Electro-osmosis represents the movement of fluid in contact with a solid under applied electric field. It is one of the best ways to transport fluids in microchannel without mechanical moving parts and it can generate flow rates as large as several milliliters per minute and pressures as large as hundreds of atmospheres. This has opened up huge research interests to create major improvisations in micro and nanofluidic devices that would exploit the possibility of getting control over the fluid flow.
The present project deals with diffusio and electro osmotic phenomena with an experimental emphasis on the influence of interface conditions. The understanding of solute-wall interaction is crucial, as it comprises some important aspects like the wall slip, velocity and charge distribution, that can affect the EOF. Also, studies have shown that surface properties greatly influence the so-called zeta potential which needs to be exploited further. With that note, various surface wall modifications; including Titanium dioxide coated surfaces instead of bare silica, are considered. The reversal of direction of EOF i.e. changing the polarity gives higher EOF for Ti than silica, thus proving different possibilities for inhomogeneous surface modifications. Hence, the influence of surface potential and thus diffusion and electro osmotic effects for catalytic processes is very relevant.
Furthermore, devices under various conditions like, different neutral solutes, as well as diffusion channel dimensions and the presence of gas bubbles, to provide experimental input for the solute- wall interaction energy, via measurements of wall normal forces, are fabricated. Besides electro osmotic flow measurements, the electrical response of ion concentration gradient induced flow is measured. Also, different experimental techniques are employed viz., fluorescence lifetime imaging (FLIM) to get adequate concentration gradients measurements, micro particle imaging velocimetry (microPIV) and total internal reflection fluorescence (TIRF) to study velocity profiles in detail. And simultaneously, numerical simulations would be carried out to predict and validate the various solid-fluid interfacial properties.
Finally, the different outcomes could be utilized in the designing of ion exchange membranes with tailored interface structures and a full-fledged working model could be possibly realised under optimised conditions. These structures will assist the osmotic phenomena and thereby enhance the performance in a fundamentally different manner.
UT Research Information System
MSc in Chemical and Energy Engineering- (2014-2016)
Otto von Gueriecke University, Magdeburg, Germany
B.E. in Chemical Engineering- (2008-2012)
Mumbai University, India