Clustering and microimmiscibility in alcohol-water mixtures: Evidence from molecular-dynamics simulations

We have investigated the hydrogen-bonded structures in liquid methanol and a 7:3 mole fraction aqueous solution using classical Molecular Dynamics simulations at 298 K and ambient pressure. We find that, in contrast to recent predictions from x-ray emission studies, the hydrogen-bonded structure in liquid methanol is dominated by chain and small ring structures. In the methanol-rich solution, we find evidence of microimmiscibility, supporting recent conclusions derived from neutron diffraction data.