Investigation of dye-surfactant solution mixtures
A family of dissociative direct dyes dissolves in water at pH values larger than 9. Solubilisation of the dyes is enhanced by surfactants. The present study investigates the impact of surfactants on the solution behaviour of dyes in aqueous solution at variable pH and at different amounts of metal cations. SAXS help to analyse the impact of cations on the solution behaviour of dyes.
The focus of the work lies on SANS with its technique of contrast variation by varying the D2O/H2O ratio, which are applied to investigate the morphology of the micelles loaded with dyes and the distribution of the dyestuff molecules within the mixed aggregates. A circulating system connecting the SANS cell at the beam line with a chamber with hair and a UV-vis spectrometer is developed in order to analyse the uptake and release of the dyes incorporated into surfactant micelles at variable pH and contents of metal cations and relate the information with the in-situ measured morphology of the mixed micelles.
More about Wenke Muller (ILL webpage)