Simulation of osmotic pressure in concentrated aqueous salt solutions.

Journal Article · Fri Jan 01 04:00:00 EST 2010 · J. Phys. Chem. Lett.

DOI:https://doi.org/10.1021/jz900079w· OSTI ID:969210

Luo, Y; Roux, B

Accurate force fields are critical for meaningful simulation studies of highly concentrated electrolytes. The ion models that are widely used in biomolecular simulations do not necessarily reproduce the correct behavior at finite concentrations. In principle, the osmotic pressure is a key thermodynamic property that could be used to test and refine force field parameters for concentrated solutions. Here we describe a novel, simple, and practical method to compute the osmotic pressure directly from molecular dynamics (MD) simulation of concentrated aqueous solutions by introducing an idealized semipermeable membrane. Simple models for Na+, K+, and Cl- are tested and calibrated to accurately reproduce the experimental osmotic pressure at high salt concentration, up to the solubility limit of 4-5 M. The methodology is general and can be extended to any type of solute as well as nonadditive polarizable force fields.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: NIH; SC
• OSTI ID: 969210
• Report Number(s): ANL/NE/JA-65741
• Journal Information: J. Phys. Chem. Lett., Journal Name: J. Phys. Chem. Lett. Journal Issue: 2010 Vol. 1
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
AQUEOUS SOLUTIONS
CHLORIDES
ELECTROLYTES
MOLECULAR DYNAMICS METHOD
OSMOSIS
POTASSIUM
PRESSURE DEPENDENCE
SALTS
SIMULATION
SODIUM
SOLUBILITY
SOLUTES
THERMODYNAMICS