CN110963491A - Graphene precursor and preparation method and application thereof - Google Patents
Graphene precursor and preparation method and application thereof Download PDFInfo
- Publication number
- CN110963491A CN110963491A CN201911346065.0A CN201911346065A CN110963491A CN 110963491 A CN110963491 A CN 110963491A CN 201911346065 A CN201911346065 A CN 201911346065A CN 110963491 A CN110963491 A CN 110963491A
- Authority
- CN
- China
- Prior art keywords
- graphene
- graphite
- precursor
- mixed solution
- graphene precursor
- 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.)
- Granted
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/15—Nano-sized carbon materials
- C01B32/182—Graphene
- C01B32/184—Preparation
- C01B32/19—Preparation by exfoliation
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/20—Graphite
- C01B32/21—After-treatment
- C01B32/22—Intercalation
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2204/00—Structure or properties of graphene
- C01B2204/02—Single layer graphene
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2204/00—Structure or properties of graphene
- C01B2204/04—Specific amount of layers or specific thickness
Abstract
A graphene precursor, a preparation method and application thereof belong to the technical field of graphene preparation. The graphene precursor is an intercalation graphite compound, and 24-50g of a compound capable of being converted into a large amount of gas at the temperature of 100-300 ℃ is inserted into 2-3g of the graphene precursor. The preparation method comprises the steps of adding graphite flakes into a mixed solution of sulfuric acid, phosphoric acid and potassium permanganate, carrying out ultrasonic oxidation, adding a reaction raw material of a compound capable of being converted into a large amount of gas at the temperature of 100-300 ℃, carrying out ultrasonic treatment, filtering and drying to obtain the catalyst. The application of the graphene precursor is to prepare functional graphene or a graphene nanocomposite. The graphene precursor can be expanded and converted into graphene at low temperature (100-300 ℃). The prepared functional graphene contains a large amount of oxygen-containing functional groups, so that the functional graphene can be compounded with other polymers without surface modification. In the preparation of the prepared graphene nano composite material, an organic solvent is not required, and the preparation method is environment-friendly.
Description
Technical Field
The invention relates to the technical field of graphene preparation, in particular to a graphene precursor and a preparation method and application thereof.
Background
The graphene has excellent optical, electrical and mechanical properties, and has important application prospects in the aspects of material science, micro-nano processing, energy, biomedicine, drug delivery, artificial intelligence sensing and the like. The common polymers have the disadvantages of lacking rigidity, poor electrical and thermal conductivity, and the graphene can solve the limitations of the polymers by virtue of excellent rigidity, strength and electrical conductivity.
The existing method for preparing graphene usually adopts a redox method, wherein the redox method is to heavily oxidize graphite to obtain graphene oxide, rich surface functional groups are introduced into the surface of the graphene, monolayer graphene oxide is prepared through ultrasonic dispersion stripping, and a reducing agent is adopted to reduce and remove the surface functional groups of the graphene oxide to obtain the graphene. While another common method for preparing graphene is the liquid exfoliation of graphite, studies have shown that the method also has many limitations, such as low graphene yield, long sonication and high shear mixing, and the use of large amounts of high boiling point solvents. In another method, the intercalated graphite compound is thermally expanded to prepare graphene, and since the method is subjected to heat treatment at a temperature of more than 550 ℃ and results in loss of hydrocarbon groups and hydroxyl groups, the graphene sheet prepared by the method needs surface modification to be compounded with other polymers, so that the graphene composite material is prepared. Graphene is typically exfoliated and dispersed in hydrophobic polymers using organic solvents, but the use of organic solvents is not environmentally friendly and is unacceptable in the existing polymer processing arts.
Disclosure of Invention
The prepared graphene precursor is a new intercalation graphite compound, the preparation method is simple to operate and environment-friendly, the prepared graphene precursor can be expanded and converted into graphene at low temperature, and in the graphene nanocomposite prepared from the graphene precursor, the graphene is uniformly dispersed in the composite material, so that the overall performance of the composite material is improved.
The purpose of the invention is realized by the following technical scheme:
a graphene precursor is an intercalated graphite compound, and a compound capable of being converted into a large amount of gas at the temperature of 100-300 ℃ is inserted between graphite layers, wherein 24-50g of the compound capable of being converted into the large amount of gas at the temperature of 100-300 ℃ is inserted into 2-3g of the graphene precursor, and more preferably 28-44g of the compound capable of being converted into the large amount of gas at the temperature of 100-300 ℃ is contained in 2-3g of the graphene precursor.
The compound capable of being converted into a large amount of gas at the temperature of 100-300 ℃ is one or more of urea nitrate, trinitrotoluene, pentaerythritol tetranitrate and cyclotrimethylenetrinitramine.
The graphene precursor can be expanded and converted into graphene at the temperature of 100-300 ℃.
