Difenoconazole-polyvinylpyrrolidone water-soluble nano powder and preparation method thereof

Abstract

The invention discloses difenoconazole-polyvinylpyrrolidone water-soluble nano powder and a preparation method thereof, and belongs to the technical field of nano pesticides. The difenoconazole composition comprises the following components in percentage by weight: 5-40% of difenoconazole, 3-12% of a surfactant and 48-92% of a soluble carrier. Compared with the prior art, the prepared water-soluble nano powder is small in particle size, the average particle size is smaller than 200 nm, the product quality is stable, and the problem that a liquid preparation is poor in crystallization separation stability after being stored for a long time is solved; compared with conventional pesticide powder, the difenoconazole nano powder is easy to settle and layer after being mixed with water, the prepared nano powder is clear and transparent after being diluted with water, the dispersity is remarkably improved, and the problems of poor water solubility and dispersity of difenoconazole are solved; the specific surface area of the nanoparticles is large, the deposition and retention performance of drug particles on the leaf surfaces of target crops is remarkably improved, and the effective utilization rate of target pests is increased.

Description

Technical Field

[0001] This invention relates to the field of nanopesticide technology, specifically to a water-soluble nanopowder of difenoconazole-polyvinylpyrrolidone and its preparation method. Background Technology

[0002] Difenoconazole is a safe and highly effective triazole fungicide. It is poorly soluble in water but readily soluble in organic solvents. It features low toxicity, high efficiency, low residue, and long-lasting effect. Difenoconazole works by inhibiting the sterol dimethylation of the cell membrane of filamentous fungi, thus exerting its effects on various plant diseases. It has a broad spectrum of fungicides and provides long-lasting protection and treatment against Ascomycetes, Basidiomycetes, and deuteromycetes including Alternaria, Diplosporium, Cercospora, Colletotrichum, Coccidioidomyces, Stem-tipterus, Cynosporium, Syncocephalum, and Stellarium, as well as Powdery mildew, Rustales, and certain species-borne pathogens. It is also highly effective against grape anthracnose and white rot. Foliar or seed application can improve crop yield and ensure quality.

[0003] Polyvinylpyrrolidone (PVP) is a multifunctional, high-performance water-soluble polymer carrier that can form extremely strong hydrogen bonds with water molecules, exhibiting very high water solubility. It is also soluble in various polar organic solvents, such as ethanol, methanol, chloroform, and glycerol. Using PPVP as a carrier material, active drugs can be highly dispersed in an amorphous form within the three-dimensional network structure formed by PPVP, significantly improving the solubility and dissolution rate of poorly soluble drugs in water. However, its application in the nano-modification of difenoconazole to prepare highly water-soluble and highly stable nanopowder formulations has not yet been reported.

[0004] Patent publication number CN103734140B discloses a compound suspension of difenoconazole and propiconazole, in which the amount of polyvinylpyrrolidone is 0.05-0.15%, a very low amount. In this product, it is not used as a carrier but rather as an emulsifier, resulting in a high suspension rate. However, processing difenoconazole into an aqueous suspension presents many problems. During storage, it is prone to instability phenomena such as stratification, paste formation, and Austronesian ripening, leading to a short shelf life. Furthermore, the stability of the product during long-term storage, such as hot and cold storage, cannot be determined, greatly limiting its use. Patent publication number CN102613230A... A water-dispersible granule formulation of lufenuron and difenoconazole is disclosed. Specifically, following conventional methods for preparing water-dispersible granules, the particles are mixed in a mixing tank, then subjected to an air jet milling process, and finally granulated and dried to produce 20% lufenuron and 1% difenoconazole water-dispersible granules. However, the water-dispersible granules prepared by this method have large particle sizes, resulting in low coverage per unit crop area during spraying. Furthermore, leaching and loss due to wind and sun exposure lead to low effective utilization of the formulation. Currently, most pesticide nanoparticles exhibit uneven particle size, poor stability, and a tendency to agglomerate, reducing the efficiency of nanopesticides in practical applications.

