CN107338023B - Nano composite microwave absorbent and preparation method thereof - Google Patents
Nano composite microwave absorbent and preparation method thereof Download PDFInfo
- Publication number
- CN107338023B CN107338023B CN201710581896.0A CN201710581896A CN107338023B CN 107338023 B CN107338023 B CN 107338023B CN 201710581896 A CN201710581896 A CN 201710581896A CN 107338023 B CN107338023 B CN 107338023B
- Authority
- CN
- China
- Prior art keywords
- ferroferric oxide
- silicon dioxide
- graphene oxide
- reaction
- microwave
- 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
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K3/00—Materials not provided for elsewhere
Abstract
The invention relates to a nano composite microwave absorbent and a preparation method thereof, belonging to the technical field of microwave absorbing materials. The preparation method comprises the following steps: (1) preparing core-shell structure particles of silicon dioxide coated nano ferroferric oxide; (2) preparing an amination modified silicon dioxide coated ferroferric oxide nano particle; (3) preparing a graphene oxide/silicon dioxide/ferroferric oxide nano microwave absorbent. The invention relates to a nano composite microwave absorbent and a preparation method thereof, and designs a graphene oxide/silicon dioxide/ferroferric oxide nano microwave absorbent and a preparation method thereof. The absorbent prepared by the invention has the advantages of large specific surface area, light weight, wide microwave absorption frequency, large maximum absorption strength, stable chemical property and strong applicability.
Description
Technical Field
The invention relates to a nano microwave absorbent and a preparation method thereof, in particular to a graphene oxide/silicon dioxide/ferroferric oxide nano composite microwave absorbent and a preparation method thereof, and belongs to the technical field of microwave absorbing materials.
Background
The microwave absorbing material is a functional material which enables incident electromagnetic waves to enter the material, can effectively absorb and attenuate the incident electromagnetic waves, converts the incident electromagnetic waves into energy of other forms such as heat energy and the like, and is lost or disappears due to interference. The wide application of the microwave absorbing material can well solve the problem of electromagnetic pollution brought to the life of people by electronic products. In addition, in order to meet the needs of modern war, stealth technology has become the strategic focus of the prior development of military and strong countries in the world, and as the core part of stealth technology, the research and development and application of microwave absorbing materials have become the hot spots of research in the field of military materials.
The microwave absorbing material mainly comprises an absorbent, and then a binder and related auxiliary agents. The wave absorbing performance of the microwave absorbing material mainly depends on the absorbent and the preparation process thereof. The absorbent is a main body base material for absorbing electromagnetic waves and is prepared by a specific process technology.
The absorption agent can be classified into a magnetic loss type and an electric loss type according to the attenuation mechanism of electromagnetic waves by the absorption agent.
The main magnetic loss type absorbent is a ferromagnetic absorbent, the ferromagnetic absorbent mainly refers to an iron-based alloy or ferrite, belongs to a magnetic material, and is widely researched and applied as an absorbent due to excellent magnetic loss performance, and the ferromagnetic absorbent has the defects of high specific gravity and easiness in oxidation.
The electric loss type absorbent mainly comprises carbon fiber and carbon nanotube materials, and in recent years, due to the characteristics of special two-dimensional structure, light weight and the like, graphene gradually becomes a hot electric loss absorbent, and the defect of low electromagnetic loss rate is that the electric loss absorbent is used.
Therefore, at present, research and development of a composite material with high electromagnetic loss rate, wide absorption frequency band, and light weight is the focus of the research field of electromagnetic absorption materials.
Disclosure of Invention
One of the purposes of the invention is to provide a microwave absorbent which has large specific surface area, light weight, wide microwave absorption frequency, large maximum absorption intensity, stable chemical property and strong applicability.
In order to achieve the purpose, the invention adopts the following technical scheme:
a nanocomposite microwave absorbent, characterized in that: the microwave absorbent is a core-shell structure of silicon dioxide coated nanometer ferroferric oxide and is embedded on a graphene oxide sheet layer.
Preferably, the mass ratio of the graphene oxide to the silicon dioxide to the ferroferric oxide is 90: 1: 10-10: 9: 90.
preferably, the mass ratio of the graphene oxide to the silicon dioxide to the ferroferric oxide is 70: 3: 30.
preferably, the mass ratio of the graphene oxide to the silicon dioxide to the ferroferric oxide is 50: 5: 50.
preferably, the mass ratio of the graphene oxide to the silicon dioxide to the ferroferric oxide is 30: 7: 70.
the invention also aims to provide a preparation method of the graphene oxide/silicon dioxide/ferroferric oxide nano microwave absorbent.
