[18p-PA1-1~14] 3.2 Equipment optics and materials

[18p-PA1-10] Salt Effect on Thermal Isomerization Process of Methyl Yellow in Ethanol

〇Atsuko Yano¹, Yoshie Sato¹, Ryuzi Yano¹ (1.Muroran Inst. Tech.)

Keywords:azo dye, thermal isomerization, salt

We studied the influence of alkali metal halide (NaCl, KCl, NaBr, KBr) addition on the thermal isomerization (TI) process of methyl yellow in ethanol. The TI rate increased with increasing salt concentration. K ⁺ ion showed a larger effect than Na ⁺ ion. For anion, the effect depends on the kind of counter cations slightly. We attributed the increase of the TI rate to the interaction between dye and cation. The difference in the effect of anions is explained by the difference of the concentration of the free counter cation.