The long-term exposure of asphalt pavement to ultraviolet radiation causes significant performance degradation and reduces its service life. To enhance the UV resistance of asphalt, nanocomposite modifiers have been incorporated through mechanical blending. However, their effectiveness has been largely limited by poor component uniformity. To address this issue, UV-resistant antioxidant nano-TiO2 was employed to modify the UV-shielding of layered porous carbon (PC), resulting in the synthesis of nano-TiO2 intercalated PC (TiO2/PC). The PC nanosheet was modified by TiO2 nanoparticles via in situ growth, significantly improving the dispersion homogeneity of TiO2. Comprehensive characterization (SEM/EDS/FT-IR/XPS) confirmed the successful synthesis of TiO2/PC with well-defined interfacial bonding. Compared to control samples (PC, TiO2, and TiO2 + PC), the asphalt modified by TiO2/PC-2 composite demonstrated superior UV aging resistance, lower physical aging indices and reduced rheological aging parameters. Moreover, TiO2/PC modifier prominently suppressed the formation of oxidative groups (C=O/S=O), improved the colloidal stability, and delayed the sol–gel transition of the modified asphalt. The synergistic UV shielding mechanism was attributed to the enhanced UV absorption of TiO2, multi-reflection and scattering within the PC matrix, and the radical scavenging capabilities of both components. These results provide new design insights for developing anti-UV aging modifiers for asphalt pavements.
Tian et al. (Tue,) studied this question.