An antibacterial chitosan nano-silver fiber fabric

Abstract

This invention relates to a manufacturing process for antibacterial chitosan nano-silver fiber fabric. The fabric preparation process includes: modifying chitosan with quaternary ammonium salts, then preparing chitosan-modified soybean protein fibers via impregnation; chemically plating silver onto the surface of the chitosan-modified fibers using a silver mirror reaction; and finally preparing the nano-silver fiber fabric: fiber pretreatment → cotton mixing → opening and cleaning → carding → drawing → roving → spinning → winding → warping → sizing → heddle threading → weaving. The product of this invention has environmentally friendly, antibacterial, deodorizing, and health-promoting effects.

Description

Technical Field

[0001] This invention belongs to the field of healthy fiber fabrics, and relates to an antibacterial chitosan nano-silver fiber fabric and its processing method. Background Technology

[0002] In the context of the era of "big health" and the process of consumption upgrading, clothing and health have gradually become key areas of focus. Currently, in addition to aesthetic considerations, people are increasingly emphasizing the functionality of textiles, such as health care, skin protection, antibacterial and antiviral protection, and safety and comfort. Among these, antibacterial properties are of particular concern due to the skin-friendly requirements of fabrics. Ordinary textiles do not inhibit bacteria or fungi, and the chemical structure and porous physical shape of textile fibers make them easy carriers for microbial growth. Furthermore, when the human body comes into direct contact with textiles, sweat, sebum, and other secretions become nutrients for microorganisms, not only causing odors and reducing comfort but, more importantly, adversely affecting human health. Therefore, developing antibacterial fiber fabrics is essential, allowing people to experience beauty and pleasure in their clothing while enjoying a healthy and comfortable lifestyle, which is of great significance to people's health.

[0003] Chitosan, a product of chitin deacetylation, is widely used in medicine, healthcare, environmental protection, and textile printing and dyeing due to its excellent biocompatibility, non-toxicity, and superior antibacterial properties. The antibacterial function of chitosan arises from the interaction between the positive charge in its molecules and the negative charge on the cell membrane of microorganisms, leading to the leakage of bacterial proteins and other cellular components, thus producing an antibacterial effect. It can also stimulate the resistance of many tissues. Using chitosan as a fabric finishing agent not only has antibacterial effects against Escherichia coli, Staphylococcus aureus, and Candida albicans, but also improves the insulation properties of fabrics, enhancing their abrasion resistance, colorfastness, and comfort, making it a widely used antibacterial material in the textile industry. However, under neutral or alkaline conditions, the antibacterial effect of chitosan is poor due to charge neutralization, limiting its application range. Therefore, developing a chitosan-based fiber fabric with antibacterial properties in various environments is of great significance for human health.

[0004] Silver-based antibacterial agents are among the most studied and widely used antibacterial agents. They have a broad antibacterial spectrum, are safe to use, non-irritating to the skin, and do not decompose. The bactericidal effect of silver mainly comes from its high affinity for sulfur or phosphoproteins, which allows silver to efficiently bind to and destroy the protein, enzyme, and nucleic acid structures of microorganisms. However, its application is limited due to its poor loading capacity and easy migration. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide an antibacterial chitosan nano-silver fiber fabric and its preparation method, so as to enhance the antibacterial function of the chitosan fiber fabric and broaden its application range.

[0006] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows:

[0007] An antibacterial chitosan nano-silver fiber fabric is provided. The fabric is composed of quaternary ammonium salt modified chitosan, silver ions and soybean protein fiber. The quaternary ammonium salt modified chitosan is attached to the soybean protein fiber. The silver ions are adsorbed on the surface of the quaternary ammonium salt modified chitosan and are chemically reduced to nano-silver and deposited on the fiber surface. The fiber fabric has antibacterial properties and the antibacterial rate against Escherichia coli and Staphylococcus aureus reaches 100%.

[0008] This invention develops an antibacterial chitosan nano-silver fiber fabric and its preparation method for fiber fabrics, ultimately yielding an antibacterial chitosan nano-silver fiber fabric with strong antibacterial properties and stable chemical properties.

[0009] As a preferred embodiment, the above-mentioned antibacterial chitosan nano-silver fiber fabric is characterized by: placing 2,3-epoxypropyltrimethylammonium chloride and chitosan in a four-necked flask, and adding a certain amount of isopropanol, wherein the mass ratio of the three raw materials is 1:5:10. The four-necked flask is placed in a constant temperature water bath at 85 ℃ and stirred thoroughly for 12 h. After stirring, the flask is removed. Finally, the reaction solution is thoroughly cooled, washed, vacuum filtered, purified, and dried to obtain the solid product, quaternary ammonium salt modified chitosan.

