Fluorescent whitening agent
An organic fluorochrome that absorbs radiation in the ultraviolet range then reemits the energy as visible light. First used in 1947, fluorescent whitening agents are added to papers, textiles, and detergents to give the visual appearance of a whiter, brighter material. When viewed in light that has an ultraviolet component, such as natural daylight, the fluorescent additive will emit light in addition to the normally reflected light thus making the paper or textile appear brighter. In detergents, sulfonated trazinylstilbenes are used as optical brighteners. Many manufacturers incorporate fluorescent whitening agents in the base mixture for synthetic fibers. Under ultraviolet light, materials with fluorescent whitening agents will produce a strong bluish-white emission. Examples of FWAs are derivatives of 4,4'-diaminostilbene-2,2'-disulfonic acid and coumarin derivatives such as 4-methyl-7-diethylaminocoumarin.
Synonyms and Related Terms
FWA; brightener; optical bleach; optical brightener; fluorescent brightener; fluorescent whitener
Resources and Citations
- R.Zweidler, "Why and How Fluorescent Whiteners Work" Ciba-Geigy Review, 3:38-44, 1971.
- G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 474
- Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
- Hoechst Celanese Corporation, Dictionary of Fiber & Textile Technology (older version called Man-made Fiber and Textile Dictionary, 1965), Hoechst Celanese Corporation, Charlotte NC, 1990
- Rosalie Rosso King, Textile Identification, Conservation, and Preservation, Noyes Publications, Park Ridge, NJ, 1985
- The Dictionary of Paper, American Paper Institute, New York, Fourth Edition, 1980
- Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976
- A Glossary of Paper Conservation Terms, Margaret Ellis (ed.), Conservation Center of the Institute of Fine Arts, New York City, 1998