Novel bionic cloth

Abstract

The invention relates to a novel bionic fabric which comprises a core-shell mesoporous carrier system, and the core-shell mesoporous carrier system sequentially comprises a core layer including an active component, a photocatalytic transition layer and a slow-release shell layer from inside to outside; the gradient functional structure comprises a bonding layer bonded with the fiber substrate, a water vapor conducting 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 a discrete unit form, and a mesoporous channel of the slow-release shell layer and a vertical channel of the water vapor conducting layer form a communicated substance transmission path. According to the novel bionic fabric, through the three-layer heterojunction structure of the core-shell mesoporous carrier system, the thermal decomposition temperature of the rose essential oil is increased to 180 DEG C or above, and the problem of loss of active ingredients in a traditional padding process is solved.

Description

Technical Field

[0001] The present application relates to the field of textile technology, and in particular to a novel bionic fabric. Background Art

[0002] In the field of functional textiles, traditional waterproof and antibacterial materials generally have the problem of mismatch between the sustained release cycle of functional ingredients and the service life of the materials. The active ingredients are easily inactivated prematurely due to external environmental erosion or mechanical wear, resulting in rapid attenuation of antibacterial properties. Existing hydrophobic structure designs often achieve waterproof effects through densification treatment, but such structures will hinder the directional migration of active substances to the surface of the material, forming a contradiction between hydrophobic properties and antibacterial functions. In addition, conventional high-temperature processing technology 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 seriously restricts the actual application effectiveness of functional materials. How to achieve long-term sustained release of active ingredients, construct a synergistic system of hydrophobic structure and material transmission channels, and break through the limitations of processing technology on heat-sensitive ingredients have become technical problems that need to be solved urgently. Summary of the invention

[0003] The present application provides a novel bionic fabric, comprising:

[0004] A core-shell mesoporous carrier system, which includes, from the inside to the outside, a core layer encapsulating active ingredients, a photocatalytic transition layer, and a sustained-release shell layer;

[0005] A gradient functional structure, comprising a bonding layer bonded to a fiber substrate, a water vapor conductive layer, and a hydrophobic functional layer;

[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 sustained-release shell layer and the vertical channels of the water vapor conduction layer form a connected material transfer path.

[0007] In some embodiments, the core-shell mesoporous carrier system is a heterojunction with a three-layer coating structure, which is:

[0008] the core layer, containing rose essential oil coated with β-cyclodextrin;

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

[0010] The outer shell is composed of mesoporous SiO2 with a pore size of 5.8±0.3nm and a pore volume of 1.2cm 3 / g;

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

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

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

[0014] The inner layer of the coaxial needle is injected with a carrier suspension with a solid content of 40% and a core layer pressure of 25 kPa;

[0015] The outer sheath layer was TPU melted at 180 °C 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, in the gradient functional structure:

[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 heptadecafluorodecyltriethoxysilane modified acrylate and has a thickness of 1-2 μm.

[0021] In some embodiments, the carbon nanotubes of the conductive layer have a diameter of 20 nm and a water vapor permeability of ≥5000 g / (m 2 ·day).

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

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

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

[0025] The above technical solution provided by the embodiment of the present application has 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°C, solving the problem of active ingredient loss in the traditional padding process.

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

[0028] 3. Physical confinement and chemical anchoring of Ag nanoparticles by mesoporous SiO2 shell + The release rate matches the human body's 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 conductive layer, the active ingredients are slowly released along the mesoporous-vertical channel network, while the external water molecules cannot reversely permeate due to the repulsion of the hydrophobic layer.

[0030] 5. The OH free radicals generated by the photocatalytic transition layer under ultraviolet excitation enable the fabric to achieve self-cleaning function, and the opening and closing state of the shell mesopores can be dynamically regulated by changes in the microenvironment.

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

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

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

[0034] 9. Through the non-equilibrium crystallization process of near-infrared laser sintering, lattice defects are generated in anatase TiO2, which increases the intensity of OH radical generation.

[0035] 10. Through the 1-2μm critical thickness design of the functional layer heptadecafluorodecyltriethoxysilane-modified acrylate, the contact angle reaches 152°±3°, achieving a superhydrophobic effect while maintaining air permeability. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0038] Figure 1 A flow chart of a method for preparing a novel bionic fabric provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0040] Figure 1 A flow chart of a novel bionic fabric provided in an embodiment of the present application is shown.

