A differential scanning calorimetry study of a binary system

The temperature dependence of the heat capacity change for micellization of nonionic surfactants

“…The partial molar heat of solution of dimethyl-n-C 8-10,12 amine oxides were also found to be essentially constant above the cmc, even up to the point of separation of a "mesomorphic" phase (30-50%, w/w) [24]. The heat capacity changes that are observed for much more concentrated APO10 solutions [20] occur at the boundary between liquid crystal lamellar and hexagonal phases. However, the concentrations of the APO12 solutions used for our DSC studies are far below the concentration required for the formation of another phase (40%), other than the two isotropic solutions that are present above and below the cloud point [25].…”

“…A lower and wider peak will result if the binodal is more rounded-off [18]. A rigorous thermodynamic derivation of equations that describe this process has been given [19,20]. However, the heat capacity jumps that were observed at the cloud point require an additional consideration.…”

The Lyotropic Cubic Phase of Model Associative Polymers: Small-Angle X-Ray Scattering (SAXS), Differential Scanning Calorimetry (DSC), and Turbidity Measurements

“…With such a treatment the resulting phase diagram obtained contains a single boundary instead of the In Fig. 7, we have gathered the different observations, heterogeneous region required by the phase rule (61). How-visual, viscosimetric, and DSC, in order to establish a possiever, even if both the onset and the end of each fusion peak ble phase diagram of this system.…”

DSC Analysis of Surfactant-Based Microstructures

“…Transition temperatures and enthalpies are often determined and used to draw the limits of existence of the different phases of surfactant-based systems [1][2][3][4][5][6]. Transition temperatures and enthalpies are often determined and used to draw the limits of existence of the different phases of surfactant-based systems [1][2][3][4][5][6].…”

“…Many phase diagrams are inferred from calorimetric data jointly with some other techniques. They are that (1) there are difficulties in locating very steep phase boundaries in heterogeneous systems from DSC data alone because heat capacity depends strongly on the slope of phase boundaries and so the heat capacity jumps are small [10] and (2) the determination of phase boundaries in systems with slow nucleation rate, interfacial transport problems, or inherently slow phase changes may not be possible [11]. A sample cannot be viewed during calorimetric studies, but in combination with observations in hot stage microscopy (with common and/or polarized light) the nature of phase transitions and their temperature can be determined.…”