Preparation of novel form–stable composite phase change materials with porous silica nanofibrous mats for thermal storage/retrieval

Abstract Electrospun SiO 2 nanofibrous mats have been widely utilized as substrate of form-stable phase change materials due to large specific surface area and high convection coefficient. In order to overcome the brittleness and enhance the absorption capacity of SiO 2 nanofibrous mats as substrate, flexible and hollow SiO 2 nanofibrous mats were prepared by single-spinneret electrospinning which eliminated complicated spinneret and unstable structure compared with coaxial electrospinning. Quinary fatty acid eutectics were chosen as representative fatty acid which were adsorbed in SiO 2 nanofibrous mats to form form-stable phase change materials. The results showed that hollow structure can be observed as the content of paraffin oil decreased from 1.67 to 0.70 g, and as-prepared hollow nanofibrous mats displayed favorable flexibility. DSC results demonstrated that the largest melting/crystallization enthalpy supported by hollow SiO 2 nanofibrous mats was approximately 123.80/120.50 J g −1 , which was much higher than solid SiO 2 nanofibers. More importantly, after 30 cycles, there was no obvious change for phase change temperature and enthalpy. The thermal conductivity of representative form-stable phase change materials was over three times than that of quinary fatty acid eutectics. Hence, flexible and hollow SiO 2 nanofibrous mats were excellent substrate in form-stable phase change materials and would have wide application prospects.