CN110550956B - Preparation method of graphene-polyimide-based composite sponge precursor heat-conducting film - Google Patents
Preparation method of graphene-polyimide-based composite sponge precursor heat-conducting film Download PDFInfo
- Publication number
- CN110550956B CN110550956B CN201910908958.3A CN201910908958A CN110550956B CN 110550956 B CN110550956 B CN 110550956B CN 201910908958 A CN201910908958 A CN 201910908958A CN 110550956 B CN110550956 B CN 110550956B
- Authority
- CN
- China
- Prior art keywords
- graphene oxide
- graphene
- polyimide
- polyamic acid
- 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.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
- C04B35/52—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite
- C04B35/522—Graphite
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
- C04B35/52—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite
- C04B35/524—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite obtained from polymer precursors, e.g. glass-like carbon material
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
- C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
- C04B2235/6562—Heating rate
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
- C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
- C04B2235/6567—Treatment time
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
- C04B2235/96—Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
- C04B2235/96—Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
- C04B2235/9607—Thermal properties, e.g. thermal expansion coefficient
Abstract
The invention provides a preparation method of a graphene polyimide composite sponge precursor-based heat-conducting film, which comprises the following steps: mixing a graphene oxide aqueous solution with a polyimide precursor solution to obtain a graphene oxide/polyamic acid mixed solution, freezing the graphene oxide/polyamic acid mixed solution to obtain a graphene oxide/polyamic acid frozen sponge, drying the graphene oxide/polyamic acid frozen sponge by adopting a freeze drying method to obtain a graphene oxide/polyamic acid composite sponge, placing the graphene oxide/polyamic acid composite sponge in a hot-pressing reaction furnace, performing hot-pressing oxidation pretreatment and mechanical pressurization to obtain a reduced graphene oxide/polyimide composite film, performing vacuum heat treatment and mechanical pressurization to obtain a graphene/polyimide carbon film, placing the graphene/polyimide carbon film in a high-temperature graphitization furnace, and performing graphitization on the carbon film by adopting a gradient heating method. By adopting the technical scheme of the invention, the problem of the dispersibility of the graphene is solved, the obtained film has certain flexibility, high mechanical strength, better electric and heat conductivity, and simple preparation process.
Description
Technical Field
The invention belongs to the technical field of composite materials, and particularly relates to a preparation method of a graphene polyimide composite sponge precursor-based heat-conducting film.
Background
Nowadays, with the progress of science and technology, the development of lightweight and high-degree electronic integration of modern military equipment faces increasingly severe thermal management challenges, for example, in equipment such as electronic weaponry, ultra-high speed aircraft, remote sensing satellite, radar and the like, the high-degree integration of large-scale high-power electronic components can generate a serious heat concentration problem, which threatens the working stability and safety reliability of key components of the military equipment. At the same time, the complex thermal interface in highly integrated equipment also places unique demands on flexibility on the thermal management material.
With the discovery of graphene, more and more scientists have focused their attention on this potential emerging material. Graphene is another stable nano carbon simple substance after fullerene and carbon nano tube, is an ideal two-dimensional planar material, and has good electric and heat conducting properties. Since graphene is isotropic in the plane of the sheet, there is no directionality in the in-plane thermal conduction. Therefore, graphene is used in the field of heat conduction, and development of a novel heat conduction film is very necessary and most possible. In addition, the graphene oxide film is assembled by using the graphene oxide, and then the graphene oxide film is reduced to obtain the graphene film, so that the method for preparing the graphene film is simpler. The graphene oxide contains rich oxygen-containing functional groups, can be uniformly dispersed in an organic solvent and an aqueous solution, and improves the dispersibility of the graphene. The graphene oxide film has the advantages that the graphene oxide sheet layer has large and adjustable area, the continuous sheet structure reduces the crystal boundary scattering of phonons in the transmission process, the improvement of the thermal conductivity is facilitated, and in addition, the rich oxygen-containing functional groups on the graphene oxide sheet layer can interact to generate strong interactions such as hydrogen bonds, conjugated large pi bonds and the like to improve the mechanical property of the graphene film.
Polyimide (PI) is a special engineering plastic with the advantages of good molding processability, high mechanical strength, good thermal stability and the like, and is widely applied to heat insulation materials, sound insulation materials, catalyst carriers and dielectric materials. It refers to a class of polymers containing imide rings in the main chain, with polymers containing imide structures being of the most importance. In the past fifty years, with the rapid development of the fields of aviation, aerospace, chemical industry and the like, the requirements of people on the strength and the heat resistance of materials are higher and higher. Polyimide is rapidly developed in response to this urgent demand, and thus, polyimide is widely used in various fields of national economy. In addition, the polyimide precursor can be converted into an aqueous solution through chemical modification, homogeneous phase compounding with the graphene aqueous dispersion is expected to be realized, and the graphene polyimide composite film obtained after reduction heat treatment has excellent mechanical properties, but poor heat conduction and electric conduction effects.
In summary, although graphene thermal conductive films have already entered the market, the preparation process is complex, and the mechanical properties are poor, so that the graphene films with nearly perfect thermal conductive properties cannot be widely applied to the field of heat dissipation. Therefore, the problem that graphene is uniformly dispersed in a polymer and interface thermal resistance is reduced, so that stronger interaction is obtained to achieve greater performance improvement is urgently needed to be solved.
Disclosure of Invention
Aiming at the technical problems, the invention discloses a preparation method of a graphene polyimide composite sponge precursor-based heat-conducting film, which solves the problems of the existing graphene composite film in the aspects of mechanical property and electric and heat conducting properties.
In contrast, the technical scheme of the invention is as follows:
the preparation method of the graphene polyimide composite sponge precursor-based heat-conducting film comprises the following steps:
step S1, preparing a graphene oxide aqueous solution;
step S2, preparing a polyimide precursor solution;
step S3, mixing the graphene oxide aqueous solution with a polyimide precursor solution to obtain a graphene oxide/polyamic acid mixed solution;
step S4, freezing the obtained graphene oxide/polyamide acid mixed solution to obtain a graphene oxide/polyamide acid frozen sponge;
step S5, drying the obtained graphene oxide/polyamic acid frozen sponge by adopting a freeze drying method to obtain a graphene oxide/polyamic acid composite sponge;
step S6, placing the obtained graphene oxide/polyamic acid composite sponge in a hot-pressing reaction furnace, and realizing reduction of graphene oxide and imidization of polyamic acid by adopting a hot-pressing oxidation pretreatment method; simultaneously, mechanically pressurizing the film to obtain a reduced graphene oxide/polyimide composite film; further, the reduced graphene oxide/polyimide composite film described in step S6 is prepared in a dimensionality reduction method.
Step S7, placing the obtained reduced graphene oxide/polyimide composite film in a hot-pressing reaction furnace, and carbonizing the graphene and the polyimide by adopting vacuum heat treatment; simultaneously, mechanically pressurizing the carbon film to obtain a graphene/polyimide carbon film;
and step S8, placing the obtained graphene/polyimide carbon film in a high-temperature graphitization furnace, and adopting a gradient heating method to realize graphitization of the carbon film to obtain the heat-conducting film based on the graphene/polyimide composite sponge precursor.
