CN110698924B - Graphene slurry, conductive ink and preparation method thereof - Google Patents
Graphene slurry, conductive ink and preparation method thereof Download PDFInfo
- Publication number
- CN110698924B CN110698924B CN201910974581.1A CN201910974581A CN110698924B CN 110698924 B CN110698924 B CN 110698924B CN 201910974581 A CN201910974581 A CN 201910974581A CN 110698924 B CN110698924 B CN 110698924B
- Authority
- CN
- China
- Prior art keywords
- graphene
- conductive ink
- sulfate
- graphene slurry
- ethanol
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D11/00—Inks
- C09D11/52—Electrically conductive inks
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Wood Science & Technology (AREA)
- Organic Chemistry (AREA)
- Carbon And Carbon Compounds (AREA)
- Inks, Pencil-Leads, Or Crayons (AREA)
Abstract
The invention relates to graphene slurry, conductive ink and a preparation method thereof. The raw materials of the graphene slurry comprise graphene, dibasic acid ester and ethanol; the dosage of the divalent acid ester corresponding to each 1.5g of graphene is 20-100 mL, and the dosage of ethanol is 50-250 mL; the graphene is obtained by the following preparation method: obtaining electrolyte containing sulfuric acid and sulfate; in the electrolyte, graphite is used as a positive electrode, and working voltage is applied to strip the graphite to obtain turbid liquid; removing the liquid part in the suspension, washing and ultrasonically treating the obtained solid part, then placing the solid part at the temperature of between 100 ℃ below zero and 60 ℃ below zero for 2 to 8 hours, and then placing the solid part at the temperature of between 56 ℃ below zero and 44 ℃ below zero for 35 to 55 hours. The graphene slurry is prepared by taking graphene prepared by a specific process as a raw material and matching dibasic acid ester as a main solvent, and the stability, printability and conductivity of printing ink prepared from the graphene slurry meet application requirements.
Description
Technical Field
The invention relates to the technical field of graphene materials, and particularly relates to graphene slurry, conductive ink and a preparation method of the conductive ink.
Background
With the rapid development of the electronic industry, the conductive ink is more and more widely applied in the fields of flexible printed circuits, membrane switches, radio frequency identification and the like. Compared with the traditional metal conductive ink and silver nano material conductive ink, the graphene conductive ink has higher stability and lower cost; compared with carbon-based conductive ink, the conductive ink has lower resistivity, i.e., better conductivity. The graphene serving as the conductive filler of the conductive ink has excellent conductivity, corrosion resistance and oxidation resistance, is one of the most popular and potential printing electronic materials, and has wide application prospects.
At present, two technical approaches are mainly adopted for preparing graphene conductive ink, one is graphene ink based on a liquid phase stripping method, and the other is graphene ink based on a redox method.
The liquid phase stripping method is to disperse graphite powder in solvents such as N-methyl pyrrolidone (NMP), dimethyl formamide (DMF) and the like to reduce van der Waals force between sheet layers, strip the graphite layer by layer in the solvents through external force action such as ultrasonic waves and the like, add a surfactant or a polymer to assist dispersion, and prepare the graphene conductive ink through solvent exchange and the like.
The redox method is to oxidize graphite in a strong acid and strong oxidant system, weaken the van der Waals acting force between the sheets, promote the graphite oxide to be stripped in a solvent to form graphene oxide, and then remove oxygen-containing groups through a reduction process to convert the graphene oxide into reduced graphene oxide. The dispersity of the reduced graphene oxide is reduced, and the graphene conductive ink is prepared by the aid of a surfactant or a polymer for assisting in dispersing. The dispersion of graphene oxide is also directly used as ink, but reduction treatment is required after printing to convert the printed circuit into a conductive circuit.
The yield of the graphene prepared by the liquid phase stripping method is low, a large amount of un-stripped graphite is left in the preparation process, and a repeated separation and purification process is needed; in addition, the graphene sheet layer is broken by using external forces such as ultrasound, so that graphene with smaller size is generally obtained, and the conductivity of the graphene is influenced; solvents such as NMP, DMF and the like used for stripping have strong toxicity and corrosiveness and are easy to cause harm to the environment and human health.
The method for directly using the dispersion liquid of the graphene oxide as the ink is relatively easy to prepare, stable in dispersion and wide in concentration range, but the conditions of the subsequent reduction or post-treatment process are harsh, and the common conditions such as hydrazine hydrate fumigation, hydroiodic acid fumigation, high-temperature heat treatment and the like have high tolerance requirements on a printing substrate, so that the application range of the method is limited. The conductive ink prepared by the pre-reduction method is poor in dispersibility, the concentration of graphene in the ink is low, and the conductive ink can be printed repeatedly or subjected to high-temperature heat treatment to achieve good conductivity. The pre-reduction and the post-printing reduction have the common problem that the reduction process cannot completely repair the structural defects of the graphene oxide and needs to be improved in the aspect of electrical properties.
