Pesticide nanofiber as well as preparation method and application thereof

Abstract

The invention provides a pesticide nanofiber as well as a preparation method and application thereof. The nano-fiber is prepared by adopting a blending electrostatic spinning method or a coaxial electrostatic spinning method, pesticide molecules are loaded into the nano-fiber, so that pesticide active ingredients are dispersed in a nano form, the water solubility of the pesticide active ingredients is improved, and the bioavailability of the pesticide active ingredients is improved; by utilizing the properties of different polymers, the blended and coaxial pesticide nanofibers can isolate the external environment, so that the thermal stability and the oxidation resistance of the active ingredients of the pesticide are improved; the pesticide nanofibers prepared by the two electrostatic spinning methods have a long-acting and controllable release effect, explosive burst release of pesticides is prevented, and the storage stability and the utilization rate of the pesticides are improved; according to the pesticide nanofiber prepared by utilizing an electrostatic spinning method, the dispersity of pesticide active ingredients is remarkably improved, and the contact area between the pesticide active ingredients and harmful fungi in farmland is increased, so that the biological activity of the pesticide active ingredients is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of pesticide formulations, and particularly relates to a pesticide nanofiber and its preparation method and application. Background Art

[0002] Pesticides are indispensable production materials in the process of agricultural production, and have played an important role in preventing and controlling crop diseases and pests, ensuring food production, and promoting the healthy development of agriculture. Traditional pesticide formulations have defects such as a large amount of organic solvents used, dust drift, and poor dispersibility. Most active ingredients of pesticides are organic compounds insoluble in water, and auxiliary components such as carriers, solvents, emulsifiers, and dispersants need to be added, and they are processed into appropriate formulations and applied in the form of spraying. At the initial stage of the application of traditional pesticide formulations, the concentration of pesticides surges, and over time, due to the degradation, leaching, or volatilization of the compounds, the concentration will rapidly drop below the effective concentration. This phenomenon leads to the repeated use of conventional pesticides, and ultimately leads to a series of problems, such as the resistance of pathogens and pests, non-point source pollution, eutrophication of water bodies, soil degradation, bioaccumulation in the food chain, and loss of biodiversity. The current pesticide industry in China is developing towards water-based, granular, slow / controlled release, and functional green and environmentally friendly directions, and some gratifying results have been initially achieved. However, most formulations still have disadvantages such as poor stability, easy aggregation, easy burst release at the initial stage of spraying, and poor adhesion to the target leaf surface. The pesticide formulations still need to be continuously explored and innovated.

[0003] Based on the above defects of current traditional pesticides, it is necessary to improve them. Summary of the Invention

[0004] In view of the above disadvantages or improvement requirements of the prior art, the present invention provides a pesticide nanofiber and its preparation method and application. The present invention uses a blend electrospinning method or a coaxial electrospinning method to prepare a pesticide nanofiber. The prepared pesticide nanofiber with a slow-release function not only has good thermal stability, dispersibility, and biological activity, but also can achieve environmental response (temperature, pH, etc.) and slow-release function, realize the matching of drug supply and demand with the environment, reduce the amount of pesticides used, improve the utilization rate of pesticides, and reduce the agricultural non-point source pollution caused by pesticides.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] In the first aspect, the present invention provides a pesticide nanofiber, which is prepared by a blend electrospinning method or a coaxial electrospinning method;

[0007] Among them, the preparation of the pesticide nanofiber by the blend electrospinning method specifically includes: using cyclodextrin, polymer, and pesticide active molecule as raw materials to prepare the pesticide nanofiber;

[0008] The pesticide nanofibers prepared by the coaxial electrospinning method include a core layer and a shell layer coated outside the core layer;

[0009] The core layer is a cyclodextrin-coated pesticide active molecule, and the shell layer material is a polymer.

[0010] Preferably, the cyclodextrin includes at least one of α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, methyl-β-cyclodextrin, 2-hydroxypropyl-β-cyclodextrin, 2-hydroxypropyl-γ-cyclodextrin, and 2-hydroxypropyl-α-cyclodextrin;

[0011] The polymer includes at least one of polyvinyl alcohol, polylactic acid, chitosan, ethyl cellulose, sodium alginate, gelatin, polycaprolactone, polyvinylpyrrolidone, and cellulose acetate.

[0012] Preferably, the pesticide active ingredient includes at least one of bromothalonil, chlorothalonil, difenoconazole, hexaconazole, tebuconazole, picoxystrobin, boscalid, pyraclostrobin, prothioconazole, propiconazole, carbendazim, azoxystrobin, kresoxim-methyl, trifloxystrobin, thiophanate-methyl, thiram, metalaxyl, hymexazol, fluazinam, prochloraz, cyazofamid, thifluzamide, dimethomorph, fluopicolide, oxolinic copper, tricyclazole, iprodione, diethofencarb, triadimefon, epoxiconazole, flusilazole, and fluazinam.

[0013] Preferably, the average diameter of the pesticide nanofibers prepared by the coaxial electrospinning method is 100-1000 nm;

[0014] The diameter of the core layer is 50-600 nm, and the sum of the diameters of the core layer and the shell layer is 100-1000 nm.

[0015] Preferably, per m 2 The mass of the pesticide active ingredient loaded on the pesticide nanofibers is 0.1-500 mg;

[0016] The specific surface area of the pesticide nanofibers is 100-2000 m 2 ·g -1 , and the porosity is 40-95%.

[0017] In a second aspect, the present invention also provides a method for preparing the pesticide nanofibers, and the pesticide nanofibers are prepared by the coaxial electrospinning method or the coaxial electrospinning method;

[0018] The method for preparing the pesticide nanofibers by the coaxial electrospinning method specifically includes:

[0019] Adding cyclodextrin into water to obtain a cyclodextrin solution;

[0020] Adding the polymer into water to obtain a polymer solution;

[0021] Mix the cyclodextrin solution with the polymer solution, and add the pesticide active molecule to obtain a mixed spinning solution;

[0022] Place the mixed spinning solution in an electrospinning machine to carry out electrospinning to prepare pesticide nanofibers;

[0023] The pesticide nanofibers prepared by the coaxial electrospinning method specifically include:

[0024] Add cyclodextrin to water to obtain a cyclodextrin solution;

[0025] Add the pesticide active molecule to the cyclodextrin solution and mix to obtain a core layer spinning solution;

[0026] Add the polymer to water to obtain a shell layer spinning solution;

[0027] Place the core layer spinning solution and the shell layer spinning solution in a coaxial electrospinning machine to carry out electrospinning to prepare pesticide nanofibers.

[0028] Preferably, the pesticide nanofibers prepared by the mixed electrospinning method specifically include:

[0029] Add cyclodextrin to water to obtain a cyclodextrin solution, and the mass-volume ratio of cyclodextrin to water is (1.5 - 1.55) g: 1 mL;

[0030] Add the polymer to water to obtain a polymer solution, and the mass-volume ratio of the polymer to water is (0.04 - 0.05) g: 0.96 mL;

[0031] Mix the cyclodextrin solution with the polymer solution, and add the pesticide active molecule to obtain a mixed spinning solution, and the mass ratio of cyclodextrin, pesticide active molecule, and polymer is (1.5 - 1.55):(0.06 - 0.4):(0.04 - 0.05);

[0032] Place the mixed spinning solution in an electrospinning machine to carry out electrospinning to prepare pesticide nanofibers, and the process parameters controlled by electrospinning are: the spinning voltage is 15 - 17 kV, the receiving distance is 5 - 20 cm, and the injection speed of the mixed spinning solution is 0.2 - 20 mL / h.

[0033] Preferably, the pesticide nanofibers prepared by the coaxial electrospinning method specifically include:

[0034] Add cyclodextrin to water to obtain a cyclodextrin solution, and the mass-volume ratio of cyclodextrin to water is (2.0 - 2.1) g: 1 mL;

[0035] Add the pesticide active molecule to the cyclodextrin solution and mix to obtain a core layer spinning solution;

[0036] The polymer is added to water to obtain a shell spinning solution, and the mass-volume ratio of the polymer to water is (0.04 - 0.05) g: 0.96 mL;

[0037] The core spinning solution and the shell spinning solution are placed in a coaxial electrospinning machine for electrospinning to prepare pesticide nanofibers; the mass ratio of the cyclodextrin, the pesticide active molecule, and the polymer is (2.0 - 2.1):(0.03 - 0.8):(0.04 - 0.05).

[0038] Preferably, the core spinning solution and the shell spinning solution are placed in a coaxial electrospinning machine for electrospinning to prepare pesticide nanofibers, and the process parameters controlled by the coaxial electrospinning are: the spinning voltage is 15 - 17 kV, the receiving distance is 5 - 20 cm, the injection rates of the core spinning solution and the shell spinning solution are 0.2 - 20 mL / h, and the ratio of the injection rates of the core spinning solution and the shell spinning solution is 1:(3 - 3.5).

[0039] In a third aspect, the present invention also provides an application of the pesticide nanofibers as prepared by the method for preparing the pesticide nanofibers or the pesticide nanofibers as an antibacterial agent.

