Antibacterial water-based graphene conductive ink and preparation method thereof

Abstract

The invention provides antibacterial water-based graphene conductive ink and a preparation method thereof, and relates to the technical field of functional conductive materials. The water-based graphene antibacterial coating comprises the following components in percentage by mass: 5-20% of graphene, 0.1-2% of a perylene quaternary ammonium salt-graphene antibacterial agent, 30-50% of water-based acrylic resin, 0.5-3% of a nonionic dispersant, 0.1-1% of a bio-based thickener, 0.1-0.5% of a pH regulator and 35-60% of deionized water. The perylene quaternary ammonium salt-graphene composite antibacterial agent is introduced, the synergistic ratio is optimized, and a water-based dispersion system and a ball milling process are combined for regulation and control, so that the problem of conflict between the antibacterial agent and the conductive network performance is solved while the dispersion stability and the interface bonding strength of graphene are improved; and effective unification of conductivity enhancement and broad-spectrum antibacterial characteristics is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of functional conductive materials, and in particular to an antibacterial water-based graphene conductive ink and a preparation method thereof. Background Art

[0002] Conductive inks are key materials in printed electronics technology, and their performance directly impacts the conductivity, stability, and reliability of electronic devices. Traditional conductive inks use metal nanoparticles or carbon-based materials (such as carbon black and carbon nanotubes) as conductive fillers. Metal-based systems are limited in application by high cost and susceptibility to oxidation, while carbon-based materials, while lower in cost, suffer from insufficient conductivity and poor dispersion stability.

[0003] As environmental regulations tighten, demand for water-based conductive inks continues to grow, but challenges are becoming increasingly apparent: insufficient compatibility between conductive fillers and water-based resins leads to a breakdown of the conductive network; differential water volatilization during the drying process causes incomplete conductive pathways; and poor dispersion stability of conductive fillers during long-term storage can easily lead to sedimentation of the conductive material. Furthermore, the medical and food packaging sectors are placing higher demands on the antimicrobial properties of materials. Existing antimicrobial technologies, which achieve this through the addition of silver ions, quaternary ammonium salts, or photocatalytic materials, offer antimicrobial properties but are accompanied by toxicity risks, poor long-term efficacy, and degraded conductivity, making them difficult to meet practical application requirements.

[0004] Patent Publication No. CN104962133A discloses a nano-water-based conductive ink that uses a highly polar solvent such as N-methylpyrrolidone to enhance its dispersion. However, this ink carries the risk of residual volatile organic compounds, limiting its application in areas related to biological and property safety, such as medical treatment and food packaging. Chinese Patent Publication No. CN105552376A discloses a polyvinylpyrrolidone / graphene conductive paste, its preparation method, and its application. While this solution addresses the difficulties of graphene dispersion and the easy accumulation of flakes in the conductive paste, the addition of polyvinylpyrrolidone in this solution affects the conductive properties of the paste. Summary of the Invention

[0005] To address the challenges of conventional water-based conductive inks, such as insufficient conductivity and dispersion stability, poor interfacial compatibility between conductive fillers and resins, and the difficulty in reconciling antimicrobial function and conductive properties, the present invention provides an antimicrobial water-based graphene conductive ink and its preparation method. By introducing a perylene quaternary ammonium salt-graphene composite antimicrobial agent and optimizing the synergistic ratio, combined with the aqueous dispersion system and ball milling process, this ink improves graphene dispersion stability and interfacial bonding strength while resolving the conflict between the antimicrobial agent and the conductive network properties, effectively combining enhanced conductivity with broad-spectrum antimicrobial properties.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] An antibacterial water-based graphene conductive ink, comprising the following components by mass fraction: Graphene 5-20%, perylene quaternary ammonium salt-graphene antibacterial agent 0.1-2%, water-based acrylic resin 30-50%, non-ionic dispersant 0.5-3%, bio-based thickener 0.1-1%, pH regulator 0.1-0.5%, deionized water 35-60%.

