Nano-zinc oxide modified antibacterial fiber and preparation method thereof

Abstract

The invention discloses a nano-zinc oxide modified antibacterial fiber and a preparation method thereof, and relates to the technical field of functional fiber materials. The prepared nano-zinc oxide modified antibacterial fiber is based on natural polysaccharide, natural vegetable gum and a self-prepared nano-zinc oxide compound, an electrostatic spinning process is adopted, the nano-zinc oxide modified antibacterial fiber has good antibacterial performance, anticoagulation performance, biocompatibility and physical performance and has emergency sterilization and long-acting antibacterial functions, most of materials of the nano-zinc oxide modified antibacterial fiber are from natural substances, and the nano-zinc oxide modified antibacterial fiber is environmentally friendly. The invention is green, healthy and non-toxic, and provides a green and safe solution for medical and hygienic products.

Description

Technical Field

[0001] The present invention relates to the technical field of functionalized fiber materials, in particular to a nano zinc oxide modified antibacterial fiber and a preparation method thereof. Background Art

[0002] Traditional antibacterial fibers mostly rely on chemical synthetic materials or direct loading of metal ions, and have bottlenecks such as poor biocompatibility and uncontrollable zinc ion release. In the existing technology, zinc oxide nanoparticles are easy to agglomerate in the polymer matrix, resulting in a decrease in antibacterial efficiency; at the same time, zinc ions are easily released explosively under physiological conditions, which may cause cytotoxicity, but in infection or other acidic environments, they cannot respond quickly due to the inertness of the carrier, making it difficult to achieve both efficient sterilization and long-term antibacterial effects. In addition, most processes rely on synthetic cross-linking agents or organic solvents, which goes against the trend of green manufacturing. Therefore, there is an urgent need to develop a fiber material that can achieve controlled release of zinc ions in response to the environment and has natural, green, and non-toxic ingredients, so as to provide efficient and green solutions for medical dressings, sanitary products, and personal protective equipment. Summary of the Invention

[0003] The purpose of the present invention is to provide a nano zinc oxide modified antibacterial fiber and a preparation method thereof, so as to solve the problems raised in the background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions: A method for preparing nano zinc oxide modified antibacterial fiber comprises the following steps: S1. Dissolving konjac glucomannan and natural plant gum in a citric acid buffer solution, stirring at 80-90° C. for 2-4 h, adding genipin, stirring at 50-60° C. for 1-2 h, adding a nano-zinc oxide complex, ultrasonically homogenizing for 30-60 min, degassing at room temperature, and adding a thickener solution to adjust the viscosity to 1800-2200 mPa·s to prepare a spinning gel; Furthermore, the natural plant gum is at least one of tianqing gum, tara gum, guar gum and fenugreek gum; Furthermore, the concentration of the citric acid buffer is 0.1 mol / L and the pH is 5.0; The dosage ratio of the konjac glucomannan, natural plant gum, citric acid buffer, genipin and nano zinc oxide complex is (2-3) g: (1-1.5) g: (100-150) mL: (0.05-0.1) g: (0.6-1) g; Furthermore, the thickener is one of sodium alginate, hydroxypropyl methylcellulose, and carboxymethyl cellulose; It should be noted that konjac glucomannan and natural plant gum form an interpenetrating network through hydrogen bonding and van der Waals forces in a weakly acidic environment. Genipin, as a natural cross-linking agent, reacts with the hydroxyl groups in konjac glucomannan and natural plant gum through its cyclopentane structure to form a stable covalent cross-linking network, further enhancing the three-dimensional stability of the gel. The nano-zinc oxide complex is evenly dispersed in the gel, and its surface amino and hydroxyl groups form a hydrogen bond network with the hydroxyl groups in konjac glucomannan and natural plant gum. The addition of the thickener adjusts the rheological properties of the spinning solution to ensure that the viscosity is adapted to the requirements of the electrospinning process, while enhancing the mechanical properties of the fiber after forming.

[0005] S2. The spinning gel is loaded into a syringe, connected to the nozzle container port, and spinning is started after setting process parameters. The spinning gel is vacuum dried and refrigerated for later use to obtain nano zinc oxide modified antibacterial fibers.

