Grußwort des Präsidenten zur Emeritierung von Prof. Bellmann

Meine sehr verehrten Damen und Herren, liebe Kolleginnen und Kollegen, lieber Herr Kollege Bellmann und Familie, ich freue mich, Sie alle heute Vormittag zu dieser nicht ganz gewohnlichen akademischen Feier begrusen zu durfen.

Reversible tuning of a block-copolymer nanostructure via electric fields

Block copolymers consisting of incompatible components self-assemble into microphase-separated domains yielding highly regular structures with characteristic length scales of the order of several tens of nanometres. Therefore, in the past decades, block copolymers have gained considerable potential for nanotechnological applications, such as in nanostructured networks and membranes, nanoparticle templates and high-density data storage media. However, the characteristic size of the resulting structures is usually determined by molecular parameters of the constituent polymer molecules and cannot easily be adjusted on demand. Here, we show that electric d.c. fields can be used to tune the char…

Introduction to the special issue of Polymer in honor of Axel H.E. Müller

Crystallization-induced switching of the morphology of poly(ethylene oxide)-block-polybutadiene micelles

We studied the morphology of micelles formed by a well-defined poly(1,2-butadiene)-block-poly(ethylene oxide) diblock copolymer (PB-b-PEO). Dissolved in n-heptane at 70 °C, that is, above the melting point of PEO, spherical micelles are formed due to the selectivity of the solvent for the PB-block. If the solutions are cooled down to low temperatures, the liquid PEO-block crystallizes within the cores of the spherical micelles that remain stable. If, however, the solutions are quenched to 30 °C, the spherical micelles aggregate to a novel meander-like structure within several minutes. In its final state, the meander-like super-structure is crystalline, as revealed by time-resolved wide-angl…

Tribute to Axel Müller on the occasion of his 65th birthday

Controlled solvent vapour annealing for polymer electronics

Solvent vapour annealing (SVA) is demonstrated as an attractive method to anneal polymer blend and block copolymer thin films at low temperatures. It is especially suitable for organic electronics, where sensitive materials with strong intermolecular interactions are used. We demonstrate the effect of solvent vapour exposure on the film properties of a perylene bisimide acrylate (PPerAcr) side-chain polymer with strong crystallinity at the perylene bisimide moieties. We record the film thickness, light absorption and fluorescence as a function of the relative solvent vapour pressure. At a certain threshold of relative solvent vapour pressure, we observe a disruption of the π–π stacking, whi…

Special issue – Polymer foams

Nanopattern Evolution in Block Copolymer Films: Experiment, Simulations and Challenges

The present contribution reviews novel insights into block copolymer phase behavior and nanostructure formation in confined geometries. We focus on state-of-the-art experimental and theoretical progress in this area, with an emphasis on characterization methods and techniques that provide a quantitative framework for fundamental analysis. We discuss and compare basic system parameters that are readily controlled in simulations and in experiments, and present comparative stud- ies of increasing degree of complexity concerning the phase behavior and ordering dynamics of cylinder- and lamella-forming block copolymers in thin films.