Method for preparing nanofiber doped with large-particle antibacterial agent by needle-free electrostatic spinning device

Abstract

The invention provides a method for preparing nanofiber doped with a large-particle antibacterial agent by a needleless electrostatic spinning device. The method comprises the following steps: adding a high-molecular polymer and a large-particle antibacterial substance into an organic solvent to prepare a spinning solution; electrospinning nanofibers doped with a large-particle antibacterial agent on the surface of the fabric through a needleless electrostatic spinning device; the needleless electrostatic spinning device comprises an electrode wire, a liquid brushing tank, a direct-current high-voltage power supply, a winding roller, a metal plate, a liquid storage bottle and a movable spraying brush. The electrode wire is used for replacing a needle type electrode, production efficiency is improved, and needle blockage is avoided; the liquid storage bottle reduces volatilization of the spinning liquid, the spinning liquid is continuously stirred and pumped to the liquid brushing tank to be brushed on the electrode wires, the antibacterial agent is prevented from being deposited, and the antibacterial agent is evenly distributed on the nanofibers; an air injection brush head is installed to prevent large particles from depositing on the electrode wires; according to the method, the selection limitation on the high-molecular polymer and the antibacterial agent is small, and the prepared antibacterial fabric has lasting antibacterial property.

Description

Technical Field

[0001] The present invention belongs to the technical field of textiles, and particularly relates to a method for preparing nanofibers doped with large particle antibacterial agents by a needleless electrospinning device. Background Art

[0002] Nanofibers with antibacterial effects are widely used in various industries due to their excellent properties, especially in the fields of medical and health, etc., with the advantage of having multiple effects. Antibacterial fibers can inhibit the growth of bacteria by releasing antibacterial substances and have the characteristics of long-term antibacterial. With the improvement of people's requirements for health and hygiene, antibacterial fibers will have a broader application prospect.

[0003] Currently, the preparation of antibacterial fibers mainly adopts the following several methods: 1) Blending spinning method: Blending antibacterial substances with polyester chips to make antibacterial fibers. 2) Composite spinning method: Finishing antibacterial fibers with other fibers together to obtain antibacterial fibers with various structures through composite textile processes. 3) Post-finishing method: After the yarn or fabric is finished, finishing the antibacterial agent onto the fiber to endow the fiber with antibacterial properties. 4) Ion exchange method: Using fibers with ion exchange groups to displace a layer of antibacterial ions on the fiber surface through ion exchange reactions. 5) Sizing finishing method: Adding antibacterial agents at appropriate processing stages according to the types and properties of the selected antibacterial agents.

[0004] The blending spinning method has relatively little limitation on materials, can make the antibacterial agent evenly distributed in the fiber, and the antibacterial performance is long-term stable, so it is the most widely used. However, for the situation where antibacterial substances are insoluble in the spinning solution, especially large particle antibacterial substances, there is a lack of efficient preparation means. Electrospinning uses the action of electric field force to stretch and refine the spinning solution, and collects antibacterial nanofibers on the receiving device. However, during the spinning process, antibacterial substances will deposit in the needle tube, resulting in uneven distribution of the antibacterial agent doped in the fiber, and large particle antibacterial substances will also block the needle head, affecting the spinning efficiency. Summary of the Invention

[0005]

Technical Problem

[0006] During electrospinning, insoluble large particle antibacterial substances in the spinning solution will deposit in the needle tube, resulting in uneven distribution of the antibacterial substances doped in the fiber, blocking the needle head, and affecting the spinning efficiency. Currently, there is a lack of efficient electrospinning means to spin nanofibers with evenly doped insoluble large particle antibacterial substances.

[0007]

Technical Solution

[0008] In view of the above problems, the present invention proposes a technique for preparing nanofibers doped with large particle antibacterial agents through a needleless electrospinning device. An electrode wire is used instead of a traditional needle electrode to improve the production efficiency of electrospinning and avoid the problem of needle clogging. The insoluble antibacterial agent is added to the spinning solution, stirred thoroughly, transferred to a liquid storage bottle, and continuously stirred. At the same time, it is pumped to a brush liquid tank to reciprocate on the electrode wire to brush the spinning solution, avoiding the uneven distribution of antibacterial particles in the fibers caused by the deposition of antibacterial agents, reducing the volatilization of the spinning solution, and saving costs. An air jet brush head is installed under the electrode wire to prevent large particles from depositing on the electrode wire and reduce the equipment maintenance cost.

