Synergistic optimization of mechanical and corrosion resistance properties of epoxy resin modified with green synthetic silica/graphene nanoplatelets composite particles

• Developed an eco-friendly aqueous mechanochemical method for silica/graphene nanoplatelets composite particles. • Combined nano-enhancement and micro-barrier effects for epoxy resin optimization. • Achieved rapid epoxy curing (140 °C/8min, >95 % conversion) with 15 % crosslinking enhancement. • Improved tensile strength of epoxy resin by 60 % (61.8 MPa) with 83 % retention in pH 12 seawater. This study innovatively designed and developed a green and sustainable mechanochemical synthesis strategy to prepare SiO 2 /GNPs (graphene nanoplatelets) composite particles with multi-scale structures utilizing water as the medium. This prepared composite cleverly combines the nano-enhancement effect of GNPs with the micron-scale barrier properties of SiO 2 , to assist in achieving high-performance epoxy resin (Ep). The modified Ep system achieves 95 % cure at 140 °C in 8 min, with a 15 % increase in crosslink density, providing a new approach for rapid curing processes. The tensile strength of the modified Ep reaches 61.8 MPa (60 % increase). After being immersed in seawater at 60 °C and pH 12 for 672 h, the modified Ep maintains a strength of 51.3 MPa (with a retention rate of 83 %), significantly outperforming the unmodified Ep (16.7 MPa, 43 %). This Ep system, which combines rapid curing, high strength and toughness, and excellent corrosion resistance, provides an innovative path for the development of high-performance fiber-reinforced polymer composites for marine engineering applications.