WO2024153171A1

WO2024153171A1 - Pesticide emulsion having liquid crystal structure, preparation method therefor and use thereof

Info

Publication number: WO2024153171A1
Application number: PCT/CN2024/072966
Authority: WO
Inventors: 贾鑫; 李萌; 张倩; 尚亚卓; 许世武; 高波; 孟凡成; 闫博; 李丹亚; 熊有鹏
Original assignee: 石河子大学; 华东理工大学; 沃达农业科技股份有限公司
Priority date: 2023-01-19
Filing date: 2024-01-18
Publication date: 2024-07-25
Also published as: CN118355902A

Abstract

The present invention relates to a pesticide emulsion having a liquid crystal structure, a preparation method therefor and a use thereof. The emulsion comprises a pesticide active ingredient and a liquid crystal emulsifier. According to the present invention, by constructing an "onion-like" layered structure of an oil layer/liquid crystal layer/water layer (O/LC/W), the pesticide is limited and solubilized between the water layer and the oil layer, and the drug loading ratio is approximately 100%. The liquid crystal pesticide emulsion of the present invention involves a simple and green preparation process, can be prepared on a large scale, and is adapted to various pesticides; the pesticide emulsion is superior to similar traditional water dispersible pesticide formulations in terms of dispersion stability, target deposition efficiency and the like, and is particularly suitable for use in the actual complex environment.

Description

A pesticide emulsion with liquid crystal structure and its preparation method and application

The present invention claims the priority of a prior application with patent number 202310058633.7, entitled “A pesticide emulsion with a liquid crystal structure, its preparation method and application”, filed with the State Intellectual Property Office of China on January 19, 2023. The entire text of the prior application is incorporated into the present invention by reference.

Technical Field

The invention belongs to the field of pesticide formulations, and in particular relates to a pesticide emulsion with a liquid crystal structure and a preparation method and application thereof.

Background technique

As an important agricultural production material, pesticides have made great contributions to reducing crop losses and ensuring food security. However, their unscientific and unsafe use has brought many negative impacts on agricultural sustainable development, agricultural modernization, and even human health, such as water pollution, ecological damage, and food safety issues, which have become prominent issues restricting the sustainable and stable development of my country's agriculture. In addition, the long-term use of pesticides presents the problem of high quantity and low efficiency, which not only leads to enhanced resistance of pests and diseases, but also destroys the ecological structure of the soil, thus affecting the yield of crops. Therefore, it is imperative to continuously improve the level of scientific and technological innovation, promote the integrated development of technical and preparation, and achieve the "reduction in application and increase in efficiency" of pesticides, and study safe and environmentally friendly pesticide formulations.

Most pesticide technicals are compounds that are insoluble or slightly soluble in water, and solvents and adjuvants need to be added to promote their dispersion in water. Water dispersants, which are a mixture of a certain proportion of technical and adjuvants, are currently the main formulation in my country's pesticide market because they are easy to measure, easy to manufacture, and have mature processes. They account for about 60% of the total. Such formulations include wettable powder (WP), water-dispersible granules (WG), suspension concentrates (SC), and emulsions in water (EW). Among them, emulsions (EW) are dust-free, with less organic solvent added, and can reduce instability phenomena such as Ostwald ripening, agglomeration, flocculation, and stratification by adding emulsifiers. It is a formulation with better performance. However, emulsions only account for 5%. The reason for this is that in addition to the problem of process scale-up, the most critical problem is the lack of high-performance emulsifiers. At present, commercial pesticide emulsifiers are mainly anionic and non-ionic surfactants, such as calcium alkylbenzene sulfonate (500#), castor oil/alkylphenol polyoxyethylene ether (EL, BY, NP series), which improve the wetting and spreading properties of fat-soluble pesticides to improve the efficacy, but still cannot meet the actual use needs of pesticides in complex environments. The problems of this type of pesticide dispersant are as follows: the pesticide components are easily ineffective due to interaction with surfactants and adjuvants; they are very easy to break the emulsion and aggregate and precipitate under conditions of dilution, acid and alkali, high salt concentration, etc.; the adhesion and sustained release properties on the leaves are poor, and the utilization rate of pesticides is low due to environmental factors such as leaching, bouncing, and light decomposition; and the waste of resources and environmental pollution caused by the large-scale use of pesticides, surfactants and adjuvants has become a serious social problem that threatens human health. Therefore, it is urgent to develop new pesticide emulsions that do not require adjuvants, are environmentally friendly, and have high stability in complex environments.

Summary of the invention

In order to improve the defects of the above-mentioned prior art, the purpose of the present invention is to provide a pesticide emulsion with a liquid crystal structure and a preparation method and application thereof.

The purpose of the present invention is achieved through the following technical solutions:

A liquid crystal structured pesticide emulsion contains a fat-soluble pesticide and a liquid crystal emulsifier.

According to an embodiment of the present invention, the pesticide emulsion contains a fat-soluble pesticide, a liquid crystal emulsifier, oil, a thickener, an organic solvent and water.

According to an embodiment of the present invention, the fat-soluble pesticide can be a fat-soluble pesticide technical or a pesticide formulation, and the formulation is, for example, a suspension, a wettable powder, a dust, a granule, an emulsifiable concentrate, an aqueous solution, and the like.

According to an embodiment of the present invention, the fat-soluble pesticide is, for example, one or more of thiadipyridamole, thiadipyridamole, diuron, ostiamycin, abscisic acid, ethephon, indolebutyric acid, cypermethrin, thiamethoxam, etc. In some embodiments, the fat-soluble pesticide is thiadipyridamole, thiadipyridamole, and diuron. The mass fraction of the fat-soluble pesticide in the pesticide emulsion can be 0.5%-20%, for example, 1%-15% or 1%-10%, and specifically 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%.

According to an embodiment of the present invention, the liquid crystal emulsifier may be selected from one or more of alkyl glycosides, phosphates, lecithins, sucrose esters, stearoyls, and olive esters. For example, it is a lecithin emulsifier, such as a lecithin liquid crystal emulsifier; the mass fraction of the emulsifier may be 1%-10%, 2%-9%, and specifically 3%, 4%, 5%, 6%, 7%, and 8%.

According to the embodiment of the present invention, the thickener can be selected from one or more of pectin, xanthan gum, carboxymethyl cellulose, starch, agar, alginic acid and sodium lignin sulfonate; for example, carboxymethyl cellulose; the mass fraction of the thickener can be 0.1%-5%, 0.5%-4%, specifically 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3% and the like.

According to the embodiment of the present invention, the oil is preferably a liquid oil. The liquid oil can be a vegetable oil, an animal oil, or a synthetic oil. The vegetable oil is selected from one or more of peanut oil, soybean oil, linseed oil, castor oil, rapeseed oil, avocado oil, and coconut oil. The animal oil is selected from one or more of squalane and squalene. Synthetic oil is selected from one or more of caprylic capric triglyceride, isooctyl palmitate, isopropyl myristate, isooctyl stearate, isononyl isononanoate, dioctyl carbonate, and diisostearyl malate. The mass fraction of the liquid oil in the present invention can be 1%-20%, 2%-15% or 3%-12%, specifically 4%, 5%, 6%, 7%, 8%, 9%, 10%, and 11%.

