Modeling Simple Alcohols in Two Dimensions

摘要

The alcohol-water mixtures were studied within a two-dimensional model. The MB model was used for modeling water and alcohol molecules were modeled as non-flexible chains consisting of two-dimensional Lennard-Jones disks with the first disk having two hydrogen-bonding arms. The model was explored using NPT Monte Carlo computer simulation. The results were compared with the experimental thermodynamic properties of methanol/water mixtures. The qualitative agreement was obtained for the excess volume of mixing,but due to the surface/volume effects not properly captured by two dimensional models,the excess enthalpy of mixing cannot be represented correctly by this model. Further,we studied the transfer of a single alcohol molecule into water,focusing on the trends exhibited by the methanol,ethanol,propanol,n-butanol series. While small alcohol molecules show the correct trend the flexibility of the alcohol molecules should be taken into account to improve the agreement for higher alcohols.