# Molecular Dynamics-Based Study of Graphene/Asphal Mechanism of Interaction
## 4 Conclusions  
In this study, the interaction between different types of graphene and asphalt was systematically analyzed based on molecular dynamics simulation technology to explore the enhancement mechanism of graphene on the self-healing performance of asphalt, and the conclusions pointed out the following:  
1. The 4-component, 12-molecule model was used to construct the molecular model of matrix asphalt and polymerization-modified asphalt; the molecular model of graphene with different sizes and layers was successfully constructed by using cut  
Figure 16: Graphene-modified asphalt mean square displacement MSD versus time curve.  
Figure 17: Diffusion coefficients of graphene-modified asphalt molecular models at various temperatures.  
graphite and supercrystalline constructions, etc., and the reasonableness of the model was verified by indexes such as energy, density, and solubility parameters.
2. The size and number of layers of PGR have a significant effect on its interaction with asphalt components, and the polar components in asphalt interact more strongly with PGR; when the size and number of layers of PGR are fixed, its interfacial binding with ACR-modified asphalt is the highest, followed by SBS-modified asphalt, and 70\(\upmu\) matrix asphalt is the worst; the interfacial binding between PGR and asphalt mainly relies on the van der Waals interaction between interfacial molecules; multilayer graphene molecular modeling was successfully constructed with different sizes and numbers of layers, and the model was verified by energy, dissolution parameters, and other indicators. Van der Waals interaction: multilayer graphene on the mechanical properties of matrix asphalt strengthens the role of more apparent, and small-sized graphene is more suitable for enhancing the low-temperature performance of polymer-modified asphalt.
3. Based on the relative molecular concentration and MSD function, the self-healing process and mechanism of PGR-modified asphalt were comprehensively evaluated. PGR bridged asphalt molecules through rapid heat transfer and \(\uppi\)-\(\uppi\) stacking with aromatic ring-containing substances, which significantly improved the free diffusion ability of asphalt molecules, shortened the asphalt healing time, and enhanced the overall self-healing performance of asphalt.
4. Despite the above findings, the study may need to improve the realism of the simulation and the accuracy of the model construction. Future research could consider experimental validation of the simulation results and explore the effects of different modifiers and asphalt formulations on the self-healing ability.  
Methodology, J.L.; validation, Y.F.; data curation, C.Z.; writing--original draft preparation, C.Z.; writing--review and editing, J.X.; C.W. supervision, L.S.; project administration, Y.F. All authors have read and agreed to the published version of the manuscript.  
This work was funded by the Science and Technology Major Project of Shanxi Province (No. 202201090301014).  
Not applicable.  
The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author.  
The authors declare no conflict of interest.