Selected sugar acids as highly effective deflocculants for concentrated nanoalumina suspensions

The possibility to fabricate nanoceramic materials by techniques based on colloidal processing requires the use of effectively working deflocculants (dispersing agents) which are able to stabilize and decrease the viscosity of aqueous nanopowders suspensions. Galacturonic and lactobionic acids have been used in the research as deffloculants for nanoalumina; they allowed to obtain ceramic suspensions of high solid loading (50 vol%) and relatively low viscosity (ca. 4 Pa s at a shear rate 10 s−1). High solid loading could be achieved through combining three factors: the application of sugar acids as deflocculants, water leaching of the nanopowders from the surface impurities and precise defoaming of the slurries. Density of sintered bodies equalled 98% TD.