[0008] Preferably, the antibacterial water-based graphene conductive ink comprises the following components by mass fraction: Graphene 8-15%, perylene quaternary ammonium salt-graphene antibacterial agent 0.5-1%, water-based acrylic resin 35-40%, non-ionic dispersant 1-2%, bio-based thickener 0.3-0.6%, pH regulator 0.2-0.3%, deionized water 40-55%.

[0009] More preferably, the number of graphene layers is ≤5, and the diameter of the graphene sheets is 1 to 5 μm.

[0010] Preferably, the solid content of the water-based acrylic resin is 30-50%.

[0011] Preferably, the nonionic dispersant is one or more of polyethylene glycol PEG-400, Tween 80 or alkyl glycoside.

[0012] Preferably, the bio-based thickener is one or more of nanocellulose, sodium carboxymethyl cellulose, xanthan gum or sodium alginate.

[0013] Preferably, the pH regulator is one or more of ammonia water, sodium hydroxide, potassium hydroxide or sodium bicarbonate.

[0014] The present invention also provides a method for preparing an antibacterial water-based graphene conductive ink, comprising the following steps: (1) mixing graphene, deionized water, and a nonionic dispersant in proportion and stirring to form a premixed solution; (2) transferring the premixed solution obtained in step (1) into a ball mill, adding perylene quaternary ammonium salt-graphene antibacterial agent and zirconium oxide grinding balls for ball milling to obtain a graphene dispersion; (3) adding an aqueous acrylic resin to the graphene dispersion obtained in step (2), stirring and mixing to obtain an aqueous graphene resin; (4) adding a bio-based thickener to the aqueous graphene resin obtained in step (3) and stirring, then adding a pH regulator to adjust the pH to 8.0-9.0, and filtering through a 200-mesh sieve to remove impurities to obtain an antibacterial aqueous graphene conductive ink.

[0015] Preferably, the ball-to-material ratio of the zirconia grinding balls in step (2) is 4-6:1, and the particle size is 0.5-1 mm; the ball mill speed is 200-400 rpm, the ball milling time is 4-8 hours, and the ball milling temperature is 25-40°C.

[0016] More preferably, in step (4), a bio-based thickener is added to the aqueous graphene resin and stirred to form a mixture, and the viscosity of the mixture is 500 to 2000 mPa·s.

[0017] Compared with the prior art, the present invention has the following beneficial effects: (1) Through the synergistic effect of the perylene quaternary ammonium salt-graphene composite antibacterial agent and graphene, the antibacterial performance is improved while the conductive network is avoided from being damaged, thereby achieving a synergistic improvement in the antibacterial performance and the conductive performance; (2) Through the joint regulation of the non-ionic dispersant and the ball milling process, the graphene dispersion uniformity and interface bonding strength are significantly improved, thereby ensuring the long-term storage stability of the ink; (3) By using a bio-based thickener and a water-based resin system, the risk of volatile organic compounds is avoided, so that the antibacterial water-based conductive ink provided by the present invention can be applied to advanced manufacturing fields such as flexible electronic devices, biomedical sensors, smart packaging, and wearable devices; (4) The component ratio and process parameters are optimized to ensure that the ink viscosity is adapted to the requirements of screen printing, while simplifying the production process and reducing energy consumption; (5) Through the synergistic effect of the pH regulator and the bio-based thickener, the rheological stability of the system is improved, and the conductive channel is avoided from breaking during the drying process. DETAILED DESCRIPTION

[0018] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0019] Example 1

[0020] This embodiment provides a general antibacterial water-based graphene conductive ink formula, specifically comprising:

[0021] An antibacterial water-based graphene conductive ink, comprising the following components by mass fraction: Graphene 5-20%, perylene quaternary ammonium salt-graphene antibacterial agent 0.1-2%, water-based acrylic resin 30-50%, non-ionic dispersant 0.5-3%, bio-based thickener 0.1-1%, pH regulator 0.1-0.5%, deionized water 35-60%.

