Ionic partitioning of KCl in AOT reverse micelles from molecular dynamics simulations

Max Crowder; Isabel Lizarraga; Joshua D. Patterson; Arun K. Sharma

doi:10.1016/j.fluid.2023.113904

Ionic partitioning of KCl in AOT reverse micelles from molecular dynamics simulations

Max Crowder, Isabel Lizarraga, Joshua D. Patterson, Arun K. Sharma

Department of Biology and Chemistry

Research output: Contribution to journal › Article › peer-review

Abstract

Reverse micelles are an important class of nanoreactors providing an array of applications. The structure and dynamics of aqueous reverse micelles have been intensely investigated, yet there are many subtleties involved in characterizing the arrangement of water and ionic species within these aggregates. The interfacial arrangement of water and dopants added to bis(2-ethylhexyl) sulfosuccinate sodium salt (AOT) reverse micelles were investigated by fully atomistic molecular dynamics simulations. Reverse micelles of increasing water to surfactant ratio were doped with concentrations of KCl from 0.0 to 1.0 M to analyze the partitioning of ions and water. Detailed analysis of pair density functions reveals that Cl− ions are embedded deep in the aqueous interior, and the K+ ions display a remarkable affinity for the interface. Our results confirm the existence of multiple layers of water, and an ordered multi-layer ionic arrangement that is driven by the negatively charged surfactant headgroup.

Original language	American English
Journal	Fluid Phase Equilibria
Volume	574
DOIs	https://doi.org/10.1016/j.fluid.2023.113904
State	Published - Nov 2023

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Ionic partitioning of KCl in AOT reverse micelles from molecular

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@article{949346871c534205b63ecde9cbc3769d,

title = "Ionic partitioning of KCl in AOT reverse micelles from molecular dynamics simulations",

abstract = "Reverse micelles are an important class of nanoreactors providing an array of applications. The structure and dynamics of aqueous reverse micelles have been intensely investigated, yet there are many subtleties involved in characterizing the arrangement of water and ionic species within these aggregates. The interfacial arrangement of water and dopants added to bis(2-ethylhexyl) sulfosuccinate sodium salt (AOT) reverse micelles were investigated by fully atomistic molecular dynamics simulations. Reverse micelles of increasing water to surfactant ratio were doped with concentrations of KCl from 0.0 to 1.0 M to analyze the partitioning of ions and water. Detailed analysis of pair density functions reveals that Cl− ions are embedded deep in the aqueous interior, and the K+ ions display a remarkable affinity for the interface. Our results confirm the existence of multiple layers of water, and an ordered multi-layer ionic arrangement that is driven by the negatively charged surfactant headgroup.",

author = "Max Crowder and Isabel Lizarraga and Patterson, \{Joshua D.\} and Sharma, \{Arun K.\}",

year = "2023",

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doi = "10.1016/j.fluid.2023.113904",

language = "American English",

volume = "574",

journal = "Fluid Phase Equilibria",

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TY - JOUR

T1 - Ionic partitioning of KCl in AOT reverse micelles from molecular dynamics simulations

AU - Crowder, Max

AU - Lizarraga, Isabel

AU - Patterson, Joshua D.

AU - Sharma, Arun K.

PY - 2023/11

Y1 - 2023/11

N2 - Reverse micelles are an important class of nanoreactors providing an array of applications. The structure and dynamics of aqueous reverse micelles have been intensely investigated, yet there are many subtleties involved in characterizing the arrangement of water and ionic species within these aggregates. The interfacial arrangement of water and dopants added to bis(2-ethylhexyl) sulfosuccinate sodium salt (AOT) reverse micelles were investigated by fully atomistic molecular dynamics simulations. Reverse micelles of increasing water to surfactant ratio were doped with concentrations of KCl from 0.0 to 1.0 M to analyze the partitioning of ions and water. Detailed analysis of pair density functions reveals that Cl− ions are embedded deep in the aqueous interior, and the K+ ions display a remarkable affinity for the interface. Our results confirm the existence of multiple layers of water, and an ordered multi-layer ionic arrangement that is driven by the negatively charged surfactant headgroup.

AB - Reverse micelles are an important class of nanoreactors providing an array of applications. The structure and dynamics of aqueous reverse micelles have been intensely investigated, yet there are many subtleties involved in characterizing the arrangement of water and ionic species within these aggregates. The interfacial arrangement of water and dopants added to bis(2-ethylhexyl) sulfosuccinate sodium salt (AOT) reverse micelles were investigated by fully atomistic molecular dynamics simulations. Reverse micelles of increasing water to surfactant ratio were doped with concentrations of KCl from 0.0 to 1.0 M to analyze the partitioning of ions and water. Detailed analysis of pair density functions reveals that Cl− ions are embedded deep in the aqueous interior, and the K+ ions display a remarkable affinity for the interface. Our results confirm the existence of multiple layers of water, and an ordered multi-layer ionic arrangement that is driven by the negatively charged surfactant headgroup.

U2 - 10.1016/j.fluid.2023.113904

DO - 10.1016/j.fluid.2023.113904

M3 - Article

VL - 574

JO - Fluid Phase Equilibria

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