Size Modification of Nanographite System of Activated Carbon Fibers Studied by EPR
M. Kempińskia, W. Kempińskib and M. Śliwińska-Bartkowiaka
aInstitute of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland
bInstitute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, 60-179 Poznań, Poland
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Received: 24 04 2005;
We report results of EPR measurements of activated carbon fibers. Experiments made for pristine activated carbon fibers and activated carbon fibers with adsorbed molecules (CCl4, C6H5NO2, and H2O) confirmed the localized character of paramagnetic centers observed in the system. Pristine activated carbon fibers are characterized by single Lorentzian line. Broader component of EPR signal appears when guest molecules are adsorbed in nanopores. The strongest localization is observed for water-filled activated carbon fibers nanopores (with hydrophobic pore walls) where changes in distance between nanographite particles were monitored by the g-shift to higher values. This process is related to stronger spin-orbit interaction of electrons trapped at nanographite particles compressed by guest molecules.
DOI: 10.12693/APhysPolA.108.339
PACS numbers:42.81.Uv, 73.20.-r, 73.22.-f, 76.30.-v, 74.78.Na