A magnetic electrode

Abstract

The present invention provides a magnetic electrode, and magnetic particles will not be adsorbed to the side of the electrode. The magnetic electrode comprises a non-magnetic shell with an opening at the top, a cover, a magnet, a high magnetic permeability cylinder, a non-magnetic metal connector and a non-magnetic electrode sheet, wherein the cover is fixedly connected to the top of the non-magnetic shell; the cover is provided with a metal connector hole; the magnet is arranged in the non-magnetic shell; the high magnetic permeability cylinder is arranged between the non-magnetic shell and the magnet, and surrounds the magnet in the entire length direction of the magnet, and the lower end of the high magnetic permeability cylinder abuts against the inner side of the bottom of the non-magnetic shell; the non-magnetic electrode sheet is arranged on the outer end surface of the bottom of the non-magnetic shell, and forms electrical insulation with both the high magnetic permeability cylinder and the magnet; a through hole is provided in the side wall of the non-magnetic shell, and the non-magnetic metal connector is arranged in the through hole, the lower end of which is connected to the non-magnetic electrode sheet, and the upper end extends out of the cover.

Description

Technical Field

[0001] The invention relates to a magnetic electrode and belongs to the field of electrode manufacturing. Background Art

[0002] Electrodes are widely used in various electrochemical reactions, including but not limited to oxidation, reduction, electrolysis, electrolysis and electrodeposition. With the development of the times, electrodes have been used to prepare electrochemical sensors for the detection of substances since the 1980s. The principle is that the target substance contacts the electrode, and a redox reaction occurs to generate or consume electrons to generate current changes.

[0003] How to accurately adsorb the target substance on the electrode sheet without adsorbing it to other places and ensuring that other impurities are not adsorbed has become the key to the preparation of electrochemical sensors. Magnetic electrodes can adsorb magnetic particles. If the substance to be detected is magnetic or has magnetic properties after modification, it can be adsorbed on the magnetic electrode, thereby simply and efficiently improving the measurement sensitivity and stability of the electrode. Existing magnetic electrodes usually use glassy carbon electrodes, platinum electrodes, etc. with high conductivity and chemical stability as electrochemical sensors, combined with magnetic materials (such as permanent magnets), and use magnetic materials as the source of magnetism, such as the magnetic glassy carbon electrode disclosed in Chinese patent document CN102590301A. Using permanent magnets as a magnetic source is simple and has strong magnetism. However, due to their strong magnetism, magnetic particles are easily adsorbed to the side of the electrode instead of the electrode sheet at the bottom of the electrode. This will cause the following problems: (1) It is difficult to remove the particles on the side of the electrode after the test. Wiping and polishing can easily damage the electrode, resulting in a decrease in reaction efficiency. (2) Since the magnetic lines of force of the permanent magnet material are too dispersed, the magnetic particles cannot be accurately adsorbed to the electrode sheet, which has a great impact on the reaction effect and requires careful selection and control. (3) When using magnetic particles for electrochemical detection, due to the different concentrations of the solution being detected, the degree of binding between the magnetic particles and the substance being detected is also different. In addition, the solution may contain some other magnetic impurities. Untreated permanent magnet electrodes often cannot screen the particles and adsorb all of them, resulting in unsatisfactory differences in the detection results of different concentrations. Summary of the invention

[0004] In view of this, the present invention provides a magnetic electrode, in which the magnetic particles are not adsorbed to the side of the electrode, but adsorbed to the electrode sheet at the bottom.

[0005] Specifically, the following technical solutions are included:

[0006] A magnetic electrode comprises a non-magnetic shell with an open top and electrical insulation, a cover, a magnet, a high magnetic permeability cylinder, a non-magnetic metal connector and a non-magnetic electrode sheet.

[0007] The sealing cover is fixedly connected to the top of the non-magnetic housing;

[0008] The sealing cover is provided with a metal joint hole;

[0009] The magnet is disposed in the non-magnetic housing, with one pole of the magnet facing the bottom of the non-magnetic housing;

[0010] The high magnetic permeability tube has a relative magnetic permeability of not less than 5000, is disposed between the non-magnetic shell and the magnet, does not contact the high magnetic permeability tube and surrounds the magnet in the entire length direction of the magnet, and the lower end of the high magnetic permeability tube abuts against the inner side of the bottom of the non-magnetic shell;

[0011] The non-magnetic electrode sheet is arranged on the bottom outer end surface of the non-magnetic shell, and is located below the magnet, and the non-magnetic electrode sheet is electrically insulated from the high magnetic permeability cylinder and the magnet;

[0012] A through hole is arranged in the side wall of the non-magnetic shell, and the non-magnetic metal connector is arranged in the through hole, with the lower end connected to the non-magnetic electrode sheet and the upper end extending out of the cover through the metal connector hole.

