Positively charged super-hydrophobic powder for controlling termites as well as preparation method and application of positively charged super-hydrophobic powder

Abstract

The invention provides positively charged super-hydrophobic powder for preventing and treating termites as well as a preparation method and application of the positively charged super-hydrophobic powder, and belongs to the technical field of pesticide formulation processing. The positively charged super-hydrophobic powder takes super-hydrophobic silicon dioxide as a carrier, and other raw materials comprise a medicament and a functional additive. The preparation method comprises the following steps: dissolving the medicament and the functional additive in acetone, spraying on the super-hydrophobic silicon dioxide, uniformly stirring, and crushing to obtain the super-hydrophobic powder with positive charges. According to the prepared super-hydrophobic powder, the lasting period can be prolonged, the drug use frequency and the drug use amount are reduced, and pollution to water and soil is reduced. Positive charges generated by mutual friction between powder particles and negative charges of termite body walls attract each other, so that the adhesive force and the distribution uniformity of the powder are improved. The powder is low in toxicity, long in poisoning time after being contacted with termites and beneficial for the termites to carry the medicament to return to nests, and nest cleaning is achieved. And the application method is simple and efficient, the targeting property is strong, the toxicity to other organisms and human bodies is lower, and the safety is higher.

Description

Technical Field

[0001] This invention belongs to the field of pesticide formulation processing technology, and particularly relates to a positively charged superhydrophobic powder for termite control, its preparation method and application. Background Technology

[0002] Termites are a distinctive group of social insects that primarily feed on cellulose-containing materials such as wood, and are able to degrade and digest cellulose, the most important component of wood. This lifestyle of termites has significant ecological importance in accelerating the material cycle of wood and other plant materials on Earth. In tropical and subtropical regions, termite resources are abundant, and they help decompose and cycle about one-third of dead wood and debris each year. However, when they feed on wooden components of houses and buildings, building materials, landscaping trees, and other commercial products, or when they nest on buildings and dams, they become pests.

[0003] The active ingredients in existing termite control agents include bifenthrin, imidacloprid, fipronil, and chlorpyrifos, primarily in emulsifiable concentrates, suspension concentrates, and powders. The advantages of these agents are their high toxicity and effective killing of termites, with some agents having a long residual effect. The disadvantages are their high toxicity, rapid onset of poisoning, and difficulty for worker ants to carry the pesticide back to the nest to feed the king, queen, and nymphs, thus hindering the goal of nest clearing. Furthermore, the high toxicity of these agents poses risks not only to environmental organisms such as fish, shrimp, bees, and earthworms, but also to the safety of personnel applying the pesticides. Meanwhile, traditional termite powders mostly use inorganic materials such as kaolin, diatomaceous earth, and talc, or organic materials such as starch and cellulose powder as fillers. The advantage is that the materials are cheap and readily available, but the disadvantage is that these traditional powders are prone to moisture absorption and clumping, thus losing their usability. Moreover, since termites live underground or in damp environments, traditional powders quickly mix with the moist soil after being sprayed and lose their ability to adhere to termites, requiring repeated application, resulting in unnecessary waste and pollution.

[0004] The exoskeleton of insects such as termites is mainly composed of chitin and protein, covered by a thin waxy layer to prevent moisture evaporation. Chitin is a natural high-molecular-weight polysaccharide containing negatively charged groups (such as acetamino and hydroxyl groups) in its molecular structure; the charge of proteins depends on their amino acid composition and the pH value of the environment, but under near-neutral conditions, many proteins also tend to be negatively charged. Therefore, the surface of the termite body wall itself is biased towards a negative charge. Improving the powder's adhesion to the termite body wall by carrying a positive charge can significantly increase the efficacy of the pesticide. Replacing the traditional powder carrier with an innovative superhydrophobic material and using functional additives to give the powder a positive charge can effectively solve the above problems. However, methods for preparing positively charged powders using superhydrophobic silica as a powder carrier have not been reported. Therefore, researching a termite control agent prepared using superhydrophobic silica as a powder carrier, combined with a pesticide with low toxicity and low environmental risk, and incorporating positively charged functional additives, is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] To address the aforementioned problems in the prior art, this invention provides a positively charged superhydrophobic powder for termite control, its preparation method, and its application. The main component of this superhydrophobic powder is superhydrophobic silica, characterized by its extremely loose texture, strong adsorption capacity, and extreme difficulty in wetting. Furthermore, this invention adds functional additives to imbue the superhydrophobic powder with a positive charge, thereby achieving termite control.

