Vol 77, No 12 - Abstracts

JSCS Vol 77, No.12

Publication of this issue is financially co-supported by

Faculty of Technology and Metallurgy, University of Belgrade

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This issue of the Journal of the Serbian Chemical Society contains selected papers from the First International Conference on the Processing, Characterisation and Application of Nanostructured Materials and Nanotechnology (NanoBelgrade 2012), held in Belgrade, Serbia, 26–28 September, 2012. The Conference was organized by the Nanotechnology and Functional Materials Centre, Faculty of Technology and Metallurgy, University of Belgrade (NANOTECH FTM) within the FP7 project “Reinforcing of the Nanotechnology and Functional Materials Centre” (No. 245916).

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J. Serb. Chem. Soc. 77 (12)1687 (2012) Editorial

EDITORIAL

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J. Serb. Chem. Soc. 77 (12) 1689–1699 (2012)

UDC 544.558:61:576:61.088:614.48.014.4:539.12; JSCS–4381; doi: 10.2298/JSC121020142P Original scientific paper

Application of non-equilibrium plasmas in medicine

ZORAN LJ. PETROVIĆ, NEVENA PUAČ, GORDANA MALOVIĆ, SAŠA LAZOVIĆ, DEJAN MALETIĆ, MAJA MILETIĆ*, SLAVKO MOJSILOVIĆ**, PAVLE MILENKOVIĆ* AND DIANA BUGARSKI**

Institute of Physics, University of Belgrade, Pregrevica 118, 11080 Zemun, Serbia

*Faculty of Dental Medicine, University of Belgrade, Dr Subotića 8, Serbia

**Institute for Medical Research, University of Belgrade, Dr Subotića - starijeg 4, Serbia

(Received 20 October, revised 10 December 2012)

The potential of plasma applications medicine, the connections to nanotechnologies and the results obtained by our group are reviewed. A special issue in plasma medicine is the development of the plasma sources that would achieve non-equilibrium at atmospheric pressure in an atmospheric gas mixture with no or only marginal heating of the gas, and with desired properties and mechanisms that may be controlled. Our studies have shown that control of radicals or chemically active products of the discharge, such as ROS (reactive oxygen species) and/or NO, may be used to control the growth of the seeds. Simultaneously, a specially designed plasma needle and other sources were shown to be efficient to sterilize not only colonies of bacteria but also planktonic sAMples (microorganisms protected by water) or bio films. Finally, it was shown that plasma might induce differentiation of stem cells. Non-equilibrium plasmas may be used in detection of different specific markers in medicine. For exAMple proton transfer mass spectroscopy may be employed in the detection of volatile organic compounds without their dissociation and thus as a technique for instantaneous measurement of the presence of markers for numerous diseases.

Keywords: low temperature plasmas; plasma technologies; sterilization; functionalization; stem cells.

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J. Serb. Chem. Soc. 77 (12) 1701–1707 (2012)

UDC 533.9+666.293.35+678.031–036.7:621.3.004.12:539.24; JSCS–4382; doi: 10.2298/JSC121022137V Original scientific paper

Plasma etching of polystyrene latex particles for the preparation of graphene oxide nanowalls

LUCA VALENTINI and SILVIA BITTOLO BON

Università di Perugia, Dipartimento di Ingegneria Civile e Ambientale, Strada di Pentima 4, INSTM, UdR Perugia, 05100 Terni, Italy

(Received 22 October 2012)

Graphene oxide nanowalls were prepared by casting an aqueous dispersion of polystyrene latex particles onto a graphene oxide film followed by tetrafluoromethane plasma etching. Mild plasma etching conditions allowed the oxygen functional groups on the graphene oxide nanowalls to be retained. It was found that exposure to a xenon light source of such graphene oxide nanowalls coated with a gold thin film results in an increase in the electrical conductivity.

Keywords: nanostructures; etching; electrical properties characterization; electrical conductivity.

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J. Serb. Chem. Soc. 77 (12) 1709–1722 (2012)

UDC 664.644.7–034.21+541.13+542.913:614.48:61.000.57:620.017:539.24; JSCS–4383; doi: 10.2298/JSC121108148S Original scientific paper

Controlled production of alginate nanocomposites with incorporated silver nanoparticles aimed for biomedical applications

JASMINA STOJKOVSKA, JOVANA ZVICER, ŽELJKA JOVANOVIĆ, VESNA MIŠKOVIĆ-STANKOVIĆ and BOJANA OBRADOVIĆ

Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade, Serbia

(Received 8 November, revised 15 December 2012)

The production of nanocomposite alginate microbeads with electrochemically synthesized silver nanoparticles (AgNPs) based on the electrostatic extrusion technique was investigated with respect to their potentials for utilization in pharmaceutical and biomedical applications. It was shown that electrochemical synthesis of AgNPs results in the reduction of practically all the Ag+ present in the initial solution, yielding stable Ag/alginate colloid solutions that were demonstrated to be suitable for sterilization, manipulation, and electrostatic extrusion with retention of the AgNPs. The presence of AgNPs in the alginate colloid solutions had negligible effects on the size of the produced Ag/alginate microbeads, which was mainly determined by the electrostatic potential applied during the extrusion. On the other hand, the incorporation of AgNPs within the alginate hydrogel induced slight changes in biomechanical properties of the microbeads determined in a biomimetic bioreactor. Thus, packed beds of nanocomposite Ag/alginate microbeads exhibited a slightly higher dynAMic compression modulus as compared to that of control alginate microbeads (154±4 and 141±2 kPa, respectively). On the other hand, the equilibrium unconfined compression modulus was significantly lower for the nanocomposite microbeads as compared to that of the controls (34±2 and 47±1 kPa, respectively).

Keywords: electrochemical synthesis; electrostatic extrusion; sterilization; biomechanical properties

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J. Serb. Chem. Soc. 77 (12) 1723–1733 (2012)

UDC *Chitosan+678.742–.31:67.017:620.01:62–416; JSCS–4384; doi: 10.2298/JSC121121139D; Original scientific paper

Processing and nanomechanical properties of chitosan/poly(ethylene oxide) blend films

JELENA D. ĐOKIĆ, ALEKSANDAR KOJOVIĆ, DUŠICA STOJANOVIĆ, ALEKSANDAR MARINKOVIĆ, GORAN VUKOVIć, RADOSLAV ALEKSIĆ and PETAR S. USKOKOVIĆ

Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11120 Belgrade, Serbia

(Received 21 November, revised 10 December 2012)

Chitosan-based films have found increasing implementation in a variety of fields, AMong which are as drug delivery carriers, in the packaging industry and as water purification filters. Therefore, in order to achieve mechanical integrity of such films while preserving processability and biocompatibility, chitosan-based films are fabricated in the forms of blends with poly(ethylene oxide) (PEO). A nano-indentation study was undertaken in order to investigate the nanomechanical properties and surface morphology of chitosan films in blends with various content of PEO. The results of differential scanning calorimetry, water uptake and nano-indentation revealed that films with an 80/20 blend ratio of chitosan/PEO showed the optimal values of reduced modulus and hardness. It appears that the incorporation of the synthetic PEO in chitosan films could lower the manufacturing costs while preserving the mechanical integrity of the films.

Keywords: chitosan; poly(ethylene oxide); polymer blend film; nano-indentation.

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J. Serb. Chem. Soc. 77 (12) 1735–1746 (2012)

UDC 536.51+546.669–31:547.441–036.7+535.37:546.18+539.12; JSCS–4385; doi: 10.2298/JSC121021140L; Original scientific paper

Thermographic properties of Eu³⁺- and Sm³⁺-doped Lu₂O₃ nanophosphor

VESNA LOJPUR, ŽELJKA ANTIĆ, RADENKA KRSMANOVIĆ, MINA MEDIĆ, MARKO G. NIKOLIĆ and MIROSLAV D. DRAMIĆANIN

Vinča Institute of Nuclear Sciences, University of Belgrade, P. O. Box 522, 11001 Belgrade, Serbia

(Received 21 October, revised 8 December 2012)

SAMples of Lu2O3:Eu3+ (3 at. % Eu) and Lu2O3:Sm3+ (1 at. % Sm), were prepared via the polymer complex solution method using poly(ethylene glycol) as the fuel and as nucleation agent for crystallization process. Knowing that lutetium oxide has high chemical stability and temperature resistance, in this study, the possibility for its application in high-temperature phosphor thermometry was investigated. This non-contact technique uses the thermal dependence of phosphor fluorescence to measure temperature remotely. The structural and morphological properties were investigated by X-ray powder diffraction (XRPD) analysis and transmission electron microscopy (TEM). The obtained results confirmed that this synthesis yields the desired crystalline structure with particle sizes in the range from 30 to 50 nm. Photoluminescence emission measurements were recorded in the temperature range from AMbient up to 873 K. The obtained results demonstrated the performance of Eu3+- and Sm3+-doped Lu2O3 as high temperature thermographic phosphors of very good sensitivity.

Keywords: Lu2O3; Eu3+; Sm3+; thermometry; FIR; luminescence.

