A carbon nanocomposite conductive material and its application in cable shielding layer

Abstract

The present invention discloses a carbon nanocomposite conductive material and its application in cable shielding layers, belonging to the technical field of conductive shielding materials. The material comprises 20-35 parts of magnetic iron / PEDOT:PSS nanoparticles and 40-65 parts of a carbon nanomaterial; the magnetic iron / PEDOT:PSS nanoparticles are obtained by modifying the surface of magnetic iron nanoparticles with 3,4-ethylenedioxythiophene:poly(styrene sulfonic acid); and the carbon nanomaterial is one or more of carbon black, graphene oxide, reduced graphene oxide, and carbon nanotubes. By using the carbon material as the conductive material and adding the magnetic iron / PEDOT:PSS nanoparticles to replace some of the conductive fillers, the cable has the advantages of strong anti-interference ability, light weight, high strength, and good flexibility.

Description

Technical Field

[0001] The present invention belongs to the technical field of conductive shielding materials, and in particular relates to a carbon nanocomposite conductive material and its application in a cable shielding layer. Background Art

[0002] Monitoring medical devices are primarily used for clinical monitoring, providing real-time monitoring of patients' heart rate, blood pressure, blood oxygen, fetal heart rate, respiration, and other physiological parameters. These devices provide real-time information on patients' vital signs and assist medical staff in observing their physical condition. However, functional failures or malfunctions during use can lead to monitoring failures and even mislead medical staff in their diagnosis and treatment. Monitoring medical devices typically transmit small signals. At low frequencies, the wavelength is generally much larger than the length of the holes in the casing. Electromagnetic waves in space have difficulty passing through the holes in the metal casing. However, the device's external cables, including power cables, signal cables, and ground cables, can be several wavelengths long. These cables act as receiving antennas, receiving electromagnetic interference waves in space and inducing interference voltages or currents, which are then coupled into the device via common-mode conduction.

[0003] A common cable structure includes a conductor, insulation layer, shielding layer, and outer sheath. The shielding layer effectively blocks electromagnetic interference. Traditional electromagnetic shielding materials are metal, a rigid material that primarily utilizes the metal's inherent conductivity and magnetism to reflect, absorb, and attenuate electromagnetic waves. Conductive metals include silver and copper, while magnetic metals include pure iron and iron-nickel alloys. However, one of the main drawbacks of metal electromagnetic shielding materials is their heavy weight. Furthermore, metal's high rigidity makes it difficult to adapt to flexible surfaces or bends, limiting its application in monitoring medical device cables. In recent years, a number of novel electromagnetic shielding materials have emerged, including fillers such as conductive rubber, conductive foam, and conductive adhesives, as well as surface-coated electromagnetic shielding materials such as conductive fabrics. These materials have greatly expanded the application of electromagnetic shielding technology in various fields. Carbon nanomaterials, with their excellent electromagnetic shielding properties, superior mechanical properties, good chemical stability, and corrosion resistance, are excellent fillers for insulation layers. However, their shielding effectiveness against interference from low-frequency magnetic fields is limited. Summary of the Invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the present invention provides a carbon nanocomposite conductive material, which uses carbon material as a conductive material and adds magnetic iron / PEDOT:PSS nanoparticles to replace part of the conductive filler, so that the cable has the advantages of strong anti-interference ability, light weight and good flexibility. The magnetic iron / PEDOT:PSS nanoparticles are grafted with conductive polymers on the surface of the magnetic iron nanoparticles, thereby improving the dispersibility, stability and conductivity of the magnetic iron nanoparticles. The magnetic core has excellent magnetic properties, and the outer layer is a conductive polymer, which can achieve electromagnetic synergy between magnetic loss and dielectric loss.

[0005] The technical solution for achieving the purpose of the present invention is as follows: a carbon nanocomposite conductive material, comprising, by weight, 20 to 35 parts of magnetic iron / PEDOT:PSS nanoparticles and 40 to 65 parts of carbon nanomaterials; the magnetic iron / PEDOT:PSS nanoparticles are obtained by modifying the surface of magnetic iron nanoparticles with 3,4-ethylenedioxythiophene:poly(styrenesulfonic acid); the carbon nanomaterial is one or more of carbon black, graphene oxide, reduced graphene oxide, and carbon nanotubes.

