A preparation method of a carbon nanofiber reinforced carbon material fiber fabric

Abstract

The present invention belongs to the technical field of carbon material fibers, and discloses a preparation method of a carbon nanofiber reinforced carbon material fiber fabric. The preparation method is as follows: Fix the weakly twisted carbon material fiber tow on an electrospinning nanofiber yarn machine, form a carbon nanofiber membrane by electrospinning and uniformly wrap it on the weakly twisted carbon material fiber tow, then wind it into a roll, and then weave the wound fibers into a fabric, and sequentially perform hot pressing and carbonization treatments on the fabric to obtain a carbon nanofiber reinforced carbon material fiber fabric; Weak twisting means that the twist is 5 to 13 turns / meter. The present invention first coats the carbon nanofibers on the carbon material fibers to improve the interfacial bonding strength between the nanofibers and the carbon material fibers, and then performs hot pressing and carbonization treatments on the fabric prepared therefrom to further improve the mechanical properties, electrical conductivity and thermal conductivity of the fabric, making it show great application prospects in the fields of high-performance composite materials, intelligent textiles, etc.

Description

Technical Field

[0001] The invention belongs to the technical field of carbon material fibers and relates to a method for preparing carbon nanofiber reinforced carbon material fiber fabric. Background Art

[0002] Carbon fiber, with its excellent mechanical properties, high specific surface area and good conductivity, shows great application potential in the fields of energy, environment and composite materials. However, despite the broad prospects, fabrics woven from carbon fiber are not perfect and still face some problems that need to be solved. Among them, the defects between carbon fiber fibers have become the key factor restricting the improvement of the overall performance of fabrics. The root cause of these defects is that the interfacial bonding force between fibers is obviously insufficient. Specifically, the surface of graphene sheets is smooth, which makes the physical contact area between fibers relatively small, thereby weakening the interfacial bonding force. Similarly, the surface of carbon fiber itself is smooth and chemically inert, and its interfacial bonding mainly depends on physical forces, such as van der Waals forces, which is relatively weak. In addition, carbon nanotubes also have a smooth surface, and the interfacial bonding force between fibers is also relatively weak. The consequence of low interfacial bonding strength is that slippage is easy to occur between fibers, which not only hinders the effective transmission of electrons between fibers, but also reduces the tensile strength and conductivity of the fabric.

[0003] Therefore, in the process of weaving carbon fiber into fabric, a large number of voids will be formed due to the staggered arrangement and stacking of the fibers and the weak interfacial bonding force between the carbon fiber fibers. These voids not only destroy the structural continuity of the fabric, but also seriously affect its mechanical properties and functionality. In addition, the voids will lead to uneven stress distribution, which is easy to cause local stress concentration and crack propagation under the action of external loads, significantly reducing the tensile strength, toughness and fatigue resistance of the fabric. At the same time, the presence of voids will also reduce the effective contact area between fibers, reduce friction and mechanical interlocking, and further weaken the overall mechanical properties of the fabric. In terms of electrical and thermal conductivity, voids will also interrupt the electron transmission path, increase the interface contact resistance, and reduce the electrical conductivity; at the same time, voids also hinder the effective transfer of heat and reduce thermal conductivity.

[0004] In order to further improve the performance of fiber fabrics, existing technologies usually use sizing agents or resins to modify them, but these non-conductive or low-thermal-conductivity organic layers will hinder the electron transfer and heat transfer between fibers, reducing electrical and thermal conductivity. In addition, the introduction of sizing agents or resins may also form an uneven covering layer, resulting in further degradation of performance in local areas, and when the sizing agents or resins are removed, the fiber surface will also be damaged.

[0005] For example, a kind of interface-enhanced carbon fiber sizing agent, its preparation method and application method disclosed in the patent application with the publication number of CN119433988A can effectively enhance the bonding ability between the sizing agent, carbon fiber and matrix resin, thus effectively improving the interface performance of carbon fiber composites. However, as an organic material, the sizing agent will form an insulating layer on the fiber surface, hindering the transmission of electrons and phonons, thereby reducing the electrical conductivity and thermal conductivity of the fiber.

[0006] Although there are also methods in the prior art to enhance fiber performance by introducing functional coatings through electrochemical deposition technology, chemical corrosion or oxidation may occur on the fiber surface during the process, especially under high voltage or long-term deposition conditions. For example, the literature (Electrodeposited carbon nanostructured nickel composite coatings: A review[J].Heliyon, 10(8):e26051[2025-02-28].DOI:10.1016 / j.heliyon.2024.e26051.) mentions that depositing graphene oxide (GO) on the surface of carbon fiber by electrochemical deposition method can significantly improve the interfacial bonding strength between carbon fiber and epoxy resin matrix, and at the same time improve the mechanical properties of the composite material. However, the electrochemical deposition method will cause chemical corrosion or oxidation on the fiber surface, and the structure will be damaged, resulting in the decline of the mechanical, electrical and thermal conductivity of the fiber.

