A method for preparing a carbon fiber probe

Abstract

The embodiment of this specification discloses a method for preparing a carbon fiber probe. The method comprises inserting a carbon fiber into a glass tip with a conical opening tip; using epoxy resin glue to seal and bond the carbon fiber and the glass tip, and allowing one end of the carbon fiber to partially leak out of the conical opening tip; using hot melt glue to cover the partial carbon fiber, and leaking out the tail end of the partial carbon fiber; fixing the sealed glass tip and the carbon fiber as a whole, and polishing one end of the carbon fiber to a smooth plane in cross section; using conductive silver glue to connect a metal wire to the other end of the carbon fiber, thereby forming a carbon fiber probe with one end of the polished carbon fiber as the working electrode and the metal wire as the electrode outlet. The manufacturing process is low-cost and simple to process. The manufactured carbon fiber probe has a flat and smooth interface, stable performance itself, and more accurate subsequent measurement results.

Description

Technical Field

[0001] This specification relates to the field of corrosion electrochemistry, and in particular to a method for preparing a carbon fiber probe. Background Art

[0002] Micro-area scanning electrochemical technology is often used for non-contact micro-area morphology and electrochemical micro-area testing, and has high measurement resolution and spatial resolution. Experiments usually use microelectrodes with a diameter of less than 100μm as probes. Currently common probe manufacturing methods include mechanical forming, electrochemical corrosion, electron beam deposition, ion beam milling, and field evaporation. The conventionally manufactured probe tip often uses laser sintering and physical cutting methods to remove excess hot melt adhesive at the front end to expose the needle cross section, resulting in deformation of the probe cross section. This may cause subsequent electrochemical information measurements due to unstable contact between the probe and the material being measured, resulting in distorted measurement results.

[0003] Based on this, a more precise preparation scheme for carbon fiber probes is needed. Summary of the Invention

[0004] The embodiments of this specification provide a method for preparing a carbon fiber probe to solve the following technical problem: a more accurate method for preparing a carbon fiber probe is required.

[0005] To solve the above technical problems, the present invention provides a method for preparing a carbon fiber probe, comprising:

[0006] The carbon fiber is inserted into a glass tip having a conical opening tip;

[0007] The carbon fiber and the glass tip are sealed and glued together using epoxy resin glue, and one end of the carbon fiber is exposed from the conical opening tip to partially expose the carbon fiber;

[0008] Using hot melt adhesive to cover the portion of carbon fibers, and leaving the tail end portion of the portion of carbon fibers exposed;

[0009] Fixing the sealed glass tip and carbon fiber as a whole, and polishing one end of the carbon fiber until the cross section is a smooth plane;

[0010] Conductive silver glue is used to connect the metal wire to the other end of the carbon fiber to form a carbon fiber probe with one end of the polished carbon fiber as a working electrode and the metal wire as an electrode outlet.

[0011] At least one of the above technical solutions adopted in one or more embodiments of this specification can achieve the following beneficial effects: by inserting carbon fiber into a glass tip with a conical opening tip; using epoxy resin glue to seal and bond the carbon fiber and the glass tip, and allowing one end of the carbon fiber to partially leak out of the conical opening tip; using hot melt glue to cover the partial carbon fiber, and leaking out the tail end of the partial carbon fiber; fixing the sealed glass tip and carbon fiber as a whole, and polishing one end of the carbon fiber to a smooth plane in cross section; using conductive silver glue to connect a metal wire to the other end of the carbon fiber, forming a carbon fiber probe with one end of the polished carbon fiber as the working electrode and the metal wire as the electrode outlet. The manufacturing process is low-cost and simple to process. The manufactured carbon fiber probe has a flat and smooth interface, more stable performance, and more accurate subsequent measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0013] Figure 1 A schematic flow chart of a method for preparing a carbon fiber probe provided in an embodiment of this specification;

[0014] Figure 2 A schematic diagram of the preparation of a glass tip provided in an embodiment of this specification;

