Computer simulations of solute exchange using micelles by a collision-driven fusion process

Area of Science:

• Physical Chemistry
• Colloid and Surface Chemistry

Background:

• Micelles are widely used as solute carriers in aqueous solutions.
• Understanding solute exchange kinetics is crucial for various chemical processes.

Purpose of the Study:

• To investigate the kinetic process of collision-driven solute exchange mediated by micelles.
• To elucidate the mechanisms of solute exchange and identify influencing factors.

Main Methods:

• Dissipative particle dynamics (DPD) simulations were employed.
• The study focused on hydrophobic solute molecules within aqueous micellar systems.

Main Results:

• Solute exchange involves aggregate collision, coalescence (molecular contact, neck formation, neck growth), and subsequent solute transfer/diffusion.
• Rate-limiting steps include water film rupture between aggregates and pore nucleation within surfactant films.
• Depletion force is significant during coalescence; initial collision velocity has minimal impact on fusion ratio.
• Surface tension and inter-aggregate interactions differentially affect various exchange stages.

Conclusions:

• The study provides a detailed molecular-level understanding of micelle-mediated solute exchange.
• Identified rate-limiting steps and influential factors offer insights for optimizing solute transport processes.