Multiscale Interfacial Interactions in Carbon Nanotube-Asphalt Nanocomposites: Implications for Asphalt Pavement Materials

Carbon nanotube (CNT)-asphalt nanocomposites are considered to be the next generation of pavement materials; however, the interaction between CNT and asphalt at the interface and the mechanisms of property enhancement are not well understood, which limits the application of CNT-asphalt nanocomposites. In this study, CNT is used as a representative of one-dimensional nanomaterials, and the interfacial multiscale interaction mechanism between CNT and asphalt molecules is investigated by density functional theory (DFT), molecular dynamics simulation, atomic force microscopy (AFM), gelation permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), and performance evaluation. It has been shown that CNT and asphalt substrates are very compatible at the atomic scale, mainly due to π-π stacking, mechanical entanglement, and van der Waals forces. The interfacial energy barrier is −2.63 (kcal/mol)/Ų and the shear barriers are 52.70 MPa, with asphaltene and aromatic making the greatest contribution to interfacial stress transfer. This research provides a theoretical basis for the targeted tuning of properties and establishes the basis for CNT-asphalt nanocomposites for highway applications.