Mechanical Properties of Polymer Composites Reinforced by 3D Interlocking CNTs—Graphene: A Molecular Dynamics Study

ABSTRACT The tendency of nanofillers to agglomerate within the polymer matrix severely restricts their reinforcing efficiency for the matrix. This study innovatively designs Rebar graphene with a unique 3D interlocking structure by covalently bonding carbon nanotubes to graphene. This study systematically investigates its effect on enhancing the mechanical properties of composite materials, clarifying the interfacial reinforcement mechanisms via adsorption and pull‐out simulations, and reveals the role of dense effective thickness layers around Rebar graphene through atomic distribution analysis. These multi‐dimensional findings elucidate the superior synergistic reinforcement mechanism of Rebar graphene, providing novel insights for high‐performance composite design. Adsorption simulations reveal that this structure significantly restricts PE chain mobility through interlocking, with reduced MSD and about 200 % higher interfacial interaction energy, strengthening interfacial bonding. Pull‐out simulations show Rebar graphene/PE achieves a peak pull‐out force of 5.26 nN, 134.8 % higher than graphene/PE, with slower force attenuation during debonding, indicating better interfacial load transfer and toughness. Atomic distribution analysis confirms that Rebar graphene promotes a dense, effective thickness layer of PE chains around it, further enhancing stiffness. These findings clarify Rebar graphene's synergistic reinforcement mechanism from interfacial, load transfer, and microstructure aspects, offering key theoretical support for high‐performance nanofiller‐reinforced polymer composite design.