[0006] The preparation method of the magnetic iron / PEDOT:PSS nanoparticles is as follows:

[0007] S1. The hydroxyl groups on the surface of the magnetic iron nanoparticles react with the halogenated acyl halide to obtain modified magnetic iron nanoparticles;

[0008] S2. The halogen atoms of the modified magnetic iron nanoparticles are used to initiate the polymerization of sodium 4-vinylbenzenesulfonate to obtain magnetic iron nanoparticles with surface grafted poly(styrenesulfonic acid), and then 3,4-ethylenedioxythiophene is polymerized by benzoyl oxide to obtain magnetic iron / PEDOT:PSS nanoparticles.

[0009] More preferably, the preparation method of the magnetic iron / PEDOT:PSS nanoparticles is as follows:

[0010] S1. Ultrasonic dispersion of magnetic iron nanoparticles in an anhydrous solvent. Under an inert atmosphere, an acid-binding agent is added. A halogenated acyl halide is dissolved in an anhydrous solvent and slowly added dropwise to the mixture. The mixture is stirred at room temperature for 24–48 h, centrifuged, and the solid product is collected and vacuum-dried to obtain modified magnetic iron nanoparticles.

[0011] S2. Sodium 4-vinylbenzenesulfonate, chloride or bromide salt, and polar protic solvent are added to a reactor under stirring. The modified magnetic iron nanoparticles obtained in step S1 are added together with sodium hydroxide solution. The pH is adjusted to 6-10. After freeze-thaw degassing, cuprous ions and ligand 2,2'-bipyridine are added and reacted at room temperature for 3-6 hours. After the reaction is completed, oxygen is introduced into the reaction system under ice bath conditions to terminate the polymerization reaction. The pH is adjusted to 4-6, and the solution is centrifuged. The solid product is collected and dispersed in water. The solution is divided into two equal parts, and benzoyl peroxide is added to one part and 3,4-ethylenedioxythiophene is added to the other part. The two solutions are mixed and stirred continuously at room temperature for 16-48 hours. The resulting solution is post-treated to obtain magnetic iron / PEDOT:PSS nanoparticles.

[0012] Preferably, the magnetic iron nanoparticles are magnetic Fe3O4 nanoparticles, magnetic NiFe2O4 nanoparticles, magnetic CoFe2O4 nanoparticles, magnetic MnFe2O4 nanoparticles and magnetic BaFe 12 O 19 One or more nanoparticles.

[0013] Preferably, the magnetic iron nanoparticles are magnetic iron nanoparticles containing hydroxyl groups on the surface;

[0014] Preferably, the magnetic iron nanoparticles are obtained by a hydrothermal method.

[0015] More preferably, the magnetic iron nanoparticles are magnetic NiFe2O4 nanoparticles.

[0016] Specifically, the preparation method of the magnetic NiFe2O4 nanoparticles is as follows:

[0017] Ferric nitrate and nickel nitrate were added to deionized water at room temperature, and then 4-5 mol / L sodium hydroxide solution was slowly added to adjust the pH to 9.5-10.5. After mechanical stirring for 0.5-1 h, the solution was transferred to a Teflon-lined steel autoclave, sealed and heated at 110 °C for 10-12 h, and then naturally cooled to room temperature. The resulting solution was centrifuged, and the obtained particles were dried in an oven at 50-60 °C for 10-12 h. The above particles were placed in a muffle furnace and heated to 400 °C at a heating rate of 2-5 °C / min, maintained at 400 °C for 2 hours, and then naturally cooled to room temperature to obtain magnetic NiFe2O4 nanoparticles.

[0018] Specifically, the molar ratio of the ferric nitrate to the nickel nitrate is 2:1.

[0019] Preferably, in step S1, the halogenated acyl halide is one or more of 4-chloromethylbenzoyl chloride, 3-(chloromethyl)benzoyl chloride, 2-bromoisobutyryl bromide, 2-chloroisobutyryl chloride, chloroacetyl chloride and bromoacetyl bromide; the acid binding agent is at least one of triethylamine and pyridine; the solvent is one or more of dimethyl sulfoxide, dichloromethane and dimethylformamide; and the mass ratio of the magnetic iron nanoparticles: the acid binding agent: the halogenated acyl halide is 1: (1.5-2): (0.5-1).