Overall, the performance of the ink prepared from the graphene obtained by the above conventional method needs to be improved to meet the requirements of the application on ink stability, printability and printed circuit conductivity.
Disclosure of Invention
Based on this, the main object of the present invention is to provide a graphene paste. The graphene slurry is prepared by taking graphene prepared by a specific process as a raw material and adopting dibasic ester as a main solvent in a matching manner, and the stability, the printability and the conductivity of a printed circuit of the ink prepared from the graphene slurry meet application requirements.
The purpose of the invention is realized by the following technical scheme:
the graphene slurry is characterized in that raw materials for preparing the graphene slurry comprise graphene, dibasic ester and ethanol; the dosage of the dibasic acid ester corresponding to each 1.5g of the graphene is 20 mL-100 mL, and the dosage of the ethanol is 50 mL-250 mL;
wherein the graphene is obtained by the following preparation method:
(1) obtaining electrolyte containing sulfuric acid and sulfate;
(2) in the electrolyte, graphite is used as a positive electrode, and working voltage is applied to strip the graphite to obtain turbid liquid;
(3) removing the liquid part in the suspension, washing and ultrasonically treating the obtained solid part, then placing the solid part at the temperature of between 100 ℃ below zero and 60 ℃ below zero for 2 to 8 hours, and then placing the solid part at the temperature of between 56 ℃ below zero and 44 ℃ below zero for 35 to 55 hours.
In one embodiment, the molar ratio of the sulfuric acid to the sulfate in the electrolyte is not more than 3, and the sum of the molar concentrations of the sulfuric acid and the sulfate in the electrolyte is 0.01 mol/L-1 mol/L.
In one embodiment, the molar ratio of the sulfuric acid to the sulfate is 0.5-2, and the sum of the molar concentrations of the sulfuric acid and the sulfate in the electrolyte is 0.05-0.3 mol/L.
In one embodiment, the stripping takes platinum as the negative electrode; or/and the sulfate is selected from at least one of ammonium sulfate, sodium sulfate and potassium sulfate; or/and the working voltage is 1V-20V.
In one embodiment, every 1.5g of the graphene corresponds to 25 mL-40 mL of dibasic ester and 80 mL-120 mL of ethanol.
The invention provides a preparation method of graphene slurry, which comprises the following steps:
(1) obtaining electrolyte containing sulfuric acid and sulfate;
(2) in the electrolyte, graphite is used as a positive electrode, and working voltage is applied to strip the graphite to obtain turbid liquid;
(3) removing a liquid part in the suspension, washing and ultrasonically treating an obtained solid part, then placing the solid part at the temperature of between 100 ℃ below zero and 60 ℃ below zero for 2 to 8 hours, and then placing the solid part at the temperature of between 56 ℃ below zero and 44 ℃ below zero for 35 to 55 hours to obtain graphene;
(4) and mixing the graphene, the dibasic acid ester and the ethanol, homogenizing, and removing the ethanol to obtain graphene slurry.
In one embodiment, the conditions of the homogenization process comprise: the speed is 3000 rpm-10000 rpm, and the time is 30 min-80 min.
The invention also aims to provide application of the graphene paste in preparation of conductive ink.
The invention also aims to provide a conductive ink, and the raw materials for preparing the conductive ink comprise the graphene slurry and an organic cosolvent; the mass of the organic cosolvent is 0.05-200 times of the mass of the graphene slurry.
In one embodiment, the mass of the organic cosolvent is 10-200 times of the mass of the graphene slurry, the raw materials for preparing the conductive ink further comprise a surfactant and/or a film-forming resin, and the mass of the surfactant is 0.2-4% of the mass of the graphene slurry; the mass of the film-forming resin is 0.8-15% of that of the graphene slurry;
or the mass of the organic cosolvent is 0.05-2 times of the mass of the graphene slurry, the raw materials for preparing the conductive ink also comprise a surfactant and a film-forming resin, and the mass of the surfactant is 0.2-10% of the mass of the graphene slurry; the mass of the film-forming resin is 1-20% of the mass of the graphene slurry.
In one embodiment, the organic co-solvent is selected from at least one of ethanol, n-propanol, isopropanol, ethylene glycol, diethylene glycol, propylene glycol methyl ether, ethylene glycol butyl ether, triethylene glycol butyl ether, dimethyl sulfoxide, pentanediol, and hexanediol; or/and the surfactant is one or two of anionic and nonionic; and/or the film-forming resin is at least one selected from vinyl chloride-vinyl acetate resin, epoxy resin, polyurethane resin, polyacrylic resin, ethyl cellulose and nano cellulose.
