Multiscale Simulation of Branched Nanofillers on Young's Modulus of Polymer Nanocomposites.

Shengwei Deng

doi:10.3390/polym10121368

Abstract

Nanoscale tailoring the filler morphology in experiment offers new opportunities to modulate the mechanical properties of polymer nanocomposites. Based on the conventical rod and experimentally available tetrapod filler, I compare the nanofiller dispersion and elastic moduli of these two kinds of nanocomposites via molecular dynamics simulation and a lattice spring model. The results show that the tetrapod has better dispersion than the rod, which is facilitate forming the percolation network and thus benefitting the mechanical reinforcement. The elastic modulus of tetrapod filled nanocomposites is much higher than those filled with rod, and the modulus disparity strongly depends on the aspect ratio of fillers and particle-polymer interaction, which agrees well with experimental results. From the stress distribution analysis on single particles, it is concluded that the mechanical disparity between bare rod and tetrapod filled composites is due to the effective stress transfer in the polymer/tetrapod composites.

Highlights

The incorporation of rigid particles with dimensions in the nanometer or micrometer range into polymers affords engineers an opportunity to design polymer composites with optimized mechanical properties [1,2]
Alivisatos et al prepared the nanoscale tetrapod with surface treatment and showed its superior ability in mechanical reinforcement of polymer nanocomposites as fillers, which was mainly contributed by the orientation of the strong X-type bonds at the nanoparticle-ligand interface [22]
The mechanical response of polymer composites is modeled by 3D Lattice Spring Model (LSM), while the equilibrium structure is simulated by molecular dynamics method

Summary

Introduction

The incorporation of rigid particles with dimensions in the nanometer or micrometer range into polymers affords engineers an opportunity to design polymer composites with optimized mechanical properties [1,2]. Different filler morphologies usually result in the disparity of mechanical properties in corresponding polymer composites [11,12]. As a shape-isotropic filler, the tetrapod particle [14,15] is usually made of various semiconductor materials and shows significant potential in the electrical [16] and optical [17,18] applications. The tetrapod has four pods binding together in one point as the center and stretching to each corner of the tetrahedron [19]. This peculiar shape may potentially be an alternative to fibers or rods as additives for mechanical reinforcement of polymers [20,21]. The tetrapod varieties, such as three-dimensional aerographite networks [24]

Results

Discussion

Conclusion