Category: Polymer and Soft Matter Seminar

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. […]

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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.

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.

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.

Institute of Organic 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. […]

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4:15 pm in seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle

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.

10:15 am in seminar room 1.27 Von-Danckelmann-Platz 4, 06120 Halle

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.

15:00  (online)

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.

9:15 am @ lecture hall, Härtelstraße 16/18, 04107 Leipzig

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.

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.

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