Polymer and Soft Matter Seminars
Forthcoming Events
The Polymer- and Sofmatter Seminars will take place on Tuesdays at 4.15 pm in seminar room 1.27 at Von-Danckelmann-Platz 4.
Tue, 19.07.2022
4.15 pm in seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
We try to offer the hybrid option, but cannot guarantee it!
Prof. Dr. Nail Fatkullin
Institute of Physics, Kazan Federal University, Russia
" The Deuteron NMR Hahn Echo Decay in Polymer Melts."
A self-consistent approximation beyond the Redfield limit and
without using the Anderson–Weiss approximation for Hahn Echo of
deuteron spins belonging to polymer chains undergoing reptation is
formulated. The dynamical heterogeneity of the polymer segments
created by the end segments, which is shown has a frequency nature,
is also taken into account . Recent experiments with polyethylene
oxide melts will be discussed.
Past Events
Tue, 28.06.2022
4.15 pm in seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
We try to offer the hybrid option, but cannot guarantee it!
Prof. Zbigniew Bartczak
Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Lodz, Poland
“Deformation instabilities and lamellae fragmentation during plastic deformation of polyethylene”
The outstanding mechanical performance of semicrystalline polymers can be attributed to their unique morphology and the robust phase interconnectivity through numerous chains intersecting the amorphous-crystalline interface. Deformation of a semicrystalline polymer is a complicated process, involving all elements of their complex morphology. In this process, different micro-mechanisms are activated at various stages. Furthermore, the active mechanisms can be adjusted with advancing strain due to interactions between adjacent amorphous and crystalline layers, which are tightly connected and therefore are forced to deform jointly. These interactions can also lead to some deformation instabilities, which in turn, may effect in opening new deformation paths and/or launch alternative mechanisms previously inaccessible, and therefore may appear very important part of the deformation sequence. [...]
Details
Bartczak_2022_06_28.pdf
(487.8 KB) vom 04.05.2022
Meeting No: 932 2177 9598
Passcode: 547489
Tue, 21.06.2022
4:15 pm in seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
We try to offer the hybrid option, but cannot guarantee it!
Dr. Franziska Lissel
TU Dresden, Independent Research Group Leader - Functional Electronic Materials/
Leibniz-Institut für Polymerforschung Dresden e.V. (IPF)
"Triblock Copolymers- Using Nanophase Separation to Achieve Low Modulus, Elastic Deformation and Good Mobility in Polymer Semiconductors"
Polymer electronics are competitive for applications such as wearable sensors which require high mechanical functionality (e.g., elasticity), but only moderate electronic functionality (e.g., charge carrier mobility). Still, the elastic modulus of polymer semiconductors (PSCs) (0.1 - 1 GPa for typical PSCs) is orders of magnitudes away from human skin (0.1 - 10 MPa). Different pathways were explored to achieve low-modulus PSCs, e.g. non conjugated spacers [1], backbone regioregularity [2], or sidechains modifications [3], to name a few, but lowering the modulus is generally associated with a decrease in mobility.
[...]
Details
2022_06_PMSM_Lissel.pdf
(335.7 KB) vom 13.06.2022
Meeting No: 932 2177 9598
Passcode: 547489
Fri, 17.06.2022 - Special Event!
9:15 am @ lecture hall, Härtelstraße 16/18, 04107 Leipzig
Prof. Bernd Reif
Solid state NMR spectroscopy, Faculty of Chemistry, Technical University of Munich
"Aggregation kinetics and amyloid fibril structure probed by solution and MAS solid-state NMR spectroscopy"
Abstract:
Systemic antibody light chains (AL) amyloidosis is characterized by deposition of amyloid fibrils derived from a particular antibody light chain.
In this talk, I will show solution and MAS solid-state NMR experiments to characterize the aggregation of a particular patient protein. The focus is put on a human protein sequence for which adipose and heart tissue material is available from a patient. It is shown that ex vivo material allows to reproduce the amyloid fibril structure in vitro by employing a seeding procedure. MAS solid-state NMR experiments yield information on the conformation of the amyloidogenic core and allow to probe interactions with small molecules that potentially interfere with the aggregation process.
It has been shown that soluble oligomeric protein has a direct cytotoxic effect on cardiomyocytes prior to protein aggregation and organ malfunction. Removal of circulating pathogenic light chains by chemotherapy yields a drastic reduction of the concentration of biomarkers reporting on cardiac dysfunction. Using solution-state NMR spectroscopy, we follow the individual steps involved in protein misfolding at atomic resolution. We show that the natively folded protein first partially unfolds, before it converts into a high molecular weight molten globule like structure. Oligomer formation implies high local concentrations of aggregation prone regions which catalyze the subsequent conversion into amyloid fibrils. We show that the topology of the aggregated state is determined by balanced electrostatic interactions in the core of the fibril, resulting in an anti-parallel arrangement of the beta-sheets around the conserved disulfide bond.
Tue, 31.05.2022 - Special Event online
4.15 pm (online)
Dr. Rufina Alamo
FAMU-FSU College of Engineering, Department of Chemical and Biomedical Engineering, Florida State University in Tallahassee, USA
Crystallization of Precision Polyethylene-Like Materials
Abstract:
Recent studies of polymorphism, melting behavior and crystallization kinetics of polyethylenes with moieties placed at an exact equal distance along the backbone will be presented with especial focus on the crystalline properties of precision polyethylenes with halogens, acetals and esters under rapid and isothermal crystallization from the melt. All display unusual discrete inversions in the temperature coefficient of the crystallization kinetics which correlate with transitions between crystalline structures differing in packing symmetry (polymorphs), or in a step-increase in crystal thickness. The origin of the rate minima will be discussed.
Meeting No: 932 2177 9598
Passcode: 547489
Fri, 20.5.2022 - Special Event!
10:15 am in seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
We try to offer the hybrid option, but cannot guarantee it!
