On the problem of field-gradient NMR measurements of intracrystalline diffusion in small crystallites--water in NaA zeolites as an example.
Necessary conditions for measuring intracrystalline diffusion in small crystal size systems via field-gradient NMR are discussed. As an illustrative case self-diffusion coefficients of water adsorbed in NaA zeolites (average crystal diameter about 1 microm) have been measured by 1H-NMR stimulated echoes in static magnetic field gradients of up to 180 T/m in the temperature range of 254-344 K. Obtaining intracrystalline diffusion coefficients necessitates a sufficiently high spatial resolution only provided by such large field gradients.
Gutsze
Aleksander
A
Medical Academy of Bydgoszcz, Department of Biophysics, ul. Jagiellonska 13, PL-85-067 Bydgoszcz, Poland.
Masierak
Wlodzimierz
W
Geil
Burkhard
B
Kruk
Danuta
D
Pahlke
Hannes
H
Fujara
Franz
F