[0009] The first object of the present invention is to provide a needleless electrospinning device, including components: an electrode wire, a brush liquid tank, a DC high-voltage power supply, a winding roller, a metal plate, a liquid storage bottle, and a moving spray brush; the electrode wire is connected in series with the brush liquid tank; the electrode wire is connected to the positive pole of the DC high-voltage power supply; a metal plate is arranged directly above the electrode wire; the electrode wire is parallel to the metal plate; the metal plate is connected to the negative pole of the DC high-voltage power supply or grounded; the liquid storage bottle is connected to the brush liquid tank; the brush liquid tank reciprocates on the electrode wire; the moving spray brush reciprocates directly below the electrode wire; the winding roller drives the fabric to move between the electrode wire and the metal plate. The needleless electrospinning device is as Figure 1 shown.

[0010] In an embodiment of the present invention, the electrode wire is a smooth metal wire; the distance between the electrode wire and the metal plate is 10 - 30 cm; the needleless electrospinning device has a plurality of electrode wires arranged in parallel; the distance between adjacent two electrode wires is 300 - 500 mm; the length of the electrode wire is 25 - 60 cm. The electrode wire is the emitter of the spinning solution, and the length of each electrode wire is set according to the required fiber membrane size.

[0011] In an embodiment of the present invention, the liquid storage bottle is a sealed bottle for containing the spinning solution; the liquid storage bottle is provided with a stirring device. The liquid storage bottle is sealed to prevent the rapid volatilization of organic solvents in the spinning solution. During electrospinning, the stirring device stirs the spinning solution to make the insoluble large particle antibacterial agent evenly distributed in the spinning solution, and then evenly distributed in the electrospun polymer nanofibers.

[0012] In a preferred embodiment of the present invention, a magnetic stirring device is provided in the liquid storage bottle.

[0013] In an embodiment of the present invention, the moving spray brush sprays air flow and a small amount of organic solvent onto the electrode wire. With the help of a weak air flow, the insoluble large particle antibacterial agent can be better deposited on the fabric along with the fibers. A small amount of solvent will be accompanied during the air jet process of the moving spray brush to assist the brush liquid tank to drive a small amount of large particle antibacterial agents deposited on the electrode wire, avoiding the rapid volatilization of the spinning solution on the electrode wire, and the deposition of the polymer and large particle antibacterial agents on the electrode wire.

[0014] During electrospinning, the spinning solution stored in the liquid storage bottle is pumped to the brushing trough. The brushing trough moves back and forth to brush the spinning solution onto the electrode wire. The moving spraying brush sprays a weak air flow and a small amount of solvent onto the electrode wire. Under the action of the electric field and the weak air flow, the spinning solution on the electrode wire forms polymer nanofibers and deposits on the fabric. When the moving spraying brush sprays air, the air flow drives the solvent to be ejected.

[0015] The second object of the present invention is to provide a method for preparing nanofibers doped with large particle antibacterial agents by using the above needleless electrospinning device, comprising the steps of:

[0016] S1. Adding a polymer and a large particle antibacterial substance to an organic solvent, and stirring evenly to obtain a spinning solution;

[0017] S2. Electrospinning nanofibers doped with large particle antibacterial agents onto the surface of the fabric through the needleless electrospinning device to obtain an antibacterial fabric.

[0018] In an embodiment of the present invention, the polymer is selected from one or more of polycaprolactone, polyurethane, polyacrylonitrile, polystyrene, polyvinylidene fluoride, polylactic acid, and polymethyl methacrylate.

[0019] In an embodiment of the present invention, the organic solvent is selected from one or more of acetone, N,N-dimethylformamide (DMF), dimethylacetamide, tetrahydrofuran, and ethanol.

[0020] In an embodiment of the present invention, the large particle antibacterial substance is an antibacterial functional substance with a diameter greater than 2 μm and insoluble or slightly soluble in the organic solvent.

