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Your search keyword '"Maksimović, Tijana"' showing total 2 results
Start Over Author "Maksimović, Tijana" Publisher institute of technical sciences of sasa
2 results on '"Maksimović, Tijana"'

1. Synthesis and characterization of new dysprosium doped phosphate tungsten bronze

Author

Maksimović, Tijana, Maksimović, Jelena, Tančić, Pavle, Joksović, Ljubinka, Pagnacco, Maja, and Nedić, Zoran

Subjects
batteries, Fourier-transform infrared spectra (FTIR), fuel cells, Dysprosium phosphate tungsten bronze, thermal analysis, catalyst
Abstract

Dysprosium phosphate tungsten bronze has been successfully synthesized and characterized (TGA, DSC, FTIR). For the preparation of dysprosium phosphate tungsten bronze (Dy-PWB), as a starting material is used 12-tungstophosporic heteropoly acid H3PW12O40×29H2O (PWA), which was first transformed into H3PW12O40×6H2O (6-PWA) by heating of PWA at 80 °C in a kiln. Aqueous solution H3PW12O40×6H2O is then commingled with aqueous solution of DyCl3×6H2O, slightly heated in order to start the crystallization process and left during the night to finish the crystallization. The obtained salt DyPW12O40×nH2O is then heated in furnace, from room temperature to 600 °C, whereby the yellow crystals of dysprosium phosphate tungsten bronze are formed. The structure and its phase transformations were characterized by thermal analysis (TGA and DSC) and Fourier-transform infrared spectra (FTIR). In this paper, the dysprosium phosphate tungsten bronze has been synthesized and characterized for the first time in order to obtain more information about its structure, chemical features and potential practical application. The potential practical application of Dy-PWB is in its installation in batteries and fuel cells, as catalyst for the reduction of oxygen in acidic electrolytes. Due to the specific yellow color and its thermal stability, Dy-PWB could also be used as a pigment.

Published
2021

2. The Briggs-Rauscher reaction as an unusual detector for a different type of bronzes

Author

Maksimović, Tijana, Maksimović, Jelena, Mudrinić, Tihana, Nedić, Zoran, Joksović, Ljubinka, Mojović, Zorica, Pagnacco, Maja, Maksimović, Tijana, Maksimović, Jelena, Mudrinić, Tihana, Nedić, Zoran, Joksović, Ljubinka, Mojović, Zorica, and Pagnacco, Maja

Abstract

The Briggs-Rauscher (BR) reaction is an oscillating reaction in which the oxidation of malonic acid (CH2(COOH)2) in the presence of hydrogen peroxide (H2O2) and potassium iodate (KIO3) is catalyzed with a metal ion (usually manganese ion (Mn2+)) in an acid solution (HClO4). It is well known that the BR reaction represents a chemical system that is extremely sensitive to the addition of different types of analytes. Every change in oscillatory dynamics, caused by analyte addition, can be used for the assessment of analyte concentration, as well as its potential antiradical activities. The basic idea of this work is to use the oscillatory reaction, as an unusual and novel system for distinguishing different types of insoluble materials such as bronzes, specifically phosphate tungsten bronze (PWB) and phosphate molybdenum bronze (PMoB). Regarding the results obtained, the increasing mass of PWB leads to a significant decrease of BR oscillatory time, while the addition of PMoB has not affected the BR reaction dynamics. The obtained different behavior of PWB and PMoB introduced the BR reaction as a systemdetector for these two types of bronzes. In order to investigate the mechanism of bronzes action in BR oscillatory reaction, the pH and electric conductivity measurements, as well as inductively coupled plasma and the cyclic voltammetry measurements were done. This work extends the practical aspect of the BR reaction for the examination of solid materials. Furthermore, the obtained results open a new section of oscillatory reaction usage in material science and catalysis in general.

Published
2019

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