By adopting the technical scheme of the invention, the graphene is uniformly dispersed in the polymer, the interface thermal resistance is reduced, and the obtained film has high heat conductivity and high electric conductivity, higher tensile strength and certain flexibility.
In a further improvement of the present invention, in step S3, the concentration of graphene oxide in the graphene oxide aqueous solution is 1-10 mg/mL. Preferably, the concentration of the graphene oxide in the graphene oxide aqueous solution is 4-6 mg/mL.
As a further improvement of the present invention, step S1 includes: taking graphene oxide slurry, adding deionized water, and stirring for 60-120min at a stirring speed of 100-700 r/min; carrying out ultrasonic treatment for 30-60 min at the frequency of 10-100 KHz to obtain a graphene oxide aqueous solution;
as a further improvement of the invention, in step S3, the concentration of the polyamic acid in the polyimide precursor solution is 15-20 mg/mL.
As a further improvement of the present invention, in the graphene oxide/polyamic acid mixed solution in step S3, the concentration of graphene oxide is 10wt% to 90 wt%. Further, the concentration of the graphene oxide is preferably 60wt% to 90 wt%.
As a further improvement of the invention, the mechanical pressurization in the step S6 and the step S7 is carried out under the pressure of 20MPa-30MPa, and the pressure is released when the pressure is maintained until the temperature is reduced to 200 ℃.
As a further improvement of the invention, the heat treatment temperature of the hot-pressing oxidation pretreatment method in the step S6 is 300-350 ℃, and the constant temperature is kept for 1-1.5 h.
As a further improvement of the present invention, the conditions of the vacuum heat treatment in step S7 are: the temperature is 900-1000 ℃, and the constant temperature is kept for 2-2.5 h. .
As a further improvement of the present invention, the conditions of the gradient temperature raising method in step S7 are: heating to 1200 deg.C at a heating rate of 20 deg.C/min, heating to 2200 deg.C at a heating rate of 10 deg.C/min, and holding for 30 min; the heating rate is 5 ℃/min, the temperature is continuously heated to 2800 ℃, and the temperature is reduced to the room temperature after the constant temperature is kept for 120 min.
As a further improvement of the present invention, step S2 includes: dispersing monomer diamine diaminodiphenyl ether in a polar solvent, and then adding dianhydride pyromellitic dianhydride, wherein the molar ratio of the dianhydride pyromellitic dianhydride to the monomer diamine diaminodiphenyl ether is 100: 95-99; stirring to make it fully react to obtain polyamic acid (PAA) solution; after the reaction is finished, washing, filtering, cleaning and drying to obtain a solid matter; and uniformly stirring the solid matter and an aqueous solution of Triethylamine (TEA) to obtain a water-soluble polyimide precursor solution. Further, the polar solvent is dimethylacetamide.
Specifically, the preparation method of the graphene polyimide composite sponge precursor-based heat-conducting film comprises the following steps:
firstly, preparing a graphene oxide aqueous solution:
weighing graphene oxide slurry, and adding deionized water; stirring for 60-120min at a stirring speed of 100-700 r/min; and carrying out ultrasonic treatment for 30-60 min at the frequency of 10-100 KHz to obtain the graphene oxide aqueous solution.
The graphene oxide slurry is prepared by a Hummer's modification method. The concentration of the graphene oxide slurry is 20 mg/mL; the concentration of the graphene oxide in the graphene oxide aqueous solution is 1 mg/mL-10 mg/mL, preferably 4 mg/mL-6 mg/mL.
Secondly, preparing a polyimide precursor solution:
uniformly dispersing monomer diamine diaminodiphenyl ether (ODA) powder in a polar solvent dimethylacetamide (DMAc) solution by using an electromagnetic stirrer; continuously adding dianhydride pyromellitic dianhydride (PMDA) powder into the mixed solution in a small amount, and stirring for 5 hours to fully react to obtain polyamide acid (PAA) solution; the molar concentration ratio of PMDA to ODA is 100: 95-99;
after the polycondensation reaction is finished, washing the stirred solution by a large amount of deionized water to obtain yellow precipitate polyamic acid fiber; removing the residual deionized water after filtering, cleaning and drying to obtain a solid with the mass fraction of 5%; and stirring a solid material corresponding to 1g of PAA solution, 0.48g of Triethylamine (TEA) solution and 18.52mL of deionized water at room temperature for 6 hours to obtain a water-soluble polyimide precursor.
Wherein, in the polyimide precursor solution, the concentration of the polyamic acid is 15-20 mg/mL.
Thirdly, preparing a graphene oxide/polyamic acid mixed solution:
and (3) mixing the graphene oxide aqueous solution obtained in the step one with the polyimide precursor solution obtained in the step two, stirring for 2 hours, and fully reacting to obtain graphene oxide/polyamic acid mixed solutions with different concentrations.
Wherein, in the graphene oxide/polyamic acid mixed solution, the concentration of the graphene oxide is 10wt% -90wt%, preferably 60wt% -90 wt%.
Fourthly, preparing the high-orientation graphene oxide/polyamic acid frozen sponge:
and D, directionally freezing the graphene oxide/polyamide acid mixed solution obtained in the step three by using liquid nitrogen to obtain the high-directional graphene oxide/polyamide acid freezing sponge with different shapes.
Fifthly, preparing the highly-oriented graphene oxide/polyamic acid composite sponge:
and (4) drying the high-orientation graphene oxide/polyamic acid frozen sponge obtained in the fourth step by adopting a freeze drying method to obtain the high-orientation graphene oxide/polyamic acid composite sponge.
Sixthly, preparing the reduced graphene oxide/polyimide composite film:
placing the highly oriented graphene oxide/polyamic acid composite sponge obtained in the fifth step into a hot-pressing reaction furnace, and realizing reduction of graphene oxide and imidization of polyamic acid by a one-step method by adopting a hot-pressing oxidation pretreatment process; when the temperature is raised to 200 ℃, mechanical pressurization is carried out, and the pressure is 20MPa-30 MPa; continuously heating to 300-350 ℃, and keeping the temperature for 1-1.5 h; cooling, and when the temperature is as low as 200 ℃, removing the pressure; and continuously cooling to room temperature to obtain the reduced graphene oxide/polyimide composite film.
Seventhly, preparing the graphene/polyimide carbon film:
placing the reduced graphene oxide/polyimide composite film obtained in the sixth step into a hot-pressing reaction furnace, and carbonizing the graphene and the polyimide by adopting a high-temperature vacuum heat treatment process; when the temperature is raised to 200 ℃, mechanical pressurization is carried out, and the pressure is 20MPa-30 MPa; continuously heating to 900-1000 ℃, and keeping the temperature for 2-2.5 h; cooling, and when the temperature is as low as 200 ℃, removing the pressure; and continuously cooling to room temperature to obtain the graphene/polyimide carbon film.
Eighthly, preparing the heat-conducting film based on the graphene/polyimide composite sponge precursor:
placing the graphene/polyimide carbon film obtained in the step seven into a high-temperature graphitization furnace, and adopting a gradient temperature raising method to realize graphitization of the carbon film; heating to 1200 deg.C at a heating rate of 20 deg.C/min, heating to 2200 deg.C at a heating rate of 10 deg.C/min, and holding for 30 min; heating at a rate of 5 deg.C/min to 2800 deg.C for 120 min; and cooling to room temperature to obtain the graphene/polyimide composite sponge precursor-based heat-conducting film.
