How is C60 made
To achieve high purity solvent free carbon 60, natural graphite needs to undergo a series of steps in a lab environment.
Electric arc discharge (creation of fullerene soot):
In this process graphite is placed in a vacuum chamber where electric current is being ran through a graphite anode and cathode. During this process temperatures can rise up to 4000 degrees centigrade. Once finalised, the result is so called fullerene soot. One could visualise this as graphite dust which in essence is a collection of different types of carbon.
Soxhlet extraction (separation of different fullerenes):
At this point, a solvent is added to the fullerene soot and the mixture is placed in a distillation unit. Then the mixture is being heated up. The magic of this process is that different fullerenes boil at different temperatures and can thus be distilled separately.
Now that the different fullerenes are separated the solvents can be removed. In order to achieve this, the mixture is being placed in a rotor which then is placed in a hot bath. As the rotor spins the heat causes the solvents to evaporate and what will ultimately be left is powdered C60.
In these final steps the powder is typically first being washed off to remove any potential solvents which might not have evaporated in the previous step. Thereafter the C60 is placed in a vacuum oven for final drying. Now ultimately what we are left with is highly pure solvent free C60!