SEMINAR: Nucleation and growth of nanoparticles under dynamic...

SEMINAR: Nucleation and growth of nanoparticles under dynamic...

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Speaker: Sašo Šturm

Title: Nucleation and growth of nanoparticles under dynamic conditions: from cosmic dust to functional nanomaterials

Date/Time: December 14, 2018 / 11:40 - 12:30

Place: FENS L029

Abstract: Despite the enormous research work in the area of nanoparticles synthesis, typically from aqueous solutions or from supersaturated vapour, the fundamental reasons that control the phase transformation and nucleation of stable polymorphs otherwise considered metastable in the bulk form, are not fully understood. As a result, the efficient industrial scale-up is most commonly hindered by pour understanding of crystallization and growth mechanisms on nanoparticles from precursors during the nucleation stage. The nucleation pathways in supersaturated vapour are simpler when compared with the formation of stable nuclei in water solution, as water makes a hydrated layer surrounding individual pre-nuclei particles. In relation to this, significant advances in the development of novel functional nanomaterials can be achieved by using suitable research methods that allow in situ dynamic investigations of nanomaterials in their native environments at the highest spatial and temporal resolution. That includes nanoscale dynamic studies of nucleation and growth of nanomaterials from aqueous solutions and supersaturated vapour phase. For high-resolution dynamic studies of nanoparticles formation in aqueous environments we have recently implemented an interdisciplinary research platform for in situ transmission electron microscopy (TEM) in liquid. This ground-breaking approach opens a wide range of possibilities in high-resolution in situ dynamic studies where case-by-case specialized experiments can be performed by proper redesign of liquid chambers, allowing the direct study of nucleation and growth of nanoparticles from solutions at elevated temperatures. On the other hand, homogeneous nucleation conditions in supersaturated vapour can be most efficiently realized under the microgravity condition (~10-1 G), which was achieved during the parabolic flight of the airplane. By proper sampling, these experiments provide valuable information of nucleation stage, vital for well controlled synthesis of nanoparticles.

Bio: Assoc. Prof. dr. Sašo Šturm received his PhD in material science from the Faculty of Natural Sciences and Engineering, University of Ljubljana in 2003. He has been employed at the Jožef Stefan Institute (JSI) since 1991. He was a Max Planck Society Post-Doctoral Fellow (Stuttgart, Germany) in 2003-2004 in the group of Prof. Manfred Rühle where he was responsible for the analytical TEM section. He was a visiting scientist at the Graz Centre for Electron Microscopy (Austria), the Tokyo University of Science (Japan) and the Faculty of engineering, Toyama University (Japan) for the period of around one month. During these visits he had mastered various advanced techniques of transmission electron microscopy (TEM). In Spring 2014, he was a Visiting Professor at Sabanci University. Currently he is Head of the Department for Nanostructured Materials at JSI, an associate professor at University of Ljubljana and associate professor at Jožef Stefan International Postgraduate School, where he is giving lectures on various topics of TEM. He also serves as Director of the CNRS‐JSI International Associated Laboratory. He received an award as a “best early career scientist” in 2005 at the EDGE conference dedicated to electron energy loss spectroscopy (EELS) community for his work on spatially resolved EELS of planar faults. He served as the 2013-2017 president of the Slovene Society for Microscopy, actively shaping the future of Slovene microscopy.

Contact: Emre Erdem & Erdinç Öztürk & Emre Özlü