Electrokinetic instabilities in co-flowing ferrofluid and buffer solutions with matched electric conductivities

Flexible Ferrofluids: Design and Applications

“…The flow rates of fluids as well as sizes and features of droplets are controlled in a consecutive integral way, while the manipulation of discrete droplets could hardly be achieved. In this system, ferrofluids could serve as either a dispersed phase or a continuous phase . For example, as a dispersed phase, ferrofluids experience both magnetoviscous effect and magnetic drag effect, which impact the formation of ferrofluid droplets and are determined by relative flow rates and intensity of external magnetic fields; as a continuous phase, ferrofluids could facilitate fabrication of polymer droplets, adjust the droplet shape, and aggregate droplets into chains with certain length, relying on the magnetic buoyancy force and dipole–dipole interactions produced by a designed magnetic field .…”

Nonlinear dependence (on ionic strength, pH) of surface charge density and zeta potential in microchannel electrokinetic flow

“…The electrokinetic (EK) involves the phenomena in which a liquid moves tangentially to a charged surface, where a better understanding gives rise to other related phenomenon such as electrophoresis, electroosmosis, and streaming potential. And gives rise to the foundation for many current advances in technological applications, such as microfluidic systems for lab-on-a-chip technologies [ 1 ], transportation in microchannel-based devices, chemical and biological detection [ [2] , [3] , [4] , [5] ]; nanofluid preparation and stabilization studies [ 6 , 7 ]; soil analyses [ 8 ], and nanostructure materials for energy harvesting [ [9] , [10] , [11] , [12] ]. Silica and silicate glass surfaces, for example, are the most common materials used to fabricate microchannels for chemical and biological transport processes [ [13] , [14] , [15] ].…”

“…Knowing the EK interaction between this type of material and different electrolytes results in better understanding and characterization of these processes. Moreover, this knowledge can improve fluid transport in micro and nanoscale microfluidic devices to accomplish better mixing and transport enhancement in microchannels [ 4 , [16] , [17] , [18] ].…”

Joule heating effects on electrokinetic flows with conductivity gradients

“…Therefore, understanding the principle of EKI becomes significant for both an improved fluid transport via the suppressed EKI and an enhanced fluid mixing via the promoted EKI [16]. This subject has been studied by various research groups using experimental, theoretical, and numerical approaches [17–27] since EKI was demonstrated by the Santiago group [28].…”