Gradient pore microcapsule, functional viscose fiber and preparation method and application thereof

Abstract

The invention discloses a gradient pore microcapsule, a functional viscose fiber and a preparation method and application of the functional viscose fiber, and belongs to the technical field of functional viscose fibers. The preparation method comprises the following steps: firstly, providing a gradient pore microcapsule which takes a porous adsorption material as an inner core, adsorbing functional components by the porous adsorption material, and coating the functional components by a wall material; the porous adsorption material comprises surface micropores and inner core mesopores. Secondly, providing a functional viscose fiber which is prepared by compounding the gradient pore microcapsules with a viscose spinning solution and then spinning by a wet method; the gradient pore microcapsules account for 3-8% of the total mass of the viscose spinning stock solution. Then, the invention provides a preparation method of the functional viscose fiber, which comprises the following steps: preparing a porous adsorption material-functional component compound, preparing microcapsules loaded with functional components, preparing a composite viscose spinning solution, and spinning. Finally, the functional viscose fibers are used for producing home textile products, adult pajamas and infant clothes. The requirements of industrial high-efficiency production and practical application are met.

Description

Technical Field

[0001] This invention specifically relates to a gradient pore microcapsule, a functional viscose fiber, its preparation method and application, and is particularly suitable for the stable loading and sustained release of hydrophobic active ingredients, belonging to the field of functional textile materials technology. Background Technology

[0002] Viscose fiber, due to its excellent moisture absorption, breathability, and wearing comfort, is widely used in the textile and apparel industry, such as in underwear and bedding. However, as people's living standards and demands for quality of life gradually improve, the functional requirements for textile materials are also increasing. For example, in summer, with more mosquitoes and insect bites causing skin irritation, the demand for textiles with mosquito-repellent properties is growing. Similarly, the declining sleep quality among modern people is becoming increasingly prominent, leading to a growing demand for textiles with sleep-inducing functions. Currently, most functional viscose fibers are designed for a single function, and different functional products often employ different production processes, resulting in complex processes and high costs. Therefore, developing a functional viscose fiber that can encompass multiple functions and expand the application of viscose fiber in high-end bedding, sleepwear, and infant clothing is a problem that needs to be addressed.

[0003] Existing functional viscose fibers still have the following drawbacks: First, the preparation technologies for different functional products are independent of each other. For example, mosquito-repellent viscose fiber generally adopts single-pore adsorption technology, while aromatic antibacterial multifunctional viscose fiber and sleep-inducing fiber generally adopt conventional microencapsulation technology (such as CN101935893A, CN103305953A, CN103225123A, etc.). The two types of functional viscose fibers do not share a common technology system, resulting in duplicated production equipment and high process costs. Second, for loading single functional ingredients, a single pore structure is often used, which makes it difficult to accurately adapt to the molecular size of different functional ingredients (e.g., DEET molecules have a size of 1.2-1.8 nm, while the main components of lavender essential oil have a molecular size of 2.5-4 nm). This leads to uneven adsorption and poor loading stability (e.g., after 5 washes, the mosquito repellency rate of mosquito repellent viscose fiber drops to below 50%; more than 60% of the sleep-inducing essential oil in sleep-inducing viscose fiber evaporates within 72 hours). Third, insufficient compatibility between functional components and viscose spinning solution system can easily lead to problems such as high spinning breakage rate (the spinning breakage rate of both mosquito repellent viscose fiber and sleep aid viscose fiber exceeds 10%) and easy loss of functional components.

[0004] Microencapsulation technology can improve the stability of functional ingredients, but existing microencapsulation technologies are mostly customized for single functional ingredients or composite modified additives (such as CN105113036A and CN110791830A), and have not formed a universal multifunctional system to adapt to different functional ingredients.

[0005] Therefore, there is an urgent need for a microcapsule technology and preparation process that can be applied to the different properties of various functional components and viscose spinning processes, and can ensure good load stability and high spinning efficiency of multifunctional viscose fiber products. Summary of the Invention

[0006] To address the problems of poor load stability and low spinning efficiency in existing multifunctional viscose fiber products, this invention proposes a gradient pore microcapsule, functional viscose fiber, its preparation method, and its applications. In this invention, gradient pore microcapsule technology is employed to provide a universally adaptable design for the different characteristics of various functional components and viscose spinning processes. This simplifies the production process while meeting diverse application needs (such as mosquito repellent, sleep aid, antibacterial, and fragrance), ensuring good load stability of functional components and high spinning efficiency, thus meeting the requirements of efficient industrial production and practical applications.

[0007] To achieve the above technical objectives, the following technical solution is proposed: The primary objective of this technical solution is to provide: a gradient pore microcapsule, comprising a porous adsorbent material, a functional component, and a wall material, wherein the gradient pore microcapsule has a porous adsorbent material as its core, and the functional component is adsorbed by the porous adsorbent material and then coated by the wall material to form the microcapsule. The mass ratio of porous adsorption material to functional component is 1:2 to 5, and the mass ratio of porous adsorption material to wall material is 1:3 to 8. The porous adsorbent material comprises surface micropores and core mesopores. The pore size of the surface micropores is 1.5–2 nm, and the pore size of the core mesopores is 5–30 nm. A gradient pore structure of surface micropores and core mesopores is employed, which can serve as a universal adsorbent structure and is adaptable to functional components of different molecular sizes, such as mosquito repellents and sleep-inducing agents, to meet the combined regulatory requirements of adsorption and release. In this porous adsorbent material, the pore size of the surface micropores can be matched with the molecular size (1.2–1.8 nm) of functional components such as mosquito repellents, forming a physical barrier layer and delaying the release of mosquito repellents; the pore size of the core mesopores can be matched with the molecular size (2.5–4 nm) of functional components such as essential oil sleep-inducing agents, providing ample storage space and delaying the volatilization of sleep-inducing essential oils, thus achieving effective adsorption and slow release of different functional components. The functional ingredient is a hydrophobic active ingredient.

[0008] Furthermore, the porous adsorbent material has a particle size of 50–200 nm and a specific surface area of ​​100–500 m². 2 / g, pore volume 0.3~1.2cm 3 / g. It can be adapted to the encapsulation requirements of microcapsules with different functions and subsequent spinning processes.

[0009] Furthermore, the porous adsorbent material is porous silica, porous activated carbon, or mesoporous molecular sieve.

[0010] Furthermore, the porous adsorbent material is a modified porous adsorbent material grafted with a silane coupling agent. The density of active groups on the surface of the modified porous adsorbent material is 1.0–2.5 mmol / g, and the grafting rate is controlled at 5–12%. Specifically, the silane coupling agent grafting modification is performed on the porous adsorbent material to further enhance the adsorption stability of different functional components and the compatibility of the microcapsules. This modification treatment can be used as a general modification treatment, effectively adapting to the chemical bonding requirements of different functional components such as mosquito repellent and sleep-inducing ingredients. The modification mechanism involves the following: the alkoxy groups in the silane coupling agent hydrolyze to form Si-OH, which undergoes dehydration condensation with the Si-OH on the surface of the porous adsorbent material to form Si-O-Si bonds. The grafted amino or epoxy active groups can form stable chemical bonds (hydrogen bonds + amide bonds) with the hydroxyl groups of mosquito repellent ingredients and the carboxyl groups of essential oil sleep-inducing ingredients, respectively, replacing traditional physical adsorption and reducing the desorption rate of various functional components by more than 80%. The grafting rate after modification is controlled at 5-12%. If the grafting rate is lower than 5%, stable bonds cannot be formed; if the grafting rate is higher than 12%, it will clog the pores, thereby reducing the loading capacity.

