A green anti-pollution electrode and a preparation method thereof

Abstract

The application belongs to the technical field of electrochemical sensors, and particularly relates to a green anti-pollution electrode and a preparation method thereof. The preparation raw materials of the green anti-pollution electrode include a substrate and ink. The preparation raw materials of the ink include a binder, nano-clay, a conductive material, polyvinyl alcohol and a solvent. By optimizing the selection of each component and controlling the proportion, the ink prepared by the synergistic effect between the raw materials has excellent rheological properties, thermal stability and viscosity, so that the electrode prepared has excellent anti-pollution performance and good electrochemical performance, is low in cost, environment-friendly and suitable for large-scale production and application.

Description

Technical Field

[0001] This invention belongs to the field of electrochemical sensor technology, specifically relating to a green anti-pollution electrode and its preparation method. Background Technology

[0002] With the increasing attention given to disposable electrochemical sensors, the demand for printable conductive inks in printed electrode manufacturing has grown significantly. However, existing technologies have several problems: commercially available conductive inks are expensive, limiting large-scale applications; traditional conductive inks are based on organic solvents, which, while easy to prepare, are toxic, flammable, and environmentally unfriendly, contradicting the principles of green chemistry.

[0003] In recent years, water-based inks have attracted attention due to their low cost, non-toxicity, and environmental friendliness. However, most binders are non-conductive, and their addition reduces the conductivity of the ink. Furthermore, the binder concentration and its ratio to conductive materials have a critical impact on the performance of both the ink and the electrode. Meanwhile, the rheological properties, thermal stability, and viscosity of conductive inks are crucial to their usability, printability, and electrode performance, yet these properties are often overlooked in research and development. In addition, complex matrices in real-world samples can interfere with electrochemical analysis, and existing electrodes lack sufficient research on their anti-fouling properties, making it difficult to meet the needs of practical applications.

[0004] Therefore, there is an urgent need to develop a low-cost, environmentally friendly, and high-performance electrochemical working electrode, especially one with good anti-pollution properties, and a corresponding ink, to solve the current problems. Summary of the Invention

[0005] The purpose of this invention is to provide a green, anti-fouling electrode with excellent anti-fouling properties and good electrochemical performance, and it is low in cost, environmentally friendly, and suitable for large-scale production applications.

[0006] A green, anti-fouling electrode, the raw materials for its preparation include a substrate and an ink.

[0007] Preferably, the substrate includes any one of PET, filter paper, A4 paper, and photographic paper.

[0008] Preferably, the raw materials for preparing the ink include binders, nano-clays, conductive materials, polyvinyl alcohol, and solvents.

[0009] Preferably, the adhesive includes one or more of polyethylene glycol, shellac, carboxymethyl cellulose, and sodium alginate; more preferably, it is polyethylene glycol.

[0010] Preferably, the average molecular weight of the polyethylene glycol is 3000-5000; more preferably, it is 4000.

[0011] In some preferred embodiments, the polyethylene glycol is sourced from Shanghai Maclean Biochemical Technology Co., Ltd.

[0012] Preferably, the nano-clay includes one or two of nano-attapulgite and nano-montmorillonite; more preferably, it is nano-montmorillonite.

[0013] The preparation method of the nano-montmorillonite includes the following steps:

[0014] S1. Add deionized water to montmorillonite, stir at 600-1000 r / min for 1-3 h, then add the modifier solution dropwise. After the addition is complete, heat to 75-85℃, stir at 400-600 r / min for 20-30 h, let stand, take the upper suspension, centrifuge, collect the precipitate, wash the precipitate with deionized water until the filtrate is neutral, vacuum dry, grind through a 200 mesh sieve to obtain modified montmorillonite;

[0015] S2. Prepare silane hydrolysis solution, add modified montmorillonite, heat to 75-85℃, stir at 400-600r / min for 1-3h, centrifuge, collect the precipitate, wash 2-3 times with anhydrous ethanol, dry at 100℃ for 6h, grind through a 200-mesh sieve to obtain the final product.

[0016] Preferably, the average particle size of the montmorillonite is 50-100 nm.

[0017] In some preferred embodiments, the montmorillonite is sourced from Topway New Materials (Guangzhou) Co., Ltd.

[0018] Preferably, in step S1, the mass ratio of montmorillonite to deionized water is 1:(100-200).

[0019] Preferably, in step S1, the method for preparing the modifier solution is as follows: add the modifier to anhydrous ethanol and stir until completely dissolved, adjust the pH of the solution to 3-4, and stir at 400-600 r / min for 10 min to obtain the solution.

[0020] Preferably, the modifier comprises octadecylamine.

[0021] Preferably, the mass ratio of the modifier to anhydrous ethanol is 1:(80-100).

[0022] Preferably, in step S1, the amount of modifier added is 8%-12% of the mass of montmorillonite.

[0023] Preferably, in step S1, the specific conditions for vacuum drying are: vacuum degree of 0.008-0.009 MPa, temperature of 55-65℃, and time of 10-15 h.

