Synthesis of zeolite NaA at room temperature: The effect of synthesis parameters on crystal size and its size distribution

• Published in: Advanced powder technology : the international journal of the Society of Powder Technology, Japan Japan, 2013-05, Vol.24 (3), p.689-696
• Main Authors: Zhang, Xu, Tang, Dingxing, Jiang, Guojun
• Format: Article
• Language: English
• Subjects: Characterization; Crystallization; Synthesis; Zeolite NaA
• ISSN: 0921-8831; 1568-5527
• DOI: 10.1016/j.apt.2012.12.010

Crystal size distributions of zeolite NaA obtained from different crystallization times (a) 24h, (b) 48h, (c) 72h, (d) 96h, (e) 120h, and (f) 144h. ND is number percentage of crystals having the spherical equivalent diameter D. [Display omitted] ► Although 72h product was fully crystalline, the crystals were able to continue to grow. ► Longer aging time led to the mean particle size of crystals decreased slightly. ► The effect of stirring speed on the crystalline end products was investigated. ► The aluminum source had much more obviously influence on the crystal phase of final product than the silicon source did. Zeolite NaA crystals were prepared by hydrothermal synthesis under room-temperature conditions. The products were characterized by XRD, SEM, IR and particle size analysis. Some influence parameters such as crystallization time, aging time, stirring speed, different sources of silicon and aluminum on the crystalline end products were studied. The results showed that crystallization time was a crucial factor for the final products, well-shaped crystals could be obtained at the crystallization time of 72h. While further prolonging the crystallization time more, crystals continued to grow, along with the changes of crystal size distributions. The crystals obtained with the aging time of 1, 1.5, 2 and 3h show the mean particle sizes of 368, 356, 338 and 314nm, with the crystal size distribution ranges of 82–435, 70–441, 54–450 and 40–476nm, respectively. Longer aging time leads to the mean particle size of crystal decrease. Whilst, the stirring speed affects the particle size distribution only slightly. Moreover, the aluminum source has much more obviously influence on the crystal phase of final product than the silicon source does in this system.