Termite bait based on cellulose waste and its high-temperature high-pressure preparation process and application

Abstract

This invention belongs to the field of pest control and biomaterial application technology, specifically relating to a termite bait based on cellulose waste and its high-temperature, high-pressure preparation process and application. The bait uses sugarcane bagasse powder and bark powder as the main cellulose matrix, supplemented with glucose, xylose, casein, and granulated sugar as attractants, and incorporates a chitosan-graphene oxide composite nano-insecticide. This bait exhibits high stability in humid environments, is not prone to mold, and maintains its attractant properties and efficacy for a long period. Indoor and buried tests have verified that the prepared bait significantly increases the termite feeding rate and mortality rate compared to the control group, demonstrating a comprehensive advantage of strong attractant properties, slow-release effect, and environmental friendliness.

Description

Technical Field

[0001] This invention belongs to the field of pest control and biomaterial application technology, specifically relating to a termite bait based on cellulose waste and its high-temperature and high-pressure preparation process and application. Background Technology

[0002] Termites are highly destructive social insects that can gnaw on cellulose-containing materials such as wooden buildings, dams, and trees, causing severe economic losses. Current termite control measures mainly include chemical spraying, soil barriers, and bait trapping. Among these, bait trapping technology has become a key research focus in recent years due to its advantages of requiring less pesticide, causing less environmental pollution, and achieving good colony control.

[0003] However, existing baits still have several problems: First, the bait substrate is mostly made of wood flour or starch-based materials, which, although attractive to some, have a loose structure, are prone to moisture absorption and mold growth, and are difficult to maintain a long-term attraction effect; Second, the chemical insecticides used are mostly in a free state, which are easily deactivated by humidity and temperature, and their rapid release can easily trigger a repulsion response in termites, causing them to avoid the bait; Third, the uneven dispersion of pesticides in the bait leads to unstable toxicity, poor colony spread, and difficulty in achieving sustained eradication; Fourth, the traditional bait production process is energy-intensive and has low utilization rates, lacking effective utilization of agricultural and forestry waste, and is difficult to meet the development needs of green pest control.

[0004] In recent years, the application of nanomaterials in pesticide sustained release and ecological control has gradually emerged. Chitosan is a widely available, biodegradable, and biocompatible natural polysaccharide. Its molecules contain amino and hydroxyl groups, enabling it to complex and cross-link with metal ions or pesticide molecules. Used as a carrier, it can significantly improve pesticide stability and sustained-release performance. Graphene oxide (GO), with its high specific surface area and abundant oxygen-containing functional groups, can further improve the dispersibility and mechanical properties of materials when combined with chitosan, making it an ideal nanoparticle drug delivery matrix. Furthermore, forming a composite structure of chitosan and graphene oxide can impart excellent adsorption and sustained-release properties to the material while maintaining biodegradability.

[0005] On the other hand, termites have a strong feeding preference for natural lignocellulose. Related studies have shown that bait with cellulose as its main component has good palatability and attractant effects on termites, and can remain stable in moist soil for a long time after proper treatment. Therefore, if cellulose waste (such as sugarcane bagasse, bark powder, etc.) can be used as a carrier and combined with a nano-slow-release insecticide system, it is hoped that the insecticide can be released sustainably while ensuring its attractiveness to termites.

[0006] In summary, current technologies lack a termite bait that simultaneously possesses strong attractant properties, slow-release properties, mold resistance, and environmental friendliness. Addressing the issues of existing baits such as susceptibility to mold, short-lived efficacy, unstable structure, and heavy environmental burden, there is an urgent need to develop a novel eco-friendly termite bait material based on renewable resources and incorporating nanotechnology for controlled-release, in order to achieve long-term, safe control of termite colonies. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a termite bait based on cellulose waste, its high-temperature and high-pressure preparation process, and its application.

[0008] A termite bait based on cellulose waste comprises, by weight: 1 part bark powder, 10 parts sugarcane bagasse, 0.5 parts glucose, 0.5 parts xylose, 0.3 parts casein and 0.5 parts white sugar, and 3 parts nano-insecticide.

[0009] The nano-insecticide is selected from chitosan-graphene oxide composite material nanoparticles loaded with acaricides.

