Domain size polydispersity effects on the structural and dynamical properties in lipid monolayers with phase...

Area of Science:

• Soft Matter Physics
• Surface Science
• Biophysics

Background:

• Lipid monolayers with phase coexistence exhibit domain size polydispersity.
• Domain size distribution effects on monolayer properties are theoretically underexplored.
• Dipolar interactions between domains are crucial for understanding monolayer structure and dynamics.

Purpose of the Study:

• Investigate the impact of domain size polydispersity on lipid monolayer properties.
• Analyze the consequences of using monodisperse models for interaction strength determination.
• Examine the relationship between polydispersity, interaction strength, and monolayer dynamics.

Main Methods:

• Brownian dynamics simulations of lipid monolayers with normally distributed domain sizes.
• Systematic variation of polydispersity and interaction strength parameters.
• Analysis of radial distribution function (RDF), mean square displacement, and self-diffusion coefficient D(t).

Main Results:

• Polydispersity significantly affects interaction strength, leading to underestimation in monodisperse models.
• RDF from polydisperse models can approximate monodisperse models with adjusted interaction strength, even at 40% polydispersity.
• Small interaction strengths or polydispersities yield good agreement in dynamics between polydisperse and monodisperse systems.

Conclusions:

• Domain size polydispersity is a critical factor influencing lipid monolayer properties and inter-domain interactions.
• Monodisperse models require careful parameter fitting to accurately represent polydisperse systems.
• Understanding polydispersity is essential for accurate theoretical and experimental analysis of lipid monolayers.