Abstract
Permanganate ions in aqueous solutions were reduced to form manganese dioxide nanoparticles by the sonochemical method. The processes of the sonochemical reduction were monitored by the spectroscopic method. The reduction rates were accelerated in the presence of polymers or surfactants, but the formed colloidal dispersions become to be less stable. Colloidal dispersions of manganese dioxide in pure water were stable more than several months. This result gave the different trend from the case of noble metal nanoparticles. Characterization of the synthesized nanoparticles was carried out by electron microscopy observation. The average particle size was about 14 nm when the initial concentration of potassium permanganate was 0.1 mM.
