SEDIMENTATION VOLUMES AND RIGIDITY IN SUSPENSIONS OF SODIUM SOAPS IN MINERAL OILS

Abstract

The equilibrium sedimentation volumes of sodium soaps in suspension in mineral oils have been measured. The sedimentation volume increases greatly with decrease in viscosity index of the oil. Flow–pressure relations, determined with a torsional viscosimeter, show that suspensions with large sedimentation volumes possess rigidity, whereas the flow is Newtonian in suspensions having small sedimentation volumes. Variation in sedimentation volume is therefore caused by difference in the tendency toward agglomeration or attraction between particles, leading to the formation of branched chains and scaffolding structures, with consequently greater sedimentation volumes.