Nevenka Rajic

Publications (23) View all

• Article: Entrapment of ethyl vanillin in calcium alginate and calcium alginate/poly(vinyl alcohol) beads

  Steva Levic, Verica Djordjevic, Nevenka Rajic, Milan Milivojevic, Branko Bugarski, Viktor Nedovic
  Chemical Papers 02/2013; 67(2):221-228.
• Article: Novel kinetic model of the removal of divalent heavy metal ions from aqueous solutions by natural clinoptilolite.

  Mina Jovanovic, Nevenka Rajic, Bojana Obradovic
  [show abstract] [hide abstract]
  ABSTRACT: Removal of heavy metal ions from aqueous solutions using zeolites is widely described by pseudo-second order kinetics although this model may not be valid under all conditions. In this work, we have extended approaches used for derivation of this model in order to develop a novel kinetic model that is related to the ion exchange mechanism underlying sorption of metal ions in zeolites. The novel model assumed two reversible steps, i.e. release of sodium ions from the zeolite lattice followed by bonding of the metal ion. The model was applied to experimental results of Cu(II) sorption by natural clinoptilolite-rich zeolitic tuff at different initial concentrations and temperatures and then validated by predictions of ion exchange kinetics of other divalent heavy metal ions (i.e. Mn(II), Zn(II) and Pb(II)). Model predictions were in excellent agreements with experimental data for all investigated systems. In regard to the proposed mechanism, modeling results implied that the sodium ion release rate was constant for all investigated metals while the overall rate was mainly determined by the rate of heavy metal ion bonding to the lattice. In addition, prediction capabilities of the novel model were demonstrated requiring one experimentally determined parameter, only.
  Journal of hazardous materials 07/2012; 233-234:57-64. · 4.14 Impact Factor
• Article: Structure investigation of fluorinated aluminophosphate ULM-3 Al templated by 3-methylaminopropylamine

  N Zabukovec Logar, G Mali, N Rajic, S Jevtic, M Rangus, A Golobic, V Kaucic
  Journal of Solid State Chemistry 05/2010; 183(5):1055-1062. · 2.16 Impact Factor
• Article: On the thermal degradation of 3-methylaminopropylamine captured inside the aluminum phosphate analog of ULM-3

  N Rajic, D Stojakovic, S Jevtic, N Z Logar, G Mali, V Kaucic
  Journal of Thermal Analysis and Calorimetry. 01/2010; 101(3):919-924.
• Source

  Available from: Viktor Nedovic

  Article: Microencapsulation of Flavors in Carnauba Wax

  Milanovic Jelena, Manojlovic Verica, Levic Steva, Rajic Nevenka, Nedovic Viktor, Bugarski Branko
  [show abstract] [hide abstract]
  ABSTRACT: The subject of this study is the development of flavor wax formulations aimed for food and feed products. The melt dispersion technique was applied for the encapsulation of ethyl vanillin in wax microcapsules. The surface morphology of microparticles was investigated using scanning electron microscope (SEM), while the loading content was determined by HPLC measurements. This study shows that the decomposition process under heating proceeds in several steps: vanilla evaporation occurs at around 200 °C, while matrix degradation starts at 250 °C and progresses with maxima at around 360, 440 and 520 °C. The results indicate that carnauba wax is an attractive material for use as a matrix for encapsulation of flavours in order to improve their functionality and stability in products.
  Sensors. 01/2010;