A nano-silver modified fiber membrane material and a preparation method and application thereof

Abstract

The application belongs to the technical field of materials, and particularly relates to a kind of nanometer silver modified fiber membrane materials and its preparation method and application.The preparation method comprises: S1: after pretreatment, plastic raw materials are obtained plastic fragments;S2: the plastic fragments are added to the organic solvent and stirred to form a uniform transparent plastic solution; chitosan biopolymer and reducing glucose are dissolved in a binary solvent system to obtain a uniform chitosan-glucose solution;S3: the plastic solution, chitosan-glucose solution is mixed to obtain a mixed solution, and then an electrospinning process is used to obtain a reducing nanofiber membrane;S4: the reducing nanofiber membrane is immersed in silver nitrate aqueous solution for reaction to obtain a nanometer silver modified fiber membrane material.The fiber membrane material obtained by the application has good flexibility and air permeability, and has high nanometer silver content and excellent antibacterial performance, which makes it have significant application potential in many fields.

Description

Technical Field

[0001] This invention belongs to the field of materials technology, specifically relating to a nano-silver modified fiber membrane material, its preparation method, and its application. Background Technology

[0002] As an irreplaceable and important component in the packaging materials field, the recycling of polyethylene terephthalate (PET) has received great attention. According to statistics, the global demand for PET reached 33 million tons in 2015, and it is expected to grow at a rate of 6.9% between 2017 and 2025. The annual consumption of PET materials worldwide continues to rise, and a large amount of PET products are not effectively recycled. A large amount of PET is landfilled or flows into the natural environment, which not only wastes a lot of non-renewable resources, but also produces a large amount of microplastics that enter the natural environment due to degradation, seriously threatening the health and stability of the ecosystem.

[0003] Fiber manufacturing processes have made significant progress in recent years. Using electrospinning, fibers of various specifications can be produced based on different electric field parameters, ranging from a minimum of 50 nanometers to a maximum of 800 nanometers. Furthermore, due to the unique fiber structure, its large porosity and specific surface area make it highly suitable for developing functional materials for next-generation high-tech products. However, as an emerging material, this type of manufacturing process still faces limitations and shortcomings, falling far short of current needs. In particular, its functionality is relatively weak, lacking features such as bacterial protection, thus limiting its application in key industries such as healthcare.

[0004] Silver-containing compounds have gained popularity due to their excellent antibacterial properties. Existing literature reveals that silver-based antibacterial agents exert their functions primarily through the following mechanisms: firstly, silver nanoparticles can directly act on the surface structure of microbial cells; secondly, silver ions disrupt the metabolism of endogenous substances in bacteria. However, most current experiments are based on commercially available raw materials, with relatively few systematic studies on the recycling of PET materials. Furthermore, key technical bottlenecks in the preparation technology of silver nanoparticle carriers, such as uneven particle dispersion and poor interfacial bonding, still need to be overcome. Summary of the Invention

[0005] The purpose of this invention is to provide a nano-silver modified fiber membrane material, its preparation method and application, so as to realize the recycling of waste plastics such as PET and maximize resource utilization.

[0006] Therefore, the present invention provides the following technical solution.

[0007] One aspect of the present invention provides a method for preparing a nano-silver modified fiber membrane material, the method comprising the following steps: S1: Plastic fragments are obtained by pre-treating plastic raw materials; S2: Add the plastic fragments to an organic solvent and stir until a homogeneous and transparent plastic solution is formed; Chitosan biopolymer and reduced glucose were dissolved together in a binary solvent system to obtain a homogeneous chitosan-glucose solution. S3: The plastic solution and chitosan-glucose solution are mixed to obtain a mixture, and then a reduced nanofiber membrane is obtained by electrospinning. S4: The reduced nanofiber membrane is immersed in an aqueous solution of silver nitrate to react and obtain a nanosilver modified fiber membrane material.

[0008] In a preferred embodiment of the present invention, in step S1, the plastic raw material is selected from one or a mixture of two or more of polyethylene furanate, polybutylene terephthalate, and polyethylene terephthalate.

[0009] In a preferred embodiment of the present invention, step S1, the pretreatment includes crushing, washing and drying.

[0010] In a preferred embodiment of the present invention, the washing is performed by using deionized water in conjunction with an ultrasonic cleaner for deep cleaning.

[0011] In a preferred embodiment of the present invention, the drying conditions are: temperature 40-100℃, time 3-24h.

[0012] In a preferred embodiment of the present invention, in step S1, the size of the plastic fragment is 5-8 mm.

[0013] In a preferred embodiment of the present invention, in step S2, the organic solvent is selected from one or a mixture of two or more of hexafluoroisopropanol, resorcinol, 1-methyl-2-pyrrolidone, benzyl alcohol, dimethylformamide, and dimethyl sulfoxide.

[0014] In a preferred embodiment of the present invention, in step S2, the stirring conditions are: rotation speed 200-800 rpm, time 1-12 h.

[0015] In a preferred embodiment of the present invention, in step S2, the mass concentration of the plastic solution is 10%-20%.

[0016] In a preferred embodiment of the present invention, in step S2, the viscosity of the chitosan biopolymer is 50-2000 mPa·s.

[0017] In a preferred embodiment of the present invention, in step S2, the mass ratio of the chitosan biopolymer to the reduced glucose is 1:(1-4).

[0018] In a preferred embodiment of the present invention, in step S2, the binary solvent system is formed by mixing a first solvent and a second solvent; The first solvent is selected from any one of trifluoroacetic acid, phenol, dichloromethane, and chloroform; The second solvent is selected from any one of hexafluoroisopropanol, dichloromethane, and tetrachloroethane.

[0019] In a preferred embodiment of the present invention, the mass ratio of the first solvent and the second solvent is (5-1):1.

[0020] In a preferred embodiment of the present invention, in step S2, the binary solvent system is selected from any one of the following: trifluoroacetic acid / hexafluoroisopropanol mixed solvent, trifluoroacetic acid / dichloromethane mixed solvent, phenol / tetrachloroethane mixed solvent, dichloromethane / hexafluoroisopropanol mixed solvent, and chloroform / hexafluoroisopropanol mixed solvent.

[0021] In a preferred embodiment of the present invention, in step S2, the dissolution process is as follows: first, the mixture is initially mixed by magnetic stirring for 30 min, and then dispersed by ultrasonic treatment for 30 min to obtain a completely dissolved homogeneous solution.

[0022] In a preferred embodiment of the present invention, in step S2, the ultrasonic conditions are: power 200-1000 W, time 5-30 min.

[0023] In a preferred embodiment of the present invention, in step S3, the volume ratio of the plastic solution and the chitosan-glucose solution is 1:1.

[0024] In a preferred embodiment of the present invention, in step S3, the mixing is a stirring mixture, and the stirring mixture conditions are: 500 rpm and 30 min.

[0025] In a preferred embodiment of the present invention, in step S3, the electrospinning process conditions are as follows: voltage of 15-18 KV, feed speed of 0.1-0.5 mL / h, nozzle-receiver distance of 12-16 cm, ambient temperature of 25℃, and humidity of 10-30%.

[0026] In a preferred embodiment of the present invention, in step S4, the concentration of the silver nitrate aqueous solution is 0.05-0.3 mol / L.

[0027] In a preferred embodiment of the present invention, in step S4, the reaction conditions are: temperature of 60°C and time of 30 min.

