Nanofiber with core-shell structure for carrying pesticide and preparation method thereof

Abstract

The application provides a core-shell structure pesticide-loaded nanofiber and a preparation method thereof, and relates to the technical field of pesticides.The application is aimed at solving the problem that the existing pesticide application method not only causes waste of resources, but also causes serious pollution to the environment.The technical points of the application include: preparation of a spinning solution: cellulose acetate and polymethyl methacrylate are dissolved in N,N-dimethylformamide to obtain a mixed solution;pesticides that need to be released slowly are added to the mixed solution to obtain a spinning solution;preparation of the nanofiber: the spinning solution is added to an electrostatic spinning device for electrostatic spinning to obtain the pesticide-loaded nanofiber.The pesticide-loaded nanofiber with the core-shell structure has the following advantages: the cellulose acetate in the interior plays a supporting role;the carboxyl groups of the polymethyl methacrylate in the exterior act as functional groups, which not only enable the pesticides in the core-shell structure to be released slowly, but also enable the carboxyl groups to adsorb heavy metal ions in water.

Description

Technical Field

[0001] This invention relates to the field of pesticide technology, and more specifically, to a core-shell structured pesticide-loaded nanofiber and its preparation method. Background Technology

[0002] Nanofibers' unique size endows them with many properties distinct from traditional fibers, enabling them to play important roles in various fields. Nanofibers have shown great potential as drug delivery matrices; this intelligent drug delivery system can improve drug utilization and therapeutic efficacy while reducing side effects. An ideal drug carrier must possess good biocompatibility, low toxicity, high drug loading capacity, and low immunogenicity, while simultaneously enabling intelligent regulation of drug release behavior.

[0003] Pesticides are a crucial agricultural material foundation for ensuring global food production. However, their widespread use poses serious threats and potential risks to the ecological environment and human health. Therefore, pesticides are typically processed into formulations for application, ensuring uniform coverage of their active ingredients. With the rapid advancement of nanotechnology, traditional agriculture and the pesticide industry are developing towards higher efficiency, environmental friendliness, and intelligent control. This opens up new avenues for addressing long-standing application challenges such as low pesticide utilization and residual pollution. By constructing systems such as drug-loaded nanoparticles and intelligent responsive formulations, nanotechnology optimizes the targeted delivery and controlled release mechanisms of pesticides, providing scientific support for overcoming the high consumption and low efficiency of traditional application methods.

[0004] Traditional pesticide application methods often suffer from low utilization rates. Large amounts of pesticides drift into the air or run off into soil and water during spraying, resulting in resource waste and severe environmental pollution. However, these highly water-soluble pesticide nanofibers can significantly increase pesticide utilization. The tiny size and high specific surface area of ​​the nanofibers allow pesticides to be distributed more evenly on the surface of crops, making them easier for crops to absorb and utilize. Furthermore, the water-based manufacturing process reduces production costs and the use of organic solvents, pushing pesticides towards safety, greenness, simplicity, efficiency, and water-based solutions. This not only meets the requirements of sustainable development in modern agriculture but also provides strong technical support for ensuring the quality and safety of agricultural products and the ecological environment. Summary of the Invention

[0005] The technical problem to be solved by this invention is:

[0006] Existing pesticide application methods not only waste resources but also cause serious environmental pollution.

[0007] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0008] This invention provides a method for preparing pesticide-loaded nanofibers, comprising the following steps:

[0009] Preparation of spinning solution: Cellulose acetate (CA) and polymethacrylic acid (PMAA) are dissolved in N,N-dimethylformamide (DMF) to obtain a mixture; the pesticide to be released slowly is added to the mixture to obtain the spinning solution;

[0010] Preparation of nanofibers: The spinning solution was added to an electrospinning device for electrospinning to obtain the pesticide-loaded nanofibers.

[0011] Furthermore, in the preparation step of the spinning solution, cellulose acetate (CA) and polymethacrylic acid (PMAA) are mixed in a mass ratio of (1.5-2.5):1.

[0012] Furthermore, the preparation of the spinning solution specifically includes the following steps:

[0013] Cellulose acetate (CA) and polymethacrylic acid (PMAA) were weighed and N,N-dimethylformamide (DMF) was added as a co-solvent. The mass ratio of cellulose acetate:polymethacrylic acid:N,N-dimethylformamide was (1.5-2.5):1:16. The mixture was dissolved by gradient heating: first, it was dissolved at 80 ℃ for 3 h, and then the temperature was raised to 90 ℃ for 2 h to promote the deentanglement of molecular chains to obtain a mixture. The pesticide to be released was added to the mixture, and the solution was homogenized by magnetic stirring to obtain the spinning solution.

