Effects of Some Factors on Zeta-Potential of Aqueous Silicon Nitride Suspensions

摘要

The present study aims to illustrate how the zeta potential of aqueous silicon nitride powder suspension can be effected by the type and amounts of electrolytes. The experimental results show that a suitable electrolyte with moderate concentration which is not specially adsorbed on the surface of silicon nitride particles, leads to an appropriate ionic strength in dispersing medium. The introduction of dispersant to suspension increases the zeta potential efficiently and shifts the isoelectric point (IEP) of silicon nitride particles. The IEP changes of silicon nitride powders are also investigated after the powders treated by dispersant, heating to 500℃ in hydrogen or air atmosphere and leaching with different solutions, respectively.