Berlin 2005 – scientific programme
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DS: Dünne Schichten
DS 24: Postersitzung II
DS 24.6: Poster
Tuesday, March 8, 2005, 17:00–19:00, Poster TU B
Comparative studies of interactions between intense pulsed laser and gold nanoparticles in water and toluene phases — •Zhangquan Peng1, Thomas Walther2, and Karl Kleinermanns1 — 1Institut für Physikalische Chemie und Electrochemie I, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany — 2Center of Advanced European Studies and Research, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
Gold nanoparticles were surface-modified with a pH-sensitive monolayer of 4-aminothiophene (4-ATP) in water phase. By varying the pH value of the solution, nanoparticles could be quantitatively transferred into toluene phase in a two-phase (water/toluene) system. The nanoparticles in both water and toluene phase were irradiated by an intense pulsed laser at 532 nm. The products in solution were examined by transmission electron microscopy (TEM) and optical absorption spectroscopy. Besides, the effects of the presence of excess protecting ligands including 4-ATP and SH(CH2)8SH on the photo-fragmentation kinetics and product morphology have been studied. Experimental results showed that gold nanoparticles in toluene phase are more prone to be photo-fragmentated into small metallic clusters than in water phase, independent of the existence of protecting ligands. The dielectric and heat conduction properties of the solvents have been invoked to explain the observed phenomena.