Preparation method of core-shell magnetic microspheres

A magnetic microsphere and core-shell technology, applied in the field of preparation of core-shell magnetic microspheres, to achieve excellent electrochemical performance and electromagnetic performance, high yield, and the effect of improving electrochemical performance and electromagnetic performance

Active Publication Date: 2020-02-07
DALIAN UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, there are few reports on the preparation of the core-shell structure of magnetic nanosheet-coated carbon spheres as microwave absorbers and electrode materials. In view of this, the development of a magnetic nanosheet-coated carbon with simple process, high yield and good repeatability Spherical microwave absorbers and electrode materials have important practical research significance

Method used

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  • Preparation method of core-shell magnetic microspheres
  • Preparation method of core-shell magnetic microspheres
  • Preparation method of core-shell magnetic microspheres

Examples

Experimental program
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Effect test

Embodiment 1

[0032] Step 1: Weigh 0.4g of resorcinol and dissolve it in 83ml of a mixed reaction solvent with a volume ratio of 7:1:0.3. After the resorcinol is completely dissolved, add 0.56ml of formaldehyde and continue to stir for 24 hours at room temperature. Centrifuge, separate, wash with water and ethanol several times, and dry to obtain phenolic microspheres.

[0033] Step 2: Weigh 0.5g of phenolic microspheres and 0.0005mol of ferric nitrate and ultrasonically disperse them in a mixed solvent containing 80ml of isopropanol and 15ml of glycerin, inject them into a hydrothermal synthesis kettle with a volume of 100ml and react at 190°C for 12h, and cool naturally to room temperature. After centrifugation, separation, washing with water and ethanol for several times, and drying, put it into a tube furnace for high-temperature calcination at 700°C for 2 hours in an inert atmosphere to obtain carbon / iron tetroxide core-shell magnetic microspheres. from Figure 5 It can be seen from t...

Embodiment 2

[0035] Step 1: Add 3.46ml tetraethyl orthosilicate to 83ml mixed reaction solvent with a volume ratio of 7:1:0.3, add 0.4g resorcinol and 0.56ml formaldehyde after 60min, and continue stirring at room temperature for 24h after adding. Centrifuge, separate, wash with water and ethanol several times, and dry to obtain silica / phenolic core-shell microspheres.

[0036] Step 2: Weigh 0.45g of silica / phenolic core-shell microspheres and 0.0005mol of ferric nitrate and ultrasonically disperse them in a mixed solvent containing 80ml of isopropanol and 15ml of glycerin, inject them into a hydrothermal synthesis kettle with a volume of 100ml and react at 190°C for 8h , naturally cooled to room temperature, centrifuged, separated, washed several times with water and ethanol, dried, put into a tube furnace in an inert atmosphere at 700 ° C for 2 h at high temperature, etched with 1 mol / L sodium hydroxide at 70 ° C for 10 hours, The hollow carbon / Fe3O4 double-shell magnetic microspheres ar...

Embodiment 3

[0038] Step 1: Add 3.46ml tetraethyl orthosilicate to 83ml mixed reaction solvent with a volume ratio of 7:1:0.3, add 0.4g resorcinol and 0.56ml formaldehyde after 60min, and continue stirring at room temperature for 24h after adding. Centrifuge, separate, wash with water and ethanol several times, and dry to obtain silica / phenolic core-shell microspheres.

[0039] Step 2: Weigh 0.3g of silica / phenolic core-shell microspheres and 0.0005mol of ferric nitrate and ultrasonically disperse them in a mixed solvent containing 80ml of isopropanol and 15ml of glycerin, inject them into a hydrothermal synthesis kettle with a volume of 100ml and react at 190°C for 12h , naturally cooled to room temperature, centrifuged, separated, washed with water and ethanol several times, dried, placed in an inert atmosphere in a tube furnace for calcination at 700°C for 2 hours, etched with 1mol / L sodium hydroxide at 60°C for 12 hours, The hollow carbon / Fe3O4 double-shell magnetic microspheres are ob...

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Abstract

The invention provides a preparation method of core-shell magnetic microspheres, and belongs to the technical field of functional material preparation. The preparation method comprises the steps thatfirstly, monodispersed phenolic aldehyde microspheres or monodispersed silicon dioxide phenolic aldehyde core-shell microspheres are synthesized; then the microspheres and ferric salts are dispersed in a mixing solvent containing glycerinum and isopropanol, added into a hydrothermal reaction still for an airtight high-pressure solvothermal reaction, and a phenolic aldehyde microsphere/glycerinum ferric core-shell structure product or a silicon dioxide/phenolic aldehyde/glycerinum ferric core double-shell structure product are correspondingly obtained; and finally, the phenolic aldehyde microsphere/glycerinum ferric core-shell structure product is calcined in an inert atmosphere in a tube furnace to form carbon/ferroferric oxide core-shell magnetic microspheres, and the silicon dioxide/phenolic aldehyde/glycerinum ferric core double-shell structure product is subjected to high-temperature calcination and alkali etching by inert gas to obtain hollow carbon/ferroferric oxide double-shellmicrospheres. The preparation method is simple, magnetic nanosheets and carbon are compounded successfully, the electromagnetic property of the magnetic nanosheets is improved, the nanosheets adoptedon an outer layer can effectively inhibit a skin effect, the prepared products have the excellent electromagnetic property, and the preparation method of the core-shell magnetic microspheres can be used for electromagnetic wave absorption and shielding fields.

Description

technical field [0001] The invention relates to a preparation method of core-shell magnetic microspheres, belonging to the technical field of preparation of functional materials. Background technique [0002] Core-shell microspheres have attracted extensive attention because of their special structure, controllable composition and morphology. Among them, the micro-sheets of iron after high-temperature treatment, the sheet-like structure can enhance the microscopic magnetic properties, and at the same time inhibit the skin effect to a certain extent, the phenolic resin has the advantages of high residual carbon rate, low cost, excellent electrochemical properties and electromagnetic properties. , are widely used in fuel cells, lithium-ion batteries, ultra-supercapacitors and other energy storage components and electromagnetic wave absorption fields. However, there are few reports on the preparation of the core-shell structure of magnetic nanosheet-coated carbon spheres as mi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01J13/06H01F1/11C08G8/22
CPCB01J13/06C08G8/22H01F1/112
Inventor 陈平陈冠震郭翔于祺陈博涵
Owner DALIAN UNIV OF TECH
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