Phase diagram is a powerful tool to guide the exploitation of thermal energy materials. Heat storage technology of phase-change material (PCM) was widely used to solve major energy utilization problems on large energy consumption and low utilization efficiency. In this work, a novel solid-liquid phase diagram of the binary system octadecanoic acid (C18-acid) + octadecanol (C18-OH) was investigated using the differential scanning calorimeter (DSC). The phase-change temperature and phase-change enthalpies against the composition of C18-acid and C18-OH were determined experimentally, and then the binary phase diagram of T–X (X expresses the mass fraction of C18-OH in the two components of C18-acid and C18-OH) was established for the first time. The phase diagram belongs to a binary simple system with one eutectic point, and the content of C18-OH at eutectic point is 0.4 in mass fraction. Neither solid solution nor copolymer was formed. The thermal chemical properties on the phase-change latent heat (Q), phase-change temperature (Tp), and the thermal conductivity (λ) for the composition at the eutectic point of the binary system are 198.7 J·g−1, 44.2°C, and 0.2352 W·m−1·K−1, respectively. This result indicates that the material at eutectic point has a great potential to be used as energy storage material for supply of heat and scouring bath.

中文翻译：

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十八烷酸和十八烷醇二元体系的固液相图和共晶点组合物的热化学性质

相图是指导热能材料开发的有力工具。相变材料（PCM）蓄热技术被广泛应用于解决能源消耗大、利用效率低的重大能源利用问题。在这项工作中，使用差示扫描量热仪 (DSC) 研究了十八烷酸 (C18-酸) + 十八烷醇 (C18-OH) 的新型固液相图。实验确定了 C18-酸和 C18-OH 组成的相变温度和相变焓，然后得到了 T-X 的二元相图（X 表示 C18-OH 在两种组分中的质量分数） C18-酸和C18-OH）首次建立。相图属于具有一个共晶点的二元简单系统，共晶点C18-OH的质量分数为0.4。既没有形成固溶体也没有形成共聚物。二元体系共晶点成分的相变潜热(Q)、相变温度(Tp)和热导率(λ)的热化学性质为198.7 J·g-1, 44.2 °C 和 0.2352 W·m-1·K-1，分别。该结果表明，共晶点材料作为供热和煮练浴的储能材料具有很大的潜力。分别。该结果表明共晶点材料作为供热和煮练浴的储能材料具有很大的潜力。分别。该结果表明共晶点材料作为供热和煮练浴的储能材料具有很大的潜力。