The invention also discloses a graphene polyimide composite sponge precursor-based heat-conducting film prepared by the preparation method of the graphene polyimide composite sponge precursor-based heat-conducting film.
Compared with the prior art, the invention has the beneficial effects that:
the preparation method disclosed by the invention is simple in process and low in cost, the graphene oxide is used as a raw material, the lamellar area of the graphene oxide is large and adjustable, and the continuous lamellar structure reduces the crystal boundary scattering of phonons in the transmission process, so that the thermal conductivity is favorably improved; the highly oriented three-dimensional graphene oxide/polyamide acid composite sponge is constructed by using the oxygen-containing groups on the graphene oxide sheet layer and taking the graphene oxide as a cross-linking agent of polyamide acid, so that the problem of the dispersibility of the graphene is solved, and the highly oriented three-dimensional graphene oxide/polyamide acid composite sponge has certain flexibility, high mechanical strength and better electric and heat conducting properties, and is expected to be a heat dissipation material of a flexible device to be applied to practical electronic equipment.
Secondly, the technical scheme of the invention adopts a dimensionality reduction method, polyamide acid is crosslinked and imidized under the action of pressure and heat, graphene oxide is reduced to graphene, a hot-pressing oxidation pretreatment process can be completed, effective interface contact is established, strong interaction is generated between sheet layers, and then the defects of a composite film sample are reduced through a high-temperature vacuum heat treatment process and a graphitization treatment process, so that the mechanical property of the film is improved, the heat conductivity and the electric conductivity of the film are improved, and the heat conductivity and the electric conductivity are more stable and excellent.
Thirdly, according to the technical scheme, the thickness and flexibility of the graphene film can be controlled by adjusting the concentration of the dispersion liquid, the mechanical pressure, the heat treatment temperature and the reaction time; the preparation method can be widely applied to industrial production.
Drawings
FIG. 1 is a schematic preparation scheme of example 1.
Fig. 2 is a photograph of the highly oriented graphene oxide/polyamic acid composite sponge prepared in example 1.
Fig. 3 is a photograph of the graphene/polyimide composite sponge precursor-based thermal conductive film prepared in example 1 and its flexibility.
Fig. 4 is a graph of the relative resistance change rate of the graphene/polyimide composite sponge precursor-based thermal conductive film of example 1 after 10000 times of bending.
Detailed Description
Preferred embodiments of the present invention are described in further detail below.
Example 1
A graphene/polyimide composite sponge precursor-based heat-conducting film is prepared by the following steps, and a schematic diagram of a preparation flow is shown in figure 1:
firstly, preparing a graphene oxide aqueous solution: measuring 20mL of graphene oxide slurry, and adding deionized water; stirring for 60min under the condition that the stirring speed is 700 r/min; and carrying out ultrasonic treatment for 30min at the frequency of 100KHz to obtain the graphene oxide aqueous solution.
Wherein the concentration of the graphene oxide slurry is 20 mg/mL; the concentration of the graphene oxide in the graphene oxide aqueous solution is 5 mg/mL.
Secondly, preparing a polyimide precursor solution:
1.98g of monomeric diamine diaminodiphenyl ether (ODA) powder was uniformly dispersed in 83mL of a polar solvent dimethylacetamide (DMAc) solution using an electromagnetic stirrer; continuously adding 2.18g of dianhydride pyromellitic dianhydride (PMDA) powder into the mixed solution in a small amount, and stirring for 5 hours to fully react to obtain a polyamide acid (PAA) solution; the molar concentration ratio of PMDA to ODA is 100: 99.
After the polycondensation reaction is finished, washing the stirred solution by a large amount of deionized water to obtain yellow precipitate polyamic acid fiber; removing the residual deionized water after filtering, cleaning and drying to obtain a solid with the mass fraction of 5%; and stirring a solid material corresponding to 1g of PAA solution, 0.48g of Triethylamine (TEA) solution and 18.52mL of deionized water at room temperature for 6 hours to obtain a water-soluble polyimide precursor.
Wherein, in the polyimide precursor solution, the concentration of the polyamic acid is 20 mg/mL.
Thirdly, preparing a graphene oxide/polyamic acid mixed solution:
and (3) mixing the graphene oxide aqueous solution obtained in the step one with the polyimide precursor solution obtained in the step two, stirring for 2 hours, and fully reacting to obtain graphene oxide/polyamic acid mixed solutions with different concentrations.
Wherein, in the graphene oxide/polyamic acid mixed solution, the concentration of the graphene oxide is 70 wt%.
Fourthly, preparing the high-orientation graphene oxide/polyamic acid frozen sponge:
and D, directionally freezing the graphene oxide/polyamide acid mixed solution obtained in the step three by using liquid nitrogen to obtain the high-directional graphene oxide/polyamide acid freezing sponge with different shapes.
Fifthly, preparing the highly-oriented graphene oxide/polyamic acid composite sponge:
and (4) drying the high-orientation graphene oxide/polyamic acid frozen sponge obtained in the fourth step by adopting a freeze drying method to obtain the high-orientation graphene oxide/polyamic acid composite sponge.
Sixthly, preparing the reduced graphene oxide/polyimide composite film:
placing the highly oriented graphene oxide/polyamic acid composite sponge obtained in the fifth step into a hot-pressing reaction furnace, and realizing reduction of graphene oxide and imidization of polyamic acid by a one-step method by adopting a hot-pressing oxidation pretreatment process; when the temperature is raised to 200 ℃, mechanical pressurization is carried out, and the pressure is 25 MPa; continuously heating to 350 ℃, and keeping the temperature for 1 h; cooling, and when the temperature is as low as 200 ℃, removing the pressure; and continuously cooling to room temperature to obtain the reduced graphene oxide/polyimide composite film.
Seventhly, preparing the graphene/polyimide carbon film:
placing the reduced graphene oxide/polyimide composite film obtained in the sixth step into a hot-pressing reaction furnace, and carbonizing the graphene and the polyimide by adopting a high-temperature vacuum heat treatment process; when the temperature is raised to 200 ℃, mechanical pressurization is carried out, and the pressure is 25 MPa; continuously heating to 1000 ℃, and keeping the temperature for 2 hours; cooling, and when the temperature is as low as 200 ℃, removing the pressure; and continuously cooling to room temperature to obtain the graphene/polyimide carbon film.
Eighthly, preparing the heat-conducting film based on the graphene/polyimide composite sponge precursor: placing the graphene/polyimide carbon film obtained in the step seven into a high-temperature graphitization furnace, and adopting a gradient temperature raising method to realize graphitization of the carbon film; heating to 1200 deg.C at a heating rate of 20 deg.C/min, heating to 2200 deg.C at a heating rate of 10 deg.C/min, and holding for 30 min; heating at a rate of 5 deg.C/min to 2800 deg.C for 120 min; and cooling to room temperature to obtain the graphene/polyimide composite sponge precursor-based heat-conducting film.
