title: Gelation in semiflexible polymers.
abstract: Molecular dynamics simulations have been employed to study the formation of a physical gel by semiflexible polymer chains. The formation of a geometrically connected network of these chains is investigated as a function of temperature and rate of cooling. The stiffness of the molecules is controlled via a potential between beads separated by two bonds. As the temperature is lowered, a percolated homogeneous solution phase separates to form a high-density, non-percolated nematic fluid and a low-density gas phase. On further decreasing the temperature, the chains are dynamically arrested preventing the completion of the vapor-liquid (VL) phase separation. As a result, the chains are stuck in a three-dimensional network of nematic bundles forming a percolated gel. Apart from temperature, the rate of cooling also plays an important role in the formation of the gel. Cooling the system at a faster rate yields gel while slower rates result in complete VL phase separation.
authors.affiliation: Department of Chemical Engineering, Columbia University, New York, New York 10027, USA. venkat.pdm@gmail.com
authors.forename: Venkat
authors.initials: V
authors.lastname: Padmanabhan
authors.forename: Sanat K
authors.initials: SK
authors.lastname: Kumar