guest ::
| Home > Publications database > Thermal Density Fluctuations and Polymorphic Phase Transitions of Ethane (C 2 D 6 ) in the Gas/Liquid and Supercritical States |
| Home > Publications database > Thermal Density Fluctuations and Polymorphic Phase Transitions of Ethane (C 2 D 6 ) in the Gas/Liquid and Supercritical States |
| Journal Article | FZJ-2024-03508 |
; ;
2024
Americal Chemical Society
Washington, DC
This record in other databases: 
Please use a persistent id in citations: doi:10.1021/acs.jpcb.4c01422 doi:10.34734/FZJ-2024-03508
Abstract: The phase behavior of the liquid C2D6 below and above the critical point was investigated using small-angle neutron scattering (SANS) in temperature and pressure ranges from 10 to 45 °C and 20 to 126 bar, respectively. The scattering of thermal fluctuations of the molecular density was determined and thus the gas–liquid and Widom lines. At the same time, we observed additional scattering of droplets of more densely packed C2D6 molecules above the gas–liquid line and in the supercritical fluid regime from just below the critical point for all temperatures at about ΔP = 10 bar above the Widom line. This line is interpreted as the Frenkel line. These results are consistent with our previous studies on CO2 and thus indicate a universal phase behavior for monomolecular liquids below and above the critical point. The interpretation of the Frenkel line as the lower limit of a polymorphic phase transition is in contrast to the usual interpretation as the limit of a dynamic process. The correlation lengths (ξ) of the thermal density fluctuations at the critical point and at the Widom line are determined between 20 and 35 Å and thus in the range of the droplet radius between 60 and 80 Å. These long-range fluctuations appear to suppress the formation of droplets, which can only form at about 10 bar above the critical point and the Widom line when ξ becomes smaller than 10 Å.
Keyword(s): Basic research (1st) ; Chemistry (2nd)
; 
; 
; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; Essential Science Indicators ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Science Citation Index Expanded ; Web of Science Core Collection
|
The record appears in these collections: |
PDF