The above object of the present invention is achieved by the following technical solutions:
a preparation method of a nano composite microwave absorbent comprises the following steps:
(1) preparation of core-shell structure particles of silicon dioxide coated nano ferroferric oxide
Weighing a proper amount of ferroferric oxide nano particles, dispersing the ferroferric oxide nano particles in absolute ethyl alcohol, and then performing ultrasonic dispersion to obtain a ferroferric oxide ethyl alcohol solution; transferring the dispersed ferroferric oxide ethanol solution into a three-neck bottle, and adding TEOS (tetraethyl orthosilicate) and NH3·H2O, fully stirring for reaction; after the reaction is finished, repeatedly washing the solution by using absolute ethyl alcohol until the washed solution does not become turbid any more; vacuum drying the obtained precipitate to obtain silicon dioxide coated ferroferric oxide nano particles;
(2) preparation of amination modified silicon dioxide coated ferroferric oxide nano particle
Taking a certain amount of the silica-coated ferroferric oxide nanoparticles prepared in the step (1), activating, dispersing into an organic solvent to obtain silica-coated ferroferric oxide nanoparticle activation dispersion liquid, adding KH550 (gamma-aminopropyltriethoxysilane), and fully stirring for reaction; after the reaction is finished, cooling to room temperature, and then centrifuging, washing and vacuum drying to obtain amination modified silicon dioxide coated ferroferric oxide nano particles;
(3) preparation of graphene oxide/silicon dioxide/ferroferric oxide nano microwave absorbent
And (3) adding the aminated modified silicon dioxide coated ferroferric oxide nano particles prepared in the step (2) into a solvent in which graphene oxide is dispersed, adding EDAC (carbodiimide) and NHS (N-hydroxysuccinimide), fully stirring for reaction, filtering, washing, and drying in vacuum to obtain the graphene oxide/silicon dioxide/ferroferric oxide nano microwave absorbent.
Preferably, the concentration of the ethanol solution of ferroferric oxide in the step (1) is 0.5mg/ml-10 mg/ml.
The ultrasonic dispersion power is 150w-300w, and the ultrasonic time is 20 minutes-6 hours.
Preferably, the amount of TEOS added in the step (1) is NH3·H210-80% of the mass of O; addition of NH3·H2The amount of O is 50-300% of the weight of the ferroferric oxide nano particles.
Preferably, the rotation speed of the stirring in the step (1) is 200 to 800 revolutions per minute, the reaction temperature is 20 to 80 ℃, and the time is 1 to 24 hours.
Preferably, the rotation speed of the stirring in the step (2) is 200 to 800 revolutions per minute, the reaction temperature is 20 to 80 ℃, and the time is 1 to 24 hours.
Preferably, the temperature of the vacuum drying in the step (1) and the step (2) is 50-150 ℃ and the time is 8-24 hours.
Preferably, the temperature of the activation in the step (2) is 50-120 ℃ and the time is 1-10 hours.
Preferably, the organic solvent in the step (2) is ethanol, toluene or ethylene glycol.
Preferably, the concentration of the silica-coated ferroferric oxide nanoparticle activation dispersion liquid in the step (2) is 0.5mg/ml-10 mg/ml.
Preferably, the adding amount of the KH550 in the step (2) is 1-20% of the mass of the silica-coated ferroferric oxide nanoparticles.
Preferably, the reaction temperature of adding KH550 in the step (2) is 60-85 ℃ and the time is 1-10 hours.
Preferably, the graphene oxide-dispersed solvent in the step (3) includes water, ethanol, ethylene glycol or toluene.
Preferably, the concentration of the dispersion liquid composed of the graphene oxide dispersed solvent and the graphene oxide in the step (3) is 0.1mg/ml-5 mg/ml.
Preferably, the addition amount of the graphene oxide in the step (3) is 10-900% of the mass of the aminated silica-coated ferroferric oxide nanoparticles.
Preferably, the adding amount of EDAC (carbodiimide) in the step (3) is 20% -100% of the mass of NHS, and the total weight of EDAC and NHS is 50% -150% of the total weight of graphene oxide and aminated silica-coated ferroferric oxide nanoparticles.
The invention has the advantages that:
the invention relates to a nano composite microwave absorbent and a preparation method thereof, and designs a graphene oxide/silicon dioxide/ferroferric oxide nano microwave absorbent and a preparation method thereof. The absorbent prepared by the invention has the advantages of large specific surface area, light weight, wide microwave absorption frequency, large maximum absorption strength, stable chemical property and strong applicability.
The invention is further illustrated by the following figures and detailed description of the invention, which are not meant to limit the scope of the invention.
Drawings
Fig. 1 is an XRD test chart of graphene oxide, ferroferric oxide nanoparticles and graphene oxide/silicon dioxide/ferroferric oxide nano-absorbent.
Fig. 2-1 to 2-6 are transmission electron microscope test charts of the ferroferric oxide nanoparticles, the silica-coated ferroferric oxide nanoparticles, and the graphene oxide/silica/ferroferric oxide nano-absorber, respectively.
