CN107720728A - A kind of terahertz electromagnetic wave stealth material based on graphene - Google Patents
A kind of terahertz electromagnetic wave stealth material based on graphene Download PDFInfo
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Abstract
The invention provides a kind of terahertz electromagnetic wave stealth material, is porous graphene foamed material, porosity is more than 99%, and pore size is at 10 200 μm.After it by single-layer graphene oxide by being made dispersion liquid, high-temperature solvent thermal response is carried out in confined conditions, obtains grapheme foam, and drying and high-temperature roasting obtain.The invention purport has good terahertz electromagnetic wave Stealth Fighter, and electromagnetic wave can realize strong absorb in the case of different incidence angles in broadband.
Description
Technical field
The present invention relates to the stealthy application field of terahertz electromagnetic wave, particularly a kind of terahertz electromagnetic wave based on graphene
Stealth material.
Background technology
Terahertz electromagnetic wave, i.e. frequency be 0.1THz-10THz (30 μm of -3mm of wavelength) electromagnetic wave, have energy it is low, when
Between high resolution, the advantages of spatial resolution is high, frequency spectrum is wide, and in molecular spectrum, the vibration of most of molecules rotates energy
Level and pattern ylid Chuihua molecule Interaction Force and hydrogen bond are all located in the range of terahertz electromagnetic wave.With high energy laser sources
Development, the intensity of Terahertz light source significantly improves so that terahertz electromagnetic wave is in the application neck such as imaging, military, detection, communication
Domain is developed rapidly, although relevant THz source and terahertz electromagnetic wave Detection Techniques are all progressively developing, with
Correlation terahertz electromagnetic wave absorb, filtering, modulation, the field but slower development such as polarization.
Terahertz radar is the main direction of studying of Terahertz military field, compared with common millimeter wave, microwave radar, too
Hertz electromagnetic wave bandwidth is wider, can carry information content and more enrich, and wavelength is shorter, therefore detection accuracy, resolution ratio improve, and are fighting
Terahertz radar has powerful detection, tracking, recognition capability on field.China and part American-European countries, which all have developed, belongs to this
The terahertz imaging radar installations of the specific frequency section of state.
With the development of Terahertz the radar exploration technique, ground for the terahertz electromagnetic wave stealth material of Terahertz radar
Study carefully design also to become more and more important.Electromagnetic wave stealth material, the most important seek to realize strong inhale under broadband, extensive angle
Receive.
At present, the research of terahertz electromagnetic wave stealth material is also fewer, belongs to front line science technical field, in order to obtain
The material of excellent properties, probing direction are roughly divided into two classes, and one kind is by structure design, is regulated and controled using sub-wavelength structure array
Electrical conductivity and magnetic conductivity, so as to produce the Meta Materials absorbed more by force on a specific frequency；Also one kind is to rely on material in itself
Dielectric property, attempt to obtain the absorbent properties of the terahertz electromagnetic wave under wide bandwidth.
Meta Materials, regulate and control electrical conductivity and magnetic conductivity using sub-wavelength structure array, it is stronger so as to produce on a specific frequency
Absorb.Hu Tao et al. devise the Terahertz frequency range absorber based on metamaterial structure, simulate and obtain on 1.12THz
98% absorbs, and experimental data reaches 70% absorption in 1.3THz；With the development of Meta Materials, absorbent properties are updated,
Fabio Alve et al. pass through SiO2/ Al bases metamaterial structure obtains 98% absorption intensity in 4.1THz frequencies.But due to
The factor of structure design, this batch of Meta Materials remain difficult to the premium properties for keeping terahertz electromagnetic wave to absorb under wideband wide-angle.Cause
One major defect of this Meta Materials, precisely due to the design of structure, which result in, to obtain high-selenium corn, super material in a certain frequency
Expect to become the band width that terahertz electromagnetic wave absorbs one factor for limiting Meta Materials practical application.Although pass through complexity
Technological design, synthesized the bimodal absorbing structure of Terahertz and three the peaks even Meta Materials of multimodal absorbing structure, but frequency
The limitation of width still has.
