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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.


Appearanceof silica particles incorporating ZnSe-based NCs prepared usingSolution 2: (a) cyclohexane solution undervisible light, (b) cyclohexane solution under UV light (wavelength: 365 nm), (c)powder under visible light, and (d) powder under UV light (wavelength: 365 nm).
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fig2: Appearanceof silica particles incorporating ZnSe-based NCs prepared usingSolution 2: (a) cyclohexane solution undervisible light, (b) cyclohexane solution under UV light (wavelength: 365 nm), (c)powder under visible light, and (d) powder under UV light (wavelength: 365 nm).

Mentions: Aftercentrifuge in the final step of preparation, the supernatant contained small silicaparticles and precipitate contained larger silica particles. Both supernatant and precipitate showedbright blue PL. The small silicaparticles were homogeneously dispersed in the supernatant (cyclohexane solution)at room temperature. The supernatantobtained by using Solution 2 showed brighter PL than that obtained by usingSolution 1. Figures 1(a) and 1(b) showthe appearance of the silica particles incorporating ZnSe-based NCs prepared using Solution 2under visible light and under UV light, respectively. The cyclohexane solution was almost colorlessand transparent under visible light (see Figure 1(a)) and emitted bright bluePL under UV light irradiation (see Figure 1(b)). On the other hand, the powder of small silicaparticles extracted from the above supernatant by using acetonitrile was white undervisible light (see Figure 1(c)) and emitted blue PL under UV light (see Figure 1(d)).


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)

Appearanceof silica particles incorporating ZnSe-based NCs prepared usingSolution 2: (a) cyclohexane solution undervisible light, (b) cyclohexane solution under UV light (wavelength: 365 nm), (c)powder under visible light, and (d) powder under UV light (wavelength: 365 nm).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig2: Appearanceof silica particles incorporating ZnSe-based NCs prepared usingSolution 2: (a) cyclohexane solution undervisible light, (b) cyclohexane solution under UV light (wavelength: 365 nm), (c)powder under visible light, and (d) powder under UV light (wavelength: 365 nm).
Mentions: Aftercentrifuge in the final step of preparation, the supernatant contained small silicaparticles and precipitate contained larger silica particles. Both supernatant and precipitate showedbright blue PL. The small silicaparticles were homogeneously dispersed in the supernatant (cyclohexane solution)at room temperature. The supernatantobtained by using Solution 2 showed brighter PL than that obtained by usingSolution 1. Figures 1(a) and 1(b) showthe appearance of the silica particles incorporating ZnSe-based NCs prepared using Solution 2under visible light and under UV light, respectively. The cyclohexane solution was almost colorlessand transparent under visible light (see Figure 1(a)) and emitted bright bluePL under UV light irradiation (see Figure 1(b)). On the other hand, the powder of small silicaparticles extracted from the above supernatant by using acetonitrile was white undervisible light (see Figure 1(c)) and emitted blue PL under UV light (see Figure 1(d)).

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.