Magnetic stone fiber based on bionic multi-stage pores and dynamic response and preparation method and application thereof

Abstract

This invention relates to the field of magnetic fibers, and more particularly to a biomimetic multi-level channel and dynamic response-based magnetic Bianstone fiber, its preparation method, and its application. The magnetic Bianstone fiber comprises a multi-level channel carbon-based framework derived from biomass cellulose hydrogel and subjected to low-temperature carbonization; magnetic nanoparticle composite units loaded within the framework channels; and a far-infrared mineral functional layer coating the outer surface of the framework and the magnetic nanoparticle composite units. The far-infrared mineral functional layer comprises Bianstone powder and a dielectric material layer coating it. This invention achieves efficient and stable integration of magnetic, far-infrared radiation, and antibacterial functions by constructing a biomimetic multi-level channel and core-shell hierarchical structure. It significantly improves the performance degradation problems caused by easy component aggregation and weak interfacial bonding in traditional multifunctional fibers. Furthermore, through in-situ loading and coating technology, it achieves high performance while also considering process feasibility and structural stability.

Description

Technical Field

[0001] This invention relates to the field of magnetic fibers, and more particularly to a magnetic Bianstone fiber based on biomimetic multi-level channels and dynamic response, its preparation method, and its application. Background Technology

[0002] In the field of functional fiber materials, endowing fibers with multiple functions such as magnetism, far-infrared radiation, and antibacterial properties is an important research direction for expanding their applications in high-end textiles, healthcare, and smart fabrics.

[0003] Currently, common technical approaches mainly fall into two categories. One category involves preparing single-function fibers. For example, this involves introducing iron oxide nanoparticles into the fiber matrix through blending or in-situ synthesis to obtain magnetism, or adding mineral powders such as Bianstone or ceramics to enhance far-infrared emission performance. However, fibers prepared using this method have limited functionality and struggle to meet market demands for integrated and intelligent materials. The other category attempts to composite multiple functional materials. For instance, this involves directly blending magnetic particles with far-infrared powder and then spinning them, or using a multi-layer coating process to attach different functional materials layer by layer to the fiber surface.

[0004] While these methods theoretically achieve functional integration, they often face significant challenges in practice. First, different functional materials, such as inorganic magnetic particles and mineral powders, exhibit poor dispersion compatibility within the polymer matrix. Simple physical blending easily leads to the agglomeration of functional components within or on the surface of the fiber. This not only results in uneven functional distribution and affects the consistency of performance, but may also cause detachment during subsequent processing or use due to weak interfacial bonding, leading to rapid functional degradation. Second, directly mixing substances with different properties may cause mutual constraints on performance. For example, high levels of certain inorganic additives may damage the mechanical properties of the fiber, making it brittle and hard; while adding large amounts of functional powder to achieve strong magnetic or far-infrared effects can significantly reduce the fiber's spinnability, hand feel, and wearing comfort.

[0005] More importantly, existing technologies often focus on the simple superposition of functions, i.e., the "1+1=2" model, while lacking effective design for the synergistic effects between functional units. For example, the magnetic component and the far-infrared component are merely "neighbors" in a physical sense within the fiber, lacking any linkage in their working mechanisms. How to construct a stable fiber structure that allows different functional units to not only be stably and uniformly loaded, but also, through ingenious spatial architecture and interface design, potentially promote positive reinforcement and synergistic enhancement of performance, such as enabling the energy of one external stimulus (e.g., a magnetic field) to be effectively transferred and optimize the performance of another function (e.g., far-infrared emission), is a topic that those skilled in the art have been continuously exploring but has not yet solved well.

[0006] In addition, some studies have adopted high-temperature processing to achieve stable load on functional materials, but this may cause irreversible structural damage to some temperature-sensitive functional materials (such as certain crystal forms of minerals or easily reduced magnetic oxides), leading to failure of core functions.

[0007] Therefore, developing a composite fiber that can balance multiple functionalities, structural stability, potential synergy among components, and mild manufacturing process remains a direction worthy of in-depth research in this field. Summary of the Invention

[0008] This application aims to overcome the shortcomings of existing technologies, such as poor dispersion of functional components in multifunctional composite fibers, weak interfacial bonding, rapid performance degradation, and lack of synergistic effects among various functions. Therefore, it provides a magnetic Bianstone fiber based on biomimetic multilevel channels and dynamic response, its preparation method, and its application to overcome the above-mentioned deficiencies.

