A nano-intelligent pesticide slow-release material and a preparation method for its aqueous dispersion controlled-release preparation

Abstract

The present invention discloses a nano-intelligent pesticide slow-release material and a preparation method of its aqueous dispersion controlled-release preparation, comprising the following steps: S1. Prepare nano-hollow silica by the hard template method; S2. Modify to prepare an environment-responsive nano-hollow silica; S3. Load pesticide active substances by the solvent evaporation method to obtain an environment-responsive pesticide slow-release agent; S4. Prepare a nano-intelligent pesticide aqueous dispersion controlled-release preparation. The prepared nano-hollow silica is spherical in shape, with a particle diameter of 80-100 nm; the nano-hollow silica prepared by this method can be used to directly embed pesticide active substances; it has the characteristic of environmental responsiveness. The preparation method of the present invention has low cost, mild reaction conditions, and no three wastes; the product has a high loading rate, good water dispersibility, a long effective period, and reduces the number of pesticide applications; it has the characteristic of environmental responsiveness. When the temperature rises and the pH decreases, the polymer shell swells and collapses, and the pesticide is rapidly released, which can improve the utilization efficiency of the pesticide.

Description

Technical Field

[0001] The present invention belongs to the technical fields of material preparation and pesticide slow release, and particularly relates to a nano intelligent pesticide slow release material and a preparation method of a water-dispersible controlled release preparation thereof. Background Art

[0002] Pesticides have the advantages of high efficiency, speed, economy, simple operation, and low labor intensity in preventing and controlling crop diseases, pests, and weeds, and play an irreplaceable and important role in the integrated pest management. In 2016, the production volume of chemical pesticides in China reached 3.778 million tons, and the usage volume reached 1.8 million tons, among which the main ones were conventional pesticide formulations such as emulsifiable concentrates, wettable powders, and emulsions.

[0003] Due to problems such as a large amount of organic solvents used, dust drift, and poor dispersibility existing in conventional pesticide formulations, and the lack of the ability to control the release of active ingredients, more than 90% of the pesticide active ingredients are lost in the environment near the target. The main reasons for pesticide loss include application techniques, physicochemical properties, and environmental factors such as wind speed, humidity, temperature, leaching, deposition, rain wash, and degradation (photolysis, hydrolysis, and microbial degradation). The long-term and large-scale and inefficient application of pesticides has led to the excessive pesticide residues in vegetables, fruits, grains, soil, and water bodies in China, which not only poses a serious threat to non-target organisms and human health, but also causes the destruction of the structure and function of the ecosystem.

[0004] Therefore, it is extremely urgent to develop an environmentally friendly long-acting nano pesticide slow release agent with high performance, low cost, easy water dispersion, and high stability, and it has also become a research hotspot in related fields.

[0005] Compared with traditional pesticide slow release agents, the slow release agents of nano pesticides have many advantages. For example, the release rate of pesticides can be adjusted reasonably by adjusting external controllable conditions (such as enzymes, pH value, temperature, etc.), which can improve the biological activity and utilization rate of pesticides, and can also reduce the usage amount of various organic solvents and surfactants, and is of great significance for alleviating environmental pollution, maintaining ecological balance, and promoting the development of green agriculture.

[0006] In the past decade, various nano materials including carbon nano materials, polymers, nano hollow silica particles, clay, and other porous inorganic materials have been developed as carriers for pesticide delivery. The pesticide delivery system based on nano hollow silica materials has attracted much attention due to its high pesticide loading capacity, excellent stability and biological activity, easy preparation, and industrialization potential.

[0007] At present, the main method for preparing nano-hollow silica is the template method. Gao Yunhao from Huazhong Agricultural University used polystyrene as the hard template, cetyltrimethylammonium bromide (CTAB) as the surfactant and pore expander, and tetraethyl orthosilicate (TEOS) as the silicon source to prepare nano-hollow silica. Finally, nano-hollow silica with a particle size of about 500 nm, a pore size of 2.96 nm, and a specific surface area of 711.28 m 2 / g was obtained (Gao Yunhao, Master's Thesis of Huazhong Agricultural University, 2018).

[0008] Li Zhuzhu from Beijing University of Chemical Technology (L-X Wen, Z-Z Li, H-K Zou, et al. Controlled release of avermectin from porous hollow silica nanoparticles[J]. Pest Management Science, 2005, 61(6):583.) used nano-calcium carbonate as the hard template, surfactant as the soft template, and sodium silicate as the silicon source to prepare nano-hollow silica with a diameter of about 70 nm, a wall thickness of about 15 nm, and a pore size of 4 nm. The impregnation method at normal temperature and pressure was used to load avermectin, and the sustained-release time was less than two days, and there was no stimulus-responsive sustained-release behavior in complex environments such as temperature and pH.

[0009] In the above preparation methods, polystyrene microspheres are expensive and difficult to meet the needs of large-scale applications. At the same time, surfactants are added in both preparation methods, and calcination or chemical means are required to remove the surfactants, which is time-consuming and energy-consuming, thus increasing the emission of three wastes. Summary of the Invention

[0010] The first technical problem to be solved by the present invention is to provide a preparation method of a nano-intelligent pesticide sustained-release material. In this preparation method, surfactants are not used in the step of preparing nano-hollow silica, reducing the emission of three wastes; and this method does not require calcination, reducing energy consumption and time; at the same time, the pesticide sustained-release agent prepared by this method has been applied and demonstrated in high-value cash crops such as citrus; the pesticide sustained-release agent of this nano-hollow silica material exhibits stimulus-responsive sustained-release behavior in complex environments such as temperature and pH, has good water dispersion stability, compared with the commercial emulsifiable concentrate formulation with the same active ingredient, the usage amount of the pesticide technical is reduced by 1 / 3, the effective period is extended by 30%, the number of pesticide applications is reduced, the pesticide utilization rate is improved, and thus the impact of pesticides on the environment is reduced.

[0011] The second technical problem to be solved by the present invention is to provide a preparation method of a water-dispersible controlled-release preparation of a nano-intelligent pesticide sustained-release material.

[0012] To solve the above first technical problem, the present invention adopts the following technical solutions:

[0013] A method for preparing a nano smart pesticide sustained-release material comprises the following steps:

[0014] S1. Preparation of hollow nano-silica by hard template method

[0015] S1-1, adding the nano calcium carbonate filter cake into deionized water, stirring and dispersing in a high-speed stirrer for 30-120 minutes, and preparing a nano calcium carbonate suspension with a concentration of 6-50wt%;

[0016] S1-2, measuring the nano-calcium carbonate suspension, accurately preparing a sodium silicate solution containing a silicon dioxide concentration of 2-50wt%, according to a silicon dioxide / calcium carbonate mass ratio of 0.02-0.4; raising the temperature of the nano-calcium carbonate suspension to 30-90°C, uniformly adding the sodium silicate solution to the nano-calcium carbonate suspension within 2-3h for reaction, and adjusting the pH value to a certain range with an organic acid or an inorganic acid with a concentration of 1-10wt%, and aging for 1-10h after the addition is completed;

[0017] S1-3, cooling the reaction solution, filtering, washing and drying to obtain CaCO3@SiO2 composite particles, the drying temperature being 40-200°C;

[0018] S1-4, placing the CaCO3@SiO2 composite particles in an organic acid or inorganic acid solution, slowly stirring for 1-50 hours, removing the nano calcium carbonate, filtering and drying to obtain nano hollow silica, the drying temperature is 40-200°C;

[0019] S2. Modification and preparation of environmentally responsive nano hollow silica

[0020] S2-1, functionalizing the surface of nano hollow silica: adding 26-27 mL of ethanol, 5-7 mL of deionized water, 1.7-1.8 mL of vinyl triethoxysilane, 0.1-0.25 g of nano hollow silica and 0.03-0.05 mL of 25 wt% ammonia water into a reactor to obtain a mixed solution, raising the temperature of the mixed solution to 40-70° C. and stirring for 1-3 h, centrifuging, washing and drying to obtain surface functionalized nano hollow silica;

[0021] S2-2, Grafted environmentally responsive polymer:

[0022] Add 85 - 95 mL of deionized water, 0.52 - 0.56 g of potassium persulfate, 0.7 - 0.75 g of N - isopropylacrylamide, 0.25 - 0.30 g of acrylic acid, 0.14 - 0.15 g of sodium dodecyl sulfate, and 0.1 - 0.3 g of the functionalized nano - hollow silica obtained in step S2 - 1 into the reactor. Under a nitrogen atmosphere, raise the temperature of the above - mentioned mixed solution to 50 - 90 °C, and react for 4 - 6 h to carry out free - radical precipitation polymerization; centrifuge, wash, and dry to obtain a nano - intelligent pesticide slow - release material, namely, environmentally responsive nano - hollow silica grafted with poly(N - isopropylacrylamide - b - acrylic acid);

[0023] S3. Load the pesticide active substance by the solvent evaporation method

[0024] Loading method: Add the environmentally responsive nano - hollow silica grafted with poly(N - isopropylacrylamide - b - acrylic acid) obtained in step S2 - 2, the pesticide active substance, and then add an organic solvent or water into the flask. Under reduced pressure, obtain an environmentally responsive nano - hollow silica pesticide slow - release agent grafted with poly(N - isopropylacrylamide - b - acrylic acid);

[0025] To solve the above - mentioned second technical problem, the present invention provides a preparation method for a water - dispersible controlled - release preparation of a nano - intelligent pesticide slow - release material, which includes the following steps:

[0026] S4. Prepare a nano - intelligent pesticide water - dispersible controlled - release preparation

[0027] Disperse the environmentally responsive nano - hollow silica pesticide slow - release agent grafted with poly(N - isopropylacrylamide - b - acrylic acid) obtained in step S3 in water under high - speed stirring to obtain a nano - intelligent pesticide water - dispersible controlled - release preparation.

[0028] According to certain embodiments of the present invention, in step S1 - 1, the particle size of the nano - calcium carbonate is 70 nm.

[0029] According to certain embodiments of the present invention, in step S1 - 1, the concentration of the nano - calcium carbonate is 6 - 40 wt%.

[0030] According to certain embodiments of the present invention, in step S1 - 2, the mass ratio of silica to nano - calcium carbonate is 0.05 - 0.4.

[0031] According to certain embodiments of the present invention, in step S1 - 2, raise the temperature of the nano - calcium carbonate suspension to 35 - 85 °C.

[0032] According to certain embodiments of the present invention, in step S1 - 2, the concentration of silica in the sodium silicate solution is 2 - 40 wt%.

[0033] According to certain embodiments of the present invention, in step S1-2, the organic acid or inorganic acid solution is one or more of hydrochloric acid, sulfuric acid, nitric acid, acetic acid, selenic acid, phosphoric acid, perchloric acid, hydrofluoric acid, hydrobromic acid, hydroiodic acid, hydrocyanic acid, sulfurous acid, nitrous acid, citric acid, lactic acid, tartaric acid, malic acid, metatartaric acid, oxalic acid, fumaric acid solution.

[0034] According to certain embodiments of the present invention, in step S1-2, the pH value is controlled at 8-13.

[0035] According to certain embodiments of the present invention, in step S1-2, the aging time is 1-6 h.

[0036] According to certain embodiments of the present invention, in step S1-4, the stirring time is 1-40 h.

[0037] According to certain embodiments of the present invention, in step S1-4, the organic acid or inorganic acid solution is one or more of hydrochloric acid, sulfuric acid, nitric acid, acetic acid, selenic acid, phosphoric acid, perchloric acid, hydrofluoric acid, hydrobromic acid, hydroiodic acid, hydrocyanic acid, sulfurous acid, nitrous acid, citric acid, lactic acid, tartaric acid, malic acid, metatartaric acid, oxalic acid, fumaric acid solution.

[0038] According to certain embodiments of the present invention, in step S2-1, the addition amount of the nano-hollow silica is 0.15-0.20 g, and the temperature is 50-70 °C.

[0039] According to certain embodiments of the present invention, in step S2-2, the reaction temperature of the mixed solution is 50-80 °C, and the reaction time is 4-5 h.

[0040] According to certain embodiments of the present invention, in step S3, the organic solvent is one or more of methanol, ethanol, acetone, chloroform, dichloromethane, dimethyl sulfoxide, N-N dimethylformamide.

[0041] According to certain embodiments of the present invention, in step S3, the pesticide active substance is one or more of insecticides, fungicides, herbicides, plant growth regulators and antidotes.

[0042] To solve the above second technical problem, the present invention provides a nano-intelligent pesticide water-dispersible controlled-release preparation prepared by the above preparation method.

[0043] Any range described in the present invention includes the end values and any numerical value between the end values, as well as any sub-range constituted by any numerical value between the end values or the end values.

[0044] Unless otherwise specified, each raw material in the present invention can be obtained by purchasing from the market, and the equipment used in the present invention can be conventional equipment in the field or can be referred to the existing technologies in the field.

[0045] Compared with the prior art, the present invention has the following beneficial effects :

[0046] 1) In the process of preparing nano-hollow silica in the present invention, no surfactant needs to be added, and nano-hollow silica can be formed without calcination;

[0047] 2) The nano-hollow silica prepared in the present invention is spherical in shape, and the particle size is 80 - 100 nm;

[0048] 3) The nano-intelligent pesticide slow-release material prepared in the present invention has a high drug loading rate (up to 47.93%);

[0049] 4) For the nano-intelligent pesticide slow-release material and its aqueous dispersion controlled-release preparation prepared in the present invention, the release rate and the total release amount increase with the increase of temperature and the decrease of pH;

[0050] 5) For the nano-intelligent pesticide slow-release material and its aqueous dispersion controlled-release preparation prepared in the present invention, compared with the commercial emulsifiable concentrate dosage form with the same amount of active ingredient, the dosage of the pesticide technical material is reduced by 1 / 3, and the residual effect period is extended by more than 30%;

[0051] 6) The preparation method of the nano-hollow silica in the present invention has low cost, simple operation and is easy to be industrially produced. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The following further describes in detail the specific embodiments of the present invention with reference to the drawings.

