Antibacterial protective film for high-frequency contact surface and method for preparing the same

Abstract

The application discloses an antibacterial protective film for high-frequency contact surfaces and a preparation method, and specifically relates to the following: metal peroxide nanoparticles and quaternary ammonium chitosan are used as shell materials, polyvinyl alcohol is used as a core material, coaxial electrospinning is carried out, cross-linking is carried out, and finally, the antibacterial protective film for high-frequency contact surfaces is obtained through drying. The antibacterial protective film for high-frequency contact surfaces with a core-shell structure and a thorn-like fiber morphology is constructed, quaternary ammonium chitosan semi-coated metal peroxide particles are used as shell spike materials, quaternary ammonium chitosan and metal peroxide particles are used for synergistic antibiosis, and polyvinyl alcohol is used as a flexible core material, so that effective antibacterial components are concentrated on the surface of the fiber, and the problem that existing high-frequency contact surfaces cannot block the spread of bacteria in a short time is solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of fiber membrane preparation, and particularly relates to a preparation method of an antibacterial protective film for high-frequency contact surfaces, and also relates to the antibacterial protective film for high-frequency contact surfaces. BACKGROUND

[0002] The common disinfection method in public places is to periodically spray disinfectant water. The effective bactericidal components such as sodium hypochlorite in the disinfectant water volatilize into the air with alcohol, which has a relatively irritating odor and is harmful to the body. The traditional method of periodically spraying disinfectant water for sterilization can wet the surface of objects, volatilize irritating odors, and is limited by the frequency of spraying, and cannot achieve real-time sterilization to block the spread of bacteria. The most effective method to solve the above problems is to cover a layer of antibacterial protective film on the high-frequency contact surface, which can achieve real-time sterilization. The antibacterial protective film can protect the surface of the object and does not volatilize harmful gases, and can achieve the goal of real-time and rapid adsorption of bacteria to block the spread of bacteria and inactivation.

[0003] A Chinese patent "Template-free chitosan@inorganic SiO2 nanofiber aerogel and preparation method and application thereof" (application number: 202310603535.7, publication number: CN116651406A, publication date: August 29, 2023) discloses a template-free chitosan@inorganic SiO2 nanofiber aerogel and a preparation method and application thereof, which has three antibacterial effects of adsorption / complexation / contact. However, the single bacteriostatic component limits the sterilization rate in a short time, and real-time sterilization cannot be achieved. A Chinese patent "Antibacterial and oil-proof high-barrier self-assembled film and preparation method and application thereof" (application number: 202311116298.8, publication number: CN117050363A, publication date: November 14, 2023) discloses an antibacterial and oil-proof high-barrier self-assembled film and a preparation method and application thereof, which can effectively improve the performance of waterproofing, oil-proofing, and barrier, and introduce a composite antibacterial agent to improve the antibacterial performance. However, nano-titanium dioxide is a photocatalyst, and its antibacterial performance depends on ultraviolet irradiation. It is difficult to ensure sufficient ultraviolet irradiation on high-frequency contact surfaces in public places such as elevator buttons, door handles, and counters, and the antibacterial effect is inhibited. A Chinese patent "Antibacterial fiber membrane releasing peroxide in situ patterning and preparation method thereof" (application number: 202311041833.8, publication number: CN117071180A, publication date: November 17, 2023) discloses an antibacterial fiber membrane releasing peroxide in situ patterning and a preparation method thereof. When the antibacterial fiber membrane contacts the wound surface, the soluble polymer in the fiber shell dissolves to form a nano-groove structure in situ patterning on the fiber surface, which is beneficial to cell adhesion and proliferation along the fiber direction. At the same time, metal peroxide nanoparticles in the fiber shell are rapidly released to achieve simultaneous sterilization and promote vascular regeneration effect. However, the antibacterial effect still relies on the release of metal peroxide in a large amount of liquid environment. SUMMARY

[0004] The purpose of the present application is to provide a preparation method of an antibacterial protective film for high-frequency contact surfaces, which solves the problem that existing high-frequency contact surfaces cannot block the spread of bacteria in a short time.

[0005] Another purpose of the present application is to provide the above antibacterial protective film for high-frequency contact surfaces.