[0015] Figure 3 A schematic diagram of polishing a cross section of a probe provided in an embodiment of this specification;

[0016] Figure 4 This is a schematic diagram of the structure of the carbon fiber probe prepared in the examples of this specification;

[0017] Figure 5 A schematic diagram comparing the stability of the polished carbon fiber probe provided in the examples of this specification and the conventionally prepared probe under neutral conditions;

[0018] Figure 6 This is a comparative example diagram of the bending resistance of the polished carbon fiber probe provided in the embodiment of this specification and the conventionally prepared probe;

[0019] Figure 7 This is a schematic diagram of the measurement of the probe provided in the embodiment of this specification in a strong acid environment with a pH value of 0.5;

[0020] Figure 8 This is a schematic diagram of the measurement of the probe provided in the embodiments of this specification in a strong alkaline environment with a pH value of 13.5. DETAILED DESCRIPTION

[0021] The embodiments of this specification provide a method for preparing a carbon fiber probe.

[0022] In order to help those skilled in the art better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this specification, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0023] like Figure 1 As shown, Figure 1 The process diagram of a method for preparing a carbon fiber probe provided in the embodiment of this specification specifically includes:

[0024] S201: Insert the carbon fiber into a glass tip having a conical opening tip.

[0025] A glass tip with a conical opening can be made as follows: Figure 2 As shown, Figure 2 This is a schematic diagram of the preparation of a glass tip provided in an embodiment of this specification. The glass probe in this figure is a prepared glass tip with a conical opening tip.

[0026] Pass a 0.9-1.0 mm glass capillary through the Figure 2 The fixed platform is mounted on the guide rails shown and securely clamped with alligator clips. A hot runner spring heater coil is fixed to the center of the capillary. When heated, the center of the glass capillary melts and is pulled apart by the counterweight, ultimately forming a glass tip with a conical opening. A single carbon fiber with a diameter of 7 μm is inserted into the glass capillary, leaving approximately 2 mm of the fiber exposed on the side of the glass tip.

[0027] The diameter of the conical opening of the glass tip is usually slightly larger than the diameter of the carbon fiber to facilitate subsequent fixation of the carbon fiber and the glass tip. For example, the diameter of the conical opening can be 8 μm.

[0028] When using carbon fiber as a probe, since the diameter of the carbon fiber is uniformly standardized and has the same effective working area, the preparation is repeatable and is not affected by human operation and environmental factors.

[0029] S203, using epoxy resin glue to seal the carbon fiber and the glass tip, and letting one end of the carbon fiber partially leak out of the conical opening tip.

[0030] After the carbon fiber is inserted into the glass tip, one end of the carbon fiber can be pre-exposed from the conical opening tip to form a portion of the carbon fiber having a preset length. For example, the preset length can be 2 mm or shorter, that is, the length of the exposed portion of the carbon fiber does not exceed 2 mm.

[0031] Specifically, epoxy resin glue can be such as epoxy resin AB glue. For example, epoxy resin AB glue is prepared according to the weight ratio of component A: component B of 3:1. After stirring evenly, the bubbles in the epoxy resin are removed by ultrasonic treatment for 3 minutes. An appropriate amount of epoxy resin is absorbed with a rubber-tipped dropper and squeezed into the interface between the carbon fiber and the glass tip so that the epoxy resin glue rises at the tip of the conical opening. The carbon fiber is sealed at the probe tip by capillary phenomenon, and the position of the carbon fiber is fixed to prevent water and other unknown substances from entering the glass tip. After waiting for 10 hours, the epoxy resin is completely cured to seal the carbon fiber and the glass tip, thereby achieving sealing and fixation of the carbon fiber and the glass tip.

[0032] S205, using hot melt adhesive to cover the portion of carbon fibers, and leaving the tail end portion of the portion of carbon fibers exposed.