[0007] Therefore, it is of great significance to study a preparation method of carbon nanofiber-reinforced carbon material fiber fabric to solve the above problems. Summary of the Invention

[0008] The purpose of the present invention is to solve the problems existing in the prior art and provide a preparation method of carbon nanofiber-reinforced carbon material fiber fabric.

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

[0010] A preparation method of a carbon nanofiber-reinforced carbon material fiber fabric. The weakly twisted carbon material fiber tow is fixed on an electrospinning nano-yarn machine (the electrospinning nano-yarn machine is a prior art, and the specific fixing method of the weakly twisted carbon material fiber tow is as follows: the end of the carbon material fiber tow on the spinning reel is manually drawn out from the conical wire guide on the left side, the drawn fiber tow is subjected to tension adjustment through a control device, and then the tow is led out to the guide hole on the right side and fixed on the chuck of the wire winding device, and the wire winding speed of the tow is controlled by the motor drive system). Carbon nanofiber membranes are formed by electrospinning and uniformly wrapped on the weakly twisted carbon material fiber tow, realizing the protection and weavability of the surface of the carbon material fiber tow, improving the wear resistance and the tensile property of the composite fiber at the same time, and then wound into a shaft. After that, the wound fiber tow is woven into a fabric, and the fabric is subjected to hot pressing and carbonization treatments in sequence to obtain the carbon nanofiber-reinforced carbon material fiber fabric;

[0011] Weak twisting means that the twist is 5 - 13 turns per meter. The twist refers to the number of twists of the yarn per unit length, usually expressed in turns per meter (tpm) or turns per inch (tpi). The twist of weak twisting is generally 20 - 50% lower than that of standard twisting, and in this invention, it is defined as 5 - 13 tpm. Weak twisting can make the weak parts of the carbon material fibers become tight and hold each other, preventing slippage or breakage, thus making the strength of the fibers uniform;

[0012] After electrospinning carbon nanofibers on the surface of the carbon material fibers, the surface microstructure of the carbon material fibers can be significantly improved, making it more rough and having active sites. This structural change helps to improve the interfacial bonding strength between the carbon nanofibers and the carbon material fibers;

[0013] During the process of weaving the carbon material fibers into a fabric, due to the interlaced arrangement and stacking mode between the fibers, a large number of void structures are formed between the fibers. These voids not only destroy the structural continuity of the fabric but also seriously affect its mechanical properties and functionality. Carbon nanofibers have an extremely high aspect ratio and flexibility. In this invention, by coating the carbon nanofibers obtained by electrospinning on the carbon material fiber tow, a continuous bridging structure can be formed between the fiber lap joints. Through the expansion and connection of the bridging structure, a three-dimensional network structure is formed, thus effectively transmitting and dispersing external loads and reducing stress concentration. This bridging structure can also improve the denseness of the fabric and enhance the mechanical interlocking effect between the fibers, thereby improving the overall mechanical properties of the fabric (such as tensile strength, fatigue resistance). Moreover, carbon nanofibers have excellent electrical and thermal conductivity, and can form continuous conductive and heat-conductive channels between the fiber lap joints. Such channels can not only improve the electrical conductivity of the fabric but also enhance the thermal conductivity of the fabric.

[0014] After the wound fibers are woven into a fabric, the fabric is first subjected to hot pressing to reduce the voids and defects inside the fabric, improve the overall density and mechanical properties of the material, and then carbonized. Through the structural rearrangement and graphitization process at high temperature, not only can non-carbon elements in the fibers be eliminated to form a highly ordered carbon structure, but also the mechanical properties, electrical conductivity and thermal conductivity of the fabric can be further improved. Moreover, the porous interfaces existing in the fibers can penetrate the resin to enhance the bonding force with the resin.

[0015] As a preferred technical solution:

[0016] For a method for preparing a carbon nanofiber reinforced carbon material fiber fabric as described above, the carbon material fiber is a graphene fiber, a carbon nanotube fiber or a carbon fiber.

[0017] For a method for preparing a carbon nanofiber reinforced carbon material fiber fabric as described above, the spinning solution used in electrospinning is prepared by adding a catalyst to a polyacrylonitrile (PAN) solution, a pitch solution or a viscose fiber solution, and the catalyst is ZnCl 2 、FeCl 3 and one or more of nickel powder.

[0018] For a method for preparing a carbon nanofiber reinforced carbon material fiber fabric as described above, the concentration of the polyacrylonitrile solution is 10-20 wt%, the concentration of the pitch solution is 10-20 wt%, the concentration of the viscose fiber solution is 10-20 wt%, and the catalyst dosage is 0.1-5 wt% of the polyacrylonitrile, pitch or viscose fiber.

[0019] For a method for preparing a carbon nanofiber reinforced carbon material fiber fabric as described above, the electrospinning process parameters are: voltage 10-30 kV, distance between the spinneret and the collection device (i.e., the electrospinning nanofiber yarn machine) 10-20 cm, injection pump propulsion rate 0.5-1.5 mL / h, fiber reel winding rate 10-40 cm / min, drying temperature 60-100 °C, spinning time 1-8 h.

