Conductive graphene yarn and preparation method and application thereof

Abstract

The invention discloses a conductive graphene yarn and a preparation method and application thereof, and belongs to the technical field of conductive fibers. The conductive graphene yarn prepared by the method is obtained by blending and spinning high-dispersion graphene oxide A, polyacrylonitrile and polyvinylpyrrolidone, soaking the mixture in a hydroxylamine hydrochloride solution for the first time, soaking the mixture in high-dispersion graphene oxide B for the second time, and finally soaking the mixture in the hydroxylamine hydrochloride solution for the third time. The high-dispersion graphene oxide A is obtained by adsorbing aromatic amino acid on the surface of graphene oxide through non-covalent interaction such as pi-pi; the high-dispersion graphene oxide B is obtained by adsorbing cinnamyl aldehyde on the surface of graphene oxide through non-covalent interaction such as pi-pi; the prepared conductive graphene yarn is good in conductivity, higher in tensile strength and good in antibacterial property.

Description

Technical Field

[0001] The invention relates to a conductive graphene yarn and a preparation method and application thereof. Background Art

[0002] With the advancement of miniaturization and multifunctionality in electronic devices, electronic or conductive textiles have garnered particular attention due to their potential applications in energy storage, supercapacitors, solar cells, medical devices, and more. Compared to traditional solid materials, textiles, with their unique properties of stretchability, foldability, and washability, are ideal carriers for integrating electronic functions. Therefore, how to impart excellent electrical conductivity to textiles has become a research hotspot.

[0003] Since its discovery, graphene (G) has rapidly attracted the attention of various fields around the world with its excellent optical, electrical and mechanical properties and wide application potential. As a single-layer SP2 hybridized carbon atom structure, graphene is arranged in a perfect honeycomb lattice and is the basic building block of all carbon materials. It can be directly applied to conductive wires, electrodes, supercapacitors, sensors and other fields. In addition, by configuring the spinning solution and utilizing methods such as filling, coating, spraying and mixing, graphene fibers are also widely used in the vast textile field including wearable devices and smart textiles. However, the problem that graphene is insoluble in most organic and inorganic solvents limits its direct preparation method of the substrate.

[0004] Graphene oxide (GO), an oxidized form of graphene, contains various oxygen functional groups such as carboxylic acid, epoxy, and hydroxyl groups, and is soluble in conventional solutions. Although GO retains some of the excellent properties of graphene, such as thermal conductivity and mechanical properties, the structural defects caused by its surface oxygen functional groups severely weaken these properties, especially the near-complete loss of electrical conductivity. However, GO can be reduced through physical or chemical methods to restore its superior electrochemical and photochemical properties.

[0005] Polyacrylonitrile (PAN), also known as acrylic, achieved early industrial production in the field of man-made fibers. Due to its excellent spinnability, chemical stability, and thermal stability, PAN is often used as a polymer in electrospinning processes. In recent years, research on the preparation of conductive fibers by composite spinning using PAN as a matrix and incorporating GO has been increasing. However, the difficulty of uniformly dispersing GO in the spinning solution and its tendency to agglomerate after reduction hinder the formation of an effective conductive network within the fiber, thereby limiting the fiber's conductive properties. Furthermore, the reduction in fiber flexibility after thermal reduction of GO is a pressing issue that needs to be addressed.

[0006] In order to solve the above problems, the applicant proposed a conductive graphene yarn and a preparation method thereof. Summary of the Invention

[0007] The purpose of the present invention is to provide a conductive graphene yarn and a preparation method and application thereof, so as to solve the technical problems mentioned in the above background technology.

[0008] The technical solution for achieving the purpose of the present invention is:

[0009] In a first aspect, the present invention provides a conductive graphene yarn, comprising a graphene / polyacrylonitrile fiber and a graphene layer coated on the outside of the graphene / polyacrylonitrile fiber; highly dispersed graphene oxide A is first blended with polyacrylonitrile and polyvinyl pyrrolidone and spun, then soaked in a hydroxylamine hydrochloride solution for the first time, then soaked in a highly dispersed graphene oxide B for a second time, and finally soaked in a hydroxylamine hydrochloride solution for a third time to obtain the result.

[0010] Furthermore, the highly dispersed graphene oxide A is obtained by adsorbing aromatic amino acids on the surface of graphene oxide through non-covalent interactions such as π-π.