According to the embodiment of the present invention, the organic solvent can be a polar or non-polar solvent, such as one or more of n-butanol, methanol, chloroform, anhydrous ethanol, cyclohexane, n-hexane, ether, dichloromethane, dimethyl sulfoxide, N,N-dimethylformamide; for example, dimethyl sulfoxide; the mass fraction of the organic solvent can be 0.5%-40%, 1%-35%, 2%-30%, or 3%-20%, specifically 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%.

According to the embodiment of the present invention, the mass fraction of water may be 50%-90%, for example, 60%, 65%, 70%, 75%, 80%, 85%.

According to an embodiment of the present invention, the pesticide emulsion may further contain a pH regulator; for example, one or more of sodium hydroxide, potassium hydroxide, hydrochloric acid, phosphoric acid or citric acid may be selected. In some embodiments of the present invention, the pH regulator may be sodium hydroxide and citric acid.

In some embodiments of the present invention, the pesticide emulsion contains: 0.5%-20% fat-soluble pesticide technical, 1%-10% liquid crystal emulsifier, 1%-20% oil, 0.1%-5% thickener, 1%-40% organic solvent, and 50%-90% water.

In some embodiments of the present invention, the pesticide emulsion contains: 0.5%-20% fat-soluble pesticide suspending agent, 1%-10% liquid crystal emulsifier, 1%-20% oil, 0.1%-5% thickener, 1%-40% organic solvent, and 50%-90% water.

In some embodiments of the present invention, the pesticide emulsion contains: 0.5%-20% uniconazole, 1%-10% lecithin liquid crystal emulsifier, 1%-20% oil, 0.1%-5% thickener, 1%-40% organic solvent, and 50%-90% water.

In some embodiments of the present invention, the pesticide emulsion contains: 1%-10% uniconazole, 1%-10% lecithin liquid crystal emulsifier, 1%-15% oil, 0.1%-4% thickener, 1%-40% organic solvent, and 50%-90% water.

In some embodiments of the present invention, the pesticide emulsion contains: 0.5%-20% thidiazuron-diuron, 1%-10% lecithin liquid crystal emulsifier, 1%-20% oil, 0.1%-5% thickener, 1%-40% organic solvent, and 50%-90% water.

In some embodiments of the present invention, the pesticide emulsion contains: 1%-10% thidiazuron-diuron, 1%-10% lecithin liquid crystal emulsifier, 1%-15% oil, 0.1%-4% thickener, 1%-40% organic solvent, and 50%-90% water.

According to the embodiment of the present invention, the liquid crystal pesticide emulsion has a layered structure of oil/liquid crystal/water (O/LC/W).

The present invention also provides a method for preparing the above liquid crystal structure pesticide emulsion, comprising the following steps:

1) Preparation of oil phase: mixing the liquid crystal emulsifier with the liquid oil, and heating to make the emulsifier and the liquid oil miscible;

2) Preparation of aqueous phase: mixing thickener with water;

3) Preparation of dispersed solvent phase: dissolving the fat-soluble original drug in an organic solvent, then adding liquid oil and mixing;

4) Homogenization and emulsification: Pour the oil phase and the dispersed solvent phase into the water phase and stir to obtain a pesticide emulsion.

In some embodiments of the present invention, in the above step 1), the heating temperature is 60-90°C, preferably 70-80°C.

In some embodiments of the present invention, in the above step 2), the obtained aqueous phase is heated to 60-90°C, preferably 70-80°C.

In some embodiments of the present invention, in the above step 3), the obtained dispersed solvent phase is heated to 60-90°C, preferably 70-80°C.

In some embodiments of the present invention, in the above step 4), the oil phase and the dispersed solvent phase are sequentially poured into the water phase at a temperature of 60-90° C., and high shear homogenization is performed (for example, the rotation speed is 4000-10000 r/min) to obtain an emulsion. In some embodiments, after high shear homogenization, the mixture is stirred at a low speed at 25-35° C. to cool, for example, at a rotation speed of 300-1000 r/min for 10-20 minutes to cool.

In some embodiments of the present invention, the preparation method comprises the following steps:

1) Preparation of oil phase: Add liquid crystal emulsifier to liquid oil and heat in a water bath at 70-80°C to make the liquid crystal emulsifier and liquid oil miscible;

2) Preparation of water phase: Add a certain amount of thickener to water under stirring, stir to form a uniform solution, and then place in a 70-80°C water bath and heat to the same temperature as the oil phase;

3) Preparation of dispersed solvent phase: Add fat-soluble original drug to organic solvent, ultrasonicate, then add liquid oil, further ultrasonicate to disperse and dissolve, and place in a 70-80°C water bath to keep the temperature constant with the oil phase;

4) Homogenization and emulsification: pour the oil phase and the dispersion solvent phase into the water phase in sequence at a water bath temperature of 70-80°C, and perform homogenization and dispersion at a speed in the range of 5000-8000 r/min, for example, for 3-15 minutes;

5) taking out the prepared pesticide emulsion; cooling it for 10-20 minutes with mechanical stirring at a controlled external temperature of 25-32° C. and a rotation speed of 300-800 r/min, and bottling it for storage.

1') Preparation of oil phase: mixing the liquid crystal emulsifier with the liquid oil, and heating to make the emulsifier and the liquid oil miscible;

2') Preparation of aqueous phase: Mix thickener with water;

3') Preparation of blank liquid crystal emulsion: pour the oil phase into the water phase and stir to obtain a blank liquid crystal emulsion;

4') Pesticide emulsion: The fat-soluble pesticide is mixed with a blank liquid crystal emulsion to obtain a pesticide emulsion.

In some embodiments of the present invention, in the above step 1'), the heating temperature is 60-90°C, preferably 70-80°C.

In some embodiments of the present invention, in the above step 2'), the obtained aqueous phase is heated to 60-90°C, preferably 70-80°C.

In some embodiments of the present invention, in the above step 3'), the oil phase is poured into the water phase at a temperature of 60-90°C, and high shear homogenization is performed (for example, the rotation speed is 4000-10000 r/min) to obtain an emulsion. In some embodiments, after high shear homogenization, the mixture is stirred at a low speed at 25-35°C to cool down, for example, stirred at a rotation speed of 300-800 r/min for 10-20 minutes to cool down.

In some embodiments of the present invention, in the above step 4'), the pesticide is in the form of a pesticide formulation, such as a suspension, a wettable powder, etc.

1') Preparation of oil phase: Add liquid crystal emulsifier to liquid oil and heat in a water bath at 70-80°C to make the liquid crystal emulsifier and liquid oil miscible;

2') Preparation of water phase: Add a certain amount of thickener to water under stirring, stir to form a uniform solution, and then put it into a 70-80°C water bath and heat it to a temperature substantially the same as that of the oil phase;

3') Preparation of blank liquid crystal emulsion: pour the oil phase into the water phase at a water bath temperature of 70-80°C, perform homogeneous dispersion at a speed in the range of 5000-8000 r/min, for example, for 3-15 min, and cool down;

4') Preparation of pesticide emulsion: Mix the pesticide suspension with the blank liquid crystal emulsion to obtain the pesticide emulsion.

The present invention also provides the application of the liquid crystal pesticide emulsion in crops, for example, in promoting the growth and yield of crops. The application method can be selected from drip irrigation, foliar spraying, wound application and other methods to be applied to crop planting.