[0053] Figure 1 It is the transmission electron microscope image of the inorganic template calcium carbonate used for preparing nano-hollow silica in Example 1;

[0054] Figure 2 It is the transmission electron microscope image of nano-hollow silica in Example 1;

[0055] Figure 3 It is the adsorption and desorption isotherm curve of nano-hollow silica in Example 1;

[0056] Figure 4 It is the pore size distribution curve of nano-hollow silica in Example 1;

[0057] Figure 5 It is the thermogravimetric curve of the environment-responsive nano-hollow silica avermectin slow-release agent in Example 1;

[0058] Figure 6Release curve of the environment-responsive nano-hollow silica abamectin sustained-release agent in Example 1;

[0059] Figure 7 Water dispersion photo of the nano-intelligent abamectin water-dispersible controlled-release preparation in Example 1;

[0060] Figure 8 Field control efficacy diagram of the nano-intelligent abamectin water-dispersible controlled-release preparation and the commercial emulsifiable concentrate dosage form in Example 1;

[0061] Figure 9 Field control efficacy diagram of the nano-intelligent cyantraniliprole water-dispersible controlled-release preparation and the commercial emulsifiable concentrate dosage form in Example 1. Detailed implementation manners

[0062] To illustrate the present invention more clearly, the present invention will be further described below in conjunction with preferred embodiments. Those skilled in the art should understand that the content specifically described below is illustrative rather than restrictive, and should not be used to limit the protection scope of the present invention.

[0063] As an aspect of the present invention, the present invention provides a preparation method of a nano-intelligent pesticide sustained-release material, including the following steps:

[0064] S1. Prepare nano-hollow silica by the hard template method

[0065] S1-1. Add nano-calcium carbonate filter cake into deionized water, stir and disperse it on a high-speed stirrer for 30 - 120 min to prepare a nano-calcium carbonate suspension with a concentration of 6 - 50 wt%;

[0066] S1-2. Measure the nano-calcium carbonate suspension, accurately prepare a sodium silicate solution with a silica concentration of 2 - 50 wt%, according to the mass ratio of silica / calcium carbonate of 0.02 - 0.4; raise the temperature of the nano-calcium carbonate suspension to 30 - 90 °C, and add the sodium silicate solution into the nano-calcium carbonate suspension at a constant speed within 2 - 3 h for reaction. At the same time, adjust and maintain the pH value within a certain range with an organic acid or inorganic acid with a concentration of 1 - 10 wt%. After the feeding is completed, age for 1 - 10 h;

[0067] S1-3. Cool the reaction solution, filter, wash, and dry it to obtain CaCO3@SiO2 composite particles, and the drying temperature is 40 - 200 °C;

[0068] S1-4. Place the CaCO3@SiO2 composite particles in a solution of an organic acid or inorganic acid, stir slowly for 1 - 50 h, remove the nano-calcium carbonate, filter and dry to obtain nano-hollow silica, and the drying temperature is 40 - 200 °C;

[0069] S2. Modify to prepare environment-responsive nano-hollow silica

[0070] S2-1. Functionalize the surface of nano-hollow silica: Add 26 - 27 mL of ethanol, 5 - 7 mL of deionized water, 1.7 - 1.8 mL of vinyltriethoxysilane, 0.1 - 0.25 g of nano-hollow silica, and 0.03 - 0.05 mL of 25 wt% ammonia water into a reactor to obtain a mixed solution. Raise the temperature of the above mixed solution to 40 - 70 °C and stir it thoroughly for 1 - 3 h, then centrifuge, wash, and dry to obtain surface-functionalized nano-hollow silica;

[0071] S2-2. Graft an environmentally responsive polymer:

[0072] Add 85 - 95 mL of deionized water, 0.52 - 0.56 g of potassium persulfate, 0.7 - 0.75 g of N-isopropylacrylamide, 0.25 - 0.30 g of acrylic acid, 0.14 - 0.15 g of sodium dodecyl sulfate, and 0.1 - 0.3 g of the functionalized nano-hollow silica obtained in step S2-1 into a reactor. Under a nitrogen atmosphere, raise the temperature of the above mixed solution to 50 - 90 °C, and the reaction time is 4 - 6 h for free radical precipitation polymerization; centrifuge, wash, and dry to obtain a nano-intelligent pesticide sustained-release material, namely environmentally responsive nano-hollow silica grafted with poly(N-isopropylacrylamide-b-acrylic acid);

[0073] S3. Load pesticide active substances by solvent evaporation method

[0074] Loading method: Add the environmentally responsive nano-hollow silica grafted with poly(N-isopropylacrylamide-b-acrylic acid) obtained in step S2-2, pesticide active substances, and then add an organic solvent or water into a flask. Under reduced pressure, obtain an environmentally responsive nano-hollow silica pesticide sustained-release agent grafted with poly(N-isopropylacrylamide-b-acrylic acid);

[0075] As another aspect of the present invention, the present invention provides a preparation method for a water-dispersible controlled-release preparation of a nano-intelligent pesticide sustained-release material:

[0076] S4. Prepare a water-dispersible controlled-release preparation of nano-intelligent pesticide

[0077] Disperse the environmentally responsive nano-hollow silica pesticide sustained-release agent grafted with poly(N-isopropylacrylamide-b-acrylic acid) obtained in step S3 in water under high-speed stirring to obtain a water-dispersible controlled-release preparation of nano-intelligent pesticide.

[0078] The field efficacy test method for the water-dispersible controlled-release preparation of nano-intelligent pesticide prepared by the present invention: Conduct a field efficacy test on high-value economic crops such as citrus with the water-dispersible controlled-release preparation of nano-intelligent pesticide obtained in step S4, and compare the efficacy with a commercial emulsifiable concentrate formulation.

[0079] In some embodiments, in step S1-1, the concentration of the nano calcium carbonate is 6-40 wt%, including but not limited to 6-30 wt%, 6-20 wt%, 6-40 wt%, 12-40 wt%, 24-40 wt%.

[0080] In some embodiments, in step S1-2, the mass ratio of silica to nano calcium carbonate is 0.05-0.4, including but not limited to 0.05-0.3, 0.05-0.2, 0.05-0.1, 0.1-0.3, 0.1-0.2.

[0081] In some embodiments, in step S1-2, the temperature of the nano calcium carbonate suspension is raised to 35-85 °C, including but not limited to 35-80 °C, 35-75 °C, 35-70 °C, 35-65 °C, 35-60 °C, 35-55 °C, 35-50 °C, 35-45 °C, 35-40 °C, 40-85 °C, 40-80 °C, 40-75 °C, 40-70 °C, 40-65 °C, 40-60 °C, 40-55 °C, 40-50 °C, 45-85 °C, 45-80 °C, 45-75 °C, 45-70 °C, 45-65 °C, 45-60 °C, 45-55 °C, 45-50 °C, 50-85 °C, 50-80 °C, 50-75 °C, 50-70 °C, 50-65 °C, 50-60 °C, 50-55 °C.