[0040] The pesticide nanofibers, the preparation method and the application thereof of the present invention have the following beneficial effects compared with the prior art:

[0041] The present invention is prepared by adopting a blended electrospinning method or a coaxial electrospinning method. The pesticide molecules are loaded into the nanofibers, so that the pesticide active ingredients are dispersed in a nano form, improving their water solubility and enhancing their bioavailability. At the same time, by utilizing the properties of different polymers, the blended and coaxial pesticide nanofibers can isolate the external environment, improving the thermal stability and antioxidant property of the pesticide active ingredients. At the same time, the pesticide nanofibers prepared by the two electrospinning methods both have a long-acting and controllable release effect, preventing the explosive sudden release of pesticides, and improving the storage stability and utilization rate of pesticides; the pesticide nanofibers prepared by the electrospinning method of the present invention significantly improve the dispersibility of the pesticide active ingredients, increasing the contact area between the pesticide active ingredients and the harmful fungi in the farmland, thereby enhancing the biological activity of the pesticide active ingredients. The selected nanofiber matrix materials of the present invention all have good biocompatibility. Therefore, the prepared nano-pesticides are green and environmentally friendly formulations. Description of the Drawings

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0043] Figure 1 For Figure 1 SEM and TEM images of different nanofibers; among them, a is the SEM image of HPβCD / PVA blended nanofibers in Comparative Example 1, b is the SEM image of bromothalonil-HPβCD nanofibers in Comparative Example 2, c is the SEM image of bromothalonil-HPβCD / PVA blended nanofibers prepared in Example 1 of the present invention, and d is the TEM image of bromothalonil-HPβCD / PVA core-shell nanofibers prepared in Example 26 of the present invention;

[0044] Figure 2 The standard curve graph in this embodiment;

[0045] Figure 3 Thermogravimetric analysis graphs of bromothalonil, bromothalonil-HPβCD / PVA blended nanofibers obtained in Example 1 of the present invention, and bromothalonil-HPβCD / PVA core-shell nanofibers prepared in Example 26 of the present invention;

[0046] Figure 4 Infrared spectra graphs of bromothalonil, bromothalonil-HPβCD / PVA blended nanofibers prepared in Example 1 of the present invention, and bromothalonil-HPβCD / PVA core-shell nanofibers prepared in Example 26 of the present invention;

[0047] Figure 5 X-ray diffraction graphs of bromothalonil, bromothalonil-HPβCD / PVA blended nanofibers prepared in Example 1 of the present invention, and bromothalonil-HPβCD / PVA core-shell nanofibers prepared in Example 26 of the present invention;

[0048] Figure 6 Inhibitory effect graphs of different nanofibers on Gibberella fujikuroi; among them, a is the blank control group, b is the mycelium of Gibberella fujikuroi treated with the original bromothalonil drug, c is the mycelium of Gibberella fujikuroi treated with the bromothalonil-HPβCD / PVA blended nanofibers obtained in Example 1 of the present invention, and d is the mycelium of Gibberella fujikuroi treated with the bromothalonil-HPβCD / PVA core-shell nanofibers obtained in Example 26 of the present invention. Detailed implementation manners

[0049] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0050] In the description of the present invention, it should be understood that the relationships indicating orientations or positions such as "upper" are based on the orientations or positions shown in the drawings, or the orientations or positions in which the inventive product is usually placed during use, or the orientations or positions commonly understood by those skilled in the art. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0051] The description order of the following embodiments is not intended to limit the preferred order of the embodiments. Additionally, in the description of the present application, the term "comprising" means "including but not limited to". The various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be construed as a rigid limitation to the scope of the present invention; therefore, it should be considered that the described range description has specifically disclosed all possible sub-ranges and individual values within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and individual numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any cited number (fraction or integer) within the indicated range.

[0052] The embodiments of the present application provide a pesticide nanofiber, which is prepared by a blend electrospinning method or a coaxial electrospinning method;

[0053] Among them, the preparation of the pesticide nanofiber by the blend electrospinning method specifically includes: preparing the pesticide nanofiber with cyclodextrin, polymer, and pesticide active molecule as raw materials;

[0054] The preparation of the pesticide nanofiber by the coaxial electrospinning method includes a core layer and a shell layer coated outside the core layer;

[0055] The core layer is cyclodextrin-coated pesticide active molecule, and the shell layer material is polymer.

[0056] In some embodiments, the cyclodextrin includes at least one of α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, methyl-β-cyclodextrin, 2-hydroxypropyl-β-cyclodextrin, 2-hydroxypropyl-γ-cyclodextrin, and 2-hydroxypropyl-α-cyclodextrin;

[0057] The polymer includes at least one of polyvinyl alcohol, polylactic acid, chitosan, ethyl cellulose, sodium alginate, gelatin, polycaprolactone, polyvinylpyrrolidone, and cellulose acetate.

[0058] In some embodiments, the pesticidal active ingredient includes at least one of bromothalonil, chlorothalonil, difenoconazole, hexaconazole, tebuconazole, picoxystrobin, boscalid, pyraclostrobin, prothioconazole, propiconazole, carbendazim, azoxystrobin, kresoxim-methyl, trifloxystrobin, thiophanate-methyl, thiram, metalaxyl, hymexazol, fluazinam, prochloraz, cyazofamid, thifluzamide, dimethomorph, fluopicolide, copper quinolate, tricyclazole, iprodione, diethofencarb, triadimefon, flutriafol, flusilazole, and fluazinam.

[0059] The pesticidal nanofibers prepared by the coaxial electrospinning method in the present invention include a core layer and a shell layer coated outside the core layer. Among them, the core layer is a hydrophilic polymer (i.e., cyclodextrin) coating the pesticidal active molecule, and the shell layer uses a hydrophobic polymer. The shell layer provides protection for the core layer, prevents the invasion of moisture, enables the pesticidal in the core layer to have a long-acting and controllable release effect, prevents its explosive burst release, and improves the storage stability and utilization rate of the pesticide;

[0060] In some embodiments, the average diameter of the pesticidal nanofibers prepared by the blended electrospinning method is 100 - 1000 nm;

[0061] In some embodiments, the diameter of the core layer is 50 - 600 nm, and the sum of the diameters of the core layer and the shell layer is 100 - 1000 nm.

[0062] In some embodiments, per m 2 The mass of the pesticidal active ingredient loaded by the pesticidal nanofibers is 0.1 - 500 mg.

[0063] In some embodiments, the specific surface area of the pesticidal nanofibers is 100 - 2000 m 2 ·g -1 , and the porosity is 40 - 95%.

[0064] The present invention can prepare pesticides with poor water solubility into drug-loaded nanofibers with intelligent responsiveness, high drug loading capacity, and high encapsulation efficiency by using uniaxial blending and coaxial electrospinning methods. Such drug-loaded nanofibers can not only protect the active ingredients of pesticides, but also improve water solubility and enhance bioavailability. At the same time, they have the characteristics of multi-stimulus-responsive drug release, which is beneficial to the targeted recognition and delivery of pesticides in crop plants. Specifically, the present invention uses physical adsorption, chemical bonding, hydration, supramolecular interaction, ion exchange, hydrogen bonding, intermolecular forces and other interactions to load pesticide active molecules into the core layer of blended nanofibers or coaxial nanofibers, significantly improving the dispersibility of pesticide active ingredients, increasing the contact area between pesticide active ingredients and harmful fungi in farmland, thereby improving the biological activity of pesticide active ingredients, and enabling the slow release of pesticide active molecules at a certain concentration, which can achieve the effects of extending the pesticide persistence period, reducing the number of pesticide applications, and improving pesticide utilization rate, etc., so as to economically, safely and effectively control harmful organisms. The polymer component in the nanofibers can also be used to isolate the environment to improve the thermal stability and antioxidant properties of pesticide active ingredients. The purpose of the present invention is to minimize the demand for pesticides in crops and gradually achieve more effective and safer pesticide use. The present invention can reduce the use of organic solvents during pesticide application, reduce pesticide residues, improve pesticide utilization rate, and reduce agricultural non-point source pollution; the pesticide nanofibers prepared by the electrospinning technology of the present invention significantly improve the dispersibility of pesticide active ingredients and increase the contact area between pesticide active ingredients and harmful fungi in farmland, thereby improving the biological activity of pesticide active ingredients. The nanofiber matrix materials selected in the present invention all have good biocompatibility. Therefore, the prepared nano-pesticides are green and environmentally friendly formulations.

[0065] Based on the same inventive concept, the present invention also provides a preparation method of the above-mentioned pesticide nanofibers, and the pesticide nanofibers are prepared by using a blended electrospinning method or a coaxial electrospinning method;

[0066] The blended electrospinning method is used to prepare pesticide nanofibers, which specifically includes:

[0067] S1. Add cyclodextrin into water to obtain a cyclodextrin solution;

[0068] S2. Add a polymer into water to obtain a polymer solution;

[0069] S3. Mix the cyclodextrin solution and the polymer solution, and add pesticide active molecules to obtain a mixed spinning solution;

[0070] S4. Place the mixed spinning solution in an electrospinning machine for electrospinning to prepare pesticide nanofibers;

[0071] The coaxial electrospinning method is used to prepare pesticide nanofibers, which specifically includes:

[0072] S1. Add cyclodextrin to water to obtain a cyclodextrin solution;

[0073] S2. Add a pesticide active molecule to the cyclodextrin solution and mix to obtain a core layer spinning solution;

[0074] S3. Add a polymer to water to obtain a shell layer spinning solution;

[0075] S4. Place the core layer spinning solution and the shell layer spinning solution in a coaxial electrospinning machine for electrospinning to prepare pesticide nanofibers.

[0076] In some embodiments, the pesticide nanofibers are prepared by a co - spinning electrospinning method, specifically including:

[0077] Add cyclodextrin to water to obtain a cyclodextrin solution, and the mass - to - volume ratio of cyclodextrin to water is (1.5 - 1.55) g:1 mL;

[0078] Add a polymer to water to obtain a polymer solution, and the mass - to - volume ratio of the polymer to water is (0.04 - 0.05) g:0.96 mL;

[0079] Mix the cyclodextrin solution and the polymer solution, and add a pesticide active molecule to obtain a mixed spinning solution. The mass ratio of cyclodextrin, pesticide active molecule, and polymer is (1.5 - 1.55):(0.06 - 0.4):(0.04 - 0.05);

[0080] Place the mixed spinning solution in an electrospinning machine for electrospinning to prepare pesticide nanofibers. The process parameters controlled by electrospinning are: the spinning voltage is 15 - 17 kV, the receiving distance is 5 - 20 cm, and the injection rate of the mixed spinning solution is 0.2 - 20 mL / h.

[0081] Specifically, for the co - spinning electrospinning method or the coaxial electrospinning method to prepare pesticide nanofibers, the equipment used is preferably an electrospinning machine. The electrospinning machine used in the co - spinning electrospinning method consists of a high - voltage power supply, one injection pump, one syringe, and one collector. Use the syringe to suck up the mixed spinning solution and fix it on the injection pump, and at the same time push the mixed spinning solution at a certain flow rate to obtain a pesticide nanofiber membrane through the electrospinning equipment. The electrospinning machine used in the coaxial electrospinning method consists of a high - voltage power supply, two injection pumps, two syringes, and one collector. Use two syringes to suck up the core layer spinning solution and the shell layer spinning solution respectively, fix them on two injection pumps respectively, and at the same time push the core layer spinning solution and the shell layer spinning solution at different flow rates to obtain a pesticide nanofiber membrane with a core - shell structure through the electrospinning equipment.

[0082] Specifically, before performing blended electrospinning, the present invention preferably further includes: subjecting the mixed spinning solution to ultrasonic degassing; the temperature of the ultrasonic treatment is preferably room temperature; the time of the ultrasonic treatment is preferably 5 to 20 minutes, more preferably 10 minutes; the power of the ultrasonic treatment is preferably 120 to 180 W, more preferably 150 W; the ultrasonic treatment is preferably ultrasonic bath treatment. The present invention removes the gas in the mixed spinning solution required for electrospinning through ultrasonic treatment, avoiding the influence of the gas on the fiber structure obtained by subsequent electrospinning; in the present invention, the conditions for electrospinning in the preparation process of blended nanofibers include: the spinning voltage is 15 to 17 kV, preferably 15 kV; the receiving distance of the collector is 5 to 20 cm, preferably 10 to 20 cm, more preferably 12 to 17 cm, and most preferably 15 cm; the pushing speed of the syringe pump is preferably 0.2 to 20 mL / h, more preferably 0.5 to 10 mL / h; the time of electrospinning is preferably 0.5 to 3 h, more preferably 1 to 2 h.

[0083] In some embodiments, the method for preparing pesticide nanofibers by coaxial electrospinning specifically includes:

[0084] Adding cyclodextrin to water to obtain a cyclodextrin solution, and the mass-volume ratio of cyclodextrin to water is (2.0 to 2.1) g: 1 mL;

[0085] Adding a pesticide active molecule to the cyclodextrin solution and mixing to obtain a core layer spinning solution;

[0086] Adding a polymer to water to obtain a shell layer spinning solution, and the mass-volume ratio of the polymer to water is (0.04 to 0.05) g: 0.96 mL;

[0087] Placing the core layer spinning solution and the shell layer spinning solution in a coaxial electrospinning machine for electrospinning to obtain pesticide nanofibers; the mass ratio of cyclodextrin, pesticide active molecule, and polymer is (2.0 to 2.1): (0.03 to 0.8): (0.04 to 0.05).

[0088] In some embodiments, placing the core layer spinning solution and the shell layer spinning solution in a coaxial electrospinning machine for electrospinning to obtain pesticide nanofibers, wherein the process parameters controlled by the coaxial electrospinning are: the spinning voltage is 15 to 17 kV, the receiving distance is 5 to 20 cm, and the pushing speeds of the core layer spinning solution and the shell layer spinning solution are 0.2 to 20 mL / h, and the ratio of the pushing speeds of the core layer spinning solution and the shell layer spinning solution is 1: (3 to 3.5).

[0089] Specifically, before performing coaxial electrospinning, the present invention preferably further includes: the core layer spinning solution and the shell layer spinning solution

[0090] Perform ultrasonic degassing separately; the temperature of the ultrasonic treatment is preferably room temperature; the time of the ultrasonic treatment is preferably 5 - 20 min, more preferably 10 min; the power of the ultrasonic treatment is preferably 120 - 180 W, more preferably 150 W; the ultrasonic treatment is preferably carried out in a water bath. The present invention removes the gas in the spinning solution by ultrasonic treatment to avoid the influence of the gas on the fiber structure obtained by subsequent electrospinning.

[0091] In some embodiments, the conditions for electrospinning in the process of preparing pesticide nanofibers by coaxial electrospinning include: the spinning voltage is 15 - 17 kV, preferably 15 kV; the receiving distance of the collector is 5 - 20 cm, preferably 10 - 20 cm, more preferably 12 - 17 cm, and most preferably 13 cm; the injection speed of the injection pump for pushing the shell layer spinning solution is preferably 0.2 - 20 mL / h, more preferably 0.5 - 10 mL / h, and most preferably 3 mL / h; the injection speed of the injection pump for pushing the core layer spinning solution is preferably 0.2 - 20 mL / h, more preferably 0.5 - 10 mL / h, and most preferably 1 mL / h.

[0092] In a third aspect, the present invention also provides an application of the above-mentioned pesticide nanofibers or the pesticide nanofibers prepared by the above-mentioned preparation method as a bacteriostatic agent in agriculture.

[0093] In some embodiments, the preferred application methods are: seed dressing method, seed soaking method, dipping method, seed fuming method, soil treatment method, film mulching pesticide application method, seed coating method or bubble dropping method, more preferably the seed dressing method or the seed soaking method; the application rate of the environmentally responsive intelligent release nano - pesticide is preferably 50 - 500 mg / mu, more preferably 80 - 320 mg / mu.

[0094] The following further illustrates the pesticide nanofibers of the present application, their preparation methods and applications with specific examples. This part further illustrates the content of the present invention with specific examples, but should not be construed as a limitation of the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0095] Example 1

[0096] The present application provides a method for preparing pesticide nanofibers, using the co - spinning electrospinning method, which includes the following steps:

[0097] S1. Dissolve 1.5000 g of hydroxypropyl β - cyclodextrin in 1 mL of deionized water, and stir evenly to obtain a hydroxypropyl β - cyclodextrin solution with a mass - to - volume ratio of 150%.

[0098] S2. Place 0.04 g of polyvinyl alcohol in 0.96 mL of water, stir it at 300 rpm at 90 °C until completely dissolved to obtain a PVA solution with a mass fraction of 4%;

[0099] S3. Mix the hydroxypropyl-β-cyclodextrin solution in S1 and the PVA solution in S2 to obtain an HPβCD / PVA mixed solution. Add 0.1294 g of bromothalonil (i.e., 1,2-dibromo-2,4-dicyanobutane) to the HPβCD / PVA mixed solution, and stir it at 300 rpm at 25 °C for 12 h to fully mix and dissolve it to obtain a bromothalonil-HPβCD / PVA mixed spinning solution;

[0100] S4. Place the bromothalonil-HPβCD / PVA mixed spinning solution in an ultrasonic cleaner, and ultrasonicate it at a power of 150 W for 10 min at room temperature (25 °C) to remove gas;

[0101] S5. Use a syringe to suck up the bromothalonil-HPβCD / PVA mixed spinning solution after ultrasonic degassing in S4, fix the syringe on the injection pump of the electrospinning equipment, set the injection speed of the injection pump to 0.5 mL / h, and control the electrospinning process parameters to obtain bromothalonil-HPβCD / PVA blended nanofibers, that is, pesticide nanofibers are prepared. The process parameters controlled by electrospinning are: the spinning voltage is 15 kV, the receiving distance is 15 cm, and the spinning time is 2 h.

[0102] Example 2

[0103] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 1, except that 0.2587 g of bromothalonil is used instead of 0.1294 g of bromothalonil in Example 1, and the rest of the processes are the same as those in Example 1.

[0104] Example 3

[0105] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 1, except that 0.0647 g of bromothalonil is used instead of 0.1294 g of bromothalonil in Example 1, and the rest of the processes are the same as those in Example 1.

[0106] Example 4

[0107] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 1, except that 0.1293 g of chlorothalonil is used instead of 0.1294 g of bromothalonil in Example 1, and the rest of the processes are the same as those in Example 1.

[0108] Example 5

[0109] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 1, except that 0.1976 g of difenoconazole is used instead of 0.1294 g of bromothalonil in Example 1, and the remaining processes are the same as those in Example 1.

[0110] Example 6

[0111] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 1, except that 0.1527 g of hexaconazole is used instead of 0.1294 g of bromothalonil in Example 1, and the remaining processes are the same as those in Example 1.

[0112] Example 7

[0113] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 1, except that 0.1497 g of tebuconazole is used instead of 0.1294 g of bromothalonil in Example 1, and the remaining processes are the same as those in Example 1.

[0114] Example 8

[0115] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 1, except that 0.1787 g of picoxystrobin is used instead of 0.1294 g of bromothalonil in Example 1, and the remaining processes are the same as those in Example 1.

[0116] Example 9

[0117] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 1, except that 0.1669 g of boscalid is used instead of 0.1294 g of bromothalonil in Example 1, and the remaining processes are the same as those in Example 1.

[0118] Example 10

[0119] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 1, except that 0.1886 g of pyraclostrobin is used instead of 0.1294 g of bromothalonil in Example 1, and the remaining processes are the same as those in Example 1.

[0120] Example 11

[0121] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 1, except that 0.1674 g of prothioconazole is used instead of 0.1294 g of bromothalonil in Example 1, and the remaining processes are the same as those in Example 1.

[0122] Example 12

[0123] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 1, except that 0.1664 g of propiconazole is used instead of 0.1294 g of bromothalonil in Example 1, and the remaining processes are the same as those in Example 1.

[0124] Example 13

[0125] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 1, except that 0.0930 g of carbendazim is used instead of 0.1294 g of bromothalonil in Example 1, and the remaining processes are the same as those in Example 1.

[0126] Example 14

[0127] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 1, except that 0.1962 g of azoxystrobin is used instead of 0.1294 g of bromothalonil in Example 1, and the remaining processes are the same as those in Example 1.

[0128] Example 15

[0129] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 1, except that 0.1524 g of kresoxim-methyl is used instead of 0.1294 g of bromothalonil in Example 1, and the remaining processes are the same as those in Example 1.

[0130] Example 16

[0131] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 1, except that 0.1986 g of trifloxystrobin is used instead of 0.1294 g of bromothalonil in Example 1, and the remaining processes are the same as those in Example 1.

[0132] Example 17

[0133] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 1, except that 0.1665 g of thiophanate-methyl is used instead of 0.1294 g of bromothalonil in Example 1, and the remaining processes are the same as those in Example 1.

[0134] Example 18

[0135] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 1, except that 0.1169 g of thiram is used instead of 0.1294 g of bromothalonil in Example 1, and the remaining processes are the same as those in Example 1.

[0136] Example 19

[0137] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 1, except that 0.1359 g of metalaxyl is used instead of 0.1294 g of bromothalonil in Example 1, and the remaining processes are the same as those in Example 1.

[0138] Example 20

[0139] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 1, except that 0.0482 g of hymexazol is used instead of 0.1294 g of bromothalonil in Example 1, and the remaining processes are the same as those in Example 1.

[0140] Example 21

[0141] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 1, except that 0.2262 g of fluazinam is used instead of 0.1294 g of bromothalonil in Example 1, and the remaining processes are the same as those in Example 1.

[0142] Example 22

[0143] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 1, except that 0.1832 g of prochloraz is used instead of 0.1294 g of bromothalonil in Example 1, and the remaining processes are the same as those in Example 1.

[0144] Example 23

[0145] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 1, except that 0.1580 g of cyazofamid is used instead of 0.1294 g of bromothalonil in Example 1, and the remaining processes are the same as those in Example 1.

[0146] Example 24

[0147] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 1, except that 0.2568 g of thifluzamide is used instead of 0.1294 g of bromothalonil in Example 1, and the remaining processes are the same as those in Example 1.

[0148] Example 25

[0149] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 1, except that 0.1886 g of dimethomorph is used instead of 0.1294 g of bromothalonil in Example 1, and the remaining processes are the same as those in Example 1.

[0150] Example 26

[0151] This example provides a preparation method of pesticide nanofibers. Using the coaxial electrospinning method, the specific steps are as follows:

[0152] S1. Dissolve 2.0000 g of hydroxypropyl-β-cyclodextrin in 1 mL of deionized water and stir evenly to obtain a hydroxypropyl-β-cyclodextrin solution with a mass-volume ratio of 200%;

[0153] S2. Place 0.04 g of polyvinyl alcohol in 0.96 mL of water, stir it at 300 rpm at 90 °C until completely dissolved to obtain a PVA solution with a mass fraction of 4%, and obtain the shell spinning solution;

[0154] S3. Add 0.3449 g of bromothalonil to the hydroxypropyl-β-cyclodextrin solution in S1, stir it at 300 rpm at 25 °C for 12 h to fully mix and dissolve, obtain the bromothalonil-HPβCD solution, and obtain the core spinning solution;

[0155] S4. Place the shell spinning solution and the core spinning solution in an ultrasonic cleaner respectively, and ultrasonically clean them at a power of 150 W for 10 min at room temperature (25 °C) to remove gas;

[0156] S5. Use two syringes to suck the shell spinning solution and the core spinning solution after ultrasonic degassing in S4 respectively, fix the syringes on the two injection pumps of the coaxial electrospinning device respectively, set the injection speed of the injection pump corresponding to the shell spinning solution to 1.5 mL / h, set the injection speed of the injection pump corresponding to the core spinning solution to 0.5 mL / h, control the coaxial electrospinning process parameters, and obtain bromothalonil-HPβCD / PVA core-shell nanofibers, that is, prepare pesticide nanofibers; the process parameters controlled by electrospinning are: the spinning voltage is 15 kV, the receiving distance is 15 cm, and the spinning time is 2 h.

[0157] Example 27

[0158] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 26, except that 0.1725 g of bromothalonil is used instead of 0.3449 g of bromothalonil in Example 26, and the rest of the processes are the same as those in Example 26.

[0159] Example 28

[0160] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 26, except that 0.1150 g of bromothalonil is used instead of 0.3449 g of bromothalonil in Example 26, and the rest of the processes are the same as those in Example 26.

[0161] Example 29

[0162] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 26, except that 0.1725 g of chlorothalonil is used instead of 0.3449 g of bromothalonil in Example 26, and the rest of the processes are the same as those in Example 26.

[0163] Example 30

[0164] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 26, except that 0.2635 g of difenoconazole is used instead of 0.3449 g of bromothalonil in Example 26, and the remaining processes are the same as those in Example 26.

[0165] Example 31

[0166] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 26, except that 0.2037 g of hexaconazole is used instead of 0.3449 g of bromothalonil in Example 26, and the remaining processes are the same as those in Example 26.

[0167] Example 32

[0168] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 26, except that 0.1996 g of tebuconazole is used instead of 0.3449 g of bromothalonil in Example 26, and the remaining processes are the same as those in Example 26.

[0169] Example 33

[0170] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 26, except that 0.2382 g of picoxystrobin is used instead of 0.3449 g of bromothalonil in Example 26, and the remaining processes are the same as those in Example 26.

[0171] Example 34

[0172] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 26, except that 0.2226 g of boscalid is used instead of 0.3449 g of bromothalonil in Example 26, and the remaining processes are the same as those in Example 26.

[0173] Example 35

[0174] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 26, except that 0.2515 g of pyraclostrobin is used instead of 0.3449 g of bromothalonil in Example 26, and the remaining processes are the same as those in Example 26.

[0175] Example 36

[0176] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 26, except that 0.2233 g of prothioconazole is used instead of 0.3449 g of bromothalonil in Example 26, and the remaining processes are the same as those in Example 26.

[0177] Example 37

[0178] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 26, except that 0.2220 g of propiconazole is used instead of bromothalonil in Example 112, and the remaining processes are the same as those in Example 26.

[0179] Example 38

[0180] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 26, except that 0.1240 g of carbendazim is used instead of 0.3449 g of bromothalonil in Example 26, and the remaining processes are the same as those in Example 26.

[0181] Example 39

[0182] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 26, except that 0.2616 g of azoxystrobin is used instead of 0.3449 g of bromothalonil in Example 26, and the remaining processes are the same as those in Example 26.

[0183] Example 40

[0184] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 26, except that 0.2032 g of kresoxim-methyl is used instead of 0.3449 g of bromothalonil in Example 26, and the remaining processes are the same as those in Example 26.

[0185] Example 41

[0186] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 26, except that 0.2649 g of trifloxystrobin is used instead of 0.3449 g of bromothalonil in Example 26, and the remaining processes are the same as those in Example 26.

[0187] Example 42

[0188] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 26, except that 0.2221 g of thiophanate-methyl is used instead of 0.3449 g of bromothalonil in Example 26, and the remaining processes are the same as those in Example 26.

[0189] Example 43

[0190] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 26, except that 0.1559 g of thiram is used instead of 0.3449 g of bromothalonil in Example 26, and the remaining processes are the same as those in Example 26.

[0191] Example 44

[0192] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 26, except that 0.1812 g of metalaxyl is used instead of 0.3449 g of bromothalonil in Example 26, and the remaining processes are the same as those in Example 26.

