Biological environment-friendly clothing material with self-cleaning function and preparation method thereof

Abstract

The invention discloses a biological environment-friendly clothing material with a self-cleaning function and a preparation method of the biological environment-friendly clothing material. According to the invention, the environmental friendliness is obviously improved, and natural components which can be completely biodegraded are adopted and can be quickly decomposed in the natural environment, so that the micro-plastic pollution is reduced; the self-cleaning function is enhanced, and through the synergistic effect of the bionic hydrophobic surface and photocatalytic decomposition, automatic falling and decomposition of stains are achieved; the durability is enhanced, a dynamic self-repairing network can automatically repair daily wear, the service life is prolonged, and the bio-based raw materials are natural, skin-friendly and excellent in air permeability. The supercritical fluid processing and microwave shaping technology replaces a high-energy-consumption process; emission of toxic substances is eliminated, and organic solvents and fluorine-containing compounds are forbidden in the whole process; raw material loss is reduced, and the using amount of functional materials is reduced through an accurate structure regulation and control technology; the maintenance cost is simplified, and the washing frequency and the use of chemical cleaning agents are reduced due to the self-cleaning characteristic; waste is compressed, and resource utilization of by-products is achieved through a closed-loop production system.

Description

Technical Field

[0001] The present invention belongs to the technical field of clothing materials, and specifically relates to a bio-environmental protection clothing material with self-cleaning function and its preparation method. Background Art

[0002] Bio-environmental protection clothing materials are sustainable clothing materials made from bio-based raw materials, with the characteristics of environmental protection, renewable and biodegradable. Such materials usually come from plant, microbial or animal fibers, such as corn fiber, bamboo fiber, seaweed fiber and spider silk protein, etc. They reduce the dependence on fossil fuels and lower carbon emissions during the production process. Bio-environmental protection clothing materials not only have good breathability and moisture absorption and sweat discharge performance, but also can reduce the use of chemical substances and lower environmental pollution. Clothing made from these materials not only reflects the concept of green consumption, but also promotes the sustainable use of biological resources, and is an important development direction for the future clothing industry.

[0003] However, in the prior art, traditional clothing materials generally have environmental pollution problems caused by poor biodegradability, are prone to toxic substance residues due to relying on chemical waterproof coatings, have single and insufficiently persistent self-cleaning functions, have high energy consumption during the production process and cause secondary pollution by using organic solvents. At the same time, it is difficult to balance the mechanical properties and functional stability of the materials, and frequent maintenance and cleaning are required, generating a large amount of waste. Summary of the Invention

[0004] The purpose of the present invention is to provide a bio-environmental protection clothing material with self-cleaning function and its preparation method to solve the above-mentioned problems.

[0005] The technical solution adopted by the present invention is as follows: A bio-environmental protection clothing material with self-cleaning function and its preparation method, the clothing material includes: 45 parts of biodegradable polylactic acid nanofibers, 30 parts of chitin nanofibers, 25 parts of silk fibroin grafted nanofibers, 12 parts of polydopamine-coated titanium dioxide nanorods, 8 parts of zinc oxide quantum dot composites, 10 parts of fluorinated cellulose nanocrystals, 15 parts of bio-based self-healing polyurethane elastomers, 6 parts of natural enzyme-loaded mesoporous silica spheres, 3 parts of sodium copper chlorophyllin composite photosensitizer, 20 parts of castor oil-based waterborne crosslinking agent, 4 parts of starch-derived nanocapsule carriers;

[0006] Among them, the uniform coating of polydopamine-coated titanium dioxide nanorods is realized by mimicking mussel protein adhesion technology, and the core-shell structure thickness is controlled at 5-8 nm;

[0007] The bio-based self-healing polyurethane elastomer uses a castor oil derivative as the soft segment and an amino acid containing a dynamic disulfide bond as the hard segment.

[0008] In a preferred embodiment, the manufacturing process includes the following steps:

[0009] S1: Mix poly(lactic acid) (PLA) nanofibers, chitin nanofibers, and silk fibroin nanofibers in a ratio of 45:30:25. Using coaxial electrospinning technology, the inner spinning solution contains 1 wt% citric acid ester plasticizer, and the outer layer is a sodium alginate reinforcing phase. Control the voltage at 40 kV and the receiving roller speed at 1200 rpm to form a double-network structure nanofiber substrate;

[0010] S2: Immerse titanium dioxide nanorods in dopamine-Tris buffer solution and oscillate for deposition for 24 hours. Blend them with zinc oxide quantum dots in a mass ratio of 3:1, and form a heterojunction photocatalytic composite system at 60 °C through the sol-gel method;

[0011] S3: On the surface of the substrate, use biomimetic mineralization technology to alternately deposit the composite obtained in step S2 and sodium copper chlorophyllin in simulated body fluid for 3 cycles to construct a chloroplast-like multi-layer membrane structure;

