Ultrasonic Vibration Potentials in Non-Ionic Liquids

Abstract

Recently Hunter [Proc. Phys. Soc. (London) 71, 857 (1958)] has called attention to ultrasonically produced alternating potential differences in conductivity water. Rutgers and Rigole [Trans. Faraday Soc. 54, 139 (1958)] also have reported ultrasonic vibration potentials in distilled water and several pure organic liquids including n-heptane. A satisfactory explanation was not advanced by these authors but they suggest that such effects in pure liquids seriously complicate the interpretation of previous work in ionic solutions [e.g., J. Acoust. Soc. Am. 25, 456 (1953)]. Further research at Western Reserve University with pulse-modulated ultrasonic waves indicates that these apparent effects in non-ionic liquids are associated with the glass or plastic mountings for the metal electrodes and that a condenser-microphone mechanism probably is involved. Since the internal impedance associated with such a source of alternating potentials is high, it does not appear to cause any appreciable difficulties in the measurements in ionic solutions where the internal impedance is much lower. (This research has been supported by the Office of Naval Research.)