阅读说明：本技术 缓释型辛硫磷农药及其制备方法 (Slow-release phoxim pesticide and preparation method thereof ) 是由 耿佃国 董美丽 于 2019-09-30 设计创作，主要内容包括：本发明涉及有机-无机复合材料领域,具体涉及一种缓释型辛硫磷农药及其制备方法。将萘乙酸根插层水滑石前体,再将辛硫磷插层水滑石前体,得到辛硫磷/萘乙酸插层的水滑石,再将该水滑石放入含双氧水、乙醇、水的混合溶液中超声处理,得到缓释型辛硫磷农药,其化学式为：[(M<Sup>2+</Sup>)<Sub>1-x</Sub>(M<Sup>3+</Sup>)<Sub>x</Sub>(OH)<Sub>2</Sub>]<Sup>x+</Sup>(NAA<Sup>-</Sup>)<Sub>x</Sub>(Phoxim)<Sub>y</Sub>·mH<Sub>2</Sub>O,其中x＝0.25-0.33,y＝0.04-0.05,m＝3-6,m为层间结晶水分子的数量,M<Sup>2+</Sup>为二价金属离子,M<Sup>3+</Sup>为三价金属离子,Phoxim为辛硫磷。本发明的缓释型辛硫磷农药,插层结构稳定,可以长时间释放出辛硫磷,起到缓释效果。其制备方法易于实现。(The invention relates to the field of organic-inorganic composite materials, in particular to a slow-release phoxim pesticide and a preparation method thereof. The method comprises the following steps of intercalating naphthalene acetic acid into a hydrotalcite precursor, intercalating phoxim into the hydrotalcite precursor to obtain phoxim/naphthylacetic acid intercalated hydrotalcite, putting the hydrotalcite into a mixed solution containing hydrogen peroxide, ethanol and water for ultrasonic treatment to obtain the slow-release phoxim pesticide, wherein the chemical formula is as follows: [ (M) 2+ ) 1‑x (M 3+ ) x (OH) 2 ] x+ (NAA ‑ ) x (Phoxim) y ·mH 2 O, wherein x is 0.25-0.33, y is 0.04-0.05, M is 3-6, M is the number of interlayer crystalline water molecules, M is 2+ Is a divalent metal ion，M 3+ Is trivalent metal ion, and Phoxim is Phoxim. The slow release type phoxim pesticide has stable intercalation structure, can release phoxim for a long time and has slow release effect. The preparation method is easy to realize.)

1. A slow-release phoxim pesticide is characterized in that: firstly, preparing a hydrotalcite precursor, intercalating naphthylacetic acid radicals into the hydrotalcite precursor to form a hydrophobic environment containing a large number of naphthalene groups between layers, mixing the hydrotalcite with an acetone solution of phoxim, diffusing the phoxim into the layers of the hydrotalcite to obtain the phoxim/naphthylacetic acid intercalated hydrotalcite, and finally putting the phoxim/naphthylacetic acid intercalated hydrotalcite into a mixed solution containing hydrogen peroxide, ethanol and water for ultrasonic treatment to obtain the slow-release phoxim pesticide; the chemical formula is as follows:

[(M²⁺)_1-x(M³⁺)_x(OH)₂]^x+(NAA^-)_x(Phoxim)_y·mH₂O

wherein x is 0.25-0.33, y is 0.04-0.05, M is 3-6, M is the number of interlayer crystal water molecules, M is²⁺Is a divalent metal ion, M³⁺Is trivalent metal ion, and Phoxim is Phoxim.

2. The slow-release phoxim pesticide according to claim 1, wherein the pesticide comprises the following components in percentage by weight: m²⁺Is Mg²⁺、Ni²⁺Or Zn²⁺。

3. The slow-release phoxim pesticide according to claim 1, wherein the pesticide comprises the following components in percentage by weight: m³⁺Is Al³⁺。

4. A preparation method of the slow-release phoxim pesticide as claimed in claim 1, which is characterized by comprising the following steps:

(1) preparation of hydrotalcite precursor: preparation of interlayer anion NO₃ ^－Or Cl^－Layer plate divalent and trivalent metal ion molar ratio M²⁺/M³⁺Hydrotalcite precursor NO 2-3₃-LDHs or Cl-LDHs;

will M²⁺Soluble salts of (A) and (B)³⁺Preparing a salt-forming mixed solution from the soluble salt of (A), wherein M²⁺/M³⁺The molar ratio is 2-3, M²⁺In a molar concentration of 0.1-1.0M, M³⁺The molar concentration of (A) is 0.05-0.5M; NaOH is used as an alkali solution, wherein the molar concentration of the NaOH is 1.0-5.0M, and N is generated at room temperature₂Under the protection condition, adding the salt mixed solution and the alkali solution into a four-mouth bottle by a double-drop method, adjusting the pH value to 6-10 by using 0.1-5.0M NaOH solution after the addition is finished, crystallizing the obtained slurry for 12-72h at 60-90 ℃, putting the product into a centrifuge, centrifuging for 3-5min at the rotation speed of 2500-₂Washing with water to neutrality; taking out a sample, and drying at 50-90 ℃ for 20-48h to obtain a hydrotalcite precursor;

said M²⁺The soluble salt of (A) is a hydrochloride or nitrate salt, M³⁺The soluble salt is hydrochloride or nitrate, in the salt mixed solution, M²⁺Soluble salts of (A) and (B)³⁺The soluble salts of (A) are of the same kind;

(2) naphthylacetate intercalated hydrotalcite:

dissolving sodium naphthaleneacetate in a solvent to remove CO₂Adding the hydrotalcite precursor obtained in the step (1) into the deionized water, and N₂Protective heating to 5Reacting at 0-70 deg.C for 12-48h under stirring, centrifuging the product in a centrifuge at 2500-₂Washing with water to neutrality, and drying at 50-90 deg.C for 20-48h to obtain naphthylacetic acid intercalated hydrotalcite NNA-LDHs;

(3) the phoxim is fixed between layers of naphthylacetic acid intercalated hydrotalcite:

dissolving phoxim in acetone, adding the naphthylacetic acid intercalated hydrotalcite NNA-LDHs obtained in the step (2) into the acetone, and adding the obtained product into the acetone to obtain the N-substituted naphthalene sulfonic acid intercalated hydrotalcite₂Under protection and stirring, heating at 40-45 ℃ for 12-48h, fully washing the product with acetone, putting the product into a centrifuge, centrifuging at the rotation speed of 2500-;

(4) and (3) carrying out aftertreatment on the phoxim/naphthylacetic acid intercalated hydrotalcite:

and (3) putting the Phoxim/naphthylacetic acid intercalated hydrotalcite Phoxim/NNA-LDHs obtained in the step (3) into a mixed solution containing hydrogen peroxide, ethanol and water for ultrasonic treatment for 15-60min, and drying at 50-70 ℃ for 5-10h to obtain the slow-release Phoxim pesticide.

5. The preparation method of the slow-release phoxim pesticide as claimed in claim 4, characterized in that: in the mixed solution of hydrogen peroxide, ethanol and water, the mass concentrations of the hydrogen peroxide, the ethanol and the water are respectively as follows: 5-10%, 25-35% and 60-70%.

6. The preparation method of the slow-release phoxim pesticide as claimed in claim 5, characterized in that: in the mixed solution of hydrogen peroxide, ethanol and water, the mass concentrations of the hydrogen peroxide, the ethanol and the water are respectively as follows: 5%, 30% and 65%.

Technical Field

The invention relates to the field of organic-inorganic composite materials, in particular to a slow-release phoxim pesticide and a preparation method thereof.

Background

Phoxim (Phoxim) is an important organophosphorus pesticide, and the chemical name of the Phoxim is as follows: O-alpha-cyanophenylamino-O, O-diethylthiophosphate, Phoxim, has the international generic name Phoxim, with trade names including: phoxim, betanitrilon, betacyanon, hydroxyiminoctadine, benazepin, etc. The phoxim has the characteristics of stomach toxicity, contact poisoning, long residual effect under dark conditions and the like, and can be used for preventing and treating stem borers such as longicorn and the like. In addition, the pesticide has good effect on larvae of various lepidoptera pests harming crops such as peanuts, wheat, rice, fruit trees, vegetables, mulberries, tea and the like, has a certain killing effect on worm eggs, and is also suitable for preventing and controlling warehouse and sanitary pests. Therefore, the phoxim is a recognized organophosphorus pesticide with high efficiency, low toxicity and low residue. However, the pesticide has a plurality of problems in use, namely that phoxim is unstable, and is easy to decompose and lose efficacy when meeting strong light, high temperature, excessive water and alkaline substances. Secondly, the preparation of phoxim is mainly missible oil, water is added for spraying when the preparation is used, phoxim is easy to decompose under the existence of illumination and water, and the pesticide is easy to drift and run off, so that the pesticide cannot act on an ideal position, and the use effect is influenced. And thirdly, the organic solvent in the phoxim missible oil pollutes the environment. Fourthly, the pesticide effect time of phoxim is short, the pesticide effect is kept for 2 to 4 days by spraying, and the pesticide effect is kept in soil for about 1 month. Therefore, the pesticide effect of the phoxim is prolonged, the decomposition is avoided, the characteristic of high efficiency of phoxim disinsection is exerted, and the key for improving the application of phoxim pesticide is realized.

Hydrotalcite compounds are a typical anionic intercalation material, also called Layered Double Hydroxide (LDHs) with chemical composition [ M²⁺ _1-xM³⁺ _x(OH)₂]^x+(A^n–)_x/n·mH₂And O. The material is composed of parallel plates with a permanent positive charge. M²⁺，M³⁺I.e. divalent and trivalent metal cations, with exchangeable anions A between the layers^n-To maintain charge balance. The elements between the hydrotalcite laminates have strong covalent bond, the anions between the laminates attract each other by electrostatic attraction, and the whole crystal is electrically neutral. Due to the adjustable and controllable property of the metal ions and the anions between the layers of the laminate, the hydrotalcite material is widely applied to catalysisChemical reaction, absorption, medicine slow release, ion exchange and other fields.

Chinese patent CN104255352A discloses a preparation method of a pesticide slow-release heat-insulating material containing phoxim, which comprises the steps of shearing rice stems by mechanical shearing, mixing the rice stems, phoxim raw pesticide, sodium sulfate, urea and potassium sulfate, adding water for wetting, fully and uniformly stirring, filtering and drying to obtain the pesticide slow-release heat-insulating material containing phoxim. The method is used for the bamboo shoot ground coverage management, can prevent and control the soil insects of the bamboo shoots, has good prevention and control effects, has long lasting period in soil, and does not cause pesticide residues in the bamboo shoots to influence food safety; and the bamboo shoot growing medium can play a role in regulating and controlling the heat preservation and moisture preservation of the bamboo shoot field, promotes the growth of the bamboo shoots, accelerates the growth of the bamboo shoots in the bamboo shoot field and generates better economic benefit.

Although phoxim is widely applied in the field of pesticides, the defects of instability, easy decomposition by visible light, need of regular spraying and the like limit the application of phoxim. If the phoxim intercalation layer is arranged between hydrotalcite layers, when in use, the phoxim intercalation hydrotalcite is buried in soil, and the phoxim can be slowly spread out from the hydrotalcite, thereby playing the role of slowly releasing the pesticide. At present, no published documents and patents of phoxim intercalated hydrotalcite are found in China.

Disclosure of Invention

The invention aims to provide a slow-release phoxim pesticide and a preparation method thereof, the prepared phoxim pesticide is a hydrotalcite material with phoxim/naphthylacetic acid intercalation, the photic/naphthylacetic acid intercalation structure is more stable, and the material is resistant to light, high temperature and acid and alkali, can release phoxim for a long time when being soaked in water or soil, and has the effect of slow release of pesticide.

The slow release phoxim pesticide of the invention is: firstly, preparing a hydrotalcite precursor, intercalating naphthylacetic acid radicals into the hydrotalcite precursor to form a hydrophobic environment containing a large number of naphthalene groups between layers, mixing the hydrotalcite with an acetone solution of phoxim, diffusing the phoxim into the layers of the hydrotalcite to obtain the phoxim/naphthylacetic acid intercalated hydrotalcite, and finally putting the phoxim/naphthylacetic acid intercalated hydrotalcite into a mixed solution containing hydrogen peroxide, ethanol and water for ultrasonic treatment to obtain the slow-release phoxim pesticide; the chemical formula is as follows:

[(M²⁺)_1-x(M³⁺)_x(OH)₂]^x+(NAA^-)_x(Phoxim)_y·mH₂O

wherein x is 0.25-0.33, y is 0.04-0.05, M is 3-6, M is the number of interlayer crystal water molecules, M is²⁺Is a divalent metal ion, M³⁺Is trivalent metal ion, and Phoxim is Phoxim.

Said M²⁺Is Mg²⁺、Ni²⁺Or Zn²⁺Preferably Zn²⁺。

Said M³⁺Is Al³⁺。

The preparation method of the slow-release phoxim pesticide comprises the following steps:

(1) preparation of hydrotalcite precursor: preparation of interlayer anion NO₃ ^－Or Cl^－Layer plate divalent and trivalent metal ion molar ratio M²⁺/M³⁺Hydrotalcite precursor NO 2-3₃-LDHs or Cl-LDHs;

will M²⁺Soluble salts of (A) and (B)³⁺Preparing a salt-forming mixed solution from the soluble salt of (A), wherein M²⁺/M³⁺The molar ratio is 2-3, M^{2 +}In a molar concentration of 0.1-1.0M, M³⁺The molar concentration of (A) is 0.05-0.5M; NaOH is used as an alkali solution, wherein the molar concentration of the NaOH is 1.0-5.0M, and N is generated at room temperature₂Under the protection condition, adding the salt mixed solution and the alkali solution into a four-mouth bottle by a double-drop method, adjusting the pH value to 6-10 by using 0.1-5.0M NaOH solution after the addition is finished, crystallizing the obtained slurry for 12-72h at 60-90 ℃, putting the product into a centrifuge, centrifuging for 3-5min at the rotation speed of 2500-₂Washing with water to neutrality; taking out a sample, and drying at 50-90 ℃ for 20-48h to obtain a hydrotalcite precursor;

said M²⁺The soluble salt of (A) is a hydrochloride or nitrate salt, M³⁺The soluble salt is hydrochloride or nitrate, in the salt mixed solution, M²⁺Soluble salts of (A) and (B)³⁺The soluble salts of (A) are of the same kind;

(2) naphthylacetate intercalated hydrotalcite:

dissolving sodium naphthaleneacetate in a solvent to remove CO₂Adding the hydrotalcite precursor obtained in the step (1) into the deionized water, and N₂Heating to 50-70 deg.C under protection, reacting for 12-48h while stirring, centrifuging the product in a centrifuge at rotation speed of 2500-₂Washing with water to neutrality, and drying at 50-90 deg.C for 20-48h to obtain naphthylacetic acid intercalated hydrotalcite NNA-LDHs;

(3) the phoxim is fixed between layers of naphthylacetic acid intercalated hydrotalcite:

dissolving phoxim in acetone, adding the naphthylacetic acid intercalated hydrotalcite NNA-LDHs obtained in the step (2) into the acetone, and adding the obtained product into the acetone to obtain the N-substituted naphthalene sulfonic acid intercalated hydrotalcite₂Under protection and stirring, heating at 40-45 ℃ for 12-48h, fully washing the product with acetone, putting the product into a centrifuge, centrifuging at the rotation speed of 2500-;

(4) and (3) carrying out aftertreatment on the phoxim/naphthylacetic acid intercalated hydrotalcite:

and (3) putting the Phoxim/naphthylacetic acid intercalated hydrotalcite Phoxim/NNA-LDHs obtained in the step (3) into a mixed solution containing hydrogen peroxide, ethanol and water for ultrasonic treatment for 15-60min, and drying at 50-70 ℃ for 5-10h to obtain the product slow-release Phoxim pesticide.

Wherein: in the mixed solution of hydrogen peroxide, ethanol and water, the mass concentrations of the hydrogen peroxide, the ethanol and the water are respectively as follows: 5-10%, 25-35% and 60-70%. The preferred mass concentrations of hydrogen peroxide, ethanol and water are respectively as follows: 5%, 30% and 65%.

The particles of the Phoxim/naphthylacetic acid intercalated hydrotalcite Phoxim/NNA-LDHs obtained in the step (3) are easy to agglomerate together, the outlets are blocked, and some organic small molecules are adsorbed at the openings of the hydrotalcite laminate, so that the outward diffusion of the interlayer Phoxim is not facilitated, namely the slow release of the Phoxim is not facilitated, therefore, the Phoxim/naphthylacetic acid intercalated hydrotalcite Phoxim/NNA-LDHs needs to be subjected to the post-treatment of the step (4). In the step (4), the hydrotalcite particles agglomerated together can be broken through ultrasonic treatment; hydrogen peroxide can enter between hydrotalcite layers, and oxygen released in the ultrasonic process can oxidize part of organic micromolecules adsorbed at the openings of the hydrotalcite laminates; the ethanol can dissolve organic micromolecules adsorbed by the hydrotalcite laminate, and the mixed solution of hydrogen peroxide, ethanol and water is adopted for treatment, so that the slow release effect of the phoxim is ensured.

The invention has the following beneficial effects:

the invention utilizes interlayer ion exchangeability, laminate controllability and laminate structure positioning effect of hydrotalcite to make Naphthalene Acetate Anion (NAA)^-) Firstly, the intercalation enters into the hydrotalcite interlayer to prepare the organic-inorganic nano composite material. And introducing phoxim into hydrotalcite interlayers of the naphthylacetic acid intercalation by utilizing a hydrophobic environment formed by the naphthylacetic acid among the hydrotalcite interlayers to prepare the layered composite material containing the high-dispersion phoxim. The naphthalene also has large delocalized pi bond and is close to phoxim in property, so that the prepared phoxim/naphthylacetic acid intercalated hydrotalcite material has stable intercalated structure. The hydrotalcite can release phoxim for a long time when being soaked in water or soil.

The invention utilizes hydrophobic environment rich in delocalized pi bond provided by hydrotalcite interlaminar naphthylacetic acid, can assemble phoxim with unique physicochemical property into hydrotalcite interlaminar to realize the immobilization and high dispersion of phoxim, and in the prepared phoxim/naphthylacetic acid intercalated hydrotalcite material, the interaction force of phoxim and naphthylacetic acid is strong, and the intercalated structure is stable; meanwhile, a series of phoxim/naphthylacetic acid intercalated hydrotalcite materials can be prepared by changing the divalent trivalent metal ion types of the hydrotalcite laminate, the materials can release phoxim for a long time to play a role in pesticide slow release, and the preparation method is simple and easy to implement and easy to realize.

XRD characterization is carried out on the hydrotalcite material prepared by the invention, and the result shows that the hydrotalcite with phoxim/naphthylacetic acid intercalation is successfully prepared. The XRD structure parameters show that the naphthylacetic acid adopts a single-layer arrangement mode of an axial vertical laminate between hydrotalcite layers, and the interlayer spacing is further increased after the phoxim enters the layers. And the unit cell parameter a value is similar to that of other hydrotalcite, which shows that the product has a complete layered structure. From the condition that the intercalation product releases phoxim in aqueous solution, more than 0.0500 g of phoxim can be released from each gram of phoxim/naphthylacetic acid intercalation hydrotalcite, and the release time lasts more than 60 days.

In the phoxim/naphthylacetic acid intercalated hydrotalcite material, the phoxim/naphthylacetic acid intercalated structure is more stable, light-resistant, high temperature-resistant, acid-resistant and alkali-resistant, and has a slow release effect. Meanwhile, the special metal hydroxide structure of the hydrotalcite can treat acid soil. Therefore, the phoxim/naphthylacetic acid intercalated hydrotalcite can be used as a slow-release pesticide, is particularly suitable for being used in acid soil, and has high application value.

Drawings

FIG. 1 is a schematic structural diagram of phoxim/naphthylacetic acid intercalated hydrotalcite;

FIG. 2 is an X-ray powder diffraction pattern of the phoxim/naphthylacetic acid intercalated hydrotalcite prepared in example 1;

in fig. 2: a-a hydrotalcite precursor; b-naphthylacetic acid intercalated hydrotalcite; c-phoxim/naphthylacetic acid intercalated hydrotalcite;

FIG. 3 is the release curve of phoxim released from phoxim/naphthylacetic acid intercalated hydrotalcite.

Detailed Description

The present invention will be further described with reference to the following examples.