Research Projects

The justification driving the proposal is clearly two-fold: I. To have an understanding on the fundamentals behind the self-propulsion of a technologically relevant system i.e. active emulsion droplet atop a surfactant containing water bath. Using emulsion droplets composed of two immiscible liquids, such as oil and water, and stabilized by a surfactant, it is possible to led them to become self-propelled under appropriate conditions. This allowed the droplets to move in a controlled manner and to transport a molecular payload to specific locations. Understanding and tunability of self-propelling droplets atop a surfactant containing structured aqueous bath can certainly improve material designing rule defying its performance. II. To clearly contribute to the long-standing fundamental counter-intuitive understanding on the self-propelling active emulsion droplets and particles. This area is rich of physical challenges that deals with mimicking the biological collective phenomena, such as, motion in bacterial colonies, and at the same time advance experimental studying of rheology, patterning instability, and phase transitions in systems far from thermodynamic equilibrium. Especially for system of liquid crystal-water emulsion droplets propelling atop aqueous surfactant bath, molecular processes fueling droplet via stabilizing the emulsions are an established concept. While it is understandable surface tension, viscosity of propelling medium must have role on the Marangoni flow and subsequently on the active droplet motion, a molecular level phenomenon that happening through symmetry breaking and anisotropy of surfactant molecules (micelles) are yet to see insight from the aspect of micellar structure and active droplet chemical structures. So there are debates to know when symmetry breaking follows a standard linear instability, nonlinear instability, or no symmetry breaking at all. This is important when the micellar structure of surfactant molecules shows strong morphological transitions which could be tracked through rheological signatures, simultaneously and controllably, through molecular additives. The key challenge of the present proposal thus lies at the consideration of creating an experimentally accessible plan where these aspects will be looked in-detail, along with such droplet's encapsulation ability being micro-carrier. While role of viscosity of the surfactant media on the propulsion of LC (liquid crystal) emulsion droplet is know it doesn’t disentangle the role of structure of micellar media, and LC chemical structure and its phase transition clearly. After ensuring possible unified correlation between those, it proceeds to enable primary output as extended knowledge-base and more robust handle to control microrheology, transport of micro-carriers atop structured soft matter bath. This will be extended to practical problems, such as targeted delivery of active pharmaceutical ingredients encapsulated through emulsion droplets.