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J. Serb. Chem. Soc. 77 (12) 1747–1757 (2012)

UDC 667.2–037+549.514.6:544.526.5+542.92; JSCS–4386; doi: 10.2298/JSC121015130D; Original scientific paper

A study of the photocatalytic degradation of the textile dye CI Basic Yellow 28 in water using a P160 TiO₂-based catalyst

VELJKO ĐOKIĆ, JELENA VUJOVIĆ, ALEKSANDAR MARINKOVIĆ, RADA PETROVIĆ, ĐORĐE JANAĆKOVIĆ, ANTONIJE ONJIA* and DUŠAN MIJIN

Faculty of Technology and Metallurgy, University of Belgrade, karnegijeva 4, P. O. Box 3503, 11120 Belgrade, Serbia

*Vinča Institute of Nuclear Sciences, University of Belgrade, P. O. Box 522, 11001 Belgrade, Serbia

(Received 15 November, revised 4 December 2012)

The photocatalytic degradation of the synthetic textile dye CI Basic Yellow 28 (BY28) in water, using a recently synthesized P160 TiO2-based catalyst, under OsrAM ultra-vitaluxÒ lAMp (300 W) light, was studied. The effects of the operational parAMeters, such as initial concentration of catalyst, initial dye concentration and pH, were studied. The salt effect (NaCl, Na2CO3, Na2SO4 and NaNO3) was also investigated. It was found that the optimal concentration of catalyst is 2.0 g L-1. a pseudo first-order kinetic model was illustrated using the Langmuir–Hinshelwood Mechanism and the adsorption equilibrium constant and the rate constant of the surface reaction were calculated (KBY = 6.126 L mg-1 and kC = 0.272 mg L-1 min-1, respectively). the photodegradation rate was higher in weak acidic than in high acidic and alkaline conditions. The presence of CO32- ions increased the photodegradation rate while Cl-, SO42- and NO3- decreased the reaction rate. The rate of photodegradation of BY28 was measured using UV–Vis spectroscopy.

Keywords: TiO2; photocatalysis; pseudo first-order kinetic model; Langmuir––Hinshelwood Mechanism; salt effect.

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J. Serb. Chem. Soc. 77 (12) 1759–1773 (2012)

UDC 677.12+547.422+547.823:66.081+546.57:615.28; JSCS–4387; doi: 10.2298/JSC121018143M Original scientific paper

Antimicrobial oxidized hemp fibers with incorporated silver particles

JOVANA MILANOVIĆ, TATJANA MIHAILOVIĆ, KATARINA POPOVIĆ and MIRJANA KOSTIĆ

Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11120 Belgrade, Serbia

(Received 18 October, revised 10 December 2012)

In this study, antimicrobial silver-loaded hemp fibers were prepared by selective TEMPO-mediated oxidation, i.e., oxidation with sodium hypochlorite, catalytic AMount of sodium bromide and the 2,2,6,6-tetrAMethylpiperidine-1-oxy radical (TEMPO), followed by silver sorption from aqueous silver nitrate solution. The most suitable experimental conditions for the selective TEMPO-mediated oxidation were determined by changing the oxidation conditions, i.e., the concentration of sodium hypochlorite and the duration of oxidation. The obtained results showed that the maximum sorption capacity of 0.703 mmol of silver per grAM of modified hemp fibers was obtained for the sAMple oxidized with 9.67 mmol NaClO per grAM of fibers for 4 h. SEM Microphotographs of the modified hemp fibers with incorporated silver showed uniformly distributed silver particles on the surface of fibers, with isometric shapes and sizes from 10 to 100 nm, despite the fact that silver was sorbed from an ionic solution. The antibacterial activity of the TEMPO-oxidized hemp fibers with silver particles was confirmed in vitro against two strains: Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922), and the antifungal activity against Candida albicans (ATCC 24433). The best antimicrobial activity of silver-loaded TEMPO-oxidized hemp fibers was showed against strain S. aureus.

Keywords: hemp fibers; TEMPO-mediated oxidation; silver sorption; antimicrobial textile.

