Dusan K. Bozanic

Publications (15) View all

• Source

  Available from: Radenka Krsmanović Whiffen

  Article: Inhibition of Microbial Growth by Silver-Starch Nanocomposite Thin Films.

  Dušan K Božanić, Vladimir Djoković, Suzana Dimitrijević-Branković, Radenka Krsmanović, Michael McPherson, P Sreekumari Nair, Michael K Georges, Thottackad Radhakrishnan
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  ABSTRACT: A sago starch biopolymer with embedded silver nanoparticles has been studied as a material for the prevention of microbial growth. Approximately 8 nm in size, silver nanoparticles have been synthesized by reduction of the silver salt in aqueous solution in the presence of sago starch using sodium borohydride as a reducing agent. The obtained solutions were cast on glass plates to obtain thin supported silver-starch nanocomposite films. The morphology of the nanocomposites was investigated by scanning and transmission electron microscopy. UV-Vis absorption spectroscopy showed that during the film formation a part of the silver nanoparticles has been trapped in the water present in the sample, which enabled their partial oxidation into active Ag(+) species. The oxidation of the silver nanoparticles was confirmed by X-ray photoelectron spectroscopy. The antimicrobial activity tests have shown that the nanocomposite material can be successfully employed to prevent the viability and growth of the common pathogens Staphylococcus aureus, Escherichia coli and Candida albicans.
  Journal of Biomaterials Science Polymer Edition 11/2010; · 1.69 Impact Factor
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  Available from: Dusan K. Bozanic

  Article: Optimization of photoluminescence of Y(2)O(3):Eu and Gd(2)O(3):Eu phosphors synthesized by thermolysis of 2,4-pentanedione complexes.

  B Antic, J Rogan, A Kremenovic, A S Nikolic, M Vucinic-Vasic, D K Bozanic, G F Goya, P H Colomban
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  ABSTRACT: Spherical shaped nanoparticles of series Y(2 - x)Eu(x)O(3) (x = 0.06, 0.10, 0.20, and 2) and Gd(2 - x)Eu(x)O(3) (x = 0.06, 0.10) were prepared by thermolysis of 2,4-pentanedione complexes of Y, Gd, and Eu. The bixbyite phase of Gd(2 - x)Eu(x)O(3) samples was formed at 500 degrees C, whereas the thermal decomposition of Y and Eu complexes' mixtures occurred at higher temperatures. Linearity in the concentration dependence on lattice parameter confirmed the formation of solid solutions. The distribution of Eu(3+) in Gd(2 - x)Eu(x)O(3) was changed with thermal annealing: in the as-prepared sample (x = 0.10) the distribution was preferential at C(3i) sites while in the annealed samples, Eu(3+) were distributed at both C(2) and C(3i) sites. Rietveld refinement of site occupancies as well as emission spectra showed a random distribution of cations in Y(2 - x)Eu(x)O(3). The photoluminescence (PL) measurements of the sample showed red emission with the main peak at 614 nm ((5)D(0)-(7)F(2)). The PL intensity increased with increasing concentration of Eu(3+) in both series. Infrared excitation was required to obtain good Raman spectra. The linear dependence of the main Raman peak wavenumber offers a non-destructive method for monitoring the substitution level and its homogeneity at the micron scale.
  Nanotechnology 06/2010; 21(24):245702. · 3.98 Impact Factor
• Article: Biopolymer-protected CdSe nanoparticles.

  D K Bozanić, V Djoković, N Bibić, P Sreekumari Nair, M K Georges, T Radhakrishnan
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  ABSTRACT: A synthetic procedure for the encapsulation of cadmium selenide (CdSe) nanoparticles in a sago starch matrix is introduced. The nanocomposite was investigated using structural, spectroscopic, and thermal methods. TEM micrographs of the nanocomposite showed spherical CdSe particles of 4-5 nm in size coated with a biopolymer layer. The absorption edges of both the aqueous solution and the thin film of the CdSe-starch nanocomposite were shifted toward lower wavelengths in comparison to the value of the bulk semiconductor. Infrared measurements revealed that the interaction of CdSe nanoparticles and starch chains takes place via OH groups. Although the onset of the temperature of decomposition of CdSe-starch nanocomposite is lower than that of the pure matrix, thermogravimetric analysis also showed that introduction of CdSe nanoparticles significantly reduced starch degradation rate leading to high residual mass at the end of the degradation process.
  Carbohydrate research 08/2009; 344(17):2383-7. · 2.03 Impact Factor
• Source

  Available from: Vesna V Vodnik

  Article: Optical properties of shaped silver nanoparticles.

  Vesna V Vodnik, Dugan K Bozanić, Natasa Bibić, Zoran V Saponjić, Jovan M Nedeljković
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  ABSTRACT: The influence of shape and dielectric property of surrounding media on surface plasmon absorption band of silver nanoparticles was studied. Spherical silver nanoparticles (d = 5.6 nm) synthesized in water using NaBH4 as a reducing agent are transferred in non-polar solvent (chloroform) with phase-transfer reagent oleylamine. The absorption spectrum of oleylamine-capped silver nanoparticles dispersed in chloroform shows a strong surface plasmon resonance band that is 19 nm red-shifted compared to unmodified particles in water. The values for peak position and corresponding half widths are compared with theoretical calculations based on Mie theory. Prismatic and plate-like silver nanoparticles were synthesized in water using trisodium citrate as a reducing agent and cetyltrimethylammonium bromide as stabilizer. Due to structural anisotropy of prismatic and plate-like silver nanoparticles three surface plasmon resonance bands were observed in absorption spectrum. Nanocomposites consisting of non-spherical silver nanoparticles and polyvinyl alcohol exhibit different optical properties compared to water colloid. Instead of three surface plasmon bands, nanocomposite film has only one peak at 460 nm. Reason for appearance of single surface plasmon resonance band in nanocomposite film was discussed according to Maxwell-Garnet theory.
  Journal of Nanoscience and Nanotechnology 08/2008; 8(7):3511-5. · 1.56 Impact Factor
• Source

  Available from: Adriaan Stephanus Luyt

  Article: Viscoelastic properties and antimicrobial activity of cellulose fiber sheets impregnated with Ag nanoparticles.

  Levente Csóka, Dušan K Božanić, Veronika Nagy, Suzana Dimitrijević-Branković, Adriaan S Luyt, George Grozdits, Vladimir Djoković
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  ABSTRACT: A silver nanoparticle colloid was prepared by a modified Tollens method using d-glucose as the reduction agent. The obtained nanoparticles were used for the modification of pine, linter and recycled cellulose fibers. Although the silver contents were relatively low (0.05-0.13 wt.%), the cellulose-sheets prepared from the modified fibers show improved mechanical and viscoelastic properties. The tensile index (strength) increased with up to 30% in comparison to the index of the sheets obtained from the untreated fibers. The influence of the nanoparticles on the viscoelastic properties of the cellulose sheets was investigated by dynamic mechanical analysis (DMA) in the temperature range from -120 to 20 °C and with a force frequency of 100 Hz. A broad relaxation transition positioned at -80 °C was observed in the loss modulus spectrum of all the cellulose sheets, while the Ag-modified sheets exhibited higher storage moduli values in the whole temperature range. The antimicrobial activity tests show that the pine, silver and recycled cellulose fiber sheets with silver nanoparticles can be successfully employed to prevent the viability and growth of the common pathogens Staphylococcus aureus, Escherichia coli and Candida albicans.
  Carbohydrate polymers. 10/2012; 90(2):1139-46.