Sonochemical dissolution of MnO2 colloids
The dissolution of colloidal MnO2 in aqueous solution induced by ultrasound has been investigated in the absence and presence of aliphatic alcohols at a pH of 4.5. It was found that the presence of the alcohols greatly enhanced the amount and rate of the dissolution of MnO2. It is shown that the rate of dissolution can be directly related to the Gibbs surface excess of the alcohol at the air/water interface. A simple quantitative model is proposed to account for these observations.