[0082] In some embodiments, in step S1-2, the concentration of silica in the sodium silicate solution is 2-40 wt%.

[0083] In some embodiments, in step S1-2, the organic acid or inorganic acid solution is one or more of hydrochloric acid, sulfuric acid, nitric acid, acetic acid, selenic acid, phosphoric acid, perchloric acid, hydrofluoric acid, hydrobromic acid, hydroiodic acid, hydrocyanic acid, sulfurous acid, nitrous acid, citric acid, lactic acid, tartaric acid, malic acid, metatartaric acid, oxalic acid, fumaric acid solution.

[0084] In some embodiments, in step S1-2, the pH value is controlled at 8-13.

[0085] In some embodiments, in step S1-2, the aging time is 1-6 h, including but not limited to 1-5 h, 1-4 h, 1-3 h, 1-2 h, 2-6 h, 2-5 h, 2-4 h, 2-3 h, 3-6 h, 3-5 h, 3-4 h, 4-6 h, 4-5 h.

[0086] In some embodiments, in step S1-4, the stirring time is 1-40 h, including but not limited to 1-30 h, 1-20 h, 1-10 h, 1-5 h, 5-30 h, 5-20 h, 5-10 h, 10-30 h, 20-30 h, 10-20 h, 15-30 h, 15-20 h.

[0087] In some embodiments, in step S1-4, the organic acid or inorganic acid solution is one or more of hydrochloric acid, sulfuric acid, nitric acid, acetic acid, selenic acid, phosphoric acid, perchloric acid, hydrofluoric acid, hydrobromic acid, hydroiodic acid, hydrocyanic acid, sulfurous acid, nitrous acid, citric acid, lactic acid, tartaric acid, malic acid, metatartaric acid, oxalic acid, fumaric acid solution.

[0088] In some embodiments, in step S2-1, the addition amount of the nano-hollow silica is 0.15-0.20 g, and the temperature is 50-70 °C.

[0089] In some embodiments, in step S2-2, the reaction temperature of the mixed solution is 50-80 °C, and the reaction time is 4-5 h.

[0090] In some embodiments, in step S3, the organic solvent is one or more of methanol, ethanol, acetone, chloroform, dichloromethane, dimethyl sulfoxide, N-N dimethylformamide.

[0091] In some embodiments, in step S3, the pesticide active substance is one or more of insecticides, fungicides, herbicides, plant growth regulators and antidotes.

[0092] Example 1

[0093] A nano-intelligent abamectin sustained-release material and a preparation method for its aqueous dispersion controlled-release preparation, comprising the following steps:

[0094] Step 1: Prepare nano-hollow silica by the hard template method

[0095] First, add the nano calcium carbonate filter cake to deionized water, stir and disperse it on a high-speed mixer for 30 minutes, and measure 800mL of 6wt% calcium carbonate suspension. According to the mass ratio of silica to calcium carbonate of 30wt%, accurately prepare a sodium silicate solution containing 2wt% silica, and raise the temperature of the suspension to 60°C. Add the sodium silicate solution to the calcium carbonate suspension at a uniform rate within 2 hours to react, and adjust the pH value to 10-11 with 10wt% hydrochloric acid. After the addition is completed, age for 1-10 hours, and after the addition is completed, age for 2 hours. Cool the reaction solution, filter it with suction, and then dry it at a temperature of 100-110°C for 12 hours to obtain CaCO3@SiO2 composite particles. Then dissolve it with dilute hydrochloric acid (pH less than 1) for 10 hours, filter, wash, and dry to obtain nano hollow silica. Figure 1 This is the transmission electron microscopy image of the inorganic template calcium carbonate used, with a particle size of 70nm; Figure 2 This is a transmission electron microscope image of nano hollow silica, with a particle size of 80-100nm; Figure 3 is the adsorption-desorption isotherm curve of nano hollow silica; Figure 4 is the pore size distribution curve of nano hollow silica;

[0096] Step 2: Modification and preparation of environmentally responsive nano hollow silica

[0097] Before grafting the polymer, the surface of the nano hollow silica needs to be functionalized: To functionalize the surface of the nano hollow silica: add ethanol (26.6 mL), deionized water (6.6 mL), vinyl triethoxysilane (1.76 mL) and nano hollow silica (0.1 g), 25% ammonia water (0.04 mL) into a three-necked flask, raise the temperature of the above mixed solution to 40-70°C and stir well for 2 hours, centrifuge, wash and dry to obtain surface functionalized nano hollow silica. Grafted environmentally responsive polymer: Add deionized water (90 mL), potassium persulfate (0.54 g), n-isopropylacrylamide (0.732 g), acrylic acid (0.27 g), sodium dodecyl sulfate (0.145 g) and the above-mentioned surface functionalized nano hollow silica (0.1 g) to a three-necked flask, and perform free radical precipitation polymerization under a nitrogen atmosphere, raise the temperature of the above-mentioned mixed solution to 50-90°C, and the reaction time is 4-6 h. Centrifuge, wash, and dry to obtain a nano smart pesticide slow-release material, i.e., poly(N-isopropylacrylamide-b-acrylic acid) grafted environmentally responsive nano hollow silica;

[0098] Step 3: Loading pesticide active substances by solvent evaporation

[0099] First, weigh 1.0 g of the pesticidal active substance abamectin and dissolve it in 50 mL of acetone. Weigh 1.0 g of the environmentally responsive nano-hollow silica synthesized in the second step and add them to a round-bottom flask simultaneously. Then, ultrasonically treat the suspension in a water bath for 0.5 h, and evaporate the solvent in a rotary evaporator. The water bath temperature is set at 40 °C. The initial pressure is set at 480 mbar, and then it is gradually reduced by 100 mbar every 0.5 h until the pressure drops to 20 mbar, and then it is maintained at the final pressure for 1 h. Use a spatula to take out the environmentally responsive nano-hollow silica pesticide sustained-release agent from the flask to obtain the nano-intelligent abamectin sustained-release material;

[0100] Determine the encapsulation efficiency of the nano-intelligent abamectin sustained-release material. The determination method is carried out by thermogravimetric method. The specific operation is as follows: use a thermogravimetric analyzer (Waters Discovery TGA5500, USA). The determination conditions are: the heating rate is 10 °C / min, the heating range is 30 - 800 °C, and air is used as the protective gas. The weight loss rate is the encapsulation efficiency of the pesticide. The pesticide encapsulation efficiency is calculated according to the following formula:

[0101] Pesticide encapsulation efficiency = amount of pesticide in the sustained-release agent / total mass of the sustained-release agent × 100% Equation (1)

[0102] Finally, according to Equation (1), the drug loading rate is measured to be 47.93%, Figure 5 which is the thermogravimetric curve of the environmentally responsive nano-hollow silica abamectin sustained-release agent.

