Preparation method and application of bacterial cellulose-based composite nanogenerator

Abstract

The present invention discloses a preparation method and application of a bacterial cellulose-based composite nanogenerator, belonging to the field of nanogenerator and power monitoring technology. Through solution blending technology, graphene oxide and cobalt ferrite are embedded in a bacterial cellulose matrix to prepare a composite material with a stable structure. The electromagnetic properties, triboelectric properties, and mechanical stability of each composite material are systematically evaluated to screen the optimal formulation. The composite material is used to prepare a nanogenerator, and a composite structure including a friction layer and an electromagnetic induction coil is designed. By monitoring the power fluctuations output by the nanogenerator, the real-time state of the transformer's leakage magnetic field is directly reflected. The present invention utilizes the preparation method and application of the bacterial cellulose-based composite nanogenerator to achieve self-powered monitoring of power transformers, improving the accuracy and real-time performance of leakage magnetic field detection.

Description

Technical Field

[0001] The present invention relates to the technical field of nanogenerators and power monitoring, and in particular to a preparation method and application of a bacterial cellulose-based composite nanogenerator. Background Art

[0002] Power transformers are core equipment for power transmission and distribution. Their safe and stable operation is crucial for ensuring the overall reliability and efficiency of the power grid. Transformer leakage magnetic field, the leakage of magnetic fields generated during transformer operation, can not only interfere with the surrounding electromagnetic environment but also adversely affect nearby electrical equipment and communication lines. It can even accelerate equipment aging and increase the risk of failure.

[0003] Different types of transformer faults (such as winding short circuits, core faults, and insulation degradation) can cause significant changes in the leakage magnetic field characteristics. These changes, such as increases or decreases in magnetic field intensity and variations in distribution, make it possible to identify potential transformer faults by monitoring the leakage magnetic field. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method and application of a bacterial cellulose-based composite nanogenerator. The generator utilizes the excellent mechanical properties of bacterial cellulose composite materials and the special effects of nanomaterials to convert mechanical energy and electromagnetic energy into electrical energy, and realizes real-time monitoring of the transformer leakage magnetic field by monitoring electrical energy fluctuations.

[0005] To achieve the above object, the present invention provides a method for preparing a bacterial cellulose-based composite nanogenerator, comprising the following steps:

[0006] S1. Graphene oxide and cobalt ferrite are embedded in a bacterial cellulose matrix through solution blending technology to prepare a structurally stable composite material.

[0007] S2. Systematically evaluate the electromagnetic properties, triboelectric properties, and mechanical stability of each composite material to select the optimal formula;

[0008] S3. Use the composite materials with the optimal formula to prepare composite nanogenerators.

[0009] Preferably, the S1 specifically includes:

[0010] S11, cutting the bacterial cellulose hydrogel into 2×2 cm block samples, stirring using a high shear homogenizer for 30 min to prepare a 10 mg / mL bacterial cellulose aqueous solution;

[0011] S12, successively dispersing predetermined amounts of graphene oxide powder and cobalt ferrite powder in appropriate solvents to form uniform graphene oxide suspensions and cobalt ferrite suspensions;

[0012] S13, mixing the prepared graphene oxide suspension and the cobalt ferrite suspension in an optimal ratio, and further dispersing them by ultrasonic treatment to obtain a mixed suspension in which the nanoparticles are evenly distributed;

[0013] S14, slowly adding the obtained mixed suspension to the bacterial cellulose aqueous solution, and continuing to stir, so that the graphene oxide and cobalt ferrite are evenly embedded in the bacterial cellulose matrix to obtain a mixed solution;

[0014] S15. Pour the mixed solution into a mold for vacuum defoaming treatment for 10 minutes, and then perform heating and drying treatment to prepare a composite material with stable structure and excellent performance.

[0015] Preferably, the limiting conditions for uniformly embedding graphene oxide and cobalt ferrite in the bacterial cellulose matrix in S14 include: the content of graphene oxide is limited to a range of 0.2% to 1.2% of the total mass of the composite material; the content of cobalt ferrite is limited to a range of 0.2% to 1% of the total mass of the composite material.

[0016] Preferably, the limiting conditions for uniformly embedding graphene oxide and cobalt ferrite in the bacterial cellulose matrix in S14 include: the content of graphene oxide is limited to a range of 0.5% to 0.8% of the total mass of the composite material; the content of cobalt ferrite is limited to a range of 0.2% to 0.6% of the total mass of the composite material.

