Preparation method of degradable seedling to enhance immune function of vegetables
By using a seedling tray with conductive circuitry prepared from corn stalk fiber and polypyrrole-polycaprolactone composite, the problems of non-degradability and lack of immune function of the seedling tray were solved, realizing the biodegradability of the seedling tray and enhancing the immune function of vegetables, thus promoting the healthy growth of vegetables.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NINGXIA UNIVERSITY
- Filing Date
- 2025-01-24
- Publication Date
- 2026-06-09
AI Technical Summary
Existing seedling substrates are non-degradable and lack protective mechanisms to enhance the immune function of vegetables, thus failing to effectively promote healthy vegetable growth.
Using a mixture of corn stalk fiber and gelatinized corn starch as the base material, combined with polypyrrole-polycaprolactone complex and micro bio-batteries, seedling trays with conductive circuits were prepared by 3D printing technology, which can achieve biodegradation and enhance the immune function of vegetables.
It achieves the biodegradation of seedling trays, reduces soil pollution, promotes the growth and development of vegetable roots, enhances the vegetables' own immunity, reduces the use of chemical pesticides, and realizes green and sustainable vegetable production.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of seedling tray technology. More specifically, this invention relates to a method for preparing a biodegradable seedling tray that enhances the immune function of vegetables. Background Technology
[0002] Fruits and vegetables are an indispensable part of people's daily diet, and their yield and quality directly affect people's quality of life and health. In vegetable cultivation, seedling raising is a crucial step; high-quality seedlings lay a solid foundation for vegetable growth, significantly improving survival rate, growth rate, and resistance to pests and diseases. However, currently common seedling trays suffer from problems such as non-degradable materials and limited functionality. Existing technologies, such as the invention patent application CN105746226A, which discloses a method for preparing a biodegradable seedling tray, solve the problem of non-degradable materials. However, this seedling tray only provides simple support and fixation for seedlings, lacking the ability to enhance the immune function of vegetables and failing to provide additional protective mechanisms, thus still requiring improvement. Summary of the Invention
[0003] One objective of this invention is to provide a method for preparing a biodegradable seedling tray that enhances the immune function of vegetables. This tray not only achieves biodegradation and reduces soil pollution, but also enhances the immune function of vegetables and promotes their healthy growth.
[0004] To achieve these objectives and other advantages of the present invention, according to one aspect of the present invention, a method for preparing a biodegradable seedling tray with enhanced vegetable immune function is provided, comprising the following steps:
[0005] Step 1: Prepare corn stalk fiber, crush it to a particle size of 1-3 mm, dry it, add 15-20% by mass of gelatinized corn starch solution, stir evenly, and make seedling base material, wherein the mass ratio of corn stalk fiber to corn starch is (5-8):2.
[0006] Step 2: Dissolve polycaprolactone solution in chloroform to prepare a solution with a mass fraction of 10-15%, add polypyrrole, and stir magnetically at 50-60℃ for 6-8 hours to obtain polypyrrole-polycaprolactone composite.
[0007] Step 3: The seedling tray material is made into an outer layer of the seedling tray. An inner layer of the seedling tray made of the polypyrrole-polycaprolactone composite is set inside the outer layer of the seedling tray and connected to a micro bio-battery. Multiple conductive lines made of the polypyrrole-polycaprolactone composite are set inside the inner layer of the seedling tray, and finally the biodegradable seedling tray with enhanced vegetable immune function is obtained.
[0008] The microbial battery can be made based on the principle of microbial fuel cells. Specifically, 3D printing technology can be used to make a microbattery shell using polylactic acid as the material. A proton exchange membrane is used to separate the interior of the microbattery shell into an anode chamber and a cathode chamber. Graphite felt is placed in the anode chamber as the anode. The anode is immersed in the bacterial solution of electrogenic microorganisms such as Geobacterium, Shewanella, and Bacillus. A platinum carbon electrode is placed in the cathode chamber as the cathode and a cathode electrolyte is injected. This is how a microbial battery is assembled.
[0009] Preferably, the molecular weight of polycaprolactone in step two is 10,000-20,000.
[0010] Preferably, the molecular weight of the polypyrrole in step two is 100,000-200,000.
