A method of manufacturing a marine conductivity sensor electrode

Abstract

The application discloses a preparation method of a marine conductivity sensor electrode and the electrode, and relates to the field of sensing electrode manufacturing. The preparation method of the marine conductivity sensor electrode comprises polymer substrate carbonization treatment and carbonized substrate graphitization treatment. The preparation method of the marine conductivity sensor electrode realizes dense forming of the polymer substrate and ordered gradient conversion of the carbon structure, and is free of a mask and chemical reagent residues. The prepared electrode has high density, excellent conductive stability, outstanding seawater corrosion resistance, controllable size precision and weak polarization effect, and is suitable for the miniaturization, long-termization and high-precision marine conductivity monitoring requirements.

Description

Technical Field

[0001] This application relates to the field of sensor electrode manufacturing technology, and in particular to a method for preparing an electrode for a marine conductivity sensor. Background Technology

[0002] Marine conductivity sensing technology is a key support for marine environmental monitoring, deep-sea resource exploration, and early warning of marine engineering safety. With the rapid development of marine observation equipment towards miniaturization, long-term operation, and high precision, extremely high demands are placed on the comprehensive performance of conductivity electrodes, which are core sensing components. The conductivity stability, seawater corrosion resistance, structural density, and molding precision of the electrodes directly determine the reliability of marine conductivity monitoring data and the service life of the equipment. Carbon-based electrodes, with their advantages of controllable cost, excellent chemical inertness, and ease of precision structural fabrication, have become a key research and development direction in the field of marine conductivity sensing.

[0003] Currently, marine conductivity electrodes mainly employ three technical approaches: metal electrodes, sintered graphite electrodes, and polymer-based carbon composite electrodes. Metal electrodes exhibit excellent conductivity, but they are prone to electrochemical corrosion and metal ion dissolution in high-salt, high-pressure, and complex marine environments, causing measurement signal drift. Furthermore, the high cost of precious metal raw materials hinders large-scale application. Sintered graphite electrodes have high porosity and insufficient density, making them susceptible to impedance fluctuations due to seawater intrusion. Additionally, the sintering process makes it difficult to achieve high-precision molding of miniaturized and irregularly shaped electrodes, limiting their applicability. Traditional polymer-based carbon paste composite electrodes have a simple molding process, but the weak interfacial bonding between the carbon phase and the matrix makes them prone to pulverization and structural failure under high-temperature and seawater erosion conditions. Moreover, the uneven distribution of the carbon phase leads to poor conductivity stability, failing to meet the requirements for long-term in-situ high-precision conductivity monitoring.

[0004] To address the aforementioned technical shortcomings, there is an urgent need to improve the fabrication technology of existing marine conductivity sensor electrodes. Summary of the Invention

[0005] In view of this, this application provides a marine conductivity sensor electrode and its preparation method. The marine conductivity sensor electrode provided by this application has the characteristics of high density, high conductivity stability and excellent seawater corrosion resistance, which effectively solves the problems of low forming accuracy, weak interface bonding and easy failure in service of traditional electrodes. The prepared electrode is suitable for miniaturized and long-term marine conductivity monitoring needs and can be widely used in the field of high-end marine observation equipment.

[0006] In the first aspect, this application discloses a method for preparing an electrode for a marine conductivity sensor, the technical solution of which is as follows: A method for fabricating an electrode for a marine conductivity sensor includes the following steps: The polymer substrate material is carbonized to obtain a carbonized substrate; The carbonized substrate is graphitized to obtain an electrode for a marine conductivity sensor.

[0007] Optionally, the carbonization process is performed under laser scanning conditions, wherein the laser linewidth of the laser scanning is 5~10μm, the scanning speed is 5~10mm / s, and the power is 0.05~0.3W, and the laser used for the laser scanning is a femtosecond laser or a nanosecond laser.

[0008] Optionally, the graphitization process is performed under laser scanning conditions, wherein the laser linewidth of the laser scanning is 8~10μm, the scanning speed is 6~8mm / s, and the power is 0.05~0.15W, and the laser used for the laser scanning is a femtosecond laser or a nanosecond laser.

[0009] Optionally, the method for preparing the polymer substrate material includes the following steps: After spreading the polymer powder and molding aid on a high-temperature resistant base plate, it is smoothed with a scraper and pre-shaped at 180~220℃, and then heat-preserving and shaping at 230~250℃ to obtain the polymer base material.

[0010] Optionally, the mass ratio of the polymer powder to the molding aid is 1:0.02~0.05.

[0011] Optionally, the polymer powder is selected from one or more of polyimide powder, polytetrafluoroethylene powder, polyethylene terephthalate powder, or composite modified polymer powder.

[0012] Optionally, the molding aid is selected from one or more of polyethylene glycol, polyvinylpyrrolidone, or dibutyl phthalate.

[0013] Optionally, the pre-treatment is carried out under nitrogen protection, and the pre-treatment time is 2-3 hours.

[0014] Optionally, the heat preservation and shaping treatment is carried out under nitrogen protection, and the heat preservation and shaping treatment time is 1 to 2 hours.

[0015] Optionally, the method for preparing the composite modified polymer powder includes the following steps: Nano-silica, KH560 and anhydrous ethanol were mixed and then subjected to organic modification treatment to obtain organically modified nano-silica. The organically modified nano-silica, polyvinylpyrrolidone, and water were mixed and then subjected to organic coating treatment to obtain a composite modified polymer. The composite modified polymer is granulated and pulverized sequentially to obtain the composite modified polymer powder.

[0016] Optionally, the mass-volume ratio of the nano-silica, KH560 and anhydrous ethanol is 1g:(0.03~0.08)g:(10~20)mL.

[0017] Optionally, the particle size of the nano-silica is 50~200nm.

[0018] Optionally, the organic modification treatment is carried out under stirring conditions, with a stirring temperature of 50~70℃ and a stirring time of 3~5h.

[0019] Optionally, the mass-volume ratio of the organic modified nano-silica, polyvinylpyrrolidone and water is 1g:(0.02~0.06)g:(15~30)mL.

[0020] Optionally, the organic coating treatment is performed at a temperature of 40-60°C for 2-4 hours.

[0021] Optionally, the pulverization is carried out in a high-speed universal pulverizer with a rotation speed of 8000~12000 r / min and a time of 10~30 min.

[0022] Optionally, before spreading the polymer powder and molding aid, the polymer powder is pretreated, and the pretreatment includes the following steps: The polymer powder, anhydrous ethanol, and water are mixed and then subjected to ultrasonic treatment, followed by drying to complete the pretreatment.

[0023] Optionally, the mass-to-volume ratio of the polymer powder, anhydrous ethanol, and water is 1 g: (5~10) mL: (20~40) mL.

[0024] Optionally, the ultrasonic treatment is performed at a temperature of 40-60°C, a power of 100-300W, a frequency of 20-40kHz, and a duration of 2-4 hours.

[0025] Optionally, the drying temperature is 60~80℃ and the time is 1~2h.

[0026] Secondly, this application discloses a marine conductivity sensor electrode, which is prepared by the method for preparing marine conductivity sensor electrodes described in the aforementioned scheme.

[0027] The method for preparing marine conductivity sensor electrodes disclosed in the first aspect of this application employs an integrated process design encompassing polymer powder pretreatment, gradient temperature-controlled substrate preparation, precise laser carbonization, and laser-directed graphitization. This method scientifically combines polymer powder, composite modified powder, and molding aids, precisely controlling key parameters at each step, including the ultrasonic power and temperature of powder pretreatment, the temperature and holding time of substrate shaping, and the linewidth, speed, and power of laser carbonization and graphitization. This achieves dense molding of the polymer substrate and orderly transformation of the carbon structure, effectively solving problems such as uneven powder dispersion, weak substrate adhesion, and poor controllability of carbonization and graphitization in traditional electrode preparation. It also avoids issues such as low electrode density, insufficient conductivity stability, and deterioration in seawater corrosion resistance caused by process defects. Therefore, compared to existing technologies, the preparation method provided in this application has advantages such as strong process controllability, excellent parameter adaptability, and high preparation efficiency. Furthermore, through interface optimization of the composite modified powder and segmented laser processing, the structural integrity and overall service performance of the electrode are further improved.