Fig. 3-1 to 3-4 show the electromagnetic reflectivities of graphene oxide, ferroferric oxide nanoparticles, silica-coated ferroferric oxide nanoparticles, and graphene oxide/silica/ferroferric oxide nano-absorbers, respectively.
Detailed Description
Example 1:
a preparation method of a graphene oxide/silicon dioxide/ferroferric oxide nano microwave absorbent comprises the following steps:
(1) weighing 100mg of commercially available ferroferric oxide nano particles, dispersing the commercially available ferroferric oxide nano particles in 200ml of commercially available absolute ethyl alcohol, and then ultrasonically dispersing the commercially available absolute ethyl alcohol for 1 hour by using a 150w ultrasonic dispersing machine to obtain a ferroferric oxide ethanol solution; pouring the dispersed ferroferric oxide ethanol solution into a three-neck bottle, adding 25mg of commercial TEOS and 100mg of commercial NH3·H2O, stirring at the rotating speed of 400 revolutions per minute by using a high-speed stirrer, wherein the reaction temperature is 35 ℃, and stirring for reaction for 1 hour; after the reaction is finished, repeatedly washing the solution by using commercially available absolute ethyl alcohol until the washed solution does not become turbid any more; carrying out vacuum drying on the obtained precipitate for 12 hours at the temperature of 80 ℃ by using a vacuum drying oven to obtain 107mg of silicon dioxide coated ferroferric oxide nano particles;
(2) activating 100mg of the silica-coated ferroferric oxide nanoparticles obtained in the step (1) at 70 ℃ for 4 hours, dispersing the silica-coated ferroferric oxide nanoparticles into 100ml of commercially available toluene, adding 1mg of commercially available KH550, stirring the mixture by using a high-speed stirrer at a rotating speed of 400 rpm, stirring the mixture for reaction at a reaction temperature of 80 ℃ for 1 hour, cooling the mixture to room temperature after the reaction is finished, centrifuging and washing the mixture, and performing vacuum drying on the mixture for 12 hours at a temperature of 80 ℃ by using a vacuum drying oven to obtain 101mg of aminated modified silica-coated ferroferric oxide nanoparticles;
(3) and (3) adding 30mg of the aminated modified silica-coated ferroferric oxide nanoparticles obtained in the step (2) into 200ml of water in which 70mg of commercially available graphene oxide is dispersed, adding 25mg of commercially available EDAC and 50mg of commercially available NHS, stirring at the rotating speed of 400 revolutions per minute by using a high-speed stirrer, reacting at the temperature of 30 ℃ for 1 hour under stirring, filtering, washing, and drying in vacuum for 12 hours at the temperature of 80 ℃ by using a vacuum drying oven to obtain 100mg of graphene oxide/silica/ferroferric oxide nano absorbent.
Example 2:
a preparation method of a graphene oxide/silicon dioxide/ferroferric oxide nano microwave absorbent comprises the following steps:
(1) weighing 100mg of commercially available ferroferric oxide nano particles, dispersing the commercially available ferroferric oxide nano particles in 100ml of commercially available absolute ethyl alcohol, and then ultrasonically dispersing the commercially available absolute ethyl alcohol for 3 hours by using a 200w ultrasonic dispersing machine to obtain a ferroferric oxide ethanol solution; pouring the dispersed ferroferric oxide ethanol solution into a three-neck bottle, adding 30mg of commercial TEOS and 120mg of commercial NH3·H2O, stirring and reacting for 4 hours at the reaction temperature of 45 ℃ by using a high-speed stirrer at 500 revolutions per minute; after the reaction is finished, repeatedly washing the solution by using commercially available absolute ethyl alcohol until the washed solution does not become turbid any more; carrying out vacuum drying on the obtained precipitate for 15 hours at 70 ℃ by using a vacuum drying oven to obtain 108mg of silicon dioxide coated ferroferric oxide nano particles;
(2) activating 100mg of the silica-coated ferroferric oxide nanoparticles obtained in the step (1) at 60 ℃ for 3 hours, dispersing the silica-coated ferroferric oxide nanoparticles into 50ml of commercially available ethanol, adding 5mg of commercially available KH550, stirring the mixture for reaction for 2 hours at the reaction temperature of 60 ℃ by using a high-speed stirrer for 500 revolutions per minute, cooling the mixture to room temperature after the reaction is finished, centrifuging, washing, and vacuum-drying the mixture for 24 hours at 70 ℃ by using a vacuum drying oven to obtain 105mg of aminated and modified silica-coated ferroferric oxide nanoparticles;
(3) and (3) adding 50mg of aminated modified silica-coated ferroferric oxide nanoparticles prepared in the step (2) into 100ml of commercially available ethanol in which 50mg of commercially available graphene oxide is dispersed, adding 30mg of commercially available EDAC and 50mg of commercially available NHS, stirring and reacting for 24 hours at the reaction temperature of 30 ℃ by using a high-speed stirrer at 500 revolutions per minute, filtering, washing, and vacuum-drying for 15 hours at the temperature of 70 ℃ by using a vacuum drying oven to obtain 100mg of graphene oxide/silica/ferroferric oxide nano absorbent.
