CN113395888A - Hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material and preparation method thereof - Google Patents
Hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material and preparation method thereof Download PDFInfo
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- CN113395888A CN113395888A CN202110452069.8A CN202110452069A CN113395888A CN 113395888 A CN113395888 A CN 113395888A CN 202110452069 A CN202110452069 A CN 202110452069A CN 113395888 A CN113395888 A CN 113395888A
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
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Abstract
The invention belongs to the field of material chemistry, and particularly relates to a hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material and a preparation method thereof. The hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material provided by the invention is prepared by adding ferric salt and a surfactant into ethylene glycol dispersion liquid containing graphene oxide, adding a reducing agent into the mixed solution under an ultrasonic stirring state, transferring the solution into a reaction kettle after the reducing agent is completely dissolved, reacting at a high temperature for a period of time, washing and drying the obtained precipitate, and thus obtaining the hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material. As the nano hollow ferroferric oxide uniformly grows on the surface of the reduced graphene oxide, the magnetic loss capacity is enhanced, and the electromagnetic impedance matching characteristic is improved, so that the effective absorption bandwidth (RL <10dB) can reach more than 5GHz when the thickness of the composite wave-absorbing material and the paraffin wax mixed material is 2.5 mm.
Description
Technical Field
The invention relates to the field of material chemistry, in particular to a hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material and a preparation method thereof.
Background
With the development of modern electronic information technology, the wide application of military and civil electronic equipment provides huge power for social and economic construction. However, the living environment is seriously polluted by the electromagnetic radiation and interference generated by the electronic equipment, and the health of human beings is influenced. In order to effectively control electromagnetic radiation pollution and reduce electromagnetic wave harm, one of the key technologies is to develop a high-performance electromagnetic wave absorbing material, wherein a two-dimensional material represented by graphene has a unique microstructure, physicochemical properties and good dielectric loss capability, and is a hot spot of research in the field of electromagnetic wave absorption.
In recent years, graphene has attracted more and more attention as a new dielectric material due to its low density and good physical and chemical properties. Graphene oxide is a two-dimensional (2D) structure obtained by modifying a graphene sheet having a basal plane containing hydroxyl groups and epoxy groups, and is widely used in the fields of chemistry, energy, catalysis, environmental pollution control, and the like. However, since the impedance matching mechanism of the graphene oxide material is poor, the material for attenuating electromagnetic energy by dielectric loss is not favorable for electromagnetic absorption. Since the microwave loss mechanism includes dielectric loss and magnetic loss, these factors must be effectively complemented to improve the wave absorbing performance of the material.
Disclosure of Invention
Due to the defects in the prior art, the invention provides a hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material with a high electromagnetic wave shielding effect.
Specifically, the technical scheme of the invention is as follows:
a preparation method of a hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material comprises the following steps:
s1, preparing a dispersion liquid of graphene oxide;
s2, adding an iron salt and a surfactant into the dispersion liquid of the graphene oxide, and uniformly mixing to obtain a mixed liquid;
s3, adding a reducing agent into the mixed solution, reacting at high temperature, filtering the reaction system, and taking the reaction precipitate;
and S4, washing and drying the reaction precipitate to obtain the hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material.
Preferably, the iron salt is a soluble iron salt.
Preferably, the iron salt is one or more of ferric thiocyanate, potassium ferricyanide, ferric citrate, ferrocene, ferric sulfate, ferric nitrate, ferric chloride or potassium tetrachloroferrite.
Preferably, the surfactant is any one or more of sodium dodecyl benzene sulfonate, polyvinylpyrrolidone, polyvinyl alcohol or block high molecular polymer.
Preferably, the reducing agent is any one or more of urea, hydrazine, citric acid, vitamin C, sodium sulfide, sodium sulfite, sodium borohydride or sodium borate.
Preferably, the molar ratio of the reducing agent to the iron salt is 1: (1-3).
Preferably, in S2, adding an iron salt and a surfactant to the dispersion of graphene oxide, and uniformly mixing the iron salt and the surfactant, the method includes:
and adding iron salt and a surfactant into the dispersion liquid of the graphene oxide, and ultrasonically stirring for 0.5-3 h.
Preferably, the high-temperature reaction method is to heat the mixed solution added with the reducing agent to 150-220 ℃ and react for 16-24 h.
Preferably, the solvent of the dispersion of graphene oxide is ethylene glycol.
A hollow ferroferric oxide/reduced graphene oxide nano-composite wave-absorbing material is prepared by any one of the preparation methods of the hollow ferroferric oxide/reduced graphene oxide nano-composite wave-absorbing material.