In the photo of the highly-oriented graphene oxide/polyamic acid composite sponge prepared in the fifth step of the embodiment, as shown in fig. 2, it can be seen from the photo that the highly-oriented graphene oxide/polyamic acid composite sponge is yellowish brown and has a flat surface, the cut inner sheet layer is in an oriented tube bundle structure along the growth direction of the ice crystal, the vertical direction is in a honeycomb-like hole structure, and the structure has a positive effect on the formation of the graphene/polyimide composite sponge precursor-based heat conducting film in the later period.
As shown in fig. 3, the thermal conductive film based on the graphene/polyimide composite sponge precursor prepared in the eighth step of the embodiment and the flexible photo thereof show that the prepared low-defect graphene film has a smooth surface, is free from wrinkles or bubbles, has certain flexibility, and can be bent by 180 degrees and folded into various shapes;
as shown in fig. 4, a graph of a relative resistance change rate of the graphene/polyimide composite sponge precursor-based heat conductive film prepared in the eighth step of the present embodiment after 10000 times of bending shows that resistance is not significantly increased, which indicates that the film has good working stability.
In this embodiment, by testing the thermal conductivity and the electrical conductivity of the sample, the thermal conductivity of the graphene/polyimide composite sponge precursor-based thermal conductive film is 1467W m-1 K-1The conductivity reaches 1.8 multiplied by 105 S m-1The value of the graphene/polyimide composite sponge precursor-based heat-conducting film is similar to that of the graphene composite film with high heat conductivity and high electric conductivity reported at present, and meanwhile, the graphene/polyimide composite sponge precursor-based heat-conducting film prepared by the embodiment has high tensile strength which reaches 150 MPa and is about 4 times that of the existing graphene film, has certain flexibility, and meets the actual application requirements in the fields of national defense and military equipment and intelligent electronics.
Example two:
a graphene/polyimide composite sponge precursor-based heat-conducting film is prepared by the following steps:
firstly, preparing a graphene oxide aqueous solution:
measuring 20mL of graphene oxide slurry, and adding deionized water; stirring for 60min under the condition that the stirring speed is 700 r/min; and carrying out ultrasonic treatment for 30min at the frequency of 100KHz to obtain the graphene oxide aqueous solution.
Wherein the concentration of the graphene oxide slurry is 20 mg/mL; the concentration of the graphene oxide in the graphene oxide aqueous solution is 5 mg/mL.
Secondly, preparing a polyimide precursor solution:
1.98g of monomeric diamine diaminodiphenyl ether (ODA) powder was uniformly dispersed in 83mL of a polar solvent dimethylacetamide (DMAc) solution using an electromagnetic stirrer; continuously adding 2.18g of dianhydride pyromellitic dianhydride (PMDA) powder into the mixed solution in a small amount, and stirring for 5 hours to fully react to obtain a polyamide acid (PAA) solution; the molar concentration ratio of PMDA to ODA is 100: 99.
After the polycondensation reaction is finished, washing the stirred solution by a large amount of deionized water to obtain yellow precipitate polyamic acid fiber; removing the residual deionized water after filtering, cleaning and drying to obtain a solid with the mass fraction of 5%; and stirring a solid material corresponding to 1g of PAA solution, 0.48g of Triethylamine (TEA) solution and 18.52mL of deionized water at room temperature for 6 hours to obtain a water-soluble polyimide precursor.
Wherein, in the polyimide precursor solution, the concentration of the polyamic acid is 20 mg/mL.
Thirdly, preparing a graphene oxide/polyamic acid mixed solution:
and (3) mixing the graphene oxide aqueous solution obtained in the step one with the polyimide precursor solution obtained in the step two, stirring for 2 hours, and fully reacting to obtain graphene oxide/polyamic acid mixed solutions with different concentrations.
Wherein, in the graphene oxide/polyamic acid mixed solution, the concentration of the graphene oxide is 90 wt%.
Fourthly, preparing the high-orientation graphene oxide/polyamic acid frozen sponge:
and D, directionally freezing the graphene oxide/polyamide acid mixed solution obtained in the step three by using liquid nitrogen to obtain the high-directional graphene oxide/polyamide acid freezing sponge with different shapes.
Fifthly, preparing the highly-oriented graphene oxide/polyamic acid composite sponge:
and (4) drying the high-orientation graphene oxide/polyamic acid frozen sponge obtained in the fourth step by adopting a freeze drying method to obtain the high-orientation graphene oxide/polyamic acid composite sponge.
Sixthly, preparing the reduced graphene oxide/polyimide composite film:
placing the highly oriented graphene oxide/polyamic acid composite sponge obtained in the fifth step into a hot-pressing reaction furnace, and realizing reduction of graphene oxide and imidization of polyamic acid by a one-step method by adopting a hot-pressing oxidation pretreatment process; when the temperature is raised to 200 ℃, mechanical pressurization is carried out, and the pressure is 30 MPa; continuously heating to 300 ℃, and keeping the temperature for 1.5 h; cooling, and when the temperature is as low as 200 ℃, removing the pressure; and continuously cooling to room temperature to obtain the reduced graphene oxide/polyimide composite film.
Seventhly, preparing the graphene/polyimide carbon film:
placing the reduced graphene oxide/polyimide composite film obtained in the sixth step into a hot-pressing reaction furnace, and carbonizing the graphene and the polyimide by adopting a high-temperature vacuum heat treatment process; when the temperature is raised to 200 ℃, mechanical pressurization is carried out, and the pressure is 30 MPa; continuously heating to 900 ℃, and keeping the temperature for 2.5 hours; cooling, and when the temperature is as low as 200 ℃, removing the pressure; and continuously cooling to room temperature to obtain the graphene/polyimide carbon film.
Eighthly, preparing the heat-conducting film based on the graphene/polyimide composite sponge precursor:
placing the graphene/polyimide carbon film obtained in the step seven into a high-temperature graphitization furnace, and adopting a gradient temperature raising method to realize graphitization of the carbon film; heating to 1200 deg.C at a heating rate of 20 deg.C/min, heating to 2200 deg.C at a heating rate of 10 deg.C/min, and holding for 30 min; heating at a rate of 5 deg.C/min to 2800 deg.C for 120 min; and cooling to room temperature to obtain the graphene/polyimide composite sponge precursor-based heat-conducting film.
In the embodiment, the graphene/polyimide based material is obtained by testing the thermal conductivity and the electric conductivity of a sampleThe thermal conductivity of the composite sponge precursor heat-conducting film is 1450W m-1 K-1The conductivity reaches 1.75 multiplied by 105 S m-1The value of the graphene/polyimide composite sponge precursor-based heat-conducting film is similar to that of the graphene composite film with high heat conductivity and high electric conductivity reported at present, and meanwhile, the graphene/polyimide composite sponge precursor-based heat-conducting film prepared by the embodiment has higher tensile strength which reaches 147 MPa and is about 4 times that of the existing graphene film, has certain flexibility, and meets the actual application requirements in the fields of national defense and military equipment and intelligent electronics.
Example 3
A graphene/polyimide composite sponge precursor-based heat-conducting film is prepared by the following steps:
firstly, preparing a graphene oxide aqueous solution:
measuring 20mL of graphene oxide slurry, and adding deionized water; stirring for 120min under the condition that the stirring speed is 100 r/min; and carrying out ultrasonic treatment for 60min at the frequency of 10KHz to obtain the graphene oxide aqueous solution.
Wherein the concentration of the graphene oxide slurry is 20 mg/mL; the concentration of the graphene oxide in the graphene oxide aqueous solution is 4 mg/mL.
