Adsorption Behavior of Polymer Chain with Different Topology Structure at the Polymer-Nanoparticle Interface.

Qingliang Song,Xianghong Wang,Linli He,Yongyun Ji,Shiben Li

doi:10.3390/polym10060590

Abstract

The effect of the polymer chain topology structure on the adsorption behavior in the polymer-nanoparticle (NP) interface is investigated by employing coarse-grained molecular dynamics simulations in various polymer-NP interaction and chain stiffness. At a weak polymer-NP interaction, ring chain with a closed topology structure has a slight priority to occupy the interfacial region than linear chain. At a strong polymer-NP interaction, the “middle” adsorption mechanism dominates the polymer local packing in the interface. As the increase of chain stiffness, an interesting transition from ring to linear chain preferential adsorption behavior occurs. The semiflexible linear chain squeezes ring chain out of the interfacial region by forming a helical structure and wrapping tightly the surface of NP. In particular, this selective adsorption behavior becomes more dramatic for the case of rigid-like chain, in which 3D tangent conformation of linear chain is absolutely prior to the 2D plane orbital structure of ring chain. The local packing and competitive adsorption behavior of bidisperse matrix in polymer-NP interface can be explained based on the adsorption mechanism of monodisperse (pure ring or linear) case. These investigations may provide some insights into polymer-NP interfacial adsorption behavior and guide the design of high-performance nanocomposites.

Highlights

Polymer nanocomposites that consist of mixtures of polymers and organic/inorganic particles are a new member of composite materials, which have been used in a wide variety fields [1].The macroscopic properties of nanocomposites depend on the microscopic morphology of constituent nanoparticle (NP) in the polymer matrix [2,3,4,5,6], and are sensitive to the polymer conformation, especially the local packing at polymer-NP interface
It is found that for the weak polymer-NP interaction, ring chain are slightly preferred to occupy the interfacial region than linear chain, due to its closed topology structure and regardless of
It is found that for the weak polymer-NP interaction, ring chain are slightly preferred to occupy the interfacial region than linear chain, due to its closed topology structure and regardless of chain stiffness

Summary

Introduction

Polymer nanocomposites that consist of mixtures of polymers and organic/inorganic particles are a new member of composite materials, which have been used in a wide variety fields [1]. There is no general experimental, theoretical, and simulation consensus about the accurate characterization and interpretation of the interfacial region, especially considering the adsorption mechanism of polymer chains with polydispersity close to the surface of NP. We have involved this issue by exploring the interfacial adsorption mechanism by varying the polymer-NP interaction, which may be the main factor in determining the interfacial behavior. In order to further characterize the adsorption mechanism and local packing of bidisperse matrix with different topologies in the polymer-NP interfacial region, we focus on the mixtures of ring and linear polymer chain in nanocomposites

Model and Methods

Results and Discussion

Conclusions