Do ternary liquid mixtures exhibit negative main Fick diffusion coefficients?†
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DOI:
10.1039/c8cp06795cURI (для ссылок/цитирований):
https://pubs.rsc.org/en/content/articlelanding/2019/cp/c8cp06795c#!divAbstracthttps://elib.sfu-kras.ru/handle/2311/129470
Автор:
Kozlova, S.
Mialdun, A.
Ryzhkov, I.
Janzen, T.
Vrabec, J.
Shevtsova, V.
Коллективный автор:
Институт космических и информационных технологий
Кафедра прикладной математики и компьютерной безопасности
Дата:
2019Журнал:
Physical Chemistry Chemical PhysicsКвартиль журнала в Scopus:
Q1Квартиль журнала в Web of Science:
Q1Библиографическое описание:
Kozlova, S. Do ternary liquid mixtures exhibit negative main Fick diffusion coefficients?† [Текст] / S. Kozlova, A. Mialdun, I. Ryzhkov, T. Janzen, J. Vrabec, V. Shevtsova // Physical Chemistry Chemical Physics. — 2019. — Т. 21. — С. 2140-2152Аннотация:
Experimental data on Fick diffusion coefficients of ternary and higher mixtures depend on the reference
frame; those which are in common use are associated with the average velocity either with respect to
volume, mass or mole number. In this study, the dependence of diffusion coefficients on the reference
frame is thoroughly analyzed for three ternary mixtures of different types. The first one, tetralin–isobutylbenzene–
dodecane, can almost be considered as ideal, the second one, cyclohexane–toluene–methanol,
exhibits liquid–liquid phase separation and the third one, water–ethanol–triethylene glycol, contains three
associating species and is also strongly non-ideal. Experimental diffusion coefficient data sampled in the
volume reference frame are transformed to the molar and mass reference frames. The required partial
molar volumes are derived from present density measurements. Four additional mixtures are considered
along a single or two composition paths. A highlight of this study is the existence of a strong similarity of
the main diffusion coefficients in the volume and mass reference frames for all considered mixtures. When
the excess volume is small, the coefficients in the molar reference frame are also similar. However, for the
mixture with a large excess volume (containing water), the diffusion coefficients in the molar reference
frame differ significantly, even indicating negative main diffusion coefficients. It is shown that negative main
diffusion coefficients appear due to relatively large experimental uncertainties of cross diffusion coefficients,
which are propagated and amplified by frame transformation.