[0017] Preferably, the S2 specifically includes:

[0018] S21. Conduct systematic performance tests on the composite materials prepared by each formula, including electromagnetic performance tests, dielectric performance tests, triboelectric performance tests, and mechanical performance tests;

[0019] S22. Statistically analyze the performance test results and use appropriate mathematical models or optimization algorithms to find the optimal balance between electromagnetic performance, triboelectric performance, and mechanical stability, thereby selecting the optimal formula;

[0020] S23. Conduct stability and durability tests on the composite materials with the optimal formula to ensure the reliability and stability of the experimental results.

[0021] Preferably, the S21 includes the following operations before the triboelectric performance test:

[0022] A high-performance vertical contact-separation mode friction nanogenerator structure is constructed, and composite materials are used as the positive friction layer material. By comparing the output performance or surface energy of the friction nanogenerator, the appropriate negative friction layer material is selected.

[0023] Preferably, the positive friction layer material and the negative friction layer material are circular samples with a diameter of 55 mm, and the negative friction layer material is one of fluorinated ethylene copolymer, polyimide, and polytetrafluoroethylene.

[0024] Preferably, the S3 specifically includes:

[0025] S31, processing the composite material with the optimal formula screened out into a friction layer of a specific shape and size;

[0026] S32. Design and prepare electromagnetic induction coils, selecting appropriate wire diameter, number of turns, and layout;

[0027] S33, assembling the friction layer and the electromagnetic induction coil according to a preset layout and position to form a composite structure;

[0028] S34. Electrically connect and package the composite structure to obtain a composite nanogenerator.

[0029] The present invention provides an application of a composite nanogenerator based on a bacterial fiber composite material, and an application of the composite nanogenerator prepared by the above-mentioned preparation method in transformer leakage magnetic field monitoring.

[0030] The present invention provides a device for monitoring the leakage magnetic field of a power transformer, comprising the following devices:

[0031] A composite nanogenerator prepared by the above-mentioned preparation method;

[0032] Signal processing system for collecting and analyzing power fluctuation data output by the generator;

[0033] a processor for processing the signal and converting the data into status information of the transformer leakage magnetic field;

[0034] The operation interface is used to display the real-time data and historical trends of the transformer leakage magnetic field, as well as to perform fault warning and performance evaluation.

[0035] Therefore, the present invention adopts the above-mentioned preparation method and application of the bacterial cellulose-based composite nanogenerator, which has the following beneficial effects:

[0036] (1) The innovative integration of electromagnetic and triboelectric effects realizes a dual energy conversion mechanism, significantly improving energy collection efficiency and system stability. The generator utilizes the high mechanical strength and biocompatibility of bacterial cellulose to prepare a composite material with stable structure and excellent performance, achieving accurate real-time monitoring of the leakage magnetic field of the power transformer.

[0037] (2) It not only enhances the safety and stability of the power system, but also expands the application scope of electromagnetic field monitoring. At the same time, the characteristics of its bio-based materials are in line with the trend of green development, promoting resource recycling and sustainable development, and has great value in the fields of power monitoring and new energy materials.

[0038] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a flow chart of a preparation method and application example of a bacterial cellulose-based composite nanogenerator of the present invention;

[0040] Figure 2 This is a preparation method of a bacterial cellulose-based composite nanogenerator of the present invention and the hysteresis loops of the composite material under different formulations of the application embodiment;

[0041] Figure 3 This is a schematic diagram of the structure of a tribo-electromagnetic composite nanogenerator provided by a preparation method and application example of a bacterial cellulose-based composite nanogenerator of the present invention;

[0042] Figure 4 The present invention provides a preparation method of a bacterial cellulose-based composite nanogenerator and a flowchart of a power transformer leakage magnetic field monitoring state provided by an application embodiment. DETAILED DESCRIPTION

[0043] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0044] Unless otherwise defined, technical or scientific terms used in the present invention shall have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs.

[0045] Example

[0046] like Figure 1 As shown, the present invention provides a method for preparing a bacterial cellulose-based composite nanogenerator, comprising the following steps:

[0047] S1. Graphene oxide and cobalt ferrite are embedded in a bacterial cellulose matrix through solution blending technology to prepare a structurally stable composite material.

[0048] Among them, bacterial cellulose has excellent mechanical properties, high porosity and good biocompatibility, so it is used as the substrate; the addition of graphene oxide significantly improves the conductivity and mechanical strength of the composite material; cobalt ferrite as a magnetic material gives the composite material the property of being sensitive to electromagnetic fields.

