Method for large-scale, continuous and efficient graphite oxide stripping

A graphite and high-efficiency technology, applied in the field of large-scale continuous and efficient exfoliation of graphite oxide, can solve the problems of low concentration, low production efficiency, poor dispersion stability, etc., and achieve the effect of continuous and fast production process, high production efficiency and controllable size.

Active Publication Date: 2016-12-14
NANJING UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the graphene oxide prepared by mechanical exfoliation is mostly 2-10 layers or thin-layer graphite oxide microflakes, and the microscopic uniform dispersion of the exfoliated solid product in the solution cannot be achieved, and the resulting dispersion has poor stability.
[0006] At present, the exfoliation method of graphite oxide generally has p

Method used

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  • Method for large-scale, continuous and efficient graphite oxide stripping
  • Method for large-scale, continuous and efficient graphite oxide stripping
  • Method for large-scale, continuous and efficient graphite oxide stripping

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0043] Use the optimized Hummers method to add 50 mesh natural flake graphite to 98wt% concentrated sulfuric acid, stir well and add potassium permanganate in an ice water bath, react for 20-30 minutes and then raise the temperature to 50°C, fully react to obtain graphite oxide, use deionization After the water is diluted, an appropriate amount of hydrogen peroxide is added, and then the graphite oxide is washed with deionized water in the purification equipment until the pH of the filtrate is 6.0-7.0. The obtained graphite oxide layer has a spacing of 0.7-0.9 nm, and diffraction peaks appear at 2θ of 9-12°.

[0044] The graphite oxide slurry discharged from the purification equipment is transported to the pipeline circulating high-speed shearing equipment, and its concentration is diluted to 0.5g / L by adding deionized water. The round-hole stator head is used and the outlet valve is closed at 1000 revolutions per minute. Shearing and peeling for 20 minutes at a rotation speed of...

Embodiment 2

[0050] Use Hummers method to add 800 mesh natural flake graphite and NaNO to 98wt% concentrated sulfuric acid under ice water bath 3 And potassium permanganate, stir for 2h and then raise the temperature to 60℃, fully react to obtain graphite oxide, dilute with deionized water and add proper amount of hydrogen peroxide, then wash the graphite oxide with deionized water in the purification equipment until the filtrate pH is 6.0 -7.0. The obtained graphite oxide layer has a spacing of 0.7-0.9 nm, and diffraction peaks appear at 2θ of 9-12°.

[0051] Add deionized water to the graphite oxide discharged from the purification equipment, dilute its concentration to 4g / L, enter the reactor-type high-speed shearing equipment, adopt a claw-type stator head, and shear and peel for 8 minutes at a speed of 12000 rpm to obtain Partially exfoliated graphene oxide dispersion.

[0052] After high-speed shearing, the partially peeled graphene oxide dispersion is pumped into a continuous trough ult...

Embodiment 3

[0057] Use the Staudenmaier method to add 10000 mesh natural flake graphite to the mixture of 98wt% concentrated sulfuric acid and 65wt% nitric acid, stir thoroughly in an ice-water bath, add potassium nitrate, react for 24h to obtain graphite oxide, dilute with deionized water and oxidize in the purification equipment The graphite was washed with deionized water until the pH of the filtrate was 6.0-7.0. The obtained graphite oxide layer has a spacing of 0.7-0.9 nm, and diffraction peaks appear at 2θ of 9-12°.

[0058] Add deionized water to the graphite oxide discharged from the purification equipment, dilute its concentration to 10g / L, enter the probe-type high-speed shearing equipment, adopt a long-hole stator head, shear and peel for 20s at a speed of 30,000 revolutions / minute, and obtain a part Exfoliated graphene oxide dispersion.

[0059] The partially peeled graphene oxide dispersion after high-speed shearing enters the continuous tube ultrasonic equipment directly under t...

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Abstract

The invention provides a method for large-scale, continuous and efficient graphite oxide stripping. The method comprises the following steps that purified and diluted graphite oxide dispersion liquid is delivered to a high-speed shear device, a high-speed water flow produced in the process of a high-speed mechanical shear method bumps and impacts graphite oxide to perform rapid macroscopic dispersion and partial stripping of graphite oxide; the graphite oxide dispersion liquid is introduced to a continuous ultrasonic device, the partially stripped graphite oxide having good macroscopic dispersion is rapidly stripped to obtain a single layer by virtue of a high-pressure and high-speed microjet produced by the ultrasonic cavitation effect in the process of an ultrasonic stripping method, and the microcosmic, uniformly dispersed and stable graphite oxide dispersion liquid is obtained. The method strengthens dispersion and stripping of the graphite oxide through a coupling shear field and an ultrasonic field, the obtained graphene oxide is high in single-layer rate, high in concentration and controllable in size, has the advantages of being continuous and rapid in production process, high in production efficiency, low in cost and the like and is suitable for large-scale production of graphite oxide and graphene.

Description

Technical field [0001] The invention belongs to the technical field of novel nanomaterials, and specifically relates to a method for large-scale continuous and efficient exfoliation of graphite oxide. Background technique [0002] Graphene has received extensive attention for its excellent properties in optics, electricity, mechanics, and heat. Its industrialization and large-scale applications have become current hot spots. Graphene preparation methods mainly include mechanical peeling method, chemical vapor deposition method, epitaxial growth method, redox method, etc. Among them, mechanical peeling method, chemical vapor deposition method, epitaxial growth method can produce graphene with fewer defects, but Its production capacity is difficult to expand and is not suitable for large-scale production of graphene. The chemical redox method is currently one of the most promising methods for the preparation of graphene on a low-cost scale. The chemical redox method generally fir...

Claims

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Application Information

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IPC IPC(8): C01B31/04
CPCC01B2204/02C01B2204/32C01P2004/04
Inventor 暴宁钟李畅沈丽明史叶勋何大方
Owner NANJING UNIV OF TECH
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