Polarizable polymer chain under external electric field in a dilute polymer solution

TL;DR

This paper investigates how an external electric field influences the shape and phase transitions of polarizable polymer chains in dilute solutions, revealing coil swelling and globule-coil transitions depending on field strength and monomer polarizability.

Contribution

The study introduces a self-consistent field theory model to describe electric field effects on polymer conformations, including the first-order globule-coil transition at high polarizability.

Findings

Electric field causes coil swelling in polymers.

Strong fields induce globule-coil transitions.

Transition nature depends on monomer polarizability.

Abstract

We study the conformational behavior of polarizable polymer chain under an external homogeneous electric field within the Flory type self-consistent field theory. We consider the influence of electric field on the polymer coil as well as on the polymer globule. We show that when the polymer chain conformation is a coil, application of external electric field leads to its additional swelling. However, when the polymer conformation is a globule, a sufficiently strong field can induce a globule-coil transition. We show that such $"$field-induced$"$ globule-coil transition at the sufficiently small monomer polarizabilities goes quite smoothly. On the contrary, when the monomer polarizability exceeds a certain threshold value, the globule-coil transition occurs as a dramatic expansion in the regime of first-order phase transition. The developed theoretical model can be applied to predicting polymer globule density change under external electric field in order to provide more efficient processes of polymer functionalization, such as sorption, dyeing, chemical modification, etc.