Dendritic mesoporous silica nano pesticide continuous preparation device

Abstract

The continuous preparation device comprises a reaction kettle, a raw material intermediate storage tank, a cylindrical concentration room and a purification room, the outer wall of the reaction kettle is provided with a heating layer, the top of the reaction kettle is provided with a raw material inlet and a digital control screen, and the bottom of the reaction kettle is connected with a waste liquid collecting tank; the reaction kettle is connected with the barrel-shaped concentration room through the water segregator, an outlet of the barrel-shaped concentration room is connected with a feeding hole of the purification room, the purification room is connected with the product receiving tank, and the purification room is also connected with the reaction kettle through a reflux pipeline. According to the device, large-scale and continuous production of the dendritic mesoporous silica nano-pesticide is realized, the structure is accurately regulated and controlled, the process compatibility is high, and the productivity of the nano-pesticide is improved.

Description

Technical Field

[0001] This utility model belongs to the field of pesticide processing technology, specifically a continuous preparation device for dendritic mesoporous silica nanopesticides. Background Technology

[0002] Dendritic mesoporous silica is characterized by its unique divergent pore structure and high specific surface area (>900m²). 2 With its pore size of 2-50 nm and controllable pore size ( / g), it has become an ideal carrier for pesticide slow-release formulations. However, traditional preparation methods suffer from problems such as complex processes, high costs, and difficulty in large-scale production, which limit its industrial application.

[0003] Traditional methods rely on template agents (such as cetyltrimethylammonium p-toluenesulfonate, CTATOs) and co-surfactants (such as F127) to achieve pore control through multi-step reactions (such as high-temperature hydrothermal synthesis, centrifugal washing, and template agent removal), which are cumbersome and time-consuming. Batch production easily leads to uneven particle size (e.g., particle size fluctuations within the 20-200 nm range), low pore structure consistency, and product aggregation, requiring additional treatment for dispersion. Moreover, existing devices are mostly laboratory-grade batch reactors, making continuous production difficult, resulting in low yields and high costs, and failing to meet the large-scale demand for nano-pesticides in the agricultural sector.

[0004] As pesticide slow-release agents develop towards intelligent and responsive technologies (such as pH-sensitive, enzyme-responsive, and reactive oxygen species-triggered release), higher requirements are placed on carrier surface modification (such as amination and metal ion loading). However, existing equipment struggles to simultaneously complete carrier synthesis and functionalization modification in continuous production, leading to process chain disruptions.

[0005] Furthermore, the organic solvents (such as dichloromethane and ethyl acetate) and template agent residues used in traditional preparation processes may cause environmental pollution, while the high energy consumption of batch production further exacerbates cost pressures. Therefore, there is an urgent need to develop green, low-energy-consumption, and continuous preparation equipment. Utility Model Content

[0006] This invention addresses the aforementioned deficiencies by providing a continuous preparation device for dendritic mesoporous silica nanopesticides. This device enables large-scale and continuous production of dendritic mesoporous silica nanopesticides, offering precise structural control, high process compatibility, and improved nanopesticide production capacity.

[0007] The present invention relates to a continuous preparation device for dendritic mesoporous silica nanopesticides, comprising a reaction vessel, a raw material intermediate storage tank, a cylindrical concentration chamber, and a purification chamber. The reaction vessel has a heating layer on its outer wall, a raw material inlet and a digital control panel at the top, and a waste liquid collection tank at the bottom. The reaction vessel is connected to the cylindrical concentration chamber via a water separator for separating reaction byproducts. The inner diameter of the connecting pipe between the reaction vessel and the cylindrical concentration chamber is 10-50 mm, and the pipe is made of 316L stainless steel. The outlet of the cylindrical concentration chamber is connected to the inlet of the purification chamber, and the purification chamber is connected to a product receiving tank. The purification chamber is also connected to the reaction vessel via a reflux pipe.

[0008] The raw material intermediate storage tanks include raw material solid powder intermediate storage tanks, raw material acid intermediate storage tanks, raw material methanol intermediate storage tanks, raw material pesticide liquid intermediate storage tanks, adjuvant intermediate storage tanks, and disposable water intermediate storage tanks. They are connected to the raw material inlet of the reactor through metering pumps. Each raw material intermediate storage tank is equipped with a pressure sensor and a flow controller with an accuracy of ±0.1mL.

