Super-hydrophobic nanomaterials, methods of making and using the same

Abstract

The application discloses super-hydrophobic nanometer material and a preparation method and application thereof. The super-hydrophobic nanometer material takes a hydrophobic polymer material as a main body, embeds hydrophobic modified two-dimensional inorganic nanometer material in the main body, and distributes or embeds the hydrophobic modified two-dimensional inorganic nanometer material on the surface of the main body. The super-hydrophobic nanometer material has a super-hydrophobic antibacterial adhesion and high-efficiency contact type sterilization dual function, has a self-cleaning characteristic, has high and persistent bacteriostatic efficiency, has a wide application prospect in wound repair and prevention of wound infection as a new type of dressing, and can be flexibly constructed into a multi-layer structure composite film dressing together with a hydrophilic nanometer fiber film to guarantee the biocompatibility of a dressing and a tissue contact surface and has high safety.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of super-hydrophobic nanomaterial and its preparation method and application, especially a kind of super-hydrophobic nanomaterial with super-hydrophobic antibacterial adhesion and contact type bactericidal characteristics and its preparation method and application. BACKGROUND

[0002] Open wound is easy to be colonized by bacteria, and further form biofilm. Once biofilm is formed, bacteria will multiply in large numbers and are difficult to remove, resulting in a low-grade inflammatory state of the wound, and eventually may form a chronic wound that is difficult to heal, causing a heavy burden on the medical system.

[0003] Current strategies to prevent biofilm formation mainly include using release or contact type bactericides to directly kill bacteria that are colonized in the wound, or using super-hydrophobic antifouling surfaces to prevent bacteria from colonizing in the wound. However, the bactericidal effect of release type bactericides is positively correlated with the dosage, and as the bactericides are continuously released and consumed, their bactericidal effect gradually decreases. Contact type bactericides have no self-cleaning ability, which leads to the residue of dead bacteria, reducing their subsequent bactericidal efficiency. Antifouling surfaces only have high efficiency at low viable bacterial concentrations, and when the viable bacterial concentration reaches a certain threshold, the antifouling surface may lose its ability to resist bacterial adhesion.

[0004] Common two-dimensional inorganic materials include graphene, transition metal disulfide, transition metal oxide, black phosphorus, hexagonal boron nitride, graphite-like carbon nitride, layered double hydroxide, etc. The sheet structure often has sharp edges, like a "nanosword" effect, which can pierce the biofilm, and can also extract the bilayer phospholipid through van der Waals force and electrostatic force, both of which can destroy the structural integrity of the biofilm. Although small size graphene is currently widely used, there is no research showing that the film is broken by the "nanosword" effect of graphene at this size, which may be weakened at small size. SUMMARY

[0005] The present application aims to provide a super-hydrophobic nanomaterial that can improve the bacteriostatic efficiency of the wound in a humid and bacterial environment, and its preparation method and application.

[0006] Technical solution: The super-hydrophobic nanomaterial according to the present application takes hydrophobic polymer material as the main body, embeds hydrophobic modified two-dimensional inorganic nanomaterial in the main body, and distributes or embeds hydrophobic modified two-dimensional inorganic nanomaterial on the surface of the main body; wherein the sheet thickness of the hydrophobic modified two-dimensional inorganic nanomaterial is less than 5 nm, and the sheet diameter is 1-400 nm (preferably 10-400 nm); the diameter of the super-hydrophobic nanomaterial is 0.1-10 μm, the water contact angle is greater than 150°, and the porosity is 20%-80% (preferably 50%-60%).

[0007] Preferably, the hydrophobic high molecular material is selected from the group consisting of ethylene-vinyl acetate copolymer, polylactic acid, polyorthoester, dimethicone, polymethyl methacrylate, polyacrylonitrile, polyurethane, polyimide, polycaprolactone, polylactic acid-glycolic acid copolymer, polyvinylidene fluoride, polyethylene, polytetrafluoroethylene, polyetherimide, polystyrene, polydimethylsiloxane, polyester, nylon.

[0008] Preferably, the super-hydrophobic nanomaterial of the present application has a uniaxial, coaxial or multi-axial structure; when it is a uniaxial structure, the hydrophobic high molecular material embedded with the hydrophobic modified two-dimensional inorganic nanomaterial is the main body; when it is a coaxial or multi-axial structure, the hydrophobic high molecular material embedded with the hydrophobic modified two-dimensional inorganic nanomaterial is the main body of the outer layer.

[0009] Preferably, the super-hydrophobic nanomaterial of the present application has a single-layer, double-layer or multi-layer structure.

[0010] According to the Wenzel-Cassie wetting model, the present application uses electrospinning technology to incorporate the hydrophobic modified two-dimensional nanosheet material into the nanofiber with hydrophobic high molecular material as the main body, to construct super-hydrophobic nanofiber and fiber membrane with a micro-rough surface. The structural characteristics of the nanofiber are that the hydrophobic two-dimensional inorganic nanomaterial is completely embedded in the interior of the hydrophobic nanofiber or inserted on the surface of the hydrophobic nanofiber; the nanofiber structure is not limited to uniaxial, coaxial, multi-axial and other different forms, the uniaxial nanofiber has hydrophobic high molecular material as the main body, and the coaxial or multi-axial nanofiber has hydrophobic high molecular material as the main body of the outer layer structure; the dressing composed of nanofiber membrane is characterized by containing the super-hydrophobic nanofiber membrane of the present application, but is not limited to single-layer, or double-layer, multi-layer membrane and other different forms composed of other functional materials.

[0011] The excellent antibacterial dressing should have the dual functional characteristics of super-hydrophobic antibacterial adhesion and contact type sterilization, which complement each other and play a high efficient bacteriostatic effect. Based on the resistance of the super-hydrophobic surface to the initial adhesion of bacteria, and by using the contact type physical sterilization characteristics to further resist bacterial invasion, the super-hydrophobic surface prevents the failure of the anti-adhesion interface caused by too high concentration of live bacteria. More importantly, the "self-cleaning characteristics" of the super-hydrophobic surface can quickly remove dead bacteria residues, maintaining its contact type sterilization performance.

[0012] Electrospinning uses high voltage electrostatic to pull the polymer solution into micron to nanometer level fibers to form nanofiber membrane. Because of its porous structure similar to the extracellular matrix of skin cells, it can provide a surface for cell adhesion, provide the best microenvironment for tissue growth and repair, and at the same time has the advantages of water permeability, air permeability, large specific surface area, etc., which is beneficial to liquid absorption, cell respiration and gas permeation, prevents wound drying and dehydration, and is considered as a potential dressing for wound healing.

