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Please use this identifier to cite or link to this item: http://ir.ncue.edu.tw/ir/handle/987654321/1542

Title: Synthesis and Properties of Water-Soluble Core–Shell–Shell Silica–CdSe/CdS–Silica Nanoparticles
Authors: Lin, Y.-W.;Liu, C.-W.;Chang, H.-T.
Contributors: 化學系
Keywords: QUANTUM DOTS
NANOSTRUCTURES
SILICA
SYNTHETIC METHODS
LUMINESCENCE
Date: 2006
Issue Date: 2010-11-10T06:37:58Z
Abstract: This paper describes the synthesis of highly water-soluble and fluorescent core–shell–shell silica–CdSe/CdS–silica nanoparticles (CSS silica–QDs–silica NPs). We used cadmium nitrate and 1,1-dimethyl-2-selenourea precursors to synthesize CdSe quantum dots (QDs)in aqueous solution under simultaneous illumination with a diode-pumped solid state green laser and a Xe–Hg lamp. After passivation of the CdSe QDs with CdS, the CdSe/CdS QDs were then conjugated covalently to (3-mercaptopropyl)trimethoxysilane (MPS); we call these nanoparticles "MPS-QDs". We mixed the MPS-QDs with tetraethoxysilane (TEOS), ethanol, and NH3. By controlling the concentrations of the reagents, the stirring speed, and the reaction time, we synthesized CSS silica–QDs–silica NPs having sizes ranging from 75 to 190 nm. The incubation time for preparing the MPS-QDs and their concentrations are important parameters in determining the morphologies of the CSS silica–QDs–silica NPs. When we mixed 50 nM MPS-QDs, 1.1 mM TEOS, and 78 mM NH3 and reacted them at a stirring speed of 750 rpm, we obtained 85-nm-diameter CSS silica–QDs–silica NPs having a QD shell thickness of about 20 nm. The CSS silica–QDs–silica NPs provide a strong photoluminescence intensity (quantum yield 88%)and exhibit enhanced stability both photochemically and in high-conductivity media (e.g., 1.0 M NaCl).
Relation: J. Nanosci. Nanotechnol., 6, 1092-1100
Appears in Collections:[化學系] 期刊論文

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