Material in which viscosity increases with the rate of shear strain
Not to be confused with Dilatancy (granular material).
A dilatant (/daɪˈleɪtənt/, /dɪ-/) (also termed shear thickening) material is one in which viscosity increases with the rate of shear strain. Such a shear thickening fluid, also known by the initialism STF, is an example of a non-Newtonian fluid. This behaviour is usually not observed in pure materials, but can occur in suspensions.
A dilatant is a non-Newtonian fluid where the shear viscosity increases with applied shear stress. This behavior is only one type of deviation from Newton's law of viscosity, and it is controlled by such factors as particle size, shape, and distribution. The properties of these suspensions depend on Hamaker theory and Van der Waals forces and can be stabilized electrostatically or sterically. Shear thickening behavior occurs when a colloidal suspension transitions from a stable state to a state of flocculation. A large portion of the properties of these systems are due to the surface chemistry of particles in dispersion, known as colloids.
This can readily be seen with a mixture of cornstarch and water (sometimes called oobleck), which acts in counterintuitive ways when struck or thrown against a surface. Sand that is completely soaked with water also behaves as a dilatant material — this is the reason why when walking on wet sand, a dry area appears directly underfoot.
Rheopecty is a similar property in which viscosity increases with cumulative stress or agitation over time. The opposite of a dilatant material is a pseudoplastic.
A dilatant (/daɪˈleɪtənt/, /dɪ-/) (also termed shear thickening) material is one in which viscosity increases with the rate of shear strain. Such a shear...
but flows easily when not under pressure. However, oobleck is actually a dilatant fluid, since it does not show the time-dependent, shear-induced change...
critical state soil mechanics; highly overconsolidated clayey soils are dilatant, while normally consolidated soils tend to be contractive. The shear strength...
n = 1 then the fluid is a Newtonian fluid. n > 1 then the fluid is a dilatant. The relationship between the shear stress and shear rate in a casson fluid...
=K(T){\dot {\gamma }}^{n-1}} This expression can also be used to describe dilatant (shear thickening) behaviour, where the value of n is greater than 1. Bingham...
significantly deviate from this behavior. For example: Shear-thickening (dilatant) liquids, whose viscosity increases with the rate of shear strain. Shear-thinning...
originally for a sol-gel transformation. Bingham plastic Calcium Sulfate Dilatant Kaye effect Nanocellulose Polymer Silly putty Morrison, Ian (2003). "Dispersions"...
likely to cause the fluid pressure to rise until it is sufficient to cause dilatant fracturing. Dewatering of sediment that has been underthrust and accreted...
to the amount of force applied, Silly Putty can be characterized as a dilatant fluid. Silly Putty is also a fairly good adhesive. When newspaper ink was...
has the opposite rheological property: it is negative thixotropic, or dilatant, allowing the demonstration of "walking on custard". Wikibooks Cookbook...
on the shear rate at which it is measured. The apparent viscosity of a dilatant fluid is higher when measured at a higher shear rate (η4 is higher than...
Non-Newtonian fluids can be either plastic, Bingham plastic, pseudoplastic, dilatant, thixotropic, rheopectic, viscoelastic. In some applications, another rough...
lubricates the articulating joints[page needed] shock absorption — as a dilatant fluid, that possesses rheopectic properties, becoming more viscous under...
materials scientists Richard Palmer and Philip Green experimented with a dilatant liquid with non-Newtonian properties. Unlike water, this liquid was free-flowing...
assembly and a driven shaft at the other end. The drum is filled with a dilatant fluid, often silicone-based, to about 80% by volume. When the two sets...
studied in the 1880s was the properties of granular materials, including dilatant materials. In 1903 appeared his 250-page book The Sub-Mechanics of the...
increasing with relative deformation, and are called shear-thickening or dilatant materials. Since Sir Isaac Newton originated the concept of viscosity,...
Laumonier, Bernard; Blanco, Oscar (1999). "Fluidized hydrothermal breccia in dilatant faults during thrusting: the Colombian emerald deposits". Geological Society...
interpretation, developing a model in which the aether might, like pine pitch, be dilatant (fluid at slow speeds and rigid at fast speeds). Thus the Earth could move...
incorporates features similar to Batman's own batsuit. The main bodysuit uses dilatant-based armor and contains encrypted radio, GPS, and biotelemetry transmitters...
results in mixing or mass transport without required directed bulk motion. dilatant A substance with the ability to increase in volume when its shape is changed...
non-Newtonian. Shear thickening fluids (or STF), which are the same as dilatants, are one type of non-Newtonian fluid. Magnetorheological fluids (or MRF)...
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