[0022] In some preferred implementation cases, the antibacterial water-based graphene conductive ink comprises the following components by mass fraction: The product comprises 8-15% graphene, 0.5-1% perylene quaternary ammonium salt-graphene antimicrobial agent, 35-40% water-based acrylic resin, 1-2% nonionic dispersant, 0.3-0.6% bio-based thickener, 0.2-0.3% pH adjuster, and 40-55% deionized water. The technical benefits of the product lie in the fact that the perylene quaternary ammonium salt-graphene antimicrobial agent forms a composite conductive-antimicrobial dual-functional unit with graphene, synergizing the hydrogen bonding stabilization of the nonionic dispersant and the film-forming properties of the water-based acrylic resin to construct a three-dimensional conductive network at the interface. The quaternary ammonium groups in the antimicrobial agent molecules are then directed to anchor at graphene defect sites, inhibiting microbial attachment and enhancing carrier transfer efficiency. The synergistic regulation of the bio-based thickener and pH adjuster further stabilizes the system's rheological properties, achieving a balanced improvement in conductivity, antimicrobial properties, and printability.

[0023] In some more preferred embodiments, the number of graphene layers is ≤5, and the graphene sheet diameter is 1-5 μm. The technical benefit is that using fewer, larger-sized graphene layers can reduce sheet stacking defects, enhance carrier migration efficiency, and provide a larger specific surface area for loading antimicrobial agents.

[0024] In some preferred embodiments, the solid content of the water-based acrylic resin is 30-50%. The technical effect is that by controlling the resin solid content, the film-forming property and viscosity are balanced, ensuring the continuity and density of the conductive network while preventing excessive ink viscosity from affecting printability.

[0025] In some preferred embodiments, the nonionic dispersant is one or more of polyethylene glycol PEG-400, Tween 80, or an alkyl glycoside. The technical benefit is that the nonionic dispersant stabilizes the graphene dispersion through the synergistic effects of hydrogen bonding and steric hindrance, while preventing charge interference from damaging the conductive network.

[0026] In some preferred embodiments, the bio-based thickener is one or more of nanocellulose, sodium carboxymethyl cellulose, xanthan gum, or sodium alginate. The technical benefit of this is that the bio-based thickener optimizes the ink's rheological properties through molecular chain entanglement and hydrogen bonding, adapting to printing process requirements. Its naturally biodegradable nature also enhances the system's environmental compatibility.

[0027] In some preferred embodiments, the pH adjuster is one or more of ammonia, sodium hydroxide, potassium hydroxide, or sodium bicarbonate. This allows for precise control of the pH value of the system to maintain a stable dispersion of the resin, preventing oxidation of the graphene or ineffectiveness of the thickener due to excessive alkalinity or acidity, while also ensuring process safety.

[0028] This embodiment also provides a method for preparing a general antibacterial water-based graphene conductive ink, which specifically includes the following steps: (1) mixing graphene, deionized water, and a nonionic dispersant in proportion and stirring to form a premixed solution; (2) transferring the premixed solution obtained in step (1) into a ball mill, adding perylene quaternary ammonium salt-graphene antibacterial agent and zirconium oxide grinding balls for ball milling to obtain a graphene dispersion; (3) adding an aqueous acrylic resin to the graphene dispersion obtained in step (2), stirring and mixing to obtain an aqueous graphene resin; (4) adding a bio-based thickener to the aqueous graphene resin obtained in step (3) and stirring, then adding a pH regulator to adjust the pH to 8.0-9.0, and filtering through a 200-mesh sieve to remove impurities to obtain an antibacterial aqueous graphene conductive ink.

[0029] In some preferred implementation cases, the ball-to-material ratio of the zirconia grinding balls in step (2) is 4 to 6:1, and the particle size is 0.5 to 1 mm; the ball mill speed is 200 to 400 rpm, the ball milling time is 4 to 8 hours, and the ball milling temperature is 25 to 40° C. The technical effect is that, through the coordinated matching of the ball-to-material ratio and the ball size, efficient exfoliation of graphene sheets and uniform loading of the antibacterial agent are achieved under low shear stress, avoiding sheet breakage caused by excessive ball milling; precise control of temperature and speed ensures the thermal stability of the dispersed system, while promoting the directional anchoring of perylene quaternary ammonium salt molecules on the graphene surface, forming a stable conductive-antibacterial composite interface.

