The influence of ultrasonic waves on manganese dioxide sol

The influence of ultrasonic waves at 1 Mc/s and power 225 watts per square centimeter on both the positively and negatively charged manganese dioxide sols has been investigated. The negatively charged sol becomes unstable on exposure and it coagulates automatically on long exposure. The negative acclimatisation towards silver nitrate and copper sulphate was also studied and it was observed that the negatively charged manganese dioxide sol shows this effect more pronouncedly after exposure to the ultrasonic waves. If the coagulum obtained after the addition of electrolytes is washed and suspended in fresh quantity of distilled water and exposed to ultrasonic waves, it rapidly passes into the colloidal state. The positively charged sol also becomes unstable on exposure to ultrasonic waves

The influence of ultrasonic waves on the viscosity and stability of vanadium pentoxide sol

The vanadium pentoxide sol when exposed to ultrasonic waves shows an increased value of hydrogen ion concentration and conductivity. It is postulated that this change is due to either supersaturation of metavanadic acid in presence of the high frequency waves or to the production of peroxyvanadic acid under the influence of hydrogen peroxide which is known to be formed in traces under these conditions. The change in viscosity of vanadium pentoxide sol in presence of electrolytes under the influence of ultrasonic waves has also been recorded