The invention has the advantages that: according to the hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material, nano hollow ferroferric oxide uniformly grows on the surface of reduced graphene oxide, so that the magnetic loss capacity is enhanced, the electromagnetic impedance matching characteristic is improved, the dielectric loss capacity of the composite material is further enhanced due to electronic polarization, dipole polarization and interface polarization generated inside a heterostructure formed by the hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material and the reduced graphene oxide, and finally, the hollow ferroferric oxide/reduced graphene oxide nano material is endowed with good wave-absorbing performance through the synergistic effect of the magnetic loss and the dielectric loss, and when the thickness of the composite wave-absorbing material and a paraffin wax mixed material is 2.5mm, the effective absorption bandwidth (RL <10dB) can reach more than 5 GHz.
In the preparation method of the hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material, because ferric salt and a surfactant are added into ethylene glycol dispersion liquid containing graphene oxide, iron-bearing elements can be uniformly adsorbed on the surface of the graphene oxide with negative charges through ultrasonic treatment, the existence of the surfactant can enable the whole system to stably exist, and local agglomeration is avoided.
Drawings
FIG. 1 is a schematic diagram of three-dimensional reflection loss of a hollow ferroferric oxide/reduced graphene oxide nanocomposite wave-absorbing material and hollow ferroferric oxide in examples 1-3 and a comparative example;
FIG. 2 is a Scanning Electron Microscope (SEM) image and a Transmission Electron Microscope (TEM) image of the hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material in example 2;
FIG. 3 is a graph of the relative dielectric constant (a-b), the dielectric tangent loss (c), the relative magnetic permeability (d-e) and the magnetic tangent loss (f) of the hollow ferroferric oxide and hollow ferroferric oxide/reduced graphene oxide nanocomposite wave-absorbing material.
Detailed Description
The present invention will be described in further detail with reference to the following examples, which are provided for illustration only and are not intended to limit the scope of the present invention.
Specifically, the sources of the raw materials used in the following examples are as follows:
graphene oxide, using Nanjing Xiancheng nanomaterial science and technology Limited: the sheet diameter is 0.5-5 mu m, the thickness is 0.8-1.2nm, and the number of layers is as follows: 1-6 layers of graphene oxide.
The rest chemical reagents are all commercial raw materials.
Example 1
Hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material
The embodiment provides a hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material, which comprises the following specific preparation method:
0.125g of graphene oxide is added into 80ml of ethylene glycol solution, and ultrasonic treatment is carried out for 30min at the ultrasonic power of 500W. Then, under the condition of 500r/min, 5.4g of ferric chloride hexahydrate and 0.4g of polyvinylpyrrolidone are sequentially added into the graphene oxide glycol dispersion liquid, and the ultrasonic stirring is continued for 1.5 hours to obtain a mixed solution. 2.5g of urea was added to the mixed solution under ultrasonic stirring, and the obtained solution was transferred to a reaction vessel of 100ml in specification and reacted at 200 ℃ for 20 hours. After the reaction was completed and cooled naturally, the precipitate was washed three times with deionized water and dried in a vacuum oven at 60 ℃Drying for 12H to obtain the hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material (H-Fe)3O4@0.125g RGO)。
Example 2
Hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material
The embodiment provides a hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material, which comprises the following specific preparation method:
0.25g of graphene oxide is added into 80mL of glycol solution, and ultrasonic treatment is carried out for 30min at the ultrasonic power of 500W. Then, under the condition of 500r/min, 5.4g of ferric chloride hexahydrate and 0.4g of polyvinylpyrrolidone are sequentially added into the graphene oxide glycol dispersion liquid, and the ultrasonic stirring is continued for 1.5 hours to obtain a mixed solution. 2.5g of urea was added to the mixed solution under ultrasonic stirring, and the obtained solution was transferred to a reaction vessel of 100ml in specification and reacted at 200 ℃ for 20 hours. After the reaction is finished and the reaction product is naturally cooled, the precipitate is washed three times by deionized water and dried in a vacuum drying oven at the temperature of 60 ℃ for 12 hours to obtain the hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material (H-Fe)3O4@0.25g RGO)。
Example 3
Hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material
The embodiment provides a hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material, which comprises the following specific preparation method:
0.5g of graphene oxide is added into 80ml of ethylene glycol solution, and ultrasonic treatment is carried out for 30min at the ultrasonic power of 500W. Then, under the condition of 500r/min, 5.4g of ferric chloride hexahydrate and 0.4g of polyvinylpyrrolidone are sequentially added into the graphene oxide glycol dispersion liquid, and the ultrasonic stirring is continued for 1.5 hours to obtain a mixed solution. 2.5g of urea was added to the mixed solution under ultrasonic stirring, and the obtained solution was transferred to a reaction vessel of 100ml in specification and reacted at 200 ℃ for 20 hours. After the reaction was completed and cooled naturally, the precipitate was washed three times with deionized water and dried under vacuum at 60 ℃Drying in a drying oven for 12 hours to obtain the hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material (H-Fe)3O4@0.5g RGO)。
Comparative example
Hollow ferroferric oxide
The preparation method of the hollow ferroferric oxide provided by the comparative example comprises the following steps:
5.4g of ferric chloride hexahydrate and 0.4g of polyvinylpyrrolidone are added into the ethylene glycol dispersion, and ultrasonic stirring is continued for 1.5 hours to obtain a mixed solution. 2.5g of urea was added to the mixed solution under ultrasonic stirring, and the obtained solution was transferred to a reaction vessel of 100ml in specification and reacted at 200 ℃ for 20 hours. And after the reaction is finished and the mixture is naturally cooled, washing the precipitate with deionized water for three times, and drying the precipitate in a vacuum drying oven at the temperature of 60 ℃ for 12 hours to obtain the hollow ferroferric oxide.
