CN119569903A - A method for preparing a pesticide droplet stabilizer based on corncobs - Google Patents
A method for preparing a pesticide droplet stabilizer based on corncobs Download PDFInfo
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- 239000003381 stabilizer Substances 0.000 title claims abstract description 33
- 238000000034 method Methods 0.000 title claims abstract description 16
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- 239000001913 cellulose Substances 0.000 claims abstract description 42
- 239000007788 liquid Substances 0.000 claims abstract description 26
- 238000012360 testing method Methods 0.000 claims abstract description 17
- 239000002121 nanofiber Substances 0.000 claims abstract description 15
- 238000002360 preparation method Methods 0.000 claims abstract description 13
- 238000000605 extraction Methods 0.000 claims abstract description 8
- 239000002159 nanocrystal Substances 0.000 claims abstract description 8
- 230000000087 stabilizing effect Effects 0.000 claims abstract description 7
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 36
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- 239000003921 oil Substances 0.000 claims description 15
- 238000003756 stirring Methods 0.000 claims description 15
- 229920001046 Nanocellulose Polymers 0.000 claims description 12
- 238000000197 pyrolysis Methods 0.000 claims description 12
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- 239000000835 fiber Substances 0.000 claims description 9
- 238000002156 mixing Methods 0.000 claims description 9
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- 239000000243 solution Substances 0.000 claims description 9
- 238000006460 hydrolysis reaction Methods 0.000 claims description 7
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- 238000005406 washing Methods 0.000 claims description 7
- YAXWOADCWUUUNX-UHFFFAOYSA-N 1,2,2,3-tetramethylpiperidine Chemical compound CC1CCCN(C)C1(C)C YAXWOADCWUUUNX-UHFFFAOYSA-N 0.000 claims description 6
- RKMGAJGJIURJSJ-UHFFFAOYSA-N 2,2,6,6-Tetramethylpiperidine Substances CC1(C)CCCC(C)(C)N1 RKMGAJGJIURJSJ-UHFFFAOYSA-N 0.000 claims description 6
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 6
- 229960000583 acetic acid Drugs 0.000 claims description 6
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- SUKJFIGYRHOWBL-UHFFFAOYSA-N sodium hypochlorite Chemical compound [Na+].Cl[O-] SUKJFIGYRHOWBL-UHFFFAOYSA-N 0.000 claims description 6
- 238000001291 vacuum drying Methods 0.000 claims description 6
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Abstract
The invention discloses a preparation method of a pesticide droplet stabilizer based on corncob, which mainly comprises the following steps of pretreatment of the corncob, acquisition of corncob cellulose, extraction of cellulose nanocrystalline, extraction of cellulose nanofiber, characterization of the corncob nanofiber stabilizer and preparation and test of the pesticide droplet stabilizer based on the corncob. The method can successfully extract natural cellulose nanocrystals and cellulose nanofibers from the corncob, can be applied to stabilizing pesticide droplets, and realizes the stabilization of pesticide liquid, and has important significance for the high-value utilization of the corncob and the stabilization of the pesticide liquid.
Description
Technical Field
The invention belongs to the technical field of high-value utilization of agricultural engineering straws, and particularly relates to a preparation method of a pesticide liquid drop stabilizer based on corncobs.
Background
In modern agricultural production, the application of pesticides plays an important role in preventing and controlling crop diseases and insect pests and guaranteeing grain safety. However, there are problems in the use of pesticides, such as drifting and evaporation of the pesticide droplets during spraying, which not only reduce the effective utilization rate of the pesticide, but also may cause environmental pollution. In order to increase the efficiency of use of pesticides and reduce their impact on the environment, researchers have developed various pesticide adjuvants to improve the performance of pesticide formulations. The liquid drop stabilizer is used as an important pesticide auxiliary agent, can effectively increase the surface tension stability of liquid drops, reduce the evaporation rate of the liquid drops, and can also enhance the adhesiveness of the liquid drops on the surfaces of crops. Conventional drop stabilizers mostly employ synthetic chemicals, such as surfactants, etc., but these synthetic chemicals tend to be expensive and may adversely affect the ecological environment.
In recent years, with popularization of sustainable development concepts and advancement of technology, the utilization of natural renewable resources as pesticide adjuvants has become a research hotspot. Corncob is a common byproduct in agricultural production and is always burnt and wasted, but the corncob has rich cellulose, hemicellulose, lignin and other components, and is a potential low-cost and environment-friendly raw material source.
The invention aims to provide a preparation method of a pesticide drop stabilizer based on corncob, which can effectively utilize agricultural wastes, reduce environmental pollution and improve the economy and effectiveness of pesticide use. According to the technical scheme, the liquid drop stabilizer with excellent performance and low cost can be obtained, and the liquid drop stabilizer has important significance for high-value utilization of corn stalks and stabilization of agricultural liquid.
Disclosure of Invention
The invention aims to realize high-value utilization of corncob, and provides a preparation method of a pesticide droplet stabilizer based on the corncob, which improves the targeted utilization rate of pesticide droplets, and has the advantages of simpler production process and lower production cost.
The preparation method of the pesticide liquid drop stabilizer based on the corncob comprises the following steps:
step one, pretreatment of corncob, specifically comprising the following steps.
(1) Crushing, namely putting the corncob with the water content lower than 20% into a stirrer, and chopping for 10 minutes;
(2) Filtering, and passing the corncob powder through a 35-mesh screen;
Step two, obtaining corncob cellulose, which specifically comprises the following steps.
(1) And (3) alkali treatment, namely mixing the pretreated corncob powder with a sodium hydroxide aqueous solution with the mass fraction of 2% according to a solid-to-liquid ratio of 1:20, stirring for 4-6 hours at the temperature of 90-100 ℃, and further optimizing the porous structure of the corncob and increasing the specific surface area of the corncob through temperature pyrolysis. The optimization of pyrolysis conditions can be guided by the Arrhenius equation:
Where k is the pyrolysis reaction rate constant, A is the frequency factor, E a is the activation energy, R is the ideal gas constant, and T is the pyrolysis temperature.
(2) Removing alkali, and cleaning for 5-8 times by using distilled water;
(3) Rinsing, namely bleaching the fibers by using an equivalent amount of acetic acid buffer solution (2.7% of NaOH and 7.5% of glacial acetic acid) and chlorite (1.7% of NaClO 2 solution) solution, wherein the bleaching treatment is carried out for 6-8 hours at 80 ℃;
(4) The bleached fibers were repeatedly washed in distilled water until the pH of the fibers became 7, and dried in an air circulation oven at 40 ℃ for 24 hours, the purified material being the treated pure cellulose.
And thirdly, extracting cellulose nanocrystals, wherein the method specifically comprises the following steps.
(1) Extracting nanocrystals, placing each gram of pure cellulose sample into 15mL of H 2SO4 (9.17 mol/L) for hydrolysis, and continuously stirring at 45 ℃ for 1-2 hours;
(2) Diluting to remove acid, diluting the suspension 10 times with cold water to stop hydrolysis reaction, and centrifuging at 7500rpm for more than 10 minutes to remove excessive acid;
(3) Dialyzing the precipitate with tap water to remove inactive sulfate groups, salts and soluble sugars until the pH reaches 7;
(4) And (5) drying, carrying out ultrasonic treatment on the dialyzed matter for 10 minutes, and carrying out vacuum drying to obtain the corncob cellulose nanocrystalline.
And step four, extracting cellulose nanofibers, wherein the method specifically comprises the following steps.
(1) Treating tetramethylpiperidine, suspending corncob cellulose in water containing TEMPO (1 mmol/L) and sodium bromide (10 mmol/L), and continuously stirring at a liquid-solid ratio of 100-120;
(2) Adjusting the pH value, adding NaOH, and adjusting the pH value of the reaction system to 10.5;
(3) Tetramethylpiperidine mediated oxidation, at 25deg.C, an aqueous NaClO solution (10 mmol/g cellulose) was added to initiate TEMPO mediated oxidation, followed by NaOH to maintain pH at 10.5 for 2 hours;
(4) Washing, repeatedly adding ethanol for 6 times to obtain a solid substance, and washing with deionized water for 10 times;
(5) Centrifugal drying, the solid is treated by centrifugation (8000 rpm,5 minutes), and the corncob cellulose nanofiber is obtained by vacuum drying for 48 hours.
And fifthly, characterizing the corn cob nanofiber stabilizer, wherein the characterization method specifically comprises the following steps.
