One-Dimensional Anomalous Diffusion of Gold Nanoparticles in a Polymer Melt

TitleOne-Dimensional Anomalous Diffusion of Gold Nanoparticles in a Polymer Melt
Publication TypeJournal Article
Year of Publication2019
AuthorsJ-J Song, R Bhattacharya, H Kim, J Chang, T-Y Tang, H Guo, SK Ghosh, Y Yang, Z Jiang, H Kim, TP Russell, G Arya, S Narayanan, and SK Sinha
JournalPhysical Review Letters
Start Page107802
Date Published03/2019

We investigated the dynamics of polymer-grafted gold nanoparticles loaded into polymer melts using x-ray photon correlation spectroscopy. For low molecular weight host matrix polymer chains, normal isotropic diffusion of the gold nanoparticles is observed. For larger molecular weights, anomalous diffusion of the nanoparticles is observed that can be described by ballistic motion and generalized Lévy walks, similar to those often used to discuss the dynamics of jammed systems. Under certain annealing conditions, the diffusion is one-dimensional and related to the direction of heat flow during annealing and is associated with an dynamic alignment of the host polymer chains. Molecular dynamics simulations of a single gold nanoparticle diffusing in a partially aligned polymer network semiquantitatively reproduce the experimental results to a remarkable degree. The results help to showcase how nanoparticles can under certain circumstances move rapidly in polymer networks.

Short TitlePhysical Review Letters