[0006] The technical solution adopted by the present application is that the preparation method of the antibacterial protective film for high-frequency contact surfaces uses metal peroxide nanoparticles and quaternary ammonium chitosan as shell layer materials, polyvinyl alcohol as core material, carries out coaxial electrospinning, carries out crosslinking, and finally dries to obtain the antibacterial protective film for high-frequency contact surfaces.

[0007] The present application is also characterized in that,

[0008] The specific implementation is as follows:

[0009] Step 1, prepare the shell precursor of the antibacterial protective film for high-frequency contact surfaces; specifically:

[0010] Step 1.1, dissolve quaternary ammonium chitosan and polyvinyl alcohol in deionized water, heat and stir in a water bath, cool to room temperature, and obtain a quaternary ammonium chitosan solution;

[0011] Step 1.2, dissolve metal salt and polyvinylpyrrolidone in deionized water, stir in an ice water bath at 0-2℃, then add NaOH aqueous solution, then add H2O2 solution drop by drop, and continue to stir in ice water bath for 20-40min, then wash with ethanol multiple times by centrifugation, then add to the quaternary ammonium chitosan solution, stir for 4-6h, and prepare metal peroxide nanoparticles coated with quaternary ammonium chitosan, which is the shell precursor of the antibacterial protective film for high-frequency contact surfaces;

[0012] Step 2, dissolve polyvinyl alcohol in deionized water, heat and stir in a water bath, and prepare the core precursor of the antibacterial protective film for high-frequency contact surfaces;

[0013] Step 3, construct the high-frequency contact surface antibacterial protective film with a thorn-like core-shell structure;

[0014] Step 3.1, place the shell precursor of the antibacterial protective film for high-frequency contact surfaces prepared in step 1 in the shell extrusion equipment in the electrospinning equipment, place the core precursor of the antibacterial protective film for high-frequency contact surfaces prepared in step 2 in the core layer extrusion equipment in the electrospinning equipment, carry out coaxial electrospinning, and obtain a composite nanofiber membrane;

[0015] Step 3.2, the glutaraldehyde solution is dissolved in anhydrous ethanol to prepare a glutaraldehyde cross-linking solution with a volume concentration of 4-6%, and the dried composite nanofiber membrane is placed in the glutaraldehyde cross-linking solution for water bath heating cross-linking, and the cross-linked composite nanofiber membrane is dried for 10-20 min to prepare the high-frequency contact surface antibacterial protective film with a thorn-like core-shell structure.

[0016] In step 1.1, the heating and stirring temperature is 70-90 DEG C, and the heating and stirring time is 2-3 h; the mass ratio of quaternized chitosan, polyvinyl alcohol and deionized water is 0.1-0.15:0.4-0.6:10-15.

[0017] In step 1.2, the metal salt is at least one of cupric chloride dihydrate and silver nitrate; the mass ratio of the metal salt, polyvinylpyrrolidone and deionized water is 0.15-0.2:1-1.5:50-70.

[0018] In step 2, the heating and stirring temperature is 70-90 DEG C, and the heating and stirring time is 2-3 h.

[0019] In step 3.1, during electrospinning, the voltage is set to 18 kV, the injection speed is set to 0.0003 mm / s-0.0006 mm / s, the distance between the spinneret and the collection plate is 20 cm, and the spinning time is 4.5 h.

[0020] In step 3.2, the heating temperature is 50-60 DEG C, and the heating time is 35-45 min.

[0021] Another technical solution adopted by the present application is that the high-frequency contact surface is protected by the antibacterial protective film prepared by the above method.

[0022] The present application has the following advantages:

[0023] 1. In the present application, metal peroxide nanoparticles are exposed on the surface of the fiber to form a thorn-like fiber morphology, and metal peroxide nanoparticles and quaternized chitosan are uniformly distributed on the surface of the fiber. When the skin surface (such as the finger pulp) contacts the antibacterial protective film, on the one hand, a large number of positively charged amino groups on the quaternized chitosan molecules are electrostatically attracted to the negatively charged bacteria to capture the bacteria, which can effectively prevent the bacteria from falling off and thus spreading, and at the same time has bactericidal ability; on the other hand, the secretion such as sweat on the skin surface is weakly acidic, which can induce the reaction of metal peroxide nanoparticles with water molecules in the humid environment to release metal ions and a large amount of hydrogen peroxide and hydroxyl radicals and other reactive oxygen species (ROS), and the oxidative stress caused by excessive ROS can damage biological molecules such as proteins, lipids, RNA and DNA, thereby inactivating the bacteria on the high-frequency contact surface in a short time. The two work together to inactivate the bacteria in a short time, thereby blocking the transmission path of the bacteria on the high-frequency contact surface.