[0009] To achieve the above-mentioned objectives, the present invention is implemented through the following technical solution: In a first aspect, the present invention provides a magnetic Bianstone fiber based on biomimetic hierarchical channels and dynamic response, comprising: A hierarchical porous carbon-based framework derived from biomass cellulose hydrogel and subjected to low-temperature carbonization; Magnetic nanoparticle composite units loaded within the framework channels; And, a far-infrared mineral functional layer covering the outer surface of the framework and the magnetic nanoparticle composite unit; The far-infrared mineral functional layer comprises Bianstone powder and a dielectric material layer covering it.

[0010] As shown in the background section, existing technologies for preparing multifunctional fibers possessing magnetic properties, efficient far-infrared radiation, and long-lasting antibacterial properties typically face a dilemma: While simple physical blending or surface coating processes are convenient, the functional components are unevenly dispersed within the fiber matrix, resulting in weak interfacial bonding. These components are easily detached during use due to friction and washing, leading to rapid functional degradation. Furthermore, the multiple properties are merely mechanically superimposed, failing to produce a synergistic effect greater than the sum of its parts. On the other hand, attempts to enhance the bonding between components through complex chemical modifications or high-temperature treatments often damage the inherent properties of certain functional materials (such as certain magnetic oxides or minerals with specific crystal structures) or cause the fiber itself to lose flexibility, resulting in a trade-off. In particular, establishing an effective "dialogue" mechanism between the magnetic and far-infrared units within the fiber—allowing an externally inputted energy (such as magnetic field energy) to be efficiently converted into another functional output (such as stronger far-infrared radiation), rather than simply existing independently—is crucial for improving the material's intelligence and application efficiency, and is a crucial element generally lacking in existing solutions.

[0011] To address the aforementioned issues, the inventive concept of this application stems from a dual consideration of the ordered structure and functional synergy of materials. Its core lies not in simply mixing powders with different functions, but in constructing a stable, interconnected, and responsive main structure capable of precisely supporting and connecting various functional units. Therefore, the determination of the technical solution of this invention begins with the biomimetic design of the framework. This invention chooses biomass cellulose hydrogel as the starting point because it naturally possesses a three-dimensional interconnected network of interwoven nanofibers at the microscopic level, which, after freeze-drying, can form a multi-level porous structure ranging from micrometers to nanometers. This structure not only provides a huge specific surface area and abundant anchoring points for the subsequent loading of functional components, but its interconnectivity also ensures smooth energy or material transport paths. However, this physical framework alone is insufficient in terms of mechanical stability and the ability to "bond" the various functional components, and lacks inherent electrical / thermal bridges to facilitate functional synergy. Therefore, this invention also introduces a crucial "low-temperature carbonization treatment." This treatment is carried out at a relatively mild temperature, and its purpose is not to completely transform the framework into a brittle pure carbon material, but rather to partially carbonize it. This process ingeniously preserves the original three-dimensional network morphology and elasticity of biomass cellulose nanofibers while generating a thin, continuous carbon layer on their surface. This carbon layer acts like a conductive and thermally conductive "coat" for the entire skeletal network, greatly enhancing the strength of the framework. More importantly, it constructs a rapid energy conduction channel that runs through the entire structure, laying a crucial physical foundation for subsequent "dialogue" between functional units.

[0012] Having established this multi-level porous carbon-based framework after low-temperature carbonization "strengthening" and "empowerment," this invention needs to further address the issue of how functional components "reside" and "function." Regarding the introduction of magnetic functionality, this invention does not employ the method of directly adsorbing existing magnetic nanoparticles, as this would primarily involve physical adsorption between the particles and the framework, resulting in limited binding force and difficulty in precisely controlling the distribution. Instead, a strategy of "in-situ construction" of the composite unit is chosen: the two-dimensional material dispersion and the iron source precursor are infiltrated into the framework pores, and through a hydrothermal reaction, magnetic iron(III) oxide nanoparticles are directly grown in situ on the surface of the two-dimensional material. The resulting magnetic nanoparticle composite unit exhibits a strong chemical bond between the magnetic particles and the two-dimensional material substrate, while the entire composite unit is tightly bound to the carbonized framework through interactions during the hydrothermal process. This design offers several advantages: First, the high dispersion of the magnetic particles prevents agglomeration, ensuring uniformity and stability of the magnetism; second, the selected two-dimensional material itself has excellent photothermal conversion capabilities, which, combined with the magnetocaloric effect of the magnetic particles, makes the unit a highly efficient dual-response "heat source"; third, the composite unit is firmly "locked" inside the channels of the skeleton, preventing it from falling off.

