A biomimetic cloth

Abstract

The application relates to a biomimetic cloth, comprising: a core-shell mesoporous carrier system which comprises, from inside to outside, a core layer for occluding active ingredients, a photocatalytic transition layer and a slow-release shell layer; a gradient functional structure which comprises a binding layer combined with a fiber substrate, a water vapor conduction layer and a hydrophobic functional layer; wherein the core-shell mesoporous carrier system is embedded in the hydrophobic functional layer of the gradient functional structure in the form of discrete units, and the mesoporous channels of the slow-release shell layer and the vertical channels of the water vapor conduction layer form a material transmission path in communication. The biomimetic cloth of the application has a three-layer heterojunction structure of the core-shell mesoporous carrier system, so that the thermal decomposition temperature of rose essential oil is increased to above 180 DEG C, and the problem of active ingredient loss in the traditional dip coating process is solved.

Description

Technical Field

[0001] This application relates to the field of textile technology, and in particular to a biomimetic fabric. Background Technology

[0002] In the field of functional textiles, traditional waterproof and antibacterial materials generally suffer from a mismatch between the sustained-release period of functional ingredients and the service life of the materials. Active ingredients are prone to premature deactivation due to environmental erosion or mechanical wear, leading to a rapid decline in antibacterial performance. Existing hydrophobic structural designs often achieve waterproofing through densification processes, but such structures hinder the directional migration of active substances to the material surface, creating a contradiction between hydrophobic properties and antibacterial functions. Furthermore, conventional high-temperature processing has a significant destructive effect on heat-sensitive active ingredients (such as plant essential oils), and the thermal decomposition loss of active ingredients during processing severely restricts the practical application effectiveness of functional materials. How to achieve long-term sustained release of active ingredients, construct a synergistic system of hydrophobic structures and material transport channels, and overcome the limitations of processing technology on heat-sensitive ingredients have become urgent technical challenges. Summary of the Invention

[0003] This application provides a biomimetic fabric, comprising:

[0004] A core-shell mesoporous carrier system, comprising, from the inside out, a core layer containing active ingredients, a photocatalytic transition layer, and a sustained-release shell layer;

[0005] The gradient functional structure includes a bonding layer, a water vapor conducting layer, and a hydrophobic functional layer bonded to a fiber substrate;

[0006] The core-shell mesoporous carrier system is embedded in the hydrophobic functional layer of the gradient functional structure in the form of discrete units, and the mesoporous channels of the slow-release shell and the vertical channels of the water vapor conduction layer form a connected material transport path.

[0007] In some embodiments, the core-shell mesoporous carrier system is a heterojunction with a three-layer coating structure, consisting of the following layers from the inside out:

[0008] The core layer contains rose essential oil coated with β-cyclodextrin;

[0009] The intermediate transition layer is composed of anatase TiO2 with a grain size of 8-10 nm.

[0010] The outer shell is composed of mesoporous SiO2 with a pore size of 5.8±0.3nm and a pore volume of 1.2cm³ / g;

[0011] The core layer and the intermediate transition layer, as well as the intermediate transition layer and the outer shell, are connected by chemical bonds.

[0012] In some embodiments, the shell layer contains mesoporous SiO2 loaded with Ag nanoparticles.

[0013] In some embodiments, the core-shell mesoporous carrier system is prepared by a microfluidic dynamic molding process, including:

[0014] The inner layer of the coaxial needle is injected with a carrier suspension containing 40% solids, and the core layer pressure is 25 kPa.

[0015] The outer sheath layer is made of molten TPU at 180℃ with a flow rate of 0.8 mL / min;

[0016] The near-infrared laser sintering parameters are: wavelength 980nm, power 5-20W, pulse frequency 100Hz, and spot movement speed 5mm / s.

[0017] In some embodiments, the gradient functional structure includes:

[0018] The bonding layer is an isocyanate-terminated polyurethane prepolymer with a thickness of 2-3 μm;

[0019] The conductive layer is a vertically arranged carbon nanotube layer with a thickness of 5-8 μm;

[0020] The functional layer is a heptadecafluorodecyltriethoxysilane-modified acrylate with a thickness of 1-2 μm.

[0021] In some embodiments, the carbon nanotubes of the conductive layer have a diameter of 20 nm, and the water vapor permeability of the conductive layer is ≥5000 g / (m²·day).

[0022] In some embodiments, the contact angle of the functional layer is 152°±3°.

[0023] In some embodiments, the spacing between carbon nanotubes in the vertically arranged carbon nanotube layer is 50-80 nm, and the porosity is 65%-75%.

[0024] In some embodiments, the free -NCO group content in the terminal isocyanate-based polyurethane prepolymer of the bonding layer is 4.2 wt%, and the hydrogen bonding energy with cotton fibers is ≥28 kJ / mol.

[0025] The technical solutions provided in this application have the following advantages compared with the prior art:

[0026] 1. Through the three-layer heterojunction structure of the core-shell mesoporous carrier system (β-cyclodextrin core layer / TiO2 transition layer / SiO2 shell layer), the thermal decomposition temperature of rose essential oil is increased to above 180℃, solving the problem of active ingredient loss in traditional padding process.

