Eco-Friendly Preparation of Graphene Nanoplatelet/Poly(vinyl alcohol) Nanocomposites for Thermal Management

The overheating problem in rapidly advancing nano- and microelectronics has put forward an urgent need for thermal dissipation. While graphene-based polymer nanocomposites exhibit exceptional thermal dissipation properties, their widespread applications are hindered by complex manufacturing processes and the generation of harmful byproducts. In this work, flexible graphene nanoplatelet (GNP)/poly(vinyl alcohol) (PVA) composite films with graphene content ranging from 3.1 to 20.9 wt % were fabricated through a two-step process involving dry-state ball-milling of expanded graphite and PVA at 600 rpm for 24 h via deionized water solvent casting. The two-step process is simple and eco-friendly. Meanwhile, the GNPs formed by ball-milling exhibit superior dispersibility in water and fewer structural defects due to the protective PVA layer formed on the surface. Consequently, the produced composite film obtains an excellent in-plane thermal conductivity of 13.40 W/m K, outperforming that of previously reported graphene-based composite materials with comparable GNP content. Given its simplicity and eco-friendliness, the current method is expected to advance the wide applications of graphene-based composites for thermal management in the fields of electronics, aerospace, clean energy, etc.