Laser synergistically modified polydopamine metallized carbon fiber material and preparation method thereof

Abstract

The application belongs to the technical field of carbon fiber materials, and relates to a laser-assisted modified polydopamine metalized carbon fiber material and a preparation method thereof. The preparation method is as follows: first, a laser texturing treatment is performed on the surface of a carbon fiber substrate, then the carbon fiber substrate is soaked in a solution containing dopamine hydrochloride, a polydopamine coating carbon fiber substrate is obtained through reaction, then the polydopamine coating carbon fiber substrate is treated in a Cl2 and N2 mixed atmosphere, then alkali washing and acid washing are sequentially performed, a carbon fiber substrate loaded with a modified polydopamine coating is obtained, finally, the carbon fiber substrate loaded with the modified polydopamine coating is subjected to a metallization treatment, and a metalized carbon fiber material is prepared. The prepared metalized carbon fiber material comprises a carbon fiber substrate, a modified polydopamine functionalized intermediate layer, and a metal phase distributed in the modified polydopamine functionalized intermediate layer and on the surface of the modified polydopamine functionalized intermediate layer. The method is simple and easy to implement, and the prepared product has significantly improved conductivity, bonding force and electromagnetic shielding resistance.

Description

Technical Field

[0001] This invention belongs to the field of carbon fiber material technology, and relates to a laser-assisted modified polydopamine metallized carbon fiber material and its preparation method. Background Technology

[0002] Metallized carbon fiber combines the lightweight, high strength, and flexibility of carbon fiber with the excellent electrical and thermal properties of metals. It can replace traditional metal materials to a certain extent in fields such as electromagnetic shielding, lightning protection, de-icing / anti-icing, power transmission, supercapacitors, signal sensing, and integrated composite material structures and functions. It is an innovation that transcends the limitations of material properties and has shown unique application value in multiple fields. It is an important technical path to realize the multi-functionality of materials.

[0003] In existing metallization methods, traditional electroless plating processes typically require sensitizing and activating solutions containing heavy metals (such as palladium, Pd). This not only increases costs but also poses a serious environmental threat due to the wastewater. Vacuum deposition can produce high-purity, highly conductive metal films, but the equipment is expensive, investment costs are high, and it is difficult to achieve uniform deposition on complex three-dimensional surfaces. Electroplating offers high coating uniformity and high plating efficiency, but it has limitations on fibrous substrates, is difficult to apply to complex surfaces, and incurs high environmental costs.

[0004] Polydopamine (PDA) can be used to functionalize materials and serve as a chemical bridge connecting carbon fibers and metal nanoparticles. However, the bond between PDA and smooth carbon fibers is only formed by van der Waals forces and a small number of hydrogen bonds, resulting in low interfacial peel strength. At the same time, PDA has few metal ion reduction sites on its surface, and nanoparticles are prone to agglomeration and detachment.

[0005] For example, CN117944290A discloses a fiber-metal laminate with enhanced interlayer properties based on dopamine and its preparation method. It utilizes the self-polymerization reaction of introduced dopamine on the metal surface to form a polydopamine coating, thereby enhancing the interfacial bonding between the metal layer and the polymer matrix. The fiber-metal laminate with enhanced interlayer properties is then prepared by hot pressing. However, this prior art only chemically functionalizes the metal surface through acid washing and dopamine immersion, and the interfacial enhancement mainly relies on the active groups and π-electron cloud of dopamine. In this case, the metal phase or functionalized layer mainly adheres to the substrate surface, resulting in problems such as interfacial debonding, insufficient bonding stability, and limited long-term reliability.

[0006] The literature (A facile and green strategy to achieve metallized woven carbonfiber through the triple roles of dopamine in in-situ thermal reduction of Ag[J]. Composites Communications.2023.101585) utilizes the in-situ thermal reduction of Ag by PDA to prepare a simple and efficient CF-PDA@Ag electromagnetic interference shielding material. However, it only uses qualitative testing of tape adhesion without quantitative testing, and does not consider the issue of limited long-term reliability.

