An asymmetric continuous dehumidifying material of a fiber substrate, and a preparation method and application thereof

Abstract

The application provides an asymmetric continuous dehumidification material of a fiber substrate and a preparation method and application thereof, wherein the asymmetric continuous dehumidification material comprises a fiber substrate, a deliquescent metal salt is loaded on a first end of the fiber substrate to form an adsorption end; the adsorption end can capture gaseous water molecules from the environment and deliquesce in situ into a salt solution; a carbon-based photothermal material is loaded on a second end of the fiber substrate to form a desorption end, and the salt solution is transmitted along the fiber substrate to the desorption end; the desorption end generates high temperature under light radiation, so that liquid water is in situ gasified. The adsorption end of the application captures water molecules in the air and converts them into liquid water, and the liquid water is spontaneously and directionally pumped to the desorption end by relying on the moisture concentration gradient between the adsorption end and the desorption end and the inherent capillary binding force of the fiber substrate, and the carbon-based photothermal material of the desorption end absorbs light radiation to generate local high temperature, and liquid water molecules are in situ gasified, so that continuous moisture transport is realized.

Description

Technical Field

[0001] This invention relates to the technical field of dehumidifying materials, and in particular to an asymmetric continuous dehumidifying material with a fiber substrate, its preparation method, and its application. Background Technology

[0002] Indoor temperature and humidity control is crucial for protecting public health, improving human comfort, and maintaining industrial productivity. Traditional space dehumidification primarily relies on compressor-based mechanical vapor compression air conditioning systems. This traditional technology, when handling latent heat loads, requires excessive cooling of air below the dew point, and may even necessitate reheating, resulting in extremely high energy consumption and inevitably exacerbating the global greenhouse effect. To reduce the enormous energy consumption of mechanical compression, low-energy dehumidification technologies based on moisture-absorbing materials have received widespread attention. Depending on the core materials and driving methods, existing technologies mainly exhibit the following development paths, but all face insurmountable technical bottlenecks.

[0003] Regarding adsorption technology: Solid dehumidifying materials based on porous materials (such as silica gel, molecular sieves, MOFs, etc.) face problems such as high desorption regeneration temperatures and easy collapse of microscopic channels. These porous media, which rely on static water storage within the material's pores, inevitably reach a moisture saturation bottleneck under sustained high temperature and humidity conditions, thus losing their dehumidification capacity. Once saturated, dehumidification must be interrupted, and high-grade thermal energy must be input for desorption and regeneration, resulting in a discontinuous and unsteady-state dehumidification process. Regarding desorption technology: Traditional dehumidification systems typically require large amounts of high-grade electrical energy or fossil thermal energy to regenerate and dehydrate the adsorbent. Existing fixed-bed dehumidification systems suffer from severe energy flow network solidification problems; traditional equipment must be configured with two physical beds to perform adsorption and desorption tasks separately and switch periodically. This alternating operation paradigm not only leads to unsteady-state fluctuations in the system, but the complex mechanical structure also significantly increases the difficulty of system control, resulting in multi-stage energy conversion losses during moisture desorption. In recent years, to completely eliminate the dependence on fossil fuels for the regeneration and desorption process, photothermal conversion technology has been introduced into the dehumidification field. Studies have shown that novel composite materials such as graphene oxide and carbon nanotubes can efficiently absorb sunlight and convert it into localized heat energy, achieving in-situ desorption of moisture. However, most existing photothermal composite dehumidification materials employ homogeneous mixtures or symmetrical structures, lacking a physical mechanism to guide the directional flow of moisture. This results in spatial interference between the adsorption and desorption processes within the material under illumination, making it impossible to achieve stable unidirectional pumping with continuous adsorption on one side and continuous photothermal evaporation on the other.

[0004] Existing patent CN107059251A discloses a method for preparing a unidirectional hygroscopic nanofiber multilayer composite membrane with a wetting gradient, comprising the following steps: dispersing hydrophilic nanomaterials in a solvent, sonicating to uniformly disperse the nanomaterials, then dissolving a hydrophilic polymer in the above dispersion to obtain spinning solution A1, and depositing a hydrophilic nanofiber membrane on a receiving substrate by electrospinning; dispersing hydrophilic nanomaterials in a solvent, sonicating to uniformly disperse the nanomaterials, then dissolving a hydrophilic polymer in the above dispersion to obtain spinning solution A2; dissolving a hydrophobic polymer in a solvent to obtain spinning solution B1; depositing at least one conductive layer on the hydrophilic nanofiber membrane by electrospinning the above two spinning solutions; dissolving a hydrophobic polymer in a solvent to obtain spinning solution B2, and depositing a hydrophobic nanofiber membrane on the conductive layer by electrospinning to obtain a unidirectional hygroscopic nanofiber multilayer composite membrane with a wetting gradient. In this technical solution, the guiding layer contains a physically spliced ​​layer with interfacial resistance. This is because it employs electrospinning technology, and since the hydrophilic, guiding, and hydrophobic layers are deposited in stages, physical phase interfaces and microscopic gaps inevitably exist between the layers. In microfluidics, these discontinuous phase interfaces interrupt the continuous transmission of capillary forces, generating significant interfacial mass transfer resistance. When water crosses these layers, the transport rate experiences a significant step-like decrease. Therefore, the resulting multi-layered fiber composite membrane can only meet the needs of slow drainage and is completely unable to support high-intensity industrial / building-grade dehumidification water pumping.

[0005] In summary, traditional dehumidification methods suffer from drawbacks such as high energy consumption, complex mechanical structures, and limited application scenarios. Existing dehumidification technologies cannot simultaneously meet the core requirements in a single material system: (1) they fail to overcome the capacity bottleneck of static pore adsorption, making it impossible to achieve true continuous and dynamic dehumidification with zero mechanical energy consumption; (2) the desorption energy consumption of the materials is high, and the lack of precise configuration design makes it difficult to perfectly integrate indoor moisture capture, natural capillary force pumping, and outdoor solar-driven in-situ desorption. These urgent engineering problems severely restrict the development of near-zero carbon air conditioning systems. Therefore, developing new composite dehumidification materials with high adsorption capacity, rapid adsorption-desorption kinetics, and low energy consumption is a current research focus in the industry. Summary of the Invention

[0006] This invention aims to at least partially solve one of the problems in related technologies. Therefore, one objective of this invention is to provide an asymmetric continuous dehumidification material with a fiber substrate. The adsorption end captures water molecules in the air and converts them into liquid water. The liquid water molecules are spontaneously and directionally pumped to the desorption end by the moisture concentration gradient between the adsorption and desorption ends and the inherent capillary binding force of the fiber substrate. The carbon-based photothermal material at the desorption end absorbs light radiation to generate localized high temperatures, vaporizing the liquid water in situ, thereby achieving continuous moisture transport.

[0007] An asymmetric continuous desiccant material with a fiber substrate includes a fiber substrate, wherein a first end of the fiber substrate is loaded with a deliquescent metal salt to form an adsorption end; the adsorption end is capable of capturing gaseous water molecules from the environment and deliquescing them in situ into a salt solution.

[0008] The second end of the fiber substrate is loaded with carbon-based photothermal material to form a desorption end, and the salt solution is transported along the fiber substrate to the desorption end; the desorption end generates high temperature under light radiation, causing the liquid water to vaporize in situ.

[0009] Furthermore, the deliquescent metal salt includes at least one of lithium chloride, calcium chloride, and zinc chloride.

[0010] Furthermore, the carbon-based photothermal material includes at least one of carbon nanotubes and carbon black.

[0011] Furthermore, the fiber substrate has a thickness of 0.5-3 mm and a specific surface area ≥300 m². 2 / g, porosity ≥60%.

[0012] The second objective of this application is to provide a method for preparing an asymmetric continuous dehumidification material with a fiber substrate, including:

[0013] A deliquescent metal salt is loaded at the first end of the fiber substrate by impregnation.

[0014] Carbon-based photothermal materials are loaded at the second end of the fiber substrate by impregnation.

[0015] Furthermore, before forming the adsorption and desorption ends, the process also includes: pretreatment of the fiber substrate.

[0016] The fiber substrate was ultrasonically cleaned using a mixed solution of anhydrous ethanol and deionized water.

[0017] The ultrasonically cleaned fiber substrate is dried at 60-80℃ to obtain a hydrophilic fiber substrate.

