SEPARATION OF FULLERENE C60 AND C70 USING CRYSTALLIZATION
The present invention provides a method for separating two highly pure fullerenes from a mixture of fullerenes comprising crystallizing a first fullerene component and a second futlerene component, wherein the phase equilibrium behavior of the mixture fed to a crystallizer is characterized by a region(s) where a pure fullerene of the two fullerenes or the solid solution or solvate thereof can be crystallized out. In particular, the present invention provides a method for simultaneously separating two highly pure fullerenes from a mixture of fullerenes via crystallization, which comprises (i) adjusting the amount of a solvent in the mixture fed to a first crystallizer to obtain a phase equilibrium behavior such that a first fullerene components of the two fullerenes, in the form of a pure crystal, a solid solution crystal, or a solvate crystal is obtained during crystallization; (ii) adjusting the amount of a solvent in the mixture fed to a second crystallizer, operating at a different temperature compared to the first crystallizer, to obtain a phase equilibrium behavior such that a second fullerene component of the two fullerenes, in the form of a pure crystal, a solid solution crystal, or a solvate crystal is obtained during crystallization; and additionally (iii) purifying the solid solution or the solvate into a highly pure fullerene, when the solid product from the crystallizers is in the form of a solid solution or a solvate. The method according to the present invention allows to obtain up to 99.99% pure fullerenes, with relatively low production and separation cost. The method can be applied for various two fullerenes-solvent systems.