阅读说明：本技术 一种空心核壳结构Fe3O4@SiO2@PANI吸波剂及制备方法 (Hollow core-shell structure Fe3O4@SiO2@ PANI wave absorbing agent and preparation method thereof ) 是由 丁娟 程立刚 吴宝龙 庄昕 于 2021-07-16 设计创作，主要内容包括：本发明涉及新材料领域,尤其涉及一种空心核壳结构Fe-(3)O-(4)@SiO-(2)@PANI吸波剂及制备方法,包括步骤1：Fe-(3)O-(4)纳米球制备；步骤2：Fe-(3)O-(4)纳米球的活化；步骤3：核壳结构Fe-(3)O-(4)@SiO-(2)的制备；步骤4：苯胺单体的提纯；步骤5：Fe-(3)O-(4)@SiO-(2)@PANI复合材料的制备；本发明所提供的制备方法操作简便,实验条件可控,减少了实验步骤,成本低,适合于多种核壳结构材料的制备方法,能够广泛地应用于制备多组分、核壳结构的吸波材料,得到的Fe-(3)O-(4)@SiO-(2)/PANI复合材料,空心核壳结构清晰,纳米颗粒成球状。(The invention relates to the field of new materials, in particular to a hollow core-shell structure Fe 3 O 4 @SiO 2 The @ PANI wave absorbing agent and the preparation method thereof comprise the following steps of 1: fe 3 O 4 Preparing nanospheres; step 2: fe 3 O 4 Activation of nanospheres; and step 3: core-shell structure Fe 3 O 4 @SiO 2 Preparing; and 4, step 4: purifying aniline monomers; and 5: fe 3 O 4 @SiO 2 Preparing a @ PANI composite material; the preparation method provided by the invention is simple and convenient to operate, controllable in experimental conditions, low in cost, suitable for preparation methods of various core-shell structure materials, capable of reducing experimental steps, and widely applied to preparation of multi-component core-shell structure wave-absorbing materials, and the obtained Fe 3 O 4 @SiO 2 the/PANI composite material has clear hollow core-shell structure and spherical nano particles.)

1. Hollow core-shell structure Fe₃O₄@SiO₂@PANIThe preparation method of the wave absorbing agent is characterized by comprising the following steps:

S1、Fe₃O₄preparing nanospheres: dissolving ferric trichloride hexahydrate in ethylene glycol, adding polyethylene glycol and anhydrous sodium acetate, uniformly mixing, reacting by adopting a one-step hydrothermal method, magnetically separating a product, washing by water and anhydrous ethanol, and drying in vacuum to obtain magnetic black powder;

S2、Fe₃O₄activation of nanospheres: dispersing the black powder obtained in the step 1 and polyvinylpyrrolidone in water, uniformly stirring, and then carrying out magnetic separation on the product to obtain activated Fe₃O₄The nanospheres are washed by water and absolute ethyl alcohol and then dried;

s3 core-shell structure Fe₃O₄@SiO₂The preparation of (1): preparing a mixed solution of absolute ethyl alcohol, water and ammonia water, and adding activated Fe₃O₄Ultrasonically dispersing nanospheres, dropwise adding ethyl orthosilicate, and stirring the mixed solution at room temperature; carrying out suction filtration on a product after reaction, washing a precipitate by water and absolute ethyl alcohol, and drying in vacuum to obtain the Fe with the core-shell structure₃O₄@SiO₂A complex;

S4、Fe₃O₄@SiO₂preparation of @ PANI composite material: fe obtained in step S3₃O₄@SiO₂Uniformly dispersing the compound in water, adding aniline monomer, performing ultrasonic dispersion, then adding hydrochloric acid and ammonium persulfate, stirring until the color of the solution changes from reddish brown to blackish green, and preparing to obtain Fe₃O₄@SiO₂@ PANI complex.

