Modeling Self-Assembly of the Surfactants into Biological Bilayer Membranes with Special Chemical Structure Using Dissipative Particle Dynamics Method

Authors

1 Center of Excellence in Energy Conversion, Department of Mechanical Engineering, Isfahan University of Technology, Isfahan, P.O. Box 8415683111, Iran

2 Center of Excellence in Energy Conversion, School of Mechanical Engineering, Sharif University of Technology, Tehran, P.O. Box 11155-9567, Iran

3 Department of Mechanical Engineering at Foolad Institute of Technology, Fooladshahr, Isfahan, P.O. Box 84915651 Iran

Abstract

The aim of this study is to simulate the self-assembly of the surfactant molecules with special chemical structure and bending stiffness into bilayer membranes using a mesoscopic Dissipative Particle Dynamics (DPD) method. Thesurfactants are modeled with special chemical structure and bending stiffness. To confirm that the novel model is physical, we determine the interaction parameters based on matching the compressibility and solubility of the DPD system with real physics of the fluid. To match the mutual solubility for binary fluids, we use the relation between DPD parameters and -parameters in Flory-Huggins-type models. Unsaturated bonds can change the stiffness of a lipid membrane which is modeled by introducing a bond bending potential. To verify our model we investigate the effect of surfactant structure like chain length and stiffness of those molecules on the properties of the modeled membrane as area per surfactant. To validate our results, we also compare them with the theoretical calculations as well as with the experimental and other existing simulations results. We show that there is a good coincidence between all of the results.

Keywords