[0011] Preferably, in step three, the biodegradable seedling tray with enhanced vegetable immune function is manufactured using 3D printing technology. The specific steps are as follows:
[0012] Step A: Based on the needs of vegetable seedling cultivation, design a 3D model of the seedling tray using CAD software, and design the routing and distribution of the conductive lines inside the seedling tray.
[0013] Step B: Load the seedling tray raw material and polypyrrole-polycaprolactone composite into the barrel of a dual-nozzle 3D printer, set the printing temperature to 180-200℃, the printing speed to 30-50 mm / s, the outer layer thickness of the seedling tray is 0.2-0.3 mm, the inner layer thickness of the seedling tray is 0.05-0.1 mm, and the diameter of the conductive line is 0.1-0.2 mm.
[0014] Step C: Start the 3D printer and print layer by layer according to the set model and parameters. After printing, dry and polish the surface to obtain the biodegradable seedling tray that enhances the immune function of vegetables.
[0015] Preferably, the conductive lines extend radially from the center to the edge at the bottom of the inner layer of the seedling tray, and are distributed in a grid pattern in the middle of the inner layer of the seedling tray, with a grid spacing of 5-8 mm.
[0016] Preferably, the outer layer of the seedling tray has a thickness of 0.25 mm, and the inner layer of the seedling tray has a thickness of 0.08 mm.
[0017] Preferably, the diameter of the conductive line is 0.15 mm.
[0018] Preferably, the mass ratio of corn stalk fiber to corn starch in step one is 3:1.
[0019] The present invention has at least the following beneficial effects: The method for preparing a biodegradable seedling tray that enhances the immune function of vegetables provided by the present invention can not only solve the environmental pollution problem caused by traditional seedling trays, but also promote the growth and development of vegetable roots, enhance the vegetables' own immunity, reduce the use of chemical pesticides, and realize the green and sustainable production of vegetables.
[0020] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Detailed Implementation
[0021] The present invention will now be described in further detail through specific embodiments, so that those skilled in the art can implement it based on the description.
[0022] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.
[0023] It should be noted that, unless otherwise specified, the experimental methods described in the following implementation plan are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified.
[0024] Example 1
[0025] A method for preparing a biodegradable seedling tray that enhances the immune function of vegetables includes the following steps:
[0026] Step 1: Collect corn stalks, remove impurities, and crush them to a particle size of 1-3mm. Place the crushed corn stalk fibers in an oven and dry them at 80℃ until constant weight for later use.
[0027] Step 2: Take corn starch, add an appropriate amount of water to prepare a corn starch solution with a mass fraction of 18%, and gelatinize the solution under heating and stirring conditions until a uniform gelatinized corn starch solution is formed.
[0028] Step 3: Add the prepared corn stalk fiber to the gelatinized corn starch solution and stir thoroughly with a stirrer to make seedling base material, wherein the mass ratio of corn stalk fiber to corn starch is 3:1.
[0029] Step 4: Take polycaprolactone with a molecular weight of 15,000, dissolve it in chloroform to prepare a 10% polycaprolactone solution, add polypyrrole with a molecular weight of 150,000, place the mixed solution in a constant temperature water bath at 55°C, and stir with a magnetic stirrer at a speed of 300 r / min for 7 hours to obtain the polypyrrole-polycaprolactone composite.
[0030] Step 5: Based on the seedling requirements of common leafy vegetables, design a 3D model of the seedling tray using CAD software. Design conductive lines that extend radially from the center to the edge at the bottom of the inner layer of the seedling tray, and are distributed in a grid pattern in the middle of the inner layer of the seedling tray, with a grid spacing of 6 mm. Load the prepared seedling tray raw material and polypyrrole-polycaprolactone composite into the two barrels of a dual-nozzle 3D printer, respectively. Set the printing temperature to 190℃, the printing speed to 40 mm / s, the outer layer thickness of the seedling tray to 0.25 mm, the inner layer thickness of the seedling tray to 0.08 mm, and the diameter of the conductive lines to 0.15 mm.