[0013] The application significantly improves the biofilm affinity of nanosheets, makes up for size defects, strengthens the "nanometer knife" effect, and further constructs a new type of dressing with super-hydrophobic antibacterial adhesion and contact type sterilization characteristics by cooperating with electrospinning technology.

[0014] The preparation method of the super-hydrophobic nanomaterial in a single-layer structure comprises the following steps:

[0015] (1) dispersing the hydrophobic modified two-dimensional inorganic nanomaterial in a solvent, and adding a hydrophobic polymer material to prepare a hydrophobic spinning solution;

[0016] (2) performing uniaxial, coaxial or multi-axial electrospinning on the hydrophobic spinning solution in step (1) as an outer layer solution, and drying to obtain the super-hydrophobic nanomaterial.

[0017] In the above step (1), the solvent is selected from ethanol, methanol, acetic acid, formic acid, N,N-dimethylformamide, dimethyl sulfoxide, acetone, n-hexane, chloroform, dichloromethane, tetrahydrofuran, formamide, acetonitrile, ethyl acetate, N-methyl-2-pyrrolidone and N,N-dimethylacetamide. Dispersion is performed by water bath ultrasonic, the ultrasonic time is 1-120 min, the stirring time is 8-30 h, the standing defoaming time is 0.5-24 h, the mass fraction of the hydrophobic polymer material is 2%-30%, and the mass fraction of the hydrophobic modified two-dimensional inorganic nanomaterial is 0.1%-5%.

[0018] Preferably, the preparation method of the hydrophobic modified two-dimensional inorganic nanomaterial comprises the following steps:

[0019] (1) preparing a homogeneous dispersion system of nanosheets

[0020] Method one: uniformly dispersing the nanosheets in a reaction liquid phase system;

[0021] Method two: fully grinding the nanosheets;

[0022] Method three: heating the nanosheets to a molten state;

[0023] (2) preparing hydrophobic nanosheets

[0024] Mixing the homogeneous dispersion system of nanosheets prepared in step (1) with a hydrophobic modification reagent, and modifying the hydrophobic groups to the surface of the nanosheets through chemical or physical action;

[0025] (3) collecting and purifying the hydrophobic nanosheets

[0026] Washing the hydrophobic nanosheets prepared in step (2) with water or ethanol to remove the solvent to obtain the hydrophobic modified two-dimensional inorganic nanomaterial.

[0027] Specifically, the dispersion in step (2) uses water bath ultrasonic power of 100-1000 W, ultrasonic time of 0.5-12 h, uses probe ultrasonic power of 50-500 W, and ultrasonic time of 10-120 min; the liquid phase in the homogeneous dispersion system includes one or more of water, ethanol, methanol, dimethyl sulfoxide, formamide, N,N-dimethylformamide, acetone, tetrahydrofuran, dichloromethane and trichloromethane; the reaction stirring speed of the substitution reaction, addition reaction, free radical reaction or physical action is 300-1500 rpm, and the heating temperature interval is 25-600 DEG C; the grinding is realized by high-energy ball milling method, the diameter of the stainless steel ball used is 1-10 mm, and the grinding time is 1-12 h.

[0028] More specifically, the hydrophobic sheet layer in step (1-3) can be prepared by any one of the following methods A-F:

[0029] A. The two-dimensional material is dispersed in a reaction system by water bath ultrasonic, the amine hydrophobic group is added, and condensation reflux reaction is carried out at high temperature. The product hydrophobic nanosheet layer is collected by filtration, washed with appropriate amount of ethanol for 3-5 times, centrifuged and dried to obtain the hydrophobic nanosheet layer.

[0030] B. The two-dimensional material is dispersed in a reaction system by water bath ultrasonic, the thiol hydrophobic group is added, and reaction is carried out under water bath ultrasonic condition. The product hydrophobic transition metal disulfide is collected by centrifugation, washed with appropriate amount of ethanol for 2-3 times under water bath ultrasonic, centrifuged and dried to obtain the hydrophobic nanosheet layer.

[0031] C. The two-dimensional material is ground with stainless steel balls for 48-96 h, the alcohol hydrophobic group is added, and the grinding is continued for 12-24 h. The product is dispersed in the solvent, the supernatant is collected by low-speed centrifugation, and then collected by high-speed centrifugation. The hydrophobic nanosheet layer is obtained by vacuum drying.

[0032] D. The two-dimensional material and the amine hydrophobic group are co-melted at 120-200 DEG C for 4-7 days under nitrogen protection, and a pharmaceutically acceptable organic solvent is added. The product is dispersed and washed under water bath ultrasonic, the supernatant is collected by low-speed centrifugation, and the small molecules are removed by ultrafiltration. The organic phase is volatilized to obtain the hydrophobic nanosheet layer.

[0033] E. The two-dimensional material and the carboxylic acid hydrophobic group are dispersed or dissolved in the above-mentioned solvent, and heated and stirred at constant temperature until the solvent is completely volatilized. The obtained solid mixture is transferred to a muffle furnace, heated to 300-500 DEG C at a speed of 5-10 DEG C / min, and reacted for 2-8 h. The product is washed with appropriate amount of ethanol for 3-5 times, centrifuged and vacuum dried to obtain the hydrophobic nanosheet layer.

[0034] F, dispersing or dissolving the two-dimensional material with sodium hydroxide into the aqueous phase and stirring for 12-24 h, adding the carboxylic hydrophobic group and heating the reaction, continuously stirring for 5-7 days under nitrogen protection until complete reaction. After filtering and water washing the above reaction product, vacuum drying to obtain the hydrophobic nanosheet layer.

[0035] Further preferably, the nanosheet layer is selected from graphene oxide, reduced graphene oxide, transition metal dichalcogenide, black phosphorus, hexagonal boron nitride, graphite-like phase carbon nitride, layered double hydroxide; and the hydrophobic modification reagent is selected from stearylamine, cetylamine, myristylamine, laurylamine, n-decylamine, hexadecane diamine, dodecane diamine, octadecanethiol, hexadecanethiol, tetradecanethiol, dodecanethiol, n-decanethiol, lauryl alcohol, stearic acid, hexadecanoic acid, myristic acid, lauric acid, n-decanoic acid.