[0021] In an embodiment of the present invention, the large particle antibacterial substance is zinc-aluminum layered double hydroxide (Zn-Al LDH).

[0022] In an embodiment of the present invention, the polymer content in the spinning solution is 10-20 wt%, and the large particle antibacterial substance content is 0.5-2 wt%.

[0023] In an embodiment of the present invention, the parameters of electrospinning are as follows: the spinning voltage is 20-40 kV; the reciprocating movement speed of the brushing trough 2 is 100-300 mm / s; the reciprocating movement speed of the moving spraying brush 7 is 200-400 mm / s, and it reciprocates once every 20-40 s, and the air spraying speed is 0.5-1.5 m / s; the pumping speed of the spinning solution by the liquid storage bottle 6 is 0.5-10 mL / h; the width of the fabric 8 is 550-1600 mm; the rotation speed of the winding roller 4 is 1.0-20.0 m / min.

[0024] The method of the present invention has wide applicability to fabrics, and woven or non-woven fabrics of conventional materials can be well applied in the present invention.

[0025] In one embodiment of the present invention, the preparation method of zinc-aluminum layered double hydroxide (Zn-Al LDH) includes the steps:

[0026] S1. Dissolve zinc nitrate hexahydrate (Zn(NO3)2·6H2O) and aluminum nitrate nonahydrate (Al(NO3)3·9H2O) in water to obtain a salt solution. Under stirring conditions, gradually add the salt solution and the NaOH aqueous solution dropwise into a beaker for mixing. After the addition is completed, continue stirring and maintain the pH of the mixed solution throughout the process.

[0027] S2. Hydrothermally treat the mixed solution obtained in step S1, separate the solid product and wash it until the pH is neutral, then dry and calcine it to obtain Zn-Al LDH powder.

[0028] In one embodiment of the present invention, in step S1 of the preparation method of Zn-Al LDH, the molar ratio of Zn(NO3)2·6H2O to Al(NO3)3·9H2O is (1-2):(0.5-0.75).

[0029] In one embodiment of the present invention, in step S1 of the preparation method of Zn-Al LDH, the molar ratio of Zn(NO3)2·6H2O to Al(NO3)3·9H2O is preferably 3:0.75.

[0030] In one embodiment of the present invention, in step S1 of the preparation method of Zn-Al LDH, every 100 mL of the salt solution contains 2-3.5 mol of Zn(NO3)2·6H2O.

[0031] In one embodiment of the present invention, in step S1 of the preparation method of Zn-Al LDH, the NaOH concentration of the NaOH aqueous solution is 0.3-0.7 mol / L.

[0032] In one embodiment of the present invention, in step S1 of the preparation method of Zn-Al LDH, the volume ratio of the salt solution to the NaOH aqueous solution is (0.8-1.2):(0.8-1.2).

[0033] In one embodiment of the present invention, in step S1 of the preparation method of Zn-Al LDH, the time for continuous stirring is 20-40 min.

[0034] In one embodiment of the present invention, in step S1 of the preparation method of Zn-Al LDH, maintain the pH of the mixed solution at 9.8-10.2.

[0035] In one embodiment of the present invention, in step S2 of the preparation method of Zn-Al LDH, the temperature of the hydrothermal treatment is 110-130 °C, the pressure of the hydrothermal treatment is 1.1-1.4 atm, and the time of the hydrothermal treatment is 9-11 h.

[0036] In one embodiment of the present invention, in step S2 of the preparation method of Zn-Al LDH, hydrothermal treatment is carried out in a high-pressure reaction kettle.

[0037] In one embodiment of the present invention, in step S2 of the preparation method of Zn-Al LDH, washing is carried out with water and ethanol.

[0038] In one embodiment of the present invention, in step S2 of the preparation method of Zn-Al LDH, the drying temperature is 50-80 °C, and the drying duration is 10-18 h.

[0039] In one embodiment of the present invention, in step S2 of the preparation method of Zn-Al LDH, the calcination temperature is 550-650 °C, and the calcination time is 5-7 h.

[0040] The third object of the present invention is to provide the antibacterial fabric prepared by the above method.

