Effects of liquid medium and ball-milling on the surface group and aqueous dispersibility of Si3N4 powder

Influences of liquid medium and ball-milling process on the particle surface group and aqueous dispersibility of silicon nitride powder were investigated in this paper. After ball-milling in different liquids, the particle surface group and aqueous dispersibility of silicon nitride powder have different alternations. For the powders treated with identical ball-milling process in different liquids, the subsequent calcination in static air recoveries the same surface characteristics and hence the same aqueous dispersibility. Ball-milling process has significant effect on the particle surface group and its aqueous dispersibility. Under conditions of high weight ratio of milling-balls to powders and large rotary speed, the reaction of ruptured Si–O–Si surface groups with ethanol is dominant and the large amount of Si–O–C–R structures depresses its aqueous dispersibility remarkably.