[0011] Furthermore, the silane coupling agent is γ-aminopropyltriethoxysilane or γ-glycidoxypropyltrimethoxysilane.

[0012] Furthermore, when the gradient pore microcapsules are mosquito-repellent microcapsules, the functional components include a mosquito-repellent functional component and auxiliary components. The mosquito-repellent functional component accounts for 40-70% of the total mass of the functional components, and the auxiliary components account for 30-60% of the total mass of the functional components. The mosquito-repellent functional component is DEET, and the auxiliary components are one or a mixture of any two or more of lemon eucalyptus oil, citronella oil, and menthol; or, the functional component is picaridin. These types of functional components have good mosquito-repellent effects, high safety, and are suitable for use with close-fitting textiles.

[0013] Furthermore, when the gradient pore microcapsules are sleep-inducing microcapsules, the functional components include one or a mixture of any two or more of lavender essential oil, chamomile essential oil, and sandalwood essential oil. Lavender essential oil, chamomile essential oil, and sandalwood essential oil have aromatic scents, and the sleep-inducing microcapsules can also be used as aromatic microcapsules; that is, the gradient pore microcapsules are microcapsules with both sleep-inducing and aromatic functions. Specifically, the purity of lavender essential oil, chamomile essential oil, and sandalwood essential oil is ≥95%, the linalool content in lavender essential oil is ≥35%, and the linalyl acetate content is ≥20%; the relative density at 25℃ is 0.890~0.920; the refractive index at 20℃ is 1.455~1.470; it is a colorless to pale yellow transparent liquid with a characteristic herbal floral scent. The chamomile essential oil contains ≥0.8% chamomile essential oil. The sandalwood essential oil contains ≥85% santalol. The essential oils containing these functional ingredients are natural and gentle, with significant sleep-inducing effects. They also have antibacterial properties, a pleasant aroma, and can enhance the comfort of using the fiber.

[0014] Furthermore, when the gradient pore microcapsules are antibacterial microcapsules, the functional component is an antibacterial active ingredient. The antibacterial active ingredient is tea tree oil or eucalyptus oil. Specifically, tea tree oil contains ≥30% terpinene-4-ol and ≤15% eucalyptol; its relative density at 25℃ is 0.870–0.890, and its refractive index at 20℃ is 1.470–1.480; it is a colorless to pale yellow transparent liquid with a characteristic herbal aroma; the total bacterial count is ≤100 CFU / g, and it contains no pathogenic bacteria. Eucalyptus oil contains ≥70% eucalyptol; its relative density at 25℃ is 0.900–0.920, and its refractive index at 20℃ is 1.458–1.470; it is a colorless to pale blue-green transparent liquid with a characteristic cool camphor aroma; the total bacterial count is ≤100 CFU / g, and it contains no pathogenic bacteria.

[0015] Furthermore, the wall material is chitosan, polylactic acid, or a gelatin-gum arabic blend. Specifically, the chitosan has a degree of deacetylation ≥85% and a viscosity of 100–300 mPa·s; the polylactic acid has a number-average molecular weight of 20,000–80,000; and the gelatin-gum arabic blend has a gelatin to gum arabic mass ratio of 1–2:1. This type of wall material exhibits good biocompatibility, biodegradability, and film-forming properties, effectively encapsulating the corresponding porous adsorbent material-functional component complex, reducing the volatilization and loss of various functional components. For example, sleep-inducing microcapsules use a gelatin-gum arabic blend with a denser film formation, effectively delaying essential oil volatilization; mosquito-repellent microcapsules use chitosan with better biocompatibility, suitable for close-fitting use. In addition, the selection of this type of wall material also ensures its compatibility with viscose spinning systems. Different functional components can use the same or different wall materials. When different wall materials are used, the compatibility and film-forming properties of the wall material with the corresponding functional components must be ensured. The film thickness of the wall material is controlled to be 50-150 nm.

[0016] Furthermore, the gradient pore microcapsules have a particle size of 200–500 nm. This is compatible with the spinning pores of viscose fibers (500–800 nm), effectively preventing spinning blockage while ensuring a soft fiber feel (friction coefficient ≤ 0.35).

[0017] The second objective of this technical solution is to provide: a functional viscose fiber, which is prepared by wet spinning after being compounded with gradient pore microcapsules and viscose spinning solution; the gradient pore microcapsules account for 3-8% of the total mass of the viscose spinning solution. This amount of addition can ensure the functional effect and mechanical properties of the viscose fiber. If the addition amount is too low, the functional effect will be insufficient; if the addition amount is too high, the fiber strength will decrease. The product specifications of the functional viscose fiber include: breaking strength ≥2.1cN / dtex, functional retention rate ≥70% after 50 washes, and breaking elongation: 15-20%.

[0018] Furthermore, the functional viscose fibers include mosquito-repellent viscose fibers, sleep-inducing viscose fibers, antibacterial viscose fibers, and aromatic viscose fibers.

