A self-generating nano-silver PVDF composite fiber, its preparation method and application

Abstract

This application provides a self-generating nano-silver PVDF composite fiber, comprising polyvinylidene fluoride (PVDF) and nano-silver, which are combined via electrospinning. By introducing AgNPs into the piezoelectric material PVDF and fabricating it into micro-electric nanofibers using electrospinning, this fiber possesses both the long-lasting, broad-spectrum antibacterial properties of nano-silver and the ability to continuously generate microcurrents on the wound surface. It does not rely on external devices such as fixed power supplies and electrode pads required for commonly used clinical electrical stimulation, making it highly significant and effective in reducing post-burn / traumatic infection, promoting wound healing, and ensuring patient safety and timely recovery. This solves the problem of poor stability and environmental limitations of PVDF nanocomposite membranes, which negatively impact wound healing. This application also provides a method for preparing the self-generating nano-silver PVDF composite fiber and its application in preparing dressings for treating burns and wounds.

Description

Technical Field

[0001] This application relates to the fields of medical and biotechnology, and mainly to a self-generating nano-silver PVDF composite fiber, its preparation method, and its application. Background Technology

[0002] Human skin possesses a transskin potential of approximately 20-50 mV. When the skin is damaged and a wound forms, a persistent endogenous current, called the "injury current," is generated at the wound site, participating in the entire wound healing process. Studies have shown that applying appropriate voltage or current to the wound site at various stages of wound healing can effectively promote wound healing. Electrostimulation therapy has advantages such as being non-invasive, easy to operate, having a wide range of indications, and few complications.

[0003] Piezoelectric materials are crystalline materials that exhibit a voltage between their two ends when subjected to pressure, and are widely used in tissue engineering, biomedicine, and other fields. Polyvinylidene fluoride (PVDF) is a typical piezoelectric polymer. PVDF is typically fabricated into a nanocomposite membrane, consisting of an outer coating, a bactericidal layer, a gel layer, and a release liner. This nanocomposite membrane can generate ozone upon near-infrared light excitation. In use, simply apply the product to the wound and irradiate it with near-infrared light to activate the bactericidal function of the nanocomposite membrane, achieving a sterile environment without the need for repeated bandaging. Simultaneously, the gel's sustained release at the wound site can directionally deliver growth factors to target cells, promote angiogenesis, and assist in the differentiation of mesenchymal stem cells into exosomes, providing continuous drug delivery and promoting wound healing. However, its use is limited by the reliance on near-infrared light, and the ozone-generating capacity of the nanocomposite membrane may be affected by environmental conditions, usage time and other factors, resulting in significant variations in the stability and durability of its bactericidal effect. In addition, the multi-layered structure makes it difficult to guarantee stability, which may affect the control of growth factors and bactericidal dosage during use, thus affecting the wound healing effect.

[0004] Because PVDF nanocomposite membranes have poor stability during use and are limited by the usage environment, they affect the wound healing effect. Summary of the Invention

[0005] To address the problem that PVDF nanocomposite membranes suffer from poor stability and are limited by the usage environment, thus affecting wound healing, this application provides a self-generating nano-silver PVDF composite fiber. The composite fiber comprises polyvinylidene fluoride and nano-silver, which are combined by electrospinning technology.

[0006] Based on the current status of clinical development of PVDF piezoelectric materials, AgNPs were introduced into PVDF piezoelectric materials, and electrospinning technology was used to make the composite into filamentous nanofibers. The aim was to obtain a novel micro-electric nano-topical dressing that has antibacterial properties when used externally on wounds, while also having a continuous self-discharge function to promote wound healing. This improved the stability of the PVDF nanocomposite film and made it unrestricted by the usage environment, providing a better treatment option for the clinical treatment of burns and trauma.

[0007] Optionally, the mass ratio of the nano-silver to the polyvinylidene fluoride is 0.1~0.5:6.

[0008] Optionally, the mass ratio of the nano-silver to the polyvinylidene fluoride is 0.1:3.

[0009] This application also provides a method for preparing self-generating nano-silver PVDF composite fibers, comprising the following steps:

[0010] S1: Mix polyvinylidene fluoride with an organic solvent to obtain the first spinning solution;

[0011] S2: Add nano-silver to the first spinning solution and mix to obtain the second spinning solution;

[0012] S3: Electrospin the second spinning solution to obtain the self-generating nano-silver PVDF composite fiber.

[0013] Optionally, the organic solvent is N,N-dimethylformamide.

