Computational simulation of interfacial properties in nanodiamond-reinforced epoxy nanocomposites

The mechanical properties of nanocomposites are strongly governed by the interfacial characteristics between the reinforcement and the matrix, yet the underlying interfacial mechanisms and molecular structures remain incompletely understood. Here, the molecular structure and interface models of ND–epoxy system are constructed to investigate how nanodiamond (ND) structure affects interfacial behavior in ND/epoxy composites – including interfacial interactions, binding energy, and ND–epoxy shear strength – with consideration of electrostatic and van der Waals interactions, and deformation induced by atomic-scale interactions within a computational efficient method. The results show that ND structure significantly influences interfacial behavior, with the semi-amorphous ND exhibiting the highest interfacial strength when compared with crystalline (cubic and hexagonal) and totally amorphous ND. These findings provide molecular-level insight to guide materials design and optimization of ND/epoxy nanocomposites for next-generation high-performance applications, including aerospace structures, military vehicles, and the automotive industry.