The preparation method of the graphene precursor comprises the following steps:
(1) preparing a mixed solution: according to the mass ratio, sulfuric acid: phosphoric acid: potassium permanganate (100-: (50-100): (1-2) weighing raw materials, mixing sulfuric acid and phosphoric acid, adding potassium permanganate, and controlling the temperature to be less than or equal to 10 ℃ to obtain a mixed solution;
(2) dissolving graphite flakes in the mixed solution, performing ultrasonic oxidation at 0-10 ℃, washing, and filtering to obtain graphite with the oxidation degree (mass ratio of C/O elements) of 7-15; according to mass ratio, graphite flake: mixed solution ═ 2-3: (120-172);
(3) mixing graphite with the oxidation degree of 7-15 with water, and ultrasonically mixing to obtain a graphite water solution with the mass concentration of 1.1% -1.3%;
(4) adding a non-acid raw material of a compound capable of being converted into a large amount of gas at the temperature of 100-300 ℃ into a graphite aqueous solution, ultrasonically mixing the mixture at the temperature of-5-0 ℃ until the solution is uniform, dropwise adding the acid raw material to generate the compound capable of being converted into the large amount of gas at the temperature of 100-300 ℃, ultrasonically treating the mixture to obtain a stable suspension, filtering and drying the suspension to obtain a graphene precursor; wherein, the oxidation degree is 7-15 graphite according to the mass ratio: non-acid raw material ═ (2-3): (12-55), the addition amount of the acid-based raw material is determined according to the stoichiometric ratio of the acid-based raw material to the non-acid-based raw material.
In the step (2), the graphite flake is a natural graphite flake, the transverse dimension is 500 microns +/-10 microns, and the carbon content is more than 99.6 wt%.
In the step (2), the ultrasonic frequency of the ultrasonic oxidation is 40-42KHz, and the ultrasonic oxidation time is 1-1.5 h.
And (3) in the step (2), adding water for washing, wherein the added water has the effect of stopping oxidation during washing and is washed until the pH value is 7.
In the step (3), the ultrasonic mixing time is preferably 2-5 min.
In the step (4), the non-acid raw material of the compound capable of being converted into a large amount of gas at 100-300 ℃ is determined according to the prepared compound capable of being converted into a large amount of gas at 100-300 ℃, and the corresponding relationship is as follows: urea nitrate-urea, pentaerythritol tetranitrate-pentaerythritol.
In the step (4), the time for ultrasonically mixing the solution until the solution is uniform is preferably 10-15 min.
In the step (4), the acid raw material is determined according to the prepared compound capable of being converted into a large amount of gas at the temperature of 100-300 ℃, and in the case of urea nitrate, the acid raw material is nitric acid, the nitric acid is preferably a nitric acid aqueous solution with the mass concentration of 65-75 wt%, in the case of pentaerythritol tetranitrate, the acid raw material is nitric acid, and the nitric acid is preferably a nitric acid aqueous solution with the mass concentration of 65-75 wt%.
In the step (4), the time for ultrasonic treatment to obtain a stable suspension is preferably 20-30 min.
In the step (4), the drying temperature is 30 +/-2 ℃, and the drying time is 10-12 h.
In the step (4), preferably, the graphite having an oxidation degree of 7 to 15: urea ═ 2-3: (12-24), graphite having an oxidation degree of 7-15: pentaerythritol ═ 2-3: (27-55).
Preferably, the mass ratio of urea: 70 wt% aqueous nitric acid (30-40): (55-65), more preferably 35: 57; pentaerythritol: 70 wt% aqueous nitric acid solution ═ 2-6: (5-24), more preferably 4: 15.
an application of a graphene precursor in preparing functional graphene or a graphene nano composite material.
The method for preparing the functional graphene comprises the following steps:
placing the graphene precursor in 100-300 ℃ epoxy resin, and mixing until the graphene precursor is completely stripped and dispersed to obtain a mixed solution; the addition amount of the epoxy resin is based on the full stripping and dispersion of the graphene precursor.
And adding acetone into the mixed solution for washing, and drying the solid matter to obtain powdery functional graphene.
The surface of the functional graphene contains a large number of oxygen-containing functional groups, namely Raman Id/IgThe ratio is 0.1-0.6, and the conductivity is 600-1000S/cm.
The functional graphene comprises three kinds of graphene with transverse sizes; respectively as follows:
a first single layer graphene having a lateral dimension of 2-6 μm, having a thickness of 0.5-1.0 nm;
the second graphene with the transverse dimension of 600-900nm has the thickness of 5.2 +/-1.95 nm;
the third graphene with the lateral dimension of 200-500nm has a thickness of 0.5-1.0 nm.
The method for preparing the graphene nanocomposite comprises the following steps:
the method comprises the following steps: placing the graphene precursor in 100-phase 300 ℃ epoxy resin, and mixing until the graphene precursor is completely stripped and dispersed to obtain a mixed solution; the amount of the graphene precursor and the epoxy resin is mixed according to the proportion of the graphene nanocomposite material required to be prepared, and preferably, the volume percentage of graphene in the graphene nanocomposite material is 0.5-2.5 vol%, and more preferably 1.03% -2.07%;
step two: mixing the mixed solution at 95-105 deg.C, stirring for 30min-2h to obtain black suspension; and cooling the black suspension to 35-40 ℃, adding a curing agent, uniformly stirring, removing impurities and bubbles, and heating and curing to obtain the graphene nanocomposite.
