Copper nanoparticle-deposited graphite sheets for highly thermally conductive polymer composites with reduced interfacial thermal resistance

Highly thermally conductive polymer-based composites are becoming increasingly important for effectively removing the accumulated heat of thermal management devices. However, interfacial thermal resistance (ITR) seriously affects the heat transfer performance of composites. Herein, after mildly modifying the commercial graphite, copper nanoparticles (CuNPs) are deposited on the surface of modified graphite (MGr) by chemically reducing. And the CuNPs-deposited MGr (MGr/Cu) hybrids are mixed with epoxy resin to prepare composites. Through the improved interfacial contact and interconnection between CuNPs and MGr, the heat conduction pathways will be easy to form in epoxy matrix. And the MGr/Cu hybrids exhibit well compatibility with epoxy matrix. Consequently, the resultant composite exhibits a high thermal conductivity of 4.57 W m −1 K −1 at 50 wt% MGr/Cu loading. Fitting the experimental value with Foygel nonlinear model further reveals that the ITR is 3.92 × 10 −6 m 2 K W −1 for MGr/Cu/epoxy composites, which decreases by 27.94% than that of Gr/epoxy composites. Moreover, our composite displays well heat dissipation potential in thermal management application. This strategy provides an effective guidance for reducing the ITR inside polymer composites to prepare thermal management materials. Graphic Abstract The thermal conductivity is improved via thermally conductive Cu bridges between modified graphite and the improved compatibility between graphite and epoxy.