[0020] For a method for preparing a carbon nanofiber reinforced carbon material fiber fabric as described above, the thickness of the carbon nanofiber membrane is 27-30 nm, and the average diameter of the fibers in the carbon nanofiber membrane is 240-260 nm.

[0021] For a method for preparing a carbon nanofiber reinforced carbon material fiber fabric as described above, the temperature of hot pressing is 200-300 °C, the pressure is 10-50 MPa, and the time is 10-30 min, so as to reduce the voids and defects inside the fabric and improve the overall density and mechanical properties of the material.

[0022] A preparation method of a carbon nanofiber reinforced carbon material fiber fabric as described above, the temperature of the carbonization treatment is 1300-1600 °C, and the time is 50-80 min. In this way, the carbon atoms in the fiber can be rearranged to form a more stable graphite structure, significantly improving the mechanical, electrical and thermal conductivity of the fabric.

[0023] A preparation method of a carbon nanofiber reinforced carbon material fiber fabric as described above, the weaving method is weaving or knitting.

[0024] A preparation method of a carbon nanofiber reinforced carbon material fiber fabric as described in any one of the above, compared with the comparative sample, the electrical conductivity of the carbon nanofiber reinforced carbon material fiber fabric is increased by 35-100%, the thermal conductivity is increased by 25-95%, the tensile strength is increased by 80-200%, and the flexural fatigue life is increased by 25-80%;

[0025] The preparation of the comparative sample is different from the preparation of the carbon nanofiber reinforced carbon material fiber fabric only in that the material used for weaving is the untreated carbon material fiber tow.

[0026] Beneficial effects:

[0027] (1) By coating the carbon nanofibers obtained by electrospinning on the carbon material fibers, the present invention can form a continuous bridging structure between the fiber lap joints, forming a three-dimensional network structure between the fiber lap joints, thereby effectively transmitting and dispersing external loads and reducing stress concentration. This bridging structure can also improve the denseness of the fabric and enhance the mechanical interlocking effect between the fibers, thereby improving the overall mechanical properties of the fabric and making it have good weavability; in addition, after electrospinning carbon nanofibers on the surface of the carbon material fibers, the surface microstructure of the carbon material fibers can be significantly improved, making it rougher and having active sites. This structural change helps to improve the interfacial bonding strength between the nanofibers and the carbon material fibers.

[0028] (2) The present invention first performs hot pressing treatment on the fabric to reduce the voids and defects inside the fabric and improve the overall density and mechanical properties of the material, and then undergoes carbonization treatment. Through the structural rearrangement and graphitization process at high temperature, not only can the non-carbon elements in the fiber be eliminated to form a highly ordered carbon structure, but also the mechanical properties, electrical conductivity and thermal conductivity of the fabric can be further improved. Moreover, the porous interface existing in the fiber can penetrate the resin to improve the bonding force with the resin.

[0029] (3) The carbon nanofiber reinforced carbon material fiber fabric prepared by the present invention has excellent mechanical properties, thermal conductivity and electrical conductivity, showing great application prospects in the fields of high-performance composites, smart textiles, etc. Description of the drawings

[0030] Figure 1 Schematic diagram of the working process of the electrospinning nano-spinning machine used in the present invention;

[0031] Figure 2 Schematic diagram before the fabric is subjected to hot pressing and carbonization treatment in the present invention;

[0032] Figure 3 Schematic diagram after the fabric is subjected to hot pressing and carbonization treatment in the present invention;

[0033] In the figure, 1 - wire outlet shaft, 2 - carbon material fiber bundle after weak twisting, 3 - motor I, 4 - conical wire guide, 5 - spinneret, 6 - carbon material fiber bundle wrapped with nanofiber membrane, 7 - guiding hole, 8 - wire take-up shaft, 9 - motor II. Specific embodiments

[0034] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0035] To ensure that the performance of the substances used in each embodiment and comparative example is disclosed sufficiently, the manufacturers and brands of the substances are specified. Products of other manufacturers and brands that meet the limitations of the present invention are also feasible.

[0036] The test methods for the relevant performance indicators in the following embodiments and comparative examples are as follows:

[0037] Conductivity of fiber: Take the wound fiber bundle in each embodiment as a sample, then lay the sample flat on an insulating PET film and fix both ends with conductive double-sided tape to ensure that the contact section of the sample with the four-probe is straight and free of bending. In the fiber test mode of the four-probe conductivity tester, press the probe onto the surface of the sample, then apply a current of 10 μA through the four-probe conductivity tester, and read the voltage value V. The resistance value R = V / I, and then calculate the conductivity of the sample according to the measured data. The calculation formula is: Conductivity = 4l / (R⋅πd 2 ), where l is the probe spacing (1.59 mm) and d is the diameter of the sample.

[0038] Thermal conductivity of fiber: Take the wound fiber bundle in each embodiment as a sample, and then test the thermal conductivity of the sample with reference to the standard Q / 110000 BH008-2018.

[0039] Tensile strength of the fiber: The wound fibers prepared in each example were used as samples, and tested with an electronic universal material testing machine (manufacturer: Instron; model: 34FM-100 / 300). Then, the tensile strength (unit: MPa) was obtained based on the measured data. The calculation formula is: Tensile strength = F max / A, where F max is the maximum load (unit: N) borne by the sample during the tensile process, and A is the cross-sectional area of the sample (unit: mm²).

[0040] Bending fatigue life of the fiber: The wound fibers prepared in each example were used as samples respectively. Then, the samples were cut into 5 cm lengths and their diameters were measured. After that, the samples were fixed in the fixture of a bending fatigue testing machine (manufacturer: Shanghai Zhongchen Digital Technology Equipment; model: JWQ06). After ensuring good contact between the samples and the fixture, the position of the fixture was adjusted to make the samples at a predetermined bending angle (90°) and the bending frequency was set to 5 Hz. Then, the bending fatigue testing machine was started to apply repeated bending loads until the fibers broke, and the number of cycles at the time of fiber failure was recorded, which is the bending fatigue life.

[0041] Electrical conductivity of the fabric: The carbon nanofiber-reinforced carbon material fiber fabrics prepared in each example and the control samples were respectively cut into 20 mm × 20 mm sizes. Then, the cut fabrics were used as samples for testing. The specific process is as follows: First, the samples were laid flat on the test bench and the edges were fixed with a transparent pressing plate (to prevent wrinkling). Then, in the fabric testing mode of a four-probe electrical conductivity tester, the probes contacted the surface of the samples with a pressure of 50 mN. After applying a current of 10 mA through the four-probe electrical conductivity tester, the surface resistance (i.e., the sheet resistance, unit: Ω / sq) was obtained. Then, the electrical conductivity of the samples (unit: S / m) was calculated based on the measured data. The calculation formula is: Electrical conductivity = , where t is the thickness of the sample.

[0042] Thermal conductivity of the fabric: The carbon nanofiber-reinforced carbon material fiber fabrics prepared in each example and the control samples were used as samples respectively. Then, the samples were tested with reference to the standard of GB / T 8722-2019 "Determination Method for Thermal Conductivity of Carbon Materials". Based on the flash method, the thermal diffusivity α (unit: m² / s) of the fabric was measured. Then, the specific heat capacity c p (unit: J / (kg·K)) of the samples was measured by DSC. The density of the samples was measured using GB / T 4668-1995 "Determination of the Density of Woven Fabrics". Then, the thermal conductivity λ (unit: W / (m·K)) was obtained through the calculation formula based on the measured data. The calculation formula is: λ = α ⋅ c p ⋅ ρ, where ρ is the density.

[0043] Tensile strength of the fabric: The carbon nanofiber-reinforced carbon material fiber fabrics prepared in each example and the comparative samples were used as samples respectively. Then, referring to the standard ASTM D5035-11(2020) "Breaking Strength and Elongation of Textile Fabrics (Strip Method)", the samples were tested to obtain the maximum breaking strength (N). Then, the tensile strength (MPa) was calculated based on the obtained data. The calculation formula is: Tensile strength = Maximum breaking strength (N) / (Effective width of the sample (i.e., clamping width) × Fabric thickness (unit: mm 2 )).

[0044] Bending fatigue life of the fabric: The carbon nanofiber-reinforced carbon material fiber fabrics prepared in each example and the comparative samples were cut into standard sizes (25 mm × 50 mm) as samples respectively and tested using a dynamic mechanical analyzer. The specific process is as follows: In the three-point bending mode, the sample was first placed horizontally between two fixed support points (span L = 40 mm). Subsequently, through a preliminary experiment, the maximum allowable bending angle of the sample was determined (the sample was quasi-statically bent until fracture to obtain δmax, and δcyclic = 0.5 × δmax was set, and converted to a bending angle θ = 10°). The cyclic bending angle was determined to be 10°. Then, the three-point bending stress was calculated (the calculation formula for the three-point bending stress is: Three-point bending stress = 3FL / 2bh 2 , where F is the applied load (N), which is given in real-time by the test software, L is the span, b is the width of the sample (i.e., 25 mm), and h is the thickness of the sample (unit: μm)). Then, the displacement control mode was selected, and a vertical downward periodic load was applied through a movable loading head at the center of the two fixed support points (i.e., the loading head moved up and down in a sine wave form with a frequency of 1 Hz). At the start of the test, the load-displacement curve was monitored in real-time until the load dropped to the fracture of the sample, and the number of cycles from the initial loading to the complete fracture of the sample was recorded, which is the bending fatigue life of the fabric.

