Dispersion of surface-modified of Si3N4 powder in water phase

The surface of Si3N4 powders was modified by oxidation at 1000°C in air. The results show that main component of powders by oxidation is Si3N4, and it is coated by silicon oxide layer (SiO2 is the primary ingredient). Dispersion property and Zeta-potential of surface-modified Si3N4 powders are greatly higher than those of surface with unmodified Si3N4 powders in water phase, with the increase of oxidation time, the dispersion and Zeta-potential of surface-modified Si3N4 in water phase first increases and then decreases. Surface-modified Si3N4 has a new peak of Si-O in FTIR spectrum.