Diffusion of a Janus nanoparticle in an explicit solvent: A molecular dynamics simulation study

TL;DR

This study uses molecular dynamics simulations to analyze how Janus nanoparticles diffuse in a dense fluid, revealing that surface wettability influences their translational and rotational behavior.

Contribution

It provides new insights into the diffusion dynamics of Janus particles with asymmetric wettability in explicit solvent environments.

Findings

Diffusion coefficients increase with decreasing nonwetting surface energy.

Nonwetting hemisphere tends to rotate towards displacement direction.

Rotational and translational diffusion are coupled in Janus particles.

Abstract

Molecular dynamics simulations are carried out to study the translational and rotational diffusion of a single Janus particle immersed in a dense Lennard-Jones fluid. We consider a spherical particle with two hemispheres of different wettability. The analysis of the particle dynamics is based on the time-dependent orientation tensor, particle displacement, as well as the translational and angular velocity autocorrelation functions. It was found that both translational and rotational diffusion coefficients increase with decreasing surface energy at the nonwetting hemisphere, provided that the wettability of the other hemisphere remains unchanged. We also observed that in contrast to homogeneous particles, the nonwetting hemisphere of the Janus particle tends to rotate in the direction of the displacement vector during the rotational relaxation time.