[0006] Furthermore, the process parameters are: temperature 25°C, humidity 25-35%, operating voltage 20-25kV, distance between the fixed needle collector and the high-speed orientation receiver 15-20cm, needle inner diameter 0.2-0.4mm, fixed speed of the high-speed orientation receiver 800-1000r / min, and flow rate 0.6-1mL / h.

[0007] Furthermore, the preparation steps of the nano zinc oxide composite are as follows: A1. Mix a tannic acid solution with a zinc nitrate solution, adjust the pH to 8.5-10.5, and ultrasonically react at 120-180°C for 4-6 hours. Collect the precipitate by centrifugation, wash, dry, and then treat with O2 plasma for 3-8 minutes. Disperse the precipitate in an 85-95% by mass ethanol solution. Add acetate buffer to adjust the pH to 4-6, add 3-aminopropyltriethoxysilane, reflux at 60°C for 2 hours, centrifuge, wash, and dry to obtain nano-zinc oxide. Furthermore, the concentration of the tannic acid solution is 0.05-0.1 mol / L; Furthermore, the concentration of the zinc nitrate solution is 0.05-0.1 mol / L; Furthermore, the concentration of the acetate buffer is 0.1 mol / L; Furthermore, the usage ratio of the tannic acid solution, zinc nitrate solution, ethanol solution and 3-aminopropyltriethoxysilane is (10-20) mL:100 mL:(100-150) mL:(1.25-1.6) g; It should be noted that tannic acid reacts with Zn 2+ The chelation and template effect of ZnO crystals regulate the anisotropic growth of ZnO crystals to form nano-ZnO particles with increased specific surface area; O2 plasma treatment introduces hydroxyl groups on the surface of nano-ZnO; 3-aminopropyltriethoxysilane modification introduces amino groups on the surface of nano-ZnO.

[0008] A2. Dissolve β-cyclodextrin in deionized water, stir at 80°C until transparent, add tea saponin, ultrasonicate at room temperature for 30 minutes, react with stirring at 60°C for 6-8 hours, centrifuge to obtain the supernatant, filter through a 0.2-0.25 μm filter membrane, add sodium polyacrylate, dialyze at 10 kDa, and freeze-dry to obtain a shell material powder; Furthermore, the dosage ratio of the β-cyclodextrin, deionized water, tea saponin and sodium polyacrylate is (5-10) g: (100-200) mL: (1-2) g: (0.1-0.3) g; A3. Disperse nano-zinc oxide, shell material powder and polyvinyl pyrrolidone in deionized water, adjust the pH to 4-5, ultrasonicate at 50°C for 30 minutes, stir for 3-4 hours, collect the precipitate by centrifugation, and freeze-dry to obtain a nano-zinc oxide composite; Furthermore, the dosage ratio of the nano zinc oxide, shell material powder, polyvinyl pyrrolidone and deionized water is (1-2) g: (1.5-3) g: (0.05-0.1) g: (100-200) mL.

[0009] It should be noted that nano-zinc oxide combines with the hydroxyl group of the shell material through amino groups, β-cyclodextrin anchors the triterpene hydrophobic group of tea saponin through hydrophobic cavities to form a core-shell structured nano-zinc oxide complex, and the cross-linked network of konjac glucomannan and plant gum limits the migration of the nano-complex through steric hindrance. The hydrogen bonding between the hydroxyl group of the shell material and konjac glucomannan and plant gum also participates in the fixation of the nano-zinc oxide complex. Sodium polyacrylate is used as a dispersant, and its carboxylate group prevents the shell material from agglomerating through electrostatic repulsion.

[0010] It should be noted that the carboxylate of sodium polyacrylate and Zn 2+ They bind to each other through coordination bonds under acidic conditions and partially dissociate to release Zn at physiological pH (7.35-7.45). 2+ The sugar chain hydroxyl groups of tea saponin are protonated under acidic conditions, which increases the hydrophilicity of the shell, promotes swelling, and accelerates the Zn 2+ Release, swelling is weakened at physiological pH, slowing down Zn 2+ Release. In an acidic environment, tea saponin swelling dominates and releases Zn rapidly. 2+ Sterilization; Under physiological pH environment, nano zinc oxide is inhibited from dissolving and releasing Zn 2+ , but sodium polyacrylate and Zn 2+ The coordination bonds between them dissociate to release some Zn 2+ , while electrostatic repulsion maintains dispersion and delays Zn 2+Release, extending the antibacterial effect. The shell of the nano zinc oxide complex restricts the migration of ZnO through a hydrophobic barrier and hydrogen bond network, reducing the mobility of ZnO. On the other hand, through physical, chemical and environmental pH response design, it provides a sustained-release carrier for zinc oxide, achieving both emergency sterilization and long-term antibacterial effects.

