Coordination and Reduction Processes in the Synthesis of Dendrimer-Encapsulated Pt Nanoparticles
Authors:
- 7 October 2009
- journal article
- research article
- Published by American Chemical Society (ACS) in Langmuir
- Vol. 26 (4) , 2339-2345
Abstract
We synthesized Pt nanoparticles encapsulated in poly(amidoamine) (PAMAM) dendrimers by Pt(2+) coordination and subsequent reduction by NaBH(4). To optimize the experimental conditions for the Pt nanoparticle synthesis, we systematically examined the effects of pH, temperature, coordination time, and surface functional groups of the dendrimers on coordination and NaBH(4) reduction by UV-vis spectroscopy and transmission electron microscopy (TEM) measurements. We used generation-4 dendrimers (hydroxyl-terminated PAMAM dendrimers; G4-OH) and generation-4.5 dendrimers (carboxyl-terminated PAMAM dendrimers; G4.5-COO(-)). According to our results, dendrimer-encapsulated Pt nanoparticles with a narrow size distribution were obtained at high Pt(2+) coordination ratios (alpha), while nonencapsulated Pt nanoparticles were formed at low alpha values. To enhance alpha, it was necessary to use a neutral G4-OH solution or an acidic G4.5-COO(-) solution. Temperature had a marked effect on the coordination rate, with an increase in the temperature from room temperature to 50 degrees C, and the coordination time decreased from 10 days to 1-2 days.Keywords
This publication has 75 references indexed in Scilit:
- Nanoparticles as Recyclable Catalysts: The Frontier between Homogeneous and Heterogeneous CatalysisAngewandte Chemie International Edition, 2005
- Integrated Nanoparticle–Biomolecule Hybrid Systems: Synthesis, Properties, and ApplicationsAngewandte Chemie International Edition, 2004
- Preparation of Hydrophobically Modified Poly(amidoamine) Dendrimer-Encapsulated Gold Nanoparticles in Organic SolventsJournal of Colloid and Interface Science, 2000
- Nanoparticle Arrays on Surfaces for Electronic, Optical, and Sensor ApplicationsChemphyschem, 2000
- Dendrimer Templates for the Formation of Gold NanoclustersMacromolecules, 2000
- Role of Poly(amidoamine) Dendrimers for Preparing Nanoparticles of Gold, Platinum, and SilverLangmuir, 2000
- A review of modern transition-metal nanoclusters: their synthesis, characterization, and applications in catalysisJournal of Molecular Catalysis A: Chemical, 1999
- Poly(Amidoamine) Dendrimer-Templated Nanocomposites. 1. Synthesis of Zerovalent Copper NanoclustersJournal of the American Chemical Society, 1998
- Preparation of Cu Nanoclusters within Dendrimer TemplatesJournal of the American Chemical Society, 1998
- Chemical catalysis by colloids and clustersChemical Reviews, 1993