Naslov
Signatures of micro-heterogeneity in various binary mixtures

Autori
Zoranić, Larisa ; Požar , Martina ; Mijaković , Marijana ; Kežić-Lovrinčević, Bernarda ; Sokolić , Franjo ; Perera , Aurélien

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

Izvornik
Joint EMLG/JMLG Annual Meeting 2015 "Molecular Liquids Meet Ionic Liquids - From Fundamentals to Applications": abstracts / - , 2015, 139-139

Skup
Joint EMLG/JMLG Annual Meeting

Mjesto i datum
Rostock, Njemačka, 2015

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
binary mixtures ; microheterogeneity ; molecular dynamics ; Kirkwood-Buff theory ; cluster analysis ; structure factors

Sažetak
There is a difference in the organization between simple liquids such as benzene or alkane and those we call complex liquids, which are characterized by a strong local order, such as that created by hydrogen bonding [1]. In mixtures involving complex liquids, such as aqueous mixtures, this local order results in a local segregation of species [1, 2]. The resulting micro-heterogeneity must be distinguished from concentration fluctuations [1, 2]. We analyze several pathways to characterize this distinction. The first consists in enforcing the analogy with the micellar systems and micro-emulsions, in which the organized domains produce a pre-peak in the total scattered intensity obtained by neutron or Xray measurements. Observing the pre-peak as a domain signature in water-alcohol mixtures is challenging due the nature of fluctuations of Hbond network of water [3, 4]. Instead, replacing water by benzene allows a direct observation of the domain pre-peak [4] when the solute is an associating species, such as alcohols. In the second method we identify the locally segregated species using the site-site cluster distributions and calculate averages only over sites which are part of the clusters. This approach allows to separate the clustering of bonding from non-bonding sites. Using the clusters size distributions and cluster correlation functions we describe how the shape of micro-segregated domains changes depending on the concentrations in various binary mixtures that have benzene and water as solvents and alkanes, acetone and alcohol as solutes. The third method consists in computing the Kirkwood-Buff integrals (KBIs) that contain information of the concentration fluctuations. However, one can obtain indirect information about the local micro-heterogeneous structure from their shape as function of the solute mole fraction [4]. REFERENCES [1] Perera A., B. Kežić, F. Sokolić and L. Zoranić “Micro-Heterogeneity in Complex Liquids”, Molecular Dynamics (Vol 2), Ed. L. Wang (InTech, Rijeka) (2012) [2] Perera A., L. Zoranić, F. Sokolić and R. Mazighi “A comparative Molecular Dynamics study of water-methanol and acetone-methanol mixture.” Journal of Molecular Liquids 159, SI(1) ; 52-59 (2011) [3] Perera A. and B. Kezic “Aqueous tert-butanol mixtures: A model for molecular-emulsions Fluctuations and micro- heterogeneity in mixtures of complex liquids” Journal of Chemical Physics 37(1), 014501 (2012) [4] Požar M., J.B Seguier, J. Guerche, R. Mazighi, L. Zoranić, M. Mijaković, B. Kežić-Lovrinčević, F. Sokolić and A. Perera “Simple and complex disorder in binary mixtures” Physical Chemistry Chemical Physics 17 9885 (2015)

Izvorni jezik
Engleski

Znanstvena područja
Fizika

POVEZANOST RADA