Still another object of the present invention is to provide a method for preparing the above conductive ink, the method comprising: mixing the above raw materials.
Compared with the prior art, the invention has the following beneficial effects:
the graphene paste is prepared by taking graphene prepared by a specific process (taking graphite as a positive electrode, stripping a graphite electrode in an electrolyte containing sulfuric acid and sulfate, washing and ultrasonically treating a solid part of obtained turbid liquid and then carrying out proper low-temperature treatment) as a raw material and adopting dibasic ester as a main solvent, and the ink prepared by the graphene paste has the advantages of meeting application requirements on stability, printability and printed circuit conductivity. In addition, the method has the advantages of simple and mild overall process, environmental protection, adjustable performance and suitability for large-scale production.
Drawings
Fig. 1 is a scanning electron micrograph of the electrically exfoliated graphene powder of example 1;
FIG. 2 shows XRD, Raman, and XPS measurements of the electrically exfoliated graphene of example 1;
FIG. 3 is a photograph of the dispersibility of the low concentration conductive ink of example 1;
FIG. 4 is a photograph of a film coated with the high concentration conductive ink of example 1;
fig. 5 is a photograph of a high concentration graphene conductive ink pattern print;
fig. 6 is a scanning photograph of the high-concentration graphene conductive ink after coating, film forming and annealing.
Detailed Description
In order that the invention may be more fully understood, reference will now be made to the following description. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
The embodiment of the invention provides graphene slurry, and raw materials for preparing the graphene slurry comprise graphene, dibasic acid ester and ethanol; the dosage of the dibasic acid ester corresponding to each 1.5g of the graphene is 20 mL-100 mL, and the dosage of the ethanol is 50 mL-250 mL;
wherein the graphene is obtained by the following preparation method:
(1) obtaining electrolyte containing sulfuric acid and sulfate;
(2) in the electrolyte, graphite is used as a positive electrode, and working voltage is applied to strip the graphite to obtain turbid liquid;
(3) removing the liquid part in the suspension, washing and ultrasonically treating the obtained solid part, then placing the solid part at the temperature of between 100 ℃ below zero and 60 ℃ below zero for 2 to 8 hours, and then placing the solid part at the temperature of between 56 ℃ below zero and 44 ℃ below zero for 35 to 55 hours.
In one embodiment, in the step (1), the molar ratio of the sulfuric acid to the sulfate in the electrolyte is not more than 3, and the sum of the molar concentrations of the sulfuric acid and the sulfate in the electrolyte is 0.01mol/L to 1 mol/L.
In one embodiment, in the step (1), the molar ratio of the sulfuric acid to the sulfate is 0.5-2, and the sum of the molar concentrations of the sulfuric acid and the sulfate is 0.05-0.3 mol/L.
In one embodiment, in step (1), the sulfate salt is selected from at least one of ammonium sulfate, sodium sulfate, and potassium sulfate.
In one embodiment, in step (2), the stripping is performed with platinum as the negative electrode. It is understood that other materials may be used for the negative electrode material. In order to enhance the peeling effect, the negative electrode and the positive electrode may be formed in a sheet form, such as graphite foil or platinum foil.
In one embodiment, in the step (2), the operating voltage is 1V to 20V.
In one embodiment, in step (3), the liquid portion of the suspension is removed by a method including, but not limited to, suction filtration.
In one embodiment, in step (3), the washing is performed by sequentially washing with water and ethanol, and it is understood that the water is deionized water.
In one embodiment, in step (3), the time for the ultrasonic treatment is 10min to 60 min.
In one embodiment, the dosage of the dibasic ester corresponding to each 1.5g of the graphene is 25 mL-40 mL, and the dosage of the ethanol is 80 mL-120 mL.
According to the embodiment of the invention, the graphene prepared by a specific method is used as a raw material, and the divalent acid ester is used as a main solvent to prepare the graphene slurry, so that the graphene slurry with excellent dispersion stability can be prepared, and the use of a solvent or a reducing agent with strong toxicity and corrosivity is effectively avoided, and the preparation method is green and environment-friendly. The graphene with controllable oxygen content obtained by the preparation process has high quality (I) D /I G A value of about-0.5) and is easily dispersible. Specifically, the oxygen content of the graphene raw material adopted in this embodiment is 5% to 20%. The Raman characterization shows that the 2D peak of the peeled graphene is 2710cm -1 G peak at-1586cm -1 D peak is-1356 cm -1 And lowest I D /I G The value is about-0.4, and the quality is high; the peak position is 27 degrees after characterization by XRD; XPS shows that the bonding position of C-C bond is 284.8eV, the bonding position of C-OH bond is 285.5eV, the bonding position of C ═ O bond is 287.6eV, the bonding position of C (O) -O bond is 290.1eV, and the peak position of graphene is met. These data indicate that the exfoliation material is graphene and the exfoliation quality is good.
The embodiment also provides a preparation method of the graphene slurry, which includes the following steps:
(1) obtaining electrolyte containing sulfuric acid and sulfate;
(2) in the electrolyte, graphite is used as a positive electrode, and working voltage is applied to strip the graphite to obtain turbid liquid;
(3) removing a liquid part in the suspension, washing and ultrasonically treating an obtained solid part, then placing the solid part at the temperature of between 100 ℃ below zero and 60 ℃ below zero for 2 to 8 hours, and then placing the solid part at the temperature of between 56 ℃ below zero and 44 ℃ below zero for 35 to 55 hours to obtain graphene;
(4) and mixing the graphene, the dibasic acid ester and the ethanol, homogenizing, and removing the ethanol to obtain graphene slurry.
In one embodiment, the conditions of the homogenization process comprise: the speed is 3000 rpm-10000 rpm, and the time is 30 min-80 min.
In one embodiment, the method of removing the ethanol includes, but is not limited to, heating.
The embodiment of the invention also provides application of the graphene slurry in preparation of conductive ink.
The embodiment of the invention also provides the conductive ink, and the preparation raw materials of the conductive ink comprise the graphene slurry and an organic cosolvent; the mass of the organic cosolvent is 0.05-200 times of that of the graphene slurry.
The stable graphene slurry is compounded to prepare the graphene conductive ink suitable for various printing, printing and coating processes, and the material system and the preparation technology have strong universality. Aiming at different high and low concentration graphene conductive ink and printing technology, no additional development of a separate process is needed.
According to the content of graphene in the conductive ink, the conductive ink can be divided into high-concentration graphene conductive ink and low-concentration graphene conductive ink. The high-concentration graphene conductive ink can be suitable for technologies such as silk-screen printing, gravure printing, flexo printing and blade coating. The low-concentration graphene conductive ink can be suitable for ink-jet printing, spraying and other technologies.
In one embodiment, the mass of the organic cosolvent is 10-200 times of the mass of the graphene slurry, the raw materials for preparing the conductive ink further comprise a surfactant and/or a film-forming resin, and the mass of the surfactant is 0.2-4% of the mass of the graphene slurry; the mass of the film-forming resin is 0.8-15% of the mass of the graphene slurry. The formula is low-concentration graphene conductive ink and can be suitable for ink-jet printing, spraying and other technologies.
In one embodiment, the mass of the organic cosolvent is 0.05 to 2 times of the mass of the graphene slurry, the raw materials for preparing the conductive ink further comprise a surfactant and a film-forming resin, and the mass of the surfactant is 0.2 to 10 percent of the mass of the graphene slurry; the mass of the film-forming resin is 1-20% of the mass of the graphene slurry. The graphene conductive ink with the formula is high-concentration graphene conductive ink, and is suitable for technologies such as silk screen printing, gravure printing, flexo printing and blade coating.
In one embodiment, the organic co-solvent is selected from at least one of ethanol, n-propanol, isopropanol, ethylene glycol, diethylene glycol, propylene glycol methyl ether, ethylene glycol butyl ether, triethylene glycol butyl ether, dimethyl sulfoxide, pentanediol, and hexanediol; or/and the surfactant is one or two of anionic and nonionic; and/or the film-forming resin is at least one selected from vinyl chloride-vinyl acetate resin, epoxy resin, polyurethane resin, polyacrylic resin, ethyl cellulose and nano cellulose.
It is a further object of an embodiment of the present invention to provide a method for preparing the above conductive ink, the method comprising: mixing the above raw materials.
In one embodiment, the mixing is performed by using a revolution and rotation mixer, and the mixing conditions include: the rotating speed is 500-3000 rpm, and the time is 1-30 min.
The raw materials involved in this example are all commercially available raw materials, among which dibasic acid ester, jinteng chemical industry.
Example 1
(1) Preparation of graphene slurry
1) 100mL of a mixed electrolyte of sulfuric acid and ammonium sulfate (deionized water as a solvent) with a molar ratio of 1:1 was prepared, and the total concentration was 0.1mol/L, and the mixture was charged into a 120mL electrolytic cell.
2) Graphite foil of 2cm × 5cm and platinum sheet of 2cm × 2cm were used as positive and negative electrodes, respectively, and 10V was applied to gradually peel the graphite foil.