[0045] Example 1

[0046] A preparation method of a carbon nanofiber-reinforced carbon material fiber fabric is as follows:

[0047] (1) Preparation of raw materials;

[0048] Carbon material fiber tow: Composed of 600 graphene fiber filaments (manufacturer: Hangzhou Gaoxi Technology Co., Ltd., grade: GK-3000);

[0049] Catalyst: ZnCl 2 ;

[0050] Polyacrylonitrile (PAN) solution: The concentration is 10 wt%, the solvent is N,N-dimethylformamide (DMF), the manufacturer of polyacrylonitrile is Shanghai Macklin Biochemical Co., Ltd., the CAS number is 25014-41-9, and the product number is P823208;

[0051] (2) Prepare the spinning solution;

[0052] Add the catalyst to the polyacrylonitrile (PAN) solution to prepare the spinning solution; among them, the dosage of the catalyst is 0.1 wt% of polyacrylonitrile (PAN);

[0053] (3) After weakly twisting the carbon material fiber bundle on the twisting machine, as Figure 1 shown, place the weakly twisted carbon material fiber bundle 2 on the wire outlet shaft 1. After starting the conical wire guide 4 and the wire winding shaft 8 through the motor I 3 and the motor II 9, the weakly twisted carbon material fiber bundle 2 will pass through the conical wire guide 4, and then use electrospinning to spray the spinning solution prepared in step (2) through the spinneret 5 to form a nanofiber membrane and uniformly wrap it on the weakly twisted carbon material fiber bundle 2 to obtain a carbon material fiber bundle 6 wrapped with a nanofiber membrane. After passing through the guiding hole 7, it is wound into a shaft by the wire winding shaft 8; among them, the thickness of the carbon nanofiber membrane is 27 nm, the average diameter of the fibers in the carbon nanofiber membrane is 240 nm, and the twist of the weak twist is 5 turns / meter;

[0054] The electrospinning process parameters are: voltage 10 kV, distance between the spinneret and the collecting device 10 cm, injection pump propulsion rate 0.5 mL / h, fiber reel wire winding rate 10 cm / min, drying temperature 60 °C, spinning time 1 h;

[0055] After winding, the diameter of the fiber bundle is 0.5 mm, the conductivity is 100 S / m, the thermal conductivity is 50 W / (m·K), the tensile strength is 100 MPa, and the bending fatigue life is 1000 times;

[0056] (4) First, arrange the wound fiber bundle into yarn, then twist it at a twist of 100 turns / meter, and then introduce the yarn into the knitting point of the knitting machine and knit at a speed of 50 revolutions per minute. Finally, wind up the knitted fabric; among them, the pitch is adjusted to 1 mm, the warp density is 20 pieces / cm, the weft density is 15 pieces / cm, and the tension is 5 N;

[0057] (5) Perform hot pressing and carbonization treatments on the fabric in sequence (before and after the fabric undergoes hot pressing and carbonization treatments, as Figure 2 , Figure 3 shown), to obtain a carbon nanofiber-reinforced carbon material fiber fabric; among them, the temperature of the hot pressing is 200 °C, the pressure is 10 MPa, the time is 10 min, the temperature of the carbonization treatment is 1300 °C, and the time is 50 min.

[0058] The thickness of the finally obtained carbon nanofiber reinforced carbon material fiber fabric is 0.5 mm, the electrical conductivity is 135 S / m, the thermal conductivity is 62.5 W / (m·K), the tensile strength is 180 MPa, and the bending fatigue life is 1300 times;

[0059] Then a comparative sample is prepared, and its preparation method is basically the same as steps (1)-(5), except that: the carbon material fiber tow in step (1) is replaced by the fiber tow after winding in step (3);

[0060] Compared with the comparative sample, the electrical conductivity of the carbon nanofiber reinforced carbon material fiber fabric is increased by 35%, the thermal conductivity is increased by 25%, the tensile strength is increased by 80%, and the bending fatigue life is increased by 25%.

[0061] Example 2

[0062] A method for preparing a carbon nanofiber reinforced carbon material fiber fabric comprises the following steps:

[0063] (1) Preparation of raw materials;

[0064] Carbon material fiber tow: composed of 1200 carbon nanotube fiber filaments (manufacturer: Jiangsu Xianfeng Nano Materials Technology Co., Ltd., product number: 100592);

[0065] Catalyst: FeCl 3 ;

[0066] Asphalt solution: with a concentration of 15 wt%, the solvent is acetone (manufacturer: Merck Chemical Technology (Shanghai) Co., Ltd., CAS number 67-64-1), and the manufacturer of asphalt is Shanghai Aladdin Biochemical Technology Co., Ltd., product number: R139415;

[0067] (2) Preparation of the spinning solution;

[0068] The catalyst is added to the asphalt solution to prepare the spinning solution; wherein, the dosage of the catalyst is 3 wt% of the asphalt;

[0069] (3) After weakly twisting the carbon material fiber tow on a twisting machine, the weakly twisted carbon material fiber tow is fixed on an electrospinning nanofiber yarn machine, and then the spinning solution prepared in step (2) is used to form a carbon nanofiber membrane by electrospinning and uniformly wrap it on the weakly twisted carbon material fiber tow, and then wind it into a roll; wherein, the thickness of the carbon nanofiber membrane is 28 nm, the average diameter of the fibers in the carbon nanofiber membrane is 252 nm, and the twist of the weak twist is 9 turns / m;

[0070] The process parameters of electrospinning are as follows: voltage 20 kV, distance between the spinneret and the collection device 15 cm, injection pump feeding rate 1 mL / h, fiber reel winding rate 21 cm / min, drying temperature 80 °C, spinning time 5 h;