Beneficial effects:

(1) The present invention adopts an "onion-like" layered liquid crystal emulsion system of oil layer/liquid crystal layer/water layer (O/LC/W) to encapsulate one or more pesticides between the oil core and the oil/water layer separated by liquid crystals, with an encapsulation rate of nearly 100%. The liquid crystal pesticide emulsion system of the present invention can be applied to different pesticide application environments, such as foliar spraying, drip irrigation and wound spraying.

(2) Compared with the pesticide water dispersants (wettable powders, suspensions, emulsions) with small molecule surfactants as adjuvants, the liquid crystal pesticide emulsion of the present invention does not require the addition of excipients, disintegrants, stabilizers and other adjuvants in the preparation process, is environmentally friendly and widely compatible with a variety of pesticides; in actual complex environments (such as high dilution, pH changes, ion concentration changes, storage and transportation temperature changes, mechanical vibrations), it has excellent thermodynamic stability and is not prone to demulsification such as pesticide precipitation and sedimentation; it has better wetting and spreading properties on the target, promoting its effective deposition; and it has excellent sustained release properties and good diffusivity in the drip irrigation system, significantly improving the utilization rate of pesticides. It is superior to traditional pesticide water dispersants in terms of performance and utilization rate.

(3) The liquid crystal pesticide emulsion described in the present invention has an excellent "pruning and shaping" effect on crops (such as cotton, corn, etc.), and is effective in shortening internodes, dwarfing plants, promoting lateral bud growth and flower bud formation, increasing chlorophyll accumulation, etc., and can also increase crop yields.

(4) The pesticide preparation method adopted by the present invention has a simple operation process, is less time-consuming, has a small energy loss, and can be prepared on a large scale, which is conducive to the batch production of pesticide emulsions.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows the microscopic morphology and macroscopic photographs of blank liquid crystal emulsion (Blank-LCE), 1% uniconazole liquid crystal emulsion (UZ-LCE), 1% uniconazole Tween-20 emulsion (UZ-TW20), 1% uniconazole ethanol solution (UZ-EtOH) and the corresponding 10-fold dilutions.

FIG. 2 is a microscopic morphology of uniconazole liquid crystal emulsions (UZ-LCE) with mass fractions of 1%, 3%, and 5%, respectively.

FIG3 is a microscopic morphology of a 1% uniconazole liquid crystal emulsion and samples thereof diluted 10 ³ , 10 ⁴ , and 10 ⁵ times, respectively.

FIG. 4 shows the microscopic morphology and Zeta potential of 1% thiamethoxazole liquid crystal emulsion at pH=3, 7, and 11.

FIG. 5 shows the microscopic morphology and Zeta potential of 1% pheniconazole liquid crystal emulsion when the mass fraction of diammonium phosphate is 3%, 5%, and 10%.

Figure 6 shows the microscopic morphology of the 1% linconazole liquid crystal emulsion before and after centrifugal shaking (3000r/min, 30min) (a, b); and the microscopic morphology of the emulsion after a low-temperature cycle (c) or a high-temperature cycle (d) treatment, wherein the low-temperature cycle treatment transfers the UZ-LCE from a 25°C constant temperature box to a -18°C refrigerator for 24 hours, and then takes it out and places it in a 25°C constant temperature box for storage for 24 hours; the high-temperature cycle treatment transfers the UZ-LCE from a 25°C constant temperature box to a 60°C oven for 24 hours, and then takes it out and places it in a 25°C constant temperature box for storage for 24 hours.

FIG7 shows the bouncing behaviors of deionized water, 1% tert-butyl ether ethanol solution, 1% tert-butyl ether Tween-20 emulsion, blank liquid crystal emulsion and 1000-fold dilution of 1% tert-butyl ether liquid crystal emulsion on cotton leaves.

Figure 8 shows the steady-state rheological curves, thixotropic curves and dynamic viscoelastic curves of UZ-LCE emulsions at different drug loadings (the concentrations of clofosinate were 0%, 0.5%, 5%, 10% and 20%, respectively), different pH values (pH = 3, 7 and 11) and different diammonium phosphate concentrations (0%, 3%, 5%, 10%).

Figure 9 shows the diffusion efficiency (C _t /C ₀ ) of 5% UZ-LCE and 5% UZ-EtOH in a simulated drip irrigation device (Figure A) over time (Figure B), where C _t and C ₀ represent the concentration of UZ in the outflow liquid and the initial concentration of the liquid flowing into the pipe at time t, respectively.

FIG. 10 shows the drug release curves (left) and fitted kinetic curves (right) of 5% chloranil liquid crystal emulsion and 5% chloranil ethanol solution.

Figure 11 shows the evaluation of the efficacy of different uniconazole formulations after application during the flowering period of cotton. Among them, uniconazole liquid crystal emulsion (UZ-LCE) was applied by leaf spraying and drip irrigation, and uniconazole ethanol solution (UZ-EtOH), uniconazole Tween-20 emulsion (UZ-TW 20) and deionized water (CK) were applied by drip irrigation. (a) Plant height, (b) Plant height growth rate, (c) Three-stage height, (d) Cumulative number of flowers, (e) Chlorophyll SPAD value, (f) Field experiment comparison of drip irrigation and spraying of UZ-LCE. Figure 12 shows the defoliation effect comparison of deionized water (CK), conventional defoliant (540g/L thiadiazole·diuron suspension), conventional defoliant and Anrongle compound preparation, and conventional defoliant liquid crystal emulsion in cotton field experiments, and the change diagram of defoliation rate and number of cotton bolls before and after application.

Detailed ways

The technical scheme of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary illustrations and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope that the present invention is intended to protect.

The percentages (%) in the present invention are all weight percentages (wt %).

Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

Example 1

In the first step, 4 g of lecithin liquid crystal emulsifier is added to 6 g of rapeseed oil, and heated in a water bath at 70° C.-75° C. to dissolve the emulsifier in the rapeseed oil to obtain an oil phase.

In the second step, 1 g of sodium carboxymethyl cellulose is slowly added into 80 g of citric acid buffer solution (pH=3) under stirring, and the solution is continuously stirred to form a uniform solution, and then placed in a water bath and heated to 70° C.-75° C. to obtain an aqueous phase.

In the third step, 5 g of oxadiazole original drug was dissolved in 8.4 mL of dimethyl sulfoxide, and ultrasonic-assisted dissolution was performed. Then 4 g of rapeseed oil was added, ultrasonically mixed, and the temperature was kept constant at 70°C-75°C in a water bath to obtain a solvent phase.

The fourth step is to quickly pour the oil phase into the water phase at a water bath temperature of 70°C-75°C, and then quickly add the solvent phase, and homogenize at a speed of 5000-8000 r/min for 3-8 minutes to make it homogenous and uniform. Finally, under the condition of an external water bath temperature of 25-32°C, stir at a speed of 300-800 r/min for 10-20 minutes to cool it down to obtain 100g of uniconazole liquid crystal emulsion (UZ-LCE), that is, obtain 5% uniconazole liquid crystal emulsion.

Comparative Example 1-1

5 g of uniconazole original drug was dissolved in 95 g of ethanol to form a 5% uniconazole ethanol solution UZ-EtOH, which was recorded as control 1-1.

Comparative Example 1-2

The preparation method is basically the same as that of Example 1, except that the composite liquid crystal emulsifier in the first step is replaced with an equal amount of Tween-20 emulsifier to obtain emulsion UZ-TW20, which is recorded as Control 1-2.

