Dynamics of Marangoni-Driven Elliptical Janus Particles

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Masanta, Pabitra, Sarkar, Ratan, Parmananda, Punit, Chelakkot, Raghunath
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911335085768704
author Masanta, Pabitra
Sarkar, Ratan
Parmananda, Punit
Chelakkot, Raghunath
author_facet Masanta, Pabitra
Sarkar, Ratan
Parmananda, Punit
Chelakkot, Raghunath
contents We investigate the spontaneous motion of an elliptical Janus particle, driven by Marangoni forces, on a water surface to understand how particle shape and size influence its dynamics. The Janus particle is one-half infused with a substance such as camphor, which lowers the surface tension upon release onto the water surface. The resulting surface tension gradient generates Marangoni forces that propel the particle. For fully camphor-infused (non-Janus) particles, previous studies have shown that motion occurs along the short axis of the ellipse. However, for Janus particles, our experiments reveal a much richer steady-state dynamics, depending on both the particle's eccentricity and size. To understand these dynamics, we develop a numerical model that captures the connection between the spatio-temporal evolution of the camphor concentration field and the Marangoni force driving the particle. Using this model, we simulate the motion of particles with varying eccentricities - from nearly circular to highly elongated shapes. The simulations qualitatively reproduce all the trajectories observed in experiments and provide insights into how particle geometry influences the dynamics of chemically driven anisotropic particles. With the help of the numerical model, we compute a full phase diagram characterising the dynamical states as a function of surfactant properties.
format Preprint
id arxiv_https___arxiv_org_abs_2512_20283
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Dynamics of Marangoni-Driven Elliptical Janus Particles
Masanta, Pabitra
Sarkar, Ratan
Parmananda, Punit
Chelakkot, Raghunath
Soft Condensed Matter
Adaptation and Self-Organizing Systems
Fluid Dynamics
We investigate the spontaneous motion of an elliptical Janus particle, driven by Marangoni forces, on a water surface to understand how particle shape and size influence its dynamics. The Janus particle is one-half infused with a substance such as camphor, which lowers the surface tension upon release onto the water surface. The resulting surface tension gradient generates Marangoni forces that propel the particle. For fully camphor-infused (non-Janus) particles, previous studies have shown that motion occurs along the short axis of the ellipse. However, for Janus particles, our experiments reveal a much richer steady-state dynamics, depending on both the particle's eccentricity and size. To understand these dynamics, we develop a numerical model that captures the connection between the spatio-temporal evolution of the camphor concentration field and the Marangoni force driving the particle. Using this model, we simulate the motion of particles with varying eccentricities - from nearly circular to highly elongated shapes. The simulations qualitatively reproduce all the trajectories observed in experiments and provide insights into how particle geometry influences the dynamics of chemically driven anisotropic particles. With the help of the numerical model, we compute a full phase diagram characterising the dynamical states as a function of surfactant properties.
title Dynamics of Marangoni-Driven Elliptical Janus Particles
topic Soft Condensed Matter
Adaptation and Self-Organizing Systems
Fluid Dynamics
url https://arxiv.org/abs/2512.20283