## Two Types of Liquid Phase Separation Induced by Soft Centrifugation in Aqueous Ethyl Acetate Using Ethanol as Cosolvent

2023
##### Authors
Stemplinger, Simon
Zemb, Thomas
Horinek, Dominik
Journal article
Published
##### Published in
Research : A Science Partner Journal ; 6 (2023). - 0026. - Science Partner Journals (SPJ). - ISSN 2096-5168. - eISSN 2639-5274
##### Abstract
Water/ethyl acetate/ethanol is widely used as a “green” extractant system. We show that 2 different types of phase separation can be induced upon centrifugation in this ternary system using ethanol as a cosolvent of water and ethyl acetate: centrifuge-induced criticality and centrifuge-induced emulsification. The expected composition profiles of samples after centrifugation can be represented by bent lines in a ternary phase diagram when gravitational energy is added to the free energy of mixing. The experimental equilibrium composition profiles behave qualitatively as expected and can be predicted using a phenomenological theory of mixing. The concentration gradients are small except near the critical point, as expected for small molecules. Nevertheless, they are usable when accompanied by temperature cycles. These findings open new possibilities of centrifugal separation, even if control is delicate during temperature cycles. These schemes are accessible even at relatively low centrifugation speed for molecules that float and sediment with apparent molar masses several hundred times larger than the molecular mass.
540 Chemistry
##### Cite This
ISO 690CÖLFEN, Helmut, Rose ROSENBERG, Dirk HAFFKE, Simon STEMPLINGER, Thomas ZEMB, Dominik HORINEK, 2023. Two Types of Liquid Phase Separation Induced by Soft Centrifugation in Aqueous Ethyl Acetate Using Ethanol as Cosolvent. In: Research : A Science Partner Journal. Science Partner Journals (SPJ). 6, 0026. ISSN 2096-5168. eISSN 2639-5274. Available under: doi: 10.34133/research.0026
BibTex
@article{Colfen2023-01Types-66423,
year={2023},
doi={10.34133/research.0026},
title={Two Types of Liquid Phase Separation Induced by Soft Centrifugation in Aqueous Ethyl Acetate Using Ethanol as Cosolvent},
volume={6},
issn={2096-5168},
journal={Research : A Science Partner Journal},
author={Cölfen, Helmut and Rosenberg, Rose and Haffke, Dirk and Stemplinger, Simon and Zemb, Thomas and Horinek, Dominik},
note={Article Number: 0026}
}

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<dcterms:abstract>Water/ethyl acetate/ethanol is widely used as a “green” extractant system. We show that 2 different types of phase separation can be induced upon centrifugation in this ternary system using ethanol as a cosolvent of water and ethyl acetate: centrifuge-induced criticality and centrifuge-induced emulsification. The expected composition profiles of samples after centrifugation can be represented by bent lines in a ternary phase diagram when gravitational energy is added to the free energy of mixing. The experimental equilibrium composition profiles behave qualitatively as expected and can be predicted using a phenomenological theory of mixing. The concentration gradients are small except near the critical point, as expected for small molecules. Nevertheless, they are usable when accompanied by temperature cycles. These findings open new possibilities of centrifugal separation, even if control is delicate during temperature cycles. These schemes are accessible even at relatively low centrifugation speed for molecules that float and sediment with apparent molar masses several hundred times larger than the molecular mass.</dcterms:abstract>
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Yes