ESR Analysis of Industrial Needle-Coke Samples

Industrial needle-coke samples are studied. Their paramagnetic characteristics are determined over a broad range of magnetic fields. For some samples, no pronounced signal from the microwave resonator is observed. This indicates that the conversion of the molecular structure to coke is complete in those samples. For some samples, the ESR spectra contain two sharply resolved signals from centers associated with aliphatic and aromatic fragments. That indicates incomplete structural transformation.