Graphene aerogel and preparation method and application thereof

A graphene aerogel, graphene hydrogel technology, applied in graphene, electrical components, magnetic field/electric field shielding and other directions, can solve the problems of poor crystallization, fine embedded particle size, and difficulty in deep processing and application of microcrystalline graphite, Achieve the effect of reducing process steps, realizing industrial production and saving preparation time

Active Publication Date: 2018-01-16
苏州涤致良特种防护装备科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Compared with flake graphite, the crystallization of microcrystalline graphite is not as complete as flake graphite, and the embedded particles are too fine. Impurity minerals are mostly present in graphite microcrystals in the form of dissemination or interlamellar inclusions. Most of the impurities are wrapped in microcrystalline graphite, giving Deep processing and application of microcrystalline graphite bring difficulties

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  • Graphene aerogel and preparation method and application thereof
  • Graphene aerogel and preparation method and application thereof
  • Graphene aerogel and preparation method and application thereof

Examples

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reference example 1

[0075] Preparation of graphene oxide:

[0076] 1) Low-temperature pre-oxidation: Add 1.5g of microcrystalline graphite powder and 1.5g of sodium nitrate powder into 40mL of concentrated sulfuric acid, and stir and react in an ice-water bath at 0°C for 1 hour to obtain a low-temperature pre-oxidized graphite solution;

[0077] 2) Low-temperature oxidation: Divide 4.5g of potassium permanganate into 4 parts, and add it to the low-temperature pre-oxidized graphite solution obtained in step 1) every 30 minutes, and stir and react in an ice-water bath at 0°C for 2 hours to obtain a low-temperature oxidized graphite solution;

[0078] 3) Medium-temperature oxidation: Put the low-temperature oxidized graphite solution obtained in step 2) into a three-necked flask, stir and react in a medium-temperature water bath at 38°C for 20 hours, and then add 150 mL of deionized water dropwise under constant temperature conditions. The dropping speed of water is 0.3mL / s, when the volume of addi...

Embodiment 1

[0084] (1) Pre-reduction treatment: Add 30 mg of L-ascorbic acid to 10 mL of the graphene oxide solution (pH=5.5) obtained in Reference Example 1 with a mass concentration of 3 mg / mL and mix. The pH value after mixing is 5.6. No adjustment is required. 150W, frequency 40kHz, after ultrasonic dispersion for 5 minutes, pre-reduction treatment was carried out at 80°C for 30 minutes to obtain a semi-reduced graphene hydrogel;

[0085] (2) Final reduction treatment: Add 90 mg of L-ascorbic acid to the semi-reduced graphene hydrogel obtained in step (1), and perform ultrasonic treatment for 1 min at a power of 150 W and a frequency of 40 kHz, and then proceed at 80 ° C. Final reduction treatment for 30 minutes to obtain graphene hydrogel;

[0086] (3) Alkali soaking: Soak the graphene hydrogel obtained in step (2) in a 0.12mol / L potassium hydroxide solution for 3 hours, and replace it with a fresh 0.12mol / L potassium hydroxide solution every 1 hour to continue Soak and wash the hyd...

Embodiment 2

[0094] (1) Pre-reduction treatment: Add 60 mg of L-ascorbic acid to 10 mL of the graphene oxide solution (pH=5.5) obtained in Reference Example 1 with a mass concentration of 3 mg / mL and mix. The pH value after mixing is 5.7. No adjustment is required. 180W, frequency 40kHz, after ultrasonic dispersion for 5 minutes, pre-reduction treatment was carried out at 80°C for 60 minutes to obtain a semi-reduced graphene hydrogel;

[0095] (2) Final reduction treatment: Add 60 mg of L-ascorbic acid to the semi-reduced graphene hydrogel obtained in step (1), and perform ultrasonic treatment for 1 min at a power of 180 W and a frequency of 40 kHz, and then proceed at 80 ° C. Final reduction treatment for 60 minutes to obtain graphene hydrogel;

[0096] (3) Alkali soaking: Soak the graphene hydrogel obtained in step (2) in a 0.1mol / L sodium hydroxide solution for 4 hours, and replace it with a fresh 0.1mol / L sodium hydroxide solution every 1 hour to continue Soak and wash the hydrogel un...

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Abstract

The invention discloses a graphene aerogel and a preparation method and an application thereof, wherein the aerogel is prepared from the following method: (1) pre-reduction treatment: adding a reducing agent to a graphene oxide solution, mixing, carrying out ultrasonic dispersion, and carrying out pre-reduction treatment, to obtain a semi-reduction graphene hydrogel; (2) final reduction treatment:adding a reducing agent, carrying out ultrasonic treatment, and then carrying out final reduction treatment, to obtain a graphene hydrogel; and (3) acid / alkali soaking: placing the graphene hydrogelin an acid or alkali aqueous solution, soaking, washing the hydrogel to be neutral, sucking out the excess liquid, and carrying out freeze drying, to obtain the graphene aerogel. The graphene aerogelis applied to electromagnetic wave absorption materials. The graphene aerogel obtained by the method has small density and good integrality, and has a certain mechanical strength and resillency; the prepared wave absorbing material has good electromagnetic wave absorption performance, and the wave absorbing performance can be adjusted; and the method has the advantages of simple process, short production cycle, low cost and good benefits, and is suitable for industrialized production.

Description

technical field [0001] The invention relates to an airgel and its preparation method and application, in particular to a graphene airgel and its preparation method and application. Background technique [0002] Due to its unique microstructure, graphene exhibits excellent performance in the fields of mechanics, electricity, optics, catalysis and environmental protection. Since Mikhailov and Liang et al. have studied the interference and response characteristics of graphene in electromagnetic waves, they have found that graphene is in X Since graphene electrons have nonlinear response characteristics to frequency radiation, nearly 240 literatures on graphene applied to electromagnetic shielding and wave-absorbing materials can be retrieved from SCI Web of Science so far. Researchers in China, the United States, Russia, France, Italy, Turkey, India and South Korea are concerned. Both theory and practice have shown that the microwave absorption of graphene / polymer nanocomposit...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B32/19H05K9/00
Inventor 谢炜廖晨博朱旭坤徐尚匡加才邓应军曾鹤智
Owner 苏州涤致良特种防护装备科技有限公司
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