The synthesis of fine seed particles and secondary growth of SilicoAluminoPhosphate‐34 (SAPO‐34) thin films on porous tubular α‐Al2O3 and stainless steel supports have been implemented with focus on the synthesis parameters and conditions by hydrothermal method. The type of organic structure directing agents —morpholine and tetraethyl ammonium hydroxide or their mixture, agitation method of the raw materials, aging time and crystallization conditions were studied for appropriate formation of the uniform and small size SAPO‐34 particles. Formation of SAPO‐34 crystalline phase was confirmed by the X‐ray diffraction (XRD) analyses and scanning electron microscopy (SEM) images. The mean size and particle size distribution were calculated from the images of SEM. The range of the particles prepared by different procedures varied from 0.7 ± 0.12 to 2.0 ± 0.7 µm. The finest and most uniform‐size seeds were employed in layer formation by secondary growth on the surface of α‐alumina and stainless steel substrates. The resulted thicknesses of the SAPO‐34 top‐layer for secondary growth ranged from 1.4 to 3.7 µm, whereas they varied in a broad range of 1.8–10.1 µm when in situ crystallization was applied. It was revealed that applying secondary growth with the most uniform synthesized seeds leads to formation of the appropriate fine and uniform layer on both types of the supports.
Ultrasonic waves for homogenizing the starting materials deserved a promoting way for faster, simpler and lower cost for synthesis of SAPO‐34 seeds, and performing external mechanical agitation during crystallization process achieved homogeneous particles. © 2012 Curtin University of Technology and John Wiley & Sons, Ltd.