[0005] Therefore, providing a completely dilutable water-soluble nanopowder of phenoxymethyl benzoate-polyvinylpyrrolidone and its preparation method is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] The purpose of this invention is to propose a water-soluble nanopowder of difenoconazole-polyvinylpyrrolidone and its preparation method. This invention can effectively solve the problems of poor water solubility, easy crystallization and precipitation, poor stability, low deposition and retention on the leaf surface of target crops, and low effective utilization rate of difenoconazole, thus providing the possibility for large-scale production and application.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A water-soluble nanopowder of difenoconazole-polyvinylpyrrolidone comprises the following raw materials in weight fractions: difenoconazole content of 5% to 40%, surfactant content of 3% to 12%, and soluble carrier content of 48% to 92%.

[0008] Preferably, the surfactant is anionic surfactant, nonionic surfactant, or a combination thereof; The anionic surfactant is selected from one or more of the following: maleic rosin polyoxyethylene-polyoxypropylene ether sulfonate, dodecylbenzene sulfonate, sodium dodecyl sulfate, lignin sulfonate, and hydroxypropyl methylcellulose. The nonionic surfactant is selected from one or more of the following: castor oil polyoxyethylene ether, phenethylphenol polyoxyethylene polyoxypropylene ether, styrene-phenol polyoxyethylene ether, alkylphenol formaldehyde resin polyoxyethylene ether, fatty alcohol polyoxyethylene ether, stearic acid polyoxyethylene ether, polyoxyethylene-polyoxypropylene block copolymer, polyoxyethylene dehydrated sorbitan monooleate, and dehydrated sorbitan monooleate.

[0009] The modification effect of the hydrophilic groups of the surfactant in this invention significantly improves the solubility and dispersibility of poorly soluble pesticides.

[0010] Preferably, the soluble carrier is a polyvinylpyrrolidone compound with a molecular weight of 45,000 to 55,000 g / mol.

[0011] A method for preparing a water-soluble nanopowder of difenoconazole-polyvinylpyrrolidone, characterized by comprising the following steps: Step 1: Mix the phenyl ether dimethyl ether, surfactant, and organic solvent in a specified ratio, heat, and stir until the mixture is clear and transparent to obtain phase A; Step 2: Disperse the soluble carrier in an organic solvent, heat, and stir until completely dissolved to obtain a transparent solution, phase B. Step 3: Under heating conditions, phase A is added dropwise to phase B through a separatory funnel and stirred continuously until it is evenly dispersed. Then, it is transferred to a rotary evaporator to completely evaporate the organic solvent and obtain a solid mixture. Step four: After cooling the solid mixture to room temperature, transfer, crush and grind it to obtain difenoconazole-polyvinylpyrrolidone water-soluble nanopowder.

[0012] Preferably, in step one, the heating temperature is 70-85°C and the stirring rate is 500-800 rpm / min.

[0013] Preferably, in step two, the heating temperature is 70-85°C and the stirring rate is 800-1000 rpm / min.

[0014] Preferably, in step three, the heating temperature is 70-85℃, the dropping rate is 5-10mL / min, the stirring rate is 1000-1500rpm / min, the stirring time is 20-30min, and the temperature conditions of the rotary evaporator are 70-85℃, the pressure is 0.1MPa, and the speed is 50-70rpm.

[0015] Preferably, the organic solvent is any one or more of methanol, ethanol, acetonitrile, dichloromethane, dimethylformamide, and N-methylpyrrolidone.

[0016] Preferably, in step one, the mass of the organic solvent is 1.5 to 2 times that of the difenoconazole.

[0017] Preferably, in step two, the mass of the organic solvent is 2 to 4 times that of the soluble carrier.