[0030] In some preferred implementation cases, a bio-based thickener is added to the aqueous graphene resin in step (4) and stirred to form a mixture, wherein the viscosity of the mixture is 500 to 2000 mPa·s. The technical effect is that the viscosity is adjusted to match the screen printing process window, thereby ensuring a balance between ink leveling and thixotropy. At the same time, the molecular chain entanglement of the bio-based thickener cooperates with the orientation of the graphene sheets, inhibiting the breakage of the conductive path caused by the difference in water volatilization during the drying process, thereby enhancing the uniformity of film formation and the consistency of conductivity.

[0031] Example 2

[0032] This embodiment provides an antibacterial water-based graphene conductive ink, comprising the following components by weight: Graphene 15%, perylene quaternary ammonium salt-graphene antibacterial agent 1%, water-based acrylic resin 40%, deionized water 42.5%, PEG-4002%, xanthan gum 0.4%, ammonia water 0.1%.

[0033] This embodiment also provides a method for preparing an antibacterial water-based graphene conductive ink, which specifically includes the following steps: (1) Graphene, deionized water, and PEG-400 were mixed in proportion and stirred at 400 rpm for 10 minutes to form a premixed solution; (2) The premixed solution obtained in step (1) was transferred to a ball mill, and the perylene quaternary ammonium salt-graphene antibacterial agent and zirconium oxide grinding balls (ball-to-material ratio 5:1, particle size 1 mm) were added, and the mixture was ball milled at 300 rpm for 6 hours, and the temperature was controlled to be ≤40°C to obtain a graphene dispersion; (3) adding an aqueous acrylic resin to the graphene dispersion obtained in step (2) at a stirring speed of 150 rpm for 30 minutes to obtain an aqueous graphene resin; (4) adding xanthan gum thickener to the aqueous graphene resin obtained in step (3) and stirring until the viscosity reaches 500-2000 mPa·s (25° C.), then adding a pH regulator to adjust the pH to 8.0, and filtering through a 200-mesh sieve to remove impurities to obtain an antibacterial aqueous graphene conductive ink.

[0034] Example 3

[0035] This embodiment provides an antibacterial water-based graphene conductive ink, comprising the following components by weight: Graphene 8%, perylene quaternary ammonium salt-graphene antibacterial agent 0.1%, water-based acrylic resin 35%, deionized water 54.7%, PEG-400 1.5%, xanthan gum 0.5%, and ammonia water 0.3%.

[0036] This embodiment also provides a method for preparing an antibacterial water-based graphene conductive ink, which specifically includes the following steps: (1) Graphene, deionized water, and PEG-400 were mixed in proportion and stirred at 400 rpm for 10 minutes to form a premixed solution; (2) transferring the premixed solution obtained in step (1) into a ball mill, adding perylene quaternary ammonium salt-graphene antibacterial agent and zirconium oxide grinding balls (ball-to-material ratio 5:1, particle size 0.5-1 mm), and ball milling at 300 rpm for 6 hours, controlling the temperature to ≤40°C, to obtain a graphene dispersion; (3) adding an aqueous acrylic resin to the graphene dispersion obtained in step (2) at a stirring speed of 150 rpm for 30 minutes to obtain an aqueous graphene resin; (4) adding xanthan gum thickener to the aqueous graphene resin obtained in step (3) and stirring until the viscosity reaches 500-2000 mPa·s (25° C.), then adding a pH regulator to adjust the pH to 8.0, and filtering through a 200-mesh sieve to remove impurities to obtain an antibacterial aqueous graphene conductive ink.

[0037] Example 4

[0038] This embodiment provides an antibacterial water-based graphene conductive ink, comprising the following components by weight: Graphene 12%, perylene quaternary ammonium salt-graphene antibacterial agent 0.5%, water-based acrylic resin 45%, deionized water 40%, PEG-400 2.5%, xanthan gum 0.3%, and ammonia water 0.2%.

