Adsorption Isotherm, Kinetic and Mechanism Studies on the Surface Modification of SiC powder with Disperse Black BL

Well dispersed modified SiC powder was prepared via disperse black BL (DBBL). High density SiC green body was prepared by the modified SiC powder. The modified SiC powder was obtained via putting in 1.2 wt% DBBL through agitating for 2 h. The slurry obtained by modified SiC powder with a 50 vol % solid content has a viscosity of 0.430 Pa.s. The dense SiC green body (2.43 g/cm(3)) was obtained via slip casting. The electron microscopy as well as thermogravimetry were applied to determine the adsorption of the modifier on the SiC powder. Experimental data shows that the adsorption kinetics equation of DBBL on the SiC powder obeys the pseudo-first-order kinetics model. And the isotherm equation agrees with the Langmuir model. The experiment dates indicate that the adsorption mode of DBBL was physical adsorption.