Investigations on hydrothermal synthesis parameters in preparation of nanoparticles of LTA zeolite with the aid of TMAOH

In this work, nanocrystals of LTA zeolite with crystallite sizes ranging from 30 to 70 nm were synthesized successfully. Tetramethylammonium hydroxide (TMAOH) was used as template. The effects of organic and inorganic cations as well as crystallization conditions including aging time, synthesis time, and synthesis temperature on size of the zeolites were studied. The crystallite size was adjusted by varying the compositions of synthesis gel and also crystallization conditions. The final products were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The obtained results showed that zeolite size decreases significantly and zeolite size distribution becomes narrow by increasing aging time, and organic cation content. Moreover, the zeolite crystallite size increases significantly by increasing inorganic cation content. It was found that reaction time has a great effect on crystallinity of the synthesized zeolites. It was indicated that nucleation is completed after 3 days and no further nucleation occurs after.

The effects of synthesis parameters including aging time, synthesis time, and synthesis temperature as well as organic and inorganic cations on size and morphology of the zeolite LTA were studied in this work. Zeolite LTA with crystal sizes between 30 and 70 nm was synthesized successfully at the optimum conditions.Figure optionsDownload as PowerPoint slideHighlights
► Synthesis and characterization of nano-sized LTA powder by adjusting organic template.
► Investigation of inorganic cations effect on the morphology of NaA nanocrystals.
► Development of a reproducible procedure for preparation of nano-sized zeolite NaA crystals.