The slurries of nano-sized ceramic powder precursors looked
like milk. It became very clear, when the slurries permeated
through -Al2O3 membrane with an average pore size of about
0.2 m (Fig. 1). The retention is above 99%, which was determined
by a colorimeter. The results indicated that the membrane was
appropriate for washing slurries consisting of nanometer ceramic
powder precursors