[0019] The third objective of this technical solution is to provide a method for preparing functional viscose fibers, comprising the following steps: S1: Preparation of porous adsorbent material-functional component complex The modified porous adsorbent material (ensuring consistency in the general system) is added to an organic solvent and ultrasonically dispersed for 30–60 min to ensure uniform dispersion and increase the contact area with the functional component. Then, the functional component is added and stirred at 150–200 r / min at 30–45 °C for 2–4 h to ensure full adsorption of the functional component. The organic solvent is removed by vacuum distillation to obtain the porous adsorbent material-functional component complex. The volume (L) to mass (kg) ratio of the organic solvent to the functional component is 5–8:1. This limitation ensures the complete dissolution of the functional component while preventing pore blockage of the porous adsorbent material. The organic solvent is ethanol or ethyl acetate, both with a purity ≥99.5%. Regarding dispersion time, if it is less than 30 minutes, the modified porous adsorbent material will be unevenly dispersed, resulting in a component adsorption deviation of >15%; if it is more than 60 minutes, the gradient pore structure in the modified porous adsorbent material will be destroyed, and the surface micropore collapse rate will be >20%. Regarding adsorption temperature, if it is below 30℃, the adsorption reaction rate of the functional components is slow, and the reaction needs at least 8 hours to complete; if it is above 45℃, the stability of the functional components decreases, and they are prone to volatilization, resulting in a volatilization loss of more than 8%. The stirring rate can increase the loading of functional components and reduce the deviation of adsorption uniformity. S2: Preparation of microcapsules loaded with functional ingredients S2.1: Add the porous adsorbent material-mosquito repellent compound obtained in step S1 to deionized water and ultrasonically disperse for 10-20 minutes to form a suspension; A wall material solution is prepared by dissolving the wall material in deionized water. S2.2: The wall material solution is added to the suspension at a rate of 0.06–0.3 L / h, the pH is adjusted to 4.0–6.0, and the mixture is stirred at a constant temperature of 50–60 °C for 1–2 h to promote uniform deposition of the wall material on the surface of the composite; a crosslinking agent is added, and stirring is continued for 0.5–1 h to enhance the degree of crosslinking of the wall material and improve the stability of the microcapsules; the microcapsules are centrifuged, washed, and freeze-dried (to avoid the volatilization of functional components caused by high-temperature drying) to obtain microcapsules loaded with functional components; Microcapsules loaded with functional ingredients were dissolved in deionized water to obtain a microcapsule solution with a mass fraction of 12-20%. The crosslinking agent is either glutaraldehyde or sodium tripolyphosphate, with glutaraldehyde concentration of 25-50% and sodium tripolyphosphate purity ≥98%. The amount of crosslinking agent added is 5-15% of the total mass of the wall material. The crosslinking agent reacts with the wall material to form a stable wall material structure, improving the washability and stability of the microcapsules. The amount of crosslinking agent added helps avoid localized over-crosslinking that could lead to wall material embrittlement. This pH value effectively ensures the film density of the wall material and the stability of functional components. For example, when pH < 4.0, the wall material is prone to precipitation; when pH > 6.0, the stability of mosquito repellent ingredients decreases, and essential oil functional components are easily oxidized. S3: Preparation of composite viscose spinning solution The viscose spinning solution is added to a reaction vessel and heated to 40–50°C. Then, the microcapsule aqueous solution obtained in step S2.2 is added at a rate of 0.18–0.9 L / h, and the mixture is stirred for 1–2 h to ensure that the microcapsules are uniformly dispersed in the viscose spinning solution. After grinding and degassing treatment (degassing treatment can remove air bubbles in the spinning solution and avoid problems such as yarn breakage and fuzz during the spinning process), a composite viscose spinning solution is obtained. The viscose spinning solution has a viscosity of 500–1000 mPa·s, a cellulose content of 8–12%, and a sodium hydroxide content of 5–8%. The mass ratio of gradient pore microcapsules to viscose spinning solution is 3–8:92. The grinding media particle size is 0.5–1 mm, the grinding time is 30–60 min, and the particle size of the microcapsule aggregates after grinding is ≤1 μm. The degassing treatment pressure is -0.08–-0.1 MPa, and the degassing time is 60–90 min. S4: Spinning The composite viscose spinning solution obtained in step S3 is spun using a wet spinning method, and then solidified, stretched, washed and dried in a coagulation bath to obtain functional viscose fibers. The spinning speed is 50-100 m / min, and the stretching ratio is 1.2-1.8 times. The washing process adopts a three-stage water washing method. The water temperature of the first stage water washing is 30-40℃, the water temperature of the second stage water washing is 40-50℃, and the water temperature of the third stage water washing is 50-60℃. The washing time of each stage water washing is 10-15 min. The drying temperature is 80–100℃, the drying time is 60–120 min, and the moisture content of the dried functional viscose fiber is controlled to be 8–12%. The coagulation bath allows for rapid coagulation of the composite viscose spinning solution, forming fibers with a uniform structure. The coagulation bath comprises 8–12% sulfuric acid, 15–20% sodium sulfate, and 1–3% zinc sulfate (by mass). Zinc sulfate acts as a cross-linking agent, reacting with cellulose molecules to further improve the fiber's mechanical properties. The coagulation bath temperature is 45–55°C. This temperature setting ensures both efficient spinning coagulation and the stability of the functional components within the gradient-pore microcapsules. For example, below 45°C, the coagulation rate is too slow, leading to microcapsule migration and aggregation; above 55°C, the wall material degrades (degradation rate > 12%), affecting the stability of the functional components, etc.

[0020] The fourth objective of this technical solution is to provide: the use of the above-mentioned functional viscose fibers in the production of home textile products, adult sleepwear and infant clothing.

[0021] The beneficial technical effects of adopting this technical solution are as follows: I. In this invention, the problems of independent and cumbersome preparation processes for different functional (mosquito repellent, sleep aid) viscose fibers in existing technologies are addressed. The single-pore loading structure cannot adequately adapt to the molecular sizes of different functional components, leading to poor loading stability. Insufficient compatibility between functional components and the spinning system results in high spinning breakage rates and easy loss of functional components. By employing porous adsorption materials (including surface micropores and core mesopores, with surface micropores having a pore size of 1.5–2 nm and core mesopores having a pore size of 5–30 nm) to adsorb functional components, the shared gradient pore structure can better adapt to the molecular sizes of different functional components, achieving independent and effective adsorption of different functional components. Furthermore, the modification treatment and wall material system can simultaneously ensure the loading stability of different functional components, reducing the desorption rate of functional components by more than 80%. In addition, the process parameters can be adapted to the preparation requirements of different functional products, significantly simplifying the production process and reducing equipment investment. Specifically: Second, in this invention, by controlling various conditions in the preparation process (such as the type of wall material and the amount of microcapsule added), the efficacy of viscose fiber products is ensured, as well as the sustainability and stability of the production process. For example, viscose fiber products with mosquito-repellent function can use chitosan, which has better biocompatibility, as the wall material, to meet the needs of close-fitting wear; viscose fiber products with sleep-inducing function can use gelatin-gum arabic compound, which forms a denser film, to enhance the sustained-release effect of essential oils. In addition, the loading of multiple functional components does not interfere with each other, so as to meet the needs of application scenarios; Third, this invention also solves the compatibility problem between microcapsules with different functions and viscose spinning solutions. In this invention, the compatibility between the microcapsule solution and the spinning solution is significantly improved, and the dispersion uniformity is also improved. The resulting functional viscose fibers have a breaking strength of over 2.3 cN / dtex and a breaking elongation of over 17%, exhibiting both good functional effects and excellent mechanical properties, meeting the requirements for use in textiles, apparel, and bedding. Fourth, the preparation process involved in this invention is simple and controllable, which can significantly improve production efficiency and reduce costs, making it suitable for large-scale industrial production. It also covers multiple functions such as mosquito repellent and sleep aid, and can be applied to various fields such as summer pajamas, outdoor clothing, high-end bedding, and infant clothing. Combined with its excellent functional durability and safety (no skin irritation), it has good market application prospects. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the gradient pore microcapsule with mosquito-repellent function in Example 1; Figure 2 The image shows the microstructure of the viscose fiber with mosquito-repellent function in Example 5 (A is the cross section, B is the longitudinal section). Figure 3 This is a partial test report of the viscose fiber with mosquito-repellent function in Example 5. Figure 4 This is a partial test report for the viscose fiber with antibacterial function in Example 5, where pure viscose fiber specifically refers to fiber that does not contain other fibers. Figure 5 This is part of the test report for the antibacterial viscose fiber in Example 5. Detailed Implementation

[0023] The technical solutions in the embodiments are described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] The technical solutions in the embodiments are described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] When conducting performance tests on functional viscose fibers (breaking strength, breaking elongation, mosquito repellency, and retention rate of sleep-inducing components), the following testing methods are used: I. Fracture Strength Test Test standard: GB / T 14337-2008 "Test Method for Tensile Properties of Synthetic Short Fibers"; Testing equipment: Single-fiber electronic strength tester, model YG001A; Test method: 1. Sampling: Randomly select at least 30 single fibers from the finished fiber and cut them to a length of 20 mm (fixed length system). 2. Humidity conditioning: Place in an environment with a temperature of 20±2℃ and a relative humidity of 65±4% for more than 24 hours; 3. Tensile test: Clamp both ends of the fiber in the tensile testing machine fixture and stretch it at a constant rate until it breaks. Record the maximum load at which it breaks. Test conditions: 1. Clamping distance: 20 mm; 2. Tensile rate: 10 mm / min; 3. Pretension: 0.05 cN / dtex; 4. Environmental conditions: Temperature 20±2℃, relative humidity 65±4%; Breaking strength (cN / dtex) = Breaking load (cN) ÷ Fiber linear density (dtex).