[0018] Furthermore, a deliquescent metal salt is loaded onto the first end of the fiber substrate by impregnation, specifically including:

[0019] Prepare a deliquescent metal salt solution with a mass fraction of 10-30 wt%;

[0020] The first end of the pretreated fiber substrate is immersed in the deliquescent metal salt solution;

[0021] The impregnated fiber substrate is dried until the deliquescent metal salts are fully crystallized and anchored in the fiber network.

[0022] Furthermore, carbon-based photothermal materials are loaded onto the second end of the fiber substrate via an impregnation method, specifically including:

[0023] Prepare a 3-10 wt% dispersion of carbon-based photothermal material;

[0024] A carbon-based photothermal material dispersion was applied to the second end of a fiber substrate by an impregnation method.

[0025] The impregnated fiber substrate is dried until the carbon-based photothermal material is anchored in the fiber network.

[0026] The third objective of this application is to provide an application of a fiber-based asymmetric continuous dehumidification material for controlling indoor humidity, wherein the adsorption end is located indoors and the desorption end is located outdoors.

[0027] Furthermore, the fiber-based asymmetric continuous dehumidifying material is used in conjunction with the building system to regulate indoor temperature and humidity;

[0028] The building system includes a transparent cover plate and a heat storage wall arranged sequentially from the outside to the inside, with an air gap between the transparent cover plate and the heat storage wall. The heat storage wall has an installation through hole, the fiber substrate passes through the installation through hole, the adsorption end is located on the inner side of the heat storage wall, and the desorption end is located between the heat storage wall and the transparent cover plate.

[0029] Furthermore, the top and bottom of the heat storage wall are respectively provided with an indoor air supply vent and an indoor air return vent, and the top and bottom of the transparent cover are respectively provided with an outdoor air exhaust vent and an outdoor air inlet.

[0030] In winter mode, asymmetric continuous dehumidification material is used to dehumidify the room; during the day, the indoor air supply vents and indoor return air vents are opened to send the solar energy collected by the heat storage wall into the room using the thermosiphon effect; the outdoor air inlet and outdoor exhaust vents are closed to prevent cold outdoor air from intruding into the air gap; at night, the indoor air supply vents, indoor return air vents, outdoor air inlet and outdoor exhaust vents are closed, so that the air gap forms an insulation layer.

[0031] In summer mode, asymmetric continuous dehumidification material is used to dehumidify the room; during the day, the indoor air supply vents and indoor return vents are closed to prevent hot outdoor air or air from the air gap from flowing into the room; the outdoor air inlet and outdoor exhaust vents are opened to exhaust the heat of the air gap to the outside using the chimney effect; at night, the indoor air supply vents and indoor return vents are closed, and the outdoor air inlet and outdoor exhaust vents are opened to circulate cold outdoor air and reduce the temperature of the heat storage wall.

[0032] Furthermore, the adsorption end surface of the asymmetric continuous dehumidification material is provided with a surface direct contact resistance heating mesh. The network structure of the surface direct contact resistance heating mesh is sparse and maintains direct physical thermal contact with the liquid aqueous solution seeping from the desorption end surface.

[0033] Furthermore, the surface direct-contact resistance heating mesh is connected to the controller and the power supply;

[0034] When there is solar radiation, the controller cuts off the power to the surface direct contact resistance heating grid;

[0035] When there is no solar radiation, the controller turns on the power to the surface direct contact resistance heating grid.

[0036] Furthermore, the fiber-based asymmetric continuous dehumidification material is used to form a hot air-assisted all-weather intelligent continuous dehumidification system;

[0037] The hot air-assisted all-weather intelligent continuous dehumidification system includes an indoor isolation chamber. The upper end of the isolation chamber is provided with a dehumidified air circulation channel, and the lower end of the isolation chamber is provided with a hot air regeneration circulation channel. A heat insulation plate is provided between the dehumidified air circulation channel and the hot air regeneration circulation channel. An asymmetric continuous dehumidification material is provided inside the isolation chamber. The adsorption end of the asymmetric continuous dehumidification material is located in the dehumidified air circulation channel, and the desorption end of the asymmetric continuous dehumidification material is located in the hot air regeneration circulation channel. The symmetric continuous dehumidification material penetrates through the heat insulation plate.

[0038] Furthermore, the dehumidified air circulation channel is provided with a first air inlet and a first air outlet at both ends, which are located indoors; the hot air regeneration circulation channel is provided with a second air inlet and a second air outlet at both ends, which are located indoors, and a heating module is provided inside the hot air regeneration circulation channel.

[0039] Compared with the prior art, the technical solution provided in this application has the following advantages: The first end of the fiber substrate in this application is loaded with a deliquescent metal salt to form an adsorption end; the deliquescent metal salt forms a molecular-level chemical anchor with the surface of the fiber substrate, which is used to actively capture gaseous water molecules from the environment and deliquesce in situ into a dilute salt solution; the second end of the fiber substrate is loaded with a carbon-based photothermal material to form a desorption end; the carbon-based photothermal material builds a micro-nano network and has broadband photothermal conversion capability; the adsorption end captures water molecules in the air and converts them into liquid water. The liquid water relies on the moisture concentration gradient between the adsorption end and the desorption end and the inherent capillary binding force of the fiber substrate to spontaneously and directionally pump the liquid water molecules to the desorption end. The carbon-based photothermal material at the desorption end absorbs light radiation to generate local high temperature, which vaporizes the liquid water in situ, thereby realizing continuous moisture transport. This invention breaks through the industry bottleneck of traditional dehumidifying materials relying on static pore water storage and being easily saturated through a three-dimensional asymmetric decoupling design of "adsorption end adsorption - fiber substrate transport - desorption end desorption". The entire water pumping and desorption regeneration process relies entirely on the natural concentration gradient of the solution, the inherent capillary force of the fiber, and the photothermal effect. The system achieves dynamic and continuous water vapor pumping with time synchronization and spatial separation without the need for any high-energy-consuming machinery (such as electric water pumps or compressors).

[0040] This application employs an impregnation method to deeply embed photothermal materials into the pores of continuous fibers. This not only strengthens the material but also constructs an extremely precise capillary pumping network. The powerful capillary suction force of the continuous fiber substrate can adaptively respond to the evaporation pull of the photothermal layer. When the photothermal layer rapidly vaporizes water under strong light, the faster the evaporation, the greater the capillary negative pressure, and the faster the liquid water at the bottom is pulled upwards. The transport rate of liquid water and the heat energy converted from solar energy achieve a dynamic balance. Even under extreme conditions of prolonged exposure to extremely strong light, the photothermal layer always maintains an optimal evaporation state of slight wetting, neither drying out nor becoming flooded, maintaining extremely efficient and stable vaporization, and completely solving the pain point of mass transfer mismatch in the continuous desorption process.

[0041] This invention utilizes the efficient full-spectrum absorption of solar radiation by carbon-based photothermal materials for desorption and regeneration. Without the need for complex mechanical structures, it liberates the dehumidification process from dependence on traditional fossil fuel-powered electricity, creating a perfect zero-carbon emission thermodynamic closed loop that aligns with the global near-zero carbon building (NZEB) strategy. Furthermore, unlike the rigid, bulky metal casings of traditional dehumidification equipment, this invention is based on a fiber fabric substrate, combining excellent lightweight design and structural flexibility. This allows asymmetric continuous dehumidification materials to be easily cut and seamlessly integrated into building exterior wall breathing layers and smart dehumidifying curtains, greatly expanding its application areas. Attached Figure Description

[0042] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0043] 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, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] In the attached image:

[0045] Figure 1 This is a structural mechanism diagram of the asymmetric continuous dehumidification material in this application;

[0046] Figure 2 The moisture absorption properties of fiber materials loaded with different types of deliquescent metal salts in this application;

[0047] Figure 3 The energy absorption performance of the carbon-based photothermal material in this application across the entire solar spectrum;

[0048] Figure 4 Under illumination (1kW·m) in this application -2 Thermal imaging of temperature changes of carbon-based photothermal materials and pure fiber fabrics;

[0049] Figure 5 This is a flowchart illustrating the preparation process of the fiber-based asymmetric dehumidification composite material in this application.

[0050] Figure 6 The dehumidification performance of the composite material of fiber substrate loaded with lithium chloride and carbon nanotubes in this application;

[0051] Figure 7 The dehumidification performance of the composite material of calcium chloride supported on activated carbon fiber substrate in this application;

[0052] Figure 8 The dehumidification performance of the composite material with fiber substrate loaded with calcium chloride and carbon black in this application;

[0053] Figure 9 This application describes the change in dehumidification capacity of the carbon-based photothermal material before and after loading it onto the fiber substrate.

