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Absorption of Dyes by Keratin under Near Neutral Conditions *
Author(s) -
Marshall J.
Publication year - 1969
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.1478-4408.1969.tb02903.x
Subject(s) - chemistry , orange (colour) , monobasic acid , sodium , dibasic acid , chloride , salt (chemistry) , nuclear chemistry , chromatography , food science , organic chemistry
The absorption by keratin of the monobasic dye Orange II (C.I. Acid Orange 7) and the dibasic dye Sunset Yellow FCF (C.I. Food Yellow 3) from a dyebath containing the sodium salt of the dye and different amounts of sodium chloride at two pH values (5.1 and 6 0) was studied. Salting‐on and salting‐off were observed with Orange II but not with Sunset Yellow. Theoretical curves were constructed to fit the empirical absorption isotherms. A constant affinity term enabled a fit with the Orange II curves to be obtained, but an affinity term that decreased with increasing salt concentration was required to obtain a fit with the Sunset Yellow curves. The effect of these factors on the diffusion coefficients of the dye anions in the presence of salt is discussed.