[0049] The specific operations of S1 are:

[0050] S11, cutting the bacterial cellulose hydrogel into 2×2 cm block samples, stirring using a high shear homogenizer for 30 min to prepare a 10 mg / mL bacterial cellulose aqueous solution;

[0051] S12, successively dispersing predetermined amounts of graphene oxide powder and cobalt ferrite powder in appropriate solvents, respectively, and using a high-efficiency stirring device or ultrasonic assistance to form a uniform and stable graphene oxide suspension and cobalt ferrite suspension;

[0052] S13, mixing the prepared graphene oxide suspension and cobalt ferrite suspension in an optimal ratio, and further dispersing them by ultrasonic treatment to obtain a mixed suspension with uniformly distributed nanoparticles; wherein the ultrasonic treatment is performed intermittently to avoid overheating and particle aggregation;

[0053] S14, slowly adding the obtained mixed suspension to the bacterial cellulose aqueous solution, and continuing to stir, so that the graphene oxide and cobalt ferrite are evenly embedded in the bacterial cellulose matrix to obtain a mixed solution;

[0054] S15. Pour the mixed solution into a mold for vacuum defoaming treatment for 10 minutes, and dry it at 60° C. for 12 hours, thereby preparing a composite material with stable structure and excellent performance.

[0055] S2. Systematically evaluate the electromagnetic properties, triboelectric properties, and mechanical stability of each composite material to select the optimal formula. The specific operations are as follows:

[0056] S21. Conduct systematic performance tests on the composite materials prepared from each formulation, including electromagnetic performance tests, dielectric performance tests, triboelectric performance tests, and mechanical performance tests;

[0057] Among them, an electromagnetic performance testing system is used to measure the electromagnetic parameters such as hysteresis loop, magnetic permeability, resistivity, etc. of composite materials of various formulas to evaluate their ability to respond to changes in the leakage magnetic field of the power transformer; a dielectric performance testing system is used to test the dielectric constant and dielectric loss of composite materials under different formulas; a triboelectric testing device is constructed to simulate the friction contact in the actual working environment, and measure parameters such as the amount of charge, output voltage and current generated by the composite materials during the friction process to evaluate their triboelectric conversion efficiency; through mechanical testing methods such as stretching, compression, and bending, the fatigue resistance, toughness and long-term stability of the composite materials are evaluated to ensure their reliability in complex working environments.

[0058] The following operations were performed before the triboelectric performance test: a high-performance vertical contact-separation mode friction nanogenerator structure was constructed, a composite material was used as the positive friction layer material, and a suitable negative friction layer material was selected by comparing the output performance or surface energy of the friction nanogenerator; the positive friction layer material and the negative friction layer material were circular specimens with a diameter of 55 mm, and the negative friction layer material was one of fluorinated ethylene copolymer, polyimide, and polytetrafluoroethylene.

[0059] S22. Statistically analyze the performance test results and use a suitable mathematical model or optimization algorithm to find the optimal balance between electromagnetic performance, triboelectric performance, and mechanical stability, thereby selecting the optimal formula;

[0060] The graphene oxide content is limited to 0.2% to 1.2% (preferably 0.5% to 0.8%) of the total weight of the composite material to ensure that it effectively enhances the triboelectric properties of the composite material without reducing the mechanical stability or electromagnetic properties due to excessive content. The cobalt ferrite content is limited to 0.2% to 1% (preferably 0.2% to 0.6%) of the total weight of the composite material to optimize its electromagnetic response characteristics and synergize with the graphene oxide to enhance the overall performance of the composite material.

[0061] Figure 2 Figure 2 shows the hysteresis loops of composite materials under different formulations. With the increase of cobalt ferrite in the formulation (from 0.2wt.% to 1wt.%), the residual magnetization and saturation magnetization of the composite material show a gradual increasing trend, which indicates that the hysteresis loop performance of the material has been significantly improved.

[0062] S23. Conduct stability and durability tests on the composite materials with the optimal formula to ensure the reliability and stability of the experimental results.

[0063] S3. Using the composite material with the optimal formula screened out, a composite nanogenerator is prepared. The specific operation is as follows:

[0064] S31. Process the composite material with the best formula into a friction layer of specific shape and size to ensure its surface is smooth and mechanically strong, suitable for long-term operation;

[0065] S32. Design and prepare the electromagnetic induction coil, selecting the appropriate wire diameter, number of turns, and layout to ensure that the coil can effectively induce current in the transformer leakage magnetic field;

[0066] S33, assembling the friction layer and the electromagnetic induction coil according to a preset layout and position to form a composite structure, such as Figure 3 shown.