[0024] 2. The application constructs an antibacterial fiber membrane with a thorny core-shell structure for high-frequency contact surfaces, wherein the shell layer is a functional part that plays a role in adsorption and antibacterial effect, and quaternized chitosan semi-coated metal peroxide particles are used as the shell layer thorn material of the antibacterial fiber membrane for high-frequency contact surfaces, quaternized chitosan and metal peroxide particles form a semi-coated structure, and the cationic properties of quaternized chitosan can both adsorb bacteria and have antibacterial ability, and work synergistically with metal peroxide to achieve adsorption and rapid inactivation of bacteria, effectively blocking the spread of bacteria on high-frequency contact surfaces; the core is mainly used to improve the mechanical properties, and polyvinyl alcohol is used as the flexible core material of the antibacterial fiber membrane for high-frequency contact surfaces, which not only supports the shell layer, but also improves the spinning performance and flexibility of the fiber membrane. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a schematic diagram of the antibacterial protective film structure for high-frequency contact surfaces of Example 1;

[0026] Figure 2 is the antibacterial activity of the antibacterial protective film of each example when contacted with bacteria for 1 h;

[0027] Figure 3 is a detection diagram of the generation of hydrogen peroxide by the antibacterial protective film of Example 1. DETAILED DESCRIPTION

[0028] The application will be described in detail below in combination with the drawings and specific embodiments.

[0029] The preparation method of the antibacterial protective film for high-frequency contact surfaces of the application uses metal peroxide nanoparticles and quaternized chitosan as the shell layer material, and polyvinyl alcohol as the core material, performs coaxial electrospinning, crosslinking, and finally drying to obtain the antibacterial protective film for high-frequency contact surfaces.

[0030] The following steps are specifically implemented:

[0031] Step 1, preparation of the shell layer precursor of the antibacterial protective film for high-frequency contact surfaces;

[0032] Step 1.1, quaternized chitosan and polyvinyl alcohol are dissolved in deionized water, heated and stirred in a water bath, cooled to room temperature, and a quaternized chitosan solution is obtained;

[0033] The heating and stirring temperature is 70-90℃, and the heating and stirring time is 2-3h;

[0034] The mass ratio of quaternized chitosan, polyvinyl alcohol and deionized water is 0.1-0.15:0.4-0.6:10-15;

[0035] Step 1.2, the metal salt and polyvinylpyrrolidone are dissolved in deionized water, 0.15 mol / L NaOH aqueous solution is added under the condition of 0-2℃ ice water bath stirring, then H2O2 solution is added dropwise, and the ice water bath stirring is continued for 20-40 min, then the product is washed with ethanol for several times by centrifugation, then the product is added to the quaternary ammonium chitosan solution, and stirred for 4-6 h to obtain the quaternary ammonium chitosan coated metal peroxide nanoparticles, which are the shell precursor of the antibacterial protective film for high-frequency contact surface;

[0036] The metal salt is at least one of copper chloride dihydrate and silver nitrate;

[0037] The mass ratio of the metal salt, polyvinylpyrrolidone and deionized water is 0.15-0.2:1-1.5:50-70;

[0038] The concentration of the NaOH aqueous solution is 0.15 mol / L; the volume concentration of the H2O2 solution is 3%; in order to ensure sufficient reaction, excess NaOH aqueous solution and H2O2 solution are added, the volume of the NaOH aqueous solution is 15-25 mL according to 2.5-3 times of the amount of substance of the metal salt, and the volume of the H2O2 solution is 95-115 mL according to 83-89 times of the amount of substance of the metal salt.