[0024] Preferably, in step S2, the method for preparing the silane hydrolysate is as follows: adjust the pH of the ethanol aqueous solution to 4-5, add the silane coupling agent, and stir at 200-400 r / min for 25-35 min to obtain the solution.

[0025] Preferably, the ethanol aqueous solution contains 70%-80% ethanol by mass.

[0026] Preferably, the silane coupling agent includes one or more of KH550 and KH560.

[0027] Preferably, the mass ratio of the silane coupling agent to the aqueous ethanol solution is 1:(60-100).

[0028] Preferably, in step S2, the mass of the silane coupling agent is 4%-6% of the mass of the modified montmorillonite.

[0029] Modification with octadecylamine and silane coupling agents improved the interlayer spacing of montmorillonite and its compatibility with polyethylene glycol, thereby enhancing the electrochemical stability of the electrode and the thermal stability of the ink. This is because, on the one hand, octadecylamine protonates under acidic conditions to form octadecylamine ions, which react with Na+ in the interlayer of montmorillonite. + Ca 2+ When inorganic cations undergo ion exchange, they widen the interlayer spacing and replace inorganic ions that easily cause electrochemical interference, reducing signal fluctuations caused by ion migration during testing. Furthermore, the long-chain alkyl structure of octadecylamine enhances the steric hindrance between layers, and its high heat resistance delays interlayer collapse of montmorillonite at high temperatures, thus improving the thermal stability of the ink. On the other hand, the silanol groups generated after the hydrolysis of the silane coupling agent undergo a condensation reaction with the hydroxyl groups on the surface of montmorillonite, forming stable covalent bonds. Meanwhile, the amino group at the other end forms hydrogen bonds with the hydroxyl groups of PEG, significantly reducing the surface energy of montmorillonite, preventing aggregation, and making the ink less prone to settling during standing. This also improves the uniformity of ink spreading on the substrate during printing. The combination of these two factors allows montmorillonite to both physically block contaminants through its layered structure and improve electrode anti-fouling properties, while also synergistically working with PEG, conductive materials, and other components to ensure the continuity and structural stability of the conductive network in the ink, ultimately achieving a simultaneous improvement in electrode electrochemical performance and reliability.

[0030] Preferably, the mass ratio of the adhesive to the conductive material is 1:(1-2).

[0031] By combining polyethylene glycol binder with conductive materials, the conductivity of the ink and the electrochemical activity of the electrode are improved. This is because polyethylene glycol has good film-forming and dispersible properties, which can encapsulate graphite particles and make them uniformly dispersed, while flake graphite provides macroscopic conductive pathways, and conductive carbon black fills the pores to build a continuous conductive network. The three work together to ensure a stable output signal of the electrode in electrochemical testing.

[0032] Preferably, the total mass ratio of the nano-clay and the binder to the mass ratio of the conductive material is 1:(1-2).

[0033] By controlling the total mass ratio of nano-clay to binder and the mass ratio of conductive material, the conductivity, printability, and thermal stability of the ink were improved, while the mechanical strength and thermal stability of the electrode were enhanced. This is because, at a specific ratio, nano-clay can both assist the binder in dispersing graphite particles to prevent agglomeration and anchor itself in the binder film-forming system to enhance the ink's cohesion, ensuring that the ink film maintains both good conductive pathways and strong structural stability.

[0034] Preferably, the mass ratio of the binder to the nano-clay is 1:(1-3).

[0035] By adjusting the mass ratio of binder to nanoclay, the conductivity, printability, rheological properties, thermal stability, and electrode antifouling properties of the ink can be improved. This is because the hydroxyl groups of polyethylene glycol form hydrogen bonds with the active sites of nanoclay, and the nanoclay is dispersed in the polyethylene glycol system in an intercalated form. This not only gives the ink rheological properties suitable for printing, but also enhances the thermal stability of the film after film formation through the layered structure of nanoclay, while the interlayers can physically block contaminants.

[0036] Preferably, the conductive material includes a carbon-based material.

[0037] Preferably, the carbon-based material includes graphite and conductive carbon black.

[0038] Preferably, the mass ratio of graphite to conductive carbon black is (5-10):1.

[0039] Preferably, the graphite is flake graphite with a mesh size of 1000-3500.

[0040] Preferably, the conductive carbon black is conductive carbon black with an average particle size of 20-45 nm.

[0041] In some preferred embodiments, both the graphite and the conductive carbon black are sourced from Jiangsu Xianfeng Nanomaterials Technology Co., Ltd.

[0042] By combining flake graphite of a specific particle size with conductive carbon black, the conductivity and electrochemical active area of ​​the electrode are improved. This is because the flake graphite lays out the main conductive pathways, while the conductive carbon black fills the gaps to construct a microscopic conductive network. The two work together to make the electrode's conductive network continuously connected from the macroscopic to the microscopic level, exhibiting characteristics of low resistance and high current response.

[0043] Preferably, the degree of alcoholysis of the polyvinyl alcohol is 87.0%~89.0%, and the viscosity is 4.6~5.4 cP.