[0013] For the realization of far-infrared functionality, this invention also avoids simply mixing in Bianstone powder. Since Bianstone powder directly exposed to the surface is prone to loss and has low energy transfer efficiency with the internal "heat source," the solution employs a "wrapping" strategy: Bianstone powder is introduced onto the surface of the framework loaded with magnetic units and coated with a dielectric material layer (such as silicon dioxide). This dielectric material layer, formed via a sol-gel method, acts like a dense yet porous "shell," encapsulating the Bianstone powder and firmly bonding it to the framework and the external magnetic units. This shell first solves the problem of Bianstone powder fixation, significantly improving the durability of the function. More importantly, the design of this coating structure forms a sophisticated synergy with the internal carbonized framework and magnetic heating units. When an external magnetic field or light is applied, the internal magnetic composite units (such as MXene@Fe3O4) generate heat. At this point, the highly efficient thermally conductive network constructed by the carbon-based skeleton formed during the initial low-temperature carbonization begins to function. It can rapidly and evenly conduct the heat generated by the internal "heat source" to the outer Bianstone@dielectric material layer. After the Bianstone minerals receive sufficient and uniform thermal energy excitation, their far-infrared radiation performance can be fully and stably utilized. In other words, the outer far-infrared mineral functional layer does not work in isolation; its effectiveness is significantly enhanced by the internal heating units and the interconnecting thermally conductive skeleton. This achieves a directional synergistic chain from "magnetic / optical energy input" to "heat conduction" and then to "far-infrared radiation enhancement output," endowing the fiber with intelligent characteristics of dynamic response.

[0014] Thus, from the inventive concept to the final determination of the technical solution, this invention forms a clear logical thread: providing load space and mass transfer channels through a biomimetic multi-level porous structure; endowing the framework with energy transfer capabilities while preserving the structure through low-temperature carbonization; constructing a robustly integrated composite unit with both magnetic and photothermal conversion capabilities in situ within the channels as a built-in responsive "heat source"; and constructing a robustly encapsulated far-infrared mineral functional layer on the outer layer as an energy output terminal. The entire solution, through meticulous structural design, organizes different functional units in an orderly manner within a stable system, and through the bridging effect of the carbonized framework, connects and synergizes their potential performance.

[0015] The resulting technological advancements demonstrate significant progress and synergy compared to existing technologies. Firstly, in terms of functional stability, the functional units are firmly bonded to the framework through chemical and physical methods such as in-situ synthesis, coating, and low-temperature carbonization integration, rather than simple physical doping. This significantly improves resistance to shedding and attenuation, resulting in a markedly extended service life. Secondly, in terms of functional performance, the fiber exhibits strong and stable magnetic responsiveness, and its far-infrared emission efficiency is also at a high level. Particularly noteworthy is that, due to the design of the internal heat-conducting network and responsive "heat source," its far-infrared radiation performance can be further enhanced under external magnetic field or light stimulation, exhibiting dynamic responsiveness and performance adjustability not found in ordinary hybrid materials. Regarding antibacterial properties, the inherent characteristics of the silica coating layer, the mineral effect of Bianstone, and the potential auxiliary bactericidal effect brought about by thermal effects collectively contribute to a stable and highly efficient antibacterial effect.

[0016] In summary, this technical solution, through a combination of strategies including "structural design," "in-situ composite," "interface coating," and "low-temperature carbonization integration," not only effectively improves the common problems of uneven dispersion of functional components and weak interfacial bonding in multifunctional fibers, but also, by constructing an intrinsic energy transfer path, initially achieves positive synergy and dynamic enhancement between magnetic, photothermal, and far-infrared functions. This results in a substantial improvement and enhancement of the prepared fiber in terms of overall performance stability, efficiency, and intelligence compared to existing technologies.

[0017] Preferably, the magnetic nanoparticle composite unit comprises a composite structure formed by two-dimensional materials and magnetic iron oxide nanoparticles.

[0018] This invention pre-constructs a composite structure of magnetic iron oxide nanoparticles and two-dimensional materials, and then loads it as a monolithic unit within a multi-level porous framework. This approach is not simply a physical mixing or sequential addition of the two materials. The principle lies in the fact that the two-dimensional material (such as MXene) not only serves as a carrier with a high specific surface area, effectively dispersing and anchoring the iron oxide nanoparticles to prevent aggregation and migration, but more importantly, its excellent electrical conductivity and photothermal conversion capabilities, combined with the inherent magnetocaloric effect of iron oxide, make this composite unit a highly efficient multi-mode responsive "heat source." This "heat source" can efficiently generate heat under magnetic field or light stimulation, and through a carbon-based framework network formed by low-temperature carbonization, it rapidly conducts the heat energy to the outer far-infrared functional layer, thus establishing a physical channel for "energy input-conversion-transfer" within the material. This combines the magnetic particles and the two-dimensional material into an inseparable composite functional unit. This composite unit not only retains its magnetism but also introduces new energy conversion properties, transforming it from a passive functional component into an active response core.

