Naslov
Camel back shaped Kirkwood–Buff integrals

Autori
Perera, Aurélien ; Požar, Martina ; Lovrinčević, Bernarda

Izvornik
The Journal of chemical physics (0021-9606) 156 (2022), 12; 124503, 11

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
liquid-mixture ; ethanol ; heptane ; Kirkwood-Buff integrals ; double-extrema ; computer simulations ; molecular-dynamics

Sažetak
Some binary mixtures, such as specific alcohol–alkane mixtures or even water–tbutanol, exhibit two humps “camel back” shaped Kirkwood–Buff integrals (KBIs). This is in sharp contrast with the usual KBIs of binary mixtures having a single extremum. This extremum is interpreted as the region of maximum concentration fluctuations, usually occurs in binary mixtures presenting appreciable micro-segregation, and corresponds to where the mixture exhibits a percolation of the two species domains. In this paper, it is shown that two extrema occur in binary mixtures when one species forms “meta-particle” aggregates, the latter acts as a meta-species, and they have their own concentration fluctuations, hence their own KBI extremum. This “meta-extremum” occurs at a low concentration of the aggregate-forming species (such as alcohol in alkane) and is independent of the other usual extremum observed at mid-volume fraction occupancy. These systems are a good illustration of the concept of the duality between concentration fluctuations and micro-segregation.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija

POVEZANOST RADA