[0027] 2. Through the heterojunction energy band structure of the photocatalytic transition layer (anatase TiO2) and the Ag-supported mesoporous SiO2 shell, photogenerated electrons migrate from TiO2 to Ag, suppressing carrier recombination and improving antibacterial efficiency.

[0028] 3. Through the physical confinement and chemical anchoring of Ag nanoparticles by the mesoporous SiO2 shell, the Ag⁺ release rate matches the human sweat secretion cycle, reducing the risk of silver deposition on the skin.

[0029] 4. Through the connection path between the core-shell mesoporous carrier system and the vertical channel of the water vapor conduction layer, the active ingredients are slowly released along the mesoporous-vertical channel network, while external water molecules cannot permeate in the reverse direction due to the repulsion of the hydrophobic layer.

[0030] 5. The fabric achieves self-cleaning function by generating ·OH free radicals under ultraviolet excitation through the photocatalytic transition layer, and dynamically regulates the opening and closing state of the shell mesopores through changes in the microenvironment.

[0031] 6. By separating the hydrophobic layer and the conductive layer in the gradient functional structure, the vertically arranged carbon nanotube layers can ensure water vapor permeability, breaking through the bottleneck of mutual restriction between hydrophobicity and air permeability.

[0032] 7. By combining the free -NCO groups of the isocyanate-based polyurethane prepolymer at the bonding layer end and the hydrogen bonding energy ≥28kJ / mol, a high-density covalent bond network is formed at the interface, which resists washing and peeling and extends service life.

[0033] 8. By matching the core layer pressure and sheath layer flow rate through the microfluidic dynamic molding process, the carrier suspension is completely encapsulated by molten TPU, shortening the heat exposure time of essential oils and reducing processing loss rate.

[0034] 9. The non-equilibrium crystallization process of near-infrared laser sintering causes lattice defects in anatase TiO2, thereby increasing the intensity of ·OH radical generation.

[0035] 10. By designing a critical thickness of 1-2 μm for the functional layer modified with heptadecafluorodecyltriethoxysilane, a contact angle of 152°±3° is achieved, realizing superhydrophobicity while maintaining breathability. Attached Figure Description

[0036] 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.

[0037] 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.

[0038] Figure 1 This is a flowchart illustrating a method for preparing a biomimetic fabric, as provided in an embodiment of this application. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0040] Figure 1 A flowchart of a biomimetic fabric provided in an embodiment of this application is shown.

[0041] like Figure 1 As shown, this application provides a biomimetic fabric, comprising:

[0042] A core-shell mesoporous carrier system, comprising, from the inside out, a core layer containing active ingredients, a photocatalytic transition layer, and a sustained-release shell layer;

[0043] The gradient functional structure includes a bonding layer, a water vapor conducting layer, and a hydrophobic functional layer bonded to a fiber substrate;

[0044] The core-shell mesoporous carrier system is embedded in the hydrophobic functional layer of the gradient functional structure in the form of discrete units, and the mesoporous channels of the slow-release shell and the vertical channels of the water vapor conduction layer form a connected material transport path.

[0045] The core layer immobilizes the active ingredient through inclusion, the photocatalytic transition layer generates free radicals under external stimuli (such as ultraviolet light), and the mesoporous channels of the slow-release shell control the release rate of the active ingredient through a confinement effect. In the gradient functional structure, the binding layer is stably bonded to the fiber substrate through intermolecular forces, the vertically arranged channels of the water vapor conduction layer allow moisture to escape in a directional manner, and the hydrophobic functional layer forms a waterproof barrier through low surface energy materials. When the core-shell carrier is embedded in the hydrophobic layer, its shell mesoporous channels and the vertical channels of the water vapor conduction layer form a continuous pathway, allowing the active ingredient to be slowly released outward along the mesoporous-vertical channel network. At the same time, external water molecules cannot penetrate in the reverse direction due to the repulsion of the hydrophobic layer, achieving a coexistence of unidirectional release of active substances and waterproof performance.

[0046] The connection path between mesoporous channels and vertical channels ensures the continuous release of active ingredients while avoiding the blockage of release channels caused by the dense structure of traditional coatings. The photocatalytic transition layer releases free radicals to achieve self-cleaning. Under UV excitation, the free radicals generated by the photocatalytic transition layer react with the substances in the shell mesoporous layer. The ·OH free radicals react with the organic molecules (such as residual surfactants or environmental pollutants) adsorbed in the shell pores to generate CO2 and H2O. This process causes a local increase in gas pressure in the pores, physically opening the mesoporous channels. When UV irradiation stops, the gas in the channels slowly diffuses out through the mesopores, the electrostatic balance is re-established, and the mesopores return to their initial pore size, realizing a closed-loop regulation of "stimulus response-pore size adjustment-release control". The separation design of the hydrophobic layer and the conductive layer in the gradient functional layer ensures water vapor permeability through the vertical channels, breaking through the technical bottleneck of mutual restriction between hydrophobicity and air permeability.

[0047] In some embodiments, the core-shell mesoporous carrier system is a heterojunction with a three-layer coating structure, consisting of the following layers from the inside out:

[0048] The core layer contains rose essential oil coated with β-cyclodextrin;

[0049] The intermediate transition layer is composed of anatase TiO2 with a grain size of 8-10 nm.

[0050] The outer shell is composed of mesoporous SiO2 with a pore size of 5.8±0.3nm and a pore volume of 1.2cm³ / g;

[0051] The core layer and the intermediate transition layer, as well as the intermediate transition layer and the outer shell layer, are connected by chemical bonds. The shell layer contains mesoporous SiO2 loaded with Ag nanoparticles.

[0052] In the core layer, β-cyclodextrin encapsulates rose essential oil through molecular cavities, and its supramolecular forces can inhibit the volatilization of essential oil and form a thermodynamically stable system.

[0053] The anatase TiO2 in the intermediate transition layer constructs a high specific surface area photocatalytic interface with a grain size of 8-10 nm. When excited by ultraviolet light, it generates a strong oxidizing ·OH radical through electron-hole pair separation. At the same time, its nanoscale grain arrangement forms a molecular sieve effect.

[0054] The mesoporous SiO2 shell physically confines and chemically anchors Ag nanoparticles through its ordered pore structure. Under the triggering of ambient humidity, an oxidation reaction occurs on the surface of Ag nanoparticles to generate Ag⁺. The size effect of the mesoporous channels causes Ag⁺ to migrate outward in a diffusion-controlled mode. The coordination between the hydroxyl groups on the SiO2 surface and the Ag particles forms a dynamic dissociation-readsorption equilibrium. By adjusting the tortuosity of the pores, the Ag⁺ release rate is matched with the human sweat secretion cycle.

[0055] β-cyclodextrin inclusion increases the thermal decomposition temperature of essential oils to over 180℃, solving the loss problem of traditional padding process; heterojunction band structure enables photogenerated electrons to migrate from TiO2 to Ag, suppressing carrier recombination, resulting in higher antibacterial efficiency compared to single-layer structure; chemical bonding enables the three-layer structure to avoid peeling failure of traditional physical coating layers under mechanical friction.

[0056] The above mechanism enables the Ag⁺ release curve to exhibit the characteristic of first rapidly establishing an antibacterial concentration and then maintaining it stably. Compared with traditional silver-based antibacterial materials, it can reduce the total release of silver ions. At the same time, it inhibits the aggregation and inactivation of Ag particles through mesoporous confinement, thereby improving the antibacterial rate and duration. Furthermore, due to the matching design between the slow release rate and the sweat rinsing rate, it reduces the risk of silver deposition on the skin, thus overcoming the bottleneck of the contradiction between long-lasting antibacterial effect and safety.

[0057] In some embodiments, the core-shell mesoporous carrier system is prepared by a microfluidic dynamic molding process, including:

[0058] The inner layer of the coaxial needle is injected with a carrier suspension containing 40% solids, and the core layer pressure is 25 kPa.

[0059] The outer sheath layer is made of molten TPU at 180℃ with a flow rate of 0.8 mL / min;

[0060] The near-infrared laser sintering parameters are: wavelength 980nm, power 5-20W, pulse frequency 100Hz, and spot movement speed 5mm / s.

[0061] The inner carrier suspension forms a stable jet under a core layer pressure of 25 kPa, enabling uniform distribution of the core layer encapsulated active ingredients. The 40% solid content provides sufficient carrier density. The outer layer of 180℃ molten TPU forms a continuous sheath layer at a flow rate of 0.8 mL / min, and its thermoplastic properties solidify and set after cooling. When a near-infrared laser (980 nm wavelength) scans at a pulse frequency of 100 Hz, the photothermal conversion material in the TPU selectively absorbs energy. The 5 mm / s moving speed causes local melting and recrystallization in the sintering area. While a 5.8 nm mesoporous structure is formed in the shell layer, the directional growth of TiO2 grain size in the transition layer (8-10 nm anatase phase) is achieved through power adjustment of 5-20 W, ultimately forming a chemical bonding interface of the core-shell heterojunction.

[0062] Microfluidic dynamic molding technology overcomes the high-temperature damage bottleneck of traditional padding methods by coupling fluid dynamics and photothermal effects: matching the core layer pressure and sheath layer flow rate allows the carrier suspension to be completely encapsulated by molten TPU, shortening the heat exposure time of the essential oil and reducing the processing loss rate; by precisely controlling the time and position of laser sintering, energy barriers are formed in the mesoporous channels, and the Ag⁺ slow release rate is stably controlled; at the same time, lattice defects are generated in anatase TiO2 during rapid non-equilibrium crystallization, which enhances the generation intensity of ·OH free radicals.

[0063] In some embodiments, the gradient functional structure includes:

[0064] The bonding layer is an isocyanate-terminated polyurethane prepolymer with a thickness of 2-3 μm;

[0065] The conductive layer is a vertically arranged carbon nanotube layer with a thickness of 5-8 μm;

[0066] The functional layer is a heptadecafluorodecyltriethoxysilane modified acrylate with a thickness of 1-2 μm and a contact angle of 152°±3°.

[0067] The bonding layer uses active NCO groups in the isocyanate-terminated polyurethane prepolymer to form hydrogen bonds with hydroxyl groups on the fiber surface, creating a high-bonding-energy interface to resist washing and peeling.

[0068] Vertically arranged carbon nanotubes in the conductive layer establish a water vapor diffusion path through their axially interconnected channels, and the 50-80nm pores between the nanotubes enable rapid moisture permeation driven by capillary force.

[0069] The functional layer is modified with heptadecafluorodecyltriethoxysilane to form a low surface energy topology through the directional arrangement of surface fluorinated segments. Its submicron-level thickness control allows the hydrophobic functional layer to both cover the pore edges of the conductive layer to prevent liquid water penetration and avoid completely sealing the vertical channels to maintain air permeability.

[0070] This gradient design extends the material's service life through the strong interfacial anchoring effect of the bonding layers. The high porosity of the vertical carbon nanotube layer at a thickness of 5-8 μm significantly improves water vapor permeability. The critical thickness design of the functional layer at 1-2 μm achieves a superhydrophobic effect with a contact angle of 152°±3°, while keeping the air permeability loss rate at a low level. The 152°±3° contact angle brings the functional layer to the superhydrophobic critical point (θ>150°), and the droplet roll-off angle is <5°, giving the fabric self-cleaning capabilities. The thickness gradient matching of the three-layer structure can balance mechanical properties and functional efficiency.

[0071] In some embodiments, the carbon nanotubes of the conductive layer have a diameter of 20 nm, and the water vapor permeability of the conductive layer is ≥5000 g / (m²·day).

[0072] When the diameter of carbon nanotubes is precisely controlled at 20nm, a graphene-like wall is formed in its inner cavity, creating a low-resistance sliding boundary layer. Water molecules migrate rapidly along the tube wall under the action of van der Waals forces. The 20nm tube diameter is orders of magnitude different from the size of common bacteria (200-2000nm), which physically blocks microbial penetration while ensuring moisture permeability.

[0073] In some embodiments, the spacing between carbon nanotubes in the vertically arranged carbon nanotube layer is 50-80 nm, and the porosity is 65%-75%.

[0074] Precise control of nanotube spacing enables water molecules to form low-resistance diffusion paths along the tube walls (capillary effect occurs when the spacing is smaller than the size of water molecule clusters), while specific porosity, by regulating the nanotube stacking density, forms a continuous, interconnected three-dimensional network of pores while maintaining structural mechanical strength. By limiting the tube spacing to 50-80 nm and the porosity to 65%-75%, water vapor molecules preferentially migrate longitudinally through the vertically aligned nanotube gaps. At the same time, high porosity ensures maximum gas exchange interface, thereby forming a breathable-waterproof dynamic balance mechanism with the upper hydrophobic functional layer.

[0075] In some embodiments, the free -NCO group content in the terminal isocyanate-based polyurethane prepolymer of the bonding layer is 4.2 wt%, and the hydrogen bonding energy with cotton fibers is ≥28 kJ / mol.

[0076] The terminal isocyanate-based polyurethane prepolymer of the bonding layer undergoes a directional reaction between the unreacted isocyanate groups at the ends of its molecular chains and the hydroxyl groups on the surface of cotton fibers, forming a high-density urethane covalent bond network. Simultaneously, polar groups (such as ether and urea bonds) in the polyurethane backbone generate multiple hydrogen bonds with cellulose molecules. When the hydrogen bonding energy reaches 28 kJ / mol, this interaction effectively overcomes the swelling stress caused by water molecule penetration, ensuring stable interfacial adhesion of the bonding layer even in a dynamically wetting environment. The content of free -NCO groups regulates the degree of crosslinking in the prepolymer, enabling the polyurethane to form a moderately crosslinked elastomer structure during curing. This avoids both brittle fracture caused by excessive crosslinking and interfacial slippage caused by insufficient crosslinking, significantly extending the service life of the functional coating and solving the problem of overall performance degradation caused by interfacial failure in traditional waterproof and antibacterial fabrics.

[0077] This application also provides a method for preparing a biomimetic fabric, including the following steps:

[0078] S1. Mix β-cyclodextrin and rose essential oil at a molar ratio of 1:1.2 and stir in a 50°C water bath for 4 hours to form a core layer solution with an inclusion rate of 87%.

[0079] S2. An anatase TiO2 sol with a grain size of 9 nm was prepared by hydrolyzing tetrabutyl titanate and calcining it as a transition layer.

[0080] S3. A mesoporous SiO2 shell sol with a pore size of 5.8 nm and a pore volume of 1.2 cm³ / g was synthesized by template method;

[0081] S4. A TiO2 transition layer and a SiO2 shell layer are sequentially deposited on the surface of the core layer using a layer-by-layer self-assembly method, and chemical bonds are formed between the layers through a silane coupling agent.

[0082] S5. Spray a polyurethane prepolymer solution with a free -NCO group content of 4.2wt% onto the surface of the fiber substrate, and then heat-cur it to form a 3μm thick bonding layer.

[0083] S6. A vertically aligned carbon nanotube layer with a diameter of 20 nm and a thickness of 8 μm is grown on the bonding layer by chemical vapor deposition.

[0084] S7. Spin-coat heptadecafluorodecyltriethoxysilane-modified acrylate onto the surface of the carbon nanotube layer to form a 2μm thick functional layer.

[0085] S8. A coaxial microfluidic device is used. The inner layer is injected with a suspension containing 40wt% core-shell carrier at a pressure of 25kPa, and the outer layer is delivered with a molten TPU sheath at 0.8mL / min.

[0086] S9. Apply 980nm near-infrared laser irradiation to the extrudate, control the power to be 15W, the pulse frequency to be 100Hz, and the spot movement speed to be 5mm / s for dynamic sintering, so that the carrier unit is embedded in the functional layer.

[0087] The method of the present invention will now be described in detail with reference to embodiments, comparative examples and experimental data. Example

[0088] This embodiment provides a method for preparing biomimetic fabric, the method comprising the following steps:

[0089] Step 1: Mix β-cyclodextrin and rose essential oil at a molar ratio of 1:1.2 and stir in a 50℃ water bath for 4 hours to form a core layer solution with an inclusion rate of 87%. Mix tetrabutyl titanate and ethanol at a volume ratio of 1:5, add nitric acid to adjust the pH to 3.5, hydrolyze, and calcine at 450℃ for 2 hours to obtain anatase TiO2 sol with a grain size of 9nm as a transition layer. Mix tetraethyl orthosilicate and hexadecyltrimethylammonium bromide at a molar ratio of 1:0.15 and react under ammonia catalysis for 12 hours. After calcination at 550℃ to remove the template agent, a mesoporous SiO2 shell sol with a pore size of 5.8nm and a pore volume of 1.2cm³ / g is obtained. By using a layer-by-layer self-assembly method, a TiO2 transition layer and a SiO2 shell layer are sequentially deposited on the surface of the core layer, and chemical bonds are formed between the layers through the silane coupling agent KH-550 to obtain a three-layer heterojunction carrier of SiO2-TiO2-β-CD / essential oil.

[0090] Step 2: A polyurethane prepolymer solution with 4.2 wt% free -NCO groups was sprayed onto the surface of a cotton fiber substrate. After thermosetting at 80℃, a 3 μm thick bonding layer was formed, with a measured hydrogen bond energy of 29 kJ / mol with the cotton fiber. Vertically aligned carbon nanotubes were grown on the bonding layer using chemical vapor deposition (CVD). The growth temperature was controlled at 680℃ and the acetylene flow rate at 50 sccm, resulting in a carbon nanotube array conductive layer with a diameter of 20 nm, a spacing of 60 nm, a porosity of 70%, a layer thickness of 8 μm, and a water vapor permeability of 5200 g / (m²·day). A 2 μm thick functional layer was formed on the surface of the carbon nanotube layer by spin coating, using a mixture of heptadecafluorodecyltriethoxysilane and acrylate monomers at a 1:8 molar ratio.

[0091] Step 3: Using a coaxial microfluidic device, an inner needle (100 μm in diameter) injects an ethanol suspension containing 40 wt% core-shell carrier at a pressure of 25 kPa, while an outer needle (300 μm in diameter) delivers molten TPU at 180°C as a sheath layer at a flow rate of 0.8 mL / min. The extrudate is then irradiated with a 980 nm near-infrared laser and selectively sintered at a power of 15 W, a pulse frequency of 100 Hz, and a spot movement speed of 5 mm / s, precisely embedding the carrier units into the functional layer. Example

[0092] This embodiment provides a method for preparing biomimetic fabric, the method comprising the following steps:

[0093] Step 1: Mix β-cyclodextrin and rose essential oil at a molar ratio of 1:1.2 and stir in a 50℃ water bath for 4 hours to form a core layer solution with an inclusion rate of 87%. Mix tetrabutyl titanate and ethanol at a volume ratio of 1:5, add nitric acid to adjust the pH to 3.5, hydrolyze, and calcine at 450℃ for 2 hours to obtain anatase TiO2 sol with a grain size of 8nm as a transition layer. Mix tetraethyl orthosilicate and hexadecyltrimethylammonium bromide at a molar ratio of 1:0.15 and react under ammonia catalysis for 12 hours. After calcination at 550℃ to remove the template agent, a mesoporous SiO2 shell sol with a pore size of 5.8nm and a pore volume of 1.2cm³ / g is obtained. By using a layer-by-layer self-assembly method, a TiO2 transition layer and a SiO2 shell layer are sequentially deposited on the surface of the core layer, and chemical bonds are formed between the layers through the silane coupling agent KH-550 to obtain a three-layer heterojunction carrier of SiO2-TiO2-β-CD / essential oil.

[0094] Step 2: A polyurethane prepolymer solution with 4.2 wt% free -NCO groups was sprayed onto the surface of a cotton fiber substrate. After thermosetting at 80℃, a 2 μm thick bonding layer was formed, with a measured hydrogen bond energy of 29 kJ / mol with the cotton fiber. Vertically aligned carbon nanotubes were grown on the bonding layer using chemical vapor deposition (CVD). The growth temperature was controlled at 680℃ and the acetylene flow rate at 50 sccm, resulting in a 5 μm thick carbon nanotube array conductive layer with a diameter of 20 nm, a spacing of 60 nm, a porosity of 70%, and a water vapor permeability of 5200 g / (m²·day). A 1 μm thick functional layer was formed on the surface of the carbon nanotube layer by spin coating, using a mixture of heptadecafluorodecyltriethoxysilane and acrylate monomers at a 1:8 molar ratio.

[0095] Step 3: Using a coaxial microfluidic device, an inner needle (100 μm in diameter) injects an ethanol suspension containing 40 wt% core-shell carrier at a pressure of 25 kPa, while an outer needle (300 μm in diameter) delivers molten TPU at 180°C as a sheath layer at a flow rate of 0.8 mL / min. The extrudate is then irradiated with a 980 nm near-infrared laser and selectively sintered at a power of 10 W, a pulse frequency of 100 Hz, and a spot movement speed of 5 mm / s, precisely embedding the carrier units into the functional layer. Example

[0096] This embodiment provides a method for preparing biomimetic fabric, the method comprising the following steps:

[0097] Step 1: Mix β-cyclodextrin and rose essential oil at a molar ratio of 1:1.2 and stir in a 50℃ water bath for 4 hours to form a core layer solution with an inclusion rate of 87%. Mix tetrabutyl titanate and ethanol at a volume ratio of 1:5, add nitric acid to adjust the pH to 3.5, hydrolyze, and calcine at 450℃ for 2 hours to obtain anatase TiO2 sol with a grain size of 10nm as a transition layer. Mix tetraethyl orthosilicate and hexadecyltrimethylammonium bromide at a molar ratio of 1:0.15 and react under ammonia catalysis for 12 hours. After calcination at 550℃ to remove the template agent, obtain a mesoporous SiO2 shell sol with a pore size of 5.8nm and a pore volume of 1.2cm³ / g. By using a layer-by-layer self-assembly method, a TiO2 transition layer and a SiO2 shell layer are sequentially deposited on the surface of the core layer, and chemical bonds are formed between the layers through the silane coupling agent KH-550 to obtain a three-layer heterojunction carrier of SiO2-TiO2-β-CD / essential oil.

[0098] Step 2: A polyurethane prepolymer solution with 4.2 wt% free -NCO groups was sprayed onto the surface of a cotton fiber substrate. After thermosetting at 80℃, a 3 μm thick bonding layer was formed, with a measured hydrogen bond energy of 29 kJ / mol with the cotton fiber. Vertically aligned carbon nanotubes were grown on the bonding layer using chemical vapor deposition (CVD). The growth temperature was controlled at 680℃ and the acetylene flow rate at 50 sccm, resulting in a carbon nanotube array conductive layer with a diameter of 20 nm, a spacing of 80 nm, a porosity of 70%, a layer thickness of 8 μm, and a water vapor permeability of 5200 g / (m²·day). A 2 μm thick functional layer was formed on the surface of the carbon nanotube layer by spin coating, using a mixture of heptadecafluorodecyltriethoxysilane and acrylate monomers at a 1:8 molar ratio.

[0099] Step 3: Using a coaxial microfluidic device, an inner needle (100 μm in diameter) injects an ethanol suspension containing 40 wt% core-shell carrier at a pressure of 25 kPa, while an outer needle (300 μm in diameter) delivers molten TPU at 180°C as a sheath layer at a flow rate of 0.8 mL / min. The extrudate is then irradiated with a 980 nm near-infrared laser and selectively sintered at a power of 15 W, a pulse frequency of 100 Hz, and a spot movement speed of 5 mm / s, precisely embedding the carrier units into the functional layer.

[0100] This comparative example provides a method for preparing a biomimetic fabric, the method comprising the following steps:

[0101] Step 1: Mix β-cyclodextrin and rose essential oil at a molar ratio of 1:1.2 and stir in a 50℃ water bath for 4 hours to form a core layer solution with an inclusion rate of 87%. Mix tetraethyl orthosilicate and hexadecyltrimethylammonium bromide at a molar ratio of 1:0.15 and react for 12 hours under ammonia catalysis. After calcination at 550℃ to remove the template agent, a mesoporous SiO2 shell sol with a pore size of 5.8 nm and a pore volume of 1.2 cm³ / g is obtained. A SiO2 shell layer is deposited on the core layer surface using a layer-by-layer self-assembly method, with chemical bonds formed between the layers through a silane coupling agent KH-550, thus preparing a SiO2-β-CD / essential oil heterojunction carrier.

[0102] Step 2: A polyurethane prepolymer solution with 4.2 wt% free -NCO groups was sprayed onto the surface of a cotton fiber substrate. After thermosetting at 80℃, a 3 μm thick bonding layer was formed, with a measured hydrogen bond energy of 29 kJ / mol with the cotton fiber. Randomly arranged carbon nanotubes were grown on the bonding layer using chemical vapor deposition (CVD). The growth temperature was controlled at 680℃ and the acetylene flow rate at 50 sccm, resulting in a carbon nanotube array conductive layer with a diameter of 20 nm, a spacing of 60 nm, a porosity of 70%, and a thickness of 8 μm. The water vapor permeability reached 5200 g / (m²·day). A 2 μm thick functional layer was formed on the surface of the carbon nanotube layer by spin coating of a mixture of heptadecafluorodecyltriethoxysilane and acrylate monomers at a molar ratio of 1:8.

[0103] Step 3: Using a coaxial microfluidic device, an inner needle (100 μm in diameter) injects an ethanol suspension containing 40 wt% core-shell carrier at a pressure of 25 kPa, while an outer needle (300 μm in diameter) delivers molten TPU at 180°C as a sheath layer at a flow rate of 0.8 mL / min. The extrudate is then irradiated with a 980 nm near-infrared laser and selectively sintered under conditions of 25 W power, 100 Hz pulse frequency, and 5 mm / s spot movement speed, precisely embedding the carrier unit into the functional layer.

[0104] This comparative example provides a method for preparing a biomimetic fabric, the method comprising the following steps:

[0105] Step 1: Mix β-cyclodextrin and rose essential oil at a molar ratio of 1:1.2 and stir in a 50℃ water bath for 4 hours to form a core layer solution with an inclusion rate of 87%. Mix tetrabutyl titanate and ethanol at a volume ratio of 1:5, add nitric acid to adjust the pH to 3.5, hydrolyze, and calcine at 450℃ for 2 hours to obtain anatase TiO2 sol with a grain size of 9nm as a transition layer. Mix tetraethyl orthosilicate and hexadecyltrimethylammonium bromide at a molar ratio of 1:0.15 and react under ammonia catalysis for 12 hours. After calcination at 550℃ to remove the template agent, a mesoporous SiO2 shell sol with a pore size of 8.0nm and a pore volume of 1.2cm³ / g is obtained. By using a layer-by-layer self-assembly method, a TiO2 transition layer and a SiO2 shell layer are sequentially deposited on the surface of the core layer, and chemical bonds are formed between the layers through the silane coupling agent KH-550 to obtain a three-layer heterojunction carrier of SiO2-TiO2-β-CD / essential oil.

[0106] Step 2: A polyurethane prepolymer solution with 4.2 wt% free -NCO groups was sprayed onto the surface of a cotton fiber substrate. After thermosetting at 80℃, a 3 μm thick bonding layer was formed, with a measured hydrogen bond energy of 29 kJ / mol with the cotton fiber. Vertically aligned carbon nanotubes were grown on the bonding layer using chemical vapor deposition (CVD). The growth temperature was controlled at 680℃ and the acetylene flow rate at 50 sccm, resulting in a carbon nanotube array conductive layer with a diameter of 20 nm, a spacing of 60 nm, a porosity of 70%, a layer thickness of 8 μm, and a water vapor permeability of 5200 g / (m²·day). A 3 μm thick functional layer was formed on the surface of the carbon nanotube layer by spin coating of a mixture of heptadecafluorodecyltriethoxysilane and acrylate monomers at a molar ratio of 1:8.

[0107] Step 3: Using a coaxial microfluidic device, an inner needle (100 μm in diameter) injects an ethanol suspension containing 40 wt% core-shell carrier at a pressure of 25 kPa, while an outer needle (300 μm in diameter) delivers molten TPU at 180°C as a sheath layer at a flow rate of 0.3 mL / min. The extrudate is then irradiated with a 980 nm near-infrared laser and selectively sintered under conditions of 15 W power, 100 Hz pulse frequency, and 5 mm / s spot movement speed, precisely embedding the carrier unit into the functional layer.

[0108] 1. Referring to GB / T 3922-2013 "Test Method for Light Fastness of Textiles", the samples were placed in a xenon lamp aging chamber (irradiation intensity 0.35W / m²) for continuous irradiation for 240 hours, and the essential oil content was quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS).

[0109] 2. Using a contact angle measuring instrument (ASTM D5946 standard), measure the water contact angle after 50 washes in dynamic mode and take the average value at 5 different locations.

[0110] 3. Ag⁺ sustained-release rate: The sample was immersed in physiological saline at 37°C, and the concentration of Ag⁺ in the solution was detected daily by atomic absorption spectrometry (AAS). The amount released per unit area was calculated to obtain the Ag⁺ sustained-release rate.

[0111] 4. According to ASTM E96 standard, the water vapor transmission rate is obtained by measuring the mass of water vapor passing through a unit area sample within 24 hours under conditions of 38℃ and 90%RH.

[0112] 5. X-ray photoelectron spectroscopy (XPS) was used to analyze the interface between the binding layer and cotton fibers. The hydrogen bond strength was calculated by the O1s orbital binding energy shift, and the hydrogen bond binding energy was obtained.

[0113] The experimental results are shown in Table 1.

[0114] Table 1. Comparison of Key Performance Indicators between the Examples and Comparative Examples

[0115]

[0116] The three-layer heterojunction design of the core-shell mesoporous support system in Examples 1-3 significantly improved the stability of the active ingredients. The anatase TiO2 transition layer has a grain size controlled at 8-10 nm, and its high specific surface area allows the intensity of ·OH free radicals generated by UV excitation to reach over 1200 a.u., effectively decomposing residual pollutants and delaying the oxidation and deactivation of essential oils. The precise pore size (5.8±0.3 nm) of the shell layer mesoporous SiO2 and the Ag⁺ loading form a molecular sieve effect, stabilizing the Ag⁺ release rate in the range of 0.75-0.80 μg / (cm²·day). In Comparative Example 1, after removing the TiO2 transition layer, the core-shell support lost its photocatalytic and slow-release synergistic regulation function. Due to the lack of electron trapping effect of TiO2, the Ag⁺ migration rate in the mesoporous channels accelerated, leading to a burst release phenomenon (3.20 μg / (cm²·day)). At the same time, environmental pollutants could not be decomposed by ·OH free radicals in time, accelerating the oxidation of essential oils (residual rate 42%).

[0117] Vertically arranged carbon nanotubes in the gradient functional layer achieve a water vapor permeability ≥4800 g / (m²·day) through an oriented pore structure (spacing 50-80 nm). In contrast, when random dispersed carbon nanotubes were used in Comparative Example 1, the permeability decreased to 1800 g / (m²·day) due to increased channel tortuosity. A functional layer thickness of 1-2 μm, combined with the fluorocarbon chain orientation of heptadecafluorodecylsilane, maintains a contact angle above 150°. However, in Comparative Example 2, the excessively thick functional layer (3 μm) leads to disordered molecular arrangement, causing the contact angle to plummet to 102°.

[0118] The synergistic effect of microfluidic process parameters is particularly crucial. When the core layer pressure is maintained at 25 kPa and the sheath layer flow rate is 0.8 mL / min, the embedding integrity of the core-shell carrier in the TPU matrix reaches over 95%. However, in Comparative Example 2, when the flow rate is reduced to 0.3 mL / min, the processing loss rate increases to 71% due to insufficient melt encapsulation. Precise control of the laser sintering power (5-20 W) avoids thermal decomposition of the carrier. In Comparative Example 1, the excessively high laser power (25 W) leads to local melting of the SiO2 shell layer, and the β-cyclodextrin in the core layer undergoes thermal decomposition due to the lack of thermal buffer protection from the TiO2 transition layer. The carrier structure breakage rate increases to 45%, ultimately resulting in uneven distribution of active ingredients in the hydrophobic functional layer and a sharp drop in the contact angle to 98°.

[0119] These data verify the synergistic effect of the technical features in the claims: the core-shell carrier delays the deactivation of active ingredients, the gradient structure balances the moisture permeability and hydrophobicity, and the dynamic molding process reduces processing losses. Together, these three features solve the three major problems of short functional lifespan, structural contradictions, and process defects in current biomimetic fabrics.

[0120] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0121] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A biomimetic fabric, characterized in that, include: A core-shell mesoporous carrier system, comprising, from the inside out, a core layer containing active ingredients, a photocatalytic transition layer, and a sustained-release shell layer; The gradient functional structure includes a bonding layer, a water vapor conducting layer, and a hydrophobic functional layer bonded to a fiber substrate. The bonding layer is a polyurethane prepolymer with isocyanate-terminated ends and a thickness of 2-3 μm; the conducting layer is a vertically arranged carbon nanotube layer with a thickness of 5-8 μm; and the functional layer is a heptadecafluorodecyltriethoxysilane-modified acrylate with a thickness of 1-2 μm. The core-shell mesoporous carrier system is embedded in the hydrophobic functional layer of the gradient functional structure in the form of discrete units, and the mesoporous channels of the slow-release shell layer and the vertical channels of the water vapor conduction layer form a connected material transport path. The core-shell mesoporous carrier system is a heterogeneous structure with a three-layer coating structure, which, from the inside out, consists of: The core layer contains rose essential oil coated with β-cyclodextrin; The intermediate transition layer is composed of anatase TiO2 with a grain size of 8-10 nm. The outer shell is composed of mesoporous SiO2 loaded with Ag nanoparticles, with a pore size of 5.8±0.3nm and a pore volume of 1.2cm³ / g; The core layer and the intermediate transition layer, as well as the intermediate transition layer and the outer shell, are connected by chemical bonds.

2. The biomimetic fabric according to claim 1, characterized in that, The core-shell mesoporous carrier system is prepared using a microfluidic dynamic molding process, including: A core-shell carrier suspension with a solid content of 40% was injected into the inner layer of the coaxial needle, and the core layer pressure was 25 kPa. The outer sheath layer is made of molten TPU at 180℃ with a flow rate of 0.8 mL / min; The near-infrared laser sintering parameters are: wavelength 980nm, power 5-20W, pulse frequency 100Hz, and spot movement speed 5mm / s.

3. The biomimetic fabric according to claim 1, characterized in that, The carbon nanotubes in the conductive layer have a diameter of 20 nm, and the water vapor permeability of the conductive layer is ≥5000 g / (m²·day).

4. The biomimetic fabric according to claim 1, characterized in that, The contact angle of the functional layer is 152°±3°.

5. The biomimetic fabric according to claim 1, characterized in that, The vertically arranged carbon nanotube layer has a spacing of 50-80 nm between carbon nanotubes and a porosity of 65%-75%.

6. The biomimetic fabric according to claim 1, characterized in that, The free -NCO group content in the terminal isocyanate-based polyurethane prepolymer of the bonding layer is 4.2wt%, and the hydrogen bonding energy with cotton fiber is ≥28kJ / mol.

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