[0011] Compared with the prior art, the present invention has the following beneficial effects: The nano zinc oxide modified antibacterial fiber prepared by the present invention is based on a complex of natural polysaccharides, natural plant gums and nano zinc oxide, which enables the rapid release of zinc ions in an acidic environment to effectively kill bacteria, while maintaining a sustained release and long-lasting antibacterial effect in a physiological pH environment, and has both emergency response and continuous antibacterial functions; the materials of the nano zinc oxide modified antibacterial fiber prepared by the present invention are mostly derived from natural substances, are green, healthy, non-toxic, and have good biocompatibility. It is prepared by an electrospinning process, providing a green and safe solution for medical and sanitary products. DETAILED DESCRIPTION

[0012] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are within the scope of protection of the present invention.

[0013] Preparation method of nano zinc oxide composite: A1. Mix 20 mL of 0.1 mol / L tannic acid solution with 100 mL of 0.1 mol / L zinc nitrate solution, adjust the pH to 10, and ultrasonically react at 160°C for 4 h. Collect the precipitate by centrifugation, wash, dry, and treat with O2 plasma for 5 min. Disperse the precipitate in 150 mL of 90% ethanol solution, adjust the pH to 5 by adding 0.1 mol / L acetate buffer, add 1.45 g of 3-aminopropyltriethoxysilane, reflux at 60°C for 2 h, centrifuge, wash, and dry to obtain nano-zinc oxide. A2. Dissolve 10 g of β-cyclodextrin in 150 mL of deionized water, stir at 80°C until transparent, add 1.88 g of tea saponin, ultrasonicate at room temperature for 30 min, stir at 60°C for 8 h, centrifuge to obtain the supernatant, filter through a 0.25 μm filter membrane, add 0.2 g of sodium polyacrylate, dialyze at 10 kDa, and freeze-dry to obtain shell material powder; A3. Disperse 2 g of nano zinc oxide, 3 g of shell material powder and 0.1 g of polyvinyl pyrrolidone in 200 mL of deionized water, adjust the pH to 4.5, ultrasonically treat at 50°C for 30 min, stir for 4 h, collect the precipitate by centrifugation, and freeze-dry to obtain a nano zinc oxide complex.

[0014] Example 1 A method for preparing nano zinc oxide modified antibacterial fiber comprises the following steps: S1. 30 g of konjac glucomannan and 15 g of tara gum were dissolved in 1500 mL of 0.1 mol / L citric acid buffer at a pH of 5.0, and the mixture was stirred at 85° C. for 3 h. 1 g of genipin was added, and the mixture was stirred at 55° C. for 2 h. 100 g of nano-zinc oxide complex was added, and the mixture was ultrasonically homogenized for 45 min. After degassing at room temperature, 120 mL of 2% hydroxypropyl methylcellulose buffer was added to adjust the viscosity to 2000 mPa·s to prepare a spinning gel. S2. Load the spinning gel into the syringe, connect the nozzle container mouth, set the process parameters: temperature 25℃, humidity 30%, working voltage 22kV, fixed needle collector and high-speed orientation receiver distance 18cm, needle inner diameter 0.3mm, high-speed orientation receiver fixed speed 1000r / min, flow rate 0.8mL / h, start spinning, vacuum dry and refrigerate for use, to obtain nano zinc oxide modified antibacterial fiber.

