swelling

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Related to turgescence: plasmolyse

swelling

an abnormal enlargement of a bodily structure or part, esp as the result of injury

Swelling

 

an increase in volume of solid bodies caused by their absorption of liquids or vapors from the environment. The capacity to swell is a characteristic property of bodies consisting of macromolecular compounds (polymers). Swelling is caused by diffusion processes, which are usually accompanied by solvation (the binding of a low-molecular-weight substance by a polymer).

A distinction is made between limited and unlimited swelling. In the first case the macromolecules are bonded fairly strongly, and swelling stops after having reached a certain limit. The swelled body retains its shape and a distinct boundary with the liquid phase. In the second case, mutual diffusion of the solvent and the polymer gradually leads to the disappearance of the interphase boundary between the swelling body and the liquid. Such swelling culminates in complete dissolution of the polymer. For example, limited swelling is exhibited by gel-like ion-exchange resins in water and by vulcanized rubber in benzene; unlimited swelling is exhibited by all polymers that are soluble in a particular solvent. In some cases, such as the gelatin-water system, limited swelling gives way to unlimited swelling with increasing temperature. Swelling is also a property of some minerals with a lamellar crystal lattice—for example, the montmorillonites. Upon swelling in water, such materials may undergo spontaneous dispersion, leading to the formation of highly disperse colloidal systems.

Swelling has wide use in industry and in everyday life. It frequently accompanies bonding of polymer materials, processing of polymers to produce various articles, production of rubber adhesives, and other processes, such as preparation of many foods and many natural processes (germination of seeds and spores).

REFERENCES

Tager, A. A. Fizikokhimiia polimerov. 2nd ed. Moscow, 1968. Page 314.
Voiutskii, S. S. Kurs kolloidnoi khimii. Moscow, 1964. Page 482.

L. A. SHITS

swelling

The volume increase caused by wetting, absorption of moisture, or chemical changes.
References in periodicals archive ?
For signal grass no difference was observed from the first to the third instar, and for the fifth instar and the entire nymph phase the maintenance of turgescence of the leaf by agar was not favorable.
For the white varieties, leaves show on the blade or at the edge of some zones which lose their turgescence and become yellowish-orange (Fig.
Viability of ectomycorrhizal root tips was based on turgescence and color, as described by Harvey et al.
But he immediately adds that what takes place in each of Twombly's works is an attack on seriousness, on decorum, one that "takes on the appearance of an incongruity, a mockery, a deflation, as if the humanist turgescence was suddenly pricked.
In short, it fulfills the precise function that Lacan attributes to the phallus as bearer of the subject's basic libidinal investment: "Ce quelque chose de l'organisme ou la vie, ou la turgescence vitale, est symbolisee .