All-carbon-based bamboo wood mildew preventive as well as preparation method and application thereof

Abstract

The invention discloses an all-carbon-based bamboo mould inhibitor and a preparation method and application thereof.The all-carbon-based bamboo mould inhibitor is prepared from nitrogen-doped carbon quantum dots and an organic bactericide, and the organic bactericide interacts with polar groups on the surfaces of the nitrogen-doped carbon quantum dots through covalent bonds and non-covalent bonds to be loaded on the surfaces of the nitrogen-doped carbon quantum dots; the mass ratio of the nitrogen-doped carbon quantum dots to the organic bactericide is 1: (10-20). On one hand, the nitrogen-doped carbon quantum dots and the organic fungicide have the effects of efficient synergism and prevention and control efficiency improvement, and due to the fact that the nitrogen-doped carbon quantum dots have certain bacteriostatic activity and form a synergistic interaction effect with the organic mildew preventive, the concentration of effective mildew-proof components in unit volume can be higher, and the effect is more comprehensive. On the other hand, the nitrogen-doped carbon quantum dots have super-strong permeability, deep protection can be achieved, the better mildew-proof effect can be achieved with the lower drug loading amount, and the prevention and treatment efficiency is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of bamboo protection technology, and in particular to a full carbon-based bamboo antifungal agent, its preparation method, and its application. Background Technology

[0002] Bamboo, as a rapidly growing renewable resource, is widely used due to its high strength, high toughness, and good processability. However, bamboo is rich in nutrients and has a porous structure, making it highly susceptible to biological attack such as mold. Under suitable temperature and humidity conditions, mold proliferates rapidly, causing mold spots on the surface, severely damaging its appearance and commercial value, and even affecting its structural performance. Therefore, implementing effective anti-mold treatment is crucial to ensuring the long-term use of bamboo.

[0003] Currently, mildew prevention mainly relies on two methods: physical and chemical. Physical methods (such as heat treatment) are energy-intensive, and their effectiveness decreases when the bamboo absorbs moisture again after treatment. Chemical mildew inhibitors are the most widely used, often applied through methods such as impregnation, and include organophosphates, organoiodines, and quaternary ammonium salts. However, traditional chemical mildew inhibitors have significant drawbacks: First, they pose environmental and health risks; some highly toxic agents may pollute the environment and harm health, making it difficult to meet environmental protection requirements. Second, they have poor resistance to leaching; many water-soluble agents are easily leached in humid and hot environments, leading to reduced effectiveness and secondary pollution. Third, their penetration depth is limited, especially for high-density bamboo, where the agent has difficulty penetrating deeply, and protection is limited to the surface. Fourth, they may alter the color, odor, or mechanical properties of the bamboo.

[0004] Researchers are exploring green anti-mold agents, but these often suffer from poor efficacy, instability, and rapid volatilization or loss, making it difficult to provide long-lasting protection. Therefore, the field of bamboo anti-mold urgently needs to develop new treatment technologies that can overcome the shortcomings of traditional agents, achieving high permeability, excellent anti-loss properties, and efficient anti-mold treatment, while ensuring the green and environmentally friendly nature of the materials and processes. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a full carbon-based bamboo anti-mildew agent with good anti-mildew effect and anti-leaking properties, as well as its preparation method and application.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A carbon-based bamboo antifungal agent, comprising nitrogen-doped carbon quantum dots and an organic bactericide, wherein the organic bactericide is loaded onto the surface of the nitrogen-doped carbon quantum dots by interacting with polar groups on the surface of the nitrogen-doped carbon quantum dots through covalent and non-covalent bonds, wherein the nitrogen-doped carbon quantum dots are nitrogen-doped carbon quantum dots containing quaternary ammonium salt groups in their molecular structure, and the mass ratio of the nitrogen-doped carbon quantum dots to the organic bactericide is 1:10-20.

[0007] As a further improvement to the above technical solution: The organic bactericide comprises, by weight, the following components: 10-15 parts of isothiazolinone derivative, 10-15 parts of flutriafol, 3-5 parts of fluazinam aniline, 1-3 parts of silane coupling agent, 15-25 parts of phenoxyethanol, 15-20 parts of dipropylene glycol methyl ether, and 30-40 parts of surfactant.

[0008] The surfactant includes at least one of alkylphenol polyoxyethylene ether and alkyl sulfonate.

[0009] Preferably, the nitrogen-doped carbon quantum dots have a particle size of 2-10 nm so that they can easily penetrate the microstructure of bamboo.

[0010] Preferably, the isothiazolinone derivative includes at least one of N-octyl-4-isothiazolin-3-one or n-butyl-1,2-benzisothiazolin-3-one.

[0011] As a general inventive concept, the present invention also provides a method for preparing the aforementioned all-carbon-based bamboo antifungal agent, comprising the following steps: mixing nitrogen-doped carbon quantum dots and an organic bactericide at a mass ratio of 1:10 to 20, and stirring the mixture at a temperature of 40 to 60°C, so that the organic bactericide molecules are loaded on the surface of the nitrogen-doped carbon quantum dots, thereby obtaining the all-carbon-based bamboo antifungal agent.

[0012] As a further improvement to the above technical solution: The stirring rate of the stirring reaction is 1200–3000 rpm, and the reaction time is 30–60 min.

[0013] The preparation of the nitrogen-doped carbon quantum dots includes the following steps: The crude product was obtained by hydrothermal reaction using chitosan quaternary ammonium salt as a carbon source at a temperature of 150–200 °C. Centrifuge the crude product, take the supernatant and dialysis to purify it to obtain the purified solution; The purified solution was freeze-dried to obtain nitrogen-doped carbon quantum dots.

