Dean Vidakovic
Rubber-based paper roll covers are a multi-component system consisting of up to 20 components, which mostly have complex cross-implications. In the final application, the layers are built up in a two- or three-layer system. The topmost functional layer (superstructure) is of decisive importance for the final paper quality and experiences a multitude of influences from liquids over pressure towards friction and temperature.
To fulfil those manifold requirements, the complex multi-component system is systematically broken down, followed by a close look on chemical, structural and morphological peculiarities of the surface. For that, a variety of complementary microscopic and spectroscopic techniques, such as transmission electron microscopy (TEM), atomic force microscopy (AFM), electron energy loss spectroscopy (EELS), X-ray diffraction (XRD) and quantitative nanomechanical mapping (QNM) are applied. The correlation of all these methods makes it then possible to go beyond topography and, in particular, focus on the interface between different polymer phases (polar/nonpolar), the type of reinforcement by different fillers and activators to understand their implications on the final performance.
In doing so, the links between chemistry, micro- / nanostructure and the resulting physical-mechanical properties are discussed as a prerequisite for targeted future development.
Wolfgang Lakata
Interfaces and surfaces play a crucial role in nature as well as in numerous technological processes. Sum frequency generation vibrational (SFG-VS) infrared (IR) spectroscopy has emerged as an exemplary technique for their investigation. It offers high sensitivity and intrinsic surface specificity eliminating background from bulk material. We present a SFG-VS spectrometer optimized for high sensitivity and low integration time, achieved through high repetition-rate, which also incorporates techniques for effective suppression of non-resonant background contributions. This robust and versatile implementation shall contribute to the advancement of SFG-VS spectroscopy to a standard method in fundamental and industrial research.
Anmol Androta
Chirality plays an important role across diverse fields, including chemistry, materials science, biology, and the pharmaceutical industry, where determining the absolute configuration is crucial because it directly governs the physical, chemical, and biological properties of enantiomers. In particular, chiral crystals have attracted growing interest due to their potential in enantioselective catalysis, chiral sensing, and the development of advanced functional materials. In this work, we investigate chiral symmetry breaking in molecular crystals, an inherently interdisciplinary problem. Under non-equilibrium conditions, an initially symmetric (achiral) system can become unstable, leading to the spontaneous emergence of a non-zero enantiomeric excess. We focus on a rare isomorphic series of five achiral derivatives that crystallize in chiral forms while maintaining remarkable structural similarity. A key aspect of this study is the use of UV irradiation to “freeze” chirality in the solid state. This process locks stereogenic centers into a preferred configuration, enabling enantiomer separation and facilitating a transition from supramolecular to molecular chirality. This capability significantly enhances control over chiral properties at the molecular level. To probe the mechanisms of chirality emergence, we employ a range of characterization techniques and examine the interplay between molecular structure, intermolecular interactions, and crystal symmetry. Additionally, we introduce a single reflection resonant X-ray diffraction approach to determine absolute configuration of chiral crystals. This method is particularly valuable for systems with limited accessible reflections, where conventional single crystal X-ray diffraction method require statistically more data for reliable assignment.