Ultrafine electrospun fiber based on ionic liquid/AlN/copolyamide composite as novel form-stable phase change material for thermal energy storage

A novel form-stable phase change material (FSPCM) based on ionic liquid/aluminum nitride/copolyamide composite were fabricated from electrospinning approach. The ionic liquid 1-hexadecyl-3-methylimidazolium bromide (IL) was chosen as phase change materials while nano aluminum nitride (AlN) and copolyamide 6/12 (CoPA) were chesen as additive and supporting matrix, respectively. The surface morphology and heat storage property had been systematically investigated by Scanning Electronic Microscopy (SEM) and Differential Scanning Calorimetry (DSC), respectively. Results showed that the diameter of the phase change fibers are 0.92–1.07 μm and was influenced by the IL and AlN content. With 57 wt% of IL and 5 wt% of AlN, the composite fiber achieved a fusion enthalpy of 86.4 J/g and the thermal conductivity was increased by 165.2% compared to that of IL/CoPA. Thermogravimetric Analysis (TGA) and thermal cycle test also indicated a good thermal stability and reusability of the composite fiber. Furthermore, Fourier Transform Infrared Spectroscopy (FTIR) and X-Ray Diffraction (XRD) analyses indicated that new hydrogen bonds between IL and CoPA were formed in the composite and showed a significant effect on the thermal performance of the composite fibers. The electrospun composite fiber based on ionic liquids can be applied as form-stable phase change material in thermal energy storage and temperature regulation.