A special-shaped dual-phase polydopamine synergistically modified carbon fiber reinforced epoxy resin composite material and a preparation method thereof

Abstract

The application discloses a special-shaped two-phase polydopamine synergistically modified carbon fiber reinforced epoxy resin composite material and a preparation method thereof. The method induces dopamine to self-assemble in situ on the surface of the fiber through a drawing load, promotes the coating to spontaneously break to form a polydopamine lamellar structure, and significantly improves the interfacial bonding strength. Meanwhile, a special-shaped two-phase synergistic system of the fiber surface lamellar and the resin matrix microspheres is constructed, mechanical interlocking, crack deflection and the physical confinement effect of the nano microspheres are utilized, and the synchronous jump of the interfacial strength and toughness of the composite material is realized. In addition, the process removes the cumbersome oxidant treatment, is simple and environment-friendly, can be adapted to the existing production line, effectively solves the bottleneck that the traditional modification technology is complex and difficult to be scaled down, and provides a feasible path for the green manufacturing of high-performance composite materials.

Description

Technical Field

[0001] This invention belongs to the field of surface and interface modification technology of materials, and relates to a heterogeneous biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material and its preparation method. Background Technology

[0002] Carbon fiber reinforced resin matrix composites, with their superior high specific strength, excellent designability, outstanding fatigue resistance, and corrosion resistance, have become key materials in high-end equipment manufacturing fields such as aerospace and wind power generation, playing an irreplaceable role in promoting cost reduction and efficiency improvement, energy conservation and emission reduction, and achieving dual-carbon goals. However, despite their broad application prospects, the reliability of these composites during long-term service still faces severe challenges. The most prominent bottleneck lies in the chemical inertness of the carbon fiber surface, resulting in weak interfacial bonding between the carbon fiber and the resin matrix, which easily induces interfacial delamination failure. At the same time, existing material systems often fall into the dilemma of strength and toughness inversion, making it difficult to achieve simultaneous improvement of interfacial strength and toughness.

[0003] To address this interfacial challenge, researchers have conducted extensive research. Polydopamine (PDA), due to its extremely high reactivity, universal adhesion to various solid surfaces, and its simple preparation, good biocompatibility, and biodegradability, is considered a highly promising material for carbon fiber surface modification. However, current research shows that PDA-based modification techniques still have significant limitations: current modification strategies mainly rely on the self-polymerization of dopamine monomers, which often only forms a coating structure of randomly stacked nanoparticles on the carbon fiber surface, failing to construct PDA sheets with specific orientations or structures, thus failing to meet the interfacial design requirements of high-performance composite materials. Furthermore, as a unique nanostructural unit, the application of PDA nanospheres in the interfacial regulation and performance optimization of composite materials is still unexplored, and their potential for synergistic reinforcement and toughening remains untapped. More importantly, existing carbon fiber surface modification technologies generally suffer from cumbersome processes, involve large amounts of chemical reagents leading to poor environmental performance, and are difficult to integrate with industrial production lines, severely restricting the large-scale application of high-performance composite materials. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a heterogeneous biphase polydopamine synergistic modification carbon fiber reinforced epoxy resin composite material and its preparation method, thereby solving the problem that existing modification technologies are unable to overcome the inversion of interfacial strength and toughness caused by the surface inertness of carbon fibers. Furthermore, existing polydopamine modification methods have simple structures, complex processes, and are not environmentally friendly, failing to meet the technical problems of large-scale preparation of high-performance composite materials.

[0005] This invention is achieved through the following technical solution: A method for preparing a heterogeneous biphase polydopamine-modified carbon fiber reinforced epoxy resin composite material includes the following steps: S1: After impregnating the carbon fiber precursor in an acetone solution and refluxing it, it is washed with deionized water and dried to obtain deionized carbon fiber. S2: Apply tensile loads to both ends of the de-adhesive carbon fiber, immerse the de-adhesive carbon fiber in dopamine impregnation solution, and dry it after the impregnation reaction to obtain polydopamine nanosheet modified carbon fiber. S3: The polydopamine nanosheet modified carbon fiber is added to an epoxy resin containing polydopamine nanospheres to react and obtain a shaped biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material.

[0006] Preferably, the carbon fiber precursor is a single carbon fiber filament or a carbon fiber bundle.

[0007] Preferably, the condensation reflux temperature is 80~100℃ and the time is 12~96h; when cleaning and drying with deionized water, the drying temperature is 60~80℃ and the time is 2~4h.

[0008] Preferably, when the carbon fiber precursor is a single carbon fiber filament, the applied tensile load is 0.019~0.030 N; when the carbon fiber precursor is a carbon fiber bundle, the carbon fiber bundle contains 1000~48000 single carbon fiber filaments, and the applied load is the product of the number of single filaments and the ultimate tensile load of a single filament.

[0009] Preferably, the dopamine impregnation solution is prepared by adding dopamine hydrochloride to a tris(hydroxymethyl)aminomethane aqueous solution, and then dispersing it evenly by ultrasonication to obtain the dopamine impregnation solution; the pH value of the tris(hydroxymethyl)aminomethane aqueous solution is 7.5~9.0; the mass ratio of dopamine hydrochloride to tris(hydroxymethyl)aminomethane aqueous solution is 1:(100~2000).

[0010] Preferably, the de-adhesive carbon fiber is immersed in dopamine impregnation solution for 10-48 h, and the drying temperature after impregnation reaction is 60-80℃ for 2-4 h.

[0011] Preferably, the volume ratio of the polydopamine nanosheet modified carbon fiber to the epoxy resin containing polydopamine nanospheres is (30~70):(70~30).