[0014] Optionally, the polyvinylidene fluoride has an average molecular weight Mw of 1,000,000 g / mol; N,N-dimethylformamide (DMF, ACS spectral grade, ≥ 99.8%); and nano silver powder (AgNPs, ≥ 99.9%).

[0015] Optionally, the concentration of polyvinylidene fluoride in the first spinning solution is 12 wt%.

[0016] Optionally, the PVDF powder is weighed using an electronic balance, and the DMF is measured and weighed using a graduated cylinder. 12% by mass of polyvinylidene fluoride (PVDF) and dimethylformamide (DMF) are added to a beaker and stirred at a constant temperature (60°C) in a water bath with a magnetic stirrer until dissolved.

[0017] Optionally, in the second spinning solution, the mass ratio of the nano-silver to the polyvinylidene fluoride is 0.1~0.5:6.

[0018] Optionally, dissolve the nano-silver powder in 1 mL of DMF while maintaining the PVDF / DMF ratio at 12 wt%. Add AgNPs to the PVDF at a ratio of 0.2:6 and continue stirring for 30 min to mix thoroughly.

[0019] Optionally, the electrospinning parameters include: solution feed rate of 0.4–0.7 ml / h, spinning temperature of 34.4–42.5 °C, spinning relative humidity of 10–11%, receiving device rotation speed of 1400–1550 rpm, and receiving distance of 10–13 cm.

[0020] Optionally, the solution propulsion speed is 0.6 ml / h, the receiving device rotation speed is 1500 rpm, and the receiving distance is 12 cm.

[0021] Optionally, the second spinning solution is pumped out using a needleless syringe to slowly draw it out, avoiding the generation of air bubbles, and excess second spinning solution is wiped off the syringe. Air bubbles are expelled from the syringe and tubing for stable electrospinning. The solution is pumped uniformly at a rate of 0.6 ml / h from an 18-gauge syringe needle (tip diameter approximately 1.27 mm) fixed to the positive electrode as a spinneret. For safety, a voltage of +19.87 V and -1.93 kV is applied next to the metal tube. A grounded roller rotating at 1500 rpm is placed 12 cm away from the needle, and the roller rotates at a uniform speed to collect the PVDF / AgNPs piezoelectric nanofibers, obtaining the self-generating silver nanofiber PVDF composite fiber.

[0022] This application also provides the use of the above-mentioned composite fibers in the preparation of dressings for treating burns and trauma.

[0023] This application provides a self-generating nano-silver PVDF composite fiber, comprising polyvinylidene fluoride (PVDF) and nano-silver, which are combined via electrospinning. AgNPs are introduced into the piezoelectric material PVDF and fabricated into micro-electric nanofibers using electrospinning technology. This allows the fiber to possess the long-lasting, broad-spectrum antibacterial properties of nano-silver while continuously generating microcurrents on the wound surface, promoting wound healing. This discharge-driven healing function directly converts the mechanical energy of dressing deformation generated by local wound activity into electrical energy, without relying on external devices such as fixed power supplies and electrode pads commonly used in clinical electrical stimulation. This is of great significance and effectiveness in reducing post-burn / traumatic infection, promoting wound healing, ensuring patient safety, and facilitating timely recovery. It solves the problem of poor stability and environmental limitations of PVDF nanocomposite membranes during use, which negatively impacts wound healing.

[0024] This application also provides a method for preparing self-generating nano-silver PVDF composite fibers, and their application in preparing dressings for treating burns and wounds. Attached Figure Description

[0025] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 Flowchart of a method for preparing self-generating nano-silver PVDF composite fibers;

[0027] Figure 2 This is a schematic diagram of an electrostatic spinning machine.

[0028] Illustration:

[0029] Among them, 1-pump; 2-conduit; 3-needle; 4-drum; 5-voltage knob. Detailed Implementation

[0030] The embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described below do not represent all embodiments consistent with this application. They are merely examples of systems and methods consistent with some aspects of this application as detailed in the claims.

[0031] Piezoelectric materials are crystalline materials that exhibit a voltage between their two ends when subjected to pressure. The mechanism is as follows: piezoelectric crystals have low symmetry. When deformed by external force, the relative displacement of positive and negative ions in the unit cell causes the centers of positive and negative charges to no longer coincide, leading to macroscopic polarization of the crystal. Therefore, when a piezoelectric material deforms under pressure, opposite charges appear on its two ends. A typical piezoelectric polymer is stretched and polarized polyvinylidene fluoride (PVDF).