[0007] Therefore, it is of great significance to study a laser-assisted modified polydopamine metallized carbon fiber material and its preparation method to solve the problems existing in the prior art. Summary of the Invention

[0008] The purpose of this invention is to solve the problems existing in the prior art and to provide a laser-synergistic modified polydopamine metallized carbon fiber material and its preparation method.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A method for preparing laser-assisted modified polydopamine metallized carbon fiber material includes the following steps:

[0011] (1) Laser texturing treatment of the carbon fiber matrix surface;

[0012] (2) The carbon fiber matrix after surface laser texturing treatment is immersed in a solution containing dopamine hydrochloride to allow dopamine to undergo an auto-oxidative polymerization reaction on the surface of the carbon fiber matrix, thereby obtaining a carbon fiber matrix with polydopamine coating.

[0013] (3) The carbon fiber matrix with polydopamine coating was treated in a mixed atmosphere of Cl2 and N2, then transferred to NaOH solution for alkaline washing, and then acid washed with HCl solution to obtain carbon fiber matrix loaded with modified polydopamine coating.

[0014] (4) The carbon fiber matrix loaded with modified polydopamine coating is immersed in a metal salt solution to reduce the metal ions to metal atoms. Metal nanoparticles can be generated without the addition of an external reducing agent, thus obtaining metallized carbon fiber material.

[0015] As a preferred technical solution:

[0016] The method for preparing laser-modified polydopamine metallized carbon fiber material as described above, in step (1), the carbon fiber matrix is ​​in the form of fiber, woven fabric, felt or nonwoven fabric. Before laser texturing treatment of the carbon fiber matrix surface, it is first cleaned and dried to remove the slurry and impurities on its surface.

[0017] The preparation method of laser-synergistic modified polydopamine metallized carbon fiber material as described above, step (1) laser texturing treatment refers to scanning and irradiating the surface of the carbon fiber matrix under the protection of inert gas using a pulsed laser (preferably a picosecond or femtosecond laser) through a computer-controlled galvanometer scanning system according to a preset pattern (such as a straight line, grid or spiral). The laser power is 2~15W, the scanning speed is 100~1000mm / min, and the laser wavelength is 355~532nm.

[0018] In the laser-assisted modification of polydopamine metallized carbon fiber material preparation method described above, step (2) of the solution containing dopamine hydrochloride also contains a buffer, such as Tris-HCl, to adjust the pH value to 8.0~9.0.

[0019] In the laser-assisted modified polydopamine metallized carbon fiber material preparation method described above, the temperature of the self-oxidation polymerization reaction in step (2) is 20~60℃ and the time is 6~24h.

[0020] In the laser-assisted modification method for preparing polydopamine-metallized carbon fiber materials as described above, in step (3), the volume ratio of Cl2 to N2 in the Cl2 and N2 mixed atmosphere is 1:8 to 1:12, and the treatment is carried out at room temperature in the Cl2 and N2 mixed atmosphere for 2 to 5 minutes. The volume ratio of Cl2 to N2 in the mixed atmosphere is used to control the chemical state of the polydopamine surface. Its purpose is to ensure the modification effect while avoiding excessive corrosion or structural damage to the polydopamine layer and carbon fiber matrix.

[0021] In the laser-assisted modified polydopamine metallized carbon fiber material preparation method described above, in step (3), the concentration of NaOH solution is 0.05~0.15mol / L, the concentration of HCl solution is 0.05~0.15mol / L, the alkaline washing time is 8~12min, and the acid washing time is 3~5min.

[0022] The method for preparing laser-assisted modified polydopamine metallized carbon fiber material as described above, in step (4), the metal salt is silver nitrate, the concentration of the metal salt solution is 0.01~0.2mol / L, the soaking temperature is 20~40℃, and the soaking time is 20~60min.

[0023] The preparation method of laser-synergistic modified polydopamine metallized carbon fiber material as described above, after soaking in step (4), the product after reaction is taken out, rinsed repeatedly with deionized water, and then dried to obtain metallized carbon fiber material; the drying temperature is 50~80℃, and the drying time is 0.5~2h.

