586 results on '"Gvozdenović, Milica"'
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2. Electrochemical synthesis and characterization of poly(o-toluidine) as high energy storage material
- Author
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Gvozdenović, Milica M., Jugović, Braninir Z., Jokić, Bojan M., Džunuzović, Enis S., and Grgur, Braninimir N.
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- 2019
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3. The initial characteristics of the polypyrrole based aqueous rechargeable batteries with supercapattery characteristics
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Grgur, Branimir N., Janačković, Marija, Jugović, Branimir Z., and Gvozdenović, Milica M.
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- 2019
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4. Characteristics of the citrate-based zinc-polyaniline secondary cell with supercapattery behavior
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Grgur Branimir N., Gvozdenović Milica M., Jugović Branimir Z., and Trišović Tomislav Lj.
- Subjects
polyaniline ,zinc ,batteries ,pseudocapacitors ,citrates ,Chemistry ,QD1-999 - Abstract
The electrochemical characteristics of zinc–polyaniline (PANI) secondary cell in the electrolyte containing 0.8 M Na citrate, 0.3 M NH4Cl and 0.3 M ZnCl2 is investigated. Based on the measurements of potentials and voltage of the cell during charge/discharge for the currents in the range of 18 to 45 mA, the specific electrode capacity of 85 to 55 mA h g-1, the specific energy of 60–40 mW h g-1 and the specific power of 150–350 mW g-1, is determined. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. ON172046: Electrochemical synthesis and characterization of nanostructured functional materials for applications in new technologies]
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- 2019
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5. Photo-assisted electrochemical oxidation of the urea onto TiO2-nanotubes modified by hematite
- Author
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Omymen, Waleed M., Rogan, Jelena R., Jugović, Branimir Z., Gvozdenović, Milica M., and Grgur, Branimir N.
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- 2017
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6. Polyaniline stabilization of magnetic particles and immobilization of α-amylase
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Radovanović Mirjana N., Nikolić Milan P., Đurović Vesna M., Jugović Branimir Z., Gvozdenović Milica M., Grgur Branimir N., and Knežević-Jugović Zorica D.
- Subjects
Adsorption ,α-Amylase ,Magnetic particles ,Polyaniline ,Zeta potential ,FTIR ,Chemical technology ,TP1-1185 - Abstract
Magnetic particles (MAG), obtained by standard procedure of coprecipitation of Fe2+and Fe3+ in an excess of ammonia, and polyaniline modified magnetic particles MAG-PANI were used as carriers for immobilization of α-amylase from Bacillus licheniformis. The formation of a polyaniline layer (PANI) on MAG particles was achieved by chemical polymerization of aniline. Immobilization was carried out by adsorption, as a simple, inexpensive and fast method that allows retention of a large portion of the initial activity of the immobilized enzyme. FTIR spectroscopy was used to characterize the obtained particles and to confirm changes dueto formation of a PANI layer and conjugation of α-amylase on the particle surfaces. Particle size distribution was bimodal and three-modal for MAG and MAG-PANI, respectively. Appearance of a fraction of smaller MAG-PANI particles than MAG particles could be attributed to the formation of PANI particles without the MAG core. Measured values of Zeta potential for MAG-PANI were higher as compared to MAG indicating stabilization of particles in the presence of PANI. Relevant kinetic parameters for immobilized enzyme were determined from the Hanes plot. The apparent Km constant was 1.91 and 1.48 g L–1 for MAG-A and MAG-PANI-A, respectively, while m was 0.19 g L–1 min–1 for MAG and 0.32 g L–1 min–1 for MAG-PANI. The obtained values of Km indicated that modification of MAG by PANI enhanced kinetic properties of the immobilized enzyme. Moreover, the modification of MAG by PANI showed the increase in both pH and thermal stabilities of the immobilized enzyme. Studies of the operational activity of the immobilized enzyme on MAG-PANI have shown that 98.8% of starch was hydrolyzed over 20.0 min. In the first cycle in the packed bed reactor operated in a recycling mode, but approximately five times longer period was required to hydrolyze 93.5 of starch in the fifth cycle. In the continuous packed bed reactor without recycling, the degree of starch hydrolysis was not changed significantly during 4 h and was 88.8±1.6%, whereas the half-life of the biocatalyst was 6.2 h. Although coating MAG particles with a polyaniline offers many advantages, the main disadvantage is possible appearance of residues of aniline monomers and dimmers. The potential toxicity of these residues requires precise composition analysis of the product of starch hydrolysis catalyzed by α-amylase adsorbed onto MAG-PANI. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III 46010]
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- 2018
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7. Improvement of the epoxy coating properties by incorporation of polyaniline surface treated TiO2 nanoparticles previously modified with vitamin B6
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Radoman, Tijana S., Džunuzović, Jasna V., Grgur, Branimir N., Gvozdenović, Milica M., Jugović, Branimir Z., Miličević, Dejan S., and Džunuzović, Enis S.
