Dresden 2009 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

CPP: Fachverband Chemische Physik und Polymerphysik

CPP 42: Polymer Physics IV

CPP 42.10: Vortrag

Freitag, 27. März 2009, 12:45–13:00, ZEU 160

Semi-flexible hydrogen-bonded and non-hydrogen bonded lattice polymers — •Krawczyk Jaroslaw¹, Prellberg Thomas², and Aleksander L. Owczarek³ — ¹Technische Universität Dortmund — ²School of Mathematical Sciences, University of London, UK — ³The University of Melbourne, Australia

We investigate the addition of stiffness to the lattice model of hydrogen-bonded polymers in two and three dimensions. We find that, in contrast to polymers that interact via a homogeneous short-range interaction, the collapse transition is unchanged by any amount of stiffness: this supports the physical argument that hydrogen bonding already introduces an effective stiffness. Contrary to possible physical arguments, favouring bends in the polymer does not return the models behaviour to that comparable with the semi-flexible homogeneous interaction model, where the canonical θ -point occurs for a range of parameter values. In fact, for sufficiently large bending energies the crystal phase disappears altogether, and no phase transition of any type occurs. We also compare the order-disorder transition from the globule phase to crystalline phase in the semi-flexible homogeneous interaction model to that for the fully-flexible hybrid model with both hydrogen and non-hydrogen like interactions. We show that these phase transitions are of the same type and are a novel polymer critical phenomena in two dimensions. That is, it is confirmed that in two dimensions this transition is second-order, unlike in three dimensions where it is known to be first order.