[0019] Preferably, the two-dimensional material is MXene, and the magnetic iron oxide nanoparticles are grown in situ on the surface or between the layers of the MXene to form a core-shell or embedded structure.

[0020] Preferably, the MXene is a few-layer Ti3C2T x , where T is at least one of the functional groups -OH, -O or -F.

[0021] Preferably, the dielectric material layer is silicon dioxide, which is formed into a porous coating layer by a sol-gel method.

[0022] Secondly, the present invention also provides a method for preparing the magnetic Bianstone fiber, which includes the following steps: (S.1) Provide biomass cellulose hydrogel, which is freeze-dried to form a three-dimensional aerogel framework with multi-level pores; (S.2) Introduce and fix magnetic nanoparticle composite units in the pores of the aerogel framework to obtain a magnetic framework; (S.3) Introduce Bianstone powder into the surface and channels of the magnetic skeleton and coat it with a dielectric material layer to form a precursor; (S.4) The precursor is subjected to low-temperature carbonization treatment at 200°C to 400°C in an inert atmosphere to obtain the composite fiber.

[0023] Preferably, step (S.2) specifically includes: immersing the aerogel framework in a hydrothermal reaction precursor solution containing a two-dimensional material dispersion and iron salt, and reacting it in a closed reaction vessel at 120-180°C, so that iron oxide nanoparticles are generated in situ on the surface of the two-dimensional material and simultaneously loaded onto the framework.

[0024] Preferably, the biomass cellulose is bacterial cellulose; The two-dimensional material is MXene; The iron salt is at least one of ferric chloride and ferrous sulfate.

[0025] Preferably, step (S.3) specifically includes: immersing the magnetic skeleton in an alcohol-water solution containing Bianstone powder and silicon source compound, and forming a silicon dioxide coating layer on the surface of Bianstone powder and skeleton through a hydrolysis-condensation reaction.

[0026] Preferably, the specific procedure for the low-temperature carbonization treatment in step (S.4) is as follows: under a nitrogen or argon atmosphere, the temperature is increased to 300±10℃ at a heating rate of 1-5℃ / min and held for 1-4 hours.

[0027] Thirdly, the present invention also provides the application of the magnetic Bianstone fiber in the preparation of physiotherapy fabrics, intelligent temperature-regulating clothing or medical antibacterial dressings with magnetothermal or photothermal response functions.

[0028] Therefore, the present invention has the following beneficial effects: (1) By constructing a biomimetic multi-level channel and core-shell hierarchical structure, the efficient and stable integration of magnetic, far-infrared radiation and antibacterial functions is realized, which significantly improves the performance degradation problem caused by easy aggregation of components and weak interfacial bonding in traditional multifunctional fibers. (2) By leveraging the conductive and thermally conductive network formed by low-temperature carbonization and the synergistic effect of MXene@Fe3O4 composite units, the fiber is endowed with both magnetic field and photothermal responsiveness, which enables the external energy input to dynamically enhance the far-infrared output and improve the intelligence of the material. (3) The fiber has excellent comprehensive performance, with high magnetic responsiveness, high far-infrared emissivity and high antibacterial properties, and the various functions are synergistically enhanced through structural design. (4) The preparation process is mild, and the in-situ loading and coating technology ensures the strong binding of functional components, achieving high performance while taking into account process feasibility and structural stability. Detailed Implementation

[0029] The present invention will be further described below with reference to specific embodiments. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below are generally only some, not all, of the embodiments of the present invention. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0030] Example 1 This embodiment provides a method for preparing magnetic Bianstone fibers based on biomimetic hierarchical channels and dynamic response, which specifically includes the following steps: (1) Preparation of bacterial cellulose hydrogel: Acetobacter xylinum strain was inoculated into static culture medium (containing 2.5 wt% glucose, 0.5 wt% yeast extract, 1.0 wt% peptone, pH 5.0) and cultured at 30℃ for 7 days to obtain a bacterial cellulose wet gel membrane with a thickness of about 5 mm. The membrane was repeatedly washed with deionized water until neutral and treated with 1 wt% NaOH solution at 80℃ for 2 hours to remove residual bacteria and impurities. The membrane was then washed again with deionized water until neutral to obtain purified bacterial cellulose hydrogel.

[0031] (2) Constructing a three-dimensional porous framework: The hydrogel obtained in step (1) was pre-frozen in an ultra-low temperature freezer at -50°C for 12 hours, and then transferred to a freeze dryer and dried for 48 hours under the conditions of cold trap temperature of -80°C and vacuum degree of less than 10 Pa to obtain a bacterial cellulose aerogel framework.