[0014] This invention uses an organic, green antifungal agent as the main carrier and biomass (chitosan quaternary ammonium salt) as the raw material to prepare nitrogen-doped carbon quantum dots. The entire treatment system is non-toxic and biodegradable. The treatment process does not use any toxic or harmful chemicals, resulting in safe and environmentally friendly bamboo products that meet the stringent health and environmental requirements of the high-end market, thus enhancing the product's added value and market competitiveness. The nitrogen-doped carbon quantum dots of this invention contain quaternary ammonium salt groups in their structure, giving them a certain degree of bactericidal activity compared to other nitrogen-doped carbon quantum dots that also contain nitrogen in their structure.

[0015] The hydrothermal reaction takes 10–15 hours.

[0016] Preferably, the chitosan quaternary ammonium salt is 2-hydroxypropyltrimethylammonium chloride chitosan (HAC-chitosan), and the quaternary ammonium salt structure can endow the final product with excellent antibacterial activity.

[0017] Preferably, during centrifugation, the centrifugal force is 13,000~18,000 rpm, and during dialysis purification, the molecular weight cutoff is <1 kDa.

[0018] Preferably, the preparation of the organic bactericide includes the following steps: stirring and emulsifying the aforementioned raw materials of the organic bactericide until they are clear and transparent, to obtain a water-soluble organic antifungal agent.

[0019] As a general inventive concept, the present invention also provides an application of the aforementioned all-carbon-based bamboo antifungal agent in bamboo antifungal treatment.

[0020] The application includes the following steps: placing the bamboo to be treated in a full carbon-based bamboo anti-mold agent, using normal pressure soaking, vacuum impregnation or vacuum-pressure impregnation process to allow the full carbon-based bamboo anti-mold agent to fully penetrate into the bamboo, drying and curing to obtain bamboo treated with anti-mold agent.

[0021] Includes at least one of Scheme A and Scheme B: Option A: When using a vacuum-pressure impregnation process, the following steps are included: First, the impregnation tank containing bamboo is evacuated to -0.05 to -0.08 MPa and held for 30 to 60 minutes. Then, a full carbon-based bamboo antifungal agent is injected and held at 1.5 to 2.0 MPa for 1 to 2 hours. This invention utilizes nitrogen-doped carbon quantum dots (which are nanoscale in size and have excellent surface activity) as a carrier. Their extremely small size allows them to easily penetrate the high-density structure and micropores of bamboo. Through the synergistic effect of the vacuum-pressurization process and the small-size penetration of nitrogen-doped carbon quantum dots, the organic antifungal agent is delivered deep into the interior of the bamboo, overcoming the limitation of traditional agents that can only act on the surface, and achieving three-dimensional, deep protection from the surface to the interior.

[0022] Option B: The drying and curing process includes the following steps: placing the bamboo at a temperature of 60-80°C to dry, so that the nitrogen-doped carbon quantum dots and organic bactericides in the all-carbon-based bamboo antifungal agent are deposited and cured on the inner walls of the micropores (such as cell cavities and vessels) of the bamboo (the nitrogen-doped carbon quantum dots and organic bactericides in the all-carbon-based bamboo antifungal agent form a strong physical adsorption or chemical bond with the bamboo matrix, thereby achieving in-situ fixation of the antifungal agent), until the moisture content of the bamboo reaches the target value.

[0023] Preferably, in Scheme B, the target value is 8% to 14%.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention discloses a fully carbon-based bamboo antifungal agent, comprising nitrogen-doped carbon quantum dots and an organic bactericide. The organic bactericide is loaded onto the surface of the nitrogen-doped carbon quantum dots by covalent and non-covalent bonds interacting with polar groups (-OH, -COOH, -NH2, etc.) on the surface of the nitrogen-doped carbon quantum dots. The mass ratio of nitrogen-doped carbon quantum dots to organic bactericide is 1:10-20. On one hand, nitrogen-doped carbon quantum dots and organic bactericide exhibit a highly synergistic effect, enhancing the control efficiency. Because nitrogen-doped carbon quantum dots contain quaternary ammonium salt groups in their molecular structure, they possess inherent antibacterial activity, forming a synergistic effect with the organic antifungal agent. This results in a higher concentration of effective antifungal components per unit volume and a more comprehensive effect. On the other hand, nitrogen-doped carbon quantum dots have superior permeability, facilitating deep protection and achieving better antifungal effects with lower agent loading, significantly improving control efficiency.

[0025] The present invention relates to the application of a fully carbon-based bamboo antifungal agent in bamboo antifungal treatment. Based on the fact that the organic antifungal agent has been coupled to the surface of nitrogen-doped carbon quantum dots, the drying and curing stage promotes its firm bonding with the bamboo matrix, which significantly reduces the dissolution and loss rate of the antifungal agent in humid and hot environments. This not only ensures the durability of the antifungal effect, but also avoids secondary environmental pollution caused by agent loss. Detailed Implementation

[0026] The present invention will be further described in detail below. Unless otherwise specified, the instruments or materials used in the present invention are commercially available.

[0027] Example 1 This embodiment provides a full carbon-based bamboo anti-mildew agent, the raw materials of which include nitrogen-doped carbon quantum dots and an organic bactericide. The organic bactericide is loaded onto the surface of the nitrogen-doped carbon quantum dots by interacting with polar groups (-OH, -COOH, -NH2, etc.) on the surface of the nitrogen-doped carbon quantum dots through covalent and non-covalent bonds. The nitrogen-doped carbon quantum dots are nitrogen-doped carbon quantum dots with quaternary ammonium salt groups in their molecular structure. The mass ratio of nitrogen-doped carbon quantum dots to organic bactericide is 1:10.

[0028] The preparation method of the all-carbon-based bamboo anti-mildew agent of this embodiment includes the following steps: 1.1 Preparation of nitrogen-doped carbon quantum dots (N-CQDs) 2.0 g of 2-hydroxypropyltrimethylammonium chloride chitosan (HAC-chitosan) was weighed and dissolved in 100 mL of deionized water. The solution was transferred to a 200 mL high-pressure reactor and hydrothermally reacted at 180 °C for 12 hours. After cooling, the reaction product was centrifuged at 15,000 rpm for 20 minutes, and the supernatant was collected. The supernatant was dialyzed against a dialysis bag with a molecular weight cutoff of 1000 Da for 72 hours, and finally freeze-dried to obtain powdered nitrogen-doped carbon quantum dots for later use.

