rubber elastomer-based composite material were uniformly dispersed within the silicone rubber elastomer matrix, making it difficult to form an efficient continuous conductive path. Even at higher liquid metal mass fractions, they exhibited poor electromagnetic shielding and infrared stealth performance. In contrast, the self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite materials in Examples 1-6 showed better performance at low Ti3C2T. x The liquid metal exhibits superior electromagnetic shielding and infrared stealth performance. This is due to the Ti3C2T content in the double-layer asymmetric self-adhesive silicone rubber elastomer-based electromagnetic shielding and infrared stealth composite material. x Liquid metal coatings can form efficient continuous conductive paths at lower Ti3C2T levels. x The composite material can be endowed with excellent electromagnetic shielding and infrared stealth properties at a liquid metal mass fraction, without affecting the self-adhesive properties of the multi-dynamic reversible bond silicone rubber elastomer layer.

[0074] Schematic diagrams of the preparation of self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite materials in Examples 1-6 are shown below. Figure 1 As shown. The resulting composite material uses a multi-dynamically reversible bonded silicone rubber elastomer as a self-adhesive layer, with Ti3C2T as the base. x The liquid metal serves as a highly conductive layer, possessing characteristics such as self-adhesion, recyclability, high electromagnetic shielding effectiveness, and infrared stealth. A digital photograph of the self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material obtained in Example 5 is shown below. Figure 2 As shown, the Ti3C2T composite material obtained has a Ti3C2T content. x The liquid metal coating is uniformly distributed and exhibits good flexibility. A cross-sectional scanning electron microscope image of the self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material obtained in Example 5 is shown below. Figure 3 As shown, the resulting composite material has a double-layer asymmetric structure. A digital photograph of the self-adhesive silicone rubber obtained in Example 5 adhering to a stainless steel surface and lifting weights is shown below. Figure 4 As shown, the resulting composite material has good self-adhesion properties to the stainless steel substrate, and can successfully bond the stainless steel sheet to a 500g weight and lift it smoothly.

[0075] This invention endows silicone rubber with excellent self-adhesive properties by introducing multiple dynamic reversible bonds, specifically by introducing Ti3C2T... x MXene reduces the surface tension of liquid metal, improving its substrate adhesion and ductility. By coating MXene / liquid metal onto the surface of a self-adhesive silicone rubber elastomer using a scraping method, a highly efficient continuous conductive layer is formed, resulting in an asymmetric structure self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material that combines high electromagnetic shielding effectiveness and infrared stealth performance. This solves the problems of poor electromagnetic shielding and infrared stealth performance, difficulty in achieving self-adhesion, and complex assembly processes in practical applications of traditional polymer elastomer-based conductive composite materials.

[0076] Thanks to Ti3C2T x The high electrical conductivity and low infrared emissivity of the liquid metal layer, combined with the excellent self-adhesive properties of the multi-dynamically reversible bonded silicone rubber elastomer layer, result in an asymmetric self-adhesive silicone rubber elastomer-based composite material that exhibits both excellent electromagnetic shielding and infrared stealth properties. Furthermore, it can directly adhere to the surface of the protected area, avoiding the need for additional adhesives or complex assembly techniques. In addition, the resulting self-adhesive silicone rubber elastomer-based composite material demonstrates excellent full-cycle recyclability, maintaining its superior electromagnetic shielding, infrared stealth, self-adhesive, and mechanical properties even after recycling. The preparation method employed in this invention is simple, efficient, environmentally friendly, and easily scalable for large-scale processing and application. Therefore, the self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material prepared in this invention has significant application value in aerospace, electronics, and smart wearable electronic devices.

Claims

1. A method for preparing a self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material, characterized in that, Specifically, the steps include the following: Step 1: Synthesis of a self-adhesive silicone rubber elastomer based on multiple dynamic reversible bonds; the specific process of Step 1 is as follows: First, aminopropyl-terminated polydimethylsiloxane and isophorone diisocyanate are added to tetrahydrofuran and reacted at room temperature under a nitrogen atmosphere for 12-24 h; then, 2,6-pyridinedicarboxaldehyde is dissolved in N,N-dimethylformamide and added to the reaction system, and the reaction continues for 12-24 h; a metal ion compound is dissolved in methanol solution, added to the reaction system, and the reaction continues for 6-12 h; after the reaction is completed, the resulting solution is poured into deionized water and stirred continuously to promote the product to precipitate in a flocculent manner; the product is washed repeatedly with deionized water; finally, the product is dried in a vacuum oven at 45-60℃ to obtain a self-adhesive silicone rubber elastomer based on multiple dynamic reversible bonds of hydrogen bonds, imine bonds, and metal coordination bonds; In step 1, the metal ion compound is any one of cobalt chloride, ferric chloride, zinc chloride, copper chloride, magnesium chloride, calcium chloride, and nickel chloride, and the molar ratio of 2,6-pyridinedicarboxaldehyde to the metal ion is 4:1 to 4:

3. Step 2, Preparation of Ti3C2T x MXene ethanol dispersion; Step 3: Prepare Ti3C2T based on the product obtained in Step 2. x / Liquid metal paste; the specific process of step 3 is as follows: Ti3C2T x MXene ethanol dispersion and liquid metal were added to a polytetrafluoroethylene beaker, and Ti3C2T was stirred magnetically. x MXene was mixed with liquid metal until the ethanol was completely evaporated, and then vacuum dried to obtain Ti3C2T. x / Liquid metal paste; in step 3, Ti3C2T x / Ti3C2T in liquid metal paste x The mass fraction of MXene is 1~3wt%, and the liquid metal is a gallium indium tin alloy; Step 4: Based on the products obtained in Steps 1 and 3, prepare an asymmetric self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material using a blade coating method. The specific process of Step 4 is as follows: dissolve the self-adhesive silicone rubber elastomer obtained in Step 1 in tetrahydrofuran solvent, pour it into a polytetrafluoroethylene mold, and dry it to obtain a self-adhesive silicone rubber elastomer film; then, using a blade coating method, apply the Ti3C2T... x A self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material with an asymmetric structure is prepared by uniformly coating a liquid metal paste onto the surface of a self-adhesive silicone rubber film.

2. The preparation method of the self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material according to claim 1, characterized in that, In step 1, the sum of the molar amounts of isophorone diisocyanate and 2,6-pyridinedicarboxaldehyde is equal to the molar amount of aminopropyl-terminated polydimethylsiloxane.

3. The method for preparing the self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material according to claim 1, characterized in that, The specific process of step 2 is as follows: Ti3AlC2 ceramic powder is added to a hydrochloric acid / lithium fluoride mixed solution and stirred at 50°C for 24-48 hours to obtain a black dispersion, thereby completely etching the aluminum layer in Ti3AlC2; deionized water is added to the black dispersion, and after centrifugation, the supernatant is discarded. The mixture is repeatedly washed until the pH of the supernatant is ≥6, at which point centrifugation is stopped; then, Ti3C2T is prepared by centrifugation and oscillation exfoliation. x MXene aqueous dispersion; finally, Ti3C2T was separated by centrifugation. x The solvent in the MXene aqueous dispersion was replaced with anhydrous ethanol to obtain Ti3C2T. x MXene ethanol dispersion.

4. The preparation method of the self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material according to claim 3, characterized in that, In step 2, the Ti3AlC2 ceramic powder has a size of 200-400 mesh, and the ratio of Ti3AlC2, lithium fluoride, and hydrochloric acid is 1-2g: 1-2g: 20-40mL. x The size of MXene sheets ranges from 0.1 to 5. μ m.

5. A self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material, prepared by the preparation method of the self-adhesive silicone rubber-based electromagnetic shielding and infrared stealth composite material as described in any one of claims 1 to 4.

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