Forschung

Wir untersuchen intermolekulare und intramolekulare Strukturbildung mit dem Ziel, Bildungsmechanismen zu verstehen und darauf aufbauend Steuerungsmöglichkeiten in den entsprechenden Prozessen zu entwickeln. Es werden statische und dynamische Lichtstreuung (LS), Neutronenkleinwinkelstreuung (SANS) und normale und anomale Röntgenkleinwinkelstreuung (SAXS) eingesetzt, wobei ein Schwerpunkt im Einsatz zeitaufgelöster Experimente mit den eben genannten Streumethoden liegt.
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Conformational changes of proteins or DNA as well as the formation of hierarchical structures with proteins are common processes in living cells. Their investigation in vitro is usually based on experimental conditions with properly adjusted pH, salinity, temperature and concentrations of the components directly involved in the respective process. Although such in vitro experiments provide first insights into the mechanisms of the processes under consideration, they totaly neglect the crowded environment in cells, generated by the presence of osmolytes, chaperones and the many other…

Numerous synthetic, low molecular weight compounds like organic azo-dyestuffes form fiber-like aggregates in aqueous solution in close analogy to the self-assembly of various proteins in living systems. The underlying processes can be regarded as physical polymerisations leading to a structural diversity, just as complex as in case of macromolecular chemistry. Several low molecular weight gelators and dyestuffs, with the cationic dyestuff pseudo-isocynanine chloride (PIC) as the most recent example, have been selected for a detailed investigation of their self-assembly with time-resolved light…

Nucleation and growth of particles are essential features of the formation of stable and metastable solid phases in a bottom-up approach and are thus of fundamental relevance to countless processes in nature and industry. Typical examples are the formation of nanoparticles from supersaturated solutions of carbonates, phosphates and silicates relevant to biomineralization and scale formation in pipes, the generation of high performance nanoparticles of noble metals or of metal organic frameworks (MOF) and, to give but an example from organic chemistry, the growth of eumelanin based biological…

Anionic polyelectrolyte chains act extremely sensitive towards the addition of specifically interacting cations (SIC). This sensitive response can be further modulated by variations of pH, temperature and ionic strength with additional inert salts. Typical SICs, which interact specifically with the anionic carboxylate residues of polyacrylates or with the anionic sulfonate residues of poly(styrene sulfonate) are alkaline earth cations. This is signaled by a drastic change of the polyelectrolyte coil dimensions and eventually in a precipitation of the respective polyelectrolyte salt, once the…

Materials from biobased polymers are considered by the EU to be of high priority. Accordingly, the research project PLANOM aims at a use of polylactides for optical applications like lenses, reflectors or light guides, where it is supposed to replace poly(methyl methacrylate) and polycarbonate. Our group contributes to this project with two topics: (i) Polymers, predominantly polylactides and colloidal or polymeric additives will be characterized by means of light scattering or Fraunhofer diffraction. These characterization techniques reveal the molar mass and or the size of the respective…

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