Therefore, the dielectric property based on material in itself, obtain terahertz electromagnetic wave high-efficient wide-frequency absorb it is another kind of too
Hertz stealth material is particularly important.
For CNT series terahertz electromagnetic wave stealth material, Lehman et al. by vertical alignment carbon nano pipe array
(VANTA) it is connected with thermoelectric pile, the normal reflection ability of the controlled-length apparatus part by adjusting CNT, most long 1.5mm carbon
Nano-tube array obtains the reflection close to 1% in 760GHz frequency, but band width and unmeasured.Tae-in Jeon
Et al. single-walled carbon nanotube is prepared for by arc process, then mixed by methylcellulose, slurry rolled on quartz plate
Film forming, in the terahertz time-domain spectroscopy system for the polarization that obtained film is put between 0.2-2.0THz frequencies, test single wall carbon
Nanotube is passing through property perpendicular to polarization direction or parallel to the terahertz electromagnetic wave on polarization direction.Then, Tae-In
Jeon et al. have studied the front and rear absorption in 0.2-3THz frequency ranges of single-walled carbon nanotube fluorination by the way that single-walled carbon nanotube is fluorinated
Property, after fluorination, a large amount of carriers are migrated to F2, absorbent properties from SWCNTs and significantly improved, but still do not reach strong suction
The requirement of receipts.
For the materials such as graphite terahertz electromagnetic wave absorbent properties, M.A.Seo et al. by by the 26um of different content
The graphite powder of particle diameter mixes with PMMA powder, hot-forming obtained thickness~230-320um thin-film material, further that gained is thin
Film has carried out the transmission test in 0.1-1.6THz frequency bands in terahertz time-domain spectroscopy system, and material is calculated by transmission results
The dielectric constant and refractive index of material, so as to which the absorbent properties of material and reflecting properties be calculated, it is in content of graphite
Under conditions of 35.7%, 1THz frequency ranges have reached~80% absorption.Deng et al. passes through terahertz time-domain spectroscopy system, contrast
Graphite, oildag, SiC, 3M Velvet-coating normal reflection ability.Graphite is anti-under 0.1-2THz with oildag
Penetrate more than 50%, and SiC and 3M Velvet-coating reflection is relatively low, only 20% or so.In order to further reduce
Reflection, the SiC of different-grain diameter size is sprayed on 3M velvet-coating paint, increases surface roughness, further
Reduce normal reflection.Although the material thickness of mixed coating is the several times of VANTA films, the SiC and 3M of 300um sizes
Velvet-coating volume ratios 1:The mixed coating of 5 mixing, in the reflection of 0.2-0.5THz frequency bands less than 0.3%, and
The reflection of 0.5-2.0THz frequency bands is less than 0.1%.Pedro Chamorro-Posada et al. pass through terahertz time-domain spectroscopic technology
It has studied four kinds of sp2 carbon materials to be well mixed with PE powder progress low content, then hot-forming diameter 13mm sheet material, including
Individual layer redox graphene, few layer graphene oxide, unordered needle coke and high starch breeding.Adding 2.5wt% graphite, Jiao
After charcoal and GO, absorption spectra compared to pure PE 2.2THz frequencies occur three shape are similar and absworption peak that intensity is different, graphite
The peak value of absorption spectra has reached 130cm-1, and the peak that these three same positions occur has corresponded to the suction of the vibration-rotation energy level of sp2 carbon
Receive spectrum.And for rGO/PE sheet materials, absorption coefficient is in obvious rise trend from low to high, shows as significantly conductance effect
Should, and the content for improving rGO helps to increase absorption coefficient, and rGO contents are raised to 5wt% from 1.5wt%, and absorption coefficient exists
During 2THz 26cm-1 is increased to from 7cm-1.Carbon material stealth capabilities are all also weaker mostly at present.