[0032] (3) Loading magnetic nanoparticle composite units: Prepare a precursor solution by adding 20 mL of few-layer Ti3C2T with a concentration of 2 mg / mL. x (T is mainly -OH, -O) MXene aqueous dispersion was mixed with 30 mL of 0.1 mol / L FeCl3·6H2O aqueous solution and stirred until homogeneous. The aerogel framework obtained in step (2) was completely immersed in the precursor solution and placed in a 100 mL polytetrafluoroethylene-lined high-pressure reactor, and reacted at 150 °C for 12 hours. After natural cooling, the product was removed, washed three times alternately with deionized water and ethanol, and dried under vacuum at 60 °C to obtain a magnetic framework loaded with MXene@Fe3O4 core-shell structure (Fe3O4 nanoparticles grown in situ on MXene sheets).

[0033] (4) Coating with a far-infrared mineral functional layer: Prepare a coating solution by dispersing 1.0 g of Bianstone powder with an average particle size of 2 μm in a mixed solution consisting of 40 mL of anhydrous ethanol, 10 mL of deionized water and 2 mL of concentrated ammonia, and sonicating for 30 minutes. Then, slowly add 1.5 mL of tetraethyl orthosilicate (TEOS) under vigorous stirring, and continue stirring at room temperature for 6 hours. Immerse the magnetic skeleton obtained in step (3) into the above reaction solution, let it stand for 2 hours, remove it, preliminarily dry it at 80°C, and then heat treat it at 150°C for 1 hour to form a functional layer of Bianstone powder coated with silica, thus obtaining the precursor.

[0034] (5) Low-temperature carbonization integration: The precursor obtained in step (4) is placed in a tube furnace and heated to 300°C at a heating rate of 3°C / min under the protection of argon atmosphere, and held at this temperature for 2 hours. Then it is naturally cooled to room temperature to obtain the magnetic Bianstone fiber material based on biomimetic multi-level channels and dynamic response.

[0035] Example 2 This embodiment provides a method for preparing magnetic Bianstone fibers based on biomimetic hierarchical channels and dynamic response, which specifically includes the following steps: Steps (1)-(2) are the same as in Example 1.

[0036] (3) Loading magnetic nanoparticle composite units: Prepare a precursor solution by adding 20 mL of 1 mg / mL few-layer Ti3C2T x(T is mainly -OH, -O) MXene aqueous dispersion was mixed with 30 mL of 0.05 mol / L FeCl3·6H2O aqueous solution and stirred until homogeneous. The aerogel framework obtained in step (2) was completely immersed in the precursor solution and placed in a 100 mL polytetrafluoroethylene-lined high-pressure reactor, and reacted at 120 °C for 18 hours. After natural cooling, the product was removed, washed three times alternately with deionized water and ethanol, and dried under vacuum at 60 °C to obtain a magnetic framework loaded with MXene@Fe3O4 core-shell structure (Fe3O4 nanoparticles grown in situ on MXene sheets).

[0037] (4) Coating with a far-infrared mineral functional layer: Prepare a coating solution by dispersing 0.5 g of Bianstone powder with an average particle size of 2 μm in a mixed solution consisting of 50 mL of anhydrous ethanol, 15 mL of deionized water, and 2 mL of concentrated ammonia. Sonicate the solution for 30 minutes. Then, slowly add 0.8 mL of tetraethyl orthosilicate (TEOS) under vigorous stirring and continue stirring at room temperature for 4 hours. Immerse the magnetic framework obtained in step (3) in the above reaction solution, let it stand for 2 hours, remove it, preliminarily dry it at 80°C, and then heat treat it at 150°C for 2 hours to form a functional layer of Bianstone powder coated with silica, thus obtaining the precursor.

[0038] (5) Low-temperature carbonization integration: The precursor obtained in step (4) is placed in a tube furnace and heated to 200°C at a heating rate of 1°C / min under the protection of argon atmosphere, and held at this temperature for 4 hours. Then it is naturally cooled to room temperature to obtain the magnetic Bianstone fiber material based on biomimetic multi-level channels and dynamic response.

[0039] Example 3 This embodiment provides a method for preparing magnetic Bianstone fibers based on biomimetic hierarchical channels and dynamic response, which specifically includes the following steps: Steps (1)-(2) are the same as in Example 1.

