Hydrophilic Cu-Graphene Heterostructure Fillers for the Enhancement of the Thermal Performance of Poly(vinyl Alcohol)-Based Composites

Developing polymer-based composites using high-performance heterostructure fillers is of significant importance for the thermal management of electronic devices. Herein, hydrophilic copper-graphene (Cu-GNP) heterostructure fillers modified with amino functional groups via polydopamine surface modification and calcination reduction were prepared. Subsequently, Cu-GNP/poly(vinyl alcohol) (PVA) thermal conductive composites were fabricated using a solution blending method, where hydrogen bonds were formed between the fillers and the PVA matrix. For composites containing 20 wt % Cu-GNP fillers, their in-plane thermal conductivity reaches 18.49 W·m^–1·K^–1 and the tensile strength is 25.97 MPa, representing increases of 20.61% and 24.25%, respectively, compared to GNP/PVA composites with equivalent filler contents. This improvement is attributed to the enhanced interaction between Cu-GNP and the PVA matrix due to the formation of hydrogen bonds. Additionally, these composites also exhibit a certain level of electrical insulation properties, making them promising candidates for heat dissipation applications in electronic devices.