Hydrothermal synthesis of nanostructure NaA zeolite: The effect of synthesis parameters on zeolite seed size and crystallinity

In this research, nanostructure NaA zeolite was synthesized via hydrothermal method. As mentioned in the literature, the recommended molar composition for NaA zeolite synthesis was Na2O/Al2O3 ratio of 2-3, but in our work, NaA zeolite was synthesized with new molar compositions by the emphasis on both molar ratios of Na2O/Al2O3 and SiO2/Al2O3. Also, the effects of reaction time and temperature on morphology and crystallinity of the synthesized zeolites were investigated. The final products were characterized by X-ray diffraction and scanning electron microscopy (SEM). The obtained results showed that both of the investigated molar ratios are controlling parameters in the synthesis of zeolites. In addition, it is found that the reaction time has a great effect on the crystallinity of the synthesized zeolites. Also, the zeolite seeds size increases significantly by increasing reaction temperature. Finally, to obtain NaA zeolite with desirable particle size, crystallinity and morphology, an optimum synthesis conditions can be proposed. (c) 2008 Elsevier Ltd. All rights reserved.