Stability Improvement and Thermal Properties of Paraffin Containing Carbon Nanotubes with a Surfactant

Phase change materials are considered as one of the best energy storage methods. The disadvantage of these materials is their low thermal conductivity,which reduces its performance. For this reason, in the recent years many efforts were conducted to improve the thermal conductivity of the phase changematerials. The dispersing multiwall carbon nanotubes (MWCNT) with high thermal conductivity in the phase change material have been introduced as aconvenient method to increase the effective thermal conductivity. But the focused studies have not been done for the stability and the dispersion ofnanoparticles in the paraffin. Therefore, in this study, thermal characteristics of paraffin/ nanoparticles composite with and without surfactant has beenevaluated. The paraffin/carbon nanotubes composites with 0, 0.5, 0.7, 1, 3 and 5wt% were prepared in two series, with and without the surfactant. Thesurfactant can improve dispersion of the nanoparticles efficiently. The stability and the dispersion of the nanoparticles in the composites have been evaluatedfor the first time by using the scanning electron microscopy after and before the alternative thermal cycles. The results showed the distribution of nanoparticles in the composite and thermal stability with the SSL is still better than the composite without surfactant.

Keywords:

Carbon nanotubes , phase change material , thermal stability , energy storage , Thermal characterization