[0193] Example 45

[0194] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 26, except that 0.0642 g of hymexazol is used to replace 0.3449 g of bromothalonil in Example 26, and the remaining processes are the same as those in Example 26.

[0195] Example 46

[0196] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 26, except that 0.3016 g of fluazinam is used to replace 0.3449 g of bromothalonil in Example 26, and the remaining processes are the same as those in Example 26.

[0197] Example 47

[0198] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 26, except that 0.2443 g of prochloraz is used to replace 0.3449 g of bromothalonil in Example 26, and the remaining processes are the same as those in Example 26.

[0199] Example 48

[0200] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 26, except that 0.2017 g of cyazofamid is used to replace 0.3449 g of bromothalonil in Example 26, and the remaining processes are the same as those in Example 26.

[0201] Example 49

[0202] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 26, except that 0.3425 g of thifluzamide is used to replace 0.3449 g of bromothalonil in Example 26, and the remaining processes are the same as those in Example 26.

[0203] Example 50

[0204] The preparation method of the pesticide nanofibers provided in this example is the same as that in Example 26, except that 0.2516 g of dimethomorph is used to replace 0.3449 g of bromothalonil in Example 26, and the remaining processes are the same as those in Example 26.

[0205] Comparative Example 1

[0206] This comparative example provides a preparation method of pesticide nanofibers, adopting a coaxial electrospinning method, including the following steps:

[0207] S1. Dissolve 1.6000 g of hydroxypropyl-β-cyclodextrin in 1 mL of deionized water, and stir evenly to obtain a hydroxypropyl-β-cyclodextrin solution with a mass-to-volume ratio of 160%;

[0208] S2. Place 0.04 g of polyvinyl alcohol in 0.96 mL of water, and stir it at 300 rpm at 90 °C until it is completely dissolved to obtain a PVA solution with a mass fraction of 4%;

[0209] S3. Mix the hydroxypropyl-β-cyclodextrin solution in S1 and the PVA solution in S2 to obtain an HPβCD / PVA mixed solution. Add 0.1294 g of bromothalonil (i.e., 1,2-dibromo-2,4-dicyanobutane) to the HPβCD / PVA mixed solution, and stir it at 300 rpm at 25 °C for 12 h to fully mix and dissolve it to obtain a bromothalonil-HPβCD / PVA mixed spinning solution;

[0210] S4. Place the bromothalonil-HPβCD / PVA mixed spinning solution in an ultrasonic cleaner, and ultrasonicate it at a power of 150 W for 10 min at room temperature (25 °C) to remove gas;

[0211] S5. Use a syringe to suck up the bromothalonil-HPβCD / PVA mixed spinning solution after ultrasonic degassing in S4, fix the syringe on the injection pump of the electrospinning device, set the injection speed of the injection pump to 0.5 mL / h, and control the electrospinning process parameters to obtain bromothalonil-HPβCD / PVA blended nanofibers, that is, pesticide nanofibers are prepared. The process parameters controlled by electrospinning are: the spinning voltage is 15 kV, the receiving distance is 15 cm, and the spinning time is 2 h.

[0212] Comparative Example 2

[0213] This comparative example provides a method for preparing pesticide nanofibers, which adopts a blended electrospinning method, including the following steps:

[0214] S1. Dissolve 1.6000 g of hydroxypropyl-β-cyclodextrin in 1 mL of deionized water, and stir evenly to obtain a hydroxypropyl-β-cyclodextrin solution with a mass-to-volume ratio of 160%;

[0215] S2. Add 0.1293 g of bromothalonil to the hydroxypropyl-β-cyclodextrin solution in S1, and stir it at 300 rpm at 25 °C for 12 h to fully mix and dissolve it to obtain a bromothalonil-HPβCD mixed spinning solution;

[0216] S4. Place the bromothalonil-HPβCD / PVA mixed spinning solution in an ultrasonic cleaner, and ultrasonicate it at a power of 150 W for 10 min at room temperature (25 °C) to remove gas;

[0217] S5. Use a syringe to aspirate the bromothalonil-HPβCD / PVA mixed spinning solution after ultrasonic degassing in S4, fix the syringe on the injection pump of the electrospinning equipment, set the injection speed of the injection pump to 0.5 mL / h, control the electrospinning process parameters, and obtain bromothalonil-HPβCD blended nanofibers, that is, prepare pesticide nanofibers. The process parameters controlled by electrospinning are: the spinning voltage is 15 kV, the receiving distance is 15 cm, and the spinning time is 2 h.

[0218] Comparative Example 3

[0219] This comparative example provides a method for preparing pesticide nanofibers. The same as Example 1, except that in step S1, 1.8000 g of hydroxypropyl-β-cyclodextrin is dissolved in 1 mL of deionized water and stirred evenly to obtain a hydroxypropyl-β-cyclodextrin solution with a mass-to-volume ratio of 180%. The remaining processes are the same as those in Example 1.

[0220] Comparative Example 4

[0221] This comparative example provides a method for preparing pesticide nanofibers. The same as Example 1, except that in step S1, 1.2000 g of hydroxypropyl-β-cyclodextrin is dissolved in 1 mL of deionized water and stirred evenly to obtain a hydroxypropyl-β-cyclodextrin solution with a mass-to-volume ratio of 120%. The remaining processes are the same as those in Example 1.

[0222] Comparative Example 5

[0223] This comparative example provides a method for preparing pesticide nanofibers. The same as Example 1, except that in the step, 0.02 g of polyvinyl alcohol is placed in 0.98 mL of water, and it is stirred at 90 °C at a speed of 300 rpm until completely dissolved to obtain a PVA solution with a mass fraction of 2%. The remaining processes are the same as those in Example 1.

[0224] Comparative Example 6

[0225] This comparative example provides a method for preparing pesticide nanofibers. The same as Example 1, except that in the step, 0.06 g of polyvinyl alcohol is placed in 0.94 mL of water, and it is stirred at 90 °C at a speed of 300 rpm until completely dissolved to obtain a PVA solution with a mass fraction of 6%. The remaining processes are the same as those in Example 1.

[0226] Comparative Example 7

[0227] This comparative example provides a method for preparing pesticide nanofibers. The same as Example 1, except that in step S3, 0.2588 g of bromothalonil is added to the HPβCD / PVA mixed solution, and it is stirred at 25 °C at a speed of 300 rpm for 12 h to fully mix and dissolve, obtaining a bromothalonil-HPβCD / PVA mixed spinning solution. The remaining processes are the same as those in Example 1.

[0228] Comparative Example 8

[0229] This comparative example provides a method for preparing pesticide nanofibers. The same as Example 1, except that in step S3, 0.0647 g of bromothalonil was added to the HPβCD / PVA mixed solution, and stirred at 25 °C at a speed of 300 rpm for 12 h to fully mix and dissolve it to obtain a bromothalonil-HPβCD / PVA mixed spinning solution; the remaining processes were the same as those in Example 1.

[0230] Comparative Example 9

[0231] This comparative example provides a method for preparing pesticide nanofibers. The same as Example 1, except that the spinning voltage of the electrospinning machine was adjusted to 12 kV, and the remaining processes were the same as those in Example 1.

[0232] Comparative Example 10

[0233] This comparative example provides a method for preparing pesticide nanofibers. The same as Example 1, except that the spinning voltage of the electrospinning machine was adjusted to 18 kV, and the remaining processes were the same as those in Example 1.

[0234] Comparative Example 11

[0235] This comparative example provides a method for preparing pesticide nanofibers. The same as Example 1, except that the receiving distance was adjusted to 12 cm, and the remaining processes were the same as those in Example 1.

[0236] Comparative Example 12

[0237] This comparative example provides a method for preparing pesticide nanofibers. The same as Example 1, except that the receiving distance was adjusted to 18 cm, and the remaining processes were the same as those in Example 1.

[0238] Comparative Example 13

[0239] This comparative example provides a method for preparing pesticide nanofibers by coaxial electrospinning method, which specifically includes the following steps:

[0240] S1. Dissolve 2.0000 g of hydroxypropyl β-cyclodextrin in 1 mL of deionized water, and stir evenly to obtain a hydroxypropyl β-cyclodextrin solution with a mass-to-volume ratio of 200%, which is used as the core layer spinning solution;

[0241] S2. Place 0.04 g of polyvinyl alcohol in 0.96 mL of water, and stir it at 90 °C at a speed of 300 rpm until it is completely dissolved to obtain a PVA solution with a mass fraction of 4%, and obtain the shell layer spinning solution;

[0242] S3. Respectively place the shell spinning solution and the core spinning solution in an ultrasonic cleaner, and under the environment of room temperature (25 °C), ultrasonically treat for 10 min at a power of 150 W to remove gas;

[0243] S4. Respectively use two syringes to suck up the shell spinning solution and the core spinning solution after ultrasonic degassing in S3, fix the syringes on two injection pumps of a coaxial electrospinning device respectively, set the pushing speed of the injection pump corresponding to the shell spinning solution to 1.5 mL / h, set the pushing speed of the injection pump corresponding to the core spinning solution to 0.5 mL / h, control the coaxial electrospinning process parameters, and obtain HPβCD / PVA core-shell nanofibers, that is, prepare pesticide nanofibers; the process parameters controlled by electrospinning are: the spinning voltage is 15 kV, the receiving distance is 15 cm, and the spinning time is 2 h.

