Thermal Properties of Heat Storage Composites Containing Multi-walled Carbon Nanotubes1

摘要

To overcome the low thermal conductivity problem of palmitic acid (PA), multi-walled carbon nanotubes (MWNT) were dispersed into melting PA for their high thermal conductivities and low weight. The PA/MWNT composites are proved to be very stable. As expected, the differential scanning calorimetry (DSC) shows the melting point of composites fall in some scale, compared with pure PA. Although the latent heat of melting of composites is lower than pure PA, the latent heat capacity of the composites was large and the latent heat of form-stable composite PCM with MWNT in mass ratios of 5% had satisfying latent heat capacity for LHTES applications. Different from other work, this paper report thermal conductivity of the pure PA and the composites at different temperature. The most important thermal conductivity of PCM is the thermal conductivity at melting point and at temperature near the melting point. The composite with 5wt% MWNT can increase the thermal conductivity to 0.45W/mK near the melting point. Compared with pure PA, of the 5 wt % PA/MWNT composite increases the mean thermal conductivity by 36% in solid and 56% in liquid, respectively.