Project Details
Projekt
Cryo scanning electron microscope
Subject Area
Materials Science
Term
Funded in 2021
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 467965905
The subject of the proposal is a cryo scanning electron microscope (cryo SEM) with a thermal emitter, which specifically meets the requirements for the examination of poorly conductive plastic-based and biological samples. In addition to a high imaging performance at low acceleration voltages, this requires an operating mode in low vacuum and a system for energy dispersive X-ray spectroscopy (EDX) with high sensitivity. For sample preparation of the sensitive materials, the use of cryo argon ion polishing promises the fabrication of high-quality cross sections, through which a significantly increased informative value of the SEM images is achieved in many samples or an evaluation is made possible at all. Using a cryopreparation unit, it will be possible to examine samples that are not stable at room temperature by cooling them with liquid nitrogen during preparation and examination. At the same time, freezing and thawing processes can be simulated, examined and monitored using SEM imaging.The requested system complements the equipment already available at Leibniz University Hannover. In particular, cryo SEM examinations and sample preparation using argon ion polishing are made possible for the first time.The recurring research tasks to be processed with the requested system include the evaluation of fiber surfaces, nonwovens, interface qualities and failure mechanisms in the development of fiber-reinforced plastics. For the evaluation of the fiber-matrix adhesion, in addition to fracture surface analysis, the cross section analysis using argon ion polishing will be used.When developing new recycling approaches for plastics, SEM investigations serve to analyze the structure of complex materials (including multi-layer composites) in order to develop suitable processing strategies based on them. SEM analyzes of the intermediate and end products provide information about the influence of processing steps on the material characteristics.In projects on the marine degradability of plastics, test specimens from field tests are to be examined, which often show significant biological coverage. With argon ion polishing, cross sections can be produced here that do not destroy the biofilms. This makes it possible to evaluate the degradation mechanisms inside the specimen.In the research field of cryotechnology, the influences of the process parameters of freezing and thawing processes of biosamples (suspended cells, tissue) as well as combination products (polymeric carrier structures with cells / tissue from tissue engineering and regenerative medicine) are to be investigated. The cryopreparation unit enables the typical process steps to be simulated. At the same time, structural influences can be quantified with a resolution that is superior to the cryo microscopy available at the IMP.
DFG Programme
Major Research Instrumentation
Major Instrumentation
Kryo-Rasterelektronenmikroskop
Instrumentation Group
5120 Rasterelektronenmikroskope (REM)
Applicant Institution
Gottfried Wilhelm Leibniz Universität Hannover