[0244] Comparative Example 14

[0245] The preparation method of the pesticide nanofibers provided in this comparative example is the same as that in Example 26, except that 1.8000 g of hydroxypropyl-β-cyclodextrin is used to replace 2.0000 g of hydroxypropyl-β-cyclodextrin in Example 26, and the rest of the processes are the same as those in Example 26.

[0246] Comparative Example 15

[0247] The preparation method of the pesticide nanofibers provided in this comparative example is the same as that in Example 26, except that 1.5000 g of hydroxypropyl-β-cyclodextrin is used to replace 2.0000 g of hydroxypropyl-β-cyclodextrin in Example 26, and the rest of the processes are the same as those in Example 26.

[0248] Comparative Example 16

[0249] The preparation method of the pesticide nanofibers provided in this comparative example is the same as that in Example 26, except that in step S2, 0.02 g of polyvinyl alcohol is placed in 0.98 mL of water, and it is stirred at 90 °C at a rotation speed of 300 rpm until completely dissolved to obtain a PVA solution with a mass fraction of 2%, and the shell spinning solution is obtained; the rest of the processes are the same as those in Example 26.

[0250] Comparative Example 17

[0251] The preparation method of the pesticide nanofibers provided in this comparative example is the same as that in Example 26, except that in step S2, 0.06 g of polyvinyl alcohol is placed in 0.94 mL of water, and it is stirred at 90 °C at a rotation speed of 300 rpm until completely dissolved to obtain a PVA solution with a mass fraction of 6%, and the shell spinning solution is obtained; the rest of the processes are the same as those in Example 26.

[0252] Comparative Example 18

[0253] The preparation method of the pesticide nanofibers provided in this comparative example is the same as that in Example 26, except that the spinning voltage of the electrospinning machine is adjusted to 12 kV, and the remaining processes are the same as those in Example 26.

[0254] Comparative Example 19

[0255] The preparation method of the pesticide nanofibers provided in this comparative example is the same as that in Example 26, except that the spinning voltage of the electrospinning machine is adjusted to 18 kV, and the remaining processes are the same as those in Example 26.

[0256] Comparative Example 20

[0257] The preparation method of the pesticide nanofibers provided in this comparative example is the same as that in Example 26, except that the receiving distance is adjusted to 12 cm, and the remaining processes are the same as those in Example 26.

[0258] Comparative Example 21

[0259] The preparation method of the pesticide nanofibers provided in this comparative example is the same as that in Example 26, except that the receiving distance is adjusted to 18 cm, and the remaining processes are the same as those in Example 26.

[0260] Comparative Example 22

[0261] The preparation method of the pesticide nanofibers provided in this comparative example is the same as that in Example 26, except that the pushing speed of the injection pump corresponding to the shell spinning solution is set to 1.0 mL / h, and the pushing speed of the injection pump corresponding to the core spinning solution is set to 0.5 mL / h, and the remaining processes are the same as those in Example 26.

[0262] Comparative Example 23

[0263] The preparation method of the pesticide nanofibers provided in this comparative example is the same as that in Example 26, except that the pushing speed of the injection pump corresponding to the shell spinning solution is set to 2.0 mL / h, and the pushing speed of the injection pump corresponding to the core spinning solution is set to 0.5 mL / h, and the remaining processes are the same as those in Example 26.

[0264] Performance Test

[0265] (1) Fiber morphology analysis: Take the HPβCD / PVA blended nanofibers prepared in Comparative Examples 1 - 12 and the bromothalonil - HPβCD / PVA blended nanofibers obtained in Example 1 of the present invention, and observe and measure the fiber diameter using a SU - 8010 field emission scanning electron microscope (SEM). Use a Hitachi H - 7650 transmission electron microscope (TEM) to observe the core - shell structure in the longitudinal direction of the bromothalonil - HPβCD / PVA core - shell nanofibers prepared in Example 26 of the present invention and Comparative Examples 13 - 23.

[0266] As Figure 1As shown, where a is the SEM image of HPβCD / PVA blended nanofibers in Comparative Example 1, b is the SEM image of bromothalonil-HPβCD nanofibers in Comparative Example 2, c is the SEM image of bromothalonil-HPβCD / PVA blended nanofibers prepared in Example 1 of the present invention, and d is the TEM image of bromothalonil-HPβCD / PVA core-shell nanofibers prepared in Example 26 of the present invention.

[0267] As can be seen Figure 1 from it, the bromothalonil-HPβCD / PVA blended nanofibers prepared in the present invention exhibit neat and independent properties. The fiber surface is smooth without beads, and there are no nodules or twists. The morphology and orientation are good, and it has certain operability. The Nano Measure software was used to determine the average fiber diameter by randomly measuring 100 fibers in each image. The average diameter of the blended nanofibers prepared in Example 1 was measured to be 516 ± 102 nm. It can be clearly observed that the bromothalonil-HPβCD / PVA core-shell nanofibers prepared in the present invention have a clear core-shell structure.

[0268] Table 1 below shows the average diameter and fiber morphology of the nanofibers prepared in Example 1 and Comparative Examples 1-12.

[0269] Table 1 - Average diameter and fiber morphology of the nanofibers prepared in Example 1 and Comparative Examples 1-12

[0270] Sample Name Average Diameter Fiber Morphology Example 1 516±102nm Uniform, continuous, bead-free Comparative Example 1 479±88nm Uniform, continuous, bead-free Comparative Example 2 887±681nm Non-uniform, continuous, wide fiber diameter distribution Comparative Example 3 576±177nm Uniform, continuous, bead-free, wide fiber diameter distribution Comparative Example 4 466±177nm Non-uniform, continuous, bead-free, wide fiber diameter distribution Comparative Example 5 667±288nm Non-uniform, continuous, with small bead-like substances Comparative Example 6 552±172nm Uniform, continuous, bead-free, wide fiber diameter distribution Comparative Example 7 533±132nm Relatively uniform, continuous, bead-free, relatively wide fiber diameter distribution Comparative Example 8 504±119nm Relatively uniform, continuous, bead-free, relatively wide fiber diameter distribution Comparative Example 9 685±312nm Non-uniform, discontinuous, bead-free, wide fiber diameter distribution Comparative Example 10 475±109nm Non-uniform, discontinuous, bead-free Comparative Example 11 587±187nm Uniform, continuous, bead-free Comparative Example 12 532±226nm Uniform, continuous, bead-free

[0271] Table 2 shows the average diameter and fiber morphology of the nanofibers prepared in Example 26 and Comparative Examples 13-23.

[0272] Table 2 - Average diameter and fiber morphology of the nanofibers prepared in Example 26 and Comparative Examples 13-23

[0273]

[0274]

[0275] As can be seen from Table 1, the nanofibers obtained in Comparative Examples 2-12 have a wide, discontinuous, non-uniform fiber diameter distribution or cannot form uniform and continuous nanofibers.

[0276] As can be seen from Table 1, after adding PVA, PVA and HPβCD can form a three-dimensional interpenetrating network through intermolecular hydrogen bonds, which can significantly improve the viscoelasticity of the spinning solution and overcome the problem of uneven spinning caused by the low viscosity and high surface tension of the HPβCD solution. Therefore, compared with the pure HPβCD solution, after adding PVA, the preparation efficiency of the mixed spinning solution is higher, the spinning process is more stable, and the nanofibers are more uniform. In Comparative Example 3, the high concentration of HPβCD led to a larger average diameter of the nanofibers and a wide diameter distribution; in Comparative Example 4, the low concentration of HPβCD led to a smaller average diameter of the nanofibers and a wide diameter distribution. In Comparative Example 5, the low concentration of PVA led to a larger average diameter of the nanofibers and a wide diameter distribution, and small bead-like substances appeared; in Comparative Example 6, the high concentration of PVA led to a smaller average diameter of the nanofibers and a wide diameter distribution. As can be seen from Comparative Examples 7 and 8, the drug concentration has little effect on the nanofibers. And as can be seen from Comparative Examples 9 and 10, when the voltage increases, the nanofibers will break and become discontinuous; when the voltage decreases, the nanofibers will become uneven. As can be seen from Comparative Examples 11 and 12, the spinning distance has little effect on the nanofibers, but it will make the diameter distribution wider. Through Comparative Examples 14-17, it can be seen that it is difficult to form a core-shell structure when the concentration ratio of PVA and HPβCD is different. Through Comparative Examples 18 and 19, it can be seen that the nanofibers break and are discontinuous at a low voltage (12 kV), and bead-like substances are formed; a core-shell structure cannot be formed at a high voltage (18 kV). Through Comparative Examples 20 and 21, it can be seen that a core-shell structure can be formed when the receiving distance is between 12-18 cm, but there are differences in its diameter distribution. Through Comparative Examples 22 and 23, it can be seen that a core-shell structure cannot be formed when the flow rate ratio of the core-shell spinning solution changes (at a core-shell spinning solution flow rate of 1:2 and 1:4).

