Highly conductive, high mechanical stability aramid / conductive material composite fiber and method of making same
By infiltrating PEDOT:PSS into aramid fibers in a gel state and combining it with sulfuric acid treatment, the problems of low composite strength and easy detachment of the conductive layer in aramid/conductive composite fibers were solved, achieving high conductivity and high mechanical stability, which is suitable for flexible electronics, smart fabrics and other fields.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- WUHAN TEXTILE UNIV
- Filing Date
- 2026-05-18
- Publication Date
- 2026-06-26
Smart Images
Figure CN122279780A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of composite fiber technology, specifically to a highly conductive and mechanically stable aramid / conductive composite fiber and its preparation method. Background Technology
[0002] Aramid, as a high-performance specialty fiber, possesses ultra-high mechanical strength, excellent high-temperature resistance, and chemical corrosion resistance, making it an ideal scaffold substrate for preparing high-strength functional materials. However, aramid itself is an insulator, and its lack of conductivity greatly limits its application in high-end fields such as conductivity, antistatic properties, and flexible electronics.
[0003] To impart conductivity to aramid fibers, existing technologies often employ methods such as surface coating, blend spinning, and surface in-situ polymerization to composite conductive materials with aramid. However, coating only forms a conductive layer on the aramid surface, resulting in poor interfacial strength between the fiber and the conductive polymer. This leads to defects such as easy detachment of the conductive layer, low composite strength, and a sharp decrease in conductivity after repeated bending or stretching. Blending spinning requires mixing the conductive material with the aramid spinning solution before spinning, which disrupts the orientation and crystalline structure of the aramid molecular chains, causing a significant loss of mechanical strength in the aramid skeleton. Furthermore, the conductive material is unevenly dispersed in the aramid spinning solution and prone to agglomeration, making it impossible to construct a continuous and efficient conductive pathway, resulting in poor conductivity. While surface in-situ polymerization can form a relatively tightly bonded conductive layer on the aramid surface, it suffers from poor reaction controllability, numerous local agglomeration defects, uneven conductive layer thickness, difficulty in penetrating the aramid fiber interior, and the tendency for the conductive layer to crack and detach during subsequent processing. Summary of the Invention
[0004] In view of the technical problems existing in the background art, this application provides a highly conductive and mechanically stable aramid / conductive material composite fiber and its preparation method, aiming to solve the technical problems of low composite strength, easy detachment of conductive layer, large loss of mechanical strength and limited improvement of electrical conductivity in the existing aramid / conductive material composite fiber preparation process.
[0005] In a first aspect, this application provides a method for preparing highly conductive and mechanically stable aramid / conductive composite fibers, comprising the following steps: S1, add aramid staple fiber to dimethyl sulfoxide and dissolve at room temperature to obtain aramid spinning solution; S2, the aramid spinning solution is extruded into a coagulation bath through a wet spinning process to obtain undried gel-state aramid fibers; S3, the undried gelled aramid fiber is immersed in a PEDOT:PSS solution to allow PEDOT:PSS to penetrate into the interior of the gelled aramid fiber; S4. After impregnation, the fiber is removed and dried to obtain aramid / conductive material composite fiber.
[0006] Furthermore, the preparation method further includes the following steps: post-treating the aramid / conductive composite fiber obtained in step S4 with a sulfuric acid solution of 50-80% by mass, and drying it to obtain the sulfuric acid-post-treated aramid / conductive composite fiber.
[0007] Furthermore, in step S3, the immersion temperature is 20 ~ 40℃, and the immersion time is 1 ~ 24h.
[0008] Furthermore, the sulfuric acid post-treatment temperature is 18℃~90℃, and the time is 1~6 hours.
[0009] Furthermore, in step S2, the spinning speed is 1 ~ 10 mL / h, the inner diameter of the spinning needle is 0.5 ~ 1 mm, the coagulation bath is deionized water, and the coagulation bath temperature is 20 ~ 30℃.
[0010] Further, in step S1, the mass concentration of the aramid spinning solution is 0.5 ~ 5 wt%.