3) The stripped suspension was poured into a suction filter and washed three times with 300mL of deionized water and 300mL of ethanol in this order.
4) And then, transferring the graphene powder into a beaker, adding 200mL of deionized water, carrying out ultrasonic crushing for 10min, placing the beaker in a refrigerator at minus 80 ℃ for pre-freezing for 6h, and then placing the beaker in a freeze dryer for freeze drying for 48h at minus 50 ℃ to obtain graphene powder with the oxygen content of 8%.
The scanning electron microscope photograph of the graphene powder prepared in the step is shown in fig. 1, and the test results of XRD, raman and XPS are shown in fig. 2. As can be seen from fig. 1 and 2, the surface of the exfoliated graphene is wrinkled, and the functional group bonding position characterized by XRD, raman peak position and XPS is characterized as successfully exfoliated graphene and is determined as 8% graphene. The Raman characterization shows that the 2D peak of the stripped graphene is 2710cm -1 G peak at 1586cm -1 D peak is-1356 cm -1 And I is D /I G The value is about-0.6, and the quality is high; the peak position is 27 degrees according to the characterization of XRD; XPS shows that the bonding position of C-C bond is 284.8eV, the bonding position of C-OH bond is 285.5eV, the bonding position of C ═ O bond is 287.6eV, the bonding position of C (O) -O bond is 290.1eV, and the peak position of graphene is met. These data indicate that the release material isGraphene, and the stripping quality is better.
5) Mixing 1.5g of the obtained graphene powder, 30mL of dibasic ester and 100mL of ethanol, and homogenizing and dispersing at 8000rpm for 60 min; and adding the mixed solution into a rotary evaporator, and taking out after 30min to obtain the graphene slurry with the stable dispersion of about 50 mg/mL.
(2) Preparation of graphene ink
1) Preparation of Low-concentration graphene ink
10mg of ethyl cellulose (film forming agent) and 0.5mg of sodium dodecyl sulfate (surfactant) were dissolved in 60mL of isopropanol (organic cosolvent), and uniformly mixed with 1g of graphene slurry to obtain a graphene ink having a graphene content of about 1 mg/mL. The inks can be used for spray or ink jet printing.
Referring to fig. 3, the low-concentration graphene ink prepared in this embodiment still maintains good dispersibility and stability after being placed for one month, as can be seen from fig. 3.
2) Preparation of high-concentration graphene ink
Firstly, uniformly mixing 62.5mg of ethyl cellulose (film forming agent), 5mL of isopropanol (organic cosolvent) and 10mg of sodium dodecyl sulfate (surfactant), then adding graphene slurry, and then adding 5g of graphene slurry into a revolution-rotation mixer under the dispersion condition of 2000rpm for 20 min. And stirring uniformly to obtain the graphene ink with the graphene content of about 30 mg/mL. The ink can be used for screen printing.
As can be seen from fig. 4, the high concentration graphene ink is stable and can be coated as a film; in addition, as can be seen from FIG. 5, the ink can be applied to screen printing, and the printing line width resolution can reach 40 μm; the graphene film after annealing according to fig. 6 shows that the surface of the graphene film after annealing is stable. And the surface resistance was 0.623. omega./notch when the film thickness was 31 μm.
Example 2
(1) Preparation of graphene slurry
1) 100mL of mixed electrolyte of sulfuric acid and sodium sulfate (solvent is deionized water) with the molar ratio of 0.5 is prepared, the total concentration is 0.3mol/L, and the mixed electrolyte is filled into a 120mL electrolytic cell.
2) Graphite foil of 2cm × 5cm and platinum sheet of 2cm × 2cm were used as positive and negative electrodes, respectively, and 10V was applied to gradually peel the graphite foil.
3) The stripped suspension was poured into a suction filter and washed three times with 300mL of deionized water and 300mL of ethanol in this order.
4) Then transferring into a beaker, adding 200mL of deionized water, carrying out ultrasonic crushing for 10min, placing in a refrigerator at-100 ℃ for pre-freezing for 2h, and then placing in a freeze dryer for freeze drying at-56 ℃ for 35 h.
5) Mixing 1.5g of the obtained graphene powder, 25mL of dibasic ester and 80mL of ethanol, and homogenizing and dispersing at 8000rpm for 60 min; and adding the mixed solution into a rotary evaporator, and taking out after 30min to obtain the graphene slurry with the stable dispersion of about 60 mg/mL.
(2) Preparation of graphene ink
1) Preparation of Low-concentration graphene ink
The film-forming resin is vinyl chloride-vinyl acetate resin, and the mass of the film-forming resin is 4% of that of the graphene slurry; the surfactant is sodium dodecyl benzene sulfonate, and the mass of the surfactant is 0.2% of that of the graphene slurry; the organic cosolvent is ethylene glycol, and the graphene ink with the graphene content of 0.8mg/mL is prepared. The ink can be used for spray coating or ink jet printing.
The preparation method comprises the following steps: dissolving vinyl chloride-vinyl acetate copolymer and sodium dodecyl benzene sulfonate in ethylene glycol, and then uniformly mixing with the graphene slurry.
2) Preparation of high-concentration graphene ink
The film-forming resin is vinyl chloride-vinyl acetate resin, and the mass of the film-forming resin is 10% of that of the graphene slurry; the surfactant is sodium dodecyl benzene sulfonate, and the mass of the surfactant is 10% of that of the graphene slurry; the organic co-solvent was ethylene glycol, and 45mg/mL graphene ink was prepared.
The preparation method comprises the following steps: firstly, uniformly mixing vinyl chloride-vinyl acetate copolymer, ethylene glycol and sodium dodecyl benzene sulfonate, then adding graphene slurry, and dispersing for 20min under the condition that the revolution and rotation mixer is 2000 rpm.
The performances of the graphene, the graphene paste and the conductive ink prepared in the embodiment are close to those of the embodiment 1.
Example 3
(1) Preparation of graphene slurry
1) 100mL of mixed electrolyte of sulfuric acid and sodium sulfate (solvent is deionized water) with the molar ratio of 1.5 is prepared, the total concentration is 0.2mol/L, and the mixed electrolyte is filled into a 120mL electrolytic cell.
2) Graphite foil of 2cm × 5cm and platinum sheet of 2cm × 2cm were used as positive and negative electrodes, respectively, and 10V was applied to gradually peel the graphite foil.
3) The stripped suspension was poured into a suction filter and washed three times with 300mL of deionized water and 300mL of ethanol in this order.
4) Then transferring into a beaker, adding 200mL of deionized water, carrying out ultrasonic crushing for 10min, placing in a refrigerator at-60 ℃ for pre-freezing for 8h, and then placing in a freeze dryer for freeze drying at-44 ℃ for 55 h.
5) Mixing 1.5g of the obtained graphene powder, 50mL of dibasic ester and 120mL of ethanol, and homogenizing and dispersing at 8000rpm for 60 min; and adding the mixed solution into a rotary evaporator, and taking out after 30min to obtain the graphene slurry with the stable dispersion of about 30 mg/mL.
(2) Preparation of graphene ink
1) Preparation of Low-concentration graphene ink
The film-forming resin is vinyl chloride-vinyl acetate resin, and the mass of the film-forming resin is 2% of that of the graphene slurry; the surfactant is sodium dodecyl benzene sulfonate, and the mass of the surfactant is 4% of that of the graphene slurry; the organic co-solvent was ethylene glycol, and 0.5mg/mL of graphene ink was prepared. The inks can be used for spray or ink jet printing.
The preparation method comprises the following steps: dissolving vinyl chloride-vinyl acetate copolymer and sodium dodecyl benzene sulfonate in ethylene glycol, and then uniformly mixing with the graphene slurry.
2) Preparation of high-concentration graphene ink
The film-forming resin is vinyl chloride-vinyl acetate resin, and the mass of the film-forming resin is 10% of that of the graphene slurry; the surfactant is sodium dodecyl benzene sulfonate, and the mass of the surfactant is 10% of that of the graphene slurry; the organic co-solvent was ethylene glycol, and 25mg/mL of graphene ink was prepared.
The preparation method comprises the following steps: firstly, uniformly mixing vinyl chloride-vinyl acetate copolymer, ethylene glycol and sodium dodecyl benzene sulfonate, then adding graphene slurry, and dispersing for 20min under the condition that the revolution and rotation mixer is 2000 rpm.
The performances of the graphene, the graphene paste and the conductive ink prepared in the embodiment are close to those of the embodiment 1.
Example 4
This example is a modification of example 1, and the applied voltage is mainly 5V in a modification to example 1.
As a result: the efficiency of the graphene peeled off at this operating voltage was lower than that of example 1, and I D /I G The value is 0.89, the quality is poor, the surface resistance of a slurry coating film is 2.749 omega/port (0.9 omega/port in example 1), and the conductivity of the slurry prepared by the subsequent graphene and a printing material applied by the ink is influenced to a certain extent.
Comparative example 1
This comparative example is a comparative example of example 1, and the difference with respect to example 1 is mainly "(1) step 5 of preparing graphene slurry"), specifically including:
mixing 1.5g of the obtained commercial graphene powder, 30mL of dibasic ester and 100mL of ethanol, and homogenizing and dispersing at 8000rpm for 60 min; and adding the mixed solution into a rotary evaporator, and taking out after 30min to obtain graphene slurry of about 50 mg/mL.
