The absorption of Chrysophenine G by cotton: a test of quantitative theories of direct dyeing

Abstract

The investigation of the equilibrium absorption of Chrysophenine G by cotton has been extended to a wide range of salt/dye ratios in the dyebath. The results do not agree with the predictions of a current quantitative theory of the direct dyeing of cellulose.The substantivity ratio appears to increase indefinitely with increase of the salt/dye ratio, while the theory predicts that it should approach a finite limit ; and, contrary to the theory, the relation between the substantivity ratio and the salt/dye ratio depends on the salt concentration. '' Internal " adsorption isotherms have been calculated from the results.They approximate to the Freundlich type, differing considerably from the linear form assumed in the formulation of the theory, and depend on the salt concentration. The failure of the theory to fit the experimental results may be caused principally by the unavoidable use of concentrations in place of activities in its formulation.

The role of auxiliaries in the immersion dyeing of textile fibres part 2: Analysis of conventional models that describe the manner by which inorganic electrolytes promote direct dye uptake on cellulosic fibres

“…As recounted, although the mechanism by which added electrolyte promotes both the rate and extent of uptake of direct dyes (and other dye anions) onto cellulosic fibres has received considerable attention [eg (9,30,32,33,35,(47)(48)(49)(50)(51)(52)(53)(54)(55)(56); see (2) for a summary], our understanding of this highly complex subject leaves much to be desired. However, such a situation deserves to be Hopefully, this, necessarily very brief, discussion of our current understanding of the highly complex areas of water structure and water-electrolyte interactions goes some way to explain why the mechanism by which added electrolyte promotes both the rate and extent of uptake of direct dyes (and other dye anions) onto cellulosic fibres is not fully resolved.…”

Nonlinear modeling of equilibrium sorption of selected anionic adsorbates from aqueous solutions on cellulosic substrates. Part 1: model development

“…V is commonly used to compare and contrast the difference in physical structures of cellulosic substrates (Standing 1954;Holmes 1958;Carrillo et al 2002;Ibbett et al 2006Ibbett et al , 2007. As implied in Eq.…”

Nonlinear modeling of equilibrium sorption of selected anionic adsorbates from aqueous solutions on cellulosic substrates: part 2: experimental validation

“…2 (Freundlich 1926;Vickerstaff 1954), and is often expressed as a log-linear model shown in Eq. 3 (Marshall and Peters 1947;Peters and Vickerstaff 1948;Standing 1954;Holmes 1958;Porter and Perkins 1970;Carrillo et al 2002;Ibbett et al 2006;Ibbett et al 2007), …”