[0039] Step 2, preparation of the core precursor of the antibacterial protective film for high-frequency contact surface;

[0040] The polyvinyl alcohol is dissolved in deionized water, and heated and stirred in a water bath to obtain the core precursor of the antibacterial protective film for high-frequency contact surface;

[0041] The heating and stirring temperature is 70-90℃, and the heating and stirring time is 2-3 h;

[0042] The mass fraction of the polyvinyl alcohol is 8%-10%;

[0043] Step 3, construction of the high-frequency contact surface antibacterial protective film with thorn-like core-shell structure;

[0044] Step 3.1, the precursor of the shell layer of the high-frequency contact surface antibacterial protective film prepared in step 1 is placed in the shell layer extrusion device in the electrospinning equipment, and the core precursor of the high-frequency contact surface antibacterial protective film prepared in step 2 is placed in the core layer extrusion device in the electrospinning equipment, and coaxial electrospinning is carried out to obtain a composite nanofiber membrane;

[0045] During electrospinning, the voltage is set to 18 kV, the push injection speed is set to 0.0003 mm / s-0.0006 mm / s, the distance between the spinneret and the collection plate is 20 cm, and the spinning time is 4.5 h;

[0046] Step 3.2, the glutaraldehyde solution is dissolved in anhydrous ethanol to prepare a glutaraldehyde cross-linking solution with a volume concentration of 4-6%, and the dried composite nanofiber membrane is placed in the glutaraldehyde cross-linking solution for water bath heating cross-linking, and the cross-linked composite nanofiber membrane is dried for 10-20 min to prepare a high-frequency contact surface antibacterial protective film with a thorn-like core-shell structure;

[0047] The heating temperature is 50-60 DEG C, and the heating time is 35-45 min.

[0048] The volume concentration of the glutaraldehyde solution is 50%;

[0049] The present application solves the problem that the existing high-frequency contact surface cannot block the spread of bacteria in a short time by constructing an antibacterial protective film for high-frequency contact surface with a core-shell structure and a thorn-like fiber morphology, using quaternary ammonium chitosan semi-coated metal peroxide particles as a shell layer spike material, quaternary ammonium chitosan and metal peroxide particles for synergistic antibacterial effect, and using polyvinyl alcohol as a flexible core material to concentrate effective antibacterial ingredients on the fiber surface.

[0050] Example 1

[0051] 0.15g of quaternary ammonium chitosan and 0.5g of polyvinyl alcohol are weighed into 15mL of deionized water, heated in a water bath at 70 DEG C for 3h, and cooled to room temperature. 0.2g of copper chloride dihydrate and 1.5g of polyvinylpyrrolidone are weighed into 70mL of deionized water, and stirred in an ice water bath at 0-2 DEG C. 25mL of 0.15mol / L NaOH aqueous solution is added, 115mL of 3% volume concentration H2O2 solution is added dropwise, and the ice water bath stirring is continued for 40min. After washing with ethanol several times by centrifugation, the quaternary ammonium chitosan coated metal peroxide nanoparticles are added to the cooled quaternary ammonium chitosan solution, stirred for 6h, and then placed in the shell extrusion equipment of the electrospinning equipment as the shell layer precursor of the antibacterial protective film for high-frequency contact surface. 1g of polyvinyl alcohol is weighed into 10mL of deionized water, heated in a water bath at 70 DEG C for 3h, and then placed in the core extrusion equipment of the electrospinning equipment as the flexible core precursor of the antibacterial protective film for high-frequency contact surface. The voltage is set to 18kV, the push injection speed is set to 0.0003mm / s, the distance between the spinneret and the collection plate is 20cm, and coaxial electrospinning is carried out for 4.5h. Finally, in a fume hood, a glutaraldehyde cross-linking solution is prepared, 5mL of 50% volume concentration glutaraldehyde solution is dissolved in 45mL of anhydrous ethanol to obtain a glutaraldehyde cross-linking solution with a volume concentration of 5%, and the obtained fiber membrane is dried and placed in 50mL of the cross-linking solution, heated in a water bath at 55 DEG C for 40min. The cross-linked composite nanofiber membrane is dried at room temperature for 20min to prepare the antibacterial protective film for high-frequency contact surface.