[0011] Furthermore, the highly dispersed graphene oxide B is obtained by adsorbing cinnamaldehyde on the surface of graphene oxide through non-covalent interactions such as π-π.

[0012] In a second aspect, the present invention provides a method for preparing the conductive graphene yarn as described in the first aspect, the preparation steps comprising:

[0013] (1) Highly dispersed graphene oxide A is mixed with N,N-dimethylformamide, and then ultrasonically dispersed and polyacrylonitrile and polyvinyl pyrrolidone are added, and stirring is continued for 3.5 to 4.5 hours to obtain a polyacrylonitrile composite spinning solution;

[0014] (2) electrospinning the polyacrylonitrile composite spinning solution obtained in step (1), soaking the solution in deionized water for 2 h to remove polyvinyl pyrrolidone, and drying the solution in an oven at 60° C. for 23 to 25 h to obtain graphene oxide / polyacrylonitrile fibers;

[0015] (3) soaking the graphene oxide / polyacrylonitrile fiber obtained in step (2) in a hydroxylamine hydrochloride solution, and adjusting the pH to about 7 with a sodium hydroxide solution, and then reacting at a constant temperature of 74 to 76° C. for 2.5 to 3.5 hours, then adding ammonia water and heating the temperature to 88 to 92° C., continuing the constant temperature oscillation reaction for 55 to 65 minutes, removing the fiber, washing it with deionized water until the washed solution is neutral and drying it, and then immersing it in an aqueous solution dissolved with 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide at a constant temperature of 30° C. for 12 hours, removing the fiber, washing it with deionized water 3 to 4 times, and drying it to obtain the graphene / polyacrylonitrile fiber;

[0016] (4) adding the graphene / polyacrylonitrile fiber prepared in step (3) to an ethanol dispersion of 1-5 mg / mL highly dispersed graphene oxide B with a mass of 15 times that of the graphene / polyacrylonitrile fiber, followed by adding 0.4-4 parts by mass of potassium hydroxide with a mass of the graphene / polyacrylonitrile fiber, and ultrasonically immersing the mixture at 60° C. for 1-20 h;

[0017] (5) The graphene / polyacrylonitrile fiber soaked in step (4) is subjected to constant temperature oscillation reaction at 90° C. in a mixture of hydroxylamine hydrochloride and ammonia water for 55 to 65 minutes.

[0018] Furthermore, the preparation method of the highly dispersed graphene oxide A is as follows: 0.2 to 0.4 parts by mass of aromatic amino acid and 2 parts by mass of N,N-dimethylformamide are mixed, ultrasonicated for 10 to 20 minutes, and then a graphene oxide dispersion containing 15 parts by mass of graphene oxide is added, ultrasonicated at 50°C for 5 hours, filtered, and then vacuum dried at 70°C for 24 hours to obtain highly dispersed graphene oxide A.

[0019] Furthermore, the preparation method of the highly dispersed graphene oxide B is as follows: 0.4 to 0.8 parts by mass of cinnamaldehyde and 2 parts by mass of N,N-dimethylformamide are mixed, ultrasonicated for 10 to 20 minutes, and then a graphene oxide dispersion containing 15 parts by mass of graphene oxide is added, ultrasonicated at 50°C for 5 hours, filtered, and then vacuum dried at 70°C for 24 hours to obtain highly dispersed graphene oxide B.

[0020] Furthermore, in the step (1), the mass ratio of highly dispersed graphene oxide A, N,N-dimethylformamide, polyacrylonitrile and polyvinyl pyrrolidone is 5-10:70-90:5-20:3-12.

[0021] Furthermore, in the step (3), the mass ratio of the graphene oxide / polyacrylonitrile fiber, the hydroxylamine hydrochloride solution, the ammonia water, and the aqueous solution dissolved with 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide is 2:100:0.35-0.36:200; wherein the concentration of the hydroxylamine hydrochloride solution is 0.4 mol / L, the concentration of the ammonia water is 30%, and the mass ratio of 1-ethyl-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide, and water in the aqueous solution dissolved with 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide is 1.18-1.20:0.23-0.25:100.

[0022] Furthermore, the mass ratio of hydroxylamine hydrochloride to 30% ammonia water in the mixed solution of hydroxylamine hydrochloride and ammonia water is 1:7.18-7.28.

[0023] In a third aspect, the present invention provides an application of the conductive graphene yarn as described in the first aspect, wherein the conductive graphene yarn is applied to wearable devices, smart textiles, and acts as a conductor in a circuit.