[0028] In a preferred embodiment of the present invention, the changes during the reaction in step S4 are as follows: 0-5 min: a silver mirror reaction occurs on the fiber surface; 5-15 min: the solution changes from colorless to light yellow; 15-30 min: the color deepens to brownish-brown.

[0029] In a preferred embodiment of the present invention, step S4 further includes a washing and drying process after the reaction is completed.

[0030] In a preferred embodiment of the present invention, the drying conditions are: temperature 50-70°C, time 10-14 h.

[0031] Another aspect of the present invention provides the following applications of the nano-silver modified fiber membrane material prepared according to the preparation method described above: (i) Application in the preparation of medical protective products; (ii) Applications in the preparation of food packaging products; and (iii) Application in the preparation of water treatment products.

[0032] In a preferred embodiment of the present invention, the medical protective product includes a surgical isolation membrane and an antibacterial medical device covering membrane.

[0033] In a preferred embodiment of the present invention, the food packaging product includes cold chain packaging materials.

[0034] In a preferred embodiment of the present invention, the water treatment product includes an antibacterial filter membrane.

[0035] By employing the above technical solution, the present invention has at least the following advantages: This invention innovatively uses waste plastics, such as PET packaging, as raw materials, and prepares nanofiber carriers through an integrated dissolution and spinning process. Silver nanoparticles are then loaded using a chemical reduction method to prepare nano-silver modified fiber membrane materials. Furthermore, by optimizing the preparation process conditions, characterizing the structure and properties of the raw materials, testing and evaluating the performance, and exploring the feasibility of applications in real-world conditions, this invention aims to address current shortcomings in related fields. This invention not only enables the treatment of waste PET but also yields a new type of functional material, broadening the application range of PET materials and providing a scientific basis for the replacement of similar PET materials in the future. This invention is of great significance for developing a circular economy and promoting the development of renewable green materials.

[0036] The fiber membrane material obtained by this invention has good flexibility and air permeability, and can be used in many situations; at the same time, the material has a high content of nano-silver, which has excellent antibacterial properties, making it show significant application potential in many fields.

[0037] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below. Attached Figure Description

[0038] Figure 1 A flowchart illustrating the preparation process of the nano-silver modified fiber membrane material of the present invention is shown. Figure 2 SEM images of the fiber membrane materials prepared according to the present invention are shown; wherein, the upper image is the SEM image of PET / Ag-1 prepared in Example 1, and the lower image is the SEM image of PET-1 prepared in Comparative Example 1. Figure 3 The EDS diagram of PET / Ag-1 prepared in Example 1 of the present invention is shown; Figure 4 The FTIR spectra of PET / Ag-1 prepared in Example 1 of the present invention and PET-1 prepared in Comparative Example 1 are shown. Figure 5 The XRD patterns of PET / Ag-1 prepared in Example 1 of the present invention and PET-1 prepared in Comparative Example 1 are shown. Figure 6 The mechanical properties of PET / Ag prepared in Examples 1-3 and PET prepared in Comparative Examples 1-3 are shown in the diagram. Figure 7 The antibacterial properties of PET / Ag-1 prepared in Example 1 and PET-1 prepared in Comparative Example 1 are shown in the diagram. Detailed Implementation

[0039] To make the technical means, creative features, achieved objectives, and effects of this invention readily understandable, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0040] The following embodiments involve and mention: 1. Experimental materials Chitosan (high viscosity, greater than 400 mPa.s) was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. D(+)-anhydrous glucose, purchased from Sinopharm Chemical Reagent Co., Ltd.; Trifluoroacetic acid (TFA, 99%) was purchased from Beijing Innocare Technology Co., Ltd. Hexafluoroisopropanol (HFIP, 99%) was purchased from Beijing Innocare Technology Co., Ltd. Plastic raw material: Commercially available drinking mineral water bottles (PET material).

[0041] 2. Experimental apparatus Micro-infusion pump, WZS-50F6, Zhejiang Smith Medical Instruments Co., Ltd.; High voltage power supply, HB-Z203-1AC, Ningbo Jiangdong Guanda Trading Co., Ltd.

[0042] Example 1: Preparation of PET / Ag-1 nano-silver modified fiber membrane material (1) First, the mineral water bottle raw material (PET) is processed into 5-8 mm fragments to obtain PET fragments. Then, the obtained PET fragments are thoroughly cleaned using deionized water and an ultrasonic cleaner. Finally, the cleaned PET fragments are placed in a vacuum drying oven at 60 ℃ for 12 h to ensure complete drying, thus obtaining pretreated PET fragments.

[0043] (2) In the solution preparation stage, a dual-solvent system is used to treat different components separately, specifically including: ① Add the pretreated PET fragments to hexafluoroisopropanol organic solvent and stir continuously for 60 min under the action of magnetic stirrer (500 rpm) until a homogeneous transparent viscous solution with a mass concentration of 15% is formed, i.e., a PET solution with a concentration of 15wt%. ② Chitosan and D(+)-anhydrous glucose were dissolved together in a trifluoroacetic acid and hexafluoroisopropanol solvent system at a mass ratio of 1:4 (the mass ratio of trifluoroacetic acid to hexafluoroisopropanol was 2:1), wherein the total mass ratio of chitosan and D(+)-anhydrous glucose to the mass ratio of trifluoroacetic acid and hexafluoroisopropanol solvent system was 1:2. The mixture was first initially mixed by magnetic stirring for 30 minutes, and then dispersed by ultrasonic treatment for 30 minutes to obtain a completely dissolved homogeneous solution, i.e., a chitosan-glucose solution.

[0044] (3) Preparation of reducing nanofiber membranes using electrospinning, specifically including: The above PET solution and chitosan-glucose solution were placed in a magnetic stirrer at a volume ratio of 1:1 and stirred at 500 rpm for 30 min until a homogeneous, transparent, viscous solution was formed. The mixture was then allowed to stand to allow for complete dispersion of the components. Subsequently, an electrospinning process (using a micro-injection pump combined with a high-voltage power supply) was employed to form a fibrous membrane from the obtained mixture. The electrospinning process conditions were: voltage of 18 kV, feed rate of 0.3 mL / h, nozzle-receiver distance of approximately 15 cm, ambient temperature of 25 ℃, and humidity of 20%, resulting in a reduced nanofiber membrane.

[0045] (4) The obtained reduced nanofiber membrane was immersed in an aqueous solution containing 0.1 mol / L AgNO3, and then placed in a constant temperature water bath at 60℃ for 30 min. During the treatment, the following was observed: 0-5 min: a silver mirror reaction appeared on the fiber surface; 5-15 min: the solution changed from colorless to light yellow; 15-30 min: the color deepened to brownish-red. After the treatment, the fiber membrane was taken out and rinsed three times with deionized water. Finally, it was vacuum dried at 60℃ for 12 h to obtain the nano-silver modified fiber membrane material, abbreviated as PET / Ag-1.

[0046] Example 2: Preparation of PET / Ag-2 nano-silver modified fiber membrane material (1) First, the mineral water bottle raw material (PET) is processed into 5-8 mm fragments to obtain PET fragments. Then, the obtained PET fragments are thoroughly cleaned using deionized water and an ultrasonic cleaner. Finally, the cleaned PET fragments are placed in a vacuum drying oven at 60 ℃ for 12 h to ensure complete drying, thus obtaining pretreated PET fragments.

[0047] (2) In the solution preparation stage, a dual-solvent system is used to treat different components separately, specifically including: ① Add the pretreated PET fragments to hexafluoroisopropanol organic solvent and stir continuously for 180 min under the action of a magnetic stirrer (800 rpm) until a homogeneous, transparent, viscous solution with a mass concentration of 20% is formed, i.e., a PET solution with a concentration of 20wt%. ② Chitosan and D(+)-anhydrous glucose were dissolved together in a trifluoroacetic acid / dichloromethane mixed solvent system at a mass ratio of 1:2 (the mass ratio of trifluoroacetic acid / dichloromethane was 4:1). The total mass ratio of chitosan and D(+)-anhydrous glucose to the mass ratio of the trifluoroacetic acid / dichloromethane mixed solvent system was 1:2. The mixture was initially mixed by magnetic stirring for 30 min, and then further dispersed by ultrasonic treatment (1000W power) for 30 min to obtain a completely dissolved homogeneous solution, i.e., a chitosan-glucose solution.

[0048] (3) Preparation of reducing nanofiber membranes using electrospinning, specifically including: The above PET solution and chitosan-glucose solution were placed in a magnetic stirrer at a volume ratio of 1:1 and stirred at 500 rpm for 30 min until a homogeneous, transparent, viscous solution was formed. The mixture was then allowed to stand to allow for complete dispersion of the components. Subsequently, an electrospinning process (using a micro-injection pump combined with a high-voltage power supply) was employed to form a fibrous membrane from the obtained mixture. The electrospinning process conditions were: voltage 17 kV, feed rate 0.2 mL / h, nozzle-receiver distance approximately 13 cm, ambient temperature 25 ℃, and humidity 10%, resulting in a reduced nanofiber membrane.

[0049] (4) The obtained reduced nanofiber membrane was immersed in an aqueous solution containing 0.2 mol / L AgNO3, and then placed in a constant temperature water bath at 60℃ for 30 min. During the treatment, the following was observed: 0-5 min: a silver mirror reaction appeared on the fiber surface; 5-15 min: the solution changed from colorless to light yellow; 15-30 min: the color deepened to brownish-red. After the treatment, the fiber membrane was taken out and rinsed three times with deionized water. Finally, it was vacuum dried at 60℃ for 12 h to obtain the nano-silver modified fiber membrane material, abbreviated as PET / Ag-2.

[0050] Example 3: Preparation of PET / Ag-3 nano-silver modified fiber membrane material (1) First, the mineral water bottle raw material (PET) is processed into 5-8 mm fragments to obtain PET fragments. Then, the obtained PET fragments are thoroughly cleaned using deionized water and an ultrasonic cleaner. Finally, the cleaned PET fragments are placed in a vacuum drying oven at 60 ℃ for 12 h to ensure complete drying, thus obtaining pretreated PET fragments.

[0051] (2) In the solution preparation stage, a dual-solvent system is used to treat different components separately, specifically including: ① Add the pretreated PET fragments to hexafluoroisopropanol organic solvent and stir continuously for 12 hours under the action of a magnetic stirrer (200 rpm) until a homogeneous, transparent, viscous solution with a mass concentration of 10% is formed, i.e., a PET solution with a concentration of 10wt%. ② Chitosan and D(+)-anhydrous glucose were dissolved together in a phenol / tetrachloroethane mixed solvent system (phenol / tetrachloroethane mass ratio was 4:1) at a mass ratio of 1:3, wherein the total mass ratio of chitosan and D(+)-anhydrous glucose to the mass ratio of the phenol / tetrachloroethane mixed solvent system was 1.2:3. The mixture was first initially mixed by magnetic stirring for 30 min, and then further dispersed by ultrasonic treatment (800W) for 30 min to obtain a completely dissolved homogeneous solution, i.e., a chitosan-glucose solution.

[0052] (3) Preparation of reducing nanofiber membranes using electrospinning, specifically including: The above PET solution and chitosan-glucose solution were placed in a magnetic stirrer at a volume ratio of 1:1 and stirred at 500 rpm for 30 min until a homogeneous, transparent, viscous solution was formed. The mixture was then allowed to stand to allow for complete dispersion of the components. Subsequently, an electrospinning process (using a micro-injection pump combined with a high-voltage power supply) was employed to form a fibrous membrane from the obtained mixture. The electrospinning process conditions were: voltage 16 kV, feed rate 0.2 mL / h, nozzle-receiver distance approximately 13 cm, ambient temperature 25 ℃, and humidity 30%, resulting in a reduced nanofiber membrane.

[0053] (4) The obtained reduced nanofiber membrane was immersed in an aqueous solution containing 0.3 mol / L AgNO3, and then placed in a constant temperature water bath at 60℃ for 30 min. During the treatment, the following was observed: 0-5 min: a silver mirror reaction appeared on the fiber surface; 5-15 min: the solution changed from colorless to light yellow; 15-30 min: the color deepened to brownish-red. After the treatment, the fiber membrane was taken out and rinsed three times with deionized water. Finally, it was vacuum dried at 60℃ for 12 h to obtain the nano-silver modified fiber membrane material, abbreviated as PET / Ag-3.

[0054] Example 4: Preparation of PEF / Ag nano-silver modified fiber membrane material (1) First, the plastic raw material (polyethylene furanate, abbreviated as PEF) is processed into 5-8 mm fragments to obtain PEF fragments. Then, the obtained PEF fragments are thoroughly cleaned using deionized water and an ultrasonic cleaner. Finally, the cleaned PEF fragments are placed in a vacuum drying oven at 60 ℃ for 12 h to ensure complete drying, thus obtaining pretreated PEF fragments.

[0055] (2) In the solution preparation stage, a dual-solvent system is used to treat different components separately, specifically including: ① Add the pretreated PEF fragments to hexafluoroisopropanol organic solvent and stir continuously for 180 min under the action of magnetic stirrer (speed 800 rpm) until a homogeneous transparent viscous solution with a mass concentration of 20% is formed, that is, a PEF solution with a concentration of 20wt%. ② Chitosan and D(+)-anhydrous glucose were dissolved together in a trifluoroacetic acid / dichloromethane mixed solvent system at a mass ratio of 1:3 (the mass ratio of trifluoroacetic acid / dichloromethane was 3:1). The total mass ratio of chitosan and D(+)-anhydrous glucose to the mass ratio of the trifluoroacetic acid / dichloromethane mixed solvent system was 1:3. The mixture was first initially mixed by magnetic stirring for 30 minutes, and then further dispersed by ultrasonic treatment (1000W power) for 30 minutes to obtain a completely dissolved homogeneous solution, i.e., a chitosan-glucose solution.

[0056] (3) Preparation of reducing nanofiber membranes using electrospinning, specifically including: The above PEF solution and chitosan-glucose solution were placed in a magnetic stirrer at a volume ratio of 1:1 and stirred at 500 rpm for 30 min until a homogeneous, transparent, viscous solution was formed. The mixture was then allowed to stand to allow for complete dispersion of the components. Subsequently, an electrospinning process (using a micro-injection pump combined with a high-voltage power supply) was employed to form a fibrous membrane from the obtained mixture. The electrospinning conditions were: voltage 15 kV, feed rate 0.5 mL / h, nozzle-receiver distance approximately 12 cm, ambient temperature 25 ℃, and humidity 10%, resulting in a reduced nanofiber membrane.

