What is thixotropic material?
Thixotropic materials display a viscosity that decreases with shear rate and time of shear as well. They possess a solid structure that requires time to form under high pressure (or low temperature) and that structure is disrupted by shear stress.
Is toothpaste a thixotropic mixture?
Many products used in daily life can be characterized by their thixotropic behavior. Thixotropy is the property that explains why personal care products like hair gels and toothpaste are liquid when squeezed out of the tube but recover to their initial solid state afterwards in order to remain in place.
What is thixotropic behavior?
In rheology thixotropic behavior is defined as time-dependent behavior. It means a reduction of the structural strength during a constant shear load phase and a more or less rapid but complete regeneration of the structure during the subsequent rest phase.
What is a thixotropic fluid and give an example?
Thixotropic: Apparent viscosity for thixotropic fluids decreases with time under constant applied shear stress. Example: Crude oil, lipstick, certain paints, and Printing Ink.
What are rheopectic fluids?
Rheopectic fluids, such as some lubricants, thicken or solidify when shaken. The opposite and much more common type of behaviour, in which fluids become less viscous the longer they undergo shear, is called thixotropy. Examples of rheopectic fluids include gypsum pastes and printer inks.
Is synovial fluid thixotropic?
Synovial fluid exhibits non-Newtonian flow characteristics: The viscosity coefficient is not a constant, and the fluid is not linearly viscous. Instead, it exhibits thixotropic characteristics: Viscosity decreases and the fluid thins over a period of continued stress.
Is tomato sauce thixotropic?
The effect of manothermosonication on tomato pectic enzymes and tomato paste rheological properties. Journal of Food Engineering, 53: 273–278. [CROSSREF] [Crossref], [Web of Science ®], [Google Scholar] also found that tomato paste exhibits a thixotropic behavior when the samples were sheared at 99 s−1 for 5 min.
What is the example of thixotropic fluid?
Examples of thixotropic materials include many gels and colloids, as well as common food products such as ketchup and yogurt. However, thixotropic properties are especially essential in paints and coatings.
What are thixotropic materials?
Thixotropic materials display a viscosity that decreases with shear rate and time of shear as well. They possess a solid structure that requires time to form under high pressure (or low temperature) and that structure is disrupted by shear stress.
What are thixotropic agents in paint?
Thixotropic agents are added to give the paint the correct rheologic properties such as viscosity and sag resistance (sagging is defined as the downward movement of a paint film on a vertical surface during curing, resulting in an uneven coating having a thick lower edge) and to prevent settling of the pigments during storage.
Thixotropic behavior occurs if, when exposed to high shear rates, the microstructure gradually breaks down and the fluid becomes less viscous, and if, when exposed to low shear rates, the microstructure is gradually rebuilt and the fluid becomes more viscous. This is common for colloidal dispersions.
What is a thixotropic loop?
A thixotropic loop is the hysteretic response obtained in a shear stress vs. shear rate plot ( Fig. 2.9) when a material is submitted to a cyclic shear history – typically, a series of up and down shear rate ramps, cf. Fig. 2.4.