Charge Regulation Stabilizes the Formation of Ionic Liquid‐Based Amphiphilic Oligomer Droplet Interface Bilayers

• DOI: 10.1002/macp.202400337
• Publication Date: 2025-04-08T19:00:18Z
• Authors: Zening Liu; Graham J. Taylor; Yingdong Luo; Kunlun Hong; Robert L. Sacci; John Katsaras; Jan‐Michael Carrillo; Benjamin Doughty; Charles Patrick C...
• Keywords: Oligomer; Interface (matter)

Abstract Amphiphilic charged oligomers (oligodimethylsiloxane – methylimidazolium cation, ODMS‐MIM (+) ), assemble into bilayers using the droplet interface bilayer (DIB) platform, possess similar size and functionality as phospholipid bilayers, but exhibit increased stability. The oligomer ionic headgroups (MIM ) are covalently bound to monodisperse, short‐chain ( n = 13) hydrophobic tails (ODMS). These self‐assemble monolayer brushes at oil–aqueous of water droplets that influenced by both cationic headgroups, nature attached in organic phase. Charge regulation (CR) stabilizes formation ordered, molecularly close‐packed brush phases, which results highly insulating, stable DIB membranes, with contributions from specific ion‐pairing effects, Debye screening, voltage‐dependent electrocompressive stresses. In oil phase, interactions between hexadecane, a good solvent for ODMS, result extended waiting times compared DIBs, hexadecane is poor solvent. Close agreement experimental values predictions two key parameters, critical membrane thickness, h c , maximal grafted headgroup density, Γ 0 validate an electrostatic CR model consisting adsorption partial neutralization counterions interface.