[0020] More preferably, the chloride salt in step S2 is at least one of potassium chloride and sodium chloride, and the bromide salt is at least one of sodium bromide and potassium bromide; the cuprous ion is at least one of cuprous bromide or cuprous chloride; the concentration of the sodium hydroxide solution is 1~2 mol / L; the mass ratio of the modified magnetic iron nanoparticles to sodium 4-vinylbenzenesulfonate is 1:(1.5~10); the molar ratio of the sodium 4-vinylbenzenesulfonate, cuprous ions, ligand 2,2'-bipyridine, chloride salt or bromide salt is (180~230):(0.5~1):(1~2):(0.05~10); the mass ratio of sodium 4-vinylbenzenesulfonate, 3,4-ethylenedioxythiophene and benzoyl peroxide is (2~5):1:(0.5~2); the polar protic solvent is at least one of water and methanol, or water and ethanol, and the volume fraction of alcohol in the solution is 0~50%.

[0021] Preferably, the post-treatment step in step S2 is to wash the obtained solution with chloroform at least twice, adjust the pH of the obtained aqueous solution to 6-8, centrifuge, and collect the solid product to obtain magnetic iron / PEDOT:PSS nanoparticles.

[0022] The invention also discloses application of the carbon nanocomposite conductive material in a cable shielding layer.

[0023] Preferably, the cable shielding layer comprises, by weight, 90-100 parts of rubber, 10-20 parts of reinforcing agent, 60-95 parts of carbon nanocomposite conductive material, 4-5 parts of silane coupling agent, 1-1.3 parts of antioxidant, 2-4 parts of vulcanizing agent, and 1-2 parts of accelerator; the cable shielding layer is prepared by the following steps:

[0024] (1) After the carbon nanocomposite conductive material is stirred and dispersed, a reinforcing agent and a coupling agent are poured into a vacuum kneader, and then the silicone rubber is slowly added. During the mixing process, the carbon nanocomposite conductive material is added in batches. The kneader vacuum valve and exhaust valve are closed and then mixed. After the filler and the rubber are evenly mixed, the kneader is heated to 145-155 °C and mixed for 2-3 h. Then, vacuum kneading is carried out at 115-125 °C for 1-2 h. After cooling to room temperature, the silicone rubber masterbatch is obtained.

[0025] (2) Add antioxidant, vulcanizer and accelerator to the silicone rubber masterbatch using a double-roll mill, mix evenly and produce sheets, which are then extruded onto the cable insulation layer through an extruder. After vulcanization, the cable shielding layer is obtained.

[0026] Preferably, the vulcanization conditions of the silicone rubber masterbatch in step (2) are a temperature of 160-185°C, 5-20 min, and a pressure of 1.5-2.5 MPa.

[0027] Beneficial effects

[0028] The present invention has the following beneficial effects: The present invention provides a carbon nanocomposite conductive material, which uses carbon material as a conductive filler and magnetic iron / PEDOT:PSS nanoparticles to partially replace the conductive filler, thereby making the cable shielding layer have the advantages of strong anti-interference ability, light weight, high strength, and good flexibility. Modified magnetic iron nanoparticles are used as an initiator, and aqueous reversible deactivated free radical polymerization is used to directly polymerize sodium 4-vinylbenzenesulfonate. Compared with styrene polymerization followed by grafting of sulfonic acid groups, the resulting PSS has a 100% grafting rate. The magnetic iron / PEDOT:PSS nanoparticles have a conductive polymer grafted onto the surface of the magnetic iron nanoparticles, thereby improving the dispersibility, stability, and conductivity of the magnetic iron nanoparticles. The magnetic core has excellent magnetic properties, and the outer layer is a conductive polymer, which can achieve electromagnetic synergy between magnetic loss and dielectric loss, thereby effectively shielding electromagnetic interference at low, medium, and high frequencies. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the synthesis route and structure of magnetic iron / PEDOT:PSS nanoparticles of the present invention;

[0030] Figure 2 This is the infrared spectrum during the synthesis of magnetic iron / PEDOT:PSS nanoparticles of the present invention; DETAILED DESCRIPTION

[0031] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0032] In the examples, the experimental methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are all commercially available unless otherwise specified.