[0024] By adopting the above technical solution, the present invention has the following beneficial effects:

[0025] (1) The conductive graphene yarn of the present invention comprises a graphene / polyacrylonitrile fiber and a graphene layer coated on the outside of the graphene / polyacrylonitrile fiber; highly dispersed graphene oxide A is first blended with polyacrylonitrile and polyvinyl pyrrolidone and spun, then soaked in a hydroxylamine hydrochloride solution for the first time, then soaked in a highly dispersed graphene oxide B for a second time, and finally soaked in a hydroxylamine hydrochloride solution for a third time to obtain the conductive graphene yarn. The conductive graphene yarn has good conductivity, higher tensile strength, better flexibility, toughness and antibacterial properties, and can be used as a conductor, conductive fabric, supercapacitor, etc. The process of the present invention is simple, the cost is low, and it is easy to industrialize.

[0026] (2) The present invention improves the dispersibility of graphene oxide by introducing polar groups such as amino groups, carboxyl groups, and aldehyde groups on the surface of graphene oxide through aromatic amino acids and cinnamaldehyde through non-covalent interactions such as π-π. At the same time, cinnamaldehyde has good antibacterial and antioxidant properties. Cinnamaldehyde is adsorbed on the surface of graphene oxide through non-covalent interactions such as π-π to obtain highly dispersed graphene oxide B, which is then attached to the outside of graphene / polyacrylonitrile fiber, effectively improving the antibacterial properties of the conductive graphene yarn.

[0027] (4) The present invention first blends highly dispersed graphene oxide A with polyacrylonitrile and polyvinyl pyrrolidone and spins the blended fibers, and then soaks the blended fibers in deionized water to remove the polyvinyl pyrrolidone, thereby obtaining a porous graphene oxide / polyacrylonitrile fiber, thereby ensuring that the graphene oxide / polyacrylonitrile fiber is fully soaked. The graphene oxide / polyacrylonitrile fiber is then soaked in a hydroxylamine hydrochloride solution, and the graphene oxide is chemically reduced to obtain graphene. At the same time, the polyacrylonitrile fiber is also subjected to amidoximation. The amino groups of the amidoximated polyacrylonitrile fiber react and graft with the carboxyl groups on the surface of the highly dispersed graphene oxide A, thereby firmly dispersing the graphene in the graphene / polyacrylonitrile fiber, thereby ensuring the conductivity and mechanical properties of the graphene / polyacrylonitrile fiber.

[0028] (5) The present invention attaches the highly dispersed graphene oxide B layer to the outside of the graphene / polyacrylonitrile fiber by soaking, and the aldehyde group on the highly dispersed graphene oxide B layer reacts with the amino group on the graphene / polyacrylonitrile fiber to form an imine bond connection, and then soaks it in a hydroxylamine hydrochloride solution to reduce the graphene oxide in the highly dispersed graphene oxide B layer, and uniformly attaches the conductive graphene layer to the outside of the graphene / polyacrylonitrile fiber, thereby ensuring the conductivity and mechanical properties of the conductive graphene yarn. At the same time, the conductive graphene layer is connected to the graphene in the graphene / polyacrylonitrile fiber through the imine bond to form a conductive path, further enhancing the conductivity of the conductive graphene yarn.

[0029] (6) The graphene / polyacrylonitrile fiber and the graphene in the graphene layer of the present invention are obtained by chemically reducing graphene oxide with hydroxylamine hydrochloride. Compared with the traditional thermal reduction method, it can effectively avoid the problem of brittle mechanical properties of the yarn after reduction, and effectively expand the application of conductive graphene yarn in the field of smart wearable textiles. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments and in conjunction with the accompanying drawings, wherein

[0031] Figure 1 The conductive graphene yarn and the fabric woven with the conductive graphene yarn according to an embodiment of the present invention are shown in FIG.

[0032] The numbers in the accompanying drawings are: 1-conductive graphene yarn, 2-fabric woven from conductive graphene yarn. DETAILED DESCRIPTION

[0033] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0034] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.

[0035] The following examples are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0036] The aromatic amino acid used is tryptophan.