[0010] The chitosan mentioned herein has a molecular weight of 2.0 × 10⁻⁶. 4 The degree of deacetylation is 92.6%.

[0011] As a preferred embodiment, a certain amount of quaternary ammonium salt modified chitosan is dissolved in an aqueous solution of 1 g / L acetic acid to prepare a modified chitosan solution with a mass concentration of 4 g / L. Then, 4 wt% citric acid, 4 wt% sodium hypophosphite and 0.2 wt% triethanolamine (TEA) are added to prepare a chitosan treatment solution with a bath ratio of 1:50.

[0012] Preferably, the soybean protein fiber is ultrasonically treated in acetone for 20 min, followed by ultrasonic treatment in anhydrous ethanol for 10 min, and finally ultrasonic treatment in deionized water for 10 min. After removing the fiber, it is dried at 70 °C. The dried soybean fiber is then placed in a 0.1 mol / L sodium hydroxide solution and soaked at 50–70 °C for 30–60 min. After soaking, it is removed, washed with water until neutral, and then dried for later use.

[0013] The soybean protein fiber has a protein content higher than 20%, a breaking strength of 4.1 cN / dtex, a breaking elongation of ±3%, and a moisture regain of 7.5%. Acetone ultrasonic treatment removes oily solvents from the fiber manufacturing process, while sodium hydroxide treatment oxidizes the hydroxyl groups on the fiber surface to carboxyl groups, giving it a negative surface charge in aqueous solution. This allows the carboxyl group to interact with the amino and hydroxyl groups in chitosan molecules through hydrogen bonds, thus ensuring stable adhesion of chitosan to the fiber surface.

[0014] Preferably, the pretreated soybean protein fiber is immersed in the modified chitosan treatment solution, and after being immersed at a constant temperature of 60 ℃ for 30 min, it is taken out, neutralized with dilute alkali solution, washed with water until neutral, and then pre-dried in a constant temperature oven at 80 ℃ for 5 min, baked at 160 ℃ for 3 min, and finally thoroughly cleaned and dried with distilled water using ultrasonic waves to obtain chitosan modified soybean protein fiber.

[0015] The mass ratio of soybean protein fiber to chitosan solution was 1:50, and the concentration of dilute alkali solution was 0.1 mol / L.

[0016] As a preferred option, reducing solution A is prepared by mixing 40 g / L glucose and 4 g / L tartaric acid solutions to form solution C, boiling for 10 min, and then adding anhydrous ethanol after cooling. The volume ratio of anhydrous ethanol to solution C is 1:20 to obtain reducing solution A.

[0017] As a preferred method, prepare silver ammonia solution B as follows: First, prepare 20 g / L silver nitrate, add NH3·H2O dropwise while stirring continuously, and a yellowish-brown precipitate will form. As ammonia is gradually added, the color gradually darkens. Continue adding until the precipitate is completely dissolved. Then, add 10 g / L sodium hydroxide to adjust the pH to 11. The solution will again form a yellowish-brown precipitate. Continue adding ammonia until the solution is completely clear to obtain silver ammonia solution B.

[0018] Preferably, chitosan-modified soybean protein fibers are placed in silver ammonia solution B to adsorb silver ammonia ions. Solutions A and B are then heated to 50 °C, mixed, and stirred until homogeneous. The mixture is then treated at 50 °C for 90 min in a room-temperature shaking dyeing machine. The fibers are then removed into a Buchner funnel, thoroughly washed with distilled water, filtered, and dried in a 60 °C oven to obtain chitosan-silver nanofibers.

[0019] Among them, because the amino and hydroxyl groups in chitosan have a stable coordination effect on silver ions, silver ions can be adsorbed on the surface of the fiber. At the same time, silver ions can be effectively reduced in situ to silver nanoparticles by hydroxyl groups, thus producing silver nanofibers.

[0020] As a preferred method, chitosan nano-silver fibers are processed through cotton mixing, cotton opening and cleaning, cotton carding, drawing, roving, spinning, winding, warping, sizing, threading, and weaving to obtain antibacterial chitosan nano-silver fiber fabric.

