Self-hygroscopic and conductive integrated carbon fiber rod, its preparation method and application

Abstract

This invention discloses a self-hygroscopic and conductive integrated carbon fiber rod, its preparation method, and its applications. The self-hygroscopic and conductive integrated carbon fiber rod comprises: a conductive carbon matrix serving as a conductive framework, which is obtained by multiple gradient carbonization processes of the carbon fiber rod; a silane coupling agent and a moisture-absorbing component uniformly loaded and distributed on the surface and / or within the pores of the conductive carbon matrix; the moisture-absorbing component having hydrophilic functional groups; one end of the silane coupling agent being covalently bonded to the conductive carbon matrix, and the other end being covalently or coordinately bonded to the moisture-absorbing component. The carbon fiber rod of this invention integrates the electron transport properties of the conductive carbon matrix and the moisture capture properties of the moisture-absorbing component. By organically integrating self-hygroscopic and VOCs degradation and purification functions, it overcomes the limitations of traditional single-function carbon-based materials, achieving a synergistic integration of dual functions, and has broad application prospects in indoor air treatment, intelligent environmental control, and other fields.

Description

Technical Field

[0001] This invention belongs to the field of functional carbon material preparation and environmental purification technology, specifically relating to a self-hygroscopic and conductive integrated carbon fiber rod, its preparation method and application. Background Technology

[0002] With industrial expansion and the widespread use of interior decoration, the emission and accumulation of volatile organic compounds (VOCs) such as formaldehyde and benzene have become a core issue threatening the atmospheric environment and human health. These pollutants are highly toxic, difficult to degrade, and easily dispersed. Long-term exposure can induce respiratory diseases, gene mutations, and other health risks. Therefore, developing efficient, stable, and environmentally friendly gaseous pollutant purification technologies has significant practical value.

[0003] Current indoor air pollutant treatment technologies generally face significant bottlenecks. For example, adsorption methods (such as activated carbon) can only achieve physical enrichment of pollutants, but cannot completely degrade them, easily leading to adsorption saturation and secondary pollution. Furthermore, their adsorption capacity is limited and regeneration costs are high. Photocatalytic oxidation methods (such as TiO2-based photocatalysts) rely on ultraviolet light excitation, resulting in low quantum efficiency and weak visible light response. The catalysts are also prone to deactivation, requiring complex light source equipment for practical applications, limiting their use in dark environments. While plasma methods can generate reactive species such as ·OH to oxidize pollutants, they have high energy consumption and easily produce NO. x The process produces byproducts and the equipment is large, making it unsuitable for indoor or small-scale purification scenarios; catalytic combustion requires operation at temperatures above 200°C, resulting in high energy consumption, which is difficult to meet the needs of room temperature purification.

[0004] To overcome the aforementioned technological limitations, industry researchers have focused on purification pathways that "activate moisture with an electric field to generate highly reactive oxidizing species," with nano-water ion technology being a prime example. This technology condenses moisture in the air and applies a high voltage, splitting it into nano-sized water particles. The ·OH free radicals contained in these particles then react with VOCs in a redox reaction, degrading pollutants into CO2 and H2O. Because it does not require high temperatures and has no potential for secondary pollution, it is widely used in the field of air purification. However, this technology still has unavoidable drawbacks: firstly, it relies on condensation devices to enrich moisture, requiring complex temperature control and water supply systems, and cannot operate autonomously in environments without an external water source or in low humidity conditions; secondly, the generated nano-water particles are prone to agglomeration and deactivation, and their contact efficiency with pollutants is significantly affected by airflow conditions, making it difficult to achieve efficient and stable purification.

[0005] To address the water-dependent issue of nano-water ion technology, some patents in the industry have attempted to combine water absorption and conductivity through carbon material modification. For example, CN114575157B discloses a method for preparing highly absorbent and conductive carbon fiber rods, which, through stepwise carbonization and hydrophilic modification, balances high water absorption capacity with good conductivity, thus assisting in the generation of ·OH radicals in nano-water ion technology. CN115448288B discloses a carbon rod electrode that can capture more water mist through siphoning, improving the efficiency of hydroxide ion generation. However, these existing technologies have not yet overcome the core bottlenecks: they can only achieve passive water absorption, relying on external water sources or water mist supply, lacking the self-hygroscopic ability to capture free moisture in the air, and cannot stably provide the moisture required for electrochemical reactions in low-humidity environments. At the same time, the hygroscopic components and conductive framework are only combined through physical adsorption or simple hydrophilic modification, resulting in weak interfacial bonding. Long-term use can easily lead to component detachment, potentially causing rapid performance degradation.

[0006] Furthermore, existing materials share a common problem of "functional fragmentation": materials with self-hygroscopic properties (such as calcium chloride, carboxylates, and sulfonates) are mostly insulators or semiconductors with extremely poor conductivity, making it difficult to achieve efficient electrolysis of water molecules and in-situ generation of active species under an electric field; while highly conductive carbon materials (such as carbon fibers and graphene composites) have excellent electron transport properties, they generally lack self-hygroscopic properties and cannot operate independently without an external water source. In addition, the significant differences in physical properties such as wettability and coefficient of thermal expansion between self-hygroscopic and conductive materials make it difficult for traditional composite strategies (such as mechanical mixing and physical impregnation) to achieve a tight molecular-level bond between the two phases, further limiting the synergistic efficiency of "hygroscopic-conductive-active species generation".

[0007] Therefore, how to construct an integrated material structure that combines self-hygroscopic and conductive properties to achieve in-situ and stable generation of ·OH radicals without external water source, while improving the structural stability and cycle performance of the material, has become a core challenge that urgently needs to be overcome in the field of gaseous pollutant purification technology. Summary of the Invention

[0008] The main objective of this invention is to provide a self-hygroscopic and conductive integrated carbon fiber rod and its preparation method, thereby overcoming the shortcomings of the prior art.

[0009] Another object of the present invention is to provide the application of the self-moisture-absorbing and conductive integrated carbon fiber rod.

[0010] To achieve the aforementioned objectives, the technical solution adopted by this invention includes:

[0011] The first aspect of this invention provides a self-moisture-absorbing and conductive integrated carbon fiber rod, comprising:

[0012] The conductive carbon matrix, which serves as the conductive framework, is prepared by multiple gradient carbonization processes on carbon fiber rods.

[0013] A silane coupling agent and a hygroscopic component are uniformly loaded and distributed on the surface of the conductive carbon matrix and / or inside the pores contained therein. The hygroscopic component has hydrophilic functional groups. One end of the silane coupling agent is covalently bonded to the conductive carbon matrix, and the other end of the silane coupling agent is covalently or coordinately bonded to the hygroscopic component.

[0014] A second aspect of this invention provides a method for preparing a self-hygroscopic and conductive integrated carbon fiber rod, comprising:

[0015] Carbon fiber rods are subjected to multiple gradient carbonization processes to obtain a conductive carbon matrix that serves as a conductive framework.

[0016] The conductive carbon matrix is ​​brought into full contact with a hygroscopic dispersion containing at least a silane coupling agent and a hygroscopic component, and then dried to obtain a composite modified carbon fiber rod; the silane coupling agent and the hygroscopic component are uniformly loaded and distributed on the surface of the conductive carbon matrix and / or inside the pores contained therein;

[0017] The composite modified carbon fiber rod is subjected to stabilization treatment to obtain a self-hygroscopic and conductive integrated carbon fiber rod. The hygroscopic component has hydrophilic functional groups. One end of the silane coupling agent is covalently bonded to the conductive carbon matrix, and the other end of the silane coupling agent is covalently or coordinately bonded to the hygroscopic component.

[0018] A third aspect of the present invention provides a self-moisture-absorbing and conductive integrated carbon fiber rod prepared by the above-described preparation method.

[0019] A fourth aspect of the present invention provides the application of the self-moisture-absorbing and conductive integrated carbon fiber rod in fields such as air purification or intelligent environmental control.

[0020] Compared with the prior art, the beneficial effects of the present invention include at least the following:

[0021] (1) The self-hygroscopic and conductive integrated carbon fiber rod provided by the present invention achieves a synergistic integration of "self-hygroscopic and conductive" performance by combining high hygroscopic capacity and excellent conductivity through a gradient carbonized skeleton and hygroscopic component loading structure design. Under the environment of 25℃ and humidity of 30~90%, its self-hygroscopic rate reaches 2.5~8.0 g / (g·h) and no external water source is required; it can be stably cycled 500~800 times, with a resistance retention rate ≥95.5% and a hygroscopic performance retention rate ≥93.7%; the material resistance is only 0.5~2.0Ω and the resistivity is 10 -4 ~10 -2 With a conductivity of Ω·m, it is comparable to existing patents, but adds a self-moisture-absorbing function, achieving dual-function synergy;

[0022] (2) Under a DC voltage of 220V, the self-moisturizing and conductive integrated carbon fiber rod provided by the present invention can promote the electrochemical oxidation reaction of adsorbed water, generate ·OH free radicals in situ efficiently and stably, and enhance the degradation of VOCs: when the initial concentration of VOCs is 100 mg / m³ 3 The reaction chamber has a volume of 1 m³. 3 Under the condition of using 0.5 g of carbon rod, the VOCs decomposition efficiency is ≥93% within 1 hour; even in a low humidity environment with a relative humidity of 30%, the decomposition efficiency is still ≥90%, which can completely degrade VOCs into harmless substances such as CO2 and H2O.

[0023] (3) The self-hygroscopic and conductive integrated carbon fiber rod structure provided by the present invention has significantly improved structural stability and service life. One end of the silane coupling agent forms a CO-Si covalent bond with the carbon skeleton, and the other end forms a covalent bond or coordination bond with the organic / inorganic components of the moisture-absorbing coating. This solves the technical problem of weak interfacial bonding and easy detachment between the carbon-based skeleton and the moisture-absorbing component in traditional composite materials. After 800 cycles of moisture absorption and electrolysis, the carbon rod structure, moisture absorption rate and conductivity have not deteriorated significantly, effectively avoiding problems such as coating detachment and performance degradation, and significantly extending the service life of the material. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1A , Figure 1B These are, respectively, the morphological image and the enlarged image of the original carbon fiber rod in Embodiment 1 of the present invention;

[0026] Figure 1C , Figure 1D These are, respectively, morphological images and magnified images of the carbon fiber rods after gradient carbonization regulation in Embodiment 1 of the present invention;

[0027] Figure 1E , Figure 1F These are, respectively, the morphology of carbon fiber after composite modification and stabilization treatment of carbon fiber rods in Example 1 of the present invention and its magnified image;

[0028] Figure 2 This is a macroscopic morphological photograph of the original carbon fiber rod in Embodiment 1 of the present invention;

[0029] Figure 3These are macroscopic morphology photographs of carbon fiber rods after gradient carbonization regulation in Embodiment 1 of the present invention.

