Light-to-Thermal Conversion and Thermoregulated Capability of Coaxial Fibers with a Combined Influence from Comb-like Polymeric Phase Change Material and Carbon Nanotube

A series of coaxial fibers with poly(ethylene terephthalate) (PET) as sheath and poly(tetradecyl acrylate) (PTA) comb-like polymeric phase change material as core have been prepared via an electrospinning technology with carbon nanotube (CNT) dispersed into a core component, denoted as PET/PTA-x CNT, where x is the mass fraction of CNT. The morphology, structure, and thermal performance of coaxial fibers are characterized. Good thermal stability below 300 °C is shown due to the sheath–core structure for PET/PTA-x CNT coaxial fibers. Light-to-thermal conversion effect is contributed from the wide UV–vis light absorbance of CNT and phase change of PTA, and PET/PTA-2% CNT reaches 60 °C after 600 s illumination under 100 mW/cm2. Furthermore, a comparable temperature variation is proved for the covered bottle with PET composite membrane containing PET/PTA-2% CNT coaxial fibers, and after 900 s illumination, the inner temperature of the bottle gets to 38 °C, which is 3 °C higher than that of the PET-covered one. The investigations of light-to-thermal conversion and thermoregulated ability of fibers guide an approach to thermal management material and greenhouse film application.