TY - JOUR
T1 - Entropy of hydrophobic hydration
T2 - a new statistical mechanical formulation
AU - Lazaridis, Themis
AU - Paulaitis, Michael E.
N1 - Funding Information:
Acknowledgments: We are grateful to Prof. R.H. Wood for numeroush elpful discussions. We also thank Prof. W.L. Jorgensenf or making the programB OSS availablet o us and Dr. Wallace for communicatingto us unpublishedr esults. This work was supportedb y the National Science Foundation (grant CPE8351228). Partial supportw as also providedb y Union Carbide,M erck and Exxon.
PY - 1993/2
Y1 - 1993/2
N2 - A statistical mechanical formulation is presented for the entropy of solution of simple molecules in water. The formulation is based on the Green-Wallace expansion for the entropy in terms of multiparticle correlation functions, which is derived here for rigid polyatomic fluids and for mixtures. With a factorization assumption for the solute-water correlation function we have been able to separate the translational and orientational contributions to the entropy of solution. This approach is applied to an infinitely dilute solution of methane in water. The required correlation functions are obtained by Monte Carlo simulation. The orientational contribution, which is due directly to the orientational asymmetry of water-water interactions, is found to be comparable to the translational contribution. We find that the large entropies and heat capacities of hydrophobic hydration can be accounted for by solute-water correlations alone and that large perturbations in water structure are not required to explain hydrophobic behavior.
AB - A statistical mechanical formulation is presented for the entropy of solution of simple molecules in water. The formulation is based on the Green-Wallace expansion for the entropy in terms of multiparticle correlation functions, which is derived here for rigid polyatomic fluids and for mixtures. With a factorization assumption for the solute-water correlation function we have been able to separate the translational and orientational contributions to the entropy of solution. This approach is applied to an infinitely dilute solution of methane in water. The required correlation functions are obtained by Monte Carlo simulation. The orientational contribution, which is due directly to the orientational asymmetry of water-water interactions, is found to be comparable to the translational contribution. We find that the large entropies and heat capacities of hydrophobic hydration can be accounted for by solute-water correlations alone and that large perturbations in water structure are not required to explain hydrophobic behavior.
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U2 - 10.1016/0378-3812(93)87005-L
DO - 10.1016/0378-3812(93)87005-L
M3 - Article
AN - SCOPUS:0027543648
SN - 0378-3812
VL - 83
SP - 43
EP - 49
JO - Fluid Phase Equilibria
JF - Fluid Phase Equilibria
IS - C
ER -