I&EC 152 |
| Monolayer-protected CdSe and ZnSe quantum dots (QDs) were synthesized in a green solvent (water). Several water-soluble thiols were used to protect the semiconducting core from surface oxidation and to improve the water solubility of the QDs for possible biological applications. Differences in the spectral properties of the QDs were observed as a function of reaction time and protecting thiol ligand, as well as metal:thiol ratio. The stability of the QDs in different pH environments was studied, with the QDs decomposing in acidic conditions. The diameter of the QDs was calculated from UV-vis spectra and investigated by high-resolution transmission electron microscopy. Separation of the QDs by size was performed using reversed-phase HPLC with green solvents (e.g., methanol, isopropanol). From fluorescence spectra of separated QDs, full-width at half-maximum values of 15 nm and less were observed. |
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Nanotechnology and the Environment: Emphasis on Green Nanotechnology
8:30 AM-12:30 PM, Thursday, April 10, 2008 Morial Convention Center -- Rm. 231, Oral
Division of Industrial & Engineering Chemistry |