In the first step, existing graphene in the mixed solution comprises three kinds of graphene with transverse sizes; respectively as follows:
a first single layer graphene having a lateral dimension of 2-6 μm, having a thickness of 0.5-1.0 nm;
the second graphene with the transverse dimension of 600-900nm has the thickness of 5.2 +/-1.95 nm;
the third graphene with the lateral dimension of 200-500nm has a thickness of 0.5-1.0 nm.
In the second step, the stirring speed is 500-700 rpm.
In the second step, the process of removing bubbles is adopted, and the vacuum pumping is carried out at the temperature of 30-40 ℃ until the bubbles disappear, wherein the time is preferably 15-30 min.
In the second step, the type and the dosage of the curing agent are determined according to the epoxy resin, and the curing condition is determined according to the type of the epoxy resin and the type of the curing agent.
Compared with pure epoxy resin, the prepared graphene nano composite material has the advantages that the conductivity is improved by 9-11 orders of magnitude, the Young modulus is improved by 16% -25%, and the fracture toughness is improved by 72-80%.
The principle that graphene can be expanded and converted at low temperature is explained by urea nitrate: urea and nitric acid are adopted for reaction, no by-product is generated, the obtained urea nitrate is embedded into the graphite layer and used as a graphene precursor, the decomposition temperature of the urea nitrate in the graphene precursor is low (140-152 ℃), explosion occurs, and the graphite layer is expanded and stripped to obtain graphene.
The graphene precursor is peeled and dispersed in the epoxy resin to obtain functional graphene with various nano scales, and the functional graphene with various nano scales is used as a multi-gradient nano filler and added into the epoxy resin to toughen the epoxy resin. The method for toughening the epoxy resin is simpler and more convenient, and simultaneously, due to the addition of the graphene, the prepared graphene nanocomposite has electric conductivity, the graphene can be uniformly dispersed in the epoxy resin, and the performance of the graphene nanocomposite is integrally improved.
Compared with the prior art, the graphene precursor and the preparation method and the application thereof have the beneficial effects that:
(1) the invention develops a graphene precursor capable of expanding and converting at low temperature (100-300 ℃).
(2) The obtained functional graphene is a graphene sheet with multiple specifications and nanometer sizes, and the surface of the graphene sheet contains a large number of oxygen-containing functional groups, so that the graphene sheet can be compounded with other polymers without surface modification.
(3) In the process of preparing the graphene nanocomposite, an organic solvent is not required, and the method is environment-friendly.
Drawings
Fig. 1 is a flow chart of a preparation process of a graphene precursor (i.e., a layered graphite compound) according to example 1 of the present invention;
fig. 2 is a flow chart of a process for preparing functional graphene and a nanocomposite thereof according to embodiment 1 of the present invention.
Detailed Description
The present invention will be described in further detail with reference to examples.
In the following examples, the materials used are commercially available except where otherwise specified, wherein the raw graphite flakes used are natural graphite flakes, grade 3763, purity 99.6%, and transverse dimension 500 um.
The mass purity of the adopted potassium permanganate is 99.00 wt%.
The adopted nitric acid is nitric acid aqueous solution with the mass concentration of 70 wt%.
The adopted sulfuric acid is concentrated sulfuric acid with the mass concentration of 98 wt%.
The adopted phosphoric acid is 85 wt% phosphoric acid by mass concentration.
In the following examples, the epoxy resin used was bisphenol A epoxy resin, 5.24-5.49 equivalents/kg; the curing agent matched with the epoxy resin is Mw230 polyoxypropylene, and the weight ratio of the epoxy resin to the curing agent is 100: 35.
all materials were used as received without further purification.
Example 1
A preparation method of a graphene precursor is shown in a process flow diagram of figure 1, and comprises the following steps:
(1) in a 250mL beaker, 10g of sulfuric acid and 5g of phosphoric acid were mixed, and 0.1g of potassium permanganate was slowly dissolved therein by stirring with a glass rod at a temperature of 10 ℃ or less to obtain a mixed solution.
(2) To the mixed solution, 0.25g of a coarse graphite piece was added, and then the beaker was transferred to an ultrasonic bath (in which the power of an ultrasonic instrument was 200W and the ultrasonic frequency was 42KHz) at 10 ℃ or lower for simultaneous oxidation and ultrasonic treatment for 1 hour. The oxidation is then stopped by slow addition of water, washed thoroughly with water and filtered to a pH of 7, at which point graphite having a degree of oxidation of 7 to 15 has been obtained.
(3) Subsequently, 20g of distilled water was added to 0.25g of graphite having an oxidation degree of 7 to 15, and ultrasonication was carried out for 2 to 3 minutes to obtain an aqueous graphite solution.