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- 2016
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8. Oxygen reduction on SILAR deposited iron oxide onto graphite felt electrode
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Grgur, Branimir N., Jugović, Branimir Z., and Gvozdenović, Milica M.
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- 2016
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9. Photoelectochemical behavior of TiO2-NT’s modified with SILAR deposited iron oxide
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Omymen, Waleed M., Ebshish, Ali S., Jugović, Branimir Z., Trišović, Tomislav Lj., Gvozdenović, Milica M., and Grgur, Branimir N.
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- 2016
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10. Biofuel cell based on horseradish peroxidase immobilized on copper sulfide as anode for decolorization of anthraquinone AV109 dye
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Šekuljica, Nataša Ž., Gvozdenović, Milica M., Knežević-Jugović, Zorica D., Jugović, Branimir Z., and Grgur, Branimir N.
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- 2016
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11. Polypyrrole|zinc supercapattery with the aqueous electrolyte
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Janačković Marija, Gvozdenović Milica, and Grgur Branimir
- Subjects
polypyrrole ,electrochemical polymerization ,specific power ,Ragone plot ,supercapattery ,Chemical technology ,TP1-1185 - Abstract
Polypyrrole (PPY) electrode was obtained by electrochemical oxidative polymerization of pyrrole on graphite electrode from aqueous electrolyte containing 0.1 mol dm–3 pyrrole monomer and 1.0 mol dm–3 HCl. Polymerization was achieved at the constant current density of 2 mA cm–2 during 1 h. The estimated active mass of PPY (assuming that the maximal doping degree of 0.33 was achieved and the polymerization efficiency of 100%) was 14 mg. Electrochemical characterization of PPY electrode was performed by galvanostatic experiments of charge (doping) and discharge (dedoping) with different current densities in the range between 0.5 and 1.5 mA cm–2. The experiments were performed in aqueous electrolyte containing 2.0 mol dm–3 NH4Cl and 1.1 mol dm–3 ZnCl2. Based on galvanostatic charge/discharge curves, following parameters of PPY electrode were evaluated: discharge capacity, specific discharge capacity, charge capacity, specific charge capacity, and Columbic efficiency. Both charge and discharge capacities were dependent on charge/discharge currents. The values decreased by increasing charge/discharge current, except for the lowest current density where Columbic efficiency exceeded 100%, which was explained by involvement of cations, from the electrolyte, in the doping process. An electrochemical cell in which PPY electrode served as a cathode and zinc electrode as the anode with an aqueous electrolyte containing 2.0 mol dm–3 NH4Cl and 1.1 mol dm–3 ZnCl2, was formed and relevant electrochemical and electrical parameters of the cell were estimated and discussed. Charge of the Zn|PPY cell was dependent on the charge/discharge current. Charge of the cell started between 0.5 and 0.7 V and proceeded up to 1.5 V, while the open circuit voltage of the fully discharged cell was 1.3 V. Specific discharge capacity of Zn|PPY cell, calculated based on discharge times, ranged from 95 to 70 mA h g–1, decreasing linearly with increasing discharge current density. On the other hand, calculated values of the theoretical capacity of the Zn|PPY cell was 105 mA g–1, meaning that practically 90% of the theoretical capacity can be achieved by discharging the cell with low current densities, while 67% of the theoretical capacity was obtained with the highest used current density. Based on Ragon parameters, the estimated values of specific energy that ranged between 46 and 68 W h kg–1, and the specific power between 125 and 380 W kg–1, Zn|PPY cell might be classified as a “supercapattery”. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. ON172046]
