Frictional Phenomena. VIII

Publisher Website
Google Scholar
Abstract
GEL formation in colloidal systems causes the viscosity of such systems to vary with the stress: these are called non‐Newtonian liquids. Because the physical cause of such behavior is related to the gel structure, the phenomenon is called structural viscosity. Three particular features are observed with such systems: a non‐linearity of the rate of shear vs. stress relation in the case of stationary flow; a finite relaxation process for suddenly applied stresses or deformations; and a frequency dependent dynamic viscosity in the case of alternating processes. The chief experimental facts in these three fields are presented, together with certain semitheoretical equations best suited to describe the experiments.