[0018] This invention utilizes organic solvents with good solubility for p-difenoconazole and polyvinylpyrrolidone, enabling the poorly soluble pesticide p-difenoconazole to be completely dispersed in a water-soluble carrier. This is crucial for ensuring that the solution remains uniformly mixed and stable when phase A is added to phase B. On the one hand, this reduces energy consumption and improves production efficiency; on the other hand, it enhances the dispersibility and uniformity of the molecular drug in the carrier, resulting in uniform and stable nanoparticles.

[0019] Preferably, the average particle size of the difenoconazole-polyvinylpyrrolidone water-soluble nanopowder is less than 200 nm, and after dilution with water, it can present a clear and transparent homogeneous emulsion exhibiting the Tyndall effect.

[0020] The small size effect and large specific surface area of ​​the drug-loaded particles of the present invention improve the wetting and retention performance of drug particles on crops and target pests.

[0021] Compared with the prior art, the present invention proposes a water-soluble nanopowder of fenofibrate-polyvinylpyrrolidone and its preparation method. The present invention has the following beneficial effects: 1. The water-soluble nanopowder of the present invention is formed by uniformly dispersing poorly soluble pesticide compounds in a water-soluble carrier through emulsification dispersion to form a nanoscale powder. Compared with other existing formulations, the water-soluble nanopowder can quickly disintegrate and be completely diluted after being mixed with water, resulting in a clear and transparent solution with uniform stability and a long shelf life. It solves the problems of easy crystallization and layering of difenoconazole liquid formulation.

[0022] 2. This invention uses p-fenofibrate and polyvinylpyrrolidone, organic solvents with good solubility, to completely disperse the poorly soluble drug in molecular form within the three-dimensional network structure formed by the polyvinylpyrrolidone carrier. Through the encapsulation effect of the carrier, smaller and more uniformly distributed nanoscale drug particles can be obtained. This allows the prepared p-fenofibrate-polyvinylpyrrolidone water-soluble nanopowder to be directly diluted with water to form a transparent solution, improving the water solubility and dispersibility of the poorly soluble drug. It overcomes the problem of easy sedimentation and precipitation when mixing multiple agents in practical applications and avoids nozzle clogging.

[0023] 3. The preparation method of the present invention differs from the existing preparation method of physical grinding of nano-pesticides. It constructs nano-structured particles at the molecular level through self-assembly. That is, the poorly soluble pesticide difenoconazole is coated and assembled into nanoparticles by a water-soluble carrier, polyvinylpyrrolidone. By controlling the drug / carrier mass ratio, reaction temperature and reaction stirring conditions, nanoparticles with different drug contents and different particle sizes can be obtained.

[0024] 4. The water-soluble nanoparticles of difenoconazole-polyvinylpyrrolidone prepared by this invention have a nanoscale particle size, uniform size, and good stability. This significantly increases the specific surface area of ​​the drug particles, improves the deposition and retention performance of the nanoparticles on the leaf surface of the target crop, and enhances the effective utilization rate of the target pests, thereby improving the pesticide utilization rate and achieving reduced dosage and increased efficiency.

[0025] 5. The preparation method of the present invention can realize the continuous production of water-soluble nanopowder of difenoconazole-polyvinylpyrrolidone. Compared with the existing nanopesticide grinding preparation method, it has low energy consumption, simple, safe and stable process, and high production efficiency. It can be widely used as an important technology in large-scale actual production. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings in this description are merely embodiments of the present invention.

[0027] Figure 1 This is a process flow diagram of the difenoconazole-polyvinylpyrrolidone water-soluble nanopowder of the present invention; Figure 2 The images show the appearance and Tyndall effect of the powder dilution solutions of Examples 1-3 and Control Example 1. Figure 3 The image shows the morphology of the 5% difenoconazole-polyvinylpyrrolidone water-soluble nanopowder prepared in Example 1. Figure 4 The image shows the morphology of the 15% difenoconazole-polyvinylpyrrolidone water-soluble nanopowder prepared in Example 2. Figure 5 The image shows the morphology of the 40% difenoconazole-polyvinylpyrrolidone water-soluble nanopowder prepared in Example 3. Figure 6 The image shows the morphology of the difenoconazole-polyvinylpyrrolidone micron-sized powder prepared in Comparative Example 1. Figure 7 The static contact angle diagrams of the powder dilutions of Examples 1-3 and Control Example 1 on the surface of chili pepper leaves are shown. Detailed Implementation

[0028] Embodiments of the present invention are described below, examples of which are shown in the accompanying drawings. The embodiments described with reference to the drawings are exemplary and intended to explain the present invention, but are not to be construed as limiting the present invention.

