Solid Solutions Treatment of Calorimetric Purity Data

Structural and Thermal Properties of Unpurified and Purified 12-Hydroxystearic Acid Solutions

“…On heating, a sharp and large endothermic peak for p-12-HSA powder was observed at 80.9°C, which is close to the value of the melting temperature for 12-HSA powder with 99% purity [12]. We attempted to calculate the purity of p-12-HSA sample from the endothermic peak by using the fractional melting method [13,14], to estimate sample purity as 96 %. In a cooling process, a very sharp exothermic peak observed at 74.2°C is attributed to the crystallization of 12-HSA.…”

Low-temperature adiabatic calorimetry of salol and benzophenone and microscopic observation of their crystallization: finding of homogeneous-nucleation-based crystallization

“…The equilibrium temperature was estimated by extrapolating the temperature against time curve to infinite time with an exponential function, and is plotted as a function of the reciprocal of fraction melted, f −1 . By fitting the Mastrangelo-Dornte equation (14) to the temperature dependence of f −1 in the crystalline sample formed at T = 305 K, the mole fraction purity was evaluated to be (0.9995 ± 0.0001), and the melting temperature at which f −1 = 0 was taken to be (314.97 ± 0.01) K. The molar enthalpy and entropy of fusion were evaluated to be (19.16 ± 0.02) kJ · mol −1 and (60.86 ± 0.06) J · K −1 · mol −1 , respectively. In the crystalline sample formed by the lowtemperature crystallization at T = 220 K, the fusion started at lower temperatures and proceeded over a wider temperature range than in the crystal formed at T = 305 K, as shown in the figure.…”

Measured relative enthalpy of anhydrous crystalline aluminum trifluoride, AlF3, from 273 to 1173 K and derived thermodynamic properties from 273 to 1600 K

“…In th e exa mple illus trated , the impurity de presses the transition te mpe rature of th e pure s ub stan ce, TIc. to a finit e te mpe rature interval TI to T2 , th e sample at any intermediate te mperature 3 A similar tre at me nt has been publi shed by Mastrangelo an d Dornl e [12]. Their final eq uations, whil e derived for th e fu s ion process onl y and expressed in te rm s of slightl y less general parameters , ca n be s hown to be equivalent 10 eqs (9 ) a nd (11) be low.…”

“…from which were calculated T tr = 727.6 OK N2 = 0.0004 (12) } (13) and the dashed curve drawn through the transJtlOn region in figure 1. This curve fit s the points within their precision , and it may be added that a value N2 = 0.0004 is plausible (e .g., if du e to MgF2 , thi s would correspond to 0.01 weight pe rce nt of Ma whi ch is consistent with table 1).…”