Effect of the Dielectric Constant on the Solubility of Acetone in Water

Molecular dynamics
simulations for liquid acetone, the pure component
and mixed with water, are performed to analyze the effect that the
dielectric constant has on the solubility. The CGenFF and OPLS/AA
force fields, together with two TraPPE_UA models, are used to simulate
acetone, while the TIP4P/ϵ model is applied for water. The calculated
dielectric constant of acetone models at room conditions follows a
linear relation with their molecular dipole moment, allowing us to
understand, in simulations, the miscibility problem of acetone in
water. The experimental liquid and liquid–vapor properties
as the pure component are reasonably well reproduced with those force
fields. The TraPPE_UA04 and TraPPE_UA05 models predict dielectric
constants for acetone in the liquid phase of 9 and 12, respectively.
The experimental value is 21. The values obtained with the OPLS/AA
and CGenFF models are 15 and 23, respectively. All of the models used,
except CGenFF, give inhomogeneous mixtures at both low and moderate
concentrations of acetone.