[0012] Preferably, the preparation of the epoxy resin containing polydopamine nanospheres specifically involves: S31: Add an aqueous solution of dopamine hydrochloride to a mixed solution containing ammonia, ethanol and deionized water, react in the dark, centrifuge at 6000~10000 rpm, wash with deionized water at least 3 times and freeze dry at -30~-60℃ to obtain polydopamine nanospheres. S32: Add the polydopamine nanospheres to an epoxy resin to obtain the epoxy resin containing the polydopamine nanospheres. In the mixed solution containing ammonia, ethanol and deionized water, the mass ratio of ammonia, ethanol and deionized water is 1:(5-15):(20-50); in the aqueous solution of dopamine hydrochloride, the mass ratio of dopamine hydrochloride to water is 1:(10-30); and the volume ratio of the aqueous solution of dopamine hydrochloride to the mixed solution containing ammonia, ethanol and deionized water is (10-15):1.

[0013] Preferably, the amount of polydopamine nanospheres added is 0.5 wt.% to 10 wt.% of the epoxy resin.

[0014] A heterogeneous biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material was prepared by the above method.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects: This invention discloses a method for preparing a carbon fiber reinforced epoxy resin composite material with heterogeneous biphase polydopamine synergistic modification. This method effectively solves the problem of inverted interfacial strength and toughness caused by the surface inertness of carbon fibers, as well as the bottlenecks of complex processes, simple structures, and difficulty in large-scale application in existing technologies, through a stretching load-induced and heterogeneous biphase polydopamine synergistic strategy. To address the problems of carbon fiber surface inertness and weak interfacial bonding, this method introduces a stretching load, utilizing mechanical action to accelerate the in-situ self-assembly and polymerization of dopamine on the fiber surface. This not only achieves rapid and environmentally friendly surface modification but also promotes spontaneous fracture of the coating to form a polydopamine sheet structure with a mechanical interlocking effect, thereby significantly improving interfacial bonding strength. To address the shortcomings of the inability to simultaneously improve interfacial strength and toughness and the limited structural options of modification methods, this invention constructs a heterogeneous biphase synergistic system of fiber surface sheets and microspheres in the resin matrix. On the one hand, the layered structure dissipates energy through mechanical interlocking and crack deflection mechanisms, significantly improving toughness. On the other hand, the introduced polydopamine nanospheres construct a covalent and hydrogen bond network within the matrix and utilize physical confinement effects to restrict chain segment movement, enhancing the resin's cohesive strength and achieving a simultaneous leap in both strength and toughness. In this heterogeneous biphase polydopamine-modified carbon fiber reinforced epoxy resin composite, the polydopamine sheets are tightly adhered to the carbon fiber surface. The abundant active groups on their surface form strong covalent bonds, hydrogen bonds, and π-π conjugated interactions with the epoxy resin matrix, greatly enhancing the chemical adhesion at the interface. Simultaneously, due to tensile loading, the polydopamine coating on the carbon fiber surface spontaneously fractures to form a sheet-like structure. During curing, the epoxy resin penetrates and fills the gaps between these sheets, forming a robust mechanical interlocking structure. Moreover, the polydopamine nanospheres, uniformly dispersed in the epoxy resin, construct a covalent and hydrogen bond network within the matrix and restrict the movement of resin polymer chains through physical confinement effects, thereby improving the resin's cohesive strength. Therefore, when subjected to external forces or interfacial debonding, the polydopamine sheets on the surface cause crack deflection and branching; simultaneously, the polydopamine nanospheres in the matrix undergo debonding and cavitation, inducing localized plastic deformation of the surrounding epoxy resin, and frictional sliding occurs between adjacent microspheres. These processes collectively construct a highly efficient microscale energy dissipation network, achieving a simultaneous and significant improvement in the interfacial strength and toughness of the composite material. Furthermore, this process is simple, eliminating the cumbersome oxidant treatment, and is compatible with existing carbon fiber production lines, solving the problems of poor environmental performance and difficulty in large-scale implementation of traditional technologies. It provides a practical and feasible technical path for the low-cost, green manufacturing of high-performance composite materials.

[0016] Furthermore, the carbon fiber precursor is either a single carbon fiber filament or a carbon fiber bundle, which expands the applicability of this modification method, making it not only suitable for laboratory-level single fiber research, but also fully compatible with the bundled state of multiple fibers commonly found in industrial production, thus enhancing the universality and industrial application potential of the patented technology.

[0017] Furthermore, the condensation reflux temperature is 80~100℃, and the time is 12~96h; when washing and drying with deionized water, the drying temperature is 60~80℃, and the time is 2~4h. Reasonable condensation reflux parameters ensure thorough removal of sizing agent and impurities from the carbon fiber surface, exposing more active sites; while suitable drying conditions effectively avoid damage to the carbon fiber's bulk strength from high temperatures, while ensuring uniform drying of the fiber surface, providing a high-quality substrate for subsequent dopamine modification, thereby guaranteeing the interfacial properties of the final composite material.

[0018] Furthermore, when the carbon fiber precursor is a single carbon fiber filament, the applied tensile load is 0.019~0.030N; when the carbon fiber precursor is a carbon fiber bundle containing 1000~48000 carbon fiber filaments, the applied load is the product of the number of filaments and the ultimate tensile load of a single filament. Specific stress ranges are provided for single filaments, while a product formula based on the number of filaments is provided for the bundle. This dynamically adjusted mechanical loading method ensures that each carbon fiber, regardless of its size, receives consistent and appropriate mechanical stress during impregnation. This is crucial for inducing the directional growth and spontaneous fracture of the polydopamine coating into a sheet-like structure, and is the core process guarantee for achieving synergistic toughening of irregularly shaped dual-phase fibers.