[0012] S4: Dissolve fluorinated cellulose nanocrystals and self-healing polyurethane elastomer in supercritical CO2 fluid, add 0.5% nano-silica aerogel as a rheology regulator, and form a micron-scale honeycomb-like hydrophobic coating through microfluidic spinning technology;

[0013] S5: Use ultrasonic-vacuum impregnation method to implant natural enzyme-loaded mesoporous silica spheres into the fiber pores, control the negative pressure at 0.08 MPa, and the impregnation time at 30 min. Then activate the immobilized enzyme activity by heat at 60 °C;

[0014] S6: Integrate the photosensitizer composite layer and the hydrophobic coating by aerosol-assisted chemical deposition, control the deposition temperature at 80 °C, and the carrier gas flow rate at 15 L / min to form a gradient wettability surface;

[0015] S7: Carry out 48-hour biological-induced self-assembly under the condition of 85% relative humidity to promote the oriented arrangement of the chitin-silk fibroin system;

[0016] S8: After treating with low-temperature plasma for 5 min, impregnate with a castor oil-based crosslinking agent for interface strengthening, and finally complete the preparation through bio-enzymatic washing finishing and microwave shaping.

[0017] In a preferred embodiment, in step S1, biodegradable polylactic acid nanofibers, chitin nanofibers and silk fibroin grafted nanofibers are mixed in a mass ratio of 45:30:25. Among them, PLA fibers are pre-dissolved in a mixed solvent with a volume ratio of dichloromethane to acetone of 3:1 to prepare a spinning solution with a concentration of 12 wt%. Chitin fibers are dissolved in a 1 mol / L acetic acid solution to a concentration of 8 wt%, and silk fibroin fibers are dissolved in a 9.3 mol / L lithium bromide aqueous solution and then purified by dialysis. Using a coaxial electrospinning device, 1 wt% citrate plasticizer is added to the inner layer spinning solution, and 2 wt% sodium alginate aqueous solution is coated as the reinforcing phase on the outer layer. Set the flow rate of the inner layer injection pump to 0.8 mL / h, the outer layer flow rate to 1.2 mL / h, the electrospinning voltage to be stable at 40 kV, the ambient temperature to be controlled at 25 ± 2 °C, and the relative humidity to be maintained below 45%. The receiving device uses an aluminum drum with a diameter of 200 mm, the rotation speed is precisely adjusted to 1200 rpm, the fiber deposition time lasts for 6 hours, and finally a double-network structure substrate with a thickness of 0.15 ± 0.02 mm is formed, and the surface fiber diameter is controlled in the range of 80 - 120 nm.

[0018] In a preferred embodiment, in step S2, the titanium dioxide nanorods prepared by the hydrothermal method are immersed in a dopamine-Tris buffer solution with a concentration of 2 mg / mL, the pH value of the buffer solution is precisely adjusted to 8.5, placed in a constant temperature oscillator and continuously oscillated at a speed of 200 rpm for 24 hours, and the reaction temperature is maintained at 35 °C. After taking out, it is centrifuged and washed three times to remove unreacted monomers, and composite particles with a polydopamine coating layer thickness of 5 - 8 nm are obtained. The treated titanium dioxide nanorods and zinc oxide quantum dots are mixed in a mass ratio of 3:1, 0.1 mol / L zinc nitrate ethanol solution is added as a precursor, and a sol-gel method is used to stir and react in a 60 °C water bath for 4 hours, and the stirring rate is set to 500 rpm. After the reaction, it is prepared into a heterojunction composite powder with a particle size distribution of 200 - 500 nm under the conditions of an inlet temperature of 180 °C and an outlet temperature of 80 °C through a spray drying device, and the specific surface area reaches 240 m 2 / g.

[0019] In a preferred embodiment, in step S3, the simulated body fluid is configured to contain inorganic ion components such as 142 mmol / L of NaCl, 5 mmol / L of KCl, and 2.5 mmol / L of CaCl2, and the temperature is maintained at 36.5 °C to simulate the human environment. The photocatalytic composite powder obtained in step S2 and sodium copper chlorophyllin are dispersed in the simulated body fluid at a mass ratio of 5:1, and the concentration is controlled to be 0.5 mg / mL. An automatic dipping device is used for alternate deposition. Each cycle includes: the substrate is immersed in the photocatalytic suspension for 30 minutes, and after taking out, it is purged with nitrogen to form a single-layer film; then it is transferred to the chlorophyll solution and left standing for 20 minutes. The cycle is repeated 3 times, and after each deposition, it is dried under hot air conditions at 50 °C for 15 minutes, and finally a multi-layer film structure with a thickness of about 800 nm is formed, and the visible light absorption rate is increased to 92%.

[0020] In a preferred embodiment, in step S4, nanocrystalline cellulose fluoride and bio-based self-healing polyurethane elastomer are mixed at a mass ratio of 2:3, dissolved in supercritical CO2 fluid, the system pressure is set to 15 MPa, the temperature is controlled at 40 °C, and the stirring rate is maintained at 600 rpm for 2 hours to form a homogeneous solution. 0.5 wt% of nano-silica aerogel is added as a rheology modifier, and a microfluidic spinning device is used for processing. The pore diameter of the spinneret is selected to be 50 μm, the solution extrusion pressure is maintained at 8 MPa, and the receiving distance is 20 cm. The ambient temperature is adjusted to 30 °C, and the CO2 phase change rate is controlled to be 0.5 mL / min to form a hexagonal honeycomb structure with a pore diameter of 20 - 50 μm, and the coating thickness is uniformly 25 ± 3 μm. The static water contact angle test shows that the initial value is 152°.

[0021] In a preferred embodiment, in step S5, a phosphate buffer solution containing 2 wt% lipase and 1.5 wt% protease is configured, the pH value is adjusted to 7.4, and it is mixed with mesoporous silica spheres at a volume ratio of 1:5. An ultrasonic-vacuum co-impregnation system is used, the ultrasonic frequency is set to 40 kHz, the power density is 0.5 W / cm 2 , and the action time is 20 minutes; the vacuum degree is maintained at 0.08 MPa, and the impregnation time is extended to 30 minutes. After loading, it is transferred to a hot air drying oven. In the first stage, it is slowly dried at 45 °C for 2 hours, and in the second stage, the temperature is raised to 60 °C and maintained for 1 hour to activate the enzyme activity. Finally, the enzyme activity retention rate reaches more than 85%, and the enzyme loading amount per unit carrier reaches 120 mg / g.

[0022] In a preferred embodiment, in step S6, an aerosol-assisted chemical deposition apparatus is used. The precursor solution is a 0.2 mol / L zinc stearate ethanol solution. The working frequency of the nebulizer is 1.7 MHz. High-purity nitrogen is selected as the carrier gas, and the flow rate is precisely controlled at 15 L / min. The temperature of the deposition chamber is divided into zones: the front section is 80 °C for solvent volatilization, the middle section is 120 °C to promote molecular orientation, and the rear section is 60 °C to achieve slow coagulation and forming. The deposition angle is adjusted to 45°, the substrate transfer speed is set at 0.5 m / min, and continuous deposition is carried out 5 times to form a functional layer with a thickness of 1.2 μm. The surface energy gradient gradually decreases from 36 mN / m to 18 mN / m, achieving superhydrophobic performance with a water droplet rolling angle less than 5°.

[0023] In a preferred embodiment, in step S7, the composite substrate is placed in a thermostatic and humidistatic chamber. The temperature is set at 37 °C to simulate the biological environment, and the relative humidity is regulated to 85% through a saturated salt solution and maintained for 48 hours. During the self-assembly process, a 0.5 T steady magnetic field is applied to promote the oriented arrangement of the β-sheet structure in chitin molecules. At the same time, the substrate bears periodic mechanical stress, with the strain amplitude controlled at 0.5% and the frequency at 1 Hz. Through on-line laser scanning confocal microscopy monitoring, it is confirmed that the fiber orientation degree increases from the initial 45% to 82%, and the tensile modulus increases to 3.2 GPa.

[0024] In a preferred embodiment, in step S8, a low-temperature plasma treatment system is used. The power is set at 100 W, the working gas is a mixture of argon and oxygen in a ratio of 9:1, the total flow rate is 20 sccm, the treatment time is 5 minutes, and the electrode spacing is maintained at 10 mm. Subsequently, it is impregnated with a 15 wt% castor oil-based aqueous crosslinking agent for 20 minutes, with a bath ratio of 1:30. The crosslinking stage adopts a segmented temperature-rising process: pre-crosslinking at 50 °C for 30 minutes, main crosslinking at 75 °C for 45 minutes, and finally final curing at 120 °C for 15 minutes. Biological enzyme washing uses a mixed solution of 0.5 g / L cellulase and 0.3 g / L protease, and is oscillated at 50 °C for 40 minutes. Microwave shaping is carried out at a frequency of 2450 MHz, with a power density of 3 W / cm 2 , with an action time of 90 seconds, and the final moisture content of the finished product is controlled below 8%.

[0025] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows:

[0026] 1. In the present invention, the environmental friendliness is significantly improved. Natural components that can be completely biodegradable are used, which can be quickly decomposed in the natural environment, reducing microplastic pollution; the self-cleaning function is enhanced. Through the synergistic effect of the biomimetic hydrophobic surface and photocatalytic decomposition, stains can be automatically shed and decomposed; the durability is strengthened. The dynamic self-healing network can autonomously repair daily wear and extend the service life; the wearing comfort is optimized. The bio-based raw materials are naturally skin-friendly and have excellent breathability.

