Method for constructing plant leaf surface bionic wax coat by using beewax

Abstract

The invention relates to the technical field of agricultural biological materials and plant protection, and particularly discloses a method for constructing a bionic wax coat on a plant leaf surface by using beewax, and the bionic wax coat with a micro-nano structure is formed on the plant leaf surface by compounding beewax and a natural plasticizer, reinforcing a nano material and performing a low-temperature atomization coating process. The coating has hydrophobic, anti-ultraviolet and antibacterial functions, can remarkably improve the stress resistance of plants, is environment-friendly and economical, and is suitable for leaf surface protection of field crops, fruits, vegetables and ornamental plants.

Description

Technical Field

[0001] The present invention relates to the technical field of agricultural biomaterials and plant protection, and specifically discloses a method for constructing a bionic wax layer on plant leaves using beeswax. Background Art

[0002] The natural wax layer on plant leaves is composed of hydrophobic lipid compounds secreted by epidermal cells. It has core functions such as reducing water evaporation, protecting against ultraviolet radiation, and preventing the invasion of pathogens. However, in agricultural production, crops are often damaged by environmental stress (such as high temperature and drought), pests and diseases, or mechanical damage, and their natural wax layer is often destroyed, resulting in a significant decrease in stress resistance. To compensate for this shortcoming, existing technologies mainly use the following methods:

[0003] Chemical synthetic coating:

[0004] Artificial hydrophobic materials such as silicone preparations and polyethylene wax are widely used for leaf protection, but they have obvious defects:

[0005] Chemical residues may penetrate into plant tissues and interfere with stomatal opening and closing and photosynthesis;

[0006] Synthetic materials are difficult to degrade, and long-term use leads to soil pollution. For example, the half-life of polyethylene wax in the soil is more than 100 years.

[0007] Genetic engineering improvements:

[0008] Overexpression of wax synthesis-related genes (such as CER1 and KCS) can enhance plant wax secretion, but there are the following limitations:

[0009] Gene editing takes a long time (usually 3 to 5 years) and requires customized development for different crops, which is very costly.

[0010] The ecological risks and consumer acceptance issues of genetically modified crops restrict their promotion.

[0011] Physical covering technology:

[0012] Although coatings such as paraffin and mineral oil can form a physical barrier temporarily, they have weak bonding with the leaf surface (adhesion ≤ 0.5 MPa) and are easily washed off by rain or friction. They require frequent re-coating, increasing field maintenance costs by 30% to 50%.

[0013] In recent years, research on natural wax substitutes (such as palm wax and rice bran wax) has made some progress, but their individual applications still face the following bottlenecks:

[0014] Poor film-forming properties: Pure natural wax has a high melting point (such as beeswax 62-65°C), and high-temperature melting spraying can easily burn leaf tissue;

[0015] Low mechanical strength: The natural wax layer is very brittle and is prone to cracking in an environment with a daily temperature difference of more than 15°C, resulting in protection failure;

[0016] Single function: Existing natural coatings lack bionic structural design and cannot simulate the micro-nano topological structure of natural wax layers (such as lotus leaf effect and anti-adhesion properties).

[0017] Beeswax is considered a potential alternative material due to its excellent biocompatibility and hydrophobicity, but when used directly:

[0018] The adhesion of pure beeswax coating on the leaf surface is only 1.2-1.5N / cm 2 , significantly lower than the natural wax layer (3.0-4.5N / cm 2 );

[0019] The lack of nanoscale reinforcement phase leads to insufficient wear resistance (coating breakage rate > 60% after 100 frictions).

[0020] Therefore, there is an urgent need for a method for constructing a bionic coating based on beeswax modification, which can achieve efficient and environmentally friendly leaf protection through material compounding, structural design and process optimization. In view of this, the inventors provide a method for constructing a bionic wax layer on plant leaves using beeswax to solve the above problems. Summary of the Invention

[0021] The present invention provides a method for constructing a bionic wax layer on plant leaves using beeswax. By optimizing the film-forming properties of beeswax, introducing nano-reinforced materials and bionic structure design, the problems of poor coating adhesion, single function and complex process in the prior art are solved.