[0013] The non-magnetic property of the present invention refers to a relative magnetic permeability of no more than 1.5, preferably no more than 1. The non-magnetic shell can be made of a known and commonly used material, such as polytetrafluoroethylene, polypropylene plastic, polycarbonate, polyimide, polyether ketone or polystyrene. These materials are resistant to high temperature and corrosion, can be applied to various reaction conditions, maintain a stable temperature for a long time, keep the electrode stable in magnetic field strength, and make the reaction state more stable. The cover can also be made of a non-magnetic electrically insulating material, such as the material selected for the aforementioned non-magnetic shell, but the material used can be the same as or different from the non-magnetic shell.

[0014] As is common knowledge in the art, the non-magnetic electrode sheet is made of conductive material.

[0015] The top of the non-magnetic metal connector is used to connect to the external circuit, and the bottom is electrically connected to the non-magnetic electrode sheet. It has good conductivity, a relative magnetic permeability of no more than 1.5, and will not interfere with the magnetic field. The optional materials are copper, aluminum, copper-clad steel, copper-clad aluminum, copper alloy or aluminum alloy.

[0016] The present invention uses the magnet in the non-magnetic shell to provide a magnetic source for the non-magnetic electrode sheet, and surrounds the magnet with the high magnetic permeability tube disposed between the non-magnetic shell and the magnet. Since the relative magnetic permeability of the high magnetic permeability tube is not less than 5000, and the relative magnetic permeability of the air and the non-magnetic shell is only about 1, the magnetic lines of force emitted from the magnet can be effectively restrained and conducted along the wall of the high magnetic permeability tube, and the side of the magnetic electrode (i.e., the outer wall of the non-magnetic shell) will not generate obvious magnetic force, so that the magnetic force is concentrated on the non-magnetic electrode sheet. Obviously, the surrounding refers to the surrounding in the entire circumferential direction.

[0017] As an improvement of the present invention, the magnetic electrode further comprises a high magnetic permeability chassis with a relative magnetic permeability of not less than 5000.

[0018] The high magnetic permeability chassis is fixed to the inner side of the bottom of the non-magnetic shell, and its projection on the non-magnetic electrode sheet does not exceed the non-magnetic electrode sheet, and the bottom surface of the high magnetic permeability cylinder is at least 1 mm higher than the bottom surface of the high magnetic permeability chassis;

[0019] The projection of the magnet on the high magnetic permeability chassis does not exceed the high magnetic permeability chassis;

[0020] The high magnetic permeability chassis is electrically insulated from the non-magnetic electrode sheet.

[0021] The high magnetic permeability chassis and the high magnetic permeability cylinder work together to strengthen the binding and guidance of the magnetic lines of force, and can further make the magnetic lines of force evenly distributed on the non-magnetic electrode sheet, thereby facilitating the uniform adsorption of magnetic particles on the non-magnetic electrode sheet and facilitating the reaction. Preferably, the magnet is cylindrical, the high magnetic permeability chassis and the non-magnetic electrode sheet are circular (obviously, the circular shape here does not take into account the thickness of the high magnetic permeability chassis and the non-magnetic electrode sheet), and the magnet, the high magnetic permeability chassis and the non-magnetic electrode sheet are coaxially arranged; the diameter of the high magnetic permeability chassis is not less than the diameter of the magnet, and not greater than the diameter of the non-magnetic electrode sheet.

[0022] As an improvement of the present invention, the magnetic electrode further comprises a non-magnetic magnetic joint.

[0023] The cover is provided with a magnet joint hole;

[0024] The lower end of the non-magnetic magnet joint extends into the high magnetic permeability cylinder and is fixedly connected to the top of the magnet, and the upper end extends from the cover through the magnet joint hole and is fixedly connected to the cover axially movable.

[0025] In this improved solution, the magnet can follow the non-magnetic magnet connector to adjust its position up and down in the non-magnetic housing, thereby adjusting the magnetic field strength around the non-magnetic electrode sheet at the bottom. The non-magnetic magnet connector can be made of non-magnetic materials such as aluminum, copper, and austenitic stainless steel. Preferably, the fixed connection between the non-magnetic magnet connector and the cover is a threaded connection, or the non-magnetic magnet connector forms a slidable interference fit between the magnet connector hole and the cover.

[0026] Preferably,

[0027] The cover is detachably fixedly connected to the top of the non-magnetic housing;

[0028] The non-magnetic electrode sheet does not retain magnetism.

[0029] The so-called “no residual magnetism” means that after the external magnetic field is removed, the non-magnetic electrode sheet has no obvious residual magnetism.

[0030] Preferably, the high magnetic permeability tube and the high magnetic permeability chassis both have low coercivity. Coercivity represents the ability of a magnetic material to resist demagnetization, and low coercivity means that no significant residual magnetism will be generated after the magnetic field is removed. Preferably, the low coercivity in the present invention refers to a coercivity between 0 and 30 amperes per meter (A / m).

[0031] The high magnetic permeability tube and the high magnetic permeability chassis can be made of various known and commonly used materials that meet the requirements, such as Permalloy, super Permalloy, Sendust, Fe-based and Co-based amorphous or nano magnetic alloys, and the materials of the two can be the same or different.