[0039] This embodiment also provides a method for preparing an antibacterial water-based graphene conductive ink, which specifically includes the following steps: (1) Graphene, deionized water, and PEG-400 were mixed in proportion and stirred at 400 rpm for 10 minutes to form a premixed solution; (2) transferring the premixed solution obtained in step (1) into a ball mill, adding perylene quaternary ammonium salt-graphene antibacterial agent and zirconium oxide grinding balls (ball-to-material ratio 5:1, particle size 0.5-1 mm), and ball milling at 300 rpm for 6 hours, controlling the temperature to ≤40°C, to obtain a graphene dispersion; (3) adding an aqueous acrylic resin to the graphene dispersion obtained in step (2) at a stirring speed of 150 rpm for 30 minutes to obtain an aqueous graphene resin; (4) adding xanthan gum thickener to the aqueous graphene resin obtained in step (3) and stirring until the viscosity reaches 500-2000 mPa·s (25° C.), then adding a pH regulator to adjust the pH to 8.0, and filtering through a 200-mesh sieve to remove impurities to obtain an antibacterial aqueous graphene conductive ink.

[0040] Example 5

[0041] This embodiment provides an antibacterial water-based graphene conductive ink, comprising the following components by weight: Graphene 10%, perylene quaternary ammonium salt-graphene antibacterial agent 2%, water-based acrylic resin 38%, deionized water 49.5%, PEG-400 1.8%, xanthan gum 0.6%, and ammonia water 0.1%.

[0042] This embodiment also provides a method for preparing an antibacterial water-based graphene conductive ink, which specifically includes the following steps: (1) Graphene, deionized water, and PEG-400 were mixed in proportion and stirred at 400 rpm for 10 minutes to form a premixed solution; (2) transferring the premixed solution obtained in step (1) into a ball mill, adding perylene quaternary ammonium salt-graphene antibacterial agent and zirconium oxide grinding balls (ball-to-material ratio 5:1, particle size 0.5-1 mm), and ball milling at 300 rpm for 6 hours, controlling the temperature to ≤40°C, to obtain a graphene dispersion; (3) adding an aqueous acrylic resin to the graphene dispersion obtained in step (2) at a stirring speed of 150 rpm for 30 minutes to obtain an aqueous graphene resin; (4) adding xanthan gum thickener to the aqueous graphene resin obtained in step (3) and stirring until the viscosity reaches 500-2000 mPa·s (25° C.), then adding a pH regulator to adjust the pH to 8.0, and filtering through a 200-mesh sieve to remove impurities to obtain an antibacterial aqueous graphene conductive ink.

[0043] Comparative Example 1

[0044] The difference between this comparative example and Example 2 is that the antibacterial agent component used in this comparative example is a quaternary ammonium salt.

[0045] This comparative example provides an antibacterial water-based graphene conductive ink, comprising the following components by mass fraction: Graphene 15%, quaternary ammonium antibacterial agent 1%, water-based acrylic resin 40%, deionized water 42.5%, PEG-4002%, xanthan gum 0.4%, ammonia water 0.1%.

[0046] This comparative example also provides a method for preparing an antibacterial water-based graphene conductive ink, which specifically comprises the following steps: (1) Graphene, deionized water, and PEG-400 were mixed in proportion and stirred at 400 rpm for 10 minutes to form a premixed solution; (2) transferring the premixed solution obtained in step (1) into a ball mill, adding a quaternary ammonium salt antibacterial agent and zirconium oxide grinding balls (ball-to-material ratio 5:1, particle size 1 mm), and ball milling at 300 rpm for 6 hours, controlling the temperature to ≤40°C, to obtain a graphene dispersion; (3) adding an aqueous acrylic resin to the graphene dispersion obtained in step (2) at a stirring speed of 150 rpm for 30 minutes to obtain an aqueous graphene resin; (4) adding xanthan gum thickener to the aqueous graphene resin obtained in step (3) and stirring until the viscosity reaches 500-2000 mPa·s (25° C.), then adding a pH regulator to adjust the pH to 8.0, and filtering through a 200-mesh sieve to remove impurities to obtain an antibacterial aqueous graphene conductive ink.