Comparative Examples 1-3

The preparation method is basically the same as that of Example 1, except that in the third step, no uniconazole original drug is added to obtain a blank liquid crystal emulsion Blank-LCE, which is recorded as Control 1-3.

Comparative Examples 1-4

An equal amount of 100 g of deionized water was used as blank control CK, recorded as control 1-4.

Example 2

In the third step, 1 g of oxadiazole original drug was dissolved in 6.7 mL of n-butanol and ultrasonically assisted in the dissolution, and then 4 g of rapeseed oil was added, ultrasonically mixed, and the temperature was kept constant at 70°C-75°C in a water bath to obtain a solvent phase.

The fourth step is to quickly pour the oil phase into the water phase at a water bath temperature of 70°C-75°C, and then quickly add the solvent phase, and homogenize at a speed of 5000-8000 r/min for 3-8 minutes to make it homogenous and uniform. Finally, under the condition of an external water bath temperature of 25-32°C, stir at a speed of 300-800 r/min for 10-20 minutes to cool down to obtain 100g of uniconazole liquid crystal emulsion (UZ-LCE), that is, obtain 1% uniconazole liquid crystal emulsion.

Comparative Example 2-1

1 g of uniconazole original drug was dissolved in 99 g of ethanol to form a 1% uniconazole ethanol solution UZ-EtOH, which was recorded as control 2-1.

Comparative Example 2-2

The preparation method is basically the same as that of Example 2, except that the composite liquid crystal emulsifier in the first step is replaced with an equal amount of Tween-20 emulsifier to obtain emulsion UZ-TW20, which is recorded as control 2-2.

Comparative Examples 2-3

The preparation method is basically the same as that of Example 2, except that in the third step, no original drug of uniconazole is added to obtain a blank liquid crystal emulsion Blank-LCE, which is recorded as Control 2-3.

Comparative Examples 2-4

An equal amount of 100 g of deionized water was used as blank control CK, recorded as control 2-4.

The emulsions obtained in Example 2 and Comparative Examples 1-3 were observed under a polarizing microscope, and their original concentrations and microscopic images after ten-fold dilution are shown in Figure 1. Among them, (a ₁ ) and (a ₂ ) are microscopic images of the original concentration and ten-fold dilution of Blank-LCE obtained in Comparative Example 3, (b ₁ ) and (b ₂ ) are microscopic images of the original concentration and ten-fold dilution of the pesticide emulsion obtained in Example 2, (c ₁ ) and (c ₂ ) are microscopic images of the original concentration and ten-fold dilution of the UZ-TW20 emulsion obtained in Comparative Example 2, and (d ₁ ) and (d ₂ ) are microscopic images of the original concentration and ten-fold dilution of the ethyl oxadiazole solution obtained in Comparative Example 1. As can be seen from the figure, the "cross-shaped" liquid crystal structure of the blank liquid crystal (Blank-LCE) obtained in Comparative Example 3 (Figures (a ₁ ), (a ₂ )) and the uniconazole liquid crystal emulsion UZ-LCE (Figures (b ₁ ), (b ₂ )) obtained in Example 2 is obvious, which is highly consistent with the structural characteristics of lamellar liquid crystals. Compared with the blank liquid crystal, the droplet size increases after loading uniconazole (UZ) (wt=1%), and the uniformity of the liquid crystal texture decreases, but the droplets are still densely distributed, and no obvious pesticide crystals are precipitated, indicating that uniconazole is completely encapsulated in the droplets. After diluting it 10 times, the emulsion maintains a uniform texture. Although the dilution causes the distribution density of the droplets to decrease, its particle size does not change significantly, and no pesticide crystals are precipitated. In sharp contrast, the UZ-TW20 obtained in Comparative Example 2 (Figures (c ₁ ), (c ₂ )) contains tiny emulsion droplets, accompanied by the precipitation of a large number of 20 μm-50 μm oxadiazole crystals, and the precipitated oxadiazole aggregates and precipitates at the bottom of the bottle (Figure c ₁ ); after diluting it 10 times, the emulsion droplets completely disappear, exacerbating the aggregation and precipitation of the pesticide (Figure c ₂ ). The UZ-EtOH obtained in Comparative Example 1 is a 1% oxadiazole ethanol solution (Figure d ₁ ), but after diluting it 10 times, oxadiazole rapidly precipitates and aggregates and precipitates at the bottom of the bottle (Figure d ₂ ).

Example 3

The difference between this embodiment and embodiment 2 is that the content of clofosazole is changed to 3g and 5g, and the contents of each part are shown in Table 1, and 3% clofosazole liquid crystal emulsion and 5% clofosazole liquid crystal emulsion are obtained respectively. The emulsions of embodiments 2 and 3 are observed under a polarizing microscope, and their microscopic morphology is shown in Figure 2. It can be seen from the figure that with the increase of drug loading, the size of the emulsion droplets increases significantly, and the amount of pesticide encapsulated in the emulsion droplets increases significantly. When the concentration of clofosazole is 5%, the emulsion droplets are filled fully, and no clofosazole crystals are precipitated.

Table 1 Formulations of UZ-LCE with different mass fractions

Example 4

The dilution stability of liquid crystal pesticide emulsion was evaluated.

The 1% chloranil liquid crystal pesticide emulsion prepared in Example 2 was diluted 10 ³ , 10 ⁴ , and 10 ⁵ times with deionized water to obtain a diluted dispersion. The 1% chloranil liquid crystal original emulsion and the diluted dispersions after dilution by 10 ³ , 10 ⁴ , and 10 ⁵ were observed under a polarizing microscope, and the microscopic morphology thereof is shown in FIG3 . As can be seen from FIG3 , the UZ-LCE was further diluted multiple times. As the dilution multiple increased from 10 ³ to 10 ⁵ times, the liquid crystal texture at the outer edge of the emulsion droplet was intact, and no UZ crystal leakage and precipitation were observed. It can be seen that UZ-LCE has significant dilution stability and can overcome the technical problems of dilution demulsification, precipitation, aggregation, and sedimentation commonly found in traditional pesticide water dispersants.

Example 5

The adaptability of UZ-LCE to water quality was evaluated by changing the pH of the liquid crystal emulsion.

The method of Example 2 was basically followed, except that the citric acid buffer solution in the second step was replaced by water (pH=7) or sodium hydroxide aqueous solution (pH=11), and the other conditions remained unchanged, to obtain UZ-LCE with pH of 7 and 11, respectively.

Figure 4 shows the microscopic morphology and Zeta potential of Example 2 and the 5% chloramphenicol liquid crystal emulsion prepared above when the aqueous phase has a pH of 3, 7, and 11, observed under a polarizing microscope. As shown in Figure 4, under the experimental pH conditions, the droplets in UZ-LCE are evenly distributed, and the outer edge liquid crystal texture is intact; when the pH is 11, a small amount of droplets are broken at the outer edge due to the hydrolysis of the emulsifier. This shows that UZ-LCE has good stability at different pH values, and its stability under acidic and neutral conditions is better than that under alkaline conditions. By measuring the Zeta point determination, it is proved that the stability of the emulsion is based on the electrostatic repulsion of the droplet surface. Considering that UZ-LCE will be released with acidic fertilizers in the drip irrigation system in the future, UZ-LCE with pH = 3 was selected for study.

