Leak-Proof Reversible Thermochromic Microcapsule Phase Change Materials with High Latent Thermal Storage for Thermal Management

Abstract

In this study, a range of reversible thermochromic microencapsulated phase change materials (RTPCMs) encapsulated in silica (SiO2) microcapsules modified with a silane coupling agent was successfully created and produced. The structure and composition of these thermochromic microcapsules were analyzed using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM), while their heat storage capacity was evaluated using differential scanning calorimetry (DSC). SEM images revealed that these microcapsules exhibited a spherical shape with a well-defined core–shell structure. Both DSC and thermogravimetric (TG) analyses demonstrated that microcapsules modified with MPTMS exhibited a favorable enthalpy of phase transition (98.57 J/g). Furthermore, the contact angle of the microcapsules was substantially enhanced, reducing the leakage rate from 6.2% to 1.2%, and the thermal conductivity of the RTPCMs increased by 300% after incorporating the SiO2 shell layer. Notably, MPTMS-modified microcapsules not only exhibited high latent heat storage and release capacity but also maintained excellent shape stability, thermal stability, phase transition reliability, and durability. Additionally, these microcapsules displayed thermochromic properties during phase transition and were successfully integrated into textile applications. Hence, the dual-functional microencapsulated phase change materials (PCMs) explored in this study hold significant promise for various thermal management applications, including energy-efficient buildings, smart material coatings, and thermal sensors.