Ultrasonic Dispersion of Al–AlN and Al 2 O 3 Nanopowder Agglomerates and of Nanostructured AlOOH Particles

The influence of the ultrasonic radiation of power 10–60 W and frequency 22 and 2.64⋅103 kHz on the deagglomeration of Al–AlN, Al2O3, and AlOOH nanopowders in ethanol has been studied by using a dynamic light scattering method. It has been shown that the number-average size of the agglomerates decreases to 0.5 μm during their ultrasound dispersion at a frequency of 22 kHz for 20 min and subsequently it does vary on varying insonation duration and ultrasonic power. Two-stage ultrasonic treatment of the agglomerates at frequencies of 22 and 2.64⋅103 kHz increases the fraction of 0.2–0.5 μm particles. It has been found that efficient deagglomeration of nanopowders can be attained by sequentially increasing the ultrasonic radiation frequency.