Abstract Energy preservation is one of the serious concerns in recent years to reduce fossil fuels consumption and greenhouse gases. Magnetic microcapsules based on n-hexadecane/Fe3O4 core and poly methyl methacrylate (PMMA) shell were designed as an innovative type of dual-functional phase change materials. Fe3O4 nanoparticles were first synthesized by co-precipitation method and then modified with oleic acid. Then, they were incorporated into suspension polymerization in the presence of MMA and n-hexadecane. FTIR and SEM analyses confirmed the presence of all components in the magnetic microcapsules with a wrinkled morphology and uniform size in averagely 180 µm. They revealed reasonable thermal storage properties and high thermal cycling performance according to DSC thermograms. The encapsulation efficiency and thermal storage ability were calculated by the extracted data from DSC analysis for all the samples and their thermal conductivities were measured too. Magnetometry studies approved superparamagnetic properties of the obtained microcapsules with low remanence and coercivity. With such a dual-functional feature, the introduced magnetic microcapsules could show potential applications in some high-tech fields with providing both thermal regulating and magnetic responsive properties.

中文翻译：

---

对温度和磁场变化具有双重响应性的丙烯酸PCM微胶囊的制备

摘要 节能是近年来减少化石燃料消耗和温室气体排放的严重问题之一。基于正十六烷/Fe3O4 核和聚甲基丙烯酸甲酯 (PMMA) 壳的磁性微胶囊被设计为一种创新的双功能相变材料。Fe3O4纳米颗粒首先通过共沉淀法合成，然后用油酸改性。然后，在 MMA 和正十六烷存在下将它们加入悬浮聚合中。FTIR 和 SEM 分析证实磁性微胶囊中存在所有成分，具有皱纹形态和平均 180 µm 的均匀尺寸。根据 DSC 热谱图，它们显示出合理的热存储性能和高热循环性能。通过提取所有样品的 DSC 分析数据计算封装效率和热存储能力，并测量它们的热导率。磁力测量研究证实了所获得的具有低剩磁和矫顽力的微胶囊的超顺磁性。凭借这样的双重功能，引入的磁性微胶囊可以在一些高科技领域显示出潜在的应用，同时提供热调节和磁响应特性。