[0029] Nitrogen-doped carbon quantum dots are nitrogen-doped carbon quantum dots with quaternary ammonium salt groups in their molecular structure. The average particle size of nitrogen-doped carbon quantum dots is about 5 nm.

[0030] 1.2 Preparation of Organic Antifungal Agent Mother Liquor Weigh the following components by weight: 12 parts of isothiazolinone derivative (in this example, N-octyl-4-isothiazolin-3-one; in other examples, it may be n-butyl-1,2-benzisothiazolin-3-one), 14 parts of flutriafol, 5 parts of fluazinam aniline, 1 part of KH-550 silane coupling agent, 18 parts of phenoxyethanol, 18 parts of dipropylene glycol methyl ether, and 32 parts of alkylphenol polyoxyethylene ether. Stir and mix at room temperature until a clear and transparent organic antifungal agent stock solution is formed, and set aside for later use.

[0031] 1.3 Combination of nitrogen-doped carbon quantum dots with antifungal agent mother liquor Add 0.8 kg of the antifungal agent stock solution obtained in step 1.2 to a 10 L reactor, start mechanical stirring (2500 rpm), and heat to 50 °C. Then, slowly add 80 g of the nitrogen-doped carbon quantum dot powder obtained in step 1.1 into the reactor. Allow the mixture to react continuously for 50 minutes at 50 °C and 2500 rpm to complete the coupling. After the reaction is complete, dilute the reaction solution with tap water and bring the volume to 10 L to obtain the finished all-carbon-based bamboo antifungal agent.

[0032] The application of a fully carbon-based bamboo anti-mildew agent in the anti-mildew treatment of bamboo includes the following steps: Vacuum-pressure impregnation treatment of bamboo: Place a batch of bamboo boards to be treated in the impregnation equipment, start the vacuum pump to evacuate to -0.06 MPa, maintain for 45 minutes, and inject the finished all-carbon-based bamboo anti-mildew agent under vacuum until the boards are completely submerged. Due to the high uniformity and stability of the finished all-carbon-based bamboo anti-mildew agent, the injection process is ensured to be smooth. Turn off the vacuum system, apply a pressure of 1.8 MPa, and maintain the pressure for 1.5 hours.

[0033] Drying and curing the impregnated bamboo: Take out the impregnated board, clean the surface and let it air dry naturally for 24 hours. Then, transfer the board into the drying kiln and heat it to 70°C for constant temperature drying until the moisture content drops to 12%.

[0034] Example 2 This embodiment provides a full carbon-based bamboo anti-mildew agent. The raw materials include nitrogen-doped carbon quantum dots and an organic bactericide. The organic bactericide is loaded onto the surface of the nitrogen-doped carbon quantum dots by interacting with polar groups (-OH, -COOH, -NH2, etc.) on the surface of the nitrogen-doped carbon quantum dots through covalent and non-covalent bonds. The nitrogen-doped carbon quantum dots are nitrogen-doped carbon quantum dots containing quaternary ammonium salt groups in their molecular structure. The mass ratio of nitrogen-doped carbon quantum dots to organic bactericide is 1:15.

[0035] The preparation method of the all-carbon-based bamboo antifungal agent in this embodiment is largely the same as that in Example 1, except that the mass ratio of nitrogen-doped carbon quantum dots to the antifungal agent mother liquor is 1:15, and includes the following steps: 1.1 Preparation of nitrogen-doped carbon quantum dots (N-CQDs) 2.0 g of 2-hydroxypropyltrimethylammonium chloride chitosan (HAC-chitosan) was weighed and dissolved in 100 mL of deionized water. The solution was transferred to a 200 mL high-pressure reactor and hydrothermally reacted at 180 °C for 12 hours. After cooling, the reaction product was centrifuged at 15,000 rpm for 20 minutes, and the supernatant was collected. The supernatant was dialyzed against a dialysis bag with a molecular weight cutoff of 1000 Da for 72 hours, and finally freeze-dried to obtain powdered nitrogen-doped carbon quantum dots for later use.

[0036] Nitrogen-doped carbon quantum dots are nitrogen-doped carbon quantum dots with quaternary ammonium salt groups in their molecular structure. The average particle size of nitrogen-doped carbon quantum dots is about 5 nm.

[0037] 1.2 Preparation of Organic Antifungal Agent Mother Liquor Weigh the following components by weight: 10 parts isothiazolinone derivative (N-octyl-4-isothiazolin-3-one in this example), 12 parts flutriafol, 3 parts fluoxetine aniline, 3 parts KH-550 silane coupling agent, 17 parts phenoxyethanol, 15 parts dipropylene glycol methyl ether, and 40 parts alkylphenol polyoxyethylene ether. Stir and mix at room temperature until a clear and transparent organic antifungal agent stock solution is formed, and set aside for later use.

[0038] 1.3 Combination of nitrogen-doped carbon quantum dots with antifungal agent mother liquor Add 0.8 kg of the antifungal agent stock solution prepared in step 1.2 to a 10 L reactor, start mechanical stirring (2500 rpm), and heat to 50 °C. Then, slowly add 53.3 g of nitrogen-doped carbon quantum dot powder prepared in step 1.1 into the reactor. Allow the mixture to react continuously for 50 minutes at 50 °C and 2500 rpm to complete the coupling. After the reaction is complete, dilute the reaction solution with tap water and bring the volume to 10 L to obtain the finished all-carbon-based bamboo antifungal agent.

[0039] The application of a fully carbon-based bamboo anti-mildew agent in the anti-mildew treatment of bamboo includes the following steps: Vacuum-pressure impregnation treatment of bamboo: A batch of bamboo boards to be treated is placed in the impregnation equipment. The vacuum pump is started to evacuate to -0.06 MPa and maintained for 45 minutes. Under vacuum, the finished carbon-based bamboo anti-mildew agent is injected until the boards are completely submerged. Due to the high uniformity and stability of the composite liquid, the injection process is ensured to be smooth. The vacuum system is turned off, a pressure of 1.8 MPa is applied, and the pressure is maintained for 1.5 hours.