[0041] like Figure 1 As shown, the present application provides a novel bionic fabric, comprising:

[0042] A core-shell mesoporous carrier system, which includes, from the inside to the outside, a core layer encapsulating active ingredients, a photocatalytic transition layer, and a sustained-release shell layer;

[0043] A gradient functional structure, comprising a bonding layer bonded to a fiber substrate, a water vapor conductive layer, and a hydrophobic functional layer;

[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 sustained-release shell layer and the vertical channels of the water vapor conduction layer form a connected material transfer path.

[0045] The core layer fixes the active ingredients through inclusion complexation, the photocatalytic transition layer generates free radicals under external stimulation (such as ultraviolet rays), and the mesoporous channels of the sustained-release shell layer control the release rate of the active ingredients through the confinement effect; in the gradient functional structure, the binding layer is stably combined with the fiber substrate through intermolecular forces, the vertically arranged channels of the water vapor conduction layer allow directional discharge of moisture, 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, the mesoporous channels of its shell layer and the vertical channels of the water vapor conduction layer form a continuous passage, so that the active ingredients can be slowly released outward along the mesoporous-vertical channel network. At the same time, external water molecules cannot reversely penetrate due to the repulsive effect of the hydrophobic layer, realizing the coexistence of unidirectional release of active substances and waterproof performance.

[0046] The connecting path between the mesoporous channel and the vertical channel ensures the continuous release of active ingredients while avoiding the blockage of the release channel caused by the dense structure of traditional coatings; while the photocatalytic transition layer releases free radicals to achieve self-cleaning, the free radicals generated by the photocatalytic transition layer under ultraviolet excitation react with the substances in the shell mesopores, and the ·OH free radicals react with the organic molecules adsorbed in the shell pores (such as residual surfactants or environmental pollutants) to generate CO2 and H2O. This process causes the local gas pressure in the pores to increase, physically stretching the mesoporous channel; when the ultraviolet irradiation stops, the gas in the pores slowly diffuses and escapes through the mesopores, the electrostatic balance is re-established, and the mesopores return to their initial pore size, realizing the 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 the water vapor permeability through the vertical channel, breaking through the technical bottleneck of the mutual restriction of hydrophobicity and permeability.

[0047] In some embodiments, the core-shell mesoporous carrier system is a heterojunction with a three-layer coating structure, which is:

[0048] the core layer, containing rose essential oil coated with β-cyclodextrin;

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

[0050] The outer shell is composed of mesoporous SiO2 with a pore size of 5.8±0.3nm and a pore volume of 1.2cm 3 / g;

[0051] The core layer and the intermediate transition layer, and the intermediate transition layer and the outer shell layer are connected via chemical bonds, and the mesoporous SiO2 of the shell layer is loaded with Ag nanoparticles.

[0052] β-cyclodextrin in the core layer includes rose essential oil through the molecular cavity, and its supramolecular force can inhibit the volatilization of essential oil and form a thermodynamically stable system.

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

[0054] The mesoporous SiO2 shell physically confines and chemically anchors the Ag nanoparticles through its ordered pore structure. When triggered by ambient humidity, the surface of the Ag nanoparticles undergoes oxidation to generate Ag + The size effect of the mesoporous channel makes Ag + 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-re-adsorption equilibrium, which adjusts the pore tortuosity to make Ag + The release rate matches the human sweat secretion cycle.

[0055] β-cyclodextrin inclusion increases the thermal decomposition temperature of essential oils to above 180°C, solving the loss problem of traditional padding process; the heterojunction band structure enables photogenerated electrons to migrate from TiO2 to Ag, inhibiting carrier recombination, and has higher antibacterial efficiency than a single-layer structure; chemical bond connection enables the three-layer structure to avoid the peeling failure of traditional physical coatings under mechanical friction.

[0056] The above mechanism makes Ag + The release curve shows the characteristics of first quickly establishing an antibacterial concentration and then maintaining it steadily. 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 the mesoporous confinement effect, thereby improving the antibacterial rate and maintenance time. In addition, due to the matching design of the sustained release rate and the sweat flushing rate, the risk of silver deposition on the skin is reduced, breaking through the bottleneck of the contradiction between long-term antibacterial and safety.

