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The storage of thermal energy in phase change materials (PCMs) has found wide applications that enable energy conservation and management. Paraffin is a major PCM with its low cost, wide availability, and relatively high latent heat, yet its low thermal conductivity may become a drawback in high-power applications. In this study, composites of paraffin were prepared with multiwalled carbon nanotubes and activated carbon by a dispersion technique to overcome these drawbacks. Thermal, chemical, and physical influences of incorporating carbon additives with varying structures in paraffin composites on thermal storage capacity were determined. Results indicated that the thermal conductivities of paraffin-activated carbon composites (PACC) and paraffin multiwalled carbon nanotube composites (PCNC) were improved by a factor of 39.1 and 34.1%, respectively, compared with the conductivity of pure paraffin. As a bonus, the thermal energy storage capacities of PCNCs were enhanced by 9.6%, whereas this remained unchanged for PACCs. Copyright (C) 2015 John Wiley & Sons, Ltd.

Paraffin is a common phase-change-material (PCM) exploited in many thermal and solar energy storage applications. Its relatively large latent heat with a stable phase change, nontoxicity and noncorrosivity are the main reasons. Paraffin's low thermal conductivity may become a drawback for high power applications. In this study, the effect of adding nanomaterials to enhance paraffin's thermal performance is investigated. Nanomagnetite (Fe3O4) particles were prepared by sol-gel method for this investigation. Once characterization of nanomagnetite was done, it was added at 1%, 5%, 10%, and 15% ratios to paraffin (melting range: 46-48 degrees C) to obtain a paraffin nanocomposite. Thermal characterization with Differential Scanning Calorimeter (DSC) shows that the latent heat storage capacity of paraffin has been increased for 10% nanomagnetite composite, while the melting temperature range remained the same. (C) 2014 Elsevier B.V. All rights reserved.