[0033] The raw materials and equipment used in the embodiments and comparative examples are described below:

[0034] In the examples, the experimental methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are all commercially available unless otherwise specified.

[0035] The raw materials and equipment used in the embodiments and comparative examples are described below:

[0036] Rubber: Methyl vinyl silicone rubber (MVQ110-3), vinyl content 0.19~0.24%;

[0037] Reinforcing agent: fumed silica, brand HP-200, purchased from Jiangxi Hongbai New Materials Co., Ltd.

[0038] Carbon nanomaterials: carbon nanotubes, from the carbon environment;

[0039] Silane coupling agent: vinyltriethoxysilane, purchased from Shanghai MacLean Biochemical Technology Co., Ltd.;

[0040] Antioxidant: Antioxidant 1010, purchased from Dongguan Guangsiyuan Polyurethane Materials Co., Ltd.

[0041] Curing agent: 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, Shanghai MacLean Biochemical Technology Co., Ltd.

[0042] Accelerator: triallyl isocyanurate, purchased from Shanghai MacLean Biochemical Technology Co., Ltd.

[0043] Ferric nitrate: purchased from Shanghai MacLean Biochemical Technology Co., Ltd.

[0044] Nickel nitrate: purchased from Sinopharm Reagent;

[0045] Sodium 4-vinylbenzenesulfonate: Guangzhou Yuanda New Materials;

[0046] 4-Chloromethylbenzoyl chloride: purchased from Shanghai MacLean Biochemical Technology Co., Ltd.

[0047] Cuprous chloride: purity ≥99.95%, Shanghai Boer Chemical Reagent Co., Ltd.;

[0048] 2,2'-Bipyridine: Guangzhou Yuanda New Materials;

[0049] 3,4-Ethylenedioxythiophene: purchased from Shanghai MacLean Biochemical Technology Co., Ltd.

[0050] Sodium polystyrene sulfonate: molecular weight: 50,000-100,000, purchased from Guangdong Wengjiang Chemical Reagent;

[0051] Benzoyl peroxide: purchased from Sinopharm Reagent.

[0052] Magnetic iron nanoparticles (NiFe2O4), homemade

[0053] 0.2 mol of ferric nitrate and 0.1 mol of nickel nitrate were added to 1000 ml of deionized water at room temperature, and then 5 mol / L sodium hydroxide solution was slowly added to adjust the pH to 10. After mechanical stirring for 0.5 h, the solution was transferred to a Teflon-lined steel autoclave, sealed and heated at 110 °C for 12 h, and then naturally cooled to room temperature. The resulting solution was centrifuged, and the obtained particles were dried in an oven at 60 °C for 12 h. The above particles were placed in a muffle furnace and heated to 400 °C at a heating rate of 3 °C / min, maintained at 400 °C for 2 h, and then naturally cooled to room temperature to obtain magnetic iron nanoparticles (NiFe2O4).

[0054] Magnetic iron / PEDOT:PSS nanoparticles 1

[0055] S1. 10 g of magnetic iron nanoparticles were ultrasonically dispersed in an anhydrous solvent. Under an inert atmosphere, 22 ml of triethylamine was added. 8 g of 4-chloromethylbenzoyl chloride was dissolved in anhydrous dimethyl sulfoxide and slowly added dropwise to the mixture. The mixture was stirred at room temperature for 48 h, centrifuged, and the solid product was collected and vacuum dried to obtain modified magnetic iron nanoparticles.

[0056] S2. 18 mmol (3.7 g) of sodium 4-vinylbenzenesulfonate, 0.05 mmol of sodium chloride, 25 ml of deionized water, and 11 ml of methanol solution were added to a reactor under stirring. 1.6 g of the modified magnetic iron nanoparticles obtained in step S1 were added together with 1 mol / L sodium hydroxide solution. The pH was adjusted to 6-7. After freeze-thaw degassing, 0.05 mmol of cuprous chloride and 0.1 mmol of ligand 2,2'-bipyridine were added. The reaction was allowed to react at room temperature for 3 h. After the reaction was completed, oxygen was introduced into the reaction system under ice bath conditions to terminate the polymerization reaction. The pH was adjusted to 4.5-5.5. The solution was centrifuged, the solid product was collected, and the solution was dispersed in water. The solution was divided into two equal parts. 3.0 g of benzoyl peroxide was added to one part, and 1.48 g of 3,4-ethylenedioxythiophene was added to the other part. The two solutions were mixed and stirred continuously at room temperature for 48 min. h, and the resulting solution was washed three times with chloroform. The pH of the resulting aqueous solution was adjusted to 6-8, and the solid product was collected by centrifugation to obtain magnetic iron / PEDOT:PSS nanoparticles 1.