Example 3:
a preparation method of a graphene oxide/silicon dioxide/ferroferric oxide nano microwave absorbent comprises the following steps:
(1) weighing 100mg of commercially available ferroferric oxide nano particles, dispersing the commercially available ferroferric oxide nano particles in 70ml of anhydrous ethanol, and then ultrasonically dispersing the commercially available anhydrous ethanol for 2 hours by using a 250w ultrasonic dispersing machine to obtain a ferroferric oxide ethanol solution;transferring the dispersed ferroferric oxide ethanol solution into a three-neck bottle, adding 40mg of commercial TEOS and 140mg of commercial NH3·H2O, stirring and reacting for 2 hours at the reaction temperature of 50 ℃ by using a high-speed stirrer at 500 revolutions per minute; after the reaction is finished, repeatedly washing the solution by using commercially available absolute ethyl alcohol until the washed solution does not become turbid any more; carrying out vacuum drying on the obtained precipitate for 12 hours at the temperature of 90 ℃ by using a vacuum drying oven to obtain 111mg of silicon dioxide coated ferroferric oxide nano particles;
(2) activating 100mg of the silicon dioxide coated ferroferric oxide nano particles obtained in the step (1) at 50 ℃ for 2 hours, dispersing the silicon dioxide coated ferroferric oxide nano particles into 70ml of commercially available ethylene glycol, adding 4mg of commercially available KH550, stirring the mixture for reaction for 3 hours at the reaction temperature of 70 ℃ by using a high-speed stirrer for 300 revolutions per minute, cooling the mixture to room temperature after the reaction is finished, centrifuging and washing the mixture, and performing vacuum drying on the mixture for 8 hours at 120 ℃ by using a vacuum drying oven to obtain 104mg of amino modified silicon dioxide coated ferroferric oxide nano particles;
(3) and (3) adding 70mg of the aminated modified silica-coated ferroferric oxide nanoparticles prepared in the step (2) into 70ml of commercially available toluene in which 30mg of commercially available graphene oxide is dispersed, adding 35mg of commercially available EDAC and 60mg of commercially available NHS, stirring and reacting for 15 hours at the reaction temperature of 25 ℃ by using a high-speed stirrer at 500 revolutions per minute, filtering, washing, and vacuum-drying for 24 hours at the temperature of 80 ℃ by using a vacuum drying oven to obtain 100mg of graphene oxide/silica/ferroferric oxide nano absorbent.
Example 4
A preparation method of a graphene oxide/silicon dioxide/ferroferric oxide nano microwave absorbent comprises the following steps:
(1) weighing 100mg of commercially available ferroferric oxide nano particles, dispersing the commercially available ferroferric oxide nano particles in 120ml of commercially available absolute ethyl alcohol, and then ultrasonically dispersing the commercially available absolute ethyl alcohol for 2 hours by using a 300w ultrasonic dispersing machine to obtain a ferroferric oxide ethanol solution; transferring the dispersed ferroferric oxide ethanol solution into a three-neck bottle, adding 40mg of commercial TEOS and 140mg of commercial NH3·H2O, stirring and reacting for 4 hours at the reaction temperature of 45 ℃ by using a high-speed stirrer at 300 revolutions per minute; after the reaction was completed, the solution was repeatedly washed with commercially available absolute ethanol until the reaction was completedUntil the cleaned solution does not become turbid any more; carrying out vacuum drying on the obtained precipitate for 8 hours at 70 ℃ by using a vacuum drying oven to obtain 111mg of silicon dioxide coated ferroferric oxide nano particles;
(2) activating 100mg of the silicon dioxide coated ferroferric oxide nano particles obtained in the step (1) at 80 ℃ for 8 hours, dispersing the silicon dioxide coated ferroferric oxide nano particles into 80ml of commercially available ethanol, adding 5mg of commercially available KH550, stirring the mixture for reaction for 4 hours at the reaction temperature of 85 ℃ by using a high-speed stirrer at 500 revolutions per minute, cooling the mixture to room temperature after the reaction is finished, centrifuging and washing the mixture, and performing vacuum drying on the mixture for 10 hours at the temperature of 60 ℃ by using a vacuum drying oven to obtain 105mg of aminated modified silicon dioxide coated ferroferric oxide nano particles;
(3) and (3) adding 30mg of the aminated modified silica-coated ferroferric oxide nanoparticles obtained in the step (2) into 200ml of commercially available ethylene glycol in which 70mg of commercially available graphene oxide is dispersed, adding 25mg of commercially available EDAC and 50mg of commercially available NHS, stirring and reacting for 4 hours at the reaction temperature of 30 ℃ by using a high-speed stirrer at 400 revolutions per minute, filtering, washing, and vacuum-drying for 8 hours at the temperature of 150 ℃ by using a vacuum drying oven to obtain 100mg of graphene oxide/silica/ferroferric oxide nano absorbent.
