Antibacterial anti-ultraviolet bio-based lyocell fabric and preparation method thereof

Abstract

The invention relates to the technical field of knitted fabrics, in particular to an antibacterial and uvioresistant bio-based lyocell fabric and a preparation method thereof.The fabric comprises a three-layer composite structure formed by connecting bio-based lyocell yarns, wherein an outer layer is formed by weft knitting of composite yarns formed by nylon-66 fibers and first functional fibers; the first functional fiber comprises bio-based lyocell fiber, thermochromic zinc oxide particles, a nano-silver / graphene hybrid material, a hydrophobic pore switch polymer and a cross-linking agent; the middle layer is formed by performing weft knitting on second yarns formed by second functional fibers, and the second functional fibers comprise bio-based lyocell fibers, temperature-sensitive microcapsules and humidity expansion gel and are formed by an acrylic acid / sodium alginate interpenetrating network; the third functional fiber in the inner layer comprises a bio-based lyocell fiber, a Janus type double-sided microcapsule, a porous graphene frame, a phase change material and other conditioning agents, and the third functional fiber in the inner layer comprises a bio-based lyocell fiber, a Janus type double-sided microcapsule, a porous graphene frame, a phase change material and other conditioning agents.

Description

Technical Field

[0001] The present invention relates to the technical field of knitted fabrics, and specifically provides an antibacterial and anti-ultraviolet bio-based lyocell fabric and a preparation method thereof. Background Art

[0002] With the continuous improvement of people's attention to health and environmental protection, the development of textiles with functions such as antibacterial and anti-ultraviolet has become a research hotspot. Traditional textiles have deficiencies in functionality and are difficult to meet the needs of modern consumers.

[0003] Existing textiles have the following problems: 1. Static nature of antibacterial and anti-ultraviolet functions: The antibacterial effect of traditional antibacterial fabrics (such as silver ion and copper ion fibers) decays with the use time and cannot dynamically adjust the release rate according to the environmental temperature and humidity.

[0004] Anti-ultraviolet materials (such as zinc oxide and titanium dioxide) usually adopt fixed coatings and cannot adaptively adjust the protection level according to the ultraviolet intensity, resulting in insufficient protection in high-temperature and high-ultraviolet environments or limited breathability in low-light conditions.

[0005] 2. Insufficient temperature and humidity regulation ability: Existing cool-sensation fabrics (such as menthol microcapsules) only rely on temperature triggering for release and cannot re-adsorb cool-sensation molecules when the temperature decreases, resulting in poor functional durability.

[0006] Ordinary breathable fabrics (such as mesh structures) have fixed breathability and cannot dynamically adjust when the humidity increases, and are prone to a stuffy feeling after sweating.

[0007] 3. Poor synergistic effect of multi-layer functional materials: The functions of each layer of traditional composite fabrics are independent. For example, the outer layer is only anti-ultraviolet, the middle layer is only antibacterial, and the inner layer is only moisture-absorbing. Lack of a cross-layer linkage mechanism leads to fragmented overall performance.

[0008] Therefore, the present invention aims to provide a bio-based lyocell fabric with multifunctions such as antibacterial, anti-ultraviolet, temperature regulation, and humidity response to meet the market demand for high-performance textiles. Summary of the Invention

[0009] In view of the deficiencies of the prior art, the present invention provides an antibacterial and anti-ultraviolet bio-based lyocell fabric and a preparation method thereof. The fabric has functions of dynamic antibacterial, anti-ultraviolet, temperature and humidity response, and breathability adjustment, and is applicable to fields such as medical protection, sportswear, and outdoor equipment.

[0010] According to the first aspect of the present invention, there is provided an antibacterial and anti-ultraviolet bio-based lyocell fabric, including a three-layer composite structure connected by bio-based lyocell yarns: The outer layer (intelligent protection layer) is formed by weft knitting a composite yarn composed of 15 - 30% by mass of nylon - 66 fibers and 70 - 85% by mass of the first functional fiber. Among them, the first functional fiber, by mass percentage, includes: 80% - 85% bio - based lyocell fiber; 5% - 8% thermochromic zinc oxide microparticles; 3% - 5% nano - silver / graphene hybrid material; 2% - 5% hydrophobic pore - switch polymer; 3% - 4% cross - linker; The middle layer (dual - response functional layer) is formed by weft knitting a second yarn composed of a second functional fiber. The second functional fiber, by mass percentage, includes: 60% - 70% bio - based lyocell fiber; 10% - 15% temperature - sensitive microcapsules with a poly(N - isopropylacrylamide) (PNIPAM) shell and menthol and tea tree essential oil as the core materials; 8% - 12% humidity - swelling gel composed of an acrylic acid / sodium alginate interpenetrating network; 3% - 5% thermally conductive graphene sheets; 2% - 12% other functional additives; The inner layer (adaptive comfort layer) is formed by weft knitting a third yarn composed of a third functional fiber. The third functional fiber, by mass percentage, includes: 70% - 80% bio - based lyocell fiber; 10% - 15% Janus - type double - sided microcapsules with sodium alginate on the hydrophilic side and polylactic acid on the hydrophobic side; 5% - 10% porous graphene framework; 2% - 8% phase - change material (PCM); 1% - 5% other regulators; The core synergy of the outer layer (intelligent protection layer) is reflected in the cooperation between the nano - silver / graphene hybrid material and thermochromic zinc oxide. The high thermal conductivity of graphene significantly improves the diffusion efficiency of silver ions, increasing the antibacterial effect by 40% compared with traditional nano - silver materials. At the same time, the zinc oxide microparticles undergo lattice expansion at high temperatures, producing a synergistic enhancement effect with the ultraviolet absorption characteristics of graphene, so that the ultraviolet protection factor (UPF) can be increased from the reference value of 50 to 70 at 35°C. The synergistic effect between the hydrophobic pore - switch polymer and graphene is reflected in the humidity response. When the environmental humidity exceeds 65%, the polymer shrinks to open the micropores, and the graphene sheets are simultaneously oriented to form an efficient gas - conducting channel, comprehensively increasing the air permeability by 60%.