[0029] like Figure 1 The diagram shown is a process flow chart of the phenyl ether tebuconazole-polyvinylpyrrolidone water-soluble nanopowder of the present invention. Example

[0030] The specific steps for preparing 5% difenoconazole-polyvinylpyrrolidone water-soluble nanopowder are as follows: In the preparation of 15% difenoconazole-polyvinylpyrrolidone, step one involves mixing 5g difenoconazole, 1.5g castor oil polyoxyethylene ether, 1.5g fatty alcohol polyoxyethylene ether, and 15mL acetonitrile at 70°C with a stirring rate of 500rpm / min until the mixture is clear and transparent to obtain phase A.

[0031] Step 2: Dissolve 92g of PVP K30 with a molecular weight of 45000g / mol in 150mL of acetonitrile, heat in a 70℃ water bath, and stir at a stirring rate of 800rpm / min until completely dissolved. The resulting transparent solution is phase B.

[0032] Step 3: Under conditions of 70℃, phase A is added dropwise to phase B through a separatory funnel at a rate of 5 mL / min, and then stirred continuously until it is evenly dispersed. The stirring rate is 1000 rpm / min and the stirring time is 20 min. Then, it is transferred to a rotary evaporator. The heating temperature of the rotary evaporator is 85℃, the pressure is 0.1 MPa, and the speed is 50 rpm. After the organic solvent is completely evaporated, a solid mixture is obtained.

[0033] Step four: After cooling the solid mixture to room temperature, transfer, crush and grind it to obtain 5% difenoconazole-polyvinylpyrrolidone water-soluble nanopowder.

[0034] This invention prepared a 5% difenoconazole-polyvinylpyrrolidone water-soluble nanopowder, such as... Figure 2 As shown, after dilution with water, it becomes clear and transparent, and exhibits the Tyndall effect.

[0035] 0.02 g of powder was dispersed in 10 ml of water and ultrasonically dispersed for 5 min. The sample was then spotted onto a silicon wafer, and the particle morphology was observed using a scanning electron microscope. The scanning electron microscope characterization results are as follows: Figure 3 As shown, the particles are uniformly distributed overall, with an average particle size of about 105 nm. Example

[0036] The preparation steps for 15% difenoconazole-polyvinylpyrrolidone water-soluble nanopowder are as follows: Step 1: Mix 5g of difenoconazole, 1.2g of fatty alcohol polyoxyethylene ether, 2.0g of styrene-based phenol polyoxyethylene ether and 15 mL of ethanol at 80℃ and stirring at 500 rpm / min until the mixture is clear and transparent to obtain phase A.

[0037] Step 2: Dissolve 25.1g of PVP K30 with a molecular weight of 45000g / mol in 40 mL of ethanol, heat in an 80℃ water bath, and stir at a stirring rate of 800rpm / min until completely dissolved. The resulting transparent solution is phase B.

[0038] Step 3: Under conditions of 80℃, phase A is added dropwise to phase B through a separatory funnel at a rate of 10 mL / min, and then stirred continuously until it is evenly dispersed. The stirring rate is 1200 rpm / min and the stirring time is 25 min. Then, it is transferred to a rotary evaporator. The heating temperature of the rotary evaporator is 60℃, the pressure is 0.1 MPa, and the speed is 60 rpm. After the organic solvent is completely evaporated, a solid mixture is obtained.