[0067] The triboelectric layer is exposed to a vibration-prone environment, while the electromagnetic induction coil is placed close to or near the transformer to detect leakage magnetic fields. This structure requires a rational layout of the electromagnetic induction element and the triboelectric layer to ensure they work together to maximize energy conversion efficiency. By adjusting parameters such as the relative position, contact area, and friction pattern between the triboelectric layer and the electromagnetic induction element, the generator's energy conversion efficiency can be optimized.

[0068] S34. Electrically connect and package the composite structure to obtain a composite nanogenerator, ensuring that the triboelectric effect and electromagnetic induction effect can be independently and synergistically converted into electrical energy output, while protecting internal components from environmental factors.

[0069] The present invention provides an application of a composite nanogenerator based on bacterial fiber composite materials. When a transformer winding is deformed or short-circuited between turns, it will directly affect the winding current, thereby causing a significant change in the leakage magnetic field inside the transformer. Clearly understanding the distribution of the leakage magnetic field near the winding under normal transformer operation and various defects is crucial for identifying winding defects. Different fault types correspond to different changes in the leakage magnetic field. Therefore, in order to accurately analyze the fault type of the transformer, the embodiment constructs a friction-electromagnetic composite nanogenerator to sense the changes in the transformer leakage magnetic field and ultimately determine the fault type of the transformer.

[0070] The application of the composite nanogenerator prepared by the above preparation method in transformer leakage magnetic field monitoring includes the following steps:

[0071] S1. Integrate the prepared tribo-electromagnetic composite nanogenerator into the power transformer monitoring system. During the integration process, ensure that the generator fits tightly into the leakage magnetic field area of the power transformer to effectively capture magnetic field changes and convert them into electrical energy.

[0072] S2. Connect the composite nanogenerator to a signal processing system to collect and analyze real-time data on the generator's output power fluctuations, including key parameters such as voltage, current, and power. To ensure data accuracy and reliability, the collected raw data must be preprocessed, including denoising, filtering, and calibration, to eliminate the effects of environmental interference and measurement errors on data analysis.

[0073] S3. Through algorithmic processing, power fluctuation data (including frequency, amplitude, and phase difference) is converted into information on the strength and direction of the transformer's leakage magnetic field, enabling online monitoring of the transformer's leakage magnetic field status, fault warning, and performance evaluation. By comparing characteristic parameters with thresholds or patterns for normal or faulty states, it is possible to determine whether the transformer has leakage magnetic field anomalies and further determine the type, extent, and location of the anomaly. A visual interface is provided to showcase real-time data and historical trends.

[0074] S4. Further utilize time series analysis, machine learning prediction models, and other methods to predict the leakage magnetic field trend over the next period of time based on historical data and current status. Once a possible failure risk or abnormal state is discovered, a warning signal is issued in a timely manner so that operation and maintenance personnel can take appropriate measures to intervene and repair.

[0075] S5. Establish a comprehensive data management system to store, manage, and visualize collected power data and analysis results. Data visualization tools can be used to present complex power fluctuations and leakage magnetic field conditions to maintenance personnel in the form of charts and curves, helping them to more quickly and accurately understand the transformer's operating status and potential problems.

[0076] The present invention provides a device for monitoring the leakage magnetic field of a power transformer, such as Figure 4 As shown, the following equipment is included:

[0077] A composite nanogenerator prepared by the above-mentioned preparation method;

[0078] Signal processing system for collecting and analyzing power fluctuation data output by the generator;

[0079] a processor for processing the signal and converting the data into status information of the transformer leakage magnetic field;

[0080] The operation interface is used to display the real-time data and historical trends of the transformer leakage magnetic field, as well as to perform fault warning and performance evaluation.

[0081] The operation interface has various operation instructions. When the executable instructions are executed, the processor executes the above-mentioned embodiment of a composite nanogenerator based on bacterial cellulose composite material and its application in power transformer leakage magnetic field monitoring. The operation interface instructions are configured as follows:

[0082] According to the change of the output result of the friction-electromagnetic composite nanogenerator, the change degree of the leakage magnetic field is determined; according to the change degree of the leakage magnetic field, the fault type of the transformer is determined.