[0054] Figure 10 This is an optical microscope schematic diagram of the continuous fiber junction between the adsorption end and the desorption end in this application.

[0055] Figure 11 This is an example of a passive continuous dehumidification application based on asymmetric composite materials in this application;

[0056] Figure 12This is a schematic diagram of the photoelectric dual-modal all-weather building dehumidification integrated system in this application;

[0057] Figure 13 This is a schematic diagram of the hot air-assisted all-weather intelligent continuous dehumidification system in this application.

[0058] Reference numerals: 1. Transparent cover; 2. Heat storage wall; 3. Indoor air supply vent; 4. Indoor air return vent; 5. Outdoor air inlet; 6. Outdoor air exhaust vent; 7. Air gap; 8. Inner wall; 9. Outer wall; 10. Sunlight; 11. Surface direct contact resistance heating mesh; 12. Controller; 21. Asymmetric continuous dehumidification material; 22. Dehumidified air circulation channel; 23. Hot air regeneration circulation channel; 24. Heating module; 25. First air outlet; 26. Second air outlet; 27. Isolation chamber. Detailed Implementation

[0059] To provide a clearer understanding of the technical features, objectives, and effects of this invention, specific embodiments are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by terms such as "front," "rear," "upper," "lower," "left," "right," "longitudinal," "horizontal," "vertical," "horizontal," "top," "bottom," "inner," "outer," "head," and "tail" are based on the orientations or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific orientation. They are only for the convenience of describing this technical solution and do not indicate that the referred mechanism or element must have a specific orientation; therefore, they should not be construed as limitations on this invention.

[0060] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "linking," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. When an component is referred to as being "on" or "below" another component, the component can be located "directly" or "indirectly" on the other component, or there may be one or more intermediary components. The terms "first," "second," "third," etc., are only for the convenience of describing this technical solution and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0061] In the following description, specific details such as particular system structures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, mechanisms, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0062] This application provides an asymmetric continuous dehumidification material with a fiber substrate, comprising a fiber substrate, wherein a first end of the fiber substrate is loaded with a deliquescent metal salt to form an adsorption end; the adsorption end is capable of capturing gaseous water molecules from the environment and deliquescing them in situ into a salt solution; the salt solution is transported along the fiber substrate to the desorption end; a second end of the fiber substrate is loaded with a carbon-based photothermal material to form a desorption end, wherein the desorption end generates high temperature under light radiation, causing liquid water to vaporize in situ.

[0063] The operating mechanism of the continuous dehumidification system in this application includes: the adsorption end captures gaseous water molecules in the air, making them a dilute salt solution; relying on the moisture concentration gradient between the adsorption and desorption ends and the inherent capillary binding force of the fiber substrate, the water molecules in the dilute salt solution are spontaneously and directionally pumped to the desorption end, while the metal salt particles have a good anchoring effect with the fiber substrate and are fixed at the adsorption end; the carbon-based photothermal material at the desorption end absorbs solar radiation to generate local high temperature, which vaporizes the liquid water in situ, thereby realizing continuous moisture transport.

[0064] It should be noted that during long-term use, a small amount of the dilute salt solution at the adsorption end will inevitably migrate. Therefore, it is necessary to replenish the salt solution at the adsorption end regularly.

[0065] like Figure 1 As shown, the asymmetric continuous dehumidification material in this application comprises, sequentially along the mass transfer direction, three interconnected components: an adsorption end, a fiber substrate, and a desorption end. In this application, the fiber substrate is selected from hydrophilic fiber fabrics with abundant natural micro- and nano-pores. Preferably, the fiber substrate thickness is between 0.5 and 3 mm, and the specific surface area is ≥300 m². 2 / g, porosity ≥60%. The interwoven fiber bundles inside the fiber substrate form a three-dimensional capillary network, which serves as the core channel for fluid transport and can provide powerful liquid capillary pumping force without external mechanical power.

[0066] Adsorption end and its characteristics: The adsorption end is located at the first end of the fiber substrate, uniformly loaded with deliquescent metal salts, including but not limited to common chemical desiccants such as lithium chloride (LiCl), calcium chloride (CaCl2), and zinc chloride (ZnCl2). Binding characteristics: The pretreated fiber substrate surface has a large number of polar hydroxyl groups (-OH). These hydroxyl groups interact with metal ions, and this molecular-level anchoring ensures a tight bond between the metal ions and the fiber skeleton, allowing them to be uniformly distributed on the fiber substrate, resulting in a strong water absorption capacity at the adsorption end. The moisture absorption capacity of different deliquescent metal salts at 25℃ and 70% relative humidity is as follows: Figure 2 As shown.

[0067] Desorption end and its characteristics: The desorption end is located at the second end of the fiber substrate and is loaded with carbon-based photothermal materials, including but not limited to carbon nanotubes and carbon black. Preferably, activated carbon fiber (ACF) can be directly selected to perfectly combine the carbon-based photothermal material with the fiber substrate, forming a uniform photothermal conversion network. The carbon-based photothermal material has a wide-band full-spectrum absorption capability (light absorption rate >90%), such as... Figure 3 As shown), it can efficiently convert solar energy into thermal energy, thereby achieving excellent photothermal driven desorption, such as... Figure 4 As shown, a continuous three-dimensional network is constructed using carbon-based photothermal materials and a fiber substrate. This ensures rapid water transport while simultaneously creating a stable "wet-dry gradient" on the desorption side, maintaining efficient evaporation of water molecules. Indoor air is absorbed by the adsorption end to form a solution, which then passes through the fiber substrate to the desorption end under the influence of concentration gradient and capillary force. Under sunlight, the moisture is heated and vaporized in situ, achieving continuous dynamic dehumidification.

[0068] This application relates to an air water capture and desorption system encompassing continuous multiphase transitions between gas and liquid phases. The core principle of this application is not simply liquid conduction, but a highly complex and precise thermal-mass coupling process, possessing disruptive technological innovation, as detailed below:

[0069] First, the fiber substrate used in this application has abundant microscopic and mesoscopic pore structures, resulting in strong water diffusion capabilities. Furthermore, our fiber material itself possesses air-capturing water capabilities due to its porous structure. Second, this application utilizes the strong chemical potential of the deliquescent metal salt loaded in the fiber substrate to actively capture gaseous water molecules from the air and transform them into a liquid aqueous solution. Third, under the combined pumping action of concentration difference, temperature difference, and continuous fiber capillary force at the adsorption end, the liquid water rapidly diffuses. Finally, driven by the solar thermal energy of the photothermal material at the desorption end, the liquid water transforms back into gaseous water, rapidly desorbs, and is released into the environment, thus achieving a multiphase continuous conversion process of gas capture, liquid transport, and gas release. Finally, the microscopic mechanism of this invention involves the synergistic effect of multiple forces (gravity, chemical adsorption force, capillary force, and gradient driving force) and continuous reactions at multiple interfaces, realizing a complete closed loop of "gas capture - liquid pumping - gas release," exhibiting a disruptive innovative effect. This mechanism of active harvesting and directional diffusion of atmospheric moisture on a single static material is impossible to achieve with existing technologies.

[0070] This application also provides a method for preparing a fiber-based asymmetric continuous dehumidification material; such as Figure 5 As shown, it includes the following steps:

[0071] S1: Fiber substrate pretreatment, the purpose of which is to stimulate the hydrophilicity of the fiber substrate, specifically includes: immersing the fiber substrate in a mixed solution containing anhydrous ethanol and deionized water in equal volume ratio, ultrasonically cleaning for 1-2 hours to remove surface natural oils and slurry, and then drying at 60-80℃ to expose abundant cellulose hydroxyl groups and obtain a highly hydrophilic fiber substrate.

[0072] S2: Impregnation method for loading deliquescent metal salts, the purpose of which is to construct a homogeneous moisture-absorbing layer, specifically includes: preparing a deliquescent metal salt solution with a mass fraction of 10-30wt%; immersing the first end of the pretreated fiber substrate in the deliquescent metal salt solution for 2-4 hours, and then taking out the fiber substrate for drying to form an adsorption end.

[0073] S3: The purpose of loading carbon-based photothermal materials by impregnation is to construct a photothermal hydrophobic interface and form an asymmetric loading desorption end. Specifically, it includes: preparing a carbon-based photothermal material dispersion; immersing the second end of the fiber substrate obtained in step S2 in the carbon-based photothermal material dispersion; and then drying it to form a photothermal desorption end.