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J. Serb. Chem. Soc. 77 (12) 1775–1785 (2012)

UDC 661.183.8+539.217+544.02:621.71; JSCS–4388; doi: 10.2298/JSC121018132R Original scientific paper

Effect of cooling rate on the microstructure and porosity of alumina produced by freeze casting

JESÚS M. RODRÍGUEZ-PARRA, RODRIGO MORENO and MARÍA ISABEL NIETO

Institute of CerAMics and Glass, CSIC, Kelsen 5, 28049 Madrid, Spain

(Received 18 November, revised 3 December 2012)

Freeze casting is a well-known shaping technique for the production of materials with directional porosity. One of the major problems is the difficulty to control the cooling rate, thus leading to gradients in pore size and homogeneity. This work deals with the manufacture of alumina cerAMics with directional porosity by freeze casting of aqueous suspensions. An experimental set-up was prepared in order to apply different cooling rates. Freeze casting tests were performed with an aqueous alumina suspension after optimization of its rheological behavior. The porosity and microstructural features of the sintered bodies produced under different experimental conditions were studied and analyzed. It was concluded that the cooling rate influences the microstructure while the final temperature has a much lower influence. In addition, microstructural analysis showed that there was a gradient in the directionality of the pores, being lower at the bottom and the top and higher in the central region of the specimens.

Keywords: suspensions; shaping; cerAMics; porous materials; alumina; microstructures.

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J. Serb. Chem. Soc. 77 (12) 1787–1798 (2012)

UDC 546.472+549.753.1–36+66.021.1/.4:57.001.365:615.28–188; JSCS–4389; doi: 10.2298/JSC121019131R; Original scientific paper

Biocompatibility and antimicrobial activity of zinc(II)-doped hydroxyapatite, synthesized by a hydrothermal method

ŽELJKO RADOVANOVIĆ, ĐORĐE VELJOVIĆ, BOJAN JOKIĆ, SUZANA DIMITRIJEVIĆ, GORDANA BOGDANOVIĆ*, VESNA KOJIĆ*, RADA PETROVIĆ AND DJORDJE JANAĆKOVIĆ

Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade, Serbia

*Oncology Institute of Vojvodina, Institutski put 4, 21204 Sremska KAMenica, Serbia

(Received 19 November, revised 3 December 2012)

In order to obtain multifunctional materials with good biocompatibility and antimicrobial effect, hydroxyapatite (HAp) doped with Zn2+ was synthesized by a hydrothermal method. Powders with different content of zinc ions were synthesized and compared with undoped HAp to investigate the influence of Zn2+ on the antimicrobial activity of HAp. Analyses of undoped and Zn2+-doped powders before and after thermal treatment at 1200 °C were performed by SEM and XRD. The antimicrobial effects of the powders were exAMined in relation to Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans in liquid medium. The results showed that the obtained powders had good antimicrobial activity, but higher antimicrobial activities of the powders doped with Zn2+ were observed after annealing at 1200 °C. For powders annealed at 1200 °C, in vitro biocompatibility tests: reduction of the tetrazolium salt 3-(4,5-dimethylthazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT test) and Trypan Blue dye exclusion test (DET test) with MRC-5 fibroblast cells in liquid medium were performed. Based on the MTT and DET tests, it was shown that the powders do not have a significant cytotoxic effect, which was confirmed by SEM analysis of MRC-5 fibroblast cells after their in vitro contact with the powders.

Keywords: HAp; Zn; α-TCP; biocide; MTT assay; MRC-5.

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J. Serb. Chem. Soc. 77 (12) 1799–1806 (2012)

UDC 544.478+546.92:661.183.8:66.061+66.094.3+547.426:539.12; JSCS–4390; doi: 10.2298/JSC121116147P; Original scientific paper

Catalyst materials based on plasma-processed alumina nanopowder

ERIKS PALCEVSKIS, LIDIJA KULIKOVA, VERA SERGA, ANTONS CVETKOVS, SVETLANA CHORNAJA*, ELINA SPROGE* and KONSTANTINS DUBENCOVS*

Institute of Inorganic Chemistry, Riga Technical University, 34 Miera str., Salaspils, LV-2169, Latvi

*Faculty of Material Science and Applied Chemistry Riga Technical University, 14/24 Azenes str., Riga, LV-1048, Latvia

(Received 16 November, revised 10 December 2012)

A platinum catalyst for glycerol oxidation by molecular oxygen has been developed applying an extractive-pyrolytic method and using, as a support, a fine alumina powder with an average particle size of 30–60 nm processed by plasma technology. The extractive-pyrolytic method (EPM) allows affixing small AMounts of catalytic metals (1–5 %) with the particle size ranging from several nanometers to several tens of nanometers onto the surface of the support. The prepared material, 4.8 wt. % platinum on nano-sized alumina, could be used as a catalyst for glycerol oxidation by oxygen with conversions up to 84 %, in order to produce some organic acids (glyceric and lactic acid) with a selectivity of about 60 %.

Keywords: platinum catalyst; extractive-pyrolytic method; glycerol oxidation.

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