2. Hollow core-shell structure Fe according to claim 1₃O₄@SiO₂The preparation method of the @ PANI wave absorbing agent is characterized by comprising the following steps: in the step S1, the feeding ratio of the ferric chloride hexahydrate, the glycol, the polyethylene glycol 2000 and the anhydrous sodium acetate is 1.35g to 40mL to 1g to 3-4 g; fe described in step S2₃O₄The mol ratio of the nanospheres to the polyvinylpyrrolidone is 1: 1-2; in the mixed solution described in step S3The volume ratio of the absolute ethyl alcohol to the deionized water to the ammonia water is 4:1: 0.1-0.2; the molar ratio of the hydrochloric acid to the ammonium persulfate in the step S4 is 3-4: 1.

3. Hollow core-shell structure Fe according to claim 1₃O₄@SiO₂The preparation method of the @ PANI wave absorbing agent is characterized by comprising the following steps: in the step S1, the reaction temperature of the hydrothermal method is 200 ℃ and the reaction time is 8 h.

4. Hollow core-shell structure Fe according to claim 1₃O₄@SiO₂The preparation method of the @ PANI wave absorbing agent is characterized by comprising the following steps: the water and absolute ethyl alcohol washing in the step S1-step S4 are repeated for multiple times; the water is deionized water.

5. Hollow core-shell structure Fe according to claim 1₃O₄@SiO₂The preparation method of the @ PANI wave absorbing agent is characterized by comprising the following steps: in the step S3, the ultrasonic dispersion time is 10 min; the stirring is mechanical stirring for 10 hours; the vacuum drying temperature is 60 ℃ and the vacuum drying time is 24 h.

6. Hollow core-shell structure Fe according to claim 1₃O₄@SiO₂The preparation method of the @ PANI wave absorbing agent is characterized by comprising the following steps: in the step S4, the aniline monomer needs to be purified, and the specific method is as follows: and (3) distilling aniline under reduced pressure, heating to 130 ℃, starting to collect fractions which are colorless transparent liquids, and then heating to 140 ℃ for continuous distillation for 2 hours to obtain purified aniline monomers.

7. Hollow core-shell structure Fe according to claim 1₃O₄@SiO₂The preparation method of the @ PANI wave absorbing agent is characterized by comprising the following steps: the ultrasonic dispersion time in the step S4 is 10 min; the stirring is mechanical stirring for 24 h.

8. Hollow core-shell structure Fe₃O₄@SiO₂The @ PANI wave absorbing agent is characterized in that: the wave absorber is prepared by the preparation method of any one of claims 1 to 7.

Technical Field

The invention relates to the field of new materials, in particular to a hollow core-shell structure Fe₃O₄@SiO₂A @ PANI wave absorbing agent and a preparation method thereof.

Background

The rapid development of electronic information technology brings great convenience to the production and life of people for electronic equipment such as satellite communication, mobile phones, radars and the like, however, electromagnetic pollution caused by electromagnetic wave radiation, interference and the like greatly harms the living environment of human beings. Therefore, the wave-absorbing material has wide application in both military and civil use. Military affairs, the wide application of radar reconnaissance technology makes national security greatly threatened, therefore, stealth technology can be adopted to defend the recognition, positioning and tracking of radar, and the survivability of weaponry on the battlefield is improved. For civil use, the electromagnetic wave absorbing material can be used as an anechoic room material, an electromagnetic wave shielding and electromagnetic wave absorbing material in buildings and textiles. Therefore, research into high-performance electromagnetic wave absorbing materials is becoming more urgent.

