The dye brings people a more colorful life, it is widely used in fabric dyeing andprinting. As the representative of the typical dyes, methylene blue (MB), acridineorange (AO), and eosin Y (EY) have unique optical properties about chemical andphysical. Under ambient condition, there are two kinds of dye molecules in thesolution, which are monomer and dimer respectively, in a state of monomer–dimerdynamic equilibrium. The absorption spectra properties of these two kinds moleculesare different. We studied the...