Revealing the Influence of the Strength of Coulomb Interactions on the Viscosity and Interfacial Tension of Ionic Liquid Cosolvent Mixtures

详细信息    查看全文

• 作者：Andreas P. Fr&ouml ; ba ; Peter Wasserscheid ; Dirk Gerhard ; Heiko Kremer ; Alfred Leipertz
• 刊名：Journal of Physical Chemistry B
• 出版年：2007
• 出版时间：November 8, 2007
• 年：2007
• 卷：111
• 期：44
• 页码：12817 - 12822
• 全文大小：72K
• 年卷期：v.111,no.44(November 8, 2007)
• ISSN：1520-5207

文摘

Within this work, viscosity and interfacial tension of selected ionic liquid cosolvent mixtures, [EMIM][EtOSO₃](1-ethyl-3-methyl-immidazolium ethyl sulfate) with water and ethanol, were studied as a function of compositionby surface light scattering (SLS) and the pendant drop method in a consistent manner, allowing a close insightinto the nature of interactions. Here, we show that the viscosity behavior clearly reflects the bulk structure ofthe ionic liquid cosolvent mixtures and correlates to the fluid structure at the phase boundary. In contrast toformer work, we found the viscosity of ionic liquid [EMIM][EtOSO₃] to be decreasing the stronger by smallamounts of the cosolvents and the lower their dielectric constant. Furthermore, two distinct trends for thedependence of the viscosity on the cosolvent concentration were resolved. These were assigned to ion-dipole interactions dominating in the salt-rich region and to dipole-dipole interactions in the diluted one. Acrossover between both regions is reflected by the interfacial tension data, where it seems that up to a "critical"concentration almost no cosolvent is present at the phase boundary.