[0031] Step 6: Start the 3D printer and print layer by layer according to the set model and parameters. After printing, place the seedling tray in an oven and dry it at 60°C for 2 hours to remove residual solvent. Then, use sandpaper to polish the surface of the seedling tray to make it smooth. Install the micro bio-battery to connect it with the inner layer of the seedling tray, and finally obtain a biodegradable seedling tray that enhances the immune function of vegetables.
[0032] Example 2
[0033] A method for preparing a biodegradable seedling tray that enhances the immune function of vegetables includes the following steps:
[0034] Step 1: Collect corn stalks, remove impurities, and crush them to a particle size of 1-3mm. Place the crushed corn stalk fibers in an oven and dry them at 80℃ until constant weight for later use.
[0035] Step 2: Take corn starch, add an appropriate amount of water to prepare a corn starch solution with a mass fraction of 20%, and gelatinize the solution under heating and stirring conditions until a uniform gelatinized corn starch solution is formed.
[0036] Step 3: Add the prepared corn stalk fiber to the gelatinized corn starch solution and stir thoroughly with a stirrer to make seedling base material, wherein the mass ratio of corn stalk fiber to corn starch is 5:2.
[0037] Step 4: Take polycaprolactone with a molecular weight of 20,000, dissolve it in chloroform to prepare a polycaprolactone solution with a mass fraction of 15%, add polypyrrole with a molecular weight of 200,000, place the mixed solution in a constant temperature water bath at 60°C, and stir with a magnetic stirrer at a speed of 300 r / min for 8 hours to obtain the polypyrrole-polycaprolactone composite.
[0038] Step 5: Based on the seedling requirements of common leafy vegetables, design a 3D model of the seedling tray using CAD software. Design conductive lines that extend radially from the center to the edge at the bottom of the inner layer of the seedling tray, and are distributed in a grid pattern in the middle of the inner layer of the seedling tray, with a grid spacing of 8 mm. Load the prepared seedling tray raw material and polypyrrole-polycaprolactone composite into the two barrels of a dual-nozzle 3D printer, respectively. Set the printing temperature to 200℃, the printing speed to 50 mm / s, the outer layer thickness of the seedling tray to 0.2 mm, the inner layer thickness of the seedling tray to 0.1 mm, and the diameter of the conductive lines to 0.2 mm.
[0039] Step 6: Start the 3D printer and print layer by layer according to the set model and parameters. After printing, place the seedling tray in an oven and dry it at 60°C for 2 hours to remove residual solvent. Then, use sandpaper to polish the surface of the seedling tray to make it smooth. Install the micro bio-battery to connect it with the inner layer of the seedling tray, and finally obtain a biodegradable seedling tray that enhances the immune function of vegetables.
[0040] Example 3
[0041] A method for preparing a biodegradable seedling tray that enhances the immune function of vegetables includes the following steps:
[0042] Step 1: Collect corn stalks, remove impurities, and crush them to a particle size of 1-3mm. Place the crushed corn stalk fibers in an oven and dry them at 80℃ until constant weight for later use.
[0043] Step 2: Take corn starch, add an appropriate amount of water to prepare a corn starch solution with a mass fraction of 15%, and gelatinize the solution under heating and stirring conditions until a uniform gelatinized corn starch solution is formed.
[0044] Step 3: Add the prepared corn stalk fiber to the gelatinized corn starch solution and stir thoroughly with a stirrer to make seedling base material, wherein the mass ratio of corn stalk fiber to corn starch is 4:1.
[0045] Step 4: Take polycaprolactone with a molecular weight of 15,000, dissolve it in chloroform to prepare a 10% polycaprolactone solution, add polypyrrole with a molecular weight of 100,000, place the mixed solution in a constant temperature water bath at 50°C, and stir with a magnetic stirrer at a speed of 300 r / min for 6 hours to obtain the polypyrrole-polycaprolactone composite.