[0037] (Example 1)

[0038] A method for preparing a conductive graphene yarn, the preparation steps comprising:

[0039] (1) Highly dispersed graphene oxide A was mixed with N,N-dimethylformamide, and then ultrasonically dispersed for 3 hours until uniformly dispersed. Polyacrylonitrile and polyvinyl pyrrolidone were added, and the mixture was stirred at 50°C for 3.5 hours to obtain a polyacrylonitrile composite spinning solution; wherein the mass ratio of highly dispersed graphene oxide A, N,N-dimethylformamide, polyacrylonitrile, and polyvinyl pyrrolidone was 5:75:20:12;

[0040] (2) The polyacrylonitrile composite spinning solution obtained in step (1) was subjected to electrospinning and then friction spinning to form yarn, which was then immersed in deionized water for 2 h to remove polyvinyl pyrrolidone and dried in an oven at 60° C. for 23 h to obtain graphene oxide / polyacrylonitrile fiber; the electrospinning parameters were set as follows: 24 kV DC voltage, 20 cm needle receiving distance, and solution injection speed of 5 mm / min.

[0041] (3) The graphene oxide / polyacrylonitrile fiber prepared in step (2) was immersed in a 0.4 mol / L hydroxylamine hydrochloride solution, and the pH was adjusted to about 7 with a 20% sodium hydroxide solution, and then the fiber was subjected to constant temperature oscillation reaction at 74°C for 2.5 h, and then 30% ammonia water was added and the temperature was raised to 88°C, and the constant temperature oscillation reaction was continued for 55 min, and the fiber was removed and washed with deionized water until the washed solution was neutral and dry, and then immersed in an aqueous solution of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide and the constant temperature oscillation reaction was carried out at 30°C for 12 h, and the fiber was removed and washed with deionized water. The graphene / polyacrylonitrile fiber was washed with ionized water four times and dried to obtain the graphene / polyacrylonitrile fiber; wherein the mass ratio of the graphene oxide / polyacrylonitrile fiber, the hydroxylamine hydrochloride solution, the ammonia water, and the aqueous solution containing 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide was 2:100:0.35:200; and the mass ratio of 1-ethyl-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide, and water in the aqueous solution containing 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide was 1.18:0.23:100;

[0042] (4) The graphene / polyacrylonitrile fiber prepared in step (3) is added to an ethanol dispersion of 5 mg / mL highly dispersed graphene oxide B with a mass of 15 times that of the graphene / polyacrylonitrile fiber, followed by adding 2 parts by mass of potassium hydroxide with a mass of the graphene / polyacrylonitrile fiber, and ultrasonically soaking the mixture at 60° C. for 15 h; wherein the mass ratio of hydroxylamine hydrochloride to 30% ammonia water in the mixture of hydroxylamine hydrochloride and ammonia water is 1:7.18.

[0043] (5) The graphene / polyacrylonitrile fiber soaked in step (4) was subjected to constant temperature oscillation reaction at 90° C. in a mixture of hydroxylamine hydrochloride and ammonia water for 55 minutes.

[0044] The preparation method of the highly dispersed graphene oxide A is as follows: 0.2 parts by mass of aromatic amino acid and 2 parts by mass of N,N-dimethylformamide are mixed, ultrasonicated for 10 minutes, a graphene oxide dispersion containing 15 parts by mass of graphene oxide is added, ultrasonicated at 50° C. for 5 hours, filtered, and then vacuum dried at 70° C. for 24 hours to obtain highly dispersed graphene oxide A.

[0045] The preparation method of the highly dispersed graphene oxide B is as follows: 0.4 parts by mass of cinnamaldehyde and 2 parts by mass of N,N-dimethylformamide are mixed, and after ultrasonication for 10 minutes, a graphene oxide dispersion containing 15 parts by mass of graphene oxide is added, and ultrasonication is carried out at 50° C. for 5 hours. After filtration, it is placed in a vacuum drying at 70° C. for 24 hours to obtain highly dispersed graphene oxide B.

[0046] (Example 2)

[0047] A method for preparing a conductive graphene yarn, the preparation steps comprising:

[0048] (1) Highly dispersed graphene oxide A was mixed with N,N-dimethylformamide, and then ultrasonically dispersed for 3 hours until uniformly dispersed. Polyacrylonitrile and polyvinyl pyrrolidone were added, and the mixture was stirred at 50°C for 4 hours to obtain a polyacrylonitrile composite spinning solution; wherein the mass ratio of highly dispersed graphene oxide A, N,N-dimethylformamide, polyacrylonitrile, and polyvinyl pyrrolidone was 5:75:20:12;

[0049] (2) The polyacrylonitrile composite spinning solution obtained in step (1) was subjected to electrospinning and then friction spinning to form yarn, which was then immersed in deionized water for 2 h to remove polyvinyl pyrrolidone and dried in an oven at 60° C. for 24 h to obtain graphene oxide / polyacrylonitrile fiber; the electrospinning parameters were set as follows: 24 kV DC voltage, 20 cm needle receiving distance, and solution injection speed of 5 mm / min.

