RESUMO
In recent years, graphene has been introduced into phase change materials (PCMs) to improve thermal conductivity to enhance the heat transfer efficiency in thermal energy storage. However, graphenes tend to aggregate in PCMs, leading to the low thermal conductivity efficient enhancement (TCEE), anisotropic thermal conductivity, and deterioration of mechanical performance of PCMs. In this work, we fabricated biomimetic thermally conductive solid-solid PCMs (SSPCMs) by facile blending of the graphene into well-designed polyurethane SSPCMs, in which the graphene established a controllable and highly efficient isotropic thermally conductive pathway based on the π-π stacking between the graphene and the polymer aromatic ring segment. The as-fabricated SSPCMs showed high TCEE (156.78%), excellent flexibility (328% elongation at break), high enthalpy value (>101 J/g), and solid-solid phase transition properties, under 2% loading of graphene. The proportion of in-plane to through-plane thermal conductivity can be adjusted by an elaborate design of the aromatic ring segment in polyurethane SSPCMs. We further demonstrated mechanical flexibility and photothermal property of the composites to reveal their potential in practical applications.
RESUMO
The structure of the electrochemically crystallized title compound, (C(10)H(8)S(8))(3)[CoCl(4)](2), consists of two types of bis-(ethyl-enedithio)tetra-thia-fulvalene (BEDT-TTF) radical cation stacks separated by sheets of tetra-hedral [CoCl(4)](2-) anions. One of the BEDT-TTF mol-ecules is generated by inversion. There are short Sâ¯S contacts between the stacks in the a direction and short C-Hâ¯Cl contacts between the radical cations and the anions.