Preparation of Thermal Conductivity-Enhanced, Microencapsulated Phase Change Materials Using Cellulose-Assisted Graphene Dispersion for Thermal Regulation in Textiles.

To improve the poor thermal conductivity of microencapsulated phase change materials (MPCMs), a strategy was designed with effective combinations between graphene nanosheets (GNs) and shells to prepare thermally conductive MPCMs-GNs by using cellulose nanofibers (CNFs) to assist GN dispersion. The experiments and theoretical calculations both illustrated that CNFs effectively prevented GNs from aggregating due to the strong Van der Walls interactions between CNFs and GNs. The morphologies and structures of MPCMs with and without GNs were characterized by SEM, FTIR and XRD. The thermal properties of MPCMs were evaluated by DSC, TG, and a thermal conductivity test. The MPCMs with 10 wt.% GNs exhibited a melting enthalpy as high as 187.2 J/g and a thermal conductivity as high as 1.214 (W/m⋅K). The results indicate that the prepared MPCMs possessed a good thermal stability. In addition, MPCMs-GNs exhibited outstanding mechanical properties using a nano-indentation test. With an excellent melting enthalpy and thermal conductivity, the prepared MPCMs-GNs/textile showed a potential ability to be used for comfort thermal regulation.