Dresden 2017 – scientific programme
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O: Fachverband Oberflächenphysik
O 113: Thin Films, Nanostructures and Nanoparticles II
O 113.8: Talk
Friday, March 24, 2017, 12:15–12:30, ZEU 114
In-situ Small-angle X-ray Scattering and UV-vis spectroscopy Investigations of the Formation and Growth of Inorganic Nanoparticles by Microwave-Assisted Solvothermal Synthesis — •Robert Wendt1, Eike Gericke1, Dragomir Tatchev2, Armin Hoell3, Markus Wollgarten3, Simone Raoux3, and Klaus Rademann1 — 1Humboldt-Universität zu Berlin, Berlin, Germany — 2Bulgarian Academy of Sciences, Sofia, Bulgaria — 3Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany
Microwave-assisted solvothermal syntheses (MWASS) have become subject of renewed fundamental interests in the preparation of crystalline and monodisperse inorganic nanoparticles (NPs). Main features of MWASS are distinguished control and exact on-line determination of pressure and temperature inside the autoclave-type reactors. The advantage is the efficient internal volumetric "in-core" heating by direct coupling of MW energy to the reaction molecules. It allows high heating rates with small thermal gradients and strongly decreased reaction times based on the Arrhenius law. This work includes innovative in-situ investigations of the formation and growth mechanisms of inorganic NPs by this new developed MWASS-system. It allows exact additions of precursor solution into the sealed reactor and withdrawals of colloid solution at any time. Thereby, we are able to investigate and characterize the NPs in a time-range of seconds by in-situ UV-Vis spectroscopy and SAXS and ex-situ by TEM, EELS and EXAFS. These results provide new insights in the formation and growth mechanisms.