Bridging Scales in EPDM Composites: Experimental Validation and MD Simulation of ANFs @ SiO ₂ Surface Modification

ABSTRACT The dispersion of fillers in rubber matrices and their interfacial compatibility have long been key challenges in rubber industry applications. This study employs different silane coupling agents (SCAs) to enhance both the dispersion of silica‐grafted aramid nanofibers (ANFs@SiO ₂ ) in ethylene propylene diene monomer rubber (EPDM) and the interfacial interactions between them. Through a combined experimental and molecular simulation approach, we systematically investigate the structure–property relationship of SCAs‐modified ANFs@SiO ₂ /EPDM nanocomposites. Results show that vinyl‐tri‐(2‐methoxyethoxy)‐silane modified composites exhibit the highest binding energy ( E _binding ), lowest mean square displacement (MSD), and smallest fractional free volume (FFV). These characteristics lead to optimized thermodynamic compatibility, superior mechanical properties, and enhanced solvent resistance. The present work establishes an effective strategy for investigating nanoparticle surface modification effects on rubber composite interfaces at the molecular level.