1. Preparation of Au and Au–Pt nanoparticles within PMMA matrix using UV and X-ray irradiation
- Author
-
Ilknur Tunc, Sefik Suzer, Eda Ozkaraoglu, and Süzer, Şefik
- Subjects
X-ray photoelectron spectroscopy ,Polymers and Plastics ,Particle growths ,X ray photoelectron spectroscopy ,Diffusion ,Nucleation ,Electron spectroscopy ,Particle ,Nanoparticle ,Pmma matrixes ,Pt alloys ,Photochemistry ,UV lights ,Nanoparticle formations ,Photoelectricity ,Ultraviolet spectroscopy ,Growth kinetics ,Materials Chemistry ,Photochemical reductions ,Nanotechnology ,Metal ions ,Polymer ,chemistry.chemical_classification ,Room temperatures ,Photoelectron spectroscopy ,Polymethyl methacrylate ,Photochemical degradation ,X-ray analysis ,Ultraviolet radiation ,Photoreduction and photo-patterning ,Reaction rates ,Materials science ,Metal ions in aqueous solution ,Kinetics ,Alloy ,Reaction mediums ,engineering.material ,Photoionization ,Platinum alloys ,Platinum ,Ions ,Photons ,Contrast measurements ,Nucleation and growth ,X rays ,Xps analyses ,Organic Chemistry ,VIS spectroscopies ,Close proximities ,Spectrum analysis ,Enhanced diffusions ,chemistry ,engineering ,Nanoparticles ,Growth (materials) ,Gold ,Higher temperatures ,Gold alloys - Abstract
Au and Au-Pt alloy nanoparticles are prepared and patterned at room temperature within the PMMA polymer matrix by the action of 254 nm UV light or X-rays. The polymer matrix enables us to entangle the kinetics of the photochemical reduction from the nucleation and growth processes, when monitored by UV-vis spectroscopy. Accordingly, increase of the temperature to 50 degrees C of the reaction medium increases the nucleation and growth rates of the nanoparticle formation by more than one order of magnitude, due to enhanced diffusion and nucleation at the higher temperature, but has no effect on the photochemical reduction process. Presence of Pt ions also increases the same rate, but by a factor two only. Similar photochemical reduction and particle growth take also place within the PMMA matrix, when these metal ions are subjected to prolonged exposure to X-rays, as evidenced by XPS analysis. Both angle-resolved and charge-contrast measurements using XPS reveal that the resultant Au and Pt species are in close proximity to each other, indicating the Au-Pt alloy formation to be the most likely case. (C) 2008 Elsevier Ltd. All rights reserved.
- Published
- 2009
- Full Text
- View/download PDF