阅读说明：本技术 一种多孔四氧化三铁粉体及其制备方法 (Porous ferroferric oxide powder and preparation method thereof ) 是由 刘恒峰 刘猛 于 2021-08-26 设计创作，主要内容包括：本发明公开了一种多孔四氧化三铁粉体及其制备方法,具体涉及四氧化三铁技术领域,包括：淀粉、吸波填料原料、分散剂原料和硝酸铁。本发明可有效提高多孔四氧化三铁粉体在生产制备过程中的分散性,同时提高多孔四氧化三铁粉体在水溶液中分散性能和分散持久性；配方中的淀粉为原料提供碳源,淀粉与硝酸铁配合制成多孔活性炭和四氧化三铁复合材料,可有效加强四氧化三铁的多孔性能,进而提高四氧化三铁的吸波性能；分散剂中的铁酞菁、石墨烯和无水乙醇在共混之后进行超声处理、水浴振荡处理,反应生成高分散性三维多孔碳基铁材料,可有效加强四氧化三铁粉体的分散性能。(The invention discloses porous ferroferric oxide powder and a preparation method thereof, and particularly relates to the technical field of ferroferric oxide, which comprises the following steps: starch, wave-absorbing filler raw materials, dispersant raw materials and ferric nitrate. The invention can effectively improve the dispersibility of the porous ferroferric oxide powder in the production and preparation process, and simultaneously improve the dispersibility and the dispersion durability of the porous ferroferric oxide powder in the aqueous solution; starch in the formula provides a carbon source for raw materials, and the starch and ferric nitrate are matched to prepare a porous activated carbon and ferroferric oxide composite material, so that the porous property of the ferroferric oxide can be effectively enhanced, and the wave-absorbing property of the ferroferric oxide is improved; iron phthalocyanine, graphene and absolute ethyl alcohol in the dispersing agent are subjected to ultrasonic treatment and water bath oscillation treatment after being blended, and the high-dispersity three-dimensional porous carbon-based iron material is generated through reaction, so that the dispersing performance of ferroferric oxide powder can be effectively enhanced.)

1. A porous ferroferric oxide powder is characterized in that: comprises the following components in percentage by weight: 28.40-30.60% of starch, 6.10-7.30% of wave-absorbing filler, 17.40-19.20% of dispersing agent and the balance of ferric nitrate.

2. The porous ferroferric oxide powder according to claim 1, characterized in that: the wave-absorbing filler comprises the following components in percentage by weight: 42.20-49.40% of carbon fibers, and the balance of nano silicon carbide; the dispersant comprises the following components in percentage by weight: 0.84-0.98% of iron phthalocyanine, 7.20-8.80% of graphene, and the balance of absolute ethyl alcohol.

3. The porous ferroferric oxide powder according to claim 2, characterized in that: comprises the following components in percentage by weight: 28.40% of starch, 6.10% of wave-absorbing filler, 17.40% of dispersing agent and 48.10% of ferric nitrate; the wave-absorbing filler comprises the following components in percentage by weight: 42.20 percent of carbon fiber and 57.80 percent of nano silicon carbide; the dispersant comprises the following components in percentage by weight: 0.84% of iron phthalocyanine, 7.20% of graphene and 91.96% of absolute ethyl alcohol.

4. The porous ferroferric oxide powder according to claim 2, characterized in that: comprises the following components in percentage by weight: 30.60% of starch, 7.30% of wave-absorbing filler, 19.20% of dispersing agent and 42.90% of ferric nitrate; the wave-absorbing filler comprises the following components in percentage by weight: 49.40 percent of carbon fiber and 40.60 percent of nano silicon carbide; the dispersant comprises the following components in percentage by weight: 0.98% of iron phthalocyanine, 8.80% of graphene and 90.22% of absolute ethyl alcohol.

5. The porous ferroferric oxide powder according to claim 2, characterized in that: comprises the following components in percentage by weight: 29.50% of starch, 6.70% of wave-absorbing filler, 18.30% of dispersing agent and 45.50% of ferric nitrate; the wave-absorbing filler comprises the following components in percentage by weight: 45.80% of carbon fiber, 54.20% of nano silicon carbide; the dispersant comprises the following components in percentage by weight: 0.91% of iron phthalocyanine, 8.00% of graphene and 91.09% of absolute ethyl alcohol.

