Microcapsules composed of stearic acid core and polyethylene glycol‐based shell as a microcapsule phase change material

• Published in: International journal of energy research Vol. 45; no. 6; pp. 9677 - 9684
• Main Authors: Wang, Rui, Kang, Yujie, Lei, Tianxu, Li, Sijia, Zhou, Ziyi, Xiao, Yao
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Inc 01.05.2021; Hindawi Limited
• Subjects: Enthalpy; enthalpy change; Melting; microcapsule phase change materials; Microcapsules; Microencapsulation; Phase change materials; Phase transitions; Polyethylene glycol; Solidification; Solids; Stearic acid; Storage capacity; Storage conditions; Temperature; Thermal cycling; Thermal energy; Thermal stability; Thermodynamic properties
• ISSN: 0363-907X; 1099-114X
• DOI: 10.1002/er.6431

Summary The shell materials of the existing microcapsule phase change materials (PCMs) are always not PCMs, so the enthalpy change (ΔH) in the phase transition processes of these microcapsule PCMs is much smaller compared with the pure encapsulated PCMs (the core materials), reducing the storage ability for thermal energy of the microcapsules. Herein, we prepared microcapsules composed of stearic acid (SA) core and polyethylene glycol (PEG)‐based shell as a microcapsule PCM. The PEG‐based shell is a solid‐solid PCM with cross‐linked network, which is in solid state even at 80°C, avoiding the leakage and lose of the whole microcapsule PCM. Additionally, the microcapsule PCM has high ΔH of 113.4 and 115.3 J g−1 during their solidification and melting procedures respectively, displaying outstanding storage capacity for thermal energy. The microcapsule PCM shows dual temperature range in the melting/solidification process resulting in a wide effective temperature range, and has better thermal stability than pure SA. Moreover, the thermal property of the microcapsules changes a little after 100 times of thermal cycling, indicating high thermal reliability of the material.