[0032] The C-F bonds in PVDF are highly polar, and two fluorine atoms are bonded to one carbon atom at the same time. This gives the PVDF monomer unit an extremely large dipole moment (5.8 × 10⁻³⁰ C·m), which has strong piezoelectric properties. It is widely used in fields such as the preparation of battery separators, piezoelectric membranes, filter membranes, sensors, electroacoustic transducers, tissue engineering, and biomedicine.

[0033] In the field of burns and wounds, silver nanoparticles (AgNPs) are widely used as an active ingredient in anti-infective materials due to their excellent antibacterial properties, and are applied to various burn and wound surfaces. Compared with traditional silver ions, silver nanoparticles have more durable antibacterial efficacy, broader and higher antibacterial activity, and fewer drug-resistant bacteria. They exhibit great antibacterial efficacy against common drug-resistant bacteria in burn wounds such as MRSA, Pseudomonas aeruginosa, Acinetobacter baumannii, and Candida albicans. Furthermore, AgNPs have lower cytotoxicity compared to silver ions.

[0034] Currently, there is limited research on PVDF for wound healing. The limited research mainly focuses on introducing different composites to alter the piezoelectric properties of PVDF. As an excellent piezoelectric material, PVDF also possesses good biocompatibility. By introducing different components to form composites, its piezoelectric properties and biocompatibility can be modified.

[0035] To address the problem that PVDF nanocomposite membranes suffer from poor stability and are limited by the usage environment, thus affecting wound healing, this application provides a self-generating nano-silver PVDF composite fiber. The composite fiber comprises polyvinylidene fluoride and nano-silver, which are combined by electrospinning technology.

[0036] Based on the current status of clinical development of PVDF piezoelectric materials, AgNPs are introduced into PVDF piezoelectric materials, and electrospinning technology is used to make the composite into filamentous nanofibers. The aim is to obtain a novel micro-electric nano-topical dressing that has antibacterial properties when used externally on wounds, while also having a continuous self-discharge function to promote wound healing, thus providing a better treatment option for the clinical treatment of burns / trauma.

[0037] The bactericidal function of the self-generating nano-silver PVDF composite fiber provided in this application does not depend on the irradiation of near-infrared light. When sufficient light is not available or the wound is in a position where light cannot be received, the effect is not limited. Moreover, because it is less affected by the environment, the bactericidal effect has good stability and durability.

[0038] In some embodiments, the mass ratio of the nanosilver to the polyvinylidene fluoride is 0.1~0.5:6.

[0039] In some embodiments, the mass ratio of the nanosilver to the polyvinylidene fluoride is 0.1:3.

[0040] This application also provides a method for preparing self-generating nano-silver PVDF composite fibers, comprising the following steps:

[0041] S1: Mix polyvinylidene fluoride with an organic solvent to obtain the first spinning solution;

[0042] S2: Add nano-silver to the first spinning solution and mix to obtain the second spinning solution;

[0043] S3: Electrospin the second spinning solution to obtain the self-generating nano-silver PVDF composite fiber.

[0044] In some embodiments, such as Figure 1 The diagram shows a flow chart of a method for preparing self-generating nano-silver PVDF composite fibers, wherein the organic solvent is N,N-dimethylformamide.

[0045] In some embodiments, the organic solvent is isopropyl acetate.

[0046] In some embodiments, the average molecular weight Mw of polyvinylidene fluoride is 1,000,000 g / mol; N,N-dimethylformamide (DMF, ACS spectral grade, ≥ 99.8%); and nano silver powder (AgNPs, ≥ 99.9%).

[0047] In some embodiments, the concentration of polyvinylidene fluoride in the first spinning solution is 12 wt%.

[0048] In some embodiments, such as Figure 1 As shown, PVDF powder was weighed using an electronic balance, and DMF was measured and weighed using a graduated cylinder. 12% by mass of polyvinylidene fluoride (PVDF) and dimethylformamide (DMF) were added to a beaker and stirred in a water bath with a magnetic stirrer at a constant temperature (60℃, 200 rpm) until dissolved.

[0049] In some embodiments, the mass ratio of the nano-silver to the polyvinylidene fluoride in the second spinning solution is 0.1~0.5:6.

[0050] In some embodiments, 1 mL of DMF is used to dissolve the nano-silver powder while maintaining the PVDF / DMF ratio at 12 wt%. AgNPs are added to PVDF at a ratio of 0.1:3, and stirring is continued for 30 min to ensure thorough mixing.