[0041] Beneficial effects:

[0042] By using a needleless electrospinning device to prepare nanofibers doped with insoluble large particle antibacterial agents, the antibacterial agents can be evenly distributed in the fibers, having persistent antibacterial properties; there are few restrictions on the selection of polymer polymers and antibacterial agents, and suitable antibacterial agents can be selected as needed.

[0043] Using electrode wires instead of traditional needle electrodes can improve the production efficiency of electrospinning and avoid the problem of needle clogging; adding insoluble antibacterial agents to the spinning solution, fully stirring and then transferring it to a storage bottle for continuous stirring, and at the same time pumping it to a brush liquid tank to reciprocate and brush the spinning solution on the electrode wires, avoiding the uneven distribution of antibacterial particles in the fibers caused by the deposition of antibacterial agents, reducing the volatilization of the spinning solution, saving costs, and eliminating the need for manual replacement of the spinning solution with uneven solvent volatilization during the spinning process, improving production efficiency; installing a jet brush head under the electrode wire to prevent large particles from depositing on the electrode wire and reducing the equipment maintenance cost. Description of the drawings

[0044] Figure 1 It is a structural diagram of a needleless electrode electrospray device;

[0045] In the figure: 1. Electrode wire; 2. Brush liquid tank; 3. DC high-voltage power supply; 4. Winding roller; 5. Metal plate; 6. Storage bottle; 7. Jet brush head; 8. Fabric.

[0046] Figure 2SEM image of the large particle antibacterial agent in Example 1.

[0047] Figure 3 SEM image of the antibacterial fiber prepared by the needleless electrospinning device in Example 1. Detailed implementation method

[0048] The needleless electrode electrospray device used in the example includes components: electrode wire 1, brush liquid tank 2, DC high voltage power supply 3, winding roller 4, metal plate 5, liquid storage bottle 6, moving spray brush 7; the electrode wire 1 is a smooth metal wire, two electrode wires 1 are arranged in parallel, the distance between the two electrode wires is 300 mm, and the length of the electrode wire is 40 cm; the electrode wire 1 is connected in series with the brush liquid tank 2, and the brush liquid tank 2 can reciprocate on the electrode wire 1; the electrode wire 1 is connected to the positive pole of the DC high voltage power supply 3; a metal plate 5 is arranged directly above the electrode wire 1; the electrode wire 1 is parallel to the metal plate 5; the metal plate 5 is grounded; the liquid storage bottle 6 is connected to the brush liquid tank 2; the brush liquid tank 2 reciprocates on the electrode wire 1; the moving spray brush 7 reciprocates directly below the electrode wire 1; the winding roller 4 drives the fabric 8 to move between the electrode wire 1 and the metal plate 5; the liquid storage bottle 6 is a sealed bottle and is provided with a magnetic stirring device.

[0049] During electrospinning, the spinning solution stored in the liquid storage bottle is pumped to the brush liquid tank, and the brush liquid tank reciprocates to brush the spinning solution onto the electrode wire. The moving spray brush sprays a weak air flow and a small amount of solvent onto the electrode wire. Under the action of the electric field and the weak air flow, the spinning solution on the electrode wire forms polymer nanofibers and deposits on the fabric. When the moving spray brush sprays air, the air flow drives the solvent to be ejected.

[0050] Example 1

[0051] A method for preparing doped large particle antibacterial agent nanofibers by a needleless electrospinning device, including the steps:

[0052] S1. Take 3 mol of zinc nitrate hexahydrate (Zn(NO3)2·6H2O) and 0.75 mol of aluminum nitrate nonahydrate (Al(NO3)3·9H2O) and dissolve them in 100 mL of deionized water to obtain a salt solution. Dissolve 0.05 mol of sodium hydroxide (NaOH) in 100 mL of deionized water to obtain an alkali solution. Under stirring conditions, add the salt solution and the alkali solution dropwise into a beaker and mix them. After the dropping is completed, continue stirring for 0.5 h, and maintain the pH of the mixed solution at 10 throughout the process;

[0053] S2. Hydrothermally treat the mixed solution obtained in step S1 at 120 °C and a pressure of 1.3 atm for 10 h in a high-pressure reaction kettle. Separate the solid product and wash it with deionized water and ethanol until the pH is neutral. Dry it at 60 °C for 12 h and calcine it at 600 °C for 6 h to obtain Zn-Al LDH powder;

[0054] S3. Dissolve 1 g of polycaprolactone (PCL) in 5.5 g of acetone, add 0.1 g of Zn-Al LDH powder, and stir magnetically for 24 h to obtain a spinning solution.