[0046] Step 5: Based on the seedling requirements of common leafy vegetables, design a 3D model of the seedling tray using CAD software. Design conductive lines that extend radially from the center to the edge at the bottom of the inner layer of the seedling tray, and are distributed in a grid pattern in the middle of the inner layer of the seedling tray, with a grid spacing of 5 mm. Load the prepared seedling tray raw material and polypyrrole-polycaprolactone composite into the two barrels of a dual-nozzle 3D printer, respectively. Set the printing temperature to 180℃, the printing speed to 30 mm / s, the outer layer thickness of the seedling tray to 0.3 mm, the inner layer thickness of the seedling tray to 0.05 mm, and the diameter of the conductive lines to 0.2 mm.
[0047] Step 6: Start the 3D printer and print layer by layer according to the set model and parameters. After printing, place the seedling tray in an oven and dry it at 60°C for 2 hours to remove residual solvent. Then, use sandpaper to polish the surface of the seedling tray to make it smooth. Install the micro bio-battery to connect it with the inner layer of the seedling tray, and finally obtain a biodegradable seedling tray that enhances the immune function of vegetables.
[0048] Comparative Example 1
[0049] A method for preparing a seedling tray includes the following steps:
[0050] Step 1: Collect corn stalks, remove impurities, and crush them to a particle size of 1-3mm. Place the crushed corn stalk fibers in an oven and dry them at 80℃ until constant weight for later use.
[0051] Step 2: Take corn starch, add an appropriate amount of water to prepare a corn starch solution with a mass fraction of 18%, and gelatinize the solution under heating and stirring conditions until a uniform gelatinized corn starch solution is formed.
[0052] Step 3: Add the prepared corn stalk fiber to the gelatinized corn starch solution and stir thoroughly with a stirrer to make seedling base material, wherein the mass ratio of corn stalk fiber to corn starch is 3:1.
[0053] Step 4: Based on the seedling requirements of common leafy vegetables, design a 3D model of the seedling tray using CAD software, load the prepared seedling tray material into the barrel of the 3D printer, set the printing temperature to 190℃, the printing speed to 40mm / s, and the seedling tray layer thickness to 0.3 mm.
[0054] Step 5: Start the 3D printer and print layer by layer according to the set model and parameters. After printing, place the seedling tray in an oven and dry it at 60°C for 2 hours to remove residual solvent. Then, use sandpaper to polish the surface of the seedling tray to make it smooth, thus obtaining the seedling tray.
[0055] Comparative Example 2
[0056] A method for preparing a seedling tray includes the following steps:
[0057] Step 1: Collect corn stalks, remove impurities, and crush them to a particle size of 1-3mm. Place the crushed corn stalk fibers in an oven and dry them at 80℃ until constant weight for later use.
[0058] Step 2: Take corn starch, add an appropriate amount of water to prepare a corn starch solution with a mass fraction of 18%, and gelatinize the solution under heating and stirring conditions until a uniform gelatinized corn starch solution is formed.
[0059] Step 3: Add the prepared corn stalk fiber to the gelatinized corn starch solution and stir thoroughly with a stirrer to make seedling base material, wherein the mass ratio of corn stalk fiber to corn starch is 3:1.
[0060] Step 4: Take polycaprolactone with a molecular weight of 15,000, dissolve it in chloroform to prepare a 10% polycaprolactone solution, add polypyrrole with a molecular weight of 150,000, place the mixed solution in a constant temperature water bath at 55°C, and stir with a magnetic stirrer at a speed of 300 r / min for 7 hours to obtain the polypyrrole-polycaprolactone composite.
[0061] Step 5: Based on the seedling requirements of common leafy vegetables, design a 3D model of the seedling tray using CAD software. Load the prepared seedling tray raw material and the polypyrrole-polycaprolactone composite into the two barrels of a dual-nozzle 3D printer, respectively. Set the printing temperature to 190℃, the printing speed to 40mm / s, the outer layer thickness of the seedling tray to 0.25 mm, and the inner layer thickness to 0.08 mm.
[0062] Step 6: Start the 3D printer and print layer by layer according to the set model and parameters. After printing, place the seedling tray in an oven and dry it at 60°C for 2 hours to remove residual solvent. Then, use sandpaper to polish the surface of the seedling tray to make it smooth. Install the micro bio-battery to connect it with the inner layer of the seedling tray to finally obtain the seedling tray.