[0083] Therefore, the present invention adopts the preparation method and application of the above-mentioned bacterial cellulose-based composite nanogenerator, which utilizes the excellent mechanical properties of bacterial cellulose composite materials and the special effects of nanomaterials to convert mechanical energy and electromagnetic energy into electrical energy, and realizes real-time monitoring of the transformer leakage magnetic field by monitoring electrical energy fluctuations.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a bacterial cellulose-based composite nanogenerator, characterized in that: The following steps are involved: S1. Graphene oxide and cobalt ferrite are embedded in a bacterial cellulose matrix through solution blending technology to prepare a structurally stable composite material. S11, cutting the bacterial cellulose hydrogel into 2×2 cm block samples, stirring using a high shear homogenizer for 30 min to prepare a 10 mg / mL bacterial cellulose aqueous solution; S12, successively dispersing predetermined amounts of graphene oxide powder and cobalt ferrite powder in appropriate solvents to form uniform graphene oxide suspensions and cobalt ferrite suspensions; S13, mixing the prepared graphene oxide suspension and the cobalt ferrite suspension in an optimal ratio, and further dispersing them by ultrasonic treatment to obtain a mixed suspension in which the nanoparticles are evenly distributed; S14, slowly adding the obtained mixed suspension to the bacterial cellulose aqueous solution, and continuing to stir, so that the graphene oxide and cobalt ferrite are evenly embedded in the bacterial cellulose matrix to obtain a mixed solution; The limiting conditions for uniformly embedding graphene oxide and cobalt ferrite in the bacterial cellulose matrix in S14 include: the content of graphene oxide is limited to a range of 0.2% to 1.2% of the total mass of the composite material; the content of cobalt ferrite is limited to a range of 0.2% to 1% of the total mass of the composite material; S15, pouring the mixed solution into a mold for vacuum defoaming treatment for 10 minutes, and performing heating and drying treatment, thereby preparing a composite material with stable structure and excellent performance; S2. Systematically evaluate the electromagnetic properties, triboelectric properties, and mechanical stability of each composite material to select the optimal formula; S3. Use the composite materials with the optimal formula to prepare composite nanogenerators.

2. The method for preparing a bacterial cellulose-based composite nanogenerator according to claim 1, characterized in that: The limiting conditions for uniformly embedding graphene oxide and cobalt ferrite in the bacterial cellulose matrix in S14 include: the content of graphene oxide is limited to a range of 0.5% to 0.8% of the total mass of the composite material; the content of cobalt ferrite is limited to a range of 0.2% to 0.6% of the total mass of the composite material.

3. The method for preparing a bacterial cellulose-based composite nanogenerator according to claim 1, characterized in that: The S2 specifically includes: S21. Conduct systematic performance tests on the composite materials prepared by each formula, including electromagnetic performance tests, dielectric performance tests, triboelectric performance tests, and mechanical performance tests; S22. Statistically analyze the performance test results and use appropriate mathematical models or optimization algorithms to find the optimal balance between electromagnetic performance, triboelectric performance, and mechanical stability, thereby selecting the optimal formula; S23. Conduct stability and durability tests on the composite materials with the optimal formula to ensure the reliability and stability of the experimental results.

4. The method for preparing a bacterial cellulose-based composite nanogenerator according to claim 3, characterized in that: The S21 includes the following operations before the triboelectric performance test: A high-performance vertical contact-separation mode friction nanogenerator structure is constructed, and composite materials are used as the positive friction layer material. By comparing the output performance or surface energy of the friction nanogenerator, the appropriate negative friction layer material is selected.

5. The method for preparing a bacterial cellulose-based composite nanogenerator according to claim 4, characterized in that: The positive friction layer material and the negative friction layer material are circular samples with a diameter of 55 mm. The negative friction layer material is one of fluorinated ethylene copolymer, polyimide, and polytetrafluoroethylene.

6. The method for preparing a bacterial cellulose-based composite nanogenerator according to claim 1, characterized in that: The S3 specifically includes: S31, processing the composite material with the optimal formula screened out into a friction layer of a specific shape and size; S32. Design and prepare electromagnetic induction coils, selecting appropriate wire diameter, number of turns, and layout; S33, assembling the friction layer and the electromagnetic induction coil according to a preset layout and position to form a composite structure; S34. Electrically connect and package the composite structure to obtain a composite nanogenerator.

7. An application of a composite nanogenerator based on bacterial fiber composite material, characterized by: Application of the composite nanogenerator prepared by the preparation method according to any one of claims 1 to 6 in transformer leakage magnetic field monitoring.

8. A device for monitoring leakage magnetic field of a power transformer, characterized in that: Includes the following equipment: A composite nanogenerator prepared by the preparation method according to any one of claims 1 to 6; Signal processing system for collecting and analyzing power fluctuation data output by the generator; a processor for processing the signal and converting the data into status information of the transformer leakage magnetic field; The operation interface is used to display the real-time data and historical trends of the transformer leakage magnetic field, as well as to perform fault warning and performance evaluation.

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