[0022] In order to achieve the above object, the basic solution of the present invention provides a method for constructing a bionic wax layer on plant leaves using beeswax, comprising the following steps:

[0023] (a) Beeswax and natural plasticizer are mixed in a mass ratio of 1:3-5 and melted in a water bath at 60-70°C to form a mixed wax base;

[0024] (b) adding 0.5% to 2% by weight of a plant-derived emulsifier based on the mass of beeswax to the mixed wax base and stirring until a uniform emulsion is formed;

[0025] (c) adding 1% to 5% of nano-reinforcement material to the emulsion and dispersing the mixture by ultrasonication for 20 to 40 minutes to obtain a composite beeswax emulsion;

[0026] (d) injecting the composite beeswax emulsion into an atomizing spray device, controlling the emulsion temperature to 40-50° C., adjusting the atomizing pressure to 0.2-0.6 MPa, and spraying the emulsion onto the plant leaves with a droplet size of 10-50 μm;

[0027] (e) Drying and curing at 25-35° C. to form a biomimetic wax layer with a thickness of 2-10 μm and a micron-scale concave-convex structure.

[0028] Furthermore, the natural plasticizer is one or more combinations of palm wax, candelilla wax, and rice bran wax.

[0029] Furthermore, the plant-derived emulsifier is soybean lecithin, sucrose ester or gum arabic, and its added amount is 0.8% to 1.5% of the total mass of beeswax.

[0030] Furthermore, the nano-reinforcement material is nano-silicon dioxide, cellulose nanocrystal or montmorillonite, the particle size of which is 20-200 nm, and the addition amount of nano-silicon dioxide is 2% to 4%.

[0031] Furthermore, the drying and curing in step (e) is carried out in any of the following ways:

[0032] Natural drying for 1-2 hours, ambient humidity ≤ 60%;

[0033] Warm air assisted drying, temperature 30-40℃, wind speed 2-4m / s, time 10-30 minutes.

[0034] Furthermore, the present invention also includes functional additives added to the composite beeswax emulsion, wherein the functional additives include:

[0035] Antimicrobial agents: 1% to 3% tea tree oil, peppermint extract, or nanosilver;

[0036] UV inhibitors: 0.5% to 2% titanium dioxide nanoparticles or flavonoid extracts;

[0037] Nutrients: 0.1% to 1% amino acids, alginic acid or humic acid.

[0038] Furthermore, the antibacterial agent and the anti-ultraviolet agent are compounded and added in a mass ratio of 1:1, and the total added amount does not exceed 4% of the emulsion.

[0039] Furthermore, the non-foliage area of the plant is covered with a degradable paper-based template before spraying. The degradable paper-based template is a starch-based or cellulose-based material with a thickness of 0.1-0.5 mm.

[0040] Furthermore, the atomizing spraying device includes:

[0041] Liquid storage tank: equipped with a stirrer and constant temperature control system;

[0042] Atomizing nozzle: connect the pressure regulating valve and flow meter;

[0043] Mobile bracket: equipped with a liquid storage tank and atomizing nozzle, the bracket height can be adjusted from 0.5 to 1.5 meters.

[0044] The principles and effects of this basic solution are:

[0045] 1. Breakthrough in bionic structure and performance

[0046] Micro-nano topology optimization: Through the compounding of beeswax and plasticizer and the directional dispersion of nanomaterials (such as silica), a natural wax layer-like micron-scale protrusion and nanoscale rough structure are formed, making the coating contact angle reach 150°-160°, and the hydrophobicity is improved by 40% to 60%, significantly enhancing the "self-cleaning" effect.

[0047] Strengthening of mechanical properties: The addition of nano-silica increases the hardness of the coating to 2H-3H (pure beeswax is 2HM), the wear resistance is increased by more than 3 times, and the effective period is extended to 30-45 days in field environment.

[0048] 2. Environmental compatibility and safety

[0049] All-natural ingredients: Beeswax, palm wax, and plant-derived emulsifiers are all biodegradable, with a soil degradation rate of ≥90% within 28 days, meeting organic farming standards (such as USDA Organic and EU Eco-regulation).

[0050] Low temperature process protection: 40-50℃ low temperature atomization avoids heat damage to leaves. After spraying, the chlorophyll retention rate is ≥95%, and there is no significant change in photosynthetic rate (p>0.05).

[0051] 3. Multifunctional integration and customization

[0052] Antibacterial and anti-UV synergy: The coating with tea tree essential oil and titanium dioxide has an inhibition rate of >70% on gray mold and a UV reflectivity of ≥40%, achieving "one film with multiple effects";

[0053] Nutrient slow release: The loading of nutrients such as alginate increases the nitrogen and phosphorus absorption rate of leaves by 15% to 20%, reducing the frequency of foliar fertilizer application.

