Thermodynamic of micelle formation of nonlinear block co-polymer Tetronic® T904 in aqueous salt solution

Calorimetric and spectroscopic studies have been carried out to investigate the thermodynamics of temperature-induced micellization of Tetronic® T904 [(EO15PO17)2NCH2CH2N (PO17EO15)2] in aqueous salt solutions. High-sensitivity differential scanning calorimetry (HSDSC), nuclear magnetic resonance (NMR) and Fourier transfer infrared (FTIR) measurements were used to evaluate the critical micellization temperature (CMT). The critical micellization concentration (CMC) and the thermodynamic parameters of micelle formations, namely enthalpy (ΔHmic), Gibbs energy (ΔGmic), and entropy (ΔSmic) of micellization were determined as a function of temperature and salt concentration using isothermal calorimetry (ITC). These measurements indicated spontaneous micellization with substantial enthalpy–entropy compensation of T904 micellization.