[0019] Furthermore, the dopamine impregnation solution is prepared as follows: dopamine hydrochloride is added to a tris(hydroxymethyl)aminomethane aqueous solution, and the solution is ultrasonically dispersed until uniformly dispersed to obtain the dopamine impregnation solution; the pH value of the tris(hydroxymethyl)aminomethane aqueous solution is 7.5~9.0; the mass ratio of dopamine hydrochloride to tris(hydroxymethyl)aminomethane aqueous solution is 1:(100~2000). By limiting the preparation process and key physicochemical parameters of the dopamine impregnation solution, a stable and efficient reaction basis is provided for carbon fiber surface modification. Precisely controlling the pH value of the tris(hydroxymethyl)aminomethane aqueous solution within the weakly alkaline range of 7.5~9.0 creates optimal conditions for the oxidative self-polymerization of dopamine hydrochloride, effectively promoting uniform monomer deposition; simultaneously, the combination of ultrasonic dispersion and a suitable mass ratio of 1:(100~2000) not only ensures the homogeneity of the reaction system but also avoids particle agglomeration or solution turbidity caused by excessively high monomer concentrations. This precise proportioning ensures that dopamine can form a dense and uniform coating on the fiber surface, thus laying a solid foundation for the subsequent spontaneous fracture under tensile load to form a high-quality polydopamine sheet structure.

[0020] Furthermore, the volume ratio of the polydopamine nanosheet-modified carbon fiber to the epoxy resin containing polydopamine nanospheres is (30~70):(70~30). This ratio allows the composite material to achieve fiber reinforcement, matrix toughening, and interfacial strength and toughness within a wide process window. When the fiber volume ratio is low (30:70), sufficient epoxy resin containing polydopamine nanospheres can completely coat the polydopamine nanosheets on the carbon fiber surface. The microspheres fully fill the fiber gaps, effectively eliminating interfacial defects such as dry fibers and poor wetting. Relying on the crack deflection and pull-out mechanism of PDA microspheres in the resin phase, the fracture toughness and impact resistance of the material are greatly improved, making it suitable for thin-walled, complex curved surface hand lay-up, and cast-molded components. When the fiber volume ratio is high (70:30), the high-content modified carbon fiber provides excellent tensile, flexural, and modulus load-bearing capacity, and the PDA on the fiber surface... Nanosheets form a dense covalently interlocked interface with a small amount of matrix resin, ensuring that the interfacial bonding strength does not decrease under high fiber filling, thus meeting the high strength and high stiffness requirements of load-bearing structural components. The middle section (50~60):(50~40) is the optimal balanced ratio, which can simultaneously exert the load transfer effect of carbon fiber, the interfacial anchoring effect of PDA nanosheets on the fiber surface, and the interlayer toughening effect of PDA microspheres in resin, significantly improving the interfacial bonding strength and fracture toughness of composite materials. At the same time, it is compatible with various molding processes such as vacuum infusion, resin transfer molding, and prepreg autoclave, avoiding the problems of resin flow obstruction caused by excessive fiber density, microsphere agglomeration, or overall mechanical property degradation caused by excess resin.

[0021] Furthermore, the preparation of the epoxy resin containing polydopamine nanospheres specifically involves: S31: Adding an aqueous solution of dopamine hydrochloride to a mixed solution containing ammonia, ethanol, and deionized water, reacting in the dark, centrifuging at 6000-10000 rpm, washing with deionized water at least three times, and freeze-drying at -30 to -60°C to obtain polydopamine nanospheres; S32: Adding the polydopamine nanospheres to epoxy resin to obtain the epoxy resin containing polydopamine nanospheres. This provides a green and simple process for preparing polydopamine nanospheres and their composite with epoxy resin. By controlling the morphology and particle size distribution of the microspheres through a light-shielded reaction, and then directly dispersing them into the resin, complex post-processing is avoided. This method is not only environmentally friendly but also successfully introduces the nanospheres as an independent toughening phase into the resin matrix. Combined with the lamellar structure on the fiber surface, it effectively achieves a heterogeneous dual-phase synergistic strategy, significantly improving the fracture toughness of the composite material.

[0022] Furthermore, in the mixed solution containing ammonia, ethanol, and deionized water, the mass ratio of ammonia, ethanol, and deionized water is 1:(5-15):(20-50); in the aqueous solution of dopamine hydrochloride, the mass ratio of dopamine hydrochloride to water is 1:(10-30); and the volume ratio of the aqueous solution of dopamine hydrochloride to the mixed solution containing ammonia, ethanol, and deionized water is (10-15):1. The specific ratio of ammonia as a catalyst, ethanol as a dispersion medium, and deionized water as a reaction medium can effectively regulate the polymerization kinetics of dopamine monomers and prevent the random macroscopic aggregation of microspheres. The specific volume ratio ensures the suitability of monomer concentration in the reaction system, which is beneficial for generating nanospheres with uniform size, good sphericity, and good dispersibility, thereby improving their compatibility and toughening effect in epoxy resin.

[0023] Furthermore, the amount of polydopamine nanospheres added is 0.5 wt.% to 10 wt.% of the epoxy resin. An appropriate amount of nanospheres can form an effective physical confinement effect and hydrogen bond network in the matrix, initiating energy dissipation mechanisms such as microsphere debonding, cavitation, and matrix plastic yielding, significantly improving toughness. If the addition amount is too low, a sufficient energy dissipation network cannot be constructed; if it is too high, it may cause microsphere agglomeration, becoming new stress concentration points, thus reducing material properties. This limitation ensures the optimization of the comprehensive mechanical properties of the composite material. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 The image shows the surface morphology of the polydopamine nanosheet-modified carbon fiber prepared in Example 1 of this invention. Figure 2 The image shows the surface morphology of the polydopamine nanospheres prepared in Example 1 of this invention. Figure 3 This is a comparison diagram of the interfacial bonding strength of the irregular biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material prepared in Example 1 of the present invention. Figure 4 This is a comparison diagram of the interfacial fracture toughness of the irregular biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material prepared in Example 1 of the present invention. Detailed Implementation

[0026] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0027] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0028] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0029] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0030] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0031] This invention provides a method for preparing a heterogeneous biphase polydopamine-modified carbon fiber reinforced epoxy resin composite material, comprising the following steps: S1: After impregnating the carbon fiber precursor in an acetone solution and refluxing it, it is washed with deionized water and dried to obtain deionized carbon fiber. The carbon fiber precursor is a single carbon fiber filament or a carbon fiber bundle; The condensation reflux temperature is 80~100℃, and the time is 12~96h; When cleaning and drying with deionized water, the drying temperature is 60~80℃ and the time is 2~4 hours.