[0052] Example 2

[0053] Take 0.12 g of quaternary ammonium chitosan and 0.5 g of polyvinyl alcohol into 13 mL of deionized water, heat in water bath at 85℃ for 2.5 h, cool to room temperature, take 0.19 g of silver nitrate and 1.4 g of polyvinylpyrrolidone into 66 mL of deionized water, 0-2℃ ice water bath, stirring, adding 23 mL of 0.15 mol / L NaOH aqueous solution, dropwise adding 111 mL of 3% H2O2 solution and continuing ice water bath stirring for 30 min, then washing with ethanol several times by centrifugation, adding to the cooled quaternary ammonium chitosan solution, stirring for 5.5 h, preparing quaternary ammonium chitosan coated metal peroxide nanoparticles as the shell precursor of the high-frequency contact surface antibacterial protective film, then placing in the shell extrusion equipment of the electrospinning equipment. Take 1 g of polyvinyl alcohol into 10 mL of deionized water, heat in water bath at 85℃ for 2.5 h, prepare the flexible core precursor of the high-frequency contact surface antibacterial protective film, then place in the core extrusion equipment of the electrospinning equipment. The voltage is set to 18 kV, the push injection speed is set to 0.0003 mm / s, the distance between the spinneret and the collection plate is 20 cm, and the coaxial electrospinning is carried out for 4.5 h. Finally, in the fume hood, prepare 5% glutaraldehyde crosslinking solution by taking 5 mL of 50% glutaraldehyde solution into 45 mL of absolute ethanol, dry the spun fiber membrane, and place it in 50 mL of crosslinking solution, heat in water bath at 50℃ for 45 min. Dry the crosslinked composite nanofiber membrane at room temperature for 15 min to prepare the high-frequency contact surface antibacterial protective film.

[0054] Example 3

[0055] Take 0.13 g of quaternary ammonium chitosan and 0.4 g of polyvinyl alcohol in 11 mL of deionized water, water bath heating 80℃ stirring 2.5h, cooling to room temperature, take 0.17 g of copper chloride dihydrate and 1.25 g of polyvinyl pyrrolidone in 60 mL of deionized water, 0-2℃ ice water bath, stirring 20 mL of 0.15 mol / L NaOH aqueous solution, dropwise addition of 105 mL of 3% H2O2 solution and continue ice water bath stirring for 30 min, then washed with ethanol multiple times after centrifugation, added to the cooled quaternary ammonium chitosan solution, stirring for 5h, prepared quaternary ammonium chitosan coated metal peroxide nanoparticles as the shell precursor of the high frequency contact surface antibacterial protective film, and then placed in the shell extrusion equipment of the electrospinning equipment. Take 0.9 g of polyvinyl alcohol in 10 mL of deionized water, water bath heating 80℃ stirring 2.5h, prepared the flexible core precursor of the high frequency contact surface antibacterial protective film, and then placed in the core extrusion equipment of the electrospinning equipment. The voltage is set to 18kV, the push injection speed is set to 0.0004mm / s, the distance between the spinneret and the collection plate is 20cm, and the coaxial electrospinning is carried out for 4.5h. Finally, in the fume hood, configure glutaraldehyde crosslinking liquid, take 8 mL of 50% glutaraldehyde solution in 42 mL of absolute ethanol to obtain 6% glutaraldehyde crosslinking liquid, put the composite nanofiber membrane dried in step 4 into 50 mL of crosslinking liquid, water bath heating 60℃, heating time is 35 min. The crosslinked composite nanofiber membrane is dried at room temperature for 20 min, and the high frequency contact surface antibacterial protective film is prepared.

[0056] Example 4

[0057] Take 0.10 g of quaternary ammonium chitosan and 0.6 g of polyvinyl alcohol in 10 mL of deionized water, water bath heating 75℃ stirring 2h, cooling to room temperature, take 0.16 g of copper chloride dihydrate and 1.1 g of polyvinylpyrrolidone in 55 mL of deionized water, 0-2℃ ice water bath, stirring 18 mL of 0.15 mol / L NaOH aqueous solution, dropwise addition of 3% volume concentration H2O2 solution 99 mL and continue ice water bath stirring 25 min, then washed with ethanol multiple times after centrifugation, added to the cooled quaternary ammonium chitosan solution, stirring 4.5h, prepared quaternary ammonium chitosan coated metal peroxide nanoparticles as high frequency contact surface with antibacterial protective film shell precursor, then placed in the electrospinning equipment shell extrusion equipment. Again take 0.8 g of polyvinyl alcohol in 10 mL of deionized water, water bath heating 75℃ stirring 3h, prepared high frequency contact surface with antibacterial protective film flexible core precursor, then placed in the electrospinning equipment core layer extrusion equipment. The voltage is set to 18kV, the push injection speed is set to 0.0005mm / s, the distance between the spinneret and the collection plate is 20cm, coaxial electrospinning is carried out, the spinning time is 4.5h. Finally in the fume hood, configuration glutaraldehyde crosslinking liquid, take 5mL volume concentration of 50% glutaraldehyde solution in 45mL of absolute ethanol to prepare a volume concentration of 5% glutaraldehyde crosslinking liquid, the composite nanofiber membrane after drying in step 4 is placed in 50mL crosslinking liquid, water bath heating 55℃, heating time is 40min. The crosslinked composite nanofiber membrane is dried at room temperature for 15 min, prepared high frequency contact surface with antibacterial protective film.