[0024] The present invention also provides a metallized carbon fiber material prepared by the method as described in any of the preceding claims, comprising a carbon fiber matrix, a modified polydopamine functionalized intermediate layer located on the surface of the carbon fiber matrix, and a metallic phase distributed in and on the surface of the modified polydopamine functionalized intermediate layer.

[0025] This invention constructs a composite interface structure of "laser-induced micro / nano structure – modified polydopamine functionalized layer – in-situ reduced metal nanoparticles":

[0026] The surface of the carbon fiber matrix has a multi-scale micro / nano structure formed by laser induction.

[0027] The modified polydopamine functionalized intermediate layer is bonded to the multi-scale micro / nano structure through multiple non-covalent interactions;

[0028] The metallic phase is embedded in the modified polydopamine functionalized intermediate layer in the form of metal nanoparticles and their interconnected networks.

[0029] Invention principle:

[0030] This invention constructs a unique metal-carbon fiber composite interface through a strategy combining laser irradiation and modified polydopamine functionalization. Specifically: First, laser light is used to induce the formation of micro-nano textures on the carbon fiber surface, generating micron-scale pits / grooves and superimposing nano-scale roughness features. This significantly increases the specific surface area while inducing surface sp... 2 / sp 3 The structure is rearranged and defect sites are introduced. Based on this, the modified polydopamine used has a higher density of active sites such as phenolic hydroxyl groups on its molecular chain compared to ordinary polydopamine, which can participate in coordination and reduction reactions more efficiently.

[0031] Laser-textured carbon fiber surfaces and modified polydopamine synergistically form a robust dual interface through physical interlocking (mechanical interlocking achieved by micro-nano texture) and chemical bonding (such as multiple non-covalent interactions). This interface not only enhances the bonding with the carbon fiber matrix but also provides a high density of adsorption and reduction sites for metal ions. Subsequently, metal ions are reduced in situ within the modified polydopamine layer, generating semi-embedded metal nanoparticles and their three-dimensional interconnected network, creating a transitional region with a continuous and gradual change in composition and structure between the metal phase and the organic functional layer.

[0032] This unique structure, built step by step from "laser texturing - functional modification - in-situ metallization", fundamentally avoids the problem of easy peeling caused by abrupt interface changes between traditional metal coatings and carbon fibers, thereby achieving synergistic improvement in conductivity, interfacial bonding and environmental stability.

[0033] Beneficial effects:

[0034] (1) A method for preparing laser-synergistic modified polydopamine metallized carbon fiber material of the present invention uses femtosecond or picosecond laser to prepare micro-nano structures on the surface of carbon fiber matrix material, thereby significantly improving its specific surface area and attaching active groups; PDA is phototreated in chlorine atmosphere, followed by alkaline washing and acidification, thereby promoting the chemical modification of PDA.

[0035] (2) The present invention provides a method for preparing laser-synergistic modified polydopamine metallized carbon fiber materials, which develops a new process for fiber surface metallization that synergistically anchors and chemically bridges the fiber surface, and constructs a composite interface of "laser-induced micro-nano structure-modified polydopamine functionalized layer-in-situ reduced metal nanoparticles", which greatly improves the interfacial bonding force of the material.

[0036] (3) The laser-coordinated modified polydopamine metallized carbon fiber material of the present invention has significantly improved conductivity, bonding strength and electromagnetic shielding resistance; its surface sheet resistance can be as low as 0.01Ω / □, which can meet the needs of most high-performance electromagnetic shielding, Joule heating and signal transmission applications.

[0037] (4) The laser-modified polydopamine metallized carbon fiber material of the present invention forms a dense metal layer on the surface of carbon fiber through the synergistic effect of "laser texturing + modified PDA functionalization", which significantly improves environmental durability and extends service life. The adhesion force between the metallized carbon fiber and the atomic force microscope probe was measured by AFM technology, and the bonding force can reach 327.89 nN, which is 4.16 times that of "untreated by laser texturing + conventional PDA". Attached Figure Description

[0038] Figure 1 and Figure 2 These are SEM images of the carbon fibers processed by femtosecond laser in Example 1 at different scales.

