High-strength and high-elasticity graphene aerogel free of slag falling and preparation method thereof

Abstract

The invention relates to a high-strength and high-elasticity graphene aerogel free of slag falling and a preparation method thereof. The method comprises the following steps of: well mixing a graphene oxide solution, a dimethyl siloxane oligomer and a basic catalyst, and carrying out pre-hydrolysis and pre-organization reaction to obtain a pre-lapped graphene oxide precursor; adding a foaming agent, a reducing agent and a dimethyl siloxane cross-linking agent into the pre-lapped graphene oxide precursor, stirring well, and then carrying out high-temperature reaction to obtain modified graphene wet gel; and freezing, freeze-drying and thermally annealing the modified graphene wet gel in sequence to obtain the high-strength and high-elasticity graphene aerogel free of slag falling. The graphene aerogel disclosed by the invention has a structure in which a polydimethylsiloxane network and a graphene skeleton network structure penetrate through each other, and the polydimethylsiloxane network plays a role in enhancing lap joint of graphene lamellas, especially edges, so that the problem that the graphene aerogel is easy to slag and low in strength is effectively solved.

Description

Technical field [0001] The present invention belongs to the field of graphene gel technology, and the method of preparation of graphene gas gels, and more particularly to a high-strength high-elastic graphene gas gel and preparation method thereof without removing slag. Background technique [0002] High-elastic graphene gel is a graphene sheet having a certain elasticity as a construction primitive, through various physical or chemical three-dimensional mutual attachment, forming a porous graphene three-dimensional macro Assembly. Elastic graphene gas gel has many excellent characteristics such as ultra high porosity, large specific surface area, ultra-low density, ultra-low-density, excellent conductivity, ultra-low thermal conductivity, etc. Mechanical properties, this elastic material having a larger reversible variable function has broad demand in various engineering applications including insulation, adsorption, sensor, causing strong concern. However, due to the insufficie...

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Problems solved by technology

Chinese patent application CN108525649A uses polyethyleneimine as the cross-linking agent of the graphene oxide precursor, uses sodium alginate as the reinforcing material, and the sodium alginate cross-links under the action of calcium ions to form graphite oxide with an interpenetrating network structure Graphene airgel, prepared a high-strength graphene airgel material, but without reduction reaction and high-temperature thermal annealing, the overlap between graphene sheets is relatively weak

Chinese patent application CN111100291A reports a method for preparing polybenzoxazine-enhanced three-dimensional graphene foam. Polybenzoxazine polymers are introduced into the three-dimensional graphene system, which can not only play the role of cross-linked graphene sheets, but also It can disperse and transfer stress, and then realize the construction of high-strength three-dimensional graphene structure. However, benzoxazine monomer, which is a raw material that pollutes the environment and is harmful to the body, is used in the preparation process, and it must be used later. A large amount of organic solvents are used for cleaning, which is not environmentally friendly

[0004] In short, the preparation technology of highly elastic graphene airgel has been greatly developed, but the strength of the prepared material still needs to be further improved, and the more serious Yes, there is no report trying to solve the problem of graphene airgel slag drop. Using a simple and easy method to prepare high-strength and high-elastic graphene aerogel without slag drop is of great significance for promoting its engineering application

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