High thermal performance composite PCMs loading xGnP for application to building using radiant floor heating system

The building sector is known to make a large contribution to total energy consumption and CO2 emissions. Phase change materials (PCMs) have been considered for thermal energy storage in buildings. The aim of this study was to improve the thermal conductivity of PCMs applicable as building materials using a radiant floor heating system. Using exfoliated graphite nanoplatelets (xGnP), composite PCMs were prepared by mixing and melting techniques for high dispersibility, thermal conductivity and latent heat storage. xGnP of 3 and 5 wt% was added to three types of liquid pure PCMs (octadecane, hexadecane and paraffin) with different melting points. The composite PCMs loaded with xGnP were characterized by using the SEM technique. The thermal properties of the composite PCM loaded with xGnP were determined by thermal conductivity analysis and DSC analysis. SEM morphology showed homogenous and ordered dispersion of xGnP in the three types of PCMs. The thermal conductivity of composite PCMs was increased with the xGnP loaded contents. The DSC results showed that the melting temperature and latent heat of the composite PCMs loaded with xGnP was maintained. The latent heat of composite PCMs slightly decreases when loading with xGnP. As a result, composite PCMs loaded with xGnP can be considered as energy saving building materials for a residential building using a radiant floor heating system.

► Composite PCMs loading xGnP were prepared by mixing and melting techniques.
► xGnP was well-dispersed into PCM and led to high thermal conductivity.
► As the xGnP loading contents were increased, thermal conductivity was increased.
► Latent heat storage was slightly decreased with the xGnP loading contents.