Interactions of dispersants and binders with {alpha}-alumina in aqueous suspensions
- Harvard Univ., Cambridge, MA (United States)
- Swiss Federal Inst. of Technology, Zuerich (Switzerland)
Citric acid and poly(vinyl alcohol) (PVA) are commonly used as dispersant and binder for aqueous alumina slurries. The interaction of citric acid and PVA with the alumina surface as well as the competitive reaction of these two additives on the alumina surface have been studied by measurements of the adsorption density and electrophoretic mobility. By variation of the citric acid concentration, it is possible to adjust the isoelectric point (IEP) of alumina to any pH-value between 9 and 3. For citric acid, a high adsorption density on alumina was measured over a broad pH range, whereas the adsorption of PVA is very low. The adsorption density of citric acid on alumina is not influenced by the presence of PVA, whereas the polymer is displaced by citric acid from the alumina surface. Enhanced binder migration in wet green bodies during the drying process is a consequence of this displacement.
- OSTI ID:
- 181776
- Report Number(s):
- CONF-940416--
- Country of Publication:
- United States
- Language:
- English
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