However, as can be known from the searched documents, the existing developed and relatively mature wave-absorbing materials include magnetic materials, carbon materials, conductive polymer materials, etc., and although single-component wave-absorbing materials have certain advantages, they have some disadvantages when being used as wave-absorbing materials alone: the magnetic material mainly has the defects of high density, high processing cost, easy corrosion and the like, the carbon material has poor impedance matching and poor absorption performance, and the conductive polymer material has poor stability, so that the requirements of wide frequency band, low density, strong absorption, good heat resistance and oxidation resistance of the absorbing material in the current times are difficult to meet, and therefore, the development direction of the absorbing material for the electromagnetic wave is to compound different types of materials. According to the composite material, a ferromagnetic material is selected, and silicon dioxide and a conductive polymer material form a hollow core-shell structure, so that the magnetic loss and the dielectric loss of the composite material are improved aiming at the defects of a single-component wave-absorbing material, the wave-absorbing performance is excellent, and the development direction of the current wave-absorbing material is met.

Disclosure of Invention

In order to solve the problems, the invention provides a hollow core-shell structure [email protected] [email protected] PANI wave absorbing agent and a preparation method thereof, which avoid the defects of single-component wave absorbing materials, and the obtained wave absorbing agent has controllable processing performance and excellent wave absorbing performance, and adopts the following technical scheme:

hollow core-shell structure Fe₃O₄@SiO₂The preparation method of the @ PANI wave absorbing agent comprises the following steps:

S1、Fe₃O₄preparing nanospheres: dissolving ferric trichloride hexahydrate in ethylene glycol, adding polyethylene glycol and anhydrous sodium acetate, uniformly mixing, reacting by adopting a one-step hydrothermal method, magnetically separating a product, washing by water and anhydrous ethanol, and drying in vacuum to obtain magnetic black powder;

S2、Fe₃O₄activation of nanospheres: dispersing the black powder obtained in the step 1 and polyvinylpyrrolidone in water, uniformly stirring, and then carrying out magnetic separation on the product to obtain activated Fe₃O₄The nanospheres are washed by water and absolute ethyl alcohol and then dried;

s3 core-shell structure Fe₃O₄@SiO₂The preparation of (1): preparing a mixed solution of absolute ethyl alcohol, water and ammonia water, and adding activated Fe₃O₄Ultrasonically dispersing nanospheres, dropwise adding ethyl orthosilicate, and stirring the mixed solution at room temperature; carrying out suction filtration on a product after reaction, washing a precipitate by water and absolute ethyl alcohol, and drying in vacuum to obtain the Fe with the core-shell structure₃O₄@SiO₂A complex;

S4、Fe₃O₄@SiO₂preparation of @ PANI composite material: fe obtained in step S3₃O₄@SiO₂Uniformly dispersing the compound in water, adding aniline monomer, performing ultrasonic dispersion, then adding hydrochloric acid and ammonium persulfate, stirring until the color of the solution changes from reddish brown to blackish green, and preparing to obtain Fe₃O₄@SiO₂@ PANI complex.

Further, in step S1, ferric chloride hexahydrate and ethylene glycolThe feeding ratio of the alcohol to the polyethylene glycol 2000 to the anhydrous sodium acetate is 6g to 10mL to 1g to 18-20 g; fe described in step S2₃O₄The mol ratio of the nanospheres to the polyvinylpyrrolidone is 1: 1-2; the volume ratio of the absolute ethyl alcohol to the deionized water to the ammonia water in the mixed solution in the step S3 is 4:1: 0.1-0.2; the molar ratio of the hydrochloric acid to the ammonium persulfate in the step S4 is 3-4: 1.

Further, in the step S1, the hydrothermal reaction temperature is 200 ℃ and the time is 8 h.

Further, the water and absolute ethyl alcohol washing in the step S1-step S4 are repeated washing times; the water is deionized water.

Further, the ultrasonic dispersion time in step S3 is 10 min; the stirring is mechanical stirring for 10 hours; the vacuum drying temperature is 60 ℃ and the vacuum drying time is 24 h.

Further, in step S4, the aniline monomer needs to be purified, and the specific method is as follows: and (3) distilling aniline under reduced pressure, heating to 130 ℃, starting to collect fractions which are colorless transparent liquids, and then heating to 140 ℃ for continuous distillation for 2 hours to obtain purified aniline monomers.

