title: Effect of chain stiffness on the competition between crystallization and glass-formation in model unentangled polymers.
abstract: We map out the solid-state morphologies formed by model soft-pearl-necklace polymers as a function of chain stiffness, spanning the range from fully flexible to rodlike chains. The ratio of Kuhn length to bead diameter (lK/r0) increases monotonically with increasing bending stiffness kb and yields a one-parameter model that relates chain shape to bulk morphology. In the flexible limit, monomers occupy the sites of close-packed crystallites while chains retain random-walk-like order. In the rodlike limit, nematic chain ordering typical of lamellar precursors coexists with close-packing. At intermediate values of bending stiffness, the competition between random-walk-like and nematic chain ordering produces glass-formation; the range of kb over which this occurs increases with the thermal cooling rate |Ṫ| implemented in our molecular dynamics simulations. Finally, values of kb between the glass-forming and rodlike ranges produce complex ordered phases such as close-packed spirals. Our results should provide a useful initial step in a coarse-grained modeling approach to systematically determining the effect of chain stiffness on the crystallization-vs-glass-formation competition in both synthetic and colloidal polymers.
authors.affiliation: Department of Physics, University of South Florida, Tampa, Florida 33620, USA.
authors.forename: Hong T
authors.initials: HT
authors.lastname: Nguyen
authors.affiliation: Department of Physics, University of South Florida, Tampa, Florida 33620, USA.
authors.forename: Tyler B
authors.initials: TB
authors.lastname: Smith
authors.affiliation: Department of Physics, University of South Florida, Tampa, Florida 33620, USA.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Hoy
authors.affiliation: Institute for Optoelectronics and Microsystems (ISOM) and ETSII, Polytechnic University of Madrid, Madrid, Spain.
authors.forename: Nikos Ch
authors.initials: NCh
authors.lastname: Karayiannis