[0054] 4. Process economy and universality

[0055] Low-cost equipment: The atomizing spray device does not require a complex temperature control system, and the field operation cost is reduced by 60% compared with traditional high-pressure spraying;

[0056] Broad-spectrum adaptability: By adjusting the beeswax / plasticizer ratio (1:3) and spraying parameters (pressure, droplet size), it can be adapted to crops with different leaf morphologies such as tomatoes, rice, and roses, with a coating uniformity (CV value) ≤10%.

[0057] 5. Industrial application potential

[0058] Compatible with existing agronomic processes: coating operations can be carried out simultaneously with pesticide spraying without the need for additional equipment investment;

[0059] Extend the shelf life of agricultural products: After spraying citrus, apple and other fruits, the decay rate during storage is reduced by 50% to 65%, and the commodity value is significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0061] Figure 1 A schematic diagram of a process for constructing a biomimetic wax layer on plant leaves using beeswax, as proposed in an embodiment of the present application, is shown;

[0062] Figure 2 A schematic diagram of a bionic wax layer of a method for constructing a bionic wax layer on plant leaves using beeswax, as proposed in an embodiment of the present application, is shown;

[0063] Figure 3 A schematic diagram of a preparation device for a method of constructing a biomimetic wax layer on plant leaves using beeswax, as proposed in an embodiment of the present application, is shown;

[0064] Figure 4 A comparative schematic diagram of Example 1 of a method for constructing a bionic wax layer on plant leaves using beeswax, as proposed in an embodiment of the present application, is shown;

[0065] Figure 5 A comparative schematic diagram of Example 2 of a method for constructing a bionic wax layer on plant leaves using beeswax proposed in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0066] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0067] The reference numerals in the drawings of the specification include: liquid storage tank 1, stirring shaft 2, thermostat 3, temperature sensor 4, stirring motor 5, electric push rod 6, pressure regulating valve 7, flow meter 8, atomizing nozzle 9, and movable bracket 10.

[0068] A method for constructing a bionic wax layer on plant leaves using beeswax, for example Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 As shown: The following steps are included:

[0069] Step 1: Preparation of beeswax-modified emulsion

[0070] Mix beeswax and natural plasticizer (palm wax, candelilla wax or rice bran wax) in a mass ratio of 1:3-5 and melt in a water bath at 60-70°C;

[0071] Add 0.5% to 2% of the mass of beeswax into a plant-derived emulsifier (soy lecithin or sucrose ester) and stir until a uniform emulsion is formed;

[0072] 1% to 5% of nano-reinforcement material (nano-silicon dioxide, cellulose nanocrystal or montmorillonite) is added to the emulsion, and ultrasonic dispersion is performed for 20 to 40 minutes to obtain a composite beeswax emulsion.

[0073] Step 2: Functional additive loading

[0074] Depending on the target functional requirements, one or a combination of the following ingredients is added to the emulsion:

[0075] Antimicrobial agents: 1% to 3% tea tree oil, peppermint extract, or nanosilver;

[0076] UV inhibitors: 0.5% to 2% titanium dioxide nanoparticles or flavonoid extracts;

[0077] Nutrients: 0.1% to 1% amino acids or alginic acid.

[0078] Step 3: Low temperature atomization coating

[0079] The composite beeswax emulsion is injected into the atomizing spray device, which includes:

[0080] The liquid storage tank 1 is equipped with an agitator, which includes a stirring motor 5 and a stirring shaft 2 coaxially connected to the stirring motor 5. The liquid storage tank 1 is equipped with a constant temperature control system, which includes a temperature sensor 4 installed at the bottom of the liquid storage tank 1 and a thermostat 3 electrically connected to the temperature sensor 4.

[0081] The side wall of the liquid storage tank 1 is connected to an atomizing nozzle 9: the atomizing nozzle 9 is connected to a pressure regulating valve 7 and a flow meter 8;

[0082] Mobile bracket 10: equipped with liquid storage tank 1 and atomizing nozzle 9, the bracket top plate is installed with electric push rod 6, the output end of the electric push rod 6 is installed with a connecting seat, the top of the connecting seat is connected to the liquid storage tank 1, and the adjustable range of the electric push rod 6 is 0.5-1.5m.

[0083] The atomizing spray device controls the emulsion temperature to 40-50°C;

[0084] Adjust the atomization pressure to 0.2-0.6MPa, the droplet size to 10-50μm, and the distance between the nozzle and the leaf surface to 15-30cm;

[0085] 0.5-2.0 mL / m 2 The spray amount is evenly applied on the plant leaves to form an initial wet film;

[0086] Step 4: Bionic structure solidification

[0087] Dry naturally at 25-35℃ for 1-2 hours, or use warm air at 30-40℃ to assist curing for 10-30 minutes;

[0088] Finally, a bionic wax layer with a thickness of 2-10 μm and a micron-level concave-convex structure is formed. The contact angle of the bionic wax layer is ≥150° and the ultraviolet reflectivity is ≥30%.

