A review on the micro-encapsulation of phase change materials: classification, study of synthesis technique and their applications

The requirement for energy and its management is growing in today's world. The energy sector is an area of interest for many countries around the world. To address the current fossil fuel issue, the scientific community is developing novel energy-saving experiments. Thermal energy storage is a mode of conserving energy. Thermal energy storage not only reduces energy consumption inconsistencies but also improves energy efficiency and reliability, which is an important part of energy conservation. In the realm of thermal energy storage, phase change materials (PCMs) are growing popularity and gaining awareness. By expanding, the area of heat transfer and reducing the seepage of melting materials, microcapsules improve the mechanical and thermal performance of PCMs used in the storage of thermal energy. PCM encapsulation is required to avoid PCM leakage, increase heat transmission, and control and reduce PCM reactivity with the environment. A vast number of researches on PCM microcapsules have been reported recently to explain their utility in energy systems. A complete evaluation of PCM microcapsules for thermal energy storage is presented in this paper. This review covers five topics: PCM classification, shell materials of encapsulation, microencapsulation methods, characterization of PCM microcapsules, and thermal applications. This review intends to aid researchers from diverse domains to gain a better understanding of PCM microcapsules and provide crucial guidance for future thermal energy storage using this technology.