Neutron Diffraction Study on Microinhomogeneities in Ethanol–Water Mixtures

Abstract

Neutron diffraction with isotopic substitution measurements have been made at room temperature on seven isotopically substituted ethanol–water mixtures at 0.1, 0.2 and 0.4 ethanol mole fractions, respectively, from which nine composite partial structure factors, HH, HX and XX (X denotes the weighted sum of non-substituted atoms) were derived on water–water, water–ethanol and ethanol–ethanol interactions for each of the solutions. The partial structure factors were then subjected to an empirical potential structure refinement simulation to derive all site–site pair correlation functions. An origin of the so-called microinhomogeneities in ethanol–water mixtures has been established at the molecular level on the basis of the pair correlation functions, which probably underlines the mechanism of anomalous behaviors in physico-chemical quantities and alcohol-induced denaturation of proteins in ethanol–water mixtures.