Investigating the efficacy of multidimensional MoS2/PAN fiber composites within styrene-butadiene-styrene enhanced asphalt binder

In this study, a pioneering surface modification technique in the development of fiber-modified asphalt binders, employing mussel-inspired chemistry principles, is proposed. By co-depositing tannic acid/polyethyleneimine (TA/PEI) and various crystalline forms of molybdenum disulfide (MoS2) on the surface of polyacrylonitrile (PAN) fibers, three types of PAN fibers with different surface morphologies (NF -PAN, NS -PAN, and NT -PAN) were successfully synthesized. This led to the preparation of three modified asphalt binders (NF-PAN/SBS, NS -PAN/ SBS, and NT-PAN/SBS). Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray Spectroscopy (EDS), and Atomic Force Microscopy (AFM) tests demonstrated the effective combination of two-dimensional MoS2 with PAN fibers. They confirmed the enhancement in interfacial interaction between the fibers and asphalt due to the high specific surface area and Young's modulus of NF -PAN. Further asphalt binder performance tests indicated that NF-PAN/SBS exhibited the best shear strength, viscoelastic properties, and thermal stability in hightemperature performance tests and the best creep recovery rate and stiffness modulus in low-temperature performance tests. Specifically, at a 2% fiber content, NF-PAN/SBS demonstrated improvements of 48.8% in complex modulus (G*), 55.5% in storage modulus (G'), and 45.3% in loss modulus (G") compared to the asphalt binder with unmodified PAN (PAN/SBS), and an increase of 11.04 C-degrees in thermal decomposition temperature, with an 11.17% and 24.32% improvement in creep recovery rate at low temperatures compared to PAN/SBS. Additionally, the addition of MoS2 also enhanced the microwave absorption capability of the fiber composite modified asphalt binder, providing a better internal heat source reception for subsequent road maintenance. This research offers a novel and sustainable solution for enhancing asphalt binders, particularly suitable for challenging environmental conditions. It is expected to provide more efficient and rational modification methods for fiber and nano two-dimensional material-modified asphalts and offers significant references for the composite and synergistic modification of various asphalt components.