Graphene water-based slurry and preparation method thereof

Abstract

The invention provides a preparation method of graphene water-based slurry, which comprises the steps of placing an expanded graphite aqueous solution containing a dispersing agent in liquid phase stripping equipment, and carrying out liquid phase stripping on the expanded graphite to prepare the graphene water-based slurry, wherein the dispersing agent is a segmented copolymer of polyethylene oxide and polypropylene oxide, and in the segmented copolymer, the molar ratio of an ethylene oxide monomer unit to a polypropylene oxide monomer unit is 1: 9 to 4: 6. According to the preparation method of the graphene water-based slurry, the wettability of graphene and water can be effectively improved, efficient stripping of a graphene liquid phase is achieved, and the dispersity and conductivity of the slurry can be improved.

Description

technical field [0001] The invention belongs to the field of graphene preparation, in particular to a graphene aqueous slurry and a preparation method thereof. Background technique [0002] There are many ways to prepare graphene, such as oxidation-reduction method, liquid-phase exfoliation method, chemical vapor deposition (CVD) method, micro-mechanical exfoliation method, etc. At present, redox method and liquid-phase exfoliation are mainly suitable for industrial mass production. method, wherein the graphene sheet prepared by the redox method is relatively thin, but has many defects, consumes a lot of energy, the process is complex, and it is difficult to scale up production. cause additional burden. At the same time, most downstream graphene application companies have relatively limited graphene dispersion technology, resulting in limited use of graphene. This is also the main reason for the inconsistent feedback results from different application companies for the same...

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Problems solved by technology

But relatively speaking, the graphene prepared by the liquid phase exfoliation method has more layers than the graphene prepared by the redox method, and is generally thicker, which also leads to its poorer performance.

[0003] In view of this, the liquid-phase exfoliation method generally selects a solvent system with a surface tension close to that of graphene for exfoliation production, such as NMP, DMF and other organic solvents. In recent years, the national environmental protection policy has become more stringent, and consumers' awareness of environmental protection has generally increased. At the same time, for the sake of cost reduction, most enterprises are switching from oil-based systems to water-based systems, but the surface tension of water and graphene is quite different, and graphene is difficult to wet, peel, and disperse in water systems, so special additives are needed to reduce the surface tension. Tension, in order to make graphene with low surface tension fully wetted by water

At present, on the market, most of them improve the dispersibility and wettability of graphene in water by adding dispersants, surfactants, etc., but ordinary dispersants have limited wettability to graphene, and there are many bubbles. The prepared graphene is too thick, Many layers, easy to settle

Moreover, too many bubbles will cause inaccurate solid content, uneven mixing, dispersion and coating, and the product is prone to defects, which will further cause performance deterioration

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