Multiscale Synergistically Enhanced SiO ₂ @GO/PDBS/Kevlar Composite: Regulation of Dynamic Reversibility and Impact Resistance

The shear thickening material, as a novel intelligent responsive material, has been widely applied in various protective materials, owing to its excellent impact resistance and ability to promptly and reversibly respond to changes in the external environment. To address the issues of the single dynamic response mechanism and limited energy dissipation efficiency of traditional impact-resistant materials, this study constructed a SiO2@GO/polydiborosiloxane (PDBS)/Kevlar composite material with a dynamically reversible network structure using a multiscale collaborative design strategy. The experimental results indicated that the interfacial interaction between SiO2@GO and polydiborosiloxane was significantly improved, and the prepared composite material exhibited remarkable energy absorption capabilities. By employing an in situ modification method to load silicon dioxide (SiO2) nanoparticles onto the surface of graphene oxide (GO) and integrating dynamic polydiborosiloxane with a Kevlar fiber network, a three-level energy dissipation system of “nanoreinforcement-dynamic boron–oxygen bonding-macroscopic fiber skeleton” was established. Furthermore, a series of impact experiments were conducted at both low and high speeds. The results of the Hopkinson press bar (SHPB) dynamic impact testing revealed that the maximum stress decay of the SiO2@GO/PDBS/Kevlar composite material decreased from 224.9 to 96.0 MPa at a strain rate of 5000 s–1, representing a 57.3% decrease, whereas the multiscale synergistic strategy greatly improved the impact attenuation of the multilayer armor with the SiO2@GO/PDBS/Kevlar fabric. This study provides a theoretical basis and reference for the optimization and development of lightweight, impact-resistant, and flexible protective materials.