[0032] Since the cover is detachable, the non-magnetic magnetic connector fixed on the cover and the magnet connected to the non-magnetic magnetic connector can be taken out of the non-magnetic shell together with the cover after the test. At this time, since the non-magnetic electrode sheet does not retain magnetism, the high magnetic permeability tube and the high magnetic permeability chassis have low coercive force, no residual magnetism will be generated, and the magnetic field around the non-magnetic electrode sheet disappears, so the magnetic particles adsorbed on the non-magnetic electrode sheet can be conveniently and effectively removed.

[0033] The non-magnetic electrode sheet can be made of materials commonly known in the art, preferably platinum, glassy carbon or austenitic stainless steel. These materials have high chemical stability and corrosion resistance, a relative magnetic permeability of about 1, and will not interfere with the magnetic field.

[0034] Preferably,

[0035] The magnet is cylindrical, the non-magnetic shell and the high magnetic permeability cylinder are both cylindrical, and the non-magnetic electrode sheet is circular;

[0036] The magnet, the high magnetic permeability cylinder, the non-magnetic housing and the non-magnetic electrode sheet are coaxially arranged;

[0037] The inner diameter of the high magnetic permeability cylinder is larger than the diameter of the magnet.

[0038] The magnet may be a permanent magnet or an electromagnet;

[0039] When the magnet is an electromagnet, a coil wire hole is provided on the cover, and the coil wire of the electromagnet extends out of the cover through the coil wire hole. As a known technology, the electromagnet can adjust the magnetic field strength around the non-magnetic electrode sheet by adjusting the number of coil turns, and can also be demagnetized by powering off.

[0040] In the present invention, the magnet can be made of a material with strong magnetic properties as much as possible, without worrying about the phenomenon of magnetic particles being attracted by the side leakage of the electrode. For example, the permanent magnet can be made of neodymium iron boron or cobalt boron; and the electromagnet can be made of iron silicon as the magnetic core, which has a high magnetic permeability and the number of coil turns can be adjusted. The magnet has strong magnetic properties and can effectively attract various particles.

[0041] Preferably, the thickness of the high magnetic permeability chassis is 1-4 mm, and the bottom surface of the high magnetic permeability cylinder is 1-4 mm higher than the bottom surface of the high magnetic permeability chassis. The thickness of the high magnetic permeability cylinder is preferably 1-4 mm.

[0042] Compared with the prior art, the technical solution provided by the embodiment of the present invention has at least the following beneficial effects:

[0043] 1. The present invention can effectively bind magnetic lines of force. There is almost no magnetic force on the side of the magnetic electrode. When in use, the side of the magnetic electrode will not adsorb magnetic particles, and the magnetic particles are basically all adsorbed on the non-magnetic electrode sheet at the bottom of the magnetic electrode.

[0044] 2. The magnetic field strength around the non-magnetic electrode sheet can be adjusted to produce appropriate magnetism according to the characteristics of the target particles to avoid adsorption of other particles, thereby enhancing the adsorption selectivity of the electrode and facilitating the screening of the adsorbed magnetic particles.

[0045] 3. After the electrochemical test is completed, the magnetic field around the non-magnetic electrode sheet can be easily removed, which is convenient for the subsequent recovery and transfer of magnetic particles adsorbed on the electrode, avoiding the need to clean the electrode by grinding, and reducing the loss caused by subsequent cleaning of the electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0047] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0048] Figure 2 This is a schematic diagram of the sealing structure in Example 1 of the present invention;

[0049] Figure 3 This is a schematic diagram of the structure of Embodiment 2 of the present invention;

[0050] Figure 4 This is a front view of the bottom of the magnetic electrode described in Example 1 of the present invention after the adsorption test;

[0051] Figure 5 A side view of the bottom of the magnetic electrode described in Example 1 of the present invention after an adsorption test;

[0052] Figure 6 This is a front view of the bottom of the magnetic electrode described in Example 3 of the present invention after the adsorption test;

[0053] Figure 7 A side view of the bottom of the magnetic electrode described in Example 3 of the present invention after an adsorption test;

[0054] Figure 8 This is a graph showing the adsorption test results of Comparative Example 1;

[0055] Fig. 9 This is a graph showing the adsorption test results of Comparative Example 2;

[0056] Fig.10 This is the modeling diagram of the magnetic electrode in a spherical air domain with a radius of 100 mm;

[0057] Fig.11 This is a modeling diagram of the magnetic electrode described in Example 1 of the present invention;

[0058] Fig.12 This is a streamline magnetic flux density distribution diagram of the magnetic electrode in the air according to Example 1 of the present invention;

[0059] Fig.13 The figure is a body arrow magnetic flux density distribution diagram of the magnetic electrode in the air in the magnetic electrode according to the first embodiment of the present invention;

[0060] Fig.14 The magnetic flux density model distribution diagram of the vertical line of the magnetic electrode side wall described in Example 1 of the present invention;