[0039] Figure 3 This is a TEM image of the metallized carbon fiber material from Example 1. Detailed Implementation

[0040] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0041] The test methods involved in the performance indicators in the embodiments and comparative examples of this invention are as follows:

[0042] Surface sheet resistance: tested using the four-probe method.

[0043] Shielding effectiveness: Tested using the coaxial method.

[0044] Interfacial adhesion: The adhesion force between the metal-coated carbon fiber and the atomic force microscope probe was measured using AFM technology.

[0045] Environmental durability: Refer to IEC 60068-2-14, temperature cycling -10℃~85℃, exposure time 30min, 5 cycles, and aging at 85℃ / 85% RH for 168h.

[0046] Example 1

[0047] A method for preparing laser-assisted modified polydopamine metallized carbon fiber material includes the following steps:

[0048] (1) The carbon fiber matrix (Toray T800) in the form of fibers was cleaned and dried by Soxhlet extraction.

[0049] (2) Laser texturing treatment is performed on the surface of the carbon fiber matrix after step (1):

[0050] Under inert gas protection, a femtosecond laser was used to scan and irradiate the surface of the carbon fiber matrix according to a preset straight line pattern through a computer-controlled galvanometer scanning system. The laser power was 8W, the scanning speed was 800mm / min, and the laser wavelength was 355nm.

[0051] like Figure 1 , Figure 2 As shown, after being treated with femtosecond laser, a micro-nano structure is formed on the surface of the carbon fiber, which significantly increases the specific surface area of ​​the fiber.

[0052] (3) The carbon fiber matrix after surface laser texturing treatment was immersed in a deionized aqueous solution of dopamine hydrochloride with a concentration of 8 mg / ml, and then the pH was adjusted to 8.5 with Tris-HCl. The dopamine was allowed to undergo an auto-oxidative polymerization reaction on the surface of the carbon fiber matrix at 35°C for 12 h to obtain a carbon fiber matrix with polydopamine coating.

[0053] (4) At room temperature, the carbon fiber matrix with polydopamine coating was treated in a mixed atmosphere of Cl2 and N2 with a volume ratio of 1:10 for 3 min, then transferred to a NaOH solution with a concentration of 0.1 mol / L for alkaline washing for 10 min, and then acid washed with a HCl solution with a concentration of 0.1 mol / L for 4 min to obtain the carbon fiber matrix loaded with modified polydopamine coating.

[0054] (5) At 30°C, the carbon fiber matrix loaded with modified polydopamine coating was immersed in an ethanol / water (volume ratio 1:1) solution of silver nitrate with a concentration of 0.1 mol / L for 40 min to reduce silver ions to silver atoms. After immersion, the product after reaction was taken out and rinsed repeatedly with deionized water 10 times. Then it was dried at 60°C for 1 h to obtain metallized carbon fiber material.

[0055] like Figure 3 As shown, the final metallized carbon fiber material consists of a carbon fiber matrix, a modified polydopamine functionalized interlayer located on the surface of the carbon fiber matrix, and a metallic phase distributed in and on the surface of the modified polydopamine functionalized interlayer. The surface of the carbon fiber matrix has a multi-scale micro / nano structure formed by laser induction. The modified polydopamine functionalized interlayer and the multi-scale micro / nano structure are bonded through multiple non-covalent interactions. The metallic phase is embedded in the modified polydopamine functionalized interlayer in the form of silver nanoparticles and their interconnected networks. The sheet resistance of the metallized carbon fiber material is 0.01 Ω / □; the shielding effectiveness is 65 dB; the interfacial bonding force is 327.89 nN; and the conductivity decays by 7% after cycling 5 times at -10℃ to 85℃ and aging at 85℃ / 85%RH for 168 h.

[0056] Comparative Example 1

[0057] A method for preparing laser-assisted modified polydopamine metallized carbon fiber material is basically the same as in Example 1, except that step (2) is omitted.