[0063] Vegetable growth index measurement
[0064] Take the seedling trays prepared in Examples 1-3 and Comparative Examples 1-2, fill them with an equal amount of planting soil, and sow rapeseed seeds, 3-5 seeds per hole. After the seeds germinate, retain one healthy seedling and observe and measure its growth indicators, including:
[0065] Plant height measurement: Starting from seedling emergence, the plant height of seedlings was measured every 3 days using a ruler. The data of each measurement were recorded, and the effect of different seedling trays on the growth rate of vegetables was observed. The results are shown in Table 1.
[0066] Table 1
[0067]
[0068] Stem diameter measurement: On the 10th, 15th and 20th day of seedling growth, the diameter of the base of the seedling stem was measured using vernier calipers, and the stem diameter data were recorded to evaluate the effect of the seedling base on the development of vegetable stems. The results are shown in Table 2.
[0069] Table 2
[0070]
[0071] Immune function index measurement
[0072] Take the seedling trays prepared in Examples 1-3 and Comparative Examples 1-2, fill them with an equal amount of planting soil, and sow rapeseed seeds, 3-5 seeds per hole. After the seeds germinate, retain one healthy seedling and observe and measure its immune function indicators, including:
[0073] Antioxidant enzyme activity assay: Leaf samples were collected at different stages of vegetable growth, such as seedling, vegetative growth, and maturity. Peroxidase (POD) activity was determined using a kit-based method. Peroxidase plays an important role in plant resistance to external stress and enhancing immune function; its activity level reflects the immune capacity of vegetables. The results are shown in Table 3.
[0074] Table 3
[0075] Seedling stage Growth period Maturity Example 1: POD activity (U / g FW) 283.1 ± 11.0 353.4 ± 13.2 303.2 ± 12.0 Example 2 POD activity (U / g FW) 280.5 ± 10.2 350.8 ± 12.5 300.6 ± 11.0 Example 3 POD activity (U / g FW) 278.3 ± 9.5 348.6 ± 11.8 298.4 ± 10.5 Comparative Example 1: POD activity (U / g FW) 218.4 ± 8.0 278.2 ± 9.8 238.3 ± 9.0 Comparative Example 2: POD activity (U / g FW) 262.7 ± 9.0 303.5 ± 11.2 282.6 ± 10.0
[0076] Plant hormone content determination: Leaf samples were collected at different growth stages, and the content of the plant hormone salicylic acid was determined using high-performance liquid chromatography (HPLC). Salicylic acid (SA) participates in the plant's defense response, and changes in its content can reflect the enhancement of the vegetable's immune function. The results are shown in Table 4.
[0077] Table 4
[0078] Seedling stage Growth period Maturity Example 1: SA content (ng / g FW) 122.1 ± 5.5 182.3 ± 7.5 152.7 ± 6.5 Example 2 SA content (ng / g FW) 120.5 ± 5.0 180.8 ± 7.0 150.6 ± 6.0 Example 3 SA content (ng / g FW) 118.3 ± 4.5 178.6 ± 6.5 148.4 ± 5.5 Comparative Example 1: SA content (ng / g FW) 78.3 ± 3.2 118.4 ± 5.0 98.3 ± 4.0 Comparative Example 2: SA content (ng / g FW) 100.5 ± 3.5 140.6 ± 5.5 120.5 ± 4.5
[0079] The results showed that the seedling trays prepared using the method described in Examples 1-3 had a positive promoting effect on vegetable growth and enhanced the immune function of vegetables. The seedlings cultivated using these trays exhibited better plant height, stem diameter, antioxidant enzyme activity, and salicylic acid content than those in Comparative Examples 1 and 2. This is mainly because the conductive inner layer and conductive circuits formed by the micro-biobattery and polypyrrole-polycaprolactone complex can generate an appropriate amount of current, stimulating and altering the permeability of plant root cell membranes, promoting the absorption of potassium and calcium ions, regulating the synthesis and transport of plant hormones, thereby affecting physiological processes such as photosynthesis and respiration, promoting plant growth, and enhancing plant immune function. Furthermore, the conductive circuits are designed according to the distribution of vegetable roots, ensuring full contact between the conductive circuits and the vegetable roots, thus enhancing the stimulating effect on the plant roots. In contrast, the seedling trays prepared in Comparative Example 1 only used corn stalk fiber and corn starch as biodegradable materials and did not produce the effect of promoting vegetable growth and development or enhancing immune function. In Comparative Example 2, the conductive inner layer was only placed inside the seedling tray, which is far from the root system of the vegetables and has a limited range of action, resulting in a limited effect on promoting vegetable growth and development and enhancing immune function.
[0080] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and examples shown and described herein.
Claims
1. A method for preparing a biodegradable seedling tray that enhances the immune function of vegetables, characterized in that, Includes the following steps: Step 1: Prepare corn stalk fiber, crush it to a particle size of 1-3 mm, dry it, add 15-20% by mass of gelatinized corn starch solution, stir evenly, and make seedling base material, wherein the mass ratio of corn stalk fiber to corn starch is (5-8):
2. Step 2: Dissolve polycaprolactone solution in chloroform to prepare a solution with a mass fraction of 10-15%, add polypyrrole, and stir magnetically at 50-60℃ for 6-8 hours to obtain polypyrrole-polycaprolactone composite. Step 3: The seedling tray material is made into an outer layer of the seedling tray. An inner layer of the seedling tray made of the polypyrrole-polycaprolactone composite is set inside the outer layer of the seedling tray and connected to a micro bio-battery. Multiple conductive lines made of the polypyrrole-polycaprolactone composite are set inside the inner layer of the seedling tray, and finally the biodegradable seedling tray with enhanced vegetable immune function is obtained. The microbial battery is made based on the principle of microbial fuel cells. It uses 3D printing technology to make a microbial battery shell using polylactic acid as the material. The inside of the microbial battery shell is divided into an anode chamber and a cathode chamber using a proton exchange membrane. Graphite felt is placed in the anode chamber as the anode and the anode is immersed in the bacterial solution of electrogenic microorganisms. Platinum carbon electrode is placed in the cathode chamber as the cathode and a cathode electrolyte is injected to assemble the microbial battery. The conductive lines extend radially from the center to the edge at the bottom of the inner layer of the seedling tray, and are distributed in a grid pattern in the middle of the inner layer of the seedling tray, with a grid spacing of 5-8 mm.
2. The method for preparing the biodegradable seedling tray with enhanced vegetable immune function as described in claim 1, characterized in that, In step two, the molecular weight of polycaprolactone is 10,000-20,000.
3. The method for preparing the biodegradable seedling tray with enhanced vegetable immune function as described in claim 1, characterized in that, In step two, the molecular weight of the polypyrrole is 100,000-200,000.
4. The method for preparing the biodegradable seedling tray with enhanced vegetable immune function as described in claim 1, characterized in that, In step three, the biodegradable seedling tray with enhanced vegetable immunity is manufactured using 3D printing technology. The specific steps are as follows: Step A: Based on the needs of vegetable seedling cultivation, design a 3D model of the seedling tray using CAD software, and design the routing and distribution of the conductive lines inside the seedling tray. Step B: Load the seedling tray raw material and polypyrrole-polycaprolactone composite into the barrel of a dual-nozzle 3D printer, set the printing temperature to 180-200℃, the printing speed to 30-50 mm / s, the outer layer thickness of the seedling tray is 0.2-0.3 mm, the inner layer thickness of the seedling tray is 0.05-0.1 mm, and the diameter of the conductive line is 0.1-0.2 mm. Step C: Start the 3D printer and print layer by layer according to the set model and parameters. After printing, dry and polish the surface to obtain the biodegradable seedling tray that enhances the immune function of vegetables.
5. The method for preparing the biodegradable seedling tray with enhanced vegetable immune function as described in claim 4, characterized in that, The outer layer of the seedling tray has a thickness of 0.25 mm, and the inner layer of the seedling tray has a thickness of 0.08 mm.
6. The method for preparing the biodegradable seedling tray with enhanced vegetable immune function as described in claim 4, characterized in that, The diameter of the conductive line is 0.15 mm.
7. The method for preparing the biodegradable seedling tray with enhanced vegetable immune function as described in claim 1, characterized in that, In step one, the mass ratio of corn stalk fiber to corn starch is 3:1.