Plant maintenance liquid containing plant-derived wood vinegar and preparation method thereof

Abstract

The invention relates to the technical field of plant maintenance liquid preparation, in particular to plant maintenance liquid containing plant-source wood vinegar and a preparation method of the plant maintenance liquid. The preparation method comprises the following steps: preparing activated biochar; carrying out grafting modification on the activated charcoal by using 4, 4 '-(hexafluoroisopropenyl) diphthalic anhydride; preparing self-assembled silk fibroin modified carboxyl charcoal; and preparing the plant maintenance liquid containing the plant-derived wood vinegar. The carboxyl modified charcoal is modified through self-assembled silk fibroin, the hydrophilicity of the charcoal can be improved through the self-assembled structure of the silk fibroin, and after the silk fibroin is attached to the surface of the charcoal, through the hydrophilicity of the silk fibroin, the surface of the charcoal is modified; the self-assembled silk fibroin modified carboxyl biochar has better dispersity and compatibility in a water-based environment, and the self-assembly of silk fibroin can form a porous structure, so that the adsorption capacity of the self-assembled silk fibroin modified carboxyl biochar is improved, and the loading capacity of effective components in wood vinegar is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of plant maintenance liquid preparation, and particularly relates to a plant maintenance liquid containing plant-derived wood vinegar liquid and a preparation method thereof. Background Art

[0002] Wood vinegar liquid is a reddish-brown aqueous solution produced during the pyrolysis of wood. Its main components include organic acids, phenols, esters, water, etc., and also contain various minerals and vitamins. It is formed by heating and decomposing wood under anoxic conditions and then condensing the decomposed organic substances in the wood. The organic acids, phenolic substances, and minerals in wood vinegar liquid can stimulate cell growth, promote plant photosynthesis and nutrient absorption, thereby promoting seed germination and seedling growth. Therefore, adding wood vinegar liquid to plant maintenance liquid can better promote plant germination and growth.

[0003] However, the phenols and organic acids in wood vinegar liquid contain many active functional groups such as hydroxyl and carboxyl groups. These functional groups are prone to oxidation reactions with oxygen. Moreover, when the maintenance liquid is exposed to air, especially under conditions such as high temperature and light, it will also accelerate the oxidation of phenolic acids and organic acids in wood vinegar liquid, resulting in a decrease in the content of effective components in the maintenance liquid and affecting the effect of the maintenance liquid. Therefore, in the prior art, the phenolic acids in wood vinegar liquid are often separated through some operations and stored separately. However, the operation cost of separating organic acids and phenolic acids alone is high, the yield is low, and the components in wood vinegar liquid are complex and synergistic with each other. Separating them alone has an insignificant effect on improving plant growth and survival rate. Therefore, the present invention provides a plant maintenance liquid containing plant-derived wood vinegar liquid and a preparation method thereof to solve the above problems. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a plant maintenance liquid containing plant-derived wood vinegar liquid and a preparation method thereof.

[0005] A preparation method of a plant maintenance liquid containing plant-derived wood vinegar liquid includes the following steps: S1. Prepare activated biochar: Weigh zinc chloride and deionized water, stir until evenly mixed, then add biochar, and calcine in a tube furnace to obtain activated biochar; S2. Graft-modify activated biochar with 4,4'-(hexafluoroisopropylidene) diphthalic anhydride: Add 4,4'-(hexafluoroisopropylidene) diphthalic anhydride and N,N-dimethylformamide into a reaction flask and mix evenly, then add activated biochar, and perform microwave treatment to obtain carboxyl-grafted biochar; S3. Prepare self-assembled silk fibroin-modified carboxyl biochar: Dissolve silk fibroin fibers in a lithium bromide solution and stir to react. Then, perform dialysis to obtain a self-assembled silk fibroin protein solution. Mix the self-assembled silk fibroin protein solution with an NaOH solution, and then add carboxyl-grafted biochar. Stir magnetically in a microwave reactor to obtain self-assembled silk fibroin-modified carboxyl biochar; S4. Prepare a plant maintenance solution containing plant-derived wood vinegar: Soak the self-assembled silk fibroin-modified carboxyl biochar with wood vinegar to obtain a suspension. Dissolve sodium alginate in deionized water, add the suspension, perform ultrasonic treatment, and then add water for dilution to obtain a plant maintenance solution containing plant-derived wood vinegar.

[0006] Further, the preparation of the activated biochar in step S1 includes the following steps: Weigh 1 - 3 parts by mass of zinc chloride and 20 - 25 parts by mass of deionized water, stir until evenly mixed, then add 2 - 4 parts by mass of biochar, let stand for 2 - 3 h, then heat up to 105 - 110 °C, evaporate the water in 15 - 20 min, then calcine in a tube furnace at 600 - 800 °C under a nitrogen atmosphere for 2 - 3 h, cool down to room temperature of 22 - 24 °C with the furnace, then add 30 - 35 parts by mass of deionized water, boil for 2 - 3 h to remove water, and dry the solid product in an oven at 110 - 120 °C until constant weight to obtain the activated biochar.

