Dispersion of nano-TiN powder in aqueous media

Dispersion of nano-TiN powder in aqueous media is investigated, which remains a big challenge during the preparation of Ti(C,N)-based nano-cermet. TEM images show that ultrasonic treatment for 30 min is proved to be optimal, while excessive increase of ultrasonic treatment time to 1 h does not result in better dispersion. XPS spectra reveal the existence of TiO2, which results in hydroxylated surface of the nano-TiN powder. Based on the surface properties of TiN particles, Tween 80, a non-ion polymer, is selected as the surfactant. FTIR analysis shows that Tween 80 is evidently absorbed on the surface of TiN particles. Zeta potential of the TiN suspension is influenced by pH value following the electrostatic stabilization mechanism. In the presence of Tween 80, the zeta potential values appear to be more negative with the shift of pHIEP from 3.6 to 3.1, and homogenous dispersion of nano-TiN is achieved by the stereo-hindrance effect.