[0011] There is a linkage mechanism between PNIPAM thermosensitive microcapsules and humidity swelling gel in the middle layer (dual-responsive functional layer). When the temperature exceeds 32 °C, the PNIPAM shell shrinks and ruptures to release cooling factors; in a high-humidity environment (>70%), the swelling of acrylic acid / sodium alginate gel physically squeezes the microcapsules, increasing the release rate of cooling factors to 0.4 mg / cm²·h, which is twice that under normal conditions. The combination of thermally conductive graphene sheets and phase change materials constructs an efficient thermal management system. Graphene quickly conducts body surface heat to PCM for storage, and the measured cooling duration can be extended to 5 hours, a 150% increase compared to the system without graphene.

[0012] The inner layer (adaptive comfort layer) achieves dual response to temperature and humidity through the cooperation of Janus-type double-sided microcapsules and porous graphene frameworks. Sodium alginate on the hydrophilic side releases moisturizing factors after absorbing moisture, while polylactic acid on the hydrophobic side releases cooling molecules when the body temperature rises. The porosity of the porous graphene framework can expand from the reference value of 60% to 80% when the humidity exceeds 75%. Combining with the humidity response of the microcapsules, the overall air permeability is increased by 50% while maintaining a 20% increase in skin water content.

[0013] Preferably, the particle size of the thermochromic zinc oxide microparticles is 20 - 100 nm, and the ultraviolet reflectance increases by 15% - 30% when the temperature > 35 °C.

[0014] Preferably, the loading amount of silver nanoparticles in the silver nanoparticle / graphene hybrid material is 1% - 3%, and the graphene sheet thickness is 1 - 5 nm.

[0015] The high thermal conductivity of graphene accelerates the diffusion of silver ions, improving the antibacterial efficiency; zinc oxide expands its lattice at high temperatures, overlapping with the ultraviolet absorption peak of graphene to enhance the anti-ultraviolet effect.

[0016] Preferably, the hydrophobic air pore switch polymer is a poly(methyl methacrylate)-polydimethylsiloxane (PMMA-PDMS) block copolymer, and the micropore diameter expands to 0.5 - 2 μm when the humidity > 65%.

[0017] When the humidity > 65%, PMMA-PDMS shrinks to open the micropores, and the graphene sheets are oriented to form an air conduction channel, increasing the air permeability.

[0018] Preferably, the poly(N-isopropylacrylamide) (PNIPAM) shell thickness of the temperature-sensitive microcapsules is 0.1 - 0.5 μm, and the mass ratio of the core materials menthol to tea tree essential oil is 1:1 - 1:2.

[0019] Preferably, the swelling rate of the humidity swelling gel is 150% - 250% when the relative humidity > 70%.

[0020] Preferably, the particle size of the Janus - type double - sided microcapsule is 5 - 20 μm, and the mass ratio of the hydrophilic side to the hydrophobic side is 1:1 - 1:1.5.

[0021] Preferably, the porosity of the porous graphene framework is 60% - 80%, the pore diameter is 1 - 10 μm, and the pore expansion rate is ≥50% when the humidity > 75%.

[0022] Preferably, the phase - change material (PCM) is an octadecane / silica composite, the phase - change temperature is 28 - 33 °C, and the latent heat storage ≥150 J / g.

[0023] At high temperature (>32 °C), PNIPAM shrinks to release the cooling factor, and at the same time, under high humidity (>70%), the gel expands to squeeze the microcapsules, increasing the release rate.

[0024] Graphene quickly conducts the body surface heat to the PCM for storage, prolonging the duration of the cooling sensation.

[0025] The hydrophilic side (sodium alginate) releases the moisturizing factor after absorbing moisture, and the hydrophobic side (polylactic acid) releases the cooling molecules when the body temperature rises, achieving dual humidity / temperature response.

[0026] Preferably, the other functional additives include: The antibacterial enhancer is 0% - 4%, including at least one of quaternary ammonium chitosan salts and benzalkonium chloride; The ultraviolet stabilizer is 0% - 3%, including at least one of phenyl salicylate and nano - titanium dioxide; The plasticizer is 1% - 3%, including at least one of triethyl citrate and polyethylene glycol; The cross - linker is 1% - 2%, including at least one of glutaraldehyde and epichlorohydrin.

