Dynamics of supercooled water in mesoporous silica matrix MCM-48-S

Autor:	Chung-Yuan Mou, Pei-Chun Shih, Antonio Faraone, Craig M. Brown, Li Liu, John R. D. Copley, R. M. Dimeo, S. H. Chen
Rok vydání:	2003
Předmět:	Materials science Relaxation (NMR) Biophysics Surfaces and Interfaces General Chemistry Mesoporous silica Matrix (mathematics) Nuclear magnetic resonance Chemical physics Exponent Bound water General Materials Science Neutron Soft matter Supercooling Biotechnology
Zdroj:	The European Physical Journal E. 12:59-62
ISSN:	1292-895X 1292-8941
DOI:	10.1140/epjed/e2003-01-015-3
Popis:	Using three different quasielastic neutron spectrometers with widely different resolutions, we have been able to study the microscopic translational and rotational dynamics of water, in a mesoporous silica matrix MCM-48-S, from T=300 K to 220 K, with a single consistent model. We formulated our fitting routine using the relaxing cage model. Thus, from the fit of the experimental data, we extracted the fraction of water bound to the surface of the pore, the characteristic relaxation times of the long-time translational and rotational decays, the stretch exponent describing the shape of the relaxation processes, and the power exponent determining the Q-dependence of the translational relaxation time. A tremendous slowing down of the rotational relaxation time, as compared to the translational one, has been observed.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::691a3c84d1f0c6c7a8dcaae3aacacc7d https://doi.org/10.1140/epjed/e2003-01-015-3 Zobrazit plný text záznamu Plný text ve formátu PDF