[0011] Secondly, this application provides a highly conductive and mechanically stable aramid / conductive material composite fiber, which is prepared by the preparation method described in any of the aforementioned technical solutions.
[0012] This highly conductive and mechanically stable aramid / conductive composite fiber has broad application prospects in fields such as flexible electronics, smart fabrics, wearable devices, electromagnetic shielding, and energy storage devices.
[0013] The beneficial effects of this application are as follows: This application employs a "gel-state impregnation and penetration" strategy, impregnating aramid fibers with PEDOT:PSS while they are in a gel state (not yet dried). The loose, porous structure of the gel fibers allows PEDOT:PSS to fully penetrate into the fiber interior, rather than merely remaining on the surface. EDS cross-sectional analysis confirms that PEDOT:PSS is uniformly distributed within the fiber, achieving true bulk composite rather than surface coating. This composite method preserves the strong framework of aramid while imparting good electrical conductivity to the composite fiber.
[0014] In this application, aramid and PEDOT:PSS are tightly bonded through non-covalent interactions such as hydrogen bonds, π-π stacking, and electrostatic interactions (confirmed by infrared spectroscopy), resulting in high interfacial bonding strength. Compared to traditional blending and coating methods, the method in this application retains the high mechanical properties of the aramid skeleton (the mechanical strength loss of the composite fiber after PEDOT:PSS compositing does not exceed 20%, significantly better than traditional blending methods), and also possesses superior electrical conductivity. Furthermore, the conductivity of the fiber remains stable after repeated bending and stretching, with a resistance change of no more than 3% after 1000 repeated bending cycles, significantly better than products produced by traditional coating methods.
[0015] In this application, sulfuric acid post-treatment can significantly improve the electrical conductivity of composite fibers because sulfuric acid can remove insulating PSS, induce ordered rearrangement of PEDOT chains, and improve crystallinity and carrier mobility. Concentrated sulfuric acid treatment usually yields the best results, but it can dissolve aramid fibers. This application uses sulfuric acid with a mass fraction of 50-80%, which can significantly improve the fiber's electrical conductivity without damaging it. The electrical conductivity of the composite fibers can reach 416.6 S / cm, and the mechanical properties of the fibers before and after sulfuric acid treatment are almost unaffected by the sulfuric acid.
[0016] The method of this application has broad material applicability and can be applied to a variety of conductive material systems such as conductive polymers, carbon-based materials, metal nanomaterials, and MXene, providing flexible material selection for different application scenarios.
[0017] The process described in this application is simple and controllable. The aramid / conductive composite fiber prepared has both high conductivity and high strength and stability, and has broad application prospects in fields such as flexible electronics, smart fabrics, wearable devices, electromagnetic shielding, and energy storage devices.
[0018] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description
[0019] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.
[0020] Figure 1 This is a schematic diagram of the preparation process of aramid / PEDOT composite fiber in Example 1.
[0021] Figure 2The graph shows a comparison of the electrical conductivity and mechanical properties of the composite fibers prepared by Example 1 (gel impregnation method), Comparative Example 1 (coating method), Comparative Example 2 (blending method), and pure aramid fibers.
[0022] Figure 3 The image shows the cross-sectional EDS elemental distribution of the aramid / PEDOT composite fiber prepared in Example 1; the red dots represent the distribution of sulfur on the fiber surface and cross-section.
[0023] Figure 4 The infrared spectrum of the aramid / PEDOT composite fiber prepared in Example 1.
[0024] Figure 5 The resistance change curve of the aramid / PEDOT composite fiber prepared in Example 8 after repeated bending following sulfuric acid posttreatment. Detailed Implementation
[0025] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.
[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.
[0027] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.
[0028] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.
[0029] To address the technical problems of low composite strength, easy detachment of conductive layer, large loss of mechanical strength, and limited improvement of conductivity in existing aramid / conductive composite fibers, this application provides a method for preparing highly conductive and mechanically stable aramid / conductive composite fibers. Through a "gel-state impregnation and penetration" strategy, PEDOT:PSS can penetrate into the fiber interior and form a strong interaction with aramid, thus preserving the skeletal strength of aramid while exhibiting excellent conductivity and mechanical stability.