[0051] In some embodiments, the parameters of the electrospinning include: a solution feed rate of 0.4–0.7 ml / h, a spinning temperature of 34.4–42.5 °C, a spinning relative humidity of 10–11%, a receiving device rotation speed of 1400–1550 rpm, and a receiving distance of 10–13 cm.

[0052] In some embodiments, the solution propulsion speed is 0.6 ml / h, the receiving device rotation speed is 1500 rpm, and the receiving distance is 12 cm.

[0053] In some embodiments, such as Figure 2The diagram shows the structure of an electrospinning machine. The second spinning solution is loaded into pump 1 and slowly drawn out using a needleless syringe to avoid generating air bubbles. Excess solution is wiped off the syringe. Air bubbles are expelled from the syringe and conduit 2 to stabilize the electrospinning process. The solution is pumped uniformly at a rate of 0.6 ml / h from an 18-gauge syringe needle (tip diameter approximately 1.27 mm) fixed to the positive electrode as a spinneret. For safety, the voltage knob 5 is rotated to set the voltage applied next to the metal tube to +19.87V and -1.93kV, with needle 3 as the positive electrode and drum 4 as the negative electrode. A grounded roller rotating at 1500 rpm is placed 12 cm away from the needle, rotating at a uniform speed to collect PVDF / AgNPs piezoelectric nanofibers, thus obtaining the self-generating silver nanofiber PVDF composite fiber.

[0054] This application also provides the use of the above-mentioned composite fibers in the preparation of dressings for treating burns and trauma.

[0055] Example 1:

[0056] PVDF powder was weighed using an electronic balance, and DMF was measured and weighed using a graduated cylinder. PVDF and DMF at a mass fraction of 12% were added to a beaker and stirred in a water bath with a magnetic stirrer at a constant temperature (60℃, 200 rpm) until dissolved, obtaining the first spinning solution. Nano-silver powder was dissolved using 1 mL of DMF, maintaining a PVDF / DMF ratio of 12 wt%. AgNPs were added to the PVDF at a ratio of 0.1:3, and stirring was continued for 30 minutes to ensure thorough mixing, obtaining the second spinning solution.

[0057] The second spinning solution was pumped out using a needleless syringe to slowly draw it out, avoiding the generation of air bubbles. Excess solution was wiped off the syringe. Air bubbles were expelled from the syringe and tubing to stabilize the electrospinning process. The solution was pumped uniformly at a rate of 0.6 ml / h from an 18-gauge syringe needle (tip diameter approximately 1.27 mm) fixed to the positive electrode as a spinneret. For safety, a voltage of +19.87 V and -1.93 kV was applied near the metal tube. The spinning temperature was 34.4 °C, and the relative humidity was 10%. A grounded roller rotating at 1500 rpm was placed 12 cm from the needle. The roller rotated at a uniform speed to collect PVDF / AgNPs piezoelectric nanofibers, yielding the first self-generating silver nanofiber PVDF composite fiber.

[0058] Example 2:

[0059] PVDF powder was weighed using an electronic balance, and DMF was measured and weighed using a graduated cylinder. PVDF and DMF at a mass fraction of 12% were added to a beaker and stirred in a water bath with a magnetic stirrer at a constant temperature (60℃, 200 rpm) until dissolved, obtaining the first spinning solution. Nano-silver powder was dissolved using 1 mL of DMF, maintaining a PVDF / DMF ratio of 12 wt%. AgNPs were added to the PVDF at a ratio of 0.1:6, and stirring was continued for 30 min to ensure thorough mixing, obtaining the second spinning solution.

[0060] The second spinning solution was pumped out using a needleless syringe to slowly draw it out, avoiding the generation of air bubbles. Excess solution was wiped off the syringe. Air bubbles were expelled from the syringe and tubing to stabilize the electrospinning process. The solution was pumped uniformly at a rate of 0.4 ml / h from an 18-gauge syringe needle (tip diameter approximately 1.27 mm) fixed to the positive electrode as a spinneret. For safety, a voltage of +19.87 V and -1.93 kV was applied near the metal tube. The spinning temperature was 42.5 °C, and the relative humidity was 11%. A grounded roller rotating at 1400 rpm was placed 13 cm from the needle, and the roller rotated at a uniform speed to collect PVDF / AgNPs piezoelectric nanofibers, yielding the second self-generating silver nanofiber PVDF composite fiber.