Example 6

To evaluate the interference of fertilizers released with water on the stability of the emulsion when UZ-LCE is released by drip irrigation, this example investigates the effect of the concentration of diammonium phosphate (NH ₄ H ₂ PO ₄ ), a commonly used nitrogen/phosphate fertilizer in the field, on the stability of the emulsion.

The preparation was basically carried out according to the method of Example 2, except that 3%, 5% and 10% NH ₄ H ₂ PO ₄ were added to the aqueous phase of the emulsion prepared in the second step, respectively, and the other conditions remained unchanged, and three different pesticide emulsions were obtained. The microscopic morphology and Zeta potential of the 1% uniconazole liquid crystal emulsion observed under a polarizing microscope when the mass fraction of NH ₄ H ₂ PO ₄ was 3%, 5% and 10% are shown in Figure 5. As can be seen from Figure 5, as the mass fraction of NH ₄ H ₂ PO ₄ increases from 3% to 10%, the particle size of the emulsion droplets increases significantly, the integrity and uniformity of the liquid crystal texture decrease, but a large amount of uniconazole is still encapsulated inside the emulsion droplets. The Zeta potential of the emulsion droplets under different salt concentrations is negative, and the stability of the emulsion is maintained by the electrostatic repulsion of the surface negative charge. It shows that UZ-LCE has good tolerance stability to the NH ₄ H ₂ PO ₄ concentration under experimental conditions. In the actual drip irrigation release environment, the concentration of pesticide after multiple dilutions is much lower than that in the experimental conditions. Based on this, it can be inferred that the emulsion has good fertilizer (salt) tolerance stability in the actual drip irrigation environment.

Example 7

The storage and transportation stability of liquid crystal pesticide emulsion was evaluated.

The uniconazole liquid crystal emulsion obtained in Example 2 was first centrifuged at 3000r/min for 0.5h, and then subjected to low temperature cycle and high temperature cycle respectively. The low temperature cycle was that the liquid crystal emulsion at 25°C in the constant temperature box was placed in a -18°C refrigerator for 24h, and then taken out and placed in a constant temperature box at 25°C for 24h; the high temperature cycle was that the liquid crystal emulsion at 25°C in the constant temperature box was placed in a 65°C oven for 24h, and then taken out and placed in a constant temperature box at 25°C for 24h. The microscope micrograph after each of the above steps is shown in Figure 6. It can be seen from the figure that after mechanical vibration, the droplet size, distribution density, and liquid crystal texture did not change significantly, and no uniconazole crystals were observed, indicating that the pesticide liquid crystal emulsion of the present invention has strong anti-disturbance performance during actual transportation; under low temperature and high temperature cycles, the emulsion state can be restored, proving that the pesticide liquid crystal emulsion of the present invention has excellent stability at the actual storage temperature. However, after low-temperature treatment, the liquid crystal texture is denser than that after high-temperature treatment, which may be due to the loss of a small amount of water under high temperature conditions, resulting in the reassembly of the liquid crystal layer. Therefore, it is preferred to store UZ-LCE in a sealed and cool place during storage.

Example 8

In the first step, 6 g of lecithin liquid crystal emulsifier is added to 10 g of mixed oil (4 g of rapeseed oil, 3 g of coconut oil, and 3 g of castor oil), and heated in a water bath at 70° C.-75° C. to dissolve the emulsifier in the mixed oil to obtain an oil phase.

In the second step, 0.3 g of sodium carboxymethyl cellulose was slowly added into 84 g of deionized water (pH=7) under stirring, and the solution was continuously stirred to form a uniform solution, which was then placed in a water bath and heated to 70° C.-75° C. to obtain an aqueous phase.

The third step is to quickly pour the oil phase into the water phase at a water bath temperature of 70°C-75°C, homogenize at a speed of 5000-8000 r/min for 3-8 minutes to mix them evenly, and finally stir at a speed of 300-800 r/min for 10-20 minutes to cool it down under the condition of an external water bath temperature of 25-32°C to obtain 100g of blank liquid crystal emulsion (LCE).

The fourth step is to add 20 mL of defoliant (540 g/L thiadiazole·diuron suspension), 80 mL of alkyl sulfonate additive, and 70 mL of ethephon water-soluble agent to 40 mL of blank liquid crystal emulsion, add a small amount of deionized water and shake to disperse it, mix well, add deionized water to make up to 2 L, and obtain a defoliant liquid crystal emulsion.

Comparative Example 8-1

Mix 80 mL of alkyl sulfonate additive and 70 mL of ethephon water-dispersing agent, add a small amount of water and shake to disperse them, mix well and add deionized water to make up to 2 L, as blank control CK, recorded as control 8-1.

Comparative Example 8-2

Mix 20 mL 540 g/L thidiazuron-diuron suspension, 80 mL alkyl sulfonate adjuvant and 70 mL ethephon water-soluble agent, add a small amount of deionized water and shake to disperse them. After mixing evenly, add deionized water to make up to 2 L. This is used as the conventional defoliant group, recorded as control 8-2.

Comparative Example 8-3

Mix 20mL of 540g/L thidiazuron-diuron suspension, 80mL of alkyl sulfonate adjuvant, 70mL of ethephon water-repellent and 15mL of Anrongle adjuvant, add a small amount of deionized water and shake to disperse them, mix well and add deionized water to make up to 2L, as the conventional defoliant + Anrongle group, recorded as control 8-3.

Test Example 1

The elasticity and wettability of clofosconazole in different systems were evaluated.

Test method: Take pictures with a high-speed camera.

Test process: After the samples in Example 2 and Comparative Examples 2-1 to 2-4 were diluted 1000 times, the bouncing behavior and wettability of the above dilutions on the clean cotton leaf surface were studied by a high-speed camera. The spreadability changes of uniconazole in different systems over time are shown in FIG7 .

As shown in Figure 7, the deionized water control 2-4 and the ethylenediaminetetracycline ethanol dispersion control 2-1 will bounce and splash to varying degrees when contacting the cotton leaf surface, causing the loss of pesticides; the ethylenediaminetetracycline Tween emulsion control 2-2 has a large amount of UZ precipitated crystals, and carries a large amount of ethylenediaminetetracycline crystals when colliding with the interface, and has a very poor dispersion; while the ethylenediaminetetracycline blank liquid crystal emulsion control 2-3 and the ethylenediaminetetracycline liquid crystal emulsion Example 2 have good dispersion and stability and low interfacial free energy of the emulsification system, and show significantly better wetting and spreading properties than the control.

Test Example 2

The rheological properties of pesticide formulations are closely related to their stability and leaf deposition efficiency. The rheological barrier effect can reduce the migration and diffusion of emulsion droplets; the semi-solid liquid crystal network extending throughout the continuous phase can significantly enhance the stability of the emulsion by slowing down the movement of droplets. Therefore, the rheological properties of the liquid crystal pesticide emulsion were evaluated. The following uniconazole liquid crystal emulsions (UZ-LCE) with different drug loadings, different pH values and different salt concentrations were prepared according to the method of Example 1:

1) Liquid crystal emulsions of 0.5% uniconazole, 10% uniconazole, and 20% uniconazole were prepared by a method similar to that in Example 1, with the amount of uniconazole added adjusted.

2) Ethyleneconazole liquid crystal emulsions with different pH values: According to a method similar to that of Example 1, only the citric acid buffer solution used to prepare the emulsion in the second step was replaced with water (pH=7) or sodium hydroxide aqueous solution (pH=11), and the other conditions remained unchanged, to obtain Ethyleneconazole liquid crystal emulsions with pH values of 7 and 11, respectively.