[0028] The marine conductivity sensor electrode disclosed in the second aspect of this application is prepared by the aforementioned optimized preparation method. It inherits the core advantages of this preparation process in terms of structural forming and performance control, and has the characteristics of high density, excellent conductivity stability, outstanding resistance to seawater corrosion, and controllable dimensional accuracy. It effectively overcomes the defects of traditional metal electrodes that are prone to corrosion, sintered graphite electrodes that have high porosity, and conventional carbon composite electrodes that are prone to failure. It is suitable for miniaturized and long-term marine conductivity monitoring needs, and has both practicality and reliability. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a SEM image of the marine conductivity sensor electrode provided in Embodiment 1 of this application; Figure 2 This is a SEM image of the marine conductivity sensor electrode provided in Comparative Example 1 of this application. Detailed Implementation

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Furthermore, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application.

[0032] In this application, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in its actual use or operating state, specifically the orientation shown in the accompanying drawings; while "inner" and "outer" refer to the outline of the device. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc., are used merely as illustrative purposes and do not impose numerical requirements or establish a numerical order.

[0033] In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural.

[0034] In this application, "at least one" means one or more, and "more than one" means two or more. "One or more", "at least one of the following", or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0035] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a rigid limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0036] The present application will be specifically described below through specific embodiments. The following embodiments are only some embodiments of the present application and are not intended to limit the present application.

[0037] In a first aspect, this application discloses a method for preparing an electrode for a marine conductivity sensor, comprising the following steps: The polymer substrate material is carbonized to obtain a carbonized substrate; The carbonized substrate is graphitized to obtain an electrode for a marine conductivity sensor.

[0038] In some embodiments, the carbonization process is performed under laser scanning conditions. The laser linewidth is 5-10 μm, the scanning speed is 5-10 mm / s, and the power is 0.05-0.3 W. The laser used for scanning is a femtosecond laser or a nanosecond laser. Laser carbonization only requires the power density of the laser irradiation point to exceed the carbonization temperature of the polymer substrate. By controlling the laser linewidth, scanning speed, and power, controllable carbonization of the substrate surface can be achieved, forming a uniform amorphous carbonized layer. This provides a high-quality precursor for the subsequent graphitization reaction, while avoiding substrate material peeling and structural damage caused by excessive laser energy.

[0039] In some embodiments, the graphitization process is performed under laser scanning conditions, wherein the laser linewidth of the laser scanning is 8~10μm, the scanning speed is 6~8mm / s, and the power is 0.05~0.15W, and the laser used for the laser scanning is a femtosecond laser or a nanosecond laser.

[0040] Based on the precursor characteristics of the carbonized substrate, the ordered rearrangement of carbon atoms is achieved by controlling the laser energy density, thus completing the directional transformation of amorphous carbon into the graphite phase. At the same time, the impurities remaining during the carbonization process are released in gaseous form, improving the carbon content and conductivity of the electrode. The two-step laser processing only requires low energy density to achieve the gradient transformation of the carbon structure, eliminating the risk of electrode delamination.

[0041] In some embodiments, the method for preparing the polymer substrate material includes the following steps: After spreading the polymer powder and molding aid on a high-temperature resistant base plate, it is smoothed with a scraper and pre-shaped at 180~220℃, and then heat-preserving and shaping at 230~250℃ to obtain the polymer base material.

[0042] This application employs a two-step shaping process with gradient temperature control. First, a low-temperature pre-shaping process is used to achieve the initial melting and bonding of polymer powder and molding aids to form an integral preform. Then, a high-temperature heat preservation process is used to strengthen the bonding force between the powders, making the substrate structure denser and avoiding problems such as substrate cracking and collapse during subsequent laser processing. At the same time, the scraper leveling process ensures the flatness and thickness uniformity of the substrate surface, laying the foundation for precise laser processing.

