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Description of dyeing equilibria in the application of direct dyes
Author(s) -
Gerber H.
Publication year - 1996
Publication title -
journal of the society of dyers and colourists
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.297
H-Index - 49
eISSN - 1478-4408
pISSN - 0037-9859
DOI - 10.1111/j.1478-4408.1996.tb01807.x
Subject(s) - dyeing , absorption (acoustics) , cellulosic ethanol , ion , chemistry , surface (topology) , surface charge , charge (physics) , competition (biology) , chemical physics , chemical engineering , materials science , organic chemistry , cellulose , composite material , mathematics , physics , ecology , geometry , engineering , biology , quantum mechanics
Direct dyes are absorbed on the internal surface of cellulosic substrates, the amount of surface accessible to a dye anion depending on the form and size of the anion. Thus there are surface regions for which all the dyes in a combination compete, and others that are only accessible to only one dye in a particular combination. The internal surface of the fibre also possesses an electric charge. The extent to which this initial charge is reinforced depends on the different absorption of the dye anions by different surfaces. Besides competition for dye sites, a mutual electrostatic repulsion occurs. A system of equilibrium conditions permits the absorption of different dyes in a combination that can be calculated on the basis of the absorption characteristics of the individual dyes.