Secondly, preparing a polyimide precursor solution:
1.98g of monomeric diamine diaminodiphenyl ether (ODA) powder was uniformly dispersed in 83mL of a polar solvent dimethylacetamide (DMAc) solution using an electromagnetic stirrer; continuously adding 2.18g of dianhydride pyromellitic dianhydride (PMDA) powder into the mixed solution in a small amount, and stirring for 5 hours to fully react to obtain a polyamide acid (PAA) solution; the molar concentration ratio of PMDA to ODA is 100: 99;
after the polycondensation reaction is finished, washing the stirred solution by a large amount of deionized water to obtain yellow precipitate polyamic acid fiber; removing the residual deionized water after filtering, cleaning and drying to obtain a solid with the mass fraction of 5%; and stirring a solid material corresponding to 1g of PAA solution, 0.48g of Triethylamine (TEA) solution and 18.52mL of deionized water at room temperature for 6 hours to obtain a water-soluble polyimide precursor.
Wherein, in the polyimide precursor solution, the concentration of the polyamic acid is 20 mg/mL.
Thirdly, preparing a graphene oxide/polyamic acid mixed solution:
and (3) mixing the graphene oxide aqueous solution obtained in the step one with the polyimide precursor solution obtained in the step two, stirring for 2 hours, and fully reacting to obtain graphene oxide/polyamic acid mixed solutions with different concentrations.
Wherein, in the graphene oxide/polyamic acid mixed solution, the concentration of the graphene oxide is 60 wt%.
Fourthly, preparing the high-orientation graphene oxide/polyamic acid frozen sponge:
and D, directionally freezing the graphene oxide/polyamide acid mixed solution obtained in the step three by using liquid nitrogen to obtain the high-directional graphene oxide/polyamide acid freezing sponge with different shapes.
Fifthly, preparing the highly-oriented graphene oxide/polyamic acid composite sponge:
and (4) drying the high-orientation graphene oxide/polyamic acid frozen sponge obtained in the fourth step by adopting a freeze drying method to obtain the high-orientation graphene oxide/polyamic acid composite sponge.
Sixthly, preparing the reduced graphene oxide/polyimide composite film:
placing the highly oriented graphene oxide/polyamic acid composite sponge obtained in the fifth step into a hot-pressing reaction furnace, and realizing reduction of graphene oxide and imidization of polyamic acid by a one-step method by adopting a hot-pressing oxidation pretreatment process; when the temperature is raised to 200 ℃, mechanical pressurization is carried out, and the pressure is 20 MPa; continuously heating to 300 ℃, and keeping the temperature for 1.5 h; cooling, and when the temperature is as low as 200 ℃, removing the pressure; and continuously cooling to room temperature to obtain the reduced graphene oxide/polyimide composite film.
Seventhly, preparing the graphene/polyimide carbon film:
placing the reduced graphene oxide/polyimide composite film obtained in the sixth step into a hot-pressing reaction furnace, and carbonizing the graphene and the polyimide by adopting a high-temperature vacuum heat treatment process; when the temperature is raised to 200 ℃, mechanical pressurization is carried out, and the pressure is 20 MPa; continuously heating to 900 ℃, and keeping the temperature for 2.5 hours; cooling, and when the temperature is as low as 200 ℃, removing the pressure; and continuously cooling to room temperature to obtain the graphene/polyimide carbon film.
Eighthly, preparing the heat-conducting film based on the graphene/polyimide composite sponge precursor:
placing the graphene/polyimide carbon film obtained in the step seven into a high-temperature graphitization furnace, and adopting a gradient temperature raising method to realize graphitization of the carbon film; heating to 1200 deg.C at a heating rate of 20 deg.C/min, heating to 2200 deg.C at a heating rate of 10 deg.C/min, and holding for 30 min; heating at a rate of 5 deg.C/min to 2800 deg.C for 120 min; and cooling to room temperature to obtain the graphene/polyimide composite sponge precursor-based heat-conducting film.
In this embodiment, the thermal conductivity of the graphene/polyimide composite sponge precursor-based thermal conductive film obtained by testing the thermal conductivity and the electrical conductivity of the sample is 1380W m-1 K-1The conductivity reaches 1.68 multiplied by 105 S m-1The value of the graphene/polyimide composite sponge precursor-based heat-conducting film is similar to that of the graphene composite film with high heat conductivity and high electric conductivity reported at present, and meanwhile, the graphene/polyimide composite sponge precursor-based heat-conducting film prepared by the embodiment has high tensile strength reaching 137 MPa, which is about 4 times that of the existing graphene film, has certain flexibility, and meets the actual application requirements in the fields of national defense and military equipment and intelligent electronics.
Example 4
A graphene/polyimide composite sponge precursor-based heat-conducting film is prepared by the following steps:
firstly, preparing a graphene oxide aqueous solution: measuring 20mL of graphene oxide slurry, and adding deionized water; stirring for 120min under the condition that the stirring speed is 100 r/min; and carrying out ultrasonic treatment for 60min at the frequency of 10KHz to obtain the graphene oxide aqueous solution.
Wherein the concentration of the graphene oxide slurry is 20 mg/mL; the concentration of the graphene oxide in the graphene oxide aqueous solution is 6 mg/mL.
Secondly, preparing a polyimide precursor solution:
1.98g of monomeric diamine diaminodiphenyl ether (ODA) powder was uniformly dispersed in 83mL of a polar solvent dimethylacetamide (DMAc) solution using an electromagnetic stirrer; continuously adding 2.18g of dianhydride pyromellitic dianhydride (PMDA) powder into the mixed solution in a small amount, and stirring for 5 hours to fully react to obtain a polyamide acid (PAA) solution; the molar concentration ratio of PMDA to ODA is 100: 99;
after the polycondensation reaction is finished, washing the stirred solution by a large amount of deionized water to obtain yellow precipitate polyamic acid fiber; removing the residual deionized water after filtering, cleaning and drying to obtain a solid with the mass fraction of 5%; and stirring a solid material corresponding to 1g of PAA solution, 0.48g of Triethylamine (TEA) solution and 18.52mL of deionized water at room temperature for 6 hours to obtain a water-soluble polyimide precursor.
Wherein, in the polyimide precursor solution, the concentration of the polyamic acid is 20 mg/mL.
Thirdly, preparing a graphene oxide/polyamic acid mixed solution:
and (3) mixing the graphene oxide aqueous solution obtained in the step one with the polyimide precursor solution obtained in the step two, stirring for 2 hours, and fully reacting to obtain graphene oxide/polyamic acid mixed solutions with different concentrations.
Wherein, in the graphene oxide/polyamic acid mixed solution, the concentration of the graphene oxide is 90 wt%.
Fourthly, preparing the high-orientation graphene oxide/polyamic acid frozen sponge:
and D, directionally freezing the graphene oxide/polyamide acid mixed solution obtained in the step three by using liquid nitrogen to obtain the high-directional graphene oxide/polyamide acid freezing sponge with different shapes.
Fifthly, preparing the highly-oriented graphene oxide/polyamic acid composite sponge:
and (4) drying the high-orientation graphene oxide/polyamic acid frozen sponge obtained in the fourth step by adopting a freeze drying method to obtain the high-orientation graphene oxide/polyamic acid composite sponge.
Sixthly, preparing the reduced graphene oxide/polyimide composite film:
placing the highly oriented graphene oxide/polyamic acid composite sponge obtained in the fifth step into a hot-pressing reaction furnace, and realizing reduction of graphene oxide and imidization of polyamic acid by a one-step method by adopting a hot-pressing oxidation pretreatment process; when the temperature is raised to 200 ℃, mechanical pressurization is carried out, and the pressure is 25 MPa; continuously heating to 350 ℃, and keeping the temperature for 1 h; cooling, and when the temperature is as low as 200 ℃, removing the pressure; and continuously cooling to room temperature to obtain the reduced graphene oxide/polyimide composite film.
Seventhly, preparing the graphene/polyimide carbon film:
placing the reduced graphene oxide/polyimide composite film obtained in the sixth step into a hot-pressing reaction furnace, and carbonizing the graphene and the polyimide by adopting a high-temperature vacuum heat treatment process; when the temperature is raised to 200 ℃, mechanical pressurization is carried out, and the pressure is 25 MPa; continuously heating to 1000 ℃, and keeping the temperature for 2 hours; cooling, and when the temperature is as low as 200 ℃, removing the pressure; and continuously cooling to room temperature to obtain the graphene/polyimide carbon film.
Eighthly, preparing the heat-conducting film based on the graphene/polyimide composite sponge precursor:
placing the graphene/polyimide carbon film obtained in the step seven into a high-temperature graphitization furnace, and adopting a gradient temperature raising method to realize graphitization of the carbon film; heating to 1200 deg.C at a heating rate of 20 deg.C/min, heating to 2200 deg.C at a heating rate of 10 deg.C/min, and holding for 30 min; heating at a rate of 5 deg.C/min to 2800 deg.C for 120 min; and cooling to room temperature to obtain the graphene/polyimide composite sponge precursor-based heat-conducting film.
In this embodiment, by testing the thermal conductivity and the electrical conductivity of the sample, the thermal conductivity of the graphene/polyimide composite sponge precursor-based thermal conductive film is 1460W m-1 K-1The conductivity reaches 1.76 multiplied by 105 S m-1The numerical value is similar to that of the graphene composite film with high thermal conductivity and high electric conductivity reported at present, and meanwhile, the graphene composite film is prepared by the embodimentThe graphene/polyimide composite sponge precursor-based heat-conducting film has high tensile strength reaching 146 MPa, which is about 4 times that of the existing graphene film, has certain flexibility, and meets the actual application requirements in the fields of national defense and military equipment and intelligent electronics.
Example 5
A graphene/polyimide composite sponge precursor-based heat-conducting film is prepared by the following steps:
firstly, preparing a graphene oxide aqueous solution: measuring 20mL of graphene oxide slurry, and adding deionized water; stirring for 120min under the condition that the stirring speed is 100 r/min; and carrying out ultrasonic treatment for 60min at the frequency of 10KHz to obtain the graphene oxide aqueous solution.
Wherein the concentration of the graphene oxide slurry is 20 mg/mL; the concentration of the graphene oxide in the graphene oxide aqueous solution is 6 mg/mL.
Secondly, preparing a polyimide precursor solution:
1.98g of monomeric diamine diaminodiphenyl ether (ODA) powder was uniformly dispersed in 83mL of a polar solvent dimethylacetamide (DMAc) solution using an electromagnetic stirrer; continuously adding 2.18g of dianhydride pyromellitic dianhydride (PMDA) powder into the mixed solution in a small amount, and stirring for 5 hours to fully react to obtain a polyamide acid (PAA) solution; the molar concentration ratio of PMDA to ODA is 100: 95;
after the polycondensation reaction is finished, washing the stirred solution by a large amount of deionized water to obtain yellow precipitate polyamic acid fiber; removing the residual deionized water after filtering, cleaning and drying to obtain a solid with the mass fraction of 5%; and stirring a solid material corresponding to 1g of PAA solution, 0.48g of Triethylamine (TEA) solution and 18.52mL of deionized water at room temperature for 6 hours to obtain a water-soluble polyimide precursor.
Wherein, in the polyimide precursor solution, the concentration of the polyamic acid is 15 mg/mL.
Thirdly, preparing a graphene oxide/polyamic acid mixed solution:
and (3) mixing the graphene oxide aqueous solution obtained in the step one with the polyimide precursor solution obtained in the step two, stirring for 2 hours, and fully reacting to obtain graphene oxide/polyamic acid mixed solutions with different concentrations.
Wherein, in the graphene oxide/polyamic acid mixed solution, the concentration of the graphene oxide is 10 wt%.
Fourthly, preparing the high-orientation graphene oxide/polyamic acid frozen sponge:
and D, directionally freezing the graphene oxide/polyamide acid mixed solution obtained in the step three by using liquid nitrogen to obtain the high-directional graphene oxide/polyamide acid freezing sponge with different shapes.
Fifthly, preparing the highly-oriented graphene oxide/polyamic acid composite sponge:
and (4) drying the high-orientation graphene oxide/polyamic acid frozen sponge obtained in the fourth step by adopting a freeze drying method to obtain the high-orientation graphene oxide/polyamic acid composite sponge.
Sixthly, preparing the reduced graphene oxide/polyimide composite film:
placing the highly oriented graphene oxide/polyamic acid composite sponge obtained in the fifth step into a hot-pressing reaction furnace, and realizing reduction of graphene oxide and imidization of polyamic acid by a one-step method by adopting a hot-pressing oxidation pretreatment process; when the temperature is raised to 200 ℃, mechanical pressurization is carried out, and the pressure is 25 MPa; continuously heating to 350 ℃, and keeping the temperature for 1 h; cooling, and when the temperature is as low as 200 ℃, removing the pressure; and continuously cooling to room temperature to obtain the reduced graphene oxide/polyimide composite film.
Seventhly, preparing the graphene/polyimide carbon film:
placing the reduced graphene oxide/polyimide composite film obtained in the sixth step into a hot-pressing reaction furnace, and carbonizing the graphene and the polyimide by adopting a high-temperature vacuum heat treatment process; when the temperature is raised to 200 ℃, mechanical pressurization is carried out, and the pressure is 25 MPa; continuously heating to 1000 ℃, and keeping the temperature for 2 hours; cooling, and when the temperature is as low as 200 ℃, removing the pressure; and continuously cooling to room temperature to obtain the graphene/polyimide carbon film.
Eighthly, preparing the heat-conducting film based on the graphene/polyimide composite sponge precursor:
placing the graphene/polyimide carbon film obtained in the step seven into a high-temperature graphitization furnace, and adopting a gradient temperature raising method to realize graphitization of the carbon film; heating to 1200 deg.C at a heating rate of 20 deg.C/min, heating to 2200 deg.C at a heating rate of 10 deg.C/min, and holding for 30 min; heating at a rate of 5 deg.C/min to 2800 deg.C for 120 min; and cooling to room temperature to obtain the graphene/polyimide composite sponge precursor-based heat-conducting film.
In this embodiment, the thermal conductivity of the graphene polyimide composite sponge precursor-based thermal conductive film is 1330W m by testing the thermal conductivity and the electrical conductivity of the sample-1 K-1The conductivity reaches 1.1 multiplied by 105 S m-1The value of the graphene-polyimide composite sponge precursor-based heat-conducting film is similar to that of a graphene composite film with high heat conductivity and high electric conductivity reported at present, and meanwhile, the graphene-polyimide composite sponge precursor-based heat-conducting film prepared by the embodiment has high tensile strength reaching 126 MPa, which is about 3.5 times that of the existing graphene film, has certain flexibility, and meets the actual application requirements in the fields of national defense and military equipment and intelligent electronics.
The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.
Claims (8)
1. A preparation method of a graphene polyimide composite sponge precursor-based heat-conducting film is characterized by comprising the following steps:
step S1, preparing a graphene oxide aqueous solution;
step S2, preparing a polyimide precursor solution;
step S3, mixing the graphene oxide aqueous solution with a polyimide precursor solution to obtain a graphene oxide/polyamic acid mixed solution;
step S4, freezing the obtained graphene oxide/polyamide acid mixed solution to obtain a graphene oxide/polyamide acid frozen sponge;
step S5, drying the obtained graphene oxide/polyamic acid frozen sponge by adopting a freeze drying method to obtain a graphene oxide/polyamic acid composite sponge;
step S6, placing the obtained graphene oxide/polyamic acid composite sponge in a hot-pressing reaction furnace, and realizing reduction of graphene oxide and imidization of polyamic acid by adopting a hot-pressing oxidation pretreatment method; simultaneously, mechanically pressurizing the film to obtain a reduced graphene oxide/polyimide composite film;
step S7, placing the obtained reduced graphene oxide/polyimide composite film in a hot-pressing reaction furnace, and carbonizing the graphene and the polyimide by adopting vacuum heat treatment; simultaneously, mechanically pressurizing the carbon film to obtain a graphene/polyimide carbon film;
step S8, placing the obtained graphene/polyimide carbon film in a high-temperature graphitization furnace, and adopting a gradient heating method to realize graphitization of the carbon film to obtain a heat conduction film based on the graphene/polyimide composite sponge precursor;
the mechanical pressurization in the step S6 and the step S7 is carried out under the pressure of 20MPa-30MPa, and the pressure is removed when the pressure is maintained until the temperature is reduced to 200 ℃;
the conditions of the vacuum heat treatment in step S7 are: the temperature is 900-1000 ℃, and the constant temperature is kept for 2-2.5 h.
2. The preparation method of the graphene-polyimide composite sponge precursor-based heat conducting film according to claim 1, wherein in step S3, the concentration of graphene oxide in the graphene oxide aqueous solution is 1-10 mg/mL.
3. The preparation method of the graphene polyimide composite sponge precursor-based heat conducting film according to claim 1, characterized in that: in step S3, the concentration of the polyamic acid in the polyimide precursor solution is 15-20 mg/mL.
4. The preparation method of the graphene polyimide composite sponge precursor-based heat conducting film according to claim 1, characterized in that: in the graphene oxide/polyamic acid mixed solution in the step S3, the concentration of graphene oxide is 10wt% to 90 wt%.
5. The preparation method of the graphene polyimide composite sponge precursor-based heat conducting film according to claim 4, characterized by comprising the following steps: the heat treatment temperature of the hot-pressing oxidation pretreatment method in the step S6 is 300-350 ℃, and the constant temperature is kept for 1-1.5 h.
6. The preparation method of the graphene polyimide composite sponge precursor-based heat conducting film according to claim 4, characterized by comprising the following steps: the conditions of the gradient temperature raising method in step S7 are: heating to 1200 deg.C at a heating rate of 20 deg.C/min, heating to 2200 deg.C at a heating rate of 10 deg.C/min, and holding for 30 min; the heating rate is 5 ℃/min, the temperature is continuously heated to 2800 ℃, and the temperature is reduced to the room temperature after the constant temperature is kept for 120 min.
7. The preparation method of the graphene-based polyimide composite sponge precursor heat-conducting film according to any one of claims 1 to 6, wherein the step S2 includes:
dispersing monomer diamine diaminodiphenyl ether in a polar solvent, and then adding dianhydride pyromellitic dianhydride, wherein the molar ratio of the dianhydride pyromellitic dianhydride to the monomer diamine diaminodiphenyl ether is 100: 95-99; stirring to make it fully react to obtain polyamic acid (PAA) solution; after the reaction is finished, washing, filtering, cleaning and drying to obtain a solid matter; and uniformly stirring the solid matter and an aqueous solution of Triethylamine (TEA) to obtain a water-soluble polyimide precursor solution.
8. The utility model provides a compound sponge precursor heat conduction film based on graphite alkene polyimide which characterized in that: the graphene-polyimide-based composite sponge precursor heat-conducting film is prepared by the method according to any one of claims 1 to 7.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910908958.3A CN110550956B (en) | 2019-09-25 | 2019-09-25 | Preparation method of graphene-polyimide-based composite sponge precursor heat-conducting film |
| AU2020102143A AU2020102143A4 (en) | 2019-09-25 | 2020-09-04 | Preparation method of graphene polyimide composite sponge precursor-based thermal-conductive film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910908958.3A CN110550956B (en) | 2019-09-25 | 2019-09-25 | Preparation method of graphene-polyimide-based composite sponge precursor heat-conducting film |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110550956A CN110550956A (en) | 2019-12-10 |
| CN110550956B true CN110550956B (en) | 2022-01-11 |
Family
ID=68741375
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910908958.3A Active CN110550956B (en) | 2019-09-25 | 2019-09-25 | Preparation method of graphene-polyimide-based composite sponge precursor heat-conducting film |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN110550956B (en) |
| AU (1) | AU2020102143A4 (en) |
Families Citing this family (22)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111261833B (en) * | 2020-01-19 | 2021-06-22 | 中南大学 | Self-supporting lithium metal cathode and preparation and application thereof |
| CN111909420B (en) * | 2020-08-25 | 2022-04-22 | 哈尔滨工程大学 | Preparation method and product of graphene/polyimide composite sponge flexible sensor |
| CN112521716B (en) * | 2020-12-15 | 2023-03-21 | 云南大学 | Graphene aerogel-polyimide composite membrane material and preparation method thereof |
| CN114682101B (en) * | 2020-12-30 | 2023-05-30 | 中国石油化工股份有限公司 | Carbon hollow fiber membrane and preparation method thereof |
| CN112723345B (en) * | 2021-03-26 | 2023-09-29 | 云南云天墨睿科技有限公司 | Composite graphene slurry with self-assembly property and preparation method thereof |