[0040] Drying and curing the impregnated bamboo: Take out the impregnated board, clean the surface and let it air dry naturally for 24 hours. Then, transfer the board into the drying kiln and heat it to 70°C for constant temperature drying until the moisture content drops to 12%.

[0041] Example 3 This embodiment provides a full carbon-based bamboo anti-mildew agent. The raw materials include nitrogen-doped carbon quantum dots and an organic bactericide. The organic bactericide is loaded onto the surface of the nitrogen-doped carbon quantum dots by interacting with polar groups (-OH, -COOH, -NH2, etc.) on the surface of the nitrogen-doped carbon quantum dots through covalent and non-covalent bonds. The nitrogen-doped carbon quantum dots are nitrogen-doped carbon quantum dots containing quaternary ammonium salt groups in their molecular structure. The mass ratio of nitrogen-doped carbon quantum dots to organic bactericide is 1:20.

[0042] The preparation method of the all-carbon-based bamboo antifungal agent in this embodiment is largely the same as that in Example 1, except that the mass ratio of nitrogen-doped carbon quantum dots to the antifungal agent mother liquor is 1:20, and includes the following steps: 1.1 Preparation of nitrogen-doped carbon quantum dots (N-CQDs) 2.0 g of 2-hydroxypropyltrimethylammonium chloride chitosan (HAC-chitosan) was weighed and dissolved in 100 mL of deionized water. The solution was transferred to a 200 mL high-pressure reactor and hydrothermally reacted at 180 °C for 12 hours. After cooling, the reaction product was centrifuged at 15,000 rpm for 20 minutes, and the supernatant was collected. The supernatant was dialyzed against a dialysis bag with a molecular weight cutoff of 1000 Da for 72 hours, and finally freeze-dried to obtain powdered nitrogen-doped carbon quantum dots for later use.

[0043] Nitrogen-doped carbon quantum dots are nitrogen-doped carbon quantum dots with quaternary ammonium salt groups in their molecular structure. The average particle size of nitrogen-doped carbon quantum dots is about 5 nm.

[0044] 1.2 Preparation of Organic Antifungal Agent Mother Liquor Weigh the following components by weight: 10 parts of isothiazolinone derivative (in this example, n-butyl-1,2-benzisothiazolin-3-one), 10 parts of flutriafol, 3 parts of fluopyram aniline, 2 parts of KH-550 silane coupling agent, 20 parts of phenoxyethanol, 19 parts of dipropylene glycol methyl ether, and 36 parts of alkylphenol polyoxyethylene ether. Stir and mix at room temperature until a clear and transparent organic antifungal agent stock solution is formed, and set aside for later use.

[0045] 1.3 Combination of nitrogen-doped carbon quantum dots with antifungal agent mother liquor Add 0.8 kg of the antifungal agent stock solution prepared in step 1.2 to a 10 L reactor, start mechanical stirring (2500 rpm), and heat to 50 °C. Then, slowly add 40 g of the nitrogen-doped carbon quantum dot powder prepared in step 1.1 into the reactor. Allow the mixture to react continuously for 50 minutes at 50 °C and 2500 rpm to complete the coupling. After the reaction is complete, dilute the reaction solution with tap water and bring the volume to a final volume of 10 L to obtain the finished all-carbon-based bamboo antifungal agent.

[0046] The application of a fully carbon-based bamboo anti-mildew agent in the anti-mildew treatment of bamboo includes the following steps: Vacuum-pressure impregnation treatment of bamboo: A batch of bamboo boards to be treated is placed in the impregnation equipment. The vacuum pump is started to evacuate to -0.06 MPa and maintained for 45 minutes. Under vacuum, the finished carbon-based bamboo anti-mildew agent is injected until the boards are completely submerged. Due to the high uniformity and stability of the composite liquid, the injection process is ensured to be smooth. The vacuum system is turned off, a pressure of 1.8 MPa is applied, and the pressure is maintained for 1.5 hours.

[0047] Drying and curing the impregnated bamboo: Take out the impregnated board, clean the surface and let it air dry naturally for 24 hours. Then, transfer the board into the drying kiln and heat it to 70°C for constant temperature drying until the moisture content drops to 12%.

[0048] Comparative Example 1 This comparative example describes a fully carbon-based bamboo antifungal agent. The raw materials include nitrogen-doped carbon quantum dots and an organic bactericide. The organic bactericide is loaded onto the surface of the nitrogen-doped carbon quantum dots by interacting with polar groups (-OH, -COOH, -NH2, etc.) on the surface of the nitrogen-doped carbon quantum dots through covalent and non-covalent bonds. The nitrogen-doped carbon quantum dots are nitrogen-doped carbon quantum dots containing quaternary ammonium salt groups in their molecular structure. The mass ratio of nitrogen-doped carbon quantum dots to organic bactericide is 1:8.

[0049] The preparation method of the all-carbon-based bamboo antifungal agent in this comparative example is largely the same as that in Example 3, except that the mass ratio of nitrogen-doped carbon quantum dots to organic antifungal agent is 1:8, and includes the following steps: 1.1 Preparation of nitrogen-doped carbon quantum dots (N-CQDs) 2.0 g of 2-hydroxypropyltrimethylammonium chloride chitosan (HAC-chitosan) was weighed and dissolved in 100 mL of deionized water. The solution was transferred to a 200 mL high-pressure reactor and hydrothermally reacted at 180 °C for 12 hours. After cooling, the reaction product was centrifuged at 15,000 rpm for 20 minutes, and the supernatant was collected. The supernatant was dialyzed against a dialysis bag with a molecular weight cutoff of 1000 Da for 72 hours, and finally freeze-dried to obtain powdered nitrogen-doped carbon quantum dots for later use.

