Determination of the fraction of paramagnetic centers not-fulfilling the Curie law in coal macerals by the two-temperature EPR measurement method

• Authors: Grzegorz P. Słowik , Andrzej B. Więckowski
• Languages of publication: EN

Abstracts

EN

Two-temperature electron paramagnetic resonance (EPR) measurements, applied to determine the relative contributions of paramagnetic centers – fulfilling and not-fulfilling the Curie law, were carried out. The measurements were made on the macerals – exinite and vitrinite, separated from clarain of the Polish medium-rank coal (85.6 wt% C). The two-temperature EPR measurements, presented in this work, were performed respectively, at temperatures: T1 = 293 K and T2 = 173 K for exinite, and T1 = 293 K and T2 = 153 K for vitrinite. The relative contributions X of spins not-fulfilling the Curie law present in the studied macerals were calculated. A comparison of different methods of calculating the relative contributions of paramagnetic centers – fulfilling and not-fulfilling the Curie law, present in exinite and vitrinite studied by EPR was made.

Keywords

EN

electron paramagnetic resonance (EPR); macerals; two-temperature EPR measurement

• Publisher: De Gruyter Open
• Journal: Nukleonika
• Year: 2015
• Volume: 60
• Issue: 3
• Pages: 389-393

Dates

published

1 - 7 - 2015

received

1 - 10 - 2014

accepted

30 - 1 - 2015

online

6 - 8 - 2015

Contributors

author

Grzegorz P. Słowik

• Institute of Physics, Faculty of Physics and Astronomy, University of Zielona Góra, 4a Szafrana Str., 65-516 Zielona Góra, Poland

author

Andrzej B. Więckowski

• Institute of Physics, Faculty of Physics and Astronomy, University of Zielona Góra, 4a Szafrana Str., 65-516 Zielona Góra, Poland and Institute of Molecular Physics of the Polish Academy of Sciences, 17 Smoluchowskiego Str., 60-179 Poznań, Poland

References

• 1. Szroeder, P., Rozpłoch, F., & Marciniak, W. (2003). Two-temperature EPR measurements of multi-walled carbon nanotubes. Solid State Phenom., 94, 275–278. .[Crossref]
• 2. Rozpłoch, F. (1984). Negative magnetoresistivity in pyrolytic coal. Habilitation thesis, Nicolaus Copernicus University, Toruń, Poland.
• 3. Pilawa, B. (2000). Evolution of paramagnetic centers during thermal decomposition of coal macerals. Habilitation thesis, Pedagogical University, Zielona Góra, Poland.
• 4. Duber, S., & Więckowski, A. B. (1984). Excited triplet states in bituminous coal. Fuel, 63(10), 1474–1475. DOI: 10.1016/0016-2361(84)90363-6.[Crossref]
• 5. Duber, S., & Więckowski, A. B. (1984). EPR study of excited triplet states and interactions between the molecular phases in coal. In L. Petrakis & J. P. Fraissard (Eds.), Magnetic resonance. Introduction, advanced topics and applications to fossil energy (pp. 667–678). Dordrecht: D. Reidel Publ. Co.
• 6. Więckowski, A. B., Pilawa, B., Świątkowska, L., Wojtowicz, W., Słowik, G. P., & Lewandowski, M. (2000). Thermally excited multiplet states in macerals separated from bituminous coal. J. Magn. Reson., 145(1), 62–72. DOI: 10.1006/jmre.2000.2044.[Crossref]
• 7. Więckowski, A. B., Pilawa, B., Świątkowska, L., Wojtowicz, W., & Słowik, G. (1998). Paramagnetic centres in exinite, vitrinite and inertinite. Appl. Magn. Reson., 15(3/4), 489–501. DOI: 10.1007/BF03162031.[Crossref]
• 8. Słowik, G. P., Wojtowicz, W., & Więckowski, A. B. (2005). EPR evidence for thermally excited triplet states in exinite, vitrinite and inertinite separated from bituminous coal. Acta Phys. Pol. A, 108(1), 171–176. .
• 9. Słowik, G. P., & Więckowski, A. B. (2010). Paramagnetic centres in coal macerals. Acta Phys. Pol. A, 118(3), 507–510. .
• 10. Mrozowski, S. (1965). Electron spin resonance in neutron irradiated and in doped polycrystalline graphite – Part I. Carbon, 3(3), 305–320. DOI: 10.1016/0008-6223(65)90065-5.[Crossref]
• 11. Yen, T. F., & Young, D. K. (1973). Spin excitations of bitumens. Carbon, 11(1), 33–41. DOI: 10.1016/0008-6223(73)90006-7.[Crossref]
• 12. Najder-Kozdrowska, L., Pilawa, B., Buszman, E., Więckowski, A. B., Świątkowska, L., Wrześniok, D., & Wojtowicz, W. (2010). Triplet states in DOPA-melanin and in its complexes with kanamycin and copper Cu(II) ions. Acta Phys. Pol. A, 118(4), 613–618. .
• 13. Bleaney, B., & Bowers, K. D. (1952). Anomalous paramagnetism of copper acetate. Proc. Roy. Soc. A-Math. Phys. Eng. Sci., 214(1119), 451–465. DOI: 10.1098/rspa.1952.0181.[Crossref]
• 14. Gong, D., & Yang, H. (2013). The discovery of free radicals in ancient silk textiles. Polym. Degrad. Stabil., 98(9), 1780–1783. DOI: 10.1016/j.polymdegradstab.2013.05.011.[WoS][Crossref]
• 15. Liu, J., Jiang, X., Shen, J., & Zhang, H. (2014). Chemical properties of superfine pulverized coal particles. Part 1. Electron paramagnetic resonance analysis of free radical characteristics. Adv. Powder Technol., 25(3), 916–925. DOI: 10.1016/j.apt.2014.01.021.[WoS][Crossref]

Identifiers

DOI

10.1515/nuka-2015-0069