title: Destruction and recovery of a nanorod conductive network in polymer nanocomposites via molecular dynamics simulation.
abstract: By adopting coarse-grained molecular dynamics simulation, we investigate the effects of end-functionalization and shear flow on the destruction and recovery of a nanorod conductive network in a functionalized polymer matrix. We find that the end-functionalization of polymeric chains can enhance the electrical conductivity of nanorod filled polymer nanocomposites, indicated by the decrease of the percolation threshold. However, there exists an optimal end-functionalization extent to reach the maximum electrical conductivity. In the case of steady shear flow, both homogeneous conductive probability and directional conductive probability perpendicular to the shear direction decrease with the shear rate, while the directional conductive probability parallel to the shear direction increases. Importantly, we develop a semi-empirical equation to describe the change of the homogeneous conductive probability as a function of the shear rate. Meanwhile, we obtain an empirical formula describing the relationship between the anisotropy of the conductive probability and the orientation of the nanorods. In addition, the conductivity stability increases with increasing nanorod volume fraction. During the recovery process of the nanorod conductive network, it can be fitted well by the model combining classical percolation theory and a time-dependent nanorod aggregation kinetic equation. The fitted recovery rate is similar for different nanorod volume fractions. In summary, this work provides some rational rules for fabricating polymer nanocomposites with excellent performance of electrical conductivity.
authors.affiliation: Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, People's Republic of China. zhanglq@mail.buct.edu.cn liujun@mail.buct.edu.cn.
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 100029 Beijing, People's Republic of China.
authors.forename: Dapeng
authors.initials: D
authors.lastname: Cao
authors.affiliation: Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, People's Republic of China. zhanglq@mail.buct.edu.cn liujun@mail.buct.edu.cn and Beijing Engineering Research Center of Advanced Elastomers, People's Republic of China and Engineering Research Center of Elastomer Materials on Energy Conservation and Resources, Ministry of Education, People's Republic of China.
authors.forename: Youping
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, People's Republic of China. zhanglq@mail.buct.edu.cn liujun@mail.buct.edu.cn and Beijing Engineering Research Center of Advanced Elastomers, People's Republic of China and Engineering Research Center of Elastomer Materials on Energy Conservation and Resources, Ministry of Education, People's Republic of China.
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.affiliation: Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, People's Republic of China. zhanglq@mail.buct.edu.cn liujun@mail.buct.edu.cn and State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 100029 Beijing, People's Republic of China and Beijing Engineering Research Center of Advanced Elastomers, People's Republic of China and Engineering Research Center of Elastomer Materials on Energy Conservation and Resources, Ministry of Education, People's Republic of China.
authors.forename: Liqun
authors.initials: L
authors.lastname: Zhang