Biophysics

Investigation of microheterogeneity in aqueous alcohol solutions using molecular dynamics

December 2, 2009.

Lecturer

PhD LARISA ZORANIĆ
Faculty of Science, Split

Date and time

Friday, December 11, 2009 at 2:00 PM

Location

Lecture Hall, Wing I, Ruđer Bošković Institute, Bijenička 54, Zagreb

Abstract

Recent research shows an unusual structural organization of alcohols in aqueous solutions. Namely, at the nanoscale, these systems exhibit local order that does not disrupt global homogeneity. The question is how this local property can be measured, and how local inhomogeneity is reflected in global macroscopic variables. Using the molecular dynamics method, we investigated the microstructure in liquids and solutions of alcohol and water. By analyzing correlation functions in reciprocal and direct space and the cluster distribution function, we determined the peculiarities of their structural organization. In liquids, molecules are connected into clusters or larger associations such as, for example, a network structure by the action of hydrogen bonding. Such a structural organization leads to an inhomogeneous distribution of atoms that participate in the construction of hydrogen bonds, while the molecular distribution function, as well as the function of hydrophobic atoms, preserves the properties of a homogeneous liquid. In solutions, the cause of local heterogeneity is also hydrogen bonding, since microheterogeneity refers to the local non-mixing of solution components. Microheterogeneity is a general property of aqueous solutions. This arrangement of the system at the local level does not belong to the class of order or disorder. A better definition of this new property is a challenge to experimental and theoretical methods and techniques.

*Colloquium of the Croatian Biophysical Society

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