3) Emulsions of different salt concentrations of 5% 5% 5% 6% 7% 10% NH ₄ H ₂ PO ₄ were added to the aqueous phase of the emulsion prepared in the second step, and other conditions remained unchanged, to obtain 5% 5% 5% 5% 6% 10% NH ₄ H ₂ PO ₄ liquid crystal emulsions.

The rheological stability of the prepared unicyclic azole liquid crystal emulsion was evaluated by rheometer, as shown in Figure 8. As can be seen from the figure, (ac), (df), and (gi) are the steady-state rheological curves, thixotropic curves, and dynamic viscoelastic curves of UZ-LCE under different UZ mass fractions, different pH values, and different NH ₄ H ₂ PO ₄ mass fractions, respectively. The steady-state rheological results (a, d, g) show that the drug loading and salt concentration significantly promote the increase in the initial viscosity (η _0.01 ) of UZ-LCE. Since pH has no significant effect on the droplet size, it has little effect on its initial viscosity. With the increase of shear rate (γ), the steady-state shear viscosity of UZ-LCE shows a continuous decrease, showing the shear thinning characteristics of non-Newtonian fluids. This is not only conducive to the extrusion and canning of pesticide liquid crystal emulsions during the preparation process, but also helps to disperse them when diluted and used, and promotes their effective spreading on the plant surface. From the thixotropic curves (b, e, h), it can be seen that at the experimental pH, when the drug loading of clofosazole is ≤10% or the salt concentration is ≤10%, the thixotropic curves are almost overlapped (no thixotropic ring), indicating that UZ-LCE has excellent recovery stability; when the drug loading of clofosazole is ≥10% or the salt concentration is ≥10%, the thixotropic ring increases significantly, indicating that clofosazole crystals are precipitated during the shear process and the recovery of the pesticide liquid crystal emulsion is reduced. From the dynamic viscoelastic curves (c, f, i), the storage modulus (G') is higher than the loss modulus (G") in the low-frequency region, and UZ-LCE mainly exhibits the elastic properties of a solid, which is beneficial to the storage and transportation of the pesticide liquid crystal emulsion; in the high-frequency region, the storage modulus (G') is less than the loss modulus (G"), and UZ-LCE mainly exhibits the viscous properties of a liquid, which is beneficial to the spraying and atomization of the pesticide liquid crystal emulsion when used.

Test Example 3

The diffusion performance of UZ-LCE in simulated drip irrigation was evaluated. Simulated drip irrigation diffusion experiments were conducted on the uniconazole liquid crystal emulsion prepared in Example 1 and the uniconazole ethanol solution control 1-1 prepared in Comparative Example 1-1.

Test process: The 5% uniconazole liquid crystal emulsion (UZ-LCE) prepared in Example 1 and the 5% uniconazole ethanol solution (UZ-EtOH) prepared in Comparative Example 1-1 were subjected to a simulated drip irrigation diffusion experiment (the device diagram is shown in Figure 9 (left)). 1g of UZ-LCE and 1g of UZ-EtOH were taken respectively and diluted to 1L with deionized water. 1 mL was taken from each of the samples, 4 mL of anhydrous ethanol was added to each sample, and the initial concentration C ₀ was determined by a UV-Vis spectrophotometer. Under a magnetic stirring speed of (300 r/min), a peristaltic pump (2 mL/min) was used to draw the diluted UZ-LCE and UZ-EtOH into a PETF tube (l=40 cm, d=2 cm) filled with perlite (60 g) inside. Samples were taken from the other side of the tube at regular intervals, 1 mL of the effluent was added to 4 mL of anhydrous ethanol to promote the dissolution of clofosinate, and the concentration C _t at the corresponding time was determined by a UV-Vis spectrophotometer. The results were repeated three times and the average value was taken. The relationship curve between the diffusion efficiency (C _t /C ₀ ) and the diffusion time (t) was plotted. As shown in Figure 9 (in Figure 9 , the abscissa is the diffusion time, and the ordinate is the ratio of the effluent concentration of the two clofosinate systems to the initial concentration of the influent C _t /C ₀ ).

The transfer and diffusion of UZ-LCE during drip irrigation release were investigated by the simulated drip irrigation system shown in Figure 9. Under the same experimental conditions, the pesticide was passed through the perlite filled in the long tube to simulate its actual penetration and diffusion process in the soil. The diffusion efficiency ( _Ct / _C0 ) of UZ-LCE and UZ-EtOH at different release times was measured, and the corresponding relationship curves were obtained (Figure 9 (right)). The liquid was transported at a constant power by a peristaltic pump to ensure a consistent water flow rate. The release of pesticides in the tube is mainly divided into two stages: first, it is adsorbed on the surface of the pores of the filler (perlite) in the tube; after adsorption saturation, the adsorption and desorption of the pesticide reach a dynamic equilibrium, so the concentration of thiazolinone in the outflowing liquid remains constant. In Figure 9, within the initial 20 minutes of UZ-EtOH, the concentration of clofosazole in the release liquid flowing out of the tube is 0. This is mainly due to the presence of a large number of clofosazole crystals in the UZ-EtOH dilution, which are completely deposited in the filler pores in the tube; they can only be flushed out with the water flow when the adsorption reaches saturation (about 40 minutes later). Subsequently, its diffusion efficiency fluctuates, which is mainly due to the presence of clofosazole crystals of different sizes in the outflowing liquid, resulting in sampling concentration differences. The average diffusion efficiency after stabilization is 24.89%. The above results show that there is serious precipitation of pesticides in the release process of UZ-EtOH, which makes it impossible to release it evenly to the roots of crops. For UZ-LCE, since clofosazole is encapsulated in the emulsion droplets by confined solubilization, the emulsion droplets encapsulating pesticides can easily flow out through the filler pores under the flushing of water flow, so the presence of clofosazole can be detected at the beginning of release. As time goes by, the amount of adsorption in the filler pores gradually decreases. In this stage (0-50min), the number of emulsion droplets encapsulating chloramphenicol in the effluent gradually increases, and the corresponding diffusion efficiency gradually increases. When the adsorption reaches saturation (about 50min later), the diffusion efficiency tends to be stable, and the average diffusion efficiency is 72.83%, which is nearly 3 times the diffusion efficiency of UZ-EtOH. The above results fully show that compared with chloramphenicol dispersed in ethanol, UZ-LCE can encapsulate chloramphenicol in the emulsion droplets, release it evenly with the water flow, is not easy to settle, and can significantly improve the diffusion efficiency.