[0009] The cylindrical concentration chamber is equipped with multiple molecular sieve membranes with pore sizes of 2-50 nm, which are used to selectively retain dendritic mesoporous silica precursors.

[0010] The purification room includes a centrifuge and an ultrasonic disperser, with a centrifugation speed of 5000-15000 rpm.

[0011] The heating layer has a built-in spiral electric heating wire, and the temperature control range is 25℃-200℃.

[0012] The inner wall of the reactor is coated with a polytetrafluoroethylene layer, and a stirrer is installed inside the reactor. The side wall of the reactor is equipped with a viewing window made of high-temperature resistant tempered glass for real-time observation of the reaction status.

[0013] A condensation device is provided between the water separator and the waste liquid collection tank, with a condensation temperature of -10℃ to 5℃.

[0014] The product receiving tank is equipped with a vacuum drying module, with a drying temperature of 40℃-80℃.

[0015] The beneficial effects of the continuous preparation device for dendritic mesoporous silica nanopesticides of this utility model are as follows:

[0016] 1. Continuous production: Through multi-tank linkage and modular design, the production cycle for a single batch is shortened to 6-8 hours;

[0017] 2. Structural controllability: Mesopore size deviation < ±0.3nm, branch density can be precisely controlled by acid concentration and temperature;

[0018] 3. Process compatibility: The equipment is compatible with water / organic solvent systems and supports various pesticide types such as insecticides and fungicides;

[0019] 4. Environmental benefits: Organic solvent recovery rate >85%, waste liquid generation reduced by 60%. Attached image description:

[0020] Figure 1 The diagram shown is a schematic diagram of the basic structure of this utility model.

[0021] In the diagram, 1. Reactor, 2. Liquid raw material inlet, 3. Solid raw material inlet, 4. Viewing window, 5. Heating layer, 6. Stirrer, 7. Digital control panel, 8. Metering pump, 9. Raw material solid powder intermediate storage tank, 10. Raw material acid intermediate storage tank, 11. Raw material methanol intermediate storage tank, 12. Raw material pesticide liquid intermediate storage tank, 13. Adjuvant intermediate storage tank, 14. Disposable water intermediate storage tank, 15. Waste liquid collection tank, 16. Water separator, 17. Cylindrical concentration room, 18. Purification room, 19. Centrifuge, 20. Ultrasonic disperser, 21. Product receiving tank, 22. Vacuum drying module. Detailed implementation method:

[0022] To better understand this utility model, specific examples are used below to illustrate the technical solution of this utility model in detail, but this utility model is not limited thereto.

[0023] A continuous preparation device for dendritic mesoporous silica nanopesticides includes a reaction system: a reactor 1 serves as the core reaction vessel, equipped with a heating layer 5 and a stirrer 6, used for synthesizing dendritic mesoporous silica carriers; the top of the reactor 1 is equipped with a liquid raw material inlet 2, a solid raw material inlet 3, and a digital control panel 7, while the bottom is connected to a waste liquid collection tank 15. The inner wall of the reactor 1 is coated with a polytetrafluoroethylene layer, and a stirrer is installed inside the reactor 1. A viewing window 4 is provided on the side wall of the reactor 1. The reactor 1 is connected to a cylindrical concentration chamber 17 via a water separator 16. The raw material supply system includes multiple intermediate storage tanks: a raw material solid powder intermediate storage tank 9, a raw material acid intermediate storage tank 10, a raw material methanol intermediate storage tank 11, a raw material pesticide liquid intermediate storage tank 12, an adjuvant intermediate storage tank 13, and a disposable water intermediate storage tank 14. Solid silicon sources, acid catalysts, methanol solvents, pesticide mother liquors, and adjuvants are precisely added via metering pumps 8.

[0024] Separation and purification system: The cylindrical concentration chamber 17 removes solvent by vacuum evaporation, and the purification chamber 18 contains a centrifuge 19 and an ultrasonic disperser 20 to remove impurities by centrifugation and ultrafiltration; the purification chamber 18 is also connected to the reaction vessel 1 through a reflux pipe;

[0025] Continuous control system: The digital control panel 7 monitors temperature, flow rate and stirring speed in real time to ensure stable reaction conditions.

