핵심 개념
The study reports solid-liquid equilibrium data for binary mixtures of naphthalene or biphenyl with 1-tetradecanol or 1-hexadecanol, determined using differential scanning calorimetry. The systems exhibit simple eutectic behavior, and the data are correlated using thermodynamic models.
초록
The authors used differential scanning calorimetry to obtain solid-liquid equilibrium (SLE) data for the binary mixtures of naphthalene or biphenyl with 1-tetradecanol or 1-hexadecanol. All the systems showed a simple eutectic point, and the final eutectic composition was determined using Tamman's plots.
The experimental SLE phase diagrams were described using the DISQUAC and UNIFAC (Dortmund) thermodynamic models. The DISQUAC model provided a slightly better overall description of the SLE curves compared to UNIFAC. The comparison of the two models for naphthalene + 1-alkanol mixtures revealed that the temperature dependence of the interaction parameters is more suitable in DISQUAC.
The study also investigated the systems in terms of the concentration-concentration structure factor (SCC(0)). It was shown that the positive deviations from Raoult's law become weaker as the homocoordination (self-association) of the components decreases with increasing alkanol chain length.
통계
The melting temperatures (Tm) and molar enthalpies of fusion (ΔHm) for the pure compounds are provided in Table 2.
The solid-liquid equilibrium temperatures (TSLE) for the binary mixtures are given in Table 3.
The eutectic temperatures (Teu) and the eutectic heats (ΔHeu) are listed in Table 4.
인용구
"SLE data have also gained interest due to their applications in the field of the accumulation and transference of thermal energy. Such applications are based on the heat absorbed and released during a physical state change (typically, solid-liquid transitions)."
"Due to its stability and inertness, biphenyl is employed as heat-storage material [16], and the eutectic mixture diphenyl ether + biphenyl is used as heat transfer agent [17]."
"The study of PAH mixtures is also useful to achieve a suitable description of heavy petroleum fractions, needed to avoid flocculation and deposition of asphaltenes [18,19], a crucial problem during the exploitation, transport and storage of crude oil."