[0057] (4) The obtained reduced nanofiber membrane was immersed in an aqueous solution containing 0.2 mol / L AgNO3, and then placed in a constant temperature water bath at 60℃ for 30 min. During the treatment, the following was observed: 0-5 min: a silver mirror reaction appeared on the fiber surface; 5-15 min: the solution changed from colorless to light yellow; 15-30 min: the color deepened to brownish-red. After the treatment, the fiber membrane was taken out and rinsed three times with deionized water. Finally, it was vacuum dried at 60℃ for 12 h to obtain the nano-silver modified fiber membrane material, abbreviated as PEF / Ag.

[0058] Example 5: Preparation of PBT / Ag nano-silver modified fiber membrane material (1) First, the plastic raw material (polybutylene terephthalate, PBT) was processed into 5-8 mm fragments to obtain PBT fragments. Then, the obtained PBT fragments were thoroughly cleaned using deionized water and an ultrasonic cleaner. Finally, the cleaned PBT fragments were placed in a vacuum drying oven at 60 °C for 12 h to ensure complete drying, resulting in pretreated PBT fragments.

[0059] (2) In the solution preparation stage, a dual-solvent system is used to treat different components separately, specifically including: ① Add the pretreated PBT fragments to hexafluoroisopropanol organic solvent and stir continuously for 12 hours under the action of a magnetic stirrer (200 rpm) until a homogeneous, transparent, viscous solution with a mass concentration of 10% is formed, i.e., a PBT solution with a concentration of 10wt%. ② Chitosan and D(+)-anhydrous glucose were dissolved together in a phenol / tetrachloroethane mixed solvent system (phenol / tetrachloroethane mass ratio of 5:1) at a mass ratio of 1:1, wherein the total mass ratio of chitosan and D(+)-anhydrous glucose to the mass ratio of the phenol / tetrachloroethane mixed solvent system was 1:3. The mixture was first initially mixed by magnetic stirring for 30 min, and then further dispersed by ultrasonic treatment (800W) for 30 min to obtain a completely dissolved homogeneous solution, i.e., a chitosan-glucose solution.

[0060] (3) Preparation of reducing nanofiber membranes using electrospinning, specifically including: The PBT solution and chitosan-glucose solution were placed in a magnetic stirrer at a volume ratio of 1:1 and stirred at 500 rpm for 30 min until a homogeneous, transparent, viscous solution was formed. The mixture was then allowed to stand to allow for complete dispersion of the components. Subsequently, an electrospinning process (using a micro-injection pump combined with a high-voltage power supply) was employed to form a fibrous membrane from the obtained mixture. The electrospinning conditions were: voltage 16 kV, feed rate 0.1 mL / h, nozzle-receiver distance approximately 16 cm, ambient temperature 25 ℃, and humidity 30%, resulting in a reduced nanofiber membrane.

[0061] (4) The obtained reduced nanofiber membrane was immersed in an aqueous solution containing 0.3 mol / L AgNO3, and then placed in a constant temperature water bath at 60℃ for 30 min. During the treatment, the following was observed: 0-5 min: a silver mirror reaction appeared on the fiber surface; 5-15 min: the solution changed from colorless to light yellow; 15-30 min: the color deepened to brownish-red. After the treatment, the fiber membrane was taken out and rinsed three times with deionized water. Finally, it was vacuum dried at 60℃ for 12 h to obtain the nano-silver modified fiber membrane material, abbreviated as PBT / Ag.

[0062] Comparative Example 1: Preparation of Fiber Membrane Material PET-1 The only difference between this comparative example and Example 1 is that step (4) was not performed, i.e.: (1) First, the mineral water bottle raw material (PET) is processed into 5-8 mm fragments to obtain PET fragments. Then, the obtained PET fragments are thoroughly cleaned using deionized water and an ultrasonic cleaner. Finally, the cleaned PET fragments are placed in a vacuum drying oven at 60 ℃ for 12 h to ensure complete drying, thus obtaining pretreated PET fragments.

[0063] (2) In the solution preparation stage, a dual-solvent system is used to treat different components separately, specifically including: ① Add the pretreated PET fragments to hexafluoroisopropanol organic solvent and stir continuously for 60 min under the action of magnetic stirrer (500 rpm) until a homogeneous transparent viscous solution with a mass concentration of 15% is formed, i.e., a PET solution with a concentration of 15wt%. ② Chitosan and D(+)-anhydrous glucose were dissolved together in a trifluoroacetic acid and hexafluoroisopropanol solvent system at a mass ratio of 1:4 (the mass ratio of trifluoroacetic acid to hexafluoroisopropanol was 2:1), wherein the total mass ratio of chitosan and D(+)-anhydrous glucose to the mass ratio of trifluoroacetic acid and hexafluoroisopropanol solvent system was 1:2. The mixture was first initially mixed by magnetic stirring for 30 minutes, and then dispersed by ultrasonic treatment for 30 minutes to obtain a completely dissolved homogeneous solution, i.e., a chitosan-glucose solution.

[0064] (3) Preparation of reducing nanofiber membranes using electrospinning, specifically including: The above PET solution and chitosan-glucose solution were placed in a magnetic stirrer at a volume ratio of 1:1 and stirred at 500 rpm for 30 min until a homogeneous, transparent, viscous solution was formed. The mixture was then allowed to stand to allow for complete dispersion of the components. Subsequently, an electrospinning process (using a micro-injection pump combined with a high-voltage power supply) was employed to form a fibrous membrane from the obtained mixture. The electrospinning process conditions were: voltage 18 kV, feed rate 0.3 mL / h, nozzle-receiver distance approximately 15 cm, ambient temperature 25 ℃, and humidity 20%. This yielded a reduced nanofiber membrane material, abbreviated as PET-1.

[0065] Comparative Example 2: Preparation of PET-2 Fiber Membrane Material The only difference between this comparative example and Example 2 is that step (4) was not performed, i.e.: (1) First, the mineral water bottle raw material (PET) is processed into 5-8 mm fragments to obtain PET fragments. Then, the obtained PET fragments are thoroughly cleaned using deionized water and an ultrasonic cleaner. Finally, the cleaned PET fragments are placed in a vacuum drying oven at 60 ℃ for 12 h to ensure complete drying, thus obtaining pretreated PET fragments.

[0066] (2) In the solution preparation stage, a dual-solvent system is used to treat different components separately, specifically including: ① Add the pretreated PET fragments to hexafluoroisopropanol organic solvent and stir continuously for 180 min under the action of a magnetic stirrer (800 rpm) until a homogeneous, transparent, viscous solution with a mass concentration of 20% is formed, i.e., a PET solution with a concentration of 20wt%. ② Chitosan and D(+)-anhydrous glucose were dissolved together in a trifluoroacetic acid / dichloromethane mixed solvent system at a mass ratio of 1:2 (the mass ratio of trifluoroacetic acid / dichloromethane was 4:1). The total mass ratio of chitosan and D(+)-anhydrous glucose to the mass ratio of the trifluoroacetic acid / dichloromethane mixed solvent system was 1:2. The mixture was first initially mixed by magnetic stirring for 30 minutes, and then further dispersed by ultrasonic treatment (1000W power) for 30 minutes to obtain a completely dissolved homogeneous solution, i.e., a chitosan-glucose solution.

