The use of organic compounds as phase change materials (PCMs) is limited by the low thermal conductivity of these compounds. In this study, multi-walled carbon nanotubes (MWCNTs) and carbon nanofibers (CNFs) were dispersed in n-octadecane to determine if this nanocomposite PCM would have a higher thermal conductivity than that of pure n-octadecane. The thermal conductivity of the nanocomposite PCMs was measured using the transient plane source (TPS) method at mass ...
Autoclaved aerated concrete was studied because it has potential to be used in the design of energy-efficient buildings. Three different samples were tested, each with a unique density. Of particular interest to this work was the thermal conductivity of the samples, as this material would be used as a thermally insulating concrete. The thermal conductivities were measured at various percentages of moisture content, and it was found that increasing moisture ...
In this work, the authors tested five organic phase change materials for thermophysical properties (density, heat capacity, and thermal conductivity) in order to determine the best path to prediction (BPP) for the thermal diffusivity of organic PCMs in the liquid phase. Separate BPPs were determined for alkanes and unsaturated acids. The identified BPPs were then tested on a variety of materials and the estimated thermal diffusivity was within 15% for all ...
The authors examine the melting and crystallization behavior of a polyethylene/boron nitride composite to understand an unexpected exothermic peak when the BN content was greater than 10 wt. %. Based on these observations, an optimal annealing temperature of the composite was investigated to enhance its thermal conductivity. The appearance of the peak was determined to depend on the different nucleated capability of the different BN aggregates in local area. An annealing ...
Various microfibrillar composites were prepared in situ using boron nitride as a thermally conductive filler. The multistage stretching extrusion process was used in an effort to improve thermal conductivity and mechanical properties. It was found that the addition of laminating-multiplying elements (LMEs) improved the dispersion of BN in the composite polymers and they also improved the tensile and impact strength of the polymers. It was also found that the thermal ...
