Aggregation of photolytic gold nanoparticles at the surface of chitosan films
Formation and aggregation of photolytic gold nanoparticles at the surface of chitosan (CTO) films have been investigated. When thin films of chloroauric acid salt of CTO were irradiated with UV light in wet air at room temperature for 10 min, gold nanoparticles of approximately 10 nm size are formed...
| Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1992. - 20(2004), 14 vom: 06. Juli, Seite 5918-23 |
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| Format: | Aufsatz |
| Sprache: | English |
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2004
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| Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
| Schlagworte: | Journal Article Chlorides Gold Compounds Gold 7440-57-5 gold tetrachloride, acid 8H372EGX3V Chitosan 9012-76-4 |
| Zusammenfassung: | Formation and aggregation of photolytic gold nanoparticles at the surface of chitosan (CTO) films have been investigated. When thin films of chloroauric acid salt of CTO were irradiated with UV light in wet air at room temperature for 10 min, gold nanoparticles of approximately 10 nm size are formed at the film surface. Detailed X-ray photoelectron spectroscopy (XPS) study and field emission type scanning electron microscopy (FE-SEM) observation have been carried out to characterize gold nanoparticles at the film surface. The shift of Au(4f) peak to the higher energy side and broadening of full width at half-maximum in the XPS spectrum are the direct evidence of the existence of gold atoms and small clusters in the early stage of photolysis. According to FE-SEM observation, growth in the particle diameter and aggregation of nanoparticles were observed after prolonged irradiation, and, finally, the film surface was densely covered with gold particles of 20-100-nm size. Gold atoms and clusters could move in the film and precipitate to the irradiated surface. Chemical composition analysis further suggests that gold particles at the surface are covered with an ultrathin CTO layer, which is partly oxidized by oxygen and chlorinated by chlorine during photochemical reactions |
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| Beschreibung: | Date Completed 20.03.2007 Date Revised 26.10.2019 published: Print Citation Status MEDLINE |
| ISSN: | 1520-5827 |