Rheology of alumina–nanoparticle suspensions: effects of lower saccharides and sugar alcohols

We empirically correlated the rheology of aqueous suspensions of ultrafine (40 nm diameter) γ-alumina powder with the concentration and structure of the following sugars and sugar alcohols: maltodextrin, sorbitol, maltitol, D-fructose, D-glucose and sucrose. It is shown that several monosaccharides, especially pentoses and sugar alcohols, significantly improve fluidity of aqueous suspensions and high-density pastes of alumina powder. In hexoses, the orientation of the 4-hydroxyl group plays a key role in controlling alumina-suspension rheology. The green strength and the sintering densification of slip cast alumina pellets were not affected by the addition of 5 wt.% of either arabinose, xylose, mannitol, or maltitol.