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- 2017
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12. Synthesis of iridescent crystal vanadium-oxide ceramic glazes
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Jokić, Bojan, Jokić, Bojan, Gvozdenović, Milica, Jugović, Branimir, Jokić, Bojan, Jokić, Bojan, Gvozdenović, Milica, and Jugović, Branimir
- Abstract
The crystalline phase is the dominant phase in the ceramic body with a small amount of glassy phase. The preparation of ceramic glazes with characteristics similar to glass-ceramics can be performed by controlling the raw glaze composition and nucleating agent. The choice of appropriate nucleating agents that dominate bulk crystallization can be essential. Among multiple nucleating agents such as zirconia, titania, metallic molybdenum, and wolfram particles investigation of the influence of vanadium compound was not well studied on aluminum-silicate glass-ceramics. Metal such as vanadium forms oxides in an oxidation atmosphere at lower temperatures compared to metallic molybdenum and wolfram helping elucidate the effect of oxide on the crystallization behavior. Controlling the microstructure of glass-ceramic by processing parameters further control mechanical and optical properties. The addition of vanadium–pentoxide promotes the formation of entangled flower-like crystals on the porcelain ceramic body in combination with different commercial high-temperature glazes. Red and dark red colorations due to the presence of V5+ were obtained for aluminosilicate glass with a V2O5 content in the 5-10 mass % range. A pronounced spread of crystals beyond the glazed surface is observed on densely sintered stoneware and porcelain, which enables the formation of a decorative effect using simple application techniques., Kristalna faza predstavlja dominantnu fazu porcelana i kamenine sa malim udelom staklaste faze. Priprema keramičkih glazura sa karakteristikama sličnim staklo-keramici može se vršiti kontrolisanjem sastava sirove glazure i sredstva za nukleaciju. Izbor odgovarajućih agenasa ima značajan uticaj na odvijanje procesa nukleacije. Za razliku od najčešće korišćenih nukleatora, kao što je cirkonijum, titanijum, metalni molibden i čestice volframa, ispitivanje uticaja jedinjenja vanadijuma nije dovoljno istraženo u formiranju aluminijum-silikatne staklo-keramike. Metal kao što je vanadijum formira okside u oksidacionoj atmosferi na nižim temperaturama u poređenju sa metalnim molibdenom i volframom, što omogućava proučavanje uticaja oksida na proces kristalizacije. Kontrolisanjem mikrostrukture staklo-keramike kontrolom procesnih parametara moguće je dobiti staklo-keramiku željenih mehaničkih i optičkih svojstava. Dodatak vanadijum-pentoksida promoviše formiranje umrežanih igličastih kristala nalik cvetu na porcelanskoj masi u kombinaciji sa različitim komercijalnim visokotemperaturnim glazurama. Crvena i tamnocrvena boja, uzrokovana prisustvom V5+ dobijena je u alumo-silikatnoj fazi pri koncentraciji V2O5 u opsegu od 5-10 masenih %. Na gusto sinterovanoj kamenini i porcelanu primećen je izraženi rast kristala izvan glazirane površine, što omogućava stvaranje dekorativnog efekta korišćenjem jednostavnih tehnika nanošenja.
