Experimental evidence of non-equilibrium phase separation in supercritical fluids

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Lee, Juho, Kim, Yeonguk, Jang, Jong Dae, Do, Changwoo, Ha, Min Young, Yun, Gunsu
Format: Preprint
Veröffentlicht: 2025
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866915225058410496
author Lee, Juho
Kim, Yeonguk
Jang, Jong Dae
Do, Changwoo
Ha, Min Young
Yun, Gunsu
author_facet Lee, Juho
Kim, Yeonguk
Jang, Jong Dae
Do, Changwoo
Ha, Min Young
Yun, Gunsu
contents Supercritical fluids (SCFs) have long been considered homogeneous and structureless, yet recent studies suggest the existence of transient, liquid-like clusters under dynamic processes. In this study, we provide experimental evidence of semi-stable non-equilibrium phase separation in SCFs through opacity measurements and small-angle neutron scattering (SANS). By investigating the thermophysical properties of helium, argon, and krypton during adiabatic expansion, we show that cooling dynamics vary significantly among species, influencing cluster formation. Neutron scattering measurements reveal distinct variations in signal intensity, supporting that the clusters slowly dissolve into the background with a surprisingly long time scale of tens of minutes. Given that SCFs in industrial applications frequently experience dynamic, non-equilibrium conditions rather than in strict thermodynamic equilibrium, our results provide crucial insights with potential implications for advanced material processing, energy systems, and chemical engineering.
format Preprint
id arxiv_https___arxiv_org_abs_2504_02219
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Experimental evidence of non-equilibrium phase separation in supercritical fluids
Lee, Juho
Kim, Yeonguk
Jang, Jong Dae
Do, Changwoo
Ha, Min Young
Yun, Gunsu
Soft Condensed Matter
Supercritical fluids (SCFs) have long been considered homogeneous and structureless, yet recent studies suggest the existence of transient, liquid-like clusters under dynamic processes. In this study, we provide experimental evidence of semi-stable non-equilibrium phase separation in SCFs through opacity measurements and small-angle neutron scattering (SANS). By investigating the thermophysical properties of helium, argon, and krypton during adiabatic expansion, we show that cooling dynamics vary significantly among species, influencing cluster formation. Neutron scattering measurements reveal distinct variations in signal intensity, supporting that the clusters slowly dissolve into the background with a surprisingly long time scale of tens of minutes. Given that SCFs in industrial applications frequently experience dynamic, non-equilibrium conditions rather than in strict thermodynamic equilibrium, our results provide crucial insights with potential implications for advanced material processing, energy systems, and chemical engineering.
title Experimental evidence of non-equilibrium phase separation in supercritical fluids
topic Soft Condensed Matter
url https://arxiv.org/abs/2504.02219