Inorganic Versus Organic
There are two common types of optically active additives available commercially: inorganic and organic. Inorganic OAAs exhibit large particle sizes of 5 to 10μm (no mobility), are light-stable, can have a choice of colours as shown in image above, are useful in a wide range of coating systems, and are more expensive. Some inorganic OAAs can exhibit some degree of afterglow aiding inspection.
Organic OAAs require low addition levels, are soluble in solvents and organic liquids (mobile), are blue under UV (emitting the same colour as lint, oil, grease etc.), can fade quickly, have limited use in a range of coating systems and are less expensive. They are also indistinguishable from old tar epoxy-type coatings still seen on some structures and vessels. Organic OAAs have no afterglow.
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Famous quotes containing the words inorganic and/or organic:
“Man, unlike anything organic or inorganic in the universe, grows beyond his work, walks up the stairs of his concepts, emerges ahead of his accomplishments.”
—John Steinbeck (1902–1968)
“When life has been well spent, age is a loss of what it can well spare,—muscular strength, organic instincts, gross bulk, and works that belong to these. But the central wisdom, which was old in infancy, is young in fourscore years, and dropping off obstructions, leaves in happy subjects the mind purified and wise.”
—Ralph Waldo Emerson (1803–1882)