Hydrothermal synthesis of ANA and SOD zeolite membrane in Na2O-SiO2-Al2O3-NaCl-H2O system

The membranes of zeolite ANA (analcime) and zeolite SOD (sodalite) were synthesized in the reactant system of Na2O-SiO2-Al2O3-NaCl-H2O using water glass and boehmite as the raw materials on the support of cordierite and glass, respectively. A study has been made of the influence of the molar ratio of H2O/SiO2 in the reactant, the reaction period, and the multiple synthesis on the crystallization of the membrane. The crystalline phase and the morphology of the membrane synthesized were characterized with XRD, SEM and EDX. The pervaporation of 95% (wt.) ethanol/5% (wt.) water through analcime membrane supported on cordierite showed the separation selectivity preference to water molecules, indicating that the separation process occurs in the pores of ANA zeolite inter-crystallites. Non-stoichiometric NaCl was found in SOD membrane supported on glass, and the photochromic effect exhibited after irradiation with X-ray radiation.