[0036] More preferably, the hydrophobic nanosheet layer is selected from any one of the following materials:

[0037] (I) stearylamine modified graphene oxide;

[0038] (II) stearylamine modified reduced graphene;

[0039] (III) octadecanethiol modified molybdenum disulfide;

[0040] (IV) lauryl alcohol modified black phosphorus;

[0041] (V) myristylamine modified hexagonal boron nitride;

[0042] (VI) myristic acid modified graphite-like phase carbon nitride;

[0043] (VII) lauric acid modified layered double hydroxide.

[0044] Further preferably, the amount of the hydrophobic modification reagent is 10%-80% of the mass of the nanosheet layer.

[0045] More preferably, when the super-hydrophobic nanomaterial has a single-layer / single-axis structure, it is made by single-axis electrospinning from any one of the following combinations:

[0046] (A1) stearylamine modified graphene oxide and polycaprolactone;

[0047] (A2) octadecanethiol modified molybdenum disulfide and polylactic acid;

[0048] (A3) lauryl alcohol modified black phosphorus and poly(lactic-co-glycolic acid);

[0049] (A4) myristylamine modified hexagonal boron nitride and polyurethane.

[0050] When the super-hydrophobic nanomaterial has a single-layer / coaxial structure, it is made by coaxial electrospinning from any one of the following combinations:

[0051] (B1) Myristic acid modified graphitic phase carbon nitride and hyaluronic acid-polyvinyl alcohol, polylactic acid-glycolic acid copolymer;

[0052] (B2) Lauric acid modified layered double hydroxide and chitosan-polyethylene glycol, polylactic acid-glycolic acid copolymer.

[0053] When the super-hydrophobic nanomaterial has a double-layer structure, it is made by single-axis or coaxial electrospinning from any one of the following combinations:

[0054] (C1) Nanofiber membrane made from the combination of (A1) above and hyaluronic acid-polyethylene glycol;

[0055] (C2) Nanofiber membrane made from the combination of (A4) above and polyethylene glycol-dextran;

[0056] When the super-hydrophobic nanomaterial has a multi-layer structure, it is made by single-axis electrospinning from any one of the following combinations:

[0057] (D1) Nanofiber membrane made from the combination of (C2) above and heparin.

[0058] Preferably, when the material has a single-axis structure, the electrospinning voltage is 5-30 kV, the needle inner diameter is 0.1-5 mm, the spinning environment temperature is 15-40℃, and the air relative humidity is 20%-80%; when the material has a coaxial or multi-axis structure, the electrospinning voltage is 10-50 kV, the inner tube diameter of the needle is 0.05-2 mm, the outer tube diameter is 0.1-5 mm, the outer layer solution is a hydrophobic spinning solution, the volume ratio of the outer layer solution to the inner layer solution is 0.1-10, the spinning environment temperature is 15-40℃, and the air relative humidity is 10%-40%.

[0059] Specifically, the single-axis electrospinning voltage is 5-30 kV, the needle inner diameter is 0.1-5 mm, the spinning volume is 1-30 mL, the spinning solution injection speed is 0.01-10 mL / h, the spinning time is 2-48 h, the distance between the receiving device and the spinneret is 5-30 cm, the receiving drum rotation speed is 20-200 r / min, the spinning environment temperature is 15-40℃, and the air relative humidity is 20%-80%.

[0060] Specifically, the coaxial, multi-axial electrospinning voltage is 10-50kV, the inner tube diameter of the needle is 0.05-2mm, the outer tube diameter is 0.1-5mm, the total spinning volume is 1-50mL, the volume ratio of the outer layer solution to the inner layer solution is 0.1-10, the outer layer solution is a hydrophobic spinning solution, the spinning solution injection speed is 0.01-20mL / h, the spinning time is 2-48h, the distance between the receiving device and the spinning head is 5-30cm, the receiving roller rotation speed is 20-200r / min, the spinning environment temperature is 15-40℃, and the air relative humidity is 10%-40%.

[0061] The solvent is removed by vacuum drying, the drying temperature is 20-80℃, the vacuum degree is 0-0.1Mpa, and the drying time is 3-48h.

[0062] The preparation method of the super-hydrophobic nanomaterial with a double-layer or multi-layer composite structure comprises the following steps:

[0063] (1) dispersing a hydrophilic polymer material in a solvent, stirring, and then standing to remove bubbles to prepare a hydrophilic spinning solution;

[0064] (2) performing single-axis, coaxial or multi-axis electrospinning on the hydrophilic spinning solution prepared in step (1) as an outer layer solution to prepare a single-layer ordinary nanomaterial;

[0065] (3) continuously electrospinning the single-layer super-hydrophobic nanomaterial and the single-layer ordinary nanomaterial, and drying to obtain the double-layer or multi-layer super-hydrophobic nanomaterial, and the composite material contains the single-layer super-hydrophobic nanomaterial.

[0066] In the above step (1), the solvent is selected from water, ethanol, methanol, acetic acid, formic acid, N,N-dimethylformamide, dimethyl sulfoxide, acetone, tetrahydrofuran, formamide, acetonitrile, N-methyl-2-pyrrolidone, and N,N-dimethylacetamide.

[0067] In the above step (1), the hydrophilic polymer material is selected from dextran, chitosan, heparin, alginate, hyaluronic acid, cyclodextrin, polyfructose, polyethylene glycol, polyvinyl alcohol, polyethyleneimine, polyacrylic acid, polymethacrylic acid, polyglutamic acid, and polyvinylpyrrolidone.

[0068] In the above step (1), the dispersion is performed by water bath ultrasonic, the ultrasonic time is 1-10min, the stirring time is 0-120min, the standing time for removing bubbles is 0.1-12h, and the mass fraction of the polymer is 3%-45%.

[0069] Specifically, in the step (2), the uniaxial electrospinning voltage is 5-30 kV, the needle inner diameter is 0.1-5 mm, the spinning volume is 1-30 mL, the spinning solution injection speed is 0.01-10 mL / h, the spinning time is 2-48 h, the distance between the receiving device and the spinning head is 5-30 cm, the receiving roller rotation speed is 20-200 r / min, the spinning environment temperature is 15-40℃, and the air relative humidity is 20%-80%.