[0014] Furthermore, in the preparation step of the spinning solution, the pesticide is oxamyl.

[0015] Furthermore, in the preparation step of the spinning solution, oxadixyl accounts for 5-50% of the mass fraction of cellulose acetate (CA).

[0016] Furthermore, in the preparation step of the spinning solution, oxadixyl accounts for 10-30% of the mass fraction of cellulose acetate (CA).

[0017] Furthermore, in the preparation step of the spinning solution, oxadixyl accounts for 20% of the mass fraction of cellulose acetate (CA).

[0018] Furthermore, the preparation of the nanofibers specifically includes the following steps:

[0019] Add the spinning solution to the electrospinning equipment, set the spinning parameters: voltage 16 kV, feed rate 1 mL / h, select the spinning spinneret model, and use aluminum foil as the receiving substrate to collect pesticide nanofibers.

[0020] This invention provides a pesticide-loaded nanofiber, which is prepared by the method described in the above technical solution.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] This invention relates to core-shell structured pesticide-loaded nanofibers. The internal cellulose acetate layer provides support, while the external carboxyl groups of polymethacrylic acid act as functional groups. This not only allows for the slow release of pesticides within the core-shell structure but also enables the adsorption of heavy metal ions in water. This invention, through screening, yields a pesticide release system with controllable release performance, higher thermal stability, and better biological activity. The release rate and amount of pesticides can be controlled according to actual agricultural production needs, avoiding excessive release that leads to waste and environmental pollution, while also preventing insufficient release that fails to achieve the desired bactericidal effect. The improved thermal stability allows the film to maintain stable performance under complex agricultural environmental conditions, such as high temperature and light exposure, extending the effective action time of the pesticide. Good biological activity ensures that the pesticide can fully exert its bactericidal effect, effectively inhibiting the growth and reproduction of pathogens. This invention utilizes phase separation to prepare fibers through a simple electrospinning method, which is simple and easy to operate. Attached Figure Description

[0023] Figure 1 This is a surface morphology diagram of CA@PMAA in an embodiment of the present invention;

[0024] Figure 2 SEM images of HML / CA@PMAA composite films with different addition amounts in the embodiments of the present invention;

[0025] Figure 3 This is a TEM image of HML / CA@PMAA in an embodiment of the present invention;

[0026] Figure 4 The images show the FTIR spectra of HML powder, CA@PMAA, and HML / CA@PMAA composite films in the embodiments of the present invention.

[0027] Figure 5 The thermal stability diagrams of HML powder, CA@PMAA and HML / CA@PMAA composite film in the embodiments of the present invention are shown.

[0028] Figure 6 The thermal stability diagrams of HML powder, CA@PMAA and HML / CA@PMAA composite film in the embodiments of the present invention are shown.

[0029] Figure 7 This is a graph showing the cumulative release rate of the HCP-20 formulation in HAc-NaAc buffer solution over time in the embodiments of the present invention.

[0030] Figure 8The figures show the fitting curves of (a) the zero-order release model, (b) the first-order release model, (c) the Higuchi release model, and (d) the Ritger peppas release model in the embodiments of the present invention.

[0031] Figure 9 The figure shows the growth of CA@PMAA with different HML additions on PDA medium in the embodiments of the present invention ((a) CA@PMAA (b) HCP-5 (c) HCP-10 (d) HCP-20 (e) HCP-30 (f) HCP-50). Detailed Implementation

[0032] To enable those skilled in the art to better understand the present invention, exemplary embodiments or examples of the present invention will be described below in conjunction with the accompanying drawings. Obviously, the described embodiments or examples are merely some, not all, of the embodiments or examples of the present invention. All other embodiments or examples obtained by those skilled in the art based on the embodiments or examples of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0033] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0034] Example 1

[0035] This embodiment provides a method for preparing pesticide-loaded nanofibers, including the following steps:

[0036] Preparation of spinning solution: Cellulose acetate (CA) and polymethacrylic acid (PMAA) were weighed and transferred to a sealed screw-top bottle. N,N-dimethylformamide (DMF) was added as a co-solvent. The mass ratio of cellulose acetate:polymethacrylic acid:N,N-dimethylformamide was 2:1:16. The mixture was dissolved by gradient heating: first, it was dissolved at 80 ℃ for 3 h, and then heated to 90 ℃ for 2 h to promote the deentanglement of molecular chains, resulting in a mixture. Oxyphenidyl was added to the mixture at a mass fraction of 5%, 10%, 20%, 30% and 50% of cellulose acetate (CA). The solution was homogenized by magnetic stirring for 24 h to obtain five spinning solutions of different concentrations.

