ABSTRACT
A key to understanding the technology of thickened and gelled phase change materials (PCMs) is the science of rheology, which deals with the flow properties of materials. The disparate results were finally explained by Steven Marks of the University of Delaware, who performed freeze-melt tests on clay-thickened Glauber's salt and found enhanced stability over the unthickened material. It is believed that thixotropic behavior can be coupled with any of the Newtonian or non-Newtonian behaviors. It is important to emphasize that the term "thixotropic" refers only to materials with the time-dependent properties. This nomenclature has come into erroneous, widespread common use to describe shear-thinning materials, such as pseudoplastics or Bingham plastics, including thickened phase-change materials. Chliarolithe is described as a viscous liquid above 28°C, but it can be transferred with a pump intended for use with cement or sludge. The high aspect ratio particles in mineral thickeners increase viscosity by interfering with fluid flow.