[0026] II. Elongation at break test Basis: B / T 14337-2008 "Test Method for Tensile Properties of Synthetic Short Fibers"; Testing equipment: Single-fiber electronic strength tester, model YG001A; Test method: 1. Sampling: Randomly select at least 30 single fibers from the finished fiber and cut them to a length of 20 mm (fixed length system). 2. Humidity conditioning: Place in an environment with a temperature of 20±2℃ and a relative humidity of 65±4% for more than 24 hours; 3. Tensioning: Clamp both ends of the fiber on the tensile testing machine fixture and stretch it at a constant rate until it breaks. Record the elongation at the time of fiber breakage and calculate the elongation at break. Test conditions: 1. Clamping distance: 20 mm; 2. Tensile rate: 10 mm / min; 3. Pretension: 0.05 cN / dtex; 4. Environmental conditions: Temperature 20±2℃, relative humidity 65±4%; Elongation at break (%) = [(Clamping distance at break - initial clamping distance) ÷ initial clamping distance] × 100%.

[0027] III. Mosquito Repellency Test Basis: GB / T 30127-2013 "Test and Evaluation of Mosquito Repellency Performance of Textiles"; Testing equipment: mosquito breeding box, standard test chamber, artificial arm membrane device, stereomicroscope; Test method: Arm membrane method; 1. Sample preparation: The functional fibers are spun into 20 cm × 20 cm fabric samples and equilibrated to constant weight; 2. Arm membrane method: The sample is fixed on the surface of an artificial arm membrane and placed in a test chamber containing 100 test insects (Culex pipiens pallens) for 2 hours; 3. Record the number of mosquito bites and calculate the repellency rate; Test conditions: 1. Test insects: Pale Culex pipiens adult mosquitoes that have not yet fed on blood, 3-5 days after emergence; half male and half female. 2. Environmental conditions: Temperature 25±2℃, relative humidity 60±10%, light cycle 12h light / 12h dark; 3. Blank control: Unmodified viscose fiber fabric was used; The mosquito repellency rate (%) was calculated as follows: [(Number of bites in the blank group - Number of bites in the sample group) ÷ Number of bites in the blank group] × 100%.

[0028] IV. Mosquito repellency test (after 50 washes) Test standard: GB / T 30127-2013 "Test and evaluation of mosquito repellency performance of textiles"; Testing equipment: Insect cages, mosquito breeding boxes, artificial climate chambers, electronic balances, and standard washing test machines (compliant with GB / T 8629 requirements); Test method: 1. Perform 50 standard washes on the functional viscose fiber fabric according to the method specified in GB / T 8629, and dry it to constant weight after washing; 2. Select three 5cm×5cm washed fabric samples, and set up an unwashed sample of the same type of fabric as a blank control group. 3. The test shall be conducted in accordance with the human arm mosquito trapping method (or cylinder method) in GB / T 30127-2013: the sample shall be fixed in the test device, a quantitative number of test insects (female Culex pipiens pallens that have not sucked blood 3-5 days after emergence) shall be introduced, and the number of mosquito bites or landings within 2 hours shall be recorded. 4. Calculate the mosquito repellency rate: Mosquito repellency rate (%) = (Number of mosquitoes landing in the blank control group - Number of mosquitoes landing in the sample group) / Number of mosquitoes landing in the blank control group × 100%; Test conditions: 1. Artificial climate chamber parameters: temperature (25±2)℃, relative humidity (65±5)%, light cycle 12h light / 12h darkness; 2. Number of test insects: 20-30 mosquitoes were introduced into each test group; 3. Testing environment: A laboratory environment free from wind and direct sunlight; 4. Washing conditions: Detergent concentration 0.2%, liquor ratio 1:50, washing temperature (40±2)℃, change water once every 5 washes, drying temperature (60±5)℃.

[0029] V. Retention rate test of sleep-inducing essential oil after 72 hours Test standard: GB / T 2910.1-2009 "Quantitative Chemical Analysis of Textiles - Part 1: General Test Rules" (refer to the method for pretreatment and constant weight determination of fiber samples). GB / T 18886-2019 "Determination of Adsorption Properties of Textiles" (Refer to the framework for extraction and quantification of microcapsule-loaded materials in fibers). ISO 18363-2:2018 "Determination of Vitamin E and Sterols by High Performance Liquid Chromatography of Animal and Vegetable Oils - Part 2: Reversed-Phase High Performance Liquid Chromatography" (Applicable to the quantitative analysis of essential oil components after demulsification of microcapsule wall materials); FZ / T 50030-2016 "Test Methods for Dyeing with Reactive Dyes for Viscose Fibers" (Refer to the requirements for pretreatment and stability control of viscose fiber samples); Test equipment: High performance liquid chromatograph (HPLC, equipped with a UV detector or diode array detector); High-speed centrifuge (speed ≥10000 r / min, equipped with 50 mL centrifuge tubes); Ultrasonic cell disruptor (power adjustable, 100-500 W, used for demulsification of microcapsule wall materials). Analytical balance (accuracy 0.0001g); Constant temperature and humidity chamber (compliant with GB / T 6529 requirements, temperature control accuracy ±1℃, humidity control accuracy ±2%). Vacuum drying oven (temperature range 20~80℃, vacuum degree ≤10kPa); Glassware such as stoppered conical flasks (50 mL), pipettes (1 mL, 5 mL), volumetric flasks (25 mL), 0.22 μm organic filter membranes and filters; Test method: ① Sample preparation and initial loading determination (1) Three parallel samples of 2g each (denoted as A1, A2, A3) were randomly cut from the viscose fibers with sleep-inducing function prepared by wet spinning. Blank viscose fibers of the same batch without sleep-inducing ingredients were also taken as control samples (denoted as C1, C2, C3). (2) Place the sample in a vacuum drying oven and dry it at 40°C to constant weight (the difference between two weighings is ≤0.0005 g), and record the constant weight of the sample m1; (3) Initial loading determination: Weigh 1g of the constant-weight sample, cut it into small pieces, place it in a 50 mL stoppered conical flask, add 30 mL of anhydrous ethanol (chromatographic grade), place it in an ultrasonic cell disruptor, set the power to 300 W and the ultrasonic time to 20 min, disrupt the microcapsule wall material and extract the essential oil; transfer the extract to a centrifuge tube, centrifuge at 10000 r / min for 15 min, take the supernatant and filter it through a 0.22 μm filter membrane, determine the essential oil concentration by HPLC, and calculate the initial loading of essential oil in the fiber, m. 初 (mg / g fiber).

[0030] ② 72-hour constant temperature and humidity treatment (1) Place the remaining constant weight samples A1, A2 and A3 into a constant temperature and humidity chamber and let them stand for 72 h under the set test conditions; (2) After 72 h, the sample was taken out and placed in a vacuum drying oven at 40℃ to dry to constant weight. The mass m2 was recorded. ③ Extraction and determination of essential oil residue after 72 h (1) Weigh 1g of the constant weight sample after 72h treatment, and repeat the ultrasonic crushing, centrifugation and filtration operations in step ① (3) when determining the initial load to obtain the test liquid; (2) HPLC quantitative analysis: Prepare a series of standard solutions of sleep-inducing essential oils at various concentrations (e.g., 0.02 mg / mL, 0.05 mg / mL, 0.1 mg / mL, 0.2 mg / mL, 0.5 mg / mL), and establish a standard curve (peak area-concentration linear relationship); inject the test solution into the HPLC, and calculate the residual concentration C of the essential oil according to the standard curve. 残 (mg / mL); (3) Calculate the amount of essential oil residue per unit mass of fiber: m 残 =C 残 ×V×f / ms Where: V is the final volume of the extract (mL); f is the extraction recovery correction coefficient (determined by blank spiking experiment, with a value of 0.92~0.98); m s The mass of the sample to be tested is (g). ④ Retention rate calculation Sleep-inducing essential oil microcapsules 72h retention rate (%) = m 残 / m 初 ×100%, take the average retention rate of 3 parallel samples as the final result, and retain the result to 1 decimal place; Test conditions: Temperature and humidity chamber parameters: temperature (25±2)℃, relative humidity (60±5)%, no light, airflow velocity ≤0.1m / s; Microcapsule demulsification and extraction conditions: ultrasonic cell disruptor power 300 W, ultrasonic time 20 min; extraction solvent was anhydrous ethanol (chromatographic grade), material-to-liquid ratio 1 g fiber : 30 mL solvent; high-speed centrifuge speed 10000 r / min, centrifugation time 15 min; HPLC analysis conditions: C18 reversed-phase column (250 mm × 4.6 mm, 5 μm); mobile phase: methanol-water (85:15 v / v); flow rate: 1.0 mL / min; column temperature: 30℃; detection wavelength: 275 nm (adjusted according to the type of essential oil, such as 275 nm for lavender essential oil); injection volume: 10 μL. Constant weight conditions for samples: vacuum drying oven temperature 40℃, vacuum degree 5 kPa, constant weight judgment criterion is the difference between two weighings ≤0.0005 g; Parallel sample requirements: Three parallel tests should be conducted on samples from the same batch, and the relative standard deviation (RSD) of the retention rate test results should be ≤5%.

