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In physical chemistry, supersaturation occurs with a solution when the concentration of a solute exceeds the concentration specified by the value of solubility at equilibrium. Most commonly the term is applied to a solution of a solid in a liquid , but it can also be applied to liquids and gases dissolved in a liquid.
Crystallization is the process by which solids form, ... Maximum supersaturation will take place in the coldest points.
The growth of a crystal through direct adsorption of a gas phase on to a solid surface is generally very slow. The VLS mechanism circumvents this by introducing a catalytic liquid alloy phase which can rapidly adsorb a vapor to supersaturation levels, and from which crystal growth can subsequently occur from nucleated seeds at the liquid ...
Crystal growth is a major stage of a crystallization process, ... Very commonly when the supersaturation (or degree of supercooling) is high, and sometimes even when ...
In this technique, crystallization takes place without a temperature gradient between the growth and dissolution zones. The supersaturation is achieved by a gradual reduction in temperature of the solution in the autoclave. The disadvantage of this technique is the difficulty in controlling the growth process and introducing seed crystals. For ...
If water is cooled at a rate on the order of 10 6 K/s, the crystal nucleation can be avoided and water becomes a glass—that is, an amorphous (non-crystalline) solid. Its glass transition temperature is much colder and harder to determine, but studies estimate it at about 136 K (−137 °C; −215 °F). [ 9 ]
Supersaturation of more than 1–2% relative to water is rarely seen in the atmosphere, since cloud condensation nuclei are usually present. [27] Much higher degrees of supersaturation are possible in clean air, and are the basis of the cloud chamber. There are no instruments to take measurements of supersaturation in clouds. [28]
These have been compared with the classical theory, for example for the case of nucleation of the crystal phase in the model of hard spheres. This is a model of perfectly hard spheres in thermal motion, and is a simple model of some colloids. For the crystallization of hard spheres the classical theory is a very reasonable approximate theory. [9]