Characteristic and dispersion of a treated AlN powder in aqueous solvent

Characteristic and dispersion of the aluminum nitride (AlN) treated by phosphoric acid were studied in aqueous solvent. The treated AlN powder displayed a good stabilization in aqueous ball-milling media. After 72 h ball-milling, the oxygen content of AlN powder with DP270, NH4PAA and without a dispersant were 1.84, 1.92 and 2.08 wt.%, respectively. The isoelectric points were 3.9, 3.5 and 3.35, respectively, for the treated AlN without dispersant, with NH4PAA and DP270. These two dispersants were proved to be effective dispersants by the apparent viscosity and sedimentation tests and could play a dual role in preparation of aqueous AlN suspensions. A dispersant is needed in aqueous suspensions of AlN powder treated by phosphoric acid.