Segregation in aqueous methanol enhanced by cooling and compression

Abstract

Molecular segregation in methanol-water mixtures is studied across a wide concentration range as a function of temperature and pressure. Cluster distributions obtained from both neutron diffraction and molecular dynamics simulations point to significantly enhanced segregation as the mixtures are cooled or compressed. This evolution toward greater molecular heterogenity in the mixture accounts for the observed changes in the water-water radial distribution function and there are indications also of a change in the topology of the water clusters. The observed behavior is consistent with an approach to an upper critical solution point. Such a point would appear to be ``hidden'' below the freezing line, thereby precluding observation of the two-fluid region.

14 pages, 8 figs, submitted to J. Chem. Phys

References in corpus (2)

• Methanol-water solutions: a bi-percolating liquid mixture
• Clustering and Micro-immiscibility in Alcohol-Water Mixtures: Evidence from Molecular Dynamics Simulations

Cited by in corpus (5)

• Variations of the Hydrogen Bonding and of the Hydrogen Bonded Network in Ethanol-Water Mixtures on Cooling
• Temperature-dependent structure of methanol-water mixtures on cooling: X-ray and neutron diffraction and molecular dynamics simulations
• Temperature-dependent structure of 1-propanol/water mixtures: X-ray diffraction experiments and computer simulations at low and high alcohol contents
• Hydrogen bonding and percolation in propan-2-ol -- water liquid mixtures: X-ray diffraction experiments and computer simulations
• Evolution of the hydrogen-bonded network in methanol-water mixtures upon cooling