[0043] In some embodiments, the mass ratio of the polymer powder to the molding aid is 1:0.02~0.05. At this ratio, the molding aid can fully exert its shaping and binding effects, enabling the polymer powder to form a stable substrate structure. Furthermore, excessive molding aid content will not lead to excessive impurities during subsequent laser carbonization and graphitization processes, thus ensuring the carbon phase purity and overall performance of the electrode.

[0044] In some embodiments, the polymer powder is selected from one or more of polyimide powder, polytetrafluoroethylene powder, polyethylene terephthalate powder, or composite modified polymer powder. These polymer powders all possess excellent thermal stability, chemical inertness, and laser carbonization responsiveness. After carbonization, they can form a high-purity carbon-based structure, suitable for the corrosive environment of high salt and high pressure in the ocean. The composite modified polymer powder, through interface optimization with inorganic fillers, further enhances the mechanical strength and laser processing compatibility of the substrate.

[0045] In some embodiments, the molding aid is selected from one or more of polyethylene glycol, polyvinylpyrrolidone, or dibutyl phthalate. This molding aid exhibits excellent compatibility with polymer powders, can melt and form films at low temperatures to achieve powder adhesion, and can be completely decomposed or volatilized during subsequent laser processing, leaving no residual impurities and not affecting the carbon phase structure and conductivity of the electrode.

[0046] In some embodiments, the predetermined treatment is performed under nitrogen protection, and the predetermined treatment time is 2-3 hours.

[0047] In some embodiments, the heat preservation and shaping treatment is carried out under nitrogen protection conditions, and the heat preservation and shaping treatment time is 1 to 2 hours.

[0048] In this application, the nitrogen protective atmosphere can effectively prevent the polymer powder and molding aid from undergoing oxidative degradation during the high-temperature setting process, ensuring the structural integrity and compositional uniformity of the substrate. The preset holding time can allow the melt bonding reaction to proceed fully, avoiding insufficient substrate bonding due to inadequate setting.

[0049] In some embodiments, the method for preparing the composite modified polymer powder includes the following steps: Nano-silica, KH560 and anhydrous ethanol were mixed and then subjected to organic modification treatment to obtain organically modified nano-silica. The organically modified nano-silica, polyvinylpyrrolidone, and water were mixed and then subjected to organic coating treatment to obtain a composite modified polymer. The composite modified polymer is granulated and pulverized sequentially to obtain the composite modified polymer powder.

[0050] This application prepares composite modified polymer powder through an organic modification, organic coating, granulation and pulverization process. First, KH560 is used to modify the surface of nano-silica to improve its compatibility with the organic phase. Then, polyvinylpyrrolidone is used for dense coating to form an inorganic-organic composite structure. Finally, the polymer substrate is pulverized to make the nano-silica uniformly dispersed in the polymer powder, thereby achieving a simultaneous improvement in the mechanical strength and thermal stability of the substrate.

[0051] In some embodiments, the mass-to-volume ratio of the nano-silica, KH560 and anhydrous ethanol is 1 g : (0.03~0.08) g : (10~20) mL.

[0052] In some embodiments, the particle size of the nano-silica is 50~200nm.

[0053] By limiting the dosage ratio and the particle size of nano-silica, this application can ensure that after modification with KH560, the surface of nano-silica can be grafted with a sufficient amount of organic functional groups, achieving a tight bond with the polymer phase. Anhydrous ethanol as a dispersion medium can ensure the uniform mixing of nano-silica and KH560, avoiding the agglomeration of inorganic powders.

[0054] In some embodiments, the organic modification treatment is carried out under stirring conditions, with a stirring temperature of 50~70℃ and a stirring time of 3~5h. Under these conditions, the covalent bonding reaction between KH560 and the hydroxyl groups on the surface of nano-silica can be promoted, achieving efficient modification of nano-silica. The stirring action further ensures the homogeneity of the reaction system, making the functional groups on the surface of the modified nano-silica uniformly distributed.

[0055] In some embodiments, the mass-volume ratio of the organic modified nano-silica, polyvinylpyrrolidone and water is 1 g: (0.02~0.06) g: (15~30) mL.

[0056] In some embodiments, the organic coating treatment is performed at a temperature of 40-60°C for 2-4 hours.

[0057] In this application, polyvinylpyrrolidone can form a dense organic coating layer on the surface of organically modified nano-silica through intermolecular forces. Water is used as a dispersion medium to ensure the uniformity of the coating reaction. The preset temperature and time can make the coating layer and the inorganic core tightly bonded, thereby improving the dispersion stability of the composite powder.

[0058] In some embodiments, the pulverization is carried out in a high-speed universal pulverizer at a speed of 8000~12000 r / min for 10~30 min. High-speed pulverization can prepare the composite material into powder with uniform particle size. The particle size of the powder under these pulverization parameters is suitable for the subsequent powder spreading and shaping process, with no large particle agglomerates, ensuring the uniformity of the substrate formation.

[0059] In some embodiments, before spreading the polymer powder and molding aid, the polymer powder is pretreated, and the pretreatment includes the following steps: The polymer powder, anhydrous ethanol, and water are mixed and then subjected to ultrasonic treatment, followed by drying to complete the pretreatment.

[0060] This application utilizes an ultrasonic cleaning and drying pretreatment process to effectively remove impurities such as dust and oil from the surface of polymer powder, thereby improving the cleanliness of the powder. At the same time, the ultrasonic dispersion effect can break up slight agglomerations of the powder, ensuring the uniformity of subsequent powder spreading and preventing impurities and agglomerates from causing substrate molding defects.

[0061] In some embodiments, the mass-to-volume ratio of the polymer powder, anhydrous ethanol, and water is 1 g : (5~10) mL : (20~40) mL. This mixed solvent ratio can fully wet the polymer powder, achieving efficient removal of surface impurities, without causing powder loss or excessive drying time due to excessive solvent usage, thus balancing cleaning effect and process efficiency.

[0062] In some embodiments, the ultrasonic treatment is performed at a temperature of 40-60°C, a power of 100-300W, a frequency of 20-40kHz, and a duration of 2-4 hours. The cavitation and mechanical vibration effects of ultrasound can achieve efficient removal of impurities from the powder surface. The preset temperature, power, and time can ensure the cleaning effect while avoiding damage to the polymer powder structure caused by excessive ultrasonic energy.

[0063] In some embodiments, the drying temperature is 60~80℃ and the time is 1~2 hours. Low-temperature vacuum drying can quickly remove the solvent from the surface of the polymer powder, while preventing the powder from thermally sticking due to high temperature, ensuring the looseness of the pretreated powder, and adapting it to the subsequent powder spreading and shaping process.

[0064] It should be noted that the preparation method of the marine conductivity sensor electrode in this application adopts an integrated process design of polymer powder pretreatment gradient temperature-controlled shaping substrate preparation laser precise carbonization and laser directional graphitization. By compatibility of polymer powder, composite modified powder and molding aid, and control of process parameters in each step, the dense molding of polymer substrate and orderly gradient transformation of carbon structure are achieved. This method effectively solves the technical problems of uneven powder dispersion, weak substrate bonding and poor controllability of carbonization and graphitization in traditional electrode preparation. It avoids the problems of low electrode density, insufficient conductivity stability and deterioration of seawater corrosion resistance caused by process defects. Moreover, the entire preparation process is maskless and leaves no chemical reagent residues. The process is highly controllable, has excellent parameter adaptability, high preparation efficiency, and smooth connection between each step, making it easy to promote industrialization. The process parameters can be flexibly adjusted according to the specifications and performance requirements of the electrode, and it is suitable for the preparation of various marine conductivity sensor electrodes such as two-electrode, four-electrode, and seven-electrode electrodes.

[0065] Secondly, this application discloses a marine conductivity sensor electrode, which is prepared by the method for preparing marine conductivity sensor electrodes described in the aforementioned scheme.