[0050] Nitrogen-doped carbon quantum dots are nitrogen-doped carbon quantum dots with quaternary ammonium salt groups in their molecular structure. The average particle size of nitrogen-doped carbon quantum dots is about 5 nm.

[0051] 1.2 Preparation of Organic Antifungal Agent Mother Liquor Weigh the following components by weight: 10 parts of isothiazolinone derivative (in this example, n-butyl-1,2-benzisothiazolin-3-one), 10 parts of flutriafol, 3 parts of fluopyram aniline, 2 parts of KH-550 silane coupling agent, 20 parts of phenoxyethanol, 19 parts of dipropylene glycol methyl ether, and 36 parts of alkylphenol polyoxyethylene ether. Stir and mix at room temperature until a clear and transparent organic antifungal agent stock solution is formed, and set aside for later use.

[0052] 1.3 Combination of nitrogen-doped carbon quantum dots with antifungal agent mother liquor Add 0.8 kg of the antifungal agent stock solution prepared in step 1.2 to a 10 L reactor, start mechanical stirring (2500 rpm), and heat to 50 °C. Then, slowly add 100 g of the nitrogen-doped carbon quantum dot powder prepared in step 1.1 into the reactor. Allow the mixture to react continuously for 50 minutes at 50 °C and 2500 rpm to complete the coupling. After the reaction is complete, dilute the reaction solution with tap water and bring the volume to a final volume of 10 L to obtain the finished all-carbon-based bamboo antifungal agent.

[0053] The application of a fully carbon-based bamboo anti-mildew agent in the anti-mildew treatment of bamboo includes the following steps: Vacuum-pressure impregnation treatment of bamboo: A batch of bamboo boards to be treated is placed in the impregnation equipment. The vacuum pump is started to evacuate to -0.06 MPa and maintained for 45 minutes. Under vacuum, the finished carbon-based bamboo anti-mildew agent is injected until the boards are completely submerged. Due to the high uniformity and stability of the composite liquid, the injection process is ensured to be smooth. The vacuum system is then turned off, a pressure of 1.8 MPa is applied, and the pressure is maintained for 1.5 hours.

[0054] Drying and curing the impregnated bamboo: Take out the impregnated board, clean the surface and let it air dry naturally for 24 hours. Then, transfer the board into the drying kiln and heat it to 70°C for constant temperature drying until the moisture content drops to 12%.

[0055] Comparative Example 2 This comparative example describes a fully carbon-based bamboo antifungal agent. The raw materials include nitrogen-doped carbon quantum dots and an organic bactericide. The organic bactericide is loaded onto the surface of the nitrogen-doped carbon quantum dots by interacting with polar groups (-OH, -COOH, -NH2, etc.) on the surface of the nitrogen-doped carbon quantum dots through covalent and non-covalent bonds. The nitrogen-doped carbon quantum dots are nitrogen-doped carbon quantum dots containing quaternary ammonium salt groups in their molecular structure. The mass ratio of nitrogen-doped carbon quantum dots to organic bactericide is 1:25.

[0056] The preparation method of the all-carbon-based bamboo antifungal agent in this comparative example is largely the same as that in Example 3, except that the mass ratio of nitrogen-doped carbon quantum dots to organic antifungal agent is 1:25, and includes the following steps: 1.1 Preparation of nitrogen-doped carbon quantum dots (N-CQDs) 2.0 g of 2-hydroxypropyltrimethylammonium chloride chitosan (HAC-chitosan) was weighed and dissolved in 100 mL of deionized water. The solution was transferred to a 200 mL high-pressure reactor and hydrothermally reacted at 180 °C for 12 hours. After cooling, the reaction product was centrifuged at 15,000 rpm for 20 minutes, and the supernatant was collected. The supernatant was dialyzed against a dialysis bag with a molecular weight cutoff of 1000 Da for 72 hours, and finally freeze-dried to obtain powdered nitrogen-doped carbon quantum dots for later use.

[0057] Nitrogen-doped carbon quantum dots are nitrogen-doped carbon quantum dots with quaternary ammonium salt groups in their molecular structure. The average particle size of nitrogen-doped carbon quantum dots is about 5 nm.

[0058] 1.2 Preparation of Organic Antifungal Agent Mother Liquor Weigh the following components by weight: 10 parts of isothiazolinone derivative (in this example, n-butyl-1,2-benzisothiazolin-3-one), 10 parts of flutriafol, 3 parts of fluopyram aniline, 2 parts of KH-550 silane coupling agent, 20 parts of phenoxyethanol, 19 parts of dipropylene glycol methyl ether, and 36 parts of alkylphenol polyoxyethylene ether. Stir and mix at room temperature until a clear and transparent organic antifungal agent stock solution is formed, and set aside for later use.

[0059] 1.3 Combination of nitrogen-doped carbon quantum dots with antifungal agent mother liquor Add 0.8 kg of the antifungal agent stock solution obtained in step 1.2 to a 10 L reactor, start mechanical stirring (2500 rpm), and heat to 50 °C. Then, slowly add 32 g of nitrogen-doped carbon quantum dot powder obtained in step 1.1 into the reactor. Allow the mixture to react continuously for 50 minutes at 50 °C and 2500 rpm to complete the coupling. After the reaction is complete, dilute the reaction solution with tap water and bring the volume to a final volume of 10 L to obtain the finished all-carbon-based bamboo antifungal agent.

[0060] The application of a fully carbon-based bamboo anti-mildew agent in the anti-mildew treatment of bamboo includes the following steps: Vacuum-pressure impregnation treatment of bamboo: A batch of bamboo boards to be treated is placed in the impregnation equipment. The vacuum pump is started to evacuate to -0.06 MPa and maintained for 45 minutes. Under vacuum, the finished carbon-based bamboo anti-mildew agent is injected until the boards are completely submerged. Due to the high uniformity and stability of the composite liquid, the injection process is ensured to be smooth. The vacuum system is turned off, a pressure of 1.8 MPa is applied, and the pressure is maintained for 1.5 hours.