[0070] Specifically, in the step (2), the coaxial or multi-axial electrospinning voltage is 10-50 kV, the inner tube diameter of the needle is 0.05-2 mm, the outer tube diameter of the needle is 0.1-5 mm, the total spinning volume is 1-50 mL, the volume ratio of the outer layer solution to the inner layer solution is 0.1-10, the outer layer solution is a hydrophilic spinning solution, the spinning solution injection speed is 0.01-20 mL / h, the spinning time is 2-48 h, the distance between the receiving device and the spinning head is 5-30 cm, the receiving roller rotation speed is 20-200 r / min, the spinning environment temperature is 15-40℃, and the air relative humidity is 10%-40%,

[0071] Specifically, in the step (3), the drying is performed by vacuum drying, the drying temperature is 20-80℃, the vacuum degree is 0-0.1 Mpa, and the drying time is 3-48 h.

[0072] The super-hydrophobic nanomaterials described in the application are applied in the preparation of the antibacterial dressing, and the specific application forms are super-hydrophobic nanofiber membranes and nanofibers.

[0073] Beneficial effects: Compared with the prior art, the application has the following remarkable advantages:

[0074] The super-hydrophobic nanofiber membrane layer has the dual functions of super-hydrophobic antibacterial adhesion and high-efficiency contact type sterilization, has the self-cleaning property, has high and persistent bacteriostatic efficiency, has a wide application prospect in wound repair and prevention of wound infection as a new type of dressing, can be flexibly constructed into a multi-layer structure composite dressing together with a hydrophilic nanofiber membrane to ensure the biocompatibility of the dressing and tissue contact surface, and is safe. BRIEF DESCRIPTION OF DRAWINGS

[0075] Figure 1 A transmission electron microscope image of the hydrophobic nanographene prepared in Example 1;

[0076] Figure 2 A scanning electron microscope image of the super-hydrophobic nanofiber membrane prepared in Example 8;

[0077] Figure 3 A diameter distribution diagram of the super-hydrophobic nanofiber membrane prepared in Example 8;

[0078] Figure 4 Transmission electron microscope image of the superhydrophobic nanofiber membrane prepared for Example 8;

[0079] Figure 5 Porosity of the superhydrophobic nanofiber membranes prepared for Examples 8-16;

[0080] Figure 6 Antibacterial ability of the superhydrophobic nanofiber membranes prepared for Examples 8-16;

[0081] Figure 7 Anti-adhesion ability of the superhydrophobic nanofiber membranes prepared for Examples 8-16;

[0082] Figure 8 Wound healing promoting ability of the superhydrophobic nanofiber membranes prepared for Examples 14-16. DETAILED DESCRIPTION

[0083] The technical solutions of the present application are further described below in combination with examples.

[0084] Example 1: Preparation of hydrophobic sheet layer

[0085] 100 mg of graphene oxide was placed in deionized water and ultrasonically dispersed to prepare a dispersion liquid of 5 mg / mL, 200 mg of stearylamine was added to 10 mL of ethanol solution, and the reaction was carried out at 70°C for 4 h. After the reaction was completed, the precipitate was collected by centrifugation. After ultrasonic dispersion in 10 mL of anhydrous ethanol, the precipitate was collected by high-speed centrifugation (10000 x g, 5 min), and the above washing step was repeated 3 times, and then vacuum high-temperature drying was carried out to prepare the hydrophobic nanographene.

[0086] Example 2: Preparation of hydrophobic sheet layer

[0087] 150 mg of reduced graphene oxide was placed in deionized water and ultrasonically dispersed to prepare a dispersion liquid of 3 mg / mL, 200 mg of stearylamine was added to 10 mL of ethanol solution, and appropriate amounts of EDC and NHS were added as activators, and the reaction was carried out at 120°C for 12 h. After the reaction was completed, the precipitate was collected by centrifugation. After ultrasonic dispersion in 20 mL of anhydrous ethanol, the precipitate was collected by high-speed centrifugation (10000 x g, 5 min), and the above washing step was repeated 3 times, and then vacuum high-temperature drying was carried out to prepare the hydrophobic nanographene.

[0088] Example 3: Preparation of hydrophobic sheet layer

[0089] Molybdenum disulfide 150 mg was dispersed in 20 mL ethanol by water bath ultrasonic, 150 mg octadecanethiol was added, and the reaction was carried out at 37°C for 4 h by water bath ultrasonic. After the reaction, the precipitate was collected by centrifugation. After ultrasonic dispersion in 20 mL anhydrous ethanol, the precipitate was collected by high-speed centrifugation (10000 x g, 10 min), and the above washing step was repeated for 3 times. After vacuum high-temperature drying, the hydrophobic molybdenum disulfide nanoparticles were obtained.

[0090] Example 4: Preparation of hydrophobic sheet

[0091] 1 g of black phosphorus powder was placed in a stainless steel container and ground with a stainless steel ball for 72 h. Lauric alcohol was added and the grinding was continued for 18 h. After the reaction, the reaction product was dispersed in a mixed solvent of 5 mL water and 15 mL dimethyl sulfoxide. The supernatant was collected by low-speed centrifugation (3000 x g, 5 min), and the hydrophobic black phosphorus was collected by high-speed centrifugation (12000 x g, 20 min). After washing with deionized water, the hydrophobic nanosheet was obtained by vacuum drying.

[0092] Example 5: Preparation of hydrophobic sheet

[0093] Hexagonal boron nitride 200 mg was heated to 150°C to form a molten state, and 100 mg of myristylamine was added to maintain a co-molten state for 5 days. After the reaction, 20 mL of tetrahydrofuran was added, and the product was dispersed by water bath ultrasonic. The supernatant was collected by low-speed centrifugation (3500 x g), and the precipitate was washed by repeating the above steps for 3 times. The unreacted myristylamine was removed by ultrafiltration, and the hydrophobic nanosheet was obtained by vacuum drying after removing tetrahydrofuran.

[0094] Example 6: Preparation of hydrophobic sheet

[0095] Graphite-like carbon nitride 250 mg and 150 mg of myristic acid were dispersed or dissolved in ethanol, and stirred at 50°C until the ethanol was completely volatilized. The obtained solid mixture was transferred to a muffle furnace, and heated at a uniform speed of 8°C / min to 450°C and maintained for 6 h. After collecting the reaction product and washing with ethanol for 3 times, the hydrophobic nanosheet was obtained by high-speed centrifugation (14000 x g, 20 min) and vacuum drying.