[0066] The marine conductivity sensor electrode of this application inherits the core advantages of its fabrication process in structural shaping and performance control. The substrate, shaped by gradient temperature control, exhibits high density and structural stability. Combined with the ordered transformation of carbon structure achieved through two-step laser processing, the electrode forms a uniform graphitic carbon-based structure, characterized by high density, excellent conductivity stability, outstanding resistance to seawater corrosion, and controllable dimensional accuracy. Simultaneously, the application of composite modified polymer powder further enhances the mechanical strength and structural integrity of the electrode, preventing failure issues such as cracking, pulverization, and detachment in the high-salt, high-pressure, and water-erosion environment of the ocean. Compared with traditional metal electrodes, sintered graphite electrodes, and conventional carbon composite electrodes, the marine conductivity sensor electrode of this application effectively overcomes the defects of metal electrodes, such as easy corrosion and measurement drift caused by ion dissolution; sintered graphite electrodes, such as high porosity and large impedance fluctuations; and conventional carbon composite electrodes, such as weak interfacial bonding and short service life. It also has low manufacturing cost and strong anti-fouling ability, and is suitable for the miniaturized, long-term, and high-precision marine conductivity monitoring needs. It can be widely used in conductivity sensors in the fields of marine environmental monitoring, deep-sea resource exploration, and marine engineering safety early warning, and has both practicality and reliability.

[0067] The present application will be specifically described below through specific embodiments. The following embodiments are only some embodiments of the present application and are not intended to limit the present application. Example 1

[0068] This embodiment provides a method for preparing an electrode for a marine conductivity sensor, comprising the following steps: The polyimide polymer substrate material is placed on the high-precision displacement platform of the laser processing system and carbonized using a femtosecond laser with a laser linewidth of 5μm, a scanning speed of 5mm / s, and a power of 0.05W to form a carbonized substrate. The carbonized substrate was then placed on a high-precision displacement platform and graphitized using a femtosecond laser with a linewidth of 8 μm, a scanning speed of 6 mm / s, and a power of 0.05 W, to obtain the electrode for the marine conductivity sensor.

[0069] The preparation method of the polyimide polymer substrate material includes the following steps: 100g of polyimide powder, 500mL of anhydrous ethanol and 2000mL of water were mixed and ultrasonically treated for 2h at 40℃, 100W and 20kHz. Then it was dried at 60℃ for 1h. Then it was mixed with 2g of polyethylene glycol, spread evenly on a high-temperature resistant base plate and smoothed with a scraper. It was pre-shaped at 180℃ under nitrogen protection for 2h, and then heat-set at 230℃ under nitrogen protection for 1h to obtain the polyimide polymer base material. Example 2

[0070] This embodiment provides a method for preparing an electrode for a marine conductivity sensor, comprising the following steps: The polytetrafluoroethylene polymer substrate material is placed on the high-precision displacement platform of the laser processing system and carbonized using a nanosecond laser with a laser linewidth of 8μm, a scanning speed of 8mm / s, and a power of 0.2W to form a carbonized substrate. The carbonized substrate was then placed on a high-precision displacement platform and graphitized using a nanosecond laser with a linewidth of 9 μm, a scanning speed of 7 mm / s, and a power of 0.1 W, to obtain the electrode for the marine conductivity sensor.

[0071] The preparation method of the polytetrafluoroethylene polymer substrate material includes the following steps: 100g of polytetrafluoroethylene powder, 800mL of anhydrous ethanol and 3000mL of water were mixed and ultrasonically treated for 3h at 50℃, 200W and 30kHz. Then it was dried at 70℃ for 1.5h. Then it was mixed with 4g of polyvinylpyrrolidone, spread evenly on a high-temperature resistant base plate and smoothed with a scraper. It was pre-shaped at 200℃ under nitrogen protection for 2.5h, and then heat-set at 240℃ under nitrogen protection for 1.5h to obtain polytetrafluoroethylene polymer base material. Example 3

[0072] This embodiment provides a method for preparing an electrode for a marine conductivity sensor, comprising the following steps: Polyethylene terephthalate (PET) polymer substrate material is placed on a high-precision displacement platform of a laser processing system and carbonized using a femtosecond laser with a laser linewidth of 10 μm, a scanning speed of 10 mm / s, and a power of 0.3 W to form a carbonized substrate. The carbonized substrate was then placed on a high-precision displacement platform and graphitized using a femtosecond laser with a linewidth of 10 μm, a scanning speed of 8 mm / s, and a power of 0.15 W, to obtain the electrode for the marine conductivity sensor.