[0031] Example 1 This embodiment provides: a gradient pore microcapsule with mosquito-repellent function. The gradient pore microcapsule includes a porous adsorbent material, DEET, lemon eucalyptus oil, and chitosan. The porous adsorbent material serves as the core, DEET and lemon eucalyptus oil are the functional components, and chitosan is the wall material. DEET and lemon eucalyptus oil are adsorbed by the porous adsorbent material and then coated with chitosan to form the microcapsule (e.g., Figure 1 (as shown) The mass ratio of the porous adsorbent material to the total mass of DEET and lemon eucalyptus oil is 1:2, and the mass ratio of the porous adsorbent material to chitosan is 1:3. The porous adsorbent material includes surface micropores and core mesopores. The pore size of the surface micropores is 1.5-2 nm, and the pore size of the core mesopores is 5-15 nm.

[0032] Among them, the particle size of the gradient pore microcapsules is 200-300 nm.

[0033] Porous adsorbent material: Porous silica modified with γ-aminopropyltriethoxysilane (grafting rate 8%). The porous silica particle size is 50–100 nm, and the specific surface area is 300 m² / s. 2 / g, pore volume 0.6cm 3 / g.

[0034] Functional ingredients: DEET is the active mosquito repellent ingredient, accounting for 60% of the total mass of functional ingredients; lemon eucalyptus oil is the auxiliary mosquito repellent ingredient, accounting for 40% of the total mass of functional ingredients.

[0035] Chitosan: Deacetylation degree ≥85%, viscosity 100~300mPa·s, and the thickness of the chitosan film is controlled between 50~150nm.

[0036] Example 2 This embodiment provides: a gradient pore microcapsule with mosquito repellent function. The gradient pore microcapsule includes a porous adsorbent material, picaridin and chitosan. The porous adsorbent material is the core, picaridin is the functional component and chitosan is the wall material. The picaridin is adsorbed by the porous adsorbent material and then coated by chitosan to form the microcapsule. The mass ratio of the porous adsorbent material to picaridin is 1:5, and the mass ratio of the porous adsorbent material to chitosan is 1:8. The porous adsorbent material includes surface micropores and core mesopores. The pore size of the surface micropores is 1.5–2 nm, and the pore size of the core mesopores is 10–20 nm.

[0037] Among them, the particle size of the gradient pore microcapsules is 300-400 nm.

[0038] Porous adsorption material: Porous activated carbon modified with γ-glycidyl etheroxypropyltrimethoxysilane (grafting rate 6%). The porous activated carbon has a particle size of 100–200 nm and a specific surface area of ​​400 m². 2 / g, pore volume 0.9cm 3 / g.

[0039] Functional ingredient: Picaridin, purity 99.2%, boiling point 289℃; Chitosan: Deacetylation degree ≥85%, viscosity 100~300mPa·s, and the thickness of the chitosan film is controlled between 50~150nm.

[0040] Example 3 This embodiment provides: a gradient pore microcapsule with a sleep-inducing function. The gradient pore microcapsule includes a porous adsorbent material, lavender essential oil, and a gelatin-gum arabic compound. The porous adsorbent material is used as the core, lavender essential oil is used as the functional component, and the gelatin-gum arabic compound is used as the wall material. The lavender essential oil is adsorbed by the porous adsorbent material and then coated by the gelatin-gum arabic compound to form the microcapsule. The mass ratio of the porous adsorbent material to the lavender essential oil is 1:3, and the mass ratio of the porous adsorbent material to the gelatin-gum arabic compound is 1:5. The porous adsorbent material includes surface micropores and core mesopores. The pore size of the surface micropores is 1.5-2 nm, and the pore size of the core mesopores is 5-30 nm.

[0041] Among them, the particle size of the gradient pore microcapsules is 200-500 nm.

[0042] Porous adsorbent material: a mesoporous molecular sieve modified with γ-glycidoxypropyltrimethoxysilane (grafting rate 10%). The mesoporous molecular sieve has a particle size of 50–200 nm and a specific surface area of ​​100–500 m². 2 / g, pore volume 0.3~1.2cm 3 / g.

[0043] Lavender essential oil: purity ≥95%, linalool content ≥35% in lavender essential oil.

[0044] Gelatin-gum arabic compound: Gelatin to gum arabic mass ratio 1:1.

[0045] Example 4 This embodiment provides: a gradient pore microcapsule with a sleep-inducing function. The gradient pore microcapsule includes a porous adsorbent material, chamomile essential oil, sandalwood essential oil, and a gelatin-gum arabic compound. The porous adsorbent material is used as the core, chamomile essential oil and sandalwood essential oil are used as functional components, and the gelatin-gum arabic compound is used as the wall material. The chamomile essential oil and sandalwood essential oil are adsorbed by the porous adsorbent material and then coated by the gelatin-gum arabic compound to form the microcapsule. The mass ratio of the porous adsorbent material to the total mass of chamomile essential oil and sandalwood essential oil is 1:5, and the mass ratio of the porous adsorbent material to the gelatin-gum arabic compound is 1:7. The porous adsorbent material includes surface micropores and core mesopores. The pore size of the surface micropores is 1.5-2 nm, and the pore size of the core mesopores is 5-30 nm.

[0046] Among them, the particle size of the gradient pore microcapsules is 200-500 nm.

[0047] Porous adsorption material: Porous activated carbon modified with γ-aminopropyltriethoxysilane (grafting rate 11%). Mesoporous molecular sieves have a particle size of 50–200 nm and a specific surface area of ​​100–500 m².2 / g, pore volume 0.3~1.2cm 3 / g.

[0048] Functional ingredients: Chamomile essential oil and sandalwood essential oil are both ≥95% pure, with chamomile essential oil containing ≥0.8% azadirachtin and sandalwood essential oil containing ≥85% santalol.

[0049] Gelatin-gum arabic compound: Gelatin to gum arabic mass ratio 2:1.

[0050] Example 5 Based on Example 1, this example provides: a viscose fiber with mosquito-repellent function, which is prepared by wet spinning after compounding the obtained gradient pore microcapsules with viscose spinning solution; the gradient pore microcapsules account for 5% of the total mass of the viscose spinning solution. Electron microscopy scanning and detection were performed, and the results are as follows... Figure 2-3 As shown.

[0051] The product specifications for viscose fiber with mosquito-repellent function include: breaking strength of 2.19 cN / dtex, mosquito-repellent effect of Grade A, and breaking elongation of 18%.