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

[0058] The inner layer of the coaxial needle is injected with a carrier suspension with a solid content of 40% and a core layer pressure of 25 kPa;

[0059] The outer sheath layer was TPU melted at 180 °C 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 layer carrier suspension forms a stable jet under a core layer pressure of 25kPa, so that the active ingredients encapsulated in the core layer can be evenly distributed, and the solid content of 40% provides sufficient carrier density; the outer layer 180℃ molten TPU forms a continuous sheath wrapping at a flow rate of 0.8mL / min, and its thermoplastic properties are solidified after cooling; when the near-infrared laser (980nm wavelength) is scanned at a pulse frequency of 100Hz, the photothermal conversion material in the TPU selectively absorbs energy, and the moving speed of 5mm / s causes local melting and recrystallization in the sintering area. While the shell layer forms a 5.8nm mesoporous structure, the directional growth of the transition layer TiO2 grain size (8-10nm rutile phase) is achieved through 5-20W power adjustment, and finally a chemical bonding interface of the core-shell heterojunction is formed.

[0062] The microfluidic dynamic molding process breaks through the high temperature damage bottleneck of the traditional padding method by coupling fluid dynamics with photothermal effects: the matching of the core layer pressure and the sheath layer flow rate allows the carrier suspension to be completely wrapped by the molten TPU, shortening the thermal exposure time of the essential oil and reducing the processing loss rate; by precisely controlling the time and position of laser sintering, the mesoporous channel forms an energy barrier, stably controlling the Ag + Slow release rate; at the same time, lattice defects are generated in the process of rapid non-equilibrium crystallization of anatase TiO2, which increases the intensity of OH radical generation.

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

[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 heptadecafluorodecyltriethoxysilane modified acrylate, has a thickness of 1-2 μm, and a contact angle of 152°±3°.

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

[0068] The vertically arranged carbon nanotubes in the conductive layer establish a water vapor diffusion path through their axial through-channels, and utilize the 50-80nm pores between the nanotubes to achieve rapid moisture permeability driven by capillary force.

[0069] The functional layer's heptadecafluorodecyltriethoxysilane-modified acrylate forms a low surface energy topological structure through the directional arrangement of surface fluorinated segments. Its submicron thickness control enables the hydrophobic functional layer to cover the pore edges of the conductive layer to prevent liquid water penetration, while avoiding complete closure of the vertical channels to maintain air permeability.

[0070] The gradient design extends the service life of the material through the strong interface anchoring effect of the binding layer. The high porosity of the vertical carbon nanotube layer at a thickness of 5-8μm greatly improves the water vapor permeability. The critical thickness design of the functional layer of 1-2μm makes the contact angle reach a super hydrophobic effect of 152°±3°, while controlling the air permeability loss rate at a low level. The contact angle of 152°±3° makes the functional layer reach the super hydrophobic critical point (θ>150°), and the droplet rolling angle is <5°, which makes the fabric have self-cleaning ability. The thickness gradient matching of the three-layer structure can take into account both mechanical properties and functional efficiency.

[0071] In some embodiments, the carbon nanotubes of the conductive layer have a diameter of 20 nm and a water vapor permeability of ≥5000 g / (m 2 ·day).

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

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

[0074] Precise control of the spacing between nanotubes enables water molecules to form a low-resistance diffusion path along the tube wall (capillary effect occurs when the spacing is smaller than the size of the water molecule cluster), and the specific porosity forms a continuous three-dimensional network of pores while maintaining the mechanical strength of the structure by regulating the nanotube stacking density. By limiting the tube spacing of 50-80nm and the porosity of 65%-75%, water vapor molecules are preferentially allowed to migrate longitudinally through the gaps between vertically arranged nanotubes, while the high porosity ensures that the gas exchange interface is maximized, thereby forming a dynamic balance mechanism of breathability and waterproofness with the upper hydrophobic functional layer.

