title: Ostwald Ripening Growth Mechanism of Gold Nanotriangles in Vesicular Template Phases.
abstract: The mechanism of nanotriangle formation in multivesicular vesicles (MMV) is investigated by using time-dependent SAXS measurements in combination with UV-vis spectroscopy, light, and transmission electron microscopy. In the first time period 6.5 nm sized spherical gold nanoparticles are formed inside of the vesicles, which build up soft nanoparticle aggregates. In situ SAXS experiments show a linear increase of the volume and molar mass of nanotriangles in the second time period. The volume growth rate of the triangles is 16.1 nm3/min, and the growth rate in the vertical direction is only 0.02 nm/min. Therefore, flat nanotriangles with a thickness of 7 nm and a diameter of 23 nm are formed. This process can be described by a diffusion-limited Ostwald ripening growth mechanism. TEM micrographs visualize soft coral-like structures with thin nanoplatelets at the periphery of the aggregates, which disaggregate in the third time period into nanotriangles and spherical particles. The 16 times faster growth of nanotriangles in the lateral than that in the vertical direction is related to the adsorption of symmetry breaking components, i.e., AOT and the polyampholyte PalPhBisCarb, on the {111} facets of the gold nanoplatelets in combination with confinement effects of the vesicular template phase.
authors.affiliation: Institut für Chemie, Universität Potsdam , Karl-Liebknecht-Strasse 24-25, Haus 25, 14476 Potsdam, Golm, Germany.
authors.forename: Ferenc
authors.initials: F
authors.lastname: Liebig
authors.affiliation: Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 87, 12205 Berlin, Germany.
authors.forename: Andreas F
authors.initials: AF
authors.lastname: Thünemann
authors.affiliation: Institut für Chemie, Universität Potsdam , Karl-Liebknecht-Strasse 24-25, Haus 25, 14476 Potsdam, Golm, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Koetz