[0006] To achieve the above objectives, the present invention provides the following technical solution: One of the technical solutions of the present invention: This invention provides a positively charged superhydrophobic powder for termite control, wherein the positively charged superhydrophobic powder uses superhydrophobic silica as a carrier, and the remaining raw materials include pharmaceuticals and functional additives.

[0007] Furthermore, the positively charged superhydrophobic powder comprises the following raw materials in weight percentages: 0.5-2.5% reagent, 0.1-0.5% functional additives, and the balance being superhydrophobic silica.

[0008] Furthermore, the method for preparing the superhydrophobic silica is as follows: After mixing fumed silica and ethanol, the mixture was ultrasonically dispersed and stirred under reflux. Then, sodium hydroxide and dodecyltriethoxysilane were added and stirred to react. Finally, the mixture was centrifuged, washed and dried to obtain the superhydrophobic silica.

[0009] Beneficial effects: The fumed silica selected in this invention has an aggregate particle size of 100-200 nm, which has the advantages of small particle size, large specific surface area, and easy reaction. The superhydrophobic silica prepared using it can be nanoscaled.

[0010] Furthermore, the mass ratio of the fumed silica, sodium hydroxide, and dodecyltriethoxysilane is 10:2.5:3; The ratio of the amount of fumed silica to ethanol added is 10 g: 250 mL.

[0011] Furthermore, the ethanol is anhydrous ethanol.

[0012] Furthermore, the ultrasonic power of the ultrasonic dispersion is 300-600 W, and the ultrasonic time is 10 min; The stirring and reflux temperature is 70 ℃, the time is 3 min, and the rotation speed is 1000-1500 rpm to ensure complete dispersion of silica; The stirring reaction was carried out in a water bath at 70 °C with magnetic stirring at a speed of 1200 rpm for 5 h. The centrifugation speed is 12000 rpm and the time is 5-8 min; The drying temperature is 45-60 ℃, and the time is 2-3 h.

[0013] Furthermore, the pH value is adjusted to neutral with a 0.1% hydrochloric acid solution before centrifugation; The washing process involves washing the centrifuged solid with ethanol until it becomes neutral.

[0014] Furthermore, the agent is one of chlorantraniliprole or acetonitrile; The functional additive is one of quaternary ammonium salt surfactants or biionic surfactants.

[0015] Furthermore, the functional additive is hexadecyltrimethylammonium bromide or dodecyldimethylbetaine.

[0016] Furthermore, the effective ingredient content of the chlorantraniliprole is 98%; The effective ingredient content of the acetonitrile is 97%.

[0017] The second technical solution of the present invention: The present invention also provides a method for preparing a positively charged superhydrophobic powder for termite control, comprising the following steps: The pharmaceutical agent and functional additives are dissolved in acetone, then sprayed onto the superhydrophobic silica, stirred evenly, and then pulverized to obtain the positively charged superhydrophobic powder.

[0018] Furthermore, the ratio of the amount of the pharmaceutical agent and functional additive to acetone is 5:1:100.

[0019] Furthermore, the stirring speed is 20-30 rpm, and the time is 10-15 min; The pulverization process involves pulverizing the material to pass through a 200-mesh sieve to meet the requirements for spraying.

[0020] Furthermore, the spraying is an airflow spray, and the sprayed powder completely covers the activity range of the live termites.

[0021] Furthermore, the acetone is allowed to evaporate completely before pulverizing.

[0022] The third technical solution of the present invention: The present invention also provides the application of a positively charged superhydrophobic powder for termite control in the process of termite control.

[0023] Furthermore, the specific process of the application is as follows: spraying the positively charged superhydrophobic powder onto termites; The spraying amount is 15-30 g per nest.

[0024] The beneficial effects of this invention compared to the prior art are as follows: This invention utilizes superhydrophobic silica as a carrier to prepare a positively charged superhydrophobic powder. It does not wet upon contact with water, has a large contact angle with water, and can float on the water surface for extended periods. Termites live in humid environments; using this powder can significantly extend its effective period, reduce the frequency of application, and decrease pollution to water and soil. The main component of the body wall of termites and other crawling insects is chitin, which naturally carries a weak negative charge. During spraying, the friction between the powder particles generates a weak positive charge, which attracts the negative charge on the termite body wall, greatly increasing the powder's adhesion.