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- 2023
13. Polypyrrole on graphite: An exemplary model system for comprehensive electrochemical analysis of energy storage materials
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Popović, Aleksandra S., Gvozdenović, Milica M., Janković, Ana, Jugović, Branimir, Grgur, Branimir, Popović, Aleksandra S., Gvozdenović, Milica M., Janković, Ana, Jugović, Branimir, and Grgur, Branimir
- Abstract
Electrochemical Energy Storage (EES) technologies are playing a significant role in the aspirations to decrease the usage of fossil fuels and move toward an environmentally conscious society. Due to the importance of EES technologies, more researchers are looking for an efficient and effective electrode material, which is the most important part of the EES system that possibly could result in much-needed advancements in the field. However, incoming researchers have a diverse backgrounds and as newcomers to the electrochemical community, they sometimes lack familiarity with the core concepts, well-established procedures, and methodologies that define the standards of the discipline. This issue's importance has been acknowledged, and various publications have been written to guide researchers in doing accurate evaluations. However, to the best of our knowledge, even though these publications demonstrate the methodologies and procedures for approaching the existing challenges none of them address the offered topic with an actual example. To address this gap, we present a step-by-step procedure for the electrochemical analysis of polypyrrole, a widely utilized conducting polymer with significant potential as an electrode material for supercapacitors and batteries.
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- 2023
14. Seawater zinc/polypyrrole-air cell possessing multifunctional charge-discharge characteristics
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Al-Eggiely, Ali H., Alguail, Alsadek A., Gvozdenović, Milica M, Jugović, Branimir Z., and Grgur, Branimir N.
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- 2017
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15. The influence of m-aminobenzoic acid on electrochemical synthesis and behavior of poly(aniline-co-(m-aminobenzoic acid)
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Jokić, Bojan M., Džunuzović, Enis S., Grgur, Branimir N., Jugović, Branimir Z., Trišovic, Tomislav Lj., Stevanović, Jasmina S., and Gvozdenović, Milica M.
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- 2017
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16. Electrochemical Template-Free Synthesis of Nanofibrous Polyaniline Modified Electrode for Ascorbic Acid Determination
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Popović, Nataša, Jugović, Branimir, Jokić, Bojan, Knežević-Jugovć, Zorica, Stevanović, Jasmina, Grgur, Branimir, and Gvozdenović, Milica
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- 2015
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17. Automatic devices for electrochemical water treatment with cooling of electrolyte
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Trišović Tomislav Lj., Spasojević Miroslav D., Gvozdenović Milica M., Jugović Branimir Z., and Rafailović Lidija D.
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disinfection ,electrochlorination ,active chlorine ,electrochemical treatment of water ,Chemical technology ,TP1-1185 - Abstract
The most common disinfectants for water treatment are based on chlorine and its compounds. Practically, water treatments with chlorine compounds have no alternative, since they provide, in comparison to other effective processes such as ozonization or ultraviolet irradiation, high residual disinfection capacity. Unfortunately, all of chlorine-based compounds for disinfection tend to degrade during storage, thus reducing the concentration of active chlorine. Apart from degradation, additional problems are transportation, storage and handling of such hazardous compounds. Nowadays, a lot of attention is paid to the development of electrochemical devices for in situ production of chlorine dioxide or sodium hypochlorite as efficient disinfectants for water treatment. The most important part of such a device is the electrochemical reactor. Electrochemical reactor uses external source of direct current in order to produce disinfectants in electrochemical reactions occurring at the electrodes. Construction of an electrochemical device for water treatment is based on evaluation of optimal conditions for electrochemical reactions during continues production of disinfectants. The aim of this study was to develop a low-cost electrochemical device for the production of disinfectant, active chlorine, at the place of its usage, based on newly developed technical solutions and newest