Disclosure of Invention
In view of the above, the present invention provides a method for preparing graphene/carbon nanotube/silica aerogel material, which is environment-friendly without adding alcohol solvent in the preparation process, and does not need to treat waste liquid, thereby reducing the production cost and facilitating the realization of industrial continuous production.
In order to achieve the purpose, the invention adopts the following technical scheme:
a preparation method of a graphene/carbon nanotube/silicon dioxide aerogel material comprises the following steps:
(1) mixing: mixing graphene oxide, carbon nano tubes, water glass, silica gel, polydopamine and urea according to the proportion of 1: (0.25-1.5): (2-4): (1-3): (3-5): (3-8) putting the mixture into a stirring tank according to the mass ratio, uniformly stirring and mixing, and performing dispersion treatment to obtain a dispersion liquid;
(2) heating: adding the dispersion liquid obtained in the step (1) into an oil bath pot, and heating at the temperature of 60-110 ℃ for 20-50min to obtain a graphene/carbon nanotube/silicon dioxide aerogel mixture;
(3) and (3) drying: carrying out freeze drying treatment on the graphene/carbon nanotube/silicon dioxide aerogel mixture obtained in the step (2) to obtain a blank;
(4) acid washing: washing the blank obtained in the step (3) with aqua regia, removing impurity ions, washing with deionized water until the pH is neutral, and drying to obtain graphene/carbon nanotube/silicon dioxide aerogel;
(5) and (3) sintering: and (5) performing discharge plasma sintering on the graphene/carbon nanotube/silicon dioxide aerogel obtained in the step (4), using nitrogen as a protective gas, and performing temperature of 500-700 ℃ for 0.5-8min to obtain the graphene/carbon nanotube/silicon dioxide aerogel material.
Preferably, the number of layers of the graphene oxide is less than or equal to 10, and the transverse dimension of the graphene oxide is greater than 10 μm.
As a preferred scheme, the carbon nanotube is a single-walled carbon nanotube or a multi-walled carbon nanotube, the diameter of the carbon nanotube is less than or equal to 60nm, and the length of the carbon nanotube is 10-30 μm.
As a preferable scheme, the stirring speed in the step (1) is 300-1400rpm, and the stirring time is 1-5 h.
Preferably, the dispersion treatment in step (1) is performed by one or more of a colloid mill, a homogenizer and an emulsification pump, the rotation speed is 1000-2800rpm, and the dispersion time is 0.5-1 h.
As a preferable scheme, the drying treatment in the step (3) is hot air drying treatment, the temperature is 60-100 ℃, and the time is 10-30 min.
As a preferable scheme, the aqua regia in the step (4) is a mixture of concentrated hydrochloric acid and concentrated nitric acid according to the volume ratio of 3: 1.
Compared with the prior art, the invention has obvious advantages and beneficial effects, and specifically, the technical scheme includes that:
graphene oxide, carbon nano tubes, water glass, silica gel, polydopamine and urea are mixed and stirred, discharge plasma sintering is carried out after heating and drying, and the graphene/carbon nano tube/silicon dioxide aerogel material is obtained.
To more clearly illustrate the features and effects of the present invention, the present invention is described in detail below with reference to specific examples.
Detailed Description
The invention discloses a preparation method of a graphene/carbon nanotube/silicon dioxide aerogel material, which comprises the following steps:
(1) mixing: mixing graphene oxide, carbon nano tubes, water glass, silica gel, polydopamine and urea according to the proportion of 1: (0.25-1.5): (2-4): (1-3): (3-5): (3-8) putting the mixture into a stirring tank according to the mass ratio, uniformly stirring and mixing, and performing dispersion treatment to obtain a dispersion liquid; the number of layers of the graphene oxide is less than or equal to 10, and the transverse size of the graphene oxide is greater than 10 micrometers; the carbon nano tube is a single-wall carbon nano tube or a multi-wall carbon nano tube, the tube diameter of the carbon nano tube is less than or equal to 60nm, and the length of the carbon nano tube is 10-30 mu m; the stirring speed is 300-1400rpm, the stirring time is 1-5h, the dispersion treatment is performed by one or more of a colloid mill, a homogenizer and an emulsification pump, the rotating speed is 1000-2800rpm, and the dispersion time is 0.5-1 h.
(2) Heating: and (2) adding the dispersion liquid obtained in the step (1) into an oil bath pot, and heating at the temperature of 60-110 ℃ for 20-50min to obtain a graphene/carbon nanotube/silicon dioxide aerogel mixture.
(3) And (3) drying: carrying out freeze drying treatment on the graphene/carbon nanotube/silicon dioxide aerogel mixture obtained in the step (2) to obtain a blank; the drying treatment is hot air drying treatment at 60-100 deg.C for 10-30 min.
(4) Acid washing: washing the blank obtained in the step (3) with aqua regia, removing impurity ions, washing with deionized water until the pH is neutral, and drying to obtain graphene/carbon nanotube/silicon dioxide aerogel; the aqua regia is a mixture of concentrated hydrochloric acid and concentrated nitric acid according to the volume ratio of 3: 1.
(5) And (3) sintering: and (5) performing discharge plasma sintering on the graphene/carbon nanotube/silicon dioxide aerogel obtained in the step (4), using nitrogen as a protective gas, and performing temperature of 500-700 ℃ for 0.5-8min to obtain the graphene/carbon nanotube/silicon dioxide aerogel material.
The invention is illustrated in more detail below in the following examples:
example 1
(1) Mixing: mixing graphene oxide, carbon nano tubes, water glass, silica gel, polydopamine and urea according to the proportion of 1: 0.25: 2: 1: 3: 3, putting the mixture into a stirring tank, uniformly stirring and mixing, and performing dispersion treatment to obtain a dispersion liquid; the number of layers of the graphene oxide is less than or equal to 10, and the transverse size of the graphene oxide is greater than 10 micrometers; the carbon nano tube is a single-wall carbon nano tube or a multi-wall carbon nano tube, the tube diameter of the carbon nano tube is less than or equal to 60nm, and the length of the carbon nano tube is 10-30 mu m; the stirring speed is 300rpm, the stirring time is 1h, the dispersion treatment is dispersion by a colloid mill, the rotating speed is 1000rpm, and the dispersion time is 0.5 h.
(2) Heating: and (2) adding the dispersion liquid obtained in the step (1) into an oil bath pot, and heating at 70 ℃ for 30min to obtain a graphene/carbon nanotube/silicon dioxide aerogel mixture.
(3) And (3) drying: carrying out freeze drying treatment on the graphene/carbon nanotube/silicon dioxide aerogel mixture obtained in the step (2) to obtain a blank; the drying treatment is hot air drying treatment at 65 deg.C for 18 min.
(4) Acid washing: washing the blank obtained in the step (3) with aqua regia, removing impurity ions, washing with deionized water until the pH is neutral, and drying to obtain graphene/carbon nanotube/silicon dioxide aerogel; the aqua regia is a mixture of concentrated hydrochloric acid and concentrated nitric acid according to the volume ratio of 3: 1.
(5) And (3) sintering: and (4) performing discharge plasma sintering on the graphene/carbon nanotube/silicon dioxide aerogel obtained in the step (4), using nitrogen as a protective gas, and keeping the temperature at 500 ℃ for 5min to obtain the graphene/carbon nanotube/silicon dioxide aerogel material.
Example 2
(1) Mixing: mixing graphene oxide, carbon nano tubes, water glass, silica gel, polydopamine and urea according to the proportion of 1: 1.5: 4: 3: 5: 8, putting the mixture into a stirring tank, stirring and mixing the mixture uniformly, and performing dispersion treatment to obtain a dispersion liquid; the number of layers of the graphene oxide is less than or equal to 10, and the transverse size of the graphene oxide is greater than 10 micrometers; the carbon nano tube is a single-wall carbon nano tube or a multi-wall carbon nano tube, the tube diameter of the carbon nano tube is less than or equal to 60nm, and the length of the carbon nano tube is 10-30 mu m; the stirring speed was 1400rpm, the stirring time was 5 hours, and the dispersion treatment was dispersion by a homogenizer at 2800rpm for 1 hour.
(2) Heating: adding the dispersion liquid obtained in the step (1) into an oil bath pot, and heating at 90 ℃ for 20min to obtain a graphene/carbon nanotube/silicon dioxide aerogel mixture;
(3) and (3) drying: carrying out freeze drying treatment on the graphene/carbon nanotube/silicon dioxide aerogel mixture obtained in the step (2) to obtain a blank; the drying treatment is hot air drying treatment at 90 deg.C for 20 min.
(4) Acid washing: washing the blank obtained in the step (3) with aqua regia, removing impurity ions, washing with deionized water until the pH is neutral, and drying to obtain graphene/carbon nanotube/silicon dioxide aerogel; the aqua regia is a mixture of concentrated hydrochloric acid and concentrated nitric acid according to the volume ratio of 3: 1.