[0010] The bait has a dense structure formed by high-temperature and high-pressure treatment;

[0011] The nano-insecticide is prepared through the following steps:

[0012] Step S1: Carrier preparation: Graphene oxide was dissolved in ethylene glycol under ultrasonic assistance; then an iron source and chitosan were added, and a solvothermal reaction was carried out at 200°C for 12 hours in the presence of sodium acetate. After the reaction, the mixture was cooled, centrifuged, washed, and dried to obtain an iron-doped chitosan-reduced graphene oxide composite carrier; the iron source was ferric chloride hexahydrate (III) and ferric chloride tetrahydrate (II);

[0013] Step S2: Dissolve the iron-doped chitosan-reduced graphene oxide composite carrier in acetic acid solution to form solution A; dissolve chlorfenapyr in sodium tripolyphosphate aqueous solution to form solution B; add solution B dropwise to solution A, stir the reaction, centrifuge, and freeze-dry to obtain the nano-insecticide formulation.

[0014] This invention provides a process for preparing termite bait, comprising the following steps:

[0015] Step S1: Mix the bark powder, sugarcane bagasse powder, glucose, xylose, casein, white sugar and nano-insecticide in a certain proportion;

[0016] Step S2: Heat and press the bait into a mold to form bait blocks;

[0017] Step S3: Cool and demold to obtain the finished bait.

[0018] Furthermore, in step S2, the heating and pressing step has a temperature of 150°C and a pressure of 90 MPa.

[0019] Furthermore, the present invention also provides an application of bait in termite trapping, characterized in that the bait block is buried 5-10 cm deep in the soil or around a building, and slowly releases insecticidal components in the natural environment to attract and kill termite colonies.

[0020] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0021] Highly attractive to termites and with a high feeding rate. The bait matrix uses natural cellulose waste, which matches the feeding preferences of termites and significantly improves the attraction efficiency; it also has good slow-release and sustained-release effects. Chitosan-graphene oxide nanocarriers achieve uniform dispersion and controlled release of insecticides, prolonging the efficacy period and avoiding repellency; it is moisture-resistant and mildew-resistant. Through high-temperature and high-pressure densification, the structural stability of the bait is improved, allowing it to be buried in moist soil for a long time; the materials are green and environmentally friendly. All raw materials are derived from biodegradable biomass and low-toxicity nanocomposites, realizing the resource utilization of agricultural and forestry waste; it has high killing efficiency. The nano-preparation can be transferred and diffused among termites, with a significant synergistic effect of attracting and killing, enabling group control. Therefore, this invention constructs a novel termite trapping system that combines attractiveness, slow release, and ecological compatibility, suitable for long-term control in various scenarios such as urban construction, landscaping, and flood control projects. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments. The illustrative embodiments and descriptions of this invention are only used to explain this invention and are not intended to limit this invention.

[0023] In this invention, the bark powder and sugarcane bagasse powder have a particle size of 50 mesh, and the moisture content of the powder is less than 8% after drying.

[0024] Example 1

[0025] A termite bait based on cellulose waste comprises, by weight: 1 part bark powder, 10 parts sugarcane bagasse, 0.5 parts glucose, 0.5 parts xylose, 0.3 parts casein and 0.5 parts white sugar, and 3 parts nano-insecticide.

[0026] The method for preparing the termite bait based on cellulose waste is as follows: Eucalyptus bark powder, sugarcane bagasse powder, glucose, xylose, casein, white sugar and nano-insecticide are mixed evenly, the mixture is put into a mold, and heated and pressed at 150℃ and 90MPa using a small tablet press. After keeping warm for 10 minutes, it is cooled and demolded to obtain the termite bait.

[0027] The preparation method of the nano-pesticide nano-formulation is as follows:

[0028] First, 1.6 g of chitosan-graphene oxide nanocomposite material was dissolved in 200 ml of 2% acetic acid solution, stirred continuously with a magnetic stirrer for 25 min, and then sonicated for 10 min to obtain solution A.

[0029] Next, sodium tripolyphosphate was dissolved in 200 ml of deionized water. After the sodium tripolyphosphate was completely dissolved, 1 g of chlorfenapyr was added to the sodium tripolyphosphate solution to obtain solution B. Then, solution B was added dropwise to solution A and stirred continuously for 30 min. The resulting suspension was centrifuged at 4000 rpm for 30 min, the precipitate was collected and freeze-dried to obtain the nanoparticle formulation.