[0096] Example 7: Preparation of hydrophobic sheet

[0097] 1 g of layered double hydroxide and 0.4 g of sodium hydroxide were dispersed or dissolved in 100 mL of water phase and stirred for 12 h. After adding 2 g of lauric acid, the temperature was raised to 70°C, and the stirring was continued for 5 days under nitrogen protection. The precipitate was collected by filtering the above reaction liquid, and washed with deionized water for 3 times. The hydrophobic nanosheet was obtained by vacuum drying.

[0098] Example 8: Preparation of single-layer super-hydrophobic nanofiber membrane

[0099] The product of Example 1 was added to 10 mL of a mixed solvent of chloroform: N,N-dimethylformamide (3:2, v / v), and dispersed uniformly by water bath ultrasonic for 30 min. 1.5 g of polycaprolactone was added, and the spinning solution was obtained after stirring for 10 h and standing for 2 h to remove bubbles. The spinning solution was subjected to uniaxial electrospinning according to the following parameters: spinning voltage 18 kV, receiving distance 12 cm, spinning solution injection flow rate 1 mL / h, receiving drum rotation speed 100 r / min, needle inner diameter 0.4 mm, temperature 25 °C, and humidity 50%. After spinning for 10 h, the nanofiber membrane was placed in a vacuum drying oven, the drying temperature was set to 50 °C, the vacuum degree was 0.095 MPa, and the nanofiber membrane was dried for 12 h to obtain a super-hydrophobic nanofiber membrane.

[0100] Example 9: Preparation of a single-layer super-hydrophobic nanofiber membrane

[0101] The product of Example 3 was added to 10 mL of acetone, and dispersed uniformly by water bath ultrasonic for 30 min. 1.5 g of polylactic acid was added, and the spinning solution was obtained after stirring for 10 h and standing for 2 h to remove bubbles. The spinning solution was subjected to uniaxial electrospinning according to the following parameters: spinning voltage 18 kV, receiving distance 10 cm, spinning solution injection flow rate 0.8 mL / h, receiving drum rotation speed 100 r / min, needle inner diameter 0.4 mm, temperature 25 °C, and humidity 50%. After spinning for 10 h, the nanofiber membrane was placed in a vacuum drying oven, the drying temperature was set to 35 °C, the vacuum degree was 0.095 MPa, and the nanofiber membrane was dried for 6 h to obtain a super-hydrophobic nanofiber membrane.

[0102] Example 10: Preparation of a single-layer super-hydrophobic nanofiber membrane

[0103] The product of Example 4 was added to 10 mL of a mixed solvent of dichloromethane: acetone (3:2, v / v), and dispersed uniformly by water bath ultrasonic for 30 min. 1.5 g of poly(lactic-co-glycolic acid) was added, and the spinning solution was obtained after stirring for 10 h and standing for 2 h to remove bubbles. The spinning solution was subjected to uniaxial electrospinning according to the following parameters: spinning voltage 16 kV, receiving distance 12 cm, spinning solution injection flow rate 1 mL / h, receiving drum rotation speed 100 r / min, needle inner diameter 0.4 mm, temperature 25 °C, and humidity 50%. After spinning for 10 h, the nanofiber membrane was placed in a vacuum drying oven, the drying temperature was set to 30 °C, the vacuum degree was 0.090 MPa, and the nanofiber membrane was dried for 3 h to obtain a super-hydrophobic nanofiber membrane.

[0104] Example 11: Preparation of a single-layer super-hydrophobic nanofiber membrane

[0105] The product of Example 5 was added to 10 mL of chloroform, and dispersed uniformly by water bath ultrasonic for 30 min. 1.5 g of polyurethane was stirred for 10 h, and then left to stand for 2 h to remove bubbles to obtain a spinning solution. The spinning solution was subjected to uniaxial electrospinning according to the following parameters: spinning voltage 18 kV, receiving distance 15 cm, spinning solution injection flow rate 1.5 mL / h, receiving drum rotating speed 100 r / min, needle inner diameter 0.4 mm, temperature 25 °C, humidity 50%. After spinning for 6 h, the nanofiber membrane was placed in a vacuum drying oven, and the drying temperature was set to 45 °C, and the vacuum degree was set to 0.095 MPa. After drying for 8 h, a super-hydrophobic nanofiber membrane was obtained.

[0106] Example 12: Preparation of a single-layer super-hydrophobic nanofiber membrane

[0107] Hyaluronic acid 1 g and polyvinyl alcohol 0.5 g were added to 10 mL of a mixed solvent of water: ethanol (1:2, v / v), and dispersed uniformly by water bath ultrasonic for 10 min. After stirring for 10 min, the solution was left to stand for 1 h to remove bubbles to obtain a hydrophilic electrospinning solution as an inner layer solution. Separately, the product of Example 6 was added to 5 mL of chloroform, and dispersed uniformly by water bath ultrasonic for 1 h. 0.75 g of polylactic acid-glycolic acid copolymer was stirred for 12 h, and then left to stand for 3 h to remove bubbles to obtain a hydrophobic spinning solution as an outer layer solution. The spinning solutions were subjected to coaxial electrospinning according to the following parameters: spinning voltage 30 kV, receiving distance 15 cm, spinning solution injection flow rate 0.5 mL / h, receiving drum rotating speed 120 r / min, inner tube diameter of needle 0.2 mm, outer tube diameter of needle 0.5 mm, temperature 25 °C, humidity 20%. After spinning for 10 h, the nanofiber membrane was placed in a vacuum drying oven, and the drying temperature was set to 65 °C, and the vacuum degree was set to 0.09 MPa. After drying for 36 h, a single-layer super-hydrophobic nanofiber membrane was obtained.

[0108] Example 13: Preparation of a single-layer super-hydrophobic nanofiber membrane

[0109] The hydrophilic electrospinning solution was prepared by adding 0.8 g of chitosan and 0.7 g of polyethylene glycol into 10 mL of a mixed solvent of water:formic acid (1:1, v / v), and ultrasonicating in a water bath for 15 min to disperse uniformly, and then stirring for 15 min and standing for 1 h to defoam. The hydrophobic spinning solution was prepared by adding 5 mg of the product of Example 7 into 5 mL of chloroform, and ultrasonicating in a water bath for 0.5 h to disperse uniformly, and then stirring for 12 h and standing for 3 h to defoam. The above spinning solutions were electrospun according to the following parameters: spinning voltage 25 kV, receiving distance 15 cm, spinning solution injection flow rate 1.5 mL / h, receiving drum rotation speed 180 r / min, needle inner tube diameter 0.2 mm, outer tube diameter 0.5 mm, temperature 25 °C, and humidity 20%. After spinning for 10 h, the nanofiber membrane was placed in a vacuum drying oven, and the drying temperature was set to 70 °C, and the vacuum degree was set to 0.095 MPa, and the membrane was dried for 36 h to obtain a single-layer superhydrophobic nanofiber membrane.

