关键词: 碳化硅, 分子动力学, 界面模型, 沥青, 吸附特性, 扩散系数

Abstract: To investigate the adsorption characteristics of silicon carbide (SiC) particles on asphalt, molecular dynamics simulations were employed to construct models of matrix asphalt, SiC, and the SiC/asphalt interface. The rationality of the constructed models was validated through density, energy, and radial distribution functions. The interfacial energy of the SiC/asphalt interface was analyzed at different temperatures, and the diffusion characteristics and selective adsorption of asphalt components at the interface were examined at 298 K. The simulation results were further verified by a four-component asphalt test. The results indicate that the absolute value of interfacial energy first increases and then decreases with rising temperature, reaching its maximum at 298 K. At this temperature, lighter components (saturates and aromatics) and resinsexhibit better diffusion at the SiC/asphalt interface. SiC demonstrates selective adsorption towards asphalt components, with significant accumulation of resins and lighter components at the interface. The four-component asphalt test results show that the relative contents of saturates, aromatics, and resins decrease in the SiC-modified asphalt, while the relative content of asphaltenes increases. This suggests that the selective adsorption of SiC on the four asphalt components enhances the viscosity and stiffness of asphalt, providing a theoretical basis for the study of asphalt pavement performance.

Key words: silicon carbide, molecular dynamics, interface model, asphalt, adsorption characteristics, diffusion coefficient