Dynamics of pH-sensitive nitroxide radicals in water adsorbed in ordered mesoporous molecular sieves by EPR Spectroscopy / Kovaleva Elena G.,Molochnikov Leonid S.,Golovkina Elena L.,Hartmann Martin,Kirilyuk Igor. A.,Grigor'ev Igor. A. // MICROPOROUS AND MESOPOROUS MATERIALS. - 2013. - V. 179, l. . - P. 258-264.

ISSN/EISSN:

1387-1811 / 1873-3093

Type:

Article

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.

Author keywords:

Ordered mesoporous materials; PH-sensitive nitroxide radicals; Fast (slow) radical motion; EPR spectroscopy ELECTRON-SPIN-RESONANCE; ORGANIC SOLUTES; PROBE ESR; MCM-41; ADSORPTION; SILICA; NANOCHANNEL; SURFACE; SBA-15; DIFFRACTION

DOI:

10.1016/j.micromeso.2013.05.01

Web of Science ID:

ISI:000323689400034

Соавторы в МНС:

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Другие поля

Поле	Значение
Month	SEP 15
Publisher	ELSEVIER SCIENCE BV
Address	PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
Language	English
EISSN	1873-3093
Keywords-Plus	ELECTRON-SPIN-RESONANCE; ORGANIC SOLUTES; PROBE ESR; MCM-41; ADSORPTION; SILICA; NANOCHANNEL; SURFACE; SBA-15; DIFFRACTION
Research-Areas	Chemistry; Science \& Technology - Other Topics; Materials Science
Web-of-Science-Categories	Chemistry, Applied; Chemistry, Physical; Nanoscience \& Nanotechnology; Materials Science, Multidisciplinary
Author-Email	gek1969@bk.ru lsmolochnikov@gmail.com golovkina\_e.l@mail.ru martin.hartmann@ecrc.uni-erlangen.de kirilyuk@nioch.nsc.ru grig@nioch.nsc.ru
ResearcherID-Numbers	Hartmann, Martin/C-4720-2011 Kirilyuk, Igor/R-1688-2016 Kovaleva, Elena/M-7400-2016
ORCID-Numbers	Kirilyuk, Igor/0000-0001-6033-0368 Kovaleva, Elena/0000-0002-3111-345X
Funding-Acknowledgement	Research Program of the Ministry of the Education of the Russian Federation
Funding-Text	This work was supported by the Research Program of the Ministry of the Education of the Russian Federation (2007-2011). E.G.K. thanks the Program of Cooperation ``Mikhail Lomonosov{''} between the Ministry of Education of Russian Federation and the German Service of Academic Exchanges (DAAD). We are grateful to Dr. G. Chandrasekar for assistance in the synthesis of MMS and their characterization.
Number-of-Cited-References	41
Usage-Count-Last-180-days	4
Usage-Count-Since-2013	35
Journal-ISO	Microporous Mesoporous Mat.
Doc-Delivery-Number	208OQ