[0061] Fig.15 This is a modeling diagram of the magnetic electrode described in Example 4 of the present invention;

[0062] Fig.16 This is a streamline magnetic flux density distribution diagram of the magnetic electrode in the air according to Example 4 of the present invention;

[0063] Fig.17 The figure is a body arrow magnetic flux density distribution diagram of the magnetic electrode in the air in the magnetic electrode according to the fourth embodiment of the present invention;

[0064] Fig.18 The magnetic flux density modulus distribution diagram of the vertical line of the magnetic electrode side wall described in Example 4 of the present invention;

[0065] Description of reference numerals:

[0066] 1- non-magnetic shell; 2- cover; 3- magnet; 4- high magnetic permeability tube; 5- non-magnetic metal connector; 6- non-magnetic electrode sheet; 7- metal connector hole; 8- high magnetic permeability chassis; 9- non-magnetic magnet connector; 10- magnet connector hole. DETAILED DESCRIPTION

[0067] To make the technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0068] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "top", "bottom", "inside" and "outside" are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0069] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0070] It is important to note that the construction and arrangement of the present application shown in the embodiments are only exemplary, and those who refer to this disclosure should easily understand that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, and parameter values ​​(e.g., temperature, pressure, etc.), installation arrangements, use of materials, color, changes in orientation, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, the elements shown as integrally formed may be composed of multiple parts or elements, the positions of the elements may be inverted or otherwise changed, and the nature or number or position of the discrete elements may be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present invention. The order or sequence of any process or method steps may be changed or reordered according to alternative embodiments. In the claims, any "means plus function" clause is intended to cover the structure described herein that performs the function, and is not only structurally equivalent but also equivalent structure. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present invention. Therefore, the invention is not limited to a specific embodiment, but extends to numerous modifications still falling within the scope of the appended claims.

[0071] Furthermore, in order to provide a concise description of the exemplary embodiments, not all features of the actual embodiments (i.e., those features that are not relevant to the best mode currently considered for carrying out the invention, or those features that are not relevant to implementing the invention) may be described. Moreover, the technical features involved in the different embodiments of the invention described below may be combined with each other as long as they do not conflict with each other.

[0072] The present invention provides a magnetic electrode, comprising a non-magnetic housing with an open top and electrical insulation, a cover, a magnet, a high magnetic permeability cylinder, a non-magnetic metal connector and a non-magnetic electrode sheet.

[0073] The sealing cover is fixedly connected to the top of the non-magnetic housing;

[0074] The sealing cover is provided with a metal joint hole;

[0075] The magnet is disposed in the non-magnetic housing, with one pole of the magnet facing the bottom of the non-magnetic housing;

[0076] The high magnetic permeability tube has a relative magnetic permeability of not less than 5000, is disposed between the non-magnetic shell and the magnet, does not contact the high magnetic permeability tube and surrounds the magnet in the entire length direction of the magnet, and the lower end of the high magnetic permeability tube abuts against the inner side of the bottom of the non-magnetic shell;

[0077] The non-magnetic electrode sheet is arranged on the bottom outer end surface of the non-magnetic shell, and is located below the magnet, and the non-magnetic electrode sheet is electrically insulated from the high magnetic permeability cylinder and the magnet;

[0078] A through hole is arranged in the side wall of the non-magnetic shell, and the non-magnetic metal connector is arranged in the through hole, with the lower end connected to the non-magnetic electrode sheet and the upper end extending out of the cover through the metal connector hole.

[0079] As an improvement of the present invention, the magnetic electrode further comprises a high magnetic permeability chassis with a relative magnetic permeability of not less than 5000.

[0080] The high magnetic permeability chassis is fixed to the inner side of the bottom of the non-magnetic shell, and its projection on the non-magnetic electrode sheet does not exceed the non-magnetic electrode sheet, and the bottom surface of the high magnetic permeability cylinder is at least 1 mm higher than the bottom surface of the high magnetic permeability chassis;

[0081] The projection of the magnet on the high magnetic permeability chassis does not exceed the high magnetic permeability chassis;

[0082] The high magnetic permeability chassis is electrically insulated from the non-magnetic electrode sheet.

[0083] Preferably, the magnet is cylindrical, the high magnetic permeability chassis and the non-magnetic electrode sheet are circular, and the magnet, the high magnetic permeability chassis and the non-magnetic electrode sheet are coaxially arranged; the diameter of the high magnetic permeability chassis is not less than the diameter of the magnet and not greater than the diameter of the non-magnetic electrode sheet.

[0084] As an improvement of the present invention, the magnetic electrode further comprises a non-magnetic magnetic joint.

[0085] The cover is provided with a magnet joint hole;

[0086] The lower end of the non-magnetic magnet joint extends into the high magnetic permeability cylinder and is fixedly connected to the top of the magnet, and the upper end extends out of the cover through the magnet joint hole and is fixedly connected to the cover axially movable. The non-magnetic magnet joint can be made of non-magnetic materials such as aluminum, copper, and austenitic stainless steel.

