Effect of Dispersants on the Sorption Isotherm of Nonionic Dyes on Polymers from Water.

Abstract

: Disperse dyes dissolved in aqueous dye bath bind to dispersants; the bound dye loses the affin ity for polymer substrates. Addition of a constant concentration of dispersants in the dye bath varies the shape of the sorption isotherm of disperse dyes on polymers due to the dye binding by dispersants.Computer simulation predicted that the shape of the isotherm will vary from convex to upward to linear and then to concave to upward as the concentration of the dispersant is increased. The prediction was con firmed experimentally using fl-cyclodextrin as a model compound for dispersants.Linear sorption isotherms of purified disperse dyes on polymers reported by earlier investigators were interpreted in terms of the presence of a constant concentration of dispersants in aqueous dye bath.