(4) Adding 1.75g of urea into the graphite aqueous solution, carrying out ultrasonic treatment for 10 minutes at the temperature of minus 5 ℃, and dissolving the urea to obtain a suspension; 2.85g of 70% strength by mass aqueous nitric acid solution were added dropwise to the suspension and reacted with the urea previously added to give urea nitrate, which was then sonicated again for 25 minutes to give a relatively stable suspension. Finally, the relatively stable suspension was filtered and dried in an oven at 30 ℃ for 10-12 hours. Obtaining a graphene precursor: i.e. intercalated graphite compounds.
And (II) preparing functional graphene, wherein a process flow chart is shown in figure 2.
Adding 0.25g of graphene precursor into 12.16g of epoxy resin at 200 ℃, wherein due to the rapid thermal decomposition of urea nitrate inserted between graphite layers, the rapid expansion of the interior of the epoxy resin can be seen within the first 20s, and a mixed solution is obtained;
and adding acetone into the mixed solution, washing to remove epoxy resin, and drying the solid matter to obtain the functional graphene.
And (III) preparing the graphene nanocomposite, wherein a process flow chart is shown in figure 2.
Step 1:
12.16g of epoxy resin was added to the beaker and heated to 200 ℃. When 0.249g of the graphene precursor was added to the epoxy resin, rapid thermal decomposition of urea nitrate inserted between graphite layers resulted in rapid expansion of the interior of the epoxy resin within the first 20 seconds, and a mixed solution was obtained.
Step 2:
the mixture was transferred to a three-necked flask placed in a 100 ℃ oil bath and mixed for 1 hour at 600rpm using an electric stirrer equipped with two movable blades to obtain a stable black suspension. The black mixture was cooled to 35-40 ℃, the curing agent was added to the black mixture, and stirred for 2 minutes to obtain a uniform mixture. After the curing agent is added, the viscosity of the black mixed liquid is reduced, and a plurality of impurities float on the surface, and after the impurities are removed by screening, the black mixed liquid is kept still for 15 to 20 minutes in an oven with the temperature of 30 to 40 ℃ under vacuum to remove bubbles. Pouring the mixed solution into a rubber mold preheated to 60 ℃, and then carrying out the following curing processes of (1) heating at 60 ℃ for 3 hours, (2) within 60 minutes, heating from 60 ℃ to 120 ℃ in a gradient manner, increasing the temperature by 3-5 ℃/min to 10 ℃, preserving the heat for 7-8 minutes until the temperature is increased to 120 ℃, and (3) heating at 120 ℃ for 13 hours. Finally, the graphene nanocomposite is obtained.
In the prepared graphene nanocomposite, the volume fraction of graphene is 1.03 vol%, and the conductivity of the graphene is 1.58 multiplied by 10-7S/cm, conductivity 3.38X 10 higher than that of pure epoxy resin-16Improved by 9 orders of magnitude.
On the aspect of mechanical property, when the volume fraction of the graphene is 1.03 vol%, the Young modulus is increased to 2.57GPa, which is increased by 16% compared with 2.21GPa of pure epoxy resin; the fracture toughness is 1.57 +/-0.05 MPa m1/2Compared with pure epoxy resin, the epoxy resin has 72.58 percent increase and the breaking energy release rate of 850.78 +/-58.00J m-2。
Example 2
A preparation method of a graphene precursor comprises the following steps:
(1) in a 250mL beaker, 20g of sulfuric acid and 10g of phosphoric acid were mixed, and 0.2g of potassium permanganate was slowly dissolved therein by stirring with a glass rod at a temperature of 10 ℃ or less to obtain a mixed solution.
(2) To the mixed solution, 0.3g of a coarse graphite piece was added, and then the beaker was transferred to an ultrasonic bath (in which the power of an ultrasonic instrument was 200W and the ultrasonic frequency was 42KHz) at 10 ℃ or lower for simultaneous oxidation and ultrasonic treatment for 1 hour. The oxidation is then stopped by slow addition of water, washed thoroughly with water and filtered to a pH of 7, at which point graphite having a degree of oxidation of 7 to 15 has been obtained.
(3) Subsequently, 25g of distilled water was added to 0.3g of graphite having an oxidation degree of 7 to 15, and ultrasonication was performed for 2 to 3 minutes to obtain an aqueous graphene solution.
(4) Adding 1.8g of urea into the graphene aqueous solution, carrying out ultrasonic treatment at 0 ℃ for 10 minutes, and dissolving the urea to obtain a suspension; 2.9g of 70% strength by mass aqueous nitric acid solution were added dropwise to the suspension and reacted with the urea previously added to give urea nitrate, which was then sonicated again for 30 minutes at 0 ℃ to give a relatively stable suspension. Finally, the relatively stable suspension was filtered and dried in an oven at 30 ℃ for 10-12 hours. Obtaining a graphene precursor: i.e. intercalated graphite compounds.
