Di, 18.12.2018

17:15 Uhr im Seminarraum 1.27 Von-Danckelmann-Platz 4, 06120 Halle

Prof. Walter Focke

Institute of Applied Materials, Department of Chemical Engineering, University of Pretoria, South Africa

"The effect of migration of small molecules in polymers on the design of controlled release devices for malaria vector control"

Astract:
Malaria vector control aims to prevent malaria parasite transmission by either repelling or killing the disease transmitting mosquitoes. In the latter case the insect killing is done either before humans are bitten or, rather surprisingly, afterwards! ...

Details
Focke_PMS_18_12_2018.pdf (143,4 KB)  vom 21.09.2018

Di, 4.12.2018

17:15 Uhr im Seminarraum 1.27 Von-Danckelmann-Platz 4, 06120 Halle

Prof. Kay Saalwächter

Institut für Physik, Naturwissenschaftliche Fakultät II,
Martin-Luther-Universtität Halle-Wittenberg, Halle (Saale)

“Polymeric materials: environmental perspectives"

Abstract:
Mainly due to mismanaged waste, remains of polymer materials have entered our ecosystem in large quantities and are unfortunately there to stay for centuries. While our awareness of the related problems increases, societal and political decisions have urgently to be made. An introduction into the extent of the problem and the differences in tackling it encountered in Germany and the US, and a scientific account from the viewpoint of a polymer scientist shall be given. Active participation of the audience in terms of question and answer, and discussion is highly appreciated.

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Saalwächter_PMS_04122018.pdf (486,7 KB)  vom 06.11.2018

Di, 06.11.2018

17:15 Uhr im Seminarraum 1.27 Von-Danckelmann-Platz 4, 06120 Halle

Dr. Samuli Ollila

Institute of Biotechnology, University of Helsinki, Finland

“Combining MD simulations and NMR experiments of lipid bilayers and proteins"

Abstract:
Direct comparison between MD simulations and NMR experiments can be used to interpret the experiments and improve simulation models. This has been especially useful for the studies of ion binding to lipid bilayers, oxidized lipids and disordered proteins. I will present improvement and validation of MD simulations models for lipids and proteins together with the interpretation of order parameters measured from solid state NMR and spin relaxation times measured from solution state NMR.

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Ollila_PMS_6_11_2018.pdf (143,1 KB)  vom 09.10.2018

Di, 30.10.2018

17:15 Uhr im Seminarraum 1.27 Von-Danckelmann-Platz 4, 06120 Halle

Dr. Jennifer Qing Lu

University of California, Merced, USA

"A new class of submolecular switches based on the DBCOD conformational change"

Abstract:
Dibenzocyclooctadiene  (DBCOD) is composed of a flexible eight‐membered ring fused into two  rigid phenyl rings. It can be regarded as the simplest submolecular  structure that can undergo controlled conformational changes. ...

Details
Lu_PMS_30_10_2018.pdf (174,8 KB)  vom 18.09.2018

Di, 23.10.2018

17:15 Uhr im Seminarraum 1.27 Von-Danckelmann-Platz 4, 06120 Halle

Dr. Stephen Schrettl

Universität Freiburg, Adolphe Merkle Institut, Schweiz

"Responsive Materials Based on Non-Covalent Interactions"

Abstract:
Supramolecular polymers are furnished by the assembly of monomeric units equipped with binding motifs that form directional, non-covalent interactions such as hydrogen bonds, π-interactions, or metal-ligand coordination complexes. Exposure of the bulk polymers to external stimuli such as heat, light, mechanical force, or certain chemicals disrupts the reversible and dynamic linkages, leading to a disassembly into the monomers and pronounced changes of the materials properties. [...]

Details
Schrettl_PMS_23_10_2018.pdf (287,9 KB)  vom 16.10.2018

Mo, 22.10.2018 - Sondertermin!

17:15 Uhr im Seminarraum 1.27 Von-Danckelmann-Platz 4, 06120 Halle

Prof. Siegfried Stapf

Institut für Physik, Technische Universität Ilmenau

"Relaxation and diffusion in polymer melts and solutions: new experimental approaches to probe molecular dynamics in homopolymers and copolymers"

Abstract:
The time-dependence of the rms displacements of chain segments in polymer melts has been a cornerstone of experimental tests of various chain motion models. Rouse and Reptation dynamics (below and above the entanglement limits for chain lengths, respectively) are described by characteristic power-laws. Neutron spin echo and gradient NMR studies have tested and confirmed these power-laws, but have also found discrepancies in some cases. The wide time gap between these two techniques is partially covered by NMR relaxometry. Again, relaxometry finds power-law relationships between NMR relaxation times and Larmor frequency, but both the dependence on frequency and molecular weight were shown to deviate substantially from tube-reptation predictions.

[...]

Details
Stapf_PMS_22_10_2018.pdf (145,7 KB)  vom 09.10.2018

Mi, 17.10.2018 - Sondertermin!

17:15 Uhr im Seminarraum 1.27 Von-Danckelmann-Platz 4, 06120 Halle

Prof. So Youn Kim

School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), South Korea

“Spreading Area-dependent Phase Diagram of Block Copolymer Self-assembly at the Air/Water Interface"

Abstract:
While general agreements exist for phase diagrams of BCP self-assembly in bulk or thin films, a fundamental understanding of BCP structures at the air/water interface still remain elusive. The current version of phase diagram of BCPs at the air/water interface explains morphology transition of BCPs with relative fraction of each block: block fraction is the only parameter to control the morphology. ...

Details
Kim_PMS_17_10_2018.pdf (144,5 KB)  vom 09.10.2018

Mi, 11.07.2018 - Sonderveranstaltung

17:15 Uhr im Seminarraum 1.27 Von-Danckelmann-Platz 4, 06120 Halle

Prof. Melik Demirel

Penn State College of Earth and Mineral Sciences, Department of Materials Science and Ingineering, Pennsylvania, USA

“Mapping the Energy Landscape of Repetitive Structural Proteins"

Abstract:
Despite six decades of intensive studies in fibrous proteins, a viable approach for mapping the amino-acid sequences of these proteins to self-assembly and materials properties does not yet exist. New technologies are required to synthesize pooled libraries of repetitive genes that en-code fibrous proteins, characterize the self-assembly behavior of these proteins in high-throughput, and discover sequences that form materials with novel physical properties. To address these challenges, we combined recent developments in synthetic biology and
femtosecond optics to create revolutionary fibers and materials. High-throughput screening of tandem-repeat libraries will enable the discovery of sequences with unprecedented physical properties and improve our understanding of self-assembly, leading to revolutionary advances in materials and life sciences.

Details
Demirel_PMS_11_07_2018.pdf (144 KB)  vom 14.06.2018

Di, 26.06.2018

17:15 Uhr im Seminarraum 1.27 Von-Danckelmann-Platz 4, 06120 Halle

Prof. Viktor Ivanov

Faculty of Physics, Moscow State University, Moscow, Russia

“To what extent can mesoscale computer simulation be used to predict properties of (macro)molecular systems?"

Abstract:
In this talk, I will give an overview about recent work in my group on the mesoscale computer simulation of conformational and dynamic properties of several (macro)molecular systems. In our studies, we have used the dissipative particle dynamics (DPD) method [1,2]. Following the multiscale computer simulation approach, we have developed coarse-grained (CG) models for polymer nanocomposites [3], organic and water solutions of lecithin and bile-salts [4,5], polyimides [6], precursors of polyacrylonitrile fibers, polyurethanes. ...

Details
Ivanov_PMS_26_06_2018.pdf (146,5 KB)  vom 13.06.2018

Di, 29.05.2018

17.15 Uhr im Seminarraum 1.27 Von-Danckelmann-Platz 4, 06120 Halle

Prof. Thomas Heinze

Friedrich-Schiller-Universität Jena, Institut für Organische Chemie und Makromolekulare Chemie, Jena, Deutschland

“New products from polysaccharides – simple chemistry with great effect"

Abstract:
While the commercial chemistry of polysaccharides is limited due to the low reactivity of the heterogeneous reactions, homogeneous chemistry opens paths for the design of novel and highly engineered structures. Thus, there is a need to find efficient solvents for cellulose that will be discussed to some extent. However, to design novel functional materials, not only homogeneous reactions applying special solvents but also the conversion of activated and organo-soluble polysaccharide derivatives are in the center of recent interest....

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Heinze_PMS_29_05_2018.pdf (144,6 KB)  vom 08.05.2018

Di, 08.05.2018

17.15 Uhr im Seminarraum 1.27 Von-Danckelmann-Platz 4, 06120 Halle

Dr. Samuel Kyeremateng

AbbVie Deutschland GmbH & Co. KG, Ludwigshafen

"Role of Polymers in Amorphous Solid Dispersion Formulations"

Details
Kyeremateng_PSMS_08052018.pdf (533,2 KB)  vom 03.05.2018

Di, 24.4.2018

17.15 Uhr im Seminarraum 1.27 Von-Danckelmann-Platz 4, 06120 Halle

Dr. Björn Kuttich

Technische Universität Darmstadt, Institut für Festkörperphysik
Darmstadt, Germany

“Macromolecules in spherical soft confinement"

Abstract:
Confinement effects on macromolecules, either synthetic polymers or proteins, are of great importance for nanotechnology and biology. The confinement may thereby affect both structural properties as well as the dynamics of the confined molecules. The situation is further complicated if a so-called soft confinement is considered. This type of confining geometry is deformable by the introduced guest molecules and exhibits shape variations on a time scale relevant for these.
In my talk I want to introduce two droplet phase microemulsions as soft confining geometry, based on two different surfactants, i.e. the ionic Aerosol-OT (AOT) and the non-ionic C12E4. In the absence of any guest molecule both systems show very similar structure and dynamics. However, their effect on low molecular weight polyethylene glycol (PEG) confined to the water filled core of the microemulsion differs strongly. This is caused by a different specific interaction between polymer and the respective surfactant molecules.
By applying small angle X-ray and neutron scattering as well as neutron spin echo spectroscopy and exploiting two complementary contrast situations by appropriate deuteration, structure and dynamics of the confined PEG can then be observed directly. The different dynamic contributions of the confining droplets and the confined polymer can be separated, revealing significant deviations from the polymer properties in bulk solution.

Details
Kuttich_PMS_24_04_2018.pdf (144,3 KB)  vom 16.04.2018

Di, 30.01.2018

17.15 Uhr im Seminarraum 1.27 Von-Danckelmann-Platz 4, 06120 Halle

Dr. Ana Brás

Universität zu Köln, Department Chemie, Institut für Physikalische Chemie,

Köln, Deutschland

“Structure and Dynamics of Polymers: Influence of Confinement, Architecture and Supramolecular Associations"

Abstract:
Over the last decades, synthetic polymer materials have become an important part of our everyday lives. At breakfast, we have bottles of orange juice made of polyethylene. Our car bumper is made of high impact polypropylene, the interior is largely composed of polyurethane, the tires are elastomers and parts of the bodywork are polymer mixtures. In this context, a fundamental understanding of the structure and dynamics of polymers at different time and length scales is crucial for the design of polymers with improved physical and mechanical properties for nowadays applications. There are different experimental techniques providing access to the properties of polymers from a microscopic to a macroscopic scale.

Details
Ana Brás_PSM_30.01.2018.pdf (146,4 KB)  vom 15.12.2017