Our research revolves around the study of transport phenomena and their enhancement at micro-nano scales and we use both experiments and simulations for our investigations. And up-to-date list of publications can be found here.
Enhanced and Controlled Transport
The work involves the manipulation of fluid and species transport using gradients in electrical potential, temperature and solute concentration. Application of electrohydrodynamic phenomena such as electroosmosis and electrokinetic instabilities for transport enhancement are primarily being investigated, and these can be aided by temperature and concentration gradients. The control of transport phenomena by these external fields is studies subsequently.
Our special interest is in the effect of heterogeneous surfaces on the transport phenomena and the ability to manipulate fluid flows and solvent transport using these heterogeneities at the microscale to increase the efficiency at the macroscale. Examples of applications are in increasing mass transfer for catalytic reactions and CO2 capture using solid sorbents.
Phoretic Transport Phenomena
The transport of droplets and particles is of significant importance in water treatment, drug delivery and environmental remediation. Transport of these colloids in fields of concentration and temperature gradients can be used in biological environments, while applying electric fields to drive flow has applications in water treatment and the process industry.
Using microfluidic experiments, we visualize the phoretic transport at the pore scale in both Newtonian and Non-Newtonian fluids under the influence of different externally applied fields. The microfluidic devices are developed in-house in collaboration with NanoFab at the University of Alberta. Different visualization techniques, including Fluorescence Microsopy, Particle Tracking and Fluoresence Lifetime Imaging Microscopy are available in our lab to both qualitatively and quantitatively investigate the phoretic transport phenomena.
Additionally, we work on theoretical and numerical models to describe the phoretic transport in these systems.
Electrokinetic Soil Remediation
Salt and hydrocarbon contamination in soil is a significant problem in hydrocarbon recovery methods and impacted sites should be remediated for further use. In our group, we investigate the potential of using electrokinetic methods, based on closely spaced electrodes, to remove salt from soil. Pore scale modeling is done to understand the remediation process at the pore-level, while experimental research focuses on the development of optimized electrode geometries and materials for field applications. Bench scale testing is combined with a PNP modeling approach, to systematically investigate optimal remediation strategies for different contaminations and levels of contamination.
Transport and manipulation of droplets is of interest in many areas including biology, separation systems and reaction engineering. Microfluidic systems provide the opportunity tounderstand the behaviour of manipulated droplets at the microscale. Electrophoresis (EP), an electrokinetic phenomenon, is the motion of particles or droplets in the presence of an external electric field. In this method, the direction of particles/droplets motion depends on their surface charge. The goal of this reaserch is improving the flexibility and controllability of droplet EP by using amphoteric surfactants. This type of surfactants can change the charge of droplets as a function of pH, and in extension the direction of their movement in the systems
Transport Phenomena in viscoelastic media
Viscoelastic fluids are encountered in many of industrial and biological scenarios, and understanding their properties and flow behaviour is a problem that has baffled researchers for many years. We use a combination of theory, simulations and experiments to model and understand the dynamics of viscoelastic fluids like polymers and polyelectrolytes in microfluidic systems and porous media, with applications to healthcare and oil-recovery processes.