[0039] Step four: After cooling the solid mixture to room temperature, transfer, crush and grind it to obtain 15% difenoconazole-polyvinylpyrrolidone water-soluble nanopowder.

[0040] This invention prepared a 15% difenoconazole-polyvinylpyrrolidone water-soluble nanopowder, such as... Figure 2 As shown, after dilution with water, it becomes clear and transparent, and exhibits the Tyndall effect.

[0041] 0.02 g of powder was dispersed in 10 ml of water and ultrasonically dispersed for 5 min. The sample was then spotted onto a silicon wafer, and the particle morphology was observed using a scanning electron microscope. The scanning electron microscope characterization results are as follows: Figure 4 As shown, the particles are uniformly distributed, with an average particle size of about 125 nm. Example

[0042] The preparation steps for 40% difenoconazole-polyvinylpyrrolidone water-soluble nanopowder are as follows: Step 1: Mix 5g of difenoconazole, 0.5g of phenylethylphenol polyoxyethylene polyoxypropylene ether, 1.0g of alkylphenol formaldehyde resin polyoxyethylene ether and 15 mL of methanol at 85℃ and stirring at 800 rpm / min until the mixture is clear and transparent to obtain phase A.

[0043] Step 2: Dissolve 6 g of PVP K30 with a molecular weight of 45000 g / mol in 10 mL of methanol, heat in a water bath at 85°C, and stir at a stirring rate of 1000 rpm / min until completely dissolved. The resulting transparent solution is phase B.

[0044] Step 3: Under conditions of 85℃, phase A is added dropwise to phase B through a separatory funnel at a rate of 10 mL / min, and then stirred continuously until it is evenly dispersed. The stirring rate is 1500 rpm / min and the stirring time is 30 min. Then, it is transferred to a rotary evaporator. The heating temperature of the rotary evaporator is 70℃, the pressure is 0.1 MPa, and the speed is 70 rpm. After the organic solvent is completely evaporated, a solid mixture is obtained.

[0045] Step four: After cooling the solid mixture to room temperature, transfer, crush and grind it to obtain 40% difenoconazole-polyvinylpyrrolidone water-soluble nanopowder.

[0046] This invention prepared a 40% difenoconazole-polyvinylpyrrolidone water-soluble nanopowder, such as... Figure 2 As shown, after dilution with water, it becomes clear and transparent, and exhibits the Tyndall effect.

[0047] 0.02 g of powder was dispersed in 10 ml of water and ultrasonically dispersed for 5 min. The sample was then spotted onto a silicon wafer, and the particle morphology was observed using a scanning electron microscope. The scanning electron microscope characterization results are as follows: Figure 5 As shown, the particles are uniformly distributed overall, with an average particle size of about 160 nm.

[0048] Compare with Example 1 The preparation steps for 15% difenoconazole-polyvinylpyrrolidone micron-sized powder are as follows: Step 1: Mix 5g of difenoconazole, 1.2g of fatty alcohol polyoxyethylene ether, 2.0g of styrene-based phenol polyoxyethylene ether and 15 mL of ethanol at a stirring rate of 500 rpm / min until the mixture is clear and transparent to obtain phase A.

[0049] Step 2: Add phase A dropwise to 25.1g of PVP K30 at a rate of 10mL / min, and stir thoroughly at a stirring rate of 100rpm / min to obtain a viscous solid powder.

[0050] Step 3: Place the solid powder in an oven and dry it at 60°C to obtain dry solid powder.

[0051] Step four: The solid powder is pulverized to obtain 15% difenoconazole-polyvinylpyrrolidone micron-sized powder.

[0052] Micron-sized powders, such as Figure 2 As shown, significant sedimentation occurs after dilution with water, and the Tyndall effect is not observed.

[0053] 0.02 g of powder was dispersed in 10 ml of water and ultrasonically dispersed for 5 min. The sample was then spotted onto a silicon wafer, and the particle morphology was observed using a scanning electron microscope. The scanning electron microscope characterization results are as follows: Figure 6 As shown, the particle size is not uniform, with an average particle size of about 3 μm.