[0044] In some preferred embodiments, the polyvinyl alcohol is sourced from Shanghai Maclean Biochemical Technology Co., Ltd., specifically polyvinyl alcohol 1788.

[0045] Preferably, the amount of polyvinyl alcohol added is 0.5%-1.5% of the adhesive mass.

[0046] Preferably, the solvent includes one or both of deionized water and ethanol.

[0047] Preferably, the amount of solvent added is 45%-55% of the total mass of the raw materials for ink preparation.

[0048] The preparation method of the ink includes the following steps: at room temperature, the binder and polyvinyl alcohol are added to the solvent and stirred at 300~500 r / min until completely dissolved; nano clay is added and stirred at 500~700 r / min for 1 h; conductive material is slowly added and stirred at 100~300 r / min, followed by ultrasonic treatment to obtain the ink.

[0049] By selecting polyethylene glycol (PEG) as a binder and compounding it with nano-clay, conductive materials, and polyvinyl alcohol (PVA), an integrated binding-dispersion-film-forming system was constructed, improving the ink's rheological properties, thermal stability, electrode anti-fouling properties, and electrochemical activity. This is because PEG molecules contain a large number of hydroxyl groups, which can form hydrogen bonds with the interlayer hydroxyl groups / surface sites of nano-clay. Through the intercalation effect of nano-clay, the aggregation of graphite particles is inhibited, allowing the ink to also possess shear-thinning properties suitable for screen printing. On the other hand, PEG can cross-link with PVA molecules through hydrogen bonds, strengthening film toughness, reducing the electrode water contact angle, and forming a hydration layer, achieving anti-fouling effects and easy wetting of the electrolyte. At the same time, PEG encapsulates graphite particles, helping flake graphite build macroscopic conductive pathways. Combined with conductive carbon black filling pores, the conductive network is refined, exhibiting excellent and stable electrochemical performance.

[0050] The method for preparing the green anti-pollution electrode includes the following steps: fixing the substrate on the printing table, covering the electrode pattern with a screen; pouring ink onto the screen, printing at a uniform speed 2-3 times, and then drying and curing to obtain the electrode.

[0051] Preferably, the mesh count of the wire mesh is 200-300.

[0052] Preferably, the scratching parameters are: scratcher angle of 70°~80°, pressure of 0.2~0.4MPa, and speed of 5~8cm / s.

[0053] Preferably, the specific steps of the drying and curing are as follows: first, dry at 50°C for 2-3 hours, and then place at room temperature for 20-24 hours.

[0054] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0055] 1. This invention prepares a green anti-pollution electrode. By optimizing the selection of each component and controlling the proportion, the raw materials work synergistically to prepare an ink with excellent rheological properties, thermal stability and viscosity. As a result, the prepared electrode has excellent anti-pollution properties and good electrochemical performance. It is also low in cost, environmentally friendly and suitable for large-scale production applications.

[0056] 2. This invention improves the conductivity of the ink and the electrochemical activity of the electrode by compounding polyethylene glycol binder with sheet graphite conductive material.

[0057] 3. This invention improves the conductivity and thermal stability of the ink by controlling the total mass ratio of nano-clay and binder to the mass ratio of conductive material, while also enhancing the mechanical strength and thermal stability of the electrode.

[0058] 4. By adjusting the mass ratio of binder to nano-clay, this invention can improve the rheological properties, thermal stability, and anti-fouling properties of the ink and the electrode.

[0059] 5. This invention improves the conductivity and electrochemical active area of ​​the electrode by compounding flake graphite of a specific particle size with conductive carbon black.

[0060] 6. This invention selects polyethylene glycol as a binder and combines it with nano-clay, carbon-based conductive materials, and polyvinyl alcohol to construct an integrated system of bonding-dispersion-film formation, thereby improving the rheological properties, thermal stability, electrode anti-fouling properties, and electrochemical activity of the ink.

[0061] 7. This invention improves the interlayer spacing of montmorillonite and its compatibility with polyethylene glycol by modifying it with octadecylamine and silane coupling agents, thereby improving the electrochemical stability of the electrode and the thermal stability of the ink. Attached Figure Description

[0062] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0063] Figure 1 The rheological properties of the inks prepared in Preparation Example 1 and Preparation Example 4 of this invention are shown in the following diagrams: (a) shows the relationship between viscosity and shear rate; (b) shows the relationship between G' and G" and frequency; (c) shows the relationship between G' / G" and frequency; (d) shows the relationship between G' and G" and strain; and (e) shows the relationship between G' and temperature.

[0064] Figure 2 The thermal stability diagrams are shown for the inks prepared in Preparation Example 1 and Preparation Example 4 of this invention.