[0040] (3) Loading magnetic nanoparticle composite units: Prepare a precursor solution by adding 20 mL of few-layer Ti3C2T with a concentration of 2 mg / mL. x (T is mainly -OH, -O) MXene aqueous dispersion with a mixed iron salt of ferrous sulfate (FeSO4·7H2O) and ferric chloride (total iron ion concentration 0.15 mol / L, Fe 2+ :Fe 3+The aerogel framework obtained in step (2) was completely immersed in the precursor solution and placed in a 100 mL high-pressure reactor lined with polytetrafluoroethylene. The reaction was carried out at 180 °C for 8 hours. After natural cooling, the product was removed and washed three times alternately with deionized water and ethanol. It was then vacuum dried at 60 °C to obtain a magnetic framework loaded with an MXene@Fe3O4 core-shell structure (Fe3O4 nanoparticles grown in situ on MXene sheets).

[0041] (4) Coating with a far-infrared mineral functional layer: Prepare a coating solution by dispersing 1.0 g of Bianstone powder with an average particle size of 2 μm in a mixed solution consisting of 40 mL of anhydrous ethanol, 10 mL of deionized water and 2 mL of concentrated ammonia, and sonicating for 30 minutes. Then, slowly add 1.5 mL of tetraethyl orthosilicate (TEOS) under vigorous stirring, and continue stirring at room temperature for 6 hours. Immerse the magnetic skeleton obtained in step (3) into the above reaction solution, let it stand for 2 hours, remove it, preliminarily dry it at 80°C, and then heat treat it at 150°C for 1 hour to form a functional layer of Bianstone powder coated with silica, thus obtaining the precursor.

[0042] (5) Low-temperature carbonization integration: The precursor obtained in step (4) is placed in a tube furnace and heated to 400°C at a heating rate of 5°C / min under the protection of argon atmosphere, and held at this temperature for 1 hour. Then it is naturally cooled to room temperature to obtain the magnetic Bianstone fiber material based on biomimetic multi-level channels and dynamic response.

[0043] Example 4 The difference between this embodiment and Embodiment 1 is that the type of two-dimensional material is changed (simulating other possible choices of higher-level concepts) and the silicon source is changed.

[0044] Specifically: (3) Loading magnetic nanoparticle composite units: The MXene dispersion in the precursor solution is replaced with an equal volume and concentration of graphene oxide (GO) aqueous dispersion (2 mg / mL), and the rest is the same as step (3) in Example 1.

[0045] (4) Coating the far-infrared mineral functional layer: The silicon source TEOS in the coating solution is replaced with 1.0 g sodium silicate (Na2SiO3·9H2O), and the pH of the solution is adjusted to 10 accordingly. The rest is the same as step (4) in Example 1.

[0046] Example 5 The differences between this embodiment and Embodiment 1 are as follows: (1) Preparation of plant cellulose hydrogel: 2 wt% microcrystalline cellulose was dispersed in a pre-cooled 8 wt% NaOH / 12 wt% urea aqueous solution and stirred vigorously to dissolve to obtain a transparent cellulose solution. The solution was poured into a mold and placed in a coagulation bath (5 wt% H2SO4 aqueous solution) to regenerate and form a hydrogel. The solution was then thoroughly washed with water until neutral.

[0047] (2) Construct a three-dimensional porous skeleton: Same as step (2) in Example 1.

[0048] (3) Loading magnetic nanoparticle composite units: Due to the difference between the pore structure of plant cellulose aerogel and bacterial cellulose, the concentration of MXene in the precursor solution was adjusted to 3 mg / mL and the concentration of FeCl3 was adjusted to 0.08 mol / L. The hydrothermal reaction conditions were the same as in Example 1 (150℃, 12h).

[0049] (4) Coating with far-infrared mineral functional layer: Same as step (4) in Example 1.

[0050] (5) Low-temperature carbonization integration: Same as step (5) in Example 1.

[0051] Example 6 The differences between this embodiment and Embodiment 1 are as follows: (1)-(3) Steps: Same as steps (1) to (3) in Example 1.

[0052] (4) Coating with far-infrared mineral functional layers: A combination of vapor deposition and liquid phase impregnation was used. First, the magnetic framework obtained in step (3) was placed in an atomic layer deposition (ALD) device. Using trimethylaluminum and water as precursors, an Al2O3 transition layer of about 5 nm thickness was deposited on the framework to enhance the surface hydroxyl groups. Then, it was immersed in a pre-hydrolyzed TEOS / ethanol solution (containing 0.5 g of Bianstone nanoparticles with a particle size of ~200 nm), and ultrasonically assisted impregnation was performed for 30 minutes. After removal, it was cured at 120 °C to form a SiO2 coating layer.

[0053] (5) Low-temperature carbonization integration: Under argon protection, the temperature is increased to 300℃ at 3℃ / min and then held for 2.5 hours.

