Pressure Dependence of the Hildebrand Solubility Parameter and the Internal Pressure: Monte Carlo Simulations for External Pressures up to 300 MPa
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- 作者：Neeraj Rai ; J. Ilja Siepmann ; Nathan E. Schultz ; Richard B. Ross
- 刊名：Journal of Physical Chemistry C
- 出版年：2007
- 出版时间：November 1, 2007
- 年：2007
- 卷：111
- 期：43
- 页码：15634 - 15641
- 全文大小：253K
- 年卷期：v.111,no.43(November 1, 2007)
- ISSN：1932-7455
文摘
Monte Carlo simulations were carried out to compute the Hildebrand solubility parameter and the internalpressure for n-hexane, benzene, and ethanol at a temperature of 303.15 K and for external pressures rangingfrom 0.1 to 300 MPa. In addition, the internal energy, molar volume, enthalpy of the liquid phase, and freeenergy, enthalpy, and entropy of solvation were calculated as a function of external pressure. For all threemolecules, the solubility parameter is found to increase monotonically with increasing external pressure,while the internal pressure exhibits a maximum. The magnitude of the solvation free energy decreasesmonotonically as external pressure is increased and both enthalpic and entropic terms contribute to this decreasein solubility. Analysis of radial distribution functions indicates small structural changes in the liquid phaseand differences between nonpolar and hydrogen-bonding fluids in response to external pressure changes.