[0032] S2: Apply tensile loads to both ends of the de-adhesive carbon fiber, immerse the de-adhesive carbon fiber in dopamine impregnation solution, and dry it after the impregnation reaction to obtain polydopamine nanosheet modified carbon fiber. The applied tensile load is the maximum force value that will not cause the fiber to break. Specifically, when the carbon fiber precursor is a single carbon fiber filament, the applied tensile load is 0.019~0.030 N. When the carbon fiber precursor is a carbon fiber bundle, the carbon fiber bundle contains 1,000 to 48,000 carbon fiber monofilaments. At this time, the applied load is the product of the number of monofilaments and the ultimate tensile load of a monofilament.

[0033] The dopamine impregnation solution is prepared by adding dopamine hydrochloride to a tris(hydroxymethyl)aminomethane aqueous solution and dispersing it evenly by ultrasonication to obtain the dopamine impregnation solution. The pH value of the tris(hydroxymethyl)aminomethane aqueous solution is 7.5~9.0; The mass ratio of dopamine hydrochloride to tris(hydroxymethyl)aminomethane aqueous solution is 1:(100~2000), and the mixture is ultrasonically dispersed for 3~5 min.

[0034] The impregnation reaction takes 10 to 48 hours.

[0035] The drying temperature after the impregnation reaction is 60~80℃, and the time is 2~4 h.

[0036] S3: The polydopamine nanosheet modified carbon fiber is reacted with epoxy resin containing polydopamine nanospheres to prepare a shaped biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material.

[0037] The volume ratio of the polydopamine nanosheet modified carbon fiber to the epoxy resin containing polydopamine nanospheres is (30~70):(70~30).

[0038] The preparation of the epoxy resin containing polydopamine nanospheres is specifically as follows: S31: Add an aqueous solution of dopamine hydrochloride to a mixed solution containing ammonia, ethanol and deionized water, react in the dark, centrifuge at 6000~10000 rpm, wash with deionized water at least 3 times and freeze dry at -30~-60℃ to obtain polydopamine nanospheres. S32: The polydopamine nanospheres are added to epoxy resin to obtain the epoxy resin containing polydopamine nanospheres.

[0039] In the mixed solution containing ammonia, ethanol and deionized water, the mass ratio of ammonia, ethanol and deionized water is 1:(5-15):(20-50); in the aqueous solution of dopamine hydrochloride, the mass ratio of dopamine hydrochloride to water is 1:(10-30); and the volume ratio of the aqueous solution of dopamine hydrochloride to the mixed solution containing ammonia, ethanol and deionized water is (10-15):1.

[0040] The amount of polydopamine nanospheres added is 0.5 wt.% to 10 wt.% of the epoxy resin.

[0041] This invention discloses a method for preparing a heterogeneous biphase polydopamine-modified carbon fiber reinforced epoxy resin composite material. This method differs from traditional methods that rely on strong oxidants or auxiliary external fields to accelerate polydopamine polymerization. This method achieves rapid in-situ self-assembly of polydopamine by pre-applying a stretching load. Simultaneously, this method leverages the brittle characteristics of the highly cross-linked structure to enable polydopamine to spontaneously form sheet-like structures during carbon fiber modification, greatly expanding the technical approach for polydopamine nanosheet modification of carbon fibers. Furthermore, this process is perfectly compatible with existing carbon fiber production lines, is not only simple to operate and highly efficient and environmentally friendly, but also very easy to scale up for application.

[0042] In terms of material properties, this invention employs a heterogeneous biphase polydopamine synergistic strategy, successfully breaking through the bottleneck of traditional composite materials where strength and toughness are difficult to balance, and achieving a simultaneous and significant improvement in interfacial bonding strength and fracture toughness. Specifically, the interfacial bonding strength of the composite material is increased by 32.6%~67.5% and 9.6%~21.7% compared to unmodified carbon fiber reinforced unmodified epoxy resin composite material (here, unmodified carbon fiber reinforced unmodified epoxy resin composite material refers to the original unmodified carbon fiber and epoxy resin composite material) and modified carbon fiber reinforced unmodified epoxy resin composite material (here, modified carbon fiber reinforced unmodified epoxy resin composite material refers to the polydopamine-modified carbon fiber and epoxy resin composite material), respectively. Furthermore, the interfacial fracture toughness achieves significant increases of 215.5%~338.8% and 10.4%~51.0%, respectively.

[0043] From the perspective of the mechanism of improved interfacial bonding strength, this is mainly due to the dual reinforcement of physical structure and chemical network. On the one hand, the stretching load effectively increases the deposition and polymerization rate of dopamine, forming a thicker polydopamine coating, thereby enhancing the covalent bonds, hydrogen bonds, and π-π conjugated interactions between it and epoxy resin; the polydopamine sheets formed after fracture also significantly enhance the mechanical interlocking of fibers and resin. On the other hand, the introduced polydopamine nanospheres improve the wettability of resin to fibers, further promoting interfacial bonding. These nanospheres can also construct covalent and hydrogen bond networks in the resin matrix and restrict the movement of polymer chain segments through physical confinement effects, effectively improving the cohesive strength of the resin and the overall interfacial bonding strength.

