title: Spontaneous crystallization in athermal polymer packings.
abstract: We review recent results from extensive simulations of the crystallization of athermal polymer packings. It is shown that above a certain packing density, and for sufficiently long simulations, all random assemblies of freely-jointed chains of tangent hard spheres of uniform size show a spontaneous transition into a crystalline phase. These polymer crystals adopt predominantly random hexagonal close packed morphologies. An analysis of the local environment around monomers based on the shape and size of the Voronoi polyhedra clearly shows that Voronoi cells become more spherical and more symmetric as the system transits to the ordered state. The change in the local environment leads to an increase in the monomer translational contribution to the entropy of the system, which acts as the driving force for the phase transition. A comparison of the crystallization of hard-sphere polymers and monomers highlights similarities and differences resulting from the constraints imposed by chain connectivity.
authors.affiliation: Institute of Optoelectronics and Microsystems (ISOM) and ETSII, Polytechnic University of Madrid (UPM), José Gutiérrez Abascal 2, 28006 Madrid, Spain. mlaso@etsii.upm.es.
authors.forename: Nikos Ch
authors.initials: NCh
authors.lastname: Karayiannis
authors.forename: Katerina
authors.initials: K
authors.lastname: Foteinopoulou
authors.forename: Manuel
authors.initials: M
authors.lastname: Laso
mesh_terms: D016880:Anisotropy; D003460:Crystallization; D019277:Entropy; D056004:Molecular Dynamics Simulation; D009010:Monte Carlo Method; D044367:Phase Transition; D011108:Polymers / Q000737:chemistry*; D013696:Temperature
chemical_list: D011108:Polymers