Systematic Approach for Dispersion of Silicon Nitride Powder in Organic Media: II, Dispersion of the Powder

A novel dispersant—O‐(2‐aminopropyl)‐O′‐(2‐methoxyethyl)‐polypropylene glycol (AMPG)—was developed to disperse submicrometer‐sized Si 3 N 4 powder in nonaqueous media, based on the surface chemistry of the powder. The dispersing phenomena and mechanisms have been studied systematically, both in model systems (using atomic force microscopy and ellipsometry) and in powder systems (using rheological behavior and adsorption isotherms). The results from the model systems correlated well with those from wet powder systems. It is demonstrated that highly concentrated (with a solids volume fraction of >0.50) and colloidally stable nonaqueous Si 3 N 4 suspensions can be realized using AMPG.