“…Hexagonal boron nitride nanosheets [12], herringbone style graphite nanofibers [13], Fe 3 O 4 nanoparticles [14], carbon nanotubes [15,16], carbon nanofibers [17] and graphene nanoplatelets [16,17] were proposed as promising nanofillers for preparing high-conductivity composite PCMs. However, Parameshwaran et al [18] found that increasing mass loading of nanocomposite resulted in 4% increased viscosity of PCM. So one disadvantage of dispersing high-conductivity nanomaterials into PCM is that the viscosity of the composite PCM in liquid phase increases drastically weakening or even eliminating the natural convection effect, which in turn may overweigh the enhanced heat conduction realized by thermal conductivity enhancement [16].…”