The changes in the composition of the pre-and post-complex phases were analyzed by X-ray diffraction (XRD). The morphology of the complex was observed with a Transmission Electron Microscope (Transmission Electron Microscope). And testing the electromagnetic parameters of the microwave absorbent by using a microwave network analyzer, and calculating the electromagnetic reflectivity of the microwave absorbent at 2-18 GHz.
And (3) performance testing:
1) the components of the graphene oxide, the ferroferric oxide nano-particles and the graphene oxide/silicon dioxide/ferroferric oxide nano-absorbent are tested and analyzed by using a combined multifunctional horizontal X-ray diffractometer (Ultima IV, Rigaku, Japan), wherein the analysis conditions are that the voltage is 40KV, the current is 100mA, and the angle 2 theta is 2-90 degrees.
XRD component analysis was performed on the graphene oxide, the ferroferric oxide nanoparticles, and the graphene oxide/silica/ferroferric oxide nano-absorber in examples 1 to 4, and the results are shown in fig. 1, where in fig. 1, from top to bottom, the following are sequentially performed: an XRD (X-ray diffraction) pattern of graphene oxide, an XRD pattern of ferroferric oxide nano particles and an XRD pattern of graphene oxide/silicon dioxide/ferroferric oxide nano absorbent.
As can be seen from fig. 1: the XRD pattern of graphene oxide showed a sharp peak at 11.8 ° 2 θ, corresponding to the (001) crystal plane of graphene oxide. The XRD patterns of the graphene oxide/silicon dioxide/ferroferric oxide nano-absorbers show that peaks appear at 30.3, 35.7, 43.4, 53.7, 57.1 and 62.8, the positions of these peaks are very similar to those of pure ferroferric oxide, and the peaks at 23.2 ° corresponding to the (220), (311), (400), (422), (511) and (440) crystal planes of spinel-type ferroferric oxide (JCPDS No.19-0629), respectively, can be attributed to the graphene-like structure (002), which indicates that most of the oxygen-containing functional groups of graphene oxide are removed during the process of embedding the aminated silicon dioxide coated ferroferric oxide nano-particles.
2) The morphology of the compound was observed with a Transmission Electron Microscope (Transmission Electron Microscope)
In examples 1 to 4, the ferroferric oxide nanoparticles, the silica-coated ferroferric oxide nanoparticles, and the graphene oxide/silica/ferroferric oxide nano-absorber in the examples are subjected to shape analysis by a transmission electron microscope, 10ul of a test sample dispersion is dropped on the surface of a BZ1101 XX-type micro-grid support film, and after natural drying, an F20-type TEM is selected at an acceleration voltage of 200KV to characterize the microscopic surface shape of the material, as shown in fig. 2 to 1 to 2 to 6, which are transmission electron microscope test charts of ferroferric oxide, silica-coated ferroferric oxide nanoparticles, and graphene oxide/silica/ferroferric oxide nano-absorber, wherein fig. 2 to 1 show TEM images (200nm resolution) of the ferroferric oxide nanoparticles, and we can see that the dispersibility of ferroferric oxide is poor. Fig. 2-2 shows TEM images (200nm resolution) of silica-coated ferroferric oxide nanoparticles, and the silica significantly improves the dispersibility of the ferroferric oxide. Fig. 2-3 show magnified TEM images (50nm resolution) of graphene oxide/silica/ferroferric oxide nanoabsorbers, and it can be seen that the ferroferric oxide spheres are completely encapsulated by the porous structure of the silica. Low magnification TEM image (200 n) from graphene oxide/silica/ferroferric oxide nanoabsorbersm/100nm resolution ratio) (the resolution ratio of fig. 2-4 is 200nm and the resolution ratio of fig. 2-5 is 100nm), it can be seen that the silica-coated ferroferric oxide nanoparticles are uniformly embedded on the graphene oxide, the diameter of the ferroferric oxide nanoparticles is 20-30 nm, and the ferroferric oxide nanoparticles have good dispersibility. In addition, Fe was hardly found3O4The nano particles are outside the graphene oxide nano sheet, which shows that the efficiency of synthesizing the graphene oxide/silicon dioxide/ferroferric oxide nano absorbent through condensation reaction is higher. FIGS. 2 to 6 are high resolution images (2nm resolution) of the ferroferric oxide nanoparticles, which show that the ferroferric oxide nanoparticles have a single crystal structure, the interplanar spacing between lattice fringes is 0.484nm, corresponding to the (111) crystal plane and 0.258nm corresponding to the (311) crystal plane. As can be seen from a transmission electron microscope image, the absorbent has a graphene lamellar structure, so that the specific surface area is large, and the weight is light; because the silicon dioxide coats the ferroferric oxide, the ferroferric oxide in the material is not easy to be oxidized, and the applicability of the absorbent is increased.