It is prepared for for the terahertz electromagnetic wave Stealth Fighter, Joseph Lott et al. of the material of high dielectric by tabletting
Thickness 150um barium titanate/PMMA composites, it is photonic crystal as high index of refraction ferroelectric material to make full use of barium titanate
Field generates rejection band in the Terahertz frequency range more than 0.5THz, but absorbent properties are also not strong enough.
Therefore, the high-strength terahertz electromagnetic wave stealth material of a wide-angle wideband is still lacked so far.
The content of the invention
In view of this, the invention is directed to a kind of stealth material of the terahertz electromagnetic wave based on graphene, leads to
The stealthy test of terahertz time-domain spectroscopy system is crossed, material surface reflection is low, and incidence wave damages after entering grapheme material inside
Consumption is obvious, and almost perfect to absorb, the material has good terahertz electromagnetic wave Stealth Fighter, and electromagnetic wave is in different incidences
In the case of angle can broadband realize it is strong absorb, and the material has that density is low, and compressible, corrosion-resistant, high temperature resistant etc. is all
More advantages.
The terahertz electromagnetic wave stealth material of the invention, is porous graphene foamed material, porosity 99% with
On, pore size 10-200 μm, be preferably 10-100 μm, more preferably 20-60 μm, it is optimal be 50 ± 10 μm.
Further, the real part of permittivity of the porous graphene foamed material be 0~25, imaginary part of dielectric constant be 0~
2.5。
The preparation method of the terahertz electromagnetic wave stealth material of the invention comprises the following steps：
S1：Single-layer graphene oxide (GO) is dispersed in a solvent, obtain dispersion liquid；
S2：Dispersion liquid is subjected to high-temperature solvent thermal response in confined conditions, obtains grapheme foam；
S3：Grapheme foam is dried, drying retains grapheme foam internal structure simultaneously and do not collapsed；
S4：Dried grapheme foam is subjected to high-temperature roasting in an inert atmosphere, obtains porous graphene foam material
Material.
In the step S1, single-layer graphene oxide can be prepared by crystalline flake graphite by improvement Hummer ' the s methods of classics
Obtain.
In the step S1, the solvent can be any one in water, THF, acetone, methanol, ethanol, ethylene glycol, DMF
Kind is a variety of.Suitable solvent is advantageous to the dispersed of graphene, while is advantageous to be subsequently formed the foam of grapheme foam
Stability.
In the step S1, graphene oxide content is in 0.1-20mg cm in dispersion liquid-3.Suitable graphene concentration has
Beneficial to the progress foamed during solvent thermal reaction, and obtain suitable foam volume and suitable whole density of material.
In the step S2, before and after high-temperature solvent thermal response, the Volume Changes of graphene are 1.4-3 times of (i.e. graphene bubble
The volume of foam relative to graphene dispersing solution volume multiple), preferably 1.6-1.8 times.
In the step S2, high-temperature solvent thermal response temperature is 120-240 DEG C, and pressure is 1.5-3MPa in course of reaction,
Reaction time 8-24h.Suitable reaction condition is advantageous to obtain more uniform and stable grapheme foam.
Drying in the step S3 is advantageous to prevent foaming structure in drying process preferably by freeze-drying process
Collapse.
In the step S3, before carrying out freeze-drying process, also comprise the steps：By grapheme foam from high-temperature solvent
After being taken out in the reactor (reactor) of thermal response, it is positioned in the homogeneous solvent used in dispersion liquid, then step by step puts solvent
It is changed to the solvent suitable for freeze-drying process (such as water, former solvent need not then replace when being water).Wherein, solvent is step by step put
Change the stabilization for being advantageous to grapheme foam structure.
In the step S4, the temperature of high-temperature roasting is 200-2000 DEG C, time 0.5-5h.The purpose one of high-temperature roasting
Aspect enables to grapheme foam to sinter stabilization, strength of materials increase；On the other hand the dielectric that material can be adjusted is normal
Number, is advantageous to obtain more preferable terahertz electromagnetic wave absorbent properties, dielectric constant can by adjust sintering temperature and time come
Realize, i.e., realized by adjustment of the roasting process on foam pore passage structure and influence, the porous graphite obtained through high-temperature roasting
Alkene foamed material enables to incident electromagnetic wave to enter inside graphene loose structure by repeatedly refraction reflection so as to heat
Form dissipates, and realizes the absorption to terahertz electromagnetic wave.
The stealthy foamed material of terahertz electromagnetic wave provided by the invention based on graphene has advantage：
1) Stealth Fighter is good, and the foamed material has reached -23dB to the most absorption value of terahertz electromagnetic wave；
2) wideband absorbs, and the foamed material can reach between 0.14-1.2THz (i.e. 96% test frequency range)-
The even preferably qualified absorbent properties of 10dB；
3) 0.1-1.2THz can be kept to possess -10dB (under i.e. 100% test frequency range) in the case of 45 ° of incidence angles
Even preferably qualified absorption；
4) the graphene-based foam densities are controllable and even below atmospheric density, controllable preparation obtains 0.5-5.0mg
cm-3；
5) compressible, corrosion-resistant, high temperature resistant.
Brief description of the drawings
Fig. 1 is the scanning electron microscope (SEM) photograph for the terahertz electromagnetic wave stealth material based on graphene that embodiment 1 obtains.
Fig. 2 is the normal incidence test dress in terahertz time-domain spectroscopy of the terahertz electromagnetic wave stealth material based on graphene
Put.
Fig. 3 is the oblique incidence test dress in terahertz time-domain spectroscopy of the terahertz electromagnetic wave stealth material based on graphene
Put.
Fig. 4 is the frequency domain spectra of the test of the terahertz electromagnetic wave stealth material normal incidence based on graphene of embodiment 1.
Oblique incidence test when Fig. 5 is 45 ° of the terahertz electromagnetic wave stealth material incidence angle based on graphene of embodiment 1
Frequency domain spectra.
Fig. 6 is the frequency domain spectra of the test of the terahertz electromagnetic wave stealth material normal incidence based on graphene of embodiment 2.
Oblique incidence test when Fig. 7 is 45 ° of the terahertz electromagnetic wave stealth material incidence angle based on graphene of embodiment 2
Frequency domain spectra.
Fig. 8 is the frequency domain spectra of the test of the terahertz electromagnetic wave stealth material normal incidence based on graphene of embodiment 3.
Oblique incidence test when Fig. 9 is 45 ° of the terahertz electromagnetic wave stealth material incidence angle based on graphene of embodiment 3
Frequency domain spectra.
Figure 10 is that terahertz electromagnetic wave stealth material calculates gained dielectric constant reality according to time-domain spectroscopy in embodiment 1,2,3
Portion.
Figure 11 is that terahertz electromagnetic wave stealth material calculates gained dielectric constant void according to time-domain spectroscopy in embodiment 1,2,3
Portion.
Embodiment
To further illustrate present disclosure below in conjunction with specific embodiment, but the scope of the present invention is not
It is confined to the content described by embodiment.
Embodiment 1：
The terahertz electromagnetic wave stealth material based on graphene is prepared by following methods：
1) lamella size is prepared out as 20 μm by improved classical Hummer ' s methods2Single-layer graphene oxide, take
0.03g single-layer graphene oxides, agitated, the ultrasonic processing being stirred for, full and uniform dispersion is in 100ml acetone-ethylene glycol 10:
In 1 mixed liquor, it is 0.3mg cm to obtain concentration-3Single-layer graphene oxide dispersion liquid (GO dispersion liquids)；
2) the GO dispersion liquids in 60mL steps 1 are taken to be transferred in capacity 100mL polytetrafluoroethyllining lining, then sealing is accurate
It is standby to carry out high pressure solvent thermal response kettle, it is put into and has set temperature in advance as 150 DEG C of baking oven, high temperature is carried out under design temperature of the same race
High pressure solvent thermal response, for pressure up to 1.5-3MPa, the reaction time is 8 hours in course of reaction；
3) treat that step 2 reacts complete, after reactor is cooled to room temperature, take out grapheme foam, be placed in the appearance of suitable size
In device, be impregnated in step 2 it is of the same race react in mixed solvent；
4) step 3 gained grapheme foam is reacted into mixed solvent volume ratio 1 of the same race used by water and step 3 respectively:9、
2:8、3:7、4:6、5:5、6:4、7:3、8:2、9:1、10:0 ratio is gradually replaced into pure water solvent, is put by this solvent
Change, finally give the grapheme foam being impregnated in pure water solvent；
5) grapheme foam being impregnated in obtained by step 4 in pure water solution is carried out at freezing in the case where temperature is -178 DEG C
Reason, then pass through freeze-drying process and remove the aqueous solution, obtain the grapheme foam material of structural integrity；
6) the grapheme foam material after freeze-drying process in step 5 is carried out at 600 DEG C in an inert atmosphere high
Temperature roasting 2h, is made porous graphene foamed material (the terahertz electromagnetic wave stealth material based on graphene), its density is
2.1mg cm-3；
7) the obtained porous graphene foamed material of roasting in step 6 is cut into thickness 5mm sample (see Fig. 1)；
8) sample cut in step 7 is fixed on the copper sheet of 200 μ m-thicks；
9) sample being fixed in step 8 on copper sheet is placed in terahertz time-domain spectroscopy system (see Fig. 2,3) and carried out too
The test of hertz electro-magnetic wave absorption.In the range of 0.1-1.2THz, surface reflection improves with the raising of Temperature Treatment, internal
Absorption loss improves with the raising of Temperature Treatment, and in whole frequency range, grapheme foam Terahertz stealth material shows
Excellent, 84% test frequency range reaches qualified absorption value (- 10dB), and absorption intensity is high, reaches -15dB (see Fig. 4), with
The increase of incident angle, the increase of the refraction on the light path of Terahertz incidence wave and the surface on surface even more so that stealth effect more
Excellent, when incident angle reaches 45 °, 95% test frequency range reaches qualified absorption intensity, and the peak value of absorption also breaches-
19dB (see Fig. 5), and by terahertz time-domain spectroscopy, by Nelder-Mead methods be calculated material dielectric constant (see
Figure 10,11).
Embodiment 2：
The terahertz electromagnetic wave stealth material based on graphene is prepared by following methods：
1) lamella size is prepared out as 20 μm by improved classical Hummer ' s methods2Single-layer graphene oxide, take
0.03g single-layer graphene oxides, agitated, the ultrasonic processing being stirred for, full and uniform dispersion obtain dense in 100ml acetone
Spend for 0.3mg cm-3Single-layer graphene oxide dispersion liquid (GO dispersion liquids)；
2) the GO dispersion liquids in 60mL steps 1 are taken to be transferred in capacity 100mL polytetrafluoroethyllining lining, then sealing is accurate
It is standby to carry out high pressure solvent thermal response kettle, it is put into and has set temperature in advance as 180 DEG C of baking oven, high temperature is carried out under design temperature of the same race
