Abstract
The (1)H nuclear magnetic resonance (NMR) spectra and the dipolar spin-lattice relaxation time T(1D) for (1)H in the natural natrolite (Na(2)Al(2)Si(3)O(10)·2H(2)O) have been measured in the temperature range of 190-390 K. From the temperature transformations of (1)H NMR spectra, it follows that at T > 300 K, the diffusion of water molecules along the nano-channels is observed. From experimental T(1D) data, it follows that the 180° flip motion of the water molecules takes place in natrolite. At low temperature (T < 250 K), the dipolar interaction with paramagnetic impurities as a relaxation mechanism of (1)H nuclei becomes significant.