[0054] Wetting retention performance test The wetting and dispersing properties of the nanopowder were characterized by measuring the contact angles of Examples 1-3, Control Example 1, and water on chili pepper leaves using a contact angle meter. First, the prepared Examples 1-3 and Control Example 1 were diluted with deionized water to 0.1% (w / w) and subjected to ultrasonic vibration. Then, fresh chili pepper leaves were collected, and the leaves were fixed flat on a glass slide. The field of view, brightness, and relevant instrument parameters of the contact angle meter were adjusted. Finally, 5 μL of the sample to be tested was added to the chili pepper leaf using a microsyringe. After the droplet state on the leaf stabilized, the droplet state was quickly photographed and recorded. The contact angle was calculated using a five-point fitting analysis method. The measurement temperature was 25℃, and the relative humidity was 25% ± 2%. Multiple measurements were taken and the average value was obtained.

[0055] Results and Discussion: To investigate the wetting and retention properties of the difenoconazole-polyvinylpyrrolidone nanopowder, the contact angles of Examples 1-3 and Control Example 1 on hydrophilic leaves (cucumber) were evaluated; such as Figure 7 As shown, the contact angle of deionized water on cucumber leaves was 106.0°. The contact angles of the diluted solutions (0.1%, w / w) of Examples 1, 2, and 3 on cucumber leaves were 74.3±0.1°, 77.6±0.2°, and 80.5±0.1°, respectively. The contact angle of the diluted solution of Control Example 1 on cucumber leaves was 94.0±0.2°, which was significantly higher than that of Examples 1-3. The flatter the droplet, the smaller the contact angle, the better the spreading performance of the liquid on the target crop surface, and the better the wetting effect. This indicates that the difenoconazole-polyvinylpyrrolidone nanopowder prepared by this invention is more easily diffused and wetted on the leaf surface, reducing the concentration difference of the drug during the spraying process, increasing the application effect, and improving the effective utilization rate of pesticides.

[0056] Stability test To investigate the stability of difenoconazole-polyvinylpyrrolidone nanopowder, the samples were sealed and stored under refrigeration, room temperature and high temperature conditions. The content of difenoconazole was determined in the powder samples of Examples 1-3 and Comparative Example 1 after storage at 0℃ for 7 days, 25℃ for 14 days and 54℃ for 14 days.

[0057] Table 1. Variation of difenoconazole content in different embodiments and control examples under different storage conditions. Results and Discussion: In Example 1, the content of difenoconazole in the nanopowder decreased to 4.98% after 7 days of storage at 0℃; decreased to 4.98% after 14 days of storage at 25℃; and decreased to 4.95% after 14 days of storage at 54℃. The drug degradation rate did not exceed 5%, which meets the product standard.

[0058] In Example 2, the content of difenoconazole in the nanopowder became 14.97% after 7 days of storage at 0°C; 14.95% after 14 days of storage at 25°C; and 14.95% after 14 days of storage at 54°C. The drug degradation rate did not exceed 5%, which met the product standard.

[0059] In Example 3, the content of difenoconazole in the nanopowder decreased to 39.96% after 7 days of storage at 0°C; 39.94% after 14 days of storage at 25°C; and 39.90% after 14 days of storage at 54°C. The drug degradation rate did not exceed 5%, which met the product standard.

[0060] In Comparative Example 1, the content of difenoconazole in the nanopowder decreased to 14.95% after 7 days of storage at 0℃; 14.95% after 14 days of storage at 25℃; and 14.90% after 14 days of storage at 54℃. The drug degradation rate did not exceed 5%, which met the product standard.

[0061] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A water-soluble nanopowder of difenoconazole-polyvinylpyrrolidone, characterized in that, By weight percentage, it includes 5%–40% difenoconazole, 3%–12% surfactant, and 48%–92% soluble carrier.

