Preparation of PAMAM- and PPI-metal (silver, platinum, and palladium) nanocomposites and their catalytic activities for reduction of 4-nitrophenol
Dendrimer-metal (silver, platinum, and palladium) nanocomposites are prepared in aqueous solutions containing poly(amidoamine) (PAMAM) dendrimers with surface amino groups (generations 3, 4, and 5) or poly(propyleneimine) (PPI) dendrimers with surface amino groups (generations 2, 3, and 4). The part...
Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1992. - 20(2004), 1 vom: 06. Jan., Seite 237-43 |
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Weitere Verfasser: | , |
Format: | Aufsatz |
Sprache: | English |
Veröffentlicht: |
2004
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Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
Schlagworte: | Journal Article Metals, Heavy Nitrophenols Organometallic Compounds Polyamines Polypropylenes poly(propyleneimine) Silver 3M4G523W1G Platinum mehr... |
Zusammenfassung: | Dendrimer-metal (silver, platinum, and palladium) nanocomposites are prepared in aqueous solutions containing poly(amidoamine) (PAMAM) dendrimers with surface amino groups (generations 3, 4, and 5) or poly(propyleneimine) (PPI) dendrimers with surface amino groups (generations 2, 3, and 4). The particle sizes of the metal nanoparticles obtained are almost independent of the generation as well as the concentration of the dendrimer for both the PAMAM and the PPI dendrimers; the average sizes of silver, platinum, and palladium nanoparticles are 5.6-7.5, 1.2-1.6, and 1.6-2.0 nm, respectively. It is suggested that the dendrimer-metal nanocomposites are formed by adsorbing the dendrimers on the metal nanoparticles. Studies of the reduction reaction of 4-nitrophenol by these nanocomposites show that the rate constants are very similar between PAMAM and PPI dendrimer-silver nanocomposites, whereas the rate constants for the PPI dendrimer-platinum and -palladium nanocomposites are greater than those for the corresponding PAMAM dendrimer nanocomposites. In addition, it is found that the rate constants for the reduction of 4-nitrophenol involving all the dendrimer-metal nanocomposites decrease with an increase in the dendrimer concentrations, and the catalytic activity of dendrimer-palladium nanocomposites is highest |
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Beschreibung: | Date Completed 06.01.2006 Date Revised 26.10.2019 published: Print Citation Status MEDLINE |
ISSN: | 1520-5827 |