EFFECTS OF THIOUREA ON AGGRIGATION OF THIAZINE DYES: A VISIBLE SPECTROSCOPY STUDY

Self-association of thiazine dyes in solutions is a well-known phenomenon [1]. Chemicaladditives such as thiourea (TU) alter the properties of materials[2]. We describe the effect ofconcentration on the spectral data and aggregative properties of the thiazine dyes in aqueousand aqueous TU solutions. The monomer–dimer equilibrium of the dyes was investigated.TU can interact with themselves and polar groups present in the dyes through the hydrogenbonding and can potentially alter the driving force for the dye aggregation.