[0033] Then, the hot melt glue stick can be heated, and the hot melt glue gun trigger can be used to extrude the hot melt glue. The leaked part of the carbon fiber is fully soaked with hot melt glue and then quickly pulled upward, so that the surface of the part of the carbon fiber is wrapped with a layer of uniformly thinned hot melt glue. After cooling, the end of the carbon fiber is cut with a razor blade so that only the cross-section of the tail end of the carbon fiber wrapped with hot melt glue is exposed to the environment. The cross-section of the exposed tail end of the carbon fiber is immersed in the electrolyte during the electrochemical test, and forms a current signal path with the counter electrode through the electrolyte. At the same time, the rest of the tail section of the carbon fiber is insulated and wrapped with hot melt glue to avoid affecting the current signal.

[0034] S207, fixing the sealed glass tip and carbon fiber as a whole, and polishing one end of the carbon fiber until the cross section is a smooth plane.

[0035] The sealed glass tip and carbon fiber can be fixed as a whole by physical fixation, that is,

[0036] Alternatively, the sealed glass tip and carbon fiber can be placed as a whole in a plastic tube filled with water and frozen; then the carbon fiber in the frozen plastic tube can be polished on sandpaper.

[0037] End to a smooth surface. Figure 3 As shown, Figure 3 This is a schematic diagram of polishing a cross-section of a probe provided in an embodiment of this specification. The sealed glass tip and carbon fiber are placed in a larger plastic tube filled with water. They are then placed in a refrigerator and frozen until the ice completely covers the entire probe. Afterwards, the probe is slowly polished on sandpaper.

[0038] Move the tip of the carbon fiber and the ice and plastic tube until the cross section of the carbon fiber is observed, ensuring that the carbon fiber is smooth and flat, and expose the smooth flat cross section to the environment.

[0039] The smooth plane here means that the cross section obtained by grinding should be a smooth cross section parallel to the outlet of the glass tip, or in other words, the part of carbon fiber leaking out of the tip should be a cylinder with a smooth cross section after grinding.

[0040] S209, using conductive silver glue to connect the metal wire to the other end of the carbon fiber to form a carbon fiber probe with one end of the polished carbon fiber 5 as the working electrode and the metal wire as the electrode outlet.

[0041] Specifically, metal wires such as copper wires, silver wires, etc. can be used.

[0042] For example, you can use an OK wire with the inner copper wire exposed, and insert the copper wire into the conductive silver glue so that the conductive silver glue adheres to the surface of the copper wire. Insert the copper wire with the conductive silver glue from the tail of the probe and connect it with the carbon fiber in the glass tip to form a conductive connection.

[0043] The OK wire at the other end is connected as the electrode interface, and hot melt glue is squeezed into the interface between the OK wire and the probe tail to fix the OK wire position, thereby forming a carbon fiber probe with the tip of the carbon fiber as the working electrode and the metal wire as the electrode outlet. Figure 4 As shown, Figure 4 This is a schematic diagram of the structure of the prepared carbon fiber probe provided in the examples of this specification.

[0044] Optionally, after the aforementioned carbon fiber probe is prepared, the carbon fiber probe can be placed in a pipette as a whole with only one end of the polished carbon fiber exposed, and the carbon fiber probe and the pipette can be fixed with hot melt adhesive to prepare a stable carbon fiber probe.

[0045] The method involves inserting a carbon fiber into a glass tip with a conical opening; sealing the carbon fiber and the glass tip with epoxy resin, allowing one end of the carbon fiber to partially protrude from the conical opening; coating the portion of the carbon fiber with hot melt adhesive, allowing the tail portion of the portion of the carbon fiber to protrude; fixing the sealed glass tip and carbon fiber as a whole, and polishing one end of the carbon fiber to a smooth cross-section; and connecting a metal wire to the other end of the carbon fiber with conductive silver glue to form a carbon fiber probe with one end of the polished carbon fiber as the working electrode and the metal wire as the electrode outlet. The manufacturing process is low-cost and simple to process. The resulting carbon fiber probe has a flat and smooth interface, more stable performance, and more accurate subsequent measurement results.