[0030] This application provides a method for preparing highly conductive and mechanically stable aramid / conductive composite fibers, comprising the following steps: S1, add aramid staple fiber to dimethyl sulfoxide and dissolve at room temperature to obtain aramid spinning solution; Specifically, para-aramid short fibers are added to dimethyl sulfoxide (DMSO) and stirred at 25~60℃ until completely dissolved to obtain an aramid spinning solution with a mass concentration of 0.5~5wt%. The stirring speed is 300~1000r / min and the stirring time is 72~120h to ensure that the aramid is uniformly dispersed and without obvious agglomeration.
[0031] S2, the aramid spinning solution is extruded into the coagulation bath through a wet spinning process. The spinning solution is solidified in the coagulation bath to obtain undried gel-state aramid fibers. The spinning speed is 1 ~ 10 mL / h, the inner diameter of the spinning needle is 0.5 ~ 1 mm, the coagulation bath is deionized water, and the coagulation bath temperature is 20 ~ 30℃.
[0032] S3, the undried gelled aramid fibers are immersed in a PEDOT:PSS solution, allowing PEDOT:PSS to penetrate into the interior of the gelled aramid fibers.
[0033] The immersion temperature is 20 ~ 40℃, and the immersion time is 1 ~ 24h.
[0034] S4. After impregnation, the fiber is removed and dried to obtain aramid / conductive material composite fiber.
[0035] In some embodiments, the preparation method further includes the following steps: post-treating the aramid / conductive composite fiber obtained in step S4 with a sulfuric acid solution of 50-80% by mass, and drying it to obtain the sulfuric acid-post-treated aramid / conductive composite fiber.
[0036] In this application, the mass fraction of the sulfuric acid solution is controlled to be 50-80%, preferably 75%. When the concentration is below 50%, the removal effect of PSS is not good, and the conductivity of the resulting fiber is poor. When the concentration is above 80%, it will damage the aramid fiber, and high-concentration acid can directly dissolve the aramid.
[0037] The temperature for sulfuric acid post-treatment is less than 90℃, preferably 50~70℃. The post-treatment time is 1~6 hours, preferably 3~4 hours.
[0038] The high conductivity and high mechanical stability aramid / conductive composite fiber prepared by the aforementioned technical solution maintains stable conductivity after repeated bending and stretching. After repeated bending 1000 times, the resistance change is no more than 3%, which has broad application prospects in flexible electronics, smart fabrics, wearable devices, electromagnetic shielding, energy storage devices and other fields.
[0039] The following are some specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.
[0040] I. Preparation Method Example 1 Please see Figure 1 As shown, this embodiment provides a method for preparing highly conductive and mechanically stable aramid / conductive composite fibers, including the following steps: S1, Preparation of aramid solution: Para-aramid short fibers are added to dimethyl sulfoxide (DMSO) and stirred at 500 r / min for 72 h at 18 °C to obtain an aramid spinning solution with a mass concentration of 1 wt%, ensuring that the aramid is completely dissolved and there is no obvious agglomeration.
[0041] S2, Preparation of gel-state aramid fibers: The above aramid spinning solution is wet-spun through a needle (inner diameter 0.9 mm) at a spinning speed of 6 mL / h. The coagulation bath is deionized water at 25 °C. The spinning solution is coagulated in the coagulation bath to obtain undried gel-state aramid fibers.
[0042] S3, Preliminary preparation of aramid / PEDOT composite fiber: Gel-state aramid fiber was impregnated in a PEDOT:PSS solution with a mass concentration of 1.35wt% at a temperature of 30℃ for 1 hour.
[0043] S4. After impregnation, the fiber is removed and dried at 120℃ for 0.5h to obtain aramid / PEDOT composite fiber.
