Preparation method of large-sized graphene oxide slice layer with high mechanical strength

Abstract

The invention relates to a preparation method of a large-sized graphene oxide slice layer with high mechanical strength. The preparation method comprises the following steps: firstly, adding potassium peroxodisulfate, phosphorus pentoxide and concentrated sulfuric acid to pretreat graphite, then further oxidizing the graphite with potassium permanganate under a condition of an ice bath, controlling the temperature to 4 to 6 DEG C, after the materials are stirred and diluted for a period of time, at the end of stirring, adding deionized water and hydrogen peroxide immediately for reaction, controlling the temperature to 14 to 18 DEG C in the diluting process, finally performing multi-step centrifugation, adding NaCl with the concentration of 5 mol / L into a graphene oxide disperse solution for separation of a graphene oxide slice layer, dissolving NaCl, and when the NaCl reaches a saturation degree of 30 percent, separating out precipitates; and allowing the solution to stand still over night, and removing supernate, thus obtaining the large-sized graphene oxide slice layer. According to the method, the preparation process is safe and simple; the large-sized graphene oxide slice layer with the size of 7 to 8 [mu]m can be prepared, and the size distribution is concentrated; the slice layer is high in mechanical strength; the preparation period is short; and the large-sized graphene oxide slice layer has a good application prospect.

Description

technical field [0001] The invention belongs to the field of preparation of large-scale graphene oxide sheets, in particular to a preparation method of large-size graphene oxide sheets with high mechanical strength. Background technique [0002] The performance of graphene oxide is closely related to its lateral size. The smaller the lateral size, the more hydrophilic groups, the better the water solubility, the stronger the biocompatibility, and the greater the biotoxicity; the larger the lateral size, the greater the surface Oxygen-containing functional groups are relatively few, the hydrophobicity is strong, and the surface defects are few, so its mechanical strength is enhanced. Temperature is an important condition for controlling the size of graphene oxide sheets. The lower the temperature, the smaller the degree of surface oxidation of graphene oxide and the fewer oxidized functional groups it contains, and the larger the size of graphene oxide sheets obtained after u...

AI Technical Summary

Problems solved by technology

These improved methods for the preparation of graphene oxide in KMnO 4 Oxidation reaction and deionized water dilution process will be heated to 80 ℃ or even higher temperature, the reaction is violent, has a certain degree of danger, and the preparation cycle is long, the operation is complicated, the yield is low, and the prepared graphene oxide has low mechanical strength

At present, the multi-step centrifugation method is used to control the size of graphene oxide to separate it, but the separation effect of this separation method is not good, and the large-sized graphene oxide sheets are still doped with small-sized graphene oxide sheets layer, which needs to be further separated by salting out

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