Synthesis and Characterization of Robust SiO2-PCM Microcapsules

Jinliang An,*Email

En-Hua Yang,

Fei Duan, Y

Yong Xiang

Jinglei Yang

1School of Civil Engineering, Hebei University of Engineering, Handan, Hebei 056038, China

2School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, China

3Center for Engineering Materials and Reliability, HKUST Fok Ying Tung Research Institute, Guangzhou, Guangdong 511458, China

4School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798

5School of Civil and Environmental Engineering, Nanyang Technological University, Singapore 639798

6Department of Mechanical and Aerospace Engineering, Hong Kong University of Science and Technology, Kowloon, Hong Kong SAR, China

Abstract

Inorganic SiO2 microencapsulated phase change materials (MEPCMs) have been developed via polymerization reaction and electrostatic interaction in an emulsion system. The resultant microcapsules were systematically characterized in terms of morphology, composition, thermal stability, durability and mechanical property. The energy storage capacity of the obtained microcapsules ranges from 190.5 J/g to 225.5 J/g (pure octadecane: 250.6 J/g) when the core material is octadecane at different sizes. SiO2-PCM microcapsules showed improved energy storage efficiency in terms of shorter melting and freezing durations attributed by the higher thermal conductivity of inorganic silica shell compared with that of polymer shell encapsulated PCM. Repeatable melting and freezing processes after 150 cycles revealed excellent shell tightness and thermal stability of the resultant microcapsules. The high apparent compressive strength of individual SiO2-PCM microcapsule indicated good survivability in further materials processing for energy storage. The robust SiO2-PCM microcapsules obtained from a facile fabrication approach in this study have great potential applications for developing energy efficient materials.

Synthesis and Characterization of Robust SiO2-PCM Microcapsules