Preparation method and application of agriculture and forestry drought-resistant water-retaining agent with bionic three-dimensional hydrophilic structure

Abstract

The agricultural and forestry drought-resistant water-retaining agent comprises a modified bionic hydrophilic nano base material, a molecular sieve and modified hydrophilic bentonite, and a preparation method comprises the following steps: step 1, preparing the modified bionic hydrophilic nano base material, step 2, preparing the molecular sieve, step 3, carrying out wrapping and drying treatment, step 4, preparing the modified hydrophilic bentonite, step 5, carrying out drying treatment, and step 6, preparing the agricultural and forestry drought-resistant water-retaining agent with the bionic three-dimensional hydrophilic structure. 5, outer layer material coating treatment; 6, modification treatment. The zeolite molecular sieve is used as a substrate, the service life of the water-retaining agent can be greatly prolonged and the water-retaining effect of soil can be prolonged by combining with the wrapping of the modified bionic hydrophilic nano-base material, and meanwhile, a three-dimensional hydrophilic structure is formed in the soil through the cooperation of the zeolite molecular sieve and the wrapped modified bionic hydrophilic nano-base material, so that the water-retaining effect of the soil is improved. The water absorption rate and the repeated water absorption frequency of the water-retaining agent are effectively improved, the water-retaining agent can have the effect of slowly releasing nutrients and water through cooperation of the internally absorbed treating fluid and the modified hydrophilic bentonite, and the water-retaining capacity and the drought resistance of soil are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of agricultural and forestry water retention agents, and particularly relates to a preparation method and application of an agricultural and forestry drought-resistant water retention agent with a bionic three-dimensional hydrophilic structure. Background Art

[0002] The shortage and unreasonable utilization of water resources are one of the main reasons for agricultural and forestry drought disasters; soil water retention agents, known as miniature reservoirs for plants, are organic polymer compounds with a unique three-dimensional network structure. They can quickly absorb and retain rainwater or irrigation water in the soil without leakage, thereby ensuring sufficient moisture in the rhizosphere range and slowly releasing it for plant utilization; their unique water absorption, water storage, and water retention properties play a decisive role in improving the ecological environment and windbreak and sand fixation projects, and are widely used in fields such as land desertification control, agricultural and forestry crop planting, and landscaping.

[0003] Traditional drought-resistant water retention agents have a slow water absorption rate. Only a small part of the water molecules are absorbed and retained after irrigation, and most of the irrigation water flows into the ground or is lost through surface ditches, resulting in unsatisfactory soil water retention and poor water retention effect. At the same time, the existing water retention agents have weak environmental adaptability and poor durability, and will be decomposed in the soil, leading to a decline in the soil water retention effect. Therefore, the present invention proposes a preparation method and application of an agricultural and forestry drought-resistant water retention agent with a bionic three-dimensional hydrophilic structure to solve the problems existing in the prior art. Summary of the Invention

[0004] In view of the above problems, the object of the present invention is to provide a preparation method and application of an agricultural and forestry drought-resistant water retention agent with a bionic three-dimensional hydrophilic structure. The preparation method of the agricultural and forestry drought-resistant water retention agent with a bionic three-dimensional hydrophilic structure can greatly extend the lifespan of the water retention agent and the water retention effect of the soil by using zeolite molecular sieve as the substrate and combining it with the coating of a modified bionic hydrophilic nano-substrate. At the same time, through the cooperation of the zeolite molecular sieve and the coated modified bionic hydrophilic nano-substrate, a three-dimensional hydrophilic structure is formed in the soil, effectively improving the water absorption rate and repeated water absorption frequency of the water retention agent. Moreover, through the internal absorption of the treatment liquid and the cooperation of the modified hydrophilic bentonite, the water retention agent can have the effect of slowly releasing nutrients and water, increasing the soil water holding capacity and drought resistance ability, and realizing the rational utilization of water resources and the sustainable development of agriculture and forestry.

[0005] To achieve the object of the present invention, the present invention is realized through the following technical solutions: An agricultural and forestry drought-resistant water retention agent with a bionic three-dimensional hydrophilic structure, comprising a modified bionic hydrophilic nano-substrate, a molecular sieve, and a modified hydrophilic bentonite. The modified bionic hydrophilic nano-substrate is made by reacting hydrophilic cellulose obtained by nitrating cellulose with isocyanate and mixing it with a cross-linking agent. The modified hydrophilic bentonite is made by mixing potassium salt and phosphate with nano-bentonite.

[0006] A preparation method of an agricultural and forestry drought-resistant water retention agent with a bionic three-dimensional hydrophilic structure, comprising the following steps:

[0007] Step 1: Preparation of modified bionic hydrophilic nano-substrate. First, cellulose is mixed with mixed acid for esterification reaction to obtain nitrocellulose, which is then mixed and reacted with isocyanate to obtain hydrophilic cellulose. Then, after drying, it is mixed with a crosslinking agent to obtain crosslinked hydrophilic cellulose, which is evenly divided into three parts for standby;

[0008] Step 2: Preparation of molecular sieve. Zeolite powder is ground and then subjected to acid treatment and alkali treatment with ethylenediaminetetraacetic acid and sodium hydroxide in sequence. Finally, it is washed with disodium ethylenediaminetetraacetate to obtain the molecular sieve;

[0009] Step 3: Coating and drying treatment. The molecular sieve is added to one part of crosslinked hydrophilic cellulose and stirred, and then granulated and dried. The stirring and drying are repeated with the second part of crosslinked hydrophilic cellulose to obtain the bionic water retention agent base material;

[0010] Step 4: Preparation of modified hydrophilic bentonite. First, a potassium salt and a phosphate are made into an aqueous solution and mixed to obtain a modified solution. Then, bentonite is ground into a slurry and mixed with the modified solution, and then dried and ground to obtain modified hydrophilic bentonite;

[0011] Step 5: Outer coating treatment. The modified hydrophilic bentonite is mixed and stirred with the third part of crosslinked hydrophilic cellulose to obtain the outer coating. Then, the bionic water retention agent base material prepared in Step 3 is mixed and stirred and then dried to obtain the semi-finished water retention agent;

[0012] Step 6: Modification treatment. A compound fertilizer and a microbial agent are added to water and mixed and dissolved to obtain a treatment solution. Then, the treatment solution is evenly sprayed on the semi-finished water retention agent, and finally, it is dried to obtain the drought-resistant water retention agent.

[0013] Further improvement lies in that: in Step 1, the mixed acid is made by mixing concentrated sulfuric acid and concentrated nitric acid according to a volume ratio of 2:1. After the cellulose and the mixed acid are mixed for esterification reaction, the generated light yellow cotton-like product is filtered out, and then washed three times with deionized water to obtain nitrocellulose; the drying condition of the hydrophilic cellulose is drying for 2 - 3 h under a closed condition at 50 - 60 °C.

[0014] Further improvement lies in that: in Step 2, a 0.18 mol / L aqueous solution of ethylenediaminetetraacetic acid, a 0.9 mol / L aqueous solution of sodium hydroxide, and a 0.11 mol / L solution of disodium ethylenediaminetetraacetate are used; after washing with disodium ethylenediaminetetraacetate, it is washed twice again with deionized water and dried at 220 - 280 °C for 30 - 45 min; the two drying conditions in Step 3 are drying at 120 - 160 °C for 50 - 70 min.

[0015] Further improvement lies in that: in step four, the molar ratio of potassium to phosphorus in the modified solution is 1:1; the mass ratio of the modified solution to the bentonite slurry for mixing is 20:80, and after mixing, it is dried at 300 - 450 °C for 3 - 4 h, and rapid stirring is carried out during drying; when grinding, it is sieved using a 200 - mesh sieve.

[0016] Further improvement lies in that: in step five, when mixing the bio - water - retaining agent base material with the outer packaging material, it is repeated 2 - 4 times. After each mixing, the bio - water - retaining agent base material contaminated with the outer packaging material is filtered out and dried. The drying conditions are drying at 160 - 200 °C for 20 - 30 min.

[0017] Further improvement lies in that: in step six, the mass ratio of the compound fertilizer, the microbial agent, and water for mixing is 25:5:70; the spraying of the treatment liquid needs to be carried out three times repeatedly. After the first uniform spraying of the treatment liquid, it is left standing for 10 - 15 min and then the second spraying is carried out. After the second spraying of the treatment liquid, it is left standing for 30 - 40 min and then the third spraying is carried out. After the third spraying of the treatment liquid, the semi - finished water - retaining agent is placed in an environment of 40 - 60 °C and dried for 3 - 4 h, and then cooled and taken out to obtain the drought - resistant water - retaining agent.

[0018] Application of a bio - inspired three - dimensional hydrophilic structure - based agricultural and forestry drought - resistant water - retaining agent in drought - resistance and water - retention of agricultural and forestry soils.