[0089] Example 1: Disease prevention and water retention coating on tomato leaves

[0090] Raw material ratio:

[0091] 30g beeswax, 100g palm wax (mass ratio 1:3.3);

[0092] Emulsifier: soy lecithin 0.36g (1.2% of beeswax mass);

[0093] Nano-reinforcement material: nano-silicon dioxide 0.9 g (particle size 50 nm, addition amount 3%);

[0094] Functional additives: tea tree essential oil 0.6g (2%), titanium dioxide nanoparticles 0.3g (1%).

[0095] Preparation and coating:

[0096] Melt beeswax and palm wax in a 65°C water bath, add soy lecithin and stir for 20 minutes;

[0097] Add nano-silica and ultrasonically disperse for 30 minutes, then add tea tree essential oil and titanium dioxide and mix well;

[0098] The emulsion was injected into the liquid storage tank 1, the temperature was maintained at 45°C, the atomization pressure was adjusted to 0.4 MPa, and the nozzle was 20 cm away from the leaf surface;

[0099] At 1.5 mL / m 2 The spray amount was evenly applied and dried with warm air (35°C, wind speed 3m / s) for 15 minutes.

[0100] Effect verification:

[0101] Hydrophobicity: contact angle reaches 156°, water drop roll-off time ≤ 2 seconds;

[0102] Disease resistance: The incidence of leaf mold was reduced by 72% compared with the untreated group;

[0103] Water retention: Under drought stress (35°C / 30% humidity), the relative water content of leaves increased by 38%;

[0104] Light transmittance: The leaf transmittance was 89%, which was not significantly different from the untreated group (91%).

[0105] Example 2: UV-resistant and nutrient-enhanced coating on rice leaves

[0106] Raw material ratio:

[0107] Beeswax 24g, rice bran wax 120g (mass ratio 1:5);

[0108] Emulsifier: sucrose ester 0.36 g (1.5% by mass of beeswax);

[0109] Nano-reinforcement material: cellulose nanocrystals 0.96 g (addition amount 4%);

[0110] Functional additives: flavonoid extract 0.48g (2%), alginic acid 0.12g (0.5%).

[0111] Preparation and coating:

[0112] Melt beeswax and rice bran wax at 70℃, add sucrose ester, stir and cool to 50℃;

[0113] Cellulose nanocrystals were added and ultrasonically dispersed for 40 minutes, followed by the addition of flavonoids and alginic acid;

[0114] The rice ears were covered with a biodegradable starch template, with a spraying pressure of 0.3 MPa and a droplet size of 20-30 μm;

[0115] The mixture was dried naturally for 2 hours (ambient temperature 28°C, humidity 55%).

[0116] Effect verification:

[0117] UV protection: UV reflectivity 42%, chlorophyll degradation rate reduced by 34%;

[0118] Nutrient absorption: nitrogen content in leaves increased by 18%, and phosphorus content increased by 12%;

[0119] Adhesion: After being washed by simulated rainfall (rain intensity 50mm / h), the coating retention rate is ≥85%.

[0120] Example 3: Antibacterial and decorative coating on rose leaves

[0121] Raw materials and process innovation:

[0122] Beeswax 20g, candelilla wax 80g (1:4), nanosilver 0.48g (2%), peppermint extract 0.24g (1%);

[0123] After spraying, a template was used to create a petal-like texture, and the coating had a matte texture after drying.

[0124] Functional testing:

[0125] Antibacterial property: The diameter of the inhibition zone against gray mold is 12mm (no inhibition zone in the control group);

[0126] Decorative: The coating can be loaded with edible pigments to achieve leaf color modification, with a color fastness rating of 4 (5-level standard);

[0127] Durability: Under outdoor conditions (average daily temperature 25°C), the product is valid for 28 days without cracking or falling off.

[0128] Example 4: Citrus Fruit Insect-Proofing and Fresh-Preserving Coating

[0129] Targeted design:

[0130] Beeswax and palm wax are mixed in a ratio of 1:4, and 2% nano-montmorillonite is added (to enhance barrier properties);

[0131] Add 1.5% azadirachtin extract (insect repellent) and spray on the fruit surface.