[0067] (3) Preparation of reducing nanofiber membranes using electrospinning, specifically including: The above PET solution and chitosan-glucose solution were placed in a magnetic stirrer at a volume ratio of 1:1 and stirred at 500 rpm for 30 min until a homogeneous, transparent, viscous solution was formed. The mixture was then allowed to stand to allow for complete dispersion of the components. Subsequently, an electrospinning process (using a micro-injection pump combined with a high-voltage power supply) was employed to form a fibrous membrane from the obtained mixture. The electrospinning process conditions were: voltage 17 kV, feed rate 0.2 mL / h, nozzle-receiver distance approximately 13 cm, ambient temperature 25 ℃, and humidity 10%. This yielded a reduced nanofiber membrane, abbreviated as PET-2.

[0068] Comparative Example 3: Preparation of PET-3 fiber membrane material The only difference between this comparative example and Example 3 is that step (4) was not performed, i.e.: (1) First, the mineral water bottle raw material (PET) is processed into 5-8 mm fragments to obtain PET fragments. Then, the obtained PET fragments are thoroughly cleaned using deionized water and an ultrasonic cleaner. Finally, the cleaned PET fragments are placed in a vacuum drying oven at 60 ℃ for 12 h to ensure complete drying, thus obtaining pretreated PET fragments.

[0069] (2) In the solution preparation stage, a dual-solvent system is used to treat different components separately, specifically including: ① Add the pretreated PET fragments to hexafluoroisopropanol organic solvent and stir continuously for 12 hours under the action of a magnetic stirrer (200 rpm) until a homogeneous, transparent, viscous solution with a mass concentration of 10% is formed, i.e., a PET solution with a concentration of 10wt%. ② Chitosan and D(+)-anhydrous glucose were dissolved together in a phenol / tetrachloroethane mixed solvent system (phenol / tetrachloroethane mass ratio was 4:1) at a mass ratio of 1:3, wherein the total mass ratio of chitosan and D(+)-anhydrous glucose to the mass ratio of the phenol / tetrachloroethane mixed solvent system was 1.2:3. The mixture was first initially mixed by magnetic stirring for 30 min, and then further dispersed by ultrasonic treatment (800W) for 30 min to obtain a completely dissolved homogeneous solution, i.e., a chitosan-glucose solution.

[0070] (3) Preparation of reducing nanofiber membranes using electrospinning, specifically including: The above PET solution and chitosan-glucose solution were placed in a magnetic stirrer at a volume ratio of 1:1 and stirred at 500 rpm for 30 min until a homogeneous, transparent, viscous solution was formed. The mixture was then allowed to stand to allow for complete dispersion of the components. Subsequently, an electrospinning process (using a micro-injection pump combined with a high-voltage power supply) was employed to form a fibrous membrane from the obtained mixture. The electrospinning process conditions were: voltage 16 kV, feed rate 0.2 mL / h, nozzle-receiver distance approximately 13 cm, ambient temperature 25 ℃, and humidity 30%. This yielded a reduced nanofiber membrane, abbreviated as PET-3.

[0071] Experiment 1: Physical and chemical properties testing of fiber membrane materials To investigate the differences in the physicochemical properties of the fiber membrane materials prepared in the different embodiments described above, the following tests were performed on the PET / Ag-1 fiber membrane prepared in Example 1 and the PET-1 fiber membrane prepared in Comparative Example 1: 1. Surface morphology analysis (SEM) The microstructure of the samples was analyzed using a Carl Zeiss Gemini SEM300 field emission scanning electron microscope (SEM) to investigate the morphology of the gold-sprayed samples and the dispersibility of the nano-silver. Results are shown below. Figure 2 .

[0072] like Figure 2 As shown, the microstructure of the nano-silver antibacterial membrane PET / Ag-1 prepared in Example 1 and the fiber membrane PET-1 prepared in Comparative Example 1 were observed using scanning electron microscopy (SEM). Figure 2It can be seen that the fiber membrane material obtained by electrospinning has a uniform three-dimensional network structure, with fiber diameters mainly distributed in the range of 200–500 nm. This interwoven porous structure increases the surface area of ​​the material, which is beneficial for contact with microorganisms and can improve the antibacterial effect. The fiber surface is relatively smooth and there are no obvious bead-like or fragmented phenomena, indicating that the solution concentration, applied voltage, and receiving distance are properly controlled, and the electrospinning effect is optimal under these conditions. From the high-magnification SEM image (200 nm), it can be seen that the silver nanoparticles (AgNPs) on the surface of the PET / Ag-1 fiber membrane are evenly distributed, with an approximately spherical shape and a size of about 20–50 nm. There are no obvious clusters, mainly due to the uniform effect of the reducing agent and the good coating of the polymer matrix on the silver nanoparticles.

[0073] 2. Elemental composition analysis (EDS) The elemental distribution on the sample surface was analyzed using energy-dispersive X-ray spectroscopy (EDS). The results are shown in [Figure number missing]. Figure 3 .

[0074] like Figure 3 As shown, the surface elemental composition of the sample (PET / Ag-1 prepared in Example 1) was quantitatively detected by energy dispersive spectroscopy (EDS), and the following results were obtained: 2.1 Elemental Content Analysis The carbon content is 75.62%, which is exactly the same as the theoretical carbon content of polyester materials. In the molecular structure of PET, carbon atoms are mainly distributed in two chemical environments: aromatic carbon in the benzene ring and aliphatic carbon in the methylene group, accounting for approximately 60% and 40% of the carbon element, respectively. This carbon element distribution also indicates that the material retains the basic chemical composition of PET.

[0075] The tested oxygen content was 9.13%, which is close to the theoretical value of oxygen content in the ester groups of PET molecules. The oxygen in the ester groups exists in the form of carbonyl oxygen and ether bond oxygen, with a ratio of approximately 2:1. The slightly lower oxygen content compared to the theoretical value may be due to: the presence of a certain amount of incompletely esterified end groups on the material surface; and the loss of some oxygen-containing group signals during the testing process.

[0076] When the silver content reaches 14.26%, it can be proven that nano-silver has entered the material system, and such a content gives the material sufficient antibacterial active sites. In the two forms of nano-silver, most of them are metallic silver particles with a size of 20~50nm that are attached to the fiber surface in the material through physical adsorption and chemical bonding.

[0077] The fluorine content is 0.99%. Analysis shows that the fluorine in this substance comes from the trifluoroacetic acid solvent used in the reaction. Since trifluoroacetic acid is the reaction solvent, it has been fully controlled throughout the reaction process. After purification, the fluorine content has been reduced to a very low level and will not have a significant impact on the material properties.

[0078] The test results above show that the nitrogen content is below the detection limit (less than 0.1%), which indicates that all nitrogen-containing compounds in the raw materials have been removed and no new nitrogen-containing substances have been introduced during the preparation process, indicating that the product has high purity. Moreover, the lack of nitrogen also indicates that some other potential byproducts are not present.

[0079] 2.2 Element Distribution Characteristics The surface elemental distribution map of the PET / Ag material was obtained using EDS surface scanning technology. It can be seen that silver exhibits a high degree of uniformity on the surface of the cellulose fibers. This is mainly due to the use of ultrasonic-assisted dispersion during the preparation process, and the utilization of the chelation reaction between the amino groups of chitosan and the silver nanoparticles, resulting in good silver dispersion in the prepared silver / chitosan composite material. At high magnification, uniformly sized silver particles (20-50 nm) were observed arranged along the fiber direction, with equal distances between the particles.