Preparation of (II) functional graphene
Adding 0.3g of graphene precursor into epoxy resin at 200 ℃, and observing the rapid expansion of the interior of the epoxy resin within the first 20s due to the rapid thermal decomposition of urea nitrate inserted between graphite layers to obtain a mixed solution;
and adding acetone into the mixed solution, washing to remove epoxy resin, and drying the solid matter to obtain the functional graphene.
(III) preparation of graphene nanocomposite
Step 1:
7.1g of epoxy resin was added to the beaker and heated to 200 ℃. When 0.3g of the graphene precursor was added to the epoxy resin, rapid expansion of the interior of the epoxy resin was observed within the first 20 seconds due to rapid thermal decomposition of urea nitrate inserted between graphite layers, and a mixed solution was obtained.
Step 2:
the mixture was transferred to a three-necked flask placed in a 100 ℃ oil bath and mixed for 1 hour at 600rpm using an electric stirrer equipped with two movable blades to obtain a stable black suspension. The black mixture was cooled to 35-40 ℃, the curing agent was added to the black mixture, and stirred for 2 minutes to obtain a uniform mixture. After the curing agent is added, the viscosity of the black mixed liquid is reduced, and a plurality of impurities float on the surface, and after the impurities are removed by screening, the black mixed liquid is kept still for 15 to 20 minutes in an oven with the temperature of 30 to 40 ℃ under vacuum to remove bubbles. Pouring the mixed solution into a rubber mold preheated to 60 ℃, and then carrying out the following curing processes of (1) heating at 60 ℃ for 3 hours, (2) within 60 minutes, heating from 60 ℃ to 120 ℃ in a gradient manner, increasing the temperature by 3-5 ℃/min to 10 ℃, preserving the heat for 7-8 minutes until the temperature is increased to 120 ℃, and (3) heating at 120 ℃ for 13 hours. Finally, the graphene nanocomposite is obtained.
In the prepared graphene nanocomposite, when the volume fraction of graphene is 2.07 vol%, the conductivity is 4.62 multiplied by 10-5S/cm, the percolation threshold for the conductivity was 0.8 vol%.
Example 3
A preparation method of a graphene precursor comprises the following steps:
(1) in a 250mL beaker, 8g of sulfuric acid and 4g of phosphoric acid were mixed, and 0.08g of potassium permanganate was slowly dissolved therein by stirring with a glass rod at a temperature of 10 ℃ or less to obtain a mixed solution.
(2) To the mixed solution, 0.2g of a coarse graphite piece was added, and then the beaker was transferred to an ultrasonic bath (in which the power of an ultrasonic instrument was 200W and the ultrasonic frequency was 42KHz) at 10 ℃ or lower for simultaneous oxidation and ultrasonic treatment for 1 hour. The oxidation is then stopped by slow addition of water, washed thoroughly with water and filtered to a pH of 7, at which point graphite having a degree of oxidation of 7 to 15 has been obtained.
(3) Subsequently, 15g of distilled water was added to 0.2g of graphite having an oxidation degree (C/O) of 7 to 15, and ultrasonication was performed for 2 to 3 minutes to obtain an aqueous graphene solution.
(4) Adding 1.7g of urea into the graphene aqueous solution, carrying out ultrasonic treatment at 0 ℃ for 10 minutes, and dissolving the urea to obtain a suspension; 2.8g of 70% strength by mass aqueous nitric acid solution were added dropwise to the suspension and reacted with the urea previously added to give urea nitrate, which was then sonicated again for 30 minutes at 0 ℃ to give a relatively stable suspension. Finally, the relatively stable suspension was filtered and dried in an oven at 30 ℃ for 10-12 hours. Obtaining a graphene precursor: i.e. intercalated graphite compounds.
Preparation of (II) functional graphene
Adding 0.2g of graphene precursor into epoxy resin at 200 ℃, and observing the rapid expansion of the interior of the epoxy resin within the first 20s due to the rapid thermal decomposition of urea nitrate inserted between graphite layers to obtain a mixed solution;
and adding acetone into the mixed solution, washing to remove epoxy resin, and drying the solid matter to obtain the functional graphene.
(III) preparation of graphene nanocomposite
Step 1:
12.55g of epoxy resin was added to a beaker and heated to 200 ℃. When 0.2g of the graphene precursor was added to the epoxy resin, rapid expansion of the interior of the epoxy resin was observed within the first 20 seconds due to rapid thermal decomposition of urea nitrate inserted between graphite layers, and a mixed solution was obtained.
