Self-Assembled Inverted Micelles Stabilize Ionic Liquid Domains in Supercritical CO2
- 13 August 2010
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 132 (35), 12511-12516
- https://doi.org/10.1021/ja1055005
Abstract
Molecular aggregation is a complex phenomenon that is difficult to study in detail experimentally. Here, we elucidate the formation of ionic liquid-in-carbon dioxide (IL-in-CO2) microemulsions via a computer simulation technique that demonstrates the entire process of self-aggregation at the atomic level. Our study reveals direct evidence of the existence of stable IL droplets within a continuous CO2 phase through amphiphilic surfactants. The microstructure of the nanodroplets matches very well with the small-angle neutron scattering data. A detailed investigation of the structural and energetic properties explains why guanidium acetate-based IL-in-CO2 microemulsions showed a greater stability than imidazolium hexafluorophosphate-based microemulsions in recent spectroscopic experiments. In contrast to the existing hypothesis in literature, the study reveals that the stability of the microemulsions mainly pertains to the IL anion−headgroup interactions, while the cations play a secondary role. The detailed atomic level understanding provides a deeper insight that could help in designing new surfactants for improved IL uptake in CO2.This publication has 44 references indexed in Scilit:
- Phase Behavior and Microstructures of Nonionic Fluorocarbon Surfactant in Aqueous SystemsThe Journal of Physical Chemistry B, 2008
- Self-Assembled Reverse Micelles in Supercritical CO2 Entrap Protein in Native StateJournal of the American Chemical Society, 2008
- Molecular Force Field for Ionic Liquids Composed of Triflate or Bistriflylimide AnionsThe Journal of Physical Chemistry B, 2004
- Ionic liquids and eutectic mixtures as solvent and template in synthesis of zeolite analoguesNature, 2004
- Molecular Dynamics Simulation of a Reverse Micelle Self Assembly in Supercritical CO2Journal of the American Chemical Society, 2004
- Molecular Dynamics Simulation Studies of Polyether and Perfluoropolyether Surfactant Based Reverse Micelles in Supercritical Carbon DioxideThe Journal of Physical Chemistry B, 2003
- Homogeneous Catalysis--New Approaches to Catalyst Separation, Recovery, and RecyclingScience, 2003
- Perfluoroalkanes: Conformational Analysis and Liquid-State Properties from ab Initio and Monte Carlo CalculationsThe Journal of Physical Chemistry A, 2001
- Steric Stabilization of Nanocrystals in Supercritical CO2 Using Fluorinated LigandsJournal of the American Chemical Society, 2000
- Inverse emulsion polymerization of acrylamide in supercritical carbon dioxideMacromolecules, 1994