CN114686168A - Flaky ferrite wave-absorbing material, flaky ferrite/carbon composite wave-absorbing material, and preparation method and application thereof - Google Patents
Flaky ferrite wave-absorbing material, flaky ferrite/carbon composite wave-absorbing material, and preparation method and application thereof Download PDFInfo
- Publication number
- CN114686168A CN114686168A CN202011627958.5A CN202011627958A CN114686168A CN 114686168 A CN114686168 A CN 114686168A CN 202011627958 A CN202011627958 A CN 202011627958A CN 114686168 A CN114686168 A CN 114686168A
- Authority
- CN
- China
- Prior art keywords
- precipitate
- parts
- mixed solution
- absorbing material
- ferrite
- 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.)
- Pending
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
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/75—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated
- G01N21/77—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated by observing the effect on a chemical indicator
- G01N21/78—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated by observing the effect on a chemical indicator producing a change of colour
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N9/00—Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/26—Measuring inductance or capacitance; Measuring quality factor, e.g. by using the resonance method; Measuring loss factor; Measuring dielectric constants ; Measuring impedance or related variables
- G01R27/2617—Measuring dielectric properties, e.g. constants
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/26—Measuring inductance or capacitance; Measuring quality factor, e.g. by using the resonance method; Measuring loss factor; Measuring dielectric constants ; Measuring impedance or related variables
- G01R27/2688—Measuring quality factor or dielectric loss, e.g. loss angle, or power factor
- G01R27/2694—Measuring dielectric loss, e.g. loss angle, loss factor or power factor
Landscapes
- Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Biochemistry (AREA)
- Immunology (AREA)
- Pathology (AREA)
- General Health & Medical Sciences (AREA)
- Analytical Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Plasma & Fusion (AREA)
- Power Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
- Compounds Of Iron (AREA)
- Hard Magnetic Materials (AREA)
Abstract
The invention discloses a flaky ferrite wave-absorbing material, a flaky ferrite/carbon composite wave-absorbing material, and a preparation method and application thereof. The flaky ferrite wave-absorbing material contains Fe through configuration3+Material of (5), containing Ba2+A first mixed solution of the material of (a) and a first solvent; and adjusting the pH value of the first mixed solution to 8-9, heating to 80-150 ℃, keeping for 2-5 hours, fully reacting, cleaning, filtering and drying to obtain the catalyst. The prepared flaky ferrite wave-absorbing material has higher anisotropy and magnetic effect field due to the unique hexagonal crystal structure, higher natural resonance frequency and obvious dielectrical property of ferriteThe dielectric constant is obviously reduced, the impedance matching is improved, the dual wave-absorbing capability of the ferrite with magnetic loss and dielectric loss is reserved, the propagation path of electromagnetic waves is increased, and the ferrite has obvious magnetic performance advantage under low frequency.
Description
Technical Field
The invention relates to the field of chemical materials, in particular to a flaky ferrite wave-absorbing material, a flaky ferrite/carbon composite wave-absorbing material, and a preparation method and application thereof.
Background
With the wide-range popularization of electronic equipment, electromagnetic pollution and electromagnetic interference phenomena are more and more common, the influence of electromagnetic wave radiation on the environment is increasingly increased, and the electromagnetic radiation causes direct and indirect damage to human bodies through thermal effect, non-thermal effect and cumulative effect. The wave-absorbing material can absorb or greatly weaken the electromagnetic wave energy received by the surface of the wave-absorbing material, thereby reducing the interference of the electromagnetic wave. Ferrite is a traditional wave-absorbing material which has the most research and the lowest cost and is also the most widely applied. The ferrite has the characteristics of wide raw material source, low price, simple and convenient manufacturing process, strong absorption, wider frequency band, strong corrosion resistance and low cost. However, the conventional ferrite has high density and is difficult to satisfy the principle that the relative dielectric constant and the relative magnetic permeability are as close as possible, so that the impedance is difficult to match, and therefore, the ferrite is difficult to simultaneously satisfy the requirements of high-performance wave-absorbing materials such as strong absorption, wide frequency band, light weight, thin thickness and the like.
Although the wave absorbing performance is improved after the ferrite is improved in the prior art, most of the improved ferrite can be applied only in a high-frequency band, and the application frequency band is narrow.
Disclosure of Invention
Based on the wave-absorbing material, the invention provides the flaky ferrite wave-absorbing material, the flaky ferrite/carbon composite wave-absorbing material, and the preparation method and the application thereof.
The flaky ferrite wave-absorbing material, the flaky ferrite/carbon composite wave-absorbing material, and the preparation method and the application thereof are realized by the following technical scheme.
The invention provides a preparation method of a flaky ferrite wave-absorbing material, which comprises the following steps:
s11: preparing a first mixed solution containing Fe3+Material of (5), containing Ba2+The material of (a) and a first solvent;
s12: adjusting the pH value of the first mixed solution to 8-9, heating to 80-150 ℃, and keeping for 2-5 hours for full reaction to obtain a first reactant;
s13: and cleaning the first reactant, filtering to obtain a first precipitate, and drying the first precipitate.
In one embodiment, in step S11, the first mixed solution includes the following raw materials in parts by weight: 80-150 parts of Fe3+5 to 20 parts of a material containing Ba2+400-1500 parts of a first solvent, wherein the first solvent is a polar solvent; and/or
Step S11 specifically includes: when preparing the first mixed solution, treating the mixture by ultrasonic for 5-15 min to mix the mixture evenly, and then evenly stirring the mixture for 10-30 min at the rotating speed of 600-1000 r/min at the temperature of 50-80 ℃; and/or
Step S12 specifically includes: adjusting the pH value of the first mixed solution to 8-9 by using inorganic strong base, then heating to 80-150 ℃, stirring at the rotating speed of 1500-2500 r/min for 2-5 h, fully reacting to obtain a first reactant, and adsorbing the first reactant in a reaction container by using a magnetic substance after the reaction is finished; and/or
Step S13 specifically includes: and washing the first reactant with deionized water for 3-6 times, filtering to obtain a first precipitate, and drying the first precipitate at the drying temperature of 60-120 ℃ for 8-15 h.
The invention also provides a flaky ferrite wave-absorbing material which is prepared by the preparation method of the flaky ferrite wave-absorbing material.
Further, the invention provides a preparation method of the flaky ferrite/carbon composite wave-absorbing material, which comprises the following steps:
s21: preparing a second mixed solution containing the flaky ferrite wave-absorbing material and a second solvent, adjusting the pH value of the second mixed solution to 8-9, adding a silicon source solvent, heating to 40-80 ℃, keeping for 3-6 h to obtain a second reactant, cleaning the second reactant, filtering to obtain a second precipitate, and drying the second precipitate;
s22: preparing a third mixed solution containing the second reactant, a third solvent and polyvinylpyrrolidone, cleaning the third mixed solution, filtering to obtain a third precipitate, and drying the third precipitate;
s23: preparing a Fe-containing solution containing the third precipitate and a fourth solvent3+Cleaning the fourth mixed solution, filtering to obtain a fourth precipitate, and drying the fourth precipitate;
s24: and calcining the fourth precipitate, then placing the fourth precipitate in a solution with the pH value of 8-9 for etching to obtain a fifth mixed solution, cleaning the fifth mixed solution, then filtering and drying.
In one embodiment, in step S21, the second mixed solution includes the following raw materials in parts by weight: 2-10 parts of the flaky ferrite wave-absorbing material and 1000-1700 parts of a second solvent, wherein the second solvent is a polar solvent; and/or
Step S21 specifically includes: preparing a second mixed solution, performing ultrasonic treatment for 30-50 min, adjusting the pH value of the second mixed solution to 8-9 by using inorganic weak base, adding a silicon source solvent, then heating to 40-80 ℃, stirring at the rotating speed of 400-1000 r/min for 3-6 h, enabling the mixture to react fully, adsorbing the second reactant in a reaction container by using a magnetic substance, washing the second reactant by using ethanol for 3-6 times, filtering to obtain a second precipitate, and drying the second precipitate under the conditions that the drying temperature is 60-120 ℃ and the drying time is 8-15 h, wherein the silicon source solvent is selected from at least one of gamma-aminopropyltriethoxysilane, gamma-glycidyl ether oxypropyltrimethoxysilane and ethyl orthosilicate.
In one embodiment, in step S22, the third mixed solution includes the following raw materials in parts by weight: 1-6 parts of the second reactant, 50-400 parts of the third solvent and 3-8 parts of polyvinylpyrrolidone, wherein the third solvent is a polar solvent; and/or
In step S22, mixing the second reactant and the third solvent, performing ultrasonic treatment for 20min to 40min, adding polyvinylpyrrolidone to obtain a third mixed solution, performing ultrasonic treatment for 40min to 60min, washing with distilled water for 3 to 6 times, filtering to obtain a third precipitate, and drying the third precipitate at a drying temperature of 60 ℃ to 120 ℃ for 8h to 15 h.
In one embodiment, in step S23, the fourth mixed solution includes the following raw materials in parts by weight: 1-6 parts of the third precipitate, 100-400 parts of the fourth solvent, and 5-10 parts of the Fe-containing material3+1-5 parts of pyrrole, wherein the fourth solvent is a polar solvent; and/or
Step S23 specifically includes: mixing the third precipitate and the fourth solvent, performing ultrasonic treatment for 15-30 min, and adding the Fe-containing solution3+Stirring the materials for 30-80 min, adding pyrrole, heating to 30-50 ℃, stirring for 6-12 h at a rotating speed of 400-800 r/min, allowing the materials to react fully, adsorbing the third reactant in a reaction container by using a magnetic substance, washing the third reactant for 3-6 times by using distilled water and ethanol, filtering to obtain a fourth precipitate, and drying the fourth precipitate at a drying temperature of 40-80 ℃ for 8-15 h.
In one embodiment, step S24 specifically includes: calcining the fourth precipitate under the calcining conditions of calcining temperature of 500-800 ℃ and calcining time of 2-6 h for etching to obtain a fifth mixed solution, heating the fifth mixed solution to 40-80 ℃, stirring at the rotating speed of 800-1500 r/min for 10-20 h to allow the fifth mixed solution to react fully, adsorbing the third reactant in a reaction container by using a magnetic substance, washing with distilled water for 3-6 times, filtering to obtain a fifth precipitate, and drying the fifth precipitate under the drying conditions of drying temperature of 40-80 ℃ and drying time of 8-15 h.
Furthermore, the invention provides a flaky ferrite/carbon composite wave-absorbing material which is prepared by the preparation method of the flaky ferrite/carbon composite wave-absorbing material.
The invention also provides the application of the flaky ferrite wave-absorbing material or the flaky ferrite/carbon composite wave-absorbing material in the preparation of a thermal radiation detector, a thermal radiation imager or a nondestructive detector.
Compared with the prior art, the flaky ferrite wave-absorbing material and the flaky ferrite/carbon composite wave-absorbing material have the following beneficial effects:
the prepared flaky ferrite wave-absorbing material has higher anisotropy and magnetic effective field due to the unique hexagonal crystal structure, and also has higher natural resonance frequency, the dielectricity of the ferrite obviously reduces the dielectric constant, the impedance matching is improved, and the dual wave-absorbing capacity of the ferrite with magnetic loss and dielectric loss is reserved. Furthermore, besides absorbing and reflecting loss electromagnetic waves, the flaky ferrite wave-absorbing material prepared by the preparation method can easily form a network conductive path in the matrix, obtain better interface polarization and space polarization, generate multiple reflection and multiple absorption in the cavity, increase the propagation path of the electromagnetic waves and have obvious magnetic performance advantage under low frequency.
Drawings
FIG. 1 is a scanning electron microscope image of the plate-shaped ferrite/carbon composite wave-absorbing material of example 3.
Detailed Description
The present invention may be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete. Of course, they are merely examples and are not intended to limit the present invention. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the invention, "a plurality" means at least two, e.g., two, three, etc., unless explicitly specified otherwise. In the description of the present invention, "a plurality" means at least one, e.g., one, two, etc., unless specifically limited otherwise.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
The invention provides a preparation method of a flaky ferrite wave-absorbing material, which comprises the following steps of S11-S13.
S11: preparing a first mixed solution containing Fe3+Material of (5), containing Ba2+And a first solvent.
The first mixed solution comprises the following raw materials in parts by weight: 80-150 parts of Fe3+5 to 20 parts of a material containing Ba2+400-1500 parts of a first solvent, wherein the first solvent is a polar solvent.
Further, the above-mentioned Fe-containing compound3+Is selected from FeCl3And Fe2(SO4)3At least one of the above-mentioned Ba-containing compounds2+Is selected from BaCl2And BaSO4The polar solvent is at least one selected from ethanol and water.
In one specific example, in step S11, the first mixed solution is prepared, treated with ultrasonic waves for 5min to 15min to mix uniformly, and then stirred uniformly at a rotation speed of 600r/min to 1000r/min at 50 ℃ to 80 ℃ for 10min to 30 min.
Specifically, the ultrasonic treatment time may be, for example, 5min, 6min, 7min, 8min, 9min, 10min, 11min, 12min, 13min, 14min or 15min, or 8min to 12 min.
The above method for heating the first mixed solution to 50-80 deg.C may be water bath or oil bath, and the temperature may be 50 deg.C, 65 deg.C, 70 deg.C, 75 deg.C or 80 deg.C.
Further, the rotation speed during stirring is preferably 700r/min to 900r/min, and may be, for example, 720r/min, 740r/min, 760r/min, 780r/min, 800r/min, 820r/min, 840r/min, 860r/min, 880r/min or 900r/min, and the stirring time may be 10min, 20min or 30 min.
S12: adjusting the pH value of the first mixed solution to 8-9, heating to 80-150 ℃, and keeping for 2-5 hours for sufficient reaction to obtain a first reactant;
in a specific example, the pH value of the first mixed solution is adjusted to 8-9 by inorganic strong base, then the first mixed solution is heated to 80-150 ℃ and stirred for 2-5 h at the rotating speed of 1500-2500 r/min, so that a first reactant is obtained through full reaction, and the first reactant in the reaction container is adsorbed by a magnetic substance after the reaction is finished.
Further, the inorganic strong base is at least one selected from sodium hydroxide, potassium hydroxide, calcium hydroxide, and the like.
Specifically, the pH value of the first mixed solution may be, for example, 8.1, 8.2, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, or 9.
The heating to 80-150 deg.C may be carried out in an oil bath at 80 deg.C, 85 deg.C, 90 deg.C, 95 deg.C, 100 deg.C, 105 deg.C, 110 deg.C, 115 deg.C, 120 deg.C, 125 deg.C, 130 deg.C, 140 deg.C, 145 deg.C or 150 deg.C.
The rotation speed during the stirring is preferably 1800 to 2200r/min, and may be 1820r/min, 1840r/min, 1860r/min, 1880r/min, 1900r/min, 1920r/min, 1940r/min, 1960r/min, 1980r/min, 2000r/min, 2020r/min, 2040r/min, 2060r/min, 2080r/min, 2100r/min, 2120r/min, 2140r/min, 2160r/min, 2180r/min or 2200r/min, and the stirring time may be 2 to 4 hours, for example, 2 hours, 3 hours or 4 hours.
S13: and cleaning the first reactant, filtering to obtain a first precipitate, and drying the first precipitate.
In a specific example, the first reactant is washed 3-6 times by deionized water and filtered to obtain a first precipitate, and the first precipitate is dried at the drying temperature of 60-120 ℃ for 8-15 h.
The drying temperature may be, for example, 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃, 100 ℃, 105 ℃, 110 ℃, 115 ℃ or 120 ℃, and the drying time may be 8 to 12 hours, for example, 8, 9, 10, 11 or 12 hours.
The invention also provides the flaky ferrite prepared by the preparation method of the flaky ferrite.
The flaky ferrite wave-absorbing material prepared by the method has higher anisotropy and magnetic effective field due to the unique hexagonal crystal structure, so that the flaky ferrite wave-absorbing material further has higher natural resonance frequency, the dielectricity of the ferrite is obviously reduced, the impedance matching is improved, and the dual wave-absorbing capability of the ferrite with magnetic loss and dielectric loss is reserved. Furthermore, besides absorbing and reflecting loss electromagnetic waves, the flaky ferrite wave-absorbing material prepared by the preparation method can easily form a network conductive path in the matrix, obtain better interface polarization and space polarization, generate multiple reflection and multiple absorption in the cavity, increase the propagation path of the electromagnetic waves and have obvious magnetic performance advantage under low frequency.
The invention also provides a preparation method of the flaky ferrite/carbon composite wave-absorbing material, which comprises the following steps of S21-S24.
S21: preparing a second mixed solution containing the flaky ferrite wave-absorbing material and a second solvent, adjusting the pH value of the second mixed solution to 8-9, adding a silicon source solvent, heating to 40-80 ℃, keeping the temperature for 3-6 h to obtain a second reactant, cleaning the second reactant, filtering to obtain a second precipitate, and drying the second precipitate.
The second mixed solution comprises the following raw materials in parts by weight: 2-10 parts of a flaky ferrite wave-absorbing material and 1000-1700 parts of a second solvent, wherein the second solvent is a polar solvent, and the polar solvent is at least one selected from ethanol and water.
In a specific example, the steps are specifically that the second mixed solution is prepared, then ultrasonic treatment is carried out for 30min to 50min, inorganic weak base is used for adjusting the pH value of the second mixed solution to 8 to 9, a silicon source solvent is added, then the second mixed solution is heated to 40 ℃ to 80 ℃ and stirred for 3h to 6h at the rotating speed of 400r/min to 1000r/min, the second mixed solution is fully reacted, a magnetic substance is used for adsorbing the second reactant in a reaction container, the second reactant is washed for 3 to 6 times by ethanol and filtered to obtain a second precipitate, and the second precipitate is dried under the conditions that the drying temperature is 60 ℃ to 120 ℃ and the drying time is 8h to 15 h.
Specifically, the silicon source solvent is at least one selected from the group consisting of gamma-aminopropyltriethoxysilane, gamma-glycidoxypropyltrimethoxysilane, and tetraethoxysilane, and the silicon source solvent is preferably tetraethoxysilane.
The magnetic substance is at least one selected from iron, cobalt and nickel.
Specifically, the ultrasonic treatment time is preferably 30min to 40min, and may be, for example, 30min, 31min, 32min, 33min, 34min, 35min, 36min, 37min, 38min, 39min, or 40 min.
Further, the weak inorganic base is at least one selected from ammonia water, ferric hydroxide, ferrous hydroxide and the like.
Specifically, the pH of the second mixed solution may be, for example, 8.1, 8.2, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, or 9.
The heating to 40-80 deg.C may be carried out in a water bath or oil bath at 40 deg.C, 45 deg.C, 50 deg.C, 55 deg.C, 60 deg.C, 65 deg.C, 70 deg.C, 75 deg.C or 80 deg.C.
Further, the rotation speed during stirring is preferably 400r/min to 800r/min, and may be, for example, 420r/min, 440r/min, 460r/min, 480r/min, 500r/min, 520r/min, 540r/min, 560r/min, 580r/min, 600r/min, 620r/min, 640r/min, 660r/min, 680r/min, 700r/min, 720r/min, 740r/min, 760r/min, 780r/min or 700r/min, and the stirring time may be 3h to 5h, and may be, for example, 3h, 3.5h, 4h, 4.5h or 5 h.
The drying temperature may be, for example, 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃, 100 ℃, 105 ℃, 110 ℃, 115 ℃ or 120 ℃, and the drying time may be 8 hours to 12 hours, for example, 8 hours, 9 hours, 10 hours, 11 hours or 12 hours.
S22: and preparing a third mixed solution containing the second reactant, a third solvent and polyvinylpyrrolidone, cleaning the third mixed solution, filtering to obtain a third precipitate, and drying the third precipitate.
The third mixed solution comprises the following raw materials in parts by weight: 1-6 parts of a second reactant, 50-400 parts of a third solvent and 3-8 parts of polyvinylpyrrolidone, wherein the third solvent is a polar solvent, and the polar solvent is at least one selected from ethanol and water.
In a specific example, the second reactant and the third solvent are mixed and then subjected to ultrasonic treatment for 20min to 40min, then polyvinylpyrrolidone is added to obtain a third mixed solution, the third mixed solution is subjected to ultrasonic treatment for 40min to 60min, the third mixed solution is washed for 3 to 6 times by using distilled water and filtered to obtain a third precipitate, and the third precipitate is dried under the conditions that the drying temperature is 60 ℃ to 120 ℃ and the drying time is 8h to 15 h.
The second reactant and the third solvent are mixed and then subjected to ultrasonic treatment, and the ultrasonic treatment is preferably performed for 20min to 30min, and may be performed for 20min, 21min, 22min, 23min, 24min, 25min, 26min, 27min, 28min, 29min or 30min, for example.
Further, the ultrasonic treatment time after the addition of polyvinylpyrrolidone to obtain the third mixed solution is preferably 40min to 50min, and may be, for example, 40min, 41min, 42min, 43min, 44min, 45min, 46min, 47min, 48min, 49min or 50 min.
The drying temperature may be, for example, 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃, 100 ℃, 105 ℃, 110 ℃, 115 ℃ or 120 ℃, and the drying time may be, for example, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours or 15 hours.
S23: preparing a third precipitate, a fourth solvent and Fe3+Cleaning the fourth mixed solution, filtering to obtain a fourth precipitate, and drying the fourth precipitate.
The fourth mixed solution comprises the following raw materials in parts by weight: 1-6 parts of third precipitate, 100-400 parts of fourth solvent and 5-10 parts of Fe-containing material3+And 1-5 parts of pyrrole, wherein the fourth solvent is a polar solvent, and the polar solvent is at least one selected from ethanol and water.
Specifically, the above-mentioned Fe-containing compound3+The material is selected from at least one of ferric chloride and ferric sulfate.
In a specific example, the third precipitate and the fourth solvent are mixed and subjected to ultrasonic treatment for 15-30 min, and then Fe is added3+Stirring the materials for 30-80 min, adding pyrrole, heating to 30-50 ℃, stirring for 6-12 h at the rotating speed of 400-800 r/min, allowing the materials to react fully, adsorbing a third reactant in a reaction container by using a magnetic substance, washing the third reactant for 3-6 times by using distilled water and ethanol, filtering to obtain a fourth precipitate, and drying the fourth precipitate under the conditions that the drying temperature is 40-80 ℃ and the drying time is 8-15 h.
The magnetic substance is at least one selected from iron, cobalt and nickel.
Specifically, the ultrasonic treatment time may be, for example, 15min, 16min, 17min, 18min, 20min, 22min, 24min, 26min, 28min, or 30 min.
Further, adding Fe3+The post-stirring time of the material (b) is preferably 30 to 50min, and may be, for example, 34min, 36min, 38min, 40min, 42min, 44min, 46min, 48min or 50 min.
The heating to 30-50 deg.C may be carried out in water bath or oil bath at 30 deg.C, 35 deg.C, 40 deg.C, 45 deg.C or 50 deg.C.
Further, the rotation speed during stirring is preferably 400r/min to 600r/min, for example, 420r/min, 440r/min, 460r/min, 480r/min, 500r/min, 520r/min, 540r/min, 560r/min, 580r/min or 600r/min, and the stirring time is preferably 8h to 10h, for example, 8h, 8.5h, 9h, 9.5h or 10 h.
The drying temperature may be, for example, 40 ℃, 45 ℃, 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃ or 80 ℃, and the drying time may be, for example, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours or 15 hours.
S24: and calcining the fourth precipitate, then placing the fourth precipitate in a solution with the pH value of 8-9 for etching to obtain a fifth mixed solution, cleaning the fifth mixed solution, then filtering and drying.
In a specific example, the calcination temperature is 500-800 ℃, the calcination time is 2-6 hours, the fourth precipitate is calcined under the calcination condition, the fourth precipitate is etched to obtain a fifth mixed solution, the fifth mixed solution is heated to 40-80 ℃ and stirred for 10-20 hours at the rotating speed of 800-1500 r/min to enable the fifth mixed solution to fully react, the third reactant in the reaction container is adsorbed by a magnetic substance, the fifth precipitate is obtained by washing 3-6 times with distilled water and filtering, and the fifth precipitate is dried under the drying temperature of 40-80 ℃ and the drying time of 8-15 hours.
The magnetic substance is at least one selected from iron, cobalt and nickel.
In a specific example, the calcination temperature may be, for example, 500 ℃, 550 ℃, 600 ℃, 650 ℃, 700 ℃, 750 ℃ or 800 ℃, and the calcination time is preferably 2 to 4 hours, and may be, for example, 2 hours, 2.5 hours, 3 hours, 3.5 hours or 4 hours.
Specifically, the heating method in the above step to 40-80 deg.C may be water bath or oil bath, and the temperature may be 40 deg.C, 45 deg.C, 50 deg.C, 55 deg.C, 60 deg.C, 65 deg.C, 70 deg.C, 75 deg.C or 80 deg.C.
The rotation speed during stirring is preferably 800r/min to 1200r/min, and may be, for example, 820r/min, 840r/min, 860r/min, 880r/min, 900r/min, 920r/min, 940r/min, 960r/min, 980r/min, 1000r/min, 1020r/min, 1040r/min, 1060r/min, 1080r/min, 1100r/min, 1120r/min, 1140r/min, 1160r/min, 1180r/min or 1200r/min, and the stirring time may be, for example, 10h, 11h, 12h, 13h, 14h, 15h, 16h, 17h, 18h, 19h or 20 h.
Further, the drying temperature may be, for example, 40 ℃, 45 ℃, 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃ or 80 ℃, and the drying time may be, for example, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours or 15 hours.
The carbon material is combined to coat the surface of the flaky ferrite wave-absorbing material, and microparticles with a hollow core-shell structure are formed, so that the hexagonal crystal ferrite has good matching performance, a unique flaky structure and an optimal shape of an absorbent, and has a high magnetic anisotropy equivalent field and a high natural resonance frequency. Moreover, the sheet ferrite/carbon composite wave-absorbing material obviously improves the magnetic conductivity, and simultaneously, the dual dielectric property of the ferrite obviously reduces the dielectric constant, improves the impedance matching and keeps the dual wave-absorbing capability of the ferrite with magnetic loss and dielectric loss; besides the loss electromagnetic waves such as absorption and reflection, the prepared hollow and flaky particles with special structures can more easily form a network conductive path in a matrix, obtain better interface polarization and space polarization, generate multiple reflection and multiple absorption in a cavity, increase the propagation path of the electromagnetic waves, form an effective conductive network structure and form higher dielectric loss. The wave-absorbing material prepared by the method has excellent magnetic property and dielectric property at high frequency and low frequency, and also has good substrate binding property, low density, stronger chemical stability, good corrosion resistance and oxidation resistance and better wave-absorbing property in a wider frequency band range.
The following specific examples are provided to further explain the sheet ferrite wave-absorbing material and the sheet ferrite/carbon composite wave-absorbing material of the present invention and the preparation methods thereof in detail.
Example 1
The embodiment provides a preparation method of a flaky ferrite wave-absorbing material, which comprises the following steps:
will contain 100 parts of FeCl3And 15 parts of BaCl2Dissolving in 800 parts of deionized water solution, treating with ultrasonic wave for 10min, and mixingForming a reaction solution, uniformly stirring at the rotating speed of 800r/min for 20min at the temperature of 60 ℃, slowly and uniformly adding a pH regulating solution of 10% sodium hydroxide into the reaction solution, stopping adding the regulating solution when the pH is controlled to be 8.5, continuously stirring for 3h in an oil bath at the temperature of 120 ℃ at the rotating speed of 2000r/min to enable the reaction solution to fully react, adsorbing a first reactant in a beaker by using a magnet after the reaction is finished, pouring out a supernatant, adding deionized water for continuous cleaning, and repeating the operation for 5 times to finish the cleaning of the powder. And (5) putting the cleaned precipitate into a 60 ℃ blast oven for drying treatment for 12 h.
Example 2
The embodiment provides a preparation method of a sheet ferrite/carbon composite wave-absorbing material, which comprises the following steps:
will contain 100 parts of FeCl3And 15 parts of BaCl2Dissolving in 800 parts of deionized water solution, treating with ultrasonic waves for 10min to uniformly mix to form reaction liquid, uniformly stirring at the rotating speed of 800r/min for 20min at 60 ℃, slowly and uniformly adding 10% of sodium hydroxide pH regulating solution into the reaction liquid, stopping adding the regulating solution when the pH is controlled to be 8.5, continuously stirring in an oil bath at the rotating speed of 2000r/min for 3h to fully react, adsorbing a first reactant in a beaker by using a magnetic substance after the reaction is finished, pouring out supernatant, adding deionized water for continuous cleaning, repeating the operation for 5 times to finish cleaning of powder, obtaining a first precipitate, and then putting into a 60 ℃ blast oven for drying treatment for 12 h.
Adding 2 parts of dried first precipitate into 1200 parts of absolute ethyl alcohol and 500 parts of deionized water, carrying out ultrasonic treatment for 30min to ensure that the first precipitate can be uniformly dispersed into a reaction solution, using diluted ammonia water as a pH regulating solution, controlling the pH of the reaction solution to be about 8, then dripping 1 part of tetraethoxysilane into the solution, and continuously stirring for 3h in a water bath kettle at the temperature of 60 ℃ at the rotating speed of 500 r/min. After the reaction is finished, adsorbing a second reactant in the beaker by using a magnetic substance after the reaction is finished, pouring out supernatant, washing for 5 times by using ethanol to obtain a second precipitate, and then putting the second precipitate into a 60 ℃ blast oven for drying treatment for 15 hours.
And dispersing 1 part of the dried second precipitate into 400 parts of ethanol solution, performing ultrasonic treatment for 20min, adding 3 parts of polyvinylpyrrolidone (PVP), performing ultrasonic treatment for 40min, washing with distilled water for 5 times to obtain a third precipitate, and drying in a 60 ℃ blast oven for 15 h.
Dispersing 1 part of dried third precipitate into 400 parts of deionized water, performing ultrasonic treatment for 15min, adding 5 parts of ferric chloride, stirring for 30min, adding 1 part of pyrrole, reacting for 8h at a rotating speed of 400r/min under the stirring of water bath at 40 ℃, adsorbing the third reactant in a beaker by using a magnetic substance after the reaction is finished, pouring out supernatant, respectively washing for 5 times by using distilled water and ethanol to obtain a fourth precipitate, and then putting the fourth precipitate into a blast oven at 60 ℃ for drying for 15 h.
Calcining the dried fourth precipitate at 500 ℃ for 3h in a tubular furnace under the condition of nitrogen, dispersing the calcined fourth precipitate into 100 parts of 10% sodium hydroxide solution for etching, stirring the mixture for 10h at the rotating speed of 800r/min at 40 ℃, collecting the precipitate by using a magnet, pouring out the supernatant, washing the supernatant for 5 times by using distilled water, and drying the precipitate in a forced air oven at 60 ℃ for 8 h.
Example 3
The embodiment provides a preparation method of a sheet ferrite/carbon composite wave-absorbing material, which comprises the following steps:
will contain 100 parts of FeCl3And 15 parts of BaCl2Dissolving the mixture in 800 parts of deionized water solution, treating the mixture for 10min by ultrasonic waves to uniformly mix the mixture to form reaction liquid, uniformly stirring the mixture for 20min at the speed of 800r/min at 60 ℃, slowly adding 10% of sodium hydroxide pH regulating solution into the reaction liquid at a uniform speed, stopping adding the regulating solution when the pH is controlled to be 8.5, continuously stirring the mixture for 3h in an oil bath at the speed of 2000r/min at 120 ℃ to fully react the mixture, adsorbing a first reactant in a beaker by using a magnetic substance after the reaction is finished, pouring out supernatant, adding deionized water to continuously clean the mixture, repeating the operation for 5 times to finish cleaning powder, obtaining a first precipitate, and then putting the first precipitate into a 60 ℃ blast oven to dry the mixture for 12 h.
Adding 5 parts of dried first precipitate into 1000 parts of absolute ethyl alcohol and 400 parts of deionized water, carrying out ultrasonic treatment for 40min to enable the first precipitate to be uniformly dispersed into a reaction solution, using dilute ammonia water as a pH regulating solution, controlling the pH of the reaction solution to be about 8, then dripping 3 parts of ethyl orthosilicate into the solution, and continuously stirring for 4h in a water bath kettle at the temperature of 60 ℃ at the rotating speed of 800 r/min. And (3) adsorbing a second reactant in the beaker by using a magnetic substance after the reaction is finished, pouring out supernatant, washing for 5 times by using ethanol to obtain a second precipitate, and then putting the second precipitate into a blowing oven at the temperature of 80 ℃ for drying treatment for 12 hours.
Dispersing 4 parts of the dried second precipitate into 200 parts of ethanol solution, performing ultrasonic treatment for 30min, adding 6 parts of polyvinylpyrrolidone (PVP), performing continuous ultrasonic treatment for 50min, washing with distilled water for 5 times to obtain a third precipitate, and drying in a blowing oven at 80 ℃ for 12 h.
Dispersing 4 parts of dried third precipitate into 200 parts of deionized water, carrying out ultrasonic treatment for 20min, adding 8 parts of ferric chloride, stirring for 60min, adding 3 parts of pyrrole, reacting for 10h at a rotating speed of 600r/min under the stirring of a water bath at 50 ℃, adsorbing the third reactant in a beaker by using a magnetic substance after the reaction is finished, pouring out supernatant, washing for 5 times by using distilled water and ethanol respectively to obtain a fourth precipitate, and then drying in a blast oven at 60 ℃ for 15 h.
Calcining the dried fourth precipitate at 600 ℃ for 4h under the condition of nitrogen in a tubular furnace, dispersing the calcined fourth precipitate into 200 parts of 20% sodium hydroxide solution for etching, stirring the mixture for 15h at the rotating speed of 1000r/min under the condition of 60 ℃, collecting the precipitate by using a magnet, pouring out the supernatant, washing the supernatant for 5 times by using distilled water, and drying the precipitate in a forced air oven for 15h at 60 ℃.
Example 4
The embodiment provides a preparation method of a sheet ferrite/carbon composite wave-absorbing material, which comprises the following steps:
will contain 100 parts of FeCl3And 15 parts of BaCl2Dissolving in 800 parts of deionized water solution, treating with ultrasonic wave for 10min to uniformly mix to form reaction solution, uniformly stirring at 60 ℃ at the speed of 800r/min for 20min, slowly adding 10% of sodium hydroxide pH regulating solution into the reaction solution at uniform speed, stopping adding the regulating solution when the pH is controlled at 8.5, and continuously stirring at 2000r/min in 120 ℃ oil bath for 3h to fully reactAfter the reaction is finished, adsorbing a first reactant in the beaker by using a magnetic substance, pouring out supernatant, adding deionized water for continuous cleaning, repeating the operation for 5 times to finish the cleaning of powder, obtaining a first precipitate, and then putting the first precipitate into a 60 ℃ blast oven for drying treatment for 12 hours.
Adding 10 parts of dried first precipitate into 800 parts of absolute ethyl alcohol and 200 parts of deionized water, carrying out ultrasonic treatment for 50min to ensure that the first precipitate can be uniformly dispersed into a reaction solution, using diluted ammonia water as a pH regulating solution, controlling the pH of the reaction solution to be about 9, then dripping 6 parts of tetraethoxysilane into the solution, and continuously stirring for 6h in a water bath kettle at the temperature of 80 ℃ at the rotating speed of 1000 r/min. After the reaction is finished, a second reactant in the beaker is adsorbed by a magnetic substance, the supernatant is poured out, and the second precipitate is obtained after being washed for 5 times by ethanol and then is dried in a blast oven at the temperature of 80 ℃ for 12 hours.
And dispersing 6 parts of dried second precipitate into 50 parts of ethanol solution, performing ultrasonic treatment for 40min, adding 8 parts of polyvinylpyrrolidone (PVP), performing ultrasonic treatment for 60min, washing with distilled water for 5 times to obtain a third precipitate, and drying in a blowing oven at 80 ℃ for 12 h.
Dispersing 6 parts of dried third precipitate into 100 parts of deionized water, performing ultrasonic treatment for 30min, adding 10 parts of ferric chloride, stirring for 80min, adding 5 parts of pyrrole, reacting for 12h at a rotation speed of 800r/min under the stirring of a water bath at 50 ℃, adsorbing the third reactant in a beaker by using a magnetic substance after the reaction is finished, pouring out supernatant, washing for 5 times by using distilled water and ethanol respectively to obtain a fourth precipitate, and drying in a forced air oven for 15h at 60 ℃.
Calcining the dried fourth precipitate at 800 ℃ for 6h under the condition of nitrogen in a tubular furnace, dispersing the calcined fourth precipitate into 100 parts of 10-30% sodium hydroxide solution for etching, stirring the calcined fourth precipitate at the rotating speed of 1500r/min for 20h under the condition of 60 ℃, collecting the precipitate by using a magnet, pouring out the supernatant, washing the supernatant for 5 times by using distilled water, and drying the precipitate in a blast oven at 60 ℃ for 15 h.
Example 5
The embodiment provides a preparation method of a sheet ferrite/carbon composite wave-absorbing material, which comprises the following steps:
will contain 80 parts of FeCl3And 5 parts of BaCl2Dissolving in 1500 parts of deionized water solution, treating with ultrasonic wave for 5min, mixing to obtain reaction solution, stirring at 80 deg.C at 1000r/min for 20min, slowly adding 10% sodium hydroxide pH regulator into the reaction solution at constant speed, and stopping adding the regulator when pH is controlled at 9. And then continuously stirring for 2 hours in an oil bath at 150 ℃ at the rotating speed of 2500r/min to fully react, adsorbing the first reactant in the beaker by using a magnetic substance after the reaction is finished, pouring out supernatant, adding deionized water to continuously clean, and repeating the operation for 5 times to finish the cleaning of the powder. And (4) after the first precipitate is obtained, putting the precipitate into a 60 ℃ blast oven for drying treatment for 12 hours.
Adding 5 parts of dried first precipitate into 1000 parts of absolute ethyl alcohol and 400 parts of deionized water, carrying out ultrasonic treatment for 40min to enable the first precipitate to be uniformly dispersed into a reaction solution, using dilute ammonia water as a pH regulating solution, controlling the pH of the reaction solution to be about 8, then dripping 3 parts of ethyl orthosilicate into the solution, and continuously stirring for 4h in a water bath kettle at the temperature of 60 ℃ at the rotating speed of 800 r/min. And (3) adsorbing a second reactant in the beaker by using a magnetic substance after the reaction is finished, pouring out supernatant, washing the supernatant for 5 times by using ethanol to obtain a second precipitate, and drying the second precipitate in a blowing oven at the temperature of 80 ℃ for 12 hours.
Dispersing 4 parts of dried second precipitate into 200 parts of ethanol solution, performing ultrasonic treatment for 30min, adding 6 parts of polyvinylpyrrolidone (PVP), performing continuous ultrasonic treatment for 50min, washing with distilled water for 5 times to obtain a third precipitate, and drying in a blowing oven at 80 ℃ for 12 h.
Dispersing 4 parts of dried third precipitate into 200 parts of deionized water, carrying out ultrasonic treatment for 20min, adding 8 parts of ferric chloride, stirring for 60min, adding 3 parts of pyrrole, reacting for 10h at a rotating speed of 600r/min under the stirring of a water bath at 50 ℃, adsorbing the third reactant in a beaker by using a magnetic substance after the reaction is finished, pouring out supernatant, washing for 5 times by using distilled water and ethanol respectively to obtain a fourth precipitate, and then drying in a blast oven at 60 ℃ for 15 h.
Calcining the dried fourth precipitate at 600 ℃ for 4h under the condition of nitrogen in a tubular furnace, dispersing the calcined fourth precipitate into 200 parts of 20% sodium hydroxide solution for etching, stirring the mixture for 15h at the rotating speed of 1000r/min under the condition of 60 ℃, collecting the precipitate by using a magnet, pouring out the supernatant, washing the supernatant for 5 times by using distilled water, and drying the precipitate in a forced air oven for 15h at 60 ℃.
Example 6
The embodiment provides a preparation method of a sheet ferrite/carbon composite wave-absorbing material, which comprises the following steps:
will contain 150 parts of FeCl3And 20 parts of BaCl2Dissolving in 400 parts of deionized water solution, treating with ultrasonic wave for 15min, mixing uniformly to form reaction solution, stirring uniformly at 50 ℃ at a speed of 800r/min for 20min, slowly adding 10% sodium hydroxide pH regulating solution into the reaction solution at a uniform speed, and stopping adding the regulating solution when the pH is controlled at 8. And then continuously stirring for 5 hours in an oil bath at 90 ℃ at the rotating speed of 1500r/min to enable the mixture to fully react, adsorbing a first reactant in a beaker by using a magnetic substance after the reaction is finished, pouring out supernatant, adding deionized water to continuously clean, repeating the operation for 5 times to finish cleaning of powder, and putting the first precipitate into a 60 ℃ air-blast oven to be dried for 12 hours.
Adding 5 parts of dried first precipitate into 1000 parts of absolute ethyl alcohol and 400 parts of deionized water, carrying out ultrasonic treatment for 40min to ensure that the first precipitate can be uniformly dispersed into a reaction solution, using diluted ammonia water as a pH regulating solution, controlling the pH of the reaction solution to be about 8, then dripping 3 parts of ethyl orthosilicate into the solution, and continuously stirring for 4h in a water bath kettle at the temperature of 60 ℃ at the rotating speed of 800 r/min. And (3) adsorbing a second reactant in the beaker by using a magnetic substance after the reaction is finished, pouring out the supernatant, washing the supernatant for 5 times by using ethanol to obtain a second precipitate, and then putting the second precipitate into a blowing oven at the temperature of 80 ℃ for drying treatment for 12 hours.
Dispersing 4 parts of dried second precipitate into 200 parts of ethanol solution, performing ultrasonic treatment for 30min, adding 6 parts of PVP (polyvinylpyrrolidone), performing continuous ultrasonic treatment for 50min, washing with distilled water for 5 times for later use, and drying in a blowing oven at 80 ℃ for 12h to obtain a third precipitate.
Dispersing 4 parts of dried third precipitate into 200 parts of deionized water, carrying out ultrasonic treatment for 20min, adding 8 parts of ferric chloride, stirring for 60min, adding 3 parts of pyrrole, reacting for 10h at a rotating speed of 600r/min under the stirring of a water bath at 50 ℃, adsorbing the third reactant in a beaker by using a magnetic substance after the reaction is finished, pouring out supernatant, washing for 5 times by using distilled water and ethanol respectively to obtain a fourth precipitate, and then putting the fourth precipitate into a blast oven at 60 ℃ for drying treatment for 15 h.
Calcining the dried fourth precipitate at 600 ℃ for 4h under the condition of nitrogen in a tubular furnace, dispersing the calcined fourth precipitate into 200 parts of 20% sodium hydroxide solution for etching, stirring the mixture for 15h at the rotating speed of 1000r/min under the condition of 60 ℃, collecting the precipitate by using a magnet, pouring out the supernatant, washing the supernatant for 5 times by using distilled water, and drying the precipitate in a forced air oven for 15h at 60 ℃.
Comparative example 1
This comparative example 1 provides Fe3O4The preparation method of the/carbon composite wave-absorbing material comprises the following steps:
25 parts of oily liquid Fe (CO)5Adding the mixture into 400 parts of alcohol amine solvent to be used as reaction liquid, and uniformly stirring at the speed of 400 r/min; sodium hydroxide solution with the concentration of 15% is prepared to be used as pH adjusting solution of the reaction solution. Dropwise adding a pH adjusting solution into the reaction solution, controlling the pH within 9, then adding 30 parts of hydrazine hydrate (85%) into the reaction solution, continuously stirring for 3h in a 14 ℃ oil bath kettle at the rotating speed of 1000r/min, collecting black precipitate by using a magnet after the reaction is finished, pouring out supernatant, washing paint for 5 times by using deionized water and absolute ethyl alcohol respectively, drying the precipitate in a 60 ℃ blast oven for 12h after the washing is finished, and finishing the Fe3O4And (4) preparing.
Adding 5 parts of dried first precipitate into 1000 parts of absolute ethyl alcohol and 400 parts of deionized water, carrying out ultrasonic treatment for 40min to enable the first precipitate to be uniformly dispersed into a reaction solution, using dilute ammonia water as a pH regulating solution, controlling the pH of the reaction solution to be about 8, then dripping 3 parts of ethyl orthosilicate into the solution, and continuously stirring for 4h in a water bath kettle at the temperature of 60 ℃ at the rotating speed of 800 r/min. And (3) adsorbing a second reactant in the beaker by using a magnetic substance after the reaction is finished, pouring out supernatant, washing for 5 times by using ethanol to obtain a second precipitate, and then putting the second precipitate into a blowing oven at the temperature of 80 ℃ for drying treatment for 12 hours.
Dispersing 4 parts of the dried second precipitate into 200 parts of ethanol solution, performing ultrasonic treatment for 30min, adding 6 parts of polyvinylpyrrolidone (PVP), performing continuous ultrasonic treatment for 50min, washing with distilled water for 5 times to obtain a third precipitate, and drying in a blowing oven at 80 ℃ for 12 h.
Dispersing 4 parts of dried third precipitate into 200 parts of deionized water, carrying out ultrasonic treatment for 20min, adding 8 parts of ferric chloride, stirring for 60min, adding 3 parts of pyrrole, reacting for 10h at a rotating speed of 600r/min under the stirring of a water bath at 50 ℃, adsorbing the third reactant in a beaker by using a magnetic substance after the reaction is finished, pouring out supernatant, washing for 5 times by using distilled water and ethanol respectively to obtain a fourth precipitate, and then drying in a blast oven at 60 ℃ for 15 h.
Calcining the dried fourth precipitate at 600 ℃ for 4h under the condition of nitrogen in a tubular furnace, dispersing the calcined fourth precipitate into 200 parts of 20% sodium hydroxide solution for etching, stirring the mixture for 15h at the rotating speed of 1000r/min under the condition of 60 ℃, collecting the precipitate by using a magnet, pouring out the supernatant, washing the supernatant for 5 times by using distilled water, and drying the precipitate in a forced air oven for 15h at 60 ℃.
Comparative example 2
This comparative example 2 provides Fe3O4The preparation method of the/carbon composite wave-absorbing material comprises the following steps:
5 parts of oily liquid Fe (CO)5Adding the mixture into 200 parts of alcohol amine solvent to be used as reaction liquid, and uniformly stirring at the speed of 200 r/min; preparing a sodium hydroxide solution with the concentration of 5% as a pH adjusting solution of the reaction solution. Dropwise adding a pH adjusting solution into the reaction solution, controlling the pH within 8, then adding 10 parts of hydrazine hydrate (85%) into the reaction solution, continuously stirring for 2h in a 120 ℃ oil bath kettle at the rotating speed of 800r/min, collecting black precipitate by using a magnet after the reaction is finished, pouring out supernatant, washing paint for 5 times by using deionized water and absolute ethyl alcohol respectively, drying the precipitate in a 60 ℃ blast oven for 12h after the washing is finished, and finishing the Fe3O4And (4) preparing.
Adding 5 parts of dried first precipitate into 1000 parts of absolute ethyl alcohol and 400 parts of deionized water, carrying out ultrasonic treatment for 40min to enable the first precipitate to be uniformly dispersed into a reaction solution, using dilute ammonia water as a pH regulating solution, controlling the pH of the reaction solution to be about 8, then dripping 3 parts of ethyl orthosilicate into the solution, and continuously stirring for 4h in a water bath kettle at the temperature of 60 ℃ at the rotating speed of 800 r/min. And (3) adsorbing a second reactant in the beaker by using a magnetic substance after the reaction is finished, pouring out supernatant, washing for 5 times by using ethanol to obtain a second precipitate, and then putting the second precipitate into a blowing oven at the temperature of 80 ℃ for drying treatment for 12 hours.
Dispersing 4 parts of the dried second precipitate into 200 parts of ethanol solution, performing ultrasonic treatment for 30min, adding 6 parts of polyvinylpyrrolidone (PVP), performing continuous ultrasonic treatment for 50min, washing with distilled water for 5 times to obtain a third precipitate, and drying in a blowing oven at 80 ℃ for 12 h.
Dispersing 4 parts of dried third precipitate into 200 parts of deionized water, carrying out ultrasonic treatment for 20min, adding 8 parts of ferric chloride, stirring for 60min, adding 3 parts of pyrrole, reacting for 10h at a rotating speed of 600r/min under the stirring of a water bath at 50 ℃, adsorbing the third reactant in a beaker by using a magnetic substance after the reaction is finished, pouring out supernatant, washing for 5 times by using distilled water and ethanol respectively to obtain a fourth precipitate, and then drying in a blast oven at 60 ℃ for 15 h.
Calcining the dried fourth precipitate at 600 ℃ for 4h under the condition of nitrogen in a tubular furnace, dispersing the calcined fourth precipitate into 200 parts of 20% sodium hydroxide solution for etching, stirring the mixture for 15h at the rotating speed of 1000r/min under the condition of 60 ℃, collecting the precipitate by using a magnet, pouring out the supernatant, washing the supernatant for 5 times by using distilled water, and drying the precipitate in a forced air oven for 15h at 60 ℃.
Testing and results analysis
80% of coaxial samples of the flaky ferrite wave-absorbing material and the flaky ferrite/carbon composite wave-absorbing material prepared in the embodiments 1-6 and the comparative examples 1-2 are prepared and tested, and the main steps are as follows: firstly, wave-absorbing materials are respectively mixed with paraffin according to the ratio of 8:2, the mixture is put into a high-temperature oven at 65 ℃ for heating for 10min, then the mixture is quickly taken out and uniformly mixed, a sticky solid is prepared and filled into a coaxial circular ring mold (the outer diameter of the mold is 7mm, the inner diameter of the mold is 3.04mm), samples with the thickness of 1 mm-2 mm are respectively prepared, a network vector analyzer is adopted to respectively measure the complex dielectric constant and the complex permeability, and then the reflection loss curve of the test sample along with the frequency when the thickness is 2.5mm is calculated through matlab simulation according to the electromagnetic field transmission line theory. The tap densities of the powders prepared in examples and comparative examples were measured by a tap density meter. The powders prepared in examples and comparative examples were added to 25% dilute hydrochloric acid, and the time for the solution to bubble or the solution to change color was recorded. The test results of the examples and comparative examples are shown in table 1.
TABLE 1 wave-absorbing Performance results of examples 1-6 and comparative examples 1-2
The wave-absorbing performance tests of the embodiments 1-6 show that: compared with the flaky hexagonal ferrite particles prepared in the comparative example 1, the flaky ferrite/carbon composite wave-absorbing material prepared in the examples 2 to 6 has lower density and better absorption efficiency and bandwidth, has a hollow structure and can generate multiple reflection and multiple absorption, the propagation path of electromagnetic waves is increased, and the acid and alkali corrosion resistance of the powder is greatly improved compared with the flaky hexagonal ferrite particles; in the sheet ferrite/carbon composite wave-absorbing material in embodiments 2 to 6, as the carbon coating content increases, the powder density and the magnetic permeability decrease correspondingly, the dielectric constant increases, the dielectric loss inside the material increases, an effective conductive network structure is more easily formed, the absorption efficiency is increased, but the absorption efficiency is damaged by the decrease of the magnetic permeability; the powder properties of the embodiments 3, 5 and 6 show that the prepared flaky ferrite/carbon composite wave-absorbing material has an excessively small particle size, the magnetic loss effect is improved, and the density is increased; the prepared sheet ferrite/carbon composite wave-absorbing material has overlarge grain diameter and obviously increased dielectric effect, so that a proper grain diameter size range is required to obtain better absorption performance. The SEM image of example 3 is shown in figure 1, the powder density of the flaky ferrite/carbon composite wave-absorbing material is obviously reduced, and the flaky ferrite/carbon composite wave-absorbing material is resistant toThe acid-base corrosivity is obviously improved, the magnetic loss and dielectric loss can be better achieved, the particle size is more appropriate, and the absorption efficiency and the absorption bandwidth are better. Comparative examples 1 to 2 in which Fe was used3O4The ferrite sheet is replaced, and the results show that the comparative example has low magnetic conductivity, improved dielectric, high frequency and poor impedance matching, so that the absorption efficiency intensity and bandwidth effect are not ideal. The invention well solves the problems that ferrite is used as a good matching layer material, but the ferrite has low magnetic conductivity under low frequency, is applied to the field of low-frequency wave absorption, and the like.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that various changes and modifications can be made by those skilled in the art without departing from the spirit of the invention, and these changes and modifications are all within the scope of the invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. A preparation method of a flaky ferrite wave-absorbing material is characterized by comprising the following steps:
s11: preparing a first mixed solution containing Fe3+Material of (5), containing Ba2+The material of (a) and a first solvent;
s12: adjusting the pH value of the first mixed solution to 8-9, heating to 80-150 ℃, and keeping for 2-5 hours for full reaction to obtain a first reactant;
s13: and cleaning the first reactant, filtering to obtain a first precipitate, and drying the first precipitate.
2. The method for preparing the wave-absorbing material of flaky ferrite of claim 1, wherein in step S11, the first mixed solution comprises the following raw materials in parts by weight: 80-150 parts of Fe3+5 to 20 parts of a material containing Ba2+400-1500 parts of a first solvent, wherein the first solvent is a polar solvent; and/or
Step S11 specifically includes: when preparing the first mixed solution, treating the mixture by ultrasonic for 5-15 min to mix the mixture evenly, and then evenly stirring the mixture for 10-30 min at the rotating speed of 600-1000 r/min at the temperature of 50-80 ℃; and/or
Step S12 specifically includes: adjusting the pH value of the first mixed solution to 8-9 by using inorganic strong base, then heating to 80-150 ℃, stirring at a rotating speed of 1500-2500 r/min for 2-5 h, fully reacting to obtain a first reactant, and adsorbing the first reactant in a reaction container by using a magnetic substance after the reaction is finished; and/or
Step S13 specifically includes: and washing the first reactant for 3-6 times by using deionized water, filtering to obtain a first precipitate, and drying the first precipitate at the drying temperature of 60-120 ℃ for 8-15 h.
3. A flaky ferrite wave-absorbing material, which is characterized by being prepared by the preparation method of the flaky ferrite wave-absorbing material in claim 1 or 2.
4. A preparation method of a sheet ferrite/carbon composite wave-absorbing material is characterized by comprising the following steps:
s21: preparing a second mixed solution containing the flaky ferrite wave-absorbing material of claim 3 and a second solvent, adjusting the pH value of the second mixed solution to 8-9, adding a silicon source solvent, heating to 40-80 ℃, keeping for 3-6 h to obtain a second reactant, cleaning the second reactant, filtering to obtain a second precipitate, and drying the second precipitate;
s22: preparing a third mixed solution containing the second reactant, a third solvent and polyvinylpyrrolidone, cleaning the third mixed solution, filtering to obtain a third precipitate, and drying the third precipitate;
s23: preparing a Fe-containing solution containing the third precipitate, a fourth solvent3+Cleaning the fourth mixed solution, filtering to obtain a fourth precipitate, and drying the fourth precipitate;
s24: and calcining the fourth precipitate, then placing the fourth precipitate in a solution with the pH value of 8-9 for etching to obtain a fifth mixed solution, cleaning the fifth mixed solution, then filtering and drying.
5. The preparation method of the sheet ferrite/carbon composite wave-absorbing material of claim 4, wherein in step S21, the second mixed solution comprises the following raw materials in parts by weight: 2-10 parts of the flaky ferrite wave-absorbing material and 1000-1700 parts of a second solvent, wherein the second solvent is a polar solvent; and/or
Step S21 specifically includes: preparing a second mixed solution, performing ultrasonic treatment for 30-50 min, adjusting the pH value of the second mixed solution to 8-9 by using inorganic weak base, adding a silicon source solvent, then heating to 40-80 ℃, stirring at the rotating speed of 400-1000 r/min for 3-6 h, enabling the mixture to react fully, adsorbing the second reactant in a reaction container by using a magnetic substance, washing the second reactant by using ethanol for 3-6 times, filtering to obtain a second precipitate, and drying the second precipitate under the conditions that the drying temperature is 60-120 ℃ and the drying time is 8-15 h, wherein the silicon source solvent is selected from at least one of gamma-aminopropyltriethoxysilane, gamma-glycidyl ether oxypropyltrimethoxysilane and ethyl orthosilicate.
6. The preparation method of the sheet ferrite/carbon composite wave-absorbing material of claim 4, wherein in step S22, the third mixed solution comprises the following raw materials in parts by weight: 1-6 parts of the second reactant, 50-400 parts of the third solvent and 3-8 parts of polyvinylpyrrolidone, wherein the third solvent is a polar solvent; and/or
In step S22, mixing the second reactant and the third solvent, performing ultrasonic treatment for 20min to 40min, adding polyvinylpyrrolidone to obtain a third mixed solution, performing ultrasonic treatment for 40min to 60min, washing with distilled water for 3 to 6 times, filtering to obtain a third precipitate, and drying the third precipitate at a drying temperature of 60 ℃ to 120 ℃ for 8h to 15 h.
7. The preparation method of the sheet ferrite/carbon composite wave-absorbing material of claim 4, wherein in step S23, the fourth mixed solution comprises the following raw materials in parts by weight: 1-6 parts of the third precipitate, 100-400 parts of the fourth solvent, and 5-10 parts of the Fe-containing material3+The material and 1-5 parts of pyrrole, wherein the fourth solvent is a polar solvent; and/or
Step S23 specifically includes: mixing the third precipitate and the fourth solvent, performing ultrasonic treatment for 15-30 min, and adding the Fe-containing solution3+Stirring the materials for 30-80 min, adding pyrrole, heating to 30-50 ℃, stirring for 6-12 h at the rotating speed of 400-800 r/min, allowing the materials to react fully, adsorbing the third reactant in a reaction container by using a magnetic substance, washing the third reactant for 3-6 times by using distilled water and ethanol, filtering to obtain a fourth precipitate, and drying the fourth precipitate under the conditions that the drying temperature is 40-80 ℃ and the drying time is 8-15 h.
8. The preparation method of the sheet ferrite/carbon composite wave-absorbing material according to any one of claims 4 to 7, wherein the step S24 specifically comprises: calcining the fourth precipitate under the calcining conditions of calcining temperature of 500-800 ℃ and calcining time of 2-6 h for etching to obtain a fifth mixed solution, heating the fifth mixed solution to 40-80 ℃, stirring at the rotating speed of 800-1500 r/min for 10-20 h to allow the fifth mixed solution to react fully, adsorbing the third reactant in a reaction container by using a magnetic substance, washing with distilled water for 3-6 times, filtering to obtain a fifth precipitate, and drying the fifth precipitate under the drying conditions of drying temperature of 40-80 ℃ and drying time of 8-15 h.
9. A flaky ferrite/carbon composite wave-absorbing material is characterized by being prepared by the preparation method of the flaky ferrite/carbon composite wave-absorbing material according to any one of claims 4 to 8.
10. Use of the sheet ferrite wave absorbing material of claim 3 or the sheet ferrite/carbon composite wave absorbing material of claim 9 in the preparation of a thermal radiation detector, a thermal radiation imager or a nondestructive detector.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011627958.5A CN114686168A (en) | 2020-12-30 | 2020-12-30 | Flaky ferrite wave-absorbing material, flaky ferrite/carbon composite wave-absorbing material, and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011627958.5A CN114686168A (en) | 2020-12-30 | 2020-12-30 | Flaky ferrite wave-absorbing material, flaky ferrite/carbon composite wave-absorbing material, and preparation method and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114686168A true CN114686168A (en) | 2022-07-01 |
Family
ID=82134737
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011627958.5A Pending CN114686168A (en) | 2020-12-30 | 2020-12-30 | Flaky ferrite wave-absorbing material, flaky ferrite/carbon composite wave-absorbing material, and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114686168A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101913855A (en) * | 2010-08-24 | 2010-12-15 | 中北大学 | Preparation method of iron strontium oxide magnetic nanoparticles and magnetic damping rubber thereof |
| CN102010577A (en) * | 2010-12-01 | 2011-04-13 | 南昌航空大学 | Method for preparing rare earth-doped ferrite/polythiophene/carbon nano tube microwave absorbent |
| CN102485692A (en) * | 2010-12-06 | 2012-06-06 | 沈阳理工大学 | Preparation method of two-dimensional sheet-shaped barium ferrite |
| CN106495230A (en) * | 2016-11-10 | 2017-03-15 | 无锡市明盛强力风机有限公司 | A kind of preparation method of Barium hexaferrite |
| CN108640158A (en) * | 2018-08-21 | 2018-10-12 | 河海大学 | A kind of preparation method of high-purity hexagonal sheet-like barium ferrite |
-
2020
- 2020-12-30 CN CN202011627958.5A patent/CN114686168A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101913855A (en) * | 2010-08-24 | 2010-12-15 | 中北大学 | Preparation method of iron strontium oxide magnetic nanoparticles and magnetic damping rubber thereof |
| CN102010577A (en) * | 2010-12-01 | 2011-04-13 | 南昌航空大学 | Method for preparing rare earth-doped ferrite/polythiophene/carbon nano tube microwave absorbent |
| CN102485692A (en) * | 2010-12-06 | 2012-06-06 | 沈阳理工大学 | Preparation method of two-dimensional sheet-shaped barium ferrite |
| CN106495230A (en) * | 2016-11-10 | 2017-03-15 | 无锡市明盛强力风机有限公司 | A kind of preparation method of Barium hexaferrite |
| CN108640158A (en) * | 2018-08-21 | 2018-10-12 | 河海大学 | A kind of preparation method of high-purity hexagonal sheet-like barium ferrite |
Non-Patent Citations (1)
| Title |
|---|
| 刘俊丰: "溶胶-凝胶法吸波材料钡铁氧体BaFe12O19的制备", 《中国优秀硕士学位论文全文数据库 工程科技II辑》, pages 26 - 46 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Feng et al. | Synthesis of a hierarchical carbon fiber@ cobalt ferrite@ manganese dioxide composite and its application as a microwave absorber | |
| CN110591641A (en) | Fe2O3@ MXene composite powder and preparation method thereof | |
| CN108124413B (en) | Porous hollow iron nanometer spherical electromagnetic wave absorbent material and preparation method and application | |
| CN108546547B (en) | Preparation method of multi-spectrum composite wave absorbing agent | |
| CN111377485B (en) | Preparation method of coated flaky carbonyl iron powder | |
| CN114195197B (en) | Magnetic porous carbon compound and preparation method and application thereof | |
| CN111285671A (en) | Low-frequency wave-absorbing material and preparation method thereof | |
| CN110628383B (en) | Preparation method of nano composite material for absorbing electromagnetic waves | |
| CN109627488B (en) | Graphene composite nano Fe3O4Radar wave absorbing material and preparation method thereof | |
| CN107384310A (en) | A kind of CeO2/ MWCNTs composites, preparation method and application | |
| CN108024493B (en) | Lotus seedpod structure mesoporous carbon and nano cobalt compound and preparation method and application thereof | |
| Liu et al. | A comparative study of Fe 3 O 4/polyaniline composites with octahedral and microspherical inorganic kernels | |
| CN114686168A (en) | Flaky ferrite wave-absorbing material, flaky ferrite/carbon composite wave-absorbing material, and preparation method and application thereof | |
| WO2019127991A1 (en) | Wave-absorbing agent and preparation method therefor | |
| Shen et al. | Fabrication of Z-type barium ferrite/silica composites with enhanced microwave absorption | |
| CN112442334A (en) | Barium ferrite carbon sphere composite wave-absorbing material and preparation method thereof | |
| CN114477308A (en) | MOFs derivative double-layer coated manganese ferrite wave-absorbing material and preparation method and application thereof | |
| Barick et al. | Assembly of Fe 3 O 4 nanoparticles on SiO 2 monodisperse spheres | |
| CN114749662A (en) | Flaky alloy powder/manganese-zinc ferrite/silicon dioxide wave-absorbing powder and preparation method thereof | |
| CN108410422B (en) | Preparation method of silicon-containing wave-absorbing material | |
| CN109037961B (en) | Nickel-zinc ferrite wave-absorbing material and preparation method thereof | |
| CN118026278A (en) | Ferrite composite material and preparation method and application thereof | |
| CN114085649A (en) | Non-metal graphene-based composite wave-absorbing material and preparation method thereof | |
| CN113621344B (en) | rGO/cobalt nano-rod composite wave-absorbing material and preparation method thereof | |
| CN114698356A (en) | Flaky alloy powder/manganese-zinc ferrite/carbon wave-absorbing powder and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |