During its existence, graphene has established itself as a versatile material with unique properties. However, it does have a disadvantage, the “unwillingness” to dispersed, that is, crushed to a state of dispersion, which in turn prevents the creation on its base paints and inks.
Researchers at the University of Umea (Sweden) found a relatively easy way to solve this problem, applying the graphene oxide. This is a slightly different version of carbon, which can provide a stable dispersion in water and may then be used as a graphene ink.
The difficulty lies in the fact that graphene and similar compounds of carbon (graphite, nanotubes) are hydrophobic, that is repel water. They can be dispersed with the use of aggressive organic solvents or mechanical treatments, however, the first method is toxic and the second is fraught with the formation of defects.
Scientists have proposed the use of oxidized graphene, which is hydrophilic. By combining graphene oxide with particles of other hydrophobic hydrocarbons, graphene, activated graphene, porous and activated carbon, they were able to obtain stable dispersion. As a result, even after a few days the material will settle on the bottom of the tank with an aqueous solution.
In the next experiment, the researchers added in a mixture of carbon nanotubes and tried to make her supercondensators electrodes, which caused the particles to the metal foil, dried and heated to 200 °C.
According to one of the study’s authors Alexander Talyzina, “thanks to this we get a thin film of a conductive material with a sufficiently large surface area, good conductivity and excellent properties for energy storage in supercapacitors”.
Source — Umea University