[0021] In this process, chitosan nano-silver fibers are pre-loosened and then uniformly sprayed with an antistatic agent mixture, and left to stand for at least 12 hours. The mass ratio of antistatic agent to water in the antistatic agent mixture is 1:30. For the carding process, considering the low number of fiber crimps and susceptibility to damage, a flexible carding process is adopted. The main process parameters are: dust removal knife angle 90°, dust removal knife height +2 mm, distance between licker-in and cylinder 0.13 mm, distance between flats and cylinder 0.23, 0.18, 0.18, 0.18, 0.23 mm, licker-in speed 750 r / min, cylinder speed 330 r / min, flats speed 60 mm / min, and doffer speed 20 r / min. The roving process uses low-tension drafting, with a back zone draft ratio of 1.12 and a relatively high roving twist coefficient of 102. Small packages are used, and the axial and radial winding densities are appropriately increased. The main process configuration for the warping process is as follows: pretensioning device opening delay time 0.5 s, braking device opening delay time 1.0 s, tension bar depth 0 mm, yarn pressing force 300 daN, winding speed 550 m / min. The main process configuration for the weaving process is as follows: machine speed 600 r / min, tension (4000±100) N, warp stop frame position 1.5×16, back beam position 1×9. A combination of copper rings and rubber edge supports is used to solve the problem of edge support defects in the fabric.

[0022] As a preferred method, X-ray powder diffraction (XRD) was used to analyze the phase composition of the antibacterial chitosan nanosilver fiber fabric. Scanning electron microscopy (SEM) was used to observe the surface morphology of the antibacterial chitosan nanosilver fiber fabric. A nanoparticle size analyzer was used to measure the Zeta potential of the fiber fabric at (25±1)℃. The antibacterial properties of the fiber fabric were determined by shaking flask method using Gram-positive and Gram-negative bacteria, respectively, representing Staphylococcus aureus ATCC6538 and Escherichia coli 8099.

[0023] The process involved cutting fabric samples into specified sizes and packaging them. A certain amount of fabric samples, 0.03 mol / L phosphate buffer solution, and bacterial suspension were placed in an Erlenmeyer flask and shaken at 25 ℃ for 2 min. One mL of the sample solution was then taken as the pre-shaking sample solution. The same process was repeated with the sample samples, phosphate buffer solution, and bacterial suspension in the flask, shaken at 25 ℃ for 1 h, and then one mL of the sample solution was taken as the post-shaking sample solution. The pre-shaking and post-shaking sample solutions were inoculated into Petri dishes using the agar pouring method, with two Petri dishes inoculated for each sample solution. Viable bacteria were then cultured and counted. A blank control experiment was conducted without sample samples: a certain amount of phosphate buffer solution and bacterial suspension were added to an Erlenmeyer flask, mixed thoroughly, and shaken for 1 h. One mL of the pre-shaking and post-shaking sample solutions was then taken for viable bacteria culture and counting. The experiment was repeated three times, and the inhibition rate was calculated using the following formula: ((Average colony count before shaking - Average colony count after shaking) / Average colony count before shaking) × 100%.

[0024] The antibacterial fiber fabric prepared by this invention is composed of silver ions and chitosan. Utilizing the coordination effect of the amino and hydroxyl groups on the chitosan molecular chain with silver ions, the silver ions are fixed on the chitosan surface through chemical silver plating. This not only improves the antibacterial properties of chitosan but also effectively fixes the silver ions, thus leveraging the complementary advantages of both. The fiber fabric exhibits excellent antibacterial properties, achieving a 100% inhibition rate against both Staphylococcus aureus and Escherichia coli within 18 hours.

[0025] Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects:

[0026] 1. This invention provides a chitosan nano-silver soybean fiber fabric, which is composed of quaternary ammonium salt modified chitosan, soybean fiber and silver ions. Modified chitosan is deposited on soybean fiber, and silver ions are attached to the surface of chitosan and reduced to nano-silver particles. The addition of modified chitosan and silver ions enhances the antibacterial properties of the fiber.

[0027] 2. Quaternary ammonium salt modified chitosan prevents silk fabrics from yellowing, makes them soft to the touch, and enhances the comfort of the fabric. Furthermore, due to the effective cross-linking between quaternary ammonium salt modified chitosan and silk fibroin macromolecules after high-temperature baking under the action of citric acid and sodium hypophosphite, the bond between quaternary ammonium salt modified chitosan and fiber is relatively strong.

[0028] 3. Antibacterial experiments have demonstrated that the chitosan nano-silver soybean fiber fabric provided by this invention exhibits a 99.9% inhibition rate against Staphylococcus aureus and Escherichia coli, and its antibacterial durability meets the requirements of AAA-grade antibacterial fabrics after 30 washes. This indicates that the chitosan nano-silver soybean fiber fabric provided by this invention possesses excellent antibacterial properties. Attached Figure Description

[0029] Figure 1 This is a manufacturing process for antibacterial and deodorizing nano-silver fiber fabric. Detailed Implementation

[0030] The following examples further illustrate the antibacterial and deodorizing nano-silver fiber fabric and its preparation method provided by the present invention. It should be noted that the following examples are only for further illustration of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made to the present invention by those skilled in the art based on the above description are still within the scope of protection of the present invention.

