Highly Thermally Conductive Polydimethylsiloxane Composites with Controllable 3D GO@f-CNTs Networks via Self-sacrificing Template Method

Constructing controllable thermal conduction networks is the key to efficiently improve thermal conductivities of polymer composites. In this work, graphite oxide (GO) and functionalized carbon nanotubes ( f -CNTs) are combined to prepare “Line-Plane”-like hetero-structured thermally conductive GO@ f -CNTs fillers, which are then performed to construct controllable 3D GO@ f -CNTs thermal conduction networks via self-sacrificing template method based on oxalic acid. Subsequently, thermally conductive GO@ f -CNTs/polydimethylsiloxane (PDMS) composites are fabricated via casting method. When the size of oxalic acid is 0.24 mm and the volume fraction of GO@ f -CNTs is 60 vol%, GO@ f -CNTs/PDMS composites present the optimal thermal conductivity coefficient ( λ , 4.00 W·m −1 ·K −1 ), about 20 times that of the λ of neat PDMS (0.20 W·m −1 ·K −1 ), also much higher than the λ (2.44 W·m −1 ·K −1 ) of GO/ f -CNTs/PDMS composites with the same amount of randomly dispersed fillers. Meanwhile, the obtained GO@ f -CNTs/PDMS composites have excellent thermal stability, whose λ deviation is only about 3% after 500 thermal cycles (20–200 °C).