[0074] The asymmetric continuous dehumidifying material of this invention can be obtained by bilateral impregnation of the fiber substrate. The method of this application is simple, low-cost, and has great potential for industrial mass production.

[0075] To adapt to the needs of different adsorption, mass transfer, and desorption materials, the core parameters in the preparation steps can be flexibly adjusted within a certain range. Adjustable parameters include, but are not limited to, the concentration and mass fraction of deliquescent metal salts; the area and pretreatment time of fiber fabrics; and the mass fraction and curing time of carbon-based photothermal materials.

[0076] This application utilizes an impregnation method to directly form a three-dimensional continuous skeleton flow-guiding structure from a complete and continuous three-dimensional fiber substrate. In this application, the adsorption end and the desorption end are jointly anchored at both ends of the same continuous fiber. This means that there are no physical transition layers or gaps between them, and the capillary channels of the fiber substrate are 100% interconnected from the hygroscopic zone to the photothermal evaporation zone. This seamless and integrated continuous structure completely eliminates interlayer interface resistance, allowing the adsorbed liquid water to adhere to the continuous capillary forces within the fiber, achieving smooth and rapid directional transport, much like the vascular bundles of a plant.

[0077] This application ingeniously utilizes an impregnation method to construct an asymmetric structure on a continuous fiber substrate. The fiber pores at the adsorption end are impregnated with a high concentration of deliquescent metal salts, while the fibers at the desorption end are anchored to a carbon-based photothermal material. In actual operation, the photothermal material at the desorption end absorbs sunlight to generate extremely high local temperatures for moisture evaporation; meanwhile, the hygroscopic end continuously adsorbs moisture from the air, maintaining a cool temperature close to ambient. This asymmetry imparted by the impregnation method perfectly decouples the physical spaces of adsorption and desorption—the adsorption end continuously absorbs water from the air at low temperatures, while the desorption end achieves evaporation at the high temperatures of photothermal conversion, without interference between the two. This achieves continuous, all-weather dehumidification using a single component, representing a significant innovation in existing textile technology and homogeneous materials.

[0078] This application employs an impregnation method to deeply embed photothermal materials into the pores of continuous fibers. This not only strengthens the material but also constructs an extremely precise capillary pumping network. The powerful capillary suction force of the continuous fiber substrate can adaptively respond to the evaporation pull of the photothermal layer. When the photothermal layer rapidly vaporizes water under strong light, the faster the evaporation, the greater the capillary negative pressure, and the faster the liquid water at the bottom is pulled upwards. The transport rate of liquid water and the heat energy converted from solar energy achieve a dynamic balance. Even under extreme conditions of prolonged exposure to extremely strong light, the photothermal layer always maintains an optimal evaporation state of slight wetting, neither drying out nor becoming flooded, maintaining extremely efficient and stable vaporization, and completely solving the pain point of mass transfer mismatch in the continuous desorption process.

[0079] The present application will be further explained and illustrated below through specific embodiments:

[0080] Example 1: Preparation method of "lithium chloride-fiber substrate-carbon nanotube" asymmetric composite material, as follows: Figure 5 As shown:

[0081] This embodiment discloses a method for preparing an asymmetric continuous dehumidification material with a fiber substrate. By chemically impregnating a spatially segmented fiber substrate, a three-dimensional asymmetric mass transfer configuration of "adsorption end-transport layer-desorption end" is constructed. The specific steps are as follows:

[0082] S1: Pretreatment of the fiber substrate, which is made of pure cotton fiber fabric;

[0083] A 20cm x 20cm piece of pure cotton fabric was immersed in a mixture of anhydrous ethanol and deionized water in equal volumes. It was then ultrasonically cleaned for 30 minutes at room temperature to thoroughly remove residual natural oils, waxes, and other impurities from the surface of the cotton fabric. Subsequently, the cleaned cotton fabric was dried in a 60°C forced-air drying oven. This step effectively exposes abundant polar hydroxyl groups (-OH) in cellulose, thereby obtaining a fiber substrate with high hydrophilicity and strong capillary pumping ability.

[0084] S2: Construction of the adsorption end:

[0085] (1) Select anhydrous lithium chloride (LiCl) reagent that has been stored in a sealed, dry place. According to the predetermined mass fraction (LiCl:H2O=1:9, i.e., 10wt%), accurately weigh 10g of anhydrous lithium chloride solid and add it to 90g of distilled water to prepare a LiCl impregnation solution. (Note: Because anhydrous LiCl is extremely hygroscopic, the weighing process must be carried out quickly in a dry environment to avoid absorption of air moisture, which may lead to concentration deviation.)

[0086] (2) Take the pretreated fiber substrate from S1 and vertically immerse its first end in the prepared lithium chloride solution for 2 hours. Relying on the well-developed porous capillary action inside the fiber, the LiCl solution fully penetrates into the fiber bundle in this area. Then, take out the fabric and put it in a vacuum drying oven at 80°C to dry until the moisture is completely evaporated, and the lithium chloride fully crystallizes and is firmly anchored in the fiber network through intermolecular hydrogen bonds, forming highly hygroscopic adsorption ends.

[0087] S3: Construction of the photothermal desorption end:

[0088] (1) Select dried carbon nanotube (CNT) powder and accurately weigh 5g of carbon nanotubes according to the predetermined mass fraction (CNT:H2O=1:19, i.e. 5wt%). Add it to 95g of distilled water to obtain a stable and uniform aqueous CNT dispersion.

[0089] (2) Using a local impregnation method, the second end of the fiber substrate without lithium chloride loading was vertically immersed in the carbon nanotube dispersion for 2 hours. After removal, it was placed in a vacuum drying oven at 80°C for thorough drying until the carbon nanotubes were tightly wrapped and anchored on the fiber skeleton in that area, forming a photothermal desorption end with broadband photothermal conversion characteristics. Thus, a complete "lithium chloride-fiber substrate-carbon nanotube" asymmetric continuous dehumidification composite material with a clear macroscopic phase interface was obtained.

[0090] The test results of the asymmetric continuous dehumidification material in this embodiment are as follows: Figure 6 As shown, compared to simple fiber materials, the dehumidification capacity of asymmetric continuous dehumidification materials is significantly improved. Asymmetric materials themselves possess good dehumidification capabilities, with a dehumidification rate reaching 8.10 hH. -1 At 1kWm -2 Under illumination, the photothermal conversion brought about by carbon nanotubes enables the desorption ends to operate efficiently, further increasing the dehumidification rate of the composite material to 15.84 gh. -1 Therefore, a continuous dehumidification process of "adsorption-mass transfer-desorption" is achieved.

[0091] To adapt to the different climatic environments and their requirements for moisture absorption and photothermal efficiency, the core parameters in this embodiment can be flexibly adjusted within a certain range. Size adjustability: The area of ​​the fiber fabric in S1 can be arbitrarily enlarged according to the actual size requirements of the air conditioning module; simply increase the volume of the lithium chloride solution and carbon nanotube dispersion proportionally. Salt loading adjustability: The mass ratio of anhydrous lithium chloride (LiCl) to distilled water in S2 can be optimized and adjusted according to the target adsorption capacity (e.g., the mass ratio LiCl:H2O can be set to 1:9 [10wt%], 2:8 [20wt%], or 3:7 [30wt%], etc.). Curing process adjustability: The vacuum drying temperature in S2 and S3 can be set to greater than 80℃, and the drying time can be adaptively shortened according to the set processing temperature and fabric thickness.

[0092] Example 2: Preparation method of "calcium chloride-fiber substrate-carbon nanotube" asymmetric composite material

[0093] This embodiment aims to demonstrate a preparation scheme using anhydrous calcium chloride (CaCl2) instead of lithium chloride as a desiccant. Calcium chloride also possesses excellent moisture absorption potential and is less expensive, making it suitable for cost-sensitive commercial applications. The specific steps are as follows:

[0094] S1: Pretreatment of the fiber substrate.

[0095] The specific operating parameters and requirements for this step are as described in S1 of Example 1 above, to obtain a highly hydrophilic transport substrate (20cm×20cm) with abundant exposed cellulose hydroxyl groups.

[0096] S2: Construction of the adsorption end (loading and anchoring of calcium chloride).

