1. Effect of Solute on Solubilization Ability and Micellar Structure of Dodecylbenzenesulfonate Experimental and Molecular Dynamics Study Huang-chin Hung, Jeffrey Potoff, G.S Shreve Department of Chemical Engineering and Material Science, Wayne State University, Detroit MI

2. Flow chart

3. Determination of CMC.

5. Interfacial Properties of PG210 and Dyna 270 at 25 C.

6. The Mechanism of Fluorescence Quenching.

7. Pyrene Fluorescence Quenching Experimental for DBS/Dodecane System

8. Aggregation Number Calculated from Pyrene Fluorescence Quenching Test. pyrene (mg/l)391836AverageSTD Dodecane/DBS19.320.526.321.321.851.78 Benzene/DBS19.917.114.115.316.601.46

10. Water Penetration into the Micelle

11. Structure of Molecules

12. Radial Distribution Function of DBS/Dodecane Micelle

13. Radial Distribution Function of DBS/Benzene Micelle

14. Localization of Solute in Micelle

15. Conclusion Benzene molecules can stay at outer layer of the micelle which increase the area per head group and lower the effectiness of the surfactant. Dodecane molecules stay only at core of the micelle and form a very hydrophobic region with the tail of surfactant. Smaller area per head group and higher effectiness of surfactant are observed.

16. Future Study Derive the free energy of micellation from the area per head group of MD result Derive the dielectricity constant of the head group as well as the hydrophobic interaction of the surfactant tails. Randomize the initial coordinates of micelles and study the dynamics of micelle formation Extend the study to Biosurfactants

17. Acknowledgements EPA Research Grant RG R827 132-01-0 to G.S Shreve. Dr. Don Gregory Accelerys. Dr. Yiannis Kaznessis. Dr. John F. Endicott and Dr. Patrick G. McNamara, Chemistry WSU. Kevin Hall, BS. WSU.