[0080] The surface distribution images of carbon and oxygen elements show that the peak shapes are consistent with the theoretical distribution characteristics of the PET matrix material, and exhibit a consistent distribution pattern: both carbon and oxygen signals show an increasing trend in the fiber backbone region, while the signals show the same decreasing trend in the fiber edge region. This indicates that the matrix material basically retains its complete chemical structure.

[0081] The surface scan results for fluorine showed that its distribution density was much lower than that of other elements, which is consistent with its content of 0.99%. However, measurements revealed a very small number of tiny enriched areas of fluorine (accounting for 3-5% of the entire sample area), which was due to the different solvent evaporation pathways during the preparation process.

[0082] 3. Fourier Transmission Infrared Spectroscopy (FTIR) Fourier transform infrared spectroscopy was used to test the PET / Ag-1 prepared in Example 1 and the PET-1 prepared in Comparative Example 1, respectively. The results are shown in the figure. Figure 4 .

[0083] like Figure 4 As shown, the main characteristic peaks are assigned as follows: ① The infrared spectrum of blank PET fiber (PET-1) exhibits the following characteristic changes: Characteristic vibrations of ester groups (1800–1000 cm)-1 Its strong absorption peak is located at 1719.57 cm⁻¹. -1 The stretching vibration (νC=O) of the ester carbonyl group at the position is 15.2 ± 0.3 cm. -1 This indicates that the ester bond is well-regular. The asymmetric stretching vibration of the ester group (νasC-OC) has a peak at 1250.39 cm⁻¹. -1 Symmetric stretching vibration (νsC-OC), with a spectral peak located at 1093.16 cm⁻¹. -1 Its strength ratio is 1.32:1.

[0084] Characteristic vibrations of the benzene ring (1600–600 cm⁻¹) -1 ): 1405.33 cm -1 The peak at 876.50 cm⁻¹ represents a benzene ring skeletal vibration (νC = C). This peak is Gaussian (Gaussian factor 0.92), indicating good planarity of the benzene ring. -1 The appearance of a medium-intensity peak is due to the out-of-plane bending vibration (γC—H) of the para-disubstituted benzene ring, and the position of this peak is consistent with the (875±2) cm reported in the literature.

[0085] Aliphatic chain segment vibration (3000–700 cm) -1 This spectral band reflects non-covalent interactions, primarily hydrogen bonding, between aliphatic chain segments. 2970.22 cm⁻¹ -1 (νasCH2) and 2875.18 cm -1 (νsCH2) represent the asymmetric and symmetric stretching vibrations of the methylene group, respectively; while the vibrations appearing at 724.74 cm⁻¹... -1 The band with high resolution corresponds to the in-plane rocking vibration of the methylene group (ρCH2), and the exact peak position of this band in the spectrum is (±0.5 cm). -1 () is an important parameter representing the ordered packing of molecular chains.

[0086] ②The infrared spectrum of PET / Ag-1 obtained after in-situ reduction treatment exhibits the following characteristic changes: Evidence for coordination interactions: at 503.54 cm⁻¹ -1 A new absorption band is generated at this point, which is due to the bending vibration of the Ag-O bond (γAg-O). 1717.12 cm -1 The carbonyl absorption peak at that point exhibits a red shift of 2.45 cm⁻¹. -1 This indicates that the electron cloud has shifted towards the Ag-O coordinate bond, and at 1340.23 cm⁻¹ -1 A weak absorption band of C-Ag bond appears at this point.

[0087] Molecular conformational change: the rocking vibration within the methylene plane shifts to 722.80 cm⁻¹. -1(Δν=-1.94 cm -1 The XRD results indicate that the molecular chain rigidity increases; 1094.92 cm⁻¹ -1 The COC peak at 1094.92 cm⁻¹ exhibits splitting. -1 and 1087.35 cm -1 Double peaks (interval 7.57 cm) -1 This indicates that the rotation of the ester group is hindered.

[0088] Structural stability verification: No abnormalities were observed in the 1700–1720 cm range. -1 The presence of a free carboxylic acid peak within the specified range indicates that no macromolecular hydrolysis occurred; and the peak is located at 2969.89 cm⁻¹. -1 The shift of the CH2 vibration peak at that location was very small (Δv = 0.33 cm). -1 This also indicates that the fatty acid chain segments are not significantly affected under these reaction conditions.

[0089] 4. X-ray diffraction (XRD) test Phase analysis of elements and their oxides in the samples (PET / Ag-1 prepared in Example 1 and PET-1 prepared in Comparative Example 1) was performed using a SmartLab SE X-ray powder diffractometer (Rigaku Corporation, Japan). The test conditions were: Cu-Kα radiation source (λ = 1.5406 Å), tube voltage 40 kV, tube current 40 mA, scan range 10–90° (2θ), and scan rate 5° / min. The results are shown in [Figure number missing]. Figure 5 .

[0090] like Figure 5 As shown, the pure PET sample exhibits distinct diffraction peaks at diffraction angles of 17.5° and 23.2°, which, after phase analysis, correspond to the (010) and (100) crystal planes of the PET monoclinic system, respectively. The silver-loaded PET / Ag sample, in addition to retaining the characteristic diffraction peaks of PET, shows new diffraction peaks at 2θ of 38.1°, 44.3°, 64.5°, and 77.5°. By comparing with the standard card library of the National Institute of Standards and Technology (NIST), the new diffraction peaks are assigned as follows: 38.1°: (111) crystal plane, d = 2.36 Å; 44.3°: (200) crystal plane, d = 2.04 Å; 64.5°: (220) crystal plane, d = 1.44 Å; 77.5°: (311) crystal plane, d = 1.23 Å. It is a perfect match for the standard card (PDF#04-0783) of face-centered cubic (FCC) elemental silver.

[0091] 5. Mechanical property testing The tensile properties of the specimens were analyzed using an Instron 5969 electronic universal testing machine. Samples were prepared according to the national standard GB / T 1040. Other sample dimensions included a parallel section of 21 mm, an aspect ratio of 5:1, and a thickness of 1.1 mm. Results are shown in [Figure number missing]. Figure 6 .

[0092] like Figure 6 As shown, comparing the tensile properties of the recycled PET electrospun nanofiber membrane blank control group (PET-1, PET-2, and PET-3 prepared in Comparative Examples 1-3) and the water bath in-situ reduced nanosilver experimental group (PET / Ag-1, PET / Ag-2, and PET / Ag-3 prepared in Examples 1-3), it can be seen that different water environments have a certain influence on the mechanical behavior of the materials. The standard tensile testing method was used to measure the experimental data of both groups, with three parallel samples used in each group. The differences in the intra-group means between the two groups were significant. 5.1 Mechanical properties of blank control group PET (PET-1, PET-2, and PET-3 prepared in comparative examples 1-3) The blank samples without water bath treatment exhibited excellent mechanical properties. The stress-strain curves showed typical three stages: initially linear (0–4%); a clearly defined yield plateau (greater than 150%); and after reaching the plastic deformation stage, continuous strain hardening behavior was observed until finally breaking at greater than 200%. This indicates that the original material possessed a good balance of strength and toughness.