[0026] 2. Working principle

[0027] Step 1: Solid silicon source and acid solution are hydrolyzed in a reaction vessel to generate silica sol;

[0028] Step 2: Add methanol and template agent, remove by-product water through water separator 16, and regulate the mesoporous branched structure;

[0029] Step 3: After removing excess solvent in the cylindrical concentration chamber 17, the reaction solution enters the purification chamber 18, where it is centrifuged and ultrafiltered to obtain high-purity mesoporous silica.

[0030] Step 4: The purified carrier is loaded with pesticide active ingredients in reaction vessel 1, and the final product is collected by product receiving tank 21, which is equipped with vacuum drying module 22.

[0031] Example 1

[0032] Preparation of Dendritic Mesoporous Silica Nanopesticides Loaded with Thiamethoxam

[0033] Raw materials and parameters: Solid powder precursor: Tetraethyl orthosilicate (TEOS) and hexadecyltrimethylammonium bromide (CTAB) are mixed at a mass ratio of 5:1;

[0034] Acid solution: 0.1 mol / L hydrochloric acid solution;

[0035] Pesticide solution: Thiamethoxam methanol solution (concentration 10 mg / mL);

[0036] Reaction conditions: reactor temperature 80℃, stirring speed 500rpm, reaction time 4 hours.

[0037] Operating steps:

[0038] 1. Precursor synthesis: TEOS and CTAB are continuously fed from the intermediate storage tank 9 of raw material solid powder to the reactor 1, methanol is added to adjust the viscosity, and the mixing state is monitored through the viewing window 4.

[0039] 2. Acid-catalyzed hydrolysis: Hydrochloric acid solution is injected from the intermediate storage tank 10 of the raw acid, the heating layer is started to maintain the temperature, and the water separator 16 separates the by-product water to the waste liquid collection tank 15.

[0040] 3. Pesticide loading: Thiamethoxam methanol solution and PEG-2000 adjuvant were simultaneously pumped into reactor 1 and stirred continuously for 3 hours.

[0041] 4. Purification and concentration: The reaction solution is placed in the cylindrical concentration chamber 17 for vacuum desolvation, and then centrifuged in the purification chamber 18 to remove unloaded pesticides (centrifugation speed 8000 rpm, 10 minutes).

[0042] 5. Product collection: The nano-pesticide suspension is transferred into the product receiving tank 21, and after spray drying, a solid product with a particle size of 120nm and a mesopore size of 3.8nm is obtained, with a pesticide loading of 22%.

[0043] Example 2

[0044] Continuous production of high-efficiency cyhalothrin slow-release nano-pesticides

[0045] Process optimization points:

[0046] Acid concentration gradient control: 0.05 mol / L hydrochloric acid was used in the initial stage, and then switched to 0.2 mol / L in the later stage to regulate the mesoporous branched structure;

[0047] Pesticide solvent replacement: Acetone is used instead of methanol to improve the dispersibility of fat-soluble pesticides;

[0048] Dynamic temperature program: The temperature of reactor 1 is gradually increased from 60°C to 90°C to promote the formation of mesoporous networks.

[0049] Implementation process:

[0050] 1. Branch structure control: By injecting hydrochloric acid of different concentrations in 10 stages into the intermediate raw material acid storage tank, combined with temperature gradient, multi-level channels (specific surface area 420m²) are formed. 2 / g).

[0051] 2. Pesticide loading: High-efficiency cyhalothrin acetone solution and silicon framework are synchronously self-assembled, and sodium dodecyl sulfate (SDS) is selected as an adjuvant to enhance interfacial adsorption.

[0052] 3. Online monitoring: Using the viewing window 4 in conjunction with an online particle size analyzer, the stirring speed (300-600 rpm) can be adjusted in real time to control the particle size within the range of 80-150 nm.

[0053] 4. Continuous purification: The cylindrical concentration chamber 17 uses membrane separation technology to retain nanoparticles, and the filtrate is recycled to the raw material tank to reduce waste.

[0054] 5. Performance verification: The product's sustained-release rate reaches 85% after 72 hours, which is 40% higher than that of traditional dosage forms.