[0061] Drying and curing the impregnated bamboo: Take out the impregnated board, clean the surface and let it air dry naturally for 24 hours. Then, transfer the board into the drying kiln and heat it to 70°C for constant temperature drying until the moisture content drops to 12%.

[0062] Comparative Example 3 This comparative example describes a fully carbon-based bamboo antifungal agent. The raw materials include nitrogen-doped carbon quantum dots, which are nitrogen-doped carbon quantum dots containing quaternary ammonium salt groups in their molecular structure. Organic antifungal agents are not included.

[0063] The preparation method of the all-carbon-based bamboo antifungal agent in this comparative example is largely the same as that in Example 1, except that no organic antifungal agent is added, and includes the following steps: 1.1 Preparation of nitrogen-doped carbon quantum dots (N-CQDs) 2.0 g of 2-hydroxypropyltrimethylammonium chloride chitosan (HAC-chitosan) was weighed and dissolved in 100 mL of deionized water. The solution was transferred to a 200 mL high-pressure reactor and hydrothermally reacted at 180 °C for 12 hours. After cooling, the reaction product was centrifuged at 15,000 rpm for 20 minutes, and the supernatant was collected. The supernatant was dialyzed against a dialysis bag with a molecular weight cutoff of 1000 Da for 72 hours, and finally freeze-dried to obtain powdered nitrogen-doped carbon quantum dots for later use.

[0064] Nitrogen-doped carbon quantum dots are nitrogen-doped carbon quantum dots with quaternary ammonium salt groups in their molecular structure. The average particle size of nitrogen-doped carbon quantum dots is about 5 nm.

[0065] 1.2 Nitrogen-doped carbon quantum dots dissolve in water Add 0.8 kg of tap water to a 10 L reactor, start mechanical stirring (2500 rpm), and heat to 50 °C. Then, slowly add 80 g of the nitrogen-doped carbon quantum dot powder obtained in step 1.1 into the reactor. Allow the mixture to react for 50 minutes at 50 °C and 2500 rpm to complete the coupling. After the reaction is complete, dilute the reaction solution to a total volume of 10 L with tap water to obtain the finished all-carbon-based bamboo anti-mildew agent.

[0066] The application of a fully carbon-based bamboo anti-mildew agent in the anti-mildew treatment of bamboo includes the following steps: Vacuum-pressure impregnation treatment of bamboo: A batch of bamboo boards to be treated is placed in the impregnation equipment. The vacuum pump is started to evacuate to -0.06 MPa and maintained for 45 minutes. Under vacuum, the finished carbon-based bamboo anti-mildew agent is injected until the boards are completely submerged. Due to the high uniformity and stability of the composite liquid, the injection process is ensured to be smooth. The vacuum system is turned off, a pressure of 1.8 MPa is applied, and the pressure is maintained for 1.5 hours.

[0067] Drying and curing the impregnated bamboo: Take out the impregnated board, clean the surface and let it air dry naturally for 24 hours. Then, transfer the board into the drying kiln and heat it to 70°C for constant temperature drying until the moisture content drops to 12%.

[0068] Comparative Example 4 This comparative example is a fully carbon-based bamboo anti-mildew agent, the raw materials of which include organic bactericides and do not contain nitrogen-doped carbon quantum dots.

[0069] The preparation method of the all-carbon-based bamboo anti-mildew agent in this comparative example is largely the same as that in Example 3, except that nitrogen-doped carbon quantum dots are not added, and includes the following steps: 1.1 Preparation of Organic Antifungal Agent Mother Liquor Weigh the following components by weight: 10 parts of isothiazolinone derivative (in this example, n-butyl-1,2-benzisothiazolin-3-one), 10 parts of flutriafol, 3 parts of fluopyram aniline, 2 parts of KH-550 silane coupling agent, 20 parts of phenoxyethanol, 19 parts of dipropylene glycol methyl ether, and 36 parts of alkylphenol polyoxyethylene ether. Stir and mix at room temperature until a clear and transparent organic antifungal agent stock solution is formed, and set aside for later use.

[0070] 1.2 Dilution of Antifungal Agent Add 0.8 kg of antifungal agent stock solution to a 10 L reactor, turn on mechanical stirring (2500 rpm) and heat to 50°C, allowing the mixture to react continuously for 50 minutes to complete the coupling. After the reaction is complete, dilute the reaction solution with tap water and bring the volume to 10 L to obtain the finished all-carbon-based bamboo antifungal agent.

[0071] The application of a fully carbon-based bamboo anti-mildew agent in the anti-mildew treatment of bamboo includes the following steps: Vacuum-pressure impregnation treatment of bamboo: A batch of bamboo boards to be treated is placed in the impregnation equipment. The vacuum pump is started to evacuate to -0.06 MPa and maintained for 45 minutes. Under vacuum, the finished carbon-based bamboo anti-mildew agent is injected until the boards are completely submerged. Due to the high uniformity and stability of the composite liquid, the injection process is ensured to be smooth. The vacuum system is turned off, a pressure of 1.8 MPa is applied, and the pressure is maintained for 1.5 hours.

[0072] Drying and curing the impregnated bamboo: Take out the impregnated board, clean the surface and let it air dry naturally for 24 hours. Then, transfer the board into the drying kiln and heat it to 70°C for constant temperature drying until the moisture content drops to 12%.

[0073] Comparative Example 5 This comparative example describes a bamboo antifungal agent. The raw materials include nitrogen-doped carbon quantum dots and an organic bactericide. The organic bactericide is loaded onto the surface of the nitrogen-doped carbon quantum dots by interacting with polar groups (-OH, -COOH, -NH2, etc.) on the surface of the nitrogen-doped carbon quantum dots through covalent and non-covalent bonds. The nitrogen-doped carbon quantum dots are nitrogen-doped carbon quantum dots containing quaternary ammonium salt groups in their molecular structure. The mass ratio of nitrogen-doped carbon quantum dots to organic bactericide is 1:20. The organic bactericide is a commercially available organic antifungal agent (the main component is a compound of propiconazole and tebuconazole).

