Thermal and electrical performance analysis of co-electrospun-electrosprayed PCM nanofiber composites in the presence of graphene and carbon fiber powder

Electrospinning of fatty acid ternary eutectic mixture was carried out simultaneously with electrospraying of carbon fiber powder (CFP) and graphene to fabricate nanofibers with improved thermal and electrical properties. The used phase change materials (PCMs) including capric acid (CA), palmitic acid (PA), lauric acid (LA) and their ternary eutectic were supported by polymeric matrix of polylactic acid (PLA). The electrospray mixtures were prepared by dispersion of various weight fractions of CFP and graphene into isopropanol/glycerin and tetrahydrofuran (THF), respectively. The fabricated composites have undergone characterization tests including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and thermal and electrical conductivity tests to study their properties. The layered structure of graphene was detected both inside and on the fibers surfaces. Qualitative and quantitative measurements have shown significant improvement in both thermal and electrical conductivity of the fabricated composites. In particular, the electrical conductivity of the composites has increased 0.031 S/m in the presence of the highest graphene amount. The average melting temperature of graphene and CFP composites are 14.5 and 16.9 °C, respectively. The produced PCM composites could offer potential applications in energy storage/retrieval systems operated in near ambient temperatures.