[0097] (1) Prepare a calcium chloride impregnation solution with a mass fraction of 10 wt%.

[0098] (2) Immerse half of the fiber substrate treated with S1 (10cm×20cm) vertically in the above calcium chloride solution for 2 hours. After removal, place it in an 80℃ vacuum drying oven to dry, so that the calcium chloride crystallizes and anchors in the fiber skeleton to form adsorption ends.

[0099] S3: Construction of photothermal desorption ends (asymmetric loading of carbon nanotubes)

[0100] The specific liquid preparation, ultrasonic dispersion, local impregnation, and drying operations in this step are all performed in accordance with S3 of Example 1 above. Finally, a carbon nanotube (CNT) photothermal hydrophobic layer is formed in the other half of the fiber substrate.

[0101] Thus, a complete asymmetric composite material of "calcium chloride-fiber substrate-carbon nanotube" was obtained.

[0102] Example 3: Preparation method of "zinc chloride-fiber substrate-carbon nanotube" asymmetric composite material

[0103] The preparation method of this embodiment is the same as that of Example 1, except that lithium chloride is replaced with zinc chloride, and the rest are performed in accordance with the steps in Example 1 above.

[0104] Example 4: Preparation method of "calcium chloride-activated carbon fiber" asymmetric composite material

[0105] This embodiment aims to demonstrate a preparation scheme using activated carbon fiber (ACF) instead of carbon nanotubes as a photothermal material. Activated carbon fiber achieves a perfect combination of the fiber substrate and the carbon-based photothermal material, eliminating the need for impregnation at the desorption ends and directly forming a highly efficient asymmetric photothermal desorption interface. The specific steps are as follows:

[0106] S1: Pretreatment of activated carbon fiber substrate

[0107] Same as S1 in Example 1, obtain the pretreated activated carbon fiber substrate.

[0108] S2: Construction of the adsorption end (loading and anchoring of calcium chloride)

[0109] Similar to S2 in Example 2, anhydrous calcium chloride chemical impregnation and anchoring are completed in half of the fiber substrate.

[0110] S3: Construction of the photothermal desorption end

[0111] Activated carbon fiber materials have excellent photothermal conversion properties and do not require additional processing.

[0112] Thus, a complete asymmetric composite material of calcium chloride and activated carbon fiber was successfully prepared. The test results are as follows: Figure 7 As shown, the material itself has a certain dehumidification capacity, with a dehumidification rate of up to 6.84 gh. -1 At 1kWm -2 Under illumination, the photothermal conversion brought about by activated carbon fibers accelerates the moisture transfer process, further increasing the dehumidification rate of the composite material to 12.18gh. -1 Therefore, the successful preparation of the "calcium chloride-activated carbon fiber" composite material demonstrates that asymmetric structures have great potential for design innovation, and the resulting dehumidifying composite film has universal applicability.

[0113] Example 5: Preparation method of "lithium chloride-fiber substrate-carbon black" asymmetric composite material

[0114] The preparation method in this embodiment is the same as in Example 4, except that calcium chloride is replaced with lithium chloride, and the rest are performed in accordance with the steps in Example 4 above.

[0115] Example 6: Preparation method of "calcium chloride-fiber substrate-carbon black" asymmetric composite material

[0116] This embodiment aims to demonstrate a preparation scheme using carbon black (CB) as a substitute for carbon nanotubes as a photothermal material. Carbon black is widely available and highly economical; by adding an appropriate amount of binder, a highly efficient asymmetric photothermal desorption interface can be constructed. The specific steps are as follows:

[0117] S1: Pretreatment of fiber substrate

[0118] Same as S1 in Example 1, obtain the pretreated fiber substrate.

[0119] S2: Construction of the adsorption end (loading and anchoring of calcium chloride)

[0120] Similar to S2 in Example 2, anhydrous calcium chloride chemical impregnation and anchoring are completed in half of the fiber substrate.

[0121] S3: Construction of photothermal desorption ends (asymmetric loading of carbon black)

[0122] (1) Select carbon black (CB) nanopowder with high specific surface area and prepare a carbon black / PVA composite dispersion of 5wt%, wherein the carbon black / PVA composite dispersion contains polyvinyl alcohol with a mass fraction of 0.5wt%.

[0123] (3) Immerse the unloaded area (the other half) of the fiber substrate loaded with calcium chloride in the above carbon black dispersion for 2 hours.

[0124] (4) After taking it out, place it in an 80℃ vacuum drying oven to dry it thoroughly, so that the carbon black particles are tightly coated and cross-linked on the fiber surface of the area with the assistance of PVA, forming black photothermal desorption ends.

[0125] Thus, a complete asymmetric composite material of "calcium chloride-fiber matrix-carbon black" was obtained. Its test results are as follows: Figure 8 As shown, the composite material itself has a certain dehumidification capacity, with a dehumidification rate of up to 8.10 gh. -1 At 1kWm -2 Under illumination, the photothermal conversion brought about by carbon black accelerates the moisture transfer process, further increasing the dehumidification rate of the composite material to 15.84gh. -1 Therefore, the continuous dehumidification of the "calcium chloride-fiber substrate-carbon black" composite material reflects the versatility of the asymmetric structural design.

[0126] Comparative Example 1: Single-sided photothermal transfer substrate (without hygroscopic metal salts)

[0127] This comparative example aims to verify the necessity of metal salts for active moisture capture. The specific preparation steps are as follows:

[0128] S1: Pretreatment of the fiber substrate: Same as S1 in Example 1 above.

[0129] S2: Construction of photothermal desorption end: Same as S3 in Example 1 above, carbon nanotube dispersion is directly impregnated and cured on one side of a pure fiber substrate.

[0130] The final desiccant composite material consisted only of a fiber substrate and carbon nanotubes. Compared to a pure fiber substrate, the moisture absorption capacity of the composite fiber loaded with a deliquescent metal salt was significantly improved. Test results are shown in the appendix. Figure 2 .

[0131] Comparative Example 2: Pure hygroscopic fiber substrate (without photothermal desorption ends)

[0132] This comparative example aims to verify the necessity of a carbon-based photothermal material layer for continuous solar energy desorption. The specific preparation steps are as follows:

[0133] S1: Pretreatment of the fiber substrate: Same as S1 in Example 1 above.

[0134] S2: Construction of the moisture-absorbing layer: Same as S2 in Example 1 above, the pretreated fiber substrate is impregnated and dried in a lithium chloride solution.

[0135] The final product was a moisture-absorbing composite material containing only lithium chloride-cellulose. The composite fiber with the carbon-based photothermal material loaded exhibited a faster dehumidification rate and an increased total dehumidification capacity. Test results are shown in the attached document. Figure 9 Similarly, 1kWm-2 Under illumination, the dehumidification rate of the pure hygroscopic fiber-based composite material without photothermal desorption ends is 6.52gh. -1 The composite material with photothermal desorption ends, such as the product prepared in Example 1, exhibits efficient desorption at the desorption ends due to the distribution of carbon nanotubes, achieving a dehumidification rate of 10.50 gh. -1 The efficiency was significantly improved. Therefore, the loading of carbon-based photothermal materials is essential for the continuous solar desorption process.

[0136] In summary, the core innovations of this application are reflected in the following three aspects:

[0137] First, this application achieves moisture transport synergistically between asymmetric mass transfer configuration and concentration gradient. It overcomes the functional limitations of traditional dehumidifying materials with a single coating, successfully constructing a three-dimensional asymmetric heterostructure of "adsorption end (hygroscopic metal salt) - mass transfer layer (fiber substrate) - desorption end (carbon-based photothermal material)". A deep-field optical microscope schematic diagram of the fiber interface between the adsorption and desorption ends is shown below. Figure 10 As shown in the diagram, this configuration cleverly utilizes the local concentration difference between the high-concentration moisture generated at the indoor adsorption end and the moisture evaporation at the outdoor desorption end. Combined with the inherent micro / nano capillary binding force of the natural / synthetic fiber substrate, it achieves a spontaneous, directional water vapor pumping function from the inside out. This transforms the traditional static water storage medium into a dynamic water vapor pump that requires no complex external mechanical structures or additional fossil fuel energy, realizing spatially decoupled passive liquid transport.