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

[0076] The terminal isocyanate polyurethane prepolymer of the bonding layer undergoes a directional reaction with the hydroxyl groups on the surface of the cotton fiber through the unreacted isocyanate groups at the ends of its molecular chains, forming a high-density urethane covalent bond network; at the same time, the polar groups (such as ether bonds and urea bonds) in the polyurethane main chain produce multiple hydrogen bonds with the cellulose molecules. When the hydrogen bond binding energy reaches 28kJ / mol, the interaction can effectively overcome the swelling stress caused by water molecule penetration, so that the bonding layer can still maintain stable interface adhesion in a dynamic wetting environment. The free -NCO group content can regulate the crosslinking degree of the prepolymer, so that the polyurethane forms a moderately crosslinked elastomeric structure during the curing process, which not only avoids brittle fracture caused by excessive crosslinking, but also prevents interface slip caused by insufficient crosslinking, thereby significantly extending the service life of the functional coating and solving the problem of overall performance attenuation of traditional waterproof and antibacterial fabrics due to interface failure.

[0077] The present application also provides a method for preparing a novel bionic fabric, comprising the following steps:

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

[0079] S2, hydrolyzing tetrabutyl titanate and calcining it to obtain anatase TiO2 sol with a grain size of 9 nm as a transition layer;

[0080] S3, synthesized by template method with pore diameter of 5.8nm and pore volume of 1.2cm 3 / g mesoporous SiO2 shell sol;

[0081] S4, using a layer-by-layer self-assembly method to sequentially deposit a TiO2 transition layer and a SiO2 shell layer on the surface of the core layer, and the layers are connected by chemical bonds formed by a silane coupling agent;

[0082] S5, spraying a terminal isocyanate polyurethane prepolymer solution having a free -NCO group content of 4.2 wt% on the surface of the fiber substrate, and forming a 3 μm thick bonding layer through thermal curing;

[0083] S6, chemical vapor deposition grows a vertically aligned carbon nanotube layer with a diameter of 20 nm and a thickness of 8 μm on the bonding layer;

[0084] S7, spin coating heptadecafluorodecyltriethoxysilane-modified acrylate on the surface of the carbon nanotube layer to form a 2 μm thick functional layer;

[0085] S8, using a coaxial microfluidic device, the inner layer was injected with a suspension containing 40 wt% of the core-shell carrier at a pressure of 25 kPa, and the outer layer was delivered with a 180 °C molten TPU sheath at a flow rate of 0.8 mL / min;

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

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

[0088] Example 1

[0089] This embodiment provides a method for preparing a novel bionic fabric, the method comprising the following steps:

[0090] Step 1: Mix β-cyclodextrin and rose essential oil in 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%. Mix tetrabutyl titanate and ethanol in a volume ratio of 1:5, add nitric acid to adjust the pH to 3.5, hydrolyze and calcine at 450°C for 2 hours to obtain anatase TiO2 sol with a grain size of 9nm as a transition layer. Mix tetraethyl orthosilicate and hexadecyltrimethylammonium bromide in a molar ratio of 1:0.15, react under the catalysis of ammonia water for 12 hours, and remove the template by calcination at 550°C to obtain a pore size of 5.8nm and a pore volume of 1.2cm 3 / g mesoporous SiO2 shell sol. TiO2 transition layer and SiO2 shell layer were deposited on the surface of core layer in sequence by layer-by-layer self-assembly method, and the layers were connected by chemical bonds through silane coupling agent KH-550 to obtain a three-layer heterojunction carrier of SiO2-TiO2-β-CD / essential oil.

[0091] Step 2: Spray a terminal isocyanate polyurethane prepolymer solution with a free -NCO group content of 4.2wt% on the surface of the cotton fiber substrate, and heat cure at 80°C to form a 3μm thick bonding layer. The hydrogen bond energy with the cotton fiber was measured to be 29kJ / mol. A vertically arranged carbon nanotube layer was grown on the bonding layer using chemical vapor deposition. The growth temperature was controlled at 680°C and the acetylene flow rate was 50sccm. A carbon nanotube array conductive layer with a diameter of 20nm, a spacing of 60nm, and a porosity of 70% was obtained. The layer thickness was 8μm and the water vapor permeability reached 5200g / (m 2 ·day). Heptadecafluorodecyl triethoxysilane and acrylate monomer were mixed in a molar ratio of 1:8, and a functional layer with a thickness of 2 μm was formed on the surface of the carbon nanotube layer by spin coating.

[0092] Step 3: Using a coaxial microfluidic device, the inner needle (100 μm in diameter) injects an ethanol suspension containing 40 wt% core-shell carrier at a pressure of 25 kPa, and the outer needle (300 μm in diameter) delivers 180°C molten TPU as a sheath at a flow rate of 0.8 mL / min. The extrudate is irradiated with a 980 nm near-infrared laser and selectively sintered under the conditions of 15 W power, 100 Hz pulse frequency, and 5 mm / s spot moving speed, so that the carrier unit is accurately embedded in the functional layer.

[0093] Example 2

[0094] This embodiment provides a method for preparing a novel bionic fabric, the method comprising the following steps:

[0095] Step 1: Mix β-cyclodextrin and rose essential oil in 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%. Mix tetrabutyl titanate and ethanol in a volume ratio of 1:5, add nitric acid to adjust the pH to 3.5, hydrolyze and calcine at 450°C for 2 hours to obtain anatase TiO2 sol with a grain size of 8nm as a transition layer. Mix tetraethyl orthosilicate and hexadecyltrimethylammonium bromide in a molar ratio of 1:0.15, react under the catalysis of ammonia water for 12 hours, and remove the template by calcination at 550°C to obtain a pore size of 5.8nm and a pore volume of 1.2cm 3 / g mesoporous SiO2 shell sol. TiO2 transition layer and SiO2 shell layer were deposited on the surface of core layer in sequence by layer-by-layer self-assembly method, and the layers were connected by chemical bonds through silane coupling agent KH-550 to obtain a three-layer heterojunction carrier of SiO2-TiO2-β-CD / essential oil.

[0096] Step 2: Spray a terminal isocyanate polyurethane prepolymer solution with a free -NCO group content of 4.2wt% on the surface of the cotton fiber substrate, and heat cure at 80°C to form a 2μm thick bonding layer. The hydrogen bond energy with the cotton fiber was measured to be 29kJ / mol. A vertically arranged carbon nanotube layer was grown on the bonding layer using chemical vapor deposition. The growth temperature was controlled at 680°C and the acetylene flow rate was 50sccm to obtain a carbon nanotube array conductive layer with a diameter of 20nm, a spacing of 60nm, and a porosity of 70%. The layer thickness was 5μm and the water vapor permeability reached 5200g / (m 2 ·day). Heptadecafluorodecyl triethoxysilane and acrylate monomer were mixed in a molar ratio of 1:8, and a functional layer with a thickness of 1 μm was formed on the surface of the carbon nanotube layer by spin coating.

[0097] Step 3: Using a coaxial microfluidic device, the inner needle (100 μm in diameter) was injected with an ethanol suspension containing 40 wt% of the core-shell carrier at a pressure of 25 kPa, and the outer needle (300 μm in diameter) was used to deliver 180°C molten TPU as the sheath at a flow rate of 0.8 mL / min. The extrudate was 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 moving speed of 5 mm / s, so that the carrier unit was accurately embedded in the functional layer.

[0098] Example 3

[0099] This embodiment provides a method for preparing a novel bionic fabric, the method comprising the following steps:

[0100] Step 1: Mix β-cyclodextrin and rose essential oil in 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%. Mix tetrabutyl titanate and ethanol in a volume ratio of 1:5, add nitric acid to adjust the pH to 3.5, hydrolyze and calcine at 450°C for 2 hours to obtain anatase TiO2 sol with a grain size of 10nm as a transition layer. Mix tetraethyl orthosilicate and hexadecyltrimethylammonium bromide in a molar ratio of 1:0.15, react under the catalysis of ammonia water for 12 hours, and remove the template by calcination at 550°C to obtain a pore size of 5.8nm and a pore volume of 1.2cm 3 / g mesoporous SiO2 shell sol. TiO2 transition layer and SiO2 shell layer were deposited on the surface of core layer in sequence by layer-by-layer self-assembly method, and the layers were connected by chemical bonds through silane coupling agent KH-550 to obtain a three-layer heterojunction carrier of SiO2-TiO2-β-CD / essential oil.

[0101] Step 2: Spray a terminal isocyanate polyurethane prepolymer solution with a free -NCO group content of 4.2wt% on the surface of the cotton fiber substrate, and heat cure at 80°C to form a 3μm thick bonding layer. The hydrogen bond energy with the cotton fiber was measured to be 29kJ / mol. A vertically arranged carbon nanotube layer was grown on the bonding layer using chemical vapor deposition. The growth temperature was controlled at 680°C and the acetylene flow rate was 50sccm to obtain a carbon nanotube array conductive layer with a diameter of 20nm, a spacing of 80nm, and a porosity of 70%. The layer thickness was 8μm and the water vapor permeability reached 5200g / (m 2 ·day). Heptadecafluorodecyl triethoxysilane and acrylate monomer were mixed in a molar ratio of 1:8, and a functional layer with a thickness of 2 μm was formed on the surface of the carbon nanotube layer by spin coating.

[0102] Step 3: Using a coaxial microfluidic device, the inner needle (100 μm in diameter) injects an ethanol suspension containing 40 wt% core-shell carrier at a pressure of 25 kPa, and the outer needle (300 μm in diameter) delivers 180°C molten TPU as a sheath at a flow rate of 0.8 mL / min. The extrudate is irradiated with a 980 nm near-infrared laser and selectively sintered under the conditions of 15 W power, 100 Hz pulse frequency, and 5 mm / s spot moving speed, so that the carrier unit is accurately embedded in the functional layer.

[0103] Comparative Example 1

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

[0105] Step 1: Mix β-cyclodextrin and rose essential oil in 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%. Mix ethyl orthosilicate and hexadecyltrimethylammonium bromide in a molar ratio of 1:0.15, react for 12 hours under the catalysis of ammonia water, and calcine at 550°C to remove the template agent to obtain a pore size of 5.8nm and a pore volume of 1.2cm 3 / g mesoporous SiO2 shell sol. The SiO2 shell layer was deposited on the surface of the core layer by layer self-assembly method, and the layers were chemically bonded by silane coupling agent KH-550 to obtain the SiO2-β-CD / essential oil heterojunction carrier.

[0106] Step 2: Spray a terminal isocyanate polyurethane prepolymer solution with a free -NCO group content of 4.2wt% on the surface of the cotton fiber substrate, and heat cure at 80°C to form a 3μm thick bonding layer. The hydrogen bond energy with the cotton fiber was measured to be 29kJ / mol. A randomly arranged carbon nanotube layer was grown on the bonding layer using chemical vapor deposition. The growth temperature was controlled at 680°C and the acetylene flow rate was 50sccm. A carbon nanotube array conductive layer with a diameter of 20nm, a spacing of 60nm, and a porosity of 70% was obtained. The layer thickness was 8μm, and the water vapor permeability reached 5200g / (m 2 ·day). Heptadecafluorodecyl triethoxysilane and acrylate monomer were mixed in a molar ratio of 1:8, and a functional layer with a thickness of 2 μm was formed on the surface of the carbon nanotube layer by spin coating.

[0107] Step 3: Using a coaxial microfluidic device, the inner needle (diameter 100μm) injects an ethanol suspension containing 40wt% core-shell carrier at a pressure of 25kPa, and the outer needle (diameter 300μm) delivers 180℃ molten TPU as a sheath at a flow rate of 0.8mL / min. The extrudate is irradiated with a 980nm near-infrared laser and selectively sintered under the conditions of 25W power, 100Hz pulse frequency, and 5mm / s spot movement speed, so that the carrier unit is accurately embedded in the functional layer.

[0108] Comparative Example 2

[0109] This comparative example provides a method for preparing a novel bionic fabric, the method comprising the following steps:

[0110] Step 1: Mix β-cyclodextrin and rose essential oil in 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%. Mix tetrabutyl titanate and ethanol in a volume ratio of 1:5, add nitric acid to adjust the pH to 3.5, hydrolyze and calcine at 450°C for 2 hours to obtain anatase TiO2 sol with a grain size of 9nm as a transition layer. Mix tetraethyl orthosilicate and hexadecyltrimethylammonium bromide in a molar ratio of 1:0.15, react under the catalysis of ammonia water for 12 hours, and calcine at 550°C to remove the template to obtain a pore size of 8.0nm and a pore volume of 1.2cm 3 / g mesoporous SiO2 shell sol. TiO2 transition layer and SiO2 shell layer were deposited on the surface of core layer in sequence by layer-by-layer self-assembly method, and the layers were connected by chemical bonds through silane coupling agent KH-550 to obtain a three-layer heterojunction carrier of SiO2-TiO2-β-CD / essential oil.

[0111] Step 2: Spray a terminal isocyanate polyurethane prepolymer solution with a free -NCO group content of 4.2wt% on the surface of the cotton fiber substrate, and heat cure at 80°C to form a 3μm thick bonding layer. The hydrogen bond energy with the cotton fiber was measured to be 29kJ / mol. A vertically arranged carbon nanotube layer was grown on the bonding layer using chemical vapor deposition. The growth temperature was controlled at 680°C and the acetylene flow rate was 50sccm. A carbon nanotube array conductive layer with a diameter of 20nm, a spacing of 60nm, and a porosity of 70% was obtained. The layer thickness was 8μm and the water vapor permeability reached 5200g / (m 2 ·day). Heptadecafluorodecyl triethoxysilane and acrylate monomer were mixed in a molar ratio of 1:8, and a functional layer with a thickness of 3 μm was formed on the surface of the carbon nanotube layer by spin coating.

[0112] Step 3: Using a coaxial microfluidic device, the inner needle (diameter 100 μm) injects an ethanol suspension containing 40 wt% core-shell carrier at a pressure of 25 kPa, and the outer needle (diameter 300 μm) delivers 180°C molten TPU as a sheath at a flow rate of 0.3 mL / min. The extrudate is irradiated with a 980 nm near-infrared laser and selectively sintered under the conditions of 15 W power, 100 Hz pulse frequency, and 5 mm / s spot movement speed, so that the carrier unit is accurately embedded in the functional layer.

[0113] Experimental methods

[0114] 1. According to GB / T 3922-2013 "Textiles Test Method for Color Fastness to Light", place the sample in a xenon lamp aging box (irradiation intensity 0.35W / m 2 ) After continuous irradiation for 240 h, the essential oil content was quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS).

[0115] 2. Use a contact angle meter (ASTM D5946 standard) to measure the water contact angle after washing 50 times in dynamic mode, and take the average value of 5 different positions.

[0116] 3. Ag + Sustained release rate: The sample was immersed in 37°C saline and the Ag in the solution was detected by atomic absorption spectroscopy (AAS) every day. + concentration, calculate the release per unit area, and get Ag + Sustained release rate.

[0117] 4. According to ASTM E96 standard, at 38°C and 90% RH, measure the mass of water vapor passing through a unit area of ​​a sample within 24 hours to obtain the water vapor transmission rate.

[0118] 5. X-ray photoelectron spectroscopy (XPS) was used to analyze the interface between the bonding layer and the cotton fiber, and the hydrogen bond strength was calculated by the O1s orbital binding energy displacement to obtain the hydrogen bond binding energy.

[0119] The experimental results are shown in Table 1.

[0120] Table 1 Comparison of key performance indicators of the embodiments and comparative examples

[0121]

[0122] Experimental results analysis

[0123] The three-layer heterojunction design of the core-shell mesoporous carrier system in Examples 1-3 significantly improves the stability of the active ingredients. The grain size of the transition layer anatase TiO2 is controlled at 8-10nm, and its high specific surface area enables the intensity of OH free radicals generated by ultraviolet excitation to reach more than 1200 a.u., effectively decomposing residual pollutants and delaying the oxidative inactivation of essential oils. The precise pore size of the shell mesoporous SiO2 (5.8±0.3nm) is consistent with Ag + The load forms a molecular sieve effect, and Ag + The sustained release rate is stable at 0.75-0.80μg / (cm 2 ·day). After removing the TiO2 transition layer in Comparative Example 1, the core-shell carrier lost its photocatalytic and slow-release synergistic regulation functions. + Due to the lack of electron capture by TiO2, the migration rate in the mesoporous channel is accelerated, resulting in a burst release phenomenon (3.20 μg / (cm 2·day)), and at the same time, environmental pollutants cannot be decomposed by ·OH free radicals in time, accelerating the oxidation of essential oils (residual rate 42%).

[0124] The vertically aligned carbon nanotubes of the gradient functional layer achieve a water vapor permeability of ≥4800g / (m 2 ·day), while in Comparative Example 1, when randomly dispersed carbon tubes are used, the moisture permeability decreases to 1800g / (m 2 ·day). The functional layer thickness of 1-2 μm combined with the fluorocarbon chain orientation of heptadecafluorodecylsilane keeps the contact angle above 150°, while the overly thick functional layer (3 μm) in Comparative Example 2 causes disordered molecular arrangement and the contact angle drops sharply to 102°.

