Electron paramagnetic resonance as a quantitative tool for the study of multiwalled carbon nanotubes

This paper proposes that a conjugated polymer can be used to separate nanotubes from impurities. Furthermore, electron paramagnetic resonance (EPR) measurements can be used as a quantitative tool to track the presence of nanotubes in different environments. Measurements were made on carbon nanotubes in a range of conjugated and nonconjugated host materials and compared to the crude Kratschmer generator powder. These show that EPR signal intensities, when normalized correctly, are proportional to the mass of nanotubes present. This allows quantitative comparisons between nanotube content in different systems to be made. Furthermore, this allows the comparison of different polymer hosts for their ability to not only form a binding interaction with nanotubes but for the resultant hybrid to be soluble in a given solvent.