[0138] Second, this application presents an in-situ adsorption-desorption mechanism integrating molecular-level anchoring and photothermal evaporation interfaces. This technology, through chemical anchoring (interaction between functional groups and salt ions) and physical binding (fiber capillary forces), effectively enhances the capture and storage of water molecules in the air, while mitigating solution leakage of deliquescent metal salts during dehumidification. Furthermore, the carbon-based photothermal material at the desorption end, acting as a broadband photothermal converter, efficiently absorbs solar radiation to generate localized high temperatures, vaporizing the transferred moisture in situ, perfectly realizing an in-situ adsorption-mass transfer-desorption process driven by clean energy.

[0139] Third, this application enables truly continuous latent heat treatment driven by zero carbon emissions. Based on the aforementioned asymmetric mass transfer configuration and photothermal evaporation interface, this invention achieves spatiotemporal decoupling and synchronization of moisture capture (dehumidification) and photothermal vaporization (desorption) on the same physical material. This breaks away from the intermittent operation of traditional systems that require shutdown and regeneration after saturation, achieving truly continuous dehumidification. When this composite material is applied to building envelopes, smart windows, or independent air conditioning modules, the adsorption end faces indoors to treat latent heat loads, while the desorption end faces outdoors to capture solar energy and discharge moisture. The system completely eliminates the high-energy-consuming mechanical components of traditional air conditioners, achieving decoupling of temperature and humidity treatment and renewable energy-driven operation, providing a disruptive solution for smart buildings and next-generation near-zero carbon air conditioning systems.

[0140] Example 7: Application of Asymmetric Continuous Dehumidification Materials

[0141] To highlight the value of renewable energy-driven and building-integrated applications, this embodiment discloses a feasible application of this material in the construction field. For example... Figure 11 As shown in (a), a near-zero carbon dehumidification integrated building system includes a transparent cover plate and a heat storage wall arranged sequentially from the outside to the inside. An air gap is formed between the transparent cover plate and the heat storage wall. The heat storage wall has installation through holes, through which the fiber substrate penetrates. The adsorption end is located on the inner side of the heat storage wall, and the desorption end is located between the heat storage wall and the transparent cover plate. The top and bottom of the heat storage wall are respectively provided with an indoor air supply vent and an indoor air return vent, and the top and bottom of the transparent cover plate are respectively provided with an outdoor air exhaust vent and an outdoor air inlet.

[0142] The asymmetric continuous dehumidification material serves as the core internal module. Combined with the design of indoor air supply vents, indoor return air vents, outdoor air inlets, outdoor exhaust vents, and transparent covers, it forms a passive, continuous, near-zero carbon dehumidification integrated module without mechanical structure.

[0143] The specific layout of the building system in this embodiment resembles a "sandwich" system, with the following arrangement from the outside to the inside:

[0144] (1) Transparent cover: The outermost layer, usually one or more layers of high-transmittance glass (or polycarbonate sheet). Its function is to allow sunlight to pass through and capture heat using the "greenhouse effect" while limiting the direct contact between external cold air and the wall.

[0145] (2) Air gap: The enclosed air gap between the transparent cover and the heat storage wall, which is usually 5-20 cm thick. This space is the core area for heat exchange and airflow circulation.

[0146] (3) Thermal storage wall: The main structure, constructed of high-density, high-specific-heat-capacity materials, such as concrete, brick, adobe, phase change materials, or a water-filled container. The wall thickness is generally 20-40 cm (adjusted according to climate and materials). The outer surface of the wall is usually painted dark (such as black or dark blue) to maximize the absorption of solar radiation. The inner surface remains a normal wall finish.

[0147] (4) Asymmetric continuous dehumidification material: The heat storage wall is equipped with installation through holes, and the installation method is similar to that of an integrated window air conditioner. The asymmetric continuous dehumidification material is directly installed in the installation through holes. The adsorption end of the fiber-based photothermal driven asymmetric continuous dehumidification material is placed in the indoor environment, and the desorption end is placed in the outdoor environment. During the daytime, when there is solar radiation, the high humidity air in the room is captured by the adsorption end, converted into liquid water, and directionally transported to the outdoor side within the fiber layer. The desorption end receives the outdoor solar radiation, generating a local photothermal conversion zone (temperature can reach 50-80℃), which converts the liquid water transported here into water vapor in situ and releases it into the atmosphere.

[0148] (5) Ventilation openings: Specifically, indoor air supply openings and indoor return air openings are respectively provided at the top and bottom of the heat storage wall, and outdoor exhaust openings and outdoor air inlets are respectively provided at the top and bottom of the transparent cover. Each ventilation opening is equipped with a damper (manual, electric, or thermal spring controlled) for switching modes according to season and day / night.

[0149] (6) Indoor wall surface: The inner side of the heat storage wall, i.e. the inner wall of the room, will provide heat to the room through heat radiation and heat conduction.

[0150] The winter mode is primarily used for heating and heat storage. During the day in winter, the indoor air supply and return vents are opened, utilizing the thermosiphon effect to achieve passive convection heating without fans, immediately delivering the solar energy collected by the walls into the room. Simultaneously, the outdoor air intake and exhaust vents are closed to prevent cold outdoor air from intruding into the air gap and compromising the insulation effect; it also prevents valuable hot air from being exhausted outdoors. At night in winter, all vents need to be closed, and the air within the air gap becomes still, acting as an additional insulation layer to prevent indoor hot air from escaping outdoors through the air gap and the transparent cover.

[0151] The summer mode is primarily for heat dissipation. During the day in summer, indoor air vents and return air vents are closed to prevent hot outdoor air or wall-heated air from flowing into the room and causing overheating. Outdoor air inlets and exhaust vents are opened, utilizing the chimney effect to directly exhaust heat from the walls and air gap to the outside, preventing heat load from entering the room. Simultaneously, solar radiation heats the desorption side, driving the dehumidification module to work, reducing indoor relative humidity and further reducing the indoor cooling load. At night in summer, indoor air vents and return air vents are closed, while outdoor air inlets and exhaust vents are opened, utilizing the circulation of cool outdoor air to lower the initial temperature of the walls the next day and reduce heat transfer into the room during the day.

[0152] Utilizing the innovative structure of the aforementioned building system, asymmetric continuous dehumidification materials placed between the indoor and outdoor environments can regulate humidity. Through the inherent asymmetric configuration of the material, spontaneous adsorption, mass transfer, and desorption processes are achieved, while solar energy is used for moisture transfer, enabling efficient and continuous dehumidification against the concentration gradient in the indoor environment. The structural design of the air supply and exhaust vents accelerates air circulation to a certain extent and reduces building surface temperature, thus achieving a perfect synergy between solar dehumidification and ventilation. The basic principle is as follows: Figure 11 As shown in (b) of the diagram, the asymmetric continuous dehumidification material successfully regulates indoor humidity using solar energy. The system operates entirely on passive capillary action and natural light, consuming no electrical or mechanical energy, and can effectively replace traditional mechanical dehumidification rotors. This passive temperature and humidity control wall structure utilizes solar energy without mechanical intervention. Through rational building orientation and spatial arrangement, shading and natural ventilation design, and the use of thermal insulation technology in the building envelope, it reduces the building's energy consumption, simplifies maintenance, smooths temperature and humidity fluctuations, improves indoor comfort, and has enormous commercial application potential.

[0153] Example 8: Photovoltaic Dual-Mode All-Weather Building Dehumidification Integrated System

[0154] To highlight the high energy efficiency of this asymmetric composite material in all-weather building environment control, solve the engineering limitations of dehumidification interruption at night or during continuous rainy weather, and overcome the technical defects of long heat transfer paths and large energy loss in traditional industrial hot air desorption and regeneration methods, this embodiment discloses a building system that introduces resistance wire to directly heat the desorption end.

[0155] This embodiment uses a similar wall "sandwich" integrated module configuration to Embodiment 7 (including an outermost translucent cover, an air gap, a heat storage wall, an indoor air supply vent, an indoor return air vent, an outdoor exhaust vent, and an outdoor air inlet). Its core innovation lies in the highly integrated electrothermal active modification of the outdoor desorption side of the asymmetric continuous dehumidification material embedded in the installation through-holes. For example... Figure 12 (a) and Figure 12 As shown in (b) above, the specific arrangement is as follows:

[0156] (1) Asymmetric continuous dehumidification material: directly installed in the installation through hole of the heat storage wall, with the adsorption end facing the indoor environment and the desorption end facing the outdoor air layer.