[0093] 5.2 Changes in the performance of PET / Ag in the water bath treatment group (PET / Ag-1, PET / Ag-2, and PET / Ag-3 prepared in Examples 1-3) The mechanical properties of the materials changed after water bath treatment, with the most significant changes being: the elastic deformation stage was limited to a strain range of approximately 0-3%, the original yield plateau shrank, and the fracture strain decreased substantially. This is because, under non-directional arrangement, the fiber membrane exhibits a significant anisotropic effect during stretching, resulting in substantial differences in mechanical behavior across different locations. When Ag particles are deposited on the fiber surface, they cause stress concentration, generate internal stress, and produce random cracks, thus exacerbating these differences.

[0094] The above results indicate that the internal structure of the PET / Ag film material undergoes significant changes after water bath treatment. In terms of mechanical properties, the tensile stress shows a substantial increase after water bath treatment. Due to the water bath environment, the molecular chains in the film undergo rearrangement and orientation processes. Simultaneously, the intermolecular forces within the film are strengthened. Therefore, it can withstand greater external forces without being damaged and exhibits better mechanical strength, with increased resistance to external forces. However, the film's stiffness increases after water bath treatment, and the Young's modulus value is larger, indicating that the film is more elastic. This means that the elastic deformation under external forces will change, causing the film to lose some of its original softness and elasticity.

[0095] Experiment 2: Antibacterial performance test of fiber membrane materials 1. Experimental instruments and materials 1.1 Experimental Apparatus High-temperature and high-pressure steam sterilizer: HVE-50 model, purchased from Hirayama Corporation; Clean bench: SW-CJ-2FD model, purchased from Suzhou Jingantai Company; Thermostatic oscillator: IS-RDVI type, purchased from Crystal Semiconductor, USA.

[0096] 1.2 Culture medium LB broth medium: A507002, Sangon Biotech; Agar powder: A505255-0250, Shenggong; Potato glucose agar medium: P8931, Solarbio; Potato glucose broth: P9240, Solarbio.

[0097] 1.3 Test bacteria Staphylococcus aureus: ATCC29213; Escherichia coli: ATCC25922; Candida albicans: ATCC10231.

[0098] 2. Experimental Methods This embodiment strictly follows GB / T31402—2015 "Test Method for Antimicrobial Properties of Plastic Surfaces". The plate coating count method is used, selecting valid data with colony counts of 30–300 CFU / plate, indicating statistical significance. A double control method is employed: a blank control group using pure plastic samples (PET-1) without added antimicrobial agents, and a positive control group using a standard (3M antimicrobial surgical film 6640 / 6650) that has been verified to have good antimicrobial activity. Each group is tested in parallel five times (n=5) to eliminate random error. After inoculation with standardized bacterial solutions, samples are incubated at a constant temperature and counted under aseptic conditions in a biosafety cabinet. The average inhibition rate is then calculated according to the prescribed method. The antimicrobial performance of this type of product is judged using the effectiveness criteria specified in the standard, and product information is indicated and labeled accordingly.

[0099] 3. Results and Analysis 2.1 Results (1) According to the official report issued by the Scientific Compass Testing Agency, the silver-loaded fiber materials prepared in Examples 1, 4 and 5 and the PET fiber material prepared in Comparative Example 1 underwent standardized antibacterial testing. The results are shown in the figure. Figure 7 And Table 1-3: Table 1. Escherichia coli test results Table 2. Staphylococcus aureus test chart Table 3. Candida albicans test results according to Figure 7 The test results in Tables 1-3 show that the sample (PET / Ag-1) prepared in Example 1 of this invention has excellent antibacterial properties against Escherichia coli (ATCC25922). The bacterial concentration in the control group was 4.3 × 10⁻⁶, as determined by plate count. 6 The concentration of bacteria in the treated experimental group was only 7.5 × 10⁻⁶ CFU / mL. 4 Based on the CFU / mL, the antibacterial rate of the sample PET / Ag was calculated to be 98.26%. Similarly, using the plate count method, it was found that the initial bacterial concentration of the control group against Staphylococcus aureus (ATCC29213) was 1.85 × 10⁻⁶. 5 The concentration of bacteria in the experimental group after treatment with the sample (PET / Ag) prepared in this invention was 1.65 × 10⁻⁶ CFU / mL. 4 The concentration of CFU / mL showed an antibacterial rate of 91.08%. Antifungal inhibition tests indicated that, against Candida albicans (ATCC10231), the initial concentration of the control group was 2.2 × 10⁻⁶ CFU / mL. 5The concentration of bacteria in the experimental group after treatment with the sample (PET / Ag) prepared in this invention was 1.0 × 10⁻⁶ CFU / mL. 4 The CFU / mL concentration showed an inhibition rate of 95.45%. These figures are the averages of five parallel experiments, with a standard deviation within ±3.2%, indicating good repeatability and reliability of the sample, and clearly demonstrating its effective inhibition against different types of bacteria.

[0100] (2) Comparison with commercially available antibacterial materials and literature results Table 4 Comparison with existing products Note: [1] 3M antibacterial surgical film 6640 / 6650. [2] Zhang L, et al. Solution-dipped antibacterial PET membranes:Efficiency and durability[J]. ACS Applied Materials & Interfaces, 2021, 13(8): 10234-10243. [3] Liu H, et al. High-performance antibacterial PET via magnetronsputtering of Ag nanoparticles[J]. Surface and Coatings Technology, 2022,432: 128066. 2.2 Analysis of antibacterial mechanism Based on the above antibacterial test and material structural characterization results, it can be concluded that: (1) The PET / Ag material prepared in this invention contains 14.26% nano-silver, which is far greater than the effective amount of general antibacterial materials. Scanning electron microscopy shows that the nano-silver particles are uniformly distributed on the fiber matrix, and a large number of nano-silver particles are aggregated in the internal structure of the material. It is precisely because of this special structure that the antibacterial effect of this material is very good.

[0101] (2) Mechanism of action studies show that the PET / Ag material prepared in this invention has a dual antibacterial mechanism: on the one hand, the nano-silver particles can directly contact the cell wall of microorganisms, disrupting the cell membrane structure; on the other hand, in a humid state, the nano-silver decomposes into silver ions and releases them. These positively charged silver ions penetrate the cell wall, interfering with the activity of metabolic and other active substances within the bacteria. Therefore, based on this dual mechanism, the PET / Ag material prepared in this invention has a certain antibacterial effect against common pathogens.

[0102] (3) The porous mesh structure formed by the fibers not only gives the material good air permeability, but also increases its contact with microorganisms, thereby improving antibacterial efficiency.

[0103] (4) The antibacterial effect of the PET / Ag material of the present invention is mainly achieved through the following methods: ① Physical contact destruction: Scanning electron microscopy (SEM) shows that the nano-silver particles are uniformly dispersed. According to the particle size statistical analysis, the nano-silver particles are concentrated between 50 and 80 nm, and the spacing between the silver particles is neatly distributed without obvious aggregation. Qualitative and semi-quantitative analysis of the elements on the fiber surface by energy dispersive X-ray (EDS) detection method reveals that silver (Ag) elements are abundant on the surface of the material. Surface scanning of the material shows that the element distribution on the surface of the material is relatively uniform, and the mass fraction of silver elements in the material is nearly 18 times that of the raw material, indicating that the nano-silver has achieved effective loading and uniform distribution. ② Synergistic enhancement effect: As a polysaccharide with a special molecular structure, it has many excellent physicochemical properties. The amino groups on it can generate positive charge, and when it encounters many negatively charged bacteria, it will generate electrostatic coupling. Based on these properties, chitosan, with its excellent antibacterial properties, can be incorporated into the negatively charged ions commonly present on the surface of bacteria through non-covalent interactions, achieving better antibacterial effects and providing fundamental evidence for the research and development of antibacterial and biomedical materials. ③ Polyethylene terephthalate (PET) fibers, processed through a special process, are made into functional materials with porous structures. These materials can be used as excellent carriers for controlled release of substances. The resulting hierarchical porous system, with its nanoscale pore size distribution and controllable porosity, can provide space for loading functional components such as drugs and additives. This layered, interwoven porous structure can attach functional components through surface energy and weakly polar chemical bonds, or reduce their release rate through tortuous diffusion paths. Different three-dimensional pore networks can also adjust the release kinetics as needed, enabling the loaded components to achieve long-term, controllable release in applications such as medical consumables or smart materials.