[0074] The preparation method of the bamboo antifungal agent in this comparative example is largely the same as that in Example 3, except that the type of organic antifungal agent is different, and includes the following steps: 1.1 Preparation of nitrogen-doped carbon quantum dots (N-CQDs) 2.0 g of 2-hydroxypropyltrimethylammonium chloride chitosan (HAC-chitosan) was weighed and dissolved in 100 mL of deionized water. The solution was transferred to a 200 mL high-pressure reactor and hydrothermally reacted at 180 °C for 12 hours. After cooling, the reaction product was centrifuged at 15,000 rpm for 20 minutes, and the supernatant was collected. The supernatant was dialyzed against a dialysis bag with a molecular weight cutoff of 1000 Da for 72 hours, and finally freeze-dried to obtain powdered nitrogen-doped carbon quantum dots for later use.

[0075] Nitrogen-doped carbon quantum dots are nitrogen-doped carbon quantum dots with quaternary ammonium salt groups in their molecular structure. The average particle size of nitrogen-doped carbon quantum dots is about 5 nm.

[0076] 1.2 Preparation of the antifungal agent mother liquor We selected commercially available organic antifungal agent mother liquor for bamboo.

[0077] 1.3 Combination of nitrogen-doped carbon quantum dots with antifungal agent mother liquor Add 0.8 kg of the antifungal agent stock solution from step 1.2 to a 10 L reactor, start mechanical stirring (2500 rpm), and heat to 50 °C. Then, slowly add 32 g of the nitrogen-doped carbon quantum dot powder obtained in step 1.1 into the reactor. Allow the mixture to react continuously for 50 minutes at 50 °C and 2500 rpm to complete the coupling. After the reaction is complete, dilute the reaction solution with tap water and bring the volume to a final volume of 10 L to obtain the finished all-carbon-based bamboo antifungal agent.

[0078] The application of a bamboo anti-mildew agent in the anti-mildew treatment of bamboo includes the following steps: Vacuum-pressure impregnation treatment of bamboo: A batch of bamboo boards to be treated is placed in the impregnation equipment. The vacuum pump is started to evacuate to -0.06 MPa and maintained for 45 minutes. Under vacuum, the finished bamboo anti-mildew agent is injected until the boards are completely submerged. Due to the high uniformity and stability of the composite liquid, the injection process is ensured to be smooth. The vacuum system is turned off, a pressure of 1.8 MPa is applied, and the pressure is maintained for 1.5 hours.

[0079] Drying and curing the impregnated bamboo: Take out the impregnated board, clean the surface and let it air dry naturally for 24 hours. Then, transfer the board into the drying kiln and heat it to 70°C for constant temperature drying until the moisture content drops to 12%.

[0080] Comparative Example 6 This comparative example describes a bamboo anti-mildew agent. The raw materials include nitrogen-doped carbon quantum dots and an organic bactericide. The organic bactericide is loaded onto the surface of the nitrogen-doped carbon quantum dots by covalent and non-covalent bonds interacting with polar groups (-OH, -COOH, -NH2, etc.) on the surface of the nitrogen-doped carbon quantum dots. The mass ratio of nitrogen-doped carbon quantum dots to organic bactericide is 1:20. The organic bactericide is commercially available nitrogen-doped carbon quantum dots (produced by a company in Xi'an, nitrogen-doped carbon dots | nitrogen-doped carbon quantum dots (N-CQDs)). These nitrogen-doped carbon quantum dots only contain nitrogen in their molecular structure; compared to the nitrogen-doped carbon quantum dots of this invention, which contain quaternary ammonium salt groups in their molecular structure, they lack bactericidal function.

[0081] The preparation method of the bamboo antifungal agent in this comparative example is largely the same as that in Example 3, except that the type of antifungal agent mother liquor is different, and includes the following steps: 1.1 Preparation of nitrogen-doped carbon quantum dots (N-CQDs) Commercially available nitrogen-doped carbon quantum dots were selected.

[0082] 1.2 Preparation of the antifungal agent mother liquor Weigh the following components by weight: 10 parts of isothiazolinone derivative (in this example, n-butyl-1,2-benzisothiazolin-3-one), 10 parts of flutriafol, 3 parts of fluopyram aniline, 2 parts of KH-550 silane coupling agent, 20 parts of phenoxyethanol, 19 parts of dipropylene glycol methyl ether, and 36 parts of alkylphenol polyoxyethylene ether. Mix at room temperature until a clear and transparent organic antifungal agent stock solution is formed.

[0083] 1.3 Combination of nitrogen-doped carbon quantum dots with antifungal agent mother liquor Add 0.8 kg of the antifungal agent stock solution from step 1.2 to a 10 L reactor, start mechanical stirring (2500 rpm), and heat to 50 °C. Then, slowly add 32 g of the nitrogen-doped carbon quantum dot powder obtained in step 1.1 into the reactor. Allow the mixture to react continuously for 50 minutes at 50 °C and 2500 rpm to complete the coupling. After the reaction is complete, dilute the reaction solution with tap water and bring the volume to a final volume of 10 L to obtain the finished all-carbon-based bamboo antifungal agent.

[0084] The application of a bamboo anti-mildew agent in the anti-mildew treatment of bamboo includes the following steps: Vacuum-pressure impregnation treatment of bamboo: A batch of bamboo boards to be treated is placed in the impregnation equipment. The vacuum pump is started to evacuate to -0.06 MPa and maintained for 45 minutes. Under vacuum, the finished carbon-based bamboo anti-mildew agent is injected until the boards are completely submerged. Due to the high uniformity and stability of the composite liquid, the injection process is ensured to be smooth. The vacuum system is turned off, a pressure of 1.8 MPa is applied, and the pressure is maintained for 1.5 hours.

[0085] Drying and curing the impregnated bamboo: Take out the impregnated board, clean the surface and let it air dry naturally for 24 hours. Then, transfer the board into the drying kiln and heat it to 70°C for constant temperature drying until the moisture content drops to 12%.