[0007] Further, in step S2, the graft modification of the activated biochar with 4,4'-(hexafluoroisopropylidene) diphthalic anhydride includes the following steps: Add 50 parts by mass of 4,4'-(hexafluoroisopropylidene) diphthalic anhydride and 100 - 120 parts by mass of N,N-dimethylformamide into a reaction flask and mix evenly. Then add 1 - 5 parts by mass of the activated biochar, perform microwave treatment for 10 - 20 min, take it out and heat up to 50 - 55 °C, stir at a speed of 350 - 400 r / min for 10 - 20 min, filter the reaction product by suction, and vacuum dry the solid substance at 60 - 65 °C to obtain the carboxyl-grafted biochar.

[0008] Further, the preparation of the self-assembled silk fibroin-modified carboxyl biochar in step S3 includes the following steps: S3.1. Dissolve silk fibroin fibers in a 9 - 9.5 mol / L lithium bromide solution, with the material ratio of silk fibroin fibers to the lithium bromide solution being 10 g : (100 - 120) mL. Then heat up to 60 - 65 °C, stir and react for 40 - 50 min, then let stand and cool down to room temperature of 22 - 24 °C. Subsequently, perform dialysis in deionized water at 0 - 4 °C for 72 - 75 h to obtain a self-assembled silk fibroin protein solution; S3.2. Mix 1-3 parts by mass of the self-assembled silk fibroin solution with 80-100 parts by mass of the NaOH solution, then add 1-2 parts by mass of the carboxyl grafted biochar, magnetically stir in a microwave reactor for 30-40 min, then filter to remove the liquid, wash 3-4 times with 0.1 mol / L NaOH solution, and then wash with deionized water until neutral, and dry at 65-70 °C to obtain the self-assembled silk fibroin modified carboxyl biochar.

[0009] Further, in step S4, to prepare the plant maintenance solution containing plant-derived wood vinegar liquid, the following steps are included: S4.1. Soak the self-assembled silk fibroin modified carboxyl biochar in the wood vinegar liquid for 24-26 h, and the material-liquid ratio of the wood vinegar liquid to the self-assembled silk fibroin modified carboxyl biochar is 1 g:(10-20) mL to obtain a suspension; S4.2. Dissolve 1-5 parts by volume of sodium alginate in 20-30 parts by volume of deionized water preheated to 50-60 °C, add 3-4 parts by volume of the suspension, ultrasonically treat for 10-15 min, adjust the pH value of the system to 6-7, and then dilute with 50-80 times the total volume of the system with water to obtain the plant maintenance solution containing plant-derived wood vinegar liquid.

[0010] Further, the specific preparation steps of the biochar are as follows: Cut the rice straw into small sections, wash with deionized water and then put into an oven, dry at 60-65 °C for 24-25 h, crush the dried material in a pulverizer to obtain straw powder, put the straw powder into a ceramic crucible, compact and cover the lid, and then place it in a muffle furnace that has been purged with nitrogen to remove the air in the furnace, carbonize under anoxic conditions at 500-700 °C for 2-3 h, take it out after cooling to room temperature to obtain the biochar.

[0011] Further, the specific preparation steps of the silk fiber are as follows: Soak the mulberry silk in the papain solution at a material-liquid ratio of 1 g:(45-50) mL, the mass concentration of the papain solution is 3-3.2 g / L, the pH value is 6, perform a water bath treatment at 80-85 °C for 1-1.5 h, wash and stretch, and then dry at 60-65 °C to obtain a primary degummed intermediate; Soak the primary degummed intermediate in an 8-8.5 mol / L urea solution, and the material-liquid ratio of the primary degummed intermediate to the urea solution is 1 g:(30-40) mL, perform a water bath treatment at 90-95 °C for 3-4 h, wash and then dry to constant weight to obtain a secondary degummed intermediate; Mix the secondary degummed intermediate with the sodium carbonate solution at a material-liquid ratio of 12 g:(500-550) mL, the concentration of the sodium carbonate solution is 0.5-0.6 g / L, boil for 30-35 min, wash with deionized water, repeat three times, and dry to obtain the silk fiber.

[0012] Furthermore, the molecular weight cut-off of the dialysis bag during dialysis is 8 - 14 kDa.

[0013] Furthermore, the power of the microwave reactor is 400 W, and the magnetic stirring speed is 350 r / min.