Step 2:
the mixture was transferred to a three-necked flask placed in a 100 ℃ oil bath and mixed for 1 hour at 600rpm using an electric stirrer equipped with two movable blades to obtain a stable black suspension. The black mixture was cooled to 35-40 ℃, the curing agent was added to the black mixture, and stirred for 2 minutes to obtain a uniform mixture. After the curing agent is added, the viscosity of the black mixed liquid is reduced, and a plurality of impurities float on the surface, and after the impurities are removed by screening, the black mixed liquid is kept still for 15 to 20 minutes in an oven with the temperature of 30 to 40 ℃ under vacuum to remove bubbles. Pouring the mixed solution into a rubber mold preheated to 60 ℃, and then carrying out the following curing processes of (1) heating at 60 ℃ for 3 hours, (2) heating from 60 ℃ to 120 ℃ in a gradient manner, wherein the gradient heating is 3-5 ℃/min rise by 10 ℃, keeping the temperature for 7-8min, rising at 3-5 ℃/min rise by 10 ℃, keeping the temperature for 7-8min until the temperature rises to 120 ℃, and (3) heating at 120 ℃ for 13 hours. Finally, the graphene nanocomposite is obtained.
The properties of the prepared graphene nanocomposite are as follows: 1X 10-10S/cm, 0.8 vol% is the percolation threshold for the electrical conductivity of the epoxy nanocomposite. Young's modulus: 2.42GPa, fracture toughness: 1.43MPa m1/2。。
Example 4
(one) a preparation method of a graphene precursor, which is the same as that of example 1.
(II) preparation of functional graphene
Directly stripping a graphene precursor (namely a layered graphite compound) into three types of graphene in an epoxy resin/molten base at 200 ℃ to obtain a mixed solution, and directly washing the mixed solution with acetone to obtain the functional graphene sheet.
The graphene comprises three lateral dimensions of graphene; respectively as follows:
a first single layer graphene having a lateral dimension of 4.07 μm, a thickness of 0.5nm, and a standard deviation of 1.68 μm;
a second graphene with a lateral dimension of 700nm, having a thickness of 5.2 ± 1.95 nm;
the third graphene with the lateral dimension of 200-500nm has a thickness of 0.5-1.0 nm.
The method for preparing the graphene nanocomposite comprises the following steps:
directly stripping a graphene precursor (namely a layered graphite compound) into three types of graphene in an epoxy resin/molten base at 200 ℃ to obtain a mixed solution;
and (3) mixing and stirring the mixed solution in a silicon oil bath at the temperature of 100 ℃ for 1 hour, cooling to 35 ℃, solidifying agent, removing impurities, removing bubbles, heating and curing to obtain the graphene nano composite material.
Example 5
A preparation method of a graphene precursor comprises the following steps:
(1) in a 250mL beaker, 10g of sulfuric acid and 5g of phosphoric acid were mixed, and 0.1g of potassium permanganate was slowly dissolved therein by stirring with a glass rod at a temperature of 10 ℃ or less to obtain a mixed solution.
(2) To the mixed solution, 0.25g of a coarse graphite piece was added, and then the beaker was transferred to an ultrasonic bath (in which the power of an ultrasonic instrument was 200W and the ultrasonic frequency was 42KHz) at 10 ℃ or lower for simultaneous oxidation and ultrasonic treatment for 1 hour. The oxidation is then stopped by slow addition of water, washed thoroughly with water and filtered to a pH of 7, at which point graphite having a degree of oxidation of 7 to 15 has been obtained.
(3) Subsequently, 20g of distilled water was added to 0.25g of graphite having an oxidation degree of 7 to 15, and ultrasonication was carried out for 2 to 3 minutes to obtain an aqueous graphite solution.
(4) Adding 4g of pentaerythritol into the graphite aqueous solution, carrying out ultrasonic treatment for 10 minutes at the temperature of minus 5 ℃, and dissolving the pentaerythritol to obtain a suspension; 15g of 70% strength by mass aqueous nitric acid solution were added dropwise to the suspension and reacted with the previously added pentaerythritol to form pentaerythritol tetranitrate (known as Tylan), followed by additional sonication for 25 minutes to give a relatively stable suspension. Finally, the relatively stable suspension was filtered and dried in an oven at 30 ℃ for 10-12 hours. Obtaining a graphene precursor: i.e. intercalated graphite compounds.
And (II) preparing functional graphene.
Adding 0.25g of graphene precursor into 12.16g of epoxy resin at 210 ℃, wherein due to the rapid thermal decomposition of urea nitrate inserted between graphite layers, the rapid expansion of the interior of the epoxy resin can be seen within the first 20s, and a mixed solution is obtained;
and adding acetone into the mixed solution, washing to remove epoxy resin, and drying the solid matter to obtain the functional graphene.
Claims (10)
1. A graphene precursor is characterized in that the graphene precursor is an intercalated graphite compound, the intercalated graphite compound is a compound which can be converted into a large amount of gas at the temperature of 100-300 ℃ and is inserted between graphite layers, and 24-50g of the compound which can be converted into a large amount of gas at the temperature of 100-300 ℃ is inserted into 2-3g of the graphene precursor.
2. The graphene precursor according to claim 1, wherein the compound capable of being converted into a large amount of gas at 100-300 ℃ is one or more of urea nitrate, trinitrotoluene, pentaerythritol tetranitrate, and cyclotrimethylenetrinitramine.
3. The method for preparing the graphene precursor according to claim 1 or 2, comprising the steps of:
(1) preparing a mixed solution: according to the mass ratio, sulfuric acid: phosphoric acid: potassium permanganate (100-: (50-100): (1-2) weighing raw materials, mixing sulfuric acid and phosphoric acid, adding potassium permanganate, and controlling the temperature to be less than or equal to 10 ℃ to obtain a mixed solution;
(2) dissolving graphite flakes in the mixed solution, performing ultrasonic oxidation at 0-10 ℃, washing, and filtering to obtain graphite with the oxidation degree (mass ratio of C/O elements) of 7-15; according to mass ratio, graphite flake: mixed solution ═ 2-3: (120-172);
(3) mixing graphite with the oxidation degree of 7-15 with water, and ultrasonically mixing to obtain a graphite water solution with the mass concentration of 1.1% -1.3%;
(4) adding a non-acid raw material of a compound capable of being converted into a large amount of gas at the temperature of 100-300 ℃ into a graphite aqueous solution, ultrasonically mixing the mixture at the temperature of-5-0 ℃ until the solution is uniform, dropwise adding the acid raw material to generate the compound capable of being converted into the large amount of gas at the temperature of 100-300 ℃, ultrasonically treating the mixture to obtain a stable suspension, filtering and drying the suspension to obtain a graphene precursor; wherein, the oxidation degree is 7-15 graphite according to the mass ratio: non-acid raw material ═ (2-3): (12-55), the addition amount of the acid-based raw material is determined according to the stoichiometric ratio of the acid-based raw material to the non-acid-based raw material.
4. The method according to claim 3, wherein in the step (2), the graphite sheet is a natural graphite flake, the transverse dimension of the natural graphite flake is 500 μm ± 10 μm, and the carbon content of the natural graphite flake is 99.6 wt% or more.
5. Use of the graphene precursor according to claim 1 or 2, wherein the graphene precursor is used for preparing functional graphene or for preparing graphene nanocomposites.
6. The application of the graphene precursor according to claim 5, wherein the method for preparing the functional graphene comprises the following steps:
placing the graphene precursor of claim 1 or 2 in 100-300 ℃ epoxy resin, and mixing until the graphene precursor is completely peeled and dispersed to obtain a mixed solution; wherein the adding amount of the epoxy resin is based on the full stripping and dispersion of the graphene precursor;
and adding acetone into the mixed solution for washing, and drying the solid matter to obtain powdery functional graphene.
7. The functional graphene prepared by the method of claim 6, wherein the surface of the prepared functional graphene contains a large number of oxygen-containing functional groups, namely Raman Id/IgThe ratio is 0.1-0.6, and the conductivity is 600-1000S/cm.
8. The functional graphene according to claim 7, wherein the functional graphene comprises three lateral dimensions of graphene; respectively as follows:
a first single layer graphene having a lateral dimension of 2-6 μm, having a thickness of 0.5-1.0 nm;
the second graphene with the transverse dimension of 600-900nm has the thickness of 5.2 +/-1.95 nm;
the third graphene with the lateral dimension of 200-500nm has a thickness of 0.5-1.0 nm.
9. The use of the graphene precursor according to claim 5, wherein the method for preparing the graphene nanocomposite material comprises:
the method comprises the following steps: placing the graphene precursor of claim 1 or 2 in 100-300 ℃ epoxy resin, and mixing until the graphene precursor is completely peeled and dispersed to obtain a mixed solution; mixing the amount of the graphene precursor and the amount of the epoxy resin according to the proportion of the graphene nanocomposite material required to be prepared;
step two: mixing the mixed solution at 95-105 deg.C, stirring for 30min-2h to obtain black suspension; and cooling the black suspension to 35-40 ℃, adding a curing agent, uniformly stirring, removing impurities and bubbles, and heating and curing to obtain the graphene nanocomposite.
10. The use of the graphene precursor according to claim 9, wherein in the first step, the graphene existing in the mixed solution includes three kinds of graphene with lateral dimensions; respectively as follows:
a first single layer graphene having a lateral dimension of 2-6 μm, having a thickness of 0.5-1.0 nm;
the second graphene with the transverse dimension of 600-900nm has the thickness of 5.2 +/-1.95 nm;
the third graphene with the lateral dimension of 200-500nm has a thickness of 0.5-1.0 nm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911346065.0A CN110963491B (en) | 2019-12-24 | 2019-12-24 | Graphene precursor and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911346065.0A CN110963491B (en) | 2019-12-24 | 2019-12-24 | Graphene precursor and preparation method and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110963491A true CN110963491A (en) | 2020-04-07 |
| CN110963491B CN110963491B (en) | 2022-02-01 |
Family
ID=70036123
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911346065.0A Active CN110963491B (en) | 2019-12-24 | 2019-12-24 | Graphene precursor and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110963491B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111718623A (en) * | 2020-05-18 | 2020-09-29 | 上海帕吉索纳米技术有限公司 | Graphene aqueous slurry and preparation method thereof |
| WO2022222380A1 (en) * | 2021-04-22 | 2022-10-27 | 中国石油化工股份有限公司 | Graphene powder, and preparation method therefor and application thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI640472B (en) * | 2017-10-31 | 2018-11-11 | 遠東科技大學 | Method for manufacturing graphene nanoplatelets by ultrasonic waves |
| CN108975322A (en) * | 2018-09-05 | 2018-12-11 | 七台河宝泰隆石墨烯新材料有限公司 | The method for preparing graphene slurry |
| WO2019020999A1 (en) * | 2017-07-26 | 2019-01-31 | Talga Technologies Limited | Functionalised graphene composition |
| CN109694549A (en) * | 2017-10-23 | 2019-04-30 | 中国科学院理化技术研究所 | A kind of preparation method of Graphene epoxy resin composite material |
| CN109704318A (en) * | 2019-02-27 | 2019-05-03 | 盐城师范学院 | A kind of method that explosive intercalated graphite prepares graphene |
-
2019
- 2019-12-24 CN CN201911346065.0A patent/CN110963491B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2019020999A1 (en) * | 2017-07-26 | 2019-01-31 | Talga Technologies Limited | Functionalised graphene composition |
| CN109694549A (en) * | 2017-10-23 | 2019-04-30 | 中国科学院理化技术研究所 | A kind of preparation method of Graphene epoxy resin composite material |
| TWI640472B (en) * | 2017-10-31 | 2018-11-11 | 遠東科技大學 | Method for manufacturing graphene nanoplatelets by ultrasonic waves |
| CN108975322A (en) * | 2018-09-05 | 2018-12-11 | 七台河宝泰隆石墨烯新材料有限公司 | The method for preparing graphene slurry |
| CN109704318A (en) * | 2019-02-27 | 2019-05-03 | 盐城师范学院 | A kind of method that explosive intercalated graphite prepares graphene |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111718623A (en) * | 2020-05-18 | 2020-09-29 | 上海帕吉索纳米技术有限公司 | Graphene aqueous slurry and preparation method thereof |
| WO2022222380A1 (en) * | 2021-04-22 | 2022-10-27 | 中国石油化工股份有限公司 | Graphene powder, and preparation method therefor and application thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110963491B (en) | 2022-02-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Wei et al. | Graphene nanoplatelets in epoxy system: dispersion, reaggregation, and mechanical properties of nanocomposites | |
| EP3056469B1 (en) | Production method for graphene | |
| EP3056468B1 (en) | Graphene production method | |
| CN103627139B (en) | A kind of preparation method of functional graphene oxide/epoxy resin nano composites | |
| CN110963491B (en) | Graphene precursor and preparation method and application thereof | |
| EP2554568A2 (en) | Polyimide nanocomposite and method for preparing same | |
| CN104988592B (en) | Polyvinyl alcohol/graphene composite nano fiber material and preparation method thereof | |
| CN102875973B (en) | Modified carbon nanotube/thermosetting resin composite and preparation method thereof | |
| KR101355954B1 (en) | Modified graphite, graphite/thermosetting resin nanocomposite and method of manufacturing the sames | |
| KR20130104754A (en) | Thermal conductive resin composites comprising carbon nano tubes and method of preparing the same | |
| JP2008166641A (en) | Expanded carbon fiber composite material for electromagnetic shield with thermal conductivity and electric conductivity, and manufacturing method thereof | |
| CN101891936B (en) | Preparation method of composite material based on epoxy resin and phosphazene nanotubes | |
| JP2006199813A (en) | Thermosetting resin composite material and method for producing the same | |
| CN108264765B (en) | Preparation method of toughened heat-conducting insulating cyanate resin-based composite material | |
| KR101300606B1 (en) | Manufacturing method of carbon nanotubes/polyolefin composites with superior mechanical properties | |
| CN103524691A (en) | Nano TiO2/maleimide phenolic in-situ composite resin and preparation method thereof | |
| KR102008760B1 (en) | Epoxy nanocomposite reinforced with graphene oxide decorated with nanodiamond nanocluster and method for manufacturing thereof | |
| JP2018508442A (en) | Carbon oxide nanoparticles, method for producing the same, organic / inorganic composite containing the same, and method for producing the organic / inorganic composite | |
| CN113387348A (en) | Method for preparing graphene by using composite ionic liquid | |
| CN111423596A (en) | Trackable auxiliary agent and preparation method thereof | |
| Dai et al. | Toughening of vinyl ester resins by two-dimensional MXene nanosheets | |
| KR102496995B1 (en) | Carbon fibers-reinforced epoxy composites with graphene oxide/graphitic nanofibers composites and manufacturing method thereof | |
| KR102496991B1 (en) | Carbon fiber-reinforced epoxy composites with ozone-treated graphitic nanofibers and manuacutring method thereof | |
| Li et al. | Enhanced mechanical properties of bridged graphene oxide/bismaleimide nanocomposites | |
| US11702543B2 (en) | 3D-printed nanocomposites with metal diboride nanosheets |
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 |