[0277] (2) Determination of the mechanical strength of nanofibers:

[0278] For the cymoxanil-HPβCD nanofibers prepared in Comparative Example 2 and the cymoxanil-HPβCD / PVA blended nanofibers prepared in Example 1 of the present invention, a tensile test was performed using an electronic universal testing machine (MTS E43.104) to compare the mechanical strength of the nanofibers. Mechanical strength is one of the key factors affecting the application range and application effect of composite nanofibers. As shown in Table 3, the Young's modulus of the cymoxanil-HPβCD / PVA blended nanofibers is 3.45 times that of the cymoxanil-HPβCD nanofibers. After adding PVA, the tensile strength (peak stress) increased from 0.1 MPa to 0.5 MPa, and the peak load increased from 0.543 N to 9.799 N. This shows that after adding PVA, the tensile strength of the fiber membrane is improved, and it can better withstand mechanical friction in the field.

[0279] Table 3 - Test results of the mechanical strength of the nanofibers prepared in Comparative Example 2 and Example 1

[0280] Example Peak Load (N) Peak Stress (MPa) Strain at Failure (%) Young's Modulus (MPa) Comparative Example 2 0.543 0.1 3.006 5.063 Example 1 9.799 0.5 3.177 17.479

[0281] (3) Determination of drug loading, ultraviolet stability and 72-hour release rate:

[0282] Preparation of standard sample solution: Weigh 0.05 g of cymoxanil standard sample, place it in a 100 mL volumetric flask, dissolve it with methanol and dilute to the mark, and shake well. The operating conditions of high performance liquid chromatography (HPLC) are as follows: Mobile phase: methanol: water = 60:40 (V / V); Flow rate: 1.0 mL / min; Column temperature: 30 °C; Detection wavelength: 230 nm; Injection volume: 10 μL; Retention time: 10 min. Calculate and plot the standard curve according to the HPLC determination results, as Figure 2 shown;

[0283] Preparation and determination of sample solution: For the HPβCD / PVA blended nanofibers prepared in Comparative Examples 2 - 8, the cymoxanil-HPβCD / PVA blended nanofibers obtained in Example 1 of the present invention, and the cymoxanil-HPβCD / PVA core-shell nanofibers prepared in Example 26 of the present invention, accurately weigh 10 mg of the HPβCD / PVA blended nanofibers or cymoxanil-HPβCD / PVA core-shell nanofibers prepared in different examples and comparative examples, completely dissolve them in 10 mL of ultrapure water, shake well and filter into a liquid chromatography injection vial. The HPLC injection volume is 10 μL, detect the peak area of cymoxanil, and calculate the drug cymoxanil concentration according to the standard curve. The drug loading is calculated according to the following formula:

[0284] Drug loading = (c × v) / M

[0285] In the formula: c - Concentration of cymoxanil in the nanofiber solution

[0286] v - Volume of the nanofiber solution

[0287] M - Total mass of the drug-loaded nanofibers before dissolution

[0288] Cut the above nanofibers into 1 cm × 1 cm segments, place them in a quartz petri dish, and set up a control group (stored in the dark) and an experimental group (ultraviolet irradiation). The ultraviolet irradiation parameters are as follows: Light power: 441 mW / cm 2 ; 5” energy: 1426 mJ / cm 2 ; Wavelength: 365 nm. The HPLC injection volume is 10 μL, detect the peak area of cymoxanil, and calculate the drug cymoxanil concentration according to the standard curve ( Figure 2 ). The ultraviolet residue rate (24 h) is calculated according to the following formula.

[0289] Ultraviolet residue rate (24 h) = (C1 × V1) / (C0 × V0)

[0290] In the formula: C1 - Concentration of cymoxanil in the nanofiber solution after ultraviolet irradiation

[0291] V1 - Volume of nanofiber solution after UV irradiation

[0292] C0 - Concentration of bromothalonil in nanofiber solution without UV irradiation

[0293] V0 - Volume of nanofiber solution without UV irradiation

[0294] Prepare 100 mL of PBS (pH 7.4) per portion and preheat it to 37 °C. Accurately weigh 50 mg of the fiber membrane, immerse it in 50 mL of the release medium, accurately sample 5 mL at the 72nd hour, centrifuge the sample (10,000 rpm, 5 min), take the supernatant to detect the peak area of bromothalonil, and calculate the concentration of the drug bromothalonil according to the standard curve ( Figure 2 ). The release rate at 72 h is calculated according to the following formula.

[0295] Release rate at 72 h = (c1 × v1) / (c0 × v0)

[0296] Where: c1 - Concentration of bromothalonil in nanofiber solution after 72 h

[0297] v1 - Volume of nanofiber solution after 72 h

[0298] c0 - Concentration of bromothalonil in the initial nanofiber solution

[0299] v0 - Volume of the initial nanofiber solution

[0300] The above results are shown in Table 4. Based on the above results, although the drug loading of the nanofibers without PVA blending (Comparative Example 2) is 1.76 times that of the blended nanofibers, the UV residue rate (24 h) is only 0.38 times that of the blended nanofibers, and the release rate at 72 h is 1.67 times that of the blended nanofibers. It can be seen that the UV stability and slow-release performance of the blended nanofibers are better than those of the nanofibers without PVA. The drug loading of the coaxial nanofibers is 9.69 ± 0.17%, the UV residue rate (24 h) is 70.33 ± 2.03%, and the release rate at 72 h is 45.10 ± 2.33%. The data are close to those of the blended nanofibers, showing good slow-release performance and stability.

[0301] Table 3 - Drug loading, UV residue rate, and release rate data of nanofibers prepared in different examples

[0302] Example Drug Loading (%) Ultraviolet Residual Rate (24h, %) 72h Release Rate (%) Example 1 10.57±0.21 79.52±3.01 49.70±0.98 Comparative Example 2 18.65±0.33 30.21±0.89 83.24±1.53 Comparative Example 3 11.21±0.30 68.07±4.51 55.45±3.02 Comparative Example 4 6.79±0.15 71.03±2.88 45.55±1.12 Comparative Example 5 9.49±0.20 48.49±4.99 60.09±2.10 Comparative Example 6 10.88±0.23 77.12±2.51 48.77±1.31 Comparative Example 7 10.73±0.20 71.44±7.41 51.23±0.76 Comparative Example 8 9.87±0.18 81.22±3.56 48.32±0.67 Example 26 9.69±0.17 70.33±2.03 45.10±2.33

[0303] (5) Thermal stability analysis: Appropriate amounts of the original bromothalonil drug, 5 mg of the bromothalonil-HPβCD / PVA blended nanofibers obtained in Example 1 of the present invention, and 5 mg of the bromothalonil-HPβCD / PVA core-shell nanofibers prepared in Example 26 were taken respectively and placed in a 2 mL alumina crucible. They were heated from 25 °C to 800 °C at a heating rate of 10 °C / min under the continuous flow of dry N2 (50 mL / min) throughout the process. With temperature as the abscissa and mass percentage as the ordinate, a weight loss curve was plotted, and the results are as Figure 3 shown.

[0304] Figure 3 The bromothalonil-HPβCD / PVA blended nanofibers in

[0305] are Example 1, and the bromothalonil-HPβCD / PVA core-shell nanofibers are Example 26. Figure 3

[0306] It can be seen that the main mass loss of the original bromothalonil drug starts from 171 °C and ends at 263 °C. The main mass loss of bromothalonil in the bromothalonil-HPβCD / PVA blended nanofibers prepared in Example 1 of the present invention starts from 205 °C. The main mass loss of bromothalonil in the bromothalonil-HPβCD / PVA core-shell nanofibers prepared in Example 26 of the present invention starts from 199 °C, which indicates that the thermal stability of the pesticide active ingredient can be improved by preparing blended and core-shell nanofibers. (6) FTIR analysis: 1 mg of bromothalonil, the bromothalonil-HPβCD / PVA blended nanofibers prepared in Example 1 of the present invention, and the bromothalonil-HPβCD / PVA core-shell nanofibers prepared in Example 26 were taken respectively and mixed with 100 mg of potassium bromide and ground to form a powder for Fourier transform infrared spectroscopy analysis. This analysis was performed using an ALPHA-T infrared spectrometer (Bruker VERTEX70), with the wavenumber range set to 4000 - 400 cm-1 and the resolution set to 2 cm -1 , and 32 scans were carried out. The infrared spectra are as Figure 4 shown.

[0307] Figure 4 The bromothalonil-HPβCD / PVA blended nanofibers in

[0308] are Example 1, and the bromothalonil-HPβCD / PVA core-shell nanofibers are Example 26. Figure 4 It can be seen that the original bromothalonil drug has a C≡N characteristic peak observed at 2254 cm -1 , and the characteristic peaks of PVA and HPβCD are both at 3360 cm -1 (hydroxyl group), 2945 cm -1 (alkyl group), and 1090 cm -1(C-O stretching vibration peak). Compared with the bromothalonil technical, the characteristic absorption peaks of hydroxyl groups in the bromothalonil-HPβCD / PVA blended nanofibers prepared in Example 1 of the present invention and the bromothalonil-HPβCD / PVA core-shell nanofibers prepared in Example 26 shifted to varying degrees, and the C≡N characteristic peak was not observed at 2254 cm -1 This indicates that inclusion complexation occurred between bromothalonil in the core layer solution of the blended nanofibers and core-shell nanofibers and HPβCD, forming an inclusion complex; hydrogen bonds were formed between PVA, HPβCD and bromothalonil.