[0027] The combination of quaternary ammonium chitosan salts and benzalkonium chloride not only improves the antibacterial persistence but also achieves a broad - spectrum antibacterial effect through the synergistic effect with nano - silver. Quaternary ammonium chitosan salts can ensure that the fabric still maintains good antibacterial performance after multiple washes, while benzalkonium chloride further enhances the antibacterial effect, enabling it to effectively resist a variety of pathogens.

[0028] The addition of phenyl salicylate and nano - titanium dioxide effectively prevents the degradation of the polymer by ultraviolet rays and at the same time enhances the ultraviolet scattering effect. Phenyl salicylate protects the polymer from photo - degradation by absorbing ultraviolet rays and prolongs the service life of the fabric. Nano - titanium dioxide synergistically acts with zinc oxide to further improve the ultraviolet resistance of the fabric, enabling it to effectively block ultraviolet rays and protect the skin from ultraviolet damage.

[0029] The use of triethyl citrate and polyethylene glycol (PEG-400) not only improves the flexibility of the fibers but also regulates the swelling rate of the humidity swelling gel. Triethyl citrate makes the fibers softer and enhances the comfort of the fabric. Polyethylene glycol (PEG-400) ensures the uniformity of humidity response by regulating the swelling rate of the humidity swelling gel, enabling the fabric to maintain good performance under different humidity conditions.

[0030] The addition of glutaraldehyde and epichlorohydrin enhances the crosslinking of the sodium alginate gel network and the interfacial bonding between graphene and the fibers. Glutaraldehyde is used for the crosslinking of the sodium alginate gel network, improving the stability and mechanical properties of the gel. Epichlorohydrin enhances the interfacial bonding between graphene and the fibers, improving the overall strength and stability of the fabric, making it less likely to be damaged during processing and use.

[0031] Preferably, the other regulators include: 0%-1.5% of pH regulators, including at least one of sodium lactate and sodium citrate; 0%-2% of moisturizers, including at least one of sodium hyaluronate and glycerol; 0%-1% of antistatic agents, including polyether-modified silicone oil; 0%-1% of antioxidants, including at least one of vitamin E and propyl gallate.

[0032] The combination of sodium lactate and sodium citrate can maintain the weak acidic environment of the skin (pH 5.5 - 6.0) and buffer the pH value of sweat at the same time. Sodium lactate helps to protect the natural barrier of the skin and reduce the impact of external stimuli on the skin. Sodium citrate, on the other hand, reduces the irritation of sweat to the skin by buffering the pH value of sweat, enabling the skin to remain comfortable during exercise or sweating.

[0033] The synergistic effect of sodium hyaluronate and glycerol not only locks in moisture and moisturizes but also regulates hygroscopicity to prevent the skin from drying out excessively. Sodium hyaluronate can effectively lock in moisture and keep the skin hydrated. Glycerol, by regulating hygroscopicity, prevents the skin from losing water excessively in a dry environment, ensuring that the skin always remains hydrated and soft.

[0034] The addition of polyether-modified silicone oil effectively reduces the surface resistance of the fibers and reduces the generation of static electricity. This antistatic agent can significantly improve wearing comfort, especially in a dry environment, reducing the irritation and discomfort caused by static electricity to the skin.

[0035] The combination of vitamin E and propyl gallate not only prevents the oxidative degradation of phase change materials (PCMs) and essential oils, but also extends the service life of the fabric. Vitamin E protects PCMs and essential oils from oxidative degradation through its antioxidant effect, ensuring their long-term stability and effectiveness. Propyl gallate further extends the service life of the fabric, enabling it to maintain good performance during long-term use.

[0036] The dynamic regulation process of the present invention is manifested as an intelligent closed-loop system that responds to both temperature and humidity: In terms of temperature response, when the ambient temperature rises from 25°C to 35°C, the outer layer of thermochromic zinc oxide undergoes lattice expansion, causing the ultraviolet protection coefficient to dynamically increase from 50 to 70; the middle layer of PNIPAM microcapsules synchronously shrinks and ruptures, releasing cooling factors such as menthol; the inner layer of phase change material absorbs excess heat, reducing the perceived temperature by 3 - 5°C. When the temperature drops, the system can operate reversely, and the microcapsules re-adsorb the cooling molecules, realizing the recycling of functional factors.

[0037] In terms of humidity regulation, when the relative humidity rises from 50% to 80%, the micropores of the outer layer of hydrophobic polymer open, and the pore diameter expands from 0.5μm to 2μm; the volume of the middle layer of humidity-swelling gel expands by 200%, physically squeezing the microcapsules to accelerate the release of antibacterial components; the pore channels of the inner layer of graphene expand synchronously, increasing the air permeability by 60%. This synergistic response effectively solves the problem of stuffiness of traditional fabrics in a sweaty environment.

[0038] According to the second aspect of the present invention, a method for preparing an antibacterial and anti-ultraviolet bio-based lyocell fabric is provided, including the following steps: Preparation of the outer layer: Mix bio-based lyocell fibers, thermochromic zinc oxide microparticles, nano-silver / graphene hybrid materials, and hydrophobic pore-switching polymers, and prepare the first functional fiber by melt spinning; compound the first functional fiber with nylon-66 fibers to form a composite yarn with 120 - 150 fiber roots; use weft knitting technology to make the composite yarn into the outer layer fabric; Preparation of the middle layer: Prepare temperature-sensitive microcapsules by interfacial polymerization; blend bio-based lyocell fibers, humidity-swelling gel, thermally conductive graphene sheets, and microcapsules, and prepare the second functional fiber by wet spinning; make the second functional fiber into a second yarn with 120 - 150 fiber roots; use weft knitting technology to make the second yarn into the middle layer fabric; Preparation of the inner layer: Prepare Janus - type double - sided microcapsules using microfluidic technology; blend bio - based Lyocell fibers, porous graphene frameworks, PCMs with the microcapsules, and fabricate the third functional fiber by electrospinning; make the third yarn with 120 - 150 fiber strands from the third functional fiber; use weft knitting technology to make the inner layer fabric from the third yarn; Composite lamination: Weave and laminate the outer layer, the middle layer, and the inner layer with bio - based Lyocell fiber yarns having 60 - 95 fiber strands to form a sandwich structure, obtaining the antibacterial and anti - ultraviolet bio - based Lyocell fabric.

[0039] Preferably, in the preparation of the outer layer, the melt - spinning temperature is 180 - 220 °C and the spinning speed is 500 - 800 m / min.

[0040] Preferably, in the preparation of the middle layer, the coagulation bath for wet spinning is a 10% - 15% aqueous sodium sulfate solution, and the spinning draw ratio is 1.5 - 2.5.

[0041] Preferably, in the preparation of the inner layer, the voltage for electrospinning is 15 - 25 kV and the receiving distance is 10 - 20 cm.

[0042] Preferably, this fabric can be applied to: Medical protective clothing: Persistent antibacterial and cooling in high - temperature and high - humidity environments.

[0043] Sports compression clothing: Automatically trigger a cooling sensation when running and enhance breathability when sweaty.

[0044] Outdoor windbreaker: Improve the protection level when ultraviolet rays are strong at noon.

[0045] In the present invention, by combining nano - silver / graphene hybrid materials with thermochromic zinc oxide, the antibacterial efficiency and ultraviolet protection ability are dynamically adjusted with the change of temperature and humidity. Use PNIPAM thermosensitive microcapsules to achieve reversible release / adsorption of the cooling factor, and combine with PCM phase - change materials to buffer temperature fluctuations. Through the linkage of humidity - swelling gels and porous graphene frameworks, the breathability is increased by 40% - 60% when the humidity > 65%. The ultraviolet protection of the outer layer triggers the release of the antibacterial agent in the middle layer, and the humidity regulation of the inner layer feeds back to the opening of the micropores in the outer layer, forming a "environment - fabric - skin" closed - loop response.

[0046] The present invention constructs a cross - layer linkage intelligent response system: through a three - level response architecture of outer - layer environmental perception, middle - layer function release, and inner - layer comfort adjustment, a complete closed - loop from environmental monitoring to function output is achieved; the multifunctional application of graphene materials synchronously solves key technical problems such as electrical conductivity, thermal conductivity, and mechanical enhancement; the temperature - humidity dual - variable regulation mechanism enables the fabric to simultaneously adapt to climate change and human metabolic needs. This collaborative design gives the fabric significant advantages in fields such as medical protection and sportswear, solving the core pain points of traditional functional fabrics with single response and poor durability. The present invention solves the problems of static function and irreversible adjustment in the prior art through material innovation (thermochromic zinc oxide, Janus microcapsules) and structural innovation (three - layer dynamic coordination), and its comprehensive performance indicators are greatly improved compared with existing products, having important industrial application value.

[0047] Through the synergistic effect of these functional additives and regulators, the antibacterial and anti - ultraviolet bio - based lyocell fabric of the present invention not only has excellent antibacterial and anti - ultraviolet properties, but also has good temperature - humidity response, skin affinity, and durability, meeting the needs of modern consumers for high - performance textiles. Detailed implementation mode

[0048] The embodiment of the present application provides an antibacterial and anti - ultraviolet bio - based lyocell fabric and its preparation method.

[0049] Example 1: Outer layer: A composite yarn with 120 fiber strands is made of 30% nylon - 66 fibers and 70% by mass of the first functional fiber; among them, the first functional fiber: 80% bio - based lyocell fiber, 7% thermochromic zinc oxide microparticles, 4% nano - silver / graphene hybrid material, 5% poly(methyl methacrylate) - poly(dimethylsiloxane) block copolymer, 4% cross - linker; Middle layer: A composite yarn with 120 fiber strands is made of 65% bio - based lyocell fiber, 12% temperature - sensitive microcapsules, 10% humidity - swelling gel, 3% thermally conductive graphene sheets, and 10% other functional additives; other functional additives include: 3% chitosan quaternary ammonium salt, 2% phenyl salicylate, 3% triethyl citrate, 2% glutaraldehyde; Inner layer: A composite yarn with 120 fiber strands is made of 75% bio - based lyocell fiber, 12% Janus - type double - sided microcapsules, 7% porous graphene framework, 5% octadecane / silica composite, and 1% other regulators; other regulators include: 0.5% sodium lactate, 0.5% vitamin E; The outer layer, middle layer, and inner layer are woven and compounded through a bio - based lyocell fiber yarn with 60 fiber strands to form a sandwich structure, obtaining the antibacterial and anti - ultraviolet bio - based lyocell fabric.

[0050] Example 2: Outer layer: A composite yarn with 20% nylon-66 fibers and 80% by mass of the first functional fiber, with 120 fiber strands; among them, the first functional fiber: 85% bio-based lyocell fiber, 5% thermochromic zinc oxide microparticles, 5% nano silver / graphene hybrid material, 2% poly(methyl methacrylate)-poly(dimethylsiloxane) block copolymer, 3% cross-linking agent; Middle layer: 70% bio-based lyocell fiber, 15% temperature-sensitive microcapsules, 8% humidity-expanding gel, 5% thermally conductive graphene sheets, 2% other functional additives, made into a composite yarn with 120 fiber strands; other functional additives include: 1% triethyl citrate, 1% glutaraldehyde; Inner layer: 80% bio-based lyocell fiber, 15% Janus-type double-sided microcapsules, 10% porous graphene framework, 3% octadecane / silica composite, 2% other regulators, made into a composite yarn with 120 fiber strands; other regulators include: 1% sodium hyaluronate, 1% polyether-modified silicone oil; The outer layer, middle layer, and inner layer are woven and compounded through a bio-based lyocell fiber yarn with 95 fiber strands to form a sandwich structure, obtaining an antibacterial and anti-ultraviolet bio-based lyocell fabric.

[0051] Example 3: Outer layer: A composite yarn with 15% nylon-66 fibers and 85% by mass of the first functional fiber, with 140 fiber strands; among them, the first functional fiber: 82% bio-based lyocell fiber, 8% thermochromic zinc oxide microparticles, 3% nano silver / graphene hybrid material, 4% poly(methyl methacrylate)-poly(dimethylsiloxane) block copolymer, 3% cross-linking agent; Middle layer: 60% bio-based lyocell fiber, 10% temperature-sensitive microcapsules, 12% humidity-expanding gel, 4% thermally conductive graphene sheets, 4% other functional additives, made into a composite yarn with 140 fiber strands; other functional additives include: 1% benzalkonium chloride, 1% nano titanium dioxide, 1% polyethylene glycol, 1% epichlorohydrin; Inner layer: 70% bio-based lyocell fiber, 10% Janus-type double-sided microcapsules, 5% porous graphene framework, 8% octadecane / silica composite, 5% other regulators, made into a composite yarn with 140 fiber strands; other regulators include: 1% sodium lactate, 2% glycerol, 1% polyether-modified silicone oil, 1% propyl gallate; The outer layer, middle layer, and inner layer are woven and compounded through a bio-based lyocell fiber yarn with 80 fiber strands to form a sandwich structure, obtaining an antibacterial and anti-ultraviolet bio-based lyocell fabric.

[0052] Example 4: Outer layer: A composite yarn with 150 fiber strands is made of 20% nylon-66 fibers and 80% by mass of the first functional fiber; among them, the first functional fiber: 83% bio-based lyocell fiber, 6% thermochromic zinc oxide microparticles, 4.5% nano silver / graphene hybrid material, 3.5% poly(methyl methacrylate)-poly(dimethyl siloxane) block copolymer, 3% crosslinking agent; Middle layer: A composite yarn with 150 fiber strands is made of 68% bio-based lyocell fiber, 14% temperature-sensitive microcapsules, 11% humidity-expanding gel, 3.5% thermally conductive graphene sheets, 3.5% other functional additives; other functional additives include: 1% benzalkonium chloride, 1% nano titanium dioxide, 0.5% polyethylene glycol, 1% epichlorohydrin; Inner layer: A composite yarn with 150 fiber strands is made of 72% bio-based lyocell fiber, 14% Janus-type double-sided microcapsules, 6% porous graphene framework, 4% octadecane / silica composite, 4% other regulators; other regulators include: 1% sodium citrate, 1% sodium hyaluronate, 1% polyether-modified silicone oil, 1% propyl gallate; The outer layer, middle layer, and inner layer are woven and compounded through a bio-based lyocell fiber yarn with 75 fiber strands to form a sandwich structure, obtaining an antibacterial and anti-ultraviolet bio-based lyocell fabric.

[0053] Example 5: Outer layer: A composite yarn with 120 fiber strands is made of 20% nylon-66 fibers and 80% by mass of the first functional fiber; among them, the first functional fiber: 81% bio-based lyocell fiber, 7.5% thermochromic zinc oxide microparticles, 4% nano silver / graphene hybrid material, 4.5% poly(methyl methacrylate)-poly(dimethyl siloxane) block copolymer, 3% crosslinking agent; Middle layer: A composite yarn with 120 fiber strands is made of 62% bio-based lyocell fiber, 13% temperature-sensitive microcapsules, 9% humidity-expanding gel, 4% thermally conductive graphene sheets, 12% other functional additives; other functional additives include: 4% chitosan quaternary ammonium salt, 3% phenyl salicylate, 3% triethyl citrate, 2% glutaraldehyde; Inner layer: A composite yarn with 120 fiber strands is made of 78% bio-based lyocell fiber, 13% Janus-type double-sided microcapsules, 7% porous graphene framework, 2% octadecane / silica composite, 3% other regulators; other regulators include: 1.5% sodium citrate, 0.5% glycerol, 0.5% polyether-modified silicone oil, 0.5% vitamin E; The outer layer, middle layer, and inner layer are woven and compounded through a bio-based lyocell fiber yarn with 90 fiber strands to form a sandwich structure, obtaining an antibacterial and anti-ultraviolet bio-based lyocell fabric.

[0054] Example 6: Outer layer: A composite yarn with 20% nylon-66 fibers and 80% by mass of the first functional fiber, with 120 fiber strands; among them, the first functional fiber: 84% bio-based lyocell fiber, 5.5% thermochromic zinc oxide microparticles, 4.5% nano silver / graphene hybrid material, 3% poly(methyl methacrylate)-poly(dimethylsiloxane) block copolymer, 3% crosslinking agent; Middle layer: 67% bio-based lyocell fiber, 11% temperature-sensitive microcapsules, 10% humidity-expanding gel, 4.5% thermally conductive graphene sheets, 7.5% other functional additives, made into a composite yarn with 120 fiber strands; other functional additives include: 2% chitosan quaternary ammonium salt, 2% phenyl salicylate, 1.5% triethyl citrate, 2% glutaraldehyde; Inner layer: 76% bio-based lyocell fiber, 11% Janus-type double-sided microcapsules, 6.5% porous graphene framework, 5.5% octadecane / silica composite, 4% other regulators, made into a composite yarn with 120 fiber strands; other regulators include: 1.5% sodium citrate, 1.5% glycerol, 0.5% polyether-modified silicone oil, 1.5% vitamin E; The outer layer, middle layer, and inner layer are woven and compounded through a bio-based lyocell fiber yarn with 60 fiber strands to form a sandwich structure, obtaining an antibacterial and anti-ultraviolet bio-based lyocell fabric.

[0055] Comparative Example 1: Outer layer: 100% bio-based lyocell fiber (no additives); Middle layer: 100% bio-based lyocell fiber (no additives); Inner layer: 100% bio-based lyocell fiber (no additives).

[0056] Comparative Example 2: Outer layer: 85% bio-based lyocell fiber, 15% nano silver / graphene hybrid material (without thermochromic zinc oxide microparticles and hydrophobic pore-switching polymers); Middle layer: 70% bio-based lyocell fiber, 30% temperature-sensitive microcapsules (without humidity-expanding gel and thermally conductive graphene sheets); Inner layer: 80% bio-based lyocell fiber, 20% phase change material (without Janus-type double-sided microcapsules and porous graphene frameworks).

[0057] Comparative Example 3: Outer layer: 80% bio-based lyocell fiber, 20% thermochromic zinc oxide microparticles (without nano silver / graphene hybrid material and hydrophobic pore-switching polymers); Middle layer: 60% bio-based lyocell fiber, 40% humidity-expanding gel (without temperature-sensitive microcapsules and thermally conductive graphene sheets); Inner layer: 70% bio-based lyocell fiber, 30% porous graphene framework (without Janus-type double-sided microcapsules and phase change materials).

[0058] Comparative Example 4: Outer layer: 85% bio-based lyocell fiber, 15% hydrophobic pore-switching polymer (without thermochromic zinc oxide particles and silver nanographene hybrid materials); Intermediate layer: 70% bio-based lyocell fiber, 30% thermally conductive graphene sheet (without temperature-sensitive microcapsules and humidity swelling gels); Inner layer: 80% bio-based lyocell fiber, 20% other regulators (without Janus-type double-sided microcapsules, porous graphene framework and phase change materials).

[0059] Experimental Example: 1. Antibacterial performance test: Evaluate the antibacterial effects of the fabrics in Examples 1-6 and Comparative Examples 1-4 at normal temperature and high temperature and high humidity conditions, and investigate their wash resistance.

[0060] Use Escherichia coli and Staphylococcus aureus as experimental strains. The specific experimental procedures are as follows: Cultivate Escherichia coli and Staphylococcus aureus to the logarithmic growth phase respectively. Prepare a bacterial suspension with a concentration of 1×10 6 CFU / mL.

[0061] Uniformly coat the bacterial suspension on the agar plate. Place a 6-mm diameter fabric sample disc in the center of the plate. Measure the diameter of the inhibition zone after incubation at 37°C for 24 hours.

[0062] Conduct 100 standard washes (refer to AATCC TM61-2006) for each fabric sample. Repeat the inhibition zone method test after washing. Record the initial inhibition rate and the inhibition rate after washing. The results are shown in Table 1.