[0058] The final metallized carbon fiber material has a surface sheet resistance of 0.12Ω / □, a shielding effectiveness of 55dB, an interfacial bonding strength of 107.36nN, and a conductivity attenuation of 28% after 5 cycles at -10℃ to 85℃ and aging at 85℃ / 85%RH for 168h.

[0059] Comparing Comparative Example 1 and Example 1, it can be found that the metallized carbon fiber material prepared in Example 1 is significantly better than that in Comparative Example 1 in terms of conductivity, shielding effectiveness, interfacial bonding strength, and environmental durability. This is because the carbon fiber matrix in Comparative Example 1 has not undergone laser-induced micro-nano texturing treatment, and its surface specific surface area and the number of surface active sites are limited. In addition, it lacks micro-nano scale physical interlocking structures, resulting in a smaller interfacial bonding area and lower bonding strength between the polydopamine functionalized intermediate layer and the carbon fiber matrix. The carbon fiber surface in Comparative Example 1 lacks multi-scale micro-nano structures to provide mechanical interlocking. Although it has modified PDA, the metal layer is still easy to peel off in humid and hot environments, thus resulting in poor environmental durability.

[0060] Comparative Example 2

[0061] A method for preparing laser-assisted modified polydopamine metallized carbon fiber material is basically the same as in Example 1, except that step (4) is omitted.

[0062] The final metallized carbon fiber material has a surface sheet resistance of 0.4Ω / □, a shielding effectiveness of 47dB, an interfacial bonding strength of 184.21nN, and a conductivity decay of 22% after 5 cycles at -10℃ to 85℃ and aging at 85℃ / 85%RH for 168h.

[0063] Comparing Comparative Example 2 with Example 1, it can be found that the metallized carbon fiber material prepared in Example 1 is significantly better than Comparative Example 2 in terms of conductivity, shielding effectiveness, interfacial bonding strength, and environmental durability. This is because although Comparative Example 2 has formed a micro-nano textured structure through laser treatment, the chemical state of the polydopamine layer has not been controlled. The density of active sites on its surface that can participate in the adsorption and reduction of metal ions is relatively low, resulting in insufficient adsorption and reduction of metal ions in the PDA layer, thereby reducing the metal loading. Although Comparative Example 2 has a micro-nano structure to provide mechanical locking, the density of chemical bonding sites is low, and the adhesion stability of metal particles is insufficient, resulting in poor environmental durability.

[0064] Comparative Example 3

[0065] A method for preparing laser-assisted modified polydopamine metallized carbon fiber material is basically the same as in Example 1, except that steps (2) and (4) are omitted.

[0066] The final metallized carbon fiber material has a surface sheet resistance of 0.5Ω / □, a shielding effectiveness of 45dB, an interfacial bonding strength of 78.72nN, and a conductivity attenuation of 35% after 5 cycles at -10℃ to 85℃ and aging at 85℃ / 85%RH for 168h.

[0067] Comparing Comparative Example 3 with Example 1, it can be found that the metallized carbon fiber material prepared in Example 1 is significantly better than Comparative Example 3 in terms of conductivity, shielding effectiveness, interfacial bonding strength, and environmental durability. This is because Comparative Example 3 did not perform laser-induced micro-nano texturing treatment on the carbon fiber matrix, nor did it perform chemical state regulation on the polydopamine layer. Its carbon fiber surface lacks multi-scale micro-nano structures and high-density surface active sites, and the density of active sites for metal ion adsorption and reduction in the PDA layer is relatively low. Under these circumstances, the metal phase and the carbon fiber matrix mainly rely on weak interfacial interactions, and the metal layer is prone to detachment or failure under thermal cycling and humid heat aging, resulting in a significant decrease in the overall performance of the material.

[0068] Example 2

[0069] A method for preparing laser-assisted modified polydopamine metallized carbon fiber material includes the following steps:

[0070] (1) The carbon fiber matrix (Toray T700 woven fabric) in the form of woven fabric was cleaned and dried by Soxhlet extraction.