[0030] The preparation method of the chitosan-graphene oxide nanocomposite material is as follows:

[0031] Under ice bath conditions, 2 g of graphite powder was added to 100 mL of concentrated H₂SO₄ with constant stirring. Then, 4.025 g of sodium nitrate was slowly added, followed by small batches of 10 g of KMnO₄; the mixture was then stirred for 2 hours. The flask was then placed on a magnetic stirrer in an ice bath and diluted with 100 mL of deionized water; subsequently, 20 mL of H₂O₂ was added to terminate the reaction. The resulting reaction mixture was centrifuged at 7000 rpm for 5 minutes, and the supernatant was discarded. The slurry was washed five times by replacing the supernatant with deionized water; the resulting graphite oxide was dried in a hot air oven at 60°C for 6 hours. The dried graphite oxide was ground into powder and transferred to an Erlenmeyer flask containing 100 mL of deionized water; the mixture was sonicated for 30 minutes, during which time it was placed in an ice bath to control the temperature during sonication. After ultrasonic treatment, the mixture was centrifuged at 7000 rpm for 5 minutes, the supernatant was discarded, the solid was transferred to a glass plate and dried in a hot air oven at 50°C to obtain graphene oxide.

[0032] 0.2 g of graphene oxide was dissolved in 75 mL of ethylene glycol under ultrasonic assistance and sonicated for 2 hours. Then, 0.54 g of ferric chloride hexahydrate (III) and 0.23 g of ferric chloride tetrahydrate (II) were added to the solution, followed by 1 g of chitosan. The mixture was placed on a magnetic stirrer, and 3.6 g of sodium acetate was slowly added while stirring. The mixture was stirred for another 30 minutes. The mixture was then transferred to a polytetrafluoroethylene-lined reactor and placed in an oven at 200°C for 12 hours. Before opening the reactor, it was cooled to room temperature. The resulting mixture was centrifuged to separate the solids, and washed three times each with deionized water and ethanol. The resulting solids were dried in a hot air oven at 50°C to obtain the chitosan-graphene oxide nanocomposite material.

[0033] Example 2

[0034] A termite bait based on cellulose waste comprises, by weight: 1 part bark powder, 10 parts sugarcane bagasse, 0.5 parts glucose, 0.5 parts xylose, 0.3 parts casein and 0.5 parts white sugar, and 3 parts nano-insecticide.

[0035] The method for preparing the termite bait based on cellulose waste is as follows: Eucalyptus bark powder, sugarcane bagasse powder, glucose, xylose, casein, white sugar and nano-insecticide are mixed evenly, the mixture is put into a mold, and heated and pressed at 150℃ and 90MPa using a small tablet press. After keeping warm for 10 minutes, it is cooled and demolded to obtain the termite bait.

[0036] The preparation method of the nano-pesticide nano-formulation is as follows:

[0037] First, 1.6 g of chitosan nanocomposite material was dissolved in 200 ml of 2% acetic acid solution, stirred continuously with a magnetic stirrer for 25 min, and then sonicated for 10 min to obtain solution A;

[0038] Next, sodium tripolyphosphate was dissolved in 200 ml of deionized water. After the sodium tripolyphosphate was completely dissolved, 1 g of chlorfenapyr was added to the sodium tripolyphosphate solution to obtain solution B. Then, solution B was added dropwise to solution A and stirred continuously for 30 min. The resulting suspension was centrifuged at 4000 rpm for 30 min, the precipitate was collected and freeze-dried to obtain the nanoparticle formulation.

[0039] The chitosan nanocomposite material was prepared as follows: 0.54 g of ferric chloride hexahydrate (III) and 0.23 g of ferric chloride tetrahydrate (II) were added to the solution, followed by 1 g of chitosan. The mixture was placed on a magnetic stirrer, and 3.6 g of sodium acetate was slowly added while stirring. The mixture was stirred for another 30 minutes. The mixture was then transferred to a polytetrafluoroethylene-lined reactor and placed in an oven at 200°C for 12 hours. Before opening the reactor, it was cooled to room temperature. The resulting mixture was centrifuged to separate the solid material, and washed three times each with deionized water and ethanol. The resulting solid was dried in a hot air oven at 50°C to obtain the chitosan nanocomposite material.

[0040] Example 3

[0041] A termite bait based on cellulose waste comprises, by weight: 1 part bark powder, 10 parts sugarcane bagasse, 0.5 parts glucose, 0.5 parts xylose, 0.3 parts casein and 0.5 parts white sugar, and 3 parts nano-insecticide.

[0042] The method for preparing the termite bait based on cellulose waste is as follows: Eucalyptus bark powder, sugarcane bagasse powder, glucose, xylose, casein, white sugar and nano-insecticide are mixed evenly, the mixture is put into a mold, and heated and pressed at 150℃ and 90 MPa using a small tablet press. After keeping warm for 10 minutes, it is cooled and demolded to obtain the termite bait.