[0055] Example 3

[0056] Integrated preparation of water-soluble nano-pesticide abamectin

[0057] Innovative process design:

[0058] Coprecipitation method integration: Simultaneous synthesis of silica precursors and pesticide loading;

[0059] Modification of the aqueous system: Replace some of the methanol with deionized water to reduce the amount of organic solvent used;

[0060] Automated control: The flow rate of each raw material storage tank is linked through the digital control panel 7 system to achieve precise adjustment of pH (2.5-6.0) and temperature (±1℃).

[0061] Key steps:

[0062] 1. Precursor dispersion: TEOS and CTAB are pre-dispersed in a water / methanol mixed solvent, and nitric acid is injected into the intermediate storage tank 10 of the raw material acid to adjust the pH to 3.5.

[0063] 2. In-situ loading: Avermectin aqueous solution (solubilized with β-cyclodextrin) was co-precipitated with a silicon source to generate composite nanoparticles in reactor 1.

[0064] 3. Continuous water separation: The water separator separates 5% of the reaction liquid into the waste liquid collection tank 15 every hour to maintain a low water content in the system to control the pore size (target 4.2 nm).

[0065] 4. Low-temperature purification: The purification room uses an ultrafiltration membrane (molecular weight cutoff of 10kDa) for circulating concentration, and the final product has a water content of <5%.

[0066] 5. Effect comparison: With a drug loading of 18%, field trials showed a 30% increase in control efficacy and a photolysis half-life that was twice that of traditional formulations.

[0067] Common advantages of the embodiments

[0068] 1. Continuous production: Through multi-tank linkage and modular design, the production cycle for a single batch is shortened to 6-8 hours;

[0069] 2. Structural controllability: Mesopore size deviation < ±0.3nm, branch density can be precisely controlled by acid concentration and temperature;

[0070] 3. Process compatibility: The equipment is compatible with water / organic solvent systems and supports various pesticide types such as insecticides and fungicides;

[0071] 4. Environmental benefits: Organic solvent recovery rate >85%, waste liquid generation reduced by 60%.

Claims

1. A continuous preparation device for dendritic mesoporous silica nanopesticides, characterized in that, It includes a reaction vessel, a raw material intermediate storage tank, a cylindrical concentration room, and a purification room. The outer wall of the reaction vessel is equipped with a heating layer, the top is equipped with a raw material inlet and a digital control panel, and the bottom is connected to a waste liquid collection tank. The reaction vessel is connected to the cylindrical concentration room through a water separator, the outlet of the cylindrical concentration room is connected to the inlet of the purification room, the purification room is connected to the product receiving tank, and the purification room is also connected to the reaction vessel through a reflux pipe.

2. The continuous preparation device for dendritic mesoporous silica nanopesticides according to claim 1, characterized in that, The raw material intermediate storage tanks include raw material solid powder intermediate storage tanks, raw material acid intermediate storage tanks, raw material methanol intermediate storage tanks, raw material pesticide liquid intermediate storage tanks, adjuvant intermediate storage tanks, and disposable water intermediate storage tanks. They are connected to the raw material inlet of the reactor through metering pumps. Each raw material intermediate storage tank is equipped with a pressure sensor and a flow controller.

3. The continuous preparation device for dendritic mesoporous silica nanopesticides according to claim 1, characterized in that, The cylindrical concentration chamber is equipped with multiple molecular sieve membranes with a pore size of 2-50 nm.

4. The continuous preparation device for dendritic mesoporous silica nanopesticides according to claim 1, characterized in that, The purification room includes a centrifuge and an ultrasonic disperser.

5. The continuous preparation device for dendritic mesoporous silica nanopesticides according to claim 1, characterized in that, The heating layer has a built-in spiral electric heating wire.

6. The continuous preparation device for dendritic mesoporous silica nanopesticides according to claim 1, characterized in that, The inner wall of the reactor is coated with a polytetrafluoroethylene layer, a stirrer is installed inside the reactor, and a viewing window is provided on the side wall of the reactor.

7. The continuous preparation device for dendritic mesoporous silica nanopesticides according to claim 1, characterized in that, A condensation device is provided between the water distributor and the waste liquid collection tank.

8. The continuous preparation device for dendritic mesoporous silica nanopesticides according to claim 1, characterized in that, The product receiving tank is equipped with a vacuum drying module.

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