[0052] Example 6 Based on Example 2, this example provides: a viscose fiber with mosquito-repellent function, which is prepared by wet spinning after compounding the obtained gradient pore microcapsules with viscose spinning solution; the gradient pore microcapsules account for 4% of the total mass of the viscose spinning solution; The product specifications for viscose fiber with mosquito-repellent function include: breaking strength of 2.21 cN / dtex, mosquito-repellent effect reaching Grade A, and breaking elongation of 17%.

[0053] Example 7 Based on Example 3, this example provides: a viscose fiber with a sleep-inducing function, which is prepared by wet spinning after combining the obtained gradient pore microcapsules with viscose spinning solution; the gradient pore microcapsules account for 3% of the total mass of the viscose spinning solution; The product specifications for viscose fiber with sleep-inducing function include: breaking strength 2.18 cN / dtex and breaking elongation 17%.

[0054] Example 8 Based on Example 4, this example provides: a viscose fiber with a sleep-inducing function, which is prepared by wet spinning after combining the obtained gradient pore microcapsules with viscose spinning solution; the gradient pore microcapsules account for 8% of the total mass of the viscose spinning solution; The product specifications of viscose fiber with sleep-inducing function include: breaking strength 2.21 cN / dtex and breaking elongation 18%.

[0055] Example 9 Based on Example 5, this example provides: a method for preparing viscose fiber with mosquito-repellent function, comprising the following steps: (1) Preparation of porous adsorbent material-mosquito repellent component complex Take 10g of modified porous silica (surface micropores with a pore size of 1.5–2nm, core mesopores with a pore size of 5–15nm, particle size of 50–100nm, and specific surface area of ​​300m²). 2 / g, pore volume 0.6cm 3 / g; modified with γ-aminopropyltriethoxysilane, grafting rate 8%), added to 50mL of ethanol (purity 99.7%), and ultrasonically dispersed for 40min (power 200W, frequency 40kHz); mosquito repellent functional ingredients (18g DEET and 12g lemon eucalyptus oil, DEET purity 98.5%) were added, and the mixture was stirred at 180r / min at 40℃ for 3h; ethanol was removed by vacuum distillation (pressure -0.09MPa, temperature 50℃) to obtain a porous adsorbent material-mosquito repellent component complex with a functional component loading of 64%; (2) Preparation of microcapsules loaded with mosquito-repellent ingredients Add the porous adsorbent material-mosquito repellent compound obtained in step (1) to 100 mL of deionized water and ultrasonically disperse for 30 min to form a suspension; take 10 g of chitosan and dissolve it in 100 mL of deionized water (add a small amount of acetic acid to adjust the dissolution) to prepare a wall material solution; The wall material solution was added to the suspension, the pH was adjusted to 5.0, and the mixture was stirred at 55°C for 1.5 h. 1 g of glutaraldehyde (10% of the chitosan mass) was added, and the mixture was stirred for another 0.8 h. Then, the mixture was centrifuged, washed three times with deionized water, and freeze-dried to obtain microcapsules loaded with mosquito-repellent components (particle size 200-300 nm). (3) Preparation of composite viscose spinning solution The microcapsules obtained in step (2) were prepared as an aqueous solution with a mass fraction of 20% and slowly added to the viscose spinning solution (viscosity 800 mPa·s, cellulose content 10%). After stirring for 1.5 h, the composite viscose spinning solution was obtained by grinding and degassing. The mass ratio of the microcapsules loaded with mosquito-repellent ingredients to the viscose spinning solution was 5:95. (4) Spinning and forming The composite viscose spinning solution is wet-spun through a spinning machine, and then coagulated in a coagulation bath, stretched (stretch ratio 1.5 times), washed and dried to obtain viscose fiber with mosquito repellent function. In the coagulation bath, the mass fraction of sulfuric acid is 10%, the mass fraction of sodium sulfate is 18%, the mass fraction of zinc sulfate is 2%, and the coagulation bath temperature is 50℃.

[0056] Example 10 Based on Example 6, this example provides: a method for preparing viscose fiber with mosquito-repellent function, comprising the following steps: (1) Preparation of porous adsorbent material-mosquito repellent component complex Take 8g of modified porous activated carbon (surface micropores with a pore size of 1.5–2 nm, core mesopores with a pore size of 10–20 nm, particle size of 100–200 nm, and specific surface area of ​​400 m²). 2 / g, pore volume 0.9cm 3 / g; modified with γ-glycidyl etheroxypropyltrimethoxysilane (grafting rate 6%), added to 40 mL of ethyl acetate (purity 99.5%), and ultrasonically dispersed for 30 min (power 200 W, frequency 40 kHz); 16 g of picaridin (purity 99.2%, boiling point 289 °C) was added, and the mixture was stirred at 35 °C at a speed of 150 r / min for 4 h; ethyl acetate was removed by vacuum distillation (pressure -0.09 MPa, temperature 60 °C) to obtain a porous adsorbent-mosquito repellent complex with a functional component loading of 66%; (2) Preparation of microcapsules loaded with mosquito-repellent ingredients Add the porous adsorbent material-mosquito repellent component complex obtained in step (1) to 80 mL of deionized water and ultrasonically disperse for 25 min to form a suspension; take 48 g of chitosan and dissolve it in 160 mL of deionized water to prepare a wall material solution; The wall material solution was added to the suspension, the pH was adjusted to 4.5, and the mixture was stirred at 50°C for 2 hours. 1.2 g of sodium tripolyphosphate (10% of the chitosan mass) was added, and the mixture was stirred for another 1 hour. Then, the mixture was centrifuged, washed three times with deionized water, and freeze-dried to obtain microcapsules loaded with mosquito-repellent components (particle size 300-400 nm). (3) Preparation of composite viscose spinning solution The microcapsules obtained in step (2) were prepared into an aqueous solution with a mass fraction of 18%, and slowly added to the viscose spinning solution. After stirring for 1.5 hours, the composite viscose spinning solution was obtained by grinding and degassing. The mass ratio of the microcapsules loaded with mosquito-repellent ingredients to the viscose spinning solution was 4:96. (4) Spinning and forming The composite viscose spinning solution is wet-spun through a spinning machine, and then coagulated in a coagulation bath, stretched (stretch ratio 1.4 times), washed and dried to obtain viscose fiber with mosquito repellent function. In the coagulation bath, the mass fraction of sulfuric acid is 8%, the mass fraction of sodium sulfate is 15%, the mass fraction of zinc sulfate is 1%, and the coagulation bath temperature is 45℃.

