Interaction between Silicon Carbide and Polyacrylicacid

Abstract

Interaction between α-SiC surface and polyacrylic acid(PAA) in aqueous suspensions was investigated to improve the dispersion of α-SiC particles with a median size of 0.5μm. The amount of PAA(molecular weight 10000) adsorbed on the α-SiC particles of an isoelectric point of pH2.5 was measured in 5 vol% suspensions at pH 3,5,7 and 10. The amount of PAA adsorbed decreased with increasing pH because of the electrostatic repulsion between negatively charged SiC surface and negatively charged PAA. The morphology of PAA on the SiC particles was observed by transmission electron microscopy. The influence of PAA addition on the rheology of SiC suspensions was also examined.