44654 2018 eng lecture 0 -- -- -- A scanning transmission x-ray microscopy (STXM) based methodology is introduced for determining the dimensions (shell thickness, core and total diameter) of core-shell nanoparticles which exhibit a strong x-ray absorption contrast and a well-defined interface between core and shell material. A low radiation dosage during data acquisition and, therefore, less x-ray beam induced damage of the sample is achieved by recording STXM images only at two predetermined energies of maximum absorption contrast, instead of recording a stack of images across the whole absorption edge. A model core-shell nanoparticle, polytetrafluoroethylene (PTFE) cores with polystyrene (PS) shell, is used for demonstration. Near edge x-ray absorption fine structure (NEXAFS) spectroscopy confirms the significant difference in x-ray absorption behavior between PTFE and PS. Additionally, due to the insolubility of styrene in PTFE a well-defined interface between particle core and shell is expected. In order to validate the STXM results, both the naked PTFE cores as well as the complete core-shell nanoparticles are examined by scanning electron microscopy (SEM). The introduced STXM based methodology yields particle dimensions in good agreement with the SEM results (deviation equal or less than 10%) and provides additional information such as the position of the particle core which cannot be extracted from a SEM micrograph. Geburtsname von Müller, Anja: Hermanns, A. - Birth name of Müller, Anja: Hermanns, A. DPG-Frühjahrstagung der Sektion Kondensierte Materie gemeinsam mit der EPS Berlin, Germany 11.03.2018 16.03.2018 0 Anja Müller eng uncontrolled STXM eng uncontrolled SEM eng uncontrolled PS eng uncontrolled PTFE eng uncontrolled Core-shell nanoparticles Analytische Chemie Datei im Netzwerk der BAM verfügbar ("Closed Access") Präsentation