High pressure solvent thermal response, for pressure up to 1.5-3MPa, the reaction time is 10 hours in course of reaction；
3) treat that step 2 reacts complete, after reactor is cooled to room temperature, take out grapheme foam, be placed in the appearance of suitable size
In device, be impregnated in step 2 it is of the same race react in mixed solvent；
4) by step 3 gained grapheme foam respectively by water and acetone volume ratio 1:9、2:8、3:7、4:6、5:5、6:4、7:
3、8:2、9:1、10:0 ratio is gradually replaced into pure water solvent, is replaced by this solvent, finally gives that to be impregnated in pure water molten
Grapheme foam in agent；
5) grapheme foam being impregnated in obtained by step 4 in pure water solution is carried out at freezing in the case where temperature is -178 DEG C
Reason, then pass through freeze-drying process and remove the aqueous solution, obtain the grapheme foam material of structural integrity；
6) the grapheme foam material after freeze-drying process in step 5 is carried out at 1000 DEG C in an inert atmosphere high
Temperature roasting 3h, is made porous graphene foamed material (the terahertz electromagnetic wave stealth material based on graphene), its density is
1.8mg cm-3；
7) the obtained porous graphene foamed material of roasting in step 6 is cut into thickness 5mm sample；
8) sample cut in step 7 is fixed on the copper sheet of 200 μ m-thicks；
9) sample being fixed in step 8 on copper sheet is placed in terahertz time-domain spectroscopy system (see Fig. 2,3) and carried out too
The test of hertz electro-magnetic wave absorption.In the range of 0.1-1.2THz, surface reflection improves with the raising of Temperature Treatment, internal
Absorption loss improves with the raising of Temperature Treatment, and in whole frequency range, grapheme foam Terahertz stealth material shows
Excellent, the test frequency range more than 80% reaches qualified absorption value (- 10dB), and absorption intensity is high, reach -18dB (see Fig. 6,
With the increase of incident angle, the increase of the refraction on the light path of Terahertz incidence wave and the surface on surface is even more so that stealth effect
More excellent, when incident angle reaches 45 °, 100% test frequency range reaches qualified absorption intensity, and the peak value of absorption is also dashed forward
- 21dB (see Fig. 7) is broken, and by terahertz time-domain spectroscopy, the dielectric that material is calculated by Nelder-Mead methods is normal
Number is (see Figure 10,11).
Embodiment 3：
The terahertz electromagnetic wave stealth material based on graphene is prepared by following methods：
1) lamella size is prepared out as 20 μm by improved classical Hummer ' s methods2Single-layer graphene oxide, take
0.03g single-layer graphene oxides, agitated, the ultrasonic processing being stirred for, full and uniform dispersion obtain dense in 100ml DMF
Spend for 0.3mg cm-3Single-layer graphene oxide dispersion liquid (GO dispersion liquids)；
2) the GO dispersion liquids in 60mL steps 1 are taken to be transferred in capacity 100mL polytetrafluoroethyllining lining, then sealing is accurate
It is standby to carry out high pressure solvent thermal response kettle, it is put into and has set temperature in advance as 200 DEG C of baking oven, high temperature is carried out under design temperature of the same race
High pressure solvent thermal response, for pressure up to 1.5-3MPa, the reaction time is 12 hours in course of reaction；
3) treat that step 2 reacts complete, after reactor is cooled to room temperature, take out grapheme foam, be placed in the appearance of suitable size
In device, be impregnated in step 2 it is of the same race react in mixed solvent；
4) by step 3 gained grapheme foam respectively by water and DMF volume ratios 1:9、2:8、3:7、4:6、5:5、6:4、7:
3、8:2、9:1、10:0 ratio is gradually replaced into pure water solvent, is replaced by this solvent, finally gives that to be impregnated in pure water molten
Grapheme foam in agent；
5) grapheme foam being impregnated in obtained by step 4 in pure water solution is carried out at freezing in the case where temperature is -178 DEG C
Reason, then pass through freeze-drying process and remove the aqueous solution, obtain the grapheme foam material of structural integrity；
