Abstract
Visible light absorption of the solution of 1, 4-diaminoanthraquinone (Cibacet Violet 2R) was measured, varying content of the non-ionic surfactant added as dispersing agent, to explain the connection of solubilization with the dispersed state of the dye. In further experiment the nonionic surfactant had been succeeded by polyoxyethylene glycol as dispersing agent, the chemical structure and properties of which were just the same as the hydrophilic group of the former, and the absorption spectra obtained in the same way as the above were investigated for comparison. The dye solution provided the absorption spectrum corresponding to almost molecular dispersion only when content of the non-ionic surfactant was over its CMC. The similar spectrum was observed also in the dye solution that was higher concentrated of polyoxyethylene glycol. The experimental results suggest that the dye solubilized molecularly and stoichometrically into the hydrophilic region of the surfactant micelle.
