فهرست مقالات Photoluminescence emission

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  1 - Estimation of lattice strain in ZnO nanoparticles: X-ray peak profile analysis
  P. Bindu Sabu Thomas
  10.1007/s40094-014-0141-9
  AbstractZnO nanoparticles were synthesized from chitosan and zinc chloride by a precipitation method. The synthesized ZnO nanoparticles were characterized by Fourier transform infrared spectroscopy, X-ray diffraction peak profile analysis, Scanning electron microscopy, چکیده کامل

  AbstractZnO nanoparticles were synthesized from chitosan and zinc chloride by a precipitation method. The synthesized ZnO nanoparticles were characterized by Fourier transform infrared spectroscopy, X-ray diffraction peak profile analysis, Scanning electron microscopy, Transmission electron microscopy and Photoluminescence. The X-ray diffraction results revealed that the sample was crystalline with a hexagonal wurtzite phase. We have investigated the crystallite development in ZnO nanoparticles by X-ray peak profile analysis. The Williamson–Hall analysis and size–strain plot were used to study the individual contributions of crystallite sizes and lattice strain ϵ on the peak broadening of ZnO nanoparticles. The parameters including strain, stress and energy density value were calculated for all the reflection peaks of X-ray diffraction corresponding to wurtzite hexagonal phase of ZnO lying in the range 20°–80° using the modified form of Williamson–Hall plots and size–strain plot. The results showed that the crystallite size estimated from Scherrer’s formula, Williamson–Hall plots and size–strain plot, and the particle size estimated from Transmission electron microscopy analysis are very much inter-correlated. Both methods, the X-ray diffraction and Transmission electron microscopy, provide less deviation between crystallite size and particle size in the present case. پرونده مقاله
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  2 - Effect of ZnS shell on optical properties of Ni-doped ZnSe nanocrystals
  Ehsan Soheyli Gholamreza Nabiyouni Reza Sahraei
  The present paper aims to suggest a simple/fast route for direct preparation of the Ni-doped ZnSe/ZnS core/shell NCs in aqueous solution. Using XRD measurement, the zinc blend structure and sub-5 nm average size of the NCs was proved. The FT-IR spectrum also showed the چکیده کامل

  The present paper aims to suggest a simple/fast route for direct preparation of the Ni-doped ZnSe/ZnS core/shell NCs in aqueous solution. Using XRD measurement, the zinc blend structure and sub-5 nm average size of the NCs was proved. The FT-IR spectrum also showed the passivation of the NCs surface by means of the deprotonated thiol terminals of the NAC molecules. The intensity of the dopant-related emission at about 476 nm in Ni:ZnSe doped NCs was found to experience more than four times enhancement by utilization of the extra ZnS shell. It was also observed that the increasing of the shell overcoating time from 1 to 3 h, has effective role on better passivation of the surface of the NCs and increasing of the emission intensity پرونده مقاله
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  3 - Preparation of polyethersulfone membrane coated by a nanocomposite structure
  Farhad Heidary
  Nanocomposite membranes were prepared by coating a porous Polyethersulfone (PES) support containing 8-hydroxyquinoline (as complexing agent) with poly (vinyl alcohol) (PVA)/Fe3O4 nanocomposite solution. The prepared membranes were applied for removal of Zn(II) ions from چکیده کامل

  Nanocomposite membranes were prepared by coating a porous Polyethersulfone (PES) support containing 8-hydroxyquinoline (as complexing agent) with poly (vinyl alcohol) (PVA)/Fe3O4 nanocomposite solution. The prepared membranes were applied for removal of Zn(II) ions from water. The effect of membrane modification on the membranes performance for removal of metal ions was investigated. The results indicated that presence of ligand and Fe3O4 nanoparticles in the membrane structure enhanced the ions rejection. The prepared samples were characterized by scanning electron microscopy. SEM images indicated appropriate distribution of nanoparticles in the polymeric matrix. پرونده مقاله