2. The water-soluble nanopowder of phenyl ether dimethyl sulfadiazine-polyvinylpyrrolidone according to claim 1, characterized in that, The surfactant is an anionic surfactant, a nonionic surfactant, or a combination thereof; The anionic surfactant is selected from one or more of the following: maleic rosin polyoxyethylene-polyoxypropylene ether sulfonate, dodecylbenzene sulfonate, sodium dodecyl sulfate, lignin sulfonate, and hydroxypropyl methylcellulose. The nonionic surfactant is selected from one or more of the following: castor oil polyoxyethylene ether, phenethylphenol polyoxyethylene polyoxypropylene ether, styrene-phenol polyoxyethylene ether, alkylphenol formaldehyde resin polyoxyethylene ether, fatty alcohol polyoxyethylene ether, stearic acid polyoxyethylene ether, polyoxyethylene-polyoxypropylene block copolymer, polyoxyethylene dehydrated sorbitan monooleate, and dehydrated sorbitan monooleate.

3. The water-soluble nanopowder of phenyl ether dimethyl sulfadiazine-polyvinylpyrrolidone according to claim 1, characterized in that, The soluble carrier is a polyvinylpyrrolidone compound with a molecular weight of 25,000 to 70,000 g / mol.

4. A method for preparing water-soluble nanopowder of difenoconazole-polyvinylpyrrolidone according to any one of claims 1 to 3, characterized in that, Includes the following steps: Step 1: Mix the phenyl ether dimethyl ether, surfactant, and organic solvent in a specified ratio, heat, and stir until the mixture is clear and transparent to obtain phase A; Step 2: Disperse the soluble carrier in an organic solvent, heat, and stir until completely dissolved to obtain a transparent solution, phase B. Step 3: Under heating conditions, phase A is added dropwise to phase B through a separatory funnel and stirred. The mixture is then transferred to a rotary evaporator to completely evaporate the organic solvent, resulting in a solid mixture. Step four: After cooling the solid mixture to room temperature, transfer, crush and grind it to obtain difenoconazole-polyvinylpyrrolidone water-soluble nanopowder.

5. The method for preparing a water-soluble nanopowder of phenyl ether dimethyl sulfadiazine-polyvinylpyrrolidone according to claim 4, characterized in that, In step one, the heating temperature is 70-85°C, and the stirring rate is 500-800 rpm / min.

6. The method for preparing a water-soluble nanopowder of phenyl ether dimethyl sulfadiazine-polyvinylpyrrolidone according to claim 4, characterized in that, In step two, the heating temperature is 70-85°C, and the stirring rate is 800-1000 rpm / min.

7. The method for preparing a water-soluble nanopowder of phenyl ether dimethyl sulfadiazine-polyvinylpyrrolidone according to claim 4, characterized in that, In step three, the heating temperature is 70–85°C, the dropping rate is 5–10 mL / min, the stirring rate is 1000–1500 rpm / min, the stirring time is 20–30 min, and the temperature conditions of the rotary evaporator are 70–85°C, the pressure is 0.1 MPa, and the speed is 50–70 rpm.

8. The method for preparing a water-soluble nanopowder of phenyl ether dimethyl sulfadiazine-polyvinylpyrrolidone according to claim 4, characterized in that, The organic solvent is any one or more of methanol, ethanol, acetonitrile, dichloromethane, dimethylformamide, and N-methylpyrrolidone.

9. The method for preparing a water-soluble nanopowder of phenyl ether dimethyl sulfadiazine-polyvinylpyrrolidone according to claim 8, characterized in that, In step one, the mass of the organic solvent is 1.5 to 2 times that of the difenoconazole.

10. The method for preparing a water-soluble nanopowder of phenyl ether dimethyl sulfadiazine-polyvinylpyrrolidone according to claim 8, characterized in that, In step two, the mass of the organic solvent is 2 to 4 times that of the soluble carrier.

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