[0057] Example 11 This embodiment provides a method for preparing viscose fiber with a sleep-inducing function, comprising the following steps: (1) Preparation of porous adsorbent-sedation component complex Take 8g of modified porous activated carbon (surface micropores with a pore size of 1.5–2 nm, core mesopores with a pore size of 10–20 nm, particle size of 100–200 nm, and specific surface area of ​​400 m²). 2 / g, pore volume 0.9cm 3 / g; modified with γ-glycidyl etheroxypropyltrimethoxysilane (grafting rate 6%), added to 40 mL of ethyl acetate (purity 99.5%), and ultrasonically dispersed for 30 min (power 200 W, frequency 40 kHz); 12 g of chamomile essential oil (purity 95.5%, azadirachtin content 1.0%) was added, and the mixture was stirred at 35 °C at a speed of 150 r / min for 4 h; ethyl acetate was removed by vacuum distillation (pressure -0.09 MPa, temperature 60 °C) to obtain a porous adsorbent-sleep-inducing component complex; (2) Preparation of microcapsules loaded with sleep-inducing ingredients Add the porous adsorbent-sedation component complex obtained in step (1) to 80 mL of deionized water and ultrasonically disperse for 25 min to form a suspension; take 48 g of polylactic acid and dissolve it in 160 mL of deionized water to prepare a wall material solution; The wall material solution was added to the suspension, the pH was adjusted to 4.5, and the mixture was stirred at 50°C for 2 hours. 1.2 g of sodium tripolyphosphate (10% of the mass of polylactic acid) was added, and the mixture was stirred for another 1 hour. Then, the mixture was centrifuged, washed three times with deionized water, and freeze-dried to obtain microcapsules (particle size 300-400 nm) loaded with sleep-inducing ingredients. (3) Preparation of composite viscose spinning solution The microcapsules obtained in step (2) were prepared as an aqueous solution with a mass fraction of 15%, and slowly added to the viscose spinning solution (viscosity 800 mPa·s, cellulose content 10%). After stirring for 1.5 h, the composite viscose spinning solution was obtained by grinding and degassing. The mass ratio of microcapsules loaded with sleep-inducing ingredients to viscose spinning solution was 3:97; (4) Spinning and forming The composite viscose spinning solution is wet-spun through a spinning machine, and then coagulated in a coagulation bath, stretched (stretch ratio 1.4 times), washed and dried to obtain viscose fiber with a sleep-inducing function. In the coagulation bath, the mass fraction of sulfuric acid is 8%, the mass fraction of sodium sulfate is 15%, the mass fraction of zinc sulfate is 1%, and the coagulation bath temperature is 45℃.

[0058] Example 12 This embodiment provides a method for preparing viscose fiber with a sleep-inducing function, comprising the following steps: (1) Preparation of porous adsorbent-sedation component complex Take 12g of modified mesoporous molecular sieve (surface micropores with a pore size of 1.5–2nm, core mesopores with a pore size of 20–30nm, particle size of 80–150nm, specific surface area of ​​500m²). 2 / g, pore volume 1.1cm 3 / g; modified with γ-aminopropyltriethoxysilane, grafting rate 10%), added to 60mL of ethyl acetate (purity 99.5%), and ultrasonically dispersed for 60min (power 200W, frequency 40kHz); 19.2g of sandalwood essential oil (purity 95%, santalol content 88%) was added, and stirred at 45℃ with a rotation speed of 200r / min for 2h; ethyl acetate was removed by vacuum distillation (pressure -0.09MPa, temperature 60℃) to obtain a porous adsorbent-sleep-inducing component complex; (2) Preparation of microcapsules loaded with sleep-inducing ingredients Add the porous adsorbent-sedation component complex obtained in step (1) to 120 mL of deionized water and ultrasonically disperse for 35 min to form a suspension; take 96 g of gelatin-gum arabic compound (gelatin to gum arabic mass ratio 1:1) and dissolve it in 240 mL of deionized water to prepare a wall material solution; The wall material solution was added to the suspension, the pH was adjusted to 5.5, and the mixture was stirred at 60°C for 1 hour. 7.2 g of glutaraldehyde (15% of the mass of the gelatin-gum arabic compound) was added, and the mixture was stirred for another 0.5 hours. Then, the mixture was centrifuged, washed three times with deionized water, and freeze-dried to obtain microcapsules (particle size 400-500 nm) loaded with sleep-inducing components. (3) Preparation of composite viscose spinning solution The microcapsules obtained in step (2) were prepared into an aqueous solution with a mass fraction of 10%, and slowly added to the viscose spinning solution. After stirring for 1.5 hours, the composite viscose spinning solution was obtained by grinding and degassing. The mass ratio of microcapsules loaded with sleep-inducing ingredients to viscose spinning solution is 5:95; (4) Spinning and forming The composite viscose spinning solution is wet-spun through a spinning machine, and then coagulated in a coagulation bath, stretched (stretch ratio 1.6 times), washed and dried to obtain viscose fiber with a sleep-inducing function. In the coagulation bath, the mass fraction of sulfuric acid is 12%, the mass fraction of sodium sulfate is 20%, the mass fraction of zinc sulfate is 3%, and the coagulation bath temperature is 55℃.

[0059] Example 13 This embodiment provides a method for preparing viscose fiber with antibacterial function, comprising the following steps: (1) Preparation of porous adsorbent-antibacterial component complex Take 12g of modified mesoporous molecular sieve (surface micropores with a pore size of 1.5–2nm, core mesopores with a pore size of 20–30nm, particle size of 80–150nm, specific surface area of ​​500m²). 2 / g, pore volume 1.1cm 3 / g; modified with γ-aminopropyltriethoxysilane, grafting rate 10%), added to 60mL of ethyl acetate (purity 99.5%), and ultrasonically dispersed for 60min (power 200W, frequency 40kHz); 24g of tea tree essential oil (purity 95%) was added, and stirred at 45℃ and 200r / min for 2h; ethyl acetate was removed by vacuum distillation (pressure -0.09MPa, temperature 60℃) to obtain a porous adsorbent-antibacterial component complex; (2) Preparation of microcapsules loaded with antibacterial components Add the porous adsorbent-antibacterial complex obtained in step (1) to 120 mL of deionized water and ultrasonically disperse for 35 min to form a suspension; take 96 g of gelatin-gum arabic compound (gelatin to gum arabic mass ratio 2:1) and dissolve it in 240 mL of deionized water to prepare a wall material solution; The wall material solution was added to the suspension, the pH was adjusted to 5.5, and the mixture was stirred at 60°C for 1 hour. 7.2 g of glutaraldehyde (15% of the mass of the gelatin-gum arabic compound) was added, and the mixture was stirred for another 0.5 hours. Then, the mixture was centrifuged, washed three times with deionized water, and freeze-dried to obtain microcapsules loaded with antibacterial components (particle size 400-500 nm). (3) Preparation of composite viscose spinning solution The microcapsules obtained in step (2) were prepared into an aqueous solution with a mass fraction of 17%, and slowly added to the viscose spinning solution. After stirring for 1.5 hours, the composite viscose spinning solution was obtained by grinding and degassing. The mass ratio of microcapsules loaded with antibacterial components to viscose spinning solution is 6:94; (4) Spinning and forming The composite viscose spinning solution is wet-spun through a spinning machine, and then coagulated in a coagulation bath, stretched (stretch ratio 1.6 times), washed and dried to obtain viscose fiber with antibacterial function. In the coagulation bath, the mass fraction of sulfuric acid is 10%, the mass fraction of sodium sulfate is 18%, the mass fraction of zinc sulfate is 2%, and the coagulation bath temperature is 55℃.

[0060] The antibacterial properties of the obtained viscose fibers with antibacterial function were tested, and the results are as follows: Figure 4-5 As shown.

[0061] Comparative Example 1 Based on Example 9, this comparative example uses a porous material with a single pore size to prepare viscose fibers with mosquito-repellent function. Specifically, 18g of DEET (98.5% purity) was directly mixed with 10g of porous silica with a single pore size (2nm pore size, 50-100nm particle size, specific surface area 300m² / g), and ultrasonically dispersed. The remaining steps were the same as in Example 9. Finally, viscose fibers with mosquito-repellent function were obtained.

[0062] Comparative Example 2 Based on Example 11, this comparative example uses a porous material with a single pore size to prepare viscose fibers with sleep-inducing properties. Specifically, 12g of chamomile essential oil (95.5% purity, 1.0% azadirachtin content) was directly mixed with 8g of porous activated carbon with a single pore size (2nm pore size, 100-200nm particle size, specific surface area 400m² / g), and ultrasonically dispersed. The remaining steps were the same as in Example 11. Finally, viscose fibers with sleep-inducing properties were obtained.

