Designing and Characterization of Low-Temperature Eutectic Phase Change Materials Based on Alkanes

The research presented here focuses on investigating the relationship between the structure of components and the eutectic temperature of binary systems designed as phase change material (PCM). For two-component systems containing long-chain alkanes (n-tetradecane, n-pentadecane, n-hexadecane, or n-heptadecane) and decanoic acid or 1-decanol, experimental data of the solid–liquid equilibrium are presented. The collected data were used to determine the composition and temperature of eutectic mixtures that are promising PCMs with a narrow melting point range. An essential aspect of this work is to confirm the possibility of determining eutectics of similar systems using predictive models, mainly the modified Dortmund universal quasichemical functional group activity coefficients method, without the need to perform expensive and time-consuming experimental research. The experiments were supplemented with the physicochemical characteristics (density and viscosity) of the liquid mixtures. The obtained PCM was closed in a polymer matrix to prevent material leakage into the environment, and the obtained composite materials were characterized by using scanning electron microscopy and differential scanning calorimetry techniques.