Test Example 4

The sustained release performance of the uniconazole liquid crystal emulsion prepared in Example 1 and the uniconazole ethanol solution prepared in Comparative Example 1-1 was evaluated. Test process: a 5% uniconazole solution was prepared in ethanol/water (v/v=3:7), and the corresponding absorbance A was measured by UV-Vis spectrophotometer. A standard curve of uniconazole concentration-absorbance A was made. In vitro sustained release experiments were performed on the 5% UZ-LCE obtained in Example 1 and the 5% UZ-EtOH obtained in Comparative Example 1-1. 4 g of UZ-LCE and UZ-EtOH were taken respectively, dispersed in 100 mL of ethanol/water (v/v=3:7), 5 ml of each dispersion was taken, and placed in dialysis bags (molecular weight cutoff of 1000 Da), respectively, and placed in stoppered conical flasks, and 195 mL of ethanol/water (v/v=3:7) was added. It is placed in a constant temperature incubation oscillator with a rotation speed of 300r/min for uniform vibration. Take 2mL of solution from a conical flask at regular intervals, measure the corresponding absorbance A by UV-Vis spectrophotometer, and after the measurement, pour the taken-out solution back into the original conical flask, repeat three times and take the average value. By the standard curve of clopidogrel, calculate the release amount of clopidogrel in the sample, and draw the relationship curve of release time (t) and clopidogrel release rate (release concentration/initial concentration=C _t /C ₀ , eq1). As shown in Figure 10 (wherein, the horizontal coordinate is the release time, and the vertical coordinate is the percentage of clopidogrel release).

As shown in Figure 10, in the 30% (v%) ethanol sustained-release solution, the time (t _1/2 ) required for the release of 50% of the chlorpyrifos in the UZ-EtOH dispersion system was 4.82 h, and the chlorpyrifos was completely released after 12 h; while in the UZ-LCE system, t _1/2 was 39.85 h, and the release rate of the chlorpyrifos in the UZ-LCE system was nearly 90% after 125 h, and the average release rate was about 10 times slower than that of UZ-EtOH, which had a significantly better sustained-release performance than the chlorpyrifos ethanol dispersion solution. Further, the release curves of UZ-EtOH and UZ-LCE were fitted with the first-order kinetics (the functional relationship curve of ln(C ₀ /C _t )-t), and the linear correlation coefficient (R ² ) of UZ-LCE after fitting was 0.9922, indicating that the sustained-release kinetic mechanism of the liquid crystal emulsion conforms to the first-order release kinetic model, and the pesticide release process is controlled by concentration diffusion. For UZ-EtOH, R ² = 0.8711 < 0.99, which may be related to the different existence states of clofosconazole in UZ-EtOH. The saturated clofosconazole in the ethanol aqueous solution is released first, and the internal crystals are dissolved step by step and then continue to be released. Therefore, the release of pesticides is controlled by both concentration and pesticide dissolution. From the analysis of the rate coefficient (k), k(UZ-LCE) is only 1/11 of k(UZ-EtOH), indicating that the sustained release of the former is much higher than that of the latter. Its excellent sustained release performance is mainly attributed to the stable encapsulation of pesticides by the "onion-like" O/LC/W multilayer assembly structure. Clofosconazole is solubilized in the hydrophobic microregions and the inner core. The blocking of multiple barriers during the release process further reduces the release rate.

Test Example 5

The effect of 5% uniconazole liquid crystal emulsion (UZ-LCE) obtained in Example 1 on "pruning and shaping" during cotton growth was investigated.

Test method: The cotton field experiment was carried out in the Woda Agroscience cotton experimental field, and the average plant height of cotton was >40cm (flowering period). UZ-LCE was applied by drip irrigation and foliar spraying. A blank control group (CK) (control 1-4 in comparative example 1-4), UZ-EtOH (control 1-1 in comparative example 1-1), UZ-TW20 (control 1-2 in comparative example 1-2), and Blank-LCE (control 1-3 in comparative example 1-3) were set up as control experiments for drip irrigation release. 15 plants were measured continuously in each group, and 3 rows were randomly selected, totaling 45 plants as samples. Investigate and record the growth of cotton before application. The total amount of ethylenediaminetetracycline (98%) was 6.84g/mu, which was drip-irrigated/sprayed three times with an interval of 7 days. The first dosage is 1.9g/mu, and 38g of each product of Example 1 and Control 1-1 to 1-4 is taken, and diluted about 950,000 times in the fertilizer tank for use. The second dosage is 2.28g/mu, and 45.6g of each product of Example 1 and Control 1-1 to 1-4 is taken, and diluted about 950,000 times in the fertilizer tank with water for use. The third dosage is 2.66g/mu, and 53.2g of each product of Example 1 and Control 1-1 to 1-4 is taken, and diluted about 950,000 times in the fertilizer tank for use. The spraying group is diluted to about 500 times with water in the sprayer for use. After the start of application, the growth of cotton is measured and recorded every three days. The parameters investigated include cotton plant height, upper three internode height, number of flowering, number of fruit branches, total number of nodes, and SPAD value related to chlorophyll content. Statistics and analysis of changes in various physiological parameters of cotton to evaluate the efficacy. Specific as shown in Figure 11.

As shown in Figure 11 (a), compared with the blank control CK without drug use, the plant height of all experimental groups and control groups using chloramphenicol was controlled to varying degrees. Compared with the drip irrigation control groups UZ-EtOH and UZ-W20, the plant height of UZ-LCE (drip irrigation) was shorter (82.0 cm); and the plant height of UZ-LCE (spraying) was further reduced to 78.0 cm. Obviously, UZ-LCE is better than chloramphenicol ethanol dispersion solution and traditional emulsion in controlling apical dominance of cotton. Figure (b) shows the curve of plant height growth rate over time. It can be seen that after the first ( ^1st ) and second ( ^2nd ) application of the drug, the drip irrigation control group showed different degrees of rebound, while UZ-LCE (drip irrigation) had the most stable control on plant height growth rate, which is closely related to its excellent slow-release performance; compared with UZ-LCE (drip irrigation), UZ-LCE (spraying) showed a significant rebound in growth rate after the first application, but the growth rate of plant height was immediately controlled after the second application, and the growth rate was close to 0 in the past week, indicating that UZ-LCE has a continuous and significant "branch shaping" effect on cotton, and drip irrigation release is more conducive to the stable effect of the drug. Figure (c) shows the height of the three-stage inverted pedestal in different experimental groups, which can directly reflect the effect on the growth of cotton apical buds. As can be seen from the figure, the height of the top three nodes of UZ-LCE (drip irrigation) is lower than that of the control group, while the effect of UZ-LCE (spraying) is the most significant, which once again proves the significant advantages of UZ-LCE in inhibiting cell elongation, shortening internodes, and dwarfing plants, and the effect of spraying is better than drip irrigation. Figure 11 (d) counts the maximum number of flowering of the top three nodes of different experimental groups (controlled by the growth law of cotton, the number of flowering of all experimental groups reached a peak on the 17th-20th day of drug application). Obviously, UZ-LCE (spraying) has the largest number of flowers, followed by UZ-LCE (drip irrigation), both of which are higher than the control group, indicating that UZ-LCE is significantly better than solvent dispersion and traditional emulsion in promoting flower bud formation and growth. Chlorophyll content determines the efficiency of cotton photosynthesis. In the field experiment, we found that the color of the leaves of the experimental group using UZ-LCE was generally darker than that of the control group. To this end, the SPAD values related to chlorophyll in different experimental groups were measured. From the results of Figure (e), after using UZ-LCE, the SPAD value of cotton leaves was higher than that of the control group, and UZ-LCE (spraying) was significantly higher than UZ-LCE (drip irrigation); the significance can be seen by the naked eye. In the photo of Figure (f), the green color of the leaves sprayed (right) is obviously darker than that of the drip irrigation (left). Therefore, UZ-LCE also has the effect of promoting the accumulation of chlorophyll in cotton leaves, and the effect is more obvious after spraying.

