Deterioration Effects of Oxidative Aging on Graphene-Asphalt Nanocomposite Interfaces: Multiscale Modeling

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Asphalt pavement degradation, particularly cracking, is a major infrastructure challenge.
• Graphene-asphalt nanocomposites offer potential for enhanced material properties.
• Understanding oxidative aging mechanisms is crucial for improving asphalt durability.

Purpose of the Study:

• To elucidate the interfacial degradation mechanism of graphene-asphalt nanocomposites under oxidative aging.
• To explain how oxidative aging reduces the cracking resistance of these materials.
• To analyze the multiscale coupling effects on interfacial behavior.

Main Methods:

• Density Functional Theory (DFT) and Molecular Dynamics (MD) simulations.
• Atomic Force Microscopy (AFM) for surface analysis.
• Fourier Transform Infrared (FTIR) spectroscopy and Linear Amplitude Scanning (LAS) tests for chemical and mechanical characterization.

Main Results:

• Oxidative aging reduced fatigue life by 8.6% due to decreased shear and energy barriers.
• Aging enhanced intermolecular compatibility, with van der Waals forces dominating interfacial interactions.
• Graphene-aged aromatics and saturates showed high compatibility, with benzene ring stacking observed.
• Aged aromatics and saturates promoted interfacial strength, while aged asphaltenes and resins sometimes weakened it.
• No chemical reactions were found between graphene and aged asphalt components.

Conclusions:

• Interfacial degradation in aged graphene-asphalt nanocomposites is a complex, multiscale phenomenon.
• Oxidative aging impacts both molecular interactions and macroscopic mechanical properties.
• Findings provide a theoretical foundation for developing advanced anti-aging and anti-cracking asphalt technologies.