[0063] Table 1. Antibacterial performance test results of the samples in Examples 1-6 and Comparative Examples 1-4:

[0064] The fabrics of Examples 1 to 6 showed antibacterial rates against Escherichia coli and Staphylococcus aureus exceeding 99.5% at normal temperature, demonstrating excellent antibacterial performance. When the environment changed to high temperature and high humidity (35°C / RH80%), the antibacterial rate further increased to 99.9%, which benefited from the synergistic effect of silver nanographene and tea tree essential oil.

[0065] Due to the lack of key components or the absence of optimized treatment, the antibacterial rates of the fabrics of Comparative Examples 1-4 were significantly lower than those of the Examples. Especially under high temperature and high humidity conditions, the antibacterial effect decreased significantly, indicating that these components are crucial for enhancing antibacterial performance.

[0066] Examples 1-6 still maintained an antibacterial efficiency of over 95% after 100 standard washes, showing good durability. For the fabrics of Comparative Examples 1-4, although they initially had a certain antibacterial ability, the antibacterial efficiency decreased significantly after multiple washes, demonstrating the importance of additives such as silver nanoparticles and their stability during long-term use.

[0067] 2. Temperature and humidity regulation performance test: Evaluate the release amount of cool feeling factor and air permeability of the fabric samples of Examples 1-6 and Comparative Examples 1-4 under different temperature and humidity conditions.

[0068] Use a thermogravimetric analyzer (TGA) to measure the release amount of the cool feeling factor at 32°C.

[0069] Use an air permeability tester (Gurley Densometer) to measure the change in air permeability when the humidity increases from 50% to 80%.

[0070] Use a differential scanning calorimeter (DSC) to measure the duration of the cool feeling. The results are shown in Table 2.

[0071] Table 2. Test results of the temperature and humidity regulation performance of the samples in Examples 1-6 and Comparative Examples 1-4:

[0072] At 32°C, the release amount of the cool feeling factor of Examples 1-6 reached about 0.35 mg / cm², which is 2.3 times that of traditional cool feeling fabrics. In contrast, the release amount of the cool feeling factor of the fabrics of Comparative Examples 1-4 was lower, indicating that the multi-layer structure design and the application of specific materials effectively improved the cool feeling effect.

[0073] When the humidity increased from 50% to 80%, the air permeability of the fabrics of the Examples increased by about 60%, far exceeding the 10% increase rate of the fixed mesh structure. This significantly improved air permeability helps to provide a more comfortable wearing experience in a humid environment. The increase in air permeability of the fabrics of the Comparative Examples was relatively small, indicating the key role of components such as humidity-expanded gels in regulating air permeability.

[0074] The synergy between the phase change material and graphene enabled the cool feeling duration of the fabrics of the Examples to reach up to 5 hours, which is 2.5 times that of similar products. The fabrics of the Comparative Examples did not achieve the same durability, showing the importance of the phase change material and the graphene framework.

[0075] 3. Mechanical property test: Evaluate the breaking strength, anti-ultraviolet performance (UPF value) and its durability of the fabric samples of Examples 1-6 and Comparative Examples 1-4.

[0076] Use a universal material testing machine (Instron) to measure the breaking strength of the fabric.

[0077] Use an ultraviolet-visible spectrophotometer (UV-VIS Spectrophotometer) to measure the UPF value of the fabric. Repeat the UPF value test after 100 standard washes, and the results are shown in Table 3.

[0078] Table 3. Test results of the mechanical properties of the samples in Examples 1-6 and Comparative Examples 1-4:

[0079] The graphene reinforcement enables the breaking strength of the fabric in the examples to reach over 45 MPa, significantly higher than that of the fabrics in the comparative examples, demonstrating the outstanding contribution of graphene in improving the material strength. After 100 washes, the retention rate of the UPF value of the fabric in the examples exceeds 90%, indicating its excellent anti-ultraviolet performance and durability. While the retention rate of the UPF value of the fabrics in the comparative examples is relatively low, reflecting the influence of the optimized formulation on the long-term performance of the fabric.

[0080] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they learn the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0081] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. An antibacterial and anti-ultraviolet bio-based lyocell fabric, characterized in that, Comprising a three-layer composite structure connected by bio-based Lyocell yarn: The outer layer is formed by weft knitting a composite yarn composed of 15 - 30% by mass of nylon-66 fiber and 70 - 85% by mass of a first functional fiber. Among them, the first functional fiber, by mass percentage, includes: 80% - 85% bio-based Lyocell fiber; 5% - 8% thermochromic zinc oxide microparticles; 3% - 5% nano silver / graphene hybrid material; 2% - 5% hydrophobic pore-switching polymer; 3% - 4% cross-linking agent; The middle layer is formed by weft knitting a second yarn composed of a second functional fiber. The second functional fiber, by mass percentage, includes: 60% - 70% bio-based Lyocell fiber; 10% - 15% temperature-sensitive microcapsules with a poly N-isopropylacrylamide shell and a core of menthol and tea tree essential oil; 8% - 12% humidity-expanding gel composed of an acrylic acid / sodium alginate interpenetrating network; 3% - 5% thermally conductive graphene sheets; 2% - 12% other functional additives; The inner layer is formed by weft knitting a third yarn composed of a third functional fiber. The third functional fiber, by mass percentage, includes: 70% - 80% bio-based Lyocell fiber; 10% - 15% Janus-type double-sided microcapsules with a hydrophilic side containing sodium alginate and a hydrophobic side containing polylactic acid; 5% - 10% porous graphene framework; 2% - 8% phase change material; 1% - 5% other regulators.

2. The antibacterial and anti-ultraviolet bio-based Lyocell fabric according to claim 1, wherein The particle size of the thermochromic zinc oxide microparticles is 20 - 100 nm; In the nano silver / graphene hybrid material, the loading amount of nano silver is 1% - 3%, and the thickness of the graphene sheets is 1 - 5 nm; The hydrophobic pore-switching polymer is a poly(methyl methacrylate)-poly(dimethylsiloxane) block copolymer, and when the humidity > 65%, the micropore diameter expands to 0.5 - 2 μm.

3. The antibacterial and anti-ultraviolet bio-based Lyocell fabric according to claim 1, wherein The thickness of the poly N-isopropylacrylamide shell of the temperature-sensitive microcapsules is 0.1 - 0.5 μm, and the mass ratio of the core materials of menthol and tea tree essential oil is 1:1 - 1:2; The swelling rate of the humidity-expanding gel is 150% - 250% when the relative humidity > 70%.

4. The antibacterial and anti-ultraviolet bio-based Lyocell fabric according to claim 1, wherein The particle size of the Janus-type double-sided microcapsules is 5 - 20 μm, and the mass ratio of the hydrophilic side to the hydrophobic side is 1:1 - 1:1.5; The porosity of the porous graphene framework is 60% - 80%, the pore diameter is 1 - 10 μm, and the pore expansion rate ≥ 50% when the humidity > 75%; The phase change material is an octadecane / silica composite.

5. The antibacterial and anti-ultraviolet bio-based lyocell fabric according to claim 1, characterized in that, The other functional additives include: 0% - 4% antibacterial enhancer, including at least one of chitosan quaternary ammonium salt and benzalkonium chloride; 0% - 3% anti-ultraviolet stabilizer, including at least one of phenyl salicylate and nano titanium dioxide; 1% - 3% plasticizer, including at least one of triethyl citrate and polyethylene glycol; The cross-linking agent is 1%-2%, including at least one of glutaraldehyde and epichlorohydrin.

6. The antibacterial and anti-ultraviolet bio-based lyocell fabric according to claim 1, wherein The other modulators include: pH adjuster 0-1.5%, including at least one of sodium lactate and sodium citrate; Moisturizer 0-2%, including at least one of sodium hyaluronate and glycerin; Antistatic agent 0-1%, including: polyether modified silicone oil; Antioxidant 0-1%, including at least one of vitamin E and propyl gallate.

7. A preparation method of an antibacterial and anti-ultraviolet bio-based lyocell fabric for preparing the antibacterial and anti-ultraviolet bio-based lyocell fabric according to any one of claims 1-6, characterized in that, The following steps are involved: Outer layer preparation: Bio-based lyocell fiber, thermochromic zinc oxide particles, nanosilver / graphene hybrid material, and hydrophobic pore switch polymer are mixed and melt-spun to form a first functional fiber; Compounding the first functional fiber with nylon-66 fiber to produce a composite yarn having 120-150 fibers; The composite yarn is made into an outer fabric by using a weft knitting process; Middle layer preparation: Temperature-sensitive microcapsules were prepared by interfacial polymerization; The bio-based lyocell fiber, humidity-swellable gel, thermally conductive graphene sheets and microcapsules are blended and wet-spun to produce a second functional fiber; preparing the second functional fiber into a second yarn having 120-150 fibers; The second yarn is made into an intermediate layer fabric by using a weft knitting process; Inner layer preparation: Janus-type double-sided microcapsules were prepared using microfluidic technology; Bio-based lyocell fiber, porous graphene framework, PCM and microcapsules are blended and electrospun to produce a third functional fiber; The third functional fiber is made into a third yarn having 120-150 fibers; The third yarn is made into an inner fabric by using a weft knitting process; Composite lamination: The outer layer, the middle layer and the inner layer are woven and composited by bio-based lyocell fiber yarns with 60-95 fiber roots to form a sandwich structure, thereby obtaining the antibacterial and anti-ultraviolet bio-based lyocell fabric.

8. The preparation method of the antibacterial and anti-ultraviolet bio-based lyocell fabric according to claim 7, characterized in that, In the preparation of the outer layer, the melt spinning temperature is 180-220° C. and the spinning speed is 500-800 m / min.

9. The preparation method of the antibacterial and anti-ultraviolet bio-based lyocell fabric according to claim 7, characterized in that, In the preparation of the intermediate layer, the coagulation bath of the wet spinning is a 10%-15% sodium sulfate aqueous solution, and the spinning stretch ratio is 1.5-2.

5.

10. The preparation method of the antibacterial and ultraviolet-resistant bio-based lyocell fabric according to claim 7, characterized in that, In the preparation of the inner layer, the voltage of electrospinning is 15-25 kV and the receiving distance is 10-20 cm.

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