[0103] To study the environmentally responsive release of abamectin, place 0.05 g of the nano-hollow silica pesticide sustained-release agent in a methanol-water (v / v 30:70) mixture at different temperatures and pH values for 14 days. Take 1.0 mL of the sample from the flask at different time intervals for high-performance liquid chromatography detection, and make up the taken 1.0 mL of the sustained-release solution with a methanol-water (v / v 30:70) mixture. Calculate the cumulative release rate of abamectin according to the following formula:

[0104] Pesticide cumulative release rate = pesticide content in the sustained-release solution / pesticide input amount × 100% Equation (2)

[0105] Finally, it is found that after incubation for 14 days at 28 °C, pH 7.4, 28 °C, pH 5.5, 34 °C, pH 7, and 34 °C, pH 5.5, the cumulative release amounts of abamectin measured according to Equation (2) reach 20.01%, 45.24%, 46.3%, and 73.34% respectively, Figure 6 which is the release curve of the environmentally responsive nano-hollow silica abamectin sustained-release agent;

[0106] Step 4: Prepare the nano-intelligent abamectin aqueous dispersion controlled-release preparation

[0107] Disperse the environmentally responsive nano-hollow silica pesticide sustained-release agent obtained in the above step 3 in water under high-speed stirring to obtain a nano-intelligent abamectin aqueous dispersion controlled-release preparation. Figure 7 It is the aqueous dispersion photo of the nano-intelligent abamectin aqueous dispersion controlled-release preparation;

[0108] Field efficacy test of the nano-intelligent abamectin aqueous dispersion controlled-release preparation of the present invention:

[0109] Carry out a field efficacy test of the nano-intelligent abamectin aqueous dispersion controlled-release preparation in high-value cash crops such as citrus, and compare the efficacy with that of a commercial emulsifiable concentrate formulation. Compared with the commercial emulsifiable concentrate sustained-release agent, the usage amount of the original drug is reduced by 1 / 3, and the effective period is extended by 30%. Figure 8 It is the field control effect diagram of the nano-intelligent abamectin aqueous dispersion controlled-release preparation and the commercial emulsifiable concentrate formulation.

[0110] Example 2

[0111] A preparation method of a nano-intelligent deltamethrinamide sustained-release material and its aqueous dispersion controlled-release preparation

[0112] Repeat Example 1: The only difference is that in steps 3, 4 and 5, the pesticide active substance is changed from abamectin to deltamethrinamide, and a nano-intelligent deltamethrinamide sustained-release material and its aqueous dispersion controlled-release preparation are obtained. Finally, it is found that the drug loading rate is 46.78%. After incubation for 14 days at 28 °C, pH 7.4, 28 °C, pH 5.5, 34 °C, pH 7, and 34 °C, pH 5.5, the cumulative release amounts of deltamethrinamide reach 20.32%, 47.16%, 48.21% and 75.33% respectively. Figure 9 It is the field control effect diagram of the nano-intelligent deltamethrinamide aqueous dispersion controlled-release preparation and the commercial emulsifiable concentrate formulation.

[0113] Example 3

[0114] A preparation method of a nano-intelligent fluthiacet-methyl sustained-release material and its aqueous dispersion controlled-release preparation

[0115] Repeat Example 1: The only difference is that in steps 3 and 4, the pesticide active substance is changed from abamectin to fluthiacet-methyl, and a nano-intelligent fluthiacet-methyl sustained-release material and its aqueous dispersion controlled-release preparation are obtained. Finally, it is found that the drug loading rate is 49.78%. After incubation for 14 days at 28 °C, pH 7.4, 28 °C, pH 5.5, 34 °C, pH 7, and 34 °C, pH 5.5, the cumulative release amounts of fluthiacet-methyl reach 20.25%, 49.26%, 50.33% and 79.20% respectively.

[0116] Example 4

[0117] Preparation method of a nano-intelligent metazachlor sustained-release material and its aqueous dispersion controlled-release preparation

[0118] Repeat Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance was changed from avermectin to metazachlor, obtaining a nano-intelligent metazachlor sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it was found that the drug loading rate was 45.22%. After incubation at 28 °C, pH 7.4, 28 °C, pH 5.5, 34 °C, pH 7, and 34 °C, pH 5.5 for 14 days, the cumulative release amounts of metazachlor reached 20.39%, 47.27%, 48.01%, and 77.18% respectively.

[0119] Example 5

[0120] Preparation method of a nano-intelligent sulcotrione sustained-release material and its aqueous dispersion controlled-release preparation

[0121] Repeat Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance was changed from avermectin to sulcotrione, obtaining a nano-intelligent sulcotrione sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it was found that the drug loading rate was 46.71%. After incubation at 28 °C, pH 7.4, 28 °C, pH 5.5, 34 °C, pH 7, and 34 °C, pH 5.5 for 14 days, the cumulative release amounts of sulcotrione reached 20.43%, 47.39%, 48.66%, and 74.22% respectively.

[0122] Example 6

[0123] Preparation method of a nano-intelligent azoxystrobin sustained-release material and its aqueous dispersion controlled-release preparation

[0124] Repeat Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance was changed from avermectin to azoxystrobin, obtaining a nano-intelligent azoxystrobin sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it was found that the drug loading rate was 44.29%. After incubation at 28 °C, pH 7.4, 28 °C, pH 5.5, 34 °C, pH 7, and 34 °C, pH 5.5 for 14 days, the cumulative release amounts of azoxystrobin reached 21.37%, 48.48%, 49.27%, and 76.13% respectively.

[0125] Example 7

[0126] Preparation method of a nano-intelligent azoxystrobin sustained-release material and its aqueous dispersion controlled-release preparation

[0127] Repeated Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance was changed from abamectin to tebuconazole, obtaining a nano-intelligent azoxystrobin sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it was found that the drug loading rate was 48.36%. After incubation at 28 °C, pH 7.4, 28 °C, pH 5.5, 34 °C, pH 7, and 34 °C, pH 5.5 for 14 days, the cumulative release amounts of tebuconazole reached 21.41%, 44.21%, 45.42%, and 72.17% respectively.

[0128] Example 8

[0129] Preparation method of a nano-intelligent bifenthrin sustained-release material and its aqueous dispersion controlled-release preparation

[0130] Repeated Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance was changed from abamectin to bifenthrin, obtaining a nano-intelligent bifenthrin sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it was found that the drug loading rate was 47.21%. After incubation at 28 °C, pH 7.4, 28 °C, pH 5.5, 34 °C, pH 7, and 34 °C, pH 5.5 for 14 days, the cumulative release amounts of bifenthrin reached 21.26%, 42.43%, 43.34%, and 75.44% respectively.

[0131] Example 9

[0132] Preparation method of a nano-intelligent cypermethrin sustained-release material and its aqueous dispersion controlled-release preparation

[0133] Repeated Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance was changed from abamectin to cypermethrin, obtaining a nano-intelligent cypermethrin sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it was found that the drug loading rate was 47.38%. After incubation at 28 °C, pH 7.4, 28 °C, pH 5.5, 34 °C, pH 7, and 34 °C, pH 5.5 for 14 days, the cumulative release amounts of cypermethrin reached 20.07%, 43.45%, 44.54%, and 74.32% respectively.

