What does thixotropy mean?
Thixotropy names a time-dependent change in the consistency of a material. A thixotropic substance is typically thick, paste-like, or gel-like while at rest, but becomes more fluid when it is shaken, stirred, brushed, or otherwise subjected to mechanical force. When the force is removed, its viscosity generally increases again, often returning gradually to its original state. This behavior differs from ordinary shear thinning, because thixotropy specifically includes recovery after agitation. Thixotropy is important in many familiar materials: paints can flow under a brush without running on the wall, inks can spread during writing, and certain gels become mobile when shaken. The word is also used in scientific research on rheology and the structure of fluids. Though fairly uncommon outside technical contexts, it names a distinctive and useful property found in everyday products.
nounThixotropy is the property of a material that is thick or gel-like at rest but becomes fluid and easier to mix when shaken, stirred, or otherwise subjected to shear. The material gradually returns to its original consistency when the agitation stops.
- The time-dependent property of a material or system to become less viscous or more fluid under shear and to regain its original consistency when the shear is removed.
"The paint has a pleasing thixotropy, flowing smoothly under the brush but becoming firm again on the surface."
"Thixotropy makes the ink spread easily while the pen is moving and prevents it from running once it reaches the page."
"The laboratory measured the thixotropy of the clay suspension as its viscosity changed systematically with stirring."
The plural is grammatically possible but uncommon in technical writing, where the uncountable use of the word or the adjective thixotropic is usually preferred.
"The researchers compared the thixotropies of several clay-based suspensions."
Shake a thixotropic gel and it suddenly flows; leave it alone, and it thickens again.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does thixotropy come from?
The word combines Greek roots associated with mixing and turning or changing: thixotropy literally suggests a turning or change during mixing. It was coined as a technical term in the early twentieth century to describe materials whose viscosity changes reversibly under mechanical agitation. Its principal technical derivative is thixotropic.
Related word forms
How thixotropy is actually used
This is primarily a technical term used in rheology, physical chemistry, materials science, and fields involving paints, inks, coatings, cosmetics, ceramics, and food products. In general use, it usually describes a gel or viscous liquid that can be shaken or stirred into a more fluid state.
Easily confused with thixotropy
Viscosity is a material's resistance to flow, whereas thixotropy specifically describes a change in flow behavior caused by mechanical agitation that may reverse over time.