Rheology Behind the Scenes

Materials all around us can be classified as either elastic, viscous, or viscoelastic. One can determine where a material falls within the viscosity spectrum based on its rheological properties. With its start in the 1920s, rheology is still an up-and-coming method of characterization for everyday use materials.¹ This is because materials such as plastics, paints, biological materials, and more contain both solid and liquid aspects.² Unlike its counterpart, the viscometer, a rheometer can analyze those materials unable to be defined by a single value of viscosity.³ The official definition for rheology is the science and deformation of flow. It measures stress, strain, and the relation between the two in order to provide quantitative parameters of a material’s deformation.² Rheology plays a crucial role in industrial production with everything from coatings to pharmaceuticals to foods.⁴ All stages of a material’s production from manufacturing to transport to storage and eventual use are impacted by its rheological conditions.⁴ Better understanding of these conditions can allow for improved production methods with more targeted products.

1.  Markovitz, H., The emergence of rheology. Physics Today 1968, 21 (4), 23-30.

2.  Janmey, P. A.; Schliwa, M., Rheology. Curr Biol 2008, 18 (15), R639-R641.

3.  VivaDifferences Difference Between Rheometer and Viscometer. https://vivadifferences.com/difference-between-rheometer-and-viscometer/.

4.  Rheology of Semisolid Foods. Joyner, H. S., Ed. Washington State University, USA, 2019.