Prof. Toshio Tada
Center for Tire Research , An NSF Industry/University Research Center
Influence of Constrained Tensile Deformation on Cavitation of Rubber Vulcanizates
Abstract
Durability of rubber compounds, such as crack resistance, is one of the essential characteristics required to tires, for sake of safety. Mechanism underlying crack propagation of rubber vulcanizates is explored in terms of void formation and growth in the rubber matrix. Extensive X-ray and dilatometry analysis revealed that the rubber matrix at the crack tip undergoes “multi-axial” constrained tensile deformation, causing the void formation.
Meeting No: 932 2177 9598
Passcode: 547489
Tue, 17.05.2022
4:15 pm in seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Christian W. Pester
Department of Chemical Engineering, Department of Chemistry, Department of Materials Science and Engineering, The Pennsylvania State University, USA
"Design of Advanced Functional Surfaces using Oxygen-tolerant Photopolymerization"
Abstract:
The covalent attachment of polymers has emerged as a powerful strategy for the preparation of multi-functional surfaces. This presentation highlights our work on surface-initiated photoinduced electron/energy transfer (PET) reversible addition–fragmentation chain transfer (RAFT) polymerization. Oxygen tolerance, mild reaction conditions, and the use of visible light make this approach user-friendly in its application for the design of patterned and functional organic thin films.
Tue, 07.12.2021
17:15 pm @ lecture hall 1.26 Von-Seckendorff-Platz 1, 06120 Halle
Prof. Ann-Christin Pöppler
Institute of Org. Chemistry, University of Würzburg
Felix-Bloch-Vorlesung der GDCh:
"Taking up the chase with NMR Spectroscopy - From structural insights into solid drug-polymer formulations to their fate in biorelevant media."
Abstract:
Despite the large number of publications related to drug delivery, recent (critical) comments identified a gap between academic research and benefit to the patient requiring multidisciplinary joint efforts. Through solid-state NMR spectroscopy complemented by quantum chemical calculations, insight into the conformation of guests within copolymer micelles and key intermolecular interactions can be gained. This information enables to hypothesize loading mechanisms, explain pharmaceutically relevant dissolution rates, and derive ideas for improved polymeric carrier materials. [...]
Details
Pöppler_07122021.pdf
(494.7 KB) vom 08.11.2021
Tue, 30.11.2021
17:15 pm @ lecture hall 1.26 Von-Seckendorff-Platz 1, 06120 Halle
Prof. Christian Wischke
Institute of Pharmacy, Martin Luther University Halle-Wittenberg
Structuring polymers to create multifunctional drug carriers
Abstract:
Distinct structures of polymers created on the macroscopic, morphological and molecular levels are considered as a tool to implement functions in polymeric materials, i.e. an ability of the system to show a desired effect in a specific environment. Of particular interest is the link between such polymeric structures and drug release features of polymeric carrier systems as well as their fate in a biological setting. In this talk, a number of approaches will be presented for particulate carriers and implant systems, in which structures on different hierarchical levels have contributed to the respective functions of interest.
Tue, 16.11.2021
17:15 pm @ lecture hall 1.26 Von-Seckendorff-Platz 1, 06120 Halle
Prof. Eva M. Herzig
Department of Physics, Bayreuth University
Characterizing the effect of external parameters and processing on the nanostructure of functional thin films
Abstract:
Structure formation mechanisms and structural changes in thin films due to external parameters can be revealed using time-resolved x-ray scattering. Since scattering techniques rely on the long range order within the sample, it can be very valuable to accompany such x-ray measurements with additional complementary characterization methods like time-resolved spectroscopy or optical microscopy.
Using examples from organic photovoltaics and hybrid perovskite solar cells, I will show our recent work on processing effects on nanostructure formation and related challenges to their characterization.
Tue, 26.01.2021 (Webinar)
5:15 pm
Prof. Dr. Yael Politi
TU Dresden, Germany
Chitin fibre orientation in arthropod cuticle - how is it controlled and what for?
Abstract
Chitin fiber orientation in the arthropod cuticle is regulated locally by the animal. Typically parallel fiber organisation and rotated ply wood structures are commonly observed fibre arrangement microstructures. The orientation of fibers in the cuticle has direct impact for its physical properties, e.g. mechanical and optical properties. In the talk I will describe a few examples demonstrating the impact of fiber orientation on the cuticle properties, and address the question of how it is achieved by the organisms.
Tue, 19.01.2021 (Webinar)
5:15 pm
Prof. Dr. Pierre Lutz
University of Strasbourg, France
From Isotactic Polystyrene (iPS) or Poly(p-methyl styrene) (ipPMS) to Semicrystalline iPS / POSS Hybrid Materials
Abstract:
Nanostructured organic-inorganic hybrid materials are attractive families of structural and functional polymers with designed architectures and tailor-made property profiles. Hybrid molecules combine the good properties of ceramics, like mechanical reinforcement, flame retardancy and thermal stability, with easy processability of organic polymers. Functionalized nanosiliactes and silicate nanomolecules have attracted considerable attention in materials sciences because of their very high versatility with respect to molecular design of hybrid nanoparticles and unprecedented property combinations. Semicrystalline isotactic polystyrene (iPS) and syndiotactic polystyrene (sPS) are specialty engineering plastics which exhibit improved stiffness and higher dimensional stability as compared to atactic PS. Contrary to sPS, iPS does not crystallize during polymerization and stays soluble. However during melt-compounding or by annealing iPS crystallizes. [...]
Details
Lutz_19012021.pdf
(540.9 KB) vom 09.12.2020
Tue, 15.12.2020 (Webinar)
5:15 pm
Anatoli Serghei
University Claude Bernard Lyon, France
Crystallization of nano-confined materials down to the scale of attograms and zeptograms: the impact of flow and high electric fields
The crystallization of nano-confined polymers leads to nano-materials exhibiting
physical properties different from the bulk. This is due to finite size effects, to
molecular interactions caused by the presence of interfaces as well as to orientation effects imposed by the symmetry of the confining geometry. The nano-confinement can be thus used to induce physical properties not naturally available in the bulk. Overcoming the interactions that lead to substantial changes in the properties of nano-confined materials would open the possibility of “manipulating” confinementeffects, with the perspective of inducing new material properties different from those in the bulk and in nano-confinement. In the present contribution, recent experimental developments that allow one to investigate the impact of the flow process into nanopores on the crystallization of nano-confined polymers as well as the crystallization behaviour of attograms and zeptograms of matter (1 attogram = 1E-18 grams, 1 zeptogram = 1E-21 grams) under high electric fields (1E5 V/cm) are presented. A significant difference between crystallization under static confinement and crystallization under flow in nano-confinement is reported. It is also shown that crystallization of attograms and zeptograms of matter under high electric fields leads to properties that are different from those measured in nano-confinement. Our results bring evidence for the ability of manipulating nano-confinement effects by flow or by applying high electric fields.
Tue, 07.07.2020 (Webinar)
5:15 pm
Prof. Klaus Schmidt-Rohr
Brandeis University, Waltham, Massachusetts, USA
Chain Ends at Polymer Crystallite Surfaces
Abstract:
The principle of avoidance of density anomalies in semicrystalline polymers predicts that chains will preferably end at the crystallite surface. For polyethylene, polyoxymethylene, and (partially) poly(e-caprolactone), this prediction has been confirmed by NMR experiments that probe the chain-end conformation, immobilization, localization at the crystallite surface, and clustering in the surface layer, by means of conformation-dependent chemical shifts, absence of significant motional narrowing, 1H spin diffusion and 13C spin exchange, respectively. Chain-end diffusion is also restricted.
Tue, 30.06.2020 (Webinar)
5:15 pm
Prof. Zvonimir Dogic
UC Santa Barbara, USA
Topological defects in three-dimensional active nematics
Abstract:
Two-dimensional active nematic liquid crystals generate mesoscopic active stresses that render the entire system unstable. For extensile nematics, slight bend distortions of the director field create hydrodynamic flows that further deform the director field. Upon saturating, these distortions produce pairs of motile point-like topological defects that drive large-scale turbulent-like dynamics. Such defect driven dynamics has been observed in diverse systems ranging from shaken granular rods and reconstituted cytoskeletal components to swimming bacteria and dense tissues composed of anisotropic cells. In comparison to extensively studied 2D systems, very little is known about the dynamics of three-dimensional active nematics. We describe novel methods for assembling 3D active nematic liquid crystals and our ongoing efforts to characterize both the structure and dynamics of the string-like topological defects found in these highly dynamical materials. Our results illustrate how active matter can serve as a platform for testing theoretical models of non-equilibrium statistical mechanics, developing a new class of soft machines and potentially even shedding light on self-organization processes occurring in living cells.
Tue, 04.02.2020
17:15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Dr. Fritz Keilmann
Faculty of Physics, Soft Condensed Matter Group, Ludwig-Maximilians-Universität, München
Infrared near-field microscopy
Abstract:
Infrared illumination of an AFM tip can produce infrared images ontop of topography at, surprisingly, identical super-resolution of 20 nm. In my talk I explain how and why this is possible (hint: surface waves), and describe applications.
The technique called scattering-type optical near-field microscopy (s-SNOM) enables quantitative chemical recognition of nanoscale inhomogeneities, e.g., during insulator-metal phase transitions, in polymer mixtures, or in cometary matter. It has allowed to study the nanoscale architecture of biominerals and, recently, electron correlation on twisted bilayer graphene even at LHe temperature.
Details
Keilmann_04022020.pdf
(479.2 KB) vom 10.01.2020
Tue, 28.01.2020
17:15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Dr. Andreas Lauenroth
Gründerservice, Martin-Luther-Universität Halle-Wittenberg
"Why, what, how? - Knowledge transfer and startups at MLU"
Abstract:
Which idea is a good idea? What is a proper business model? How to deal with intellectual property? Where to apply for funding?
Those and other questions should be answered by scientists interested in technology transfer - but not just on their own. Martin Luther University’s transfer and entrepreneurship office provides information, training and services to scientists, covering all aspects of research valorisation and technology transfer, including validation, legal protection and marketing of technology and inventions, engaging in research relationships with industry, and the creation of business cases for entrepreneurial spin-out activities.
Details
Lauenroth_28012020.pdf
(465.4 KB) vom 17.12.2019
Tue, 07.01.2020
17:15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Kay Saalwächter
Institut für Physik, Naturwissenschaftliche Fakultät II, Martin-Luther-Universität Halle-Wittenberg
"Molecular view on polymers adsorbed on nanoparticle surfaces"
Abstract:
The outstanding performance of modern elastomers is dominated by the reinforcement arising from nanometric fillers. The compounds’ peculiar thermo-mechanical properties cannot be explained without consideration of an interphase, i.e., a region of polymer with modified properties. Previous results support a consensus picture of adsorbed components with locally increased Tg and gradient zone of a few nm. This talk focuses on more recent results, mostly obtained by proton low-resolution NMR as a probe of the segmental dynamics, that challenge the generality of this picture. [...]
Details
Saalwächter_PMS_07012020.pdf
(496 KB) vom 19.12.2019
Tue, 17.12.2019
17:15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Dr. Ulrich Wiesner
Materials Science & Engineering Department, Cornell University, Ithaca, USA
"Structure formation and function via molecules at organic-inorganic nanomaterial interfaces"
Abstract:
Interfaces play a crucial role both in fundamental structure formation processes as well as function and properties of organic-inorganic composite nanomaterials. This talk will provide an overview of the chemistry and physics of such functional nanohybrids based on organic molecule self-assembly phenomena of low molar mass surfactants as well as macromolecular block copolymers. [...]
Details
Wiesner_17122019.pdf
(539.2 KB) vom 15.08.2019
Tue, 03.12.2019
17:15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Dr. Michael Vogel
Institut für Festkörperphysik, Technische Universität Darmstadt
"From local to diffusive dynamics in ionic liquids and polymer electrolytes: NMR studies across time and length scales"
Abstract:
The properties of liquid mixtures crucially depend on dynamical couplings of the components on various time and length scales. We exploit the capabilities of multi-nuclear and multi-method NMR approaches to investigate this interplay for two classes of materials with high technological relevance: ionic liquids and polymer electrolytes. [...]
Details
Vogel_031219.pdf
(467.6 KB) vom 15.10.2019
Tue, 19.11.2019
17:15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Dr. Pol Besenius
ohannes Gutenberg-University Mainz, Institute of Organic Chemistry, Mainz, Germany
"Multidomain Peptide Assemblies for the Design of Thermoresponsive
Supramolecular Materials"
Abstract:
Spatial and temporal control are critical properties to advance and optimize functional macromolecular materials in order to mimic key features of living systems. In my lecture, I will discuss our methodology in developing non-equilibrium states in thermoresponsive hydrogels using peptide-polymer conjugates. [...]
Details
Besenius_1911019.pdf
(1.4 MB) vom 05.11.2019
Tue, 05.11.2019
17:15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Dr. Stefan Mecking
Chemical Materials Science, Department of Chemistry, University of Konstanz, Germany
"Materials based on confined and polyethylene-like crystallization"
Abstract:
Advanced catalytic methods provide unconventional polyethylenes, like disentangled UHMWPE or plant-oil based polyethylene-like polymers with dilute main-chain functional groups. These are of interest to achieve desirable materials properties, including a non-persistent nature.
Details
Mecking_0511019.pdf
(466.2 KB) vom 05.07.2019
Tue, 29.10.2019
17:15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Dr. Ralph Colby
Department of Materials Science and Engineering, Pennsylvania State University, USA
“Liquid Crystal Mesophases in Conjugated Polymers for Flexible Electronics"
Abstract:
A correlation of glass transition temperature with the molecular structure of conjugated polymers is presented that enables prediction of the structures needed to keep Tg well below ambient temperature for flexible electronics. Many of the highest mobility polymers have interesting LC mesophases that may enable more pi-stacking for superior intermolecular transport. [...]
Details
Colby_29102019.pdf
(468.4 KB) vom 20.05.2019
Mon, 14.10.2019 - Special event!
17:15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Dr. Shi-Qing Wang
Department of Polymer Science, University of Akron, USA
“Ductility of glassy semicrystalline polymers"
Abstract:
Commodity polymers, the very majority of all polymer productions, are a key class of modern materials, due to their high specific strength. Thus, it is a central task in polymer science and engineering to study how to acquire adequate mechanical properties and improve the mechanical performance. As strong solid materials, polymers need to be either glassy or crystalline with a significant level of crystallinity. [...]
Details
Wang_14102019.pdf
(471.5 KB) vom 19.08.2019
Tue, 02.07.2019
17:15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Dr. Kostas Daoulas
Max Planck Institute for Polymer Research, Mainz
“Investigating partially-ordered mesophases of semiconducting polymers with mesoscopic models"
Abstract:
The rich phase behavior of soluble semiconducting polymers makes them interesting for basic polymer physics, allowing one to access partially-ordered states ─ microstructures located on the order-disorder scale between the two extremities set by (poly)crystalline and amorphous morphologies. Studying microstructures with varying degree of order can facilitate, e.g. understanding of polymer crystallization phenomena. [...]
Details
Daoulas_02072019.pdf
(502 KB) vom 06.05.2019
Tue, 21.05.2019
17:15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Viktor Ivanov
Institut für Physik, Naturwissenschaftliche Fakultät II,
Martin-Luther-Universtität Halle-Wittenberg
“Phase behavior of semiflexible polymers: Monte Carlo computer simulation"
Abstract:
In this talk, I will give an overview about research in my group on phase behavior of semiflexible polymers. First, I will consider pseudo-phase diagrams of single semiflexible homopolymer chains and flexible-semiflexible copolymer chains, both in the bulk solution and at an adsorbing surface. [...]
Details
Ivanov_21052019.pdf
(467.2 KB) vom 11.04.2019
Tue, 07.05.2019
17:15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Kazuya Saito
Department of Chemistry, Faculty of Pure and Applied Science, University of Tsukuba, Tsukuba, Japan
"Quasi-Binary Picture of Thermotropics: Experimental Basis and Its Outcomes"
Abstract:
Molecules of most thermotropic liquid crystals are not highly anisotropic as widely assumed but consist of hard core and flexible alkyl chain(s). We discuss the effect of this molecular structure on the understanding of thermotropic liquid crystals. Through analyzing the entropy of transitions, the molten state of chains comparable to n-alkanes is established in any liquid crystalline phases. [...]
Details
Saito_07052019.pdf
(468.3 KB) vom 25.04.2019
Tue, 30.04.2019
17:15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Dr. Mark P. Taylor
Department of Physics, Hiram College, USA
"Folding of a model biopolymer in a crowded environment"
Abstract:
At the molecular level, biological systems operate in very crowded solution environments. It has long been recognized that this crowding can affect the conformational stability and phase transitions of the biopolymers comprising such systems. Similar issues must be addressed in developing biotechnology applications based of dense arrays of surface-tethered polymers. [...]
Details
Taylor_30042019.pdf
(473.7 KB) vom 22.03.2019
Tue, 16.04.2019
17:15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Jutta Luettmer-Strathmann
Departments of Physics and Chemistry, University of Akron, Ohio, USA
“Configurational contribution to the Soret effect of proteins and ligands - An investigation with density-of-states simulations"
Abstract:
Many of the biological functions of proteins are closely associated with their ability to bind ligands and change conformations in response to changing conditions. Since binding state and conformation of a protein affect its response to a temperature gradient, they may be probed with thermophoresis. In recent years, thermophoretic techniques to investigate biomolecular interactions, quantify ligand binding, and probe conformational changes have become established. [...]
Details
Luettmer-Strathmann_16042019.pdf
(468.4 KB) vom 21.03.2019
Tue, 19.02.2019
17:15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Guilhem Baeza
Institut National des Sciences Appliquées de Lyon, France
“Isostructural Softening of the Filler Network in SBR/Silica Nanocomposites"
Abstract:
A new formulation of the widely used nanocomposites based on SBR and fractal silica fillers is proposed by substituting the usual covering and coupling agents with short chains (4 kg.mol-1) of polypropylene glycol (PPG) oligomers. We study in a systematic way the structural evolution as well as the changes in linear and non-linear mechanical properties of two series of samples varying: (i) the silica volume fraction in PPG-free samples, and (ii) the amount of PPG for a given silica content of 15 vol.%. [...]
Details
Baeza_PMS_19_19_2019.pdf
(472.7 KB) vom 04.02.2019
Tue, 08.01.2019
17:15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Kay Saalwächter
Institut für Physik, Naturwissenschaftliche Fakultät II,
Martin-Luther-Universtität Halle-Wittenberg, Halle (Saale)
“Polymer materials: more than just plastics"
Abstract:
With packaging applications being the most tangible and often debated ones, materials based upon synthetic polymers are found virtually anywhere around us - with properties and uses that could not vary more widely. This presentation, aimed in particular at early-stage students, gives some account of the long history of polymer development and use, focusing on an introduction into the main classes of polymer materials. Some specific developments, which sometimes ran parallel in Europe and the US, and took place despite of as well as because of the upheavals in the first half of the 20th century, will be highlighted.
Details
Saalwächter_PMS_08012019.pdf
(143.4 KB) vom 23.10.2018
Tue, 18.12.2018
17:15 pm @ seminar room 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
Tue, 4.12.2018
17:15 pm @ seminar room 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.
Details
Saalwächter_PMS_04122018.pdf
(486.7 KB) vom 06.11.2018
Tue, 06.11.2018
17:15 pm @ seminar room 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.
Details
Ollila_PMS_6_11_2018.pdf
(143.1 KB) vom 09.10.2018
Tue, 30.10.2018
17:15 pm @ seminar room 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
Tue, 23.10.2018
17:15 pm @ seminar room 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
Mon, 22.10.2018 - Special event!
17:15 pm @ seminar room 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
Wed, 17.10.2018 - Special event!
17:15 pm @ seminar room 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
Wed, 11.07.2018 - Special event
17:15 pm @ seminar room 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
Tue, 26.06.2018
17:15 pm @ seminar room 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
Tue, 29.05.2018
5.15 pm @ seminar room 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....
Details
Heinze_PMS_29_05_2018.pdf
(144.6 KB) vom 08.05.2018
Tue, 08.05.2018
5.15 pm @ seminar room 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
Tue, 24.4.2018
5.15 pm @ seminar room 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
Tue, 30.01.2018
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Dr. Ana Brás
Universtity of Cologne, Faculty of Mathematics and Natural Sciences, Department of Chemistry, Cologne, Germany
“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
Tue, 19.12.2017
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Dr. Rupert Schnell
Polymerscience (Technology and Innovation) , Sabic, Bergen, Netherlands
Aging of Polycarbonate - Linking material science to real world problems
Abstract:
Polycarbonate is an extremely versatile material whenever toughness and transparency are required. Toughness of PC may deteriorate under thermal and chemical treatment. Thermal influence on PC is summarized as “aging”. After more than 60 years of commercial, use PC aging is still a subject of academic research and causing problems in application. Some examples of interesting PC performance, highlights in science and challenging applications will be shown.
Details
Rupert Schnell_PSM_19.12.2017.pdf
(143.4 KB) vom 15.12.2017
Tue, 05.12.2017
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Dr. Georg Fytas
Institute of Electronic Structure and Laser, Foundation for Research and Technology - Hellas, Heraklion, Greece
"Controlling phonon propagation in architected soft matter"
Abstract:
Phononic crystals, i.e. composite materials in which a periodic distribution of elastic parameters facilitates control of the propagation of phonons, hold the promise to enable transformative material technologies in areas ranging from acoustic and thermal cloaking to thermoelectric devices. Realizing these opportunities requires strategies to deliberately ‘engineer’ the phononic band structure of materials in the frequency range of interest. ...
Details
Fytas_PSM_05.12.2017.pdf
(171.8 KB) vom 08.11.2017
Tue, 28.11.2017
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Dr. Pieter Magusin
University of Cambridge, Institute of Chemistry, Cambridge, UK
"Ex Situ and In Situ NMR of Battery Materials"
Abstract:
Our group investigates novel electrode materials for lithium, sodium and magnesium ion batteries, and the solid electrolyte interface (SEI) formed on the anodes. Both ex situ and in situ NMR methods are employed, and it is the conjunction of these two approaches which yields the most useful and relevant information. ...
Details
Magusin_PSM_28.11.2017.pdf
(149.8 KB) vom 15.11.2017
Tue. 21.11.2017
Prof. Dr. Andreas Schönhals
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Deutschland
"Structure-Property Relationships of Nanocomposite based on Polylactide and Layered Double Hydroxides as Nanofiller"
Abstract:
Polymer-based nanocomposites attracted recently a lot of attention from both the applicative and fundamental point of research. While the former point of view is due to the properties improvement compared to the corresponding matrix polymers the latter aspect is related to interaction of polymers with solid surfaces and confinement effects...
Details
Schönhals_PSM_21.11.2017.pdf
(146.1 KB) vom 18.09.2017
Tue, 24.10.2017
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Dr. Felix Scheliga
University of Hamburg, Chemistry Department, Hamburg, Germany
Polymer Characterization by Size Exclusion Chromatography: Manufacture and Applications
Abstract:
Since the early 1960´s SEC has become the most important tool for polymer characterization. Nowadays the molecular weight distribution of almost any dissolvable polymer can be obtained in a few minutes, whereas this task would have taken weeks or months before appropriate SEC columns were available.
Even though SEC has become a commonplace method, little is known about the how these SEC-materials are made. This talk is supposed to provide an overview on the manufacture of SEC gels and the various products on the market.
Details
Felix Scheliga_PSM_24.10.2017.pdf
(143.6 KB) vom 17.10.2017
Special event:
Thu, 26.10.2017
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Dr. Kerstin Blank
Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
"Molecular Force Sensors: from molecular mechanisms towards applications in biology and materials science"
Abstract
Biological systems are highly sophisticated smart materials. They are stimuli-responsive and possess impressive self-reporting and self-healing properties. They are consequently an important source of inspiration for materials scientists who aim to implement these properties in synthetic and biomimetic materials. In this context, we are specifically interested in (bio)molecules that act as molecular force sensors...
Details
Blank_PSM_27.10.2017.pdf
(145.7 KB) vom 18.09.2017
Tue, 17.10.2017
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Dr. David M. Smith
Fraunhofer Institute for Cell Therapy and Immunology, DNA Nanodevices group, Leipzig, Germany
“Bottom-up Engineering of Nanoscale Devices to Program Macroscopic Material Properties"
Abstract
Biological materials are often used as inspiration in the design of new synthetic or bio-hybrid materials; however, the molecular toolbox provided by biological systems has been evolutionarily optimized to carry out the necessary functions of cells. The resulting inability to systematically modify fundamental properties such as polymer stiffness or the association strength of crosslinking proteins in experimentally available model systems hinders a meticulous examination of the connection between molecular parameter space and resulting properties of bulk assemblies. We circumvent these limitations using model systems based on synthetically produced building blocks such as DNA strands and peptides, which are programmable on the molecular scale.
In one example, micrometer-long nanotubes with tunable diameters and rigidity can be constructed from small sets of short, DNA oligonucleotides. By systematically varying the set of DNA strands of these synthetic, semiflexible filaments, their micron-scale persistence length (Lp) can be precisely tuned. [...]
Details
Smith_PSM_17_10_2017.pdf
(111.7 KB) vom 06.10.2017
12.07.17
2.15 pm @ seminar room 1.26 Von-Seckendorff-Platz 1, 06120 Halle
Prof. Dr. Mark P. Taylor
Dept. of Physics, Hiram College, USA
Polymer folding in confined and crowded environments"
Abstract:
A flexible homopolymer chain with sufficiently short-range interactions undergoes a first-order-like transition from an expanded coil to a compact crystallite. We have recently shown that this very simple model illustrates the underlying polymer physics leading to the distinct all-or-none folding thermodynamics characterizing many small proteins [1]. Here we investigate this polymer folding transition under geometric confinement and in the presence of macromolecular crowders...
Details
MP Taylor 12.07.2017.pdf
(232.9 KB) vom 05.07.2017
04.07.17
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Dr. Jutta Luettmer-Strathmann
University of Akron, Ohio, USA
“Investigation of sexithiophene properties with Monte Carlo simulations of a coarse-grained model"
Abstract:
Thiophenes have important applications in organic electronics, energy conversion, and storage. In this study, we focus on α-sexithiophene (α-6T), a small, π-conjugated molecule whose visible light absorption and high charge carrier mobility make it interesting for applications....
Details
Luettmer-Strathmann_PSM_04.07.2017.pdf
(190.4 KB) vom 23.05.2017
30.05.17
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Dr. Sabine Beuermann
Clausthal University of Technology, Institute of Technical Chemistry, Germany
“Inducing β phase crystallinity in poly(vinylidene fluoride) via synthetic strategies or nanoparticle formation"
Abstract:
Poly(vinylidene fluoride) (PVDF) shows 5 crystalline phases, with the β phase being associated with piezo, pyro- and ferroelectric properties. Since synthesis and processing of PVDF generally yields the α phase, special treatment is required to yield β phase material...
Details
Beuermann_PSM_30.05.2017.pdf
(256.5 KB) vom 23.05.2017
02.05.17
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Dr. Martin Brehm
Martin-Luther-Universität Halle-Wittenberg, Halle, Deutschland
“The Balance of Interactions in Ionic Liquids"
Abstract:
As a newly emerging class of solvents with many promising properties, ionic liquids have received considerable attention during the last decade. These compounds can exhibit a certain degree of long-range ordering, or even microphase separation, despite of being liquids, which typically possess only local order....
Details
Brehm_PSM_02.05.2017.pdf
(128.5 KB) vom 18.04.2017
31.01.17
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. René Androsch
Institut für Polymerwerkstoffe e.V., An-Institut an der Hochschule Merseburg
“About the a'/a-crystal polymorphism of poly (L-lactic acid) (PLLA)”
Abstract:
Crystallization of the PLLA melt at temperatures higher than about 120 °C leads to formation of orthorhombic a-crystals while at lower temperatures, close to the glass transition, growth of pseudohexagonal, conformational disordered a’-crystals is favored. The a’-form is metastable...
Details
Androsch_PSM_31012017.pdf
(344.2 KB) vom 04.11.2016
24.01.17
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Sabine Ludwigs
Universität Stuttgart, Institut für Polymerchemie (IPOC), Lehrstuhl für Struktur und Eigenschaften polymerer Materialien
“Manipulation of Polymer Thin Films for Polymer Electronics & Electrochemical Devices”
Abstract:
The talk will give an overview about current activities of my research group on thin film manipulation of conjugated polymers. Recent research highlights include the tuning of aggregation of n-type semiconducting polymers via regioisomer control and the identification ...
Details
Ludwigs_PSM_24012017.pdf
(231.2 KB) vom 04.11.2016
17.01.17
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Dr. habil. Costantino Creton
Soft Matter Science and Engineering Laboratory of the ESPCI ParisTech, France
“Mechanics of interpenetrated polymer networks”
Abstract:
We have been studying for a few years the mechanics of interpenetrated networks polymerized sequentially by swelling and polymerization steps. This strategy introduces a proportion of chains inside the material that are prestretched. When such materials are deformed the molecular strain becomes quite different from the macroscopic strain giving very interesting non-linear elastic properties and a 100 times higher fracture toughness. We will discuss how to optimize such properties and what are the molecular mechanisms leading to them.
Details
Creton_PSM_17.01.2017.pdf
(230.1 KB) vom 17.11.2016
06.12.16
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Dr. Tiago Ferreira
Martin-Luther-University Halle-Wittenberg, Halle, Germany
“Molecular structure and dynamics in lipid bilayers from solid-state NMR experiments and MD simulations”
Abstract:
Lipid bilayers are essential constituents of living cells enabling cell compartmentalization and affecting membrane protein function. It is therefore important to understand how the molecular structure and dynamics of simple lipid bilayer models are affected by a number of factors,...
Details
Ferreira_PSM_06122016.pdf
(230.7 KB) vom 04.11.2016
29.11.16
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Alejandro J. Müller
University of the Basque Country, San Sebastian, Spanien
“The influence of chain topology on the crystallization of polycaprolactones (PCLs): cyclic versus linear chains"
Abstract:
Narrow polydispersity cyclic PCL samples (C-PCLs) were prepared by means of controlled click chemistry techniques in the group of Scott Garyson at Tulane University (USA). Linear PCL counterparts (L-PCLs) of almost identical molecular weights were also obtained in a Mn range spanning 2 to 22 kg/mol. The samples were studied by Differential Scanning Calorimetry (DSC), Transmission Electron Microscopy (TEM) and Polarized Light Optical Microscopy (PLOM)...
Details
Müller_PSM_29112016.pdf
(243.7 KB) vom 04.11.2016
15.11.16
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Manfred Klueppel
Deutsches Institut für Kautschuktechnologie e. V., Hannover, Germany
“Flocculation Dynamics and Reinforcement of Elastomer Nanocomposites with Conductive Fillers: A Combined Rheological and Dielectric Analysis”
Abstract:
The flocculation dynamics of carbon black filled elastomer melts is investigated by dielectric relaxation spectroscopy in the frequency range from 0.1 Hz up to 10 MHz during oszillatory shearing in a plate-plate rheometer [1]. It is demonstrated that during heat treatment at low strain amplitude, a pronounced flocculation of filler particles takes place leading to a successive increase of the shear modulus and dc-conductivity...
Details
Klüppel_PSM_15112016.pdf
(285.7 KB) vom 04.11.2016
25.10.16
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. George Rose
Johns Hopkins University, Baltimore, USA
“Protein folding: non-specific interactions promote highly specific chain organization”
Abstract:
Under suitable conditions, globular proteins can self-assemble spontaneously and reliably. An effective thermodynamic description of this folding reaction was established half a century ago, but a mechanistic understanding is still lacking. This open question has been dubbed "the protein folding problem"....
Details
Rose_PSM_25102016.pdf
(95.7 KB) vom 19.10.2016
18.10.16
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Dr. Angel Moreno
University of the Basque Country, San Sebastian, Spanien
“Single-Chain Polymer Nanoparticles: Models for Intrinsically Disordered Proteins and Soft Colloids"
Abstract:
Single chain nanoparticles (SCNPs) are an emergent and promising class of synthetic nano-objects. By means of large-scale computer simulations and small-angle neutron scattering, we design and investigate different synthesis routes, leading to SCNPs with specific structures and different properties in solution. On one hand the analysis of the conformations of SCNPs synthesized in good solvent reveals that they share basic ingredients with intrinsically disordered proteins (IDPs),…
Details
Moreno_PSM_18102016.pdf
(190.2 KB) vom 19.10.2016
20.06.16
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Dr. David J. Jones
School of Chemistry, Bio21 Institute, University of Melbourne, Melbourne, Australia
“SIDE-CHAIN ENGINEERING IN HIGH PERFORMANCE P-TYPE ORGANIC SEMICONDUCTORS FOR PRINTED OPV”
Abstract:
The Victorian Organic Solar Cell Consortium (VICOSC) has had a two-pronged approach to the development of printed OPV. One arm has focused on the scale-up of the printing process, translating laboratory-based process to commercially relevant systems. This work has used commercial materials and off the shelf printers, where available, to develop a materials agnostic printing process.[1] New materials, with suitable properties, can be “dropped-into” the program. A parallel program has developed new materials via a rigorous stage-gated process resulting in high performance n- and p-type organic semiconductors for our use. We are interested in the impact of chromophore side chains on materials performance...
Details
Jones_PSM_0200616.pdf
(218.4 KB) vom 20.05.2016
05.04.16
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Dr. Oleksandr Dolynchuk
Leibniz-Institute of Polymer Research Dresden, Insitute Theory of Polymers
“Invertible shape-memory effect in linear polyethylene and poly(ε-caprolactone)”
Abstract:
The experimental and theoretical investigation of invertible shape-memory (SM) effect in crystallizable covalent networks is in focus due to fundamental interest of underlying molecular mechanisms and various applications of SM polymers as sensors and actuators. This work studies the invertible SM behavior of crosslinked high-density polyethylene (HDPE) and poly(ε-caprolactone) (PCL)...
Details
Dolynchuk_PSM_050416.pdf
(248.6 KB) vom 31.03.2016
26.01.16
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Lillian Chong
University of Pittsburgh, Department of Chemistry
“Enhanced Sampling of Pathways and Kinetics of Rare Events using Weighted Ensembles of Trajectories”
Abstract:
The weighted ensemble (WE) path sampling strategy orchestrates quasi-independent parallel simulations that are run with intermittent communication to enhance sampling of rare events such as protein conformational changes, folding, and binding. Trajectories are pruned or replicated in a way that encourages sampling of under-explored regions without biasing the dynamics. I will present recent advances in both WE methodology and software along with applications to protein folding and binding processes in the generation of pathways, free energy landscapes, and rate constants.
Details
Chong_PSM_26012016.pdf
(119.2 KB) vom 10.11.2015
19.01.16
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Alexander Wittemann
University of Konstanz
“From nanoparticles towards “colloidal molecules” and partially beyond.”
Abstract:
The rational design of complex functional colloids from nanoscale building blocks is of significance to practical applications including sensing, photonic, and electronic devices, but it is also becoming a source of inspiration of materials scientists and engineers to create the next-generation of hierarchically organized materials. ...
Details
Wittemann_PSM_19012016.pdf
(120.2 KB) vom 10.11.2015
01.12.15
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Dr. Michael Sommer
Uni Freiburg, Institut für Makromolekulare Chemie
“Conjugated and responsive polymers: defect structures, new syntheses and high performance materials”
Abstract:
My group focuses on the development of new materials for use in opto-electronic devices as well as for sensing applications. Suitable candidates of high performance conjugated polymers have been identified as active materials for a variety of thin film devices including photovoltaic cells, field-effect transistors, light emitting diodes, batteries or supercapacitors. A major challenge that has moved into focus is the quest for simpler, greener and environmentally more benign synthesis routes while maintaining high performance, batch-to-batch reproducibility and control over molecular weight. In the first part of my talk, I will explore the scope and limitations of direct C-H activation polycondensation (DAP),...
Details
Sommer_PSM_01122015.pdf
(125 KB) vom 02.11.2015
24.11.15
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Birgit Strodel
(Computational Biochemistry Group ICS-6: Structural Biochemistry, Forschungzentrum Jülich)
“Thermodynamics and kinetics of amyloid aggregation from atomistic simulations”
Abstract:
A major cause for cellular toxicity involved in the onset of several neurodegenerative diseases is the aberrant aggregation of proteins into oligomers and eventually fibrils. In the case of Alzheimer's disease, the main aggregating protein is the amyloid β-protein with two main alloforms of 40 (Aβ40) and 42 (Aβ42) amino acids. Numerous experimental studies have shown that...
Details
Strodel_PSM_24112015.pdf
(161.1 KB) vom 10.11.2015
17.11.15
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Felix Schacher
Friedrich-Schiller-Universität Jena, Jena Center of Soft Matter
“Opportunities for Block Copolymers in Interface Design: Membranes and Hybrid Materials”
Abstract:
Block copolymers represent a unique class of building blocks for the generation of nanostructured materials in different environments – mainly driven by the inherent immiscibility of unlike segments. Our focus is put on materials which contain at least one segment which can be selectively addressed, either chemically (crosslinking, modification) or physically and how such materials can be used to "design" polymer-polymer interfaces in membrane materials or polymer-metal interfaces. In the latter case, especially core-shell hybrid materials are of interest, e.g. metal or metal oxide nanoparticles where suitable block copolymer ligands allow to control surface charge, charge density, or nature and amount of functional groups being present.
Details
Schacher_PSM_17112015.pdf
(181.7 KB) vom 24.08.2015
03.11.15
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Dr. Arnold Boersma
University of Groningen, Netherlands
"Quantification and consequences of macromolecular crowding”
Abstract:
Cells are highly crowded with proteins and polynucleotides, with concentrations ranging from 80 to 400 mg/mL. Knowledge of crowding is critical to understand cell physiology and to assess its relevance for medical science and biotechnology: Any reaction that depends on the available volume can be affected by crowding, which includes diffusion, conformation, association, folding, phase separation, and aggregation of the biopolymers....
Details
Boersma_PSM_03112015.pdf
(119.3 KB) vom 27.10.2015
27.10.15
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Dr. Ilja Gunkel
Soft Matter Physics Group, Adolphe Merkle Institute, Fribourg Switzerland
“In situ grazing-incidence small-angle X-ray scattering studies of block copolymer films during solvent vapor annealing”
Abstract:
The self-assembly of block copolymers is a powerful approach toward the fabrication of templates and scaffolds for nanostructured morphologies. Block copolymers in thin films are useful, for example, for the generation of masks for lithography applications....
Details
Gunkel_PSM_27102015.pdf
(90.6 KB) vom 16.10.2015
20.10.15
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Dr. Jörg Tiller
TU Dortmund, Lehrstuhl für Biomaterialien und Polymerwissenschaften
“Shape Memory Natural Rubber (SMNR) - A Smart Material”
Abstract:
Lowly cross-linked natural rubber forms crystals upon strain that are stable at room temperature and thus stabilize the stretched state until heat in the region of body temperature is applied. Thus, SMNR is so far the only cold programmable shape memory polymer. Since the crystals and the amorphous state can be altered in the stretched form, programmed SMNR is additionally reacting to environmental signals such as various chemical vapors, sensing and memorizing them, and reacting to those.
Details
Tiller_PSM_20102015.pdf
(89.9 KB) vom 24.08.2015
02.06.15
5.15 pm @ seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle
Prof. Ulrich H. E. Hansmann
Department of Chemistry and Biochemistry, University of Oklahoma, USA
“Simulation of Folding and Aggregation of Proteins”
Abstract:
A detailed knowledge of the processes by that proteins fold, self-assemble or aggregate is crucial for an understanding of disease pathways and the working of drugs at the level of cells. As these fundamental processes are difficult to trace in experiments, there is a need for reliable computational tools that complement experiments in studying folding and aggregation of proteins.
In this talk, I will describe some of the methods and techniques…
Details
Hansmann_PSM_02062015.pdf
(208.9 KB) vom 01.06.2015
Special Event 06.02.15
9.15 am @ seminar room 1.27 Von-Seckendorff-Platz 1, 06120 Halle
Dr. Dr. Clemens Liedel
Cornell University, Department of Materials Science and Engineering, Ithaca, USA
"Influences on the Structure Formation in Elec-tro-Responsive and Redox-Active Polymers"
Abstract:
While block copolymers can self-assemble into ordered structures with dimensions of up to a few micrometers, grains with different orientation prevent macroscopic ordering. Larger patterns are only accessible using external directing forces, for example patterned surfaces or electric fields. Additives like solvents or nanoparticles further influence the kinetics of structure formation and the kind and order of the formed morphologies….
Details
Liedel_PSM_06022015.pdf
(210.5 KB) vom 29.01.2015