Dresden 2006 – wissenschaftliches Programm

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AKB: Biologische Physik

AKB 9: Chemical Bonds and Adsorption

AKB 9.1: Vortrag

Dienstag, 28. März 2006, 11:00–11:15, ZEU 260

Polymer and peptide adsorption to attractive substrates — •Michael Bachmann and Wolfhard Janke — Institut für Theoretische Physik, Universität Leipzig, Augustusplatz 10/11, 04109 Leipzig, Germany

The interest in understanding polymer adsorption at substrates has grown quite recently with the development of high-resolution experimental equipment allowing for studying the technologically important problem of substrate-binding specificity of synthetic peptides. In our study of simple hybrid models [1,2], we investigate how solubility of the surrounding solvent and temperature influence the substrate-binding of nongrafted polymers in a cavity with an attractive surface. Applying a suitably adapted variant of the multicanonical chain-growth algorithm [3] for self-avoiding walks, we performed simulations of lattice polymers with up to 200 monomers and obtained the entire temperature-solubility pseudo-phase diagram of the hybrid system within a single simulation. We clearly separated expected thermodynamically stable phases dominated by the respective adsorbed and desorbed collapsed and random-coil conformations. Another central aspect of our study is the discussion of pseudo-phases that specifically depend on finite-size properties such as the precise number of monomers or, for peptides, the sequence of residues.

[1] M. Bachmann and W. Janke, Phys. Rev. Lett. 95, 058102 (2005).

[2] M. Bachmann and W. Janke, to be published.

[3] M. Bachmann and W. Janke, Phys. Rev. Lett. 91, 208105 (2003).