Abstract: | Investigations of the adsorption of acid dyes (l–phenyl–3–methylpyrazolone derivatives) by polyamide fibres have been carried out. It has been found that the adsorption levels are unexpectedly different for various dyes. Some of the dyes, despite high concentration in the dyebath, show adsorption within the limits of what would be predicted by consideration of the amino group content in the amorphous region of the fibre. Other dyes, despite high pH, are characterised by considerably higher adsorption than would be predicted. The results obtained suggest that the increased adsorption of the dyes is brought about by the aggregation of molecules in the fibre into dimers or their multiples. |