[0015] Example 2 S1, 26.7g of konjac glucomannan and 13.3g of tara gum were dissolved in 1350mL of 0.1mol / L, pH 5.0 citric acid buffer, stirred at 85°C for 3h, 0.83g of genipin was added, stirred at 55°C for 2h, 86.7g of nano zinc oxide complex was added, ultrasonically homogenized for 45min, degassed at room temperature, and 110mL of 2% hydroxypropyl methylcellulose buffer was added to adjust the viscosity to 2000mPa·s to prepare a spinning gel; S2. Load the spinning gel into the syringe, connect the nozzle container mouth, set the process parameters: temperature 25℃, humidity 30%, working voltage 22kV, fixed needle collector and high-speed orientation receiver distance 18cm, needle inner diameter 0.3mm, high-speed orientation receiver fixed speed 1000r / min, flow rate 0.8mL / h, start spinning, vacuum dry and refrigerate for use, to obtain nano zinc oxide modified antibacterial fiber.

[0016] Example 3 S1, 23.3g of konjac glucomannan and 11.7g of tara gum were dissolved in 1150mL of 0.1mol / L, pH 5.0 citric acid buffer, stirred at 85°C for 3h, 0.67g of genipin was added, stirred at 55°C for 2h, 73.3g of nano zinc oxide complex was added, ultrasonically homogenized for 45min, degassed at room temperature, and 95mL of 2% hydroxypropyl methylcellulose buffer was added to adjust the viscosity to 2000mPa·s to prepare a spinning gel; S2. Load the spinning gel into the syringe, connect the nozzle container mouth, set the process parameters: temperature 25℃, humidity 30%, working voltage 22kV, fixed needle collector and high-speed orientation receiver distance 18cm, needle inner diameter 0.3mm, high-speed orientation receiver fixed speed 1000r / min, flow rate 0.8mL / h, start spinning, vacuum dry and refrigerate for use, to obtain nano zinc oxide modified antibacterial fiber.

[0017] Example 4 S1. Dissolve 20 g of konjac glucomannan and 10 g of tara gum in 1000 mL of 0.1 mol / L, pH 5.0 citric acid buffer, stir at 85 ° C for 3 h, add 0.5 g of genipin, stir at 55 ° C for 2 h, add 60 g of nano-zinc oxide complex, ultrasonically homogenize for 45 min, degas at room temperature, add 80 mL of 2% mass fraction of hydroxypropyl methylcellulose buffer to adjust the viscosity to 2000 mPa s, and prepare a spinning gel; S2. Load the spinning gel into the syringe, connect the nozzle container mouth, set the process parameters: temperature 25℃, humidity 30%, working voltage 22kV, fixed needle collector and high-speed orientation receiver distance 18cm, needle inner diameter 0.3mm, high-speed orientation receiver fixed speed 1000r / min, flow rate 0.8mL / h, start spinning, vacuum dry and refrigerate for use, to obtain nano zinc oxide modified antibacterial fiber.

[0018] Comparative Example 1 The difference between this comparative example and Example 1 is that nano zinc oxide is used instead of the nano zinc oxide composite.

[0019] Preparation method of nano zinc oxide: 20 mL of 0.1 mol / L tannic acid solution was mixed with 100 mL of 0.1 mol / L zinc nitrate solution, the pH was adjusted to 10, ultrasonically reacted at 160°C for 4 h, the precipitate was collected by centrifugation, washed, dried, and treated with O2 plasma for 5 min, dispersed in 150 mL of 90% ethanol solution, 0.1 mol / L acetate buffer was added to adjust the pH to 5, 1.45 g of 3-aminopropyltriethoxysilane was added, and the mixture was refluxed at 60°C for 2 h, centrifuged, washed, and dried to obtain nano-zinc oxide. Comparative Example 2 The difference between this comparative example and Example 1 is that the nano zinc oxide composite is not used, but commercially available nano zinc oxide is used.

[0020] Commercially available zinc oxide was purchased from Xi'an Xinfengda Pharmaceutical Excipients Co., Ltd., product number 100103.