[0031] Example 1

[0032] This embodiment provides an antibacterial and deodorizing nano-silver fiber fabric and its production process, with the following formula:

[0033] 2,3-Epoxypropyltrimethylammonium chloride, chitosan, isopropanol, 1 g / L acetic acid solution, 4 g / L modified chitosan solution, 4 wt% citric acid solution, 4 wt% sodium hypophosphite solution, 0.2 wt% triethanolamine solution, 40 g / L glucose solution, 4 g / L tartaric acid solution, 20 g / L silver nitrate solution, 10 g / L sodium hydroxide solution.

[0034] The specific steps for preparing samples according to the above formula are as follows:

[0035] (1) Preparation of quaternary ammonium salt modified chitosan: 2,3-epoxypropyltrimethylammonium chloride and chitosan were placed in a four-necked flask, and a certain amount of isopropanol was added at the same time. The mass ratio of the three raw materials was 1:5:10. The four-necked flask was placed in a constant temperature water bath at 85 °C and stirred thoroughly for 12 h. Finally, the reaction solution was cooled, washed, vacuum filtered, purified and dried to obtain the solid product quaternary ammonium salt modified chitosan.

[0036] (2) Preparation of chitosan-modified soybean protein fiber: Quaternary ammonium salt modified chitosan was prepared into a 4 g / L modified chitosan solution with 1 g / L acetic acid solution. 4 wt% citric acid, 4 wt% sodium hypophosphite and 0.2 wt% triethanolamine were mixed to prepare a modified chitosan treatment solution with a bath ratio of 1:50. Soybean protein fiber was pretreated with acetone and alkalized with sodium hydroxide, dried, and then immersed in the modified chitosan treatment solution (the mass ratio of fiber to modified chitosan solution was 1:50). After being immersed at 60 ℃ for 30 min, the fiber was removed, neutralized with dilute alkali solution, and washed with water until neutral to obtain chitosan-modified soybean protein fiber.

[0037] (3) Preparation of reducing solution A and silver ammonia solution B: 40 g / L glucose was mixed with 4 g / L tartaric acid solution to obtain solution C. Anhydrous ethanol was added, with a volume ratio of anhydrous ethanol to solution C of 1:20, to obtain reducing liquid A. Then, 20 g / L silver nitrate was prepared, and NH3·H2O was added dropwise while stirring continuously, resulting in a yellow-brown precipitate. The addition was continued until the precipitate was completely dissolved. Then, 10 g / L sodium hydroxide was added to adjust the pH to 11, and a yellow-brown precipitate was formed again. Ammonia water was added dropwise until the solution was completely clear, to obtain silver ammonia solution B.

[0038] (4) Preparation of antibacterial chitosan nano-silver fiber fabric: Chitosan-modified soybean protein fiber was placed in silver ammonia solution B to adsorb silver ammonia ions. Then, solutions A and B were heated to 50 ℃ and mixed. The mixture was placed in a room temperature shaking dyeing machine and treated at 50 ℃ for 90 min. The fiber was then removed, filtered, and dried to obtain chitosan nano-silver fiber. The chitosan nano-silver fiber was then processed through cotton mixing, opening and cleaning, carding, drawing, roving, spinning, winding, warping, sizing, threading, and weaving to obtain antibacterial chitosan nano-silver fiber fabric.

[0039] In this process, chitosan nano-silver fibers are pre-loosened and then uniformly sprayed with an antistatic agent mixture, and left to stand for at least 12 hours. The mass ratio of antistatic agent to water in the antistatic agent mixture is 1:30. For the carding process, considering the low number of fiber crimps and susceptibility to damage, a flexible carding process is adopted. The main process parameters are: dust removal knife angle 90°, dust removal knife height +2 mm, distance between licker-in and cylinder 0.13 mm, distance between flats and cylinder 0.23, 0.18, 0.18, 0.18, 0.23 mm, licker-in speed 750 r / min, cylinder speed 330 r / min, flats speed 60 mm / min, and doffer speed 20 r / min. The roving process uses low-tension drafting, with a back zone draft ratio of 1.12 and a relatively high roving twist coefficient of 102. Small packages are used, and the axial and radial winding densities are appropriately increased. The main process configuration for the warping process is as follows: pretensioning device opening delay time 0.5 s, braking device opening delay time 1.0 s, tension bar depth 0 mm, yarn pressing force 300 daN, winding speed 550 m / min. The main process configuration for the weaving process is as follows: machine speed 600 r / min, tension (4000±100) N, warp stop frame position 1.5×16, back beam position 1×9. A combination of copper rings and rubber edge supports is used to solve the problem of edge support defects in the fabric.

[0040] Example 2

[0041] This embodiment provides an antibacterial and deodorizing nano-silver fiber fabric and its production process, with the following formula:

[0042] 2,3-Epoxypropyltrimethylammonium chloride, chitosan, isopropanol, 1 g / L acetic acid solution, 0 g / L modified chitosan solution, 4 wt% citric acid solution, 4 wt% sodium hypophosphite solution, 0.2 wt% triethanolamine solution, 40 g / L glucose solution, 4 g / L tartaric acid solution, 20 g / L silver nitrate solution, 10 g / L sodium hydroxide solution.

[0043] Samples were prepared according to the above formula, and the specific steps are shown in Example 1.

[0044] Example 3

[0045] This embodiment provides an antibacterial and deodorizing nano-silver fiber fabric and its production process, with the following formula:

[0046] 2,3-Epoxypropyltrimethylammonium chloride, chitosan, isopropanol, 1 g / L acetic acid solution, 2 g / L modified chitosan solution, 4 wt% citric acid solution, 4 wt% sodium hypophosphite solution, 0.2 wt% triethanolamine solution, 40 g / L glucose solution, 4 g / L tartaric acid solution, 20 g / L silver nitrate solution, 10 g / L sodium hydroxide solution.

[0047] Samples were prepared according to the above formula, and the specific steps are shown in Example 1.

[0048] Example 4

[0049] This embodiment provides an antibacterial and deodorizing nano-silver fiber fabric and its production process, with the following formula:

[0050] 2,3-Epoxypropyltrimethylammonium chloride, chitosan, isopropanol, 1 g / L acetic acid solution, 6 g / L modified chitosan solution, 4 wt% citric acid solution, 4 wt% sodium hypophosphite solution, 0.2 wt% triethanolamine solution, 40 g / L glucose solution, 4 g / L tartaric acid solution, 20 g / L silver nitrate solution, 10 g / L sodium hydroxide solution.

[0051] Samples were prepared according to the above formula, and the specific steps are shown in Example 1.

[0052] Example 5

[0053] This embodiment provides an antibacterial and deodorizing nano-silver fiber fabric and its production process, with the following formula:

[0054] 2,3-Epoxypropyltrimethylammonium chloride, chitosan, isopropanol, 1 g / L acetic acid solution, 8 g / L modified chitosan solution, 4 wt% citric acid solution, 4 wt% sodium hypophosphite solution, 0.2 wt% triethanolamine solution, 40 g / L glucose solution, 4 g / L tartaric acid solution, 20 g / L silver nitrate solution, 10 g / L sodium hydroxide solution.

[0055] Samples were prepared according to the above formula, and the specific steps are shown in Example 1.

[0056] Example 6

[0057] This embodiment provides an antibacterial and deodorizing nano-silver fiber fabric and its production process, with the following formula:

[0058] 2,3-Epoxypropyltrimethylammonium chloride, chitosan, isopropanol, 1 g / L acetic acid solution, 4 g / L modified chitosan solution, 4 wt% citric acid solution, 4 wt% sodium hypophosphite solution, 0.2 wt% triethanolamine solution, 40 g / L glucose solution, 4 g / L tartaric acid solution, 0 g / L silver nitrate solution, 10 g / L sodium hydroxide solution.

[0059] Samples were prepared according to the above formula, and the specific steps are shown in Example 1.

[0060] Example 7

[0061] This embodiment provides an antibacterial and deodorizing nano-silver fiber fabric and its production process, with the following formula:

[0062] 2,3-Epoxypropyltrimethylammonium chloride, chitosan, isopropanol, 1 g / L acetic acid solution, 4 g / L modified chitosan solution, 4 wt% citric acid solution, 4 wt% sodium hypophosphite solution, 0.2 wt% triethanolamine solution, 40 g / L glucose solution, 4 g / L tartaric acid solution, 5 g / L silver nitrate solution, 10 g / L sodium hydroxide solution.

[0063] Samples were prepared according to the above formula, and the specific steps are shown in Example 1.