[0046] The probe is prepared by conventional physical cutting. Laser sintering and physical cutting are generally used when the probe leaks. Both methods will cause the insulation layer at the probe tip to deform, which may lead to a gap between the needle tip and the insulation layer. When the probe is tested in a solution, the solution may penetrate into the gap.

[0047] This causes the measuring surface of the probe to be transformed from a leaky regular cross section into a larger irregular column, which will greatly affect the stability of the measurement results. This will have a greater impact in a strong acid and strong base environment. In a strong acid (pH value less than 1) or strong base (pH value greater than 13) solution environment, long-term strong acid and strong base environment will cause more significant corrosion to the insulation test. The probe prepared by general physical cutting is difficult to work continuously in this environment, while the embodiment of this specification can perform stable electrochemical information measurement in a strong acid and strong base environment.

[0048] To verify the probes prepared in the examples of this specification, the following performance tests may be performed subsequently: stability comparison test under neutral conditions, bending resistance comparison test, and measurement test under strong acid and strong base environments.

[0049] like Figure 5 As shown, Figure 5 This is a schematic diagram comparing the stability of the polished carbon fiber probe provided in the examples of this specification with that of a conventionally prepared probe under neutral conditions. As can be seen in this diagram, the electrochemical performance fluctuations of the polished carbon fiber probe are smaller, meaning the measurement results are more stable.

[0050] like Figure 6 As shown, Figure 6 This is a comparative example diagram of the bending resistance of the polished carbon fiber probe provided in the embodiments of this specification and the probe prepared in a conventional manner.

[0051] The specific method of the anti-bending experiment is: ten fishing lines are fixed on the surface of the m370 test sample with epoxy resin as obstacles, and the probes to be tested (including polished carbon fiber probes and conventionally prepared probes) are replaced with the probes of the m370 equipment, and the anti-bending experiment is carried out with the help of the M370 micro-area scanning electrochemical test system. The size of the X-axis scanning area is set according to the obstacle area on the test sample, and the Y-axis scanning area is set to 450μm. The scan is performed every 50μm, that is, a total of 10 back and forths. The height of the probe is adjusted so that the probe bends when passing through the obstacle. Each time the scanning test system can control the probe to go back and forth through the artificially designed obstacle, a total of 200 times, and then the electrochemical performance stability test is carried out with reference to the above steps. The experiment is repeated until the cumulative number of bending times reaches 2000 times. The experimental results show that the probes prepared in the embodiments of this specification have stronger bending resistance.

[0052] exist Figure 5 and Figure 6 The carbon fiber probe prepared by the freeze polishing method in this application is obtained, and the probe prepared by the physical cutting method is obtained by conventional methods. Part A shows the open circuit potential test results, Part B shows the self-corrosion potential test results, Part C shows the self-corrosion current density test results, and Part D shows the impedance value test results.

[0053] like Figure 7 and Figure 8 As shown, Figure 7 This is a schematic diagram of the measurement of the probe provided in the embodiment of this specification in a strong acid environment with a pH value of 0.5; Figure 8 This is a schematic diagram of the measurement of the probe provided in the embodiment of this specification in a strong alkaline environment with a pH value of 13.5. Part A is the open circuit potential test result, Part B is the self-corrosion potential test result, Part C is the self-corrosion current density test result, and Part D is the impedance value test result.

[0054] Specifically, a 3.5wt% sodium chloride solution can be used as the electrolyte to prepare a strongly acidic solution with a pH value below 1 or a strongly alkaline solution with a pH value above 13. A three-electrode system is constructed, with the other probe electrode as the counter electrode, the saturated calomel electrode as the reference electrode, and the probe as the working electrode, to conduct strong acid and strong base environment testing.

[0055] Specific tests include open circuit potential, self-corrosion potential, self-corrosion current density, and impedance value tests. The test results show that the performance of the probe can remain stable even in strong acid or strong base environments.

