Dresden 2011 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 3: Interfaces and Thin Films I

CPP 3.3: Vortrag

Montag, 14. März 2011, 11:00–11:15, ZEU 160

Mechanical Properties of Random Block Copolymer Melts in the Bulk and at Selective Substrates — •Birger Steinmüller and Marcus Müller — Institut für Theoretische Physik, Georg-August-Universität, Göttingen

Random block copolymers are interesting materials to study since they show microphase separation, while lacking longer-ranged order, in a melt. We use two different coarse-grained models to access the properties of these systems via computer simulations:

The Single-Chain-in-Mean-Field simulation (SCMF), which uses a soft, density-dependent non-bonded interaction, and the Lennard-Jones bead-spring model. For the latter model we use LAMMPS, since simulating the melt via MD allows us to access the frozen state (glass) at low temperatures.

In order to determine the mechanical properties of the melt, we equilibrate the system, then quench it below the glass transition temperature. We use this glass to calculate, via a virial expansion, the local mechanical properties, e.g., local compressibility and local shear modulus. This approach is used for bulk systems, as well as for melts in contact with a selective substrate. We compare the mechanical properties of the interface and the interphase with those of the bulk. Another type of interface in the bulk, the boundary region between domains with a high concentration of the two different sorts of monomers, is additionally considered.