[0087] Preferably,

[0088] The cover is detachably fixedly connected to the top of the non-magnetic housing;

[0089] The non-magnetic electrode sheet does not retain magnetism.

[0090] Preferably, both the high magnetic permeability cylinder and the high magnetic permeability chassis have low coercive force.

[0091] Preferably,

[0092] The magnet is cylindrical, the non-magnetic shell and the high magnetic permeability cylinder are both cylindrical, and the non-magnetic electrode sheet is circular;

[0093] The magnet, the high magnetic permeability cylinder, the non-magnetic housing and the non-magnetic electrode sheet are coaxially arranged;

[0094] The inner diameter of the high magnetic permeability cylinder is larger than the diameter of the magnet.

[0095] The magnet may be a permanent magnet or an electromagnet;

[0096] When the magnet is an electromagnet, a coil wire hole is provided on the cover, and the coil wire of the electromagnet extends out of the cover through the coil wire hole. As a known technology, the electromagnet can adjust the magnetic field strength around the non-magnetic electrode sheet by adjusting the number of coil turns, and can also be demagnetized by powering off.

[0097] Preferably, the thickness of the high magnetic permeability chassis is 1-4 mm, the bottom surface of the high magnetic permeability cylinder is 1-4 mm higher than the bottom surface of the high magnetic permeability chassis, and the thickness of the high magnetic permeability cylinder is preferably 1-4 mm.

[0098] Example 1

[0099] Figure 1-Figure 2 A magnetic electrode is shown, comprising a non-magnetic housing 1 with an open top and electrically insulated, a cover 2, a magnet 3, a high magnetic permeability cylinder 4, a non-magnetic metal connector 5, and a non-magnetic electrode sheet 6.

[0100] The cover 2 is fixedly connected to the top of the non-magnetic housing 1;

[0101] The cover 2 is provided with a metal joint hole 7;

[0102] The magnet 3 is disposed in the non-magnetic housing 1, with one pole of the magnet 3 facing the bottom of the non-magnetic housing 1;

[0103] The high magnetic permeability tube 4 has a relative magnetic permeability of not less than 5000, and is disposed between the non-magnetic shell 1 and the magnet 3. The high magnetic permeability tube 4 surrounds the magnet 3 in the entire length direction of the magnet 3, and the lower end of the high magnetic permeability tube 4 abuts against the inner side of the bottom of the non-magnetic shell 1;

[0104] The non-magnetic electrode sheet 6 is embedded in the outer end surface of the bottom of the non-magnetic shell 1 and is located below the magnet 3. The non-magnetic electrode sheet 6, the high magnetic permeability tube 4 and the magnet 3 are separated by the inner side surface of the bottom of the non-magnetic shell 1 to form electrical insulation between them.

[0105] A through hole is provided in the side wall of the non-magnetic shell 1 , and the non-magnetic metal connector 5 is provided in the through hole, with the lower end connected to the non-magnetic electrode sheet 6 , and the upper end extending out of the cover 2 through the metal connector hole 7 .

[0106] The magnet 3 is cylindrical, the non-magnetic housing 1 and the high magnetic permeability cylinder 4 are both cylindrical, and the non-magnetic electrode sheet 6 is circular;

[0107] The magnet 3, the high magnetic permeability cylinder 4, the non-magnetic housing 1 and the non-magnetic electrode sheet 6 are coaxially arranged;

[0108] The inner diameter of the high magnetic permeability cylinder 4 is larger than the outer diameter of the magnet 3 and they are not in contact with each other. In order to facilitate stable installation, the outer diameter of the high magnetic permeability cylinder 4 is consistent with the inner diameter of the non-magnetic housing 1.

[0109] The magnetic electrode also includes a high magnetic permeability chassis 8 with a relative magnetic permeability of not less than 5000.

[0110] The high magnetic permeability chassis 8 is fixed to the inner side of the bottom of the non-magnetic housing 1 . Figure 1 As shown in the figure, the high magnetic permeability chassis 8 is embedded in the inner side of the bottom of the non-magnetic shell 1, and the top surface is flush with the bottom surface of the high magnetic permeability cylinder 4. In this case, the dimension by which the bottom surface of the high magnetic permeability cylinder 4 is higher than the bottom surface of the high magnetic permeability chassis 8 is the thickness of the high magnetic permeability chassis;

[0111] The high magnetic permeability chassis 8 is circular and is coaxially arranged with the magnet 3. The diameter of the high magnetic permeability chassis 8 is not less than the diameter of the magnet 3 and not greater than the diameter of the non-magnetic electrode sheet 6.

[0112] The gap between the high magnetic permeability chassis 8 and the non-magnetic electrode sheet 6 is made of non-magnetic shell material, and the two do not contact each other, thereby forming an electrical insulation relationship. Obviously, the electrical insulation relationship between the two can also be achieved by means of electrical insulation coating.

[0113] The high magnetic permeability cylinder 4 and the high magnetic permeability base plate 8 both have low coercive force.