[0025] The superhydrophobic powder prepared by this invention is simple and efficient to use; it only needs to be sprayed onto live termites. The powder has strong drift and penetrating power, significantly reducing the amount of pesticide needed. Furthermore, this superhydrophobic powder remains loose in humid environments for a long time, exhibiting strong adhesion and easily and evenly adhering to the termite body wall. As the termites carry it back to their nest, the poison is transferred through the process of mutual cleaning among the colony, achieving a good killing effect. In addition, the superhydrophobic powder prepared by this invention is highly targeted, specifically for killing termites, while exhibiting low toxicity to other organisms and humans, making it highly safe. In acute toxicity tests on earthworms, it showed a low toxicity level, making it suitable for promotion and use in this field. 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 embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 The images show the effects of termites coming into full contact with the positively charged superhydrophobic powder of chlorantraniliprole prepared in Example 1 and the ordinary powder in the performance test of the present invention. The left side is the experimental group and the right side is the comparative example. Figure 2 The above diagram shows the distribution of the powder adsorbed on the termite body wall during the performance test of this invention. The upper diagram is the comparative example, and the lower diagram is the experimental group. Figure 3 The superhydrophobic effect of the positively charged superhydrophobic powder of chlorantraniliprole prepared in Example 1 of the present invention when placed in water during the performance test of the present invention. Figure 4 The image shows the adhesion effect of the positively charged superhydrophobic powder of chlorantraniliprole prepared in Example 1 of the present invention on termites during the performance test of the present invention. Detailed Implementation

[0028] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0029] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0030] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0031] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0032] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0033] The chlorantraniliprole and acetonitrile mentioned in the following embodiments of the present invention were purchased from Shandong Weifang Runfeng Chemical Co., Ltd. Acetone, cetyltrimethylammonium bromide and dodecyldimethyl betaine were purchased from China National Pharmaceutical Group Co., Ltd. All other raw materials can be purchased commercially.

[0034] Example 1 A method for preparing a positively charged superhydrophobic powder for termite control includes the following steps: (1) Weigh 10 g of fumed silica and disperse it in 250 mL of anhydrous ethanol. Sonicate it for 10 min at 300 W to disperse it. Stir and reflux it at 70 °C for 3 min to ensure complete dispersion of silica. Then add 2.5 g of sodium hydroxide to activate the fumed silica. Next, add 3 g of dodecyltriethoxysilane. Stir the reaction magnetically in a water bath at 70 °C for 5 h at a stirring speed of 1500 rpm. After the reaction is complete, adjust the pH value to neutral with a 0.1% dilute hydrochloric acid solution. Centrifuge at 12000 rpm for 5 min and collect the solid. Wash the solid with ethanol and then dry it in an oven at 60 °C for 2 h to obtain superhydrophobic silica for later use.

[0035] (2) Weigh 0.51 g of 98% chlorantraniliprole technical and 0.1 g of quaternary ammonium salt hexadecyltrimethylammonium bromide and dissolve them in 50 mL of acetone to obtain a drug solution. Then weigh 99.39 g of the above superhydrophobic silica into a 1 L beaker and add the above drug solution dropwise while stirring. Stir thoroughly to make the drug solution evenly distributed on the superhydrophobic silica carrier. After the acetone has completely evaporated, use a universal grinder to grind and mix it slightly and pass it through a 200 mesh sieve to obtain a positively charged superhydrophobic powder, namely 0.5% chlorantraniliprole positively charged superhydrophobic powder, where 0.5% is equivalent to 100% effective ingredient, that is, the content of the effective ingredient of chlorantraniliprole in the superhydrophobic powder.

[0036] Example 2 A method for preparing a positively charged superhydrophobic powder for termite control includes the following steps: (1) Weigh 10 g of fumed silica and disperse it in 250 mL of anhydrous ethanol. Sonicate it for 10 min at 500 W to disperse it. Stir and reflux it at 70 °C for 3 min to ensure complete dispersion of silica. Then add 2.5 g of sodium hydroxide to activate the fumed silica. Next, add 3 g of dodecyltriethoxysilane. Stir the reaction magnetically in a water bath at 70 °C for 5 h at a stirring speed of 1200 rpm. After the reaction is complete, adjust the pH value to neutral with a 0.1% dilute hydrochloric acid solution. Centrifuge at 12000 rpm for 6 min and collect the solid. Wash the solid with ethanol and then dry it in an oven at 60 °C for 3 h to obtain superhydrophobic silica.

[0037] (2) Weigh 2.58 g of 97% acetamiprid technical and 0.5 g of diionic dodecyl dimethyl betaine and dissolve them in 50 mL of acetone to obtain a drug solution. Then weigh 96.92 g of the above superhydrophobic silica into a 1 L beaker and add the above drug solution dropwise while stirring. Stir thoroughly to make the drug solution evenly distributed on the superhydrophobic silica carrier. After the acetone has completely evaporated, use a universal grinder to grind and mix it slightly and pass it through a 200 mesh sieve to obtain a positively charged superhydrophobic powder, namely 2.5% acetamiprid positively charged superhydrophobic powder, of which 0.5% is the effective ingredient equivalent to 100%, that is, the content of the effective ingredient of acetamiprid in the superhydrophobic powder.

[0038] Example 3 A method for preparing a positively charged superhydrophobic powder for termite control differs from Example 1 in that: in step (2), the amount of 98% chlorantraniliprole technical material added is 2.04 g, the amount of quaternary ammonium salt hexadecyltrimethylammonium bromide added is 0.5 g, and the amount of superhydrophobic silica added is 97.46 g. The remaining preparation methods are the same as in Example 1, resulting in a 2% chlorantraniliprole positively charged superhydrophobic powder.

[0039] Effect verification: 1. The control effect of different concentrations of chlorantraniliprole positively charged superhydrophobic powder on subterranean termites. (1) Test termites: Yellow-breasted Reticulitermes Frontotermes flaviceps Oshima Healthy, uniform worker and soldier ants were raised indoors on pine blocks for more than one week under the following conditions: temperature (27±1)℃ and humidity (80±5)%.

[0040] (2) The efficacy of chlorantraniliprole positively charged superhydrophobic powder in controlling subterranean termites was tested according to the test method in NYT 1153.2-2013 "Efficacy Test Methods and Evaluation of Termite Control Agents for Pesticide Registration Part 2: Indoor Determination of Pesticide Toxicity Transfer to Termites" with concentration gradients of 0.01%, 0.05%, 0.1%, 0.5%, 1% and 2%. The chlorantraniliprole positively charged superhydrophobic powder with a concentration of 0.5% was the positively charged superhydrophobic powder prepared in Example 1. The preparation methods and conditions of the chlorantraniliprole positively charged superhydrophobic powder with concentration gradients of 0.01%, 0.05%, 0.1%, 1% and 2% were the same as in Example 1. A blank control group (CK) was also set up.

[0041] (3) Test results The results of the indoor test on the toxicity transfer of the positively charged superhydrophobic powder of chlorantraniliprole prepared in this invention to subterranean termites are shown in Table 1. In Table 1, the termite base number 10+100 represents that 10 termites with the drug were taken each time and placed into a colony of 100 blank termites for mutual transfer.

[0042] Table 1. Results of laboratory tests on the toxicity transfer of chlorantraniliprole positively charged superhydrophobic powder to subterranean termites.

[0043] Table 1 shows the results of the indoor test on the toxicity transfer of different concentrations of chlorantraniliprole positively charged superhydrophobic powder to subterranean termites. The results indicate that the 0.01% concentration of the powder showed low activity in killing subterranean termites; when the concentration was increased to 0.05-0.1%, the toxicity transfer to subterranean termites could reach 2-3 times, and the termite mortality rate was >99.3% after 5-6 days of application; at a concentration of 0.5%, all termites died after 4 days of application; and at a concentration ≥1%, all termites died within 3 days. The test results show that the applicable concentration range of chlorantraniliprole positively charged superhydrophobic powder is 0.1-1%, preferably 0.5%. If the termite infestation is severe, the population is large, or application is difficult, the concentration of the agent can be appropriately increased.

[0044] 2. The control effect of the positively charged superhydrophobic powder of acetamiprid prepared in Example 2 on subterranean termites. (1) Test termites: Formosan subterranean termites Coptotermes formosanus Shiraki Healthy, uniform worker and soldier ants were raised indoors on pine blocks for more than one week under the following conditions: temperature (27±1)℃ and humidity (80±5)%.