[0104] Application Example 1: Application of Fiber Membrane Materials Based on the above antibacterial performance tests and safety assessments, the PET / Ag material prepared by this invention shows significant application potential in multiple fields: 1. Medical protective equipment field Application of surgical isolation membrane: According to third-party testing results, the PET / Ag material prepared by this invention fully meets the requirements of YY / T1632-2018 "Nonwoven fabrics for surgical drapes and surgical drapes" in inhibiting and killing Staphylococcus aureus, and can effectively avoid surgical incision infection.

[0105] Antibacterial medical device coating: The disposable peelable antibacterial membrane developed for devices with high infectivity such as ventilator tubing and urinary catheters has passed the ISO10993-5 cytotoxicity test, indicating that the material is non-toxic to human cells, and the antibacterial membrane can play a long-term antibacterial protective role.

[0106] 2. Food Packaging Sector Innovation in cold chain packaging materials: Simulated cold chain transportation tests were conducted to test the effect of packaging materials prepared from the nano-silver modified fiber membrane material of this invention on inhibiting and killing Escherichia coli. The results showed that its antibacterial performance exceeded that of traditional silver-based antibacterial agents by about 23%, meeting the relevant requirements of GB4806.7—2016 "Plastic Materials and Articles for Food Contact". It can come into contact with food, effectively extending the shelf life of rice and chicken and ensuring food safety.

[0107] 3. Water treatment field Antibacterial filtration membrane system: Its Staphylococcus aureus inhibition performance meets the requirements of YY / T1632-2018 standard. It can meet the requirements when used for drinking water purification or medical wastewater treatment. Its porous structure and antibacterial properties work synergistically to not only physically retain microorganisms in water, but also inactivate them. This is of great significance for improving the antibacterial function of the water treatment system and extending its service life.

[0108] Application verifications across various fields, all based on standardized testing procedures and authoritative certification systems, fully demonstrate the comprehensive advantages of the PET / Ag material prepared by this invention in terms of antibacterial properties, safety, and practical applicability.

[0109] Summarize: (1) Material structural properties The nano-silver modified fiber membrane material prepared by electrospinning technology in this invention exhibits a unique three-dimensional network structure. SEM images show that the fiber diameter is mostly between 200 and 500 nm, with a permeable pore structure. Energy dispersive spectroscopy (EDS) results reveal uniformly dispersed nano-silver particles of 20-50 nm in size, without significant agglomeration. The high content of nano-silver provides sufficient active sites; the uniform distribution prevents localized excessively high or low concentrations; and the stable release properties contribute to maintaining long-term antibacterial effects. Therefore, this unique structural feature ensures good mechanical properties and excellent antibacterial activity, making it valuable for applications in medical protection, food preservation, and other fields.

[0110] (2) Performance advantages ① Physical properties: The fiber network structure gives the PET / Ag material prepared by this invention good flexibility and air permeability, which can be used in many situations.

[0111] ② Antibacterial properties: Due to the high dispersion of nano-silver (loading 14.26%), the PET / Ag prepared in this invention exhibits a long-lasting antibacterial effect. Nano-silver has the following mechanisms of action: disrupting the cell membrane structure of microorganisms; interfering with bacterial metabolic processes; and inducing the production of reactive oxygen species.

[0112] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the methods and techniques disclosed above without departing from the scope of the present invention to create equivalent embodiments. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for preparing a nano-silver modified fiber membrane material, characterized in that, The method includes the following steps: S1: Plastic fragments are obtained by pre-treating plastic raw materials; S2: Add the plastic fragments to an organic solvent and stir until a homogeneous and transparent plastic solution is formed; Chitosan biopolymer and reduced glucose were dissolved together in a binary solvent system to obtain a homogeneous chitosan-glucose solution. S3: The plastic solution and chitosan-glucose solution are mixed to obtain a mixture, and then a reduced nanofiber membrane is obtained by electrospinning. S4: The reduced nanofiber membrane is immersed in an aqueous solution of silver nitrate to react and obtain a nanosilver modified fiber membrane material.

2. The preparation method according to claim 1, characterized in that, In step S1, the plastic raw material is selected from one or a mixture of two or more of polyethylene furanate, polybutylene terephthalate, and polyethylene terephthalate.

3. The preparation method according to claim 1, characterized in that, In step S1, the pretreatment includes crushing, washing, and drying; The washing process involves deep cleaning using deionized water and an ultrasonic cleaner. The drying conditions are: temperature 40-100℃, time 3-24 h; The plastic fragments are 5-8 mm in size.

4. The preparation method according to claim 1, characterized in that, In step S2, the organic solvent is selected from one or a mixture of two or more of hexafluoroisopropanol, resorcinol, 1-methyl-2-pyrrolidone, benzyl alcohol, dimethylformamide, and dimethyl sulfoxide. The stirring conditions are: 200-800 rpm, 1-12 h; The mass concentration of the plastic solution is 10%-20%.

5. The preparation method according to claim 1, characterized in that, In step S2, the viscosity of the chitosan biopolymer is 50-2000 mPa·s; The mass ratio of the chitosan biopolymer to the reduced glucose is 1:(1-4).

6. The preparation method according to claim 1, characterized in that, In step S2, the binary solvent system is composed of a first solvent and a second solvent; The first solvent is selected from any one of trifluoroacetic acid, phenol, dichloromethane, and chloroform; The second solvent is selected from any one of hexafluoroisopropanol, dichloromethane, and tetrachloroethane; The mass ratio of the first solvent to the second solvent is (5-1):

1.

7. The preparation method according to claim 1, characterized in that, In step S2, the dissolution process is as follows: first, the mixture is initially mixed by magnetic stirring for 30 minutes, and then dispersed by ultrasonic treatment to obtain a completely dissolved homogeneous solution; The ultrasound conditions are: power 200-1000 W, time 5-30 min.

8. The preparation method according to claim 1, characterized in that, In step S3, the volume ratio of the plastic solution to the chitosan-glucose solution is 1:1; The electrospinning process conditions are as follows: voltage 15-18 KV, feed speed 0.1-0.5 mL / h, nozzle-receiver distance 12-16 cm, ambient temperature 25℃, and humidity 10-30%.

9. The preparation method according to claim 1, characterized in that, In step S4, the concentration of the silver nitrate aqueous solution is 0.05-0.3 mol / L; The reaction conditions were: temperature 60℃ and time 30 min.

10. The following applications of the nano-silver modified fiber membrane material prepared by the preparation method according to any one of claims 1-9: (i) Application in the preparation of medical protective products; (ii) Applications in the preparation of food packaging products; and (iii) Application in the preparation of water treatment products.

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