[0086] The products of each embodiment and comparative example of the present invention were used on bamboo. Anti-mildew test experiments were designed with reference to standards GB / T 18261-2013 and LY / T 2230-2013. The damage value of the veneer was tested after 28 days. The damage value of the veneer was judged and recorded with reference to Table 3. Then, the mildew prevention efficacy of the modified veneer of the adhesive was calculated according to formula (I).

[0087] Table 1 Classification Standards for Veneer Damage Value

[0088] (I) In the formula: E represents the prevention and control efficacy (%); D1 represents the average damage value of bamboo treated using the various embodiments or comparative examples of the present invention; D0 represents the average damage value of untreated bamboo.

[0089] Table 2. Mold control efficacy of each embodiment and comparative example

[0090] The results showed that after 28 days of testing, there was a significant synergistic effect between nitrogen-doped carbon quantum dots and the organic antifungal agent mother liquor. A highly efficient "synergistic window" was established within the ratio of 1:10 to 1:20 (wt%), within which the two could fully interact, achieving a control efficacy of over 97% against bamboo. When the dosage of nitrogen-doped carbon quantum dots was below this range, its effective concentration was insufficient to form comprehensive protection.

[0091] Furthermore, the antifungal efficacy is unsatisfactory when the nitrogen-doped carbon quantum dots prepared in this invention are combined with a commercial antifungal agent, or when the mother liquor of an organic antifungal agent is combined with commercially available nitrogen-doped carbon quantum dots. The precursor used for the nitrogen-doped carbon quantum dots in the various embodiments of this invention is hydroxypropyltrimethylammonium chloride chitosan (HAC-chitosan). Because it contains quaternary ammonium salt groups, the carbon quantum dots themselves possess certain antibacterial properties. The nitrogen doping primarily emphasizes the nitrogen in the quaternary ammonium salt groups, while other nitrogen-containing carbon quantum dots lack bactericidal properties, resulting in lower bactericidal efficiency of the final bactericide. This indicates that the superior antifungal performance of this invention is not simply due to the arbitrary superposition of components, but rather highly dependent on the precise matching and synergistic effect between specific components.

[0092] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the present invention, should fall within the protection scope of the present invention.

Claims

1. A fully carbon-based bamboo antifungal agent, characterized in that: The raw materials include nitrogen-doped carbon quantum dots and organic bactericides. The organic bactericides are loaded onto the surface of nitrogen-doped carbon quantum dots by interacting with polar groups on the surface of the nitrogen-doped carbon quantum dots through covalent and non-covalent bonds. The nitrogen-doped carbon quantum dots are nitrogen-doped carbon quantum dots containing quaternary ammonium salt groups in their molecular structure. The mass ratio of nitrogen-doped carbon quantum dots to organic bactericides is 1:10 to 20.

2. The all-carbon-based bamboo antifungal agent according to claim 1, characterized in that: The organic bactericide comprises, by weight, the following components: 10-15 parts of isothiazolinone derivative, 10-15 parts of flutriafol, 3-5 parts of fluazinam aniline, 1-3 parts of silane coupling agent, 15-25 parts of phenoxyethanol, 15-20 parts of dipropylene glycol methyl ether, and 30-40 parts of surfactant.

3. The all-carbon-based bamboo antifungal agent according to claim 2, characterized in that: The surfactant includes at least one of alkylphenol polyoxyethylene ether and alkyl sulfonate.

4. A method for preparing a full carbon-based bamboo antifungal agent according to any one of claims 1 to 3, characterized in that: Includes the following steps: Nitrogen-doped carbon quantum dots and organic bactericides are mixed at a mass ratio of 1:10 to 20 and stirred at a temperature of 40 to 60°C to allow the organic bactericide molecules to be loaded onto the surface of the nitrogen-doped carbon quantum dots, thus obtaining a fully carbon-based bamboo anti-mildew agent.

5. The preparation method of the all-carbon-based bamboo antifungal agent according to claim 4, characterized in that: The stirring rate of the stirring reaction is 1200–3000 rpm, and the reaction time is 30–60 min.

6. The preparation method of the all-carbon-based bamboo antifungal agent according to claim 4, characterized in that: The preparation of the nitrogen-doped carbon quantum dots includes the following steps: The crude product was obtained by hydrothermal reaction using chitosan quaternary ammonium salt as a carbon source at a temperature of 150–200 °C. Centrifuge the crude product, take the supernatant and dialysis to purify it to obtain the purified solution; The purified solution was freeze-dried to obtain nitrogen-doped carbon quantum dots.

7. The preparation method of the all-carbon-based bamboo antifungal agent according to claim 6, characterized in that: The hydrothermal reaction takes 10–15 hours.

8. The application of a full carbon-based bamboo antifungal agent prepared by any one of claims 1 to 3 or by any one of claims 4 to 7 in the antifungal treatment of bamboo.

9. The application according to claim 8, characterized in that: The application includes the following steps: placing the bamboo to be treated in a full carbon-based bamboo anti-mold agent, using normal pressure soaking, vacuum impregnation or vacuum-pressure impregnation process to allow the full carbon-based bamboo anti-mold agent to fully penetrate into the bamboo, drying and curing to obtain bamboo treated with anti-mold agent.

10. The application according to claim 9, characterized in that: Includes at least one of Scheme A and Scheme B: Option A: When using a vacuum-pressure impregnation process, the following steps are included: First, evacuate the impregnation tank containing bamboo to -0.05 to -0.08 MPa and hold the pressure for 30 to 60 minutes. Then, inject the all-carbon-based bamboo anti-mildew agent and hold the pressure at 1.5 to 2.0 MPa for 1 to 2 hours. Option B: The drying and curing process includes the following steps: placing the bamboo at a temperature of 60-80°C to dry, so that the nitrogen-doped carbon quantum dots and organic bactericide in the all-carbon-based bamboo anti-mildew agent are deposited and cured on the inner wall of the micropores of the bamboo until the moisture content of the bamboo reaches the target value.

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