In this paper, we present the effects of graft locations on the dispersion behavior of polymer-grafted nanorods using molecular dynamics simulations. Four graft locations of chains on nanorods, i.e., end-grafted, quarter-grafted, middle-grafted and uniformly grafted, are specially designed, and the effects of graft locations are examined in both sparsely grafted case and densely grafted case. Simulation results show that the end-grafted nanorods exhibit the poorest dispersion in the matrix, whilst the body-grafted (quarter-grafted and middle-grafted) ones show the best dispersion. At low grafting density in the mushroom regime, the middle-grafted disperse slightly better than the quarter-grafted, whereas at high grafting density in the brush regime, the situation is reversed. By analyzing the conformations of graft chains (mushroom height and brush height) and the behavior of grafted nanorods, it is inferred that the inter-rod cohesive energy provides a great contribution to the dispersion, as reflected by the significant role of the center region of nanorods. In general, a dense and wide coverage of the center/middle region of nanorods by graft chains can effectively improve the nanorod dispersion. This work is expected to provide some guidance on controlling and improving the dispersion of nanorods in polymer nanocomposites.

在本文中，我们使用分子动力学模拟介绍了接枝位置对聚合物接枝纳米棒分散行为的影响。特别设计了纳米棒上链的四个接枝位置，即末端接枝，四分之一接枝，中接枝和均匀接枝，并在稀疏接枝和密集接枝情况下研究了接枝位置的影响。仿真结果表明，末端接枝的纳米棒在基质中的分散性最差，而身体接枝的（四分之一和中间接枝的）纳米棒的分散性最好。在蘑菇区的嫁接密度低的情况下，中等嫁接的分散性比四分之一嫁接的分散性好，而在灌木丛的嫁接密度高的情况下，情况则相反。通过分析接枝链的构型（蘑菇高度和刷子高度）以及接枝的纳米棒的行为，可以推断出棒间的内聚能为分散提供了很大的贡献，这反映在中心区域的重要作用上。纳米棒。通常，接枝链对纳米棒的中心/中间区域的致密且广泛的覆盖可以有效地改善纳米棒的分散性。预期这项工作将为控制和改善纳米棒在聚合物纳米复合材料中的分散性提供一些指导。接枝链对纳米棒的中心/中间区域的致密而广泛的覆盖可有效改善纳米棒的分散性。预期这项工作将为控制和改善纳米棒在聚合物纳米复合材料中的分散性提供一些指导。接枝链对纳米棒的中心/中间区域的致密而广泛的覆盖可有效改善纳米棒的分散性。预期这项工作将为控制和改善纳米棒在聚合物纳米复合材料中的分散性提供一些指导。