Understanding nanoparticle diffusion and exploring interfacial nanorheology using molecular dynamics simulations

Yanmei Song; Mingxiang Luo; Lenore L Dai

doi:10.1021/la901902t

Understanding nanoparticle diffusion and exploring interfacial nanorheology using molecular dynamics simulations

Langmuir. 2010 Jan 5;26(1):5-9. doi: 10.1021/la901902t.

Authors

Yanmei Song¹, Mingxiang Luo, Lenore L Dai

Affiliation

¹ Department of Chemical Engineering, Arizona State University, Tempe, Arizona 85287, USA.

PMID: 20038161
DOI: 10.1021/la901902t

Abstract

We have studied the dynamics of nanoparticles at polydimethylsiloxane (PDMS) oil-water interfaces using molecular dynamics (MD) simulations. The diffusion of nanoparticles in pure water and low-viscosity PDMS oil is found to be reasonably consistent with the prediction by the Stokes-Einstein equation. In addition, we have calculated the shear moduli and viscosities of bulk oil and water, as well as oil-water interfaces from single nanoparticle tracking and demonstrated the potential of probing nanorheology from an MD simulation approach. Surprisingly, we found that the lateral diffusion of nanoparticles as well as apparent interfacial nanorheology at the PDMS oil (low viscosity)-water interface are independent of the position of the nanoparticle at the interface.