Diffusion and growth of metal clusters in nanocomposites: a Kinetic Monte Carlo study

TL;DR

This paper introduces a Kinetic Monte Carlo model to simulate the diffusion and clustering of metal atoms on polymer surfaces, analyzing how deposition rate and defects influence nanocomposite formation.

Contribution

The study presents a novel Kinetic Monte Carlo simulation approach for coupled surface and bulk diffusion of metals on polymers, focusing on cluster growth and material properties.

Findings

Cluster size distribution depends on deposition rate.

Surface defects significantly influence cluster formation.

Penetration depth varies with diffusion coefficients.

Abstract

Nobel metals that are deposited on a polymer surface exhibit surface diffusion and diffusion into the bulk. At the same time the metal atoms tend to form clusters because their cohesive energy is about two orders of magnitude higher than the cohesive energy of polymers. To selfconsistently simulate these coupled processes, we present in this paper a Kinetic Monte Carlo approach. Using a simple model with diffusion coefficients taken as input parameters allows us to perform a systematic study of the behavior of a large ensemble of metal atoms on a polymer surface eventually leading to polymer nanocomposites. Special emphasis is placed on the cluster growth, cluster size distribution and the penetration of clusters into the substrate. We also study the influence of surface defects and analyze how the properties of the resulting material can be controlled by variation of the deposition rate.