Study Of Association Interactions Between Sudan Red And Sodium Dodecyl Sulfate In Aqueous Solution, Aqueous Alcohol Solution And Microemulsion

The research about the interaction between surfactants and dyes have great significancefor the chemical analysis, biotechnology and textile dyeing. So it has been a widespreadconcern in recent years. Some research shows that the molecular structure of surfactants anddyes play a decisive role for the interaction between them. However, the study about themechanism of interaction between surfactants and dyes is not complete and needs to furtherdeepen. So it is necessary to further study the effect of surfactants and develop new methodfor rapid detection and identification of dyes.In this paper the absorption spectrum of sudan red Ⅲ (SR) in aqueous solution, aqueousalcohol solution and O/W microemulsion systems with surfactant sodium dodecyl sulfate(SDS) has been determined by the UV-Vis spectrophotometer. It was found that an associationinteraction existed between the stain SR and anionic surfactant SDS in all of these systems,and this association between SDS and SR resulted in the maximum absorption wavelengthand the maximum absorbance of SR significantly changed.The absorbance of SR was measured in aqueous solution with different concentrations,methanol, ethanol, n-propanol aqueous solution, and microemulsion systems which haddifferent values of R by experiment. An appropriate association model was established toanalyse the experimental data and error analysis for the experimental data. We obtain theassociation constants of SR and SDS in aqueous solution, aqueous alcohol solution andmicroemulsion. From the results, It was found that the association between SR and SDS inaqueous solution can be promoted by adding a small amount of alcohol. Then the values ofthermodynamics functions of association ΔrGmhas also been calculated from the associationconstants of SR and SDS in microemulsion.