Molecular Simulation of Interaction Behavior Between Asphalt Components and Waste Wood Oil

Document Type

Article

Publication Date

12-2024

Department

Department of Civil, Environmental, and Geospatial Engineering

Abstract

To clarify the interaction mechanism between asphalt components and waste wood oil (WWO) in waste sawdust-based bio-asphalts in a molecular scale, five molecular models including virgin asphalt and four kinds of bio-asphalts were established based on the SARA theory by using molecular dynamics (MD) method, and their validity was verified by using the radial distribution function (RDF), energy, density, and solubility parameters. The interaction behavior between WWO and asphalt components was tracked through the analysis of interaction energy, RDF, and snapshots of stable configurations. The results show that the interaction energies between WWO and asphalt components in different bio-asphalt systems are negative, indicating that they attract each other. The order of interaction energies is WWO-resin>WWO-aromatic>WWO-asphaltene>WWO-saturate, which suggests that WWO has the largest interaction force with the resin molecules and the smallest interaction force with the saturate. The intermolecular RDF curves between WWO and four asphalt components stabilize with increasing distance and eventually converge to 1. 0, indicating that the molecules within the system show a disordered distribution over a long range. The RDF curves of WWO-resin, WWO-aromatic, and WWO-asphaltene are flat, and there are no significant peaks. However, the RDF curve of WWO-saturate has obvious fluctuations in the range of 0. 5~1. 5 nm, and the maximum peak intensity is only 1. 24, indicating that there are molecular aggregation phenomena in some regions. In addition, similar conclusions to the interaction energy and RDF analyses were found by analyzing the MD snapshots of the stable configurations. The findings demonstrate at the molecular level that WWO is compatible with asphalt components.

Publication Title

Journal of South China University of Technology (Natural Science Edition)

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