Conductivity Measurement—A Simple Method for Determining Dye / Surfactant Interaction

Abstract

Surfactants present in the dyebath are responsible for a considerable change in the state of dye in solution, predominately caused by interactions between dye and sur factant. Among several known methods for investigating these interactions, the con ductivity measurement is a simple and accessible method for determining the degree of interaction between direct or acid dye and nonylphenolethoxylates. In order to explain the results conveniently, a fraction named the conductance ratio is defined and used as a measure of the degree of dye /surfactant interaction. The kind of surfactant does indeed exert significant influence on the degree of interaction.