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)
“The following general definition of an animal: a system of different organic molecules that have combined with one another, under the impulsion of a sensation similar to an obtuse and muffled sense of touch given to them by the creator of matter as a whole, until each one of them has found the most suitable position for its shape and comfort.”
—Denis Diderot (1713–1784)