Growing Negative Pressure in Dissolved Solutes: Raman Monitoring of Solvent-Pulling Effect

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• 作者：Lionel Mercury ; Kirill I. Shmulovich ; Isabelle Bergonzi ; Aurélien Canizarès ; Patrick Simon
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：April 14, 2016
• 年：2016
• 卷：120
• 期：14
• 页码：7697-7704
• 全文大小：427K
• 年卷期：0
• ISSN：1932-7455

文摘

Negative pressure in liquids is both an experimental fact and a usually neglected state of condensed matter. Using synthetic fluid inclusions, namely closed vacuoles fabricated inside one solid host by hydrothermal processes, a Raman study was performed to examine how a superheated solvent (under negative pressure) interacts with its dissolved solutes. As a result, this contribution not only illustrates this well-known tensile state but also displays evidence that a stretched solvent is able to pull on its dissolved solutes and put them also under a stretched state. The dielectric continuum hypothesis may lead to expect a stretching effect in solutes similar to the solvent’s, but our measurements evidence a damping mechanical effect (growing with tension), most probably related to solvation shells. One practical consequence is that the (experimentally known) supersolvent properties of superheated solutions are certainly related to the change of the chemical potential of solutes which results from the damping effect. This change can determine as well a change in the thermodynamic driving force of the superheated solution toward bubble nucleation. A more complex than usual picture of the aqueous solution physical chemistry emerges from this study.