Groups of Paramagnetic Centres in Reduced and Methylated Low Rank Coal
B. Pilawa a, H. Wachowska b, M. Kozłowski b, A.B. Więckowski c,d, and L. Najder-Kozdrowska c
aCentre of Polymer and Carbon Materials of the Polish Academy of Sciences, M. Curie-Skłodowskiej 34, 41-819 Zabrze, Poland
bFaculty of Chemistry, Adam Mickiewicz University, Umultowska 89b, 61-614 Poznań, Poland
cInstitute of Physics, University of Zielona Góra, Z. Szafrana 4a, 65-516 Zielona Góra, Poland
dInstitute of Molecular Physics of the Polish Academy of Sciences, M. Smoluchowskiego 17, 60-179 Poznań, Poland
Received: January 29, 2014; In final form: August 19, 2014
Full Text PDF
Low rank Illinois No. 6 coal was studied by electron paramagnetic resonance EPR spectroscopy. The parameters of EPR spectra (spectroscopic splitting factors g, linewidths ΔBpp, concentrations of paramagnetic centres N) were measured for row and chemically treated coal (demineralized, reduced and methylated samples). The multi-component structure of experimental spectra of this coal was proved. Two groups of paramagnetic centres responsible for broad Lorentzian 1 and narrow Lorentzian 2 lines exist in studied samples. Paramagnetic centres connected with component lines revealed different behaviour during chemical treatments.

DOI: 10.12693/APhysPolA.128.264
PACS numbers: 33.35.+r, 61.66.Hq, 76.30.-v, 76.30.Rn,