[0065] Figure 3Micrographs of screen-printed electrodes made from inks prepared in Examples 1 and 4 of this invention, and their local line edges and surfaces;

[0066] Figure 4 Cyclic voltammetry (CV) diagrams of the green anti-fouling electrodes prepared in Preparation Example 9 and Preparation Example 10; wherein, (a) is shellac ink; (b) is polyethylene glycol ink; (c) is carboxymethyl cellulose ink; and (d) is sodium alginate ink;

[0067] Figure 5 CV diagrams of the green anti-fouling electrodes prepared in Example 9 and Example 11;

[0068] Figure 6 Atomic force microscopy (AFM) images of the green antifouling electrodes prepared in Examples 9 and 12; wherein, (a) is SHL ink; (b) is polyethylene glycol ink; (c) is carboxymethyl cellulose ink; (d) is sodium alginate ink; and (f) is the average roughness R of the final electrodes prepared with different inks. a and root mean square roughness R q ;

[0069] Figure 7 To assess the antifouling properties of the green antifouling electrodes prepared in Examples 9 and 12 against different types of substances;

[0070] Figure 8 The average thickness and edge perimeter of the green anti-fouling electrodes prepared in Example 9 and Example 12;

[0071] Figure 9 CV diagrams of the green anti-fouling electrodes prepared in Preparation Example 9 and Preparation Example 12. Detailed Implementation

[0072] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0073] All raw materials used in this invention are commercially available, specifically:

[0074] The average molecular weight of polyethylene glycol is 4000, and it comes from Shanghai Maclean Biochemical Technology Co., Ltd.

[0075] The montmorillonite has an average particle size of 50 nm and comes from Topyi New Materials (Guangzhou) Co., Ltd.

[0076] The flake graphite has a mesh size of 3500; the conductive carbon black has an average particle size of 30-45nm; both are from Jiangsu Xianfeng Nanomaterials Technology Co., Ltd.

[0077] The degree of hydrolysis of polyvinyl alcohol is 87.0%-89.0%, and the viscosity is 4.6-5.4 cP. It is from Shanghai Maclean Biochemical Technology Co., Ltd., and is polyvinyl alcohol 1788.

[0078] Preparation Example 1

[0079] This preparation example provides an ink whose raw materials are binder, nano-clay, conductive material, polyvinyl alcohol, and solvent.

[0080] The adhesive is polyethylene glycol.

[0081] The nano-clay is nano-montmorillonite.

[0082] The preparation method of the nano-montmorillonite includes the following steps:

[0083] S1. Add deionized water to montmorillonite, stir at 800 r / min for 2 h, then add modifier solution dropwise. After the addition is complete, heat to 80℃, stir at 500 r / min for 24 h, let stand, take the upper suspension, centrifuge, collect the precipitate, wash the precipitate with deionized water until the filtrate is neutral, vacuum dry, grind through a 200 mesh sieve to obtain modified montmorillonite.

[0084] S2. Prepare silane hydrolysis solution, add modified montmorillonite, heat to 80℃, stir at 500r / min for 2h, centrifuge, collect the precipitate, wash 3 times with anhydrous ethanol, dry at 100℃ for 6h, grind through a 200-mesh sieve to obtain the final product.

[0085] In step S1, the mass ratio of montmorillonite to deionized water is 1:150.

[0086] In step S1, the method for preparing the modifier solution is as follows: add the modifier to anhydrous ethanol and stir until completely dissolved, adjust the pH of the solution to 3.5, and stir at 500 r / min for 10 min to obtain the solution.

[0087] The modifier is octadecylamine.

[0088] The mass ratio of the modifier to anhydrous ethanol is 1:90.

[0089] In step S1, the amount of modifier added is 10% of the mass of montmorillonite.

[0090] In step S1, the specific conditions for vacuum drying are: vacuum degree of 0.0085 MPa, temperature of 60℃, and time of 12h.

[0091] In step S2, the method for preparing the silane hydrolysate is as follows: adjust the pH of the ethanol aqueous solution to 4.5, add the silane coupling agent, and stir at 300 r / min for 30 min to obtain the solution.

[0092] The ethanol aqueous solution has an ethanol mass fraction of 75%.

[0093] The silane coupling agent is KH550.

[0094] The mass ratio of the silane coupling agent to the aqueous ethanol solution is 1:80.

[0095] In step S2, the mass of the silane coupling agent is 5% of the mass of the modified montmorillonite.

[0096] The mass ratio of the adhesive to the conductive material is 1:4.5.

[0097] The total mass ratio of the nano-clay and binder to the conductive material is 1:1.5.

[0098] The mass ratio of the binder to the nano-clay is 1:2.

[0099] The conductive material is graphite and conductive carbon black in a mass ratio of 8:1.

[0100] The graphite is flake graphite.

[0101] The amount of polyvinyl alcohol added is 10% of the adhesive mass.

[0102] The solvent is deionized water, and the amount added is 50% of the total mass of the raw materials for ink preparation.

[0103] The preparation method of the ink includes the following steps: at room temperature, the binder and polyvinyl alcohol are added to the solvent and stirred at 400 r / min until completely dissolved. Nano clay is added and stirred at 600 r / min for 1 h. The conductive material is slowly added and stirred at 200 r / min, followed by ultrasonic treatment to obtain the ink.