[0063] Based on Examples 9-12 and Comparative Examples 1-2, the performance of the obtained viscose fibers with mosquito repellent function and viscose fibers with sleep-inducing function was tested (breaking strength, breaking elongation, mosquito repellent rate, and retention rate of sleep-inducing components). The results are shown in Table 1 below.

[0064] Table 1 Performance Test Results

[0065] As shown in the table above, both the mosquito-repellent and sleep-inducing viscose fiber products possess excellent mechanical properties, with breaking strengths exceeding 2.3 cN / dtex and elongation at break exceeding 17%, meeting the requirements for Class I products in GB / T14464-2017 "Viscose Fiber". Specifically, the mosquito-repellent viscose fiber product exhibits a mosquito-repelling rate of over 70% against Aedes aegypti within 2 hours, reaching the Class A standard of GB / T 30126-2013 "Test and Evaluation of Mosquito Repellent Performance of Textiles"; after 50 washes, the mosquito-repelling rate remains above 70%, far superior to mosquito-repellent viscose fibers prepared using existing technology (using porous materials with single pores). The sleep-inducing viscose fiber product retains over 91% of its sleep-inducing essential oil after 72 hours.

[0066] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A gradient pore microcapsule, characterized in that, It includes porous adsorption materials, functional components and wall materials. Among them, the gradient pore microcapsules have a porous adsorption material as the core, and the functional components are adsorbed by the porous adsorption material and then coated by the wall material to form the microcapsules. The gradient pore microcapsules have a particle size of 200–500 nm; The mass ratio of porous adsorption material to functional component is 1:2 to 5, and the mass ratio of porous adsorption material to wall material is 1:3 to 8. Porous adsorption materials include surface micropores and core mesopores. The pore size of the surface micropores is 1.5–2 nm, and the pore size of the core mesopores is 5–30 nm. The functional ingredient is a hydrophobic active ingredient.

2. The gradient pore microcapsule according to claim 1, characterized in that, The porous adsorbent material has a particle size of 50–200 nm and a specific surface area of ​​100–500 m². 2 / g, pore volume 0.3~1.2cm 3 / g.

3. The gradient pore microcapsule according to claim 1, characterized in that, The porous adsorbent material is a modified porous adsorbent material that has been grafted with a silane coupling agent. The density of active groups on the surface of the modified porous adsorbent material is 1.0 to 2.5 mmol / g, and the grafting rate of the modified porous adsorbent material is 5 to 12%.

4. The gradient pore microcapsule according to claim 1, characterized in that, When the gradient pore microcapsule is a mosquito-repellent microcapsule, the functional components include a mosquito-repellent functional component and auxiliary components. The mosquito-repellent functional component accounts for 40-70% of the total mass of the functional components, and the auxiliary components account for 30-60% of the total mass of the functional components. The mosquito-repellent functional component is DEET, and the auxiliary components are one or a mixture of any two or more of lemon eucalyptus oil, citronella oil, and menthol. Alternatively, the functional component is picaridin.

5. The gradient pore microcapsule according to claim 1, characterized in that, When the gradient pore microcapsules are sleep-inducing microcapsules, the functional ingredients include one or a mixture of any two or more of lavender essential oil, chamomile essential oil, and sandalwood essential oil; the purity of lavender essential oil, chamomile essential oil, and sandalwood essential oil is ≥95%; Among them, lavender essential oil contains ≥35% linalool and ≥20% linalyl acetate; its relative density at 25℃ is 0.890~0.920; its refractive index at 20℃ is 1.455~1.470; it is a colorless to pale yellow transparent liquid with a characteristic herbal floral fragrance; Chamomile essential oil contains ≥0.8% chamomile azadirachtin; Sandalwood essential oil contains ≥85% santalol.

6. The gradient pore microcapsule according to claim 1, characterized in that, When the gradient pore microcapsule is an antibacterial microcapsule, the functional component is an antibacterial active ingredient, which is tea tree oil or eucalyptus oil. The tea tree essential oil contains ≥30% terpinene-4-ol and ≤15% eucalyptol; its relative density at 25℃ is 0.870~0.890, and its refractive index at 20℃ is 1.470~1.480; it is a colorless to pale yellow transparent liquid with a characteristic herbal aroma; the total bacterial count is ≤100 CFU / g, and it is free of pathogenic bacteria. Eucalyptus oil contains ≥70% eucalyptol; its relative density at 25℃ is 0.900~0.920, and its refractive index at 20℃ is 1.458~1.470; it is a colorless to pale blue-green transparent liquid with a characteristic cool camphor aroma; the total bacterial count is ≤100 CFU / g, and it is free of pathogenic bacteria.

7. The gradient pore microcapsule according to claim 1, characterized in that, The wall material is chitosan, polylactic acid, or a gelatin-gum arabic compound; Among them, the degree of deacetylation of chitosan is ≥85%, and the viscosity is 100~300mPa·s; Polylactic acid has a number-average molecular weight of 20,000–80,000. In gelatin-gum arabic blends, the mass ratio of gelatin to gum arabic is 1-2:1; The thickness of the wall material film is controlled to be 50–150 nm.

8. A functional viscose fiber, characterized in that, The product is prepared by wet spinning after compounding the gradient pore microcapsules according to any one of claims 1-7 with viscose spinning solution; the gradient pore microcapsules account for 3-8% of the total mass of the viscose spinning solution. The product specifications of the functional viscose fiber include: breaking strength ≥2.1cN / dtex, functional retention rate ≥70% after 50 washes, and breaking elongation: 15-20%.

9. The functional viscose fiber according to claim 8, characterized in that, The functional viscose fibers include mosquito-repellent viscose fibers, sleep-inducing viscose fibers, antibacterial viscose fibers, and aromatic viscose fibers.

10. A method for preparing functional viscose fiber, characterized in that, The preparation method of the functional viscose fiber according to claim 8 or 9 includes the following steps: S1: Preparation of porous adsorbent material-functional component complex The modified porous adsorbent material was added to an organic solvent and dispersed evenly; the functional component was added, and the mixture was stirred at a constant temperature of 150-200 r / min for 2-4 h at 30-45 °C; then, the porous adsorbent material-functional component complex was obtained by vacuum distillation. S2: Preparation of microcapsules loaded with functional ingredients S2.1: Add the porous adsorbent material-mosquito repellent compound obtained in step S1 to deionized water, disperse it evenly, and form a suspension; A wall material solution is prepared by dissolving the wall material in deionized water. S2.2: Add the wall material solution to the suspension, adjust the pH to 4.0-6.0, and stir at 50-60℃ for 1-2 hours; add the crosslinking agent and continue stirring for 0.5-1 hour; centrifuge, wash and freeze dry to obtain microcapsules loaded with functional components; Microcapsules loaded with functional ingredients were dissolved in deionized water to obtain a microcapsule aqueous solution with a mass fraction of 12-20%. S3: Preparation of composite viscose spinning solution The viscose spinning solution is added to the reaction vessel and heated to 40-50°C; the microcapsule aqueous solution obtained in step S2.2 is added and mixed evenly; then, after grinding and degassing treatment, the composite viscose spinning solution is obtained. S4: Spinning The composite viscose spinning solution obtained in step S3 is spun using a wet spinning method, and then solidified, stretched, washed and dried in a coagulation bath to obtain functional viscose fibers.

11. The functional viscose fiber of claim 8 or 9, or the functional viscose fiber produced by the preparation method of claim 10, is used to produce home textile products, adult sleepwear, and infant clothing.

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