| CN113214583B (en) * | 2021-04-07 | 2022-04-12 | 复旦大学 | Thermal interface material with vertical sandwich structure and preparation method thereof |
| CN113185834A (en) * | 2021-04-22 | 2021-07-30 | 陕西工业职业技术学院 | Preparation method of polymer-based carbon nano composite microporous electromagnetic shielding material |
| CN113307626A (en) * | 2021-06-10 | 2021-08-27 | 深圳烯创技术有限公司 | Preparation method of graphene heat dissipation material with high infrared emissivity |
| CN113502143B (en) * | 2021-06-28 | 2022-01-14 | 浙江大学 | Production device and preparation method of graphene thermal interface material |
| CN113526957B (en) * | 2021-08-04 | 2022-11-25 | 德州宇航派蒙石墨烯科技有限责任公司 | Heat-conducting film and preparation method thereof |
| CN114133735A (en) * | 2021-12-07 | 2022-03-04 | 东莞市鸿亿导热材料有限公司 | graphene-PI film and preparation method thereof |
| CN114232388A (en) * | 2021-12-20 | 2022-03-25 | 北京交通大学 | Method for preparing high-thermal-conductivity mica paper based on freezing casting technology |
| CN114455576B (en) * | 2022-01-24 | 2023-11-10 | 南方电网科学研究院有限责任公司 | Preparation method of graphene composite material for detecting pressure change with high sensitivity |
| CN114737318B (en) * | 2022-04-18 | 2023-11-17 | 江西昌大高新能源材料技术有限公司 | Preparation method of polyimide-based high-heat-conductivity graphite nanofiber membrane |
| CN114655946A (en) * | 2022-04-28 | 2022-06-24 | 安徽碳华新材料科技有限公司 | High-flexibility graphene-like heat conduction structure prepared based on hydrothermal method |
| CN115010494B (en) * | 2022-06-01 | 2023-01-24 | 星途(常州)碳材料有限责任公司 | Preparation method of graphene heat conducting sheet for strengthening longitudinal heat flux transmission |
| CN114736019B (en) * | 2022-06-10 | 2022-09-13 | 宁波长阳科技股份有限公司 | Artificial graphite sheet with high vertical heat conduction and radiating fin comprising artificial graphite sheet |
| CN115216055A (en) * | 2022-06-23 | 2022-10-21 | 浙江美之源化妆品有限公司 | Preparation method of perfume volatilization medium graphite core rod |
| CN115073056A (en) * | 2022-07-01 | 2022-09-20 | 苏州恩多科石墨烯科技有限公司 | Graphene high-thermal-conductivity material and preparation method thereof |
| CN115304308A (en) * | 2022-08-26 | 2022-11-08 | 江苏斯迪克新材料科技股份有限公司 | Preparation method of graphene/soluble polyimide composite heat-conducting film |
| CN115785665A (en) * | 2022-12-08 | 2023-03-14 | 陕西科技大学 | High-strength MXene-based electromagnetic shielding composite film and preparation method thereof |
| CN115975233A (en) * | 2023-02-23 | 2023-04-18 | 上海继尔新材料科技有限公司 | Polyimide-based electromagnetic shielding film with pearl layered structure and preparation method and application thereof |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104355302A (en) * | 2014-10-21 | 2015-02-18 | 复旦大学 | Preparation method of graphene/polyimide-based carbon aerogel |
| CN104558606A (en) * | 2014-12-15 | 2015-04-29 | 南京新月材料科技有限公司 | Method for preparing graphene composite polyimide conductive film |
| CN106853966A (en) * | 2015-12-07 | 2017-06-16 | 株洲时代新材料科技股份有限公司 | The method for preparing high heat conduction graphite film using Graphene doping polyamic acid resin |
| CN107337928A (en) * | 2017-08-03 | 2017-11-10 | 上海理工大学 | A kind of graphene/polyimide composite film and preparation method thereof |
| CN107383873A (en) * | 2017-08-03 | 2017-11-24 | 上海理工大学 | A kind of graphene/polyimide composite film and preparation method thereof |
| CN108910865A (en) * | 2018-07-21 | 2018-11-30 | 哈尔滨工业大学 | A method of preparing graphene/graphene nanobelt mixed film |
-
2019
- 2019-09-25 CN CN201910908958.3A patent/CN110550956B/en active Active
-
2020
- 2020-09-04 AU AU2020102143A patent/AU2020102143A4/en not_active Ceased
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104355302A (en) * | 2014-10-21 | 2015-02-18 | 复旦大学 | Preparation method of graphene/polyimide-based carbon aerogel |
| CN104558606A (en) * | 2014-12-15 | 2015-04-29 | 南京新月材料科技有限公司 | Method for preparing graphene composite polyimide conductive film |
| CN106853966A (en) * | 2015-12-07 | 2017-06-16 | 株洲时代新材料科技股份有限公司 | The method for preparing high heat conduction graphite film using Graphene doping polyamic acid resin |
| CN107337928A (en) * | 2017-08-03 | 2017-11-10 | 上海理工大学 | A kind of graphene/polyimide composite film and preparation method thereof |
| CN107383873A (en) * | 2017-08-03 | 2017-11-24 | 上海理工大学 | A kind of graphene/polyimide composite film and preparation method thereof |
| CN108910865A (en) * | 2018-07-21 | 2018-11-30 | 哈尔滨工业大学 | A method of preparing graphene/graphene nanobelt mixed film |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110550956A (en) | 2019-12-10 |
| AU2020102143A4 (en) | 2020-10-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110550956B (en) | Preparation method of graphene-polyimide-based composite sponge precursor heat-conducting film | |
| CN104262588B (en) | A kind of epoxide resin conductive adhesive comprising graphite oxide thiazolinyl firming agent | |
| CN101798462B (en) | Graphene/conductive polymer composite film and preparation method thereof | |
| KR101140196B1 (en) | Polyimide Nanocomposites and Method for making the same | |
| CN102268134B (en) | Preparation method for polyimide/graphene nanocomposite material | |
| CN103483516B (en) | Preparation method of graphene oxide-boron-modified phenolic resin | |
| CN102690426B (en) | Method for preparing graphene/polymer composite material based on infrared irradiation | |
| CN108997754B (en) | Polyimide high-temperature dielectric composite film and preparation method thereof | |
| CN103589152A (en) | Preparation method for polyimide/oxidized graphene nanocomposite film | |
| CN107304490B (en) | Preparation method of graphene/polyimide composite carbon fiber | |
| CN109401314B (en) | Preparation method of graphene/polyimide composite material | |
| CN111777841B (en) | Lamellar anisotropy-based graphene/epoxy resin composite material and preparation method thereof | |
| KR101311458B1 (en) | polyimide-graphene Composite material and method of producing the same | |
| CN113604046A (en) | Preparation method of boron nitride/carbon nano tube/polyimide composite material | |
| CN110272552B (en) | Preparation method of polyimide film for graphite sintering | |
| CN107384189B (en) | Preparation method of fluorinated graphene/polyimide enameled wire | |
| CN108203543B (en) | Graphene-reinforced polyimide nanocomposite material and preparation method and application thereof | |
| CN108822317B (en) | Preparation method of graphene polyimide heating film | |
| CN103889196A (en) | Manufacturing method of high thermal conductivity artificial graphite film | |
| CN101487190B (en) | Polyimide carbon fiber sizing agent and method for producing the same | |
| CN113621155B (en) | Preparation method of nano-micron boron nitride/polyimide composite material | |
| CN111470876A (en) | High-graphitization polyimide-based graphite thick film and preparation method thereof | |
| CN105085915B (en) | A kind of high dielectric polyimides/carbon nano tube compound material and preparation method thereof | |
| Chou et al. | Highly transparent silver nanowire–polyimide electrode as a snow-cleaning device | |
| CN111662547A (en) | Molybdenum disulfide quantum dot/graphene/polymer-based super-wear-resistant self-lubricating composite material and preparation method and application thereof |
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 |