[0019] The beneficial effects of the present invention are as follows: By using zeolite molecular sieve as the substrate and combining with the wrapping of the modified bio - inspired hydrophilic nano - substrate, the lifespan of the water - retaining agent can be greatly extended, and the water - retaining effect of the soil can be prolonged. At the same time, through the cooperation of the zeolite molecular sieve and the wrapped modified bio - inspired nano - substrate, a three - dimensional hydrophilic structure is formed in the soil, effectively improving the water absorption rate and the frequency of repeated water absorption of the water - retaining agent, and further enhancing the water absorption and water - retaining effect. Moreover, through the treatment liquid absorbed internally and the modified hydrophilic bentonite, the water - retaining agent can have the effect of slowly releasing water and nutrients, reducing the fertilizer application frequency, significantly increasing the soil water - holding capacity and water - retaining ability, enhancing the drought - resistance ability of crops, and realizing the rational utilization of water resources and the sustainable development of agriculture and forestry. Description of the Drawings

[0020] Figure 1 It is a flow chart of the preparation method of the present invention. Detailed Embodiments

[0021] To deepen the understanding of the present invention, the following will further elaborate on the present invention in combination with embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation to the protection scope of the present invention.

[0022] This embodiment provides an agricultural and forestry drought-resistant water-retaining agent with a bionic three-dimensional hydrophilic structure, which includes a modified bionic hydrophilic nano-substrate, a molecular sieve, and modified hydrophilic bentonite. The modified bionic hydrophilic nano-substrate is made by mixing hydrophilic cellulose prepared by reacting cellulose with isocyanate after nitrification with a cross-linking agent. The modified hydrophilic bentonite is made by mixing potassium salt and phosphate with nano-bentonite.

[0023] Example 1

[0024] According to Figure 1 As shown, this embodiment provides a preparation method of an agricultural and forestry drought-resistant water-retaining agent with a bionic three-dimensional hydrophilic structure, which includes the following steps:

[0025] Step 1: Preparation of the modified bionic hydrophilic nano-substrate. First, mix cellulose with a mixed acid to carry out an esterification reaction. After obtaining nitrocellulose, mix it with isocyanate for reaction to obtain hydrophilic cellulose. Then, dry it under a closed condition at 60°C for 2 h and then mix it with a cross-linking agent to obtain cross-linked hydrophilic cellulose, which is evenly divided into three parts for standby. The cross-linking agent is glyoxal with a concentration of 40%. Add nitrocellulose to glyoxal at a ratio of 1:1 and mix for 5 h under the conditions of a temperature of 40°C and a pH value of 6.

[0026] The mixed acid is made by mixing concentrated sulfuric acid and concentrated nitric acid at a volume ratio of 2:1. Cellulose is mixed with the mixed acid at a molar ratio of 1:45 and undergoes an esterification reaction under the temperature condition of 28°C - 34°C. Then, filter out the generated light yellow cotton-like product, and finally rinse it three times with deionized water to obtain nitrocellulose.

[0027] [[ID=!7]]Mix nitrocellulose with a concentration of 45 g / L and isocyanate at a ratio of the molar ratio of -NCO to -OH of 5:2, and react under the condition of 50°C for 90 min to obtain hydrophilic cellulose.

[0028] Step 2: Preparation of the molecular sieve. Take zeolite powder and grind it, and then carry out acid treatment and alkali treatment successively with an aqueous solution of ethylenediaminetetraacetic acid with a concentration of 0.18 mol / L and an aqueous solution of sodium hydroxide with a concentration of 0.9 mol / L. Finally, wash it with a solution of disodium ethylenediaminetetraacetate with a concentration of 0.11 mol / L to obtain the molecular sieve.

[0029] After washing with disodium ethylenediaminetetraacetate, rinse it twice again with deionized water and dry it under the condition of 240°C for 45 min.

[0030] Step 3: Coating and drying treatment. Add the molecular sieve to one part of the cross-linked hydrophilic cellulose and stir it, then granulate and dry it. Repeat the process of stirring with the second part of the cross-linked hydrophilic cellulose and then drying to obtain the bionic water-retaining agent base material.

[0031] Among them, the drying conditions for both times are drying at 160 °C for 50 min, and the mass ratio of the molecular sieve to the cross-linked hydrophilic cellulose is 2:1.

[0032] Step 4: Prepare modified hydrophilic bentonite. First, make potassium carbonate and ammonium dihydrogen phosphate into an aqueous solution and mix them according to a molar ratio of potassium to phosphorus of 1:1 to obtain a modified solution. Then, grind the bentonite into a slurry, mix it with the modified solution, dry and pulverize it, and sieve it using a 200-mesh sieve to obtain modified hydrophilic bentonite;

[0033] Among them, the mass ratio of the modified solution to the bentonite slurry is 20:80. After mixing, dry it at 400 °C for 3.5 h, and perform rapid stirring while drying.

