Speaker: Aline Ribeiro Passos

The CoWork webinar series is dedicated to the exploitation of the coherence properties of X-rays for advanced materials characterization, with a special focus on inverse microscopy techniques, such as Coherent Diffraction Imaging (CDI), Ptychography and Holography. It is an introduction to Coherent X-ray imaging methods to facilitate the access to advanced microscopy techniques to new users and it welcomes all researchers intrigued by the spectacular coherence properties of X-rays produced at modern synchrotron sources – of which MAX IV is a first example.

Bio:

Aline Ribeiro Passos is a researcher at the Cateretê beamline at Sirius (Brazilian synchrotron light laboratory). In 2015 she received her PhD (cotutelle) in chemistry from the São Paulo State University, Brazil and the Paris-Sud University (Synchrotron SOLEIL), France. She joined the Cateretê group in 2017 as postdoctoral researcher, the main emphasis of her research was to investigate catalysts using in situ and operando Bragg CDI. Since 2019, she has been working as beamline scientist at Cateretê, her current research focuses on the study of dynamics in soft matter using X-ray photon correlation spectroscopy (XPCS).

Abstract:

Supported catalysts where noble metals precursors are added during the soft-chemistry synthesis of the support have several advantages such as high dispersion and stability. However, the introduction of metal ions into the sol-gel matrix is not straightforward, the metal precursors can aggregate or induce the gel to collapse. To ensure the best interaction between the reacting species and high dispersion of metal precursors, the nanoscopic organization and mobility mechanisms of colloidal particles while undergoing gelation should be revealed. The unique capabilities of XPCS to probe dynamics and structural evolution in non-equilibrium systems can answer fundamental questions about morphology formation during gelation for the efficient control of catalyst structure. In this presentation I will show some recent results of gelation dynamics probed by in situ XPCS at Cateretê beamline