[0045] (2) Test methods: Laboratory efficacy tests were conducted on positively charged superhydrophobic powders of acetamiprid at concentration gradients of 2.5%, 1.25%, 0.5%, and 0.25% for the control of subterranean termites. The positively charged superhydrophobic powders prepared in Example 1 were used as references, and a blank control group (CK) was also set up. The test methods were based on NYT 1153.2-2013 "Efficacy Test Methods and Evaluation of Termite Control Agents for Pesticide Registration Part 2: Indoor Determination of the Transmission of Pesticide Toxicity to Termites".

[0046] (3) Test results: The results of the indoor test on the toxicity transfer of the positively charged superhydrophobic powder of acetaminophen prepared in this invention to Formosan subterranean termites are shown in Table 2. In Table 2, the termite base number 10+100 represents that 10 termites with the drug were taken each time and placed into a colony of 100 blank termites for mutual transfer.

[0047] Table 2

[0048] Table 2 shows that the indoor test results of the toxicity transfer of different concentrations of acetamiprid positively charged superhydrophobic powder to Formosan subterranean termites indicate that the superhydrophobic powder prepared in this invention has strong toxicity to Formosan subterranean termites. At a concentration of 0.25%, all termites died after 4 days of application; at a concentration ≥1.25%, all termites died within 2 days. The test results indicate that the applicable concentration range of acetamiprid positively charged superhydrophobic powder is <0.25%, and the concentration should be controlled below 0.25% in future practical applications.

[0049] 3. Adsorption performance test Two groups of subterranean termites were set up, with 50 termites in each group. The weights were recorded, and the termites were placed in petri dishes containing 30 mg of the positively charged superhydrophobic powder of chlorantraniliprole prepared in Example 1 (experimental group) and 30 mg of commercially available 0.5% fipronil powder (control group), respectively, ensuring full contact between the termites and the powder. The contact results are as follows: Figure 1 As shown in the figure, the termites were then removed, weighed, and their weight recorded. The results are shown in Table 3.

[0050] Table 3 Performance test results of termite adsorption powder

[0051] Table 3 shows that termites adsorb slightly more of the positively charged superhydrophobic powder of chlorantraniliprole than commercially available 0.5% fipronil powder, while the distribution of the powder on the termite body wall (e.g., ...) Figure 2 As shown in the figure, the positively charged superhydrophobic powder of chlorantraniliprole can be evenly distributed on the termite body wall and has little impact on the termite's movement ability. In contrast, the commercially available 0.5% fipronil powder will form large clumps on the termite's head or feet, which seriously interferes with the termite's movement. Furthermore, the powder particles are easily dropped as the termite struggles.

[0052] When the above-mentioned positively charged superhydrophobic powder of chlorantraniliprole is placed in water, such as... Figure 3 As shown in the figure, the results indicate that the positively charged superhydrophobic powder of chlorantraniliprole exhibits strong hydrophobicity, remaining loose even in humid environments and not wetting upon contact with water. The adhesion effect of the positively charged superhydrophobic powder of chlorantraniliprole to termites is as follows: Figure 4 As shown in the figure, the results indicate that the positively charged superhydrophobic powder of chlorantraniliprole has strong adhesion to termites.

[0053] Toxicological tests (acute toxicity test of 2% chlorantraniliprole positively charged superhydrophobic powder on earthworms) 1. Selection of test samples and reference substances: The 2% chlorantraniliprole positively charged superhydrophobic powder prepared in Example 3 was selected as the test sample; 95% chlorantraniliprole technical was selected as the reference substance.

[0054] 2. Selection of experimental organisms: Sixty Eisenia fetidae earthworms were selected as experimental organisms.

[0055] 3. Test conditions: Test temperature 18.4-20.4 ℃, test humidity 76.9-82.5%, light intensity 604-754 Lx, 24 h light exposure.

[0056] 4. Test concentration: The concentration of the 2% chlorantraniliprole positively charged superhydrophobic powder prepared in Example 3 per kilogram of dry soil: 25 mg ai / kg 干土 50 mg ai / kg 干土 100 mg ai / kg 干土 200 mg ai / kg 干土 400 mg ai / kg 干土 and 800 mg ai / kg 干土 .