[0047] Comparative Example 2

[0048] The difference between this comparative example and Example 2 is that the antibacterial agent component used in this comparative example is nanosilver.

[0049] This comparative example provides an antibacterial water-based graphene conductive ink, comprising the following components by mass fraction: Graphene 15%, nano-silver antibacterial agent 1%, water-based acrylic resin 40%, deionized water 42.5%, PEG-4002%, xanthan gum 0.4%, ammonia water 0.1%.

[0050] This comparative example also provides a method for preparing an antibacterial water-based graphene conductive ink, which specifically comprises the following steps: (1) Graphene, deionized water, and PEG-400 were mixed in proportion and stirred at 400 rpm for 10 minutes to form a premixed solution; (2) transferring the premixed solution obtained in step (1) into a ball mill, adding nanosilver antibacterial agent and zirconium oxide grinding balls (ball-to-material ratio 5:1, particle size 1 mm), and ball milling at 300 rpm for 6 hours, controlling the temperature to ≤40°C, to obtain a graphene dispersion; (3) adding an aqueous acrylic resin to the graphene dispersion obtained in step (2) at a stirring speed of 150 rpm for 30 minutes to obtain an aqueous graphene resin; (4) adding xanthan gum thickener to the aqueous graphene resin obtained in step (3) and stirring until the viscosity reaches 500-2000 mPa·s (25° C.), then adding a pH regulator to adjust the pH to 8.0, and filtering through a 200-mesh sieve to remove impurities to obtain an antibacterial aqueous graphene conductive ink.

[0051] Comparative Example 3

[0052] The difference between this comparative example and Example 2 is that the antibacterial agent component used in this comparative example is a titanium dioxide composite.

[0053] This comparative example provides an antibacterial water-based graphene conductive ink, comprising the following components by mass fraction: Graphene 15%, titanium dioxide complex 1%, water-based acrylic resin 40%, deionized water 42.5%, PEG-400 2%, xanthan gum 0.4%, ammonia 0.1%.

[0054] This comparative example also provides a method for preparing an antibacterial water-based graphene conductive ink, which specifically comprises the following steps: (1) Graphene, deionized water, and PEG-400 were mixed in proportion and stirred at 400 rpm for 10 minutes to form a premixed solution; (2) The premixed solution obtained in step (1) was transferred to a ball mill, titanium dioxide composite and zirconium oxide grinding balls (ball-to-material ratio 5:1, particle size 1 mm) were added, and the mixture was ball milled at 300 rpm for 6 hours while controlling the temperature to ≤40°C to obtain a graphene dispersion; (3) adding an aqueous acrylic resin to the graphene dispersion obtained in step (2) at a stirring speed of 150 rpm for 30 minutes to obtain an aqueous graphene resin; (4) adding xanthan gum thickener to the aqueous graphene resin obtained in step (3) and stirring until the viscosity reaches 500-2000 mPa·s (25° C.), then adding a pH regulator to adjust the pH to 8.0, and filtering through a 200-mesh sieve to remove impurities to obtain an antibacterial aqueous graphene conductive ink.

[0055] Comparative Example 4

[0056] The difference between this comparative example and Example 5 is that the mass fraction of the perylene quaternary ammonium salt-graphene antibacterial agent added in this comparative example is 3%.

[0057] This comparative example provides an antibacterial water-based graphene conductive ink, comprising the following components by mass fraction: Graphene 10%, perylene quaternary ammonium salt-graphene antibacterial agent 3%, water-based acrylic resin 38%, deionized water 48.5%, PEG-400 1.8%, xanthan gum 0.6%, and ammonia water 0.1%.

