Lignin-based aqueous phase aggregate, preparation method thereof, pesticide composition and application thereof

Abstract

The invention provides a lignin-based aqueous phase aggregate, a preparation method thereof, a pesticide composition and application of the pesticide composition. The lignin-based aqueous phase aggregate has full-biomass-based components, is natural and harmless, does not need to synthesize polyelectrolyte or a small-molecular surfactant, and eliminates the ecological risk of synthetic components; the preparation process does not depend on an emulsifier, a cross-linking agent or an organic solvent, toxic risks of organic solvent residues on pesticide application personnel and crops are eliminated, the preparation process is simple, and complex steps such as shear emulsification and ultrasonic treatment are not needed; the lignin-based aqueous phase aggregate disclosed by the invention keeps stable in a wide pH, ionic strength and temperature range, does not need to depend on salt ions to adjust phase separation, and can tolerate complex environmental changes; the lignin-based aqueous phase aggregate disclosed by the invention has self-bacteriostatic activity and can be applied as a protective bactericide; the lignin-based aqueous phase aggregate has high encapsulation efficiency on various pesticides, and can play a synergistic role after encapsulating a bactericide.

Description

Technical Field

[0001] The present invention relates to the technical field of pesticide preparations, and in particular to a lignin-based aqueous phase coacervate and a preparation method thereof, a pesticide composition and applications thereof. Background Art

[0002] Aqueous coacervates are a type of liquid-liquid dispersion system that spontaneously forms through weak intermolecular interactions (such as electrostatic interactions and hydrophobic associations). Their unique dynamic membraneless structure, environmental responsiveness, and efficient material enrichment capabilities give them significant potential in drug delivery, pesticide encapsulation, and environmental remediation. Compared to traditional dispersion systems (such as emulsions and micelles), aqueous coacervates can be prepared without complex emulsification or cross-linking processes. They possess properties such as intelligent response, super-spreading, and enhanced permeation, enabling targeted controlled release of pesticides and becoming an important direction for the development of green pesticide delivery systems.

[0003] Currently, there are two main types of pesticide encapsulation technologies based on coacervates. One is microencapsulation technology, which uses coacervates as wall materials and combines emulsification cross-linking, spray drying, layer-by-layer self-assembly and other technologies to prepare solid microcapsules. Overall, it is a method for preparing solid dispersants and microcapsule suspensions. Although this type of method can delay the release of pesticides, it has significant defects: it requires multiple steps of reaction, which increases energy consumption; at the same time, it uses a large amount of organic solvents, which may be toxic to pesticide applicators and crops. The existing technology discloses a method for preparing avermectin microcapsules based on coacervation, which requires the addition of emulsifiers such as sodium lauryl sulfate and cross-linking agents such as glutaraldehyde, and there is a risk of organic solvent residues. The other type is direct encapsulation technology using aqueous phase coacervates, that is, directly dispersing and enriching pesticides in aqueous phase coacervates, omitting steps such as emulsification and cross-linking. This method has significant advantages: it reduces or even avoids the use of organic solvents, is more environmentally friendly, simpler, and more friendly to preparation personnel and pesticide users. In addition, the pesticide carrier prepared by this approach has a high encapsulation rate for pesticides. Compared with other systems such as micelles, it has stronger adhesion and spreading ability on plant leaves and a high retention rate on hydrophobic leaves.

[0004] Lignin is the second largest natural polymer material in the plant kingdom after cellulose in terms of reserves, and is also the only renewable plant resource with an aromatic ring structure that can be obtained in large quantities in nature. Its derivative, lignin sulfonate, is a polyanionic surfactant that has great application prospects in the field of pesticide carriers as a raw material for preparing aqueous coacervates. However, the construction of existing lignin-based aqueous coacervates still faces two key bottlenecks: (1) It relies on synthetic compounding agents and additives, and the preparation process is complicated. Existing lignin-based coacervates often need to be compounded with artificial synthetic polyelectrolytes, or small molecule surfactants, salts, etc. are added to regulate phase separation. These synthetic components not only increase the preparation cost, but may also bring about environmental problems such as poor biodegradability and ecotoxicity. (2) Insufficient environmental adaptability. The phase interface of existing coacervates is narrow and can only be stable within a very narrow range of pH, temperature and ionic strength. In agricultural environments, soil pH fluctuations, irrigation water salinity and temperature changes often lead to the destruction of coacervate structure, limiting its practical application in the field.

[0005] Therefore, it is still urgent to develop an aqueous phase coacervate pesticide adjuvant system with simple preparation process, green environmental protection, low cost and stable structure. Summary of the Invention

[0006] The purpose of the present invention is to overcome the defects of the prior art and provide a lignin-based aqueous phase coacervate and a preparation method thereof, a pesticide composition and its application.

[0007] The present invention provides the following technical solutions:

[0008] The invention provides a lignin-based aqueous phase coacervate comprising the following components: lignin sulfonate, polycationic amino acid, pH regulator and water.

[0009] Preferably, the polycationic amino acid is at least one of polylysine, polyarginine or polyhistidine, and preferably, the polycationic amino acid is ε-polylysine;

[0010] And / or, the lignin sulfonate includes at least one of sodium lignin sulfonate, calcium lignin sulfonate, potassium lignin sulfonate, and ammonium lignin sulfonate;

[0011] And / or, the pH adjuster is selected from one of the following substances: sodium hydroxide, ammonia water, hydrochloric acid, and sulfuric acid.

[0012] Preferably, the pH regulator is used in an amount such that the pH of the lignin-based aqueous coacervate is 2 to 11, preferably, the pH of the lignin-based aqueous coacervate is 6 to 8;

[0013] and / or, the concentration of lignin sulfonate in the lignin-based aqueous coacervate is 0.02 g / L to 20 g / L;

[0014] And / or, the concentration of the polycationic amino acid in the lignin-based aqueous coacervate is 0.02 g / L to 20 g / L.

[0015] In a second aspect, the present invention further provides a method for preparing the lignin-based aqueous coacervate, comprising the following steps:

[0016] S1, dissolving lignin sulfonate in water to obtain a lignin sulfonate precursor solution;

[0017] dissolving the polycationic amino acid in water to obtain a polycationic amino acid precursor solution;

[0018] S2, mixing the lignin sulfonate precursor solution and the polycationic amino acid precursor solution, and adding a pH regulator to adjust the pH to obtain a lignin-based aqueous phase coacervate;

[0019] Alternatively, a pH regulator is added to the lignin sulfonate precursor solution to adjust its pH, and a pH regulator is added to the polycationic amino acid precursor solution to adjust its pH;

[0020] The pH-adjusted lignin sulfonate precursor solution and the polycationic amino acid precursor solution are then mixed to obtain a lignin-based aqueous phase coacervate.

[0021] In a third aspect, the present invention further provides a use of the lignin-based aqueous coacervate or the lignin-based aqueous coacervate prepared by the preparation method in the preparation of a fungicide.

[0022] In a fourth aspect, the present invention further provides a use of the lignin-based aqueous coacervate or the lignin-based aqueous coacervate prepared by the preparation method as an adjuvant or drug-carrying system in pesticide encapsulation.

[0023] In a fifth aspect, the present invention further provides a pesticide composition comprising the lignin-based aqueous coacervate or the lignin-based aqueous coacervate prepared by the preparation method and a pesticide.

[0024] Preferably, the pesticide includes at least one of a fungicide, an insecticide, a herbicide, and a plant growth regulator; preferably, the fungicide includes at least one of prochloraz, pyraclostrobin, kasugamycin, difenoconazole, jinggangmycin, and trifloxystrobin;

[0025] And / or, the concentration of the pesticide in the pesticide composition is 0.01 to 2500 mg / L.

[0026] In a sixth aspect, the present invention further provides a method for preparing the pesticide composition, comprising the following steps: dispersing the pesticide into lignin-based aqueous coacervate to obtain the pesticide composition.

[0027] In a seventh aspect, the present invention also provides a use of the lignin-based aqueous coacervate or the lignin-based aqueous coacervate prepared by the preparation method, or the pesticide composition, or the pesticide composition prepared by the preparation method in inhibiting spore germination.

[0028] The lignin-based aqueous coacervate, preparation method thereof, pesticide composition and application thereof of the present invention have the following beneficial effects compared with the prior art:

[0029] 1. The lignin-based aqueous coacervate of the present invention comprises the following components: lignin sulfonate, polycationic amino acid, pH regulator, and water. The lignin-based aqueous coacervate of the present invention has all-biomass-based components, lignin sulfonate reserves are huge and renewable, and ε-polylysine is derived from biological fermentation (among polyhistidine, polyarginine, and polylysine, only ε-polylysine is derived from biological fermentation, while polyarginine, polyhistidine, and α-polylysine are all derived from chemical synthesis). It is natural and harmless, and does not require the synthesis of polyelectrolytes or small molecule surfactants, eliminating the ecological risks of synthetic ingredients. The preparation process does not rely on emulsifiers, cross-linking agents, or organic solvents, eliminating the risk of toxicity to pesticide applicators and crops from residual organic solvents.

[0030] 2. The preparation process of the lignin-based aqueous coacervate of the present invention is simple. Liquid-liquid phase separation can be achieved through simple mixing, without the need for complex steps such as shear emulsification and ultrasound. The lignin-based aqueous coacervate remains stable over a wide range of pH, ionic strength, and temperature, does not rely on salt ions to regulate phase separation, and can withstand complex environmental changes, greatly simplifying the process flow and reducing production energy consumption.

[0031] 3. The lignin-based aqueous coacervate of the present invention has its own antibacterial activity and can be used as a protective fungicide; the lignin-based aqueous coacervate of the present invention has a high encapsulation efficiency for a variety of pesticides and can play a synergistic role after encapsulating the fungicide. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0033] Figure 1 This is a diagram showing the formation of lignin-based aqueous coacervates at different concentration ratios prepared in Example 1.

[0034] Figure 2 The morphological characteristics and particle size distribution of the lignin-based aqueous phase coacervate prepared in Example 2.

[0035] Figure 3 The turbidity changes of the lignin-based aqueous coacervate prepared in Example 3 at different pH and temperature.

[0036] Figure 4 This is a fluorescence image of the lignin-based aqueous coacervate prepared in Example 4 enriched with hydrophilic and hydrophobic dyes.

[0037] Figure 5 This is a bar graph showing the encapsulation efficiency of prochloraz (Pro) by the lignin-based aqueous coacervate prepared in Example 5.

[0038] Figure 6 This is a bar graph showing the encapsulation efficiency of cyhalothrin (Cyh) by the lignin-based aqueous coacervate prepared in Example 6.

[0039] Figure 7 This is confirmation of the spore germination inhibitory activity of the SL / Ply aqueous coacervate (Coa.) and the SL / Ply aqueous coacervate encapsulating prochloraz (Pro) (Pro@Coa.) in Example 7. DETAILED DESCRIPTION

[0040] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0041] It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments. In addition, in the description of this application, the term "including" means "including but not limited to". Various embodiments of the present invention may be in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be understood as a rigid limitation on the scope of the invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, regardless of the range. In addition, whenever a numerical range is indicated in this article, it is meant to include any cited numbers (fractions or integers) within the indicated range. The application principle of the present invention is described in detail below in conjunction with the accompanying drawings.

[0042] The invention provides a lignin-based aqueous phase coacervate comprising the following components: lignin sulfonate, polycationic amino acid, pH regulator and water.

[0043] The present invention provides a water-based pesticide adjuvant system composed of a liquid-phase coacervate formed from lignin sulfonate and a polycationic amino acid. The system comprises the following components: lignin sulfonate, a polycationic amino acid, a pH adjuster, and water. The lignin sulfonate, as a polyanionic surfactant, possesses both hydrophilic and hydrophobic properties, providing a structural foundation for pesticide encapsulation. It also exhibits excellent UV resistance, providing protection against photosensitive pesticides. Polycationic amino acids, such as polylysine, polyarginine, and polyhistidine, are known to exhibit excellent antimicrobial efficacy and biocompatibility as antimicrobial peptides. In particular, ε-polylysine, a natural microbial fermentation product, can be utilized as a protective fungicide and exhibits excellent properties such as being green, non-toxic, and less likely to induce drug resistance. At a certain concentration, the polycationic amino acid and the polyanionic surfactant lignin sulfonate undergo liquid-liquid phase separation in water through electrostatic and hydrophobic interactions, forming an aqueous coacervate (dispersed phase). This aqueous coacervate exhibits excellent encapsulation efficiency for both hydrophobic and hydrophilic pesticides. At the same time, the agglomerates themselves have good antibacterial, UV resistance and super-spreading properties, which can enhance the synergistic effect of pesticides.

[0044] In some embodiments, the lignin sulfonate can be selected from at least one of the following substances: sodium lignin sulfonate, calcium lignin sulfonate, potassium lignin sulfonate, and ammonium lignin sulfonate; the concentration of the lignin sulfonate in the lignin-based aqueous phase coacervate can be 0.02 g / L to 20 g / L, exemplified by 0.5 g / L, 1 g / L, and 5 g / L.

[0045] In some embodiments, the polycationic amino acid can be selected from at least one of the following substances: polylysine, polyarginine and polyhistidine, preferably polylysine, and more preferably ε-polylysine; the concentration of the polycationic amino acid in the lignin-based aqueous phase coacervate can be 0.02 g / L to 20 g / L, exemplified by 0.5 g / L, 1 g / L, and 5 g / L.

[0046] Furthermore, preferably, the concentration of lignin sulfonate is 1 g / L to 8 g / L, and the concentration of polycationic amino acid is 1 g / L to 8 g / L.

[0047] In some embodiments, the pH adjuster can be selected from one or two of the following substances: hydrochloric acid, sulfuric acid, phosphoric acid, sodium hydroxide, potassium hydroxide, and ammonia water; the purpose and dosage of the pH adjuster are to make the pH of the lignin-based aqueous phase coacervate system 2 to 11, preferably to make the pH of the system 6 to 8.

[0048] Based on the same inventive concept, the present invention also provides a method for preparing the above-mentioned lignin-based aqueous coacervate, comprising the following steps:

[0049] S1, dissolving lignin sulfonate in water to obtain a lignin sulfonate precursor solution;

[0050] dissolving the polycationic amino acid in water to obtain a polycationic amino acid precursor solution;

[0051] S2, mixing the lignin sulfonate precursor solution and the polycationic amino acid precursor solution, and adding a pH regulator to adjust the pH to obtain a lignin-based aqueous phase coacervate;

[0052] Alternatively, a pH regulator is added to the lignin sulfonate precursor solution to adjust its pH, and a pH regulator is added to the polycationic amino acid precursor solution to adjust its pH;

[0053] The pH-adjusted lignin sulfonate precursor solution and the polycationic amino acid precursor solution are then mixed to obtain a lignin-based aqueous phase coacervate.

[0054] Specifically, mixing the two precursor solutions and then adjusting the pH is a rough adjustment of the system pH, while pre-adjusting the pH of the precursor solutions and then mixing them is more precise; the above two methods of adjusting the pH ultimately make the pH of the lignin-based aqueous phase coagulant 2 to 11, and more preferably make the system pH 6 to 8.

[0055] The present invention's method for preparing lignin-based aqueous coacervates involves simply mixing lignin sulfonate with a polycationic amino acid, eliminating the need for synthetic surfactants. The preparation process is simple, environmentally friendly, and stable over a wide pH and temperature range. This system can inhibit spore germination and efficiently encapsulate pesticides, enhancing their effectiveness against fungicides. This system combines carrier functionality with antibacterial activity, providing an efficient and environmentally friendly solution for the development of green pesticides.

[0056] Based on the same inventive concept, the present invention also provides the use of the above-mentioned lignin-based aqueous phase coacervate in the preparation of a fungicide.

[0057] Based on the same inventive concept, the present invention also provides the use of the above-mentioned lignin-based aqueous phase coacervate as an adjuvant or drug-carrying system in pesticide encapsulation.

[0058] The lignin-based aqueous aggregates of the present invention can be used as water-based pesticide adjuvants to encapsulate both hydrophilic and hydrophobic pesticide technicals. The aggregates themselves can be used as protective fungicides. Protective fungicides are those that adhere to crop surfaces after application, forming a film that inhibits spore germination, germ tube formation, or interferes with pathogen invasion.

[0059] Based on the same inventive concept, the present invention also provides a pesticide composition, comprising the above-mentioned lignin-based aqueous coacervate or the lignin-based aqueous coacervate prepared by the above-mentioned preparation method and a pesticide.

[0060] In some embodiments, the pesticide includes at least one of a fungicide, an insecticide, a herbicide, and a plant growth regulator; preferably, the fungicide can be selected from organic fungicides known in the art; for example, including but not limited to at least one of the following substances: prochloraz, pyraclostrobin, kasugamycin, difenoconazole, jinggangmycin, and trifloxystrobin.

[0061] In some embodiments, the concentration of the pesticide in the pesticide composition is 0.01 to 2500 mg / L, exemplified by 0.05 mg / L, 0.25 mg / L, 1 mg / L, 50 mg / L, and 1000 mg / L.

[0062] Based on the same inventive concept, the present invention also provides a method for preparing the above-mentioned pesticide composition, comprising the following steps: dispersing the pesticide into lignin-based aqueous coacervate to obtain the pesticide composition.

