Solubilization in mixed micelles studied by molecular dynamics simulations and COSMOmic

Area of Science:

• Physical Chemistry
• Computational Chemistry
• Materials Science

Background:

• Mixed micelles are crucial for pharmaceutical and industrial applications, yet molecular-level studies on their behavior are limited.
• Predicting solute partitioning in mixed micelles is vital for screening and optimizing extraction processes.
• Existing computational tools like COSMOmic require detailed micellar structures as input.

Purpose of the Study:

• To investigate the self-assembly of mixed surfactant systems using molecular dynamics (MD) simulations.
• To predict the partition behavior of various solutes within these mixed micelles using the COSMOmic model.
• To elucidate the structural influences of mixed micelle composition and size on solute partitioning equilibria.

Main Methods:

• Atomistic molecular dynamics (MD) simulations were performed for pure Brij35 and its mixtures with CTAB or SDS.
• The self-assembled micellar structures served as input for the COSMOmic model to predict phase equilibria.
• Analysis focused on the structural impact of micelle size and composition on the partitioning of diverse solutes.

Main Results:

• The study provides the first atomistic-scale investigation of Brij35/CTAB and Brij35/SDS mixed micelle self-assembly.
• Significant correlations were found between the atomic structure and composition of mixed micelles and solute partition coefficients.
• Predicted partition behaviors showed good agreement with experimental data, validating the simulation approach.

Conclusions:

• Molecular simulations offer a powerful tool for understanding mixed micellar systems and predicting solute partitioning.
• The findings deepen the fundamental knowledge of mixed micellar extraction processes.
• This research paves the way for optimizing surfactant systems for enhanced industrial and pharmaceutical applications.