[0064] Example 8

[0065] This embodiment provides an antibacterial and deodorizing nano-silver fiber fabric and its production process, with the following formula:

[0066] 2,3-Epoxypropyltrimethylammonium chloride, chitosan, isopropanol, 1 g / L acetic acid solution, 4 g / L modified chitosan solution, 4 wt% citric acid solution, 4 wt% sodium hypophosphite solution, 0.2 wt% triethanolamine solution, 40 g / L glucose solution, 4 g / L tartaric acid solution, 10 g / L silver nitrate solution, 10 g / L sodium hydroxide solution.

[0067] Samples were prepared according to the above formula, and the specific steps are shown in Example 1.

[0068] Example 9

[0069] This embodiment provides an antibacterial and deodorizing nano-silver fiber fabric and its production process, with the following formula:

[0070] 2,3-Epoxypropyltrimethylammonium chloride, chitosan, isopropanol, 1 g / L acetic acid solution, 4 g / L modified chitosan solution, 4 wt% citric acid solution, 4 wt% sodium hypophosphite solution, 0.2 wt% triethanolamine solution, 40 g / L glucose solution, 4 g / L tartaric acid solution, 15 g / L silver nitrate solution, 10 g / L sodium hydroxide solution.

[0071] Samples were prepared according to the above formula, and the specific steps are shown in Example 1.

[0072] Example 10

[0073] This embodiment provides an antibacterial and deodorizing nano-silver fiber fabric and its production process, with the following formula:

[0074] 2,3-Epoxypropyltrimethylammonium chloride, chitosan, isopropanol, 1 g / L acetic acid solution, 4 g / L modified chitosan solution, 4 wt% citric acid solution, 4 wt% sodium hypophosphite solution, 0.2 wt% triethanolamine solution, 40 g / L glucose solution, 4 g / L tartaric acid solution, 25 g / L silver nitrate solution, 10 g / L sodium hydroxide solution.

[0075] Samples were prepared according to the above formula, and the specific steps are shown in Example 1.

[0076] Comparative Example 1

[0077] In this comparative example, antibacterial chitosan nanofiber fabric was prepared using unmodified chitosan, and the formula is as follows:

[0078] Chitosan, isopropanol, 1 g / L acetic acid solution, 4 g / L chitosan solution, 4 wt% citric acid solution, 4 wt% sodium hypophosphite solution, 0.2 wt% triethanolamine solution, 40 g / L glucose solution, 4 g / L tartaric acid solution, 20 g / L silver nitrate solution, 10 g / L sodium hydroxide solution.

[0079] The specific steps for preparing samples according to the above formula are as follows:

[0080] A modified chitosan solution of 4 g / L was prepared by mixing chitosan with 1 g / L acetic acid solution. This was then mixed with 4 wt% citric acid solution, 4 wt% sodium hypophosphite solution, and 0.2 wt% triethanolamine solution to prepare a modified chitosan treatment solution at a bath ratio of 1:50. Soybean protein fibers were pretreated with acetone and alkalized with sodium hydroxide, dried, and then immersed in the chitosan treatment solution (fiber to chitosan solution mass ratio 1:50). The solution was kept at 60 ℃ for 30 min, then removed, neutralized with dilute alkali solution, and washed with water until neutral to obtain chitosan-modified soybean protein fibers.

[0081] The subsequent process is as shown in Example 1.

[0082] Example 12

[0083] (1) Effect of modified chitosan concentration

[0084] The surface morphology of the products in Examples 1-5 was characterized using scanning electron microscopy to detect the deposition of nano-silver. The reflectance of the nano-silver fabric was detected using X-ray powder diffraction to qualitatively characterize the silver content. The silver content was detected using zeta potential. The antibacterial properties of the fiber fabric were determined by shaking flask method.

[0085] Example 1 The deposition amount is moderate and the surface is smooth. 20%~60% 99.9% 99.9% Example 2 No deposits, smooth surface 65%~80% 30.3% 31.2% Example 3 Less deposition, smooth surface 30%~70% 68.7% 69.3% Example 4 The deposits are abundant and aggregated, with a rough surface. 20%~60% 99.9% 99.9% Example 5 The deposits are abundant and exhibit severe aggregation, resulting in a rough surface. 20%~60% 99.9% 99.9%

[0086] When soybean fiber is not modified with chitosan, silver ions cannot be adsorbed by the soybean fiber, resulting in no nano-silver deposition on the surface of the sample in Example 1 (chitosan concentration of 0). As the chitosan concentration increases, the amount of nano-silver deposited on the fabric surface increases and agglomeration occurs, causing the fabric to become rougher. Furthermore, the reflectivity value continuously decreases in the range of 400–700 nm, and the antibacterial rate increases with increasing chitosan concentration, indicating that increased silver content enhances the antibacterial effect of the fiber fabric. When the chitosan concentration is greater than 4 g / L, the different reflectivities essentially overlap, and the antibacterial rate reaches 99.9%. This indicates that treating soybean fiber with a 4 g / L chitosan solution can completely adsorb and reduce 20 g / L nitrate into nano-silver ions, which are then uniformly adsorbed onto the fiber fabric surface, meeting the antibacterial requirements of the fiber fabric.