[0014] A plant maintenance solution containing plant-derived wood vinegar is prepared by the preparation method of the plant maintenance solution containing plant-derived wood vinegar described above.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects: 1. In the present invention, 4,4'-(hexafluoroisopropylidene) diphthalic anhydride is used to graft the biochar activated by zinc chloride. The molecule of 4,4'-(hexafluoroisopropylidene) diphthalic anhydride contains various groups, and these groups can react with active sites such as hydroxyl or amino groups on the surface of the biochar, thereby introducing more carboxyl and hexafluoroisopropylidene groups on the surface of the biochar, increasing the density of functional groups on the surface of the biochar, and thus improving the adsorption capacity of the biochar. Moreover, 4,4'-(hexafluoroisopropylidene) diphthalic anhydride has very low toxicity, is more environmentally friendly and stable. The process of grafting modification of 4,4'-(hexafluoroisopropylidene) diphthalic anhydride and biochar is relatively simple, without the need to use excessive organic solvents, which can reduce production costs. The carboxyl grafted biochar prepared by the grafting reaction of 4,4'-(hexafluoroisopropylidene) diphthalic anhydride not only has carboxyl groups but also contains hexafluoroisopropylidene groups. The introduction of carboxyl groups can provide a large number of adsorption sites for the biochar, thereby assisting the biochar to load the components that promote plant growth and improve plant stress resistance in the wood vinegar, and providing the effects of promoting growth and improving survival rate for plants when applied to plants.

[0016] 2. In the present invention, the carboxyl modified biochar is modified by self-assembled silk fibroin. The self-assembled structure of silk fibroin can increase the hydrophilicity of the biochar. After attaching silk fibroin to the surface of the biochar, due to the hydrophilicity of silk fibroin, the self-assembled silk fibroin modified carboxyl biochar has better dispersibility and compatibility in an aqueous environment. Moreover, the self-assembly of silk fibroin can form a porous structure, which can increase the specific surface area of the biochar, thereby improving its adsorption capacity and thus improving the loading capacity for the active components in the wood vinegar. In addition, silk fibroin also has good biodegradability and can slowly decompose after application, without causing too much burden on the planted soil and being environmentally friendly.

[0017] 3. The present invention prepares a plant maintenance solution by compounding wood vinegar, biochar, and sodium alginate, which can exert the synergistic effect of the three. Wood vinegar contains organic acids, alcohols, phenols, trace elements, and other components that promote plant growth and improve stress resistance. Biochar serves as the main carrier. After loading wood vinegar on the biochar, a degradable gel film is formed through sodium alginate to reduce volatilization. Wood vinegar provides quick-acting organic nutrients, biochar adsorbs and slowly releases nutrients, and sodium alginate chelates trace elements to form a "fast-slow-steady" three-level nutrient release mode. At the same time, sodium alginate has a certain chelating effect, which can combine with metal ions to improve the utilization rate of trace elements. By chelating metal ions with sodium alginate, it can enhance the absorption capacity of the leaf surface and roots after being absorbed by plants, and further improve the absorption of the plant maintenance solution by plants, achieving the effects of promoting plant growth and stress resistance and improving the survival rate of plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a flowchart of a preparation method of a plant maintenance solution containing plant-derived wood vinegar adopted in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The following describes in detail a plant maintenance solution containing plant-derived wood vinegar and its preparation method provided by the present invention in combination with the drawings and specific embodiments. At the same time, it should be noted here that in order to make the embodiments more detailed, the following embodiments are the best and preferred embodiments. For some well-known technologies, those skilled in the art can also adopt other alternative methods for implementation; and the drawings are only for more specific description of the embodiments, and are not intended to specifically limit the present invention.

[0020] Example 1: A preparation method of a plant maintenance solution containing plant-derived wood vinegar, as Figure 1 shown, includes the following steps: S1. Prepare activated biochar: Cut rice straw into small sections of 5-6 cm, wash it with deionized water and then put it into an oven, dry it at 60 °C for 24 h. Crush the dried material in a pulverizer to obtain straw powder. Put the straw powder into a ceramic crucible, compact it, cover the lid, and place it in a muffle furnace that has been purged of air in the furnace with nitrogen. Carbonize it under anaerobic conditions at 500 °C for 2 h, take it out after cooling to room temperature to obtain biochar; Weigh 1 part by mass of zinc chloride and 20 parts by mass of deionized water, stir until evenly mixed, then add 2 parts by mass of biochar, let it stand for 2 h, then raise the temperature to 105 °C, evaporate the water in 15 min, and then calcine it in a tubular furnace at 600 °C under a nitrogen atmosphere for 2 h. Cool it to room temperature of 22 °C with the furnace, then add 30 parts by mass of deionized water, boil it for 2 h to remove water, and dry the solid product in an oven at 110 °C until it reaches a constant weight to obtain activated biochar.