[0134] Example 10

[0135] Preparation method of a nano-intelligent etoxazole sustained-release material and its aqueous dispersion controlled-release preparation

[0136] Repeated Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance is changed from abamectin to etoxazole, obtaining a nano-intelligent etoxazole sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it is found that the drug loading rate is 48.10%. After incubation for 14 days at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5, the cumulative release amounts of etoxazole reach 22.63%, 40.19%, 41.22%, and 70.13% respectively.

[0137] Example 11

[0138] Preparation method of a nano-intelligent lufenuron sustained-release material and its aqueous dispersion controlled-release preparation

[0139] Repeated Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance is changed from abamectin to lufenuron, obtaining a nano-intelligent lufenuron sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it is found that the drug loading rate is 46.21%. After incubation for 14 days at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5, the cumulative release amounts of lufenuron reach 22.27%, 41.26%, 43.66%, and 71.61% respectively.

[0140] Example 12

[0141] Preparation method of a nano-intelligent flonicamid sustained-release material and its aqueous dispersion controlled-release preparation

[0142] Repeated Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance is changed from abamectin to flonicamid, obtaining a nano-intelligent flonicamid sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it is found that the drug loading rate is 45.09%. After incubation for 14 days at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5, the cumulative release amounts of flonicamid reach 22.49%, 42.18%, 44.22%, and 73.32% respectively.

[0143] Example 13

[0144] Preparation method of a nano-intelligent buprofezin sustained-release material and its aqueous dispersion controlled-release preparation

[0145] Repeated Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance is changed from abamectin to buprofezin, obtaining a nano-intelligent buprofezin sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it is found that the drug loading rate is 45.16%. After incubation for 14 days at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5, the cumulative release amounts of buprofezin reach 22.23%, 42.24%, 43.07%, and 76.22% respectively.

[0146] Example 14

[0147] Preparation method of a nano-intelligent fipronil sustained-release material and its aqueous dispersion controlled-release preparation

[0148] Repeated Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance is changed from abamectin to fipronil, obtaining a nano-intelligent fipronil sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it is found that the drug loading rate is 45.69%. After incubation for 14 days at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5, the cumulative release amounts of fipronil reach 22.34%, 43.06%, 44.98%, and 75.32% respectively.

[0149] Example 15

[0150] Preparation method of a nano-intelligent methoxyfenozide sustained-release material and its aqueous dispersion controlled-release preparation

[0151] Repeated Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance is changed from abamectin to methoxyfenozide, obtaining a nano-intelligent methoxyfenozide sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it is found that the drug loading rate is 45.20%. After incubation for 14 days at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5, the cumulative release amounts of methoxyfenozide reach 20.16%, 44.16%, 45.62%, and 73.96% respectively.

[0152] Example 16

[0153] Preparation method of a nano-intelligent dinotefuran sustained-release material and its aqueous dispersion controlled-release preparation

[0154] Repeat of Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance is changed from abamectin to dinotefuran, obtaining a nano-intelligent dinotefuran sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it is found that the drug loading rate is 47.84%. After incubation for 14 days at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5, the cumulative release amounts of dinotefuran reach 23.22%, 49.28%, 50.22%, and 77.01% respectively.

[0155] Example 17

[0156] Preparation method of a nano-intelligent emamectin benzoate sustained-release material and its aqueous dispersion controlled-release preparation

[0157] Repeat of Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance is changed from abamectin to emamectin benzoate, obtaining a nano-intelligent emamectin benzoate sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it is found that the drug loading rate is 46.48%. After incubation for 14 days at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5, the cumulative release amounts of emamectin benzoate reach 24.16%, 48.47%, 50.12%, and 78.43% respectively.

[0158] Example 18

[0159] Preparation method of a nano-intelligent fosthiazate sustained-release material and its aqueous dispersion controlled-release preparation

[0160] Repeat of Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance is changed from abamectin to fosthiazate, obtaining a nano-intelligent fosthiazate sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it is found that the drug loading rate is 46.23%. After incubation for 14 days at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5, the cumulative release amounts of fosthiazate reach 26.68%, 45.01%, 46.45%, and 76.29% respectively.

[0161] Example 19

[0162] Preparation method of a nano-intelligent indoxacarb sustained-release material and its aqueous dispersion controlled-release preparation

[0163] Repeat Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance is changed from abamectin to indoxacarb, resulting in a nano-intelligent indoxacarb sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it is found that the drug loading rate is 47.09%. After incubation for 14 days at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5, the cumulative release amounts of indoxacarb reach 25.47%, 48.21%, 49.19%, and 70.83% respectively.

[0164] Example 20

[0165] Preparation method of a nano-intelligent hexaflumuron sustained-release material and its aqueous dispersion controlled-release preparation

[0166] Repeat Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance is changed from abamectin to hexaflumuron, resulting in a nano-intelligent hexaflumuron sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it is found that the drug loading rate is 47.29%. After incubation for 14 days at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5, the cumulative release amounts of hexaflumuron reach 23.13%, 46.52%, 48.04%, and 76.33% respectively.

[0167] Example 21

[0168] A nano-intelligent bifenazate sustained-release material and its aqueous dispersion controlled-release preparation

[0169] Repeat Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance is changed from abamectin to bifenazate, resulting in a nano-intelligent bifenazate sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it is found that the drug loading rate is 43.19%. After incubation for 14 days at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5, the cumulative release amounts of bifenazate reach 24.01%, 44.03%, 45.21%, and 71.29% respectively.

[0170] Example 22

[0171] Preparation method of a nano-intelligent chlorfenapyr sustained-release material and its aqueous dispersion controlled-release preparation

[0172] Repeated Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance was changed from abamectin to chlorfenapyr, obtaining a nano-intelligent chlorfenapyr sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it was found that the drug loading rate was 42.43%. After incubation at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5 for 14 days, the cumulative release amounts of chlorfenapyr reached 23.77%, 44.16%, 45.03%, and 73.99%, respectively.

[0173] Example 23

[0174] Preparation method of a nano-intelligent chlorfluazuron sustained-release material and its aqueous dispersion controlled-release preparation

[0175] Repeated Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance was changed from abamectin to chlorfluazuron, obtaining a nano-intelligent chlorfluazuron sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it was found that the drug loading rate was 47.07%. After incubation at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5 for 14 days, the cumulative release amounts of chlorfluazuron reached 25.13%, 43.44%, 45.09%, and 70.31%, respectively.

[0176] Example 24

[0177] Preparation method of a nano-intelligent epoxiconazole sustained-release material and its aqueous dispersion controlled-release preparation

[0178] Repeated Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance was changed from abamectin to epoxiconazole, obtaining a nano-intelligent epoxiconazole sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it was found that the drug loading rate was 46.27%. After incubation at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5 for 14 days, the cumulative release amounts of epoxiconazole reached 25.69%, 41.57%, 42.61%, and 73.22%, respectively.

