Naslov
Microheterogeneity in aqueous mixtures

Autori
Zoranić, Larisa ; Sokolić, Franjo ; Perera, Aurélien

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
The 2nd Opatija Meeting on Computational Solutions in the Life Science / Babić, Darko ; Došlić, Nađa ; Smith, David ; Tomić, Sanja ; Vlahoviček, Kristian - Zagreb : Centre for Computional Solutions in the Life Science, Ruđer Bošković Institute, 2007

ISBN
978-953-6690-69-5

Skup
The 2nd Opatija Meeting on Computational Solutions in the Life Science

Mjesto i datum
Opatija, Hrvatska, 04.09.2007. - 09.09.2007

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
Microheterogeneity; Kirkwood-Buff integrals

Sažetak
The microheterogeneity is related to the fact that associated liquids and mixtures are locally heterogeneous while being globally homogeneous. It is puzzling that liquids, which are in the equilibrium state and far from phase transitions exhibit local heterogeneity. For example, the existence of local inhomogeneity is characteristic for metastable, or even unstable states, where concentration fluctuations become more pronounced, and this instability eventually leads to the phase transition. How the fine balance between microheterogenity and concentration fluctuation is reached and what are the premises of this feature, are questions that will be discussed here. Starting from neat liquids, namely water and alcohols, we investigated the formation of microstructure through the density-density correlation functions, both in direct and reciprocal space, as well as an effective local one-body density function defined by the cluster distribution. We show that two neat alcohols, methanol and tertbutanol, have a rich microstructure: chain-like molecular association for the former and micelle-like for the latter. This proves that even in neat liquids the influence of the hydrogen bonding is to create local ordering, which is not propagated on the global scale. How does this behaviour get translated in the mixtures of hydrogen-bonded liquids? Recent findings, namely for water-methanol mixtures, indicate local immiscibility at the nanoscale level, while these mixtures are fully miscible at the macroscopic level. The resulting influence on the Kirkwood-Buff integrals, which are often considered to contain experimental evidence for microheterogeneity, are investigated.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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