Diffusion of n-hexane in 5A zeolite studied by the neutron spin-echo and pulsed-field gradient NMR techniques

The neutron spin-echo (NSE) and pulsed-field gradient (PFG) NMR techniques are applied to investigate the microdynamics of n-hexane diffusion in a commercial sample of zeolite NaCaA. In the PFG NMR measurements molecular root mean square displacements in the range from 100 nm to 2 mum are covered, while the NSE experiments applied to deuterated guest molecules provide information about the rate of molecular fluxes over distances of a few nm. Taking into account these differences, the obtained diffusivity data are found to be in reasonable agreement. (C) 2003 Elsevier Science Inc. All rights reserved.