Journal Article

FZJ-2020-02316

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Polymorphic phase transition in liquid and supercritical carbon dioxide

Pipich, V.FZJ* ; Schwahn, D. (Corresponding author)FZJ*

2020
Macmillan Publishers Limited, part of Springer Nature [London]

This record in other databases:    

Please use a persistent id in citations: http://hdl.handle.net/2128/26875  doi:10.1038/s41598-020-68451-y

Abstract: We present experiments on molecular density fluctuations in liquid and supercritical (SC) CO2 using small-angle neutron scattering. Thermal density fluctuations in SC-CO2 determine susceptibility and correlation length identifying the Widom line at their maxima. Droplet formation occurs at the gas–liquid line and between 20 and 60 bar above the Widom line, the corresponding borderline identified as the Frenkel line. The droplets start to form spheres of constant radius of ≈ 45 Å and transform into rods and globules at higher pressure. Droplet formation represents a liquid–liquid (polymorphic) phase transition of the same composition but different density, whose difference defines its order parameter. Polymorphism in CO2 is a new observation stimulating interesting discussions on the topics of gas-like to liquid-like transition in SC fluids and polymorphism since CO2 represents a “simple” van der Waals liquid in contrast to water, which is the most widely studied liquid showing polymorphism in its supercooled state.

Keyword(s): Earth, Environment and Cultural Heritage (1st) ; Materials Science (2nd)

---

Contributing Institute(s):

1. Neutronenstreuung (JCNS-1)
2. JCNS-4 (JCNS-4)
3. JCNS-FRM-II (JCNS-FRM-II)
4. Heinz Maier-Leibnitz Zentrum (MLZ)

Research Program(s):

1. 6G4 - Jülich Centre for Neutron Research (JCNS) (POF3-623) (POF3-623)
2. 6215 - Soft Matter, Health and Life Sciences (POF3-621) (POF3-621)
3. 6G15 - FRM II / MLZ (POF3-6G15) (POF3-6G15)

Experiment(s):

1. KWS-1: Small angle scattering diffractometer (NL3b)

Appears in the scientific report 2020

---

Database coverage:
; ; ; ; Article Processing Charges ; BIOSIS Previews ; Biological Abstracts ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; DOAJ Seal ; Ebsco Academic Search ; Essential Science Indicators ; Fees ; IF < 5 ; JCR ; NCBI Molecular Biology Database ; PubMed Central ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Web of Science Core Collection ; Zoological Record

---