剪切流动下Cooee沥青的非牛顿行为和分子结构：非平衡分子动力学研究
Non-Newtonian behavior and molecular structure of Cooee bitumen under shear flow: a non-equilibrium molecular dynamics study
摘要：
采用非平衡分子动力学模拟研究了剪切作用下模型沥青（Cooee沥青）的流变性和分子结构。计算了沥青混合料在不同剪切速率和温度下的剪切粘度、法向应力差和压力。模型沥青在所有温度下都是剪切稀化流体。此外，Cooee模型能够再现实验结果，显示由沥青中的扁平芳族分子堆叠组成的纳米聚集体的形成。将这些纳米聚集体浸入饱和烃分子的溶剂中。在一个固定的温度下，剪切光泽的行为是有关的溶剂分子的分子间和分子内的排列，但也在高剪切速率的纳米聚集体的平均尺寸的减少。在不同的剪切速率下，粘度随温度的变化也与纳米聚集体的尺寸和相对组成有关。由于纳米聚集体的整个样品的轻微的各向异性被认为是和量化。最后，讨论了沥青混合料在复杂系统如胶体悬浮液、聚合物溶液和缔合聚合物网络等广泛文献中的地位。
英文摘要：
The rheology and molecular structure of a model bitumen (Cooee bitumen) under shear are investigated in the non-Newtonian regime using non-equilibrium molecular dynamics simulations. The shear viscosity, normal stress differences and pressure of the bitumen mixture are computed at different shear rates and different temperatures. The model bitumen is shown to be a shear-thinning fluid at all temperatures. In addition, the Cooee model is able to reproduce experimental results showing the formation of nanoaggregates composed of stacks of flat aromatic molecules in bitumen. These nanoaggregates are immersed in a solvent of saturated hydrocarbon molecules. At a fixed temperature, the shear-shinning behavior is related to the inter- and intramolecular alignment of the solvent molecules, but also to the decrease of the average size of the nanoaggregates at high shear rates. The variation of the viscosity with temperature at different shear rates is also related to the size and relative composition of the nanoaggregates. The slight anisotropy of the whole sample due to the nanoaggregates is considered and quantified. Finally, the position of bitumen mixtures in the broad literature of complex systems such as colloidal suspensions, polymer solutions and associating polymer networks is discussed.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