[0087] (2) Effect of silver nitrate concentration

[0088] The surface morphology of the products in Examples 1, 6-11 was characterized using a scanning electron microscope to detect the deposition of nano-silver. The reflectance of the nano-silver fabric was detected using an X-ray powder diffractometer to qualitatively characterize the silver content. The antibacterial properties of the fiber fabric were determined by the shaking flask method.

[0089] Example 1 The deposition amount is moderate, and the surface is relatively smooth. 20%~60% 99.9% 99.9% Example 6 No deposits, smooth surface 60%~80% 35.2% 36.7% Example 7 Less deposition, smooth surface 50%~70% 63.5% 64.5% Example 8 Less deposition, smooth surface 40%~65% 89.3% 90.1% Example 9 Less deposition, smooth surface 30%~50% 99.9% 99.9% Example 10 There is a lot of sediment, resulting in agglomeration and a rough surface. 20%~60% 99.9% 99.9%

[0090] When the silver nitrate concentration was 0 (Example 6), no nano-silver was deposited on the surface of the fiber fabric. With increasing silver nitrate concentration, the amount of nano-silver deposited on the fabric surface increased and agglomeration occurred, making the fabric rough. The reflectance value continuously decreased in the range of 400–700 nm. When the silver nitrate concentration exceeded 20 g / L, its reflectance curve gradually overlapped with increasing silver nitrate concentration. The antibacterial performance of the fiber fabric against *Escherichia coli* and *Staphylococcus aureus* increased with increasing silver nitrate concentration, reaching an antibacterial rate of 99.9% at a silver nitrate solution concentration of 20 g / L. This indicates that the nano-silver ions on the surface of the fiber fabric were saturated. Since chitosan can only adsorb and reduce a certain amount of silver ions, the silver ion concentration easily reaches saturation, and further increasing the silver ion content does not significantly contribute to the increase in antibacterial performance. This indicates that the maximum silver nitrate concentration required for polyester fabric treated with a 4 g / L chitosan solution is 20 g / L, which meets the antibacterial requirements of the fiber fabric.

[0091] (3) The effect of quaternization modification of chitosan.

[0092] The surface morphology of the products of Example 1 and Comparative Example 1 was characterized using scanning electron microscopy to detect the deposition of nano-silver. The reflectance of the nano-silver fabric was detected using X-ray powder diffraction to qualitatively characterize the silver content. The antibacterial properties of the fiber fabric were determined by the shaking flask method.

[0093] Example 1 The deposits are abundant and the surface is relatively smooth. 20%~60% 99.9% Comparative Example 1 Less deposition, smooth surface 50%~70% 65.6%

[0094] Treatment with chitosan and quaternary ammonium salt-modified chitosan solutions significantly improved the adsorption of silver ions on soybean fiber fabric, thereby enhancing its antibacterial effect. However, quaternary ammonium salt-modified chitosan exhibited a superior antibacterial effect. Furthermore, the fiber fabric treated with quaternary ammonium salt-modified chitosan did not yellow and retained a soft feel. This is because, under the influence of citric acid and sodium hypophosphite, the quaternary ammonium salt-modified chitosan underwent effective cross-linking with soybean fiber macromolecules after high-temperature baking. This resulted in a stronger bond between the quaternary ammonium salt-modified chitosan and the fiber, enabling the adsorption of more silver ions and the deposition of more nano-silver. After 30 washes, the antibacterial rate of the chitosan nano-silver fiber fabric remained above 90% of its pre-wash level, meeting the requirements for AAA-grade antibacterial fabrics.

[0095] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. An antibacterial chitosan nano-silver fiber fabric, characterized in that: This fabric is composed of quaternary ammonium salt modified chitosan, silver ions, and soybean protein fibers. The chitosan is attached to the soybean protein fibers, and the silver ions are adsorbed on the surface of the chitosan and chemically reduced to nano-silver, which is then deposited on the fiber surface. The preparation method of the quaternary ammonium salt modified chitosan includes: placing 2,3-epoxypropyltrimethylammonium chloride and chitosan in a four-necked flask, and adding a certain amount of isopropanol. The mass ratio of the three raw materials is 1:5:8 to 1:5:

12. The four-necked flask is placed in a constant temperature water bath at 80 ℃ to 90 ℃ and stirred thoroughly for 10 h to 15 h. After stirring, the flask is removed, and the reaction solution is cooled, washed, vacuum filtered, purified, and dried to obtain the solid product, quaternary ammonium salt modified chitosan. The method for attaching quaternary ammonium salt modified chitosan to soybean protein fiber includes: preparing a 3-5 g / L modified chitosan solution by mixing quaternary ammonium salt modified chitosan with 0.8 g / L~1.2 g / L acetic acid solution; mixing 3 wt%~5 wt% citric acid, 3 wt%~5 wt% sodium hypophosphite and 0.1 wt%~0.3 wt% triethanolamine to prepare a modified chitosan treatment solution with a bath ratio of 1:45~1:55; pretreating soybean protein fiber with acetone and alkalizing with sodium hydroxide, drying it, and then immersing it in the modified chitosan treatment solution with a mass ratio of soybean protein fiber to modified chitosan solution of 1:45~1:55; immersing it at a constant temperature of 55 ℃~65 ℃ for 25 min~35 min, then removing it, neutralizing it with dilute alkali solution, and washing it with water until neutral to obtain chitosan modified soybean protein fiber; The method for converting silver ions adsorbed on the chitosan surface into nano-silver deposits on the fiber surface through chemical reduction includes: placing chitosan-modified soybean protein fibers in a silver ammonia solution to adsorb silver ammonia ions; the reducing solution is prepared as follows: mixing 35 g / L~45 g / L glucose with 3 g / L~5 g / L tartaric acid solution to obtain solution C; adding anhydrous ethanol at a volume ratio of 1:18~1:22 to obtain reducing solution A; preparing 18 g / L~22 g / L silver nitrate, adding NH3·H2O dropwise while stirring continuously, generating a yellowish-brown precipitate, continuing to add until the precipitate is completely dissolved; then adding 8 g / L~12 g / L sodium hydroxide to adjust the pH to 10~12, generating another yellowish-brown precipitate; continuing to add ammonia until completely clear to obtain silver ammonia solution B; then heating and mixing silver ammonia solution B with reducing solution A; and treating in a room temperature shaking dyeing machine at 45 ℃~55 ℃ for 80 min~100 min. After a period of time, the fibers are removed, filtered, and dried to obtain chitosan nano-silver fibers. Then, the chitosan nano-silver fibers are processed through cotton mixing, opening and cleaning, carding, drawing, roving, spinning, winding, warping, sizing, threading, and weaving to obtain antibacterial chitosan nano-silver fiber fabric.

2. The antibacterial chitosan nano-silver fiber fabric according to claim 1, characterized in that: Preparation of silver ammonia solution B: First, prepare 20 g / L silver nitrate. Add NH3·H2O dropwise while stirring continuously. A yellowish-brown precipitate will form. As ammonia water is gradually added, the color will gradually darken. Continue adding until the precipitate is completely dissolved. Then, add 10 g / L sodium hydroxide to adjust the pH to 11. The solution will again form a yellowish-brown precipitate. Continue adding ammonia water until it is completely clear to obtain silver ammonia solution B.

3. The antibacterial chitosan nano-silver fiber fabric according to claim 1, characterized in that: After pre-loosening the chitosan nano-silver fibers, an antistatic agent mixture is sprayed evenly and allowed to stand for more than 12 hours. The mass ratio of antistatic agent to water in the antistatic agent mixture is 1:

30. The carding process adopts a flexible carding process, and the main process parameters are: the dust removal knife angle is 90°, the height of the dust removal knife is +2 mm, the distance between the licker-in roller and the cylinder is 0.13 mm, the distance between the flats and the cylinder is 0.23, 0.18, 0.18, 0.18, 0.23 mm, the licker-in roller speed is 750 r / min, the cylinder speed is 330 r / min, the flats speed is 60 mm / min, and the doffer speed is 20 r / min.

4. The antibacterial chitosan nano-silver fiber fabric according to claim 3, characterized in that: The roving process uses low tension drafting, with a back zone drafting ratio of 1.

12. The roving twist coefficient is designed to be relatively large at 102. Small packages are used and the axial and radial winding densities are appropriately increased.

5. The antibacterial chitosan nano-silver fiber fabric according to claim 4, characterized in that: The main process configuration for the warping process is as follows: pretension device opening delay time 0.5 s, braking device opening delay time 1.0 s, tension bar depth 0 mm, yarn pressing force 300 daN, and winding speed 550 m / min; the main process configuration for the weaving process is as follows: machine speed 600 r / min, tension 4000±100N, warp stop frame position 1.5×16, and back beam position 1×9.

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