[0054] Comparative Example 1 This comparative example aims to illustrate the impact of lacking a low-temperature carbonization step.

[0055] The preparation process is the same as in Example 1, but after completing step (4) of coating the far-infrared mineral functional layer, the low-temperature carbonization treatment in step (5) is not performed. Instead, the precursor is dried at 150°C for 2 hours as the final material.

[0056] Comparative Example 2 This comparative example aims to illustrate the shortcomings of simple physical mixing of magnetic particles with two-dimensional materials.

[0057] (1)-(2) Steps: Same as steps (1) to (2) in Example 1.

[0058] (3) Loading magnetic units: The aerogel framework obtained in step (2) was immersed in a pre-prepared physical mixture of Fe3O4 nanoparticles and MXene sheets (the mass ratio of the two was the same as the calculated value in Example 1), and then removed and dried after immersion for 12 hours. No hydrothermal reaction was performed.

[0059] (4)-(5) Steps: Same as steps (4) to (5) in Example 1.

[0060] The following standardized tests were performed on the products of all examples (1-6) and comparative examples (1-2): Magnetic property test: Testing instrument: Vibrating Sample Magnetometer (VSM); Test Procedure: Weigh approximately 20 mg of the dried sample and wrap it in a non-magnetic film to fix it to the sample rod. Measure the hysteresis loop at room temperature within an applied magnetic field range of -20000 Oe to +20000 Oe. Read the magnetic saturation intensity (Ms, in emu / g) from the saturated magnetization region and calculate the coercivity (Hc) and remanence (Mr).

[0061] Far-infrared emissivity test Test instrument: Fourier transform infrared spectrometer (FT-IR) with integrating sphere accessory; Test Procedure: The sample was pressed into a flat, dense disc (diameter > 2 cm). Under calibration with a standard blackbody (emissivity ε = 0.99) as the background, the spectral reflectance R(λ) of the sample in the 8-14 μm far-infrared band was measured. According to Kirchhoff's law of thermal radiation, under thermal equilibrium conditions, the emissivity ε(λ) = 1 - R(λ). The average emissivity value within this band was calculated.

[0062] Antibacterial performance test Test standard: Refer to GB / T 20944.3-2008 "Evaluation of antibacterial properties of textiles - Part 3: Vibration method"; Testing procedure: Staphylococcus aureus (ATCC 6538) was used as the test strain; Preparation of bacterial culture: The activated bacterial strain was cultured in nutrient broth medium to the logarithmic growth phase, and then diluted with PBS buffer to a concentration of approximately 1 × 10⁻⁶. 5 -3×10 5 CFU / mL bacterial suspension; Inoculation and culture: Take 0.2 g of sample, cut it into small pieces, put it into an Erlenmeyer flask, and add 20 mL of bacterial suspension. A blank control was also set up, with only bacterial suspension added and no sample added. The Erlenmeyer flask was shaken at 37℃ and 150 rpm for 18 hours. Viable cell count: Immediately after contact culture, take 1 mL of the mixture from the conical flask, perform 10-fold serial dilutions with PBS, spread an appropriate amount of the dilution onto nutrient agar plates, and count the colony forming units (CFU) after incubation at 37°C for 24-48 hours. Calculate the antibacterial rate: Antibacterial rate = (average CFU of blank control - average CFU of sample) / average CFU of blank control × 100%.

[0063] Photothermal / magnetic heating performance test Test setup: fiber optic temperature sensor, 808 nm near-infrared laser, alternating magnetic field generator; Testing process: Photothermal test: A 50 mg sample was spread flat on an insulating substrate, and a fiber optic probe was used to contact the sample surface. The sample was vertically irradiated with an 808 nm laser with a power density of 1.0 W / cm², and the temperature change curve (ΔT-t) of the sample surface over 10 minutes was recorded. Magnetothermal test: The same sample was placed in an alternating magnetic field with a frequency of 300 kHz and a magnetic field strength of 20 kA / m, and the temperature change curve of the sample was recorded within 10 minutes.

[0064] II. Summary Table of Test Results .

[0065] As can be seen from the data in the table above, the core performance indicators (magnetic saturation strength, far-infrared emissivity, and antibacterial rate) of all magnetic Bianstone fibers prepared in Examples 1-6 have reached or exceeded those of the comparative examples, fully demonstrating the effectiveness and repeatability of this technical solution. Among them, Example 1, as the preferred solution, exhibits the most balanced and excellent performance.

[0066] The performance of Comparative Example 1 (uncarbonized), especially its far-infrared emissivity, antibacterial rate, and dynamic thermal response, was significantly lower than that of all other examples. This demonstrates that the low-temperature carbonization step is crucial for forming a robust conductive / thermal conductive carbon-based framework, achieving strong bonding between functional layers, and efficient energy transfer; it is the core element for generating the "dynamic response" synergistic effect.