[0104] Preparation Example 2

[0105] This preparation example provides an ink, which is prepared according to the method of Preparation Example 1, except that:

[0106] The total mass ratio of the nano-clay and binder to the conductive material is 1:2.5, 1:2, 1:1, and 1.5:1, respectively.

[0107] Preparation Example 3

[0108] This preparation example provides an ink, which is prepared according to the method of Preparation Example 1, except that:

[0109] The mass ratios of the binder and nano-clay are 2:1, 1.5:1, 1:1, and 1:1.5, respectively.

[0110] Preparation Example 4

[0111] This preparation example provides an ink, which is prepared according to the method of Preparation Example 1, except that:

[0112] The binders are shellac (SHL), carboxymethyl cellulose (CMC), and sodium alginate (SA).

[0113] Preparation Example 5

[0114] This preparation example provides an ink, which is prepared according to the method of Preparation Example 1, except that:

[0115] The nano-clay is nano-montmorillonite; the average particle size of the nano-montmorillonite is 50 nm, and it comes from Tuoyi New Materials (Guangzhou) Co., Ltd.

[0116] Preparation Example 6

[0117] This preparation example provides an ink, which is prepared according to the method of Preparation Example 1, except that:

[0118] The preparation method of the nano-montmorillonite is as follows: add deionized water to montmorillonite, stir at 800 r / min for 2 h, then add modifier solution dropwise. After the addition is complete, heat to 80℃, stir at 500 r / min for 24 h, let stand, take the upper suspension, centrifuge, collect the precipitate, wash the precipitate with deionized water until the filtrate is neutral, vacuum dry, grind through a 200 mesh sieve, and obtain the product.

[0119] Preparation Example 7

[0120] This preparation example provides an ink, which is prepared according to the method of Preparation Example 1, except that:

[0121] The preparation method of the nano-montmorillonite is as follows: prepare silane hydrolysis solution, add montmorillonite, heat to 80℃, stir at 500r / min for 2h, centrifuge, collect the precipitate, wash 3 times with anhydrous ethanol, dry at 100℃ for 6h, grind through a 200-mesh sieve to obtain the precipitate.

[0122] The mass of the silane coupling agent is 5% of the mass of montmorillonite.

[0123] Preparation Example 8

[0124] This preparation example provides an ink, which is prepared according to the method of Preparation Example 1, except that:

[0125] The conductive material is graphite.

[0126] Preparation Example 9

[0127] This preparation example provides a green anti-pollution electrode, the preparation method of which includes the following steps: fixing the substrate on the printing table, covering the electrode pattern with a screen; pouring the ink prepared in Preparation Example 1 onto the screen, printing twice at a uniform speed, and then drying and curing to obtain the electrode.

[0128] The mesh count of the wire mesh is 300.

[0129] The printing parameters are: squeegee angle of 75°, pressure of 0.3MPa, and speed of 6cm / s.

[0130] The specific steps for drying and curing are as follows: first, dry at 50℃ for 2.5 hours, then place at room temperature for 22 hours.

[0131] The substrate is PET.

[0132] Preparation Example 10

[0133] This preparation example provides a green anti-pollution electrode, which follows the method of preparation example 9, except that the ink prepared in preparation example 2 is poured out separately.

[0134] Preparation Example 11

[0135] This preparation example provides a green anti-pollution electrode, which follows the method of preparation example 9, except that the ink prepared in preparation example 3 is poured out separately.

[0136] Preparation Example 12

[0137] This preparation example provides a green anti-pollution electrode, which follows the method of Preparation Example 9, except that the ink prepared in Preparation Example 4 is poured out separately.

[0138] Preparation Example 13

[0139] This preparation example provides a green anti-pollution electrode, which follows the method of preparation example 9, except that the ink prepared in preparation example 5 is poured out separately.

[0140] Preparation Example 14

[0141] This preparation example provides a green anti-pollution electrode, which follows the method of preparation example 9, except that the ink prepared in preparation example 6 is poured out separately.

[0142] Preparation Example 15

[0143] This preparation example provides a green anti-pollution electrode, which follows the method of preparation example 9, except that the ink prepared in preparation example 7 is poured out separately.

[0144] Preparation Example 16

[0145] This preparation example provides a green anti-pollution electrode, which follows the method of preparation example 9, except that the ink prepared in preparation example 8 is poured out separately.

[0146] Example 1

[0147] This embodiment evaluates the rheological properties of the inks prepared in Preparation Example 1 and Preparation Example 4. The operation method is as follows: The ink is loaded onto the measuring plate, and the rheometer scanning parameters are set. Except for the temperature scan, the other rheological properties are set to a steady-state temperature of 25°C, and the steady-state scan shear rate range is 10. -1 -10 3 The frequency scanning frequency range is 10. -2 -10 2 The strain is 1%, and the small amplitude strain scanning range is 10. -2 -10 2 The temperature scan range is 25℃-70℃, the heating rate is 5℃ / min, and the strain is 1%.

[0148] The results are attached. Figure 1 As shown.

