Molecular dynamics simulations of Janus nanoparticles in a fluid flow.

Abstract

We study the forces and torques on individual Janus nanoparticles in a fluid flow using molecular dynamics simulations. In particular, we consider amphiphilic Janus nanospheres that have different slip boundary conditions on each hemisphere, and calculate the forces and torques experienced by them as a function of their orientation with respect to the flow direction. Furthermore, we examine nanoparticles that are deformed slightly from a spherical shape, and have no-slip boundary conditions. We compare the simulation results to the predictions of previously introduced theoretical approaches, which compute the forces and torques on particles with variable slip lengths or aspherical deformations that are much smaller than the particle radius. We found that there is good qualitative agreement between the forces and torques computed from our simulations and the theoretical predictions, and the forces quantitatively agree when the assumptions made in the theoretical descriptions are satisfied.