[0058] This comparative example also provides a method for preparing an antibacterial water-based graphene conductive ink, which specifically comprises the following steps: (1) Graphene, deionized water, and PEG-400 were mixed in proportion and stirred at 400 rpm for 10 minutes to form a premixed solution; (2) transferring the premixed solution obtained in step (1) into a ball mill, adding perylene quaternary ammonium salt-graphene antibacterial agent and zirconium oxide grinding balls (ball-to-material ratio 5:1, particle size 0.5-1 mm), and ball milling at 300 rpm for 6 hours, controlling the temperature to ≤40°C, to obtain a graphene dispersion; (3) adding an aqueous acrylic resin to the graphene dispersion obtained in step (2) at a stirring speed of 150 rpm for 30 minutes to obtain an aqueous graphene resin; (4) adding xanthan gum thickener to the aqueous graphene resin obtained in step (3) and stirring until the viscosity reaches 500-2000 mPa·s (25° C.), then adding a pH regulator to adjust the pH to 8.0, and filtering through a 200-mesh sieve to remove impurities to obtain an antibacterial aqueous graphene conductive ink.

[0059] Test example

[0060] The antibacterial water-based graphene conductive inks prepared using the formulas and methods of Examples 2-5 and Comparative Examples 1-4 were tested for antibacterial and conductive properties. The test methods are as follows: 1. Antibacterial properties were tested according to the method disclosed in GB / T21510-2008 "Test Method for Antibacterial Properties of Nanoinorganic Materials" to detect its antibacterial properties against Escherichia coli and Staphylococcus aureus; 2. The electrical conductivity was tested according to the method disclosed in JJG508-2004 "Determination of electrical conductivity of graphene materials by four-probe method" to detect its electrical conductivity.

[0061] The antibacterial properties and conductive properties of the antibacterial water-based graphene conductive inks prepared by the formulations and methods of Examples 2-5 and Comparative Examples 1-4 are shown in Table 1.

[0062] Table 1 Case Conductivity (S / m) Antibacterial rate of Escherichia coli (%) Antibacterial rate of Staphylococcus aureus (%) Example 2 ≥1500 ≥99.9 ≥99.9 Example 3 ≥800 ≥75.1 ≥70.2 Example 4 ≥1200 ≥97.2 ≥96.8 Example 5 ≥500 ≥99.9 ≥99.9 Comparative Example 1 ≤300 ≥85.2 ≥82.7 Comparative Example 2 ≤500 ≥99.8 ≥99.5 Comparative Example 3 ≤600 ≤45.3 (non-light conditions) ≤40.1 (non-light conditions) Comparative Example 4 ≤200 ≥99.9 ≥99.8

[0063] As can be seen from Table 1, the technical solution of the present invention achieves the simultaneous improvement of the antibacterial and conductive properties of the antibacterial water-based graphene conductive ink through formula and parameter optimization, showing significant technical advantages over the comparative example.

[0064] Comparative Example 1 uses ordinary quaternary ammonium salt as an antibacterial agent. Due to the lack of structural support of the graphene composite carrier, the bonding force between the quaternary ammonium salt molecules and the graphene interface is weak, resulting in a break in the conductive network, resulting in a decrease in electrical conductivity. At the same time, due to the loss of the synergistic antibacterial effect of graphene, the antibacterial rate of Escherichia coli and Staphylococcus aureus is only maintained at about 85%, which is significantly lower than the antibacterial efficiency of ≥99.9% achieved by the composite system in Example 2.

[0065] Although the introduction of the nanosilver component in Comparative Example 2 retains a high antibacterial rate, the physical accumulation of nanosilver particles between the graphene layers seriously hinders electron transmission, limiting the electrical conductivity to ≤500 S / m, and the migration of silver ions may cause performance degradation. In Example 2, a stable composite structure formed by chemically bonding perylene quaternary ammonium salt and graphene not only ensures high conductivity, but also avoids the hidden danger of metal ion migration.

[0066] Comparative Example 3 uses a titanium dioxide composite as an antimicrobial agent. Its insulating properties directly disrupt the conductive pathway, causing a sharp drop in conductivity. More critically, the photocatalytic antimicrobial mechanism completely fails in darkness, leading to a sharp drop in antimicrobial efficacy. In contrast, Example 2 utilizes a light-independent antimicrobial mechanism, highlighting the superiority of the composite antimicrobial system provided by the present invention.

