Clean Carbon 60 is BLACK

Toluene+Carbon 60=Purple

In this experiment, the color of the C60 solution in both the toluene and xylene solvents turned purple, and it was a darker purple in the TCE (Trichloroethylene), as seen in Figure 2.

The same purple color was seen in the toluene and xylene solvents possibly due to the similar structure of these two solvents consisting of a benzene ring and methyl group.

Therefore, because the solute-solvent interactions might be different, the solvent induces different optical characteristics of the C60 solutions….

Citation Information – Open Chemistry, Volume 17, Issue 1, Pages 1198-1212, eISSN 2391-5420
DOIhttps://doi.org/10.1515/chem-2019-0117.

© 2019 Teguh Endah Saraswati et al., published by De Gruyter. This work is licensed under the Creative Commons Attribution 4.0 Public License. BY 4.0

Clear: The true color of C-60

Clear: The true color of C-60

Drew Davidson

For starters, for the better part of two decades now, a purple color has been the standard for determining if a product contains C-60. A purple color!

C-60 turns purple when mixed with Olive oil. Just about everybody who manufactures this stuff makes that claim.

As it turns out, that purple color comes from residual toluene left over from the manufacturing process.

Yeah, you read that right. RESIDUAL TOLUENE! Or, residual amounts of other solvents such as benzene or xylene.

Toluene Plus Carbon 60 Makes Purple

Purple color of Toluene

Pure, unadulterated C60 is BLACK. C60 is only ever “purple” (or “magenta”) when it has interacted with solvents such as Toluene. In other cases, it may be yellow, green, pink or brown, depending on which solvent is used (see Fig. 1). The color change in C60 in various solutions is the result of “solvation shells” which are formed between the solute (C60) and solvent when they interact. This interaction changes the electrophysical properties of the C60 molecules, causing them to aggregate (i.e., cluster) into crystal formations of various shapes and sizes. It is these crystal formations of aggregated C60 that reflect specific wavelengths of light and which result in “color”. Since the electrophysical properties of the C60 are permanently altered from having interacted with a solvent, C60 remains in an aggregated, crystallized state, even after the solvent has been vaporized off. Additionally, some solvent also remains behind, being both chemically bonded to and physically trapped within the C60 molecules. Hence, re-dissolving the solid C60 “powder” that is left behind after this process into an oil will still produce a color change. It is evidence of crystallized, aggregated C60 from solvent extraction methods.

How Carbon 60 is Made

Evolution of Species During Thermal Submlimation of C60

L. Moro, P. Lazzeri, V. Micheli CMBM, Centro Materiali e Biofisica Medica Povo- Trento, 1-38050, Italy

To study the nature of the residue and possible methods for reduce or eliminate it, is relevant to many topics of the fullerene research. For example, there is a fundamental interest for the interactions between fullerenes and solvents and the stability of possible compounds or adducts. In addition the presence of solvent molecules trapped in the fullerene crystals and of solid phases of C60 wih solvents may affect the measured basic properties of C60.

How Carbon 60 is Made

Fullerene for Medicinal Purposes, A Purity Criterion towards Regulatory Considerations

Sanaz Keykhosravi 1, Ivo B. Rietveld 2 , Diana Couto 1, Josep Lluis Tamarit 3, Maria Barrio 3, René Céolin 1 and Fathi Moussa 1,*

Here we have evaluated several analytical tools to verify the purity of commercially available C60 samples. Our data clearly show that differential scanning calorimetry is the best candidate to establish a purity
criterion based on the sc-fcc transition of a C60 sample.

Here we have evaluated several analytical tools to verify the purity of commercially available C60 samples. Our data clearly show that differential scanning calorimetry is the best candidate to establish a purity
criterion based on the sc-fcc transition of a C60 sample

IMPURITIES IN c60 SAMPLES