Abstract
Dry grinding of talc was carried out using a planetary mill in the presence of metal alkoxides such as aluminum tri-sec-butoxide, silicon tetra-n-butoxide and titanium tetra-n-butoxide. These additives were found to be effective in producing fine and flaky particles with a thin width. The alkoxides having a low surface tension were spread smoothly on the whole surface forming a new surface of particles during the grinding. This resulted to the improvement of the dispersibility of groundpowders due to the reduction in adhesion forces among particles. With regard to the formation of adsorbed layer of additives, a change in the sign of residual electrostatic charge of the ground powders from negative to positive was also observed. In particular, the resuling fine powders with a desirable flaky shape is probably attributed to the chemisorption of the additive molecules on the broken bond surface, facilitating the creation of fine cracks and their propagation along the cleavage planes of talc.
