Study On The Dispersion Behavior Of Nanorods And The Configuration Of Polymer Chains In Nanocomposite Systems

The molecular dynamics simulations method is used to investigate the dispersion and orientation of nanorods in the polymer melts.While at low interfacial interaction between the polymer chain and the nanorods,it exhibits a direct contact aggregation,which greatly prevents the realization of excellent performance of nanocomposites.With the gradual enhancement of the interaction between polymer chains and nanorods,different dispersion states of nanorods can be observed under equilibrium conditions.Under moderate interaction,the nanorods are basically in a uniformly dispersed state,and under strong interaction,the nanorods show a bridging state.After gradually increasing the stiffness of the chain,the degree of dispersion of the nanorods is slightly improved.With the increase of the chain stiffness,the dispersion of nanorods is slightly increased.When a shear field is applied to the nanocomposite system,as the shear field reaches a certain strength,the dispersion degree of the nanorods is significantly improved,and the orientation degree of the nanorods is also improved to a certain extent.We have observed that under the action of appropriate chain stiffness and shear field strength,the nanorods can not only achieve a good dispersion state,but also show a certain orientation distribution law.In addition,the distribution of linear and ring chains on the surface of nanorods under different interactions is also discussed.Under the strong interaction between the polymer and the nanorods,as the stiffness of the polymer chains increases,the polymer chains on the surface of the nanorods are arranged more orderly and tightly.At the same time,when the interaction is strong,the interface area of the nanorod is occupied by the semi-flexible polymer chain,and the semi-flexible molecular chain is tightly wrapped on the nanorod,causing the flexible polymer to not stay in the interface area of the nanorod.For ring chains with a closed topology,when the interaction is weak,the semi-flexible ring polymer chains and nanorods form a nested self-assembly model.In the interface area of the nanorods,only a small amount of linear polymer is adsorbed on the surface of the nanorods,and semi-flexible ring chains preferentially occupy the interface area of the nanorods.Therefore,the selective adsorption behavior is related to the topological structure of the polymer chain.These results provide effective insights for the design of composite materials with excellent properties,to a certain extent,it also provides some valuable reference data for theoretical and experimental research.