Abstract
The field of droplet electrohydrodynamics (EHD) emerged with a seminal work of G.I. Taylor in 1966, who presented the so-called leaky dielectric model (LDM) to predict the droplet shapes undergoing distortions under an electric field. Since then, the droplet EHD has evolved in many ways over the next 55 years with numerous intriguing phenomena reported, such as tip and equatorial streaming, Quincke rotation, double droplet breakup modes, particle assemblies at the emulsion interface, and many more. These phenomena have a potential of vast applications in different areas of science and technology. This paper presents a review of prominent droplet EHD studies pertaining to the essential physical insight of various EHD phenomena. Here, we discuss the dynamics of a single-phase emulsion droplet under weak and strong electric fields. Moreover, the effect of the presence of particles and surfactants at the emulsion interface is covered in detail. Furthermore, the EHD of multi-phase double emulsion droplet is included. We focus on features such as deformation, instabilities, and breakups under varying electrical and physical properties. At the end of the review, we also discuss the potential applications of droplet EHD and various challenges with their future perspectives.
Highlights
In recent years, electrohydrodynamics (EHD) of emulsion droplets has evolved in many ways as the research gained pace in this field
Since droplet EHD is a very broad area of research and it is not possible to cover all the aspects in a single review, here we mainly focus on the behavior of a single-phase droplet with particle-free or particle-covered interface and multi-phase emulsion droplets within the perspective of their deformation, instabilities, and breakups under weak and strong external stimuli of electric fields, considering only the most prominent works (See Figure 1)
Ohnesorge Number (Oh) = μ/ ργa Electric capillary number is defined as the ratio between the magnitude of electrical stresses (ε2E20) and capillary stresses (γ/a), where γ is the interfacial tension between two liquids, and controls/delineates the droplet deformation regimes, such as stable and unstable, Capillary Number (CaE) = μ2U∞/γ = ε2E2oa/γ
Summary
Electrohydrodynamics (EHD) of emulsion droplets has evolved in many ways as the research gained pace in this field. Recent EHD studies have explored more complex EHD interface topologies related to multiple phase emulsion droplets, and covered the broader aspects, such as the emulsion instabilities, breakups, and particles manipulation at the emulsion interface forming novel colloidal assemblies [13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34] Though it has been almost six decades since the research in this area commenced, it is only until recently that a few studies pertaining to the droplet EHD with applicative prospects have been reported [35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52]. DC field, multi-core double emulsion a E: Experimental, A: Analytical, N: Numerical. b S: Silicone oil, C: Castor oil, W: DI water, G: Glycerol solution, HC: Hexane and chlorobenzene, WE: Water-ethyl alcohol mixture. c PAM: Polyacrylamide, XAN: Xanthan gum, AOT: Dioctyl sulfosuccinate sodium salt, TBAB: Tetrabutylammonium bromide
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