[0043] The preparation method of the nano-pesticide nano-formulation is as follows:

[0044] First, 1.6 g of graphene oxide nanocomposite material was dissolved in 200 ml of 2% acetic acid solution, stirred continuously with a magnetic stirrer for 25 min, and then sonicated for 10 min to obtain solution A;

[0045] Next, sodium tripolyphosphate was dissolved in 200 ml of deionized water. After the sodium tripolyphosphate was completely dissolved, 1 g of chlorfenapyr was added to the sodium tripolyphosphate solution to obtain solution B. Then, solution B was added dropwise to solution A and stirred continuously for 30 min. The resulting suspension was centrifuged at 4000 rpm for 30 min, the precipitate was collected and freeze-dried to obtain the nanoparticle formulation.

[0046] The preparation method of the graphene oxide nanocomposite material is as follows:

[0047] Under ice bath conditions, 2 g of graphite powder was added to 100 mL of concentrated H₂SO₄ with constant stirring. Then, 4.025 g of sodium nitrate was slowly added, followed by small batches of 10 g of KMnO₄; the mixture was then stirred for 2 hours. The flask was then placed on a magnetic stirrer in an ice bath and diluted with 100 mL of deionized water; subsequently, 20 mL of H₂O₂ was added to terminate the reaction. The resulting reaction mixture was centrifuged at 7000 rpm for 5 minutes, and the supernatant was discarded. The slurry was washed five times by replacing the supernatant with deionized water; the resulting graphite oxide was dried in a hot air oven at 60°C for 6 hours. The dried graphite oxide was ground into powder and transferred to an Erlenmeyer flask containing 100 mL of deionized water; the mixture was sonicated for 30 minutes, during which time the temperature was controlled in an ice bath. After ultrasonic treatment, the mixture was centrifuged at 7000 rpm for 5 minutes, the supernatant was discarded, the solid was transferred to a glass plate and dried in a hot air oven at 50°C to obtain graphene oxide.

[0048] 0.2 g of graphene oxide was dissolved in 75 mL of ethylene glycol under ultrasonic assistance and sonicated for 2 hours. Subsequently, 0.54 g of ferric chloride hexahydrate (III) and 0.23 g of ferric chloride tetrahydrate (II) were added to the solution, and 3.6 g of sodium acetate was slowly added while stirring. The mixture was stirred for another 30 minutes. The mixture was then transferred to a polytetrafluoroethylene-lined reactor and placed in an oven at 200°C for 12 hours. Before opening the reactor, it was cooled to room temperature. The resulting mixture was centrifuged to separate the solids, and washed three times each with deionized water and ethanol. The resulting solids were dried in a hot air oven at 50°C to obtain chitosan-graphene oxide nanocomposite materials.

[0049] Example 4

[0050] A termite bait based on cellulose waste comprises, by weight: 1 part bark powder, 10 parts sugarcane bagasse, 0.5 parts glucose, 0.5 parts xylose, 0.3 parts casein and 0.5 parts white sugar, and 3 parts nano-insecticide.

[0051] The method for preparing the termite bait based on cellulose waste is as follows: Eucalyptus bark powder, sugarcane bagasse powder, glucose, xylose, casein, white sugar and nano-insecticide are mixed evenly, the mixture is put into a mold, and heated and pressed at 150℃ and 90 MPa using a small tablet press. After keeping warm for 10 minutes, it is cooled and demolded to obtain the termite bait.

[0052] The preparation method of the nano-pesticide nano-formulation is as follows:

[0053] First, 1.6 g of chitosan was dissolved in 200 ml of 2% acetic acid solution, stirred continuously with a magnetic stirrer for 25 min, and then sonicated for 10 min to obtain solution A;

[0054] Next, sodium tripolyphosphate was dissolved in 200 ml of deionized water. After the sodium tripolyphosphate was completely dissolved, 1 g of chlorfenapyr was added to the sodium tripolyphosphate solution to obtain solution B. Then, solution B was added dropwise to solution A and stirred continuously for 30 min. The resulting suspension was centrifuged at 4000 rpm for 30 min, the precipitate was collected and freeze-dried to obtain the nanoparticle formulation.

[0055] Test Example 1

[0056] Indoor experiment: 1.0 g of termite bait made from cellulose waste prepared in each example was accurately weighed and placed in a glass dish; 50 worker ants and 5 soldier ants were added. The dish was covered and placed in a dark incubator at (27±1)℃ for 5 days, and the termite survival rate was recorded.

[0057] Post-burial treatment experiment: The termite bait made from cellulose waste prepared in each embodiment was buried in the soil for one month, and then removed. Then, 1.0 g of the termite bait made from cellulose waste prepared in each embodiment was accurately weighed and placed in a glass dish; 50 worker termites and 5 soldier termites were added. The dish was covered and placed in a dark incubator at (27±1)℃ for 5 days, and the termite survival rate was recorded.