[0067] While Comparative Example 2 (physical mixing) outperforms Comparative Example 1 in individual indicators such as magnetism, its magnetic saturation strength and photothermal / magnetothermal heating performance are significantly lower than those of Example 1, which uses the in-situ hydrothermal method. This indicates that the in-situ core-shell / mosaic structure of MXene@Fe3O4 can achieve a stronger bond and more effective interfacial interaction, thereby generating a stronger magnetothermal / photothermal synergy, supporting the inventive step of the claims.

[0068] Examples 2, 3, and 5 show that even with changes in some raw materials (plant cellulose), process parameters (temperature, time), or materials (GO replacing MXene), as long as the core technical path of "skeleton construction → in-situ loading → coating → low-temperature carbonization" is followed, functional fibers with satisfactory performance can be successfully prepared, indicating that the scheme has a certain process window and material adaptability.

[0069] Furthermore, all embodiments exhibited significant heating effects in photothermal and magnetocaloric tests, confirming the existence of the dynamic response chain of "magnetic field / light energy → heat → enhanced far-infrared radiation". The high wash retention rates of Examples 6 and 1 demonstrate that the Bianstone@SiO2 core-shell structure formed through sol-gel or optimized coating processes can effectively lock in functional components, endowing the product with excellent durability.

[0070] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A type of magnetic Bianstone fiber based on biomimetic multi-level channels and dynamic response, characterized in that, include: A hierarchical porous carbon-based framework derived from biomass cellulose hydrogel and subjected to low-temperature carbonization; Magnetic nanoparticle composite units loaded within the framework channels; And, a far-infrared mineral functional layer covering the outer surface of the framework and the magnetic nanoparticle composite unit; The far-infrared mineral functional layer comprises Bianstone powder and a dielectric material layer covering it.

2. The magnetic Bianstone fiber according to claim 1, characterized in that, The magnetic nanoparticle composite unit comprises a composite structure formed by two-dimensional materials and magnetic iron oxide nanoparticles.

3. The magnetic Bianstone fiber according to claim 2, characterized in that, The two-dimensional material is MXene, and the magnetic iron oxide nanoparticles are grown in situ on the surface or between the layers of the MXene to form a core-shell or embedded structure. The MXene is a few-layer Ti3C2T x , where T is at least one of the functional groups -OH, -O or -F.

4. The magnetic Bianstone fiber according to claim 1, characterized in that, The dielectric material layer is silicon dioxide, which is formed into a porous coating layer by the sol-gel method.

5. A method for preparing magnetic Bianstone fibers as described in any one of claims 1-4, characterized in that, Includes the following steps: (S.1) Provide biomass cellulose hydrogel, which is freeze-dried to form a three-dimensional aerogel framework with multi-level pores; (S.2) Introduce and fix magnetic nanoparticle composite units in the pores of the aerogel framework to obtain a magnetic framework; (S.3) Introduce Bianstone powder into the surface and channels of the magnetic skeleton and coat it with a dielectric material layer to form a precursor; (S.4) The precursor is subjected to low-temperature carbonization treatment at 200°C to 400°C under an inert atmosphere to obtain the composite fiber.

6. The method according to claim 5, characterized in that, The step (S.2) specifically includes: immersing the aerogel framework in a hydrothermal reaction precursor solution containing a two-dimensional material dispersion and iron salt, and reacting it in a closed reaction vessel at 120-180°C, so that iron oxide nanoparticles are generated in situ on the surface of the two-dimensional material and simultaneously loaded onto the framework.

7. The method according to claim 6, characterized in that, The biomass cellulose is bacterial cellulose; The two-dimensional material is MXene; The iron salt is at least one of ferric chloride and ferrous sulfate.

8. The method according to claim 5, characterized in that, The specific steps (S.3) include: immersing the magnetic skeleton in an alcohol-water solution containing Bianstone powder and silicon source compound, and forming a silicon dioxide coating layer on the surface of Bianstone powder and skeleton through a hydrolysis-condensation reaction.

9. The method according to claim 5, characterized in that, The specific procedure for the low-temperature carbonization process in step (S.4) is as follows: under a nitrogen or argon atmosphere, the temperature is increased to 300±10℃ at a heating rate of 1-5℃ / min and held for 1-4 hours.

10. The use of magnetic Bianstone fiber according to any one of claims 1-4 in the preparation of physiotherapy fabrics, intelligent temperature-regulating clothing or medical antibacterial dressings with magnetothermal or photothermal response functions.