WATER-SATURATED MESOPOROUS MCM-41 SYSTEMS CHARACTERIZED BY H-1-NMR SPIN-LATTICE RELAXATION-TIMES

Citation
Ew. Hansen et al., WATER-SATURATED MESOPOROUS MCM-41 SYSTEMS CHARACTERIZED BY H-1-NMR SPIN-LATTICE RELAXATION-TIMES, Journal of physical chemistry, 99(12), 1995, pp. 4148-4154
Citations number
24
Categorie Soggetti
Chemistry Physical
ISSN journal
00223654
Volume
99
Issue
12
Year of publication
1995
Pages
4148 - 4154
Database
ISI
SICI code
0022-3654(1995)99:12<4148:WMMSCB>2.0.ZU;2-E
Abstract
Combining spin-lattice relaxation time measurements and signal intensi ty measurements vs temperature of water confined in mesoporous molecul ar sieves (MCM-41 materials) gives information regarding the activatio n enthalpy of bound water and the width of the log-normal distribution of correlation times of the water molecules. Three different water '' phases'' are observed which have significantly different relaxation st rength. The overall spin-lattice relaxation rate is shown to be strong ly dependent on the number of silanol protons. ''Analytical'' formulas for the average spin-lattice relaxation rates are derived.