Solute Partitioning in Micelles: Combining Molecular Dynamics Simulations, COSMOmic, and Experiments
D Yordanova1, E Ritter1, T Gerlach1
1Institute of Thermal Separation Processes, Hamburg University of Technology , Eissendorfer Strasse 38, 21073 Hamburg, Germany.
The Journal of Physical Chemistry. B
|May 24, 2017
Summary
Predictive methods for solute partitioning in micelles are crucial. Molecular dynamics (MD) simulations and COSMOmic theory show good agreement for neutral solutes, aiding micellar system applications.
Area of Science:
- Physical Chemistry
- Computational Chemistry
- Supramolecular Chemistry
Background:
- Solute partitioning between micelles and aqueous phases is vital for various applications.
- Accurate theoretical prediction of this behavior is needed due to numerous micelle-solute combinations.
- Experimental data for charged solute partitioning in micelles is scarce.
Purpose of the Study:
- To evaluate and compare two theoretical methods for predicting solute partitioning in micellar systems.
- To assess the performance of molecular dynamics (MD) simulations and COSMOmic theory.
- To investigate the partitioning of both neutral and ionized solutes across different micelle types.
Main Methods:
- Molecular dynamics (MD) simulations utilizing the umbrella sampling method to compute free energy profiles.
- Application of COSMOmic, an extension of COSMO-RS theory for anisotropic systems.
- Experimental determination of micelle/water partition coefficients for validation.
- Study of diverse micelle classes: nonionic (Triton X-114), zwitterionic (miltefosine), anionic (sodium dodecyl sulfate), and cationic (cetyltrimethylammonium bromide).
Main Results:
- MD simulations and COSMOmic theory provide comparable free energy profiles for neutral solutes.
- Both theoretical methods demonstrate good agreement with experimental partition coefficients for neutral solutes.
- Deviations observed for charged solutes between the two methods and experimental data, depending on the specific system.
- Experimental data were generated for charged solute partitioning to address data scarcity.
Conclusions:
- MD simulations and COSMOmic theory are effective for predicting neutral solute partitioning in micelles.
- The methods show promise but require further refinement for accurate prediction of charged solute partitioning.
- The study provides valuable insights into micellar partitioning behavior across different solute and micelle types.
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