NMR Study of Synthetic Gallosilicate Natrolite

Solid-state 29Si and 71Ga NMR was used to study the synthetic gallosilicate Na16Ga16Si24O80 ·16H2O (Ga–natrolite). It has been shown that Ga–natrolite contains mainly Si(GaO4)3(SiO4) and Si(GaO4)2(SiO4)2-structural units and has sufficiently ordered structure. Temperature dependence of the spin–lattice relaxation time T1 of 71Ga nuclei has also been studied using solid-state NMR. Spin–lattice relaxation of the 71Ga was determined to be governed by the electric quadrupole interaction with the crystal electric field gradients modulated by translational motion of H2O molecules in the Ga–natrolite pores.

23Na Nuclear Magnetic Resonance Study of the Structure and Dynamic of Natrolite

The temperature dependences of nuclear magnetic resonance (NMR) and magic angle spinning (MAS) NMR spectra of 23Na nuclei in natrolite (Na2Al2Si3O10·2H2O) have been studied. The temperature dependences of the spin-lattice relaxation times T1 in natrolite have also been studied. It has been shown that the spin-lattice relaxation of the 23Na is governed by the electric quadrupole interaction with the crystal electric field gradients modulated by translational motion of H2O molecules in the natrolite pores. The dipolar interactions with paramagnetic impurities become significant as a relaxation mechanism of the 23Na nuclei only at low temperature (<270 K).