Deagglomeration of spray-dried submicron particles by low-power aqueous sonication

Abstract

The resistance to deagglomeration of spray-dried agglomerated particles of submicron size was investigated using an ultrasonication system in water. Submicron agglomerates consisting of water-insoluble primary particles with size of 10 or 100 nm were prepared in different shapes by varying the heating profile during spray drying. Deagglomeration experiments were performed using a low-power sonication device. Spherical agglomerates were found to be more resistant to ultrasonic forces, while dent- or doughnut-shaped agglomerates tended to break down. The results show that the shape of the agglomerate plays an important role in the energy balance of the ultrasound operation. The energy produced from the collapse of cavitation bubbles in the ultrasound vessel may be used to promote motion of the agglomerates and deagglomeration.