3) Method for testing electromagnetic reflectivity of microwave absorbent by using microwave network analyzer
Electromagnetic reflectance analysis was performed on graphene oxide, ferroferric oxide nanoparticles, silica-coated ferroferric oxide nanoparticles, and graphene oxide/silica/ferroferric oxide nanoabsorbers in examples 1-4, and electromagnetic parameters of the material were analyzed using a vector network analyzer (VNA, N5234A PAN-L, Agilent, usa), with a test frequency range of 2-18GHz, as shown in fig. 3-1, for an electromagnetic reflectance of a 5 mm thick sample filled with graphene oxide as an absorber, with a maximum reflection loss of only-14.3 dB at 7.7 GHz; as shown in fig. 3-2, for the electromagnetic reflectance of a sample with a thickness of 5 mm and with ferroferric oxide nanoparticles added as an absorbent, the maximum reflection loss is 35.3dB at 9.6 GHz; as shown in fig. 3-3, for the electromagnetic reflectance of a sample with a thickness of 5 mm and added with silica-coated ferroferric oxide nanoparticles as an absorbent, the maximum reflection loss is 51.3dB at 8.9GHz, and the maximum reflection loss is obviously higher than that of ferroferric oxide. As shown in fig. 3-4, for the electromagnetic reflectance of a sample with a thickness of 4.5 mm, in which graphene oxide/silicon dioxide/ferroferric oxide nano-absorber is added as an absorbent, the maximum reflection loss is-56.4 dB at 8.1GHz, and the absorption bandwidth with the reflection loss below-10 dB (90% of electromagnetic waves are absorbed) reaches 4.1GHz (from 6.5 to 10.6 GHz). The results show that: the graphene oxide/silicon dioxide/ferroferric oxide nano microwave absorbent has larger reflection loss and wider absorption frequency band than graphene oxide and ferroferric oxide, and the composite material can be used as a microwave absorbent with strong absorption performance.
The graphene oxide/silicon dioxide/ferroferric oxide nano composite material is used as a microwave absorbent. The graphene has high electrical conductivity and thermal conductivity, large specific surface area and light weight, the properties are favorable for absorption and attenuation of electromagnetic waves, and the introduction of ferrite particles can enhance the ferromagnetism of the graphene, so that the composite material has magnetic loss and electric loss and is favorable for realizing electromagnetic matching. The reflectivity loss of ferroferric oxide generally occurs in a lower frequency range (less than 10GHz), while the reflectivity loss of the graphite material is generally positioned in a high-frequency region, so that the compounding of the two materials is also beneficial to the widening of an absorption frequency band. The silicon dioxide can improve the dispersibility of the ferroferric oxide, prevent the ferroferric oxide in the composite material from being oxidized in a humid environment and improve the applicability of the material.
Claims (9)
1. A nanocomposite microwave absorbent, characterized in that: the microwave absorbent is a core-shell structure of nano ferroferric oxide coated by silicon dioxide and embedded on a graphene oxide sheet layer;
the preparation method comprises the following steps:
(1) preparation of core-shell structure particles of silicon dioxide coated nano ferroferric oxide
Weighing ferroferric oxide nano particles according to a proportion, dispersing the ferroferric oxide nano particles in absolute ethyl alcohol, and then performing ultrasonic dispersion to obtain a ferroferric oxide ethyl alcohol solution; transferring the dispersed ferroferric oxide ethanol solution into a three-neck bottle, and adding tetraethoxysilane and NH3·H2O, fully stirring for reaction; after the reaction is finished, repeatedly washing the solution by using absolute ethyl alcohol until the reaction is finishedThe cleaned solution does not turn turbid any more; drying the obtained precipitate in vacuum to obtain silicon dioxide coated ferroferric oxide nano particles, wherein the diameter of the ferroferric oxide nano particles is 20-30 nm;
(2) preparation of amination modified silicon dioxide coated ferroferric oxide nano particle
Taking a certain amount of the silica-coated ferroferric oxide nanoparticles prepared in the step (1) according to the proportion, activating, dispersing into an organic solvent to obtain silica-coated ferroferric oxide nanoparticle activation dispersion liquid, adding gamma-aminopropyltriethoxysilane according to the proportion, and fully stirring for reaction; after the reaction is finished, cooling to room temperature, and then centrifuging, washing and vacuum drying to obtain amination modified silicon dioxide coated ferroferric oxide nano particles;
(3) preparation of graphene oxide/silicon dioxide/ferroferric oxide nano microwave absorbent
And (3) adding the aminated modified silicon dioxide coated ferroferric oxide nano particles prepared in the step (2) into a solvent in which graphene oxide added in proportion is dispersed, adding carbodiimide and N-hydroxysuccinimide, fully stirring for reaction, filtering, washing, and drying in vacuum to obtain the graphene oxide/silicon dioxide/ferroferric oxide nano microwave absorbent.