[0044] Comparative Example 1 (Coating Method) Comparative Example 1 prepared aramid / PEDOT composite fibers using a conventional coating method. The main difference from Example 1 was that in step S3, dried aramid fibers (same specifications as in Example 1) were immersed in a PEDOT:PSS solution (same concentration as in Example 1) for 1 hour, and then removed. Subsequently, they were dried at 120°C for 0.5 hours. The rest was the same as in Example 1 and will not be repeated here.
[0045] Comparative Example 2 (Blending Method) Comparative Example 2: Aramid / PEDOT composite fibers were prepared by conventional blending method: PEDOT:PSS was added to aramid spinning solution (the concentration of aramid spinning solution was the same as in Example 1, and the amount of PEDOT:PSS added was the same as in Example 1), stirred evenly, and then wet spun (the process parameters were the same as in Example 1). After drying, composite fibers were obtained.
[0046] Example 2 The difference from Example 1 is that in step S3, the gelled aramid fibers are immersed in the PEDOT:PSS solution for 6 hours. Everything else is the same as in Example 1 and will not be repeated here.
[0047] Example 3 The difference from Example 1 is that in step S3, the gelled aramid fibers are immersed in the PEDOT:PSS solution for 2 hours. Everything else is the same as in Example 1 and will not be repeated here.
[0048] Example 4 The difference from Example 1 is that in step S3, the gelled aramid fibers are immersed in the PEDOT:PSS solution for 3 hours. Everything else is the same as in Example 1 and will not be repeated here.
[0049] Example 5 The difference from Example 1 is that in step S3, the gelled aramid fibers are immersed in the PEDOT:PSS solution for 4 hours. Everything else is the same as in Example 1 and will not be repeated here.
[0050] Example 6 The difference from Example 1 is that in step S3, the gelled aramid fibers are immersed in the PEDOT:PSS solution for 5 hours. Everything else is the same as in Example 1 and will not be repeated here.
[0051] Example 7 The difference from Example 1 is that in step S3, the gelled aramid fibers are immersed in the PEDOT:PSS solution for 7 hours. Everything else is the same as in Example 1 and will not be repeated here.
[0052] Example 8 The difference from Example 2 is that the aramid / PEDOT composite fiber obtained in Example 2 was subjected to sulfuric acid post-treatment. Specifically, the aramid / PEDOT composite fiber obtained in Example 2 was treated with a 75% sulfuric acid solution at 70°C for 1 hour, then washed with deionized water until neutral, and dried at 120°C for 0.5 hours to obtain the sulfuric acid post-treated aramid / PEDOT composite fiber.
[0053] Example 9 The difference from Example 8 is that the post-treatment temperature with sulfuric acid is 18°C. Everything else is the same as in Example 8 and will not be repeated here.
[0054] Example 10 The difference from Example 8 is that the post-treatment temperature with sulfuric acid is 30°C. Everything else is the same as in Example 8 and will not be repeated here.
[0055] Example 11 The difference from Example 8 is that the post-treatment temperature with sulfuric acid is 50°C. Everything else is the same as in Example 8 and will not be repeated here.
[0056] Example 12 The difference from Example 8 is that the post-treatment temperature with sulfuric acid is 90°C. Everything else is the same as in Example 8 and will not be repeated here.
[0057] II. Testing Methods 1. Conductivity test: The conductivity of the composite fiber was determined using the four-probe method.
[0058] 2. Mechanical property testing: The tensile strength of the composite fiber was determined using a single fiber tensile tester, and the mechanical strength loss rate was calculated.
[0059] 3. Bending resistance test: The composite fiber is repeatedly bent 1000 times, and the rate of change in resistance is recorded.
[0060] 4. EDS energy dispersive spectroscopy analysis: The elemental distribution of the composite fiber cross section was tested using an energy dispersive spectroscopy instrument.
[0061] 5. Infrared spectroscopy analysis: The chemical structure of the composite fiber was tested using a Fourier transform infrared spectrometer.
[0062] III. Analysis of Test Results for Each Embodiment and Comparative Example The electrical conductivity and mechanical properties of the composite fibers prepared by Example 1 (gel impregnation method), Comparative Example 1 (coating method), and Comparative Example 2 (blending method), as well as pure aramid fibers, were tested. The test results are shown in Table 1 and... Figure 2 As shown.
[0063] Table 1 As can be seen, compared with the blending method and the surface coating method, the gel impregnation method shows obvious advantages in the composite method of aramid and PEDOT, which can simultaneously achieve the retention of the mechanical strength of aramid and the high conductivity of the fiber.
[0064] When PEDOT is compounded with aramid using the blending method, the dispersion of PEDOT:PSS in the aramid spinning solution is poor, and polymer agglomeration is prone to occur. At the same time, the introduction of PEDOT:PSS will destroy the regular arrangement structure of aramid molecular chains, which will not only lead to a significant decrease in the mechanical properties of the composite fiber, but also prevent its electrical conductivity from achieving the desired effect.
[0065] When using the surface coating method, a PEDOT:PSS solution is coated onto the surface of dry aramid fibers. However, due to the lack of active groups on the surface of aramid molecular chains that have an affinity for PEDOT:PSS, it is extremely difficult for PEDOT:PSS to effectively adhere to the surface of aramid fibers. Even after repeated coating, a uniform coating effect cannot be achieved. Furthermore, the surface-coated PEDOT:PSS layer is very easy to fall off during actual use.
[0066] Although the surface coating method does not significantly affect the mechanical properties of aramid itself, its electrical conductivity is extremely poor, making it difficult to meet the needs of practical applications.
[0067] In the gel impregnation method, the interior of the aramid fibers in the gel state is mostly water. At this point, the aramid nanofiber structure is loose, allowing the PEDOT:PSS solution to penetrate into the fiber interior rather than merely adhering to the fiber surface. Furthermore, the PEDOT:PSS molecular chains are less prone to aggregation in this environment. This composite method retains the excellent high-strength skeletal properties of aramid while also imparting good electrical conductivity to the fiber, effectively solving the core technical defects of blending and surface coating methods.
[0068] It should be noted that pure aramid fiber itself is an insulating material and has almost no electrical conductivity. Figure 2 As shown, its conductivity is close to 0 and can be ignored.
[0069] Figure 3 The image shows the cross-sectional EDS elemental distribution of the aramid / PEDOT composite fiber prepared in Example 1.
[0070] from Figure 3 The sulfur distribution diagram of the cross-section of the aramid / PEDOT composite fiber shows that sulfur is distributed not only on the fiber surface but also inside the fiber. This indicates that PEDOT:PSS not only adheres to the fiber surface but also penetrates into the fiber interior.
[0071] Figure 4 The infrared spectrum of the aramid / PEDOT composite fiber prepared in Example 1.
[0072] As can be seen, aramid fibers at a wavenumber of 3315.5 cm⁻¹ -1 There is a significant NH stretching vibration at this location; the NH stretching vibration of the aramid / PEDOT composite fiber prepared in Example 1 exhibits a redshift of 3282.7 cm⁻¹. -1 The obvious redshift indicates that the -NH- group of aramid and the -S=O group of PSS have formed a strong hydrogen bond.
[0073] In addition, aramid fibers are at 1014.5 cm. -1 The in-plane bending of the benzene ring (CH) is observed at a point in aramid / PEDOT composite fibers. In these fibers, the in-plane bending of the benzene ring (CH) shifts to 1036.3 cm. -1 This may be due to π-π interactions between the thiophene ring of PEDOT and the benzene ring of aramid. The infrared spectrum shows that in the aramid / PEDOT composite fiber prepared in Example 1, PEDOT:PSS not only physically permeates, but hydrogen bonds and π-π interactions may have formed between PEDOT:PSS and the aramid molecular chains, making the bond between the two more robust.
[0074] The electrical conductivity and mechanical properties of the composite fibers obtained in Examples 1-7 are shown in Table 2.