[0073] The preparation method of the polyethylene terephthalate polymer substrate material includes the following steps: 100g of composite modified polymer powder, 1000mL of anhydrous ethanol and 4000mL of water were mixed and ultrasonically treated at 60℃, 300W and 40kHz for 4h. Then it was dried at 80℃ for 2h. Then it was mixed with 5g of dibutyl phthalate, spread evenly on a high-temperature resistant base plate and smoothed with a scraper. It was pre-shaped at 220℃ under nitrogen protection for 3h, and then heat-set at 250℃ under nitrogen protection for 2h to obtain polyethylene terephthalate polymer base material.

[0074] The method for preparing the composite modified polymer powder includes the following steps: 20g of nano-silica with a particle size of 200nm, 1.6g of KH560 and 400mL of anhydrous ethanol were mixed and organically modified for 5h under stirring at 70℃ to obtain organically modified nano-silica. 20g of the organically modified nano-silica, 1.2g of polyvinylpyrrolidone, and 600mL of water were mixed and organically coated at 60°C for 4h to obtain a composite modified polymer. 20g of the composite modified polymer was placed in a high-speed universal pulverizer at 260°C and pulverized at 12000r / min for 30min to obtain composite modified polymer powder. Comparative Example 1

[0075] This comparative example provides a method for preparing an electrode for a marine conductivity sensor, comprising the following steps: The polyimide polymer substrate material was placed on the high-precision displacement platform of the laser processing system and carbonized using a femtosecond laser with a laser linewidth of 5μm, a scanning speed of 5mm / s, and a power of 0.05W to obtain the electrode for the marine conductivity sensor.

[0076] The preparation method of the polyimide polymer substrate material includes the following steps: Mix 100g of polyimide powder with 2g of polyethylene glycol, spread the mixture evenly on a high-temperature resistant substrate, and then scrape it flat. Pre-shape the mixture for 2 hours under nitrogen protection and at 180°C, and then heat-set the mixture for 1 hour under nitrogen protection and at 230°C to obtain the polyimide polymer substrate material. Comparative Example 2

[0077] This comparative example provides a method for preparing an electrode for a marine conductivity sensor, comprising the following steps: The polytetrafluoroethylene polymer substrate material is placed on the high-precision displacement platform of the laser processing system and carbonized using a nanosecond laser with a laser linewidth of 8μm, a scanning speed of 8mm / s, and a power of 0.2W to form a carbonized substrate. The carbonized substrate was then placed on a high-precision displacement platform and graphitized using a nanosecond laser with a linewidth of 9 μm, a scanning speed of 7 mm / s, and a power of 0.1 W, to obtain the electrode for the marine conductivity sensor.

[0078] The preparation method of the polytetrafluoroethylene polymer substrate material includes the following steps: Mix 100g of polytetrafluoroethylene powder with 4g of polyvinylpyrrolidone, spread the mixture evenly on a high-temperature resistant base plate, and then scrape it smooth with a scraper. Pre-shape the mixture for 2.5h under nitrogen protection and at 200℃, and then heat-set the mixture for 1.5h under nitrogen protection and at 240℃ to obtain the polytetrafluoroethylene polymer base material.

[0079] The marine conductivity sensor electrodes prepared in Examples 1-3 and Comparative Examples 1-2 were tested for density, conductivity stability, seawater corrosion resistance, dimensional accuracy, and electrode polarization effect. Seawater corrosion resistance was measured as the performance retention rate after immersion in a simulated high-salt seawater environment for 30 days. Conductivity stability was measured as the impedance fluctuation value after continuous monitoring for 72 hours. Dimensional accuracy was measured as the deviation between the actual size of the formed electrode and the designed size. Electrode polarization effect was measured as the polarization potential of the electrode during operation. The test results are shown in Table 1.

[0080] Table 1

[0081] The technical solutions provided by the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for preparing an electrode for a marine conductivity sensor, characterized in that, Includes the following steps: The polymer substrate material is carbonized to obtain a carbonized substrate; The carbonized substrate is graphitized to obtain an electrode for a marine conductivity sensor.

