Effects of ultrasound-related variables on sonochemically synthesized SAPO-34 nanoparticles

The sonochemical method was developed to synthesize uniform SAPO-34 (silicoaluminophosphate molecular sieve) nanoparticles with high crystallinity using TEAOH as a structure-directing agent (SDA). The physicochemical characteristics of SAPO-34 products, i.e. crystallinity, particle size and shape can be controlled by varying the ultrasonic-related variable such as ultrasound power intensity, ultrasonic irradiation time, sonication temperature and geometrical characteristics of the ultrasonic device (e.g., sonotrode size). The products were characterized by XRD, SEM, TEM and BET. It is found that each of the parameters can play a significant role in acoustic cavitation, number of nuclei and the crystal growth. The experimental data establish that the crystallinity is related to ultrasonic intensity and diameter of the sonotrode, as well as sonication temperature. By increasing the ultrasonic power, duration and the sonication temperature, the mean sizes of particles decrease and the morphology of the products efficiently alters from spherical aggregates of cube type SAPO-34 particles to uniform spherical nanoparticles.

Increasing US power by increasing either US power intensity or the sonotrode diameter leads to smaller particle size and the morphology changes from spherical aggregates of cubic particles to uniform nanospheres.Figure optionsDownload as PowerPoint slideHighlights
► Effects of ultrasonic parameters on sonochemical synthesis of SAPO-34 nanoparticles.
► The higher crystallinity by increasing ultrasonic power, duration and sonication temperature.
► The morphology changes from spherical aggregates of cubic particles to uniform nanospheres.
► Decreasing the particle size by increasing ultrasonic power, duration and sonication temperature.