The phase change property of lauric acid confined in carbon nanotubes as nano-encapsulated phase change materials

Lauric acid (LA) impregnates in carbon nanotubes (CNTs), resulting in nano-encapsulated phase change materials (PCMs). TEM and DSC results both indicate that the filling of LA into CNTs is realized by the vacuum infiltration method. A further study of nano-encapsulated PCMs at the molecular level is investigated by molecular dynamics simulations. From the axial view of CNTs, LA molecules always keep a circular distribution inside CNTs with a radius of about 4.8 Å. The analysis on radial distribution function, the end-to-end distance and the torsion angle simultaneously verifies that the order degree of LA molecules is improved due to the nano-confined effect of CNTs. The diffusion coefficient of LA is enhanced in CNTs. The energy flux and thermal conductivity of LA molecules in CNTs are higher than those of pure LA at the same temperature. These results fully indicate the heat and mass transfer of LA in CNTs could be enhanced. The current research could contribute to a deep understanding nanoscale thermal science and to potential application in heat dissipation of nanodevices.