Thermal Properties of the Binary‐Filler Hybrid Composites with Graphene and Copper Nanoparticles

Abstract

The thermal properties of epoxy‐based binary composites comprised of graphene and copper nanoparticles are reported. It is found that the “synergistic” filler effect, revealed as a strong enhancement of the thermal conductivity of composites with the size‐dissimilar fillers, has a well‐defined filler loading threshold. The thermal conductivity of composites with a moderate graphene concentration of fg = 15 wt% exhibits an abrupt increase as the loading of copper nanoparticles approaches fCu ≈ 40 wt%, followed by saturation. The effect is attributed to intercalation of spherical copper nanoparticles between the large graphene flakes, resulting in formation of the highly thermally conductive percolation network. In contrast, in composites with a high graphene concentration, fg = 40 wt%, the thermal conductivity increases linearly with addition of copper nanoparticles. A thermal conductivity of 13.5 ± 1.6 Wm−1K−1 is achieved in composites with binary fillers of fg = 40 wt% and fCu = 35 wt%. It has also been demonstrated that the thermal percolation can occur prior to electrical percolation even in composites with electrically conductive fillers. The obtained results shed light on the interaction between graphene fillers and copper nanoparticles in the composites and demonstrate potential of such hybrid epoxy composites for practical applications in thermal interface materials and adhesives.

High thermal conductivity polylactic acid composite for 3D printing: Synergistic effect of graphene and alumina

“…Barani et al systematically studied the synergistic effect of nanocopper particles and graphene in thermal conductive materials and used a variety of different fillers to synergize with graphene to prepare high thermal conductivity materials with different properties. Under the low graphene load, the thermal conductivity of the materials obtained in this study can also be higher showing a regularity consistent with it . In this research, the thermal conductivity of composites is much higher than the same filler content reported in other literatures .…”

Globular Flower-Like Reduced Graphene Oxide Design for Enhancing Thermally Conductive Properties of Silicone-Based Spherical Alumina Composites

“…In our work, the enhanced ability of GFRGO reached 48%, about 2.1 times that of the RGO in filled S-Al 2 O 3 /PDMS composites (23%), at the filling ratio 1.0%. The GFRGO is a more effective enhancer than RGO for enhancement in the thermal conductivity of silicone-based S-Al 2 O 3 composites, which is attributed to the formation of the isotropic, continuous and stable heat-conductive pathways by the 3D near-spherical GFRGO and the spherical S-Al 2 O 3 , as well as the synergistic effect of the binary-filler hybrid [2,34,35]. Thus, the structure and dimensions of GFRGO are in favor of the improvement in the thermal conductivity of silicone-based S-Al 2 O 3 composites.…”

Synergistic Effects of Boron Nitride (BN) Nanosheets and Silver (Ag) Nanoparticles on Thermal Conductivity and Electrical Properties of Epoxy Nanocomposites

“…However, obtaining significant 2 of 13 improvement in thermal conductivity without undermining insulation properties is challenging [13]. Nanofillers, such as carbon nanotubes [14], graphene [15], and metals (such as copper [16]) leads to the decrease of insulation strength. Some ceramic fillers, including aluminum oxide [17], aluminum nitride [18], silicon carbide [19], and strontium titanate [20] induce a sharp rise in dielectric properties, while others, such as silicon dioxide, limit thermal conductivity enhancement [21].…”