The majority of swimming microorganisms involved in human functions and diseases are found in confined fluidic environments. Inspired by the motion of such swimmers, many studies have been carried out to understand the principles underlying their motion and propulsion mechanism. Among these studies is the emerging field of active colloids including micro- and nanometer scale self-propelling particles. Active colloids have the ability to move, carry and transport components in a fluidic environment. They have a wide variety of applications, including medical and biomedical applications, lab-on-chip transport, targeted drug delivery and cancer fight-agent delivery. In many cases, such active particles are suspended in a solution bound by a liquidâfluid interface, which raises interesting questions regarding the interaction of swimmers with a liquid/fluid boundary. To better understand the interactions in such soft mater systems, we study the dynamic motion of patchy and Janus particles with varying patch sizes trapped at liquid/fluid interfaces.
In this context, we have studied the Brownian and active motion of Janus and patchy particles trapped at the oil/air and water/air interfaces. Patchy particles are prepared using the GLAD deposition technique. Upon exposure to hydrogen peroxide, patchy particles display a self-induced phoretic motion by decomposing hydrogen peroxide into water and oxygen. The asymmetric distribution of the product molecules around the particles leads to the particlesâ autonomous motion. The phoretic velocity and diffusivity of patchy particles of varying patch size trapped at a liquid/fluid interface will be analyzed and compared with the case of particles immersed in the bulk solution.