Further, the ultrasonic dispersion time in step S4 is 10 min; the stirring is mechanical stirring for 24 h.

Hollow core-shell structure Fe₃O₄@SiO₂The @ PANI wave absorbing agent is prepared by adopting the preparation method.

Compared with the prior art, the invention has the beneficial effects that:

the invention provides a hollow core-shell structure Fe₃O₄@SiO₂The @ PANI wave absorbing agent is prepared by adopting a one-step hydrothermal method₃O₄Nanospheres, and then preparing Fe with a core-shell structure by adopting a solution mixing method₃O₄@SiO₂Nanospheres, and finally adding a certain amount of Fe with a core-shell structure₃O₄@SiO₂The nanospheres are compounded with aniline monomers to prepare the hollow core-shell structure Fe₃O₄@SiO₂The @ PANI composite material is used as a wave absorbing agent. The preparation methodThe method has simple operation, controllable experimental conditions, reduced experimental steps and low cost, is suitable for the preparation method of various core-shell structure materials, can be widely applied to the preparation of multi-component core-shell structure wave-absorbing materials, and can obtain Fe₃O₄@SiO₂The @ PANI composite material has clear hollow core-shell structure and spherical nano particles.

Drawings

FIG. 1 is Fe₃O₄Schematic illustration of nanospheres;

FIG. 2 shows Fe of core-shell structure₃O₄@SiO₂Schematic illustration of nanospheres;

FIG. 3 is Fe of hollow core-shell structure₃O₄@SiO₂Schematic of @ PANI composite;

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below, 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.

The invention provides a hollow core-shell structure Fe₃O₄@SiO₂The preparation method of the @ PANI wave absorbing agent comprises the following steps:

step 1: fe₃O₄Preparing nanospheres: FeCl is added₃·6H₂Dissolving O in 40mL of ethylene glycol, and adding CH₃COONa and 1.0000g polyethylene glycol 2000, of which FeCl₃·6H₂O and CH₃The molar ratio of COONa is 1: 5-6, the mixture is uniformly mixed, a one-step hydrothermal method is adopted for reaction for 8 hours at the temperature of 200 ℃, products are separated by magnetic separation, water washing and alcohol washing are carried out for multiple times, and magnetic black powder, namely Fe, is obtained after vacuum drying₃O₄Nanospheres.

Step 2: fe₃O₄Activation of nanospheres: fe obtained in the step 1₃O₄The nanospheres and PVP are dispersed in deionized water at a molar ratio of 1: 1-2 and are uniformly stirred, and then the magnetic field is appliedSeparating the product by separation, the activated Fe obtained₃O₄The nanospheres are repeatedly washed by deionized water and absolute ethyl alcohol and dried for 24h at 60 ℃.

And step 3: core-shell structure Fe₃O₄@SiO₂The preparation of (1): firstly, preparing a mixed solution of absolute ethyl alcohol, deionized water and ammonia water with a molar ratio of 4:1: 0.1-0.2, and then, activating Fe₃O₄Dispersing nanosphere in the above mixture, ultrasonic treating for 10min, and adding dropwise TEOS (tetraethyl orthosilicate) containing activated Fe₃O₄The mol ratio of the nanospheres to TEOS is 1: 3-4, and the mixed solution is stirred for 10 hours at room temperature. Finally, carrying out suction filtration on a product after reaction, repeatedly washing the precipitate with water and alcohol, and carrying out vacuum drying for 24h at the temperature of 60 ℃ to obtain the Fe with the core-shell structure₃O₄@SiO₂And (c) a complex.

And 4, step 4: and (3) purifying aniline monomers: distilling aniline under reduced pressure, heating to 130 ℃, collecting fractions which are colorless transparent liquid, then heating to 140 ℃, continuously distilling for 2h to obtain purified aniline monomer, and finally sealing and refrigerating the purified aniline monomer.

And 5: fe₃O₄@SiO₂Preparation of @ PANI composite material: weighing the product obtained in the step 3, uniformly dispersing the product in deionized water, adding a certain amount of purified aniline monomer, continuing to perform ultrasonic treatment for 10min, adding hydrochloric acid and ammonium persulfate in a molar ratio of 3-4: 1, mechanically stirring for 24h to change the color of the solution from red brown to dark green, and preparing Fe₃O₄@SiO₂@ PANI complex. And carrying out suction filtration on the obtained product, repeatedly washing with water and alcohol, and carrying out vacuum drying at 60 ℃ for 24 h.

Example 1

Step 1: 1.3500g of FeCl₃·6H₂Dissolving O in 40mL of ethylene glycol, and adding 3.6000gCH₃COONa·3H₂And O and 1.0000g of polyethylene glycol 2000 are uniformly mixed, a one-step hydrothermal method is adopted for reaction at 200 ℃ for 8 hours, the product is separated by magnetic separation, and the mixture is washed by water and alcohol for multiple times and dried in vacuum to obtain magnetic black powder, namely the Fe3O4 nanospheres.

Step 2: 0.5g of Fe obtained in the step 1₃O₄Dispersing nanospheres and 1g PVP in 200mL deionized water, stirring uniformly, then magnetically separating the product, and carrying out magnetic separation on the obtained activated Fe₃O₄The nanospheres are repeatedly washed by deionized water and absolute ethyl alcohol and dried for 24h at 60 ℃.

And step 3: firstly, a mixed solution of 80mL of absolute ethyl alcohol, 20mL of deionized water and 2mL of ammonia water is prepared, and then 0.2g of activated Fe₃O₄The nanospheres were dispersed in the above mixture, sonicated for 10min, then 0.6ml of TEOS (ethyl orthosilicate) was added dropwise, and the mixture was stirred at room temperature for 10 h. Finally, carrying out suction filtration on a product after reaction, repeatedly washing the precipitate with water and alcohol, and carrying out vacuum drying for 24h at the temperature of 60 ℃ to obtain the Fe with the core-shell structure₃O₄@SiO₂And (c) a complex.

And 4, step 4: distilling aniline under reduced pressure, heating to 130 ℃, collecting fractions which are colorless transparent liquid, then heating to 140 ℃, continuously distilling for 2h to obtain purified aniline monomer, and finally sealing and refrigerating the purified aniline monomer.

And 5: weighing the product obtained in the step 3, uniformly dispersing in deionized water, adding a certain amount of purified aniline monomer, continuing to perform ultrasonic treatment for 10min, adding 1mL of hydrochloric acid and 1.000g of ammonium persulfate, mechanically stirring for 24h to change the color of the solution from red brown to dark green, and preparing Fe₃O₄@SiO₂@ PANI complex. And carrying out suction filtration on the obtained product, repeatedly washing with water and alcohol, and carrying out vacuum drying at 60 ℃ for 24 h.

Example 2

Step 1: 1.3500g of FeCl₃·6H₂Dissolving O in 40mL of ethylene glycol, and adding 3.6000gCH₃COONa·3H₂O and 1.0000g of polyethylene glycol 2000, uniformly mixing, reacting for 8 hours at 200 ℃ by adopting a one-step hydrothermal method, magnetically separating a product, washing with water and alcohol for multiple times, and drying in vacuum to obtain magnetic black powder, namely Fe₃O₄Nanospheres.

Step 2: 0.5g of Fe obtained in the step 1₃O₄Dispersing nanospheres and 1g PVP in 200mL deionized water, stirring uniformly, then magnetically separating the product, and carrying out magnetic separation on the obtained activated Fe₃O₄The nanospheres are repeatedly washed by deionized water and absolute ethyl alcohol and dried for 24h at 60 ℃.

