Influence of nanoparticle size, loading, and shape on the mechanical properties of polymer nanocomposites

TL;DR

This study uses molecular dynamics simulations to examine how nanoparticle size, shape, and loading affect the mechanical properties of polymer nanocomposites, highlighting the importance of nanoparticle geometry and interactions.

Contribution

It provides new insights into how nanoparticle shape and size influence the reinforcement of polymer nanocomposites, especially emphasizing the effectiveness of rod-like particles.

Findings

Rod-like nanoparticles are the most effective toughening agents.

Nanoparticle size comparable to polymer monomers enhances toughness.

Strong polymer-nanoparticle interactions promote network formation and reinforcement.

Abstract

We study the influence of spherical, triangular, and rod-like nanoparticles on the mechanical properties of a polymer nanocomposite (PNC), via coarse-grained molecular dynamics simulations. We focus on how the nanoparticle size, loading, mass, and shape influence the PNC's elastic modulus, stress at failure and resistance against cavity formation and growth, under external stress. We find that in the regime of strong polymer-nanoparticle interactions, the formation of a polymer network via temporary polymer-nanoparticle crosslinks has a predominant role on the PNC reinforcement. Spherical nanoparticles, whose size is comparable to that of the polymer monomers, are more effective at toughening the PNC than larger spherical particles. When comparing particles of spherical, triangular, and rod-like geometries, the rod-like nanoparticles emerge as the best PNC toughening agents.