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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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Particle size distribution of Cu@CuAlO2-Al2O3 nanoparticles at 120 kGy and for various concentrations: (a) 5.0 × 10−5; (b) 5.4 × 10−5; (c) 5.7 × 10−5; (d) 6.0 × 10−5; and (e) 6.4 × 10−5 mol/mL.
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f8-ijms-13-11941: Particle size distribution of Cu@CuAlO2-Al2O3 nanoparticles at 120 kGy and for various concentrations: (a) 5.0 × 10−5; (b) 5.4 × 10−5; (c) 5.7 × 10−5; (d) 6.0 × 10−5; and (e) 6.4 × 10−5 mol/mL.

Mentions: Increasing ion concentration causes the bimetallic nanoparticles to become larger in size, which can be seen by shifting the center of size distribution in Figure 8 towards a larger size. Three main reasons describe these behaviors of nanoparticles. Firstly, by increasing concentration of metal ions in the solution, the rate of ion association under irradiation to form larger particles increases. Secondly, the small particles make wavy movements and collide with each other in solution, leading to particle aggregation. On the other hand, the viscosity of the aqueous solution and therefore speed of particle movement can be changed by the ratio of polymer/ions. Increasing the ion concentration (decreasing ratio of polymer/ions) can increase the collision probability. Finally, the adsorption of PVP on the surface of nanoparticles can reduce the surface energy and further agglomeration of nanoparticles [37,38]. Thus, increasing ion concentration reduces the tendency of polymer capping on the surface of nanoparticles, leading to larger particles.


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)

Particle size distribution of Cu@CuAlO2-Al2O3 nanoparticles at 120 kGy and for various concentrations: (a) 5.0 × 10−5; (b) 5.4 × 10−5; (c) 5.7 × 10−5; (d) 6.0 × 10−5; and (e) 6.4 × 10−5 mol/mL.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f8-ijms-13-11941: Particle size distribution of Cu@CuAlO2-Al2O3 nanoparticles at 120 kGy and for various concentrations: (a) 5.0 × 10−5; (b) 5.4 × 10−5; (c) 5.7 × 10−5; (d) 6.0 × 10−5; and (e) 6.4 × 10−5 mol/mL.
Mentions: Increasing ion concentration causes the bimetallic nanoparticles to become larger in size, which can be seen by shifting the center of size distribution in Figure 8 towards a larger size. Three main reasons describe these behaviors of nanoparticles. Firstly, by increasing concentration of metal ions in the solution, the rate of ion association under irradiation to form larger particles increases. Secondly, the small particles make wavy movements and collide with each other in solution, leading to particle aggregation. On the other hand, the viscosity of the aqueous solution and therefore speed of particle movement can be changed by the ratio of polymer/ions. Increasing the ion concentration (decreasing ratio of polymer/ions) can increase the collision probability. Finally, the adsorption of PVP on the surface of nanoparticles can reduce the surface energy and further agglomeration of nanoparticles [37,38]. Thus, increasing ion concentration reduces the tendency of polymer capping on the surface of nanoparticles, leading to larger particles.

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