As a result, the graphene slurry obtained by the preparation process of the comparative example directly influences the compounding process of the subsequent ink. The dispersion stability of the high-concentration and low-concentration ink is mainly influenced, phenomena of blocking a printing plate, a nozzle and the like are easily generated, and the good printing effect and the conductivity of a printing material applied by the ink are further influenced.
Comparative example 2
This comparative example is a comparative example of example 1, and the difference with respect to example 1 is mainly in the formulation of graphene slurry, and specifically, this comparative example employs N, N-Dimethylformamide (DMF) instead of dibasic ester as a host solvent.
As a result: the DMF adopted by the graphene paste of the comparative example is toxic and corrosive, and does not meet the preparation requirement of green environmental protection, so that the application range of the base material of the ink prepared by the graphene paste of the comparative example is much narrower than that of example 1, for example: in terms of substrate applicability, the printing of wearable electronic products cannot be used, and the printing can not be used for other substrates which are in contact with human bodies, such as fabrics, paper, partial plastics and the like. In addition, when DMF is used as a solvent to prepare the paste, the graphene concentration of the prepared paste is limited, and it is difficult to obtain a stably dispersed paste at a high concentration, resulting in poor printing quality in a printing process, and difficult to realize patterning and printing presentation of a high-resolution conductive circuit. When high-concentration ink is prepared, the line width of the screen printing plate is set to be 300 mu m, the printing line width is 600 mu m, the accurate control of the line width resolution is difficult to realize, the printing effect is discontinuous, the surface resistance is large and is about 2.889 kOmega/port, and the conductivity is poor.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (7)
1. The conductive ink is characterized in that raw materials for preparing the conductive ink comprise graphene slurry, an organic cosolvent, a surfactant and a film-forming resin; the mass of the organic cosolvent is 0.05-2 times of that of the graphene slurry, and the mass of the surfactant is 0.2-10% of that of the graphene slurry; the mass of the film-forming resin is 1-20% of that of the graphene slurry;
the preparation method of the graphene slurry comprises the following steps:
(1) obtaining electrolyte containing sulfuric acid and sulfate;
(2) in the electrolyte, graphite is used as a positive electrode, and a working voltage is applied to peel the graphite to obtain a turbid liquid, wherein the working voltage is 10-20V;
(3) removing a liquid part in the suspension, washing and ultrasonically treating an obtained solid part, then placing the solid part at the temperature of between 100 ℃ below zero and 60 ℃ below zero for 2 to 8 hours, and then placing the solid part at the temperature of between 56 ℃ below zero and 44 ℃ below zero for 35 to 55 hours to obtain graphene;
(4) mixing the graphene, dibasic ester and ethanol, homogenizing, and removing the ethanol to obtain graphene slurry, wherein the dosage of the dibasic ester corresponding to each 1.5g of the graphene is 20-100 mL and the dosage of the ethanol is 50-250 mL, and the conditions of the homogenizing include: the speed is 3000 rpm-10000 rpm, and the time is 30 min-80 min.
2. The conductive ink according to claim 1, wherein the molar ratio of sulfuric acid to sulfate is not more than 3, and the sum of the molar concentrations of sulfuric acid and sulfate in the electrolyte is 0.01 to 1 mol/L.
3. The conductive ink according to claim 2, wherein the molar ratio of the sulfuric acid to the sulfate is 0.5 to 2, and the sum of the molar concentrations of the sulfuric acid and the sulfate in the electrolyte is 0.05 to 0.3 mol/L.
4. The conductive ink of claim 1, wherein the stripping is with platinum as the negative electrode; and/or the sulfate is selected from at least one of ammonium sulfate, sodium sulfate and potassium sulfate.
5. The conductive ink according to any one of claims 1 to 4, wherein the amount of the dibasic ester and the amount of the ethanol are 25mL to 40mL and 80mL to 120mL, respectively, per 1.5g of the graphene.
6. The conductive ink of claim 1, wherein the organic co-solvent is selected from at least one of ethanol, n-propanol, isopropanol, ethylene glycol, diethylene glycol, propylene glycol methyl ether, ethylene glycol butyl ether, triethylene glycol butyl ether, dimethyl sulfoxide, pentanediol, and hexanediol; or/and the surfactant is one or two of anionic and nonionic; and/or the film-forming resin is at least one selected from vinyl chloride-vinyl acetate resin, epoxy resin, polyurethane resin, polyacrylic resin, ethyl cellulose and nano cellulose.