[0030] Figure 4 These are macroscopic morphological photographs of the carbon fiber morphology after composite modification and stabilization treatment of carbon fiber rods in Embodiment 1 of the present invention.

[0031] Figure 5A This is a morphological diagram of the original carbon fiber rod in Embodiment 2 of the present invention;

[0032] Figure 5B This is a morphological diagram of the self-moisture-absorbing and conductive integrated carbon fiber rod prepared in Embodiment 2 of the present invention.

[0033] Figure 6 This is a graph showing the test results of the resistance retention rate and moisture absorption capacity retention rate of the self-moisture-absorbing and conductive integrated carbon fiber rod prepared in Example 3 of the present invention under a 30% humidity environment.

[0034] Figure 7 This is a morphological diagram of the self-hygroscopic and conductive integrated carbon fiber rod obtained in Comparative Example 5.

[0035] Figure 8 These are macroscopic morphology photographs of the self-hygroscopic and conductive integrated carbon fiber rods corresponding to Comparative Examples 2 to 5. Detailed Implementation

[0036] In view of the shortcomings of the existing technology, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention. It is mainly based on the core principle of "electric field activation of moisture" in nano-water ion technology, and through structural innovation and interface design, it breaks through the functional limitations and stability defects of the existing technology, providing a new technical path for the efficient purification of gaseous pollutants. It provides an integrated carbon fiber rod with self-hygroscopic and conductive properties, which overcomes the technical bottleneck that existing materials cannot simultaneously achieve self-hygroscopic and conductive properties. It realizes the in-situ and stable generation of ·OH free radicals under the condition of no external water source, and at the same time significantly improves the structural stability and cycle service performance of the material, meeting the long-term use requirements of indoor room temperature gaseous pollutant purification, and realizing the self-hygroscopic and conductive synergy that existing patents have not achieved.

[0037] The following will further explain the technical solution, its implementation process, and its principles. However, it should be understood that within the scope of this invention, the above-mentioned technical features of this invention and the technical features specifically described below (in embodiments) can be combined with each other to form new or preferred technical solutions. Due to space limitations, they will not be described in detail here.

[0038] As one aspect of the technical solution of this invention, a self-moisture-absorbing and conductive integrated carbon fiber rod includes:

[0039] The conductive carbon matrix, which serves as the conductive framework, is prepared by multiple gradient carbonization processes on carbon fiber rods.

[0040] A silane coupling agent and a hygroscopic component are uniformly loaded and distributed on the surface of the conductive carbon matrix and / or inside the pores contained therein. The hygroscopic component has hydrophilic functional groups. One end of the silane coupling agent is covalently bonded to the conductive carbon matrix, and the other end of the silane coupling agent is covalently or coordinately bonded to the hygroscopic component.

[0041] In some embodiments, the conductive carbon matrix is ​​prepared by three-stage gradient carbonization of carbon fiber rods.

[0042] In some preferred embodiments, the method for preparing the conductive carbon matrix includes:

[0043] In a protective atmosphere, the carbon fiber rod is subjected to a first treatment prior to the first temperature to remove internal volatile molecules;

[0044] The carbon fiber rod is heated to a second temperature to perform a second treatment, so that the organic matter on the surface of the carbon fiber rod is carbonized to form an amorphous carbon matrix.

[0045] The carbon fiber rod is heated to a third temperature to perform a third treatment, so as to reconstruct the morphology of the carbon fiber rod and obtain a conductive carbon matrix.

[0046] The second temperature is greater than the first temperature and less than the third temperature.

[0047] In some preferred embodiments, the protective atmosphere is formed by a protective gas, including but not limited to nitrogen, and the flow rate of the protective gas is 50-100 mL / min.

[0048] In some preferred embodiments, the temperature is raised to a first temperature at a heating rate of 1~3℃ / min, the first temperature being 200~300℃, and the holding time of the first treatment is 2~4h.

[0049] In some preferred embodiments, the temperature is raised to a second temperature at a heating rate of 2~4℃ / min, the second temperature being 300~400℃, and the holding time for the second treatment is 2~3h.

[0050] In some preferred embodiments, the temperature is raised to a third temperature at a heating rate of 1~5℃ / min, the third temperature being 400~500℃, and the holding time for the third treatment is 1~2h.

[0051] In some embodiments, the conductive carbon substrate has a diameter of 10-20 μm and a specific surface area of ​​800-1000 m². 2 / g.

[0052] In some embodiments, the silane coupling agent includes one or more combinations of γ-glycidoxypropyltrimethoxysilane (KH-560), γ-methacryloxypropyltrimethoxysilane (KH-570), and γ-methacryloxypropyltriethoxysilane (MPTS), but is not limited thereto. The silane coupling agent forms CO-Si covalent bonds with oxygen-containing functional groups on the surface of the conductive framework through hydrolysis of hydroxyl groups, while its active functional groups form coordination or covalent bonds with the hygroscopic component.

[0053] In some implementations, the moisture-absorbing component is composed of a combination of moisture-absorbing organic matter and moisture-absorbing inorganic salt. If only moisture-absorbing organic matter is used, the performance will be insufficient; if only moisture-absorbing inorganic salt is used, there is a risk of leakage during the circulation process.

[0054] Furthermore, the hydrophilic functional groups contained in the hygroscopic component may be one or more combinations of hydroxyl, amino, sulfonic acid groups, etc., but are not limited to these.

[0055] In some preferred embodiments, the hygroscopic organic matter may include one or more combinations of ammonium salt organic matter, sulfonate organic matter, quaternary ammonium salt organic matter, sulfate organic matter, etc., but is not limited thereto.

[0056] Furthermore, the ammonium salt organic compound may include one or more of ammonium acetate, ammonium formate, triammonium citrate, etc., but is not limited to these.

[0057] Furthermore, the sulfonate organic compounds may include one or a combination of two of sodium camphor sulfonate, 2-acrylamido-2-methylpropanesulfonate, etc., but are not limited thereto.

[0058] Furthermore, the quaternary ammonium salt organic compound may be one or more of the following, but is not limited to: hexadecyltrimethylammonium chloride (CTAC), 3-hydroxypropyltrimethylammonium chloride (HPTMAC), methacryloyloxyethyltrimethylammonium chloride (DMC), dodecyltrimethylammonium chloride (DTAC), etc.

[0059] Furthermore, the sulfate organic compound may be one or more of the following, but is not limited to: ethanolamine sulfate, ethylenediamine sulfate (EDS), sodium dodecyl sulfate (SDS), sodium hexadecyl sulfate (STS), hydroxyethyl methacrylate sulfate (HEMA-S), sodium allyl sulfate (SAS).

[0060] In some preferred embodiments, the hygroscopic inorganic salt may include one or more of calcium chloride, magnesium chloride, lithium chloride, etc., but is not limited to these.

[0061] In some preferred embodiments, the mass ratio of the hygroscopic organic matter to the hygroscopic inorganic salt is 2~8:1~2.

[0062] In some embodiments, the content of conductive carbon matrix in the self-hygroscopic and conductive integrated carbon fiber rod is 80-90 wt%, the content of silane coupling agent is 2-4 wt%, and the content of hygroscopic component is 6-18 wt%.

[0063] In some embodiments, the moisture-absorbing component of the present invention is rich in hydrophilic functional groups (such as hydroxyl, amino, sulfonic acid groups, etc.), which can autonomously capture free moisture in the air without external power. At a room temperature of 25°C and a humidity of 30~90%, the self-absorbing moisture absorption rate of the self-absorbing conductive integrated carbon fiber rod is 2.5~8.0 g / (g·h) (the amount of moisture absorbed per gram of carbon rod per hour), and it can be cycled 500~800 times without the need for an external water source, with a resistance retention rate ≥95.5% and a moisture absorption performance retention rate ≥93.7%.

[0064] In some embodiments, the self-moisture-absorbing conductive integrated carbon fiber rod has a resistance of only 0.5~2.0 Ω and a resistivity of 10. -4 ~10 -2 With a conductivity of Ω·m, it is comparable to existing patents, but adds a self-moisture absorption function, achieving a synergistic integration of self-moisture absorption and conductivity.

[0065] In some embodiments, the self-moisturizing and conductive integrated carbon fiber rod can efficiently and stably generate ·OH free radicals, thereby enhancing VOCs degradation. When energized, for example, when a 220V DC voltage is applied to the carbon fiber rod, it can promote the electrochemical oxidation of adsorbed moisture, stably generating hydroxyl free radicals (·OH) in situ.

[0066] In some implementations, the initial concentration of volatile organic compounds (VOCs) is 100 mg / m³. 3 The reaction time is 1 hour, and the reaction chamber volume is 1 m³. 3 With a self-absorbing and conductive integrated carbon fiber rod dosage of 0.5 g, the decomposition efficiency of volatile organic compounds (VOCs) is ≥93%; even in a low humidity environment of 30% relative humidity, the decomposition efficiency remains ≥90%, which can completely degrade VOCs into harmless substances such as CO2 and H2O.

[0067] In some embodiments, the self-hygroscopic and conductive integrated carbon fiber rod of the present invention exhibits structural stability and significantly improved service life. This may be because: one end of the silane coupling agent forms a CO-Si covalent bond with the conductive carbon matrix, which serves as the conductive framework, and the other end forms a covalent bond or coordination bond with the organic / inorganic components of the moisture-absorbing coating. This solves the technical problem of weak interfacial bonding and easy detachment between the conductive carbon matrix and the moisture-absorbing components in traditional composite materials. After 800 cycles of moisture absorption and electrolysis, the structure, moisture absorption rate, and conductivity of the carbon fiber rod show no significant deterioration, effectively avoiding problems such as coating detachment and performance degradation, and significantly extending the service life of the material.

[0068] In summary, the self-hygroscopic and conductive integrated carbon fiber rod of the present invention integrates the electron transport properties of the conductive carbon matrix with the moisture capture properties of the hygroscopic component. The two are tightly bound together through covalent bonding or interfacial adsorption, forming a structurally stable and synergistically performing composite system. The hygroscopic component, rich in hydrophilic functional groups, can autonomously capture free moisture from the air without external power. Under DC voltage, the conductive carbon fiber rod promotes the electrochemical oxidation of moisture adsorbed in the polymer, generating highly reactive hydroxyl radicals (·OH) in situ. These radicals can undergo redox reactions with volatile organic compounds (VOCs) such as formaldehyde, degrading them into harmless substances such as carbon dioxide and water.

[0069] As another aspect of the technical solution of the present invention, the preparation method of a self-hygroscopic and conductive integrated carbon fiber rod mainly involves: performing multiple gradient carbonizations on the carbon fiber rod to obtain a conductive carbon matrix as a conductive skeleton; then, through the silane coupling agent, it is combined with a hygroscopic component, integrating the dual core functions of the conductive carbon matrix's electron transport performance and the hygroscopic component's moisture capture performance.

[0070] In some embodiments, the preparation method of the self-moisture-absorbing and conductive integrated carbon fiber rod specifically includes:

[0071] Carbon fiber rods are subjected to multiple gradient carbonization processes to obtain a conductive carbon matrix that serves as a conductive framework.

[0072] The conductive carbon matrix is ​​brought into full contact with a hygroscopic dispersion containing at least a silane coupling agent and a hygroscopic component, and then dried to obtain a composite modified carbon fiber rod; the silane coupling agent and the hygroscopic component are uniformly loaded and distributed on the surface of the conductive carbon matrix and / or inside the pores contained therein;

[0073] The composite modified carbon fiber rod is subjected to stabilization treatment to obtain a self-hygroscopic and conductive integrated carbon fiber rod. The hygroscopic component has hydrophilic functional groups. One end of the silane coupling agent is covalently bonded to the conductive carbon matrix, and the other end of the silane coupling agent is covalently or coordinately bonded to the hygroscopic component.

[0074] In some preferred embodiments, the structural features and specific preparation methods of the conductive carbon matrix are as described above, and will not be repeated here.

[0075] In some preferred embodiments, the types of silane coupling agents and hygroscopic components are as described above, and will not be repeated here.

[0076] In some preferred embodiments, the mass ratio of the hygroscopic component to the silane coupling agent is 6~18:2~4.

[0077] In some preferred embodiments, the preparation method specifically includes: mixing the hygroscopic component with water to form a mixed solution, then adding a silane coupling agent, and stirring at 50~60°C for 2~4 hours to obtain a hygroscopic dispersion.

[0078] Furthermore, the mass fraction of the hygroscopic component in the mixed solution is 10% to 25%.

[0079] In some preferred embodiments, the preparation method specifically includes: immersing the conductive carbon matrix in the hygroscopic dispersion, soaking it at 30~50℃ for 2~4h, taking it out and vacuum drying it at 60~80℃ and -0.1 MPa for 2~3h, repeating the soaking-drying process 2~4 times to obtain the composite modified carbon fiber rod.

[0080] In some preferred embodiments, the preparation method specifically includes: drying the composite modified carbon fiber rod at 80~100℃ for 4~6h, and then keeping it at 150~200℃ for 1~2h in a protective atmosphere to obtain the self-hygroscopic and conductive integrated carbon fiber rod.

[0081] In a more specific preferred embodiment of the present invention, the preparation method of a self-hygroscopic and conductive integrated carbon fiber rod adopts a step-by-step preparation strategy of "conductive skeleton construction - composite hygroscopic component modification - interface stabilization bonding", specifically including the following steps:

[0082] (1) Three-stage gradient carbonization to regulate the conductive framework: carbon fiber rods were placed in a tube furnace and nitrogen gas was introduced as a protective gas (flow rate of 50~100 mL / min). Three-stage gradient heating carbonization was carried out: First stage: the temperature was increased to 200~300℃ at a rate of 1~3℃ / min and held for 2~4h to remove low volatile molecules inside the carbon fiber rods; Second stage: the temperature was increased to 300~400℃ at a rate of 2~4℃ / min and held for 2~3h to carbonize the organic matter on the surface of the carbon fiber rods to form an amorphous carbon matrix; Third stage: the temperature was increased to 400~500℃ at a rate of 1~5℃ / min and held for 1~2h to realize the morphology reconstruction of the carbon fiber rods. After natural cooling to room temperature, a conductive framework was obtained, which provides a structural basis for subsequent hygroscopic component loading and electron transport.

[0083] (2) Preparation of hygroscopic dispersion: Weigh 2-8g of hygroscopic organic matter and 1-2g of hygroscopic inorganic salt, mix them and add them to deionized water to prepare a mixed solution with a mass fraction of 10%-25%; add 1-5 mL of silane coupling agent (such as KH-560, KH-570, MPTS) to the solution and stir at 50-60℃ for 2-4 hours to allow the hygroscopic organic matter (ammonium salts, sulfonates, quaternary ammonium salts, sulfates, etc.) and inorganic salts (calcium chloride, magnesium chloride, lithium chloride, etc.) to recombine through hydrogen bonds and coordination bonds, and introduce active groups through silane coupling agent to obtain a hygroscopic dispersion with uniform dispersion and excellent stability. The mechanism of action of the silane coupling agent is as follows: the alkoxy group (such as methoxy or ethoxy) at one end of the coupling agent molecule undergoes hydrolysis in aqueous solution to generate a hydroxyl group (-OH). This hydroxyl group can undergo dehydration condensation reaction with the oxygen-containing functional groups on the surface of the conductive framework to form a CO-Si covalent bond. The active functional group (such as epoxy group or double bond) at the other end of the coupling agent molecule can undergo addition reaction or coordination reaction with amino or hydroxyl groups in the molecules of hygroscopic organic matter (such as sulfonates or ammonium salts), and at the same time form coordination bonds with metal ions in hygroscopic inorganic salts. Ultimately, the synergistic effect of interfacial covalent bonding and coordination between the conductive framework and the hygroscopic coating is achieved, which significantly improves the bonding force and structural stability of the two.

[0084] (3) Carbon fiber rod composite modification: The conductive carbon matrix preform obtained in step (1) is immersed in the hygroscopic dispersion in step (2) and soaked at a constant temperature of 30~50℃ for 2~4h. After taking it out, it is vacuum dried at 60~80℃ and -0.1 MPa for 2~3h. The soaking-drying process is repeated 2~4 times to ensure that the hygroscopic components are uniformly loaded on the conductive skeleton.

[0085] (4) Stability treatment: First stage: Place the composite modified carbon fiber rod obtained in step (3) in a forced-air drying oven and dry it at 80~100℃ for 4~6h to remove free moisture and allow the moisture-absorbing component to be initially solidified; Second stage: Transfer the carbon fiber rod to a low-temperature tube furnace, introduce nitrogen protection, heat it to 150~200℃ at a rate of 2~4℃ / min, and keep it at the temperature for 1~2h to achieve interfacial covalent bonding between the moisture-absorbing component and the conductive skeleton through the cross-linking reaction of the silane coupling agent; After natural cooling, a self-moisture-absorbing and conductive integrated carbon fiber rod is obtained.

[0086] As another aspect of the technical solution of the present invention, it also relates to a self-moisture-absorbing and conductive integrated carbon fiber rod prepared by the above preparation method.

[0087] As another aspect of the technical solution of the present invention, it also relates to the application of the self-moisture-absorbing and conductive integrated carbon fiber rod.

[0088] Specifically, under a 220V DC voltage, the self-moisturizing and conductive integrated carbon fiber rod of this invention can promote the electrochemical oxidation reaction of adsorbed moisture, generating ·OH free radicals in situ efficiently and stably. These free radicals can undergo redox reactions with volatile organic compounds (VOCs) such as formaldehyde, degrading them into harmless substances such as carbon dioxide and water. This invention, by organically integrating self-moisturizing and VOCs degradation and purification functions, breaks through the limitations of traditional single-function carbon-based materials, achieving synergistic integration of dual functions, and has broad application prospects in fields such as indoor air treatment and intelligent environmental control.

[0089] To more clearly illustrate the objectives, technical solutions, and advantages of this invention, the following detailed description will be provided in conjunction with embodiments. Please note that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Modifications or equivalent substitutions made by those skilled in the art based on their understanding of the technical solutions of this invention are all within the protection scope of this invention.

[0090] In the following specific implementation, the carbon fiber rods, hygroscopic organic materials, hygroscopic inorganic salts, and silane coupling agents were all purchased from Aladdin Reagent (Shanghai) Co., Ltd. The performance testing standards were uniformly as follows: resistance and resistivity were tested using an electrochemical workstation; hygroscopic performance was tested using a constant temperature and humidity chamber (HS-100) under the following conditions: room temperature 25℃ and corresponding humidity environment.

[0091] Example 1

[0092] (1) Gradient carbonization regulation of conductive framework: 20g carbon fiber rods were placed in a tube furnace and nitrogen gas (flow rate of 50 mL / min) was introduced as a protective gas. Three-stage gradient heating carbonization was adopted: First stage: the temperature was increased to 200℃ at a rate of 1℃ / min and held for 2h to remove low molecular weight volatile molecules inside the carbon fiber rod; Second stage: the temperature was increased to 300℃ at a rate of 2℃ / min and held for 2h to carbonize the organic matter on the surface of the carbon fiber rod to form an amorphous carbon matrix; Third stage: the temperature was increased to 400℃ at a rate of 1℃ / min and held for 1h to realize the structural reconstruction of the carbon fiber rod; After natural cooling to room temperature, the conductive framework was obtained.

[0093] (2) Preparation of hygroscopic dispersion: Weigh 2g of sodium camphor sulfonate and 1g of calcium chloride, mix them and add 27mL of deionized water to prepare a mixed solution with a mass fraction of 10%; add 1mL of KH-560 to the mixed solution and stir at 50℃ for 2h to allow the hygroscopic sodium camphor sulfonate and hygroscopic calcium chloride to recombine through coordinate bonds to obtain a uniform hygroscopic dispersion;

[0094] (3) Carbon fiber rod composite modification: The conductive skeleton obtained in step (1) is immersed in the hygroscopic dispersion in step (2) and soaked at 30°C for 2 hours. After being taken out, it is vacuum dried at 60°C and -0.1MPa for 2 hours. The soaking-drying process is repeated twice to ensure that the hygroscopic components are uniformly loaded on the surface and inside of the conductive skeleton.

[0095] (4) Stability treatment: First stage: The composite modified carbon fiber rod is placed in a forced-air drying oven and dried at 80℃ for 4h to remove free moisture and allow the moisture-absorbing component to be initially cured; Second stage: The carbon fiber rod is transferred to a low-temperature tube furnace, nitrogen gas is introduced for protection, the temperature is raised to 150℃ at a rate of 2℃ / min, and the temperature is held for 1h to achieve interfacial covalent bonding between the moisture-absorbing coating and the conductive skeleton through the crosslinking reaction of KH-560; After natural cooling, a self-moisture-absorbing and conductive integrated carbon fiber rod is obtained.

[0096] Figure 1A , Figure 1B These are, respectively, a morphological image and a magnified image of the original carbon fiber rod used in this embodiment. Figure 1C , Figure 1D These are, respectively, the morphology diagram and its magnified view of the carbon fiber rod (conductive skeleton) after gradient carbonization regulation in step (1); the specific surface area of ​​the conductive skeleton is tested to be 800 m². 2 / g, the diameter of the carbon fiber rod is 10~14μm. Figure 1E , Figure 1F These are enlarged images of the carbon fiber morphology after composite modification and stabilization treatment of the carbon fiber rods in this embodiment. It can be seen that the original carbon fiber rod surface is smooth and flat (e.g., ...). Figure 1A , Figure 1B , Figure 2 The fiber has no obvious porous structure, and only a small amount of minute impurities remaining from the production process are present on the surface. The fiber diameter is uniformly distributed, and this smooth structure is not conducive to the loading and adsorption of subsequent moisture-absorbing components. After gradient carbonization treatment (such as...), Figure 1C , Figure 1D , Figure 3 The smooth surface of the original carbon fiber rod is disrupted, forming a rough, porous three-dimensional network structure. During gradient carbonization, the removal of low-molecular-weight volatiles and the carbonization of surface organic matter form an amorphous carbon matrix, achieving structural reconstruction of the carbon fiber rod. This structure not only increases the specific surface area of ​​the conductive framework, providing sufficient active sites for the subsequent loading of hygroscopic components, but also facilitates the rapid penetration and diffusion of water vapor, laying the structural foundation for the material's hygroscopic properties. Furthermore, the carbonized carbon fiber rod retains its complete fiber morphology, without breakage or agglomeration, ensuring the continuity of its conductive properties. Figure 1E , Figure 1F , Figure 4It is evident that the carbon fiber rods after stabilization treatment still maintain good fiber morphology, with no obvious deformation or breakage. The increase is mainly due to the thickness of the moisture-absorbing composite coating, indicating that the entire preparation process did not damage the main structure of the carbon fiber rods, thus balancing the structural integrity, electrical conductivity, and moisture absorption durability of the material.

[0097] Testing revealed that the self-absorbing moisture and conductive integrated carbon fiber rod prepared in this embodiment exhibited self-absorbing moisture rates of 2.5 g / (g·h), 3.1 g / (g·h), and 4.4 g / (g·h), respectively, at humidity levels of 30%, 60%, and 90%. The carbon fiber rod also had a resistance of 2.0 Ω and a resistivity of 1.0 Ω. 10 -2 Ω·m; can be cycled 500 times, with a resistance retention rate of 95.5% and a moisture absorption retention rate of 93.7% in a 30% humidity environment.

[0098] When a voltage of 220 V is applied, at a relative humidity of 50% and an initial formaldehyde concentration of 100 mg / m³, 3 The reaction time is 1 hour, and the reaction chamber volume is 1 cubic meter. 3 When the amount of carbon fiber rod is 0.5 g, the decomposition efficiency of carbon fiber rod for formaldehyde is 93.7%; at a relative humidity of 30%, the decomposition efficiency of carbon fiber rod for formaldehyde is 90.2%.

[0099] Example 2

[0100] (1) Gradient carbonization regulation of conductive framework: 20g carbon fiber rods were placed in a tube furnace and nitrogen gas (flow rate of 100 mL / min) was introduced as a protective gas. Three-stage gradient heating carbonization was carried out: First stage: the temperature was increased to 300℃ at a rate of 3℃ / min and held for 4h to remove low molecular weight volatile molecules inside the carbon fiber rods; Second stage: the temperature was increased to 400℃ at a rate of 4℃ / min and held for 3h to carbonize the organic matter on the surface of the carbon fiber rods to form an amorphous carbon matrix; Third stage: the temperature was increased to 500℃ at a rate of 5℃ / min and held for 2h to realize the structural reconstruction of the carbon fiber rods; After natural cooling to room temperature, the conductive framework was obtained.

[0101] (2) Preparation of hygroscopic dispersion: Weigh 8g of 2-acrylamido-2-methylpropanesulfonate and 2g of magnesium chloride, mix them and add 30mL of deionized water to prepare a mixed solution with a mass fraction of 25%; add 5mL of KH-570 to the mixed solution and stir at 60℃ for 4h to allow the hygroscopic components to recombine through coordinate bonds to obtain a uniform hygroscopic dispersion;

[0102] (3) Carbon fiber rod composite modification: The conductive skeleton obtained in step (1) is immersed in the hygroscopic dispersion in step (2) and soaked at 50°C for 4 hours. After being taken out, it is vacuum dried at 80°C and -0.1 MPa for 3 hours. The soaking-drying process is repeated 4 times to ensure that the hygroscopic components are uniformly loaded on the surface and inside of the conductive skeleton.

[0103] (4) Stability treatment: First stage: The modified carbon fiber rods were placed in a forced-air drying oven and dried at 100℃ for 6 hours to remove free moisture and allow the moisture-absorbing coating to be initially cured; Second stage: The carbon fiber rods were transferred to a low-temperature tube furnace, nitrogen gas was introduced for protection, and the temperature was raised to 200℃ at a rate of 2℃ / min and kept at that temperature for 2 hours. The moisture-absorbing coating and the conductive skeleton were covalently bonded at the interface through the crosslinking reaction of KH-570; After natural cooling, the self-moisture-absorbing and conductive integrated carbon fiber rods were obtained.

[0104] Figure 5A This is a topographic image of the original carbon fiber rod used in this embodiment. Figure 5B This is a morphological diagram of the self-moisture-absorbing and conductive integrated carbon fiber rod prepared in this embodiment.

[0105] Tests showed that the specific surface area of ​​the carbon fiber rod (conductive skeleton) after gradient carbonization control in step (1) of this embodiment was 1000 m². 2 / g, the diameter of the carbon fiber rod is 15~20μm.

[0106] At humidity levels of 30%, 60%, and 90%, the self-absorbing moisture and conductive integrated carbon fiber rods prepared in this embodiment exhibited self-absorbing moisture rates of 4.5 g / (g·h), 7.8 g / (g·h), and 8.0 g / (g·h), respectively; the carbon fiber rods had a resistance of 0.5 Ω and a resistivity of 1.0 Ω. 10 -4 Ω·m; can be cycled 800 times, with a resistance retention rate of 96.7% and a moisture absorption retention rate of 94.0% in a 30% humidity environment.

[0107] When a voltage of 220 V is applied, at a relative humidity of 50% and an initial toluene concentration of 100 mg / m³, 3 The reaction time is 1 hour, and the reaction chamber volume is 1 cubic meter. 3 Under the condition of using 0.5 g of carbon fiber rods, the decomposition efficiency of carbon fiber rods on toluene is 95.6%; at a relative humidity of 30%, the decomposition efficiency of carbon fiber rods on toluene is 92.2%.

[0108] Example 3

[0109] (1) Gradient carbonization regulation of conductive framework: 20g carbon fiber rods were placed in a tube furnace and nitrogen gas (flow rate of 80 mL / min) was introduced as a protective gas. Three-stage gradient heating carbonization was adopted: First stage: the temperature was increased to 250℃ at a rate of 2℃ / min and held for 3h to remove low molecular weight volatile molecules inside the carbon fiber rod; Second stage: the temperature was increased to 350℃ at a rate of 3℃ / min and held for 2.5h to carbonize the organic matter on the surface of the carbon fiber rod to form an amorphous carbon matrix; Third stage: the temperature was increased to 450℃ at a rate of 3℃ / min and held for 1.5h to realize the structural reconstruction of the carbon fiber rod; After natural cooling to room temperature, the conductive framework was obtained.

[0110] (2) Preparation of hygroscopic dispersion: Weigh 6g of triammonium citrate and 2g of lithium chloride, mix them and add 32mL of deionized water to prepare a mixed solution with a mass fraction of 20%; add 5mL of MPTS to the mixed solution and stir at 50℃ for 4h to allow the hygroscopic components to recombine through coordination bonds to obtain a uniform hygroscopic dispersion.

[0111] (3) Carbon fiber rod composite modification: The conductive skeleton obtained in step (1) is immersed in the hygroscopic dispersion in step (2) and soaked at 40°C for 3 hours. After being taken out, it is vacuum dried at 70°C and -0.1 MPa for 2 hours. The soaking-drying process is repeated 3 times to ensure that the hygroscopic component is uniformly loaded on the surface and inside of the conductive skeleton.

[0112] (4) Stability treatment: First stage: The composite modified carbon fiber rod is placed in a forced-air drying oven and dried at 90℃ for 5h to remove free moisture and allow the moisture-absorbing coating to be initially cured; Second stage: The carbon fiber rod is transferred to a low-temperature tube furnace, nitrogen gas is introduced for protection, the temperature is raised to 150℃ at a rate of 2℃ / min, and the temperature is held for 1h to achieve interfacial covalent bonding between the moisture-absorbing coating and the conductive skeleton through the cross-linking reaction of the silane coupling agent; After natural cooling, a self-moisture-absorbing and conductive integrated carbon fiber rod is obtained.

[0113] Tests showed that the specific surface area of ​​the carbon fiber rod (conductive skeleton) after gradient carbonization regulation in step (1) of this embodiment was 930 m². 2 / g, the diameter of the carbon fiber rod is 12~20μm.

[0114] At humidity levels of 30%, 60%, and 90%, the self-absorbing moisture and conductive integrated carbon fiber rods prepared in this embodiment exhibited self-absorbing moisture rates of 3.9 g / (g·h), 6.0 g / (g·h), and 7.5 g / (g·h), respectively; the carbon fiber rods had a resistance of 1.0 Ω and a resistivity of 1.0 Ω. 10 -3 Ω·m; can be cycled 800 times, with a resistance retention rate of 96.0% and a moisture absorption retention rate of 93.9% in a 30% humidity environment.

[0115] When a voltage of 220 V is applied, at a relative humidity of 50% and an initial toluene concentration of 100 mg / m³, 3 The reaction time is 1 hour, and the reaction chamber volume is 1 cubic meter. 3 Under the condition of using 0.5 g of carbon fiber rods, the decomposition efficiency of carbon fiber rods on toluene is 94.2%; at a relative humidity of 30%, the decomposition efficiency of carbon fiber rods on toluene is 91.6%. Figure 6 The graph shows the test results of the resistance retention rate and moisture absorption capacity retention rate of the self-moisture-absorbing conductive integrated carbon fiber rod in a 30% humidity environment.

[0116] Example 4

[0117] (1) Gradient carbonization regulation of conductive framework: 20g carbon fiber rods were placed in a tube furnace and nitrogen gas (flow rate of 80 mL / min) was introduced as a protective gas. Three-stage gradient heating carbonization was adopted: First stage: the temperature was increased to 250℃ at a rate of 2℃ / min and held for 3h to remove low molecular weight volatile molecules inside the carbon fiber rod; Second stage: the temperature was increased to 350℃ at a rate of 3℃ / min and held for 2.5h to carbonize the organic matter on the surface of the carbon fiber rod to form an amorphous carbon matrix; Third stage: the temperature was increased to 450℃ at a rate of 3℃ / min and held for 1.5h to realize the structural reconstruction of the carbon fiber rod; After natural cooling to room temperature, the conductive framework was obtained.

[0118] (2) Preparation of hygroscopic dispersion: Weigh 6g sodium dodecyl sulfate and 2g lithium chloride, mix them and add 32mL deionized water to prepare a mixed solution with a mass fraction of 20%; add 5mL KH-570 to the mixed solution and stir at 50℃ for 4h to allow the hygroscopic components to recombine through coordinate bonds and obtain a uniform hygroscopic dispersion.

[0119] (3) Carbon fiber rod composite modification: The conductive skeleton obtained in step (1) is immersed in the hygroscopic dispersion in step (2) and soaked at 40°C for 3 hours. After being taken out, it is vacuum dried at 70°C and -0.1 MPa for 2 hours. The soaking-drying process is repeated 3 times to ensure that the hygroscopic component is uniformly loaded on the surface and inside of the conductive skeleton.

[0120] (4) Stability treatment: First stage: The composite modified carbon fiber rod is placed in a forced-air drying oven and dried at 90℃ for 5h to remove free moisture and allow the moisture-absorbing coating to be initially cured; Second stage: The carbon fiber rod is transferred to a low-temperature tube furnace, nitrogen gas is introduced for protection, the temperature is raised to 150℃ at a rate of 3℃ / min, and the temperature is held for 1h to achieve interfacial covalent bonding between the moisture-absorbing coating and the conductive skeleton through the cross-linking reaction of the silane coupling agent; After natural cooling, a self-moisture-absorbing and conductive integrated carbon fiber rod is obtained.

[0121] Tests showed that the specific surface area of ​​the carbon fiber rod (conductive skeleton) after gradient carbonization control in step (1) of this embodiment was 925 m². 2 / g, the diameter of the carbon fiber rod is 12~20μm.

[0122] At humidity levels of 30%, 60%, and 90%, the self-absorbing moisture and conductive integrated carbon fiber rods prepared in this embodiment exhibited self-absorbing moisture rates of 3.8 g / (g·h), 5.9 g / (g·h), and 7.2 g / (g·h), respectively; the carbon fiber rods had a resistance of 1.0 Ω and a resistivity of 1.0 Ω. 10 -3 Ω·m; can be cycled 800 times, with a resistance retention rate of 95.9% and a moisture absorption retention rate of 93.8% in a 30% humidity environment.

[0123] When a voltage of 220 V is applied, at a relative humidity of 50% and an initial toluene concentration of 100 mg / m³, 3 The reaction time is 1 hour, and the reaction chamber volume is 1 cubic meter. 3 Under the condition of using 0.5 g of carbon fiber rods, the decomposition efficiency of carbon fiber rods on toluene is 94.0%; under a relative humidity of 30%, the decomposition efficiency of carbon fiber rods on toluene is 91.5%.

[0124] Example 5

[0125] (1) Gradient carbonization regulation of conductive framework: 20g carbon fiber rods were placed in a tube furnace and nitrogen gas (flow rate of 80 mL / min) was introduced as a protective gas. Three-stage gradient heating carbonization was adopted: First stage: the temperature was increased to 250℃ at a rate of 2℃ / min and held for 3h to remove low molecular weight volatile molecules inside the carbon fiber rod; Second stage: the temperature was increased to 350℃ at a rate of 3℃ / min and held for 2.5h to carbonize the organic matter on the surface of the carbon fiber rod to form an amorphous carbon matrix; Third stage: the temperature was increased to 450℃ at a rate of 4℃ / min and held for 1.5h to realize the structural reconstruction of the carbon fiber rod; After natural cooling to room temperature, the conductive framework was obtained.

[0126] (2) Preparation of hygroscopic dispersion: Weigh 6g of hydroxyethyl methacrylate sulfate and 2g of magnesium chloride, mix them and add 32mL of deionized water to prepare a mixed solution with a mass fraction of 20%; add 5mL of KH-570 to the mixed solution and stir at 50℃ for 4h to allow the hygroscopic components to recombine through coordinate bonds and obtain a uniform hygroscopic dispersion.

[0127] (3) Carbon fiber rod composite modification: The conductive skeleton obtained in step (1) is immersed in the hygroscopic dispersion in step (2) and soaked at 40°C for 3 hours. After being taken out, it is vacuum dried at 70°C and -0.1 MPa for 2 hours. The soaking-drying process is repeated 3 times to ensure that the hygroscopic component is uniformly loaded on the surface and inside of the conductive skeleton.

[0128] (4) Stability treatment: First stage: The composite modified carbon fiber rod is placed in a forced-air drying oven and dried at 90℃ for 5h to remove free moisture and allow the moisture-absorbing coating to be initially cured; Second stage: The carbon fiber rod is transferred to a low-temperature tube furnace, nitrogen gas is introduced for protection, the temperature is raised to 150℃ at a rate of 3℃ / min, and the temperature is held for 1h to achieve interfacial covalent bonding between the moisture-absorbing coating and the conductive skeleton through the cross-linking reaction of the silane coupling agent; After natural cooling, a self-moisture-absorbing and conductive integrated carbon fiber rod is obtained.

[0129] Tests showed that the specific surface area of ​​the carbon fiber rod (conductive skeleton) after gradient carbonization control in step (1) of this embodiment was 925 m². 2 / g, the diameter of the carbon fiber rod is 12~20μm.

[0130] At humidity levels of 30%, 60%, and 90%, the self-absorbing moisture and conductive integrated carbon fiber rods prepared in this embodiment exhibited self-absorbing moisture rates of 3.8 g / (g·h), 6.0 g / (g·h), and 7.4 g / (g·h), respectively; the carbon fiber rods had a resistance of 1.0 Ω and a resistivity of 1.0 Ω. 10 -3 Ω·m; can be cycled 800 times, with a resistance retention rate of 96.0% and a moisture absorption retention rate of 93.7% in a 30% humidity environment.

[0131] When a voltage of 220 V is applied, at a relative humidity of 50% and an initial toluene concentration of 100 mg / m³, 3 The reaction time is 1 hour, and the reaction chamber volume is 1 cubic meter. 3 Under the condition of using 0.5 g of carbon fiber rods, the decomposition efficiency of carbon fiber rods on toluene is 94.2%; at a relative humidity of 30%, the decomposition efficiency of carbon fiber rods on toluene is 91.7%.

[0132] Example 6

[0133] The difference between this embodiment and embodiment 3 is as follows:

[0134] (2) Preparation of hygroscopic dispersion: Weigh 12g hexadecyltrimethylammonium chloride and 6g magnesium chloride, mix them and add 72mL of deionized water to prepare a mixed solution with a mass fraction of 20%; add 4mL KH-570 to the mixed solution and stir at 50℃ for 4h to allow the hygroscopic components to recombine through coordination bonds and obtain a uniform hygroscopic dispersion.

[0135] At humidity levels of 30%, 60%, and 90%, the self-absorbing moisture and conductive integrated carbon fiber rods prepared in this embodiment exhibited self-absorbing moisture rates of 4.4 g / (g·h), 7.3 g / (g·h), and 7.9 g / (g·h), respectively; the carbon fiber rods had a resistance of 0.8 Ω and a resistivity of 0.8 Ω. 10 -4 Ω·m; can be cycled 600 times, with a resistance retention rate of 95.5% and a moisture absorption retention rate of 93.7% in a 30% humidity environment.

[0136] When a voltage of 220 V is applied, at a relative humidity of 50% and an initial toluene concentration of 100 mg / m³, 3 The reaction time is 1 hour, and the reaction chamber volume is 1 cubic meter. 3 Under the condition of using 0.5 g of carbon fiber rods, the decomposition efficiency of carbon fiber rods on toluene is 93.5%; at a relative humidity of 30%, the decomposition efficiency of carbon fiber rods on toluene is 91.5%.

[0137] Comparative Example 1

[0138] Compared with Example 3, this comparative example lacks modification of the moisture-absorbing component, specifically including:

[0139] (1) Gradient carbonization regulation of conductive framework: A 20g carbon fiber rod was placed in a tube furnace, and nitrogen gas (flow rate of 80 mL / min) was introduced as a protective gas. Three-stage gradient heating carbonization was carried out: First stage: the temperature was increased to 250℃ at a rate of 2℃ / min and held for 3h to remove low molecular weight volatile molecules inside the carbon fiber rod; Second stage: the temperature was increased to 350℃ at a rate of 3℃ / min and held for 2.5h to carbonize the organic matter on the surface of the carbon fiber rod to form an amorphous carbon matrix; Third stage: the temperature was increased to 450℃ at a rate of 3℃ / min and held for 1.5h to realize the structural reconstruction of the carbon fiber rod; After natural cooling to room temperature, the conductive framework was obtained.

[0140] (2) Carbon fiber rod composite modification: The conductive skeleton obtained in step (1) was immersed in 5 mL of MPTS and stirred at 50℃ for 4 h. After being taken out, it was vacuum dried at 70℃ for 2 h. The soaking-drying process was repeated 3 times.

[0141] (3) Stability treatment: First stage: The composite modified carbon fiber rods were placed in a forced-air drying oven and dried at 90℃ for 5h; Second stage: The carbon fiber rods were transferred to a low-temperature tube furnace, nitrogen gas was introduced for protection, the temperature was raised to 150℃ at a rate of 2℃ / min, and the temperature was held for 1h. The cross-linking reaction of the silane coupling agent was used to achieve interfacial covalent bonding with the conductive skeleton; After natural cooling, the conductive skeleton carbon fiber rods were obtained.

[0142] Tests showed that the specific surface area of ​​the conductive framework obtained in step (1) of this comparative example is 900 m². 2 The carbon fiber rods have a diameter of 12~18μm and a resistance of 0.9Ω. These conductive carbon fiber rods do not have moisture-absorbing properties and have a resistivity of 0.9Ω. 10 -3 Ω·m; Cyclic 800 cycles, resistance retention of 94.6% at 30% humidity. When an applied voltage of 220 V is applied, at 50% relative humidity and an initial toluene concentration of 100 mg / m³... 3 The reaction time is 1 hour, and the reaction chamber volume is 1 cubic meter. 3 With a carbon fiber rod dosage of 0.5g, only 24.6% of toluene can be adsorbed through the structure.

[0143] Comparative Example 2

[0144] Compared with Example 3, this comparative example lacks the modification with the silane coupling agent MPTS, specifically including:

[0145] (1) Gradient carbonization regulation of conductive framework: 20g carbon fiber rods were placed in a tube furnace and nitrogen gas (flow rate of 80 mL / min) was introduced as a protective gas. Three-stage gradient heating carbonization was adopted: First stage: the temperature was increased to 250℃ at a rate of 2℃ / min and held for 3h to remove low molecular weight volatile molecules inside the carbon fiber rod; Second stage: the temperature was increased to 350℃ at a rate of 3℃ / min and held for 2.5h to carbonize the organic matter on the surface of the carbon fiber rod to form an amorphous carbon matrix; Third stage: the temperature was increased to 450℃ at a rate of 3℃ / min and held for 1.5h to realize the structural reconstruction of the carbon fiber rod; After natural cooling to room temperature, the conductive framework was obtained.

[0146] (2) Preparation of hygroscopic dispersion: Weigh 6g of triammonium citrate and 2g of lithium chloride, mix them and add 32mL of deionized water to prepare a mixed solution with a mass fraction of 20%;

[0147] (3) Carbon fiber rod composite modification: The conductive skeleton obtained in step (1) is immersed in the hygroscopic dispersion in step (2) and soaked at 40℃ for 3 hours. After being taken out, it is vacuum dried at 70℃ and -0.1 MPa for 2 hours. The soaking-drying process is repeated 3 times.

[0148] (4) Stability treatment: First stage: Place the composite modified carbon fiber rod in a forced-air drying oven and dry at 90℃ for 5h to remove free moisture and allow the moisture-absorbing component to be initially cured; Second stage: Transfer the carbon fiber rod to a low-temperature tube furnace, introduce nitrogen protection, heat up to 150℃ at a rate of 2℃ / min, and keep warm for 1h; After natural cooling, self-hygroscopic and conductive integrated carbon fiber rod is obtained.

[0149] The specific surface area of ​​the conductive framework obtained in step (1) of this comparative example was tested to be 950 m². 3 The carbon fiber rods have a diameter of 12–20 μm. At humidity levels of 30%, 60%, and 90%, the self-absorption rates of these carbon fiber rods are 4.2 g / (g·h), 6.5 g / (g·h), and 7.6 g / (g·h), respectively; the electrical resistance of the carbon fiber rods is 0.9 Ω, and the resistivity is 0.7 Ω. 10 -3 Ω·m, fragile, non-recyclable. Due to the lack of a silane coupling agent, the hygroscopic component and the conductive framework are only physically adsorbed together, making it prone to cracking. Macroscopic morphology photos are shown below. Figure 8 The leftmost figure is shown in Figure A.

[0150] When a voltage of 220 V is applied, at a relative humidity of 50% and an initial toluene concentration of 100 mg / m³, 3 The reaction time is 1 hour, and the reaction chamber volume is 1 cubic meter. 3 When the carbon fiber rod dosage is 0.5 g, the decomposition efficiency of the carbon fiber rod for formaldehyde is 92.2%; at a relative humidity of 30%, the decomposition efficiency of the carbon fiber rod for toluene is 90.6%. Coating peeling leads to structural failure, but the material can only be used once.

[0151] Comparative Example 3

[0152] Compared with Example 3, this comparative example shows that excessive amounts can lead to the aggregation of the hygroscopic components, specifically including:

[0153] (1) Gradient carbonization regulation of conductive framework: 20g carbon fiber rods were placed in a tube furnace and nitrogen gas (flow rate of 80 mL / min) was introduced as a protective gas. Three-stage gradient heating carbonization was adopted: First stage: the temperature was increased to 250℃ at a rate of 2℃ / min and held for 3h to remove low molecular weight volatile molecules inside the carbon fiber rod; Second stage: the temperature was increased to 350℃ at a rate of 3℃ / min and held for 2.5h to carbonize the organic matter on the surface of the carbon fiber rod to form an amorphous carbon matrix; Third stage: the temperature was increased to 450℃ at a rate of 3℃ / min and held for 1.5h to realize the structural reconstruction of the carbon fiber rod; After natural cooling to room temperature, the conductive framework was obtained.

[0154] (2) Preparation of hygroscopic dispersion: Weigh 10g of triammonium citrate and 6g of lithium chloride, mix them and add 24 mL of deionized water to prepare a mixed solution with a mass fraction of 40%; add 5 mL of MPTS to the mixed solution and stir at 50℃ for 4h to allow the hygroscopic components to recombine through coordination bonds to obtain a uniform hygroscopic dispersion.

[0155] (3) Carbon fiber rod composite modification: The conductive skeleton obtained in step (1) is immersed in the hygroscopic dispersion in step (2) and soaked at 40°C for 3 hours. After being taken out, it is vacuum dried at 70°C and -0.1 MPa for 2 hours. The soaking-drying process is repeated 3 times to ensure that the hygroscopic coating is uniformly loaded on the surface and inside of the conductive skeleton.

[0156] (4) Stabilization treatment: First stage: The composite modified carbon fiber rods were placed in a forced-air drying oven and dried at 90℃ for 5h to remove free moisture and allow the moisture-absorbing coating to initially cure; Second stage: The carbon fiber rods were transferred to a low-temperature tube furnace, protected by nitrogen, and heated to 150℃ at a rate of 2℃ / min, and held for 1h to achieve interfacial covalent bonding between the moisture-absorbing coating and the conductive skeleton through the crosslinking reaction of the silane coupling agent; After natural cooling, self-moisture-absorbing and conductive integrated carbon fiber rods were obtained, and the macroscopic morphology photos are as follows. Figure 8 As shown in Figure B.

[0157] The specific surface area of ​​the conductive framework obtained in step (1) of this comparative example was tested to be 907 m² / g, and the diameter of the carbon fiber rod was 12~20 μm. At humidity levels of 30%, 60%, and 90%, the self-absorption rates of the carbon fiber rod were 2.4 g / (g·h), 4.5 g / (g·h), and 5.0 g / (g·h), respectively; the resistance of the carbon fiber rod was 3.5 Ω, and the resistivity was 0.7 Ω. 10 -2 Ω·m; can be cycled 150 times, with a resistance retention rate of 89.7% and a moisture absorption retention rate of 88.5% in a 30% humidity environment.

[0158] When a voltage of 220 V is applied, at a relative humidity of 50% and an initial toluene concentration of 100 mg / m³, 3 The reaction time is 1 hour, and the reaction chamber volume is 1 cubic meter. 3 Under the condition of using 0.5 g of carbon fiber rods, the decomposition efficiency of carbon fiber rods on toluene is 80.5%; at a relative humidity of 30%, the decomposition efficiency of carbon fiber rods on toluene is 75.4%. This proves that the amount of hygroscopic component needs to be controlled within the range specified above (the mass fraction of hygroscopic component in the mixed solution is 10%~25%), and excessive amount will cause the hygroscopic component to agglomerate.

[0159] Comparative Example 4

[0160] Compared with Example 3, this comparative example includes carbon fiber rods that have not undergone gradient carbonization (drying without carbonization), specifically:

[0161] (1) Provide only dried carbon fiber rods without gradient carbonization;

[0162] (2) Preparation of hygroscopic dispersion: Weigh 6g of triammonium citrate and 2g of lithium chloride, mix them and add 32mL of deionized water to prepare a mixed solution with a mass fraction of 20%; add 5mL of MPTS to the mixed solution and stir at 50℃ for 4h to allow the hygroscopic components to recombine through coordination bonds to obtain a uniform hygroscopic dispersion.

[0163] (3) Carbon fiber rod composite modification: 20g of carbon fiber rods that have not undergone gradient carbonization are immersed in the hygroscopic dispersion of step (2), soaked at 40℃ for 3h, and then vacuum dried at 70℃ and -0.1 MPa for 2h; the soaking-drying process is repeated 3 times.

[0164] (4) Stabilization treatment: First stage: The composite modified carbon fiber rods were placed in a forced-air drying oven and dried at 90℃ for 5 hours to remove free moisture and allow the hygroscopic components to initially solidify; Second stage: The carbon fiber rods were transferred to a low-temperature tube furnace, protected with nitrogen, and heated to 150℃ at a rate of 2℃ / min, and held at that temperature for 1 hour to achieve interfacial covalent bonding between the hygroscopic coating and the conductive skeleton through the crosslinking reaction of the silane coupling agent; After natural cooling, self-hygroscopic and conductive integrated carbon fiber rods were obtained, and the macroscopic morphology photos are as follows. Figure 8 As shown in Figure C.

[0165] Tests showed that the carbon fiber rods used in step (1) of this comparative example had a diameter of 12~20μm and a specific surface area of ​​260m². 2 / g. The low specific surface area leads to uneven moisture absorption load and lacks a conductive framework for support, making it impossible to form a synergistic moisture absorption-conductivity system. Therefore, moisture absorption experiments and subsequent formaldehyde decomposition experiments cannot be conducted; this demonstrates that gradient carbonization is the key to forming a high specific surface area, and without this step, the synergistic moisture absorption-conductivity function cannot be achieved.

[0166] Comparative Example 5

[0167] Compared with Example 3, this comparative example shows that the gradient carbonization control temperature is too high, specifically including:

[0168] (1) Gradient carbonization regulation of conductive framework: 20g carbon fiber rods were placed in a tube furnace and nitrogen gas (flow rate of 80 mL / min) was introduced as a protective gas. Three-stage gradient heating carbonization was adopted: First stage: the temperature was increased to 300℃ at a rate of 2℃ / min and held for 3h to remove low molecular weight volatile molecules inside the carbon fiber rod; Second stage: the temperature was increased to 500℃ at a rate of 3℃ / min and held for 2.5h to carbonize the organic matter on the surface of the carbon fiber rod to form an amorphous carbon matrix; Third stage: the temperature was increased to 800℃ at a rate of 3℃ / min and held for 1.5h to realize the structural reconstruction of the carbon fiber rod; After natural cooling to room temperature, the conductive framework was obtained.

[0169] (2) Preparation of hygroscopic dispersion: Weigh 6g of triammonium citrate and 2g of lithium chloride, mix them and add 32mL of deionized water to prepare a mixed solution with a mass fraction of 20%; add 5mL of MPTS to the mixed solution and stir at 50℃ for 4h to allow the hygroscopic components to recombine through coordination bonds to obtain a uniform hygroscopic dispersion.

[0170] (3) Carbon fiber rod composite modification: The conductive skeleton obtained in step (1) is immersed in the hygroscopic dispersion in step (2) and soaked at 40°C for 3 hours. After being taken out, it is vacuum dried at 70°C and -0.1 MPa for 2 hours. The soaking-drying process is repeated 3 times to ensure that the hygroscopic component is uniformly loaded on the surface of the conductive skeleton.

[0171] (4) Stability treatment: First stage: The composite modified carbon fiber rod is placed in a forced-air drying oven and dried at 90℃ for 5h to remove free moisture and allow the moisture-absorbing coating to be initially cured; Second stage: The carbon fiber rod is transferred to a low-temperature tube furnace, nitrogen gas is introduced for protection, the temperature is raised to 150℃ at a rate of 2℃ / min, and the temperature is held for 1h to achieve interfacial covalent bonding between the moisture-absorbing component and the conductive skeleton through the cross-linking reaction of the silane coupling agent; After natural cooling, a self-moisture-absorbing and conductive integrated carbon fiber rod is obtained. Figure 7 This is a topographic image of the carbon fiber rod; macroscopic topographic photographs are shown below. Figure 8 As shown in diagram D on the far right.

[0172] In this comparative example, the gradient carbonization temperature was too high, causing the carbon fiber rod to become brittle and crack at high temperatures, making it impossible to conduct further moisture absorption and formaldehyde removal tests. This proves that the gradient carbonization temperature must be strictly controlled within the appropriate range specified above, as excessively high temperatures will damage the structural integrity of the carbon fiber rod.

[0173] Comparative Example 6

[0174] Compared with Example 3, this comparative example uses only hygroscopic organic matter and does not add hygroscopic inorganic salts, resulting in a significant decrease in hygroscopic performance. Specifically, this includes:

[0175] (1) Gradient carbonization regulation of conductive framework: 20g carbon fiber rods were placed in a tube furnace and nitrogen gas (flow rate of 80 mL / min) was introduced as a protective gas. Three-stage gradient heating carbonization was adopted: First stage: the temperature was increased to 250℃ at a rate of 2℃ / min and held for 3h to remove low molecular weight volatile molecules inside the carbon fiber rod; Second stage: the temperature was increased to 350℃ at a rate of 3℃ / min and held for 2.5h to carbonize the organic matter on the surface of the carbon fiber rod to form an amorphous carbon matrix; Third stage: the temperature was increased to 450℃ at a rate of 3℃ / min and held for 1.5h to realize the structural reconstruction of the carbon fiber rod; After natural cooling to room temperature, the conductive framework was obtained.

[0176] (2) Preparation of hygroscopic dispersion: Weigh 8g of triammonium citrate, mix and add 32mL of deionized water to prepare a mixed solution with a mass fraction of 20%; add 5mL of MPTS to the mixed solution and stir at 50℃ for 4h to allow the hygroscopic components to recombine through coordinate bonds to obtain a uniform hygroscopic dispersion.

[0177] (3) Carbon fiber rod composite modification: The conductive skeleton obtained in step (1) is immersed in the hygroscopic dispersion in step (2) and soaked at 40°C for 3 hours. After being taken out, it is vacuum dried at 70°C and -0.1 MPa for 2 hours. The soaking-drying process is repeated 3 times to ensure that the hygroscopic component is uniformly loaded on the surface and inside of the conductive skeleton.

[0178] (4) Stability treatment: First stage: The composite modified carbon fiber rod is placed in a forced-air drying oven and dried at 90℃ for 5h to remove free moisture and allow the moisture-absorbing coating to be initially cured; Second stage: The carbon fiber rod is transferred to a low-temperature tube furnace, nitrogen gas is introduced for protection, the temperature is raised to 150℃ at a rate of 2℃ / min, and the temperature is held for 1h to achieve interfacial covalent bonding between the moisture-absorbing coating and the conductive skeleton through the cross-linking reaction of the silane coupling agent; After natural cooling, a self-moisture-absorbing and conductive integrated carbon fiber rod is obtained.

[0179] At humidity levels of 30%, 60%, and 90%, the self-absorbing moisture and conductive integrated carbon fiber rods prepared in this comparative example exhibited self-absorbing moisture rates of 1.0 g / (g·h), 1.5 g / (g·h), and 2.0 g / (g·h), respectively; the carbon fiber rods had a resistance of 3.2 Ω and a resistivity of 1.0 Ω. 10 -1 Ω·m; can be cycled 300 times, with a resistivity retention rate of 86.0% and a moisture absorption retention rate of 82.5% at 30% humidity.

[0180] When a voltage of 220 V is applied, at a relative humidity of 50% and an initial toluene concentration of 100 mg / m³, 3 The reaction time is 1 hour, and the reaction chamber volume is 1 cubic meter. 3 Under the condition of using 0.5 g of carbon fiber rods, the decomposition efficiency of carbon fiber rods on toluene is 70.5%; at a relative humidity of 30%, the decomposition efficiency of carbon fiber rods on toluene is 71.6%.

[0181] Comparative Example 7

[0182] Compared with Example 3, this comparative example only uses hygroscopic inorganic salts and does not add hygroscopic organic matter. Specifically, it includes:

[0183] (1) Gradient carbonization regulation of conductive framework: 20g carbon fiber rods were placed in a tube furnace and nitrogen gas (flow rate of 80 mL / min) was introduced as a protective gas. Three-stage gradient heating carbonization was adopted: First stage: the temperature was increased to 250℃ at a rate of 2℃ / min and held for 3h to remove low molecular weight volatile molecules inside the carbon fiber rod; Second stage: the temperature was increased to 350℃ at a rate of 3℃ / min and held for 2.5h to carbonize the organic matter on the surface of the carbon fiber rod to form an amorphous carbon matrix; Third stage: the temperature was increased to 450℃ at a rate of 3℃ / min and held for 1.5h to realize the structural reconstruction of the carbon fiber rod; After natural cooling to room temperature, the conductive framework was obtained.

[0184] (2) Preparation of hygroscopic dispersion: Weigh 8g of lithium chloride, mix and add 32mL of deionized water to prepare a mixed solution with a mass fraction of 20%; add 5mL of MPTS to the mixed solution and stir at 50℃ for 4h to allow the hygroscopic components to recombine through coordination bonds to obtain a uniform hygroscopic dispersion.

[0185] (3) Carbon fiber rod composite modification: The conductive skeleton obtained in step (1) is immersed in the hygroscopic dispersion in step (2) and soaked at 40°C for 3 hours. After being taken out, it is vacuum dried at 70°C and -0.1 MPa for 2 hours. The soaking-drying process is repeated 3 times to ensure that the hygroscopic component is uniformly loaded on the surface and inside of the conductive skeleton.

[0186] (4) Stability treatment: First stage: The composite modified carbon fiber rod is placed in a forced-air drying oven and dried at 90℃ for 5h to remove free moisture and allow the moisture-absorbing coating to be initially cured; Second stage: The carbon fiber rod is transferred to a low-temperature tube furnace, nitrogen gas is introduced for protection, the temperature is raised to 150℃ at a rate of 2℃ / min, and the temperature is held for 1h to achieve interfacial covalent bonding between the moisture-absorbing coating and the conductive skeleton through the cross-linking reaction of the silane coupling agent; After natural cooling, a self-moisture-absorbing and conductive integrated carbon fiber rod is obtained.

[0187] At humidity levels of 30%, 60%, and 90%, the self-absorbing moisture and conductive integrated carbon fiber rods prepared in this comparative example exhibited self-absorbing moisture rates of 3.3 g / (g·h), 5.0 g / (g·h), and 7.0 g / (g·h), respectively; the carbon fiber rods had a resistance of 1.0 Ω and a resistivity of 1.0 Ω. 10 -3 Ω·m. After 20 cycles, due to the leakage of some salt ions, the resistivity retention rate was 80.5% and the moisture absorption performance retention rate was 70.8% under 30% humidity conditions.

[0188] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0189] It should be understood that the above embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A self-moisture-absorbing and conductive integrated carbon fiber rod, characterized in that, include: The conductive carbon matrix, which serves as the conductive framework, is prepared by multiple gradient carbonization processes on carbon fiber rods. A silane coupling agent and a hygroscopic component are uniformly loaded and distributed on the surface of the conductive carbon matrix and / or inside the pores contained therein. The hygroscopic component has hydrophilic functional groups. One end of the silane coupling agent is covalently bonded to the conductive carbon matrix, and the other end of the silane coupling agent is covalently or coordinately bonded to the hygroscopic component.

2. The self-moisture-absorbing and conductive integrated carbon fiber rod according to claim 1, characterized in that: The conductive carbon matrix is ​​prepared by three-stage gradient carbonization of carbon fiber rods. And / or, the conductive carbon matrix has a diameter of 10~20 μm and a specific surface area of ​​800~1000 m². 2 / g.

3. The self-moisture-absorbing and conductive integrated carbon fiber rod according to claim 2, characterized in that, The method for preparing the conductive carbon matrix includes: In a protective atmosphere, the carbon fiber rod is subjected to a first treatment prior to the first temperature to remove internal volatile molecules; The carbon fiber rod is heated to a second temperature to perform a second treatment, so that the organic matter on the surface of the carbon fiber rod is carbonized to form an amorphous carbon matrix. The carbon fiber rod is heated to a third temperature to perform a third treatment, so as to reconstruct the morphology of the carbon fiber rod and obtain a conductive carbon matrix. The second temperature is greater than the first temperature and less than the third temperature.

4. The self-moisture-absorbing and conductive integrated carbon fiber rod according to claim 3, characterized in that: The protective atmosphere is formed by a protective gas, including nitrogen, and the flow rate of the protective gas is 50~100 mL / min; And / or, the temperature is raised to a first temperature at a heating rate of 1~3℃ / min, the first temperature is 200~300℃, and the holding time of the first treatment is 2~4h; The temperature is increased to the second temperature at a heating rate of 2~4℃ / min, the second temperature is 300~400℃, and the holding time of the second treatment is 2~3h; The temperature is increased to a third temperature at a rate of 1~5℃ / min, the third temperature being 400~500℃, and the holding time for the third treatment is 1~2h.

5. The self-moisture-absorbing and conductive integrated carbon fiber rod according to claim 1, characterized in that: The silane coupling agent includes one or more combinations of γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and γ-methacryloxypropyltriethoxysilane.

6. The self-moisture-absorbing and conductive integrated carbon fiber rod according to claim 1, characterized in that: The hygroscopic component is composed of hygroscopic organic matter and hygroscopic inorganic salt; And / or, the hydrophilic functional group includes one or more combinations of hydroxyl, amino, and sulfonic acid groups.

7. The self-moisture-absorbing and conductive integrated carbon fiber rod according to claim 6, characterized in that: The hygroscopic organic matter includes one or more combinations of ammonium salt organic matter, sulfonate organic matter, quaternary ammonium salt organic matter, and sulfate organic matter; And / or, the hygroscopic inorganic salt includes one or more combinations of calcium chloride, magnesium chloride, and lithium chloride; And / or, the mass ratio of the hygroscopic organic matter to the hygroscopic inorganic salt is 2~8:1~2.

8. The self-moisture-absorbing and conductive integrated carbon fiber rod according to claim 7, characterized in that: The ammonium salt organic compounds include one or more combinations of ammonium acetate, ammonium formate, and triammonium citrate. And / or, the sulfonate organic compounds include one or a combination of two of sodium camphor sulfonate and 2-acrylamido-2-methylpropanesulfonate; And / or, the quaternary ammonium salt organic compound includes one or more combinations of hexadecyltrimethylammonium chloride, 3-hydroxypropyltrimethylammonium chloride, methacryloyloxyethyltrimethylammonium chloride, and dodecyltrimethylammonium chloride; And / or, the sulfate organic compounds include one or more combinations of ethanolamine sulfate, ethylenediamine sulfate, sodium dodecyl sulfate, sodium hexadecyl sulfate, hydroxyethyl methacrylate sulfate, and sodium allyl sulfate.

9. The self-moisture-absorbing and conductive integrated carbon fiber rod according to claim 1, characterized in that: The self-hygroscopic and conductive integrated carbon fiber rod contains 80-90 wt% conductive carbon matrix, 2-4 wt% silane coupling agent, and 6-18 wt% hygroscopic component.

10. The self-moisture-absorbing and conductive integrated carbon fiber rod according to claim 1, characterized in that: At a room temperature of 25°C and a humidity of 30-90%, the self-absorbing and conductive integrated carbon fiber rod has a self-absorbing rate of 2.5-8.0 g / (g·h), can be cycled 500-800 times, has a resistance retention rate of ≥95.5%, and a moisture absorption performance retention rate of ≥93.7%. And / or, the resistance of the self-moisture-absorbing conductive integrated carbon fiber rod is 0.5~2.0 Ω, and the resistivity is 10. -4 ~10 -2 Ω·m; And / or, when the self-moisture-absorbing and conductive integrated carbon fiber rod is energized, it can promote the adsorbed moisture to undergo an electrochemical oxidation reaction to generate hydroxyl radicals in situ; And / or, at an initial concentration of volatile organic compounds of 100 mg / m³ 3 The reaction time is 1 hour, and the reaction chamber volume is 1 m³. 3 With a self-absorbing and conductive integrated carbon fiber rod dosage of 0.5 g, the decomposition efficiency of volatile organic compounds is ≥93%; even in a low humidity environment of 30% relative humidity, the decomposition efficiency is still ≥90%.

11. A method for preparing a self-moisture-absorbing and conductive integrated carbon fiber rod, characterized in that, include: Carbon fiber rods are subjected to multiple gradient carbonization processes to obtain a conductive carbon matrix that serves as a conductive framework. The conductive carbon matrix is ​​brought into full contact with a hygroscopic dispersion containing at least a silane coupling agent and a hygroscopic component, and then dried to obtain a composite modified carbon fiber rod; the silane coupling agent and the hygroscopic component are uniformly loaded and distributed on the surface of the conductive carbon matrix and / or inside the pores contained therein; The composite modified carbon fiber rod is subjected to stabilization treatment to obtain a self-hygroscopic and conductive integrated carbon fiber rod. The hygroscopic component has hydrophilic functional groups. One end of the silane coupling agent is covalently bonded to the conductive carbon matrix, and the other end of the silane coupling agent is covalently or coordinately bonded to the hygroscopic component.

12. The preparation method according to claim 11, characterized in that, include: The conductive carbon matrix was prepared by performing three gradient carbonizations on the carbon fiber rod. And / or, the diameter of the conductive carbon matrix is ​​10~20μm and the specific surface area is 800~1000 m² / g.

13. The preparation method according to claim 12, characterized in that, include: In a protective atmosphere, the carbon fiber rod is subjected to a first treatment prior to the first temperature to remove internal volatile molecules; The carbon fiber rod is heated to a second temperature to perform a second treatment, so that the organic matter on the surface of the carbon fiber rod is carbonized to form an amorphous carbon matrix. The carbon fiber rod is heated to a third temperature to perform a third treatment, thereby reconstructing the morphology of the carbon fiber rod and obtaining the conductive carbon matrix. The second temperature is greater than the first temperature and less than the third temperature.

14. The preparation method according to claim 13, characterized in that: The protective atmosphere is formed by a protective gas, including nitrogen, and the flow rate of the protective gas is 50~100 mL / min; And / or, the temperature is raised to a first temperature at a heating rate of 1~3℃ / min, the first temperature is 200~300℃, and the holding time of the first treatment is 2~4h; The temperature is increased to the second temperature at a heating rate of 2~4℃ / min, the second temperature is 300~400℃, and the holding time of the second treatment is 2~3h; The temperature is increased to a third temperature at a rate of 1~5℃ / min, the third temperature being 400~500℃, and the holding time for the third treatment is 1~2h.

15. The preparation method according to claim 11, characterized in that, include: The hygroscopic component is mixed with water to form a mixed solution, and then a silane coupling agent is added. The mixture is stirred at 50-60°C for 2-4 hours to obtain a hygroscopic dispersion.

16. The preparation method according to claim 15, characterized in that: The silane coupling agent includes one or more combinations of γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and γ-methacryloxypropyltriethoxysilane. And / or, the mass ratio of the hygroscopic component to the silane coupling agent is 6~18:2~4.

17. The preparation method according to claim 15, characterized in that: The hygroscopic component is composed of hygroscopic organic matter and hygroscopic inorganic salt; And / or, the hydrophilic functional group includes one or more combinations of hydroxyl, amino, and sulfonic acid groups.

18. The preparation method according to claim 17, characterized in that: The hygroscopic organic matter includes one or more combinations of ammonium salt organic matter, sulfonate organic matter, quaternary ammonium salt organic matter, and sulfate organic matter; And / or, the hygroscopic inorganic salt includes one or more combinations of calcium chloride, magnesium chloride, and lithium chloride; And / or, the mass ratio of the hygroscopic organic matter to the hygroscopic inorganic salt is 2~8:1~2; And / or, the mass fraction of the hygroscopic component in the mixed solution is 10% to 25%.

19. The preparation method according to claim 18, characterized in that: The ammonium salt organic compounds include one or more combinations of ammonium acetate, ammonium formate, and triammonium citrate. And / or, the sulfonate organic compounds include one or a combination of two of sodium camphor sulfonate and 2-acrylamido-2-methylpropanesulfonate; And / or, the quaternary ammonium salt organic compound includes one or more combinations of hexadecyltrimethylammonium chloride, 3-hydroxypropyltrimethylammonium chloride, methacryloyloxyethyltrimethylammonium chloride, and dodecyltrimethylammonium chloride; And / or, the sulfate organic compounds include one or more combinations of ethanolamine sulfate, ethylenediamine sulfate, sodium dodecyl sulfate, sodium hexadecyl sulfate, hydroxyethyl methacrylate sulfate, and sodium allyl sulfate.

20. The preparation method according to claim 11, characterized in that... include: The conductive carbon matrix is ​​immersed in the hygroscopic dispersion and soaked at 30~50℃ for 2~4 hours. After being taken out, it is vacuum dried at 60~80℃ and -0.1 MPa for 2~3 hours. The soaking-drying process is repeated 2~4 times to obtain the composite modified carbon fiber rod.

21. The preparation method according to claim 11, characterized in that... include: The composite modified carbon fiber rod is dried at 80~100℃ for 4~6h, and then kept at 150~200℃ for 1~2h in a protective atmosphere to obtain the self-moisture-absorbing and conductive integrated carbon fiber rod.

22. A self-moisture-absorbing conductive integrated carbon fiber rod prepared by any one of claims 11 to 21.

23. The application of the self-moisture-absorbing and conductive integrated carbon fiber rod according to any one of claims 1 to 10 and 22 in the field of air purification or intelligent environmental control.

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