Dynamics of pH-sensitive nitroxide radicals in water adsorbed in ordered mesoporous molecular sieves by EPR Spectroscopy

Journal article
(Original article)


Publication Details

Author(s): Kovaleva EG, Molochnikov LS, Golovkina EL, Hartmann M, Kirilyuk IA, Grigor'Ev IA
Journal: Microporous and Mesoporous Materials
Publisher: Elsevier
Publication year: 2013
Volume: 179
Pages range: 258-264
ISSN: 1387-1811


Abstract


A spin pH probe technique was used to study the influence of the channel diameter on the EPR spectra of pH-sensitive nitroxide radicals (NR) located in the channels of the mesoporous molecular sieves MCM-41 and SBA-15 with diameters ranging from 2.3 to 8.1 nm. From EPR spectra analysis and the results of the NR retention by the mesoporous molecular sieves upon washing with an aqueous KCl solution, the regularities of NR molecular location inside the channels were studied. The obtained dependence of the fraction of the radical molecules in the fast motional regime (with the rotational correlation times, tau(c) = 2 x 10(-11) s-9 x 10(-11)s) in the channels of the mesoporous molecular sieves as a function of pH indicates that both NR in the fast and slow motional regime (with tau(c) = 8 x 10(-9)s-7 x 10(-10)s) may be used for estimation of the solution acidity inside the channels and of the near-surface electrical potential. (C) 2013 Elsevier Inc. All rights reserved.



FAU Authors / FAU Editors

Hartmann, Martin Prof. Dr.
Professur für Katalyse


Additional Organisation
Interdisziplinäres Zentrum Erlangen Catalysis Resource Center (ECRC)


External institutions with authors

Russian Academy of Sciences / Росси́йская акаде́мия нау́к (RAS)
Ural Federal University B.N. Yeltsin
Ural State Forest Engineering University (USFEU) / Уральский государственный лесотехнический университет (УГЛТУ)


How to cite

APA:
Kovaleva, E.G., Molochnikov, L.S., Golovkina, E.L., Hartmann, M., Kirilyuk, I.A., & Grigor'Ev, I.A. (2013). Dynamics of pH-sensitive nitroxide radicals in water adsorbed in ordered mesoporous molecular sieves by EPR Spectroscopy. Microporous and Mesoporous Materials, 179, 258-264. https://dx.doi.org/10.1016/j.micromeso.2013.05.019

MLA:
Kovaleva, Elena G., et al. "Dynamics of pH-sensitive nitroxide radicals in water adsorbed in ordered mesoporous molecular sieves by EPR Spectroscopy." Microporous and Mesoporous Materials 179 (2013): 258-264.

BibTeX: 

Last updated on 2018-07-08 at 22:08