Simple and low‐cost preparation of functionalised graphene by microwave expansion combined with ball milling grafting

Abstract The preparation of functionalised graphene often involves consuming significant amounts of organic solvents, complicated steps, and expensive equipment. This study presented a simple, low‐cost, and efficient method for preparing well‐dispersed functionalised graphene. This method involved the microwave heating of commercial graphene precursors and ball milling of grafted expanded graphite, resulting in a short and straightforward preparation process without requiring large amounts of organic solvents. This process enabled the preparation of few‐layer graphene with a thickness of only 3.5 ± 0.5 nm. During this process, the majority of the surface oxygen‐containing groups were replaced by polyetheramine (D2000) at a grafting rate of up to 5.14%, which improved the interface adhesion strength between the graphene and the epoxy resin. The fabricated altered graphene notably enhanced the mechanical characteristics of the epoxy resin., that is, the toughening effect reached up to 171% with a graphene content of only 0.3 wt%, while the Young's modulus and tensile strength values increased by 54% and 39%, respectively. This process is cost‐effective, easy to operate, and highly efficient, making it suitable for the large‐scale production of well‐dispersed functionalised graphene. Highlights Pioneers mechanical chemical energy in graphene, a new materials science direction. First ball milling on microwave graphene, merging milling benefits with graphene. Ball milling cuts D2000 grafting time on graphene, boosting efficiency. Reduces organic solvent use, cutting costs and environmental effects. Ball milling lowers costs and impacts, aiding graphene material commercia‐lization.