Abstract This study focused on developing an efficient phase change material (PCM) with a stable shape that can be applied in a wide range of industries. To prevent leakage of the PCM liquid at a temperature above the melting point, we used an encapsulation method by making use of an interfacial polycondensation reaction, and attempted to develop a new PCM with excellent thermal conductivity and thermal energy storage capacity. In order to improve the functionality of the PCM in latent thermal storage applications, a magnetic material, Fe3O4, was mixed with n-eicosane and a shape-stable phase change microcapsule with a silica shell was successfully prepared. In this study, we loaded Cu metal nanoparticles on the outer wall of the capsule with the aim of improving the thermal conductivity of the material for efficient heat transfer. The results indicated that the n-eicosane-Fe3O4@SiO2@Cu microcapsule has excellent heat transfer ability owing to its high thermal conductivity and exhibits efficient thermal energy storage–release performance by suppressing supercooling. The n-eicosane-Fe3O4@SiO2@Cu microcapsule showed an encapsulation efficiency (Een) of 61.48%, an energy storage efficiency (Ees) of 61.47%, and a thermal storage capacity (Ces) of 99.99%. Moreover, the multi-cycle differential scanning calorimetry scan showed excellent thermal reliability and shape stability, even in repetitive melting–cooling processes, suggesting that it is a promising PCM that can be used in industrial applications.

中文翻译：

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n-二十烷-Fe3O4@SiO2@cu微胶囊相变材料及其改进的导热和传热性能

摘要 本研究的重点是开发一种形状稳定、可应用于广泛行业的高效相变材料 (PCM)。为了防止在高于熔点的温度下PCM液体泄漏，我们采用了一种利用界面缩聚反应的封装方法，并试图开发一种具有优异导热性和热储能能力的新型PCM。为了提高 PCM 在潜热存储应用中的功能，将磁性材料 Fe3O4 与正二十烷混合，成功制备了具有二氧化硅壳的形状稳定相变微胶囊。在这项研究中，我们在胶囊的外壁上加载了 Cu 金属纳米粒子，目的是提高材料的导热性以实现有效的热传递。结果表明，正二十烷-Fe3O4@SiO2@Cu微胶囊由于其高导热性而具有优异的传热能力，并通过抑制过冷表现出有效的热能储存-释放性能。正二十烷-Fe3O4@SiO2@Cu微胶囊的封装效率（Een）为61.48%，储能效率（Ees）为61.47%，蓄热容量（Ces）为99.99%。此外，多循环差示扫描量热扫描显示出优异的热可靠性和形状稳定性，即使在重复熔化-冷却过程中也是如此，这表明它是一种可用于工业应用的有前途的 PCM。