Abstract
The effects of solid powders on the stability of O/W type emulsion were investigated. It was found that these effects reversed at an contact angle of ca. 60° of solid powders to benzene-carbon tetrachlo ride mixture as an organic phase. Solid powders with contact angle below 60°, Carbon black #55, Philblack-I, sulfur, were found to act as an emulsion breaker.
While, solid powders with contact angle above 60°, iron, copper (II) oxide, cadmium sulfide, kaolin, were found to act as an emulsion stabilizer.
The empirical equations relating the relative settling-rate constant k to the amount of added powder were obtained. For solid powders to act as an emulsion breaker, k=0.88 Wn
where the values of n are 0.062, 0.10 and 0.17 for Carbon black #55, Philblack-I and sulfur respectively. For solid powders to act as an emulsion stabilizer, k=2.70 Wn',
where the values of n' are -0.26, -0.30, -0.35 and -0.50 for iron, cupric oxide, cadmium sulfide and kaolin respectively.