[0110] Example 14: Preparation of a double-layer membrane dressing containing a superhydrophobic nanofiber membrane

[0111] The hydrophilic electrospinning solution was prepared by adding 0.5 g of polyethylene glycol and 0.75 g of hyaluronic acid into 10 mL of a mixed solvent of water:ethanol (1:1, v / v), and ultrasonicating in a water bath for 5 min to disperse uniformly, and then stirring for 5 min and standing for 0.5 h to defoam. The above spinning solution was electrospun according to the following parameters: spinning voltage 25 kV, receiving distance 15 cm, spinning solution injection flow rate 1.0 mL / h, receiving drum rotation speed 100 r / min, needle inner diameter 0.3 mm, temperature 30 °C, and humidity 30%. After spinning for 6 h, the nanofiber membrane was placed in a vacuum drying oven, and the drying temperature was set to 40 °C, and the vacuum degree was set to 0.09 MPa, and the membrane was dried for 48 h to obtain a double-layer membrane dressing containing a superhydrophobic nanofiber membrane.

[0112] Example 15: Preparation of a double-layer membrane dressing containing a superhydrophobic nanofiber membrane

[0113] 1.0 g of polyethylene glycol was added to 8 mL of a mixed solvent of water and methanol (1:2, v / v), and dispersed evenly by ultrasonication in a water bath for 5 min. After stirring for 10 min, the mixture was allowed to stand for 0.5 h to defoam and obtain a hydrophilic electrospinning solution, which was used as the outer layer solution. Separately, 0.5 g of dextran was added to 4 mL of an aqueous solvent, and dispersed evenly by ultrasonication in a water bath for 5 min. After stirring for 10 min, the mixture was allowed to stand for 0.5 h to defoam and obtain a hydrophilic electrospinning solution, which was used as the inner layer solution. The above electrospinning solutions were coaxially electrospun onto the surface of the monolayer superhydrophobic nanofiber membrane obtained in Example (11) according to the following parameters: spinning voltage 30 kV, receiving distance 20 cm, spinning solution injection rate 2 mL / h, receiving roller rotation speed 150 r / min, needle inner tube diameter 0.5 mm, outer tube diameter 1.0 mm, temperature 25 °C, and humidity 40%. After spinning for 2 hours, the nanofiber membrane is placed in a vacuum drying oven, with a drying temperature of 75℃ and a vacuum degree of 0.095Mpa. After drying for 24 hours, a double-layer membrane dressing containing a superhydrophobic nanofiber membrane is obtained.

[0114] Example 16: Preparation of multilayer membrane dressing containing superhydrophobic nanofiber membrane

[0115] 0.5 g of heparin was added to 10 mL of a water:ethanol (1:1, v / v) mixture, and the mixture was ultrasonically dispersed in a water bath for 10 min. After stirring for 15 min, the mixture was allowed to stand for 15 min to defoam and obtain a hydrophilic electrospinning solution. The above electrospinning solution was uniaxially electrospun onto the surface of the double-layer superhydrophobic nanofiber membrane obtained in Example (15) according to the following parameters: spinning voltage 20 kV, receiving distance 18 cm, spinning solution injection rate 1.5 mL / h, receiving roller rotation speed 150 r / min, needle inner diameter 0.3 mm, temperature 25 °C, and humidity 45%. After spinning for 6 h, the nanofiber membrane was placed in a vacuum drying oven with a drying temperature of 30 °C and a vacuum degree of 0.095 MPa. After drying for 12 h, the superhydrophobic nanofiber membrane was obtained.

[0116] Example 17: Structural Characterization of Hydrophobic Two-Dimensional Sheets

[0117] The hydrophobic graphene nanoparticles prepared in Example 1 were ultrasonically dispersed in chloroform and then dropped onto the surface of a copper mesh. The surface morphology was observed using a transmission electron microscope (Hitachi HT7700, Japan). The results are as follows: Figure 1 As shown, after ultrasonic dispersion, the hydrophobic nanographene sheets are distributed in the range of 10-400 nm in size, and the sheets are stacked in single or few layers with an overall thickness of less than 5 nm, which is consistent with the characteristics of small-sized hydrophobic two-dimensional sheets.

[0118] Example 18: Structural Characterization of Superhydrophobic Nanofibers

[0119] The nanofiber membrane prepared in Example 8 was sprayed with gold, and then its surface morphology was observed using a scanning electron microscope (USA- FEI- NOVA NANOSEM 230) at a scanning voltage of 5 kV. Five 2000x electron microscope photos were taken at different areas of the sample, and the diameters of at least 100 fibers were measured using Image-J software. The structural morphology of the nanofiber is shown in Figure 2 As shown, due to the introduction of hydrophobic graphene, it is wrapped in the fiber, and due to the electrostatic force, the graphene layers have a tendency to be distributed on the edge of the fiber or to protrude, making the fiber surface not smooth, with bumps, forming a micro-nano structure with the fiber, which is the basis of the super-hydrophobic structure. The diameter distribution of the nanofiber is shown in Figure 3 The average diameter of the super-hydrophobic nanofiber is 944 ± 315 nm.

[0120] The nanofiber membrane prepared in Example 8 was dispersed in water after ultrasonic crushing, and then added dropwise to the surface of a copper mesh. Its surface morphology was observed using a transmission electron microscope (Japan Hitachi HT7700), and the results are shown in Figure 4 As shown, the hydrophobic graphene layers are embedded in the interior and surface of the nanofiber. This micro-nano embedded structure improves the hydrophobicity of the fiber membrane, while efficiently exerting the “nano knife” effect of the layers, realizing the dual functions of super-hydrophobic antibacterial adhesion and high-efficiency contact type sterilization.

[0121] The super-hydrophobic nanofiber membranes prepared in Examples 9-16 were observed and photographed under a bright field mode of an upright microscope (Germany Leica DM6B), and the diameters of at least 100 fibers were measured using Image-J software. The diameter distribution of the nanofiber prepared in each example is shown in Table 1, and the fiber diameter is distributed in the interval of 0.1-10 μm.

