Evaluation of thermal performance of bio-based phase change materials composites using carbon nanomaterials

Abstract

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.Phase change materials (PCMs) have been considered for the latent heat thermal energy storage (LHTES) in buildings. Bio-based PCMs are type of organic fatty acid ester PCMs and significantly less flammable than paraffins so it can be used safely. However, they have a low thermal conductivity which severely reduces their thermal performances. In this study, Bio-based PCMs were prepared by the stirring of carbon nanomaterials such as exfoliated graphite nanoplatelets (xGnP) and carbon nanotubes (CNT) in liquid Bio-based PCMs at different mass fractions (1.0, 3.0 and 5.0 wt%). The micro structures were characterized using scanning electron microscopy (SEM) and it showed well-dispersion of Bio-based PCMs composites. Fourier transform infrared spectroscopy (FT-IR) results showed no chemical interaction between Bio-based PCM and prepared carbon nanomaterials. The thermal conductivity of Bio-based PCMs composites were increased as increasing carbon nanomaterials loading contents. Differential scanning calorimetry (DSC) analysis results indicated that Bio-based PCM/xGnP composites maintained their large latent heat values and suitable phase change temperatures due to large surface area and well-dispersion of carbon nanomaterials. Therefore, Bio-based PCM composites can be considered as suitable candidates for latent heat thermal energy storage.