Colloid

Description

A suspension of fine particles uniformly dispersed in a medium. The particles are so small (5 to 5000 angstroms) they do not settle out. Colloidal particles and the dispersing mediums may be gaseous, liquid or solid. For example, an aerosol is a solid-gas or liquid-gas system, a suspension is a solid-liquid, an emulsion is a liquid-liquid, and a foam is a gas-liquid system. A colloid system that resembles a liquid is termed a sol, and a system that is gelatinous is called a gel. When water is one components, the systems can be called hydrosols or hydrogels. Examples of naturally occurring colloidal systems are rubber latex, milk, blood, and white egg white.

Synonyms and Related Terms

colloidal

Authority

• G.S.Brady, G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971

• Theodore J. Reinhart, Theodore J. Reinhart, 'Glossary of Terms', Engineered Plastics, ASM International, 1988

• Richard S. Lewis, Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993

• Random House, Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997

• Art and Architecture Thesaurus Online, http://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000