[0149] From the appendix Figure 1 As can be seen from Figure a, the viscosity of the polyethylene glycol ink prepared in Example 1 decreases significantly with shear rate, exhibiting typical shear-thinning characteristics of a pseudoplastic fluid, which is beneficial for improving ink uniformity and adhesion during printing. (See attached figure...) Figure 1 b and appendix Figure 1 As can be seen from Figure c, the G' and G'' values ​​of the polyethylene glycol ink prepared in Preparation Example 1 do not change significantly with increasing frequency, with G' being higher than G'', exhibiting characteristics of predominantly elasticity and stable internal structure. Compared to other inks obtained in Preparation Example 4, the polyethylene glycol ink prepared in Preparation Example 1 has better elasticity, mechanical strength, and durability, which is beneficial for maintaining the shape of the electrode and resisting deformation, thereby improving printing quality. (See Appendix...) Figure 1 As can be seen from Figure d, both G' and G'' of the ink decrease with increasing strain. At low strain, the modulus remains approximately constant, G' > G'', indicating that the solid properties of the ink are superior to its liquid properties at low strain, and the network structure does not break. As strain increases, G' becomes less than G'', the ink changes from a solid to a liquid state, and the ink's network structure begins to break. The polyethylene glycol ink prepared in Example 1 exhibits a large range of G' > G'', indicating that it can withstand a higher degree of deformation without structural damage or abrupt property changes. This characteristic is beneficial for maintaining excellent shape and integrity during printing, avoiding irregular flow, ink sagging, or excessive spreading. This effectively ensures the stability of the ink and the printing quality of the electrodes. From the attached figure... Figure 1As can be seen from the image, under temperature scanning, the G' of the polyethylene glycol ink prepared in Example 1 does not change significantly with increasing temperature. This indicates that the polyethylene glycol ink forms a stable cross-linked or internal network structure, unaffected by temperature. As temperature increases, the movement of molecular chains in the ink is restricted. However, at lower temperatures, the G' of the polyethylene glycol ink is significantly higher than that of other inks, indicating that the polyethylene glycol ink has stronger structural rigidity and mechanical stability, which is crucial for the mechanical reliability of printed electronic devices.

[0150] In summary, compared with other inks, the polyethylene glycol ink prepared in Example 1 has solid properties, shear thinning, good elasticity, and mechanical stability.

[0151] Example 2

[0152] This embodiment evaluates the thermal stability and viscosity of the inks prepared in Preparation Example 1 and Preparation Example 4. The operation method is as follows:

[0153] Thermal stability: The ink to be tested was weighed and spread evenly on the bottom of the crucible, and then placed on the sample rod of the thermogravimetric analyzer. Nitrogen was used as the protective gas. The initial temperature was set to 25℃, the final temperature to 600℃, and the heating rate to 20℃ / min. The thermal stability of the ink was then measured. The results are attached. Figure 2 As shown.

[0154] From the appendix Figure 2 It can be seen that polyethylene glycol (PEG) inks exhibit relatively high thermal stability, which may be due to the different thermal decomposition behavior of PEG compared to the other three binders. The thermal decomposition of PEG is a depolymerization process; the larger the molecular weight, the higher the pyrolysis temperature and the better the thermal stability. Furthermore, nano-clays can be adsorbed onto the PEG molecular chains through electrostatic and hydrogen bonding interactions, which can also increase the decomposition temperature of PEG inks. The binder PEG can improve the thermal stability of the ink.

[0155] Viscosity: Pour sufficient ink to be tested into the sample cup until the liquid level reaches the rotor immersion mark. Set the constant temperature water bath to 25°C to fully preheat the sample cup and sheath. After ensuring the sample temperature stabilizes, place the sample cup in the center of the viscometer base, start the viscometer, wait for the reading to stabilize, and record the stable viscosity reading. High viscosity helps improve the stability of the ink, prevents the precipitation or stratification of ink components, and forms good adhesion between the ink and the substrate.

[0156] The results are shown in Table 1.

[0157] Table 1. Viscosity of Ink

[0158]

[0159] As shown in Table 1, the polyethylene glycol ink prepared in Preparation Example 1 is a solid with a high viscosity, exceeding the measurement range of the viscometer. Despite its high viscosity, rheological analysis reveals significant shear-thinning characteristics, which are beneficial for improving ink uniformity and adhesion during printing. Furthermore, the printed electrode pattern maintains its shape well, solvent evaporation is rapid, shortening the production cycle, and ink loss is minimal during electrode printing.

[0160] Optical micrographs of the screen-printed electrodes made from the inks prepared in Examples 1 and 4, and their local line edges and surfaces, are shown in the appendix. Figure 3 From the appendix Figure 3 It can be seen that the electrodes printed with the polyethylene glycol ink prepared in Preparation Example 1 show relatively smooth edges and surfaces, indicating that the polyethylene glycol ink prepared in Preparation Example 1 has good printability, which helps it to exhibit better electrode performance.

