Form-stable phase change materials based on hierarchically channel-like silica nanofibrous mats for thermal energy storage

Abstract

Hierarchical channel-like SiO2 nanofibrous mats were prepared via microemulsion electrospinning in combination with calcination for thermal energy storage. The interior channel number of SiO2 nanofibers was flexibly regulated by tuning the proportion of continuous phase to dispersion phase. Microemulsion electrospinning, as a method of single-spinneret electrospinning, makes it versatile, simple and convenient for the preparation of hierarchical SiO2 nanofibers with multi-channel structure and high porosity. Quinary fatty acid eutectics were encapsulated in multi-channel SiO2 mats to obtain form-stable phase change materials (FSPCMs). The results indicated the crystallization enthalpy and melting enthalpy of as-fabricated FSPCMs could be up to 115.7 and 112.9 J·g−1, respectively. After 40 thermal cycles, there is no significant difference for the phase change temperature and enthalpy of FSPCMs, revealing outstanding thermal cycling stability. The study proves that microemulsion electrospinning is exactly a straightforward and universal method to fabricate the supporting substance of FSPCMs.