[0114] The magnetic electrode also includes a non-magnetic magnetic connector 9,

[0115] The cover 2 is provided with a magnet joint hole 10;

[0116] The lower end of the non-magnetic magnet joint 9 extends into the high magnetic permeability cylinder 4 and is fixedly connected to the top of the magnet 3, and the upper end extends out of the cover 2 through the magnet joint hole 10 and is fixedly connected to the cover 2 so as to be axially movable.

[0117] Figure 1The non-magnetic magnetic joint 9 and the cover 2 are connected by thread, that is, the non-magnetic magnetic joint 9 is a threaded joint, the cylindrical surface has a threaded structure, and the magnetic joint hole 10 is a threaded hole. By rotating the non-magnetic magnetic joint 9, it can be moved up and down along the axial direction, so as to adjust the position of the magnet 3 relative to the bottom of the non-magnetic housing 1, and then adjust the magnetic field strength around the non-magnetic electrode sheet 6.

[0118] The cover 2 is detachably connected to the top of the non-magnetic housing 1 ( Figure 1 The structure shown in the figure is an embedded structure, and the connection can be stabilized by interference fit);

[0119] The non-magnetic electrode sheet 6 does not retain magnetism.

[0120] The magnetic electrode of the present invention is used for electrochemical detection. After the detection is completed, the magnet 3 can be removed from the non-magnetic shell 1 together with the cover 2. At this time, since the non-magnetic electrode sheet 6 does not retain magnetism, the high magnetic permeability tube 4 and the high magnetic permeability chassis 8 have low coercive force, no residual magnetism will be generated, and the magnetism around the non-magnetic electrode sheet 6 disappears, so the magnetic particles adsorbed on the non-magnetic electrode sheet 6 can be conveniently and effectively removed.

[0121] The specific composition and dimensions of each component in the magnetic electrode are as follows:

[0122] The non-magnetic shell 1 is made of polytetrafluoroethylene, with a side wall thickness of 2mm, an outer diameter of 13mm and a height of 50mm; the cover 2 is made of polytetrafluoroethylene, with an edge thickness of 4mm and a middle protruding part thickness of 5mm; the magnet 3 is a permanent magnet neodymium iron boron magnet (NdFeB), with a diameter of 3mm and a length of 20mm; the high magnetic permeability tube 4 is made of Permalloy, with an inner diameter of 5mm, an outer diameter of 9mm, a thickness of 2mm and a length of 40mm; the non-magnetic metal connector 5 is made of red copper, with a diameter of 1mm and a length of 60mm; the non-magnetic electrode sheet 6 is made of glassy carbon sheet, with a diameter of 10mm and a thickness of 1mm; the high magnetic permeability chassis 8 is made of Permalloy, with a diameter of 6mm and a thickness of 2mm; the non-magnetic shell material between the non-magnetic electrode sheet 6 and the high magnetic permeability chassis 8 is 2mm thick, and the non-magnetic magnet connector 9 is made of austenitic stainless steel, with a diameter of 3mm and a length of 30mm.

[0123] The specific information of the above mentioned materials is as follows:

[0124] Polytetrafluoroethylene (PTFE), model: Teflon™ PTFE 62;

[0125] Neodymium iron boron magnet (NdFeB), model: N54, residual flux density is 2T;

[0126] Permalloy, model: Permalloy 80 (Ni80Fe20);

[0127] Austenitic stainless steel, type 316L.

[0128] Example 2

[0129] The rest is the same as in Example 1. On the basis of Example 1, the magnet 3 is an electromagnet, and a coil wire hole (not shown) is provided on the cover 2. The coil wire of the electromagnet extends out of the cover 2 through the coil wire hole. Figure 3 shown.

[0130] Example 3

[0131] The rest is the same as in Example 1, except that the high magnetic permeability chassis 8 is removed.

[0132] Example 4

[0133] The rest is the same as in Example 1, except that the diameter of the high magnetic permeability chassis 8 is 4 mm based on Example 1.

[0134] Comparative Example 1

[0135] The rest is the same as in Example 1, except that the high magnetic permeability tube 4 is removed from Example 1.

[0136] Comparative Example 2

[0137] The rest is the same as in Example 1, except that the high magnetic permeability tube 4 and the high magnetic permeability chassis 8 are removed from Example 1.

[0138] Comparison example

[0139] Magnetic electrodes purchased on the market

[0140] Beijing Jingke 3mm magnetic glassy carbon electrode, the experimental built-in magnet has a residual magnetic flux density of 5000 Gauss, the inner core is 3mm diameter glassy carbon, the electrode diameter is 12mm and the length is 75mm.

[0141] Application Examples

[0142] The electrodes described in the above-mentioned Example 1, Example 3, Comparative Example 1 and Comparative Example 2 were subjected to a magnetic particle adsorption test (hereinafter referred to as adsorption test) according to the following steps:

[0143] 1. Rotate the non-magnetic magnet joint of the magnetic electrode so that the bottom end of the magnet and the bottom end of the high magnetic permeability cylinder are on the same plane.

