Thermodynamic Analysis for the Binding of Methyl Orange with Nylons -The Effect of Hydrophobic Interaction-

메틸오렌지에 의한 나일론의 염색에 있어서 열역학적 특성 -소수결합의 영향-

The bindings of nylons with methyl orange were studied, and the first binding constants and thermodynamic parameters for the binding were obtained. It was found that, with increasing the methylene group of the nylons, the free energy for the binding increased negatively and the enthalpy and the entropy increased positively. The favorable free energy change for the binding appeared to be a result of favorable entropy change rather than enthalpy change. All these facts obtained can be interpreted by the hydrophobic interaction between the hydrocarbon moiety of the dye and the hydrocarbon parts of the nylons, and it is reasonable to conclude that not only the electrostatic attraction but also the hydrophobic interaction contributes to the binding of methyl orange, a typical acid dye, by nylons.