[0058] Table 1 Indoor test data

[0059]

[0060] Table 2 Test data after burial treatment

[0061]

[0062] According to the data in Tables 1 and 2 of Patent Examples 1-4, the different nanocarriers prepared in this invention exhibit significant differences in their termite-trapping effects. The results of the indoor tests (Table 1) show that the bait using the chitosan-graphene oxide nanocomposite carrier in Example 1 had the highest termite mortality rate, reaching 68.1% on day 3, rising to 92.1% on day 4, and achieving complete mortality on day 5. Example 2 (chitosan nanocomposite carrier) was second best, also achieving 100% mortality on day 5, but its overall effect was slightly slower. Examples 3 and 4 used graphene oxide single carrier and pure chitosan carrier, respectively, with significantly lower mortality rates in the early stages, only gradually increasing in the later stages, indicating that the composite structure has superior sustained-release and synergistic toxicity performance. The experimental data after one month of burial (Table 2) further verified the stability of the composite carrier: the termite mortality rate of Example 1 remained at 100% on the 5th day, significantly higher than that of Example 3 (94.5%) and Example 4 (96.2%), indicating that its efficacy lasted longer in moist soil and that the bait structure was more stable. Overall, the nanocomposite carrier formed by the synergistic addition of graphene oxide and chitosan (Example 1) showed the best performance in terms of attractancy, persistence, and environmental tolerance, confirming the significant advantages of this composite system in termite control and the effectiveness of the patented technology.

[0063] The invention employs a 200℃ high-temperature solvothermal reaction to achieve in-situ doping and lattice anchoring of iron ions (Fe³⁺ / Fe²⁺) between chitosan and graphene oxide layers. This unique synthesis process yields two unexpected technical effects: First, the high-temperature reaction induces partial carbonization or cross-linking of the chitosan molecular chains, forming a dense 'ceramic-like' nanocapsule structure. This structure effectively isolates the external high temperature, protecting the encapsulated acaricide from thermal decomposition during subsequent 150℃ bait pressing, thus ensuring the stability of the bait's efficacy during long-term burial (see Table 2 data). Second, the introduced iron ions microscopically simulate the chemical signal sources of communication among termite colonies (such as simulating biomagnetic fields or specific metalloenzyme environments), significantly reducing termites' alertness to chemical pesticides. Experimental data show that the feeding rate and lethality of the iron-containing composite carrier (Example 1) are significantly better than those of undoped or simply physically mixed carriers, demonstrating a unique biosynergistic induction effect between iron ions and the chitosan-graphene oxide system.

Claims

1. A cellulose-based waste material based termite bait, characterized in that, By mass parts include: bark powder 1 parts, bagasse 10 parts, glucose 0.5 parts, xylose 0.5 parts, 0.3 parts of casein and white sugar 0.5 parts, 3 parts of nano insecticidal preparation; The nano insecticidal preparation is selected from nanoparticles of chitosan-graphene oxide composite material loaded with buprofezin; The bait has a dense structure formed by high-temperature and high-pressure treatment; The nano insecticidal preparation is prepared by the following steps: Step S1: carrier preparation: graphene oxide is dissolved in ethylene glycol under ultrasonic assistance; then iron source and chitosan are added, and a solvothermal reaction is carried out at 200°C for 12 hours in the presence of sodium acetate; after the reaction is completed, cooling, centrifugation, washing and drying are carried out to obtain an iron-doped chitosan-reduced graphene oxide composite carrier; the iron source is ferric chloride (III) hexahydrate and ferrous chloride (II) tetrahydrate; Step S2: the iron-doped chitosan-reduced graphene oxide composite carrier is dissolved in acetic acid solution to form solution A; buprofezin is dissolved in aqueous sodium tripolyphosphate solution to form solution B; solution B is added dropwise into solution A, and after stirring and reaction, centrifugation and freeze-drying are carried out to obtain the nano insecticidal preparation.

2. A process for preparing the termite bait of claim 1, wherein The method comprises the following steps: Step S1: bark powder, bagasse powder, glucose, xylose, casein, white sugar and nano insecticidal preparation are mixed in proportion; Step S2: heating and pressing in a mold to form bait blocks; Step S3: cooling and demolding to obtain finished bait.

3. The process for preparing a termite bait of claim 2, wherein The temperature in the heating and pressing step in step S2 is 150°C, and the pressure is 90 MPa.

4. Use of the bait according to any one of claims 1 to 3 for the control of termites, characterized in that, The bait blocks are buried in the soil or around the building at a depth of 5-10 cm, slowly release the insecticidal components in the natural environment to achieve the trapping and killing of termite colonies.

Images