[0071] After winding, the diameter of the fiber bundle is 0.8 mm, the conductivity is 260 S / m, the thermal conductivity is 60 W / (m·K), the tensile strength is 200 MPa, and the flexural fatigue life is 1500 times;

[0072] (4) First, the wound fiber bundle is sorted into yarns, then twisted at a twist of 200 turns / meter, and then a knitting machine is used to form loops of the yarns and interlace the loops with each other to form a fabric at a speed of 200 revolutions per minute, and finally the woven fabric is wound up; among them, the number of needles (i.e., needle density) is 12 needles per inch, and the tension is 13 N;

[0073] (5) The fabric is subjected to hot pressing and carbonization treatments in sequence to obtain a carbon nanofiber reinforced carbon material fiber fabric; among them, the temperature of hot pressing is 240 °C, the pressure is 25 MPa, the time is 20 min, the temperature of carbonization treatment is 1460 °C, and the time is 65 min.

[0074] The finally obtained carbon nanofiber reinforced carbon material fiber fabric has a thickness of 0.7 mm, a conductivity of 435 S / m, a thermal conductivity of 96 W / (m·K), a tensile strength of 680 MPa, and a flexural fatigue life of 2295 times;

[0075] Then a comparative sample is prepared, and its preparation method is basically the same as that in steps (1) to (5), the only difference being that: the carbon material fiber bundle in step (1) is replaced with the wound fiber bundle in step (3);

[0076] Compared with the comparative sample, the conductivity of the carbon nanofiber reinforced carbon material fiber fabric is increased by 67.5%, the thermal conductivity is increased by 60%, the tensile strength is increased by 140%, and the flexural fatigue life is increased by 53%.

[0077] Example 3

[0078] A method for preparing a carbon nanofiber reinforced carbon material fiber fabric, the steps are as follows:

[0079] (1) Preparation of raw materials;

[0080] Carbon material fiber bundle: composed of 2100 carbon fiber filaments (manufacturer: Yancheng Xiangsheng Carbon Fiber Technology Co., Ltd., brand: carbon fiber filament, specification: 12K);

[0081] Catalyst: nickel powder;

[0082] Viscose fiber solution: The concentration is 20wt%, the solvent is acetone (manufactured by Merck Chemical Technology (Shanghai) Co., Ltd., CAS No. 67-64-1), the manufacturer of the viscose fiber is Xinxiang Qihang Textile Raw Materials Co., Ltd., and the specification is 300D / 50F;

[0083] (2)Prepare the spinning solution;

[0084] Add the catalyst to the viscose fiber solution to prepare the spinning solution; among them, the dosage of the catalyst is 5wt% of the viscose fiber;

[0085] (3)After weakly twisting the carbon material fiber bundle on a twisting machine, fix the weakly twisted carbon material fiber bundle on an electrospinning nanofiber yarn machine, and then use the spinning solution prepared in step (2) to form a carbon nanofiber membrane by electrospinning and uniformly wrap it on the weakly twisted carbon material fiber bundle, and then wind it into a roll; among them, the thickness of the carbon nanofiber membrane is 30nm, the average fiber diameter in the carbon nanofiber membrane is 260nm, and the twist of the weak twist is 13 turns / m;

[0086] The electrospinning process parameters are: voltage 30kV, distance between the spinneret and the collection device 20cm, injection pump propulsion rate 1.5mL / h, fiber reel winding rate 40cm / min, drying temperature 100℃, spinning time 8h;

[0087] After winding, the diameter of the fiber bundle is 1mm, the conductivity is 420S / m, the thermal conductivity is 120W / (m·K), the tensile strength is 600MPa, and the bending fatigue life is 1900 times;

[0088] (4)First, sort out the wound fiber bundle into yarn, then twist it at a twist of 300 turns / m, then introduce the yarn into the weaving point of the knitting machine and weave it at a speed of 100 revolutions per minute, and finally wind the woven fabric; among them, the pitch is adjusted to 5mm, the warp density is 40 pieces / cm, the weft density is 35 pieces / cm, and the tension is 20N;

[0089] (5)Perform hot pressing and carbonization treatments on the fabric in sequence to obtain a carbon nanofiber-reinforced carbon material fiber fabric; among them, the temperature of the hot pressing is 300℃, the pressure is 50MPa, the time is 30min, the temperature of the carbonization treatment is 1600℃, and the time is 80min.

[0090] The finally obtained carbon nanofiber-reinforced carbon material fiber fabric has a thickness of 1mm, a conductivity of 840S / m, a thermal conductivity of 234W / (m·K), a tensile strength of 1200MPa, and a bending fatigue life of 3600 times;

[0091] Then, a comparative sample was prepared. The preparation method was basically the same as steps (1) to (5), except that: the carbon material fiber tow in step (1) was replaced with the fiber tow after winding in step (3);

[0092] Compared with the comparative sample, the electrical conductivity of the carbon nanofiber-reinforced carbon material fiber fabric increased by 100%, the thermal conductivity increased by 95%, the tensile strength increased by 200%, and the flexural fatigue life increased by 80%.