[0058] Example 5

[0059] Take 0.11 g of quaternary ammonium chitosan and 0.6 g of polyvinyl alcohol into 10 mL of deionized water, heat in water bath at 90℃ for 2h, cool to room temperature, take 0.15 g of copper chloride dihydrate and 1 g of polyvinylpyrrolidone into 50 mL of deionized water, 0-2℃ ice water bath, stirring, adding 15 mL of 0.15 mol / L NaOH aqueous solution, dropwise adding 95 mL of 3% H2O2 solution and continuing ice water bath stirring for 20 min, then washing with ethanol several times, then adding to the cooled quaternary ammonium chitosan solution, stirring for 4h, preparing quaternary ammonium chitosan coated metal peroxide nanoparticles as the shell precursor of the high-frequency contact surface antibacterial protective film, and then placing it in the shell extrusion equipment of the electrospinning equipment. Then take 0.8 g of polyvinyl alcohol into 10 mL of deionized water, heat in water bath at 90℃ for 2h, prepare the flexible core precursor of the high-frequency contact surface antibacterial protective film, and then place it in the core extrusion equipment of the electrospinning equipment. The voltage is set to 18kV, the push injection speed is set to 0.0006mm / s, the distance between the spinneret and the collection plate is 20cm, and the coaxial electrospinning is carried out for 4.5h. Finally, in the fume hood, prepare glutaraldehyde crosslinking solution, take 4 mL of 50% glutaraldehyde solution to prepare 4% glutaraldehyde crosslinking solution, and then place the composite nanofiber membrane after step 4 in 50 mL of crosslinking solution, heat in water bath at 60℃ for 35 min. Dry the crosslinked composite nanofiber membrane at room temperature for 10 min to prepare the high-frequency contact surface antibacterial protective film.

[0060] The metal peroxide nanoparticles are mixed and spun with the high molecular polymer, when the skin surface (such as the finger pulp) contacts the metal peroxide nanoparticles, the skin surface secretion such as sweat is weakly acidic, which can induce the reaction of the metal peroxide nanoparticles and the water molecules in the humid environment, release metal ions and a large amount of hydrogen peroxide and hydroxyl radicals and other reactive oxygen species (ROS), and the oxidative stress caused by excessive ROS can inactivate the bacteria on the high-frequency contact surface in a short time.

[0061] Figure 1 The structure of the high-frequency contact surface antibacterial protective film of example 1 is shown in the schematic diagram, the antibacterial protective film has a core-shell structure, the core is polyvinyl alcohol, the shell layer is composed of quaternary ammonium chitosan and CuO2 nanoparticles, and the CuO2 nanoparticles are half-coated on the quaternary ammonium chitosan; Figure 2 The antibacterial activity of each example antibacterial protective film when contacting bacteria for 1h is shown in the table, 1×1cm 2The antibacterial protective film was taken out after being in contact with a certain amount of bacteria for 1 h, and then cultured for another 24 h to calculate the antibacterial rate. The antibacterial protective film of each example only contacted with bacteria for 1 h, and the antibacterial rate was more than 90%, which had obvious bactericidal effect, could realize rapid and efficient antibacterial in a short time, and the antibacterial effect was obviously improved with the increase of peroxide content. Taking the composite nanofiber film prepared in Example 1 as an example, Figure 3 is the detection diagram of hydrogen peroxide generated by the composite nanofiber film of Example 1. The 1x1 cm 2 antibacterial protective film was immersed in a phosphate buffer containing tetramethyl benzidine (40 μg / mL), and after different culture times, the phosphate buffer after culture was mixed with titanium sulfate solution (1 mg / mL) at a volume ratio of 1:1, and the absorbance of the culture solution at 412 nm was detected by a spectrophotometer to characterize the hydrogen peroxide generation capacity of the antibacterial fiber film. Before 1 h, the CuO2 nanoparticles exposed on the surface of the antibacterial protective film reacted with the environment to generate a large amount of hydrogen peroxide, and after 1 h, the CuO2 nanoparticles exposed on the surface were consumed, and the CuO2 nanoparticles inside the antibacterial protective film coated in chitosan reacted with the environment to generate a large amount of hydrogen peroxide again. The generation of a large amount of hydrogen peroxide and hydroxyl radicals and other reactive oxygen species (ROS) can cause oxidative stress and inactivate the bacteria on the high-frequency contact surface in a short time.