[0071] (2) Laser texturing treatment is performed on the surface of the carbon fiber matrix after step (1):

[0072] Under inert gas protection, a femtosecond laser was used to scan and irradiate the surface of a carbon fiber matrix according to a preset grid pattern through a computer-controlled galvanometer scanning system. The laser power was 2W, the scanning speed was 100mm / min, and the laser wavelength was 355nm.

[0073] (3) The carbon fiber matrix after surface laser texturing treatment was immersed in a deionized aqueous solution of dopamine hydrochloride with a concentration of 2 mg / ml, and then the pH was adjusted to 8.0 with Tris-HCl. The dopamine was allowed to undergo an auto-oxidative polymerization reaction on the surface of the carbon fiber matrix at 20°C for 24 h to obtain the carbon fiber matrix with PDA coating.

[0074] (4) The carbon fiber matrix with PDA coating was treated in a mixed atmosphere of Cl2 and N2 with a volume ratio of 1:12 for 5 min at room temperature, then transferred to a NaOH solution with a concentration of 0.05 mol / L for alkaline washing for 12 min, and then acid washed with a HCl solution with a concentration of 0.05 mol / L for 5 min to obtain the carbon fiber matrix loaded with modified PDA coating.

[0075] (5) At 20°C, the carbon fiber matrix loaded with modified PDA coating was immersed in an ethanol / water (volume ratio 1:1) solution of silver nitrate with a concentration of 0.01mol / L for 60min to reduce silver ions to silver atoms. After immersion, the product after reaction was taken out, rinsed repeatedly with deionized water 10 times, and then dried at 50°C for 2h to obtain metallized carbon fiber material.

[0076] The final metallized carbon fiber material consists of a carbon fiber matrix, a modified polydopamine functionalized interlayer located on the surface of the carbon fiber matrix, and a metallic phase distributed in and on the surface of the modified polydopamine functionalized interlayer. The surface of the carbon fiber matrix has a multi-scale micro / nano structure formed by laser induction. The modified polydopamine functionalized interlayer and the multi-scale micro / nano structure are bonded through multiple non-covalent interactions. The metallic phase is embedded in the modified polydopamine functionalized interlayer in the form of silver nanoparticles and their interconnected networks. The surface sheet resistance of the metallized carbon fiber material is 0.08 Ω / □; the shielding effectiveness is 62 dB; the interfacial bonding force is 312.17 nN; and the conductivity decays by 8% after 5 cycles at -10℃ to 85℃ and aging at 85℃ / 85%RH for 168 h.

[0077] Example 3

[0078] A method for preparing laser-assisted modified polydopamine metallized carbon fiber material includes the following steps:

[0079] (1) The carbon fiber matrix (Hengshen HF40) in the form of nonwoven felt was cleaned and dried by Soxhlet extraction.

[0080] (2) Laser texturing treatment is performed on the surface of the carbon fiber matrix after step (1):

[0081] Under inert gas protection, a picosecond laser was used to scan and irradiate the surface of a carbon fiber matrix according to a preset spiral pattern through a computer-controlled galvanometer scanning system. The laser power was 15W, the scanning speed was 1000mm / min, and the laser wavelength was 532nm.

[0082] (3) The carbon fiber matrix after surface laser texturing treatment was immersed in a deionized aqueous solution of dopamine hydrochloride with a concentration of 10 mg / ml, and then the pH was adjusted to 9.0 with Tris-HCl. The dopamine was allowed to undergo an auto-oxidative polymerization reaction on the surface of the carbon fiber matrix at 60°C for 6 h to obtain the carbon fiber matrix with PDA coating.

[0083] (4) The carbon fiber matrix with PDA coating was treated in a mixed atmosphere of Cl2 and N2 with a volume ratio of 1:8 for 2 min at room temperature, then transferred to a NaOH solution with a concentration of 0.15 mol / L for 8 min of alkaline washing, and then acid washed with a HCl solution with a concentration of 0.15 mol / L for 3 min to obtain the carbon fiber matrix loaded with modified PDA coating.