And step 3: firstly, a mixed solution of 80mL of absolute ethyl alcohol, 20mL of deionized water and 2mL of ammonia water is prepared, and then 0.2g of activated Fe₃O₄The nanospheres were dispersed in the above mixture, sonicated for 10min, then 0.6ml of TEOS (ethyl orthosilicate) was added dropwise, and the mixture was stirred at room temperature for 10 h. Finally, carrying out suction filtration on a product after reaction, repeatedly washing the precipitate with water and alcohol, and carrying out vacuum drying for 24h at the temperature of 60 ℃ to obtain the Fe with the core-shell structure₃O₄@SiO₂And (c) a complex.

And 4, step 4: distilling aniline under reduced pressure, heating to 130 ℃, collecting fractions which are colorless transparent liquid, then heating to 140 ℃, continuously distilling for 2h to obtain purified aniline monomer, and finally sealing and refrigerating the purified aniline monomer.

And 5: weighing the product obtained in the step 3, uniformly dispersing in deionized water, adding a certain amount of purified aniline monomer, continuing to perform ultrasonic treatment for 10min, adding 1mL of hydrochloric acid and 1.000g of ammonium persulfate, mechanically stirring for 24h to change the color of the solution from red brown to dark green, and preparing Fe₃O₄@SiO₂@ PANI complex. And carrying out suction filtration on the obtained product, repeatedly washing with water and alcohol, and carrying out vacuum drying at 60 ℃ for 24 h.

Example 3

Step 1: 1.3500g of FeCl₃·6H₂Dissolving O in 40mL of ethylene glycol, and adding 3.6000gCH₃COONa·3H₂O and 1.0000g of polyethylene glycol 2000, uniformly mixing, reacting for 8 hours at 200 ℃ by adopting a one-step hydrothermal method, magnetically separating a product, washing with water and alcohol for multiple times, and drying in vacuum to obtain magnetic black powder, namely Fe₃O₄Nanospheres.

Step 2: 0.5g of Fe obtained in the step 1₃O₄The nanosphere and 1g of PVP are dispersed in 200mL of deionized water and stirred uniformlyThen magnetically separating the product, and subjecting the obtained activated Fe₃O₄The nanospheres are repeatedly washed by deionized water and absolute ethyl alcohol and dried for 24h at 60 ℃.

And step 3: firstly, a mixed solution of 80mL of absolute ethyl alcohol, 20mL of deionized water and 2mL of ammonia water is prepared, and then 0.2g of activated Fe₃O₄The nanospheres were dispersed in the above mixture, sonicated for 10min, then 0.6ml of TEOS (ethyl orthosilicate) was added dropwise, and the mixture was stirred at room temperature for 10 h. Finally, carrying out suction filtration on a product after reaction, repeatedly washing the precipitate with water and alcohol, and carrying out vacuum drying for 24h at the temperature of 60 ℃ to obtain the Fe with the core-shell structure₃O₄@SiO₂And (c) a complex.

And 4, step 4: distilling aniline under reduced pressure, heating to 130 ℃, collecting fractions which are colorless transparent liquid, then heating to 140 ℃, continuously distilling for 2h to obtain purified aniline monomer, and finally sealing and refrigerating the purified aniline monomer.

And 5: weighing the product obtained in the step 3, uniformly dispersing in deionized water, adding a certain amount of purified aniline monomer, continuing to perform ultrasonic treatment for 10min, adding 1mL of hydrochloric acid and 1.000g of ammonium persulfate, mechanically stirring for 24h to change the color of the solution from red brown to dark green, and preparing Fe₃O₄@SiO₂@ PANI complex. And carrying out suction filtration on the obtained product, repeatedly washing with water and alcohol, and carrying out vacuum drying at 60 ℃ for 24 h.

As shown in FIGS. 1 to 3, Fe obtained by the present invention₃O₄@SiO₂The @ PANI composite material has clear hollow core-shell structure and spherical nano particles.

Although only the preferred embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art, and all changes are encompassed in the scope of the present invention.