This paper describes the formation and characterization of nanosize needle-shaped In-(OH) 3 particles. The In(OH) 3 nanopowder was prepared via the sonication of an aqueous solution of InCl 3 at room temperature and at 0 °C. At these temperatures, nonsonicated hydrolysis does not occur. The role of the ultrasound radiation and the mechanism of the reaction is discussed. The proposed mechanism is based on the sonohydrolysis of In(III) ions in the outer ring, and the liquid shell, of the collapsing bubble.

The sonochemical reaction of an aqueous solution of GaCl 3 led to the formation of gallium oxide hydroxide rolled up in a scroll-like layered structure to give cylinders 80-120 nm in diameter and 500-600 nm in length. Small amounts of metallic Ga were incorporated with these tubes. A mechanism for this reaction has been suggested where the reaction takes place in a shell surrounding the collapsing bubble.

Proteinaceous microspheres can be prepared using the sonochemical method. However, it is known that these proteins should possess at least one cysteine residue in order to obtain stable microspheres using this method. In the present study, we have produced streptavidin microspheres, using the sonochemical method, from streptavidin, which does not have any cysteine residues.