Glycoconjugated dyes: dye removal and evidence of self-assembly in solution through spectrophotometric and scattering techniques

The present work focus on the characterization of five glycoconjugated dyes. These molecules are a class of compounds synthesized conjugating a unit of lactose to specifically modified disperse chromophores. The presence of lactose enhances the water solubility of these molecules, and also makes these compounds amphiphiles. The amphiphilicity allows the self-assembly of glycoconjugated dyes in solution. The behavior of these molecules in solution was studied experimentally using a variety of techniques, including UV-Visible spectroscopy, Dynamic Light Scattering (DLS) and Small Angle X-Rays Scattering (SAXS). Moreover, using a combination of SAXS and Electronic Circular Dichroism (ECD) the shape of the objects in solution could be determined. The influence on aggregates formation and behavior in solution of some parameters, such as the solvent, the interaction with surfactants and with other glycoconjugated dyes was also studied using the same techniques. A computational study of glycoconjugated dyes was performed using Force Fields. Computational tools allowed to determine the preferential conformations assumed by these molecules as monomers and dimers. Since glycoconjugated dyes have been designed for leather and textile dyeing, an additional preliminary study on the end of the life cycle for glycoconjugated dyes was carried out using two different dye removal approaches. The first approach could be intended as a possible alternative or a support for the classical methods and involved a white rot fungus, Funalia trogii, as microorganism for dye removal. This approach was tested on glycoconjugated dyes simulated effluents. The second approach was the classical one, involving activated sludge, and was carried out on glycoconjugated dyes real leather dyeing effluents.