Abstract:

Microencapsulation of phase change materials (PCMs) provides good sealing protection for PCMs and solves the volume change and leakage problems during phase transition. However, the problems of low thermal conductivity, poor mechanical strength and thermal stability, and single function of microencapsulated phase change materials (MEPCMs) cannot be ignored. MEPCMs modification is an effective way to solve these problems. This review firstly introduced the compositions, structures and preparation methods of MEPCMs. The principles and research progress of modification methods such as multi-core materials, multi-shell layers and hybrid shells were emphatically reviewed. The performance enhancement and function expansion of MEPCMs by different modification methods and materials were outlined, mainly including enhancing their thermal conductivity, thermal storage capacity, thermal stability and mechanical strength to make them multifunctional. On this basis, the development of modified MEPCMs in photothermal conversion was elaborated. The photothermal materials, operating principles and latest progress of photothermal conversion MEPCMs were summarized. Finally, the existing problems and prospects of MEPCMs modification were discussed. It was pointed out that the modification process should be simplified, the development of multifunctional MEPCMs should be increased and the application of photothermal conversion MEPCMs in practical engineering should be promoted.

Key words: phase change materials, microencapsulated phase change materials, modification, nanomaterials, polymers, photothermal conversion

摘要：

相变材料微胶囊化为相变材料提供良好密封保护，有效地解决了相变时的体积变化和泄漏问题。但相变微胶囊热导率低、机械强度和热稳定性差、功能单一等问题不容忽视。相变微胶囊改性是解决这些问题的有效途径。本文首先对相变微胶囊的组成、结构及制备方法进行介绍。重点综述了多芯材、多壳层和杂化壳等改性方式的原理及研究进展，概述了不同改性方式和改性材料对相变微胶囊的性能提升和功能拓展，主要包括增强其导热、蓄热能力、热稳定性、力学性能等，并使其多功能化。在此基础上，对改性相变微胶囊在光热转换中的发展做了详细阐述，对光热转换相变微胶囊的光热材料、工作原理和最新进展进行总结。最后讨论了相变微胶囊改性的现存问题和未来发展方向，指出应简化改性过程，加大多功能型相变微胶囊的开发力度，加快推进光热转换相变微胶囊的实际应用。

关键词: 相变材料, 相变微胶囊, 改性, 纳米材料, 聚合物, 光热转换