[0027] 2. In the present invention, energy consumption is reduced through the preparation process, and supercritical fluid processing and microwave shaping technology replace high-energy-consuming processes; toxic substance emissions are eliminated, and organic solvents and fluorine-containing compounds are prohibited throughout the process; raw material losses are reduced, and the precise structure control technology reduces the usage amount of functional materials; maintenance costs are simplified, and the self-cleaning property reduces the washing frequency and the use of chemical cleaners; waste generation is compressed, and the closed-loop production system realizes the resource utilization of by-products. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the overall process of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] Refer to Figure 1 ,

[0031] A bio-environmental protection clothing material with self-cleaning function and its preparation method. The clothing material includes: 45 parts of biodegradable polylactic acid nanofibers, 30 parts of chitin nanofibers, 25 parts of silk fibroin grafted nanofibers, 12 parts of polydopamine-coated titanium dioxide nanorods, 8 parts of zinc oxide quantum dot composites, 10 parts of fluorinated cellulose nanocrystals, 15 parts of bio-based self-healing polyurethane elastomers, 6 parts of natural enzyme-loaded mesoporous silica spheres, 3 parts of sodium copper chlorophyllin composite photosensitizer, 20 parts of castor oil-based waterborne crosslinking agent, and 4 parts of starch-derived nanocapsule carriers;

[0032] Among them, the polydopamine-coated titanium dioxide nanorods are uniformly coated by mimicking mussel protein adhesion technology, and the core-shell structure thickness is controlled at 5-8 nm;

[0033] The bio-based self-healing polyurethane elastomer uses a castor oil derivative as the soft segment and an amino acid containing a dynamic disulfide bond as the hard segment.

[0034] The manufacturing process includes the following steps:

[0035] S1: Mix PLA nanofibers, chitin nanofibers and silk fibroin nanofibers in a ratio of 45:30:25, and adopt coaxial electrospinning technology. The inner layer spinning solution contains 1 wt% citric acid ester plasticizer, and the outer layer is a sodium alginate reinforcing phase. Control the voltage at 40 kV and the receiving roller speed at 1200 rpm to form a double-network structure nanofiber substrate;

[0036] S2: Immerse the titanium dioxide nanorods in dopamine-Tris buffer solution and oscillate for deposition for 24 hours, blend them with zinc oxide quantum dots at a mass ratio of 3:1, and form a heterojunction photocatalytic composite system at 60 °C through the sol-gel method;

[0037] S3: On the surface of the substrate, adopt the biomimetic mineralization technology, and alternately deposit the composite obtained in step S2 and sodium copper chlorophyllin in the simulated body fluid for 3 cycles to construct a chloroplast-like multi-layer film structure;

[0038] S4: Dissolve fluorinated cellulose nanocrystals and self-healing polyurethane elastomer in supercritical CO2 fluid, add 0.5% nano-aerosil as a rheology regulator, and form a micron-scale honeycomb hydrophobic coating through microfluidic spinning technology;

[0039] S5: Use the ultrasonic-vacuum impregnation method to implant natural enzyme-loaded mesoporous silica spheres into the fiber pores, control the negative pressure at 0.08 MPa, the impregnation time at 30 min, and then activate the immobilized enzyme activity by heating at 60 °C;

[0040] S6: Integrate the photosensitizer composite layer and the hydrophobic coating through aerosol-assisted chemical deposition, control the deposition temperature at 80 °C, and the carrier gas flow rate at 15 L / min to form a surface with gradient wettability;

[0041] S7: Carry out bio-induced self-assembly for 48 hours under the condition of 85% relative humidity to promote the directional arrangement of the chitin-silk fibroin system;

[0042] S8: After treatment with low-temperature plasma for 5 min, impregnate with a castor oil-based crosslinking agent for interface strengthening, and finally complete the preparation through bio-enzymatic washing finishing and microwave shaping.

[0043] In step S1, blend biodegradable polylactic acid nanofibers, chitin nanofibers and silk protein grafted nanofibers according to the mass ratio of 45:30:25. Among them, the PLA fibers are pre-dissolved in a mixed solvent with a volume ratio of dichloromethane to acetone of 3:1 to prepare a spinning solution with a concentration of 12 wt%. The chitin fibers are dissolved in 1 mol / L acetic acid solution to a concentration of 8 wt%, and the silk protein fibers are dissolved in 9.3 mol / L lithium bromide aqueous solution and then dialyzed and purified. Use a coaxial electrospinning device, add 1 wt% citrate plasticizer to the inner layer spinning solution, and coat 2 wt% sodium alginate aqueous solution as the reinforcing phase on the outer layer. Set the flow rate of the inner layer injection pump at 0.8 mL / h, the outer layer flow rate at 1.2 mL / h, the electrospinning voltage is stable at 40 kV, the environmental temperature is controlled at 25 ± 2 °C, and the relative humidity is maintained below 45%. The receiving device uses an aluminum drum with a diameter of 200 mm, the rotation speed is precisely adjusted to 1200 rpm, and the fiber deposition time lasts for 6 hours, finally forming a double-network structure substrate with a thickness of 0.15 ± 0.02 mm, and the surface fiber diameter is controlled in the range of 80-120 nm.

[0044] In step S2, the titanium dioxide nanorods prepared by the hydrothermal method are immersed in a dopamine-Tris buffer solution with a concentration of 2 mg / mL, the pH value of the buffer solution is precisely adjusted to 8.5, and it is placed in a constant temperature oscillator and continuously oscillated at a speed of 200 rpm for 24 hours, while the reaction temperature is maintained at 35 °C. After taking it out, it is centrifuged and washed three times to remove unreacted monomers, and composite particles with a polydopamine coating layer thickness of 5 - 8 nm are obtained. The treated titanium dioxide nanorods and zinc oxide quantum dots are mixed at a mass ratio of 3:1, and 0.1 mol / L zinc nitrate ethanol solution is added as a precursor, and a sol-gel method is used to stir and react in a 60 °C water bath for 4 hours, and the stirring rate is set at 500 rpm. After the reaction, a heterojunction composite powder with a particle size distribution of 200 - 500 nm is prepared by a spray drying device under the conditions of an inlet temperature of 180 °C and an outlet temperature of 80 °C, and the specific surface area reaches 240 m 2 / g.

[0045] In step S3, a simulated body fluid containing inorganic ion components such as 142 mmol / L NaCl, 5 mmol / L KCl, and 2.5 mmol / L CaCl2 is configured, and the temperature is maintained at 36.5 °C to simulate the human environment. The photocatalytic composite powder obtained in step S2 and sodium copper chlorophyllin are dispersed in the simulated body fluid at a mass ratio of 5:1, and the concentration is controlled to be 0.5 mg / mL. An automatic dipping device is used for alternate deposition, and each cycle includes: the substrate is immersed in the photocatalytic suspension for 30 minutes, and after taking it out, it is purged with nitrogen to form a single-layer film; then it is transferred to the chlorophyll solution and left standing for 20 minutes. The cycle is repeated 3 times, and after each deposition, it is dried under hot air conditions at 50 °C for 15 minutes, and finally a multilayer film structure with a thickness of about 800 nm is formed, and the visible light absorption rate is increased to 92%.

[0046] In step S4, fluorinated cellulose nanocrystals and a bio-based self-healing polyurethane elastomer are mixed at a mass ratio of 2:3, dissolved in supercritical CO2 fluid, the system pressure is set at 15 MPa, the temperature is controlled at 40 °C, and the stirring rate is maintained at 600 rpm for 2 hours to form a homogeneous solution. 0.5 wt% nano-silica aerogel is added as a rheology regulator, and a microfluidic spinning device is used for processing. The pore diameter of the spinning head is selected to be 50 μm, the solution extrusion pressure is maintained at 8 MPa, and the receiving distance is 20 cm. The ambient temperature is adjusted to 30 °C, and the CO2 phase change speed is controlled at 0.5 mL / min, forming a hexagonal honeycomb structure with a pore diameter of 20 - 50 μm, the coating thickness is uniformly 25 ± 3 μm, and the static water contact angle test shows an initial value of 152°.

[0047] In step S5, a phosphate buffer solution containing 2 wt% lipase and 1.5 wt% protease is prepared, the pH value is adjusted to 7.4, and it is mixed with mesoporous silica spheres at a volume ratio of 1:5. An ultrasonic-vacuum co-impregnation system is used, the ultrasonic frequency is set at 40 kHz, and the power density is 0.5 W / cm 2 , and the action time is 20 minutes; the vacuum degree is maintained at 0.08 MPa, and the impregnation time is extended to 30 minutes. After the loading is completed, it is transferred to a hot air drying oven. In the first stage, it is slowly dried at 45 °C for 2 hours, and in the second stage, the temperature is raised to 60 °C and maintained for 1 hour to activate the enzyme activity. Finally, the enzyme activity retention rate reaches more than 85%, and the enzyme loading amount per unit carrier reaches 120 mg / g.

[0048] In step S6, an aerosol-assisted chemical deposition device is used. The precursor solution is a 0.2 mol / L zinc stearate ethanol solution. The working frequency of the nebulizer is 1.7 MHz. High-purity nitrogen is selected as the carrier gas, and the flow rate is precisely controlled at 15 L / min. The temperature of the deposition chamber is divided into zones: the front section is 80 °C for solvent evaporation, the middle section is 120 °C to promote molecular orientation, and the rear section is 60 °C to achieve slow coagulation and forming. The deposition angle is adjusted to 45°, the substrate transfer speed is set at 0.5 m / min, and it is continuously deposited 5 times to form a functional layer with a thickness of 1.2 μm. The surface energy gradient gradually decreases from 36 mN / m to 18 mN / m, achieving superhydrophobic performance with a water contact angle less than 5°.

[0049] In step S7, the composite substrate is placed in a thermostatic and humidified chamber. The temperature is set at 37 °C to simulate the biological environment, and the relative humidity is regulated to 85% through a saturated salt solution and maintained for 48 hours. A 0.5 T steady magnetic field is applied during the self-assembly process to promote the directional arrangement of the β-sheet structure in chitin molecules. At the same time, the substrate is subjected to periodic mechanical stress, with the strain amplitude controlled at 0.5% and the frequency at 1 Hz. Through on-line laser scanning confocal microscopy monitoring, it is confirmed that the fiber orientation degree is increased from the initial 45% to 82%, and the tensile modulus is increased to 3.2 GPa.

[0050] In step S8, a low-temperature plasma treatment system is used. The power is set at 100 W, the working gas is a mixture of argon and oxygen in a ratio of 9:1, the total flow rate is 20 sccm, the treatment time is 5 minutes, and the electrode spacing is maintained at 10 mm. Subsequently, it is impregnated with a 15 wt% castor oil-based aqueous cross-linking agent for 20 minutes, and the bath ratio is 1:30. The cross-linking stage adopts a segmented heating process: pre-cross-linking at 50 °C for 30 minutes, main cross-linking at 75 °C for 45 minutes, and finally terminal curing at 120 °C for 15 minutes. Bio-enzymatic washing uses a mixed solution of 0.5 g / L cellulase and 0.3 g / L protease, and oscillates at 50 °C for 40 minutes. Microwave shaping is carried out at a frequency of 2450 MHz, with a power density of 3 W / cm 2 , and the action time is 90 seconds. Finally, the moisture content of the finished product is controlled below 8%.

[0051] In the present invention, the environmental friendliness is significantly improved by using completely biodegradable natural components, which can be rapidly decomposed in the natural environment to reduce microplastic pollution; the self-cleaning function is enhanced through the synergistic effect of the biomimetic hydrophobic surface and photocatalytic decomposition to achieve the automatic shedding and decomposition of stains; the durability is strengthened, and the dynamic self-healing network can autonomously repair daily wear and extend the service life; the wearing comfort is optimized, and the bio-based raw materials are naturally skin-friendly and have excellent breathability.

[0052] In the present invention, the energy consumption is reduced through the preparation process, and the supercritical fluid processing and microwave shaping technologies replace the high-energy-consuming processes; the emission of toxic substances is eliminated, and organic solvents and fluorine-containing compounds are prohibited throughout the process; the raw material loss is reduced, and the precise structure control technology reduces the usage of functional materials; the maintenance cost is simplified, and the self-cleaning property reduces the washing frequency and the use of chemical cleaners; the generation of waste is compressed, and the closed-loop production system realizes the resource utilization of by-products.

[0053] 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 actual relationship or order between these entities or operations. Moreover, the term "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising a..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0054] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A bio-environmental protection clothing material with self-cleaning function and its preparation method, characterized in that: The clothing material includes: 45 parts of biodegradable polylactic acid nanofibers, 30 parts of chitin nanofibers, 25 parts of silk fibroin grafted nanofibers, 12 parts of polydopamine-coated titanium dioxide nanorods, 8 parts of zinc oxide quantum dot composites, 10 parts of fluorinated cellulose nanocrystals, 15 parts of bio-based self-healing polyurethane elastomers, 6 parts of natural enzyme-loaded mesoporous silica spheres, 3 parts of sodium copper chlorophyllin composite photosensitizer, 20 parts of castor oil-based aqueous crosslinking agent, and 4 parts of starch-derived nanocapsule carriers; Among them, the polydopamine-coated titanium dioxide nanorods are uniformly coated by mimicking mussel protein adhesion technology, and the core-shell structure thickness is controlled at 5-8 nm; The bio-based self-healing polyurethane elastomer uses a castor oil derivative as the soft segment and an amino acid containing a dynamic disulfide bond as the hard segment.

2. The bio - environmental protection clothing material with self - cleaning function and its preparation method according to claim 1, characterized in that: The manufacturing process includes the following steps: S1: Mix PLA nanofibers, chitin nanofibers, and silk fibroin nanofibers in a ratio of 45:30:

25. Using coaxial electrospinning technology, the inner layer spinning solution contains 1 wt% citrate plasticizer, and the outer layer is a sodium alginate reinforcing phase. Control the voltage at 40 kV and the receiving roller speed at 1200 rpm to form a double-network structure nanofiber substrate; S2: Immerse the titanium dioxide nanorods in dopamine-Tris buffer solution and oscillate and deposit for 24 hours. Blend with zinc oxide quantum dots in a mass ratio of 3:1, and form a heterojunction photocatalytic composite system at 60 °C through the sol-gel method; S3: On the surface of the substrate, use biomimetic mineralization technology to alternately deposit the composite obtained in step S2 and sodium copper chlorophyllin in simulated body fluid for 3 cycles to construct a chloroplast-like multi-layer membrane structure; S4: Dissolve fluorinated cellulose nanocrystals and self-healing polyurethane elastomers in supercritical CO2 fluid, add 0.5% nano-aerosil as a rheology regulator, and form a micron-scale honeycomb hydrophobic coating through microfluidic electrospinning technology; S5: Use ultrasonic-vacuum impregnation method to implant natural enzyme-loaded mesoporous silica spheres into the fiber pores, control the negative pressure at 0.08 MPa, and the impregnation time at 30 min. Then activate the immobilized enzyme activity by heating at 60 °C; S6: Integrate the photosensitizer composite layer and the hydrophobic coating by aerosol-assisted chemical deposition, control the deposition temperature at 80 °C, and the carrier gas flow rate at 15 L / min to form a gradient wettability surface; S7: Carry out 48-hour bio-induced self-assembly under the condition of 85% relative humidity to promote the directional arrangement of the chitin-silk fibroin system; S8: After 5 minutes of low-temperature plasma treatment, impregnate with a castor oil-based crosslinking agent for interface strengthening, and finally complete the preparation through bio-enzyme washing finishing and microwave shaping.

3. The bio-environmental protection clothing material with self-cleaning function and its preparation method according to claim 1, characterized in that: In the step S1, the biodegradable polylactic acid nanofibers, chitin nanofibers and silk fibroin grafted nanofibers are mixed according to the mass ratio of 45:30:

25. Among them, the PLA fibers are pre-dissolved in a mixed solvent with a volume ratio of dichloromethane to acetone of 3:1 to prepare a spinning solution with a concentration of 12 wt%. The chitin fibers are dissolved in a 1 mol / L acetic acid solution to a concentration of 8 wt%, and the silk fibroin fibers are dissolved in a 9.3 mol / L lithium bromide aqueous solution and then dialyzed and purified. Using a coaxial electrospinning device, 1 wt% of a citric acid ester plasticizer is added to the inner layer spinning solution, and a 2 wt% sodium alginate aqueous solution is coated on the outer layer as a reinforcing phase. The flow rate of the inner layer injection pump is set at 0.8 mL / h, the outer layer flow rate is 1.2 mL / h, the electrospinning voltage is stabilized at 40 kV, the environmental temperature is controlled at 25 ± 2 °C, and the relative humidity is maintained below 45%. The receiving device uses an aluminum drum with a diameter of 200 mm, the rotation speed is precisely adjusted to 1200 rpm, and the fiber deposition time lasts for 6 hours, finally forming a double-network structure substrate with a thickness of 0.15 ± 0.02 mm, and the surface fiber diameter is controlled within the range of 80 - 120 nm.

4. The bio - environmental protection clothing material with self - cleaning function and its preparation method according to claim 1, characterized in that: In step S2, the titanium dioxide nanorods prepared by the hydrothermal method are immersed in a dopamine-Tris buffer solution with a concentration of 2 mg / mL, the pH value of the buffer solution is precisely adjusted to 8.5, and it is placed in a constant temperature oscillator and continuously oscillated at a speed of 200 rpm for 24 hours, and the reaction temperature is maintained at 35 °C; after taking it out, it is centrifuged and washed three times to remove unreacted monomers, and composite particles with a polydopamine coating layer thickness of 5-8 nm are obtained; the treated titanium dioxide nanorods and zinc oxide quantum dots are mixed at a mass ratio of 3:1, 0.1 mol / L zinc nitrate ethanol solution is added as a precursor, and a sol-gel method is used to stir and react in a 60 °C water bath for 4 hours, and the stirring rate is set at 500 rpm; after the reaction is completed, it is prepared into a heterojunction composite powder with a particle size distribution of 200-500 nm under the conditions of an inlet temperature of 180 °C and an outlet temperature of 80 °C through a spray drying device, and the specific surface area reaches 240 m 2 / g.

5. A bio-environmental protection clothing material with self-cleaning function and its preparation method according to claim 1, characterized in that: In the step S3, a simulated body fluid containing inorganic ion components such as 142 mmol / L of NaCl, 5 mmol / L of KCl, and 2.5 mmol / L of CaCl2 is configured, and the temperature is maintained at 36.5 °C to simulate the human environment. The photocatalytic composite powder obtained in the step S2 and sodium copper chlorophyllin are dispersed in the simulated body fluid according to a mass ratio of 5:1, and the concentration is controlled at 0.5 mg / mL. An automatic dipping device is used for alternate deposition. Each cycle includes: the substrate is immersed in the photocatalytic suspension for 30 minutes, and after taking it out, it is purged with nitrogen to form a single-layer film; then it is transferred to the chlorophyll solution and left standing for 20 minutes; the cycle is repeated 3 times, and after each deposition, it is dried under hot air conditions at 50 °C for 15 minutes, finally forming a multi-layer film structure with a thickness of about 800 nm, and the visible light absorption rate is increased to 92%.

6. The bio-environmental protection clothing material with self-cleaning function and its preparation method according to claim 1, characterized in that: In the step S4, the fluorinated cellulose nanocrystals and the bio-based self-healing polyurethane elastomer are mixed according to a mass ratio of 2:3, dissolved in supercritical CO2 fluid, the system pressure is set at 15 MPa, the temperature is controlled at 40 °C, and the stirring rate is maintained at 600 rpm for 2 hours to form a homogeneous solution; 0.5 wt% of nano-silica aerogel is added as a rheology regulator, and a microfluidic spinning device is used for processing. The pore diameter of the spinning head is selected to be 50 μm, the solution extrusion pressure is maintained at 8 MPa, and the receiving distance is 20 cm; the environmental temperature is adjusted to 30 °C, and the CO2 phase change speed is controlled at 0.5 mL / min, forming a hexagonal honeycomb structure with a pore diameter of 20 - 50 μm, and the coating thickness is uniformly up to 25 ± 3 μm. The static water contact angle test shows that the initial value is 152°.

7. The bio - environmental protection clothing material with self - cleaning function and its preparation method according to claim 1, characterized in that: In the step S5, a phosphate buffer solution containing 2 wt% lipase and 1.5 wt% protease is prepared, the pH value is adjusted to 7.4, and it is mixed with the mesoporous silica spheres at a volume ratio of 1:5; an ultrasonic-vacuum co-impregnation system is adopted, the ultrasonic frequency is set at 40 kHz, and the power density is 0.5 W / cm 2 , and the acting time is 20 minutes; The vacuum degree is maintained at 0.08 MPa, and the dipping time is extended to 30 minutes; after loading, it is transferred to a hot air drying oven. In the first stage, it is slowly dried at 45 °C for 2 hours, and in the second stage, the temperature is raised to 60 °C and kept for 1 hour to activate the enzyme activity. Finally, the enzyme activity retention rate reaches more than 85%, and the enzyme loading amount per unit carrier reaches 120 mg / g.

8. A bio-environmental protection clothing material with a self-cleaning function and a preparation method thereof according to claim 1, characterized in that: In the step S6, an aerosol-assisted chemical deposition device is used. The precursor solution is a 0.2 mol / L zinc stearate ethanol solution. The working frequency of the atomizer is 1.7 MHz. High-purity nitrogen is selected as the carrier gas, and the flow rate is precisely controlled at 15 L / min. The temperature of the deposition chamber is divided into zones: the front section is 80 °C for solvent volatilization, the middle section is 120 °C to promote molecular orientation, and the rear section is 60 °C to achieve slow setting and forming. The deposition angle is adjusted to 45°, the substrate transfer speed is set at 0.5 m / min, and deposition is carried out continuously 5 times to form a functional layer with a thickness of 1.2 μm. The surface energy gradient gradually decreases from 36 mN / m to 18 mN / m, achieving superhydrophobic performance with a water droplet rolling angle of less than 5°.

9. The bio-environmental protection clothing material with self-cleaning function and its preparation method according to claim 1, characterized in that: In the step S7, the composite substrate is placed in a thermostatic and humidistatic chamber. The temperature is set at 37 °C to simulate the biological environment. The relative humidity is regulated to 85% through a saturated salt solution and maintained for 48 hours. During the self-assembly process, a 0.5 T steady magnetic field is applied to promote the oriented arrangement of the β-sheet structure in chitin molecules. At the same time, the substrate is subjected to periodic mechanical stress, with the strain amplitude controlled at 0.5% and the frequency at 1 Hz. Through on-line laser scanning confocal microscopy monitoring, it is confirmed that the fiber orientation degree is increased from the initial 45% to 82%, and the tensile modulus is increased to 3.2 GPa.

10. The bio-environmental protection clothing material with self-cleaning function and its preparation method according to claim 1, characterized in that: In the step S8, a low-temperature plasma treatment system is adopted, with the power set at 100 W, the working gas being a mixture of argon and oxygen in a ratio of 9:1, the total flow rate being 20 sccm, the treatment time being 5 minutes, and the electrode spacing being kept at 10 mm; subsequently, it is impregnated with a castor oil-based aqueous crosslinking agent with a concentration of 15 wt%, the impregnation time being 20 minutes and the bath ratio being 1:30; in the crosslinking stage, a segmented temperature-rising process is adopted: pre-crosslinking at 50 °C for 30 minutes, main crosslinking at 75 °C for 45 minutes, and finally final curing at 120 °C for 15 minutes; for the bio-enzyme washing, a mixed solution of 0.5 g / L cellulase and 0.3 g / L protease is used, and it is oscillated and treated at 50 °C for 40 minutes; the microwave shaping is carried out at a frequency of 2450 MHz, with a power density of 3 W / cm 2 , the action time being 90 seconds, and the moisture content of the final product being controlled below 8%.

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