Understanding the liquid–liquid (water–hexane) interface

• Published in: Chemical physics letters Vol. 685; pp. 422 - 426
• Main Authors: Murad, Sohail, Puri, Ishwar K.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2017
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2017.08.013

Schematic of the simulation system. [Display omitted] •Liquid-liquid interface are investigated under an applied heat flux.•Liquid-liquid interfaces behave significantly different that solid-liquid interfaces.•Applied heat fluxes can have a significant impact on the size of the interface.•Compared to isothermal systems, the interface can be up to three times wider.•Implications for a wide range of applications that are focused on these interfaces. Nonequilibrium molecular dynamics simulations are employed to investigate the interfacial thermal resistance of nanoscale hexane-water interfaces subject to an applied heat flux. Our studies show that these liquid-liquid interfaces exhibit behavior significantly dissimilar to that of solid-liquid and solid-vapor interfaces. Notably, the thermal resistance of a hexane-water interface is contingent on the interfacial temperature gradient alone with negligible dependence on the mean interfacial temperature, while the solid-liquid dependent strongly on the interfacial temperature. Application of a heat flux also increases the interface thickness significantly as compared to an equilibrium isothermal interface. Since liquid-liquid interfaces have been proposed for diverse applications, e.g., sensors for wastewater treatment and for extraction of toxic ions from water, they can be designed to be wider by applying a heat flux. This may allow the interface to be used for other applications not possible currently because of the very limited thickness of the interface in isothermal systems.