Controlling the formation of the conductive network in the polymer nanocomposites (PNCs) is very meaningful to enhance their electrical property. In this work, we investigated the effect of grafted nanoparticles (NPs) on the conductive probability of PNCs in the quiescent state as well as under the shear field via a coarse-grained molecular dynamics simulation. It is found that the smallest percolation threshold is realized at the moderate grafting density, the moderate length of grafted chains or the moderate interaction between grafted chains and free chains. Corresponding to it, the dispersion state of NPs varies from the contact aggregation to the uniform dispersion. By analyzing the connection mode among NPs, the probability of NPs which connect three other ones reaches the maximum value at their moderate dispersion state which is responsible for the optimal conductive probability. In addition, the main cluster size is characterized to better understand the conductive network which is consistent with the percolation threshold. It is interesting to find that the percolation threshold is smaller under the shear field than under the quiescent state. The shear field induces more NPs which connect three other ones. This benefits the formation of the new conductive network. Meanwhile, the anisotropy of the conductive probability is reduced with increasing the grafting density. In summary, this work provides a clear picture on how the conductive network of grafted NPs evolves under the shear field.

控制聚合物纳米复合材料（PNC）中导电网络的形成对于提高其电性能非常有意义。在这项工作中，我们通过以下方法研究了接枝的纳米颗粒（NPs）对PNC在静态和剪切场下的导电概率的影响。粗粒度的分子动力学模拟。发现最小的渗透阈值是在中等的接枝密度，中等的接枝链长度或中等程度的接枝链与自由链之间的相互作用下实现的。相应地，NP的分散状态从接触聚集到均匀分散而变化。通过分析NP之间的连接模式，连接其他三个NP的NP的概率在其适度分散状态下达到最大值，这是最佳导电概率的原因。此外，主簇的大小可以更好地理解与渗透阈值一致的导电网络。有趣的是，在剪切场下的渗流阈值比在静态下的渗流阈值小。剪切场引起更多的NP连接另外三个NP。这有利于新的导电网络的形成。同时，随着接枝密度的增加，导电概率的各向异性减小。总而言之，这项工作提供了一个清晰的画面，说明了在剪切场下已接枝NP的导电网络如何演化。