Showing papers by "Charles H. Giles published in 1968"
TL;DR: In this paper, the shape of the arithmetic plot of the loss of dye is determined by the physical condition and environment of the coloring matter, and a change in concentration does not usually change the class of fade.
Abstract: All lightfading rates of dyed or pigmented materials can be divided into five main classes and some subgroups, according to the shape of the arithmetic plot of rate of loss of dye. The physical condition and environment of the coloring matter appear to be principal factors determinipg the shape; a change in concentration does not usually change the class of fade.Class I fades are approximately first-order curves and are indicative of dye dispersed as single molecules or very small associated units. Class II fades are initially class I but later become linear (zero order), probably because a high proportion of coloring matter either is firmly embedded in the substrate molecules or is present as relatively large associated units. Class III fades resemble the later portion of Class II for similar reasons.Class IV fades have a point of inflection, with a more rapid fade following an initial slow change or even an apparent negative fade, i.e., an increase in depth of color; class V fades accelerate continuousl...
39 citations
TL;DR: A few dyes and fluorescent brightening agents of disperse type, in hydrophobic substrates, show anomalous fading characteristics, i.e., reduced lightfastness with in creased dye concentration, a re...
Abstract: A few dyes and fluorescent brightening agents of disperse type, in hydrophobic substrates, show anomalous fading characteristics, i.e., reduced lightfastness with in creased dye concentration, a re...
17 citations