Core-sheath phase change fibers via coaxial wet spinning for solar energy active storage

Using phase change fibers (PCFs) will help buffer the changes in ambient temperature, improve the utilization of natural energy, and ease the energy crisis. However, the poor solar energy absorption efficiency and leakage of phase change materials from PCFs seriously impaired their performance in practical applications. In this work, the core-sheath structured composite PCFs with excellent temperature regulation capability and high energy storage capacity were prepared by an economical and efficient coaxial wet spinning process for the first time. The infrared absorbers, Cs 0.33 WO 3 (CWO), were incorporated into the hollow thermoplastic polyurethane (TPU) fibers to enhance solar energy absorption, and the paraffin wax (PW) was infused into the cavity of the composite fibers, giving rise to the formation of composite PW@TPU/CWO PCFs. The resultant PCFs showed a decrease in molten enthalpy and crystal enthalpy with the increasing of CWO contents, and the PCFs of PW@TPU/CWO 5 can maintain a molten enthalpy of up to 90.47 J/g and an encapsulation rate of 69.93% that were higher than almost previous reports. The simulated house model under the coverage of PCFs fabric exhibited slight temperature variation and change rate, demonstrating the excellent heat storage and regulation capability of the as-prepared PCFs. The results show great potential applications in solar energy storage, heat storage and temperature regulation areas.