[0034] Step 5: Outer coating treatment. Mix and stir the modified hydrophilic bentonite and the third portion of cross-linked hydrophilic cellulose according to a mass ratio of 2:1 to obtain an outer coating. Then, mix and stir the bio-based water retainer base material prepared in Step 3 and dry it to obtain a semi-finished water retainer;

[0035] Among them, when mixing the bio-based water retainer base material and the outer coating, repeat it 3 times. After each mixing, filter out the bio-based water retainer base material contaminated with the outer coating and dry it. The drying conditions are all drying at 180 °C for 20 min.

[0036] Step 6: Modification treatment. Add potassium dihydrogen phosphate and microbial agents to water and mix and dissolve them to obtain a treatment solution. Among them, the mass ratio of the compound fertilizer, the microbial agent, and water is 25:5:70. Then, evenly spray the treatment solution on the semi-finished water retainer, and finally perform a drying treatment to obtain a drought-resistant water retainer;

[0037] The microbial agent is directly purchased. Its components include Azotobacter chroococcum, purchased from the China Center for Type Culture Collection, with the preservation number CCTCC NO: M2016110; Micrococcus phospholyticum, purchased from the General Microbiological Center of the China Committee for Culture Collection of Microorganisms, with the preservation number CGMCC No. 7778;

[0038] The spraying of the treatment solution needs to be repeated three times. After the first uniform spraying of the treatment solution, let it stand for 15 min and then perform the second spraying. After the second spraying of the treatment solution, let it stand for 30 min and then perform the third spraying. After the third spraying of the treatment solution, place the semi-finished water retainer in an environment of 60 °C, dry it for 3.5 h, and then cool it and take it out to obtain a drought-resistant water retainer.

[0039] Example 2

[0040] Application of an agricultural and forestry drought-resistant water-retaining agent with a bionic three-dimensional hydrophilic structure in agricultural and forestry soil drought resistance and water retention, and comparison of its application with the traditional water-retaining agent sodium polyacrylate purchased on the market. Before application, the water absorption rates of the drought-resistant water-retaining agent of this application and the traditional water-retaining agent were tested and the data were recorded. Subsequently, equal amounts of the two water-retaining agents were applied to two plots of land with the same area. The percentage of soil moisture content and the percentage of nutrient content in the applied soil were detected using a soil detector on the 15th day, 25th day, 35th day, and 50th day respectively. The specific test results are shown in Table 1 below.

[0041] During the water absorption rate test, 50 g of the two water-retaining agents with the same weight were added to the same and sufficient amount of water. After waiting for 1 h, the remaining water was filtered out and weighed, and the water absorption rate was calculated.

[0042] Table 1 Data table of the comparative experiment of the drought-resistant water-retaining agent

[0043]

[0044] Among them, the water absorption rate is the percentage of the ratio of the weight of the water-retaining agent to the weight of the absorbed water, and the nutrient content is the percentage of the total amount of nitrogen, phosphorus, potassium elements and organic matter in the monitored soil.

[0045] It can be seen from the above table that the water absorption rate of the water-retaining agent prepared by the present invention is significantly higher than that of the traditional water-retaining agent. During a period of time after application, the reduction rates of the soil moisture content and nutrient content in the soil applied with the water-retaining agent prepared by this application are significantly lower than those of the traditional water-retaining agent. This is because the nitrocellulose treated with the cross-linking agent has a better three-dimensional bionic structure. The bionic water-retaining agent base material formed by combining the characteristics of the molecular sieve and the multi-layer cross-linked hydrophilic cellulose wrapped on the outer layer has better water absorption and slow-release effects, which further proves that the advantages of the water-retaining agent of this application are greater than those of the traditional water-retaining agent.

[0046] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. An agricultural and forestry drought-resistant water retainer with a bionic three-dimensional hydrophilic structure, characterized in that: It includes a modified bionic hydrophilic nano-substrate, molecular sieve and modified hydrophilic bentonite. The modified bionic hydrophilic nano-substrate is made by mixing hydrophilic cellulose, which is obtained by reacting cellulose with isocyanate after nitrification, with a cross-linking agent. The modified hydrophilic bentonite is made by mixing potassium salt and phosphate with nano-bentonite.

2. A preparation method of an agricultural and forestry drought-resistant water-retaining agent with a bionic three-dimensional hydrophilic structure, characterized in that, It includes the following steps: Step 1: Preparation of the modified bionic hydrophilic nano-substrate. First, mix cellulose with mixed acid for an esterification reaction to obtain nitrocellulose, then mix it with isocyanate for a reaction to obtain hydrophilic cellulose. After drying, mix it with a cross-linking agent to obtain cross-linked hydrophilic cellulose, and divide it evenly into three parts for standby. Step 2: Preparation of the molecular sieve. Take zeolite powder and grind it, then carry out acid treatment and alkali treatment with ethylenediaminetetraacetic acid and sodium hydroxide in sequence. Finally, wash it with disodium ethylenediaminetetraacetate to obtain the molecular sieve. Step 3: Coating and drying treatment. Add the molecular sieve to one part of the cross-linked hydrophilic cellulose and stir, then granulate and dry it. Repeat the process of stirring with the second part of the cross-linked hydrophilic cellulose and drying to obtain the bionic water-retaining agent base material. Step 4: Preparation of the modified hydrophilic bentonite. First, make an aqueous solution of potassium salt and phosphate and mix them to obtain a modified solution. Then grind bentonite into a slurry, mix it with the modified solution, and dry and grind it to obtain the modified hydrophilic bentonite. Step 5: Outer coating treatment. Mix the modified hydrophilic bentonite with the third part of the cross-linked hydrophilic cellulose and stir to obtain the outer coating. Then mix and stir the bionic water-retaining agent base material obtained in Step 3 and dry it to obtain the semi-finished water-retaining agent. Step 6: Modification treatment. Add compound fertilizer and microbial agent to water and mix and dissolve them to obtain a treatment solution. Then evenly spray the treatment solution on the semi-finished water-retaining agent, and finally carry out drying treatment to obtain the drought-resistant water-retaining agent.

3. The preparation method of an agricultural and forestry drought-resistant water-retaining agent with a bionic three-dimensional hydrophilic structure according to claim 2, wherein: In Step 1, the mixed acid is made by mixing concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 2:

1. After the cellulose and the mixed acid are mixed for an esterification reaction, filter out the generated light yellow cotton-like product, and then rinse it three times with deionized water to obtain nitrocellulose. The drying condition of the hydrophilic cellulose is drying for 2 - 3 h under a closed condition at 50 - 60 °C.

4. The preparation method of an agricultural and forestry drought-resistant water-retaining agent with a bionic three-dimensional hydrophilic structure according to claim 2, characterized in that: In Step 2, 0.18 mol / L aqueous solution of ethylenediaminetetraacetic acid, 0.9 mol / L aqueous solution of sodium hydroxide and 0.11 mol / L solution of disodium ethylenediaminetetraacetate are used. After washing with disodium ethylenediaminetetraacetate finally, rinse it twice again with deionized water and dry it for 30 - 45 min under the condition of 220 - 280 °C. The two drying conditions in Step 3 are drying for 50 - 70 min at 120 - 160 °C.

5. The preparation method of an agricultural and forestry drought-resistant water-retaining agent with a bionic three-dimensional hydrophilic structure according to claim 2, characterized in that: In Step 4, the molar ratio of potassium and phosphorus in the modified solution is 1:1; the mass ratio of the modified solution to the bentonite slurry is 20:

80. After mixing, dry it for 3 - 4 h under the condition of 300 - 450 °C, and carry out rapid stirring while drying; use a 200-mesh sieve for screening during grinding.

6. The preparation method of an agricultural and forestry drought-resistant water-retaining agent with a bionic three-dimensional hydrophilic structure according to claim 2, wherein: In Step 5, when mixing the bionic water-retaining agent base material with the outer coating, repeat it 2 - 4 times. After each mixing, filter out the bionic water-retaining agent base material contaminated with the outer coating and dry it. The drying conditions are all drying for 20 - 30 min in an environment of 160 - 200 °C.

7. The preparation method of an agricultural and forestry drought-resistant water-retaining agent with a bionic three-dimensional hydrophilic structure according to claim 2, characterized in that: In step six, the mixing mass ratio of the compound fertilizer, microbial agent and water is 25:5:70; the treatment liquid spraying needs to be carried out three times repeatedly. After the first uniform spraying of the treatment liquid, it is left standing for 10 - 15 minutes and then the second spraying is carried out. After the second spraying of the treatment liquid, it is left standing for 30 - 40 minutes and then the third spraying is carried out. After the third spraying of the treatment liquid, the semi-finished water-retaining agent is placed in an environment of 40 - 60 °C and dried for 3 - 4 hours and then cooled and taken out to obtain the drought-resistant water-retaining agent.

8. Application of a bionic three-dimensional hydrophilic structure-based agricultural and forestry drought-resistant water-retaining agent prepared by the preparation method according to claim 2 in agricultural and forestry soil drought resistance and water conservation.

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