Crystalline graphene as well as preparation method and application thereof

Abstract

The invention provides crystalline graphene, a preparation method thereof and modified asphalt, and the preparation method comprises the following steps: (1) placing high-activity Ca (OH) 2 powder in a reaction furnace, heating to a preset temperature in an inert protective atmosphere, and keeping the temperature; wherein the content of Ca (OH) 2 in the high-activity Ca (OH) 2 powder is not less than 90% by mass, the content of Mg (OH) 2 is 0.1-5% by mass, and the balance is impurities; (2) introducing a carbon source into the reaction furnace, and carrying out chemical vapor deposition reaction to obtain a solid-phase product; (3) carrying out acid pickling on the solid-phase product to obtain a crystalline graphene blank; and (4) placing the crystalline graphene blank in a furnace containing hydrogen or carbon dioxide atmosphere, and performing high-temperature etching to obtain the crystalline graphene. The crystalline graphene can be highly matched with an asphalt mixture, and the high and low temperature performance of asphalt is improved.

Description

technical field [0001] The invention belongs to the technical field of novel materials and their preparation, in particular to a crystalline graphene and its preparation method and application. Background technique [0002] Road asphalt pavement is widely used all over the world. At present, more than 95% of the roads in the world are asphalt pavement, and asphalt, as a hydrophobic material, is also widely used in the field of building waterproofing. The existing asphalt modified materials, especially the large-scale use of SBS, have solved the problems of poor temperature stability, poor water resistance, poor aging resistance and short service life of ordinary asphalt to a certain extent. [0003] However, with the rapid development of the economy and society, the traffic volume increases sharply, the traffic load increases rapidly, and the service life of asphalt roads becomes shorter. In recent years, graphene materials and technologies have become a new trend in asphal...

AI Technical Summary

Problems solved by technology

Two-dimensional graphene powder can properly improve the high-temperature performance of asphalt, but reduces the low-temperature performance of asphalt

Due to the van der Waals force, two-dimensional graphene is prone to self-agglomeration, resulting in low utilization of its specific surface area, and an overlapping interface appears in the process of forming a macroscopic body, and the interaction between the interfaces is van der Waals force, which greatly reduces The strength of the action reduces the performance of the macroscopic body, and the compatibility with asphalt is poor; some use three-dimensional graphene, but the three-dimensional graphene is not suitable for asphalt modification due to the characteristics of its preparation process, and the three-dimensional graphene is not suitable for asphalt modification. The surface of graphene material contains a large number of oxygen-containing functional groups or functional groups such as hydroxyl, carboxyl and epoxy groups. Although it is easy to mix with asphalt, these functional groups are easily sensitized to generate hydrocarbon oxygen radicals and Hydroxyl radicals, and trigger a series of free radical chain reactions, leading to premature aging of asphalt; After partial oxidation, graphene has oxygen-containing groups, and the mixture with asphalt is only a bridge between these functional groups. Graphene and asphalt cannot form a homogeneous blend system, at most it is a multi-phase system with microscopic or submicroscopic structure, and The production process for preparing these graphene is complicated, high energy consumption, high production cost, poor environmental protection effect, graphene is expensive, and it is difficult to be applied in large-scale industrialization

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