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Room temperature radiolytic synthesized Cu@CuAlO(2)-Al(2)O(3) nanoparticles.

Abedini A, Saion E, Larki F, Zakaria A, Noroozi M, Soltani N - Int J Mol Sci (2012)

Bottom Line: Results of transmission electron microscopy (TEM), energy dispersive X-ray spectrometry (EDX), and X-ray diffraction (XRD) showed that Cu@CuAlO(2)-Al(2)O(3) nanoparticles are in a core-shell structure.By controlling the absorbed dose and precursor concentration, nanoclusters with different particle sizes were obtained.The average particle diameter increased with increased precursor concentration and decreased with increased dose.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Faculty of Science, Universiti Putra Malaysia, Serdang, Selangor 43400, Malaysia; E-Mails: elias@science.upm.edu.my (E.S.); farhad.larki@gmail.com (F.L.); azmizak@science.upm.edu.my (A.Z.); monir_noroozi@yahoo.com (M.N.); nayereh.soltani@gmail.com (N.S.).

ABSTRACT
Colloidal Cu@CuAlO(2)-Al(2)O(3) bimetallic nanoparticles were prepared by a gamma irradiation method in an aqueous system in the presence of polyvinyl pyrrolidone (PVP) and isopropanol respectively as a colloidal stabilizer and scavenger of hydrogen and hydroxyl radicals. The gamma irradiation was carried out in a (60)Co gamma source chamber with different doses up to 120 kGy. The formation of Cu@CuAlO(2)-Al(2)O(3) nanoparticles was observed initially by the change in color of the colloidal samples from colorless to brown. Fourier transform infrared spectroscopy (FTIR) confirmed the presence of bonds between polymer chains and the metal surface at all radiation doses. Results of transmission electron microscopy (TEM), energy dispersive X-ray spectrometry (EDX), and X-ray diffraction (XRD) showed that Cu@CuAlO(2)-Al(2)O(3) nanoparticles are in a core-shell structure. By controlling the absorbed dose and precursor concentration, nanoclusters with different particle sizes were obtained. The average particle diameter increased with increased precursor concentration and decreased with increased dose. This is due to the competition between nucleation, growth, and aggregation processes in the formation of nanoclusters during irradiation.

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TEM images of (a) Cu nanoparticles and (b) Cu@CuAlO2-Al2O3 nanoparticles.
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f2-ijms-13-11941: TEM images of (a) Cu nanoparticles and (b) Cu@CuAlO2-Al2O3 nanoparticles.

Mentions: It is a well known fact that to prepare pure Cu, Al, or Al-Cu bimetallic nanoparticles by radiation synthesis in air without the influence of oxygen is not easy. The intended Al-Cu bimetallic nanoparticles are contaminated with oxygen. Therefore, it is safe to note that the final product of this synthesis would be Cu@CuAlO2-Al2O3 nanoparticles as we can see later from the EDX and XRD analyses. Figure 2 shows the comparison between TEM images of Cu nanoparticles and the core-shell structure of Cu@CuAlO2-Al2O3 nanoparticles. In a TEM image (Figure 2b), the shells can be partially distinguished from the cores, because the lower atomic number of Al provides less contrast in a TEM image than Cu. The boundary between the core and shell is not sharp, however, which suggests that the shells might not be pure Al, but CuAlO2 and Al2O3 instead. The same interpretation reported for other elements by M. S. Shore [29].


Room temperature radiolytic synthesized Cu@CuAlO(2)-Al(2)O(3) nanoparticles.

Abedini A, Saion E, Larki F, Zakaria A, Noroozi M, Soltani N - Int J Mol Sci (2012)

TEM images of (a) Cu nanoparticles and (b) Cu@CuAlO2-Al2O3 nanoparticles.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3472785&req=5

f2-ijms-13-11941: TEM images of (a) Cu nanoparticles and (b) Cu@CuAlO2-Al2O3 nanoparticles.
Mentions: It is a well known fact that to prepare pure Cu, Al, or Al-Cu bimetallic nanoparticles by radiation synthesis in air without the influence of oxygen is not easy. The intended Al-Cu bimetallic nanoparticles are contaminated with oxygen. Therefore, it is safe to note that the final product of this synthesis would be Cu@CuAlO2-Al2O3 nanoparticles as we can see later from the EDX and XRD analyses. Figure 2 shows the comparison between TEM images of Cu nanoparticles and the core-shell structure of Cu@CuAlO2-Al2O3 nanoparticles. In a TEM image (Figure 2b), the shells can be partially distinguished from the cores, because the lower atomic number of Al provides less contrast in a TEM image than Cu. The boundary between the core and shell is not sharp, however, which suggests that the shells might not be pure Al, but CuAlO2 and Al2O3 instead. The same interpretation reported for other elements by M. S. Shore [29].

Bottom Line: Results of transmission electron microscopy (TEM), energy dispersive X-ray spectrometry (EDX), and X-ray diffraction (XRD) showed that Cu@CuAlO(2)-Al(2)O(3) nanoparticles are in a core-shell structure.By controlling the absorbed dose and precursor concentration, nanoclusters with different particle sizes were obtained.The average particle diameter increased with increased precursor concentration and decreased with increased dose.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Faculty of Science, Universiti Putra Malaysia, Serdang, Selangor 43400, Malaysia; E-Mails: elias@science.upm.edu.my (E.S.); farhad.larki@gmail.com (F.L.); azmizak@science.upm.edu.my (A.Z.); monir_noroozi@yahoo.com (M.N.); nayereh.soltani@gmail.com (N.S.).

ABSTRACT
Colloidal Cu@CuAlO(2)-Al(2)O(3) bimetallic nanoparticles were prepared by a gamma irradiation method in an aqueous system in the presence of polyvinyl pyrrolidone (PVP) and isopropanol respectively as a colloidal stabilizer and scavenger of hydrogen and hydroxyl radicals. The gamma irradiation was carried out in a (60)Co gamma source chamber with different doses up to 120 kGy. The formation of Cu@CuAlO(2)-Al(2)O(3) nanoparticles was observed initially by the change in color of the colloidal samples from colorless to brown. Fourier transform infrared spectroscopy (FTIR) confirmed the presence of bonds between polymer chains and the metal surface at all radiation doses. Results of transmission electron microscopy (TEM), energy dispersive X-ray spectrometry (EDX), and X-ray diffraction (XRD) showed that Cu@CuAlO(2)-Al(2)O(3) nanoparticles are in a core-shell structure. By controlling the absorbed dose and precursor concentration, nanoclusters with different particle sizes were obtained. The average particle diameter increased with increased precursor concentration and decreased with increased dose. This is due to the competition between nucleation, growth, and aggregation processes in the formation of nanoclusters during irradiation.

Show MeSH