6. The preparation method of the porous ferroferric oxide powder according to any one of claims 1 to 5, characterized by comprising the following steps: the preparation method comprises the following specific steps:

the method comprises the following steps: weighing the starch, the wave-absorbing filler raw material, the dispersant raw material and ferric nitrate in parts by weight;

step two: mixing the raw materials of the dispersing agent in the step one, carrying out ultrasonic treatment for 20-30 minutes, and then carrying out oscillation treatment in water bath (24 ℃) for 1-2 hours to obtain the dispersing agent;

step three: adding the ferric nitrate in the first step into deionized water to obtain a ferric nitrate solution, then adding the starch in the first step into the ferric nitrate solution, carrying out ultrasonic oscillation treatment for 6-8 minutes, then adding the mixture into a reaction kettle, reacting for 6-8 hours at 230-250 ℃, washing and drying to obtain a solid product;

step four: adding the solid product prepared in the third step into an activation furnace, introducing carbon dioxide gas, heating to 650-790 ℃, keeping for 1-3 hours, and cooling to obtain a porous ferroferric oxide composite material;

step five: putting the wave-absorbing filler into deionized water, and carrying out ultrasonic oscillation treatment for 13-19 minutes to obtain a wave-absorbing filler dispersion liquid;

step six: adding the porous ferroferric oxide composite material prepared in the fourth step and the dispersing agent prepared in the second step into the wave-absorbing filler dispersing liquid prepared in the fifth step, and performing ultrasonic treatment for 8-10 minutes; obtaining porous ferroferric oxide particle solution;

step seven: and (3) separating the porous ferroferric oxide particle solution prepared in the sixth step, washing with distilled water for 3-4 times, then washing with absolute ethyl alcohol for 4-5 times, then performing centrifugal separation, and performing vacuum drying at 65-68 ℃ for 4-6 hours to obtain porous ferroferric oxide powder.

7. The preparation method of porous ferroferric oxide powder according to claim 6, characterized by comprising the following steps: in the second step, double-frequency ultrasonic treatment is adopted, and the ultrasonic frequency is 24KHz +1.6 MHz; in the fourth step, the gas flow speed of the carbon dioxide gas is 49L/h, the temperature is increased at the temperature rising speed of 18 ℃/min, and the temperature is kept after the temperature is raised to the highest temperature; in the third step and the fifth step, the frequency of the ultrasonic wave is 1.6-1.8 MHz; the ultrasonic frequency in the sixth step is 24-28 KHz; in the third step, the weight part ratio of the ferric nitrate to the deionized water is 1: 6-10; in the fifth step, the weight part ratio of the wave-absorbing filler to the deionized water is 1: 10-12.

8. The method for preparing porous ferroferric oxide powder according to claim 7, characterized in that: in the second step, double-frequency ultrasonic treatment is adopted, and the ultrasonic frequency is 24KHz +1.6 MHz; in the fourth step, the gas flow speed of the carbon dioxide gas is 49L/h, the temperature is increased at the temperature rising speed of 18 ℃/min, and the temperature is kept after the temperature is raised to the highest temperature; in the third step and the fifth step, the frequency of the ultrasonic wave is 1.6 MHz; the ultrasonic frequency in the sixth step is 24 KHz; in the third step, the weight portion ratio of ferric nitrate and deionized water is 1: 6; in the fifth step, the weight portion ratio of the wave-absorbing filler to the deionized water is 1: 10.

9. The method for preparing porous ferroferric oxide powder according to claim 7, characterized in that: in the second step, double-frequency ultrasonic treatment is adopted, and the ultrasonic frequency is 24KHz +1.6 MHz; in the fourth step, the gas flow speed of the carbon dioxide gas is 49L/h, the temperature is increased at the temperature rising speed of 18 ℃/min, and the temperature is kept after the temperature is raised to the highest temperature; in the third step and the fifth step, the frequency of the ultrasonic wave is 1.8 MHz; the ultrasonic frequency in the sixth step is 28 KHz; in the third step, the weight portion ratio of ferric nitrate and deionized water is 1: 10; in the fifth step, the weight portion ratio of the wave-absorbing filler to the deionized water is 1: 12.

10. The method for preparing porous ferroferric oxide powder according to claim 7, characterized in that: in the second step, double-frequency ultrasonic treatment is adopted, and the ultrasonic frequency is 24KHz +1.6 MHz; in the fourth step, the gas flow speed of the carbon dioxide gas is 49L/h, the temperature is increased at the temperature rising speed of 18 ℃/min, and the temperature is kept after the temperature is raised to the highest temperature; in the third step and the fifth step, the frequency of the ultrasonic wave is 1.7 MHz; the ultrasonic frequency in the sixth step is 26 KHz; in the third step, the weight portion ratio of ferric nitrate and deionized water is 1: 8; in the fifth step, the weight portion ratio of the wave-absorbing filler to the deionized water is 1: 11.

Technical Field

The invention relates to the technical field of ferroferric oxide, in particular to porous ferroferric oxide powder and a preparation method thereof.

Background

Ferroferric oxide is an inorganic substance, is a black crystal with magnetism, and is also called magnetic iron oxide. Are commonly used as pigments and polishing agents, and also for the manufacture of magnetic recording tapes and telecommunications equipment. The ferroferric oxide has ferromagnetism, and is called ferroferric oxide magnetic particles if the radius of formed particles is in a nanometer level. The nano ferroferric oxide magnetic powder has incomparable special performance and new application in the aspects of light, electricity, medicine, magnetic media and the like of general block materials, so the nano ferroferric oxide magnetic powder is widely applied to the fields of national defense, surface engineering, environmental engineering, chemical engineering, electronic materials, semiconductor materials and the like and has very wide application prospect. The traditional method for preparing the nano ferroferric oxide mainly comprises a precipitation method, a hydrothermal (solvothermal) method, a micro-emulsification method and a sol-gel method; the emerging preparation methods mainly comprise: microwave process, pyrolytic carbonyl precursor process, ultrasonic process, air oxidation process, pyrolysis-reduction process and polyol reduction process.

The existing ferroferric oxide powder is easy to agglomerate in the heating and drying process of preparation, and the dispersion uniformity of the product is not good.

Disclosure of Invention

In order to overcome the defects in the prior art, embodiments of the present invention provide a porous ferroferric oxide powder and a preparation method thereof.

A porous ferroferric oxide powder comprises the following components in percentage by weight: 28.40-30.60% of starch, 6.10-7.30% of wave-absorbing filler, 17.40-19.20% of dispersing agent and the balance of ferric nitrate.

Further, the wave-absorbing filler comprises the following components in percentage by weight: 42.20-49.40% of carbon fibers, and the balance of nano silicon carbide; the dispersant comprises the following components in percentage by weight: 0.84-0.98% of iron phthalocyanine, 7.20-8.80% of graphene, and the balance of absolute ethyl alcohol.

Further, the paint comprises the following components in percentage by weight: 28.40% of starch, 6.10% of wave-absorbing filler, 17.40% of dispersing agent and 48.10% of ferric nitrate; the wave-absorbing filler comprises the following components in percentage by weight: 42.20 percent of carbon fiber and 57.80 percent of nano silicon carbide; the dispersant comprises the following components in percentage by weight: 0.84% of iron phthalocyanine, 7.20% of graphene and 91.96% of absolute ethyl alcohol.

Further, the paint comprises the following components in percentage by weight: 30.60% of starch, 7.30% of wave-absorbing filler, 19.20% of dispersing agent and 42.90% of ferric nitrate; the wave-absorbing filler comprises the following components in percentage by weight: 49.40 percent of carbon fiber and 40.60 percent of nano silicon carbide; the dispersant comprises the following components in percentage by weight: 0.98% of iron phthalocyanine, 8.80% of graphene and 90.22% of absolute ethyl alcohol.

Further, the paint comprises the following components in percentage by weight: 29.50% of starch, 6.70% of wave-absorbing filler, 18.30% of dispersing agent and 45.50% of ferric nitrate; the wave-absorbing filler comprises the following components in percentage by weight: 45.80% of carbon fiber, 54.20% of nano silicon carbide; the dispersant comprises the following components in percentage by weight: 0.91% of iron phthalocyanine, 8.00% of graphene and 91.09% of absolute ethyl alcohol.

The invention also provides a preparation method of the porous ferroferric oxide powder, which comprises the following specific preparation steps:

the method comprises the following steps: weighing the starch, the wave-absorbing filler raw material, the dispersant raw material and ferric nitrate in parts by weight;

step two: mixing the raw materials of the dispersing agent in the step one, carrying out ultrasonic treatment for 20-30 minutes, and then carrying out oscillation treatment in water bath (24 ℃) for 1-2 hours to obtain the dispersing agent;

step three: adding the ferric nitrate in the first step into deionized water to obtain a ferric nitrate solution, then adding the starch in the first step into the ferric nitrate solution, carrying out ultrasonic oscillation treatment for 6-8 minutes, then adding the mixture into a reaction kettle, reacting for 6-8 hours at 230-250 ℃, washing and drying to obtain a solid product;

step four: adding the solid product prepared in the third step into an activation furnace, introducing carbon dioxide gas, heating to 650-790 ℃, keeping for 1-3 hours, and cooling to obtain a porous ferroferric oxide composite material;

step five: putting the wave-absorbing filler into deionized water, and carrying out ultrasonic oscillation treatment for 13-19 minutes to obtain a wave-absorbing filler dispersion liquid;

step six: adding the porous ferroferric oxide composite material prepared in the fourth step and the dispersing agent prepared in the second step into the wave-absorbing filler dispersing liquid prepared in the fifth step, and performing ultrasonic treatment for 8-10 minutes; obtaining porous ferroferric oxide particle solution;

step seven: and (3) separating the porous ferroferric oxide particle solution prepared in the sixth step, washing with distilled water for 3-4 times, then washing with absolute ethyl alcohol for 4-5 times, then performing centrifugal separation, and performing vacuum drying at 65-68 ℃ for 4-6 hours to obtain porous ferroferric oxide powder.

Further, in the second step, double-frequency ultrasonic treatment is adopted, and the ultrasonic frequency is 24KHz +1.6 MHz; in the fourth step, the gas flow speed of the carbon dioxide gas is 49L/h, the temperature is increased at the temperature rising speed of 18 ℃/min, and the temperature is kept after the temperature is raised to the highest temperature; in the third step and the fifth step, the frequency of the ultrasonic wave is 1.6-1.8 MHz; the ultrasonic frequency in the sixth step is 24-28 KHz; in the third step, the weight part ratio of the ferric nitrate to the deionized water is 1: 6-10; in the fifth step, the weight part ratio of the wave-absorbing filler to the deionized water is 1: 10-12.

Further, in the second step, double-frequency ultrasonic treatment is adopted, and the ultrasonic frequency is 24KHz +1.6 MHz; in the fourth step, the gas flow speed of the carbon dioxide gas is 49L/h, the temperature is increased at the temperature rising speed of 18 ℃/min, and the temperature is kept after the temperature is raised to the highest temperature; in the third step and the fifth step, the frequency of the ultrasonic wave is 1.6 MHz; the ultrasonic frequency in the sixth step is 24 KHz; in the third step, the weight portion ratio of ferric nitrate and deionized water is 1: 6; in the fifth step, the weight portion ratio of the wave-absorbing filler to the deionized water is 1: 10.

Further, in the second step, double-frequency ultrasonic treatment is adopted, and the ultrasonic frequency is 24KHz +1.6 MHz; in the fourth step, the gas flow speed of the carbon dioxide gas is 49L/h, the temperature is increased at the temperature rising speed of 18 ℃/min, and the temperature is kept after the temperature is raised to the highest temperature; in the third step and the fifth step, the frequency of the ultrasonic wave is 1.8 MHz; the ultrasonic frequency in the sixth step is 28 KHz; in the third step, the weight portion ratio of ferric nitrate and deionized water is 1: 10; in the fifth step, the weight portion ratio of the wave-absorbing filler to the deionized water is 1: 12.

Further, in the second step, double-frequency ultrasonic treatment is adopted, and the ultrasonic frequency is 24KHz +1.6 MHz; in the fourth step, the gas flow speed of the carbon dioxide gas is 49L/h, the temperature is increased at the temperature rising speed of 18 ℃/min, and the temperature is kept after the temperature is raised to the highest temperature; in the third step and the fifth step, the frequency of the ultrasonic wave is 1.7 MHz; the ultrasonic frequency in the sixth step is 26 KHz; in the third step, the weight portion ratio of ferric nitrate and deionized water is 1: 8; in the fifth step, the weight portion ratio of the wave-absorbing filler to the deionized water is 1: 11.

The invention has the technical effects and advantages that:

1. the porous ferroferric oxide powder prepared by the raw material formula can effectively improve the dispersibility of the porous ferroferric oxide powder in the production and preparation process, and simultaneously improve the dispersibility and the dispersion durability of the porous ferroferric oxide powder in an aqueous solution; the starch in the formula provides a carbon source for raw materials, after the starch and ferric nitrate are heated, reacted and washed, carbon dioxide gas is introduced for heating and activating treatment, and the porous active carbon and the ferroferric oxide composite material are obtained, so that the porous property of the ferroferric oxide can be effectively enhanced, and the wave-absorbing property of the ferroferric oxide is improved; the carbon fibers in the wave-absorbing filler and the nano silicon carbide are matched with each other, the carbon fibers are uniformly loaded on the surface of the porous ferroferric oxide under the ultrasonic action, and the nano silicon carbide is loaded in the pore channels of the porous ferroferric oxide, so that the wave-absorbing performance of the ferroferric oxide is further enhanced; iron phthalocyanine, graphene and absolute ethyl alcohol in the dispersing agent are subjected to ultrasonic treatment and water bath oscillation treatment after being blended, a high-dispersity three-dimensional porous carbon-based iron material is generated through reaction, and meanwhile, the high-dispersity three-dimensional porous carbon-based iron material is loaded into a porous ferroferric oxide pore channel under the ultrasonic action, so that the dispersing performance of ferroferric oxide powder can be effectively enhanced;

2. in the process of preparing the porous ferroferric oxide powder, the raw materials of the dispersing agent are mixed, subjected to ultrasonic treatment and subjected to water bath oscillation treatment in the second step, so that the raw materials of the dispersing agent can be ensured to fully react, and the dispersing agent can fully play a role; in the third step, blending, heating and reacting ferric nitrate and starch to obtain a semi-finished product of the active carbon and ferroferric oxide composite material; introducing carbon dioxide into the semi-finished product of the active carbon and the ferroferric oxide composite material in the fourth step, heating and preserving heat for reaction, and preparing porous active carbon and the ferroferric oxide composite material; in the fifth step, the wave-absorbing filler is subjected to ultrasonic dispersion treatment, so that subsequent processing treatment is facilitated; and in the sixth step, the porous activated carbon, the ferroferric oxide composite material, the dispersing agent and the wave-absorbing filler dispersion liquid are subjected to ultrasonic treatment, so that the high dispersibility and safety performance of the porous ferroferric oxide powder can be effectively ensured.

Detailed Description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

the invention provides porous ferroferric oxide powder which comprises the following components in percentage by weight: 28.40% of starch, 6.10% of wave-absorbing filler, 17.40% of dispersing agent and 48.10% of ferric nitrate; the wave-absorbing filler comprises the following components in percentage by weight: 42.20 percent of carbon fiber and 57.80 percent of nano silicon carbide; the dispersant comprises the following components in percentage by weight: 0.84% of iron phthalocyanine, 7.20% of graphene and 91.96% of absolute ethyl alcohol;

the invention also provides a preparation method of the porous ferroferric oxide powder, which comprises the following specific preparation steps:

the method comprises the following steps: weighing the starch, the wave-absorbing filler raw material, the dispersant raw material and ferric nitrate in parts by weight;

step two: mixing the raw materials of the dispersing agent in the step one, carrying out ultrasonic treatment for 20 minutes at the same time, and then carrying out oscillation treatment for 1 hour in a water bath (24 ℃) to obtain the dispersing agent;

step three: adding the ferric nitrate in the first step into deionized water to obtain a ferric nitrate solution, then adding the starch in the first step into the ferric nitrate solution, carrying out ultrasonic oscillation treatment for 6 minutes, then adding the mixture into a reaction kettle, reacting for 6 hours at 230 ℃, washing and drying to obtain a solid product;

step four: adding the solid product prepared in the third step into an activation furnace, introducing carbon dioxide gas, heating to 650 ℃, keeping for 1 hour, and cooling to obtain a porous ferroferric oxide composite material;

step five: putting the wave-absorbing filler into deionized water, and carrying out ultrasonic oscillation treatment for 13 minutes to obtain a wave-absorbing filler dispersion liquid;

step six: adding the porous ferroferric oxide composite material prepared in the fourth step and the dispersing agent prepared in the second step into the wave-absorbing filler dispersing liquid prepared in the fifth step, and performing ultrasonic treatment for 8 minutes; obtaining porous ferroferric oxide particle solution;

step seven: and (3) separating the porous ferroferric oxide particle solution prepared in the step six, washing with distilled water for 3 times, then washing with absolute ethyl alcohol for 4 times, then performing centrifugal separation, and performing vacuum drying at the temperature of 65 ℃ for 4 hours to obtain porous ferroferric oxide powder.

In the second step, double-frequency ultrasonic treatment is adopted, and the ultrasonic frequency is 24KHz +1.6 MHz; in the fourth step, the gas flow speed of the carbon dioxide gas is 49L/h, the temperature is increased at the temperature rising speed of 18 ℃/min, and the temperature is kept after the temperature is raised to the highest temperature; in the third step and the fifth step, the frequency of the ultrasonic wave is 1.6 MHz; the ultrasonic frequency in the sixth step is 24 KHz; in the third step, the weight portion ratio of ferric nitrate and deionized water is 1: 6; in the fifth step, the weight portion ratio of the wave-absorbing filler to the deionized water is 1: 10.

Example 2:

different from the embodiment 1, the material comprises the following components in percentage by weight: 30.60% of starch, 7.30% of wave-absorbing filler, 19.20% of dispersing agent and 42.90% of ferric nitrate; the wave-absorbing filler comprises the following components in percentage by weight: 49.40 percent of carbon fiber and 40.60 percent of nano silicon carbide; the dispersant comprises the following components in percentage by weight: 0.98% of iron phthalocyanine, 8.80% of graphene and 90.22% of absolute ethyl alcohol.

Example 3:

different from the examples 1-2, the material comprises the following components in percentage by weight: 29.50% of starch, 6.70% of wave-absorbing filler, 18.30% of dispersing agent and 45.50% of ferric nitrate; the wave-absorbing filler comprises the following components in percentage by weight: 45.80% of carbon fiber, 54.20% of nano silicon carbide; the dispersant comprises the following components in percentage by weight: 0.91% of iron phthalocyanine, 8.00% of graphene and 91.09% of absolute ethyl alcohol.

Taking the porous ferroferric oxide powder prepared in the above examples 1-3, the ferroferric oxide powder of the first control group, the ferroferric oxide powder of the second control group, the ferroferric oxide powder of the third control group, the ferroferric oxide powder of the fourth control group and the porous ferroferric oxide powder of the fifth control group, comparing the ferroferric oxide powder of the first control group with the examples without starch, comparing the ferroferric oxide powder of the second control group with the carbon fiber, comparing the ferroferric oxide powder of the third control group with the examples without nano silicon carbide, comparing the ferroferric oxide powder of the fourth control group with the examples without iron phthalocyanine, comparing the ferroferric oxide powder of the fifth control group with the examples with graphene, respectively testing the porous ferroferric oxide powder prepared in the three examples and the ferroferric oxide powder of the five control groups by eight groups, each 30 samples being a group, the test was carried out, and the test results are shown in table one:

table one:

as can be seen from the table I, when the porous ferroferric oxide powder comprises the following raw materials in proportion: comprises the following components in percentage by weight: 29.50% of starch, 6.70% of wave-absorbing filler, 18.30% of dispersing agent and 45.50% of ferric nitrate; the wave-absorbing filler comprises the following components in percentage by weight: 45.80% of carbon fiber, 54.20% of nano silicon carbide; the dispersant comprises the following components in percentage by weight: when 0.91% of iron phthalocyanine, 8.00% of graphene and 91.09% of absolute ethyl alcohol are used, the dispersibility of the porous ferroferric oxide powder in the production and preparation process can be effectively improved, and the dispersibility and the dispersion durability of the porous ferroferric oxide powder in an aqueous solution can be improved; therefore, the embodiment 3 is a preferred embodiment of the invention, the starch in the formula is used as a raw material to provide a carbon source, after the starch and ferric nitrate are heated, reacted and washed, carbon dioxide gas is introduced to heat and activate the starch, and the porous active carbon and the ferroferric oxide composite material are obtained, so that the porous performance of the ferroferric oxide can be effectively enhanced, and the wave absorbing performance of the ferroferric oxide is improved; the carbon fibers in the wave-absorbing filler and the nano silicon carbide are matched with each other, the carbon fibers are uniformly loaded on the surface of the porous ferroferric oxide under the ultrasonic action, and the nano silicon carbide is loaded in the pore channels of the porous ferroferric oxide, so that the wave-absorbing performance of the ferroferric oxide is further enhanced; iron phthalocyanine, graphene and absolute ethyl alcohol in the dispersing agent are subjected to ultrasonic treatment and water bath oscillation treatment after being blended, a high-dispersity three-dimensional porous carbon-based iron material is generated through reaction, and meanwhile, the high-dispersity three-dimensional porous carbon-based iron material is loaded into a porous ferroferric oxide pore channel under the ultrasonic action, so that the dispersing performance of ferroferric oxide powder can be effectively enhanced.

Example 4:

the invention provides porous ferroferric oxide powder which comprises the following components in percentage by weight: 29.50% of starch, 6.70% of wave-absorbing filler, 18.30% of dispersing agent and 45.50% of ferric nitrate; the wave-absorbing filler comprises the following components in percentage by weight: 45.80% of carbon fiber, 54.20% of nano silicon carbide; the dispersant comprises the following components in percentage by weight: 0.91% of iron phthalocyanine, 8.00% of graphene and 91.09% of absolute ethyl alcohol;

the invention also provides a preparation method of the porous ferroferric oxide powder, which comprises the following specific preparation steps:

the method comprises the following steps: weighing the starch, the wave-absorbing filler raw material, the dispersant raw material and ferric nitrate in parts by weight;

step two: mixing the raw materials of the dispersing agent in the step one, carrying out ultrasonic treatment for 25 minutes at the same time, and then carrying out oscillation treatment for 2 hours in a water bath (24 ℃) to obtain the dispersing agent;

step three: adding the ferric nitrate in the first step into deionized water to obtain a ferric nitrate solution, then adding the starch in the first step into the ferric nitrate solution, carrying out ultrasonic oscillation treatment for 7 minutes, then adding the mixture into a reaction kettle, reacting for 7 hours at 240 ℃, washing and drying to obtain a solid product;

step four: adding the solid product prepared in the third step into an activation furnace, introducing carbon dioxide gas, heating to 720 ℃, keeping for 2 hours, and cooling to obtain a porous ferroferric oxide composite material;

step five: putting the wave-absorbing filler into deionized water, and carrying out ultrasonic oscillation treatment for 16 minutes to obtain a wave-absorbing filler dispersion liquid;

step six: adding the porous ferroferric oxide composite material prepared in the fourth step and the dispersing agent prepared in the second step into the wave-absorbing filler dispersing liquid prepared in the fifth step, and performing ultrasonic treatment for 9 minutes; obtaining porous ferroferric oxide particle solution;

step seven: and (3) separating the porous ferroferric oxide particle solution prepared in the step six, washing with distilled water for 4 times, then washing with absolute ethyl alcohol for 5 times, then performing centrifugal separation, and performing vacuum drying at the temperature of 67 ℃ for 5 hours to obtain porous ferroferric oxide powder.

In the second step, double-frequency ultrasonic treatment is adopted, and the ultrasonic frequency is 24KHz +1.6 MHz; in the fourth step, the gas flow speed of the carbon dioxide gas is 49L/h, the temperature is increased at the temperature rising speed of 18 ℃/min, and the temperature is kept after the temperature is raised to the highest temperature; in the third step and the fifth step, the frequency of the ultrasonic wave is 1.6 MHz; the ultrasonic frequency in the sixth step is 24 KHz; in the third step, the weight portion ratio of ferric nitrate and deionized water is 1: 6; in the fifth step, the weight portion ratio of the wave-absorbing filler to the deionized water is 1: 10.

Example 5:

different from the embodiment 4, in the second step, double-frequency ultrasonic treatment is adopted, and the ultrasonic frequency is 24KHz +1.6 MHz; in the fourth step, the gas flow speed of the carbon dioxide gas is 49L/h, the temperature is increased at the temperature rising speed of 18 ℃/min, and the temperature is kept after the temperature is raised to the highest temperature; in the third step and the fifth step, the frequency of the ultrasonic wave is 1.8 MHz; the ultrasonic frequency in the sixth step is 28 KHz; in the third step, the weight portion ratio of ferric nitrate and deionized water is 1: 10; in the fifth step, the weight portion ratio of the wave-absorbing filler to the deionized water is 1: 12.

Example 6:

different from the embodiments 4-5, in the second step, double-frequency ultrasonic treatment is adopted, and the ultrasonic frequency is 24KHz +1.6 MHz; in the fourth step, the gas flow speed of the carbon dioxide gas is 49L/h, the temperature is increased at the temperature rising speed of 18 ℃/min, and the temperature is kept after the temperature is raised to the highest temperature; in the third step and the fifth step, the frequency of the ultrasonic wave is 1.7 MHz; the ultrasonic frequency in the sixth step is 26 KHz; in the third step, the weight portion ratio of ferric nitrate and deionized water is 1: 8; in the fifth step, the weight portion ratio of the wave-absorbing filler to the deionized water is 1: 11.

The porous ferroferric oxide powder prepared in the above examples 4-6, the ferroferric oxide powder of the control group six, the ferroferric oxide powder of the control group seven, the ferroferric oxide powder of the control group eight and the ferroferric oxide powder of the control group nine are respectively taken, compared with the example, the ferroferric oxide powder of the contrast group VI has no operation in the step II, the ferroferric oxide powder of the contrast group VII has no operation in the step III, compared with the example, the ferroferric oxide powder of the control group eight has no operation in step four, compared with the example, the ferroferric oxide powder of the control group nine has no operation in step six, the porous ferroferric oxide powder prepared in the three examples and the ferroferric oxide powder of the four control groups are respectively tested in seven groups, every 30 samples are taken as one group, and the test results are shown in the table two:

table two:

as can be seen from table two, example 6 is a preferred embodiment of the present invention; in the second step, the raw materials of the dispersing agent are mixed and subjected to ultrasonic treatment and water bath oscillation treatment, double-frequency ultrasonic treatment is adopted, the frequency of ultrasonic waves is 24KHz +1.6MHz, the ultrasonic waves with the frequency of 24KHz can generate cavitation effect in the mixture, the reactivity of the raw materials in the dispersing agent can be effectively improved, the ultrasonic waves with the frequency of 1.6MHz can effectively enhance the dispersion uniformity of the raw materials in the dispersing agent, and the raw materials of the dispersing agent can be ensured to be fully reacted, so that the dispersing agent can fully play a role; in the third step, blending, heating and reacting ferric nitrate and starch, wherein 1.6MHz ultrasonic wave can effectively enhance the distribution uniformity of ferric nitrate and starch, and a semi-finished product of the active carbon and ferroferric oxide composite material is prepared by reaction; introducing carbon dioxide into the semi-finished product of the active carbon and the ferroferric oxide composite material in the fourth step, heating and preserving heat for reaction, and preparing porous active carbon and the ferroferric oxide composite material; in the fifth step, the wave-absorbing filler is subjected to ultrasonic dispersion treatment, so that subsequent processing treatment is facilitated; in the sixth step, the porous activated carbon, the ferroferric oxide composite material, the dispersing agent and the wave-absorbing filler dispersion liquid are subjected to ultrasonic treatment, 28KHz ultrasonic waves can effectively generate a cavitation effect in the mixture, the cavitation effect is easier to realize mesoscopic uniform mixing, the condition of uneven local concentration can be eliminated, the material reaction speed is improved, the formation of new substances is stimulated, meanwhile, the shearing effect on agglomeration is realized, and the formation of tiny particles is facilitated; can effectively ensure the high dispersibility and safety performance of the porous ferroferric oxide powder.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.