[0021] S2. 4,4'-(Hexafluoroisopropylidene)diphthalic anhydride grafted modified activated biochar: Add 50 parts by mass of 4,4'-(hexafluoroisopropylidene)diphthalic anhydride and 100 parts by mass of N,N-dimethylformamide into a reaction flask and mix evenly. Then add 1 part by mass of activated biochar, perform microwave treatment for 10 min. After taking it out, raise the temperature to 50 °C, stir at a speed of 350 r / min for 10 min, filter the reaction product by suction, and vacuum dry the solid substance at 60 °C to obtain carboxyl grafted biochar.

[0022] S3. Prepare self-assembled silk fibroin modified carboxyl biochar: S3.1. Immerse domestic silk in papain solution at a material-liquid ratio of 1 g:45 mL. The mass concentration of the papain solution is 3 g / L, the pH value is 6, perform water bath treatment at 80 °C for 1 h, wash and stretch, and then dry at 60 °C to obtain the intermediate product of the first degumming; Immerse the intermediate product of the first degumming in 8 mol / L urea solution at a material-liquid ratio of 1 g:30 mL, perform water bath treatment at 90 °C for 3 h, wash and dry to constant weight to obtain the intermediate product of the second degumming; Mix the intermediate product of the second degumming with sodium carbonate solution at a material-liquid ratio of 12 g:500 mL. The concentration of the sodium carbonate solution is 0.5 g / L, boil for 30 min, wash with deionized water, repeat three times, and dry to obtain silk fibroin fiber; Dissolve the silk fibroin fiber in 9 mol / L lithium bromide solution at a material-liquid ratio of 10 g:100 mL, then raise the temperature to 60 °C, stir and react for 40 min, then let it stand and cool to room temperature of 22 °C, and then dialyze in deionized water at 0 °C for 72 h. The cut-off molecular weight of the dialysis bag during dialysis is 8 kDa to obtain self-assembled silk fibroin solution; S3.2. Mix 1 part by mass of self-assembled silk fibroin solution with 80 parts by mass of NaOH solution, then add 1 part by mass of carboxyl grafted biochar, magnetically stir in a microwave reactor for 30 min. The power of the microwave reactor is 400 W, and the magnetic stirring speed is 350 r / min. Then filter to remove the liquid, wash 3 times with 0.1 mol / L NaOH solution, and then wash with deionized water until neutral, and dry at 65 °C to obtain self-assembled silk fibroin modified carboxyl biochar.

[0023] S4. Prepare plant maintenance liquid containing plant-derived wood vinegar: S4.1. Soak the self-assembled silk fibroin modified carboxyl biochar with wood vinegar for 24 h at a material-liquid ratio of 1 g:10 mL to obtain a suspension; S4.2. Dissolve 1 volume part of sodium alginate in 20 volume parts of deionized water preheated to 50 °C in advance, add 3 volume parts of the suspension, ultrasonicate for 10 min, adjust the pH value of the system to 6, and then add water 50 times the total volume of the system for dilution to obtain a plant maintenance solution containing plant-derived wood vinegar liquid.

[0024] Example 2: A preparation method of a plant maintenance solution containing plant-derived wood vinegar liquid, as Figure 1 shown, includes the following steps: S1. Prepare activated biochar: Cut rice straw into small sections of 5 - 6 cm, wash with deionized water and put into an oven, dry at 60 °C for 24 h, crush the dried material in a pulverizer to obtain straw powder, put the straw powder into a ceramic crucible, compact it, cover the lid, and place it in a muffle furnace that has been purged of air in the furnace with nitrogen, carbonize under anaerobic conditions at 500 °C for 2 h, take it out after cooling to room temperature to obtain biochar; Weigh 3 mass parts of zinc chloride and 25 mass parts of deionized water, stir until evenly mixed, then add 2 mass parts of biochar, let stand for 2 h, then heat up to 105 °C, evaporate the water in 15 min, and then calcine in a tubular furnace at 600 °C under a nitrogen atmosphere for 2 h, cool down to room temperature of 22 °C with the furnace, then add 35 mass parts of deionized water, boil for 2 h to remove water, and dry the solid product in an oven at 110 °C to constant weight to obtain activated biochar.

[0025] S2. Graft-modify activated biochar with 4,4'-(hexafluoroisopropylidene) diphthalic anhydride: Add 50 mass parts of 4,4'-(hexafluoroisopropylidene) diphthalic anhydride and 120 mass parts of N,N-dimethylformamide into a reaction flask and mix evenly, then add 5 mass parts of activated biochar, perform microwave treatment for 10 min, take it out and heat up to 50 °C, stir at a speed of 350 r / min for 10 min, filter the reaction product by suction, and vacuum-dry the solid substance at 60 °C to obtain carboxyl-grafted biochar.

[0026] S3. Prepare self-assembled silk fibroin-modified carboxyl biochar: S3.1. Immerse domestic silk in a papain solution at a material-liquid ratio of 1 g:45 mL. The mass concentration of the papain solution is 3 g / L, the pH value is 6, perform water bath treatment at 80 °C for 1 h, wash and stretch, and then dry at 60 °C to obtain a primary degummed intermediate; Immerse the primary degummed intermediate in an 8 mol / L urea solution at a material-liquid ratio of 1 g:30 mL for the primary degummed intermediate and the urea solution, perform water bath treatment at 90 °C for 3 h, wash and dry to constant weight to obtain a secondary degummed intermediate; Mix the secondary degumming intermediate with sodium carbonate solution at a material-liquid ratio of 12 g: 500 mL. The concentration of the sodium carbonate solution is 0.5 g / L. Boil for 30 min, wash with deionized water, repeat three times, and dry to obtain silk fibroin fibers. Dissolve the silk fibroin fibers in 9 mol / L lithium bromide solution at a material-liquid ratio of 10 g: 100 mL. Then heat to 60 °C, stir and react for 40 min, and then let it stand and cool to room temperature of 22 °C. Subsequently, dialyze in deionized water at 0 °C for 72 h. The cut-off molecular weight of the dialysis bag during dialysis is 8 kDa to obtain a self-assembled silk fibroin protein solution. S3.2. Mix 3 parts by mass of the self-assembled silk fibroin protein solution with 100 parts by mass of NaOH solution, then add 2 parts by mass of carboxyl-grafted biochar, and magnetically stir in a microwave reactor for 30 min. The power of the microwave reactor is 400 W, and the magnetic stirring speed is 350 r / min. Subsequently, filter to remove the liquid, wash 3 times with 0.1 mol / L NaOH solution, then wash with deionized water until neutral, and dry at 65 °C to obtain self-assembled silk fibroin protein-modified carboxyl biochar.

[0027] S4. Prepare a plant maintenance solution containing plant-derived wood vinegar liquid: S4.1. Soak the self-assembled silk fibroin protein-modified carboxyl biochar in wood vinegar liquid for 24 h at a material-liquid ratio of 1 g: 20 mL to obtain a suspension. S4.2. Dissolve 5 volumes of sodium alginate in 30 volumes of deionized water preheated to 50 °C, add 4 volumes of the suspension, ultrasonicate for 10 min, adjust the system pH value to 6, and then dilute with 80 times the total volume of water in the system to obtain a plant maintenance solution containing plant-derived wood vinegar liquid.

[0028] Example 3: A preparation method of a plant maintenance solution containing plant-derived wood vinegar liquid, as Figure 1 shown, includes the following steps: S1. Prepare activated biochar: Cut the rice straw into small sections of 5 - 6 cm, wash with deionized water and then put it into an oven to dry at 60 °C for 24 h. Crush the dried material in a pulverizer to obtain straw powder. Put the straw powder into a ceramic crucible, compact it, cover the lid, and place it in a muffle furnace that has been purged of air in the furnace with nitrogen. Carbonize under anoxic conditions at 500 °C for 2 h, take it out after cooling to room temperature to obtain biochar. Weigh 1 part by mass of zinc chloride and 20 parts by mass of deionized water, stir until evenly mixed, then add 2 parts by mass of biochar, let it stand for 3 h, then heat up to 110 °C, evaporate the water in 20 min, and then calcine in a tubular furnace at 800 °C for 3 h under a nitrogen atmosphere, cool down to room temperature of 22 °C with the furnace, then add 30 parts by mass of deionized water, boil for 3 h to remove water, and dry the solid product in an oven at 120 °C until constant weight to obtain activated biochar.

[0029] S2. Graft modification of activated biochar with 4,4'-(hexafluoroisopropylidene) diphthalic anhydride: Add 50 parts by mass of 4,4'-(hexafluoroisopropylidene) diphthalic anhydride and 100 parts by mass of N,N-dimethylformamide into a reaction flask and mix evenly, then add 1 part by mass of activated biochar, perform microwave treatment for 10 min, take it out and heat up to 55 °C, stir at a speed of 400 r / min for 20 min, filter the reaction product, and vacuum dry the solid substance at 60 °C to obtain carboxyl-grafted biochar.

[0030] S3. Prepare self-assembled silk fibroin-modified carboxyl biochar: S3.1. Immerse domestic silk in papain solution at a material-liquid ratio of 1 g:50 mL. The mass concentration of the papain solution is 3.2 g / L, the pH value is 6, perform water bath treatment at 85 °C for 1.5 h, wash and stretch, and then dry at 65 °C to obtain a primary degummed intermediate; Immerse the primary degummed intermediate in 8.5 mol / L urea solution at a material-liquid ratio of 1 g:40 mL, perform water bath treatment at 95 °C for 4 h, wash and dry to constant weight to obtain a secondary degummed intermediate; Mix the secondary degummed intermediate with sodium carbonate solution at a material-liquid ratio of 12 g:550 mL. The concentration of the sodium carbonate solution is 0.6 g / L, boil for 35 min, wash with deionized water, repeat three times, and dry to obtain silk fibroin fiber; Dissolve the silk fibroin fiber in 9 mol / L lithium bromide solution at a material-liquid ratio of 10 g:100 mL, then heat up to 60 °C, stir and react for 40 min, then let it stand and cool down to room temperature of 22 °C, and then dialyze in deionized water at 0 °C for 72 h. The cut-off molecular weight of the dialysis bag during dialysis is 8 kDa to obtain a self-assembled silk fibroin solution; S3.2. Mix 1 part by mass of the self-assembled silk fibroin solution with 80 parts by mass of NaOH solution, then add 1 part by mass of carboxyl-grafted biochar, perform magnetic stirring in a microwave reactor for 30 min. The power of the microwave reactor is 400 W, and the magnetic stirring speed is 350 r / min. Then filter to remove the liquid, wash 3 times with 0.1 mol / L NaOH solution, then wash with deionized water until neutral, and dry at 65 °C to obtain self-assembled silk fibroin-modified carboxyl biochar.

[0031] S4. Preparation of a plant maintenance solution containing plant-derived wood vinegar liquid: S4.1. Soak the self-assembled silk fibroin-modified carboxylated biochar in wood vinegar liquid for 26 h, with the material-liquid ratio of wood vinegar liquid to self-assembled silk fibroin-modified carboxylated biochar being 1 g:10 mL to obtain a suspension; S4.2. Dissolve 1 volume portion of sodium alginate in 20 volume portions of deionized water preheated to 60 °C in advance, add 3 volume portions of the suspension, ultrasonicate for 15 min, adjust the pH value of the system to 7, and then dilute with 50 times the total volume of water in the system to obtain a plant maintenance solution containing plant-derived wood vinegar liquid.

[0032] Comparative Example 1: Compared with Example 1, the difference in Comparative Example 1 is that step S2 is not carried out, and biochar is used to replace carboxyl-grafted biochar in step S3.2. Specifically, it is "S3.2. Mix 1 mass portion of self-assembled silk fibroin solution with 80 mass portions of NaOH solution, then add 1 mass portion of biochar, magnetically stir in a microwave reactor for 30 min, the power of the microwave reactor is 400 W, the rotational speed of magnetic stirring is 350 r / min, then filter to remove the liquid, wash 3 times with 0.1 mol / L NaOH solution, and then wash with deionized water until neutral, and dry at 65 °C to obtain self-assembled silk fibroin-modified biochar". In the subsequent steps, self-assembled silk fibroin-modified biochar is used to replace self-assembled silk fibroin-modified carboxylated biochar, and the remaining steps remain unchanged. The obtained plant maintenance solution containing plant-derived wood vinegar liquid is denoted as Comparative Example 1.

[0033] Comparative Example 2: Compared with Example 1, the difference in Comparative Example 2 is that step S3 is not carried out, and carboxyl-grafted biochar is used to replace self-assembled silk fibroin-modified carboxylated biochar in step S4.1. Specifically, it is "S4.1. Soak carboxyl-grafted biochar in wood vinegar liquid for 24 h, with the material-liquid ratio of wood vinegar liquid to carboxyl-grafted biochar being 1 g:10 mL to obtain a suspension", and the remaining steps remain unchanged. The obtained plant maintenance solution containing plant-derived wood vinegar liquid is denoted as Comparative Example 2.

[0034] Comparative Example 3: Compared with Example 1, the difference in Comparative Example 3 is that biochar is used to replace self-assembled silk fibroin-modified carboxylated biochar in step S4.1. Specifically, it is "S4.1. Soak biochar in wood vinegar liquid for 24 h, with the material-liquid ratio of wood vinegar liquid to biochar being 1 g:10 mL to obtain a suspension", and the remaining steps remain unchanged. The obtained plant maintenance solution containing plant-derived wood vinegar liquid is denoted as Comparative Example 3.

[0035] Comparative Example 4: Compared with Example 1, the difference in Comparative Example 4 is that in step S4, self-assembled silk fibroin-modified carboxyl biochar is not added. Specifically, it is "S4.1. Dissolve 1 part by volume of sodium alginate in 20 parts by volume of deionized water preheated to 50 °C, add 3 parts by volume of wood vinegar liquid, ultrasonic for 10 min, adjust the pH value of the system to 6, and then add water diluted by 50 times the total volume of the system to obtain a plant maintenance liquid containing plant-derived wood vinegar liquid", and the remaining steps remain unchanged. The obtained plant maintenance liquid containing plant-derived wood vinegar liquid is denoted as Comparative Example 4.

[0036] Comparative Example 5: Compared with Example 1, the difference in Comparative Example 5 is that in step S4, sodium alginate is not added. Specifically, it is "S4.1. Immerse self-assembled silk fibroin-modified carboxyl biochar in wood vinegar liquid for 24 h, and the material-liquid ratio of wood vinegar liquid to self-assembled silk fibroin-modified carboxyl biochar is 1 g:10 mL to obtain a suspension; S4.2. Ultrasonic the suspension for 10 min, adjust the pH value of the system to 6, and then add water diluted by 50 times the total volume of the system to obtain a plant maintenance liquid containing plant-derived wood vinegar liquid", and the remaining steps remain unchanged. The obtained plant maintenance liquid containing plant-derived wood vinegar liquid is denoted as Comparative Example 5.

[0037] Comparative Example 6: Comparative Example 6 is a commercially available plant seed maintenance liquid.

[0038] Sow pakchoi seeds in 9 test fields of 3 m × 8 m. During the germination period after sowing, spray Examples 1-3 and Comparative Examples 1-6 on the crop soil respectively, and calculate the survival rate of pakchoi after germination, as shown in Table 1; After the pakchoi matures, collect and calculate its average yield (kg / m 2 ), as shown in Table 2.

[0039] Table 1

[0040] Table 2

[0041] As can be seen from Table 1, the survival rates in Examples 1-3 are above 97.3%, all higher than those in the comparative examples. And, Comparative Example 6 is a commercially available plant seed maintenance liquid, and the survival rate after applying the plant maintenance liquid prepared by the present invention is higher than that after applying the commercial product, indicating that the present invention has a better effect of promoting plant growth and improving the survival rate.

[0042] As can be seen from Table 2, the yields in Examples 1-3 are 2.39 kg / m 2Above, all are higher than the comparative examples. It can be seen that the raw materials of the present invention can exert a synergistic effect after being treated according to the present invention and then applied, thereby promoting plant growth. Moreover, the promoting effect of the present invention on plant growth is better than that of comparative example 6 of the commercially available product.

[0043] The above embodiments are only illustrative of the principles and effects of the present invention, and are not intended to limit the present invention.

Claims

1. A preparation method of a plant maintenance solution containing plant-derived wood vinegar liquid, characterized in that, It includes the following steps: S1. Prepare activated biochar: Weigh zinc chloride and deionized water, stir until evenly mixed, then add biochar, and calcine in a tubular furnace to obtain activated biochar; S2. Graft-modify the activated biochar with 4,4'-(hexafluoroisopropylidene) diphthalic anhydride: Add 4,4'-(hexafluoroisopropylidene) diphthalic anhydride and N,N-dimethylformamide into a reaction flask and mix evenly, then add the activated biochar, and perform microwave treatment to obtain carboxyl-grafted biochar; S3. Prepare self-assembled silk fibroin-modified carboxyl biochar: Dissolve silk fibroin fibers in a lithium bromide solution and stir to react, then perform dialysis to obtain a self-assembled silk fibroin solution. Mix the self-assembled silk fibroin solution with a NaOH solution, then add the carboxyl-grafted biochar, and perform magnetic stirring in a microwave reactor to obtain self-assembled silk fibroin-modified carboxyl biochar; S4. Prepare a plant maintenance solution containing plant-derived wood vinegar: Soak the self-assembled silk fibroin-modified carboxyl biochar with wood vinegar to obtain a suspension. Dissolve sodium alginate in deionized water, add the suspension, perform ultrasonic treatment, and then add water for dilution to obtain a plant maintenance solution containing plant-derived wood vinegar.

2. The preparation method of a plant maintenance solution containing plant-derived wood vinegar liquid according to claim 1, characterized in that, Step S1 for preparing activated biochar includes the following steps: Weigh 1-3 parts by mass of zinc chloride and 20-25 parts by mass of deionized water, stir until evenly mixed, then add 2-4 parts by mass of biochar, let it stand for 2-3 h, then heat up to 105-110 °C, evaporate the water in 15-20 min, then calcine in a tubular furnace at 600-800 °C under a nitrogen atmosphere for 2-3 h, cool down to room temperature of 22-24 °C with the furnace, then add 30-35 parts by mass of deionized water, boil for 2-3 h to remove water, and dry the solid product in an oven at 110-120 °C to constant weight to obtain activated biochar.

3. The preparation method of a plant maintenance solution containing plant-derived wood vinegar liquid according to claim 2, characterized in that, In step S2, graft-modifying the activated biochar with 4,4'-(hexafluoroisopropylidene) diphthalic anhydride includes the following steps: Add 50 parts by mass of 4,4'-(hexafluoroisopropylidene) diphthalic anhydride and 100-120 parts by mass of N,N-dimethylformamide into a reaction flask and mix evenly, then add 1-5 parts by mass of activated biochar, perform microwave treatment for 10-20 min, take it out and heat up to 50-55 °C, stir at a speed of 350-400 r / min for 10-20 min, filter the reaction product by suction, and vacuum-dry the solid substance at 60-65 °C to obtain carboxyl-grafted biochar.

4. The preparation method of a plant maintenance solution containing plant-derived wood vinegar liquid according to claim 3, characterized in that, In step S3, preparing self-assembled silk fibroin-modified carboxyl biochar includes the following steps: S3.

1. Dissolve silk fibroin fibers in a lithium bromide solution with a concentration of 9-9.5 mol / L, the material-liquid ratio of silk fibroin fibers to the lithium bromide solution is 10 g:(100-120) mL, then heat up to 60-65 °C, stir and react for 40-50 min, then let it stand and cool down to room temperature of 22-24 °C, and then dialyze in deionized water at 0-4 °C for 72-75 h to obtain a self-assembled silk fibroin solution; S3.

2. Mix 1-3 parts by mass of the self-assembled silk fibroin solution with 80-100 parts by mass of the NaOH solution, then add 1-2 parts by mass of the carboxyl grafted biochar, magnetically stir in a microwave reactor for 30-40 min, then filter to remove the liquid, wash with 0.1 mol / L NaOH solution 3-4 times, and then wash with deionized water until neutral, and dry at 65-70 °C to obtain the self-assembled silk fibroin modified carboxyl biochar.

5. The preparation method of a plant maintenance solution containing plant-derived wood vinegar liquid according to claim 4, characterized in that, In step S4, to prepare the plant maintenance solution containing plant-derived wood vinegar liquid, the following steps are included: S4.

1. Soak the self-assembled silk fibroin modified carboxyl biochar in the wood vinegar liquid for 24-26 h, and the material-liquid ratio of the wood vinegar liquid to the self-assembled silk fibroin modified carboxyl biochar is 1 g:(10-20) mL to obtain a suspension; S4.

2. Dissolve 1-5 parts by volume of sodium alginate in 20-30 parts by volume of deionized water preheated to 50-60 °C, add 3-4 parts by volume of the suspension, ultrasonicate for 10-15 min, adjust the pH value of the system to 6-7, and then add water diluted by 50-80 times the total volume of the system to obtain the plant maintenance solution containing plant-derived wood vinegar liquid.

6. The preparation method of a plant maintenance solution containing plant-derived wood vinegar liquid according to claim 2, characterized in that, The specific preparation steps of the biochar are as follows: Cut the rice straw into small sections, wash it with deionized water and then put it into an oven, dry it at 60-65 °C for 24-25 h, pulverize the dried material in a pulverizer to obtain straw powder, put the straw powder into a ceramic crucible, compact it, cover the lid, and place it in a muffle furnace that has been purged of air in the furnace with nitrogen, and carbonize it under anaerobic conditions at 500-700 °C for 2-3 h, take it out after cooling to room temperature to obtain the biochar.

7. The preparation method of a plant maintenance solution containing plant-derived wood vinegar liquid according to claim 4, characterized in that, The specific preparation steps of the silk fibroin fiber are as follows: Soak the domestic silk in a papain solution at a material-liquid ratio of 1 g:(45-50) mL, the mass concentration of the papain solution is 3-3.2 g / L, the pH value is 6, and perform a water bath treatment at 80-85 °C for 1-1.5 h, wash and stretch, and then dry at 60-65 °C to obtain a primary degummed intermediate; Soak the primary degummed intermediate in an 8-8.5 mol / L urea solution, and the material-liquid ratio of the primary degummed intermediate to the urea solution is 1 g:(30-40) mL, perform a water bath treatment at 90-95 °C for 3-4 h, wash and dry to constant weight to obtain a secondary degummed intermediate; Mix the secondary degummed intermediate with a sodium carbonate solution at a material-liquid ratio of 12 g:(500-550) mL, the concentration of the sodium carbonate solution is 0.5-0.6 g / L, boil for 30-35 min, wash with deionized water, repeat three times, and dry to obtain the silk fibroin fiber.

8. The preparation method of a plant maintenance solution containing plant-derived wood vinegar liquid according to claim 4, characterized in that, During dialysis, the cut-off molecular weight of the dialysis bag is 8-14 kDa.

9. The preparation method of a plant maintenance solution containing plant-derived wood vinegar liquid according to claim 4, characterized in that, The power of the microwave reactor is 400 W, and the magnetic stirring speed is 350 r / min.

10. A plant maintenance solution containing plant-derived wood vinegar liquid, characterized in that, It is prepared by the preparation method of the plant maintenance solution containing plant-derived wood vinegar liquid described in any one of claims 1-9.

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