[0075] Table 2 Experiments show that as the impregnation time increases, the conductivity of the resulting composite fiber increases, but the mechanical properties of the fiber decrease. In order to balance mechanical properties and conductivity, the impregnation time is controlled at 3 to 6 hours, which can obtain good conductivity without losing too much of the mechanical properties of the fiber. Moreover, the mechanical strength of the resulting composite fiber is no more than 20% lower than that of pure aramid fiber, and it still retains high mechanical properties.
[0076] The electrical conductivity and mechanical properties of the composite fibers obtained in Examples 2 and 8-12 are shown in Table 3.
[0077] Table 3 As shown in the table above, sulfuric acid post-treatment of aramid / PEDOT composite fibers can not only remove the insulating PSS in PEDOT:PSS, but also promote the PEDOT molecular chains to change from a coiled state to a straight state, which greatly improves the conductivity of the composite fibers.
[0078] Furthermore, as the temperature of the sulfuric acid solution increases, the conductivity of the fiber increases. However, excessively high sulfuric acid temperatures can damage aramid fibers. Therefore, the preferred treatment temperature is 50~70℃. Within the preferred treatment temperature range, the mechanical properties of the fiber before and after sulfuric acid treatment are almost unaffected by the sulfuric acid treatment, indicating that sulfuric acid treatment under these conditions will not damage the mechanical properties of the fiber.
[0079] Figure 5 The conductivity change curve of the aramid / PEDOT composite fiber prepared in Example 8 after repeated bending following sulfuric acid posttreatment.
[0080] As can be seen, the aramid / PEDOT composite fiber (K / P / A) prepared in Example 8 after sulfuric acid post-treatment showed a resistance change of no more than 3% after repeated bending 1000 times, indicating that the composite fiber has good bending fatigue resistance and that the bond between PEDOT and aramid is relatively strong.
[0081] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.
Claims
1. A method for preparing a highly conductive and mechanically stable aramid / conductive composite fiber, characterized in that, Includes the following steps: S1, add aramid staple fiber to dimethyl sulfoxide and dissolve to obtain aramid spinning solution; S2, the aramid spinning solution is extruded into a coagulation bath through a wet spinning process to obtain undried gel-state aramid fibers; S3, the undried gelled aramid fiber is immersed in a PEDOT:PSS solution to allow PEDOT:PSS to penetrate into the interior of the gelled aramid fiber; S4. After impregnation, the fiber is removed and dried to obtain aramid / conductive material composite fiber.
2. The method for preparing highly conductive and mechanically stable aramid / conductive composite fibers according to claim 1, characterized in that, The preparation method further includes the following steps: the aramid / conductive composite fiber obtained in step S4 is post-treated with a sulfuric acid solution with a mass fraction of 50-80%, and dried to obtain the sulfuric acid post-treated aramid / conductive composite fiber.
3. The method for preparing highly conductive and mechanically stable aramid / conductive composite fibers according to claim 1, characterized in that, In step S3, the immersion temperature is 20 ~ 40℃ and the immersion time is 1 ~ 24h.
4. The method for preparing highly conductive and mechanically stable aramid / conductive composite fibers according to claim 2, characterized in that, The temperature for sulfuric acid post-treatment is 18~90℃, and the time is 1~6 hours.
5. The method for preparing highly conductive and mechanically stable aramid / conductive composite fibers according to claim 1, characterized in that, In step S2, the spinning speed is 1 ~ 10 mL / h, and the inner diameter of the spinning needle is 0.5 ~ 1 mm.
6. The method for preparing highly conductive and mechanically stable aramid / conductive composite fibers according to claim 1, characterized in that, In step S2, the coagulation bath is deionized water, and the coagulation bath temperature is 20 ~ 30℃.
7. The method for preparing highly conductive and mechanically stable aramid / conductive composite fibers according to claim 1, characterized in that, In step S1, the mass concentration of the aramid spinning solution is 0.5 ~ 5 wt%.
8. A composite fiber of aramid / conductive material with high conductivity and high mechanical stability, characterized in that, It is prepared by the preparation method described in any one of claims 1-7.