[0021] test: 1. Antibacterial performance test: GB 15979-2002 Hygienic Standard for Disposable Sanitary Products: Antibacterial rate against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, hemolytic Streptococcus, mold, and Candida albicans; Table 1 Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Escherichia coli antibacterial rate (%) 99.8 99.5 98.7 97.3 85.2 82.6 Antibacterial rate of Pseudomonas aeruginosa (%) 99.5 99.1 98.3 96.8 83.7 80.4 Antibacterial rate of Staphylococcus aureus (%) 99.9 99.7 99.0 98.1 88.5 84.9 Antibacterial rate of hemolytic streptococci (%) 99.6 99.3 98.5 97.0 86.3 81.8 Mold antibacterial rate (%) 98.2 97.8 96.5 95.1 75.4 72.1 Candida albicans antibacterial rate (%) 97.5 96.9 95.2 93.7 70.6 68.3 2. Antibacterial long-term effect test: The samples were immersed in a blood protein-containing simulated solution (PBS buffer + 0.1% bovine serum albumin + 0.01% lysozyme + 0.05% fibrinogen, pH 7.4) for 7 days to test their antibacterial rate.

[0022] Table 2 Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Escherichia coli antibacterial rate (%) 95.3 93.8 90.5 88.7 62.4 58.9 Antibacterial rate of Staphylococcus aureus (%) 96.1 94.6 91.2 89.5 65.8 60.3 3. Anticoagulant adsorption performance: GB / T 16886.4-2017 Biological evaluation of medical devices Part 4: Selection of tests for interactions with blood BCA method (microprotein quantification).

[0023] Table 3 Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Fibrinogen adsorption capacity (μg / cm2) 3.2 3.8 4.5 5.0 12.7 15.3 IV. Cytotoxicity: GB / T 16886.5-2017 Biological Evaluation of Medical Devices Part 5: In Vitro Cytotoxicity Test Extraction conditions: 37°C, 24h, surface area / extract solution = 6cm 2 / mL, the fiber was cut into 1cm×1cm sheets with uniform thickness; cell type: L929 mouse fibroblasts, cell survival rate was assessed by MTT method, and cells with a survival rate ≥80% were considered non-toxic.

[0024] Table 4 Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Cell survival rate (%) 90.6 89.2 88.1 87.4 72.3 69.8 5. Skin irritation: GB / T 16886.10-2017 Biological evaluation of medical devices Part 10: Irritation and skin sensitization tests Extraction conditions: 37°C, 24h, surface area / extract solution = 6cm 2 / mL, the fibers were cut into 1cm×1cm sheets with uniform thickness; in vitro 3D skin model (EpiSkin) was used, and the survival rate was evaluated by MTT method after 30min of contact. A survival rate ≥70% was considered non-irritating.

[0025] Table 5 Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Cell survival rate (%) 88.6 87.2 85.1 83.4 72.3 69.8 6. Air permeability: ASTM D737-18(2023) Standard Test Method for Air Permeability of Textiles, pressure difference 100 Pa, test area 20 cm 2 , air permeability ≥100mm / s is high air permeability.

[0026] Table 6 Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Air permeability (mm / s) 135 142 148 155 120 115 7. Hygroscopicity: According to GB / T 9994-2018 Standard Moisture Regain of Textile Materials, balance at 20°C and 65% RH for 24 hours and calculate the moisture regain. A moisture regain ≤ 8% is considered excellent.

[0027] Table 7 Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Moisture regain (%) 6.8 7.1 7.2 7.4 9.3 10.1 8. Permeability: "GB / T 8939-2018 Sanitary Napkins (Pads)" simulated sweat penetration time ≤ 5s is excellent.

[0028] Table 8 Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Simulated sweat penetration time (s) 3.5 3.8 4.2 4.6 6.9 7.5 IX. Result Evaluation The nano zinc oxide modified antibacterial fiber prepared by the present invention has good antibacterial performance, anticoagulant performance, biocompatibility and physical properties, and has both emergency sterilization and long-term antibacterial functions.

[0029] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

[0030] Throughout the specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0031] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in similar ways. As long as they do not deviate from the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A method for preparing nano zinc oxide modified antibacterial fiber, characterized by: The following steps are involved: S1. Dissolving konjac glucomannan and natural plant gum in a citric acid buffer solution, stirring at 80-90° C. for 2-4 h, adding genipin, stirring at 50-60° C. for 1-2 h, adding a nano-zinc oxide complex, ultrasonically homogenizing for 30-60 min, degassing at room temperature, and adding a thickener solution to adjust the viscosity to 1800-2200 mPa·s to prepare a spinning gel; S2. The spinning gel is loaded into a syringe, connected to the nozzle container port, and spinning is started after setting process parameters. The spinning gel is vacuum dried and refrigerated for later use to obtain nano zinc oxide modified antibacterial fibers.

