Vertically Aligned Carbon Fiber/Aluminum Particle/Silicone Rubber Composites with High Thermal Conduction and Desired Mechanical Performance

To utilize the highly thermally conductive axial direction of 1-dimensional carbon fibers (CFs), numerous endeavors have been devoted to the orientation engineering of CF-filled thermally conductive composites. However, the construction of thermal transfer pathways between the aligned CFs is often neglected, which inevitable leads to great thermal resistances that affect the thermal conductivity (TC) of prepared composites. Here, we proposed a facile and scalable strategy to drastically increase the through-plane TC of vertically aligned CF/silicone rubber (V-CF/SR) composites by embedding aluminum (Al) particles into the channels between the aligned CFs during the infiltration process. The V-CF/SR composites embedded with Al particles (V-CF/Al/SR) were fabricated via electrostatic flocking of CFs followed by the infiltration of the Al/SR slurry and curing. Thanks to the vertically aligned CFs bridged by Al particles to form synergistic thermal transfer pathways, the prepared V-CF/Al/SR composites achieved a high through-plane TC of 12.32 W/m K at a low CF content of 19.42 wt % and Al loading of 52.36 wt %, which is 102.5 times higher than that of pure SR. Besides, the V-CF/Al/SR composites maintained desired flexibility, elasticity, and mechanical hardness. Considering that an excellent thermal transfer ability and good mechanical properties have been obtained, the V-CF/Al/SR composites show huge potential in advanced thermal management.