Hydrophilic Cu-Graphene\nHeterostructure Fillers for\nthe Enhancement of the Thermal Performance of Poly(vinyl Alcohol)-Based\nComposites

Developing polymer-based composites using high-performance\nheterostructure\nfillers is of significant importance for the thermal management of\nelectronic devices. Herein, hydrophilic copper-graphene (Cu-GNP) heterostructure\nfillers modified with amino functional groups via polydopamine surface\nmodification and calcination reduction were prepared. Subsequently,\nCu-GNP/poly(vinyl alcohol) (PVA) thermal conductive composites were\nfabricated using a solution blending method, where hydrogen bonds\nwere formed between the fillers and the PVA matrix. For composites\ncontaining 20 wt % Cu-GNP fillers, their in-plane thermal conductivity\nreaches 18.49 W·m<sup>–1</sup>·K<sup>–1</sup> and the tensile strength is 25.97 MPa, representing increases of\n20.61% and 24.25%, respectively, compared to GNP/PVA composites with\nequivalent filler contents. This improvement is attributed to the\nenhanced interaction between Cu-GNP and the PVA matrix due to the\nformation of hydrogen bonds. Additionally, these composites also exhibit\na certain level of electrical insulation properties, making them promising\ncandidates for heat dissipation applications in electronic devices.