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



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).


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



The volume increase caused by wetting, absorption of moisture, or chemical changes.
References in periodicals archive ?
Accuracy of fine needle aspiration cytology in diagnosis of thyroid swelling.
However, due to the large amount of water that exists in the polymer network after the polymerization reaction, the formed pores could swell again during the drying process, causing the pore structures to shrink and collapse and decreasing the swelling rate.
A 40-year-old woman presented with dyspnea, severe pain during swallowing, and a 7-day history of swelling in the left parotid gland.
In this study a simple and widely used test tube-based procedure was used that involves solvent swelling of a powdered sample with swollen sample centrifugation.
Compaction has generally positive effects for ordinary soils but when swelling soils are encountered beneath the foundations of the structures, their over compaction may lead to upward heave, on subsequent addition of moisture, causing uplift of the structures especially the lightly loaded structures (Seed et al.
Specimen adequacy in swellings of thyroid, lymph nodes and salivary glands was better with 22 gauge amounting 90%, 80% and 80% respectively, as compared to yield with 21 gauge needles which was 85%, 70% and 60% respectively.
TAM elastomer annulus packers swelling upon contact with fluids are applied in the wells of all categories in terms of zonal isolation.
Keywords: Terpolymeric hydrogel, acrylic acid, vinyl acetate, methyl acrylate, cross linker sensitive swelling model, cross linker concentration coefficient.
Ten cases of bullocks with history of acute or chronic lameness or inflammatory swelling and two cases of horses suffering from inflammatory swelling of neck region were included in the study.
Selection was based on swelling capacity in small and medium seeded genotypes.
Tell them to seek medical advice if the pain and swelling persist.