(1) Sample preparation, namely mixing corresponding volumes of water phase and oil phase (MCT) in proportion (total volume is 30 mL), and simultaneously adding a certain mass of corncob CNC and CNF (1:1) solid samples;
(2) Shear test, using FB-110J high speed shear, stirring at 12000rpm for 2min, each time operating for 1min, stopping for 30s;
(3) Emulsion samples of different parameters were prepared in order to study the volume fraction of oil Influence on emulsion performance, and under the condition that the concentration of nano cellulose particles is fixed to be 1.0% (w/v), different oil phase volume ratios are manufactured0.5 And 0.7) to study the effect of nanocellulose concentration, emulsion samples were made with cellulose particles of different concentrations (0.5%, 1.0% and 1.5% w/v) at a fixed oil phase volume ratio of 0.5;
(4) Rheological Property analysis, the rheological properties of the emulsion samples were measured at 20℃using an AR-500 rheometer, the rotor of which was a 40mm diameter parallel plate, and in steady-state flow mode, the relationship between shear rate (0.1 to 100s -1) and apparent viscosity (. Eta.) was obtained, the Linear Viscoelastic Region (LVR) was obtained by strain sweep testing (frequency 1Hz, strain range 0.1 to 100%), all dynamic tests were performed in LVR (strain = 1%), and frequency sweep was performed in the range 0.1 to 100rad/s to obtain storage modulus (G ') and loss modulus (G ' '), each measurement being preceded by an equilibrium of 5 min.
And step six, preparing and testing a pesticide droplet stabilizer based on corncob, which specifically comprises the following steps.
(1) Mixing solid pesticide particles with distilled water according to a certain proportion;
(2) Adding solid samples of corncob CNC and CNF (1:1);
(3) Stirring for 10 minutes;
(4) Testing the stability of pesticide liquid drops, calculating the sedimentation speed of the liquid drops by using Stokes law, and further evaluating the action effect of the stabilizer:
Where v is the sedimentation velocity of the droplet (m/s), ρ p is the density of the droplet (kg/m 3),ρf is the density of the fluid (kg/m 3), g is the gravitational acceleration (m/s 2), d is the diameter of the droplet (m), μ is the viscosity of the fluid (pa·s);
(5) If the stabilizing effect of the pesticide liquid drops is not achieved, changing the proportion parameters of CNC and CNF of the corncob;
(6) After the change, the stabilizing effect of the pesticide liquid drops still cannot be met, and the steps one to five are repeated until the parameter requirements are met.
Compared with the prior art, the invention has the beneficial effects that:
1. The agricultural waste of the corncob is used as the raw material, so that the problem of environmental pollution caused by corncob accumulation is solved, the recycling of resources is realized, the concept of green chemistry and sustainable development is met, good environmental benefits and social values are achieved, and the waste is turned into wealth;
2. The preparation method provided by the invention is simple and convenient to operate, low in cost and easy for large-scale production, provides a novel efficient, environment-friendly and economic pesticide droplet stabilizer for the pesticide industry, is expected to be widely applied to agricultural production, improves the yield and quality of crops, and promotes the increase of agricultural yield and income;
3. the cellulose nanocrystalline extracted by the method has high extraction efficiency, and the extraction rate is more than 10%.
Drawings
FIG. 1 is a schematic diagram of the overall process steps of the present invention
FIG. 2 is a schematic diagram of a method for obtaining cellulose from corncob according to the invention;
FIG. 3 is an extraction schematic of cellulose nanocrystals of the present invention;
FIG. 4 is an extraction schematic of cellulose nanofibers of the present invention;
FIG. 5 is a schematic representation of the characterization of the corncob nanofiber stabilizers of the present invention;
FIG. 6 is a schematic diagram of a method for preparing a pesticide droplet stabilizer based on corncob of the invention;
FIG. 7 is an optical microscope image of emulsion samples prepared in example 1 of the present invention under different oil phases;
FIG. 8 is a graph of the emulsion index of samples of emulsions prepared in accordance with example 1 of the present invention for different oil phase ratios at different storage times.
FIG. 9 is an optical microscopy image of emulsion prepared in example 1 of the present invention at different nanocellulose concentrations.
FIG. 10 is a graph showing the emulsion index of emulsion samples prepared in example 1 of the present invention at various storage times for various nanocellulose concentrations.
Detailed Description
The invention is further illustrated by the following examples in conjunction with the accompanying drawings:
Example 1A method for preparing a pesticide droplet stabilizer based on corncob, referring to fig. 1, comprises the following steps:
step one, pretreatment of corncob, referring to fig. 2, specifically comprises the following steps.
(1) Crushing, namely putting corncobs with the water content of 10% into a stirrer, and chopping for 10 minutes;
(2) Filtering, and passing the corncob powder through a 35-mesh screen;
step two, obtaining corncob cellulose, referring to fig. 2, specifically comprises the following steps.
(1) And (3) alkali treatment, namely mixing the pretreated corncob powder with a sodium hydroxide aqueous solution with the mass fraction of 2% according to the solid-to-liquid ratio of 1:20, stirring for 4 hours at 90 ℃, and further optimizing the porous structure of the corncob through temperature pyrolysis to increase the specific surface area of the corncob. The optimization of pyrolysis conditions can be guided by the Arrhenius equation:
Where k is the pyrolysis reaction rate constant, A is the frequency factor, E a is the activation energy, R is the ideal gas constant, and T is the pyrolysis temperature.
(2) Removing alkali, and washing with distilled water for 5 times;
(3) Rinsing, bleaching the fiber with an equal amount of acetic acid buffer (2.7% NaOH and 7.5% glacial acetic acid) and chlorite (1.7% NaClO 2 solution) solution, wherein the bleaching treatment is carried out at 80 ℃ for 6 hours;
(4) The bleached fibers were repeatedly washed in distilled water until the pH of the fibers became 7, and dried in an air circulation oven at 40 ℃ for 24 hours, the purified material being the treated pure cellulose.
Step three, extracting cellulose nanocrystals, referring to fig. 3, specifically comprises the following steps.
(1) Extracting nanocrystals, placing in 15mL of H 2SO4 (9.17 mol/L) for hydrolysis per gram of pure cellulose sample, the hydrolysis being carried out at 45 ℃ for 1 hour and stirring continuously;
(2) Diluting to remove acid, diluting the suspension 10 times with cold water to stop hydrolysis reaction, and centrifuging at 7500rpm for more than 10 minutes to remove excessive acid;
(3) Dialyzing the precipitate with tap water to remove inactive sulfate groups, salts and soluble sugars until the pH reaches 7;
(4) And (5) drying, carrying out ultrasonic treatment on the dialyzed matter for 10 minutes, and carrying out vacuum drying to obtain the corncob cellulose nanocrystalline.
Step four, extraction of cellulose nanofibers, referring to fig. 4, specifically includes the following steps.
(1) Tetramethylpiperidine treatment, suspending corncob cellulose in water containing TEMPO (1 mmol/L) and sodium bromide (10 mmol/L), and continuously stirring at a liquid-solid ratio of 100;
(2) Adjusting the pH value, adding NaOH, and adjusting the pH value of the reaction system to 10.5;
(3) Tetramethylpiperidine mediated oxidation, at 25deg.C, an aqueous NaClO solution (10 mmol/g cellulose) was added to initiate TEMPO mediated oxidation, followed by NaOH to maintain pH at 10.5 for 2 hours;
(4) Washing, repeatedly adding ethanol for 6 times to obtain a solid substance, and washing with deionized water for 10 times;
(5) Centrifugal drying, the solid is treated by centrifugation (8000 rpm,5 minutes), and the corncob cellulose nanofiber is obtained by vacuum drying for 48 hours.
Step five, characterization of the corn cob nanofiber stabilizer, referring to fig. 5, specifically comprises the following steps.
(1) Sample preparation, namely mixing corresponding volumes of water phase and oil phase (MCT) in proportion (total volume is 30 mL), and simultaneously adding a certain mass of corncob CNC and CNF (1:1) solid samples;
(2) Shear test, using FB-110J high speed shear, stirring at 12000rpm for 2min, each time operating for 1min, stopping for 30s;
(3) Emulsion samples of different parameters were prepared in order to study the volume fraction of oil Influence on emulsion performance, and under the condition that the concentration of nano cellulose particles is fixed to be 1.0% (w/v), different oil phase volume ratios are manufactured0.5 And 0.7) to study the effect of nanocellulose concentration, emulsion samples were made with cellulose particles of different concentrations (0.5%, 1.0% and 1.5% w/v) at a fixed oil phase volume ratio of 0.5;
(4) Rheological Property analysis, the rheological properties of the emulsion samples were measured at 20℃using an AR-500 rheometer, the rotor of which was a 40mm diameter parallel plate, and in steady-state flow mode, the relationship between shear rate (0.1 to 100s -1) and apparent viscosity (. Eta.) was obtained, the Linear Viscoelastic Region (LVR) was obtained by strain sweep testing (frequency 1Hz, strain range 0.1 to 100%), all dynamic tests were performed in LVR (strain = 1%), and frequency sweep was performed in the range 0.1 to 100rad/s to obtain storage modulus (G ') and loss modulus (G ' '), each measurement being preceded by an equilibrium of 5 min.
Step six, preparation and test of pesticide droplet stabilizer based on corncob, refer to figure 6, and specifically comprise the following.
(1) Mixing solid pesticide particles with distilled water according to a certain proportion;
(2) Adding solid samples of corncob CNC and CNF (1:1);
(3) Stirring for 10 minutes;
(4) Testing the stability of pesticide liquid drops, calculating the sedimentation speed of the liquid drops by using Stokes law, and further evaluating the action effect of the stabilizer:
Where v is the sedimentation velocity of the droplet (m/s), ρ p is the density of the droplet (kg/m 3),ρf is the density of the fluid (kg/m 3), g is the gravitational acceleration (m/s 2), d is the diameter of the droplet (m), μ is the viscosity of the fluid (pa·s);
(5) If the stabilizing effect of the pesticide liquid drops is not achieved, changing the proportion parameters of CNC and CNF of the corncob;
(6) After the change, the stabilizing effect of the pesticide liquid drops still cannot be met, and the steps one to five are repeated until the parameter requirements are met.
The optical microscope images of the emulsion samples of different oil ratios at the fixed nanocellulose concentration (1% by mass) prepared by the method are shown in fig. 7 (a: 0.3 oil ratio, b: 0.5 oil ratio, c: 0.7 oil ratio), and the emulsion indexes at different storage times are shown in fig. 8.
The emulsion optical microscope images of different nanocellulose concentrations at the fixed oil phase volume ratio (phi=0.5) prepared by the method are shown in fig. 9 (a: nanocellulose concentration is 0.5%, b: nanocellulose concentration is 1.0%, c: nanocellulose concentration is 1.5%), and the emulsion indexes at different storage times are shown in fig. 10.
Claims (6)
1. A preparation method of a pesticide droplet stabilizer based on corncob comprises the following steps:
Step one, pretreatment of corncob, specifically comprising the following steps of;
(1) Crushing, namely putting the corncob with the water content lower than 20% into a stirrer, and chopping for 10 minutes;
(2) Filtering, and passing the corncob powder through a 35-mesh screen;
step two, obtaining corncob cellulose;
Step three, extracting cellulose nanocrystals;
step four, extracting cellulose nano fibers;
fifthly, characterizing the corn cob nanofiber stabilizer;
And step six, preparing and testing a pesticide droplet stabilizer based on corncob.
2. The method for preparing the pesticide droplet stabilizer based on the corncob, as set forth in claim 1, wherein the specific steps of obtaining the corncob cellulose in the second step are as follows:
(1) Alkali treatment, namely mixing pretreated corncob powder with 2% sodium hydroxide aqueous solution according to a solid-to-liquid ratio of 1:20, stirring for 4-6 hours at 90-100 ℃, further optimizing the porous structure of the corncob through temperature pyrolysis, and guiding the optimization of pyrolysis conditions through an Arrhenius equation:
wherein k is a pyrolysis reaction rate constant, A is a frequency factor, E a is activation energy, R is an ideal gas constant, and T is a pyrolysis temperature;
(2) Removing alkali, and cleaning for 5-8 times by using distilled water;
(3) Rinsing, namely bleaching the fibers by using an equivalent amount of acetic acid buffer solution (2.7% of NaOH and 7.5% of glacial acetic acid) and chlorite (1.7% of NaClO 2 solution) solution, wherein the bleaching treatment is carried out for 6-8 hours at 80 ℃;
(4) The bleached fibers were repeatedly washed in distilled water until the pH of the fibers became 7, and dried in an air circulation oven at 40 ℃ for 24 hours, the purified material being the treated pure cellulose.
