Characterization of ceramic materials using electroacoustics
- Univ. of Sydney (Australia); and others
When a high frequency (MHz) electric field is applied to a colloidal suspension or emulsion, the (charged) particles are forced to move backwards and forwards and this generates a sound wave. This phenomenon is known as the electrokinetic sonic amplitude (or ESA) effect. We have used measurements of the ESA effect to determine the high frequency dynamic mobility of colloidal particles, and from this to determine the size and charge of colloidal particles in suspensions of interest to ceramicists. One of the main advantages of the method over the usual optical techniques is that it can be used on suspensions of arbitrary concentration. We have successfully measured systems up to concentrations of over 40% by volume. More usually, measurements at 5-25% by volume can give very reliable information on materials like silicon nitride, alumina, titania and silica. Kaolinite is a special case because it exhibits a phenomenon we have called anomalous surface conductivity which affects the dynamic mobility. For the purpose of sizing the material it turns out that one can ignore this effect provided the salt concentration is above 0.01 M. If, however, one chooses to measure the surface conduction independently, one can couple this with the dynamic mobility data to obtain additional information about the particles. Even reactive materials like cement/water slurries can be successfully characterised as a function of time in the early stages of the water contact.
- OSTI ID:
- 181783
- Report Number(s):
- CONF-940416-; TRN: 96:000418-0010
- Resource Relation:
- Conference: 96. annual meeting of the American Ceramic Society (ACS), Indianapolis, IN (United States), 25-28 Apr 1994; Other Information: PBD: 1995; Related Information: Is Part Of Ceramic transactions: Science, technology, and applications of colloidal suspensions. Volume 54; Adair, J.H.; Casey, J.A.; Randall, C.A.; Venigalla, S. [eds.]; PB: 285 p.
- Country of Publication:
- United States
- Language:
- English
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