[0055] S4. Place the spinning solution in the liquid storage bottle 6 of the needleless electrospinning device and stir magnetically. Electrospin nanofibers doped with large particle antibacterial agents onto the fabric surface through the needleless electrospinning device to obtain an antibacterial fabric. The parameters of electrospinning are as follows: the distance between the electrode wire 1 and the metal plate 5 is 20 cm, the spinning voltage is 25 kV, the reciprocating speed of the brush liquid tank 2 is 200 mm / s; the reciprocating speed of the moving spray brush 7 is 300 mm / s, reciprocating once every 30 s, and the jet speed is 1 m / s; the speed of the liquid storage bottle 6 pumping out the spinning solution is 5 mL / h; the fabric width of the fabric 8 is 1000 mm, and the rotation speed of the winding roller 4 is 10.0 m / min.

[0056] Figure 2 SEM image of the large particle antibacterial agent ZnAl LDH prepared in Example 1, showing the layered structure of ZnAl LDH. Figure 3 SEM image of the ZnAl LDH-doped nanofibers prepared in Example 1. After electrospinning, ZnAl LDH particles are wrapped inside the PCL fibers.

[0057] Zn 2+ is the main source of the antibacterial property of ZnAl LDH. The ZnAl LDH prepared in Example 1 has a high Zn 2+ content, excellent antibacterial property, and is more likely to release Zn 2+ , and the slow release amount is stable. The liquid storage bottle with a seal and a stirring device ensures the uniform distribution of ZnAl LDH in the spinning solution. The moving spray brush sprays a weak air flow and a small amount of solvent to prevent ZnAl LDH and PCL from depositing on the electrode wire and ensure the uniform distribution of ZnAl LDH in the PCL nanofibers, thereby obtaining an antibacterial fabric with uniformly deposited ZnAl LDH.

[0058] The antibacterial effect of the ZnAl LDH-doped nanofibers prepared in Example 1 was tested by a third-party testing agency. The antibacterial rate of this antibacterial fabric against Staphylococcus aureus reached 99%, confirming its excellent antibacterial effect. To further prove the long-term antibacterial performance of the multiple fibers, we conducted a 24-hour slow release test on the antibacterial fiber, sampling every 30 minutes for antibacterial effect detection, and the antibacterial rates of Escherichia coli and Staphylococcus aureus were both 99%.

[0059] Example 2

[0060] A method for preparing nanofibers doped with large particle antibacterial agents by a needleless electrospinning device, including the steps:

[0061] S1. Take 3 mol of zinc nitrate hexahydrate (Zn(NO3)2·6H2O) and 0.75 mol of aluminum nitrate nonahydrate (Al(NO3)3·9H2O) and dissolve them in 100 mL of deionized water to obtain a salt solution. Dissolve 0.05 mol of sodium hydroxide (NaOH) in 100 mL of deionized water to obtain an alkali solution. Under stirring conditions, gradually add the salt solution and the alkali solution dropwise into a beaker for mixing. After the addition is complete, continue stirring for 0.5 h, and maintain the pH of the mixed solution at 10 throughout the process;

[0062] S2. Hydrothermally treat the mixed solution obtained in step S1 in a high-pressure reaction kettle at 125 °C and a pressure of 1.4 atm for 9 h. Separate the solid product and wash it with deionized water and ethanol until the pH is neutral. Dry it at 75 °C for 12 h and calcine it at 650 °C for 5 h to obtain Zn-Al LDH powder;

[0063] S3. Dissolve 2 g of polyacrylonitrile in 7.6 g of N,N-dimethylformamide, add 0.2 g of Zn-Al LDH powder and stir magnetically for 24 h to prepare a spinning solution;

