Naslov
Microheterogeneity in Ethanol-Water Mixture

Autori
Mijaković, Marijana

Vrsta, podvrsta i kategorija rada
Ocjenski radovi, doktorska disertacija

Fakultet
Prirodoslovno matematički fakutet

Mjesto
Split

Datum
24.10

Godina
2012

Stranica
160

Mentor
Sokolić, Franjo ; Zoranić, Larisa

Ključne riječi
aqueous solutions; ethanol modelo; molecular dynamics

Sažetak
Ethanol-water liquid mixture was analysed by the method of Molecular Dynamics, over the whole composition range in steps of 0.10 mole fraction to elucidate its micro structure. From 0.08 to 0.25 mole fraction of ethanol a denser grid was used, of 0.02-0.03 steps. As expected, this mixture shoves a microheterogenous structure, and even more, it was discovered that there are at least three structural regimes along the varying of the mole fraction. Up to 0.15 mole fraction of ethanol, ethanol forms small ’hard’ clusters dispersed in water network. From 0.15 to aproximately 0.65 mole fraction of ethanol, ethanol and water form microheterogenous mixture of segregated domains, and above 0.65 mole fraction of ethanol water network loses its percolation, and segregated water clusters are found in the mixture. As water and ethanol are both associating liquids, and ethanol is one of the samllest amphipilic molecules, this rich variety of micro structure is not surprizing. As the proof the results from MD simulation are listed, rdf, coordination numbers, analysis of clustering, structure factors, running Kirkwood-Buff integrals, and snapshots, all supporting the given picture, as well as results from sound speed measurement, and previously known experimantaly data on excess enthalpy, isothermal compressibility, azeotropy and heat capacity. This is the first time such an overall picture of the microstructure of this liquid mixture is given.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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