Supercooling

(redirected from Supercooled liquid)

supercooling

[¦sü·pər′kül·iŋ]
(thermodynamics)
Cooling of a substance below the temperature at which a change of state would ordinarily take place without such a change of state occurring, for example, the cooling of a liquid below its freezing point without freezing taking place; this results in a metastable state.

Supercooling

 

cooling of matter to temperatures below those of equilibrium phase transition that brings the matter to a new state of aggregation, or another crystalline modification that does not result in a phase transition. A supercooled material is in a state of metastable equilibrium.

The phase transitions that are associated with loss of heat— condensation, crystallization, and polymorphic transformations —usually involve supercooling in their initial stages; the supercooling helps generate nuclei of the new phase in the form of tiny droplets or crystallites. It is difficult to form nuclei at the phase-transition temperature because the nuclei feature higher pressure or solubility and thus cannot be in equilibrium with the initial phase at this temperature. Under conditions where the generation and growth of nuclei of a new phase are inhibited, for example, during recrystallization of a solid and during crystallization of a highly viscous liquid, deep supercooling can be used to obtain a practically stable phase whose internal structure resembles that of phases at higher temperatures. This procedure is the basis for steel-quenching processes and for the production of glass. The degree to which water vapor is supercooled in the atmosphere determines whether precipitation will occur in the form of rain, snow, or hail.

References in periodicals archive ?
This graduate text introduces the mechanisms of glass formation related to the stability of the supercooled liquid, particularly the limiting of crystal nucleation and the limiting of their growth in relation to the formation of crystals and quasicrystals, and describes the structural changes that occur in metallic glasses during heating.
Moreover, the chaotic nature of weather is clearly apparent at the space and time scales where cloud seeding is conducted; that is, even with high-resolution data assimilation, it will be difficult to simulate the actual distribution of quantities like supercooled liquid water or precipitation on scales of a few tens of kilometers and a few hours.
NASA Glenn Research Center's Supercooled Liquid Water Content (SLWC) sensor, co-developed by Anasphere Inc.
Cold sodium acetate is an example of a supercooled liquid.
Supercooled liquid water must become ice at minus 48 C (minus 55 F) not just because of the extreme cold, but because the molecular structure of water changes physically to form tetrahedron shapes, with each water molecule loosely bonded to four others, according to the new study by University of Utah chemists Valeria Molinero and Emily Moore.
According to the new study by chemists Valeria Molinero and Emily Moore, supercooled liquid water must become ice at minus 55 F not just because of the extreme cold, but because the molecular structure of water changes physically to form tetrahedron shapes, with each water molecule loosely bonded to four others.
The powerful booster technology using supercooled liquid fuel is designed to put heavier satellites into high orbits, about 36,000 km from Earth.
g] the material reaches metastable states known as supercooled liquid (or like rubbery state).
In such clouds, warm rain processes act below the freezing level (the height at which the temperature is at 0[degrees]C), but ice particles are also initiated above the freezing level that interact with the supercooled liquid cloud droplets in a variety of ways.
to Salem with a load of supercooled liquid hydrogen.
Supercooled liquid hydrogen is injected into the intake ducts where it mixes with air before entering the cylinders for ignition.