[0063] The present invention also provides a fungicide-containing lignin-based aqueous coacervate pesticide, comprising: a fungicide and a lignin-based aqueous coacervate. The preparation method comprises the following steps: adding the fungicide to the lignin-based aqueous coacervate, thoroughly mixing, and allowing the mixture to stand; the fungicide can be selected from organic fungicides known in the art; for example, including but not limited to one, two, or more of the following: prochloraz, pyraclostrobin, kasugamycin, difenoconazole, jinggangmycin, and trifloxystrobin; the standing time is 0.1 to 24 hours, for example, 1 to 2 hours; and the standing temperature is 0 to 30°C, for example, 4°C or 20°C.

[0064] Based on the same inventive concept, the present invention also provides a use of the above-mentioned lignin-based aqueous coacervate or the above-mentioned pesticide composition in inhibiting spore germination.

[0065] The lignin-based aqueous coacervate of the present invention is entirely biomass-based, with vast reserves of renewable lignin sulfonates. The ε-polylysine is derived from biological fermentation (among polyhistidine, polyarginine, and polylysine, only ε-polylysine is derived from biological fermentation; polyarginine, polyhistidine, and α-polylysine are all derived from chemical synthesis). It is naturally harmless and does not require the synthesis of polyelectrolytes or small-molecule surfactants, eliminating the ecological risks of synthetic ingredients. The preparation process does not rely on emulsifiers, cross-linking agents, or organic solvents, eliminating the risk of toxicity to applicators and crops from residual organic solvents.

[0066] The preparation process of the lignin-based aqueous coacervate of the present invention is simple, and liquid-liquid phase separation can be achieved through simple mixing, without the need for complex steps such as shear emulsification and ultrasound. The lignin-based aqueous coacervate remains stable over a wide range of pH, ionic strength, and temperature, does not rely on salt ions to regulate phase separation, and can withstand complex environmental changes, greatly simplifying the process flow and reducing production energy consumption.

[0067] The lignin-based aqueous phase aggregate of the present invention has its own antibacterial activity and can be used as a protective fungicide. It has high encapsulation efficiency for various pesticides and can achieve a synergistic effect after encapsulating the fungicide.

[0068] The following further illustrates the lignin-based aqueous coacervate and its preparation method, pesticide composition, and its application in the present invention with reference to specific examples. This section further illustrates the present invention in conjunction with specific examples, but should not be construed as limiting the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in the art.

[0069] The raw materials and reagents used in the following examples are all commercially available products. The lignin sulfonate in the examples and figures is sodium lignin sulfonate (SL), and the polycationic amino acid is ε-polylysine (Ply).

[0070] Example 1

[0071] This embodiment provides a lignin-based aqueous coacervate, comprising the following components: sodium lignin sulfonate (SL), ε-polylysine (Ply), a pH regulator (specifically NaOH), and water;

[0072] The concentration of sodium lignin sulfonate (SL) in the lignin-based aqueous aggregate is 0.5 to 8 g / L (specifically 0.5 g / L, 1 g / L, 2 g / L, 3 g / L, 4 g / L, 5 g / L, 6 g / L, 7 g / L, and 8 g / L);

[0073] The concentration of ε-polylysine (Ply) in the lignin-based aqueous aggregates is 0.5 to 8 g / L (specifically 0.5 g / L, 1 g / L, 2 g / L, 3 g / L, 4 g / L, 5 g / L, 6 g / L, 7 g / L, and 8 g / L);

[0074] The pH of the lignin-based aqueous coacervate was 8.

[0075] The preparation method of the above-mentioned lignin-based aqueous phase coacervate comprises the following steps:

[0076] S1, dissolving lignin sulfonate in water to obtain a lignin sulfonate precursor solution;

[0077] dissolving the polycationic amino acid in water to obtain a polycationic amino acid precursor solution;

[0078] S2. Add NaOH to the lignin sulfonate precursor solution to adjust its pH to 8, and add NaOH to the polycationic amino acid precursor solution to adjust its pH to 8;

[0079] Then, the pH-adjusted lignin sulfonate precursor solution and the polycationic amino acid precursor solution are mixed in equal volumes and allowed to stand to obtain a lignin-based aqueous phase coacervate.

[0080] Example 1 studied the formation of aggregates of SL and Ply in the range of 0.5 to 8 g / L. Figure 1 As shown, within this concentration range, most concentration combinations can form aggregates. Specifically, aggregates can form at SL and Ply concentrations of 1 to 8 g / L. Aggregates can also form when the SL concentration is 0.5 g / L and the Ply concentrations are 0.5 g / L, 1 g / L, 3 g / L, 4 g / L, and 5 g / L, respectively. Aggregates can also form when the Ply concentration is 0.5 g / L and the SL concentration is 1 g / L. Micelles are defined as systems that are clear and transparent under macroscopic observation, with a turbidity below 10% and few or no spherical droplets visible under a microscope. Aggregates, on the other hand, appear as turbid emulsions with a high turbidity of above 90%, and numerous spherical droplets visible under a microscope.

[0081] Example 2

[0082] This embodiment provides a lignin-based aqueous coacervate, comprising the following components: sodium lignin sulfonate (SL), ε-polylysine (Ply), a pH regulator (specifically NaOH), and water;

[0083] Among them, the concentration of sodium lignin sulfonate (SL) in the lignin-based aqueous aggregates was 2 g / L;

[0084] The concentration of ε-polylysine (Ply) in the lignin-based aqueous aggregates was 2 g / L;

[0085] The pH of the lignin-based aqueous coacervate was 8.

[0086] The preparation method of the lignin-based aqueous phase coacervate in Example 2 is prepared by referring to the method in Example 1.

[0087] The lignin-based aqueous phase aggregates prepared in Example 2 were placed under an optical microscope to observe their morphology and to count their sizes. Figure 2 As shown, the aggregates present a spherical droplet structure with an average particle size of 1.35±0.79μm.

[0088] Example 3

[0089] This embodiment provides a lignin-based aqueous coacervate, comprising the following components: sodium lignin sulfonate (SL), ε-polylysine (Ply), a pH regulator (specifically NaOH), and water;

[0090] The concentration of sodium lignin sulfonate (SL) in the lignin-based aqueous aggregates was 1 g / L;

[0091] The concentration of ε-polylysine (Ply) in the lignin-based aqueous aggregates was 1 g / L;

[0092] The pH of the lignin-based aqueous coacervate was 8.

[0093] The preparation method of the lignin-based aqueous phase coacervate in Example 3 is prepared by referring to the method in Example 1.

[0094] The lignin-based aqueous coacervate (SL / Ply aqueous coacervate) prepared in Example 3 was examined for turbidity changes under different pH and temperature conditions using an ultraviolet spectrophotometer to evaluate the stability of the SL / Ply aqueous coacervate, where turbidity is reported as 100-%T. (Turbidity is indirectly measured by measuring the transmittance of the system. The transmittance is expressed as %T. The turbidity 100-%T is based on 100%. The remaining light-blocking ratio after deducting the transmittance ratio reflects the degree of light obstruction of the coacervate. The calculation result of 100-%T naturally has the dimension of percentage and does not need to indicate the unit.) Specifically, when the temperature is fixed at 20°C, the pH of the lignin-based aqueous coacervate prepared in Example 3 is adjusted to pH 1.75-11 (specifically, HCl or NaOH is added to the lignin-based aqueous coacervate to adjust the pH), and its turbidity change is tested; when the pH of the lignin-based aqueous coacervate prepared in Example 3 is fixed at 8, its temperature is adjusted to 20-70°C, and its turbidity change is tested. The test results are as follows: Figure 3 shown.

[0095] like Figure 3 As shown in the figure, the turbidity of the aggregates did not change significantly in the pH range of 1.75 to 8.91 and the temperature of 20 to 70 °C, indicating that the aggregates existed stably under these conditions.

[0096] Example 4

[0097] This embodiment provides a lignin-based aqueous coacervate, comprising the following components: sodium lignin sulfonate (SL), ε-polylysine (Ply), a pH regulator (specifically NaOH), and water;

[0098] Among them, the concentration of sodium lignin sulfonate (SL) in the lignin-based aqueous phase aggregates was 2.5 g / L;

[0099] The concentration of ε-polylysine (Ply) in the lignin-based aqueous aggregates was 2.5 g / L;

[0100] The pH of the lignin-based aqueous coacervate was 8.

[0101] The preparation method of the lignin-based aqueous phase coacervate in Example 4 is prepared by referring to the method in Example 1.

[0102] The hydrophilic dye methylene blue, rhodamine 6G, and the hydrophobic dye Nile red were used as representative fluorescent materials to evaluate the encapsulation ability of the lignin-based aqueous phase coacervate in Example 4 for various types of pesticide technicals.

[0103] Specifically, methylene blue, rhodamine 6G, and Nile red were added to the lignin-based aqueous coacervate in Example 4, respectively, and the final concentration of each dye was 0.03 mmol / L; Figure 4 As shown in Figure 3, laser confocal microscopy observations showed that both hydrophilic and hydrophobic dyes could be enriched in the SL / Ply coacervate droplets.

[0104] Example 5

[0105] This embodiment provides a lignin-based aqueous coacervate, which is the same as that of Example 1, except that the concentrations of SL and Ply and the pH of the prepared lignin-based aqueous coacervate are as follows:

[0106] The concentration of sodium lignin sulfonate (SL) and ε-polylysine (Ply) in the lignin-based aqueous coacervate was 0.5 g / L, and the pH of the lignin-based aqueous coacervate was 7;

[0107] The concentration of sodium lignin sulfonate (SL) and ε-polylysine (Ply) in the lignin-based aqueous coacervate was 0.5 g / L, and the pH of the lignin-based aqueous coacervate was 8;

[0108] The concentration of sodium lignin sulfonate (SL) and ε-polylysine (Ply) in the lignin-based aqueous coacervate was 1 g / L, and the pH of the lignin-based aqueous coacervate was 7;

[0109] The concentration of sodium lignin sulfonate (SL) and ε-polylysine (Ply) in the lignin-based aqueous coacervate was 1 g / L, and the pH of the lignin-based aqueous coacervate was 8;

[0110] The concentration of sodium lignin sulfonate (SL) in the lignin-based aqueous coacervate was 1 g / L, the concentration of ε-polylysine (Ply) was 2 g / L, and the pH of the lignin-based aqueous coacervate was 7;

[0111] The concentration of sodium lignin sulfonate (SL) in the lignin-based aqueous coacervate was 1 g / L, the concentration of ε-polylysine (Ply) was 2 g / L, and the pH of the lignin-based aqueous coacervate was 8;

[0112] The concentration of sodium lignin sulfonate (SL) in the lignin-based aqueous coacervate was 1 g / L, the concentration of ε-polylysine (Ply) was 3 g / L, and the pH of the lignin-based aqueous coacervate was 7;

[0113] The concentration of sodium lignin sulfonate (SL) in the lignin-based aqueous coacervate was 1 g / L, the concentration of ε-polylysine (Ply) was 3 g / L, and the pH of the lignin-based aqueous coacervate was 8;

[0114] The concentration of sodium lignin sulfonate (SL) in the lignin-based aqueous coacervate was 2 g / L, the concentration of ε-polylysine (Ply) was 1 g / L, and the pH of the lignin-based aqueous coacervate was 7;

[0115] The concentration of sodium lignin sulfonate (SL) in the lignin-based aqueous coacervate was 2 g / L, the concentration of ε-polylysine (Ply) was 1 g / L, and the pH of the lignin-based aqueous coacervate was 8;

[0116] The concentration of sodium lignin sulfonate (SL) and ε-polylysine (Ply) in the lignin-based aqueous coacervate was 2 g / L, and the pH of the lignin-based aqueous coacervate was 7;

[0117] The concentration of sodium lignin sulfonate (SL) in the lignin-based aqueous coacervate was 3 g / L, the concentration of ε-polylysine (Ply) was 1 g / L, and the pH of the lignin-based aqueous coacervate was 8;

[0118] The concentration of sodium lignin sulfonate (SL) in the lignin-based aqueous coacervate was 3 g / L, the concentration of ε-polylysine (Ply) was 2 g / L, and the pH of the lignin-based aqueous coacervate was 8;

[0119] The concentrations of sodium lignin sulfonate (SL) and ε-polylysine (Ply) in the lignin-based aqueous coacervate are 3 g / L and 3 g / L, respectively, and the pH value of the lignin-based aqueous coacervate is 8.

[0120] The encapsulation efficiency of the pesticide prochloraz (Pro) in the various lignin-based aqueous coacervates described above was tested. Specifically, a 20 g / L prochloraz ethanol solution was added to the various lignin-based aqueous coacervates described in Example 5 to a final concentration of 500 mg / L (i.e., a final prochloraz (Pro) concentration of 500 mg / L), thereby producing SL / Ply aqueous coacervates encapsulating prochloraz. The system was allowed to stand for 24 hours, and 1 mL of the supernatant was filtered through a 0.22 μm filter membrane. The filtrate was then analyzed by high-performance liquid chromatography to determine the prochloraz concentration. The encapsulation efficiency was calculated as follows:

[0121]

[0122] The total pesticide concentration refers to the final concentration of prochloraz (Pro) in the initial lignin-based aqueous phase aggregates, which is 500 mg / L.

[0123] The test results of the encapsulation efficiency of the pesticide prochloraz (Pro) by lignin-based aqueous phase aggregates are as follows: Figure 5 As shown, Figure 5The middle horizontal axis represents the concentration of sodium lignin sulfonate (SL) and ε-polylysine (Ply) in the lignin-based aqueous phase aggregates. For example, 0.5:0.5 means that the concentration of sodium lignin sulfonate (SL) is 0.5 g / L and the concentration of ε-polylysine (Ply) is 0.5 g / L.

[0124] like Figure 5 As shown in the figure, under the conditions of pH 7 and 8, the coacervates with different SL and Ply ratios showed extremely high encapsulation efficiency for prochloraz, which was maintained above 94%, which fully demonstrated that the encapsulation ability of the coacervates for prochloraz was stable and reliable.

[0125] Example 6

[0126] This embodiment provides a lignin-based aqueous coacervate, which is the same as that of Example 1, except that the concentrations of SL and Ply and the pH of the prepared lignin-based aqueous coacervate are as follows:

[0127] The concentration of sodium lignin sulfonate (SL) and ε-polylysine (Ply) in the lignin-based aqueous coacervate was 0.5 g / L, and the pH of the lignin-based aqueous coacervate was 7;

[0128] The concentration of sodium lignin sulfonate (SL) in the lignin-based aqueous coacervate was 0.5 g / L, the concentration of ε-polylysine (Ply) was 1 g / L, and the pH of the lignin-based aqueous coacervate was 7;

[0129] The concentration of sodium lignin sulfonate (SL) in the lignin-based aqueous coacervate was 0.5 g / L, the concentration of ε-polylysine (Ply) was 2 g / L, and the pH of the lignin-based aqueous coacervate was 7;

[0130] The concentration of sodium lignin sulfonate (SL) in the lignin-based aqueous coacervate was 1 g / L, the concentration of ε-polylysine (Ply) was 0.5 g / L, and the pH of the lignin-based aqueous coacervate was 7;

[0131] The concentration of sodium lignin sulfonate (SL) and ε-polylysine (Ply) in the lignin-based aqueous coacervate was 1 g / L, and the pH of the lignin-based aqueous coacervate was 7;

[0132] The concentration of sodium lignin sulfonate (SL) in the lignin-based aqueous coacervate was 1 g / L, the concentration of ε-polylysine (Ply) was 2 g / L, and the pH of the lignin-based aqueous coacervate was 7;

[0133] The concentration of sodium lignin sulfonate (SL) in the lignin-based aqueous coacervate was 2 g / L, the concentration of ε-polylysine (Ply) was 0.5 g / L, and the pH of the lignin-based aqueous coacervate was 7;

[0134] The concentration of sodium lignin sulfonate (SL) in the lignin-based aqueous coacervate was 2 g / L, the concentration of ε-polylysine (Ply) was 1 g / L, and the pH of the lignin-based aqueous coacervate was 7;

[0135] The concentrations of sodium lignin sulfonate (SL) and ε-polylysine (Ply) in the lignin-based aqueous phase coacervate are 2 g / L and 2 g / L, respectively, and the pH value of the lignin-based aqueous phase coacervate is 7.

[0136] The encapsulation efficiency of the pesticide lambda-cyhalothrin (Cyh) by the different lignin-based aqueous coacervates was tested. Specifically, a 20 g / L acetonitrile solution of lambda-cyhalothrin (Cyh) (acetonitrile was used here because the mobile phase used in the HPLC assay was acetonitrile; a greener organic solvent can be substituted in the application) was added to the different lignin-based aqueous coacervates described in Example 6 to a final concentration of 500 mg / L (i.e., a final lambda-cyhalothrin (Cyh) concentration of 500 mg / L) to produce SL / Ply aqueous coacervates encapsulating lambda-cyhalothrin (Cyh). After the system was allowed to stand for 24 hours, 1 mL of the supernatant was filtered through a 0.22 μm filter membrane, and the filtrate was used to determine the prochloraz concentration by HPLC. The encapsulation efficiency was calculated using the above formula.

[0137] The test results of the encapsulation efficiency of the pesticide cyhalothrin (Cyh) by lignin-based aqueous phase coacervates are as follows: Figure 6 As shown, Figure 6 The middle horizontal axis represents the concentration of sodium lignin sulfonate (SL) and ε-polylysine (Ply) in the lignin-based aqueous phase aggregates. For example, 0.5:0.5 means that the concentration of sodium lignin sulfonate (SL) is 0.5 g / L and the concentration of ε-polylysine (Ply) is 0.5 g / L.

[0138] like Figure 6 As shown in the figure, under pH 7, the encapsulation efficiency of cyhalothrin by SL / Ply aqueous coacervates with different ratios was stably maintained above 98%.

[0139] Example 7

[0140] The inhibitory activity of SL / Ply aqueous coacervates (Coa.) and SL / Ply aqueous coacervates encapsulating prochloraz (Pro) (Pro@Coa.) on fungal spore germination was determined. The target species was Colletotrichum gloeosporioides. Each treatment agent was mixed with the same volume of 1×10 6 ~1×10 7Spore suspensions of 100 μl / mL were mixed to achieve the final concentrations of each treatment agent as shown in Table 1 (all concentrations in the table are in mg / L). Deionized water served as the control. 80 μL of each sample was aseptically transferred to a concave glass slide. The slide was placed in a Petri dish containing moist filter paper to maintain humidity. The slide was incubated at 28°C and 85% relative humidity. Germination progress was monitored regularly until more than 90% of the spores in the control group germinated. The germination rate was calculated by photographing the spores using a brightfield microscope (20x objective magnification). At least three fields of view were observed for each sample, with a total of no fewer than 250 spores observed.

[0141] The preparation method of the Pro treatment group is as follows: Prochloraz (Pro) solid was dissolved in anhydrous ethanol to obtain Pro mother solution, which was then diluted with 0.1% Tween-80 and then mixed with the same volume of 1×10 6 ~1×10 7 The spore suspensions of 1000 μg / mL were mixed to obtain the agents with concentration gradients I to V as shown in Table 1 (i.e., the final concentrations of Pro in the agents of the Pro treatment group were 0.0625 mg / L, 0.125 mg / L, 0.25 mg / L, 0.5 mg / L, and 1 mg / L, respectively);

[0142] The preparation method of the SL treatment group was as follows: sodium lignosulfonate (SL) was diluted with water and then mixed with the same volume of 1×10 6 ~1×10 7 The spore suspensions of 1000 μg / mL were mixed to obtain the agents with final concentration gradients I to V as shown in Table 1 (i.e., the final concentrations of SL in the agents of the SL treatment group were 31.25 mg / L, 62.5 mg / L, 125 mg / L, 250 mg / L, and 500 mg / L, respectively);

[0143] The preparation method of the Ply treatment group is as follows: ε-polylysine (Ply) was diluted with water and then mixed with the same volume of 1×10 6 ~1×10 7 The spore suspensions of 1000 μg / mL were mixed to obtain the agents with final concentration gradients I to V as shown in Table 1 (i.e., the final concentrations of Ply in the agents of the Ply treatment group were 31.25 mg / L, 62.5 mg / L, 125 mg / L, 250 mg / L, and 500 mg / L, respectively);

[0144] The preparation method of the SL / Ply aqueous coacervate (Coa.) treatment group agent is as follows: prepare a lignin-based aqueous coacervate according to the method in Example 1, wherein the concentration of sodium lignin sulfonate (SL) and the concentration of ε-polylysine (Ply) in the lignin-based aqueous coacervate is 1 g / L, and the pH of the lignin-based aqueous coacervate is 7; dilute the lignin-based aqueous coacervate with water as needed, and then mix with the same volume of 1×106 ~1×10 7 The spore suspension of 1:1 coacervate was directly mixed with the spore suspension of the same volume to obtain a treatment group of 500 mg / L:500 mg / L. This group did not need to be diluted with water, while other groups with lower concentrations needed to be diluted. The final concentration gradients I to V of the agents shown in Table 1 were obtained (i.e., the final concentrations of SL and Ply in the SL / Ply aqueous coacervate (Coa.) treatment group were 31.25 mg / mL for SL and 31.25 mg / mL for Ply, 62.5 mg / mL for SL and 62.5 mg / mL for Ply, 125 mg / mL for SL and 125 mg / mL for Ply, 250 mg / mL for SL and 250 mg / mL for Ply, and 500 mg / mL for SL and 500 mg / mL for Ply).

[0145] The preparation method of the SL / Ply aqueous coacervate (Pro@Coa.) treatment group agent encapsulating prochloraz (Pro) is as follows: a lignin-based aqueous coacervate is prepared according to the method in Example 1, wherein the concentration of sodium lignin sulfonate (SL) in the lignin-based aqueous coacervate is 1 g / L, the concentration of ε-polylysine (Ply) is 1 g / L, and the pH of the lignin-based aqueous coacervate is 7; an ethanol solution of prochloraz (Pro) is added to the lignin-based aqueous coacervate to make the final concentration of prochloraz (Pro) 2 mg / L to obtain a SL / Ply aqueous coacervate (Pro@Coa.) encapsulating prochloraz (Pro); the SL / Ply aqueous coacervate (Pro@Coa.) encapsulating prochloraz (Pro) is diluted with water as needed, and then mixed with the same volume of 1×10 6 ~1×10 7The spore suspension of 100 mg / mL was mixed (after preparing a 1:1 aggregate, it was directly mixed with the same volume of spore suspension to obtain a 500 mg / L:500 mg / L treatment group. This group did not need to be diluted with water, while other groups with lower concentrations needed to be diluted) to obtain the final concentration gradients I to V of the agents shown in Table 1 (i.e., the final concentration of SL in the SL / Ply aqueous phase aggregate (Pro@Coa.) encapsulating prochloraz (Pro) was 31.25 mg / mL, the final concentration of Ply was 31.25 mg / mL, and the final concentration of Pro was 0.0625 mg / mL). , the final concentration of SL was 62.5 mg / mL, the final concentration of Ply was 62.5 mg / mL, and the final concentration of Pro was 0.125 mg / mL; the final concentration of SL was 125 mg / mL, the final concentration of Ply was 125 mg / mL, and the final concentration of Pro was 0.25 mg / mL; the final concentration of SL was 250 mg / mL, the final concentration of Ply was 250 mg / mL, and the final concentration of Pro was 0.5 mg / mL; the final concentration of SL was 500 mg / mL, the final concentration of Ply was 500 mg / mL, and the final concentration of Pro was 1 mg / mL).

[0146] Table 1 - Concentration settings for antibacterial experiments

[0147]

[0148] The relative inhibition rate was calculated as follows:

[0149]

[0150] The relative inhibition rate (%) of each treatment group under different concentrations of the drug on the gloeosporium anthracnose fungus is as follows Figure 7 shown.

[0151] like Figure 7 As shown, the antibacterial activity of Pro increased from 19.46% to 41.01% with increasing concentration. Ply, an antimicrobial peptide, exhibited strong activity in inhibiting spore germination, reaching an inhibition rate of 95.84% at 31.25 mg / L. At a concentration gradient of II, the inhibitory effect of the SL / Ply aqueous coacervate (Coa.) surpassed that of both Ply and Pro, reaching 98.30%. This effect continued to increase with increasing concentration, reaching a maximum of 99.81%, demonstrating excellent protective bactericidal properties. The pesticide system encapsulated with Pro (Pro@Coa.) also achieved an inhibition rate exceeding 99%.

[0152] The above describes the embodiments of the present invention. The above implementation results show that the water-based pesticide adjuvant system formed by the liquid phase coacervate of lignin and polyamino acid prepared by the present invention simplifies the preparation process, improves environmental friendliness, enhances stability, and has the potential to serve as a protective fungicide compared to existing systems. It also has high encapsulation efficiency for a variety of pesticides and can help enhance the efficacy of pesticides.

[0153] It can be understood that the various technical features of the above-described embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the various technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0154] The above are merely preferred embodiments of the present application and only specifically describe the technical principles of the present application. These descriptions are intended only to explain the principles of the present application and should not be construed in any way as limiting the scope of protection of the present application. Based on the explanations herein, any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present application, as well as other specific implementations of the present application that can be conceived by those skilled in the art without inventive effort, shall be included within the scope of protection of the present application.

Claims

1. A lignin-based aqueous coacervate, characterized in that: The invention comprises the following components: lignin sulfonate, polycationic amino acid, pH regulator and water.

2. The lignin-based aqueous coagulant according to claim 1, wherein The polycationic amino acid is at least one of polylysine, polyarginine or polyhistidine, preferably, the polycationic amino acid is ε-polylysine; And / or, the lignin sulfonate includes at least one of sodium lignin sulfonate, calcium lignin sulfonate, potassium lignin sulfonate, and ammonium lignin sulfonate; And / or, the pH adjuster is selected from one of the following substances: sodium hydroxide, ammonia water, hydrochloric acid, and sulfuric acid.

3. The lignin-based aqueous coagulant according to claim 1, wherein The pH regulator is used in an amount such that the pH of the lignin-based aqueous coacervate is 2 to 11. Preferably, the pH of the lignin-based aqueous coacervate is 6 to 8. and / or, the concentration of lignin sulfonate in the lignin-based aqueous coacervate is 0.02 g / L to 20 g / L; And / or, the concentration of the polycationic amino acid in the lignin-based aqueous coacervate is 0.02 g / L to 20 g / L.

4. A method for preparing the lignin-based aqueous coacervate according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1, dissolving lignin sulfonate in water to obtain a lignin sulfonate precursor solution; dissolving the polycationic amino acid in water to obtain a polycationic amino acid precursor solution; S2, mixing the lignin sulfonate precursor solution and the polycationic amino acid precursor solution, and adding a pH regulator to adjust the pH to obtain a lignin-based aqueous phase coacervate; Alternatively, a pH regulator is added to the lignin sulfonate precursor solution to adjust its pH, and a pH regulator is added to the polycationic amino acid precursor solution to adjust its pH; The pH-adjusted lignin sulfonate precursor solution and the polycationic amino acid precursor solution are then mixed to obtain a lignin-based aqueous phase coacervate.

5. Use of the lignin-based aqueous coacervate according to any one of claims 1 to 3 or the lignin-based aqueous coacervate prepared by the preparation method according to claim 4 in the preparation of a fungicide.

6. Use of the lignin-based aqueous coacervate according to any one of claims 1 to 3 or the lignin-based aqueous coacervate prepared by the preparation method according to claim 4 as an adjuvant or drug-carrying system in pesticide encapsulation.

7. A pesticide composition, characterized in that The method comprises the lignin-based aqueous phase coacervate described in any one of 1 to 3 or the lignin-based aqueous phase coacervate prepared by the preparation method according to claim 4 and pesticide.

8. The pesticide composition according to claim 7, wherein The pesticide includes at least one of a fungicide, an insecticide, a herbicide, and a plant growth regulator; preferably, the fungicide includes at least one of prochloraz, pyraclostrobin, kasugamycin, difenoconazole, jinggangmycin, and trifloxystrobin; And / or, the concentration of the pesticide in the pesticide composition is 0.01 to 2500 mg / L.

9. A method for preparing a pesticide composition according to any one of claims 7 to 8, characterized in that: The following steps are involved: The pesticide is dispersed into the lignin-based aqueous phase aggregate to obtain a pesticide composition.

10. Use of the lignin-based aqueous coacervate according to any one of claims 1 to 3, or the lignin-based aqueous coacervate prepared by the preparation method according to claim 4, or the pesticide composition according to any one of claims 7 to 8, or the pesticide composition prepared by the preparation method according to claim 9 in inhibiting spore germination.

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