[0057] Magnetic iron / PEDOT:PSS nanoparticles 2

[0058] S1. 10 g of magnetic iron nanoparticles were ultrasonically dispersed in an anhydrous solvent. Under an inert atmosphere, 22 ml of triethylamine was added. 8 g of 4-chloromethylbenzoyl chloride was dissolved in anhydrous dimethyl sulfoxide and slowly added dropwise to the mixture. The mixture was stirred at room temperature for 48 h, centrifuged, and the solid product was collected and vacuum dried to obtain modified magnetic iron nanoparticles.

[0059] S2. Add 23 mmol (4.7 g) of sodium 4-vinylbenzenesulfonate, 0.1 mmol of sodium chloride, 32 ml of deionized water, and 14 ml of methanol solution to a reactor under stirring. Add 2.0 g of the modified magnetic iron nanoparticles obtained in step S1 together with 1 mol / L sodium hydroxide solution. Adjust the pH to 6-7. After freeze-thaw degassing, add 0.1 mmol of cuprous chloride and 0.2 mmol of ligand 2,2'-bipyridine. React at room temperature for 3 h. After the reaction is completed, introduce oxygen into the reaction system under ice bath conditions to terminate the polymerization reaction. Adjust the pH to 4.5-5.5, centrifuge, collect the solid product, and disperse it in water. Divide it into two equal parts, add 3.8 g of benzoyl peroxide to one part, and add 1.88 g of 3,4-ethylenedioxythiophene to the other part. Mix the two solutions and continue stirring at room temperature for 48 min. h, and the resulting solution was washed three times with chloroform. The pH of the resulting aqueous solution was adjusted to 6-8, and the solid product was collected by centrifugation to obtain magnetic iron / PEDOT:PSS nanoparticles 2.

[0060] Magnetic iron / PEDOT:PSS nanoparticles 3

[0061] Compared with the preparation method of magnetic iron / PEDOT:PSS nanoparticles 2, the difference is that in step S2, 2.0 g of modified magnetic iron nanoparticles are replaced by 0.47 g.

[0062] Magnetic iron / PEDOT:PSS nanoparticles 4

[0063] Compared with the preparation method of magnetic iron / PEDOT:PSS nanoparticles 2, the difference is that in step S2, 2.0 g of modified magnetic iron nanoparticles are replaced by 0.94 g.

[0064] Magnetic iron / PEDOT:PSS nanoparticles 5

[0065] Compared with the preparation method of magnetic iron / PEDOT:PSS nanoparticles 2, the difference is that in step S2, 2.0 g of modified magnetic iron nanoparticles are replaced by 3.1 g.

[0066] PEDOT:PSS

[0067] 4.7 g of sodium polystyrene sulfonate was dispersed in water and divided into two equal parts. 3.8 g of benzoyl peroxide was added to one part, and 1.88 g of 3,4-ethylenedioxythiophene was added to the other part. The two solutions were mixed and stirred at room temperature for 48 h. The resulting solution was washed three times with chloroform. The pH of the resulting aqueous solution was adjusted to 6-8, centrifuged, and the solid product was collected to obtain PEDOT:PSS.

[0068] The cable shield is prepared by the following steps:

[0069] (1) After the carbon nanocomposite conductive material is stirred and dispersed, a reinforcing agent and a coupling agent are poured into a vacuum kneader, and then the silicone rubber is slowly added. During the mixing process, the carbon nanocomposite conductive material is added in batches. The kneader vacuum valve and exhaust valve are closed and then mixed. After the filler and the rubber are evenly mixed, the kneader is heated to 150 °C and mixed for 2 h, then vacuum-mixed at 115-125 °C for 1 h, and cooled to room temperature to obtain the silicone rubber masterbatch.

[0070] (2) Antioxidant, vulcanizer and accelerator were added to the silicone rubber masterbatch using a double-roll mill, and the mixture was uniformly mixed to form a sheet. After vulcanization at a temperature of 180 °C for 12 min and a pressure of 2.2 MPa, the thickness of the electromagnetic shielding rubber layer was 1 mm. After vulcanization, the cable shielding layer was obtained.

[0071] Table 1 Electromagnetic shielding rubber layer formulations of Examples 1 to 7 and Comparative Examples 1 to 3 (g)

[0072]

[0073] The following are the test methods for the performance parameters involved in the present invention:

[0074] Shore A hardness: In accordance with GB / T 531.1-2008, it indicates the hardness of vulcanized rubber.

[0075] Tensile properties: According to GB / T 528-2009, the tensile strength and elongation at break of the vulcanized rubber specimens were tested;

[0076] Electromagnetic shielding effectiveness test: GJB 8820-2015, vulcanized rubber is made into 15 cm × 15 cm square specimens with a thickness of 1 mm. The electromagnetic shielding effectiveness in the 10 kHz to 80 MHz frequency band is measured using the shielded room method.

[0077] Table 2 Electromagnetic shielding rubber layer performance test

[0078]

[0079] It can be seen from the data in Table 2 that the hard tensile properties of the prepared electromagnetic shielding rubber layer are all above 4.0 MPa, the average electromagnetic shielding effectiveness from 10 kHz to 300 kHz is greater than 50 dB, and the average electromagnetic shielding effectiveness from 300 kHz to 80 MHz is greater than 60 dB, which can meet the shielding effect of ordinary medical cables against power line interference and radio frequency interference.

[0080] It can be seen from the data of Examples 4 to 7 in Table 2 that the magnetic iron content mainly affects the electromagnetic shielding effectiveness in the frequency band of 10 kHz to 300 kHz. The higher the external PEDOT:PSS content, the higher the elongation at break of the electromagnetic shielding rubber layer. The data of Comparative Example 1 show that the physical properties and shielding properties of the electromagnetic shielding rubber layer obtained by ordinary physical blending of magnetic iron and PEDOT:PSS are poor.

[0081] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A carbon nanocomposite conductive material, comprising, by weight, 20-35 parts of magnetic iron / PEDOT:PSS nanoparticles and 40-65 parts of carbon nanomaterials; characterized in that: The magnetic iron / PEDOT:PSS nanoparticles are obtained by modifying the surface of magnetic iron nanoparticles with 3,4-ethylenedioxythiophene:poly(styrenesulfonic acid); the carbon nanomaterial is one or more of carbon black, graphene oxide, reduced graphene oxide, and carbon nanotubes; The preparation method of the magnetic iron / PEDOT:PSS nanoparticles is as follows: S1. The hydroxyl groups on the surface of the magnetic iron nanoparticles react with the halogenated acyl halide to obtain modified magnetic iron nanoparticles; S2. The halogen atoms of the modified magnetic iron nanoparticles are used to initiate the polymerization of sodium 4-vinylbenzenesulfonate to obtain magnetic iron nanoparticles with surface grafted poly(styrenesulfonic acid). Then, in a solution containing magnetic iron nanoparticles with surface grafted poly(styrenesulfonic acid), 3,4-ethylenedioxythiophene is polymerized by benzoyl oxide to obtain magnetic iron / PEDOT:PSS nanoparticles.

2. The carbon nanocomposite conductive material according to claim 1, wherein: The preparation method of the magnetic iron / PEDOT:PSS nanoparticles is as follows: S1. Ultrasonic dispersion of magnetic iron nanoparticles in an anhydrous solvent. Under an inert atmosphere, an acid-binding agent is added. A halogenated acyl halide is dissolved in an anhydrous solvent and slowly added dropwise to the mixture. The mixture is stirred at room temperature for 24–48 h, centrifuged, and the solid product is collected and vacuum-dried to obtain modified magnetic iron nanoparticles. S2. Sodium 4-vinylbenzenesulfonate, chloride or bromide salt, and a polar protic solvent are added to a reactor under stirring. The modified magnetic iron nanoparticles obtained in step S1 are added together with a sodium hydroxide solution. The pH is adjusted to 6-10. After freeze-thaw degassing, cuprous ions and a ligand 2,2'-bipyridine are added. The reaction is carried out at room temperature for 3-6 hours. After the reaction is completed, oxygen is introduced into the reaction system under ice bath conditions to terminate the polymerization reaction. The pH is adjusted to 4-6, and the solution is centrifuged. The solid product is collected and dispersed in water. The solution is divided into two equal parts. Benzoyl peroxide is added to one part and 3,4-ethylenedioxythiophene is added to the other part. The two solutions are mixed and stirred continuously at room temperature for 16-48 hours. The resulting solution is post-treated to obtain magnetic iron / PEDOT:PSS nanoparticles.

3. The carbon nanocomposite conductive material according to claim 1, wherein: The magnetic iron nanoparticles are magnetic Fe3O4 nanoparticles, magnetic NiFe2O4 nanoparticles, magnetic CoFe2O4 nanoparticles, magnetic MnFe2O4 nanoparticles and magnetic BaFe 12 O 19 One or more nanoparticles.

4. The carbon nanocomposite conductive material according to claim 2, wherein: In step S1, the halogenated acyl halide is one or more of 4-chloromethylbenzoyl chloride, 3-(chloromethyl)benzoyl chloride, 2-bromoisobutyryl bromide, 2-chloroisobutyryl chloride, chloroacetyl chloride and bromoacetyl bromide; the acid binding agent is at least one of triethylamine or pyridine; the solvent is one or more of dimethyl sulfoxide, dichloromethane or dimethylformamide; and the mass ratio of the magnetic iron nanoparticles: the acid binding agent: the halogenated acyl halide is 1: (1.5-2): (0.5-1).

5. The carbon nanocomposite conductive material according to claim 2, wherein: In step S2, the chloride salt is at least one of potassium chloride or sodium chloride, and the bromide salt is at least one of sodium bromide or potassium bromide; the cuprous ion is at least one of cuprous bromide or cuprous chloride; the concentration of the sodium hydroxide solution is 1-2 mol / L; the mass ratio of the modified magnetic iron nanoparticles to sodium 4-vinylbenzenesulfonate is 1:(1.5-10); the molar ratio of the sodium 4-vinylbenzenesulfonate, cuprous ions, ligand 2,2'-bipyridine, chloride salt or bromide salt is (180-230):(0.5-1):(1-2):(0.05-10); the mass ratio of sodium 4-vinylbenzenesulfonate, 3,4-ethylenedioxythiophene and benzoyl peroxide is (2-5):1:(0.5-2); the polar protic solvent is at least one of water and methanol, or water and ethanol, and the volume fraction of the alcohol in the solution is 0-50%.

6. The carbon nanocomposite conductive material according to claim 2, wherein: The post-treatment step in step S2 is to wash the obtained solution with chloroform at least twice, adjust the pH of the obtained aqueous solution to 6-8, centrifuge, and collect the solid product to obtain magnetic iron / PEDOT:PSS nanoparticles.

7. Use of the carbon nanocomposite conductive material according to any one of claims 1 to 6 in a cable shielding layer.

8. The use of a carbon nanocomposite conductive material in a cable shielding layer as claimed in claim 7, characterized in that: The cable shielding layer comprises, by weight, 90-100 parts of rubber, 10-20 parts of a reinforcing agent, 60-95 parts of a carbon nanocomposite conductive material, 4-5 parts of a silane coupling agent, 1-1.3 parts of an antioxidant, 2-4 parts of a vulcanizing agent, and 1-2 parts of an accelerator; the cable shielding layer is prepared by the following steps: (1) After the carbon nanocomposite conductive material is stirred and dispersed, a reinforcing agent and a coupling agent are poured into a vacuum kneader, and then the silicone rubber is slowly added. During the mixing process, the carbon nanocomposite conductive material is added in batches. The kneader vacuum valve and exhaust valve are closed and then mixed. After the filler and the rubber are evenly mixed, the kneader is heated to 145-155 °C and mixed for 2-3 h. Then, vacuum kneading is carried out at 115-125 °C for 1-2 h. After cooling to room temperature, the silicone rubber masterbatch is obtained. (2) Add antioxidant, vulcanizer and accelerator to the silicone rubber masterbatch using a double-roll mill, mix evenly and produce sheets, which are then extruded onto the cable insulation layer through an extruder. After vulcanization, the cable shielding layer is obtained.

Images