Molecular dynamics simulation study of association in trifluoroethanol/water mixtures.

Mixtures of Trifluoroethanol (TFE) and water with different proportions are studied using molecular dynamics simulations. The radial and spatial distribution functions, as well as the size distribution of TFE clusters are obtained from the trajectories. The variation of radial and spatial distribution functions with composition show that the addition of TFE enhances the water structure, but the hydrogen bonds between TFE molecules are broken as TFE is diluted with water. The TFE-rich solutions have stronger TFE-water hydrogen bonds. The clustering of TFE molecules in low concentration region is attributed to the hydrophobic interactions between CF(3) groups. The distribution of cluster sizes in solution supports these conclusions. Copyright 2009 Wiley Periodicals, Inc.