[0037] Preparation of nanofibers: 5 mL of spinning solution was injected into a needle-type syringe (10 mL) with an inner diameter of 0.9 mm. The spinning parameters were set as follows: voltage 16 kV, feed rate 1 mL / h. A No. 9 needle (inner diameter 5 mm) was selected. The pesticide nanofibers HML / CA@PMAA were collected using aluminum foil as the receiving substrate. The prepared HML / CA@PMAA composite films were named HCP-5, HCP-10, HCP-20, HCP-30, and HCP-50, respectively.

[0038] Comparative Example 1

[0039] This embodiment provides a method for preparing pesticide-loaded nanofibers, including the following steps:

[0040] Preparation of spinning solution: After weighing cellulose acetate (CA) and polymethyl methacrylate (PMAA), transfer them to a sealed screw-top bottle and add N,N-dimethylformamide (DMF) as a co-solvent. The mass ratio of CA:PMAA:DMF is 2:1:16. Dissolve and mix the system by gradient heating: first, dissolve at 80 ℃ for 3 h, then heat to 90 ℃ for 2 h to promote the deentanglement of molecular chains. Homogenize the solution by magnetic stirring for 3 h to obtain the spinning solution.

[0041] Preparation of nanofibers: 5 mL of spinning solution was injected into a needle-type syringe (10 mL specification) with an inner diameter of 0.9 mm. The spinning parameters were set as follows: voltage 16 kV, feed rate 1 mL / h. A No. 9 needle (inner diameter 5 mm) was selected. The CA@PMAA composite ultrafine fibers were collected using aluminum foil as the receiving substrate.

[0042] 2. Test Plan

[0043] 2.1. Drug Loading Determination

[0044] Dialysis bags with a molecular weight cutoff of 500 Da were cut into equal segments and activated in a solution of 2% sodium bicarbonate and 1 mol / L EDTA (pH=8.0). They were then sterilized at high temperature (100 ℃, 10 min), rinsed with pure water to remove surface residues, and finally stored in ultrapure water at 4 ℃ for later use. 2.20 g of glacial acetic acid and 8.63 g of sodium acetate were weighed and added to a beaker. Approximately 800 mL of deionized water was used to dissolve them, and the solution was transferred to a 1 L volumetric flask, brought to the mark, and thoroughly mixed. A certain amount of HML standard was weighed into a beaker, methanol was added, and the mixture was sonicated until the oxamyl standard granules were completely dissolved. The solution was then transferred to a 10 mL volumetric flask, brought to the mark with methanol, and 2 mL of the solution was filtered through a 0.22 µm filter membrane. The oxamyl content was determined by HPLC.

[0045] The release rate of drug-loaded fibers under acidic conditions was determined by dialysis. Based on the pH requirements, appropriate release media were prepared: HAc-NaAc buffer solution was used for pH=6. 0.5 g of the drug-loaded fiber membrane was placed in a prepared dialysis bag, then placed in an Erlenmeyer flask containing 200 mL of HAc-NaAc buffer solution, and continuously shaken on a shaker. At regular intervals, an equal volume of buffer solution was taken from the Erlenmeyer flask, filtered through the membrane, and transferred to a liquid chromatography sample vial for subsequent analysis. After each test, an equal amount of HAc-NaAc buffer solution was added to the Erlenmeyer flask to ensure the release system remained unsaturated. The HML content in the samples was detected by high-performance liquid chromatography (HPLC), and the cumulative HML release was calculated. Four widely used release kinetic models in drug release research were introduced to analyze the release behavior of two samples under different pH conditions.

[0046] 2.2. Antibacterial test

[0047] In this embodiment, potato dextrose agar was used as the standardized culture medium. After aliquoting, the medium was sterilized by autoclaving (121 °C, 103.4 kPa, 15 min) to ensure sterility and physicochemical stability. 200 mg of sample was weighed and sterilized under UV light for 3 h in a clean bench, followed by irradiation for 2 h. The sterilized sample was then placed in a sterilized conical flask and magnetically stirred at 30 °C for 2 h to dissolve. The solution was then aliquoted into 90 ml agar plates.

