Equilibrium properties of magnetic filament suspensions

TL;DR

This study uses Langevin dynamics to analyze the equilibrium magnetic and sedimentation properties of filament suspensions, revealing how filament length, flexibility, and external fields influence susceptibility and distribution.

Contribution

It provides new insights into how filament length, flexibility, and external fields affect magnetic susceptibility and sedimentation profiles in filament suspensions.

Findings

Filament suspensions have higher magnetic susceptibility than unlinked nanoparticles.

Susceptibility gain depends on filament length and flexibility.

Sedimentation profiles are less homogeneous for filaments under gravity or centrifugal fields.

Abstract

Langevin dynamics is used to study equilibrium properties of the suspension of magnetic filaments (chains of nanoparticles permanently crosslinked with polymers). It is shown that the filament suspension generally has a larger magnetic susceptibility than the system of unlinked nanoparticles with the same average particle concentration. However, actual susceptibility gain strongly depends on length and flexibility of filaments. It is also shown that in a strong gravitational (centrifugal) field sedimentation profiles of filaments are less homogeneous than that of unlinked particles. The spatial distribution of filaments weakly depends on the intensity of interparticle dipole-dipole interactions.