[0050] (3) The graphene oxide / polyacrylonitrile fiber prepared in step (2) was immersed in a 0.4 mol / L hydroxylamine hydrochloride solution, and the pH was adjusted to about 7 with a 20% sodium hydroxide solution, and then the reaction was carried out at 75°C for 3 hours at a constant temperature and oscillation, and then 30% ammonia water was added and the temperature was raised to 90°C, and the reaction was continued at a constant temperature and oscillation for 60 minutes, and then the fiber was removed and washed with deionized water until the washed solution was neutral and dry, and then immersed in an aqueous solution of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide and the reaction was carried out at 30°C for 12 hours at a constant temperature and oscillation, and then the fiber was removed and washed with deionized water. Washing 4 times and drying to obtain graphene / polyacrylonitrile fiber; wherein the mass ratio of graphene oxide / polyacrylonitrile fiber, hydroxylamine hydrochloride solution, ammonia water, and an aqueous solution containing 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide is 2:100:0.356:200; and the mass ratio of 1-ethyl-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide, and water in the aqueous solution containing 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide is 1.189:0.238:100;

[0051] (4) The graphene / polyacrylonitrile fiber prepared in step (3) is added to an ethanol dispersion of 5 mg / mL highly dispersed graphene oxide B with a mass of 15 times that of the graphene / polyacrylonitrile fiber, followed by adding 3 parts by mass of potassium hydroxide with a mass of the graphene / polyacrylonitrile fiber, and ultrasonically soaking the mixture at 60°C for 15 hours; wherein the mass ratio of hydroxylamine hydrochloride to 30% ammonia water in the mixture of hydroxylamine hydrochloride and ammonia water is 1:7.23.

[0052] (5) The graphene / polyacrylonitrile fiber soaked in step (4) is subjected to constant temperature oscillation reaction at 90° C. in a mixture of hydroxylamine hydrochloride and ammonia water for 60 minutes.

[0053] The preparation method of the highly dispersed graphene oxide A is as follows: 0.3 parts by mass of aromatic amino acid and 2 parts by mass of N,N-dimethylformamide are mixed, ultrasonicated for 15 minutes, a graphene oxide dispersion containing 15 parts by mass of graphene oxide is added, ultrasonicated at 50° C. for 5 hours, filtered, and then vacuum dried at 70° C. for 24 hours to obtain highly dispersed graphene oxide A.

[0054] The preparation method of the highly dispersed graphene oxide B is as follows: 0.6 parts by mass of cinnamaldehyde and 2 parts by mass of N,N-dimethylformamide are mixed, and after ultrasonication for 15 minutes, a graphene oxide dispersion containing 15 parts by mass of graphene oxide is added, and ultrasonication is carried out at 50° C. for 5 hours. After filtration, it is placed in a vacuum drying at 70° C. for 24 hours to obtain highly dispersed graphene oxide B.

[0055] (Example 3)

[0056] A method for preparing a conductive graphene yarn, the preparation steps comprising:

[0057] (1) Highly dispersed graphene oxide A was mixed with N,N-dimethylformamide, and then ultrasonically dispersed for 3 hours until uniformly dispersed. Polyacrylonitrile and polyvinyl pyrrolidone were added, and the mixture was stirred at 50°C for 4.5 hours to obtain a polyacrylonitrile composite spinning solution; wherein the mass ratio of highly dispersed graphene oxide A, N,N-dimethylformamide, polyacrylonitrile, and polyvinyl pyrrolidone was 5:75:20:12;

[0058] (2) The polyacrylonitrile composite spinning solution obtained in step (1) was subjected to electrospinning and then friction spinning to form yarn, which was then immersed in deionized water for 2 h to remove polyvinyl pyrrolidone and dried in an oven at 60° C. for 25 h to obtain graphene oxide / polyacrylonitrile fiber; the electrospinning parameters were set as follows: 24 kV DC voltage, 20 cm needle receiving distance, and solution injection speed of 5 mm / min.