[0122] Table 1. Diameter of nanofiber

[0123] Example Fiber diameter (nm) 9 3176±579 10 540±146 11 5814±790 12 179±38 13 8718±913 14 2573±699 15 1599±370 16 4025±854

[0124] Example 19: Hydrophobic ability of nanofiber membrane

[0125] The wetting ability of the surface of the super-hydrophobic nanofiber membrane prepared in Examples 8-16 was tested using a contact angle tester, and the water contact angles of the corresponding undoped layer nanofiber membrane and the nanofiber membrane doped with non-hydrophobic modified layers were also detected. When 30 μL of deionized water droplets were dropped onto the surface of the fiber and stabilized, a high-speed camera was used to take pictures, and the water contact angle value was calculated. Each sample was tested 5 times, and the average value was calculated. The results are shown in Table 2. The water contact angles of the nanofiber membranes of each group doped with super-hydrophobic layers are mostly less than 130°, and most of them show hydrophilic properties. After introducing super-hydrophobic layers, the water contact angles of the nanofiber membranes of each group are all greater than 150°, meeting the requirements of super-hydrophobicity.

[0126] Table 2. Water contact angle of superhydrophobic nanofiber membranes in Examples 8-16

[0127]

[0128] Example 20: Porosity of nanofiber membranes

[0129] Take 2 x 2 cm 2 of the nanofiber membranes prepared in Examples 8-16, weigh and place in a 5 mL graduated cylinder pre-filled with 4 mL of absolute ethanol, after standing for 10 min, weigh the wetted nanofiber membrane and record the volume of ethanol remaining in the graduated cylinder. The porosity (%) is calculated using the following formula:

[0130]

[0131] Wherein, W1, W0 respectively refer to the weight of the nanofiber membrane after wetting, before wetting, V loss , D ethanol respectively refer to the volume of ethanol lost and the density of ethanol. The porosity determination results are shown in Figure 5 , the porosity of each group of nanofiber membranes is between 20% and 80%, among which the porosity is mostly 50% to 60%, which can ensure that oxygen can permeate the nanofiber membrane, which is beneficial to wound healing, while effectively blocking the invasion of external bacteria, indicating that the nanofiber membrane can be used as an ideal wound dressing.

[0132] Example 21: Bactericidal ability of nanofiber membranes

[0133] Take 2 x 2 cm 2 of the nanofiber membranes prepared in Examples 8-16, then shake culture with 5 mL of bacterial suspension (10 6 CFU / mL) for 8 hours. The obtained bacterial solution is diluted to an appropriate concentration range, and 100 μL of the bacterial solution is evenly inoculated in a petri dish with LB medium. After incubation at 37°C overnight, the number of bacterial colonies is calculated. The inhibition rate (%) is calculated using the following formula:

[0134]

[0135] Wherein, C C , C S respectively refer to the average number of colonies in the blank control and the sample.

[0136] The bacteriostatic results are shown in Figure 6As shown, each group of nanofiber membranes without sheet layer doping had no obvious antibacterial effect due to the lack of sterilization function. The nanofiber membranes doped with non-hydrophobic modified sheet layers showed slight inhibition effect on bacteria, mainly due to the mechanical scratch of the two-dimensional sheet layer on the bacteria. The super-hydrophobic nanofiber membranes had more significant antibacterial effect on gram-positive bacteria and gram-negative bacteria due to the enhanced "nano-knife" effect and its lipid extraction effect, indicating that the super-hydrophobic nanofiber membranes had significant antibacterial capacity.

[0137] Example 22: Anti-bacterial adhesion capacity of nanofiber membranes

[0138] The anti-bacterial adhesion capacity was evaluated by taking Staphylococcus aureus, the most common bacteria in wound infection, as a model bacteria. The super-hydrophobic nanofiber membrane samples (2x2 cm 2 ) in Examples 8-16 were placed in a bacterial suspension (3 mL, 10 8 CFU / mL), and after 10 hours of co-culture, they were taken out and washed with PBS for 3 times, 5 minutes each time, and then AO / EB fluorescent dye was added for staining for 5-10 minutes. After staining, they were washed with PBS for 3 times, 5 minutes each time, and then placed on a glass slide and observed under an inverted fluorescence microscope. The bacterial adhesion area was calculated using Image-J, and the bacterial adhesion rate was calculated by comparing the area with the field area. As shown in Figure 7 , the nanofiber membranes without sheet layer doping had poor anti-bacterial adhesion performance due to the lack of bacterial killing effect, and the bacterial adhesion rate of each group was greater than 8%. The nanofiber membranes doped with non-hydrophobic modified sheet layers had a certain degree of inhibition on bacterial adhesion due to the membrane breaking effect of scratching the cell membrane. The super-hydrophobic nanofiber membranes had dual functional properties of super-hydrophobic antibacterial adhesion and high-efficiency contact type sterilization, and had more excellent anti-bacterial adhesion performance.

[0139] Example 23: Wound repair promoting capacity of nanofiber membranes

[0140] A moist and bacterial-rich wound model was constructed to evaluate the wound repair promoting capacity of the hydrophobic nanofiber membranes. A 12x12 mm full-thickness skin wound was constructed on the back of a male SD rat, and 800 μL of bacterial suspension (10 8 CFU / mL) was sprayed 5 cm above the wound every day to create a moist and bacterial-rich environment. Sterile gauze was used as a control to investigate the wound repair healing capacity of the nanofiber membranes in Examples 14-16. The dressing was replaced every 3 days, and the wound was photographed and the wound area was measured using Image J software. The wound repair rate was calculated according to the following formula:

[0141]

[0142] wherein W t and W0 are the wound area on the tth day and the original wound area, respectively.

[0143] Results of promoting wound healing, such as Figure 8 As shown, within the same time frame, the superhydrophobic nanofiber membranes in each embodiment significantly accelerated wound healing compared to sterile gauze (blank control), undoped sheets, or nanofiber membranes doped with non-hydrophobic modified sheets. Because the sterile gauze group and the undoped sheet nanofiber membrane lacked effective resistance to bacteria, the wound inflammation phase was prolonged, the entry into the proliferation phase was slow, and wound healing was slowed. The nanofiber membranes doped with non-hydrophobic modified sheets, relying on the mechanical damage of the sheets, could accelerate wound repair to some extent. Meanwhile, the hydrophobic nanofiber membranes, possessing both anti-wetting, anti-adhesion, and bactericidal effects, provided a favorable antibacterial environment, which is beneficial for benign wound repair.

Claims

1. A superhydrophobic nanomaterial, characterized in that, The hydrophobic polymer material is used as a main body, the hydrophobic modified two-dimensional inorganic nanomaterial is embedded in the main body, and the hydrophobic modified two-dimensional inorganic nanomaterial is distributed or embedded on the surface of the main body; the hydrophobic modified two-dimensional inorganic nanomaterial has a sheet thickness less than 5 nm and a sheet diameter of 1-400 nm; the super-hydrophobic nanomaterial has a diameter of 0.1-10 μm, a water contact angle greater than 150°, and a porosity of 20%-80%; The hydrophobic polymer material is selected from polylactic acid, polyurethane, polycaprolactone, and polylactic acid-glycolic acid copolymer; The preparation method of the hydrophobic modified two-dimensional inorganic nanomaterial comprises the following steps: (1) preparing a nanosheet layer homogeneous dispersion system Method one: uniformly dispersing the nanosheet layer in a reaction liquid phase system; Method two: fully grinding the nanosheet layer; Method three: heating the nanosheet layer to a molten state; The nanosheet layer is selected from graphene oxide, reduced graphene oxide, transition metal disulfide, black phosphorus, hexagonal boron nitride, graphite-like carbon nitride, and layered double hydroxide; (2) preparing a hydrophobic nanosheet layer Mixing the nanosheet layer homogeneous dispersion system prepared in step (1) with a hydrophobic modification reagent, and modifying the hydrophobic group to the surface of the nanosheet layer through chemical or physical action; The hydrophobic modification reagent is selected from stearylamine, myristylamine, octadecanethiol, lauryl alcohol, myristic acid, and lauric acid; (3) collecting and purifying the hydrophobic nanosheet layer Washing the hydrophobic nanosheet layer prepared in step (2) with water or ethanol, and removing the solvent to obtain the product.

2. The superhydrophobic nanomaterial of claim 1, wherein, The super-hydrophobic nanomaterial has a uniaxial, coaxial or multi-axial structure; when the structure is uniaxial, the hydrophobic polymer material embedded with the hydrophobic modified two-dimensional inorganic nanomaterial is used as the main body; when the structure is coaxial or multi-axial, the hydrophobic polymer material embedded with the hydrophobic modified two-dimensional inorganic nanomaterial is used as the outer main body.

3. The superhydrophobic nanomaterial of claim 1, wherein, The super-hydrophobic nanomaterial has a single-layer, double-layer or multi-layer structure.

4. The superhydrophobic nanomaterial of claim 1, wherein, The hydrophobic nanosheet layer is selected from any one of the following materials: (I) stearylamine modified graphene oxide; (II) stearylamine modified reduced graphene; (III) octadecanethiol modified molybdenum disulfide; (IV) lauryl alcohol modified black phosphorus; (V) myristylamine modified hexagonal boron nitride; (VI) myristic acid modified graphite-like carbon nitride; (VII) lauric acid modified layered double hydroxide.

5. The superhydrophobic nanomaterial of claim 2 or 3, wherein, When the super-hydrophobic nanomaterial has a single-layer / uniaxial structure, it is prepared by uniaxial electrospinning from any one of the following combinations: (A1) stearylamine modified graphene oxide and polycaprolactone; (A2) octadecanethiol modified molybdenum disulfide and polylactic acid; (A3) lauryl alcohol modified black phosphorus and polylactic acid-glycolic acid copolymer; (A4) myristylamine modified hexagonal boron nitride and polyurethane; When the super-hydrophobic nanomaterial has a single-layer / coaxial structure, it is prepared by coaxial electrospinning from any one of the following combinations: (B1) myristic acid modified graphite-like carbon nitride and hyaluronic acid-polyvinyl alcohol, polylactic acid-glycolic acid copolymer; (B2) lauric acid modified layered double hydroxide and chitosan-polyethylene glycol, polylactic acid-glycolic acid copolymer; When the super-hydrophobic nanomaterial has a double-layer structure, it is made by single-axis or coaxial electrospinning from any one of the following combinations: (C1) the nanofiber membrane made from the combination of (A1) and hyaluronic acid-polyethylene glycol; (C2) the nanofiber membrane made from the combination of (A4) and polyethylene glycol-dextran; When the super-hydrophobic nanomaterial has a multi-layer structure, it is made by single-axis electrospinning from any one of the following combinations: (D1) the nanofiber membrane made from the combination of (C2) and heparin.

6. The super-hydrophobic nanomaterial of claim 1, wherein, When the super-hydrophobic nanomaterial has a single-layer structure, (1) dispersing the hydrophobic modified two-dimensional inorganic nanomaterial in a solvent, adding a hydrophobic polymer material, and preparing a hydrophobic spinning solution; (2) electrospinning the hydrophobic spinning solution prepared in step (1), and drying to obtain the super-hydrophobic nanomaterial; When the super-hydrophobic nanomaterial has a double-layer or multi-layer structure, (1) dispersing the hydrophobic modified two-dimensional inorganic nanomaterial in a solvent, adding a hydrophobic polymer material, and preparing a hydrophobic spinning solution; (2) electrospinning the hydrophobic spinning solution prepared in step (1), and drying to obtain the super-hydrophobic nanomaterial; (3) using the single-layer super-hydrophobic nanomaterial or the single-layer ordinary nanomaterial as a substrate, continuously electrospinning another single-layer material, and drying to obtain the double-layer or multi-layer super-hydrophobic nanomaterial.

7. The superhydrophobic nanomaterial of claim 1, wherein, The amount of the hydrophobic modification reagent is 10%-80% of the mass of the nanosheet layer.

8. The superhydrophobic nanomaterial of claim 2, wherein, When the super-hydrophobic nanomaterial has a single-axis structure, the voltage for electrospinning is 5-30 kV, the inner diameter of the needle is 0.1-5 mm, the spinning environment temperature is 15-40 ℃, and the air relative humidity is 20%-80%; when the super-hydrophobic nanomaterial has a coaxial or multi-axis structure, the voltage for electrospinning is 10-50 kV, the inner tube diameter of the needle is 0.05-2 mm, the outer tube diameter of the needle is 0.1-5 mm, the outer layer solution is a hydrophobic spinning solution, the volume ratio of the outer layer solution to the inner layer solution is 0.1-10, the spinning environment temperature is 15-40 ℃, and the air relative humidity is 10%-40%.

9. Use of the super-hydrophobic nanomaterial of claim 1 in the preparation of an antibacterial dressing.

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