Interfacial Instability of Charged End-Group Polymer Brushes

Abstract

We consider a polymer brush grafted to a surface (acting as an electrode) and bearing a charged group at its free end. Using a second distant electrode, the brush is subject to a constant electric field. Based on a coarse-grained continuum model, we calculate the average brush height and find that the brush can stretch or compress depending on the applied field and charge end-group. We further look at an undulation mode of the flat polymer brush and find that the electrostatic energy scales linearly with the undulation wavenumber, $q$. Competition with surface tension, scaling as $q^2$, tends to stabilize a lateral $q$-mode of the polymer brush with a well-defined wavelength. This wavelength depends on the brush height, surface separation, and several system parameters.

6 pages, 3 figures

References in corpus (1)

• Neutral and Charged Polymers at Interfaces

Cited by in corpus (3)

• Colloquium: Phase transitions in polymers and liquids in electric fields
• On the corrections to Strong-Stretching Theory for end-confined, charged polymers in a uniform electric field
• Description of interfaces of fluid-tethered chains: advances in density functional theories and off-lattice computer simulations