[0064] S4. Place the spinning solution in the liquid storage bottle 6 of a needleless electrospinning device and stir magnetically. Electrospin nanofibers doped with large particle antibacterial agents onto the fabric surface through the needleless electrospinning device to obtain an antibacterial fabric. The parameters of electrospinning are as follows: the distance between the electrode wire 1 and the metal plate 5 is 28 cm, the electrospinning voltage is 40 kV, the reciprocating speed of the brush liquid tank 2 is 280 mm / s, the reciprocating speed of the moving spray brush 7 is 400 mm / s, it reciprocates once every 25 s, and the air jet speed is 1.5 m / s; the speed at which the liquid storage bottle 6 pumps out the spinning solution is 8 mL / h; the fabric width of the fabric 8 is 600 mm, and the rotation speed of the winding roller 4 is 14 m / min.

[0065] Example 3

[0066] A method for preparing nanofibers doped with large particle antibacterial agents by a needleless electrospinning device, including the steps:

[0067] S1. Take 3 mol of zinc nitrate hexahydrate (Zn(NO3)2·6H2O) and 0.75 mol of aluminum nitrate nonahydrate (Al(NO3)3·9H2O) and dissolve them in 100 mL of deionized water to obtain a salt solution. Dissolve 0.05 mol of sodium hydroxide (NaOH) in 100 mL of deionized water to obtain an alkali solution. Under stirring conditions, gradually add the salt solution and the alkali solution dropwise into a beaker for mixing. After the addition is complete, continue stirring for 0.5 h, and maintain the pH of the mixed solution at 10 throughout the process;

[0068] S2. Hydrothermally treat the mixed solution obtained in step S1 in a high-pressure reactor at 110 °C and a pressure of 1.1 atm for 11 h, separate the solid product, wash it with deionized water and ethanol until the pH is neutral, dry it at 55 °C for 18 h, and calcine it at 550 °C for 7 h to obtain Zn-Al LDH powder;

[0069] S3. Dissolve 1 g of polyurethane in 7.6 g of tetrahydrofuran, add 0.05 g of Zn-Al LDH powder, and stir magnetically for 24 h to prepare a spinning solution;

[0070] S4. Place the spinning solution in the liquid storage bottle 6 of the needleless electrospinning device and stir magnetically. Electrospin nanofibers doped with large particle antibacterial agents onto the fabric surface through the needleless electrospinning device to obtain an antibacterial fabric; the parameters of electrospinning are as follows: the distance between the electrode wire 1 and the metal plate 5 is 12 cm, the spinning voltage is 23 kV, the reciprocating speed of the brush liquid tank 2 is 140 mm / s, the reciprocating speed of the moving spray brush 7 is 210 mm / s, reciprocating once every 35 s, the jet speed is 0.6 m / s; the speed of the liquid storage bottle 6 pumping out the spinning solution is 2 mL / h; the width of the fabric 8 is 1200 mm, and the rotation speed of the winding roller 4 is 4 m / min.

[0071] Examples 1, 2, and 3 have high production efficiency, do not have needle clogging, and antibacterial substances and polymers will not deposit and accumulate on the electrode wire. The antibacterial agent is evenly distributed in the spinning solution, and the antibacterial agent is evenly distributed on the prepared antibacterial fabric, with persistent antibacterial properties.

[0072] The examples provided above are not intended to limit the scope covered by the present invention, nor are the described steps intended to limit their execution order. Obvious improvements made by those skilled in the art in combination with the existing common general knowledge also fall within the protection scope defined by the claims of the present invention.

Claims

1. A needleless electrospinning device, characterized in that, Comprising components: electrode wire (1), brush liquid tank (2), DC high-voltage power supply (3), winding roller (4), metal plate (5), liquid storage bottle (6), moving spray brush (7); The electrode wire (1) is connected in series with the brush liquid tank (2); the electrode wire (1) is connected to the positive pole of the DC high-voltage power supply (3); A metal plate (5) is arranged directly above the electrode wire (1); the electrode wire (1) is parallel to the metal plate (5); the metal plate (5) is connected to the negative pole of the DC high-voltage power supply (3) or grounded; The liquid storage bottle (6) is connected to the brush liquid tank (2); the brush liquid tank (2) reciprocates on the electrode wire (1); The moving spray brush (7) reciprocates directly below the electrode wire (1); the winding roller (4) drives the fabric (8) to move between the electrode wire (1) and the metal plate (5).