[0048] The antibacterial effect of HML / CA@PMAA was evaluated using the growth rate method. Different concentrations of drug-containing PDA medium were prepared and poured into 90 mm Petri dishes, with drug-free PDA medium serving as a control. After culturing Fusarium oxysporum colonies at 25 °C for 6 days, 8 mm diameter mycelial discs were collected from the colony edges and inoculated into the drug-containing medium. Three replicates were set for each drug concentration gradient. After inoculation, the Petri dishes were incubated at 28 °C for 96 h with the mycelial side facing down. The diameter of the colonies was measured using the cross-crossing method, and the mycelial growth inhibition rate was calculated based on the measured colony diameter to evaluate the antibacterial effect of different concentrations of HML / CA@PMAA.

[0049] 2.3. Characterization and Testing

[0050] Digital photography is used to observe the macroscopic characteristics of materials, scanning electron microscopy is used to observe the surface morphology of fibers, transmission electron microscopy is used to observe and analyze the microstructure, morphology, composition and other information of samples at high resolution, infrared analysis is used to test and analyze the functional group changes and thermal stability of fiber materials, and water contact angle test is used to study the water absorption and wettability of fiber surface.

[0051] 3. Discussion of Results

[0052] 3.1. Morphology of CA / PMAA and nanofibers

[0053] like Figure 1 As shown in Figure (a), the macroscopic characteristics of the CA@PMAA composite material are clearly visible. The composite material exhibits a unique fibrous film structure. These fibers form a tight and regular network system, with a smooth overall appearance and a certain degree of flexibility, without obvious agglomeration, cracking, or unevenness. Figure 1 Microscopic observations in (b) show that the film consists of a network structure of interwoven continuous nanofibers, with an average fiber diameter of 267.63 ± 12.96 nm (as shown in the inset of (b)). Transmission electron microscopy (TEM) analysis ( Figure 1 (c) clearly reveals the core-shell configuration of the composite fiber. This unique structure arises from the difference in hydrophilic properties of PMAA and hydrophobic properties of CA: under an electric field, the hydrophilic PMAA component migrates to the outer side of the fiber, while the hydrophobic CA component aggregates inward, thus spontaneously forming a core-shell heterostructure. Quantitative analysis results show ( Figure 1 (d) The average shell thickness of the core-shell fiber was measured to be 24.48 ± 0.13 nm.

[0054] 3.2. Morphology of HML / CA / PMAA core-shell fibers

[0055] like Figure 2 As shown, when the amount of HML added is 5 wt% ( Figure 2 When (a), an uneven beaded structure was observed scattered on the fiber surface. As the amount of HML added increased to 10 wt%, (a) Figure 2 (b) These fibers begin to show a tendency to elongate, and the beading phenomenon is reduced, but the fiber morphology is still not uniform. When the amount of HML added continues to increase to 20 wt% ( Figure 2 When the amount of HML added reaches 30 wt%, the fibers produced by electrospinning gradually become smooth and continuous, completely shedding the previous beaded morphology and exhibiting a more ideal fiber structure. Figure 2 When the concentration of HML increases to 50 wt%, the surface texture of the fiber begins to become rough, and discontinuities appear in some areas, indicating a decline in fiber quality. Figure 2 At time e), a large number of beaded patterns reappear on the fiber, the overall structure becomes extremely rough, and the spinning process becomes extremely slow.

[0056] 3.3. TEM Analysis of HML / CA / PMAA Core-Shell Fibers

[0057] like Figure 3 As shown, (a) CA@PMAA fiber film, (b) 5% HML / CA@PMAA, (c) 10% HML / CA@PMAA, (d) 20% HML / CA@PMAA, (e) 30% HML / CA@PMAA, (f) 50% HML / CA@PMAA); during electrospinning, the spinning solution flows and differentiates under the influence of a strong electric field. PMAA attracts water molecules and therefore aggregates towards the outer side of the fiber, while CA, because it repels water molecules, tends to aggregate towards the inner side of the fiber. This inward and outward differentiation trend forms a clearly visible core-shell structure in the fiber structure, where PMAA constitutes the shell and CA constitutes the core. When HML is added to the spinning solution for electrospinning, the nanofibers still maintain this core-shell structure. With the gradual increase of HML addition, the shell thickness of the nanofibers shows a significant increase, possibly because HML also has the ability to attract water molecules, thereby promoting the differentiation of the PMAA component in the spinning solution towards the outer side. Under the continuous influence of electrostatic force, HML and PMAA more actively aggregate to the outside, forming a distinct shell structure.