[0044] The core mechanism for improving interfacial fracture toughness lies in the construction of a multi-scale energy dissipation network. First, the resin can penetrate and fill the gaps between polydopamine sheets, forming a strong mechanical interlock. During fiber pull-out, the resin experiences various forms of resistance, including shear, compression, and friction, significantly enhancing its energy absorption capacity. Second, the discontinuity of the coating structure eliminates the constraint of the rigid interfacial layer, prompting the epoxy resin in the gap regions to undergo micro-plastic yielding and minor deformation to dissipate additional energy. Third, the polydopamine sheets effectively hinder crack propagation, inducing multiple deflections and branching of cracks, thus extending the propagation path. Finally, under stress, the polydopamine nanospheres undergo debonding and cavitation, inducing local shear yielding and plastic deformation in the epoxy matrix. Combined with the frictional sliding between adjacent microspheres, these processes work together to greatly improve the interfacial toughness of the composite material.

[0045] The present invention will be further illustrated 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.

[0046] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0047] Example 1 This embodiment provides a method for preparing a shaped biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material, specifically including the following steps: 1) The carbon fiber was impregnated in an acetone solution at 80℃ and refluxed for 48 h, then cleaned with deionized water and dried at 60℃ for 3 h to obtain the deionized carbon fiber. 2) Apply a limiting tensile load of 0.0294 N to both ends of the carbon fiber monofilament obtained in step 1). This load is the maximum force value that will not cause the fiber to break. 3) Prepare 100 g of tris(hydroxymethyl)aminomethane aqueous solution with pH 8.5, add 0.1 g of dopamine hydrochloride, and disperse by ultrasonication for 3 min to obtain dopamine impregnation solution; 4) The carbon fiber monofilament under stretching in step 2) is immersed in the dopamine impregnation solution obtained in step 3) and reacted for 24 h, and then dried at 60℃ for 3 h to obtain polydopamine nanosheet modified carbon fiber. 5) Mix ammonia, ethanol and deionized water in a mass ratio of 1:11:32 to form a mixture A. Mix dopamine hydrochloride and deionized water in a mass ratio of 1:20 to form a mixture B. Add mixture B to mixture A at a volume ratio of 12:1. React in the dark for 24 h. After centrifugation at 8700 rpm, washing with deionized water three times and freeze-drying at -50 ℃ for 48 h, polydopamine nanospheres are obtained. 6) Add 1.0 wt.% of the polydopamine nanospheres prepared in step 5) to the epoxy resin, and then combine them with the polydopamine nanosheet modified carbon fiber obtained in step 4). The volume ratio of the polydopamine nanosheet modified carbon fiber to the epoxy resin containing polydopamine nanospheres is 60:40, to obtain a shaped biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material.

[0048] The surface morphology of the polydopamine nanosheet-modified carbon fiber prepared in this embodiment is as follows: Figure 1 As shown, the sheet-like structure formed after polydopamine fractures is noteworthy. Figure 1 The observed nanospheres were obtained through physical deposition of polydopamine nanospheres formed by the self-polymerization of dopamine in the impregnation solution, while the polydopamine sheets observed on the carbon fiber surface were caused by heterogeneous nucleation and polymerization of dopamine on the carbon fiber surface during the impregnation process. The polydopamine nanospheres on the fiber surface were not artificially added. The surface morphology of the polydopamine nanospheres prepared in this embodiment is as follows. Figure 2 As shown. The interfacial bond strength of the irregularly shaped biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material prepared in this embodiment was increased by 55.8% and 17.5% compared with the unmodified carbon fiber reinforced epoxy resin composite material and the modified carbon fiber reinforced unmodified epoxy resin composite material, respectively. Figure 3 The interfacial fracture toughness increased by 338.8% and 51.0%, respectively. Figure 4 ); Example 2 This embodiment provides a method for preparing a shaped biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material, specifically including the following steps: 1) The carbon fiber was immersed in acetone solution at 100℃ and refluxed for 12 h, then cleaned with deionized water and dried at 80℃ for 2 h to obtain the deionized carbon fiber. 2) Apply a limiting tensile load of 0.0030 N to both ends of the carbon fiber monofilament obtained in step 1). This load is the maximum force value that will not cause the fiber to break. 3) Prepare 10 g of tris(hydroxymethyl)aminomethane aqueous solution with pH 8.0, add 0.1 g of dopamine hydrochloride, and disperse by ultrasonication for 5 min to obtain dopamine impregnation solution; 4) The carbon fiber monofilament under stretching in step 2) is immersed in the dopamine impregnation solution obtained in step 3) and reacted for 24 h, and then dried at 80℃ for 2 h to obtain polydopamine nanosheet modified carbon fiber. 5) Mix ammonia, ethanol and deionized water at a mass ratio of 1:11:32 to form a mixture A. Mix dopamine hydrochloride and deionized water at a mass ratio of 1:20 to form a mixture B. Add mixture B to mixture A at a volume ratio of 12:1. React in the dark for 24 h. After centrifugation at 9000 rpm, washing with deionized water 3 times and freeze-drying at -50 ℃ for 72 h, polydopamine nanospheres are obtained. 6) Add 0.5 wt.% of the polydopamine nanospheres prepared in step 5) to the epoxy resin, and then combine them with the polydopamine nanosheet modified carbon fiber obtained in step 4). The volume ratio of the polydopamine nanosheet modified carbon fiber to the epoxy resin containing polydopamine nanospheres is 30:70, to obtain a shaped biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material.

[0049] The interfacial bond strength of the irregular biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material prepared in this embodiment is increased by 32.6% and 10.6% compared with the unmodified carbon fiber reinforced epoxy resin composite material and the modified carbon fiber reinforced unmodified epoxy resin composite material, respectively, and the interfacial fracture toughness is increased by 266.9% and 27.5% compared with the unmodified carbon fiber reinforced epoxy resin composite material.

[0050] Example 3 This embodiment provides a method for preparing a shaped biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material, specifically including the following steps: 1) The carbon fiber was impregnated in acetone solution at 90℃ and refluxed for 96 h, then washed with deionized water and dried at 70℃ for 4 h to obtain the deionized carbon fiber. 2) Apply a limiting tensile load of 0.019 N to both ends of the carbon fiber monofilament obtained in step 1). This load is the maximum force value that will not cause the fiber to break. 3) Prepare 50 g of tris(hydroxymethyl)aminomethane aqueous solution with pH 9.0, add 0.1 g of dopamine hydrochloride, and disperse by ultrasonication for 3 min to obtain dopamine impregnation solution; 4) The carbon fiber monofilament under stretching in step 2) is immersed in the dopamine impregnation solution obtained in step 3) and reacted for 10 h, and then dried at 70℃ for 4 h to obtain polydopamine nanosheet modified carbon fiber. 5) Mix ammonia, ethanol and deionized water in a mass ratio of 1:5:20 to form a mixture A. Mix dopamine hydrochloride and deionized water in a mass ratio of 1:10 to form a mixture B. Add mixture B to mixture A at a volume ratio of 10:1. React in the dark for 24 h. After centrifugation at 6000 rpm, washing with deionized water 4 times and freeze-drying at -60 ℃ for 48 h, polydopamine nanospheres are obtained. 6) Add 10 wt.% of the polydopamine nanospheres prepared in step 5) to the epoxy resin, and then combine it with the polydopamine nanosheet modified carbon fiber obtained in step 4). The volume ratio of polydopamine nanosheet modified carbon fiber to epoxy resin containing polydopamine nanospheres is 50:50, to obtain a shaped biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material.

[0051] The interfacial bond strength of the irregular biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material prepared in this embodiment is increased by 47.7% and 12.1% compared with the unmodified carbon fiber reinforced epoxy resin composite material and the modified carbon fiber reinforced unmodified epoxy resin composite material, respectively, and the interfacial fracture toughness is increased by 298.3% and 31.2% compared with the unmodified carbon fiber reinforced epoxy resin composite material.

[0052] Example 4 This embodiment provides a method for preparing a shaped biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material, specifically including the following steps: 1) The carbon fiber was impregnated in an acetone solution at 80℃ and refluxed for 64 h, then cleaned with deionized water and dried at 70℃ for 3 h to obtain the deionized carbon fiber. 2) Apply a limiting tensile load of 0.026 N to both ends of the carbon fiber monofilament obtained in step 1). This load is the maximum force value that will not cause the fiber to break. 3) Prepare 100 g of tris(hydroxymethyl)aminomethane aqueous solution with pH 7.5, add 0.05 g of dopamine hydrochloride, and disperse by ultrasonication for 4 min to obtain dopamine impregnation solution; 4) The carbon fiber monofilament under stretching in step 2) is immersed in the dopamine impregnation solution obtained in step 3) and reacted for 48 h, and then dried at 70℃ for 2 h to obtain polydopamine nanosheet modified carbon fiber. 5) Mix ammonia, ethanol and deionized water at a mass ratio of 1:15:50 to form a mixture A. Mix dopamine hydrochloride and deionized water at a mass ratio of 1:30 to form a mixture B. Add mixture B to mixture A at a volume ratio of 15:1. React in the dark for 24 h. After centrifugation at 9000 rpm, washing with deionized water 4 times and freeze-drying at -30 ℃ for 48 h, polydopamine nanospheres are obtained. 6) Add 5.0 wt.% of the polydopamine nanospheres prepared in step 5) to the epoxy resin, and then combine them with the polydopamine nanosheet modified carbon fiber obtained in step 4). The volume ratio of the polydopamine nanosheet modified carbon fiber to the epoxy resin containing polydopamine nanospheres is 70:30, to obtain a shaped biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material.

[0053] The interfacial bond strength of the irregular biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material prepared in this embodiment is increased by 67.5% and 21.7% compared with the unmodified carbon fiber reinforced epoxy resin composite material and the modified carbon fiber reinforced unmodified epoxy resin composite material, respectively, and the interfacial fracture toughness is increased by 313.3% and 46.0% compared with the unmodified carbon fiber reinforced epoxy resin composite material.

[0054] Example 5 This embodiment provides a method for preparing a shaped biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material, specifically including the following steps: 1) The carbon fiber was impregnated in an acetone solution at 80℃ and refluxed for 48 h, then cleaned with deionized water and dried at 60℃ for 3 h to obtain the deionized carbon fiber. 2) Apply a limiting tensile load of 360 N to both ends of the carbon fiber bundle containing 12,000 carbon fiber monofilaments obtained in step 1). This load is the maximum force value that will not cause the fiber to break. 3) Prepare 100 g of tris(hydroxymethyl)aminomethane aqueous solution with pH 8.5, add 0.2 g of dopamine hydrochloride, and disperse by ultrasonication for 3 min to obtain dopamine impregnation solution; 4) The carbon fiber monofilament under stretching in step 2) is immersed in the dopamine impregnation solution obtained in step 3) and reacted for 24 h, and then dried at 60℃ for 3 h to obtain polydopamine nanosheet modified carbon fiber. 5) Mix ammonia, ethanol and deionized water in a mass ratio of 1:11:32 to form a mixture A. Mix dopamine hydrochloride and deionized water in a mass ratio of 1:20 to form a mixture B. Add mixture B to mixture A at a volume ratio of 12:1. React in the dark for 24 h. After centrifugation at 8700 rpm, washing with deionized water three times and freeze-drying at -50 ℃ for 48 h, polydopamine nanospheres are obtained. 6) Add 1.0 wt.% of the polydopamine nanospheres prepared in step 5) to the epoxy resin, and then combine them with the polydopamine nanosheet modified carbon fiber obtained in step 4). The volume ratio of the polydopamine nanosheet modified carbon fiber to the epoxy resin containing polydopamine nanospheres is 50:50, to obtain a shaped biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material.

[0055] The interfacial bond strength of the irregular biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material prepared in this embodiment is increased by 40.4% and 13.9% compared with the unmodified carbon fiber reinforced epoxy resin composite material and the modified carbon fiber reinforced unmodified epoxy resin composite material, respectively, and the interfacial fracture toughness is increased by 215.5% and 15.5% compared with the unmodified carbon fiber reinforced epoxy resin composite material.

[0056] Example 6 This embodiment provides a method for preparing a shaped biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material, specifically including the following steps: 1) The carbon fiber was immersed in acetone solution at 100℃ and refluxed for 12 h, then cleaned with deionized water and dried at 70℃ for 4 h to obtain the de-agent carbon fiber. 2) Apply a limiting tensile load of 456 N to both ends of the carbon fiber bundle containing 24,000 carbon fiber monofilaments obtained in step 1). This load is the maximum force value that will not cause the fiber to break. 3) Prepare 100 g of tris(hydroxymethyl)aminomethane aqueous solution with pH 7.5, add 0.5 g of dopamine hydrochloride, and disperse by ultrasonication for 4 min to obtain dopamine impregnation solution; 4) The carbon fiber monofilament under stretching in step 2) is immersed in the dopamine impregnation solution obtained in step 3) and reacted for 30 h, and then dried at 70℃ for 4 h to obtain polydopamine nanosheet modified carbon fiber. 5) Mix ammonia, ethanol and deionized water in a mass ratio of 1:11:32 to form a mixture A. Mix dopamine hydrochloride and deionized water in a mass ratio of 1:20 to form a mixture B. Add mixture B to mixture A at a volume ratio of 12:1. React in the dark for 24 h. After centrifugation at 8700 rpm, washing with deionized water three times and freeze-drying at -50 ℃ for 48 h, polydopamine nanospheres are obtained. 6) Add 3.0 wt.% of the polydopamine nanospheres prepared in step 5) to the epoxy resin, and then combine them with the polydopamine nanosheet modified carbon fiber obtained in step 4). The volume ratio of the polydopamine nanosheet modified carbon fiber to the epoxy resin containing polydopamine nanospheres is 60:40, to obtain a shaped biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material.

[0057] The interfacial bond strength of the irregular biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material prepared in this embodiment is increased by 53.6% and 14.4% compared with the unmodified carbon fiber reinforced epoxy resin composite material and the modified carbon fiber reinforced unmodified epoxy resin composite material, respectively, and the interfacial fracture toughness is increased by 244.4% and 37.5% compared with the unmodified carbon fiber reinforced epoxy resin composite material.

[0058] Example 7 This embodiment provides a method for preparing a shaped biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material, specifically including the following steps: 1) The carbon fiber was impregnated in acetone solution at 90℃ and refluxed for 96 h, then cleaned with deionized water and dried at 80℃ for 2 h to obtain the de-agent carbon fiber. 2) Apply a limiting tensile load of 1440 N to both ends of the carbon fiber bundle containing 48,000 carbon fiber monofilaments obtained in step 1). This load is the maximum force value that will not cause the fiber to break. 3) Prepare 100 g of tris(hydroxymethyl)aminomethane aqueous solution with pH 8.0, add 1.0 g of dopamine hydrochloride, and disperse by ultrasonication for 5 min to obtain dopamine impregnation solution; 4) The carbon fiber monofilament under stretching in step 2) is immersed in the dopamine impregnation solution obtained in step 3) and reacted for 10 h, and then dried at 80℃ for 2 h to obtain polydopamine nanosheet modified carbon fiber. 5) Mix ammonia, ethanol and deionized water in a mass ratio of 1:5:20 to form a mixture A. Mix dopamine hydrochloride and deionized water in a mass ratio of 1:10 to form a mixture B. Add mixture B to mixture A at a volume ratio of 10:1. React in the dark for 24 h. After centrifugation at 6000 rpm, washing with deionized water 4 times and freeze-drying at -60 ℃ for 48 h, polydopamine nanospheres are obtained. 6) Add 10.0 wt.% of the polydopamine nanospheres prepared in step 5) to the epoxy resin, and then combine them with the polydopamine nanosheet modified carbon fiber obtained in step 4). The volume ratio of the polydopamine nanosheet modified carbon fiber to the epoxy resin containing polydopamine nanospheres is 70:30, to obtain a shaped biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material.

[0059] The interfacial bond strength of the irregular biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material prepared in this embodiment is increased by 51.8% and 14.8% compared with the unmodified carbon fiber reinforced epoxy resin composite material and the modified carbon fiber reinforced unmodified epoxy resin composite material, respectively, and the interfacial fracture toughness is increased by 297.3% and 40.8% compared with the unmodified carbon fiber reinforced epoxy resin composite material.

[0060] Example 8 This embodiment provides a textured piezoelectric ceramic and its preparation method, as well as a method for preparing a carbon fiber reinforced epoxy resin composite material using a synergistic modification of a shaped biphase polydopamine, specifically including the following steps: 1) The carbon fiber was impregnated in an acetone solution at 80℃ and refluxed for 50 h, then cleaned with deionized water and dried at 60℃ for 4 h to obtain the deionized carbon fiber. 2) Apply a limiting tensile load of 30N to both ends of the carbon fiber bundle containing 1000 carbon fiber monofilaments obtained in step 1). This load is the maximum force value that will not cause the fiber to break. 3) Prepare 100 g of tris(hydroxymethyl)aminomethane aqueous solution with pH 8.0, add 0.05 g of dopamine hydrochloride, and disperse by ultrasonication for 3 min to obtain dopamine impregnation solution; 4) The carbon fiber monofilament under stretching in step 2) is immersed in the dopamine impregnation solution obtained in step 3) and reacted for 48 h, and then dried at 60℃ for 4 h to obtain polydopamine nanosheet modified carbon fiber. 5) Mix ammonia, ethanol and deionized water at a mass ratio of 1:15:50 to form a mixture A. Mix dopamine hydrochloride and deionized water at a mass ratio of 1:30 to form a mixture B. Add mixture B to mixture A at a volume ratio of 15:1. React in the dark for 24 h. After centrifugation at 9000 rpm, washing with deionized water 4 times and freeze-drying at -30 ℃ for 48 h, polydopamine nanospheres are obtained. 6) Add 0.5 wt.% of the polydopamine nanospheres prepared in step 5) to the epoxy resin, and then combine them with the polydopamine nanosheet modified carbon fiber obtained in step 4). The volume ratio of the polydopamine nanosheet modified carbon fiber to the epoxy resin containing polydopamine nanospheres is 40:60, to obtain a shaped biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material.

[0061] The interfacial bond strength of the irregular biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material prepared in this embodiment is increased by 39.8% and 9.6% compared with the unmodified carbon fiber reinforced epoxy resin composite material and the modified carbon fiber reinforced unmodified epoxy resin composite material, respectively, and the interfacial fracture toughness is increased by 269.2% and 10.4% compared with the unmodified carbon fiber reinforced epoxy resin composite material.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a heterogeneous biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material, characterized in that, Includes the following steps: S1: After impregnating the carbon fiber precursor in an acetone solution and refluxing it, it is washed with deionized water and dried to obtain deionized carbon fiber. S2: Apply tensile loads to both ends of the de-adhesive carbon fiber, immerse the de-adhesive carbon fiber in dopamine impregnation solution, and dry it after the impregnation reaction to obtain polydopamine nanosheet modified carbon fiber. S3: The polydopamine nanosheet modified carbon fiber is added to an epoxy resin containing polydopamine nanospheres to react and obtain a shaped biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material.

2. The method for preparing a heterogeneous biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material according to claim 1, characterized in that, The carbon fiber precursor is a single carbon fiber filament or a carbon fiber bundle.

3. The method for preparing a heterogeneous biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material according to claim 1, characterized in that, The reflux condensation temperature is 80~100℃ and the time is 12~96h; when cleaning and drying with deionized water, the drying temperature is 60~80℃ and the time is 2~4h.

4. The method for preparing a heterogeneous biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material according to claim 1, characterized in that, When the carbon fiber precursor is a single carbon fiber filament, the applied tensile load is 0.019~0.030 N; when the carbon fiber precursor is a carbon fiber bundle, the carbon fiber bundle contains 1000~48000 carbon fiber filaments, and the applied load is the product of the number of filaments and the ultimate tensile load of the filament.

5. The method for preparing a heterogeneous biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material according to claim 1, characterized in that, The dopamine impregnation solution is prepared by adding dopamine hydrochloride to a tris(hydroxymethyl)aminomethane aqueous solution and dispersing it evenly by ultrasonication to obtain the dopamine impregnation solution; the pH value of the tris(hydroxymethyl)aminomethane aqueous solution is 7.5~9.0; the mass ratio of dopamine hydrochloride to tris(hydroxymethyl)aminomethane aqueous solution is 1:(100~2000).

6. The method for preparing a heterogeneous biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material according to claim 1, characterized in that, The de-adhesive carbon fiber is immersed in dopamine impregnation solution for 10-48 hours, and the drying temperature after impregnation is 60-80℃ for 2-4 hours.

7. The method for preparing a heterogeneous biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material according to claim 1, characterized in that, The volume ratio of the polydopamine nanosheet modified carbon fiber to the epoxy resin containing polydopamine nanospheres is (30~70):(70~30).

8. The method for preparing a heterogeneous biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material according to claim 1, characterized in that, The preparation of the epoxy resin containing polydopamine nanospheres is specifically as follows: S31: Add an aqueous solution of dopamine hydrochloride to a mixed solution containing ammonia, ethanol and deionized water, react in the dark, centrifuge at 6000~10000 rpm, wash with deionized water at least 3 times and freeze dry at -30~-60℃ to obtain polydopamine nanospheres. S32: Add the polydopamine nanospheres to an epoxy resin to obtain the epoxy resin containing the polydopamine nanospheres. In the mixed solution containing ammonia, ethanol and deionized water, the mass ratio of ammonia, ethanol and deionized water is 1:(5-15):(20-50); in the aqueous solution of dopamine hydrochloride, the mass ratio of dopamine hydrochloride to water is 1:(10-30); and the volume ratio of the aqueous solution of dopamine hydrochloride to the mixed solution containing ammonia, ethanol and deionized water is (10-15):

1.

9. The method for preparing a heterogeneous biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material according to claim 8, characterized in that, The amount of polydopamine nanospheres added is 0.5 wt.% to 10 wt.% of the epoxy resin.

10. A heterogeneous biphase polydopamine synergistic modified carbon fiber reinforced epoxy resin composite material, characterized in that, It is prepared by the method described in any one of claims 1 to 9.

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