Functionalized Graphene Oxide Enhances Interfacial Activation and Combustion Performance of Aluminum Powder

• A hybrid GO–COOH/PVDF coating is simultaneously constructed on micron-sized aluminum powders. • Carboxylated graphene oxide enhances interfacial polarity and improves polymer–metal interaction. • The modified interface facilitates oxide-layer disruption and shifts aluminum oxidation to lower temperatures. • Multiscale simulations reveal enhanced interfacial transport and charge transfer. Enhancing interfacial activation is crucial for improving the reactivity of Al-based energetic composites. Before composite fabrication, the aluminum powder was mildly pre-treated to convert the native Al₂O₃ shell into a thin Al(OH)₃ layer. This hydroxylated surface provides higher polarity and more reactive sites. It helps form a uniform coating during spray drying and improves the contact with PVDF and graphene. In this work, graphene oxide (GO) was carboxylated to obtain functionalized GO-COOH and incorporated with poly(vinylidene fluoride) (PVDF) and aluminum to form a GO-COOH/PVDF/Al composite. The introduction of carboxyl groups increases the surface polarity of GO and strengthens its interaction with PVDF. Thermal analysis shows that GO-COOH promotes the reaction between PVDF pyrolysis products and aluminum, shifting the main oxidation peak by ∼100°C to lower temperatures and reducing the apparent activation energy to 24.6 kJ·mol⁻¹ (∼40% lower than raw Al). The composite also exhibits a faster ignition response, with the delay shortened to 15.5 ms. Multiscale simulations reveal that GO-COOH accelerates the penetration of O₂ and fluorinated radicals through the oxide layer and promotes earlier formation of Al–O and Al–F bonds, leading to rapid interfacial heating and more pronounced oxide disruption. DFT results further show enhanced charge transfer at the GO-COOH/Al interface, providing the electronic basis for improved activation. Overall, the combined results demonstrate that GO-COOH enhances aluminum reactivity through stronger interfacial polarization, faster transport of reactive species, and earlier oxide breakdown, offering an effective strategy for designing high-performance Al-based energetic materials.