| 1. |
- Dong, Lin, et al.
(författare)
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Measurement of radiative lifetime in CdSe/CdS core/shell structured quantum dots
- 2009
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Ingår i: 2009 Asia Communications and Photonics Conference and Exhibition, ACP 2009. - Washington, D.C. : OSA. - 9781557528773 ; , s. 5377385-
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Konferensbidrag (refereegranskat)abstract
- Radiative lifetime of chemically synthesized colloidal CdSe/CdS core/shell quantum dots is measured. Influence of the core size on the electron-hole pair separation is analyzed. A long radiative lifetime and the existence of electron-hole pair separation suggest high potential of these dots as gain material to achieve lasing under continuous-wave excitation.
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| 2. |
- Sugunan, Abhilash, et al.
(författare)
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Novel synthesis of gold nanoparticles in aqueous media
- 2005
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Ingår i: Materials Research Society Symposium Proceedings. - 1558998551 - 9781558998551 ; , s. 257-262
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Konferensbidrag (refereegranskat)abstract
- Aqueous synthesis of glutamate functionalized single crystal gold nanoparticles was achieved by reducing a solution of chloroauric acid with monosodium glutamate. Highly uniform size distributions of the nanoparticles can be obtained by having an excess of monosodium glutamate in the starting solution. Similar to the conventional synthesis of gold nanoparticles by reduction of chloroauric acid with trisodium citrate, the obtained particle sizes were varied in the range of 14 - 25 nm without loosing the uniformity in its size distribution by varying the concentration of the reducing agent. © 2006 Materials Research Society.
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| 3. |
- Sugunan, Abhilash, et al.
(författare)
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Nutrition-Driven Assembly of Colloidal Nanoparticles : Growing fungi assemble gold nanoparticles as microwires
- 2007
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Ingår i: Advanced Materials. - Weinheim, Germany : Wiley. - 0935-9648 .- 1521-4095. ; 19:1, s. 77-81
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Tidskriftsartikel (refereegranskat)abstract
- The use of a living fungus to 'actively' assemble presynthesized gold nano-particles over its hyphae, resulting in conducting microstructures (see figure), is reported. This physiologically (nutrition) driven process of colloidal self-organization avoids the need for sophisticated DNA/protein chemistry for facilitating interfacing with biological surfaces. The obtained gold-laden microstructures can be modified into flat ribbonlike or tubular morphologies by simple post-formation processing.
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| 4. |
- Sugunan, Abhilash, et al.
(författare)
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Zinc oxide nanowires in chemical bath on seeded substrates : Role of hexamine
- 2006
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Ingår i: Journal of Sol-Gel Science and Technology. - : Springer Science and Business Media LLC. - 0928-0707 .- 1573-4846. ; 39:1, s. 49-56
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Tidskriftsartikel (refereegranskat)abstract
- We report a study of the role of hexamine in the seeded growth of zinc oxide (ZnO) nanowires by hydrothermal mat route. We show that the growth can be made highly amsotropic (aspect ratio > 150) with almost no detectable increase in diameter (with time of hydrothermal growth) of the obtained nanowires. Results indicate that hexamine acts as a shape inducing molecule, by selectively capping the non-polar crystallographic planes of the zincite crystal. We observe nanowires with typical diameters of similar to 30 nm and lengths exceeding several microns after a 24 h growth period at 60-95 degrees C. Our observations, and reports from the literature, suggest that the concentration of the precursors in the chemical bath can significantly affect the growth rate of the wires. By keeping the concentration of the precursors in the bath at 1 mM, we have observed an extremely slow, but highly anisotropic growth of ZnO nanowires.
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| 5. |
- Toprak, Muhammet S., et al.
(författare)
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Active Cooperative Assemblies Towards Nanocomposites
- 2009
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Ingår i: ADVANCES IN MATERIAL DESIGN FOR REGENERATIVE MEDICINE, DRUG DELIVERY AND TARGETING/IMAGING. - 9781605111124 ; , s. 197-202
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Konferensbidrag (refereegranskat)abstract
- This work reports on the fabrication of novel type of assemblies bearing magnetic nanoparticles and inorganic shells prepared via a biomimetic route of complex coacervation. Magnetic nanoparticles fabricated under controlled conditions were surface modified with polyacrylic acid (PAA). Subsequently, PAA spontaneously formed spherical assemblies in contact with certain ions, such as Ca2+. The stability of these microspheres against environmental alterations such as pH, ionic strength, and dilution was increased through cross-linking. Ethylene diammine (EDA) was used as a cross-linker, which resulted in mechanically stabilized system that does not show sensitivity towards the external pH values. Important parameters for the formation of these coacervates as well as mechanism of formation and cross-linking have been evaluated by FTIR analysis. The cooperative assemblies are still active for further reaction and were used for the growth of an inorganic aluminum oxide shell. SEM analysis of these spheres showed that the structures are hollow with a large interior volume. A biocompatible outer surface combined with the magnetic functionality is very important for the targeted drug delivery devices for biomedical applications.
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