(5) And (3) sintering: and (4) performing discharge plasma sintering on the graphene/carbon nanotube/silicon dioxide aerogel obtained in the step (4), using nitrogen as a protective gas, and keeping the temperature at 700 ℃ for 1min to obtain the graphene/carbon nanotube/silicon dioxide aerogel material.
Example 3
(1) Mixing: mixing graphene oxide, carbon nano tubes, water glass, silica gel, polydopamine and urea according to the proportion of 1: 1: 3: 2: 4: 6, putting the mixture into a stirring tank, stirring and mixing the mixture uniformly, and performing dispersion treatment to obtain a dispersion liquid; the number of layers of the graphene oxide is less than or equal to 10, and the transverse size of the graphene oxide is greater than 10 micrometers; the carbon nano tube is a single-wall carbon nano tube or a multi-wall carbon nano tube, the tube diameter of the carbon nano tube is less than or equal to 60nm, and the length of the carbon nano tube is 10-30 mu m; the stirring speed is 700rpm, the stirring time is 3h, the dispersing treatment is dispersing by an emulsification pump, the rotating speed is 1800rpm, and the dispersing time is 0.8 h.
(2) Heating: adding the dispersion liquid obtained in the step (1) into an oil bath pot, and heating at the temperature of 60 ℃ for 20min to obtain a graphene/carbon nanotube/silicon dioxide aerogel mixture;
(3) and (3) drying: carrying out freeze drying treatment on the graphene/carbon nanotube/silicon dioxide aerogel mixture obtained in the step (2) to obtain a blank; the drying treatment is hot air drying treatment at 80 deg.C for 15 min.
(4) Acid washing: washing the blank obtained in the step (3) with aqua regia, removing impurity ions, washing with deionized water until the pH is neutral, and drying to obtain graphene/carbon nanotube/silicon dioxide aerogel; the aqua regia is a mixture of concentrated hydrochloric acid and concentrated nitric acid according to the volume ratio of 3: 1.
(5) And (3) sintering: and (4) performing discharge plasma sintering on the graphene/carbon nanotube/silicon dioxide aerogel obtained in the step (4), using nitrogen as a protective gas, and keeping the temperature at 500 ℃ for 8min to obtain the graphene/carbon nanotube/silicon dioxide aerogel material.
Example 4
(1) Mixing: mixing graphene oxide, carbon nano tubes, water glass, silica gel, polydopamine and urea according to the proportion of 1: 1.2: 3.5: 2.6: 3.8: 6.2, uniformly stirring and mixing the materials in a stirring tank, and performing dispersion treatment to obtain a dispersion liquid; the number of layers of the graphene oxide is less than or equal to 10, and the transverse size of the graphene oxide is greater than 10 micrometers; the carbon nano tube is a single-wall carbon nano tube or a multi-wall carbon nano tube, the tube diameter of the carbon nano tube is less than or equal to 60nm, and the length of the carbon nano tube is 10-30 mu m; the stirring speed is 1200rpm, the stirring time is 4.5h, the dispersion treatment is to sequentially carry out dispersion by a colloid mill and a homogenizer, the rotating speed is 2600rpm, and the dispersion time is 0.8 h.
(2) Heating: adding the dispersion liquid obtained in the step (1) into an oil bath pot, and heating at the temperature of 110 ℃ for 50min to obtain a graphene/carbon nanotube/silicon dioxide aerogel mixture;
(3) and (3) drying: carrying out freeze drying treatment on the graphene/carbon nanotube/silicon dioxide aerogel mixture obtained in the step (2) to obtain a blank; the drying treatment is hot air drying treatment at 75 deg.C for 16 min.
(4) Acid washing: washing the blank obtained in the step (3) with aqua regia, removing impurity ions, washing with deionized water until the pH is neutral, and drying to obtain graphene/carbon nanotube/silicon dioxide aerogel; the aqua regia is a mixture of concentrated hydrochloric acid and concentrated nitric acid according to the volume ratio of 3: 1.
(5) And (3) sintering: and (4) performing discharge plasma sintering on the graphene/carbon nanotube/silicon dioxide aerogel obtained in the step (4), using nitrogen as a protective gas, and keeping the temperature at 700 ℃ for 0.5min to obtain the graphene/carbon nanotube/silicon dioxide aerogel material.
Example 5
(1) Mixing: mixing graphene oxide, carbon nano tubes, water glass, silica gel, polydopamine and urea according to the proportion of 1: 0.5: 2.6: 2.2: 4: 7, putting the mixture into a stirring tank, uniformly stirring and mixing, and performing dispersion treatment to obtain a dispersion liquid; the number of layers of the graphene oxide is less than or equal to 10, and the transverse size of the graphene oxide is greater than 10 micrometers; the carbon nano tube is a single-wall carbon nano tube or a multi-wall carbon nano tube, the tube diameter of the carbon nano tube is less than or equal to 60nm, and the length of the carbon nano tube is 10-30 mu m; the stirring speed is 1000rpm, the stirring time is 2h, the dispersing treatment is dispersing by an emulsification pump, the rotating speed is 1800rpm, and the dispersing time is 0.9 h.
(2) Heating: and (2) adding the dispersion liquid obtained in the step (1) into an oil bath pot, and heating at 100 ℃ for 46min to obtain a graphene/carbon nanotube/silicon dioxide aerogel mixture.
(3) And (3) drying: carrying out freeze drying treatment on the graphene/carbon nanotube/silicon dioxide aerogel mixture obtained in the step (2) to obtain a blank; the drying treatment is hot air drying treatment at 60 deg.C for 30 min.
(4) Acid washing: washing the blank obtained in the step (3) with aqua regia, removing impurity ions, washing with deionized water until the pH is neutral, and drying to obtain graphene/carbon nanotube/silicon dioxide aerogel; the aqua regia is a mixture of concentrated hydrochloric acid and concentrated nitric acid according to the volume ratio of 3: 1.
(5) And (3) sintering: and (4) performing discharge plasma sintering on the graphene/carbon nanotube/silicon dioxide aerogel obtained in the step (4), using nitrogen as a protective gas, and keeping the temperature at 650 ℃ for 5min to obtain the graphene/carbon nanotube/silicon dioxide aerogel material.
Example 6
(1) Mixing: mixing graphene oxide, carbon nano tubes, water glass, silica gel, polydopamine and urea according to the proportion of 1: 1.4: 3.8: 2.6: 3.8: 6.8, uniformly stirring and mixing the materials in a stirring tank, and performing dispersion treatment to obtain a dispersion liquid; the number of layers of the graphene oxide is less than or equal to 10, and the transverse size of the graphene oxide is greater than 10 micrometers; the carbon nano tube is a single-wall carbon nano tube or a multi-wall carbon nano tube, the tube diameter of the carbon nano tube is less than or equal to 60nm, and the length of the carbon nano tube is 26 mu m; the stirring speed is 700rpm, the stirring time is 3.6h, the dispersion treatment is dispersion by a colloid mill, the rotating speed is 2500rpm, and the dispersion time is 0.6 h.
(2) Heating: adding the dispersion liquid obtained in the step (1) into an oil bath pot, and heating at 100 ℃ for 43min to obtain a graphene/carbon nanotube/silicon dioxide aerogel mixture;
(3) and (3) drying: carrying out freeze drying treatment on the graphene/carbon nanotube/silicon dioxide aerogel mixture obtained in the step (2) to obtain a blank; the drying treatment is hot air drying treatment at 100 deg.C for 10 min.
(4) Acid washing: washing the blank obtained in the step (3) with aqua regia, removing impurity ions, washing with deionized water until the pH is neutral, and drying to obtain graphene/carbon nanotube/silicon dioxide aerogel; the aqua regia is a mixture of concentrated hydrochloric acid and concentrated nitric acid according to the volume ratio of 3: 1.
(5) And (3) sintering: and (4) performing discharge plasma sintering on the graphene/carbon nanotube/silicon dioxide aerogel obtained in the step (4), using nitrogen as a protective gas, and keeping the temperature at 570 ℃ for 4min to obtain the graphene/carbon nanotube/silicon dioxide aerogel material.
The graphene/carbon nanotube/silica aerogel material prepared in the above embodiments is subjected to performance tests, and the test standards are as follows:
coefficient of thermal conductivity: testing the heat conductivity coefficient by adopting a transient hot wire method;
the results of the above tests are shown in table 1 below:
TABLE 1
As can be seen from tables 1 and 2, the graphene/carbon nanotube/silica aerogel material prepared in the above embodiments has a thermal conductivity coefficient at room temperature that is not much different from the thermal conductivity coefficient at 500 ℃ and the thermal conductivity coefficient at 650 ℃, and can normally operate at a high temperature of 500 ℃ or higher.
The design of the invention is characterized in that: graphene oxide, carbon nano tubes, water glass, silica gel, polydopamine and urea are mixed and stirred, discharge plasma sintering is carried out after heating and drying, and the graphene/carbon nano tube/silicon dioxide aerogel material is obtained.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the technical scope of the present invention, so that any minor modifications, equivalent changes and modifications made to the above embodiment according to the technical spirit of the present invention are within the technical scope of the present invention.