Preparation of core-sheath nanofibers with high latent heat by thermal cross-linking and coaxial electrospinning

Stable energy storage materials have become the research focus today. Coaxial electrospinning can prepare core-sheath nanofibers loaded with phase change materials (PCMs). This method requires the sheath solution have good spinnability and encapsulation ability. Suitable solutions can be prepared by the thermal cross-linking method to improve the properties of nanofibers. Choose hexamethylene diisocyanate (HDI) and β-cyclodextrin (β-CD) as cross-linking agents to adjust the performance of polyvinyl butyral (PVB)/N, N-dimethylformamide (DMF) solution. The adjustment of β-CD addition amount and thermal cross-linking time prepared the best sheath solution as PVB/50CD/HDI. The latent heat of nanofibers prepared by using this sheath solution could be as high as 137.05 J/g. In the meantime, the properties of nanofibers in thermal decomposition, mechanical strength , and elongation rate were also improved. The thermal cycle test proved the good stability of core-sheath nanofibers. This work lays the foundation for the further development of temperature-regulating fibers with high latent heat and performance.