[0056] The various embodiments in this specification are described in a progressive manner. Similar portions between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from the other embodiments. In particular, the device, apparatus, and non-volatile computer storage medium embodiments are generally similar to the method embodiments, so their descriptions are relatively simplified. For relevant details, refer to the descriptions of the method embodiments.

[0057] The foregoing description of this specification describes specific embodiments. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in an order different from that described in the embodiments and still achieve the desired results. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the specific order shown or the sequential order to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0058] The foregoing description is merely one or more embodiments of this specification and is not intended to limit this specification. It will be apparent to those skilled in the art that various modifications and variations may be made to one or more embodiments of this specification. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of one or more embodiments of this specification are intended to be within the scope of the claims of this specification.

Claims

1. A method for preparing a carbon fiber probe, comprising: The carbon fiber is inserted into a glass tip having a conical opening tip; The carbon fiber and the glass tip are sealed and glued together using epoxy resin glue, and one end of the carbon fiber is exposed from the conical opening tip to partially expose the carbon fiber; Using hot melt adhesive to cover the portion of carbon fibers, and leaving the tail end portion of the portion of carbon fibers exposed; The sealed glass tip and carbon fiber are placed as a whole in a plastic tube filled with water and frozen, and one end of the carbon fiber in the frozen plastic tube is polished on sandpaper to a smooth plane. The smooth plane means that the polished cross-section should be a smooth cross-section parallel to the outlet of the glass tip, or the portion of the carbon fiber leaking out of the tip should be a cylinder with a smooth cross-section after polishing; Conductive silver glue is used to connect the metal wire to the other end of the carbon fiber to form a carbon fiber probe with one end of the polished carbon fiber as the working electrode and the metal wire as the electrode outlet.

2. The method according to claim 1, wherein The glass tip with a conical opening tip is prepared in the following manner: Fix the glass capillary in the middle of the hot runner spring heating coil; The glass capillary is heated by applying electricity, so that the middle portion of the capillary is melted and the glass capillary is broken, thereby forming a glass tip with a conical opening tip.

3. The method according to claim 1, wherein the carbon fiber and the glass tip are sealed and bonded with epoxy resin glue, comprising: Epoxy resin is sucked up using a rubber-tipped dropper and squeezed into the interface between the carbon fiber and the glass tip so that the epoxy resin glue rises at the tip of the conical opening, and the epoxy resin is cured to seal and glue the carbon fiber and the glass tip.

4. The method according to claim 1, wherein The length of the leaked carbon fiber does not exceed 2 mm.

5. The method according to claim 1, wherein the hot melt adhesive is used to cover the portion of the carbon fibers and the tail end of the portion of the carbon fibers is exposed, comprising: The leaked carbon fiber is fully soaked with hot melt adhesive and pulled upward so that the surface of the carbon fiber is wrapped with a uniformly thinned layer of hot melt adhesive. After cooling, the end of the carbon fiber is cut so that only the cross section of the carbon fiber wrapped with hot melt adhesive is exposed to the environment.

6. The method of claim 1, further comprising: The entire carbon fiber probe is placed into a pipette with only one end of the polished carbon fiber exposed, and the carbon fiber probe and the pipette are fixed with hot melt adhesive.

7. The method of claim 1, wherein: The method further comprises: A three-electrode system was constructed, and the carbon fiber probe was used as the working electrode to perform strong acid and strong base environment testing.

8. The method of claim 6, wherein: A three-electrode system was constructed, and the carbon fiber probe was used as the working electrode to perform strong acid and strong base environment testing, including: A three-electrode system is constructed, with other carbon fiber electrodes as counter electrodes, a saturated calomel electrode as a reference electrode, and the carbon fiber probe as a working electrode. A 3.5wt% sodium chloride solution is used as an electrolyte to obtain a strongly acidic solution with a pH value lower than 1 or a strongly alkaline solution with a pH value higher than 13, and an open circuit test, a potentiodynamic sweep test, or an AC impedance test is performed.

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