Influence of non-ionic surfactants on the degree of association and extent of absorption of acid dyes on nylon 6

Abstract

<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" calibri;mso-fareast-theme-font:minor-latin;mso-hansi-theme-font:minor-latin;="" mso-bidi-font-family:"times="" new="" roman";mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="">The interaction of acid dyes and non-ionic surfactants in solution has been studied by the surface tension, viscosity and polarographic techniques. Positive entropy change and low enthalpy change suggest that aggregation is an entropy-determined phenomenon brought about by the hydrophobic bonding. A higher increase in reduced viscosity in the presence of surfactants is explained as an electro-viscous effect due to aggregation. The increase in particle size of acid dyes, determined by polarographic' diffusion coefficient, also suggests that the critical micelle concentration decreases with increase in the amount of surfactants. From the sorption behaviour of acid dyes in the presence and absence of surfactants on nylon 6, a possible mechanism of interaction in the dyeing process is discussed from the practical dyeing point of view to produce retarding and leveling effects.</span>