Preparation of electrospun LA-PA/PET/Ag form-stable phase change composite fibers with improved thermal energy storage and retrieval rates via electrospinning and followed by UV irradiation photoreduction method

Abstract

In this paper, novel electrospun LA-PA/PET/Ag phase change composite fibers with different amount of Ag nanoparticles were prepared via the technique of electrospinning followed by UV irradiation method. The morphological structure, thermal energy storage properties, thermal energy storage and release rates of prepared LA-PA/PET/AgNO3 and LA-PA/PET/Ag composite fibers were investigated by scanning electron microscope (SEM), high-resolution transmission electron microscope (HR-TEM), differential scanning calorimeter (DSC), and the measurement of melting and freezing times, respectively. The SEM images revealed that electrospun LA-PA/PET/AgNO3 and LA-PA/PET/Ag composite fibers possessed the smooth morphologies with cylindrical shape. The corresponding average fiber diameters gradually decreased with increasing content of the AgNO3 in the solutions, and slightly smaller than those of the LA-PA/PET composite fibers with oblate morphology and wrinkled surfaces. Yellow-brown coloration of electrospun LA-PA/PET/Ag phase change composite fibers were observed after UV irradiation treatment, which demonstrated that Ag ions were successfully reduced to Ag nanoparticles. The TEM images revealed that these reduced Ag nanoparticles were homogenously dispersed within the composite fibers. The results from DSC measurements indicated that the phase change temperatures and enthalpies of electrospun LA-PA/PET/Ag phase change composite fibers with different Ag content have not be influenced by the UVirradiation treatment. The thermal energy storage and release rates of electrospun LA-PA/PET/Ag phase change composite fibers were also improved due to the combination of reduced Ag nanoparticles. These UV-irradiated electrospun phase change composite fibers with excellent thermal energy storage properties can be acted as a novel form-stable PCMs for the applications related to storage and retrieval of thermal energy.