TY - JOUR
T1 - Hydrophobicity Varying with Temperature, Pressure, and Salt Concentration
AU - Koga, K.
AU - Yamamoto, N.
N1 - Funding Information:
One of us (K.K.) thanks Prof. Ben Widom for his insightful advice, fruitful collaboration, and warm hospitality at Cornell. K.K. also thanks Prof. Dor Ben-Amotz for helpful discussions of many aspects of the mean-field approximation. This work was supported by JSPS KAKENHI Grant No. JP26287099.
PY - 2018/4/5
Y1 - 2018/4/5
N2 - Temperature-, pressure-, and salt-concentration-induced variations in the solubility of small nonpolar solutes in aqueous solution and the corresponding variations in the solvent-induced pair attraction between such solute molecules are investigated. The variations in the solvation free energy of a solute and those in the solvent-induced pair attraction are well reproduced by a mean-field approximation in which the repulsive cores of solute molecules are treated as hard spheres and the mean-field energy of a solute molecule is taken to be the average potential energy that the solute molecule feels in solution. The mechanisms of variation in the solvation free energy and those of variation in the solvent-induced pair potential, with increasing temperature, pressure, and salt concentration, are clarified. Correlations between the solvation free energy and the solvent-induced pair potential at a contact distance in temperature, pressure, and salt concentration variations are near linear in any mode of variation, but the slope of the linear relation is dependent on the mode of variation and is determined by a ratio of the solvation thermodynamic quantities characteristic of each mode of variation.
AB - Temperature-, pressure-, and salt-concentration-induced variations in the solubility of small nonpolar solutes in aqueous solution and the corresponding variations in the solvent-induced pair attraction between such solute molecules are investigated. The variations in the solvation free energy of a solute and those in the solvent-induced pair attraction are well reproduced by a mean-field approximation in which the repulsive cores of solute molecules are treated as hard spheres and the mean-field energy of a solute molecule is taken to be the average potential energy that the solute molecule feels in solution. The mechanisms of variation in the solvation free energy and those of variation in the solvent-induced pair potential, with increasing temperature, pressure, and salt concentration, are clarified. Correlations between the solvation free energy and the solvent-induced pair potential at a contact distance in temperature, pressure, and salt concentration variations are near linear in any mode of variation, but the slope of the linear relation is dependent on the mode of variation and is determined by a ratio of the solvation thermodynamic quantities characteristic of each mode of variation.
UR - http://www.scopus.com/inward/record.url?scp=85045050224&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85045050224&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcb.7b12193
DO - 10.1021/acs.jpcb.7b12193
M3 - Article
C2 - 29357255
AN - SCOPUS:85045050224
SN - 1520-6106
VL - 122
SP - 3655
EP - 3665
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
IS - 13
ER -