[0058] 3.4. FTIR Analysis of HML / CA / PMAA Core-Shell Fibers

[0059] from Figure 4 As shown, at 3217 cm -1 At wavenumber position, HML exhibits a distinct absorption peak. This peak corresponds to the OH stretching vibration induced by intermolecular or intramolecular hydrogen bonding. Hydrogen bonding, as an important intermolecular force, plays a crucial role in the chemical structure and physical properties of substances. This absorption peak clearly reveals the vibrational characteristics of the OH group in the HML molecule under hydrogen bonding. Analysis of the infrared spectrum of the composite film revealed that the stretching peak position of the OH group in HML had changed, shifting to 3457 cm⁻¹. -1 The shift in this peak position indicates the presence of hydrogen-bonded associative states in the system. The formation of these hydrogen-bonded associative states signifies the formation of a more complex and stable structure between molecules through hydrogen bonding. This structural change manifests as a shift in the absorption peak position in the infrared spectrum, revealing new information about intermolecular interactions within the composite system. With the gradual increase of HML content, the system exhibited a series of characteristic peak changes in the infrared spectrum. At 1753 cm⁻¹... -1 At this point, the previously present C=O and CH vibrational peaks showed a decreasing trend. The C=O and CH vibrational peaks represent important chemical bond vibrations in this system, and their decrease indicates that the chemical environment of these bonds changed with the addition of HML. Meanwhile, at 1243 cm⁻¹... -1The characteristic peak of C=OH at this location also underwent significant changes, shifting towards higher wavenumber regions and eventually stabilizing at 1049 cm⁻¹. -1 This migration process indicates that the electron cloud distribution and intermolecular forces around the C=OH group have changed, thereby affecting its vibrational frequency.

[0060] 3.5. Thermal Stability Analysis

[0061] like Figure 5 As shown, the HML / CA@PMAA decomposes in three stages: the initial stage has a mass loss rate of 8.6%, mainly due to the desorption of bound water within the film; the second stage involves violent thermal decomposition, where the weight loss rate reaches its peak due to the thermal cracking reaction of the HML backbone. During dynamic heating, when the temperature exceeds the critical value of HML, the backbone breakage exhibits a self-accelerating effect, which is closely related to the synergistic depolymerization of polymer chains and high-temperature induced oxidative crosslinking. The third stage involves the deep oxidation of the carbon skeleton and the thermal decomposition of residual coke. Comparative experimental data show that the total weight loss rate of the CA@PMAA composite system is 21.7% lower than that of pure HML powder, indicating that the polymer matrix enhances the thermal stability of the material through molecular chain entanglement and steric hindrance effects.

[0062] 3.6. Water contact angle test

[0063] like Figure 6 As shown, the water contact angles of (a) CA@PMAA, (b) HCP-5, (c) HCP-10, (d) HCP-20, (e) HCP-30, and (f) HCP-50 composite films are recorded. The water contact angle of the pure CA@PMAA composite film is 130.51°, which may be due to the presence of hydroxyl and acetyl groups in CA. The hydroxyl group is hydrophilic, while the acetyl group is relatively hydrophobic. During electrospinning, CA can form a composite structure with other components, affecting the overall hydrophilicity. PMAA contains a large number of carboxylic acid groups, which are strongly hydrophilic in their dissociated state and carry a negative charge, thus attracting water molecules. As a polymer, PMAA forms an interpenetrating network or blended structure with CA during spinning, increasing porosity and surface area. The water contact angles of HCP-5, HCP-10, HCP-20, HCP-30, and HCP-50 were 137.22°, 135.92°, 130.19°, 124.85°, and 122.58°, respectively. The hydrophilicity of the nanofiber membrane improved with increasing HML content. This may be because HML contains hydroxyl or amino groups, which form hydrogen bonds with the carboxylic acid groups of PMAA or interact with the hydroxyl groups of CA, exposing more hydrophilic groups on the fiber surface and thus enhancing hydrophilicity.

