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Blue-emitting small silica particles incorporating ZnSe-based nanocrystals prepared by reverse micelle method.

Ando M, Li C, Yang P, Murase N - J. Biomed. Biotechnol. (2007)

Bottom Line: It was crucially important for this solution to include Zn(2+) ions and surfactant molecules (thioglycolic acid) to preserve the spectral properties of the final silica particles.This is because these substances in the solution prevent the surface of nanocrystals from deterioration by dissolution during processing.The resultant silica particles have an emission efficiency of 16% with maintaining the photoluminescent spectral width and peak wavelength of the initial colloidal solution.

View Article: PubMed Central - PubMed

Affiliation: Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Kansai Center, Ikeda 563-8577, Osaka, Japan.

ABSTRACT
ZnSe-based nanocrystals (ca. 4-5 nm in diameter) emitting in blue region (ca. 445 nm) were incorporated in spherical small silica particles (20-40 nm in diameter) by a reverse micelle method. During the preparation, alkaline solution was used to deposit the hydrolyzed alkoxide on the surface of nanocrystals. It was crucially important for this solution to include Zn(2+) ions and surfactant molecules (thioglycolic acid) to preserve the spectral properties of the final silica particles. This is because these substances in the solution prevent the surface of nanocrystals from deterioration by dissolution during processing. The resultant silica particles have an emission efficiency of 16% with maintaining the photoluminescent spectral width and peak wavelength of the initial colloidal solution.

No MeSH data available.


Size distribution of silica particles incorporatingZnSe-based NCs measured by dynamic light scattering method: (a) silicaparticles prepared using Solution 1 and (b) silica particles prepared usingSolution 2.
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fig3: Size distribution of silica particles incorporatingZnSe-based NCs measured by dynamic light scattering method: (a) silicaparticles prepared using Solution 1 and (b) silica particles prepared usingSolution 2.

Mentions: Figure 2 shows the size (diameter) distribution of the small silica particlesincorporating ZnSe-based NCs in the supernatant, measured by the dynamic light scatteringmethod. The silica particles prepared using Solution1 and those prepared using Solution 2 gave similar distribution curve of particlesize, however, the latter particle size was a little smaller than the formerone. Namely, the mean sizes of the silicaparticles prepared using Solution 1 and that using Solution 2 were ca. 35 and31 nm, respectively. Thesetwo kinds of silica particles had a spherical shape. Nonluminescent silica particles withoutcontaining NCs had similar size. A typicalTEM photograph of the small silica particles incorporating ZnSe-based NCs in thesupernatant is shown in Figure 3. The shape of thesesmall silica particles is spherical and the particle diametersare 20–40 nm, which are in good agreement with those measured by the dynamiclight scattering method (see Figure 2). On the other hand,the precipitate after centrifuge in the final step of preparation contained largersilica particles with diameters from a few hundreds nm to 1-2 μm. Such large silicaparticles also had a spherical shape.The results show that luminescent silica particles with variousdiameters were formed in the preparation process, and the size selection of silicaparticles was possible by centrifuge. Itwas also possible to select the size of silica particles by using syringefilters.


Blue-emitting small silica particles incorporating ZnSe-based nanocrystals prepared by reverse micelle method.

Ando M, Li C, Yang P, Murase N - J. Biomed. Biotechnol. (2007)

Size distribution of silica particles incorporatingZnSe-based NCs measured by dynamic light scattering method: (a) silicaparticles prepared using Solution 1 and (b) silica particles prepared usingSolution 2.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2266811&req=5

fig3: Size distribution of silica particles incorporatingZnSe-based NCs measured by dynamic light scattering method: (a) silicaparticles prepared using Solution 1 and (b) silica particles prepared usingSolution 2.
Mentions: Figure 2 shows the size (diameter) distribution of the small silica particlesincorporating ZnSe-based NCs in the supernatant, measured by the dynamic light scatteringmethod. The silica particles prepared using Solution1 and those prepared using Solution 2 gave similar distribution curve of particlesize, however, the latter particle size was a little smaller than the formerone. Namely, the mean sizes of the silicaparticles prepared using Solution 1 and that using Solution 2 were ca. 35 and31 nm, respectively. Thesetwo kinds of silica particles had a spherical shape. Nonluminescent silica particles withoutcontaining NCs had similar size. A typicalTEM photograph of the small silica particles incorporating ZnSe-based NCs in thesupernatant is shown in Figure 3. The shape of thesesmall silica particles is spherical and the particle diametersare 20–40 nm, which are in good agreement with those measured by the dynamiclight scattering method (see Figure 2). On the other hand,the precipitate after centrifuge in the final step of preparation contained largersilica particles with diameters from a few hundreds nm to 1-2 μm. Such large silicaparticles also had a spherical shape.The results show that luminescent silica particles with variousdiameters were formed in the preparation process, and the size selection of silicaparticles was possible by centrifuge. Itwas also possible to select the size of silica particles by using syringefilters.

Bottom Line: It was crucially important for this solution to include Zn(2+) ions and surfactant molecules (thioglycolic acid) to preserve the spectral properties of the final silica particles.This is because these substances in the solution prevent the surface of nanocrystals from deterioration by dissolution during processing.The resultant silica particles have an emission efficiency of 16% with maintaining the photoluminescent spectral width and peak wavelength of the initial colloidal solution.

View Article: PubMed Central - PubMed

Affiliation: Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Kansai Center, Ikeda 563-8577, Osaka, Japan.

ABSTRACT
ZnSe-based nanocrystals (ca. 4-5 nm in diameter) emitting in blue region (ca. 445 nm) were incorporated in spherical small silica particles (20-40 nm in diameter) by a reverse micelle method. During the preparation, alkaline solution was used to deposit the hydrolyzed alkoxide on the surface of nanocrystals. It was crucially important for this solution to include Zn(2+) ions and surfactant molecules (thioglycolic acid) to preserve the spectral properties of the final silica particles. This is because these substances in the solution prevent the surface of nanocrystals from deterioration by dissolution during processing. The resultant silica particles have an emission efficiency of 16% with maintaining the photoluminescent spectral width and peak wavelength of the initial colloidal solution.

No MeSH data available.