6) the grapheme foam material after freeze-drying process in step 5 is carried out at 1500 DEG C in an inert atmosphere high
Temperature roasting 4h, is made porous graphene foamed material (the terahertz electromagnetic wave stealth material based on graphene), its density is
1.2mg cm-3；
7) the obtained grapheme foam material of roasting in step 6 is cut into thickness 5mm sample；
8) sample cut in step 7 is fixed on the copper sheet of 200 μ m-thicks；
9) sample being fixed in step 8 on copper sheet is placed in terahertz time-domain spectroscopy system (see Fig. 2,3) and carried out too
The test of hertz electro-magnetic wave absorption.In the range of 0.1-1.2THz, surface reflection improves with the raising of Temperature Treatment, internal
Absorption loss improves with the raising of Temperature Treatment, and in whole frequency range, grapheme foam Terahertz stealth material shows
Excellent, the test frequency range more than 96% reaches qualified absorption value (- 10dB), and absorption intensity is high, reaches -20dB (see Fig. 8),
With the increase of incident angle, the increase of the refraction on the light path of Terahertz incidence wave and the surface on surface is even more so that stealth effect
More excellent, when incident angle reaches 45 °, the test frequency range more than 99% reaches qualified absorption intensity, the peak value of absorption
Also breach -23dB (see Fig. 9), and by terahertz time-domain spectroscopy, Jie of material is calculated by Nelder-Mead methods
Electric constant (see Figure 10,11).
The preferred embodiment of the invention is the foregoing is only, is not intended to limit the invention creation, it is all at this
Within the spirit and principle of innovation and creation, any modification, equivalent substitution and improvements made etc., the invention should be included in
Protection domain within.
Claims (10)
1. a kind of terahertz electromagnetic wave stealth material, it is porous graphene foamed material, porosity is more than 99%, pore size
10-200 μm, be preferably 10-100 μm, more preferably 20-60 μm, it is optimal be 50 ± 10 μm.
2. terahertz electromagnetic wave stealth material according to claim 1, it is characterised in that the porous graphene foam material
The real part of permittivity of material is 0~25, imaginary part of dielectric constant is 0~2.5.
3. a kind of preparation method of terahertz electromagnetic wave stealth material, comprises the following steps：
S1：Single-layer graphene oxide is dispersed in a solvent, obtain dispersion liquid；
S2：Dispersion liquid is subjected to high-temperature solvent thermal response in confined conditions, obtains grapheme foam；
S3：Grapheme foam is dried, drying retains grapheme foam internal structure simultaneously and do not collapsed；
S4：Dried grapheme foam is subjected to high-temperature roasting in an inert atmosphere, obtains porous graphene foamed material.
4. according to the method for claim 3, it is characterised in that in the step S1, the solvent be water, THF, acetone,
Any one or more in methanol, ethanol, ethylene glycol, DMF.
5. according to the method for claim 3, it is characterised in that in the step S1, graphene oxide content in dispersion liquid
In 0.1-20mg cm-3。
6. according to the method for claim 3, it is characterised in that in the step S2, before and after high-temperature solvent thermal response, graphite
The Volume Changes of alkene are 1.4-3 times, preferably 1.6-1.8 times.
7. according to the method for claim 3, it is characterised in that in the step S2, high-temperature solvent thermal response temperature is
120-240 DEG C, pressure is 1.5-3MPa, reaction time 8-24h in course of reaction.
8. according to the method for claim 3, it is characterised in that the drying in the step S3 uses freeze-drying process.
9. according to the method for claim 8, it is characterised in that in the step S3, before carrying out freeze-drying process, also wrap
Include following step：After grapheme foam is taken out from the reactor of high-temperature solvent thermal response, it is positioned over same used in dispersion liquid
In kind solvent, solvent is then replaced into the solvent suitable for freeze-drying process step by step.