2. The nanocomposite microwave absorber according to claim 1, wherein: the mass ratio of the graphene oxide to the silicon dioxide to the ferroferric oxide is 90: 1: 10-10: 9: 90.
3. the nanocomposite microwave absorber according to claim 1, wherein: the mass ratio of the graphene oxide to the silicon dioxide to the ferroferric oxide is 70: 3: 30, of a nitrogen-containing gas; or 50: 5: 50; or 30: 7: 70.
4. the nanocomposite microwave absorber according to claim 3, wherein: the concentration of the ferroferric oxide ethanol solution in the step (1) is 0.5-10 mg/ml, the ultrasonic power in the step (1) is 150-300 w, and the ultrasonic time is 20 minutes-6 hours.
5. The nanocomposite microwave absorber according to claim 4, wherein: the amount of the added tetraethyl orthosilicate (TEOS) in the step (1) is NH3·H210% -80% of the O amount; addition of NH3·H2The amount of O is 50-300% of the amount of the ferroferric oxide nano particles; the rotating speed of the stirring in the step (1) is 200-800 r/min, the reaction temperature is 20-80 ℃, and the reaction time is 1-24 hours.
6. The nanocomposite microwave absorber according to claim 5, wherein: the rotating speed of the stirring in the step (2) is 200-800 r/min, the reaction temperature is 20-80 ℃, and the reaction time is 1-24 hours.
7. The nanocomposite microwave absorber according to claim 6, wherein: the temperature of the vacuum drying in the step (1) and the step (2) is 50-150 ℃, and the time is 8-24 hours.
8. The nanocomposite microwave absorber according to claim 7, wherein: the activation temperature in the step (2) is 50-120 ℃, and the activation time is 1-10 hours; the organic solvent in the step (2) is ethanol, toluene or ethylene glycol; the concentration of the silicon dioxide coated ferroferric oxide nanoparticle activation dispersion liquid in the step (2) is 0.5-10 mg/ml; the addition amount of the gamma-aminopropyltriethoxysilane in the step (2) is 1-20% of the mass of the silicon dioxide coated ferroferric oxide nano particles; the reaction temperature of the gamma-aminopropyltriethoxysilane added in the step (2) is 60-85 ℃, and the reaction time is 1-10 hours.
9. The nanocomposite microwave absorber according to claim 8, wherein: the graphene oxide-dispersed solvent in the step (3) comprises water, ethanol, ethylene glycol or toluene; the concentration of the dispersion liquid consisting of the graphene oxide dispersed solvent and the graphene oxide in the step (3) is 0.1-5 mg/ml; the addition amount of the graphene oxide in the step (3) is 10-900% of the mass of the aminated silicon dioxide coated ferroferric oxide nano particle; the adding amount of the carbodiimide in the step (3) is 20-100% of the mass of the N-hydroxysuccinimide, and the total weight of the carbodiimide and the N-hydroxysuccinimide is 50-150% of the total weight of the graphene oxide and the aminated silicon dioxide coated ferroferric oxide nano particles.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710581896.0A CN107338023B (en) | 2017-07-17 | 2017-07-17 | Nano composite microwave absorbent and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710581896.0A CN107338023B (en) | 2017-07-17 | 2017-07-17 | Nano composite microwave absorbent and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107338023A CN107338023A (en) | 2017-11-10 |
| CN107338023B true CN107338023B (en) | 2020-12-01 |
Family
ID=60218115
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710581896.0A Active CN107338023B (en) | 2017-07-17 | 2017-07-17 | Nano composite microwave absorbent and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107338023B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108419426B (en) * | 2018-03-05 | 2019-11-22 | 沈阳航空航天大学 | Coated with silica magnetic graphene tiny balloon and its magnanimity preparation method |
| CN109745936B (en) * | 2019-01-22 | 2021-11-12 | 东莞市昱懋纳米科技有限公司 | Targeted microwave pretreatment method capable of improving activity of nano material and nano material |
| CN112695517B (en) * | 2020-12-16 | 2022-12-23 | 苏州飞睿纺织有限公司 | Magnetic polyester fabric and preparation method thereof |
| CN115466596B (en) * | 2022-07-20 | 2023-06-20 | 哈尔滨工业大学 | Fe-Fe 3 O 4 @mSiO 2 @RGO composite material and magnetic property controllable preparation method and application thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104910864A (en) * | 2015-07-16 | 2015-09-16 | 北京新怡源环保科技有限公司 | Flexible nano wave-absorbing material of ferroferric oxide composite silicon dioxide and grapheme and preparation method thereof |
