| Pairwise Additive Hydrophobic Effect for Alkanes In Water | ||
| Jianzhong Wu, Chemical and Environmental Engineering, University of California, Riverside, Bourns Hall A242, 900 University Avenue, Riverside, CA 92521 and John M. Prausnitz, Department of Chemical Engineering, University of California, Berkeley, CA 94720-1462 Pairwise additivity of the hydrophobic effect is indicated by reliable experimental Henry's constants for a large number of linear and branched low-molecular-weight alkanes in water. Pairwise additivity suggests that the hydrophobic effect is primarily a local phenomenon and that the hydrophobic interaction may be represented by a semi-empirical force field. By representing the hydrophobic potential between two methane molecules as a linear function of the center-to-center distance as suggested by recent first-principle molecular-dynamics simulations, we find that the contact value of the hydrophobic potential (-1.2 Kcal/mol) is between that from quantum-mechanics simulations (-2.8 Kcal/mol) and that from classical molecular dynamics (-0.5~-0.9 Kcal/mol). Extended Abstract Status: Not Uploaded | ||