[0125] The synergistic effect of microfluidic process parameters is particularly critical. When the core layer pressure is maintained at 25kPa and the sheath layer flow rate is 0.8mL / min, the embedding integrity rate of the core-shell carrier in the TPU matrix is ​​more than 95%, while when the flow rate is reduced to 0.3mL / min in Comparative Example 2, the processing loss rate increases to 71% due to insufficient melt wrapping. The precise control of the laser sintering power of 5-20W avoids thermal decomposition of the carrier, while the excessive laser power (25W) in Comparative Example 1 causes local melting of the SiO2 shell layer, and the core layer β-cyclodextrin undergoes thermal decomposition due to the lack of thermal buffer protection of the TiO2 transition layer. The carrier structure fragmentation rate increases to 45%, which ultimately leads to uneven distribution of active ingredients in the hydrophobic functional layer, and the contact angle drops sharply to 98°.

[0126] These data verify the synergistic effect of the technical features in the claims: the core-shell carrier delays the inactivation of active ingredients, the gradient structure balances moisture permeability and hydrophobicity, and the dynamic molding process reduces processing losses. The three together solve the three major problems of current bionic fabrics, namely short functional life, structural contradictions and process defects.

[0127] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of further restrictions, the elements defined by the sentence "including a..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements.

[0128] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be 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 present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A new type of bionic fabric, characterized in that: include: A core-shell mesoporous carrier system, which includes, from the inside to the outside, a core layer encapsulating active ingredients, a photocatalytic transition layer, and a sustained-release shell layer; A gradient functional structure, comprising a bonding layer bonded to a fiber substrate, a water vapor conductive layer, and a hydrophobic functional layer; 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 sustained-release shell layer and the vertical channels of the water vapor conduction layer form a connected material transfer path.

2. The novel bionic fabric according to claim 1 is characterized in that: The core-shell mesoporous carrier system is a heterojunction with a three-layer coating structure, which is as follows from the inside to the outside: the core layer, containing rose essential oil coated with β-cyclodextrin; The intermediate transition layer is composed of anatase TiO2 with a grain size of 8-10nm; The outer shell is composed of mesoporous SiO2 with a pore size of 5.8±0.3nm and a pore volume of 1.2cm 3 / g; The core layer and the intermediate transition layer, and the intermediate transition layer and the outer shell layer are connected via chemical bonds.

3. The novel bionic fabric according to claim 2 is characterized in that: The mesoporous SiO2 of the shell layer is loaded with Ag nanoparticles.

4. The novel bionic fabric according to claim 2 is characterized in that: The core-shell mesoporous carrier system is prepared by a microfluidic dynamic molding process, comprising: The inner layer of the coaxial needle is injected with a carrier suspension with a solid content of 40% and a core layer pressure of 25 kPa; The outer sheath layer was TPU melted at 180 °C 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.

5. The novel bionic fabric according to claim 1 is characterized in that: In the gradient function structure: The bonding layer is an isocyanate-terminated polyurethane prepolymer with a thickness of 2-3 μm; The conductive layer is a vertically arranged carbon nanotube layer with a thickness of 5-8 μm; The functional layer is heptadecafluorodecyltriethoxysilane modified acrylate and has a thickness of 1-2 μm.

6. The novel bionic fabric according to claim 5 is characterized in that: The diameter of the carbon nanotubes in the conductive layer is 20 nm, and the water vapor permeability of the conductive layer is ≥5000 g / (m 2 ·day).

7. The novel bionic fabric according to claim 5, characterized in that: The contact angle of the functional layer is 152°±3°.

8. The novel bionic fabric according to claim 5, characterized in that: The carbon nanotube spacing in the vertically arranged carbon nanotube layer is 50-80 nm, and the porosity is 65%-75%.

9. The novel bionic fabric according to claim 5, characterized in that: The free -NCO group content in the terminal isocyanate polyurethane prepolymer of the bonding layer is 4.2wt%, and the hydrogen bonding energy with the cotton fiber is ≥28kJ / mol.

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