Extremely high thermal conductivity of nanodiamond-polydopamine/thin-layer graphene composite films

Publication date: Available online 16 August 2018Source: Composites Science and TechnologyAuthor(s): Hui-Ching Yuan, Chi-Young Lee, Nyan-Hwa TaiAbstractThe hybrid composite films containing nanodiamonds (ND) coated with polydopamine (pDA) (ND-pDA) and reduced graphene oxide (rGO) converted from graphene oxide (GO) films are designed for achieving extremely high thermal conductivity. The ND-pDA/rGO films are successfully fabricated using the vacuum-filtration process followed by a heat treatment at 800 °C. The thermal conductivities of the films in the in-plane (K//) and through-plane (K⊥) directions are measured by the laser flash method to better understand how the addition of dopamine, the amount of ND-pDA, and the test temperature affect the thermal properties of the hybrid films.The experimental results show that the addition of dopamine results in dense structure of the ND-pDA/rGO hybrid films, which is favorable for phonon transport, and thus remarkably increase the thermal properties of the film. Additionally, films with higher ND-pDA loading possess lower in-plane but higher through-plane thermal conductivity. K// and K⊥ of 1406 and 0.677 W m−1 K−1, respectively, for 20ND-pDA/20rGO measured at 25 °C are achieved. Both the K// and K⊥ of 20ND-pDA/20rGO increase with test temperature. Maintaining such high thermal conductivities at high temperature, the hybrid films are believed to be suitable for lightweight thermal management materials with high h...

Source: Composites Science and Technology - August 16, 2018 Category: Science Source Type: research