[0064] 3.7. Drug Loading Test and Analysis

[0065] like Figure 7 The figure shows the cumulative release rate of HCP-20 formulation in HAc-NaAc buffer solution over time. It is clearly observed that in the initial stage of the experiment, the cumulative release rate of HML exhibits a relatively rapid increasing trend, which may be due to the rapid dissolution and diffusion of HML molecules on the surface of the drug-loaded system into the release medium. As time progresses, the release rate gradually slows down, entering a relatively stable release phase. This indicates that HML molecules within the drug-loaded system require a certain diffusion mechanism to be gradually released, demonstrating the regulatory role of the controlled-release system in pesticide release.

[0066] like Figure 8 As shown, the fitting curves are for (a) the zero-order release model, (b) the first-order release model, (c) the Higuchi release model, and (d) the Ritger peppas release model.

[0067] Table 1 Release kinetic equations for HML and HML-20

[0068]

[0069] Figure 8 and Table 1 show the release kinetic equations and fitting curves for each drug release model. As shown in Table 1, the kinetic fitting analysis revealed that the release process of HML showed the best fit with the first-order kinetic equation, with a coefficient of determination of 0.965, significantly higher than other models. This indicates that the release mechanism of HML is mainly concentration-driven. Analysis of the release kinetic model of HML-20 showed that the first-order kinetic equation exhibited the best fitting result, with a coefficient of determination R0. 2 The value of 0.987 is significantly better than other models, indicating that the drug release process from the composite carrier follows first-order kinetics, and its release rate is positively correlated with the amount of drug remaining in the system.

[0070] 3.8. Antibacterial test

[0071] Figure 9 The image shows the growth of *Fusarium oxysporum* on PDA medium containing different concentrations of oxadixyl fiber films on day 5. When testing the antibacterial effect against *Fusarium oxysporum*, the CA@PMAA film did not show a significant inhibitory effect. However, the inhibition rate increased significantly after the addition of HML.

[0072] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for preparing pesticide-loaded nanofibers, characterized in that, Includes the following steps: Preparation of spinning solution: Cellulose acetate and polymethacrylic acid are dissolved in N,N-dimethylformamide to obtain a mixture; the pesticide to be released slowly is added to the mixture to obtain the spinning solution; Preparation of nanofibers: The spinning solution was added to an electrospinning device for electrospinning to obtain the pesticide-loaded nanofibers.

2. The method for preparing pesticide-loaded nanofibers according to claim 1, characterized in that, In the preparation of the spinning solution, cellulose acetate and polymethacrylic acid are mixed at a mass ratio of (1.5-2.5):

1.

3. The method for preparing pesticide-loaded nanofibers according to claim 2, characterized in that, The preparation of the spinning solution specifically includes the following steps: Cellulose acetate and polymethacrylic acid were weighed, and N,N-dimethylformamide was added as a co-solvent. The mass ratio of cellulose acetate, polymethacrylic acid and N,N-dimethylformamide was (1.5-2.5):1:

16. The mixture was dissolved by gradient heating: first, it was dissolved at 80 ℃ for 3 h, and then the temperature was raised to 90 ℃ for 2 h to promote the deentanglement of molecular chains to obtain a mixture. The pesticide to be released slowly was added to the mixture, and the solution was homogenized by magnetic stirring to obtain the spinning solution.

4. The method for preparing pesticide-loaded nanofibers according to claim 3, characterized in that, In the preparation step of the spinning solution, the pesticide is oxamyl.

5. The method for preparing pesticide-loaded nanofibers according to claim 4, characterized in that, In the preparation of the spinning solution, oxadixyl accounts for 5-50% of the mass fraction of cellulose acetate.

6. The method for preparing pesticide-loaded nanofibers according to claim 5, characterized in that, In the preparation of the spinning solution, oxadixyl accounts for 10-30% of the mass fraction of cellulose acetate.

7. The method for preparing pesticide-loaded nanofibers according to claim 6, characterized in that, In the preparation of the spinning solution, oxadixyl accounts for 20% of the mass fraction of cellulose acetate.

8. The method for preparing pesticide-loaded nanofibers according to claim 5, characterized in that, The preparation of the nanofibers specifically includes the following steps: Add the spinning solution to the electrospinning equipment, set the spinning parameters: voltage 16 kV, feed rate 1 mL / h, select the spinning spinneret model, and use aluminum foil as the receiving substrate to collect pesticide nanofibers.

9. A pesticide-loaded nanofiber, characterized in that, The pesticide-loaded nanofibers are prepared by the method described in claim 1.

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