Claims

1. A method for producing an antibacterial protective film for a high-frequency contact surface, characterized by, Specifically, the following steps are implemented: Step 1, preparing a shell precursor of the antibacterial protective film for high-frequency contact surface; specifically: Step 1.1, dissolving quaternary ammonium chitosan and polyvinyl alcohol in deionized water, heating and stirring in a water bath, cooling to room temperature, and obtaining a quaternary ammonium chitosan solution; Step 1.2, dissolving a metal salt and polyvinylpyrrolidone in deionized water, stirring under the condition of 0-2℃ ice water bath, adding NaOH aqueous solution, then adding H2O2 solution drop by drop, and continuously stirring in ice water bath for 20-40min, then washing with ethanol multiple times by centrifugation, then adding to the quaternary ammonium chitosan solution, stirring for 4-6h, and preparing quaternary ammonium chitosan coated metal peroxide nanoparticles, which is the shell precursor of the antibacterial protective film for high-frequency contact surface; The metal salt is at least one of copper chloride dihydrate and silver nitrate; the mass ratio of the metal salt, polyvinylpyrrolidone and deionized water is 0.15-0.2:1-1.5:50-70; Step 2, dissolving polyvinyl alcohol in deionized water, heating and stirring in a water bath, and preparing a core precursor of the antibacterial protective film for high-frequency contact surface; Step 3, constructing a high-frequency contact surface antibacterial protective film with a thorn-like core-shell structure; Step 3.1, placing the shell precursor of the high-frequency contact surface antibacterial protective film prepared in step 1 in the shell extrusion equipment in the electrospinning equipment, placing the core precursor of the high-frequency contact surface antibacterial protective film prepared in step 2 in the core layer extrusion equipment in the electrospinning equipment, and performing coaxial electrospinning to obtain a composite nanofiber membrane; Step 3.2, dissolving glutaraldehyde solution in anhydrous ethanol to prepare a glutaraldehyde crosslinking solution with a volume concentration of 4-6%, placing the dried composite nanofiber membrane in the glutaraldehyde crosslinking solution, performing water bath heating crosslinking, drying the crosslinked composite nanofiber membrane for 10-20min, and preparing a high-frequency contact surface antibacterial protective film with a thorn-like core-shell structure.

2. The method for producing an antibacterial protective film for a high frequency contact surface according to claim 1, characterized by, In step 1.1, the heating and stirring temperature is 70-90℃, and the heating and stirring time is 2-3h; the mass ratio of quaternary ammonium chitosan, polyvinyl alcohol and deionized water is 0.1-0.15:0.4-0.6:10-15.

3. The method for preparing an antibacterial protective film for a high frequency contact surface according to claim 1, characterized in that, In step 2, the heating and stirring temperature is 70-90℃, and the heating and stirring time is 2-3h.

4. The method for preparing an antibacterial protective film for a high frequency contact surface according to claim 1, characterized in that, In step 3.1, during electrospinning: the voltage is set to 18kV, the push injection speed is set to 0.0003mm / s-0.0006mm / s, the distance between the spinneret and the collection plate is 20cm, and the spinning time is 4.5h.

5. The method for preparing an antibacterial protective film for a high frequency contact surface according to claim 1, characterized in that, In step 3.2, the heating temperature is 50-60℃, and the heating time is 35-45min.

6. An antibacterial protective film for high frequency contact surfaces, characterized by Prepared by the method of any one of claims 1-5.

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