[0061] Example 3:

[0062] PVDF powder was weighed using an electronic balance, and DMF was measured and weighed using a graduated cylinder. PVDF and DMF at a mass fraction of 12% were added to a beaker and stirred in a water bath with a magnetic stirrer at a constant temperature (60℃, 200 rpm) until dissolved, obtaining the first spinning solution. Nano-silver powder was dissolved using 1 mL of DMF, maintaining a PVDF / DMF ratio of 12 wt%. AgNPs were added to the PVDF at a ratio of 0.5:6, and stirring was continued for 30 min to ensure thorough mixing, obtaining the second spinning solution.

[0063] The second spinning solution was pumped out using a needleless syringe to slowly draw it out, avoiding the generation of air bubbles. Excess solution was wiped off the syringe. Air bubbles were expelled from the syringe and tubing to stabilize the electrospinning process. The solution was pumped uniformly at a rate of 0.7 ml / h from an 18-gauge syringe needle (tip diameter approximately 1.27 mm) fixed to the positive electrode as a spinneret. For safety, a voltage of +19.87 V and -1.93 kV was applied near the metal tube. The spinning temperature was 40.5 °C, and the relative humidity was 11%. A grounded roller rotating at 1550 rpm was placed 10 cm from the needle, and the roller rotated at a uniform speed to collect PVDF / AgNPs piezoelectric nanofibers, yielding the third self-generating silver nanofiber PVDF composite fiber.

[0064] Example 4:

[0065] PVDF powder was weighed using an electronic balance, and DMF was measured and weighed using a graduated cylinder. PVDF and DMF at a mass fraction of 12% were added to a beaker and stirred in a water bath with a magnetic stirrer at a constant temperature (60℃, 200 rpm) until dissolved, obtaining the first spinning solution. Nano-silver powder was dissolved using 1 mL of DMF, maintaining a PVDF / DMF ratio of 12 wt%. AgNPs were added to the PVDF at a ratio of 0.2:3, and stirring was continued for 30 min to ensure thorough mixing, obtaining the second spinning solution.

[0066] The second spinning solution was pumped out using a needleless syringe to slowly draw it out, avoiding the generation of air bubbles. Excess solution was wiped off the syringe. Air bubbles were expelled from the syringe and tubing to stabilize the electrospinning process. The solution was pumped uniformly at a rate of 0.5 ml / h from an 18-gauge syringe needle (tip diameter approximately 1.27 mm) fixed to the positive electrode as a spinneret. For safety, a voltage of +19.87 V and -1.93 kV was applied near the metal tube. The spinning temperature was 41.5 °C, and the relative humidity was 11%. A grounded roller rotating at 1450 rpm was placed 11 cm from the needle. The roller collected the PVDF / AgNPs piezoelectric nanofibers at a uniform speed, yielding the fourth self-generating silver nanofiber PVDF composite fiber.

[0067] Example 5:

[0068] PVDF powder was weighed using an electronic balance, and DMF was measured and weighed using a graduated cylinder. PVDF and DMF at a mass fraction of 12% were added to a beaker and stirred in a water bath with a magnetic stirrer at a constant temperature (60℃, 200 rpm) until dissolved, obtaining the first spinning solution. Nano-silver powder was dissolved using 1 mL of DMF, maintaining a PVDF / DMF ratio of 12 wt%. AgNPs were added to the PVDF at a ratio of 0.1:2, and stirring was continued for 30 minutes to ensure thorough mixing, obtaining the second spinning solution.

[0069] The second spinning solution was pumped out using a needleless syringe to slowly draw it out, avoiding the generation of air bubbles. Excess solution was wiped off the syringe. Air bubbles were expelled from the syringe and tubing to stabilize the electrospinning process. The solution was pumped uniformly at a rate of 0.4 ml / h from an 18-gauge syringe needle (tip diameter approximately 1.27 mm) fixed to the positive electrode as a spinneret. For safety, a voltage of +19.87 V and -1.93 kV was applied near the metal tube. The spinning temperature was 34.4 °C, and the relative humidity was 1%. A grounded roller rotating at 1500 rpm was placed 12 cm from the needle. The roller rotated at a uniform speed to collect the PVDF / AgNPs piezoelectric nanofibers, yielding the fifth self-generating silver nanofiber PVDF composite fiber.

[0070] Example 6: In vivo animal experiments to observe the effect of self-generating nano-silver PVDF composite fibers as a functional wound dressing to accelerate wound healing.