[0132] Comprehensive effect:

[0133] Insect control rate: fruit fly infestation rate reduced by 68%;

[0134] Freshness: After 21 days of storage, the decay rate was reduced by 55% compared with the untreated group;

[0135] Safety: Conforms to GB 2760 food contact material standard, no toxic residue.

[0136] The advantages of the present invention are as follows:

[0137] 1. Excellent bionic performance: Through micro-nano structure design, it simulates the hydrophobic and anti-adversity functions of the natural wax layer, with a contact angle of 150°-160° and an increase in ultraviolet reflectivity by 30% to 50%.

[0138] 2. Environmentally friendly: All ingredients are biodegradable, no chemical residue, and suitable for organic agriculture standards.

[0139] 3. Customizable functions: By adding antibacterial, anti-ultraviolet or nutritional agents, "one film with multiple effects" can be achieved, reducing the use of pesticides by 20% to 50%.

[0140] 4. Strong process adaptability: Low-temperature atomization process avoids heat damage and is suitable for various scenarios such as fields and greenhouses.

[0141] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for constructing a bionic wax layer on plant leaves using beeswax, characterized in that: The following steps are involved: (a) beeswax and natural plasticizer are mixed in a mass ratio of 1:3-5 and melted in a water bath at 60-70°C to form a mixed wax base; (b) adding 0.5% to 2% of the mass of beeswax to the mixed wax base and stirring until a uniform emulsion is formed; (c) adding 1% to 5% of nano-reinforcement material to the emulsion and dispersing the mixture by ultrasonication for 20-40 minutes to obtain a composite beeswax emulsion; (d): injecting the composite beeswax emulsion into an atomizing spray device, controlling the emulsion temperature to 40-50° C., adjusting the atomizing pressure to 0.2-0.6 MPa, and spraying the droplet size to 10-50 μm on the plant leaves; (e): Dry and solidify at 25-35°C to form a biomimetic wax layer with a thickness of 2-10 μm and a micron-scale concave-convex structure.

2. The method for constructing a bionic wax layer on plant leaves using beeswax according to claim 1, wherein: The natural plasticizer is one or more combinations of palm wax, candelilla wax and rice bran wax.

3. The method for constructing a bionic wax layer on plant leaves using beeswax according to claim 1, wherein: The plant-derived emulsifier is soybean lecithin, sucrose ester or gum arabic, and its added amount is 0.8% to 1.5% of the total mass of the beeswax.

4. The method for constructing a bionic wax layer on plant leaves using beeswax according to claim 1, wherein: The nano-reinforced material is nano-silicon dioxide, cellulose nano-crystal or montmorillonite, the particle size of which is 20-200nm, and the addition amount of the nano-silicon dioxide is 2%-4%.

5. The method for constructing a bionic wax layer on plant leaves using beeswax according to claim 1, characterized in that: In step (e), the drying and curing is carried out in any of the following ways: Natural drying for 1-2 hours, ambient humidity ≤ 60%; Warm air assisted drying, temperature 30-40℃, wind speed 2-4m / s, time 10-30 minutes.

6. The method for constructing a bionic wax layer on plant leaves using beeswax according to claim 1, characterized in that: Also included are functional additives added to the composite beeswax emulsion, the functional additives comprising: Antimicrobial agents: 1% to 3% tea tree oil, peppermint extract, or nanosilver; UV inhibitors: 0.5% to 2% titanium dioxide nanoparticles or flavonoid extracts; Nutrients: 0.1% to 1% amino acids, alginic acid or humic acid.

7. The method for constructing a bionic wax layer on plant leaves using beeswax according to claim 6, characterized in that: The antibacterial agent and the anti-ultraviolet agent are compounded and added in a mass ratio of 1:1, and the total added amount does not exceed 4% of the emulsion.

8. The method for constructing a bionic wax layer on plant leaves using beeswax according to claim 1, characterized in that: The non-foliage area of the plant is covered with a degradable paper-based template before spraying. The degradable paper-based template is a starch-based or cellulose-based material with a thickness of 0.1-0.5 mm.

9. The method for constructing a bionic wax layer on plant leaves using beeswax according to any one of claims 1 to 8, characterized in that: The atomizing spraying device comprises: Liquid storage tank: equipped with a stirrer and constant temperature control system; Atomizing nozzle: connect the pressure regulating valve and flow meter; Mobile bracket: equipped with a liquid storage tank and atomizing nozzle, the bracket height can be adjusted from 0.5 to 1.5 meters.

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