[0157] (2) Surface direct contact resistance heating mesh, specifically a metal resistance heating wire. In this embodiment, an S-shaped or grid-like metal resistance heating wire (such as nickel-chromium alloy wire, tungsten wire, etc.) is tightly attached to or shallowly embedded on the outermost surface of the desorption end (i.e., the surface of the photothermal conversion layer). The metal resistance heating wire network structure is sparse, does not block the sunlight from irradiating the underlying photothermal material during the day, and maintains direct physical thermal contact with the trace amount of liquid aqueous solution seeping from the surface of the desorption end.

[0158] (3) Intelligent sensing and control unit: The system is equipped with a photosensitive sensor and a microcontroller. The metal resistance heating wire is connected to the controller and the building power grid or energy storage battery through wires, which is used to intelligently switch the driving heat source according to the external irradiation conditions.

[0159] Daytime Mode (Photothermal Dominance, Zero-Carbon Passive Dehumidification): During daytime solar radiation, the controller cuts off the power to the resistance heating wire. Sunlight shines directly onto the carbon-based photothermal material at the desorption end through the gaps in the transparent cover and heating mesh. The material generates localized photothermal heat (50-80℃), converting the liquid moisture continuously transported from the adsorption end through the fiber substrate into water vapor in situ. After the vapor is discharged into the air gap, it is released into the atmosphere through the exhaust vent using the chimney effect generated by solar energy. This process achieves zero-power dehumidification.

[0160] Night / Rainy Mode (Direct Resistance Heating, Short-Path Active Dehumidification): At night or when there is no effective solar radiation, the controller automatically turns on the power to the resistance heating wire. Once energized, the heating wire rapidly generates Joule heat, directly heating the surface of the material on the desorption side. During the mass and heat transfer process of the system, the flux of the liquid aqueous solution pumped by the fiber capillary pump in the composite material is relatively stable and minimal. If a traditional method of blowing hot air is used, a large amount of heat energy would be consumed in heating ineffective air (sensible heat load), and the long heat transfer path (heating element-air-water) would result in significant energy loss. Therefore, this embodiment places the resistance wire directly against the desorption end surface, allowing the generated high-temperature heat to act directly on the liquid moisture seeping from the fiber surface. This extremely short heat transfer path allows electrical energy to be directly converted into the latent heat of water vaporization. The liquid water evaporates rapidly under direct heating, and the resulting water vapor is then directly carried away by the naturally circulating ambient airflow in the air gap and discharged outdoors.

[0161] Multimodal combined mode (photovoltaic synergy): When it is cloudy or the sunlight is weak in the evening, the system can turn on the low-power resistance heating wire to use electrical energy to supplement the solar heat, maintain the desorption end at the optimal vaporization temperature, and achieve the ultimate optimization of energy utilization.

[0162] The winter mode, as shown in Example 7, is mainly used for heating and heat storage.

[0163] The summer mode, as shown in Example 7, is primarily used for heat dissipation.

[0164] The beneficial effects of this embodiment are as follows: By directly arranging a surface-contact resistance heating grid on the desorption side surface, this application successfully achieves seamless day-night dehumidification through sunlight during the day and electric heating at night. More importantly, this design overturns the inefficient desorption process of industrial rotary dehumidifiers that involves "heating the air first, and then using the air to heat the material." By directly targeting the heat to the liquid water on the desorption side, the heat transfer path is greatly shortened, avoiding energy waste caused by heating large amounts of air. Simultaneously, this direct surface heating method has an extremely fast temperature response, perfectly preserving the spatial decoupling mechanism of "water absorption, mass transfer, and desorption" within the material, exhibiting extremely high thermodynamic efficiency and commercial application value.

[0165] Example 9: Hot Air Assisted All-Weather Intelligent Continuous Dehumidification System

[0166] To further expand the engineering application value of asymmetric continuous dehumidification materials in building environment control and industrial air treatment, and to solve the problems of adsorption saturation, cycle switching, and high regeneration energy consumption of traditional adsorption dehumidification equipment, this embodiment discloses a hot air-assisted all-weather intelligent continuous dehumidification system based on asymmetric continuous dehumidification composite materials. This embodiment utilizes the asymmetric continuous dehumidification composite materials prepared in Examples 1-6 as the core dehumidification module. Through structural design, spatial isolation between the dehumidified air channel and the regeneration air channel is achieved. Combined with a low-temperature hot air-assisted regeneration system, the adsorption, mass transfer, and desorption processes are operated synchronously and continuously.

[0167] like Figure 13 As shown, where, Figure 13 (a) is a schematic diagram of the structure of a hot air-assisted all-weather intelligent continuous dehumidification system. Figure 13 (b) is a schematic diagram of the working principle of the hot air-assisted all-weather intelligent continuous dehumidification system. In this embodiment, the hot air-assisted all-weather intelligent continuous dehumidification system includes an isolation chamber 27 located indoors. The upper end of the isolation chamber 27 is provided with a dehumidified air circulation channel 22, and the lower end of the isolation chamber 27 is provided with a hot air regeneration circulation channel 23. A heat insulation plate is provided between the dehumidified air circulation channel 22 and the hot air regeneration circulation channel 23. An asymmetric continuous dehumidification material 21 is provided inside the isolation chamber 27. The adsorption end of the asymmetric continuous dehumidification material 21 is located in the dehumidified air circulation channel 22, and the desorption end of the asymmetric continuous dehumidification material 21 is located in the hot air regeneration circulation channel 23. The asymmetric continuous dehumidification material is vertically arranged through the heat insulation plate to avoid mixing of the treated air and the regenerated air, while ensuring that the functional areas on both sides of the asymmetric dehumidification material operate independently, thereby achieving spatial separation of the adsorption area and the desorption area.

[0168] The dehumidified air circulation channel 22 is used to treat high-humidity indoor air. A first air inlet and a first air outlet 25 are respectively located at both ends of the channel, and fans are installed at each inlet and outlet. In applications such as offices and production workshops, the temperature of the high-humidity indoor air is approximately 25°C, and the relative humidity is approximately 80-90% RH. This air enters the dehumidified air circulation channel 22 through the first air inlet and comes into full contact with the adsorption end of the asymmetric continuous dehumidification material 21. Due to the strong moisture capture capacity of the adsorption end, water vapor in the air is rapidly adsorbed and converted into a liquid solution. Subsequently, the liquid moisture is directionally transported along the fiber direction from the adsorption end to the desorption end by the combined effects of capillary driving force generated by the three-dimensional continuous capillary channels inside the fiber substrate, the water vapor concentration gradient formed between the adsorption and desorption ends, and the gravity of the liquid water itself. This process does not require an additional mechanical pumping structure, achieving continuous moisture migration. The treated low-humidity air is then returned to the indoor environment through the first air outlet 25. For example, the air humidity can be reduced from 25℃ and 90% RH to around 25℃ and 40% RH, achieving continuous indoor humidity control.

[0169] The hot air regeneration circulation channel 23 provides the hot air required for desorption. A heating module 24 is installed inside the hot air regeneration circulation channel 23, and a second air inlet and a second air outlet 26 are respectively located at both ends of the channel. Centrifugal fans are installed at the second air inlet and the second air outlet 26. The heating module 24 is located between the second air inlet and the asymmetric continuous dehumidification material 21. Outdoor air is drawn into the heating module 24 through the centrifugal fan at the second air inlet. Specifically, the heating module 24 can be a PTC thermistor ceramic heating element. When energized, the PTC thermistor ceramic generates stable heat, rapidly heating the air to a temperature range of 40-80°C. Preferably, the regeneration hot air temperature is controlled at 50-70°C. Subsequently, the high-temperature, low-humidity hot air enters the regeneration channel and flows through the desorption end of the asymmetric continuous dehumidification material 21. Since the desorption end has accumulated liquid moisture transported from the adsorption end, the high-temperature hot air provides the thermal driving force, causing the liquid water to undergo a rapid phase change process. Simultaneously, the hot air reduces the partial pressure of water vapor near the desorption end, accelerating moisture release. Finally, the regenerated air carrying water vapor is discharged outdoors through a centrifugal fan at the second outlet 26. Through this process, continuous moisture absorption at the adsorption end, continuous water delivery to the fiber layer, and continuous moisture release at the desorption end are achieved. This avoids the problem of traditional adsorption dehumidification equipment requiring periodic shutdowns for regeneration.

