Introduction to Rheology Basics

Rheology Definition

• Rheology is the study of the flow and deformation of materials, particularly fluids, under applied stress.

Importance of Rheology

• Rheology is important because it helps understand the behavior of materials in various industrial and biological processes, such as manufacturing, processing, and biological systems.

Response to Shear Stress

• Fluids respond to applied stress, known as shear stress, by deforming and changing their shape.

Intrinsic Property of Fluids

• The intrinsic property of a fluid, determined by plotting Shear Stress versus change in V/L, is its viscosity.

Dynamic Viscosity

• The dynamic viscosity of a fluid is described by Newton's Law of Viscosity, which states that the shear stress is proportional to the shear rate.

Shear Thickening Behavior

• A type of fluid that exhibits shear thickening behavior is a dilatant fluid, which becomes more viscous when subjected to increasing shear stress.

Thixotropic Materials

• The defining characteristic of a thixotropic material is that it becomes less viscous when agitated or shaken and returns to its original viscosity when left still.

Elasticity

• Elasticity refers to the property of a material that allows it to return to its original shape after the removal of an applied stress.

Rheology vs. Viscosity

• The main difference between rheology and viscosity is that rheology is the study of the flow and deformation of materials under stress, while viscosity is a measure of a fluid's resistance to flow.

Pseudoplastic Materials

• In a pseudoplastic material, the dynamic viscosity decreases as the rate of shear increases.

Learn about the fundamentals of rheology, the study of flow and deformation properties of matter. Discover the importance of fluid rheology in various industries such as cosmetics, including processes like mixing, flow through pipes, and packaging.