Diffusing-Wave Spectroscopy of Concentrated Alumina Suspensions during Gelation

✍ Scribed by Hans M. Wyss; Sara Romer; Frank Scheffold; Peter Schurtenberger; Ludwig J. Gauckler

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 168 KB
• Volume: 241
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.2001.7668

✦ Synopsis

Using diffusing-wave spectroscopy, we followed the aggregation and gelation of concentrated (30 vol%) alumina suspensions. The suspensions were destabilized by either shifting the pH to the isoelectric point or by increasing the ionic strength. Both effects can be achieved continuously and homogeneously by using an enzymecatalyzed internal chemical reaction. Based on the light-scattering data, we could derive quantitative information about the sol-gel transition and the viscoelastic properties of the gels, as well as a characterization of changes in the microstructure. The elastic moduli determined from light scattering are found to be in good agreement with rheological measurements.