[0059] (3) The graphene oxide / polyacrylonitrile fiber prepared in step (2) was soaked in a 0.4 mol / L hydroxylamine hydrochloride solution, and the pH was adjusted to about 7 with a 20% sodium hydroxide solution, and then the reaction was carried out at a constant temperature of 76 ° C for 3.5 h, and then 30% ammonia water was added and the temperature was raised to 92 ° C, and the reaction was continued at a constant temperature of 65 min, and then the fiber was removed and washed with deionized water until the washed solution was neutral and dry, and then immersed in an aqueous solution of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide and the reaction was carried out at a constant temperature of 30 ° C for 12 h, and then the fiber was removed and washed with deionized water. The graphene / polyacrylonitrile fiber was washed with ionized water four times and dried to obtain the graphene / polyacrylonitrile fiber; wherein the mass ratio of the graphene oxide / polyacrylonitrile fiber, the hydroxylamine hydrochloride solution, the ammonia water, and the aqueous solution containing 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide was 2:100:0.36:200; and the mass ratio of 1-ethyl-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide, and water in the aqueous solution containing 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide was 1.20:0.25:100;

[0060] (4) The graphene / polyacrylonitrile fiber prepared in step (3) is added to an ethanol dispersion of 5 mg / mL highly dispersed graphene oxide B with a mass of 15 times that of the graphene / polyacrylonitrile fiber, followed by adding 4 parts by mass of potassium hydroxide with a mass of the graphene / polyacrylonitrile fiber, and ultrasonically soaking the mixture at 60° C. for 15 hours; wherein the mass ratio of hydroxylamine hydrochloride to 30% ammonia water in the mixture of hydroxylamine hydrochloride and ammonia water is 1:7.28.

[0061] (5) The graphene / polyacrylonitrile fiber soaked in step (4) was subjected to constant temperature oscillation reaction at 90° C. in a mixture of hydroxylamine hydrochloride and ammonia for 65 minutes.

[0062] The preparation method of the highly dispersed graphene oxide A is as follows: 0.4 parts by mass of aromatic amino acid and 2 parts by mass of N,N-dimethylformamide are mixed, and after ultrasonication for 20 minutes, a graphene oxide dispersion containing 15 parts by mass of graphene oxide is added, and ultrasonication is performed at 50° C. for 5 hours. After filtration, the mixture is placed in a vacuum drying at 70° C. for 24 hours to obtain highly dispersed graphene oxide A.

[0063] The preparation method of the highly dispersed graphene oxide B is as follows: 0.8 parts by mass of cinnamaldehyde and 2 parts by mass of N,N-dimethylformamide are mixed, and after ultrasonication for 20 minutes, a graphene oxide dispersion containing 15 parts by mass of graphene oxide is added, and ultrasonication is carried out at 50° C. for 5 hours. After filtration, the mixture is placed in a vacuum drying at 70° C. for 24 hours to obtain highly dispersed graphene oxide B.

[0064] (Comparative Example 1)

[0065] The difference between Comparative Example 1 and Example 2 is that when preparing the conductive graphene yarn, graphene oxide is first blended with polyacrylonitrile and polyvinyl pyrrolidone and spun, then soaked in hydroxylamine hydrochloride solution for the first time, then soaked in highly dispersed graphene oxide B for a second time, and finally soaked in hydroxylamine hydrochloride solution for three times. The remaining steps and components are the same as in Example 2.

[0066] (Comparative Example 2)

[0067] The difference between Comparative Example 2 and Example 2 is that when preparing the conductive graphene yarn, highly dispersed graphene oxide A is first blended with polyacrylonitrile and polyvinyl pyrrolidone and spun, then immersed in highly dispersed graphene oxide B for the first time, and finally immersed in hydroxylamine hydrochloride solution for the second time. The remaining steps and components are the same as those in Example 2.

[0068] (Comparative Example 3)

[0069] The difference between Comparative Example 3 and Example 2 is that when preparing the conductive graphene yarn, highly dispersed graphene oxide A and polyacrylonitrile are first blended and spun, then soaked in a hydroxylamine hydrochloride solution for the first time, then soaked in a highly dispersed graphene oxide B for a second time, and finally soaked in a hydroxylamine hydrochloride solution for three times. The remaining steps and components are the same as in Example 2.

[0070] (Comparative Example 4)

[0071] The difference between Comparative Example 4 and Example 2 is that when preparing the conductive graphene yarn, highly dispersed graphene oxide A is first blended with polyacrylonitrile and polyvinyl pyrrolidone and spun, then soaked in hydroxylamine hydrochloride solution for the first time, then soaked in graphene oxide for a second time, and finally soaked in hydroxylamine hydrochloride solution for three times. The remaining steps and components are the same as in Example 2.

[0072] (Comparative Example 5)

[0073] The difference between Comparative Example 5 and Example 2 is that when preparing the conductive graphene yarn, graphene oxide and polyacrylonitrile are first blended and spun, then immersed in graphene oxide for the first time, and then immersed in hydroxylamine hydrochloride solution for the second time. The remaining steps and components are the same as Example 2.

[0074] (Effect Example)

[0075] Table 1 below shows the performance test results of the conductive graphene yarns prepared in Examples 1 to 3 and Comparative Examples 1 to 5:

[0076] Table 1

[0077]

[0078]

[0079] As can be seen from Table 1, the conductive graphene yarns prepared in Examples 1 to 3 have good conductivity, flexibility and tensile strength.

[0080] The difference between Comparative Example 1 and Example 2 is that the graphene oxide / polyacrylonitrile fiber of the conductive graphene yarn is obtained only by blending graphene oxide with polyacrylonitrile and polyvinyl pyrrolidone, and no highly dispersed graphene oxide A modified with aromatic amino acids is used. The dispersion of graphene oxide in the spinning solution is poor and a smooth conductive network cannot be formed, which also causes the conductivity, flexibility and tensile strength of the conductive graphene yarn to be weaker than those of the embodiment.

[0081] The difference between Comparative Example 2 and Example 2 is that when the conductive graphene yarn is prepared, it is not soaked in the hydroxylamine hydrochloride solution for the first time, the degree of cross-linking between the highly dispersed graphene oxide A and the polyacrylonitrile is relatively small, and the graphene oxide in the graphene oxide / polyacrylonitrile fiber cannot be completely reduced, and a smooth conductive network cannot be formed in the conductive graphene yarn, which also causes the conductivity, flexibility, and tensile strength of the conductive graphene yarn to be weaker than those of the embodiment.

[0082] The difference between Comparative Example 3 and Example 2 is that the graphene oxide / polyacrylonitrile fiber is obtained only by blending and spinning highly dispersed graphene oxide A and polyacrylonitrile. The graphene oxide inside the graphene oxide / polyacrylonitrile fiber cannot be reduced and the polyacrylonitrile inside the graphene oxide / polyacrylonitrile fiber cannot be amidoximated, which also causes the conductivity, flexibility and tensile strength of the conductive graphene yarn to be weaker than those of the embodiment.

[0083] The only difference between Comparative Example 4 and Example 2 is that graphene oxide is attached to the surface of the graphene / polyacrylonitrile fiber instead of cinnamaldehyde-modified graphene oxide. The graphene oxide attached to the surface of the graphene / polyacrylonitrile fiber is uneven, and the attachment stability and conductive connectivity of the outer graphene layer outside the internal graphene / polyacrylonitrile fiber are weak, which also causes the conductivity, flexibility, and tensile strength of the conductive graphene yarn to be weaker than those of the embodiment.

[0084] Comparative Example 5 is a conductive graphene yarn of graphene oxide / polyacrylonitrile fiber wrapped with a graphene layer, and its conductivity, flexibility and tensile strength are worse than those of Examples 1 to 3.

[0085] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A conductive graphene yarn, characterized in that: The method comprises graphene / polyacrylonitrile fiber and a graphene layer coated on the outside of the graphene / polyacrylonitrile fiber; highly dispersed graphene oxide A is first blended with polyacrylonitrile and polyvinyl pyrrolidone and spun, then soaked in a hydroxylamine hydrochloride solution for the first time, then soaked in a highly dispersed graphene oxide B for the second time, and finally soaked in a hydroxylamine hydrochloride solution for the third time to obtain the obtained fiber.

2. The conductive graphene yarn according to claim 1, characterized in that The highly dispersed graphene oxide A is obtained by adsorbing aromatic amino acids on the surface of graphene oxide through non-covalent interactions such as π-π.

3. The conductive graphene yarn according to claim 1, characterized in that The highly dispersed graphene oxide B is obtained by adsorbing cinnamaldehyde on the surface of graphene oxide through non-covalent interactions such as π-π.

4. A method for preparing a conductive graphene yarn according to any one of claims 1 to 3, characterized in that: The preparation steps include: (1) Highly dispersed graphene oxide A is mixed with N,N-dimethylformamide, and then ultrasonically dispersed and polyacrylonitrile and polyvinyl pyrrolidone are added, and stirring is continued for 3.5 to 4.5 hours to obtain a polyacrylonitrile composite spinning solution; (2) electrospinning the polyacrylonitrile composite spinning solution obtained in step (1), soaking it in deionized water for 2 hours, and drying it in an oven at 60° C. for 23 to 25 hours to obtain graphene oxide / polyacrylonitrile fibers; (3) soaking the graphene oxide / polyacrylonitrile fiber obtained in step (2) in a hydroxylamine hydrochloride solution, and adjusting the pH to about 7 with a sodium hydroxide solution, and then reacting at a constant temperature of 74 to 76° C. for 2.5 to 3.5 hours, then adding ammonia water and heating the temperature to 88 to 92° C., continuing the constant temperature oscillation reaction for 55 to 65 minutes, removing the fiber, washing it with deionized water until the washed solution is neutral and drying it, and then immersing it in an aqueous solution dissolved with 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide at a constant temperature of 30° C. for 12 hours, removing the fiber, washing it with deionized water 3 to 4 times, and drying it to obtain the graphene / polyacrylonitrile fiber; (4) adding the graphene / polyacrylonitrile fiber prepared in step (3) to an ethanol dispersion of 1-5 mg / mL highly dispersed graphene oxide B with a mass of 15 times that of the graphene / polyacrylonitrile fiber, followed by adding 0.4-4 parts by mass of potassium hydroxide with a mass of the graphene / polyacrylonitrile fiber, and ultrasonically immersing the mixture at 60° C. for 1-20 h; (5) The graphene / polyacrylonitrile fiber soaked in step (4) is subjected to constant temperature oscillation reaction at 90° C. in a mixture of hydroxylamine hydrochloride and ammonia water for 55 to 65 minutes.

5. The method for preparing the conductive graphene yarn according to claim 4, wherein: The preparation method of the highly dispersed graphene oxide A is as follows: 0.2 to 0.4 parts by mass of aromatic amino acid and 2 parts by mass of N,N-dimethylformamide are mixed, ultrasonicated for 10 to 20 minutes, then a graphene oxide dispersion containing 15 parts by mass of graphene oxide is added, ultrasonicated at 50° C. for 5 hours, filtered, and then vacuum dried at 70° C. for 24 hours to obtain highly dispersed graphene oxide A.

6. The method for preparing the conductive graphene yarn according to claim 4, wherein: The preparation method of the highly dispersed graphene oxide B is as follows: 0.4 to 0.8 parts by mass of cinnamaldehyde and 2 parts by mass of N,N-dimethylformamide are mixed, ultrasonicated for 10 to 20 minutes, and then a graphene oxide dispersion containing 15 parts by mass of graphene oxide is added. The mixture is ultrasonicated at 50° C. for 5 hours, filtered, and then vacuum dried at 70° C. for 24 hours to obtain highly dispersed graphene oxide B.

7. The method for preparing the conductive graphene yarn according to claim 4, wherein: In the step (1), the mass ratio of highly dispersed graphene oxide A, N,N-dimethylformamide, polyacrylonitrile and polyvinyl pyrrolidone is 5-10:70-90:5-20:3-12.

8. The method for preparing the conductive graphene yarn according to claim 4, wherein: In the step (3), the mass ratio of graphene oxide / polyacrylonitrile fiber, hydroxylamine hydrochloride solution, ammonia water, and an aqueous solution dissolved with 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide is 2:100:0.35-0.36:200; wherein the concentration of the hydroxylamine hydrochloride solution is 0.4 mol / L, the concentration of the ammonia water is 30%, and the mass ratio of 1-ethyl-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide, and water in the aqueous solution dissolved with 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide is 1.18-1.20:0.23-0.25:

100.

9. The method for preparing the conductive graphene yarn according to claim 4, wherein: The mass ratio of hydroxylamine hydrochloride to 30% ammonia water in the mixed solution of hydroxylamine hydrochloride and ammonia water is 1:7.18-7.

28.

10. A use of the conductive graphene yarn according to any one of claims 1 to 3, characterized in that: The conductive graphene yarn is used in wearable devices, smart textiles, and serves as a conductor in a circuit.

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