[0179] Example 25

[0180] Preparation method of a nano-intelligent pyraclostrobin sustained-release material and its aqueous dispersion controlled-release preparation

[0181] Repeated Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance was changed from abamectin to pyraclostrobin, resulting in a nano-intelligent pyraclostrobin sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it was found that the drug loading rate was 45.98%. After incubation for 14 days at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5, the cumulative release amounts of pyraclostrobin reached 24.52%, 41.42%, 42.17%, and 78.19% respectively.

[0182] Example 26

[0183] Preparation method of a nano-intelligent kresoxim-methyl sustained-release material and its aqueous dispersion controlled-release preparation

[0184] Repeated Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance was changed from abamectin to kresoxim-methyl, resulting in a nano-intelligent kresoxim-methyl sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it was found that the drug loading rate was 47.89%. After incubation for 14 days at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5, the cumulative release amounts of kresoxim-methyl reached 24.68%, 45.49%, 47.51%, and 72.11% respectively.

[0185] Example 27

[0186] Preparation method of a nano-intelligent flusilazole sustained-release material and its aqueous dispersion controlled-release preparation

[0187] Repeated Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance was changed from abamectin to flusilazole, resulting in a flusilazole sustained-release agent including nano-hollow silica materials. Finally, it was found that the drug loading rate was 47.63%. After incubation for 14 days at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5, the cumulative release amounts of flusilazole reached 25.38%, 44.41%, 46.02%, and 74.19% respectively.

[0188] Example 28

[0189] Preparation method of a nano-intelligent trifloxystrobin sustained-release material and its aqueous dispersion controlled-release preparation

[0190] Repeated Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance is changed from abamectin to trifloxystrobin, obtaining a nano-intelligent trifloxystrobin sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it is found that the drug loading rate is 44.14%. After incubation for 14 days at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5, the cumulative release amounts of trifloxystrobin reach 20.37%, 40.13%, 42.11%, and 75.17% respectively.

[0191] Example 29

[0192] Preparation method of a nano-intelligent boscalid sustained-release material and its aqueous dispersion controlled-release preparation

[0193] Repeated Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance is changed from abamectin to boscalid, obtaining a nano-intelligent boscalid sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it is found that the drug loading rate is 44.01%. After incubation for 14 days at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5, the cumulative release amounts of boscalid reach 20.77%, 50.84%, 52.06%, and 74.29% respectively.

[0194] Example 30

[0195] Preparation method of a nano-intelligent cloquintocet-mexyl sustained-release material and its aqueous dispersion controlled-release preparation

[0196] Repeated Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance is changed from abamectin to cloquintocet-mexyl, obtaining a nano-intelligent cloquintocet-mexyl sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it is found that the drug loading rate is 45.03%. After incubation for 14 days at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5, the cumulative release amounts of cloquintocet-mexyl reach 20.22%, 50.34%, 52.12%, and 79.10% respectively.

[0197] Example 31

[0198] Preparation method of a nano-intelligent cloquinate sustained-release material and its aqueous dispersion controlled-release preparation

[0199] Repeated Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance is changed from abamectin to cloquintocet-mexyl, obtaining a nano-intelligent cloquintocet-mexyl sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it is found that the drug loading rate is 45.12%. After incubation for 14 days at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5, the cumulative release amounts of cloquintocet-mexyl reach 29.14%, 44.17%, 45.66%, and 79.08% respectively.

[0200] Example 32

[0201] Preparation method of a nano-intelligent clomazone sustained-release material and its aqueous dispersion controlled-release preparation

[0202] Repeated Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance is changed from abamectin to clomazone, obtaining a nano-intelligent clomazone sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it is found that the drug loading rate is 49.03%. After incubation for 14 days at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5, the cumulative release amounts of clomazone reach 19.17%, 50.23%, 51.77%, and 70.75% respectively.

[0203] Example 33

[0204] Preparation method of a nano-intelligent trinexapac-ethyl sustained-release material and its aqueous dispersion controlled-release preparation

[0205] Repeated Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance is changed from abamectin to trinexapac-ethyl, obtaining a nano-intelligent trinexapac-ethyl sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it is found that the drug loading rate is 46.34%. After incubation for 14 days at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5, the cumulative release amounts of trinexapac-ethyl reach 20.09%, 40.14%, 41.39%, and 78.46% respectively.

[0206] Example 33

[0207] Preparation method of a nano-intelligent fenclorim sustained-release material and its aqueous dispersion controlled-release preparation

[0208] Repeated Example 1: The only difference is that in Steps 3, 4, and 5, the pesticidal active substance is changed from abamectin to fenclorim, obtaining a nano-intelligent fenclorim sustained-release material and its aqueous dispersion controlled-release preparation. Finally, it is found that the drug loading rate is 45.43%. After incubation for 14 days at 28°C, pH 7.4, 28°C, pH 5.5, 34°C, pH 7, and 34°C, pH 5.5, the cumulative release amounts of fenclorim reach 20.19%, 50.41%, 50.33%, and 68.88% respectively.

[0209] Comparative Example 1

[0210] The sustained-release effect was measured by the same test method as in Example 1, and the following test results were obtained:

[0211] Li Zhuzhu from Beijing University of Chemical Technology used hollow nano-silica to load avermectin, with a pore diameter of 4 nm and a slow-release time of less than two days (L-X Wen, Z-Z Li, H-K Zou, et al. Controlled release of avermectin from porous hollow silica nanoparticles[J]. Pest Management Science, 2005, 61(6):583.), and the temperature and pH stimulus responses were not obvious. Zhao Jinhao from the Institute of Pesticide and Environmental Toxicology of Zhejiang University used porous calcium carbonate coated with metal-polyphenol film as a carrier to load prochloraz, and the slow-release time was less than 5 days (Xiao D, Cheng J, Liang W, et al. Metal-phenolic coated and prochloraz-loaded calcium carbonate carriers with pH responsiveness for environmentally-safe fungicide delivery[J]. Chemical Engineering Journal, 2021(6147):129274.). Huang Qiliang from the Institute of Plant Protection, Chinese Academy of Agricultural Sciences prepared mesoporous silica chelated with copper ions and dopamine to load azoxystrobin, with a loading rate of 17.22% and a slow-release time of less than 3 days (Xu C, Y Shan, Bilal M, et al. Copper Ions Chelated Mesoporous Silica Nanoparticles via Dopamine Chemistry for Controlled Pesticide Release Regulated by Coordination Bonding[J]. Chemical Engineering Journal, 2020, 395:125093.).

[0212] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly explaining the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or variations can be made on the basis of the above description. It is impossible to list all the implementation manners here. Any obvious changes or variations derived from the technical solutions of the present invention still fall within the protection scope of the present invention.