[0084] (5) At 40°C, the carbon fiber matrix loaded with modified PDA coating was immersed in an ethanol / water (volume ratio 1:1) solution of silver nitrate with a concentration of 0.2 mol / L for 20 min to reduce silver ions to silver atoms. After immersion, the product after reaction was taken out and rinsed repeatedly with deionized water 10 times. Then it was dried at 80°C for 0.5 h to obtain metallized carbon fiber material.

[0085] The final metallized carbon fiber material consists of a carbon fiber matrix, a modified polydopamine functionalized interlayer located on the surface of the carbon fiber matrix, and a metallic phase distributed in and on the surface of the modified polydopamine functionalized interlayer. The surface of the carbon fiber matrix has a multi-scale micro / nano structure formed by laser induction. The modified polydopamine functionalized interlayer and the multi-scale micro / nano structure are bonded through multiple non-covalent interactions. The metallic phase is embedded in the modified polydopamine functionalized interlayer in the form of silver nanoparticles and their interconnected networks. The sheet resistance of the metallized carbon fiber material is 0.07 Ω / □; the shielding effectiveness is 64 dB; the interfacial bonding force is 292.19 nN; and the conductivity decays by 9% after cycling 5 times at -10℃ to 85℃ and aging at 85℃ / 85%RH for 168 h.

[0086] Example 4

[0087] A method for preparing laser-assisted modified polydopamine metallized carbon fiber material includes the following steps:

[0088] (1) The carbon fiber matrix (Zhongfu Shenying SYT55S) in the form of fibers was cleaned and dried by Soxhlet extraction.

[0089] (2) Laser texturing treatment is performed on the surface of the carbon fiber matrix after step (1):

[0090] Under inert gas protection, a picosecond laser was used to scan and irradiate the surface of the carbon fiber matrix according to a preset spiral pattern through a computer-controlled galvanometer scanning system. The laser power was 5W, the scanning speed was 700mm / min, and the laser wavelength was 355nm.

[0091] (3) The carbon fiber matrix after surface laser texturing treatment was immersed in a deionized aqueous solution of dopamine hydrochloride with a concentration of 6 mg / ml, and then the pH was adjusted to 8.3 with Tris-HCl. The dopamine was allowed to undergo an auto-oxidative polymerization reaction on the surface of the carbon fiber matrix at 30°C for 12 h to obtain a carbon fiber matrix with polydopamine coating.

[0092] (4) At room temperature, the carbon fiber matrix with polydopamine coating was treated in a mixed atmosphere of Cl2 and N2 with a volume ratio of 1:10 for 4 min, then transferred to a NaOH solution with a concentration of 0.05 mol / L for alkaline washing for 12 min, and then acid washed with a HCl solution with a concentration of 0.1 mol / L for 3 min to obtain the carbon fiber matrix loaded with modified polydopamine coating.

[0093] (5) At 20°C, the carbon fiber matrix loaded with modified polydopamine coating was immersed in an ethanol / water (volume ratio 1:1) solution of silver nitrate with a concentration of 0.01mol / L for 30min to reduce silver ions to silver atoms. After immersion, the product after reaction was taken out, rinsed repeatedly with deionized water 10 times, and then dried at 50°C for 2h to obtain metallized carbon fiber material.

[0094] The final metallized carbon fiber material consists of a carbon fiber matrix, a modified polydopamine functionalized interlayer located on the surface of the carbon fiber matrix, and a metallic phase distributed in and on the surface of the modified polydopamine functionalized interlayer. The surface of the carbon fiber matrix has a multi-scale micro / nano structure formed by laser induction. The modified polydopamine functionalized interlayer and the multi-scale micro / nano structure are bonded through multiple non-covalent interactions. The metallic phase is embedded in the modified polydopamine functionalized interlayer in the form of silver nanoparticles and their interconnected networks. The sheet resistance of the metallized carbon fiber material is 0.1 Ω / □; the shielding effectiveness is 60 dB; the interfacial bonding force is 289.45 nN; and the conductivity decays by 9% after cycling 5 times at -10℃ to 85℃ and aging at 85℃ / 85%RH for 168 h.

