Soft matter refers to a class of materials whose basic building blocks are at least of the order of nanometers i.e. significantly larger than an atom and the appropriate energy scales are thermal. Soft materials include a myriad of systems such as colloids, polymers, microemulsions, gels, foams, liquid crystals and a number of biological materials. The word â€˜softâ€™ highlights the low elastic moduli of these materials and they are deformed by thermal or mechanical stresses comparable to the magnitude of the thermal fluctuations. Under confinement, soft matter displays interesting properties, which are not observed, in their bulk counterpart and continues to be a fertile ground for future research. The geometrical confinement is known to reduce the degrees of freedom and may as well introduce new molecular interactions among its constituents. In context of this talk, the confinement refers to soft materials at the solid surfaces, in the proximity of fluctuating membranes and inside nano-channels with hard walls. Some remarkable confinement-induced effects such as electrostatic trapping of a colloidal monolayer, buckling assisted layering transitions and the emergence of anisotropic pair correlations in colloids that are observed from experiments will be discussed. In addition, anomalous water desorption phenomena, existence of multiple glass transition temperatures in thin polymer films and the accelerated dynamics of polymers under soft confinement will be presented.
Dr. Dillip K. Satapathy obtained his M. Sc. from the Utkal University, Bhubaneswar in India and earned his Ph. D. degree from Faculty of Mathematics and Natural Sciences, Humboldt University, Berlin Germany. After postdoctoral research at Swiss Light Source (SLS), Switzerland and at the Department of Physics, University of Fribourg, Switzerland, he joined the faculty of the Physics Department of Indian Institute of Technology Madras, India, in 2012 where he is now an associate professor. His current research interests are in the area of experimental soft condensed matter physics with special focus on swelling kinetics, wrinkling, glass transition in polymer thin films, self assembly of colloids and surfactants, ferroelectric and thermoelectric properties of semi-crystalline polymers.â€‹