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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.

Show MeSH
(a) A description of one short chain of PVP polymer; (b) Resonance structures of a pyrene ring in PVP molecule [23]; (c) A proposed oversimplified mechanism of interactions between PVP and metal ions before irradiation.
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f1-ijms-13-11941: (a) A description of one short chain of PVP polymer; (b) Resonance structures of a pyrene ring in PVP molecule [23]; (c) A proposed oversimplified mechanism of interactions between PVP and metal ions before irradiation.

Mentions: An oversimplified scheme of the interactions between the PVP capping agent and metal ions before irradiation is shown in Figure 1, which shows that the Al (III) and Cu (II) ions are bound by the ionic bonds between the metallic ions and the amide group in a polymeric chain. PVP acts as a stabilizer for dissolved metallic salts through steric and electrostatic stabilization of the amide groups of the pyrrolidone rings [25]. However, the real mechanism is more complex, due to the presence of hydrogen bonds between water molecules themselves and between the water molecules and the carbonyl polarized groups or positivity nitrogen from the pyrrolidone rings. Moreover, each ion is surrounded with a shell of water molecules [26,27].


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)

(a) A description of one short chain of PVP polymer; (b) Resonance structures of a pyrene ring in PVP molecule [23]; (c) A proposed oversimplified mechanism of interactions between PVP and metal ions before irradiation.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f1-ijms-13-11941: (a) A description of one short chain of PVP polymer; (b) Resonance structures of a pyrene ring in PVP molecule [23]; (c) A proposed oversimplified mechanism of interactions between PVP and metal ions before irradiation.
Mentions: An oversimplified scheme of the interactions between the PVP capping agent and metal ions before irradiation is shown in Figure 1, which shows that the Al (III) and Cu (II) ions are bound by the ionic bonds between the metallic ions and the amide group in a polymeric chain. PVP acts as a stabilizer for dissolved metallic salts through steric and electrostatic stabilization of the amide groups of the pyrrolidone rings [25]. However, the real mechanism is more complex, due to the presence of hydrogen bonds between water molecules themselves and between the water molecules and the carbonyl polarized groups or positivity nitrogen from the pyrrolidone rings. Moreover, each ion is surrounded with a shell of water molecules [26,27].

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