Graphene can be obtained using a kitchen blender and dishwashing liquid

Despite the fact that the problem of obtaining graphene on an industrial scale is still not solved, laboratory methods for its extraction are sometimes extremely simple and accessible. The classic version is the mechanical splitting of grains of graphite using ordinary scotch tape, described in the work of Konstantin Novoselov and colleagues in 2004. This work actually began the modern era of mass research on the properties of graphene, and Novoselov and his colleague Andrey Geim received the Nobel Prize in Physics for research in 2010.

Unfortunately, the method of mechanical splitting practically does not scale - after multiple layering, you have to look for tiny, micron-length, and almost transparent crystals with a microscope. Several chemical-mechanical methods for graphene delamination have been developed using ultrasound, solvents and surfactants. Using these methods, a suspension of graphene flakes in water or a solvent is obtained - a method that is quite suitable in the laboratory, but, like mechanical splitting, is not yet very scalable.

The April issue of the journal Nature materials published a study by a team of scientists from England and Ireland, who developed a very simple, and at the same time, good method for scaling graphene. It turns out that tiny graphene flakes can be obtained by treating a graphite suspension with a mixer with a fairly high turnover. In their work, scientists mainly used Silverson's L5M laboratory mixer and specially selected reagents, but they also tested their method with a conventional Kenwood BL370 kitchen blender and Fairy dishwashing liquid as a surfactant that does not give graphene flakes to stick together. The results were quite comparable.
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Blender, the process of "beating" graphene and one of the graphene flakes under the microscope

The only device that is difficult to find in every kitchen, and which is necessary in order to separate the graphene flakes from the remaining unsplit grains of graphene, is a centrifuge. The fact is that with any methods of obtaining graphene from a suspension of graphite powder, the yield of graphene suitable for further use or experiments is rather small - for example, in an experiment with a household blender at a graphite concentration of 100 mg / ml in the initial solution after 30 minutes of beating “A graphene concentration of about 0.15 mg / ml is obtained.

Although these figures do not amaze the imagination, in comparison with other methods of graphene production, the use of mixers is very effective - much less energy is spent on getting the same amount of graphene than when using ultrasound. In addition, this method scales very well - in the laboratory, up to 100 liters of graphene slurry were obtained in one run - ultrasonic devices usually work with volumes several orders of magnitude less. Scientists believed that an industrial plant capable of mixing 10 cubic meters of solution per hour would be able to produce up to 7.5 kg of graphene.

The resulting suspension of graphene flakes can be used to create thin graphene coatings with high electrical and thermal conductivity, as well as a reinforcing agent that significantly improves the mechanical properties of plastics. Based on graphene flakes and coatings, you can make solar batteries, sensors and supercapacitors.

Although the article itself on the Nature website is available only on a paid basis, there is a free download of very detailed and informative additional materials ( PDF , 4.3 MB) with a detailed description of all experiments and a comparison of the new method of obtaining graphene with existing ones.