Claims

1. A preparation method of an environment-responsive nano-hollow silica pesticide slow-release agent, characterized in that, It includes the following steps: S1. Prepare nano-hollow silica by the hard template method S1-1. Add nano-calcium carbonate filter cake into deionized water, stir and disperse it on a high-speed stirrer for 30 - 120 min to prepare a nano-calcium carbonate suspension with a concentration of 6 - 50 wt%. S1-2. Measure the nano-calcium carbonate suspension, accurately prepare a sodium silicate solution with a silica concentration of 2 - 50 wt%, and according to the mass ratio of silica / calcium carbonate of 0.02 - 0.4; raise the temperature of the nano-calcium carbonate suspension to 30 - 90 °C, and add the sodium silicate solution into the nano-calcium carbonate suspension at a uniform speed within 2 - 3 h for reaction. At the same time, adjust and maintain the pH value within a certain range with organic acids or inorganic acids with a concentration of 1 - 10 wt%. After feeding, age for 1 - 10 h. S1-3. Cool the reaction solution, filter, wash, and dry it to obtain CaCO3@SiO2 composite particles, and the drying temperature is 40 - 200 °C. S1-4. Place the CaCO3@SiO2 composite particles in a solution of organic acid or inorganic acid, stir slowly for 1 - 50 h, remove nano-calcium carbonate, filter and dry to obtain nano-hollow silica, and the drying temperature is 40 - 200 °C. S2. Modify to prepare environment-responsive nano-hollow silica S2-1. Functionalize the surface of nano-hollow silica: Add 26 - 27 mL of ethanol, 5 - 7 mL of deionized water, 1.7 - 1.8 mL of vinyltriethoxysilane, 0.1 - 0.25 g of nano-hollow silica, and 0.03 - 0.05 mL of 25 wt% ammonia water into the reactor to obtain a mixed solution. Raise the temperature of the above mixed solution to 40 - 70 °C and stir fully for 1 - 3 h, then centrifuge, wash, and dry to obtain surface-functionalized nano-hollow silica. S2-2. Graft environment-responsive polymer Add 85 - 95 mL of deionized water, 0.52 - 0.56 g of potassium persulfate, 0.7 - 0.75 g of N-isopropylacrylamide, 0.25 - 0.30 g of acrylic acid, 0.14 - 0.15 g of sodium dodecyl sulfate, and 0.1 - 0.3 g of the functionalized nano-hollow silica obtained in step S2-1 into the reactor. Under a nitrogen atmosphere, raise the temperature of the above mixed solution to 50 - 90 °C, and the reaction time is 4 - 6 h for free radical precipitation polymerization; centrifuge, wash, and dry to obtain a nano-intelligent pesticide slow-release material, that is, environment-responsive nano-hollow silica grafted with poly(N-isopropylacrylamide-b-acrylic acid). S3. Load pesticide active substances by the solvent evaporation method Loading method: Add the poly(N-isopropylacrylamide-b-acrylic acid) grafted environment-responsive nano-hollow silica obtained in step S2-2 and pesticide active substances into the flask, and then add organic solvents or water. Under reduced pressure, obtain a poly(N-isopropylacrylamide-b-acrylic acid) grafted environment-responsive nano-hollow silica pesticide slow-release agent.

2. A preparation method of a water-dispersible controlled-release preparation of an environment-responsive nano-hollow silica pesticide slow-release agent, including all steps in the preparation method of the environment-responsive nano-hollow silica pesticide slow-release agent described in claim 1, characterized in that: It also includes the following steps: S4. Prepare a nano-intelligent pesticide aqueous dispersion controlled-release preparation The environmentally responsive nano-hollow silica pesticide sustained-release agent grafted with poly(N-isopropylacrylamide-b-acrylic acid) is dispersed in water under high-speed stirring to obtain a nano-intelligent pesticide aqueous dispersion controlled-release preparation.

3. According to the preparation method of the environment-responsive nano-hollow silica pesticide slow-release agent described in claim 1, characterized in that: In step S1-1, the particle size of the nano-calcium carbonate is 70 nm.

4. According to the preparation method of the environment-responsive nano-hollow silica pesticide slow-release agent described in claim 1, characterized in that: In step S1-1, the concentration of the nano-calcium carbonate is 6-40 wt%.

5. According to the preparation method of the environment-responsive nano-hollow silica pesticide slow-release agent described in claim 1, characterized in that: In step S1-2, the mass ratio of silica to nano-calcium carbonate is 0.05-0.

4.

6. According to the preparation method of the environment-responsive nano-hollow silica pesticide slow-release agent described in claim 1, characterized in that: In step S1-2, the temperature of the nano-calcium carbonate suspension is raised to 35-85 °C.

7. According to the preparation method of the environment-responsive nano-hollow silica pesticide slow-release agent described in claim 1, characterized in that: In step S1-2, the concentration of silica in the sodium silicate solution is 2-40 wt%.

8. According to the preparation method of the environment-responsive nano-hollow silica pesticide slow-release agent described in claim 1, characterized in that: In step S1-2, the organic acid or inorganic acid solution is one or more of hydrochloric acid, sulfuric acid, nitric acid, acetic acid, selenic acid, phosphoric acid, perchloric acid, hydrofluoric acid, hydrobromic acid, hydroiodic acid, hydrocyanic acid, sulfurous acid, nitrous acid, citric acid, lactic acid, tartaric acid, malic acid, metatartaric acid, oxalic acid, fumaric acid solutions.

9. According to the preparation method of the environment-responsive nano-hollow silica pesticide slow-release agent described in claim 1, characterized in that: In step S1-2, the pH value is controlled at 8-13.

10. The preparation method of the environment-responsive nano-hollow silica pesticide slow-release agent according to claim 1, characterized in that: In step S1-2, the aging time is 1-6 h.

11. The preparation method of the environment-responsive nano-hollow silica pesticide slow-release agent according to claim 1, characterized in that: In step S1-4, the stirring time is 1-40 h.

12. The preparation method of the environment-responsive nano-hollow silica pesticide slow-release agent according to claim 1, characterized in that: In step S1-4, the organic acid or inorganic acid solution is one or more of hydrochloric acid, sulfuric acid, nitric acid, acetic acid, selenic acid, phosphoric acid, perchloric acid, hydrofluoric acid, hydrobromic acid, hydroiodic acid, hydrocyanic acid, sulfurous acid, nitrous acid, citric acid, lactic acid, tartaric acid, malic acid, metatartaric acid, oxalic acid, fumaric acid solutions.

13. The preparation method of the environment-responsive nano-hollow silica pesticide slow-release agent according to claim 1, characterized in that: In step S2-1, the addition amount of the nano-hollow silica is 0.15-0.20 g, and the temperature is 50-70 °C.

14. The preparation method of the environment-responsive nano-hollow silica pesticide slow-release agent according to claim 1, characterized in that: In step S2-2, the reaction temperature of the mixed solution is 50-80 °C, and the reaction time is 4-5 h.

15. The preparation method of the environment-responsive nano-hollow silica pesticide slow-release agent according to claim 1, characterized in that: In step S3, the organic solvent is one or more of methanol, ethanol, acetone, chloroform, dichloromethane, dimethyl sulfoxide, N-N dimethylformamide.

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