In summary, the use of UZ-LCE during the flowering period of cotton has significantly better efficacy than oxadiazole ethanol dispersion solution and traditional emulsion. It has played a positive and significant effect in shortening internodes, dwarfing plants, promoting lateral bud growth and flower bud formation, and increasing chlorophyll accumulation, achieving the ideal "pruning and shaping" effect.

Test Example 6

The defoliation effect of the defoliant liquid crystal emulsion obtained in Example 8 on cotton defoliation was examined.

Test method: A cotton defoliant field experiment was conducted in the test field during the cotton boll opening period. Four samples were applied by foliar spraying, and a blank control group (CK) (Control 8-1 in Comparative Example 8-1), a conventional defoliant group (Control 8-2 in Comparative Example 8-2) and a conventional defoliant + Anrongle group (Control 8-3 in Comparative Example 8-3) were set up respectively, which was a control experiment of the defoliant liquid crystal emulsion prepared in Example 8 (recorded as: conventional defoliant + LCE). Five plants were continuously measured in each group, and two rows were randomly selected, with a total of 10 plants as samples.

On the day of application, a pre-application survey was conducted and relevant parameters of the cotton defoliant experiment were recorded. The relevant parameters of the survey included the number of cotton leaves and the number of cotton bolls, where the calculation of the defoliation rate and the number of cotton bolls are shown in eq2 and eq3, and the specific results are shown in Figure 12.

Number of cotton bolls = number of cotton bolls opening after pesticide application - number of cotton bolls opening before pesticide application (eq3)

After completing the parameter survey before application, apply the pesticide, and conduct parameter survey, record and analyze 10 days after application.

As can be seen from the cotton macroscopic image in Figure 12, compared with the blank control, the leaves of all the experimental groups and the control group using defoliants are more yellow, more dehydrated, more wilted, and have fewer leaves, and the leaves of the blank control (CK) group are the greenest. As can be seen from the defoliation rate graph, compared with the blank control (CK) group, the defoliation rates of the experimental groups and the control group with defoliants increased significantly, among which the defoliation rate of the defoliant liquid crystal emulsion (conventional defoliant + LCE) prepared in Example 8 is the highest. As can be seen from the cotton boll number graph before and after application, compared with the control group, the increase in the number of cotton bolls in the conventional defoliant + LCE experimental group is the largest. This shows that the defoliant liquid crystal emulsion has better defoliation efficiency and a synergistic effect in promoting cotton boll opening.

Claims

A liquid crystal structured pesticide emulsion contains a fat-soluble pesticide and a liquid crystal emulsifier.
The pesticide emulsion according to claim 1, wherein the fat-soluble pesticide is one or more of thidiazuron, thiadiazole, diuron, koningomycin, abscisic acid, ethephon, indolebutyric acid, cypermethrin, thiamethoxam, etc.; the mass fraction of the fat-soluble pesticide in the pesticide emulsion can be 0.5%-20%, for example, 1%-15% or 1%-10%.

Alternatively, the fat-soluble pesticide is a fat-soluble pesticide technical or a pesticide formulation, and the formulation is, for example, a suspension, a wettable powder, a dust, a granule, an emulsifiable concentrate, an aqueous solution, and the like.
The pesticide emulsion according to claim 1, wherein the liquid crystal emulsifier is selected from one or more of alkyl glycosides, phosphates, lecithins, sucrose esters, stearoyls, and olive esters. The mass fraction of the emulsifier can be 1%-10%, 2%-9%.
The pesticide emulsion according to any one of claims 1 to 3, wherein the pesticide emulsion further contains oil, a thickener, an organic solvent and water.
The pesticide emulsion according to claim 4, wherein the thickener is selected from one or more of pectin, xanthan gum, carboxymethyl cellulose, starch, agar, alginic acid and sodium lignin sulfonate; the mass fraction of the thickener can be 0.1%-5%, 0.5%-4%;

And/or, the oil is a liquid oil, and the liquid oil can be a vegetable oil, an animal oil, or a synthetic oil; wherein the vegetable oil is, for example, one or more selected from peanut oil, soybean oil, linseed oil, castor oil, rapeseed oil, avocado oil, and coconut oil; the animal oil is, for example, one or more selected from squalane and squalene; the synthetic oil is, for example, one or more selected from caprylic capric triglyceride, isooctyl palmitate, isopropyl myristate, isooctyl stearate, isononyl isononanoate, dicaprylyl carbonate, and diisostearyl malate; the mass fraction of the liquid oil can be 1%-20%, 2%-15%, or 3%-12%.
The pesticide emulsion according to claim 4, wherein the organic solvent is a polar or non-polar solvent, such as one or more of n-butanol, methanol, chloroform, anhydrous ethanol, cyclohexane, n-hexane, ether, dichloromethane, dimethyl sulfoxide, and N,N-dimethylformamide; the mass fraction of the solvent can be 0.5%-40%, 1%-35%, 2%-30%, or 3%-20%;

And/or, the mass fraction of the water is 50%-90% or 65-85%.
The pesticide emulsion according to any one of claims 1 to 6, wherein the emulsion further contains a pH regulator; for example, one or more of sodium hydroxide, potassium hydroxide, hydrochloric acid, phosphoric acid or citric acid can be selected;
The method for preparing the pesticide emulsion according to any one of claims 1 to 7 comprises the following steps:

1) Preparation of oil phase: mixing the liquid crystal emulsifier with the liquid oil, and heating to make the emulsifier and the liquid oil miscible;

2) Preparation of aqueous phase: mixing thickener with water;

3) Preparation of dispersed solvent phase: dissolving the fat-soluble original drug in an organic solvent, then adding liquid oil and mixing;

4) Homogenization and emulsification: Pour the oil phase and the dispersed solvent phase into the water phase and stir to obtain a pesticide emulsion.

Alternatively, the method comprises the steps of:

1') Preparation of oil phase: mixing the liquid crystal emulsifier with the liquid oil, and heating to make the emulsifier and the liquid oil miscible;

2') Preparation of aqueous phase: Mix thickener with water;

3') Preparation of blank liquid crystal emulsion: pour the oil phase into the water phase and stir to obtain a blank liquid crystal emulsion;

4') Pesticide emulsion: Pesticide is mixed with blank liquid crystal emulsion to obtain pesticide emulsion.
The method for preparing a pesticide emulsion according to claim 8, wherein in step 1), the heating temperature is 60-90° C., preferably 70-80° C.;

and/or, in step 2), the aqueous phase is heated to 60-90° C., preferably 70-80° C.;

and/or, in step 3), heating the obtained dispersed solvent phase to 60-90° C., preferably 70-80° C.;

And/or, in step 4), the oil phase and the dispersed solvent phase are poured into the water phase in sequence at a temperature of 60-90° C. and stirred to obtain an emulsion.

And/or, in the above step 1'), the heating temperature is 60-90°C, preferably 70-80°C.

And/or, in the above step 2'), the obtained aqueous phase is heated to 60-90°C, preferably 70-80°C.

And/or, in the above step 3'), pour the oil phase into the water phase at a temperature of 60-90°C and stir to obtain an emulsion.

And/or, in the above step 4'), the pesticide is in the form of a pesticide formulation, such as a suspension, a wettable powder, a dust, a granule, an emulsifiable concentrate, an aqueous solution, etc.
The use of the pesticide emulsion according to any one of claims 1 to 7 in crops, for example, for promoting the growth and increasing the yield of crops; it can be applied to crop planting by drip irrigation, foliar spraying or wound application.