3. The method for preparing the pesticide droplet stabilizer based on the corncob, which is characterized by comprising the following specific steps of:
(1) Extracting nanocrystals, placing each gram of pure cellulose sample into 15mL of H 2SO4 (9.17 mol/L) for hydrolysis, and continuously stirring at 45 ℃ for 1-2 hours;
(2) Diluting to remove acid, diluting the suspension 10 times with cold water to stop hydrolysis reaction, and centrifuging at 7500rpm for more than 10 minutes to remove excessive acid;
(3) Dialyzing the precipitate with tap water to remove inactive sulfate groups, salts and soluble sugars until the pH reaches 7;
(4) And (5) drying, carrying out ultrasonic treatment on the dialyzed matter for 10 minutes, and carrying out vacuum drying to obtain the corncob cellulose nanocrystalline.
4. The method for preparing the pesticide droplet stabilizer based on the corncob, as set forth in claim 1, wherein the specific steps of cellulose nanofiber extraction in the fourth step are as follows:
(1) Treating tetramethylpiperidine, suspending corncob cellulose in water containing TEMPO (1 mmol/L) and sodium bromide (10 mmol/L), and continuously stirring at a liquid-solid ratio of 100-120;
(2) Adjusting the pH value, adding NaOH, and adjusting the pH value of the reaction system to 10.5;
(3) Tetramethylpiperidine mediated oxidation, at 25deg.C, an aqueous NaClO solution (10 mmol/g cellulose) was added to initiate TEMPO mediated oxidation, followed by NaOH to maintain pH at 10.5 for 2 hours;
(4) Washing, repeatedly adding ethanol for 6 times to obtain a solid substance, and washing with deionized water for 10 times;
(5) Centrifugal drying, the solid is treated by centrifugation (8000 rpm,5 minutes), and the corncob cellulose nanofiber is obtained by vacuum drying for 48 hours.
5. The method for preparing the pesticide droplet stabilizer based on the corncob, which is characterized by comprising the following specific steps of:
(1) Sample preparation, namely mixing corresponding volumes of water phase and oil phase (MCT) in proportion (total volume is 30 mL), and simultaneously adding a certain mass of corncob CNC and CNF (1:1) solid samples;
(2) Shear test, using FB-110J high speed shear, stirring at 12000rpm for 2min, each time operating for 1min, stopping for 30s;
(3) Emulsion samples of different parameters were prepared in order to study the volume fraction of oil Influence on emulsion performance, and under the condition that the concentration of nano cellulose particles is fixed to be 1.0% (w/v), different oil phase volume ratios are manufacturedSamples of 0.5 and 0.7) emulsion samples were made with different concentrations (0.5%, 1.0% and 1.5% w/v) of cellulose particles at a fixed oil phase volume ratio of 0.5;
(4) Rheological Property analysis, the rheological properties of the emulsion samples were measured at 20℃using an AR-500 rheometer, the rotor of which was a 40mm diameter parallel plate, and in steady-state flow mode, the relationship between shear rate (0.1 to 100s -1) and apparent viscosity (. Eta.) was obtained, the Linear Viscoelastic Region (LVR) was obtained by strain sweep testing (frequency 1Hz, strain range 0.1 to 100%), all dynamic tests were performed in LVR (strain = 1%), and frequency sweep was performed in the range 0.1 to 100rad/s to obtain storage modulus (G ') and loss modulus (G ' '), each measurement being preceded by an equilibrium of 5 min.
6. The method for preparing the pesticide droplet stabilizer based on the corncob, as set forth in claim 1, wherein the specific steps of preparing and testing the pesticide droplet stabilizer based on the corncob in the step six are as follows:
(1) Mixing solid pesticide particles with distilled water according to a certain proportion;
(2) Adding solid samples of corncob CNC and CNF (1:1);
(3) Stirring for 10 minutes;
(4) Testing the stability of pesticide liquid drops, calculating the sedimentation speed of the liquid drops by using Stokes law, and evaluating the action effect of the stabilizer:
Where v is the sedimentation velocity of the droplet (m/s), ρ p is the density of the droplet (kg/m 3),ρf is the density of the fluid (kg/m 3), g is the gravitational acceleration (m/s 2), d is the diameter of the droplet (m), μ is the viscosity of the fluid (pa·s);
(5) If the stabilizing effect of the pesticide liquid drops is not achieved, changing the proportion parameters of CNC and CNF of the corncob;
(6) After the change, the stabilizing effect of the pesticide liquid drops still cannot be met, and the steps one to five are repeated until the parameter requirements are met.
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