Test example 1
Scanning electron microscope and transmission electron microscope
The materials provided in examples 1-3 and the comparative example were characterized by scanning electron microscopy and transmission electron microscopy, and the characterization results are shown in fig. 2.
As can be seen from FIG. 2, the prepared ferroferric oxide samples all have a hollow spherical structure, the average diameter of the cavities of the samples is 130nm, and the thickness of the shells is about 35 nm. FIGS. 2b-2d show that hollow microspheres grow on the surface of the reduced graphene sheet. As can be seen from FIGS. 2e-2h, the edge of the sample has an obvious graphene thin layer, the outline of the ferroferric oxide is clear, and the appearance of the original sphere is well maintained.
Test example 2
Three-dimensional reflection loss detection
The hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material provided by the embodiment 1-3 is subjected to three-dimensional reflection loss calculation, and the calculation method comprises the following steps:
input impedance (Z)in) The relationship to Reflection Loss (RL) can be expressed by the equation:
wherein f is the electromagnetic wave frequency, d is the coating thickness, and c is the vacuum light velocity. Z0Is the air impedance.
The results of the detection are shown in FIG. 2.
As can be seen from FIG. 1, the optimal reflection loss of the hollow ferroferric oxide is only-19.01 dB, which shows that the pure magnetic ferrite material has weak microwave absorption capacity. The optimal reflection loss of the composite wave-absorbing material provided by the embodiments 1, 2 and 3 reaches-35.85 dB, -32.93dB and-41.89 dB respectively. Compared with single hollow ferroferric oxide, the composite material sample has higher reflection loss, and proves that the introduction of dielectric type reduced graphene oxide can optimize impedance matching and improve the wave absorbing capacity.
Test example 3
Detection of relative permittivity, dielectric tangent loss, relative permeability and magnetic tangent loss
The materials provided in examples 1 to 3 and the comparative example were tested for their relative permittivity, dielectric tangent loss, relative permeability and magnetic tangent loss properties by the following methods: an Agilent N5242A PNA-X vector network analyzer is adopted to test the electromagnetic parameters of the material, and the test frequency range is 2-18 GHz. Preparation of paraffin-based coaxial ring samples: grinding the sample into powder, mixing the powder with paraffin according to the mass fraction of 50%, preparing the mixed material into a coaxial ring with the outer diameter of 7.00mm, the inner diameter of 3.04mm and the thickness of 3mm by adopting a hot pressing method, cooling to room temperature, cooling and forming, and testing.
The test results are shown in fig. 3.
As can be seen from FIG. 3, after the dielectric loss material is introduced, the real part (epsilon ') and the imaginary part (epsilon') of the dielectric constant of the composite wave-absorbing material provided in examples 1, 2 and 3 are obviously higher than that of ferroferric oxide, wherein the epsilon 'value shows a significant downward trend along with the increase of frequency, and the epsilon' value fluctuates greatly, and peaks appear at 6.5, 10 and 15GHz, indicating that a relaxation phenomenon exists inside the material. As can be seen from FIG. 3c, the dielectric property of the ferrite can be effectively improved after the graphene oxide is compositely reduced. 3d-f show that the ferrite has stronger magnetism, and the magnetic permeability of the three composite samples shows similar variation trend, which shows that the introduction of the dielectric material can optimize the impedance matching.
Claims (10)
1. A preparation method of a hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material is characterized by comprising the following steps:
s1, preparing a dispersion liquid of graphene oxide;
s2, adding an iron salt and a surfactant into the dispersion liquid of the graphene oxide, and uniformly mixing to obtain a mixed liquid;
s3, adding a reducing agent into the mixed solution, reacting at high temperature, filtering the reaction system, and taking the reaction precipitate;
and S4, washing and drying the reaction precipitate to obtain the hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material.
2. The preparation method of the hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material according to claim 1, characterized by comprising the following steps:
wherein the iron salt is a soluble iron salt.
3. The preparation method of the hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material according to claim 1, characterized by comprising the following steps:
wherein the ferric salt is one or more of ferric thiocyanate, potassium ferricyanide, ferric citrate, ferrocene, ferric sulfate, ferric nitrate, ferric chloride or potassium tetrachloroferrite.
4. The preparation method of the hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material according to claim 1, characterized by comprising the following steps:
wherein the surfactant is one or more of sodium dodecyl benzene sulfonate, polyvinylpyrrolidone, polyvinyl alcohol or block high molecular polymer.
5. The preparation method of the hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material according to claim 1, characterized by comprising the following steps:
wherein the reducing agent is any one or more of urea, hydrazine, citric acid, vitamin C, sodium sulfide, sodium sulfite, sodium borohydride or sodium borate.
6. The preparation method of the hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material according to claim 1, characterized by comprising the following steps:
wherein the molar ratio of the reducing agent to the iron salt is 1: (1-3).
7. The preparation method of the hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material according to claim 1, characterized by comprising the following steps:
wherein, in the step S2, the ferric salt and the surfactant are added into the dispersion liquid of the graphene oxide, and the method for uniformly mixing comprises the following steps:
and adding iron salt and a surfactant into the dispersion liquid of the graphene oxide, and ultrasonically stirring for 0.5-3 h.
8. The preparation method of the hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material according to claim 1, characterized by comprising the following steps:
the high-temperature reaction method comprises the step of heating the mixed solution added with the reducing agent to 150-220 ℃ for 16-24 h.
9. The preparation method of the hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material according to claim 1, characterized by comprising the following steps:
wherein the solvent of the dispersion liquid of the graphene oxide is ethylene glycol.
10. A hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material, which is characterized by being prepared by the preparation method of the hollow ferroferric oxide/reduced graphene oxide nano composite wave-absorbing material according to any one of claims 1 to 9.
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| CN102533216A (en) * | 2011-12-27 | 2012-07-04 | 合肥希创电子科技有限公司 | Ferroferric oxide/reduced graphene oxide composite wave-absorbing material with hollow hemisphere structure and preparation method |
| CN103173189A (en) * | 2013-03-06 | 2013-06-26 | 西北工业大学 | Method for preparing reduced graphene oxide/ferroferric oxide nano-grade wave-absorbing materials |
| CN103274396A (en) * | 2013-06-20 | 2013-09-04 | 电子科技大学 | Preparation method of grapheme and ferriferrous oxide composite nanometer material |
| CN103342982A (en) * | 2013-07-25 | 2013-10-09 | 哈尔滨工业大学 | Hollow spherical ferroferric oxide/graphene composite wave-absorbing material and preparation method thereof |
| CN108557899A (en) * | 2018-06-15 | 2018-09-21 | 中科广化（重庆）新材料研究院有限公司 | A kind of graphene-supported ferroferric oxide wave absorbing material and preparation method thereof |
| CN110551411A (en) * | 2019-08-30 | 2019-12-10 | 复旦大学 | Preparation method of zinc phosphate/graphene oxide composite anticorrosive pigment |
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- 2021-04-26 CN CN202110452069.8A patent/CN113395888A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102533216A (en) * | 2011-12-27 | 2012-07-04 | 合肥希创电子科技有限公司 | Ferroferric oxide/reduced graphene oxide composite wave-absorbing material with hollow hemisphere structure and preparation method |
| CN103173189A (en) * | 2013-03-06 | 2013-06-26 | 西北工业大学 | Method for preparing reduced graphene oxide/ferroferric oxide nano-grade wave-absorbing materials |
| CN103274396A (en) * | 2013-06-20 | 2013-09-04 | 电子科技大学 | Preparation method of grapheme and ferriferrous oxide composite nanometer material |
| CN103342982A (en) * | 2013-07-25 | 2013-10-09 | 哈尔滨工业大学 | Hollow spherical ferroferric oxide/graphene composite wave-absorbing material and preparation method thereof |
| CN108557899A (en) * | 2018-06-15 | 2018-09-21 | 中科广化（重庆）新材料研究院有限公司 | A kind of graphene-supported ferroferric oxide wave absorbing material and preparation method thereof |
| CN110551411A (en) * | 2019-08-30 | 2019-12-10 | 复旦大学 | Preparation method of zinc phosphate/graphene oxide composite anticorrosive pigment |
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Application publication date: 20210914 |