Dispersion and co-dispersion of ZrB2 and SiC nanopowders in ethanol

The dispersion and co-dispersion behavior of ZrB 2 and SiC nanopowders in ethanol solution was studied by sedimentation test, particle size measurement and transmission electron microscope (TEM) analysis. The dispersion behavior of ZrB 2 and SiC nanopowders in ethanol solution was strongly dependent on the pH values, types and amounts of dispersant. PEI was found to be effective for the dispersion of both ZrB 2 and SiC nanopowders in ethanol solution. With the addition of PEI, the isoelectric points of ZrB 2 and SiC nanopowders in ethanol solution were at pH 10 and pH 9.5, and shift to pH 13 and pH 12.3, respectively. The stability of ZrB 2 suspension increased with the dispersant content increasing until reached 0.7   wt% and well-dispersed SiC slurry can be obtained with more than 2.5   wt% PEI. The suitable pH value for the dispersion of ZrB 2 and SiC nanopowders should be lower than 12 and 10, respectively. The well co-dispersed ZrB 2 and SiC nanocomposite powders can be achieved by using 1   wt% or more PEI below pH 10.