Shearinduced

Shear-induced is an adjective used to describe effects that arise when a material is subjected to shear, a condition in which adjacent layers move parallel at different velocities, creating a velocity gradient. The term is widely used in soft matter physics, materials science, and rheology to distinguish phenomena that depend on flow from those that occur at rest.

In complex fluids such as polymer solutions, melts, suspensions, and emulsions, shear can realign microstructure, promote or suppress phase separation, and alter transport properties. Mechanisms include deformation and orientation of anisotropic constituents, flow-induced breakup or association of aggregates, and changes in diffusion relative to flow (such as shear-induced diffusion or migration).

Common examples include shear-induced alignment and crystallization in polymers and liquid crystalline materials, shear-induced phase separation in colloidal suspensions, and shear-dependent viscosity changes known as shear thinning or shear thickening tied to microstructure evolution. In granular materials, shear can cause dilation and the formation of shear bands. In rheology, these effects are central to processing operations and material design.

Experimental techniques such as rheometry combined with spectroscopy, rheo-optical methods, and rheo-SAXS or confocal rheology enable observation of microstructure under shear. Theoretical treatments use constitutive models that couple flow to structure evolution, such as flow-aligning theories for liquid crystals or Cahn–Hilliard-type models for phase separation under flow. Understanding shear-induced phenomena informs polymer processing, food and consumer products, and geophysical and industrial flows.