2. The method for preparing a nano zinc oxide modified antibacterial fiber according to claim 1, characterized in that: In step S1, the natural plant gum is at least one of tianqing gum, tara gum, guar gum and fenugreek gum.

3. The method for preparing a nano zinc oxide modified antibacterial fiber according to claim 1, characterized in that: In the step S1, the usage ratio of the konjac glucomannan, natural plant gum, citric acid buffer, genipin and nano zinc oxide complex is (2-3) g: (1-1.5) g: (100-150) mL: (0.05-0.1) g: (0.6-1) g.

4. The method for preparing a nano zinc oxide modified antibacterial fiber according to claim 1, characterized in that: In step S1, the thickener is one of sodium alginate, hydroxypropyl methylcellulose, and carboxymethyl cellulose.

5. The method for preparing a nano zinc oxide modified antibacterial fiber according to claim 1, characterized in that: In step S2, the process parameters are: temperature 25°C, humidity 25-35%, operating voltage 20-25 kV, the distance between the fixed needle collector and the high-speed orientation receiver is 15-20 cm, the inner diameter of the needle is 0.2-0.4 mm, the fixed speed of the high-speed orientation receiver is 800-1000 r / min, and the flow rate is 0.6-1 mL / h.

6. The method for preparing a nano zinc oxide modified antibacterial fiber according to claim 1, characterized in that: The preparation steps of the nano zinc oxide composite are as follows: A1. Mix a tannic acid solution with a zinc nitrate solution, adjust the pH to 8.5-10.5, and ultrasonically react at 120-180°C for 4-6 hours. Collect the precipitate by centrifugation, wash, dry, and then treat with O2 plasma for 3-8 minutes. Disperse the precipitate in an 85-95% by mass ethanol solution. Add acetate buffer to adjust the pH to 4-6, add 3-aminopropyltriethoxysilane, reflux at 60°C for 2 hours, centrifuge, wash, and dry to obtain nano-zinc oxide. The concentration of the tannic acid solution is 0.05-0.1 mol / L; the concentration of the zinc nitrate solution is 0.05-0.1 mol / L; A2. Dissolve β-cyclodextrin in deionized water, stir at 80°C until transparent, add tea saponin, ultrasonicate at room temperature for 30 minutes, react with stirring at 60°C for 6-8 hours, centrifuge to obtain the supernatant, filter through a 0.2-0.25 μm filter membrane, add sodium polyacrylate, dialyze at 10 kDa, and freeze-dry to obtain a shell material powder; A3. Disperse nano zinc oxide, shell material powder and polyvinyl pyrrolidone in deionized water, adjust the pH to 4-5, ultrasonically treat at 50°C for 30 minutes, stir for 3-4 hours, collect the precipitate by centrifugation, and freeze-dry to obtain a nano zinc oxide complex.

7. The method for preparing a nano zinc oxide modified antibacterial fiber according to claim 6, characterized in that: In step A1, the usage ratio of the tannic acid solution, zinc nitrate solution, ethanol solution and 3-aminopropyltriethoxysilane is (10-20) mL:100 mL:(100-150) mL:(1.25-1.6) g.

8. The method for preparing a nano zinc oxide modified antibacterial fiber according to claim 6, characterized in that: In step A2, the usage ratio of the β-cyclodextrin, deionized water, tea saponin and sodium polyacrylate is (5-10) g: (100-200) mL: (1-2) g: (0.1-0.3) g.

9. The method for preparing a nano zinc oxide modified antibacterial fiber according to claim 6, characterized in that: In step A3, the usage ratio of the nano zinc oxide, shell material powder, polyvinyl pyrrolidone and deionized water is (1-2) g: (1.5-3) g: (0.05-0.1) g: (100-200) mL.

10. A nano-zinc oxide-modified antibacterial fiber prepared by the method for preparing the nano-zinc oxide-modified antibacterial fiber according to any one of claims 1 to 9.