Claims

1. A method for preparing laser-assisted modified polydopamine metallized carbon fiber material, characterized in that... Includes the following steps: (1) Laser texturing treatment of the carbon fiber matrix surface; (2) The carbon fiber matrix after surface laser texturing treatment is immersed in a solution containing dopamine hydrochloride to allow dopamine to undergo an auto-oxidative polymerization reaction on the surface of the carbon fiber matrix, thereby obtaining a carbon fiber matrix with polydopamine coating. (3) The carbon fiber matrix with polydopamine coating was treated at room temperature in a mixed atmosphere of Cl2 and N2, then transferred to NaOH solution for alkaline washing, and then acid washed with HCl solution to obtain carbon fiber matrix loaded with modified polydopamine coating. (4) The carbon fiber matrix loaded with modified polydopamine coating is immersed in a metal salt solution to reduce the metal ions to metal atoms and obtain metallized carbon fiber material.

2. The method for preparing laser-synergistically modified polydopamine metallized carbon fiber material according to claim 1, characterized in that, In step (1), the carbon fiber matrix is ​​in the form of fiber, woven fabric, felt or nonwoven fabric. Before laser texturing treatment of the carbon fiber matrix surface, it is first cleaned and dried.

3. The method for preparing laser-synergistically modified polydopamine metallized carbon fiber material according to claim 1, characterized in that, Step (1) Laser texturing treatment refers to scanning and irradiating the surface of a carbon fiber matrix under the protection of an inert gas using a pulsed laser and a computer-controlled galvanometer scanning system according to a preset pattern. The laser power is 2~15W, the scanning speed is 100~1000mm / min, and the laser wavelength is 355~532nm.

4. The method for preparing laser-synergistically modified polydopamine metallized carbon fiber material according to claim 1, characterized in that, Step (2) The solution containing dopamine hydrochloride also contains a buffer.

5. The method for preparing laser-synergistically modified polydopamine metallized carbon fiber material according to claim 1, characterized in that, In step (2), the temperature of the auto-oxidative polymerization reaction is 20~60℃ and the time is 6~24h.

6. The method for preparing laser-synergistically modified polydopamine metallized carbon fiber material according to claim 1, characterized in that, In step (3), the volume ratio of Cl2 to N2 in the Cl2 and N2 mixed atmosphere is 1:8 to 1:12, and the treatment time in the Cl2 and N2 mixed atmosphere is 2 to 5 minutes.

7. The method for preparing laser-synergistically modified polydopamine metallized carbon fiber material according to claim 1, characterized in that, In step (3), the concentration of NaOH solution is 0.05~0.15mol / L, the concentration of HCl solution is 0.05~0.15mol / L, the alkaline washing time is 8~12min, and the acid washing time is 3~5min.

8. The method for preparing laser-synergistically modified polydopamine metallized carbon fiber material according to claim 1, characterized in that, In step (4), the metal salt is silver nitrate, and the concentration of the metal salt solution is 0.01~0.2 mol / L; the soaking temperature is 20~40℃, and the soaking time is 20~60 min.

9. The method for preparing laser-synergistically modified polydopamine metallized carbon fiber material according to claim 1, characterized in that, After soaking in step (4), the product after the reaction is removed, rinsed repeatedly with deionized water, and then dried to obtain metallized carbon fiber material; the drying temperature is 50~80℃ and the drying time is 0.5~2h.

10. The metallized carbon fiber material prepared by the method according to any one of claims 1 to 9, characterized in that: It includes a carbon fiber matrix, a modified polydopamine functionalized intermediate layer located on the surface of the carbon fiber matrix, and a metallic phase distributed in and on the surface of the modified polydopamine functionalized intermediate layer. The surface of the carbon fiber matrix has a multi-scale micro / nano structure formed by laser induction. The modified polydopamine functionalized intermediate layer is bonded to the multi-scale micro / nano structure through multiple non-covalent interactions; The metallic phase is embedded in the modified polydopamine functionalized intermediate layer in the form of metal nanoparticles and their interconnected networks.

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