[0067] Comparative Example 4 maintains a high antibacterial rate by excessively loading the perylene quaternary ammonium salt-graphene antibacterial agent, but excessive coverage of the graphene surface hinders carrier migration, and the conductivity plummets to ≤200 S / m, while causing cost and dispersion stability problems. Example 2 achieves high conductivity while achieving a broad-spectrum antibacterial performance of ≥95% by precisely controlling the composite ratio, verifying the necessity of optimizing the ratio of the present invention.

[0068] Unless otherwise specified, the raw materials and equipment used in the present invention are commonly used in the art; unless otherwise specified, the methods used in the present invention are conventional methods in the art. The above description is merely a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, alteration, or equivalent transformation of the above embodiment based on the technical essence of the present invention still falls within the scope of protection of the technical solution of the present invention.

Claims

1. An antibacterial water-based graphene conductive ink, characterized in that: Includes the following mass fraction components: Graphene 5-20%, perylene quaternary ammonium salt-graphene antibacterial agent 0.1-2%, water-based acrylic resin 30-50%, non-ionic dispersant 0.5-3%, bio-based thickener 0.1-1%, pH regulator 0.1-0.5%, deionized water 35-60%.

2. The antibacterial water-based graphene conductive ink according to claim 1, characterized in that: Includes the following mass fraction components: Graphene 8-15%, perylene quaternary ammonium salt-graphene antibacterial agent 0.5-1%, water-based acrylic resin 35-40%, non-ionic dispersant 1-2%, bio-based thickener 0.3-0.6%, pH regulator 0.2-0.3%, deionized water 40-55%.

3. An antibacterial water-based graphene conductive ink according to claim 1 or 2, characterized in that: The number of graphene layers is ≤5, and the diameter of the graphene sheets is 1 to 5 μm.

4. The antibacterial water-based graphene conductive ink according to claim 1, characterized in that: The solid content of the water-based acrylic resin is 30-50%.

5. The antibacterial water-based graphene conductive ink according to claim 1, characterized in that: The nonionic dispersant is one or more of polyethylene glycol PEG-400, Tween 80 or alkyl glycoside.

6. The antibacterial water-based graphene conductive ink according to claim 1, characterized in that: The bio-based thickener is one or more of nanocellulose, sodium carboxymethyl cellulose, xanthan gum or sodium alginate.

7. The antibacterial water-based graphene conductive ink according to claim 1, characterized in that: The pH regulator is one or more of ammonia water, sodium hydroxide, potassium hydroxide or sodium bicarbonate.

8. A method for preparing the antibacterial water-based graphene conductive ink according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) mixing graphene, deionized water, and a nonionic dispersant in proportion and stirring to form a premixed solution; (2) transferring the premixed solution obtained in step (1) into a ball mill, adding perylene quaternary ammonium salt-graphene antibacterial agent and zirconium oxide grinding balls for ball milling to obtain a graphene dispersion; (3) adding an aqueous acrylic resin to the graphene dispersion obtained in step (2), stirring and mixing to obtain an aqueous graphene resin; (4) adding a bio-based thickener to the aqueous graphene resin obtained in step (3) and stirring, then adding a pH regulator to adjust the pH to 8.0-9.0, and filtering through a 200-mesh sieve to remove impurities to obtain an antibacterial aqueous graphene conductive ink.

9. The preparation method according to claim 8, characterized in that In the step (2), the ball-to-material ratio of the zirconia grinding balls is 4-6:1, and the particle size is 0.5-1 mm; the ball mill speed is 200-400 rpm, the ball milling time is 4-8 hours, and the ball milling temperature is 25-40° C.

10. The preparation method according to claim 8 or 9, characterized in that: In the step (4), a bio-based thickener is added to the aqueous graphene resin and stirred to form a mixture, wherein the viscosity of the mixture is 500 to 2000 mPa·s.