Investigation of the Solution Behaviour of Dissociative Direct Dyes in the Presence of Surfactants at Variable pH and Salinity.
Dissociative direct dyes can be used for hair colouring. The purpose of my PhD-research lies in the investigation of the behaviour of these dyes in solution. Since hair-dye-mixtures usually also contain surfactants as well as different additives, I am investigating in which way they are influencing the solution behaviour of the dyes. Herein, the focus lies on the formation of dye-surfactant aggregates and modification of these aggregates due to triggers like a change in pH or ionic strength of the solution. I am trying to get an idea about aggregate shape and morphology as well as the underlying mechanism of aggregate formation. My studies mostly rely on scattering techniques, such as static and dynamic light scattering (DLS and SLS) and small angle neutron scattering (SANS) with the technique of contrast variation.