[0144] 2. Place the filter paper flat below the location where the electrode will be lowered.

[0145] 3. Sprinkle 0.2g of 100nm ferroferric oxide particles (magnetic particles) evenly within the 2×2cm area in the center of the filter paper.

[0146] 4. Slowly lower the electrode vertically to 2 cm from the filter paper, hold for 5 seconds, then continue to slowly lower it to 1 cm and hold for another 5 seconds to ensure particle adsorption.

[0147] 5. Observe and record the adsorption position and distribution of ferroferric oxide particles.

[0148] Figure 4 , Figure 5 This is a graph showing the adsorption test results of the magnetic electrode described in Example 1, wherein Figure 4 and Figure 5 They are the front view and side view of the bottom of the magnetic electrode after the adsorption test. The test results show that no magnetic particles are adsorbed on the side wall of the magnetic electrode, while a large number of magnetic particles are uniformly adsorbed on the non-magnetic electrode sheet. This shows that the high magnetic permeability cylinder and the high magnetic permeability chassis work together to effectively bind and concentrate the magnetic lines of force within the working range of the non-magnetic electrode sheet, reduce the side and bottom leakage of the magnetic force, and thus provide the best magnetic particle adsorption effect.

[0149] Figure 6 , Figure 7 This is a graph showing the adsorption test results of the magnetic electrode described in Example 3, wherein Figure 6 and Figure 7 The front view and side view of the bottom of the magnetic electrode after the adsorption test are shown respectively. The test results show that no magnetic particles are adsorbed on the side wall of the magnetic electrode, while a large number of magnetic particles are adsorbed on the non-magnetic electrode sheet. However, the magnetic particle adsorption density in the central area of ​​the non-magnetic electrode sheet is low, and Figure 7 Compared to Figure 5 The size of the magnetic particles adsorbed in Example 3 is uneven along the axial stacking. This shows that the high magnetic permeability tube can effectively bind and guide the magnetic lines of force, shielding the magnetic field leakage; but due to the lack of a high magnetic permeability chassis, the bottom magnetic field leaks, and the magnetic force at the center of the non-magnetic electrode sheet is not the strongest, resulting in a low particle adsorption density in the center area and a high density in the surrounding area. This situation in which the magnetic particles cannot be uniformly adsorbed on the surface of the non-magnetic electrode sheet is not conducive to the efficient conduct of electrochemistry.

[0150] Figure 8 This is a graph showing the adsorption test results of the magnetic electrode described in Comparative Example 1. The test results show that the particles on the non-magnetic electrode sheet are relatively uniformly adsorbed, but at the same time, many particles are also adsorbed on the side walls of the electrode. This is because the high magnetic permeability chassis concentrates the magnetic lines of force above the non-magnetic electrode sheet, reducing the leakage of magnetic lines of force at the bottom; and the lack of a high magnetic permeability cylinder means that the lateral magnetic lines of force are not effectively bound, resulting in lateral leakage of magnetic lines of force.

[0151] Fig. 9 The figure is a result of the adsorption test of the magnetic electrode described in Comparative Example 2. The test results show that a large number of magnetic particles are adsorbed on both the side walls of the magnetic electrode and the non-magnetic electrode sheet, but the magnetic particles adsorbed on the non-magnetic electrode sheet are unevenly distributed. This indicates that the high magnetic permeability tube and the high magnetic permeability chassis are lacking to restrain and guide the magnetic lines of force, and the magnetic lines of force are scattered freely and can reach the area where the side walls of the electrode and the bottom non-magnetic electrode sheet are located, resulting in the inability of the magnetic particles to be evenly adsorbed only on the area of ​​the non-magnetic electrode sheet that can participate in the electrochemical reaction. In this way, it is difficult to remove the particles on the side of the electrode after the electrochemical test is completed. Removing the particles by wiping and polishing can easily damage the electrode, resulting in a decrease in the reaction efficiency. At the same time, since the magnetic particles cannot be accurately adsorbed on the non-magnetic electrode sheet, it has a great impact on the reaction effect and detection sensitivity.

[0152] The adsorption test results of the magnetic electrode described in the control example are basically the same as Figure 7 same.

[0153] In summary, for the magnetic electrodes of the structures of Example 1, Example 3 and Comparative Example 1, Comparative Example 2, the results are compared as follows:

[0154]

[0155] It can be seen that the combined use of a high magnetic permeability tube and a high magnetic permeability chassis can effectively prevent significant magnetic leakage from the side and ensure that the magnetic particles are evenly distributed on the non-magnetic electrode sheet, thereby achieving the best adsorption effect.

