Effect of applied magnetic fields on the morphology of nematic nanobridges in slit pores

TL;DR

This study uses molecular dynamics simulations to explore how magnetic fields influence the shape and stability of nematic nanobridges in slit pores, revealing field-induced conformational switching and destabilization effects.

Contribution

It demonstrates the magnetic field-induced conformational switching and destabilization of nematic nanobridges, a novel insight into their behavior under external magnetic influences.

Findings

Magnetic fields can switch nanobridge conformations when applied perpendicularly.

Magnetic fields can destabilize and break nanobridges into nanodroplets.

Switching depends on the presence of locally stable conformations.

Abstract

In this paper we report a molecular dynamics study of the effect of the application of magnetic fields on the morphology of nematic nanobridges of 32000 oblate Gay-Berne particles in slit pores favouring homeotropic anchoring. In absence of magnetic fields, previous studies show that there are different conformations of the nanobridge, depending on the slit pore width $D$ and the wettability of the walls. Under the application of uniform magnetic field cycles, in which the intensity of the field is increased stepwise until a maximum value and then decreased at the same rate, switching between different nanobridge conformations can be observed if the magnetic field is applied in a perpendicular direction to the global nematic director of the nanobridge. However, there are situations in which the initial bridge conformation is recovered after the magnetic field application, indicating that the switching can only be observed if there are different locally stable nanobridge conformations under the same thermodynamic conditions. Moreover, magnetic fields can destabilize the nanobridge, leading to its breakdown into isolated nanodroplets attached to a single wall.