Process for protection of aluminum nitride powder against hydrolysis with sodium tripolyphosphate as dispersant

Abstract

In the present study, the hydrolysis behaviour of aluminum nitride (AlN) powder with and without dispersant [sodium tripolyphosphate (STPP, Na₅P₃O₁₀) has been investigated in aqueous milling media to avoid hydrolysis and improve dispersion. The moderate amount of dispersant for good dispersion was found to be 0·015 g m^-2. An increased STPP onto the particle surface was determined by X-ray diffraction and Fourier transform infrared. Sodium tripolyphosphate decreased the hydrolysis and increased the stability of AlN in aqueous media by coating grain surfaces and forming repulsive forces. Without STPP, isoelectric point was found to be between 9 and 10. On the other hand, STPP treated AlN did not interestingly show any isoelectric point.