2. The method for preparing the marine conductivity sensor electrode according to claim 1, characterized in that, The carbonization process is performed under laser scanning conditions. The laser linewidth of the laser scanning is 5~10μm, the scanning speed is 5~10mm / s, and the power is 0.05~0.3W. The laser used for the laser scanning is a femtosecond laser or a nanosecond laser.

3. The method for preparing the marine conductivity sensor electrode according to claim 1, characterized in that, The graphitization process is performed under laser scanning conditions. The laser linewidth of the laser scanning is 8~10μm, the scanning speed is 6~8mm / s, and the power is 0.05~0.15W. The laser used for the laser scanning is a femtosecond laser or a nanosecond laser.

4. The method for preparing the marine conductivity sensor electrode according to claim 1, characterized in that, The method for preparing the polymer substrate material includes the following steps: After spreading the polymer powder and molding aid on a high-temperature resistant base plate, it is smoothed with a scraper and pre-shaped at 180~220℃, and then heat-preserving and shaping at 230~250℃ to obtain the polymer base material.

5. The method for preparing the marine conductivity sensor electrode according to claim 4, characterized in that, The mass ratio of the polymer powder to the molding aid is 1:0.02~0.05; and / or The polymer powder is selected from one or more of polyimide powder, polytetrafluoroethylene powder, polyethylene terephthalate powder, or composite modified polymer powder; and / or The molding aid is selected from one or more of polyethylene glycol, polyvinylpyrrolidone, or dibutyl phthalate; and / or The pre-treatment is carried out under nitrogen protection for 2-3 hours; and / or The heat preservation and shaping treatment is carried out under nitrogen protection conditions, and the heat preservation and shaping treatment time is 1~2 hours.

6. The method for preparing the marine conductivity sensor electrode according to claim 5, characterized in that, The method for preparing the composite modified polymer powder includes the following steps: Nano-silica, KH560 and anhydrous ethanol were mixed and then subjected to organic modification treatment to obtain organically modified nano-silica. The organically modified nano-silica, polyvinylpyrrolidone, and water were mixed and then subjected to organic coating treatment to obtain a composite modified polymer. The composite modified polymer is granulated and pulverized sequentially to obtain the composite modified polymer powder.

7. The method for preparing the marine conductivity sensor electrode according to claim 6, characterized in that, The mass-to-volume ratio of the nano-silica, KH560, and anhydrous ethanol is 1 g : (0.03~0.08) g : (10~20) mL; and / or The particle size of the nano-silica is 50~200nm; and / or The organic modification treatment is carried out under stirring conditions, with a stirring temperature of 50~70℃ and a stirring time of 3~5h; and / or The mass-to-volume ratio of the organically modified nano-silica, polyvinylpyrrolidone, and water is 1 g : (0.02~0.06) g : (15~30) mL; and / or The organic coating treatment is performed at a temperature of 40-60°C for 2-4 hours; and / or The pulverization is carried out in a high-speed universal pulverizer with a rotation speed of 8000~12000 r / min and a time of 10~30 min.

8. The method for preparing the marine conductivity sensor electrode according to claim 4, characterized in that, Before spreading the polymer powder and molding aid, the polymer powder is pretreated, and the pretreatment includes the following steps: The polymer powder, anhydrous ethanol, and water are mixed and then subjected to ultrasonic treatment, followed by drying to complete the pretreatment.

9. The method for preparing the marine conductivity sensor electrode according to claim 8, characterized in that, The mass-to-volume ratio of the polymer powder, anhydrous ethanol, and water is 1 g : (5~10) mL : (20~40) mL; and / or The ultrasonic treatment is performed at a temperature of 40-60℃, a power of 100-300W, a frequency of 20-40kHz, and a duration of 2-4 hours; and / or The drying temperature is 60~80℃, and the time is 1~2 hours.

10. An electrode for a marine conductivity sensor, characterized in that, It is prepared by the method for preparing the marine conductivity sensor electrode according to any one of claims 1 to 9.

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