Diffusion of self-propelled Janus tracer in polymeric environment

TL;DR

This study computationally investigates how self-propelled Janus particles move in complex polymer environments, revealing slowed translational motion but increased rotational diffusion, with effects depending on polymer interactions.

Contribution

First computational analysis of Janus tracer dynamics in heterogeneous polymeric media, highlighting effects of polymer interactions on motion behavior.

Findings

MSD grows slowly in polymer environment compared to free tracer

MSAD increases significantly, especially with higher propulsion velocity

Sticky polymers cause sharp decline in both MSD and MSAD

Abstract

Artificially synthesized Janus particles have tremendous prospective as in-vivo drug-delivery agents due to the possibility of self-propulsion by external stimuli. Here we report the first ever computational study of translational and rotational motion of self-propelled Janus tracers in a het- erogeneous polymeric environment. The presence of polymers makes the translational mean square displacement (MSD) of the Janus tracer to grow very slowly as compared to that of a free Janus tracer, but surprisingly the mean square angular displacement (MSAD) is significantly increased as observed in a recent experiment. Moreover, with the increasing propulsion velocity, MSAD grows even faster. However, when the repulsive polymers are replaced with polymers with sticky zones, MSD and MSAD both show sharp decline.