[0161] Example 3

[0162] In this embodiment, the green anti-fouling electrodes prepared in Preparation Example 9 and Preparation Example 10 were tested using their CV curves. The operation method is as follows: an electrochemical workstation was used, and the scan rate was set to 100 mV / s. -1 The scan potential was -0.4 V to 0.8 V, with 5 mM [Fe(CN)6] containing 0.1 M KCl. 3- / 4- The solution is an electrolyte, and CV tests are performed.

[0163] The results are attached. Figure 4 As shown.

[0164] From the appendix Figure 4 It can be seen that as the mass ratio of the total mass of nano-clay and binder to the conductive material decreases from 1.5:1 to 1:1.5, the redox peak current of the electrode gradually increases, while as the ratio decreases to 1:2 and 1:2.5, the redox peak current of the electrode decreases. When the mass ratio of the total mass of nano-clay and binder to the conductive material is 1:1.5, the ink diffuses easily during the electrode printing process, and the maximum redox peak current can be clearly observed. Therefore, in Preparation Example 9, a mass ratio of the total mass of nano-clay and binder to the conductive material of 1:1.5 is the optimal ratio for preparing the ink.

[0165] The ratio of the total mass of the ink nano-clay and adhesive to the mass of the conductive material used in Preparation Example 10 is not within the scope of this invention.

[0166] Example 4

[0167] In this embodiment, the green anti-pollution electrodes prepared in Preparation Example 9 and Preparation Example 11 were tested for their CV curves, and the operation method was the same as in Example 3.

[0168] The results are attached. Figure 5 As shown.

[0169] From the appendix Figure 5 It can be seen that as the mass ratio of binder to nano-clay decreases from 2:1 to 1:2, the CV peak current of the electrode gradually increases, reaching its maximum value when the mass ratio of binder to nano-clay is 1:2. However, as the proportion of nano-clay further increases, the ink becomes too viscous and cannot be dispersed uniformly. Therefore, the electrode prepared in Preparation Example 9 with a mass ratio of binder to nano-clay of 1:2 exhibits the best electrochemical performance.

[0170] The mass ratio of ink binder to nano-clay used in Preparation Example 11 is not within the scope of this invention.

[0171] Example 5

[0172] This embodiment evaluates the water contact angle and electrochemical performance of the green antifouling electrodes prepared in Examples 9 and 12-16. The operation method is as follows:

[0173] Contact angle test: Measured using a contact angle meter. Hydrophilic surfaces with a smaller contact angle can prevent the displacement of surface water molecules, thereby inhibiting the non-specific adsorption of interfering substances and thus exhibiting antifouling properties.

[0174] Electrochemical performance evaluation: An electrochemical workstation was used, with the scanning potential set to -0.4–0.8 V, amplitude 50 mV, and pulse width 0.05 s, using 5 mM [Fe(CN)6] containing 0.1 M KCl. 3- / 4- The solution was used as the electrolyte, and differential pulse voltammetry (DPV) was used to evaluate the current density of electrodes prepared on different substrates.

[0175] The results are shown in Table 2.

[0176] Table 2 Electrochemical performance of green anti-pollution electrode

[0177]

[0178] Table 2 shows that the polyethylene glycol ink prepared in Preparation Example 1 resulted in the electrode with the smallest water contact angle and better antifouling performance. Compared to other inks, the polyethylene glycol ink exhibited the best electrochemical performance when printed on filter paper and PET boards, indicating that the prepared polyethylene glycol ink has broad adaptability to different substrates, and the printed electrodes showed excellent electrochemical performance. Preparation Example 12 used inks with different binders; Preparation Example 13 used inks without modification of nano-montmorillonite; Preparation Example 14 used inks without secondary modification of nano-montmorillonite using a silane coupling agent; Preparation Example 15 used inks without primary modification of nano-montmorillonite using octadecylamine; and Preparation Example 16 used inks without added conductive carbon black. The above comparative results indicate that the electrodes prepared using polyethylene glycol as a binder, nano-montmorillonite modified with a silane coupling agent, and conductive materials such as graphite and conductive carbon black exhibited the best antifouling effect and electrochemical performance.

[0179] Example 6

[0180] This embodiment evaluates the surface roughness of the green anti-pollution electrodes prepared in Preparation Examples 9 and 12. The procedure is as follows: The surface roughness of the electrode is tested using an atomic force microscope (AFM). The sample stage with the electrode sample fixed is placed inside the AFM scanner, and the selected probe is installed on the probe holder and tightened. The sample stage is moved, a specific area is selected for scanning, the laser and detector positions are finely adjusted, scanning parameters are set, a height map is obtained, and the roughness is calculated using software.

[0181] The results are attached. Figure 6 As shown.

[0182] From the appendix Figure 6 It can be seen that the green anti-fouling electrode prepared from the polyethylene glycol ink obtained in Preparation Example 1 has the largest surface roughness (R). a =370.4nm, R q =477nm). This is because the polyethylene glycol ink, as a soft solid, provides the electrode with greater thickness and a rougher surface. The increased surface roughness exposes more active sites and increases the actual surface area of ​​the electrode, thereby increasing the current response and electrochemical performance.