[0093] Example 4

[0094] A preparation method of a carbon nanofiber-reinforced carbon material fiber fabric is as follows:

[0095] (1) Preparation of raw materials;

[0096] Carbon material fiber tow: composed of 1700 carbon fiber filaments (manufacturer: Yancheng Xiangsheng Carbon Fiber Technology Co., Ltd., grade: carbon fiber filament, specification: 12K);

[0097] Catalyst: composed of ZnCl with a mass ratio of 1:1 2 and FeCl 3 ;

[0098] Polyacrylonitrile (PAN) solution: with a concentration of 16 wt%, the solvent is N,N-dimethylformamide (DMF). The manufacturer of polyacrylonitrile is Shanghai Macklin Biochemical Technology Co., Ltd., CAS number is 25014-41-9, and the product number is P823208;

[0099] (2) Preparation of the spinning solution;

[0100] The spinning solution was prepared by adding the catalyst to the polyacrylonitrile (PAN) solution; among them, the dosage of the catalyst was 2 wt% of polyacrylonitrile (PAN);

[0101] (3) After weakly twisting the carbon material fiber tow on a twisting machine, the weakly twisted carbon material fiber tow was fixed on an electrospinning nanofiber yarn machine, and then the spinning solution prepared in step (2) was used to form a carbon nanofiber membrane by electrospinning and uniformly wrap it on the weakly twisted carbon material fiber tow, and then wound into a roll; among them, the thickness of the carbon nanofiber membrane was 28 nm, the average diameter of the fibers in the carbon nanofiber membrane was 245 nm, and the twist of the weak twist was 10 turns / meter;

[0102] The electrospinning process parameters were: voltage 20 kV, distance between the spinneret and the collection device 16 cm, injection pump propulsion rate 0.8 mL / h, fiber reel winding rate 16 cm / min, drying temperature 70 °C, and spinning time 6 h;

[0103] After winding, the diameter of the fiber tow is 0.6 mm, the conductivity is 320 S / m, the thermal conductivity is 100 W / (m·K), the tensile strength is 500 MPa, and the flexural fatigue life is 1680 times;

[0104] (4) First, the wound fiber tow is sorted into yarn, then it is twisted at a twist of 220 turns / meter, and then the yarn is introduced into the knitting point of the knitting machine and knitted at a speed of 60 revolutions per minute. Finally, the knitted fabric is wound; among them, the pitch is adjusted to 2 mm, the warp density is 25 roots / cm, the weft density is 20 roots / cm, and the tension is 13 N;

[0105] (5) The fabric is subjected to hot pressing and carbonization treatment in sequence to obtain a carbon nanofiber reinforced carbon material fiber fabric; among them, the temperature of hot pressing is 250 °C, the pressure is 30 MPa, the time is 15 min, the temperature of carbonization treatment is 1500 °C, and the time is 70 min.

[0106] The finally obtained carbon nanofiber reinforced carbon material fiber fabric has a thickness of 0.6 mm, a conductivity of 560 S / m, a thermal conductivity of 160 W / (m·K), a tensile strength of 900 MPa, and a flexural fatigue life of 2800 times;

[0107] Then a comparative sample is prepared, and its preparation method is basically the same as that in steps (1) to (5), the difference is only that: the carbon material fiber tow in step (1) is replaced by the wound fiber tow in step (3);

[0108] Compared with the comparative sample, the conductivity of the carbon nanofiber reinforced carbon material fiber fabric is increased by 75%, the thermal conductivity is increased by 60%, the tensile strength is increased by 80%, and the flexural fatigue life is increased by 66%.

[0109] Example 5

[0110] A method for preparing a carbon nanofiber reinforced carbon material fiber fabric, the steps are as follows:

[0111] (1) Preparation of raw materials;

[0112] Carbon material fiber tow: composed of 1300 graphene fiber filaments (manufacturer: Hangzhou Goxi Technology Co., Ltd., brand: GK-3000);

[0113] Catalyst: composed of nickel powder and FeCl with a mass ratio of 1:1 3 Composition;

[0114] Viscose fiber solution: with a concentration of 14 wt%, the solvent is acetone (manufacturer: Merck Chemical Technology (Shanghai) Co., Ltd., CAS number 67-64-1), and the manufacturer of viscose fiber is Xinxiang Qihang Textile Raw Materials Co., Ltd., with a specification of 300D / 50F;

[0115] (2) Prepare the spinning solution;

[0116] Prepare the spinning solution by adding a catalyst to the viscose fiber solution; wherein, the dosage of the catalyst is 3.5 wt% of the viscose fiber.

[0117] (3) After slightly twisting the carbon material fiber bundle on a twisting machine, fix the slightly twisted carbon material fiber bundle on an electrospinning nanofiber yarn machine, and then use the spinning solution prepared in step (2) to form a carbon nanofiber membrane by electrospinning and uniformly wrap it on the slightly twisted carbon material fiber bundle, and then wind it into a roll; wherein, the thickness of the carbon nanofiber membrane is 29 nm, the average fiber diameter in the carbon nanofiber membrane is 255 nm, and the twist of the slight twist is 10 turns / meter.