2. The needleless electrospinning device according to claim 1, characterized in that, The electrode wire (1) is a smooth-surface metal wire; the needleless electrospinning device has a plurality of electrode wires (1) arranged in parallel; the distance between adjacent two electrode wires is 300 - 500 mm; the length of the electrode wire is 25 - 60 cm; the liquid storage bottle (6) is a sealed bottle; the liquid storage bottle (6) is provided with a stirring device; the moving spray brush (7) sprays air flow and organic solvent onto the electrode wire (1).

3. A method for preparing nanofibers doped with large particle antibacterial agents using the needleless electrospinning device according to claim 1, characterized in that, Including steps: S1. Add the polymer and large-particle antibacterial substance to the organic solvent, stir evenly to obtain a spinning solution; S2. Electrospin nanofibers doped with large-particle antibacterial agents onto the fabric surface through the needleless electrospinning device to obtain an antibacterial fabric.

4. The method according to claim 3, wherein The polymer is selected from one or more of polycaprolactone, polyurethane, polyacrylonitrile, polystyrene, polyvinylidene fluoride, polylactic acid, polymethyl methacrylate; the organic solvent is selected from one or more of acetone, N,N-dimethylformamide, dimethylacetamide, tetrahydrofuran, ethanol; the large-particle antibacterial substance is an antibacterial functional substance with a diameter greater than 2 μm and low solubility or insoluble in the organic solvent.

5. The method according to claim 3, characterized in that, The polymer content of the spinning solution is 10 - 20 wt%, and the large-particle antibacterial substance content is 0.5 - 2 wt%.

6. The method according to claim 3, characterized in that, The parameters of electrospinning are as follows: the distance between the electrode wire 1 and the metal plate 5 is 10 - 30 cm; the spinning voltage is 20 - 40 kV; the reciprocating speed of the brush liquid tank 2 is 100 - 300 mm / s; the reciprocating speed of the moving spray brush 7 is 200 - 400 mm / s, reciprocating once every 20 - 40 s, and the air jet speed is 0.5 - 1.5 m / s; the speed of the liquid storage bottle pumping out the spinning solution is 0.5 - 10 mL / h; the fabric 8 has a width of 550 - 1600 mm; the rotation speed of the winding roller 4 is 1.0 - 20.0 m / min.

7. The method according to claim 3, wherein The large-particle antibacterial substance is zinc-aluminum layered double hydroxide; its preparation method includes steps: S1. Dissolve Zn(NO3)2·6H2O and Al(NO3)3·9H2O in water to obtain a salt solution. Under stirring conditions, gradually add the salt solution and NaOH aqueous solution dropwise into a beaker and mix. After the dropping is completed, continue to stir, and maintain the pH of the mixed solution throughout the process; S2. Hydrothermally treat the mixed solution obtained in step S1, separate the solid product and wash it until the pH is neutral, dry it and then calcine it to obtain Zn-Al LDH.

8. The method according to claim 7, wherein The molar ratio of Zn(NO3)2·6H2O to Al(NO3)3·9H2O is (1 - 2):(0.5 - 0.75); every 100 mL of the salt solution contains 2 - 3.5 mol of Zn(NO3)2·6H2O; the concentration of NaOH in the NaOH aqueous solution is 0.3 - 0.7 mol / L; the volume ratio of the salt solution to the NaOH aqueous solution is (0.8 - 1.2):(0.8 - 1.2).

9. The method according to claim 7, wherein The time for continuous stirring is 20 - 40 min; the pH of the mixed solution is maintained at 9.8 - 10.2; the temperature of the hydrothermal treatment is 110 - 130 °C, the pressure of the hydrothermal treatment is 1.1 - 1.4 atm, and the time of the hydrothermal treatment is 9 - 11 h; the drying temperature is 50 - 80 °C, and the drying duration is 10 - 18 h; the calcination temperature is 550 - 650 °C, and the calcination time is 5 - 7 h.

10. The antibacterial fabric prepared by the method according to any one of claims 3 - 9.

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