[0183] Example 7

[0184] This embodiment evaluates the antifouling performance of the green antifouling electrodes prepared in Preparation Examples 9 and 12. The procedure is as follows: Typical model substances were selected to evaluate the antifouling performance of the electrodes. Kaolin was used as suspended particulate matter, tyrosine and tryptophan as amino acids, bovine serum albumin (BSA) as proteins, sodium alginate (SA) as polysaccharides (extracellular polymers), and humic acid (HA) and fulvic acid (FA) as humic substances in environmental samples. A Kaolin suspension with a turbidity of approximately 300 NTU and solutions of other model organic substances with a total organic carbon concentration of approximately 30 mg / L were prepared. These solutions were added to the electrode surface and incubated for 30 min. The change in peak current before and after incubation was tested using differential pulse voltammetry (DPV).

[0185] The results are attached. Figure 7 As shown.

[0186] From the appendix Figure 7 As can be seen, compared with other inks, except for FA and SA, the signal suppression rate of the model contaminants on the electrode prepared with polyethylene glycol ink is less than 20%, indicating that polyethylene glycol ink exhibits better antifouling ability against a variety of substances in the actual sample medium. Polyethylene glycol ink has excellent antifouling ability against most substances.

[0187] Example 8

[0188] In this embodiment, the average thickness and edge perimeter of the green anti-fouling electrodes prepared in Preparation Example 9 and Preparation Example 12 were measured, and the results are shown in the appendix. Figure 8 .

[0189] From the appendix Figure 8 It can be seen that the electrode prepared in Preparation Example 9 has a relatively lower average thickness and edge perimeter compared to the electrodes prepared with the other three binders in Preparation Example 12, indicating that the electrode prepared with polyethylene glycol ink has better printing resolution and fineness, and that polyethylene glycol ink has strong printability.

[0190] Example 9

[0191] In this embodiment, the green anti-pollution electrodes prepared in Preparation Example 9 and Preparation Example 12 were tested for their CV curves, and the operation method was the same as in Example 3.

[0192] The results are attached. Figure 9 As shown.

[0193] From the appendix Figure 9 It can be seen that the electrode prepared in Example 9 has a significantly higher CV redox peak current compared to the electrode prepared in Example 12. This indicates that the electrode prepared with polyethylene glycol ink has better electrochemical performance.

[0194] Therefore, the ink prepared using the raw materials and methods described in this application has excellent rheological properties, thermal stability and viscosity, which makes the prepared electrode have excellent anti-fouling properties and good electrochemical performance. Moreover, it is low in cost, environmentally friendly and suitable for large-scale production applications.

[0195] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A green, anti-pollution electrode, characterized in that, Its raw materials include substrate and ink; The raw materials for ink preparation include binder, nano-clay, conductive material, polyvinyl alcohol, and solvent; the mass ratio of binder to conductive material is 1:(1-2); the total mass ratio of nano-clay and binder to conductive material is 1:(1-2); and the mass ratio of binder to nano-clay is 1:(1-3). The adhesive is polyethylene glycol; Nano-clay is nano-montmorillonite, and its preparation method includes the following steps: S1. Add deionized water to montmorillonite, stir at 600-1000 r / min for 1-3 h, then add the modifier solution dropwise. After the addition is complete, heat to 75-85℃, stir at 400-600 r / min for 20-30 h, let stand, take the upper suspension, centrifuge, collect the precipitate, wash the precipitate with deionized water until the filtrate is neutral, vacuum dry, grind through a 200 mesh sieve to obtain modified montmorillonite; S2. Prepare silane hydrolysis solution, add modified montmorillonite, heat to 75-85℃, stir at 400-600r / min for 1-3h, centrifuge, collect the precipitate, wash with anhydrous ethanol 2-3 times, dry at 100℃ for 6h, grind through a 200-mesh sieve to obtain the final product. The method for preparing the modifier solution is as follows: add the modifier octadecylamine to anhydrous ethanol and stir until completely dissolved, adjust the pH of the solution to 3-4, and stir at 400-600 r / min for 10 min to obtain the solution; The preparation method of silane hydrolysate is as follows: adjust the pH of the ethanol aqueous solution to 4-5, add silane coupling agent, stir at 200-400 r / min for 25-35 min, and the solution is obtained.

2. The green anti-pollution electrode according to claim 1, characterized in that, The conductive material includes graphite and conductive carbon black.

3. The green anti-pollution electrode according to claim 2, characterized in that, The mass ratio of graphite to conductive carbon black is (5-10):

1.

4. The green anti-pollution electrode according to claim 2, characterized in that, The graphite is flake graphite with a mesh size of 1000-3500.

5. The green anti-pollution electrode according to claim 2, characterized in that, The average particle size of the conductive carbon black is 20-45 nm.

6. A method for preparing a green anti-pollution electrode according to any one of claims 1 to 5, characterized in that, Includes the following steps: The substrate is fixed to the printing table, and the electrode pattern is screen-covered. Pour the ink onto the screen, swipe it at a uniform speed 2-3 times, and then let it dry and cure.

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