Optimizing Conditions for Ultrasound Extraction of Fullerenes from Coal Matrices

Abstract

Conditions for ultrasound toluene extraction of synthetic C₆₀ added to powdered bituminous coal were tested. High‐performance liquid chromatography (HPLC) was used to determine the fullerene content in the obtained extracts. The results indicated a possible negative effect of sample demineralization (HCl/HF) and N₂ purging on the extraction yield of C₆₀. On the contrary, a 30% yield increase was registered when the coal was pre‐extracted with pentane or pentane/toluene. The best conditions for C₆₀ recovery in the investigated mixtures are 30 min of sonication at 280–285 K. The effects of sample filtration, sequential extraction, ultrasound bath power and treatments of C₆₀ solution alone are also discussed.

Keywords:

• Fullerene C₆₀
• Ultrasound‐assisted extraction
• Extraction yield
• Fullerene decomposition
• Coal

ACKNOWLEDGMENTS

We thank the Grant Agency of the Czech Republic (project nr. 205/07/0772 and 205/06/P348) for financial support of this work. Part of the funding was provided by the Ministry of Education, Youth and Sports of the Czech Republic (MSM 0021620855).