A study of stable ion-pairs

A study was made of the ion-pair that forms when the commercial surfactant, Ethoquad 18/25, is mixed with azo dyes such as methyl orange or methyl red. The study determined some of the physical characteristics of the ion-pair, and two attempts were made to determine the structure. Through a series of titrations it was found that the ion-pair is sensitive to pH and can be dissociated in strong acid solution. An attempt to determine the structure of the complex by infra-red analysis failed. The equilibrium constants for the Ethoquad and two different dyes were determined. On the basis of the difference in the structure of the dyes, a structure for the ion-pair was proposed