ABSTRACT

There is currently an attempt by both soft matter theorists, and simulationists to develop effective methods of coarse-graining. A few of these attempts include coarse graining over large molecules or large assembly of molecules (such as micelles) to the single-site level. Coarse-graining over large low-fractal molecules may result in soft and penetrable site descriptions. Ultra-soft particles (penetrable particles with bounded potentials) exhibit highly anomalous clustering behavior. We present a study these systems using integral equation theory, and predict a striking contact to overlap transition. In the contact regime, the structure is that of a 'normal' fluid, while the overlap regime is characterized by entropy enhancement through cluster formation. At very large volume fractions, cluster crystals phases are predicted. Both transitions are a function of the density of ultra-soft particles, their stiffness, as well as their penetrability. Cluster sizes are calculated, and anomalous structure factors are predicted in the overlap, and cluster-crystal regimes. We also present some initial results of hard and soft particle mixtures. In this way, we present the phase behavior of coarse-grained particles, and comment on the effect of coarse-graining.

ABOUT THE SPEAKER

Mukta Tripathy received her Ph.D. from the Department of Chemical and Biomolecular Engineering for the University of Illinois at Urbana-Champaign in 2010. She did her B.S. in Chemistry at Ohio State University (2001-2005). She joined as an Assistant Professor at IIT Gandhinagar in December 2010, and subsequently moved to IIT Bombay in July 2012. She works in the area of soft condensed matter theory. Her current research interests include structure, self-assembly, and phase behavior of polymer nanocomposites, Pickering emulsions, penetrable particle systems, and colloids with surface roughness.