[0057] 5. Test method: The acute toxicity test of earthworms was conducted in accordance with GB / T 31270.15-2014 "Test Guidelines for Environmental Safety Evaluation of Chemical Pesticides Part 15: Acute Toxicity Test of Earthworms".

[0058] 6. Test Results: The LC50, 95% confidence interval, and regression equation of 2% chlorantraniliprole positively charged superhydrophobic powder against Eisenia fetida for 7 days are shown in Table 4; the LC50, 95% confidence interval, and regression equation of 95% chlorantraniliprole technical grade against Eisenia fetida for 7 days are shown in Table 5.

[0059] Table 4. Toxicity of 2% Chlorantraniliprole Positively Charged Superhydrophobic Powder to Earthworms

[0060] Table 5. Toxicity of chlorantraniliprole technical grade to earthworms

[0061] The results showed that the LC50 of 2% chlorantraniliprole positively charged superhydrophobic powder against *Eisenia fetida* was 177.12 mg ai / kg after 7 days of acute toxicity. 干土 The LC50 of 95% chlorantraniliprole technical grade for Eisenia fetida over 7 days was 164.13 mg ai / kg. 干土 The LC50 value of 2% chlorantraniliprole positively charged superhydrophobic powder against Eisenia fetida at 7 days was slightly reduced, indicating that the positively charged superhydrophobic powder prepared in this invention has the advantage of reducing the toxicity to non-target organisms, and the positively charged superhydrophobic powder prepared in this invention has high safety.

[0062] 7. Conclusion: According to the pesticide toxicity classification standard, the acute toxicity level of 2% chlorantraniliprole superhydrophobic powder with positive charge to Eisenia fetida is low.

[0063] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A positively charged superhydrophobic powder for termite control, characterized in that, The positively charged superhydrophobic powder uses superhydrophobic silica as a carrier, and the remaining raw materials include pharmaceuticals and functional additives.

2. The positively charged superhydrophobic powder for termite control according to claim 1, characterized in that, The positively charged superhydrophobic powder comprises the following raw materials in weight percentages: 0.5-2.5% reagent, 0.1-0.5% functional additives, and the balance being superhydrophobic silica.

3. The positively charged superhydrophobic powder for termite control according to claim 2, characterized in that, The method for preparing the superhydrophobic silica is as follows: After mixing fumed silica and ethanol, the mixture was ultrasonically dispersed and stirred under reflux. Then, sodium hydroxide and dodecyltriethoxysilane were added and stirred to react. Finally, the mixture was centrifuged, washed and dried to obtain the superhydrophobic silica.

4. The positively charged superhydrophobic powder for termite control according to claim 3, characterized in that, The mass ratio of the fumed silica, sodium hydroxide, and dodecyltriethoxysilane is 10:2.5:3; The ratio of the amount of fumed silica to ethanol added is 10g:250mL.

5. The positively charged superhydrophobic powder for termite control according to claim 3, characterized in that, The ultrasonic power of the ultrasonic dispersion is 300-600 W, and the ultrasonic time is 10 min. The stirring reflux temperature is 70 ℃, the time is 3 min, and the rotation speed is 1000-1500 rpm; The stirring reaction was carried out in a water bath at 70 °C with magnetic stirring at a speed of 1200 rpm for 5 h. The centrifugation speed is 12000 rpm and the time is 5-8 min; The drying temperature is 45-60 ℃, and the time is 2-3 h.

6. The positively charged superhydrophobic powder for termite control according to claim 2, characterized in that, The agent is one of chlorantraniliprole or acetonitrile; The functional additive is one of quaternary ammonium salt surfactants or biionic surfactants.

7. A method for preparing a positively charged superhydrophobic powder for termite control as described in any one of claims 1-6, characterized in that, Includes the following steps: The pharmaceutical agent and functional additives are dissolved in acetone, then sprayed onto the superhydrophobic silica, stirred evenly, and then pulverized to obtain the positively charged superhydrophobic powder.

8. The preparation method according to claim 7, characterized in that, The stirring speed is 20-30 rpm, and the time is 10-15 min; The pulverization refers to pulverizing to pass through a 200-mesh sieve.

9. The application of a positively charged superhydrophobic powder for termite control as described in any one of claims 1-6 in the process of termite control.

10. The application according to claim 9, characterized in that, The specific process of the application is as follows: spraying the positively charged superhydrophobic powder onto the termites; The spraying amount is 15-30 g per nest.

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