7. The method for preparing the conductive ink according to any one of claims 1 to 6, comprising: mixing the above raw materials.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910974581.1A CN110698924B (en) | 2019-10-14 | 2019-10-14 | Graphene slurry, conductive ink and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910974581.1A CN110698924B (en) | 2019-10-14 | 2019-10-14 | Graphene slurry, conductive ink and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110698924A CN110698924A (en) | 2020-01-17 |
| CN110698924B true CN110698924B (en) | 2022-08-09 |
Family
ID=69198823
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910974581.1A Active CN110698924B (en) | 2019-10-14 | 2019-10-14 | Graphene slurry, conductive ink and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110698924B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115449264A (en) * | 2022-08-24 | 2022-12-09 | 中山大学 | Conductive ink and preparation method and application thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN205328621U (en) * | 2015-12-31 | 2016-06-22 | 焦云 | Supersound and electric field synergism peel off device of graphite alkene fast |
| CN105802314A (en) * | 2016-05-05 | 2016-07-27 | 天津卡秀堡辉涂料有限公司 | Graphene conductive coating and preparation method thereof |
| CN108641488A (en) * | 2018-05-25 | 2018-10-12 | 北京睿曼科技有限公司 | A kind of graphene dispersing solution can be used as conductive ink and preparation method thereof and a kind of conductive ink |
| CN109440220A (en) * | 2018-09-11 | 2019-03-08 | 江苏恒辉安防股份有限公司 | Cut resistant fibers and preparation method thereof |
-
2019
- 2019-10-14 CN CN201910974581.1A patent/CN110698924B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN205328621U (en) * | 2015-12-31 | 2016-06-22 | 焦云 | Supersound and electric field synergism peel off device of graphite alkene fast |
| CN105802314A (en) * | 2016-05-05 | 2016-07-27 | 天津卡秀堡辉涂料有限公司 | Graphene conductive coating and preparation method thereof |
| CN108641488A (en) * | 2018-05-25 | 2018-10-12 | 北京睿曼科技有限公司 | A kind of graphene dispersing solution can be used as conductive ink and preparation method thereof and a kind of conductive ink |
| CN109440220A (en) * | 2018-09-11 | 2019-03-08 | 江苏恒辉安防股份有限公司 | Cut resistant fibers and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110698924A (en) | 2020-01-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101805538B (en) | Lower-temperature sintered conductive ink | |
| CN104668575B (en) | A kind of nano-silver powder being dispersed in Weak solvent and its application for preparing electrically conductive ink | |
| WO2018228407A1 (en) | Graphene/metal nanobelt composite conductive ink, preparation method therefor and application thereof | |
| CN104803380B (en) | Preparation method of graphene | |
| CN108550856A (en) | Carbon nano tube/graphene composite conducting slurry and preparation method thereof | |
| CN103923529B (en) | A kind of compound oil ink, flexible super capacitor electrode and preparation method thereof | |
| CN104263082A (en) | Graphene organic silver conductive printing ink and preparation method thereof | |
| CN106519804B (en) | Graphene conductive ink and preparation method and application thereof | |
| CN105948025A (en) | Method for electrochemically preparing graphene | |
| EP2570462B1 (en) | Method of producing graphene layers and paste comprising graphene nanoplatelets | |
| CN110669384A (en) | Water-based graphene-based conductive ink and preparation method thereof | |
| CN115171978B (en) | High-conductivity aqueous slurry, preparation method thereof and high-conductivity thin film | |
| CN110698924B (en) | Graphene slurry, conductive ink and preparation method thereof | |
| KR102068258B1 (en) | Method for preparation of graphene | |
| US20170107382A1 (en) | Antioxidant conductive copper paste and method for preparing the same | |
| CN111212488B (en) | Preparation method of graphene/graphite composite aqueous electrothermal film conductive agent | |
| CN101599310A (en) | Hydrophilic nano micron-sized microphase half-detached conductive Ag/AgCl reference electrode pastes and preparation method thereof | |
| CN112048219A (en) | Water-based high-conductivity graphene printing ink and preparation method thereof | |
| CN110272664A (en) | A kind of fractal structure silver particles electrically conductive ink of silk-screen printing and preparation method thereof | |
| CN115036510B (en) | Additive-free graphene/carbon black composite conductive agent and preparation method and application thereof | |
| CN107331529B (en) | Graphene oxide slurry, miniature Graphene electrodes and preparation method thereof | |
| CN106450376A (en) | Low-resistivity conductive carbon thin film and preparation method thereof | |
| Wang et al. | Preparation of waterborne graphene paste with high electrical conductivity | |
| CN108641488A (en) | A kind of graphene dispersing solution can be used as conductive ink and preparation method thereof and a kind of conductive ink | |
| CN113371699B (en) | Green method for preparing high-quality graphene powder in large scale and ultra-low cost |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |