The interactions between surfactants and vesicles: dissipative particle dynamics.

Area of Science:

• Colloid and Surface Science
• Computational Chemistry
• Materials Science

Background:

• Vesicles formed by double-tail amphiphiles are crucial in various applications.
• Understanding surfactant-vesicle interactions is key to controlling their behavior.
• The three-stage hypothesis describes vesicle solubilization, but requires further simulation validation.

Purpose of the Study:

• To investigate surfactant interactions with double-tail amphiphile vesicles using dissipative particle dynamics.
• To elucidate the mechanism of vesicle solubilization as a function of surfactant concentration.
• To validate the three-stage hypothesis of vesicle solubilization through computational modeling.

Main Methods:

• Dissipative particle dynamics (DPD) simulations were employed.
• Vesicle solubilization was studied across varying surfactant concentrations.
• The partition coefficient (K) of surfactants between bilayer and aqueous phases was analyzed.

Main Results:

• Vesicle solubilization follows a three-stage process: vesicular, vesicle-micelle coexistence, and mixed micellar regions.
• The partition coefficient (K) is inversely related to the surfactant's hydrophile-lipophile balance (HLB).
• Simulations identified a critical surfactant concentration for solubilization onset and vesicle collapse.

Conclusions:

• DPD simulations successfully demonstrate and confirm the three-stage hypothesis of vesicle solubilization.
• Surfactant hydrophilicity (HLB) significantly influences their partitioning into the vesicle bilayer.
• The study provides a molecular-level understanding of surfactant-induced vesicle destabilization.