10. according to the method for claim 3, it is characterised in that in the step S4, the temperature of high-temperature roasting is 200-
2000 DEG C, time 0.5-5h.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109494293A (en) * | 2018-12-28 | 2019-03-19 | 同方威视技术股份有限公司 | Terahertz detector and its manufacturing method |
| CN110031923A (en) * | 2019-04-19 | 2019-07-19 | 电子科技大学 | Stretchable two-sided ultra wide band Terahertz absorbing material of formula and preparation method thereof |
| CN110182789A (en) * | 2019-05-06 | 2019-08-30 | 浙江大学 | A kind of extinction heat-insulation integrative photo-thermal evaporation material and its preparation method and application |
| CN112939478A (en) * | 2021-01-14 | 2021-06-11 | 南昌大学 | Preparation method of porous film material for shielding terahertz waves |
| CN113214788A (en) * | 2021-05-12 | 2021-08-06 | 南开大学 | Preparation method of wave-absorbing material with multiple structural designs |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102674321A (en) * | 2011-03-10 | 2012-09-19 | 中国科学院金属研究所 | Graphene foam with three dimensional fully connected network and macroscopic quantity preparation method thereof |
| CN104310386A (en) * | 2014-10-14 | 2015-01-28 | 南开大学 | Preparation method and application of graphene-based light-driven material |
| CN104671233A (en) * | 2013-11-29 | 2015-06-03 | 合肥杰事杰新材料股份有限公司 | Preparation method of foam graphene |
| CN106803592A (en) * | 2015-11-26 | 2017-06-06 | 中国科学院金属研究所 | Graphene/redox graphene hydridization nesting porous network structure material and preparation and application |
| CN107043101A (en) * | 2017-03-07 | 2017-08-15 | 中国科学院上海硅酸盐研究所 | A kind of three-dimensional porous grapheme foam material and its preparation method and application |
-
2017
- 2017-09-15 CN CN201710834370.9A patent/CN107720728A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102674321A (en) * | 2011-03-10 | 2012-09-19 | 中国科学院金属研究所 | Graphene foam with three dimensional fully connected network and macroscopic quantity preparation method thereof |
| CN104671233A (en) * | 2013-11-29 | 2015-06-03 | 合肥杰事杰新材料股份有限公司 | Preparation method of foam graphene |
| CN104310386A (en) * | 2014-10-14 | 2015-01-28 | 南开大学 | Preparation method and application of graphene-based light-driven material |
| CN106803592A (en) * | 2015-11-26 | 2017-06-06 | 中国科学院金属研究所 | Graphene/redox graphene hydridization nesting porous network structure material and preparation and application |
| CN107043101A (en) * | 2017-03-07 | 2017-08-15 | 中国科学院上海硅酸盐研究所 | A kind of three-dimensional porous grapheme foam material and its preparation method and application |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109494293A (en) * | 2018-12-28 | 2019-03-19 | 同方威视技术股份有限公司 | Terahertz detector and its manufacturing method |
| WO2020134327A1 (en) * | 2018-12-28 | 2020-07-02 | 同方威视技术股份有限公司 | Terahertz detector and manufacturing method therefor |
| US12004426B2 (en) | 2018-12-28 | 2024-06-04 | Nuctech Company Limited | Terahertz detector and method of manufacturing terahertz detector |
| CN110031923A (en) * | 2019-04-19 | 2019-07-19 | 电子科技大学 | Stretchable two-sided ultra wide band Terahertz absorbing material of formula and preparation method thereof |
| CN110182789A (en) * | 2019-05-06 | 2019-08-30 | 浙江大学 | A kind of extinction heat-insulation integrative photo-thermal evaporation material and its preparation method and application |
| CN112939478A (en) * | 2021-01-14 | 2021-06-11 | 南昌大学 | Preparation method of porous film material for shielding terahertz waves |
| CN113214788A (en) * | 2021-05-12 | 2021-08-06 | 南开大学 | Preparation method of wave-absorbing material with multiple structural designs |
| CN113214788B (en) * | 2021-05-12 | 2022-07-05 | 南开大学 | Preparation method of wave-absorbing material with multiple structural designs |
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