Liu Ya-Ru, Tang Xin, Zeng Qing, Lai Jian-Ping
School of Traffic and Transportation Engineering, Changsha University of Science and Technology, Changsha, 410114, China.
School of Physics and Chemistry, Hunan First Normal University, Changsha, 410205, China.
Sci Rep. 2024 Aug 27;14(1):19918. doi: 10.1038/s41598-024-70875-9.
Ultraviolet absorption ability of modifiers is essential to protect asphalt from ageing. However, the detailed correlation between them remains unclear. In this study, zinc oxide nanoparticles were used as modifiers, and their ultraviolet absorption ability was manipulated by magnesium and aluminum doping. The influence of ultraviolet absorption ability of the nanoparticles on asphalt ultraviolet ageing was investigated experimentally, and their correlation was revealed in detail by curve fitting. The results show that aluminum doping enhances the ultraviolet absorption ability of nanoparticles, leading to superior anti-aging performance in aluminum-doped zinc oxide modified asphalt compared to pure zinc oxide. Conversely, magnesium doping shows a contrary modification. Evaluating the ultraviolet absorption ability of nanoparticle modifiers by bandgap and absorption intensity, we found that softening point increments, viscosity ageing index, and sulfoxide index exhibit a decreasing trend mainly in the bandgap range of 3.269 to 3.334 eV, whereas carbonyl index shows a decreasing trend mainly in the lower bandgap range of 3.183 to 3.269 eV. This phenomenon is primarily due to the different reactivity of carbon and sulfur with oxygen in asphalt. Curve fitting analysis revealed an exponential correlation between the ageing index of asphalt and the ultraviolet absorption ability of nanoparticles. To achieve superior anti-ultraviolet ageing performance, the nanoparticles should possess an absorption intensity above 0.961 a.u. and a bandgap below 3.299 eV. Moreover, stronger ultraviolet absorption ability of nanoparticles is needed to prevent the formation of carbonyl compounds. The underlying correlation established in the present work has significant implications for selecting suitable modifiers to prevent ultraviolet ageing of asphalt.
改性剂的紫外线吸收能力对于保护沥青抗老化至关重要。然而，它们之间的详细关联仍不明确。在本研究中，氧化锌纳米颗粒被用作改性剂，其紫外线吸收能力通过镁和铝掺杂来调控。实验研究了纳米颗粒的紫外线吸收能力对沥青紫外线老化的影响，并通过曲线拟合详细揭示了它们之间的相关性。结果表明，铝掺杂增强了纳米颗粒的紫外线吸收能力，使得掺铝氧化锌改性沥青的抗老化性能优于纯氧化锌改性沥青。相反，镁掺杂表现出相反的改性效果。通过带隙和吸收强度评估纳米颗粒改性剂的紫外线吸收能力，我们发现软化点增量、粘度老化指数和亚砜指数主要在3.269至3.334 eV的带隙范围内呈下降趋势，而羰基指数主要在3.183至3.269 eV的较低带隙范围内呈下降趋势。这种现象主要是由于沥青中碳和硫与氧的反应活性不同。曲线拟合分析揭示了沥青老化指数与纳米颗粒紫外线吸收能力之间的指数相关性。为了实现优异的抗紫外线老化性能，纳米颗粒应具有高于0.961 a.u.的吸收强度和低于3.299 eV的带隙。此外，需要更强的纳米颗粒紫外线吸收能力来防止羰基化合物的形成。本工作中建立的潜在关联对于选择合适的改性剂以防止沥青紫外线老化具有重要意义。