[0118] The electrospinning process parameters are: voltage 20 kV, distance between the spinneret and the collection device 18 cm, injection pump propulsion rate 1.2 mL / h, fiber reel wire collection rate 30 cm / min, drying temperature 90 °C, spinning time 6 h.

[0119] After winding, the diameter of the fiber bundle is 0.7 mm, the conductivity is 400 S / m, the thermal conductivity is 95 W / (m·K), the tensile strength is 320 MPa, and the bending fatigue life is 1530 times.

[0120] (4) First, sort out the wound fiber bundle into yarn, then twist it at a twist of 260 turns / meter, and then use a knitting machine to form loops of the yarn and interlace the loops with each other to form a fabric at a speed of 240 revolutions per minute, and finally wind the woven fabric; wherein, the number of needles (i.e., needle density) is 10 needles per inch, and the tension is 17 N.

[0121] (5) Perform hot pressing and carbonization treatments on the fabric in sequence to obtain a carbon nanofiber reinforced carbon material fiber fabric; wherein, the temperature of the hot pressing is 270 °C, the pressure is 40 MPa, the time is 15 min, the temperature of the carbonization treatment is 1400 °C, and the time is 60 min.

[0122] The finally obtained carbon nanofiber reinforced carbon material fiber fabric has a thickness of 0.8 mm, a conductivity of 630 S / m, a thermal conductivity of 180 W / (m·K), a tensile strength of 800 MPa, and a bending fatigue life of 2200 times.

[0123] Then prepare a comparative sample, and its preparation method is basically the same as steps (1) to (5), the difference is only that: replace the carbon material fiber bundle in step (1) with the wound fiber bundle in step (3).

[0124] Compared with the control sample, the electrical conductivity of the carbon nanofiber reinforced carbon material fiber fabric is increased by 57.5%, the thermal conductivity is increased by 89.48%, the tensile strength is increased by 150%, and the flexural fatigue life is increased by 44%.

Claims

1. A method for preparing a carbon nanofiber reinforced carbon material fiber fabric, characterized in that: The weakly twisted carbon fiber bundle is fixed on an electrospinning nano yarn machine, a carbon nanofiber film is formed by electrospinning and uniformly wrapped on the weakly twisted carbon fiber bundle, and then rolled into a shaft, and then the rolled fiber bundle is woven into a fabric, and the fabric is sequentially hot-pressed and carbonized to obtain a carbon nanofiber reinforced carbon fiber fabric; Weak twisting refers to a twist of 5 to 13 twists / meter; The carbon material fiber is graphene fiber, carbon nanotube fiber or carbon fiber; The spinning solution used in electrospinning is prepared by adding a catalyst to a polyacrylonitrile solution, an asphalt solution or a viscose fiber solution, and the catalyst is one or more of ZnCl2, FeCl3 and nickel powder; The concentration of the polyacrylonitrile solution is 10-20wt%, the concentration of the asphalt solution is 10-20wt%, the concentration of the viscose fiber solution is 10-20wt%, and the amount of the catalyst used is 0.1-5wt% of the polyacrylonitrile, asphalt or viscose fiber.

2. The method for preparing a carbon nanofiber reinforced carbon material fiber fabric according to claim 1, characterized in that: The electrospinning process parameters are as follows: voltage 10~30 kV, distance between spinneret and collecting device 10~20 cm, syringe pump propulsion rate 0.5~1.5 mL / h, fiber reel winding rate 10~40 cm / min, drying temperature 60~100 ℃, spinning time 1~8 h.

3. The method for preparing a carbon nanofiber reinforced carbon material fiber fabric according to claim 2, characterized in that: The thickness of the carbon nanofiber membrane is 27~30 nm, and the average fiber diameter in the carbon nanofiber membrane is 240~260 nm.

4. The method for preparing a carbon nanofiber reinforced carbon material fiber fabric according to claim 1, characterized in that: The hot pressing temperature is 200~300℃, the pressure is 10~50MPa, and the time is 10~30min.

5. The method for preparing a carbon nanofiber reinforced carbon material fiber fabric according to claim 4, characterized in that: The temperature of carbonization treatment is 1300~1600℃ and the time is 50~80min.

6. The method for preparing a carbon nanofiber reinforced carbon material fiber fabric according to claim 1, characterized in that: The weaving method is braiding or knitting.

7. The method for preparing a carbon nanofiber reinforced carbon material fiber fabric according to any one of claims 1 to 6, characterized in that: Compared with the control sample, the electrical conductivity of carbon nanofiber reinforced carbon material fiber fabric increased by 35~100%, the thermal conductivity increased by 25~95%, the tensile strength increased by 80~200%, and the bending fatigue life increased by 25~80%; The preparation of the comparative sample is compared with the preparation of the carbon nanofiber reinforced carbon material fiber fabric, and the only difference is that the material used for weaving is the carbon material fiber bundle.

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