| CN106540658A (en) * | 2016-12-05 | 2017-03-29 | 湖南工业大学 | A kind of graphene oxide covalent bond coated magnetic nano composition and preparation method thereof |
-
2017
- 2017-07-17 CN CN201710581896.0A patent/CN107338023B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104910864A (en) * | 2015-07-16 | 2015-09-16 | 北京新怡源环保科技有限公司 | Flexible nano wave-absorbing material of ferroferric oxide composite silicon dioxide and grapheme and preparation method thereof |
| CN106540658A (en) * | 2016-12-05 | 2017-03-29 | 湖南工业大学 | A kind of graphene oxide covalent bond coated magnetic nano composition and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107338023A (en) | 2017-11-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107338023B (en) | Nano composite microwave absorbent and preparation method thereof | |
| Ding et al. | Electromagnetic wave absorption in reduced graphene oxide functionalized with Fe 3 O 4/Fe nanorings | |
| Li et al. | Fe@ NPC@ CF nanocomposites derived from Fe-MOFs/biomass cotton for lightweight and high-performance electromagnetic wave absorption applications | |
| Qiang et al. | Electromagnetic functionalized Co/C composites by in situ pyrolysis of metal-organic frameworks (ZIF-67) | |
| Yang et al. | Rational construction of graphene oxide with MOF-derived porous NiFe@ C nanocubes for high-performance microwave attenuation | |
| Liu et al. | Controllable synthesis and enhanced microwave absorption properties of silane-modified Ni 0.4 Zn 0.4 Co 0.2 Fe 2 O 4 nanocomposites covered with reduced graphene oxide | |
| CN109207123B (en) | Carbonyl iron powder composite wave-absorbing material with double-shell structure and preparation method thereof | |
| CN108039257B (en) | A kind of three-dimensional porous sheet ferroferric oxide/carbon nano electromagnetic wave absorbing material and preparation method thereof | |
| CN107949266B (en) | A kind of three-dimensional porous flower-like structure cobalt/carbon nano composite electromagnetic wave absorption material and preparation method thereof | |
| CN107338024B (en) | Co-Fe alloy/carbon sphere composite microwave absorbent and preparation method thereof | |
| Zhu et al. | Synthesis and electromagnetic wave absorption performance of NiCo 2 O 4 nanomaterials with different nanostructures | |
| Qiu et al. | Self-etching template method to synthesize hollow dodecahedral carbon capsules embedded with Ni–Co alloy for high-performance electromagnetic microwave absorption | |
| Li et al. | Economical synthesis of composites of FeNi alloy nanoparticles evenly dispersed in two-dimensional reduced graphene oxide as thin and effective electromagnetic wave absorbers | |
| CN105436498B (en) | A kind of porous nickel carbon composite nano-microsphere electromagnetic wave absorbent material and preparation method and application | |
| CN106800916A (en) | A kind of graphene-based tri compound absorbing material and preparation method thereof | |
| Pang et al. | Facile synthesis of a hierarchical multi-layered CNT-NiFe2O4@ MnO2 composite with enhanced microwave absorbing performance | |
| CN110041885A (en) | A kind of preparation method of redox graphene/stannic oxide nanometer composite wave-suction material | |
| Lin et al. | CoZnO/C@ BCN nanocomposites derived from bimetallic hybrid ZIFs for enhanced electromagnetic wave absorption | |
| Wang et al. | Preparation and electromagnetic-wave-absorption properties of a nitrogen-doped carbon–supported iron (II, III) oxide composite | |
| Liu et al. | Synthesis of Cu and Ni chalcogenides and evaluation of their properties for electromagnetic wave absorption | |
| Ma et al. | Tailored design of p-phenylenediamine functionalized graphene decorated with cobalt ferrite for microwave absorption | |
| CN112996375A (en) | Cu9S5/C composite material and preparation method and application thereof | |
| CN108024493A (en) | A kind of mesoporous carbon of seedpod of the lotus structure and nanometer cobalt compound and its preparation method and application | |
| CN110028930B (en) | HalS-Fe3O4@ C composite material and preparation method and application thereof | |
| Meng et al. | Yolk-shell construction of Co0. 7Fe0. 3 modified with dual carbon for broadband microwave absorption |
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 | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20180910 Address after: 102600 Daxing District Xinghua street, Beijing (two paragraph) 1 Applicant after: Beijing Print College Address before: No. 159, dragon pan Road, Nanjing, Jiangsu Applicant before: Nanjing Forestry University |
|
| TA01 | Transfer of patent application right | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |