A hydrogen bond driven self-repairing wave-absorbing composite material and its preparation method

Abstract

The present invention discloses a hydrogen-bond-driven self-healing absorbing composite material and its preparation method. A polyaniline / MXene composite with excellent conductivity is prepared by in-situ polymerization. Using the polyaniline / MXene composite as an absorber, a double-crosslinked self-healing network of polyacryloyl glycinamide and polyvinyl alcohol is constructed, resulting in a high-performance absorbing material with self-healing properties. By utilizing the high conductivity and abundant surface functional groups of MXene, the present invention uses polyaniline for surface modification and interface design to produce a composite absorbing material with a minimum return loss of -52 dB and an effective absorption bandwidth of 5.2 GHz. The addition of polyacryloyl glycinamide imparts excellent self-healing properties to the polyvinyl alcohol matrix. The resulting material has promising application prospects in the fields of absorbing and stealth materials.

Description

Technical Field

[0001] The present invention belongs to the technical field of wave-absorbing and self-healing materials, and relates to a hydrogen bond-driven self-repairing wave-absorbing composite material and a preparation method thereof. Background Art

[0002] The rapid development of modern technology and the electronics industry has brought a vast array of electronic devices into our lives. This frequent use of electronic devices is accompanied by significant amounts of electromagnetic radiation, and the resulting electromagnetic pollution has become a new social nuisance. Absorbing materials can effectively absorb electromagnetic waves and reduce electromagnetic interference, offering an effective approach to mitigating electromagnetic pollution. Furthermore, as a core component of stealth technology, the research and application of absorbing materials has become a hot topic in the field of military materials. Therefore, research on absorbing materials significantly impacts the development of both civilian electromagnetic radiation protection and military stealth.

[0003] To meet the performance requirements of thin, light, wide, and strong absorbing materials, research on absorbers is moving towards high efficiency, composite materials, compatibility, and intelligent technologies. MXene, a layered conductive metal carbide and metal nitride material, has a layered structure that provides a mechanism for electromagnetic wave absorption and multiple reflection attenuation, resulting in excellent absorption. The conductive polymer polyaniline combines the conductivity and moldability of metal with chemical and electrochemical properties lacking in metals and plastics, offering promising application prospects in the field of absorbing materials. Furthermore, most absorbing materials have poor mechanical properties and are easily damaged. Therefore, imparting self-healing properties to absorbing materials can significantly improve their utilization efficiency and service life. Summary of the Invention

[0004] The present invention relates to a hydrogen-bond-driven self-healing absorbing composite material and a preparation method thereof. First, a polyaniline / MXene composite material with good conductivity is obtained by in-situ polymerization. Then, a double-network cross-linking structure of polyvinyl alcohol and polyacryloyl glycinamide is introduced to obtain a high-performance absorbing material with self-healing properties, achieving efficient absorption and loss of electromagnetic waves. The material has good development prospects in the fields of civilian electromagnetic radiation protection and military stealth materials.

[0005] The present invention is achieved through the following technical solutions.

[0006] The present invention provides a method for preparing a hydrogen bond-driven self-repairing absorbing composite material, comprising the following steps: modifying the surface of polyaniline with MXene, introducing the polyaniline / MXene complex into a polyvinyl alcohol matrix, and introducing polyacryloyl glycinamide to obtain a absorbing composite material with a self-repairing function.

[0007] The raw materials are in the following weight proportions: 20 to 30 parts of polyaniline / MXene composite, 20 parts of polyacryloyl glycinamide and 50 to 60 parts of polyvinyl alcohol.

[0008] A method for preparing a hydrogen bond-driven self-repairing wave-absorbing composite material comprises the following steps:

[0009] Step 1: Disperse the polyaniline / MXene composite and polyvinyl alcohol in deionized water, and mix at a stirring speed of 200 r / min at 70-90° C. until the polyaniline / MXene composite is uniformly dispersed and the polyvinyl alcohol is completely dissolved, and the solid content of the polyaniline / MXene composite in the polyvinyl alcohol solution is 10%-15%;

[0010] Step 2: Add N-acryloyl glycinamide to the mixed solution obtained in step 1 and continue the reaction for 1 to 2 hours to dissolve N-acryloyl glycinamide in the polyvinyl alcohol mixed solution and initiate polymerization of N-acryloyl glycinamide in situ to obtain a double network mixed solution composed of polyacryloyl glycinamide and polyvinyl alcohol;

[0011] Step 3: Pour the mixed solution obtained in step 2 into a flat glass mold, and vacuum dry it at 50-60° C. until the water is completely evaporated to obtain a hydrogen bond-driven self-repairing absorbing composite material.

[0012] The preparation method of the polyaniline / MXene composite comprises the following steps:

[0013] (1) Add 10-15 g of LiF to 50 mL of 1 mol / L HCl solution, stir mechanically for 5-15 min, then slowly add the MAX phase, react at 30-40 °C for 24 h, and then centrifuge, wash, and dry to obtain MXene powder;

[0014] (2) 20 mL of aniline monomer and 5-10 g of MXene solid powder obtained in step (1) were dispersed in 50-100 mL of 1 mol / L protonic acid to prepare a MXene solution, and then 20-50 g of ammonium persulfate was added to the mixed solution. The mixture was reacted under magnetic stirring in an ice bath at 0°C for 4-6 hours, and the obtained product was filtered, washed, and dried to obtain a polyaniline / MXene composite.

[0015] Preferably, the MAX phase is one or more of Ti3AlC2, Ti2AlC or Ti3AlCN, and has a particle size of ≤200 mesh.

[0016] Preferably, the protonic acid is hydrochloric acid, sulfuric acid, dodecylbenzenesulfonic acid and camphorsulfonic acid.

[0017] The resulting absorbing composite material exhibits excellent electromagnetic wave absorption and loss performance, with a minimum reflection loss of -52 dB and an effective absorption bandwidth of 5.2 GHz, with a reflection loss less than -10 dB (99%), demonstrating excellent broadband absorption. Furthermore, the hydrogen-bonded double-network crosslinked structure formed by polyvinyl alcohol and polyacryloyl glycinamide ensures that the resulting absorbing material not only has good mechanical properties but also exhibits excellent self-healing properties at room temperature (repair efficiency ≥ 85%), which is of great significance for the utilization efficiency and service life of the absorbing material.

[0018] Beneficial effects of the present invention:

[0019] (1) The composite material obtained by the present invention exhibits excellent electromagnetic wave absorption and attenuation effects, with the minimum reflection loss value reaching -52dB, and the effective absorption bandwidth with reflection loss less than -10dB reaching 5.2GHz. The wave absorption performance of the composite material is closely related to the conductivity and structure of the material. The present invention adopts an in-situ polymerization method to prepare a polyaniline / MXene composite material. Both polyaniline and MXene have good conductivity, which promotes the dielectric loss of electromagnetic waves. The layered loose structure of MXene is conducive to multiple reflections and absorption of electromagnetic waves inside the material. The interface composed of polyaniline with different conductivity and MXene forms a capacitor-like structure, which promotes the attenuation of electromagnetic waves. Therefore, the material obtained by the present invention exhibits good wave absorption performance.

[0020] (2) The absorbing material obtained by the present invention has excellent self-repairing properties at room temperature, with a repair efficiency of ≥85%. The present invention adopts a double network cross-linking structure of polyvinyl alcohol and polyacryloyl glycinamide. The two amide groups on the polyacryloyl glycinamide side chain are separated by a methylene group, which has double hydrogen bond acceptors and double hydrogen bond donors. Therefore, it can not only form multiple hydrogen bonds between the polyacryloyl glycinamide chains, but also form strong hydrogen bond interactions with the hydroxyl groups on the polyvinyl alcohol molecular chain. Therefore, the absorbing material obtained by the present invention can achieve a high repair efficiency at room temperature. In addition, the double network cross-linking structure of polyvinyl alcohol and polyacryloyl glycinamide significantly improves the mechanical strength and flexibility of the absorbing composite material. DETAILED DESCRIPTION

[0021] In order to have a clearer understanding of the technical features of the present invention, the technical solution of the present invention is now described in detail below, but it should not be understood as limiting the scope of implementation of the present invention.

[0022] Example 1

[0023] (1) 12 g of LiF was added to 50 mL of 1 mol / L HCl solution, and 8 g of Ti3AlC2 was slowly added after mechanical stirring for 10 min. The mixture was reacted at 35 °C for 24 h, and then centrifuged, washed, and dried to obtain MXene powder.

[0024] (2) 20 mL of aniline monomer and 5 g of MXene solid powder were dispersed in 50 mL of 1 mol / L hydrochloric acid to prepare a MXene solution. 20 g of ammonium persulfate was then added to the mixed solution. The mixture was stirred magnetically in an ice bath at 0 °C for 4 h, and the resulting product was filtered, washed, and dried to obtain a polyaniline / MXene composite.

[0025] (3) 5 g of polyaniline / MXene composite and 10 g of polyvinyl alcohol were dispersed in 100 mL of deionized water and mixed at 80 °C at a stirring speed of 200 r / min until the polyaniline / MXene composite was uniformly dispersed and the polyvinyl alcohol was completely dissolved. Then, 4 g of N-acryloyl glycine amide was added and the reaction was continued for 2 h, so that N-acryloyl glycine amide was dissolved in the polyvinyl alcohol mixed solution and N-acryloyl glycine amide polymerization was initiated in situ to obtain a mixed solution;

[0026] (4) Pour the mixed solution obtained in step (3) into a flat glass mold, and vacuum dry it at 55° C. until the water is completely evaporated to obtain a hydrogen bond-driven self-repairing absorbing composite material.

[0027] Example 2

[0028] (1) 12 g of LiF was added to 50 mL of 1 mol / L HCl solution, and 8 g of Ti3AlC2 was slowly added after mechanical stirring for 10 min. The mixture was reacted at 35 °C for 24 h, and then centrifuged, washed, and dried to obtain MXene powder.

[0029] (2) 20 mL of aniline monomer and 5 g of MXene solid powder were dispersed in 50 mL of 1 mol / L sulfuric acid to prepare a MXene solution. 20 g of ammonium persulfate was then added to the mixed solution. The mixture was stirred under magnetic stirring in an ice bath at 0 °C for 4 h. The resulting product was filtered, washed, and dried to obtain a polyaniline / MXene composite.

[0030] (3) 5 g of polyaniline / MXene composite and 10 g of polyvinyl alcohol were dispersed in 100 mL of deionized water and mixed at 80 °C at a stirring speed of 200 r / min until the polyaniline / MXene composite was uniformly dispersed and the polyvinyl alcohol was completely dissolved. Then, 4 g of N-acryloyl glycine amide was added and the reaction was continued for 2 h, so that N-acryloyl glycine amide was dissolved in the polyvinyl alcohol mixed solution and N-acryloyl glycine amide polymerization was initiated in situ to obtain a mixed solution;

[0031] (4) Pour the mixed solution obtained in step (3) into a flat glass mold, and vacuum dry it at 55° C. until the water is completely evaporated to obtain a hydrogen bond-driven self-repairing absorbing composite material.

[0032] Example 3

[0033] (1) 12 g of LiF was added to 50 mL of 1 mol / L HCl solution, and 8 g of Ti3AlC2 was slowly added after mechanical stirring for 10 min. The mixture was reacted at 35 °C for 24 h, and then centrifuged, washed, and dried to obtain MXene powder.

[0034] (2) 20 mL of aniline monomer and 5 g of MXene solid powder were dispersed in 50 mL of 1 mol / L dodecylbenzenesulfonic acid to prepare a MXene solution. 20 g of ammonium persulfate was then added to the mixed solution. The mixture was stirred under magnetic stirring in an ice bath at 0 °C for 4 h. The resulting product was filtered, washed, and dried to obtain a polyaniline / MXene composite.

[0035] (3) 5 g of polyaniline / MXene composite and 10 g of polyvinyl alcohol were dispersed in 100 mL of deionized water and mixed at 80 °C at a stirring speed of 200 r / min until the polyaniline / MXene composite was uniformly dispersed and the polyvinyl alcohol was completely dissolved. Then, 4 g of N-acryloyl glycine amide was added and the reaction was continued for 2 h, so that N-acryloyl glycine amide was dissolved in the polyvinyl alcohol mixed solution and N-acryloyl glycine amide polymerization was initiated in situ to obtain a mixed solution;

[0036] (4) Pour the mixed solution obtained in step (3) into a flat glass mold, and vacuum dry it at 55° C. until the water is completely evaporated to obtain a hydrogen bond-driven self-repairing absorbing composite material.

[0037] Example 4

[0038] (1) 12 g of LiF was added to 50 mL of 1 mol / L HCl solution. After mechanical stirring for 10 min, 8 g of Ti2AlC was slowly added and reacted at 35 °C for 24 h. MXene powder was then obtained by centrifugation, washing, and drying.

[0039] (2) 20 mL of aniline monomer and 5 g of MXene solid powder were dispersed in 50 mL of 1 mol / L dodecylbenzenesulfonic acid to prepare a MXene solution. 20 g of ammonium persulfate was then added to the mixed solution. The mixture was stirred under magnetic stirring in an ice bath at 0 °C for 4 h. The resulting product was filtered, washed, and dried to obtain a polyaniline / MXene composite.

[0040] (3) 5 g of polyaniline / MXene composite and 10 g of polyvinyl alcohol were dispersed in 100 mL of deionized water and mixed at 80 °C at a stirring speed of 200 r / min until the polyaniline / MXene composite was uniformly dispersed and the polyvinyl alcohol was completely dissolved. Then, 4 g of N-acryloyl glycine amide was added and the reaction was continued for 2 h, so that N-acryloyl glycine amide was dissolved in the polyvinyl alcohol mixed solution and N-acryloyl glycine amide polymerization was initiated in situ to obtain a mixed solution;

[0041] (4) Pour the mixed solution obtained in step (3) into a flat glass mold, and vacuum dry it at 55° C. until the water is completely evaporated to obtain a hydrogen bond-driven self-repairing absorbing composite material.

[0042] Example 5

[0043] (1) 12 g of LiF was added to 50 mL of 1 mol / L HCl solution. After mechanical stirring for 10 min, 8 g of Ti2AlC was slowly added and reacted at 35 °C for 24 h. MXene powder was then obtained by centrifugation, washing, and drying.

[0044] (2) 20 mL of aniline monomer and 5 g of MXene solid powder were dispersed in 50 mL of 1 mol / L camphorsulfonic acid to prepare a MXene solution. 20 g of ammonium persulfate was then added to the mixed solution. The mixture was stirred magnetically in an ice bath at 0 °C for 4 h, and the resulting product was filtered, washed, and dried to obtain a polyaniline / MXene composite.

[0045] (3) 5 g of polyaniline / MXene composite and 10 g of polyvinyl alcohol were dispersed in 100 mL of deionized water and mixed at 80 °C at a stirring speed of 200 r / min until the polyaniline / MXene composite was uniformly dispersed and the polyvinyl alcohol was completely dissolved. Then, 4 g of N-acryloyl glycine amide was added and the reaction was continued for 2 h, so that N-acryloyl glycine amide was dissolved in the polyvinyl alcohol mixed solution and N-acryloyl glycine amide polymerization was initiated in situ to obtain a mixed solution;

[0046] (4) Pour the mixed solution obtained in step (3) into a flat glass mold, and vacuum dry it at 55° C. until the water is completely evaporated to obtain a hydrogen bond-driven self-repairing absorbing composite material.

[0047] As shown in Table 1, the absorbing performance and self-repairing performance parameters of the hydrogen bond driven self-repairing absorbing composite materials prepared based on Examples 1 to 5, the minimum reflection loss value (R Lmin ) is between -52dB and -48dB, and the reflection loss is less than -10dB (99%). a) between 4.5GHz and 5.2GHz, demonstrating excellent electromagnetic wave absorption and loss reduction. The resulting absorbing material has a repair efficiency (μ) of ≥85% at room temperature, demonstrating excellent self-healing properties.

[0048] Table 1. Wave absorbing properties and self-repairing performance parameters of the composite materials obtained in the examples

[0049] Group Example 1 Example 2 Example 3 Example 4 Example 5 <![CDATA[R Lmin (dB)]]> -52 -50 -51 -48 -48 <![CDATA[E a (GHz)]]> 5.0 5.2 4.7 4.9 4.5 μ(%) 86％ 87％ 85％ 86％ 85％

[0050] The above specific description further illustrates the purpose, technical solutions and beneficial effects of the invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a hydrogen bond driven self-repairing wave absorbing composite material, characterized in that: The steps include: Step 1: Disperse the polyaniline / MXene composite and polyvinyl alcohol in deionized water, and mix at a stirring speed of 200 r / min at 70-90° C. until the polyaniline / MXene composite is uniformly dispersed and the polyvinyl alcohol is completely dissolved, and the solid content of the polyaniline / MXene composite in the polyvinyl alcohol solution is 10%-15%; Step 2: Add N-acryloyl glycinamide to the mixed solution obtained in step 1 and continue the reaction for 1 to 2 hours to dissolve N-acryloyl glycinamide in the polyvinyl alcohol mixed solution and initiate in situ polymerization of N-acryloyl glycinamide to obtain a double network mixed solution composed of polyacryloyl glycinamide and polyvinyl alcohol; Step 3: Pour the mixed solution obtained in step 2 into a flat glass mold, and vacuum dry it at 50-60° C. until the water is completely evaporated to obtain a hydrogen bond-driven self-repairing absorbing composite material.

2. The method for preparing a hydrogen bond driven self-repairing absorbing composite material according to claim 1, characterized in that: The preparation method of the polyaniline / MXene composite comprises the following steps: (1) Add 10-15 g of LiF to 50 mL of 1 mol / L HCl solution, stir mechanically for 5-15 min, then slowly add the MAX phase, react at 30-40 °C for 24 h, and then centrifuge, wash, and dry to obtain MXene powder; (2) 20 mL of aniline monomer and 5-10 g of MXene solid powder obtained in step (1) were dispersed in 50-100 mL of 1 mol / L protonic acid to prepare a MXene solution, and then 20-50 g of ammonium persulfate was added to the mixed solution. The mixture was reacted with magnetic stirring in an ice bath at 0°C for 4-6 h, and the obtained product was filtered, washed, and dried to obtain a polyaniline / MXene composite.

3. The method for preparing a hydrogen bond driven self-repairing absorbing composite material according to claim 2, characterized in that: The MAX phase in step (1) is one or more of Ti3AlC2, Ti2AlC or Ti3AlCN, and has a particle size of ≤200 mesh.

4. The method for preparing a hydrogen bond driven self-repairing absorbing composite material according to claim 2, characterized in that: The protonic acid in step (2) is hydrochloric acid, sulfuric acid, dodecylbenzenesulfonic acid and camphorsulfonic acid.