[0309] (7) X-ray diffraction analysis: Using a Phillips X-ray diffractometer with Cu k-α radiation to perform diffraction analysis on the bromothalonil technical and the bromothalonil-HPβCD / PVA blended nanofibers and bromothalonil-HPβCD / PVA core-shell nanofibers obtained in Example 1 and Example 26 of the present invention. Conditions: tube voltage is 40 kV and tube current is 30 mA. The X-ray diffractometer scans at a rate of 2° / min to measure the diffraction pattern data of the sample in the range of 5-45°. The X-ray diffraction spectrum is as Figure 5 shown.

[0310] Figure 5 The bromothalonil-HPβCD / PVA blended nanofibers in

[0311] are Example 1, and the bromothalonil-HPβCD / PVA core-shell nanofibers are Example 26. Figure 5 As can be seen from

[0312] (8) Antifungal activity test: A comparative study was conducted on fungi growing naturally and fungi treated with the technical chlobenthiazone, the chlobenthiazone-HPβCD / PVA blended nanofibers prepared in Example 1, and the chlobenthiazone-HPβCD / PVA core-shell nanofibers prepared in Example 26 to evaluate the antifungal activity. Sample solutions with different chlobenthiazone contents (0.025, 0.05, 0.10, 0.20, and 0.50 μg / mL) were prepared using sterile water (the chlobenthiazone content in the chlobenthiazone solution was the same as that in the chlobenthiazone-HPβCD / PVA blended nanofibers and the chlobenthiazone-HPβCD / PVA core-shell nanofibers). The entire experiment was carried out in a sterile operating bench. When the temperature of the potato dextrose agar medium dropped to about 55 °C, 10 mL of the medium was slowly poured into a petri dish. At the same time, 1 mL of the sample solution was mixed with the medium solution, and the medium was allowed to cool and solidify. Fusarium graminearum hyphae with a diameter of 6 mm were placed in the center of the above medium. Finally, the cultures were incubated in an inverted position at 25 °C, and the growth diameters of the hyphae were recorded respectively. The results are as Figure 6 shown, where a is the blank control group, b is the Fusarium graminearum hyphae treated with the technical chlobenthiazone, c is the Fusarium graminearum hyphae of the chlobenthiazone-HPβCD / PVA blended nanofibers obtained in Example 1 of the present invention, and d is the Fusarium graminearum hyphae of the chlobenthiazone-HPβCD / PVA core-shell nanofibers obtained in Example 26 of the present invention.

[0313] It can be seen from Figure 6 this that compared with the naturally growing Fusarium graminearum, the growth of the Fusarium graminearum treated with the technical chlobenthiazone is slower, indicating that the chlobenthiazone has an antifungal effect; the diameters of the hyphae of the Fusarium graminearum treated with the chlobenthiazone-HPβCD / PVA blended nanofibers prepared in Example 1 of the present invention and the chlobenthiazone-HPβCD / PVA core-shell nanofibers prepared in Example 26 are smaller than those of the Fusarium graminearum treated with the technical chlobenthiazone, indicating that the antifungal activity of the technical chlobenthiazone can be improved by preparing the pesticide nanofibers of the present invention, which is achieved by improving the dispersibility of the technical chlobenthiazone.

[0314] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A pesticide nanofiber, characterized in that, The pesticide nanofibers are prepared by a blend electrospinning method or a coaxial electrospinning method; Among them, the preparation of pesticide nanofibers by the blend electrospinning method specifically includes: using cyclodextrin, polymer, and pesticide active molecule as raw materials to prepare pesticide nanofibers; The preparation of pesticide nanofibers by the coaxial electrospinning method includes a core layer and a shell layer coated outside the core layer; The core layer is cyclodextrin-coated pesticide active molecule, and the shell layer material is polymer.

2. The pesticide nanofiber according to claim 1, characterized in that, The cyclodextrin includes at least one of α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, methyl-β-cyclodextrin, 2-hydroxypropyl-β-cyclodextrin, 2-hydroxypropyl-γ-cyclodextrin, and 2-hydroxypropyl-α-cyclodextrin; The polymer includes at least one of polyvinyl alcohol, polylactic acid, chitosan, ethyl cellulose, sodium alginate, gelatin, polycaprolactone, polyvinylpyrrolidone, and cellulose acetate.

3. The pesticide nanofibers as described in claim 1 are characterized in that, The pesticide active ingredients include at least one of bromothalonil, chlorothalonil, difenoconazole, hexaconazole, tebuconazole, picoxystrobin, boscalid, pyraclostrobin, prothioconazole, propiconazole, carbendazim, azoxystrobin, kresoxim-methyl, trifloxystrobin, thiophanate-methyl, thiram, metalaxyl, hymexazol, fluazinam, prochloraz, cyazofamid, thifluzamide, dimethomorph, fluopicolide, oxine-copper, tricyclazole, iprodione, diethofencarb, triadimefon, epoxiconazole, flusilazole, and fluazinam.

4. The pesticide nanofibers according to claim 1, wherein, The average diameter of the pesticide nanofibers prepared by the blend electrospinning method is 100 - 1000 nm; The diameter of the core layer is 50 - 600 nm, and the sum of the diameters of the core layer and the shell layer is 100 - 1000 nm.

5. The pesticide nanofibers according to claim 1, characterized in that, Per m 2 The mass of the pesticide active ingredient loaded on the pesticide nanofibers is 0.1 to 500 mg; The specific surface area of the pesticide nanofibers is 100 to 2000 m 2 ·g -1 , and the porosity is 40 to 95%.

6. A method for preparing the pesticide nanofibers according to any one of claims 1 to 5, characterized in that, The pesticide nanofibers are prepared by a blend electrospinning method or a coaxial electrospinning method; The preparation of pesticide nanofibers by the blend electrospinning method specifically includes: Adding cyclodextrin into water to obtain a cyclodextrin solution; Adding polymer into water to obtain a polymer solution; Mixing the cyclodextrin solution and the polymer solution, and adding pesticide active molecule to obtain a mixed spinning solution; Placing the mixed spinning solution in an electrospinning machine to carry out electrospinning to prepare pesticide nanofibers; The preparation of pesticide nanofibers by the coaxial electrospinning method specifically includes: Adding cyclodextrin into water to obtain a cyclodextrin solution; Adding pesticide active molecule into the cyclodextrin solution and mixing to obtain a core layer spinning solution; Adding polymer into water to obtain a shell layer spinning solution; Placing the core layer spinning solution and the shell layer spinning solution in a coaxial electrospinning machine to carry out electrospinning to prepare pesticide nanofibers.

7. The preparation method of the pesticide nanofibers according to claim 6, characterized in that, The preparation of pesticide nanofibers by the blend electrospinning method specifically includes: Adding cyclodextrin into water to obtain a cyclodextrin solution, and the mass-volume ratio of cyclodextrin to water is (1.5 - 1.55) g:1 mL; Adding polymer into water to obtain a polymer solution, and the mass-volume ratio of polymer to water is (0.04 - 0.05) g:0.96 mL; Mix the cyclodextrin solution with the polymer solution, and add the pesticide active molecule to obtain a mixed spinning solution. The mass ratio of cyclodextrin, pesticide active molecule, and polymer is (1.5 - 1.55):(0.06 - 0.4):(0.04 - 0.05); Place the mixed spinning solution in an electrospinning machine to prepare pesticide nanofibers by electrospinning. The process parameters controlled by electrospinning are: the spinning voltage is 15 - 17 kV, the receiving distance is 5 - 20 cm, and the injection speed of the mixed spinning solution is 0.2 - 20 mL / h.

8. The preparation method of the pesticide nanofibers according to claim 6, characterized in that, The pesticide nanofibers are prepared by the coaxial electrospinning method, specifically including: Add cyclodextrin to water to obtain a cyclodextrin solution. The mass-volume ratio of cyclodextrin to water is (2.0 - 2.1) g:1 mL; Add the pesticide active molecule to the cyclodextrin solution and mix to obtain the core layer spinning solution; Add the polymer to water to obtain the shell layer spinning solution. The mass-volume ratio of the polymer to water is (0.04 - 0.05) g:0.96 mL; Place the core layer spinning solution and the shell layer spinning solution in a coaxial electrospinning machine to prepare pesticide nanofibers by electrospinning; the mass ratio of cyclodextrin, pesticide active molecule, and polymer is (2.0 - 2.1):(0.03 - 0.8):(0.04 - 0.05).

9. The preparation method of the pesticide nanofibers according to claim 8, characterized in that, Place the core layer spinning solution and the shell layer spinning solution in a coaxial electrospinning machine to prepare pesticide nanofibers by electrospinning. The process parameters controlled by coaxial electrospinning are: the spinning voltage is 15 - 17 kV, the receiving distance is 5 - 20 cm, the injection speeds of the core layer spinning solution and the shell layer spinning solution are 0.2 - 20 mL / h, and the injection speed ratio of the core layer spinning solution to the shell layer spinning solution is 1:(3 - 3.5).

10. Use of the pesticide nanofibers as claimed in any one of claims 1 - 5 or the pesticide nanofibers prepared by the preparation method as claimed in any one of claims 6 - 9 as an antibacterial agent.

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