[0071] (1) The first, second, third, fourth and fifth self-generating nano-silver PVDF composite fibers prepared in Examples 1 to 5 were soaked in 70% ethanol solution for 10 minutes and then soaked in physiological saline for 30 minutes to achieve disinfection and thorough removal of any residual solvent components in the self-generating nano-silver PVDF composite fibers. They were then used to prepare dressings for treating burns and wounds, resulting in the first, second, third, fourth and fifth self-generating nano-silver PVDF composite fiber dressings.

[0072] (2) The above-mentioned power-generating nano-silver PVDF composite fiber dressing was used to repair the skin wounds on the back of SD rats (a circular full-thickness skin with a diameter of 1 cm was removed), and the wound healing was continuously observed.

[0073] Compared to traditional gauze dressings, wounds treated with the dressing of this application generally healed by day 17, requiring dressing changes every two days during treatment. In contrast, wounds treated with traditional gauze dressings generally healed by day 25, requiring dressing changes every other day during treatment. Furthermore, the functional wound dressing of this invention adheres less to the wound surface, reducing bleeding during dressing changes, while traditional gauze dressings often adhere to the wound surface and cause bleeding.

[0074] Therefore, the self-generating nano-silver PVDF composite fiber provided in this application has the effect of accelerating wound healing when used as a functional wound dressing.

[0075] Meanwhile, mice treated with the first self-generating nano-silver PVDF composite fiber dressing recovered the fastest and had the best wound condition.

[0076] This application provides a self-generating nano-silver PVDF composite fiber, comprising polyvinylidene fluoride (PVDF) and nano-silver, which are combined via electrospinning. AgNPs are introduced into the piezoelectric material PVDF and fabricated into micro-electric nanofibers using electrospinning technology. This allows the fiber to possess the long-lasting, broad-spectrum antibacterial properties of nano-silver while continuously generating microcurrents on the wound surface, promoting wound healing. This discharge-driven healing function directly converts the mechanical energy of dressing deformation generated by local wound activity into electrical energy, without relying on external devices such as fixed power supplies and electrode pads commonly used in clinical electrical stimulation. This is of great significance and effectiveness in reducing post-burn / traumatic infection, promoting wound healing, ensuring patient safety, and facilitating timely recovery. It solves the problem of poor stability and environmental limitations of PVDF nanocomposite membranes during use, which negatively impacts wound healing.

[0077] This application also provides a method for preparing self-generating nano-silver PVDF composite fibers, and their application in preparing dressings for treating burns and wounds.

[0078] Similar parts between the embodiments provided in this application can be referred to mutually. The specific implementation methods provided above are only a few examples under the overall concept of this application and do not constitute a limitation on the scope of protection of this application. For those skilled in the art, any other implementation methods extended from the solution of this application without creative effort shall fall within the scope of protection of this application.

Claims

1. A self-generating nano-silver PVDF composite fiber, characterized in that, The composite fiber is composed of polyvinylidene fluoride and silver nanoparticles, which are combined by electrospinning technology; the mass ratio of silver nanoparticles to polyvinylidene fluoride is 0.1~0.5:

6.

2. The composite fiber according to claim 1, characterized in that, The mass ratio of the nano-silver to the polyvinylidene fluoride is 0.1:

3.

3. The method for preparing the composite fiber according to claim 1, characterized in that, Includes the following steps: S1: Mix polyvinylidene fluoride with an organic solvent to obtain the first spinning solution; S2: Add nano-silver to the first spinning solution and mix to obtain the second spinning solution; S3: Electrospin the second spinning solution to obtain the self-generating nano-silver PVDF composite fiber.

4. The preparation method according to claim 3, characterized in that, The organic solvent is N,N-dimethylformamide.

5. The preparation method according to claim 4, characterized in that, The concentration of polyvinylidene fluoride in the first spinning solution is 12 wt%.

6. The preparation method according to claim 3, characterized in that, In the second spinning solution, the mass ratio of the nano-silver to the polyvinylidene fluoride is 0.1~0.5:

6.

7. The preparation method according to claim 3, characterized in that, The parameters of the electrospinning include: The solution propulsion speed is 0.4–0.7 ml / h, the spinning temperature is 34.4–42.5℃, the spinning relative humidity is 10–11%, the receiving device rotation speed is 1400–1550 rpm, and the receiving distance is 10–13 cm.

8. The preparation method according to claim 7, characterized in that, The solution propulsion speed is 0.6 ml / h, the receiving device rotation speed is 1500 rpm, and the receiving distance is 12 cm.

9. The use of the composite fiber according to any one of claims 1 to 2 in the preparation of dressings for treating burns and wounds.

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