[0156] Modeling

[0157] The magnetic electrode described in Example 1 and Example 4 of the present invention from the bottom to the part 45mm above it was modeled using Comsol software. The bottom surface of the magnet in the magnetic electrode was connected to the upper surface of the high magnetic permeability chassis. The relative magnetic permeability of the polytetrafluoroethylene was set to 1, the residual magnetic flux density of the magnet was set to 2T, the relative magnetic permeability of the high magnetic permeability cylinder was set to 10000, the relative magnetic permeability of the non-magnetic electrode sheet was set to 1, and the relative magnetic permeability of the high magnetic permeability chassis was set to 10000. The results are as follows: Figure 10-Figure 18 The results show that for different chassis sizes, the combination of high magnetic permeability tube and high magnetic permeability chassis can effectively confine the magnetic force at the bottom of the high magnetic permeability chassis (at the non-magnetic electrode sheet), and when the residual magnetic flux density of the magnet is as high as 2T, the magnetic flux density at the side wall of the magnetic electrode is less than 0.01T.

[0158] The above description is only for the purpose of facilitating those skilled in the art to understand the technical solution of the present invention and is not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A magnetic electrode, characterized in that: It includes a non-magnetic housing with an open top and electrical insulation, a cover, a magnet, a high magnetic permeability cylinder, a non-magnetic metal connector and a non-magnetic electrode sheet. The sealing cover is fixedly connected to the top of the non-magnetic housing; The sealing cover is provided with a metal joint hole; The magnet is disposed in the non-magnetic housing, with one pole of the magnet facing the bottom of the non-magnetic housing; The high magnetic permeability tube has a relative magnetic permeability of not less than 5000, is disposed between the non-magnetic shell and the magnet, does not contact the high magnetic permeability tube and surrounds the magnet in the entire length direction of the magnet, and the lower end of the high magnetic permeability tube abuts against the inner side of the bottom of the non-magnetic shell; The non-magnetic electrode sheet is arranged on the bottom outer end surface of the non-magnetic shell, and is located below the magnet, and the non-magnetic electrode sheet is electrically insulated from the high magnetic permeability cylinder and the magnet; A through hole is arranged in the side wall of the non-magnetic shell, and the non-magnetic metal connector is arranged in the through hole, with the lower end connected to the non-magnetic electrode sheet and the upper end extending out of the cover through the metal connector hole.

2. The magnetic electrode according to claim 1, characterized in that It also includes a high magnetic permeability chassis with a relative magnetic permeability of not less than 5000. The high magnetic permeability chassis is fixed to the inner side of the bottom of the non-magnetic shell, and its projection on the non-magnetic electrode sheet does not exceed the non-magnetic electrode sheet, and the bottom surface of the high magnetic permeability cylinder is at least 1 mm higher than the bottom surface of the high magnetic permeability chassis; The projection of the magnet on the high magnetic permeability chassis does not exceed the high magnetic permeability chassis; The high magnetic permeability chassis is electrically insulated from the non-magnetic electrode sheet.

3. The magnetic electrode according to claim 2, characterized in that The magnet is cylindrical, the high magnetic permeability chassis and the non-magnetic electrode sheet are circular, and the magnet, the high magnetic permeability chassis and the non-magnetic electrode sheet are coaxially arranged; The diameter of the high magnetic permeability chassis is not less than the diameter of the magnet and not greater than the diameter of the non-magnetic electrode sheet.

4. The magnetic electrode according to claim 2, characterized in that The thickness of the high magnetic permeability cylinder is 1-4 mm, the thickness of the high magnetic permeability chassis is 1-4 mm, and the bottom surface of the high magnetic permeability cylinder is 1-4 mm higher than the bottom surface of the high magnetic permeability chassis.

5. The magnetic electrode according to claim 2, characterized in that The high permeability chassis has a low coercive force.

6. The magnetic electrode according to claim 1, characterized in that Also includes non-magnetic magnet connectors, The cover is provided with a magnet joint hole; The lower end of the non-magnetic magnet joint extends into the high magnetic permeability cylinder and is fixedly connected to the top of the magnet, and the upper end extends from the cover through the magnet joint hole and is fixedly connected to the cover axially movable.

7. The magnetic electrode according to claim 6, characterized in that The fixed connection between the non-magnetic magnetic joint and the cover is a threaded connection, or the non-magnetic magnetic joint forms a slidable interference fit between the magnetic joint hole and the cover.

8. The magnetic electrode according to any one of claims 1 to 7, characterized in that: The cover is detachably fixedly connected to the top of the non-magnetic housing; The non-magnetic electrode sheet does not retain magnetism; The high magnetic permeability cylinder has a low coercive force.

9. The magnetic electrode according to any one of claims 1 to 7, characterized in that: The magnet is cylindrical, and the non-magnetic shell and the high magnetic permeability cylinder are both cylindrical; The magnet, the high magnetic permeability cylinder and the non-magnetic housing are coaxially arranged; The inner diameter of the high magnetic permeability cylinder is larger than the diameter of the magnet.

10. The magnetic electrode according to any one of claims 1 to 7, characterized in that: The magnet is a permanent magnet or an electromagnet; When the magnet is an electromagnet, a coil wire hole is provided on the cover, and the coil wire of the electromagnet extends out of the cover through the coil wire hole.

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