Graphene material classification method

Abstract

The invention discloses a graphene material classification method which comprises the following steps: (1) selecting a graphene material, adding one or more solvents, and carrying out stirring to obtain a graphene material dispersion liquid A of which the concentration is 1-20 mg / mL; (2) under the temperature condition of 0 to 5 DEG C, conducting on first-level or higher-level centrifugation classification treatment on the graphene material dispersion liquid A. Through the combination of different dispersion degrees of graphene of different sizes in the solvents and level centrifugation classification, graphene material classification is realized, and the deprotonation effect of graphene in the organic solvents is weakened or the carbonyl effect is eliminated, so that the formed negative charge can keep the system stability. Therefore, Van der Waals force cannot be blocked by weakening of the electrostatic repulsion effect, and accordingly sedimentation of graphene sheets can be realized; the sedimentation process is accelerated through centrifugation, and accordingly rapid classification can be realized.

Description

technical field [0001] The invention relates to the field of graphene materials, in particular to a classification method for graphene materials. Background technique [0002] Graphene is a two-dimensional material with only one carbon atomic layer thickness, which is a hexagonal honeycomb planar structure formed by sp2 hybridization of carbon atoms. Due to its unique structure, it has excellent electrical conductivity, thermal conductivity, and excellent magnetic, optical, and mechanical properties, so graphene materials are widely used in batteries, coatings, catalysis, medicine, biology and other fields. At present, the methods for preparing graphene include oxidation-reduction method, vapor deposition method, mechanical exfoliation method, etc., among which the oxidation-reduction method is recognized as the most suitable graphene preparation technology for industrial production. For the graphene material itself, its size and sheet thickness often determine the quality ...

AI Technical Summary

Problems solved by technology

[0003] At present, the common classification method is filtration and separation of membrane materials. This method utilizes the difference in pore size of membrane materials to classify graphene materials, but the yield of this method is low, and the pores are easily blocked during the filtration process, so industrial production cannot be carried out; Another kind of method is physical sedimentation, and this method is that graphene solution is left standstill, utilizes the different settling speeds between different sheet sizes to achieve the purpose of separation, this method often needs to stand for a long time, and the efficiency is very low and The grading effect is not obvious; some people use the method of adding reagents to adjust the pH for grading. The biggest disadvantage of this method is that the introduction of external impurities leads to the increase of subsequent impurity removal steps, which may change the functional group structure of graphene itself while increasing economic costs.

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