[0170] With the above structure, the high-performance continuous dehumidification system in this embodiment can achieve: (1) Synchronous operation of dehumidification and regeneration processes: the adsorption and desorption regions are spatially decoupled through the asymmetric structure, eliminating the need for periodic switching of the adsorption bed. (2) Synergistic mass transfer driven by multiple forces: continuous moisture transport is achieved by utilizing capillary force, water vapor partial pressure, chemical potential gradient, gravity, and thermal driving force. (3) Applicable to various air environments: residential homes, office buildings, industrial workshops, storage warehouses, experimental environments, etc.

[0171] Compared to traditional compressor dehumidification equipment and fixed-bed adsorption dehumidification equipment, the hot air-assisted all-weather intelligent continuous dehumidification unit provided in this embodiment has the following advantages:

[0172] First, by using asymmetric continuous dehumidification composite materials, the adsorption, mass transfer and desorption processes can be carried out simultaneously in the same material, avoiding the efficiency reduction caused by the periodic switching of traditional dehumidification equipment.

[0173] Second, by separating the dehumidification channel and the regeneration channel, independent circulation of humid air treatment and hot air regeneration is achieved, thereby improving the stability of system operation.

[0174] Third, by introducing PTC thermistor ceramic hot air auxiliary components, it can maintain continuous dehumidification capability under various cloudy and indoor conditions, achieving all-weather operation.

[0175] Fourth, the unit has a simple structure and a high degree of modularity, and can be directly integrated with building air conditioning systems, fresh air systems, and industrial air handling equipment.

[0176] Therefore, the hot air-assisted all-weather intelligent continuous dehumidification system proposed in this embodiment provides a feasible technical solution for the transformation of asymmetric continuous dehumidification material 21 from laboratory material to engineered air control equipment.

[0177] It is understood that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can freely combine the above technical features without departing from the concept of the present invention, and can also make several modifications and improvements, all of which fall within the protection scope of the present invention. Therefore, all equivalent transformations and modifications made with respect to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. An asymmetric continuous dehumidifying material with a fiber substrate, characterized in that, The invention includes a fiber substrate, the first end of which is loaded with a deliquescent metal salt to form an adsorption end; the adsorption end is capable of capturing gaseous water molecules from the environment and deliquescing them in situ into a salt solution. The second end of the fiber substrate is loaded with carbon-based photothermal material to form a desorption end, and the salt solution is transported along the fiber substrate to the desorption end; the desorption end generates high temperature under light radiation, causing the liquid water to vaporize in situ.

2. The asymmetric continuous dehumidification material with a fiber substrate according to claim 1, characterized in that, The deliquescent metal salt includes at least one of lithium chloride, calcium chloride, and zinc chloride.

3. The fiber-based asymmetric continuous dehumidification material according to claim 1, characterized in that, The carbon-based photothermal material includes at least one of carbon nanotubes and carbon black.

4. The fiber-based asymmetric continuous dehumidification material according to claim 1, characterized in that, The fiber substrate has a thickness of 0.5-3 mm and a specific surface area ≥ 300 m². 2 / g, porosity ≥60%.

5. A method for preparing an asymmetric continuous dehumidifying material with a fiber substrate, characterized in that, The preparation of an asymmetric continuous dehumidifying material with a fiber substrate as described in any one of claims 1-4 includes: A deliquescent metal salt is loaded at the first end of the fiber substrate by impregnation. Carbon-based photothermal materials are loaded at the second end of the fiber substrate by impregnation.

6. The method for preparing an asymmetric continuous dehumidifying material with a fiber substrate according to claim 5, characterized in that, Before forming the adsorption and desorption ends, the process also includes: pretreatment of the fiber substrate. The fiber substrate was ultrasonically cleaned using a mixed solution of anhydrous ethanol and deionized water. The ultrasonically cleaned fiber substrate is dried at 60-80℃ to obtain a hydrophilic fiber substrate.

7. The method for preparing an asymmetric continuous dehumidifying material with a fiber substrate according to claim 6, characterized in that, A deliquescent metal salt is loaded at the first end of the fiber substrate by impregnation, specifically including: Prepare a deliquescent metal salt solution with a mass fraction of 10-30 wt%; The first end of the pretreated fiber substrate is immersed in the deliquescent metal salt solution; The impregnated fiber substrate is dried until the deliquescent metal salts are fully crystallized and anchored in the fiber network.

8. The method for preparing an asymmetric continuous dehumidifying material with a fiber substrate according to claim 6, characterized in that, Carbon-based photothermal materials are loaded at the second end of the fiber substrate via an impregnation method, specifically including: Prepare a 3-10 wt% dispersion of carbon-based photothermal material; A carbon-based photothermal material dispersion was applied to the second end of a fiber substrate by an impregnation method. The impregnated fiber substrate is dried until the carbon-based photothermal material is anchored in the fiber network.

9. The application of a fiber-based asymmetric continuous dehumidifying material, characterized in that, The fiber-based asymmetric continuous dehumidifying material according to any one of claims 1-4 is used for indoor humidity control, wherein the adsorption end is located indoors and the desorption end is located outdoors.

10. The application of the fiber-based asymmetric continuous dehumidification material according to claim 9, characterized in that, The fiber-based asymmetric continuous dehumidifying material is used in conjunction with the building system to regulate indoor temperature and humidity. The building system includes a transparent cover plate and a heat storage wall arranged sequentially from the outside to the inside. An air gap is formed between the transparent cover plate and the heat storage wall. The heat storage wall is provided with an installation through hole. The fiber substrate passes through the installation through hole, and the adsorption end is located on the inner side of the heat storage wall. The desorption end is located between the heat storage wall and the transparent cover plate. The top and bottom of the heat storage wall are respectively provided with an indoor air supply vent and an indoor air return vent, and the top and bottom of the transparent cover are respectively provided with an outdoor air exhaust vent and an outdoor air inlet. In winter mode, asymmetric continuous dehumidification material is used to dehumidify the room; during the day, the indoor air supply vents and indoor return air vents are opened to send the solar energy collected by the heat storage wall into the room using the thermosiphon effect; the outdoor air inlet and outdoor exhaust vents are closed to prevent cold outdoor air from intruding into the air gap; at night, the indoor air supply vents, indoor return air vents, outdoor air inlet and outdoor exhaust vents are closed, so that the air gap forms an insulation layer. In summer mode, asymmetric continuous dehumidification material is used to dehumidify the room; during the day, the indoor air supply vents and indoor return air vents are closed to prevent hot outdoor air or air from the air gap from flowing into the room. Open the outdoor air inlet and outlet to exhaust heat from the air gap to the outside using the chimney effect; at night, close the indoor air supply and return vents and open the outdoor air inlet and outlet to circulate cold outdoor air and lower the temperature of the heat storage wall.

11. The application of the fiber-based asymmetric continuous dehumidifying material according to claim 10, characterized in that, The surface of the adsorption end of the asymmetric continuous dehumidification material is provided with a surface direct contact resistance heating mesh. The network structure of the surface direct contact resistance heating mesh is sparse and maintains direct physical thermal contact with the liquid aqueous solution seeping from the desorption end surface.

12. The application of the fiber-based asymmetric continuous dehumidifying material according to claim 11, characterized in that, The surface direct-contact resistance heating mesh is connected to the controller and power supply; When there is solar radiation, the controller cuts off the power to the surface direct contact resistance heating grid; When there is no solar radiation, the controller turns on the power to the surface direct contact resistance heating grid.

13. The application of the fiber-based asymmetric continuous dehumidifying material according to claim 9, characterized in that, The fiber-based asymmetric continuous dehumidification material is used to form a hot air-assisted all-weather intelligent continuous dehumidification system. The hot air-assisted all-weather intelligent continuous dehumidification system includes an indoor isolation chamber. The upper end of the isolation chamber is provided with a dehumidified air circulation channel, and the lower end of the isolation chamber is provided with a hot air regeneration circulation channel. A heat insulation plate is provided between the dehumidified air circulation channel and the hot air regeneration circulation channel. An asymmetric continuous dehumidification material is provided inside the isolation chamber. The adsorption end of the asymmetric continuous dehumidification material is located in the dehumidified air circulation channel, and the desorption end of the asymmetric continuous dehumidification material is located in the hot air regeneration circulation channel. The symmetric continuous dehumidification material penetrates through the heat insulation plate.

14. The application of the fiber-based asymmetric continuous dehumidifying material according to claim 13, characterized in that, The dehumidified air circulation channel has a first air inlet and a first air outlet at both ends, which are located indoors; the hot air regeneration circulation channel has a second air inlet and a second air outlet at both ends, which are located indoors, and a heating module is installed inside the hot air regeneration circulation channel.

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