Structures of Fluorocarbon, Siloxane, and Hydrocarbon Surfactant Monolayers at Air-Water and Heptane-Water Interfaces by Molecular Dynamics Simulations
Abstract
We predict interfacial structure and properties by performing molecular dynamics simulations of surfactant monolayers at air/water and heptane/water interfaces, and their interactions with fuel. The predicted values of surface area and surface tension agree reasonably well with experimental data and validate the methods including the CHARMM36 lipid force field. Moreover, the Gibbs elasticity of perfluorocarbon and siloxane surfactants at air-water interface are greater than the two hydrocarbon surfactants considered in this study. High Gibbs elasticity and low surface tension may suggest higher stability of bubble surfaces packed with the fluorocarbon and siloxane surfactants to dilatation of the lamellae than those with the hydrocarbon surfactants. The heptane penetration distance into the heptane-water interface is also smaller for the fluorocarbon and siloxane surfactants compared to the hydrocarbon surfactants.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 26, 2020
- Accession Number
- AD1101960
Entities
People
- Katherine M. Hinnant
- Ramagopal Ananth
- Xiaochong Zhuang
Organizations
- United States Naval Research Laboratory