Small-Angle X-Ray scattering instrument

• Subject Area: Polymer Research
• Term: Funded in 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 567763721

With the help of small-angle X-ray scattering, structural sizes in the range of around one to several hundred nm can be recorded. This method therefore plays a central role in research into nanoscale systems, particularly in the field of soft, synthetic and biological matter, as well as in materials research in general. For dilute systems, this method provides information on the size, size distribution and shape of the scattering objects. Depending on the contrast, information about the internal structure (e.g. core-shell) is also accessible via the shape factor. In concentrated systems, access is gained to the structure factor, which describes the spatial distribution of the scattering objects. With the high-resolution area detectors that are now used as standard, anisotropic scattering patterns such as diffraction patterns of colloidal crystals can also be investigated and crystal structures elucidated. Not least due to the impressive technical development in the field of X-ray optics, detection and the sample environment in recent decades, such investigations are no longer restricted to large-scale research facilities (synchrotrons). A facility for X-ray scattering is being applied for, with which a scattering vector range of around four orders of magnitude is accessible. In the range of small scattering vectors, measurements down to 0.01 nm^-1 should be possible so that structure sizes above 500 nm can be resolved. The device will primarily be used by the Institutes of Chemistry and Physics at Martin Luther University Halle-Wittenberg. For use in current and planned research projects, a flexible and large-scale sample environment, which also allows the introduction of in-house constructions (e.g. tensile stress experiments), is just as important as the ability to follow kinetic processes in situ through short measurement times. In addition to measurements with an evacuated sample chamber, measurements at atmospheric pressure should also be possible. The latter measurement conditions are particularly necessary for the investigation of shear-induced phase transitions with the shear cell, which has also been applied for. The device will be used to investigate metallic and non-metallic nanoparticles and their aggregation behavior in the presence of e.g. peptides (PoLIfaces platform and planned initiative), polymeric single-chain nanoparticles, novel thermoplastic polyester elastomers, responsive polymers and micellar systems (GRK 2670). One focus of the investigations will be on the non-equilibrium behavior of model colloids with core-shell structure and high-contrast cores. These systems offer ideal contrast conditions to separate shape and structure factors of close-packed samples. This makes it possible, for example, to systematically investigate phase transitions.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Röntgenkleinwinkelstreuanlage
• Instrumentation Group: 4020 Röntgenkameras für Feinstruktur und Topographie
• Applicant Institution: Martin-Luther-Universität Halle-Wittenberg
• Leader: Professor Dr. Matthias Karg, Ph.D.