Electrical Chain Rearrangement: What Happens When Polymers in Brushes Have a Charge Gradient?

Leon A. Smook, Sissi de Beer*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

16 Downloads (Pure)

Abstract

Under the influence of electric fields, the chains in polyelectrolyte brushes can stretch and collapse, which changes the structure of the brush. Copolymer brushes with charged and uncharged monomers display a similar behavior. For pure polyelectrolyte and random copolymer brushes, the field-induced structure changes only the density of the brush and not its local composition, while the latter could be affected if charges are distributed inhomogeneously along the polymer backbone. Therefore, we systematically study the switching behavior of gradient polyelectrolyte brushes in electric fields for different solvent qualities, grafting densities, and charges per chain via coarse-grained molecular dynamics simulations. Similar to random copolymers and pure polyelectrolytes, these brushes show a mixed-phase transition: intermediate states between fully stretched and collapsed are characterized by a bimodal chain-end distribution. Additionally, we find that the total charge of the brush plays a key role in the critical field required for a complete transition. Finally, we find that gradient polyelectrolyte brushes are charge-enriched at the brush–solvent interface under stretched conditions and charge-depleted under collapsed conditions, allowing for control over the local composition and thus the surface charge of the brush due to the inhomogeneous charge along the grafted chains.
Original languageEnglish
Pages (from-to)4142–4151
Number of pages10
JournalLangmuir
Volume40
Issue number8
Early online date14 Feb 2024
DOIs
Publication statusPublished - 27 Feb 2024

Keywords

  • UT-Hybrid-D

Fingerprint

Dive into the research topics of 'Electrical Chain Rearrangement: What Happens When Polymers in Brushes Have a Charge Gradient?'. Together they form a unique fingerprint.

Cite this