Structure and Transport Property of Sodium Dodecyl Surfate Micelle in Water Phase: Molecular Dynamics Simulation Approach

Structure and Transport Property of Sodium Dodecyl Surfate Micelle in Water Phase:

Molecular Dynamics Simulation Approach

Byeong Jae Chun and Seung Soon Jang

Computational NanoBio Technology Laboratory, School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive NW, Atlanta, GA 30332-0245

We investigate the structure and transport property of micelle consists of sodium dodecyl surfate (SDS) in water phase using full atomistic molecular dynamics (MD) simulation. For this, first, SDS is geometry-optimized using B3LYP and 6-31G** and then Mulliken population analysis is performed for atomic charges.  Second, a spherical self-assembled micelle is prepared by arranging SDS molecules to have a centrosymmetric inner structure and subsequently is located in water phase. By performing MD simulation, the structure and stability of micelle are characterized by 1) radius of gyration; 2) density distribution; 3) Connolly surface area; 4) distribution of sodium atoms; 5) formation energy. The simulated structure and energy will be compared to experimental ones in order to validate our simulation protocols as well as force field. Once the equilibrated SDS micelle is validated, the transport of various small atomic and molecular species through micelle is analyzed using potential of mean force (PMF) to characterize the permeability of SDS micelle in terms of free energy barrier. We believe this study provides a molecular-level understanding of micelle for its applications towards molecular carriers and molecular reactors.