commercial components. The projected electrochemical device was constructed and mounted, and its operation was investigated. Investigations involved both functionality of individual components and device in general. The major goal of these investigations was to achieve maximal efficiency in extreme condition of elevated room temperature and humidity with a novel device construction involving coaxial heat exchanger at the solution inlet. Room operation of the proposed device was investigated when relative humidity was set to 90% and the ambient temperature of 38°C. The obtained results in such extreme operation conditions reveled that it was possible to obtain required concentration of 0.85% of active chlorine with maximal temperature of outlet electrolyte of 35.3°C, which is within the limits of optimal temperatures. [Projekat Ministarstva nauke Republike Srbije, br. 172046]
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- 2016
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18. Electrochemical and Electrical Performances of High Energy Storage Polyaniline Electrode with Supercapattery Behavior
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Gojgić, Jelena, primary, Petrović, Miloš, additional, Jugović, Branimir, additional, Jokić, Bojan, additional, Grgur, Branimir, additional, and Gvozdenović, Milica, additional
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- 2022
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19. The influence of self-doping on electrochemical synthesis and behaviour of polyaniline
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Gvozdenović, Milica M., Gvozdenović, Milica M., Jugović, Branimir, Jokić, Bojan, Džunuzović, Enis S., Grgur, Branimir, Gvozdenović, Milica M., Gvozdenović, Milica M., Jugović, Branimir, Jokić, Bojan, Džunuzović, Enis S., and Grgur, Branimir
- Abstract
Electrochemical synthesis was used to polymerize aniline and copolymerize aniline and m-aminobenzoic from aqueous acidic electrolyte containing aniline and aniline with different amount of m-aminobenzoic acid. These materials were obtained galvanostatically at graphite electrode at current density of 1.0 mA cm-2 from aqueous electrolyte containing 1.0 mol dm-3 HCl and different amount of monomers. The effect of self-doping due to meta positioned carboxylic group was observed in both synthesis parameters, morphology, degree of oxidation and electrochemical behaviour. The presence of m-aminobenzoic acid led higher copolymerization increasing with the increase of amount of m-aminobenzoic acid if comparing to polymerization potential of aniline. Moreover, the copolymer with equal amount of aniline/m-aminobenzoic acid showed electrochemical activity in neutral electrolyte which might be due to possibility of proton exchange process which can be expelled from the copolymer during oxidation process together by insertion of anions, making this material promising for use in electrochemical biosensors., Elektrohemijski postupak korišćen je za polimerizaciju anilina i kopolimerizaciju anilina i m-aminobenzoeve kiseline iz kiselog vodenog rastvora elektrolita sa različitim molskim odnosima anilina i m-aminobezoeve kiseline. Ovi materijali dobijeni su uslovima konstantne gustine struje od 1,0 mA cm-2 iz kiselog vodenog elektrolita koji je sadržavao 1,0 mol dm-3 HCl, anilin i m-aminobenzoevu kiselinu. Uticaj samo-dopovanja koji je posledica prisustva karboskilne grupe u meta položaju ispoljavao se u različitim parametrima sinteze, morfologiji dobijenih materijala, stepenu oksidacije i elektrohemijskom ponašanju. Prisustvo m-aminobenzoeve kiseline uslovilo je veći potencijal sinteze kopolimera u odnosu na polianilin koji je rastao sa porastom udela m-aminobezoeve kiseline. Kopolimer koji je dobijen iz elektrolita sa jednakim molskim odnosom anilina i m-aminobenzoeve kiseline pokazao je elektrohemijsku aktivnost u neutralnom elektrolitu koja može biti posledica razmene protona što ovaj materijal čini perspektivnim za praktičnu primenu u elektrohemijskim biosenzorima.
- Published
- 2021
20. Treatment of Waste Copper Electrolytes Using Insoluble and Soluble Anodes
- Author
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Markovic, Radmila, Stevanovic, Jasmina, Gvozdenovic, Milica, Jugovic, Branimir, Grujic, Aleksandar, Nedeljkovic, Dragutin, and Stajic-Trosic, Jasna
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- 2013
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21. The influence of thin benzoate-doped polyaniline coatings on corrosion protection of mild steel in different environments
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Elkais, Ali R., Gvozdenović, Milica M., Jugović, Branimir Z., and Grgur, Branimir N.
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- 2013
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22. Electrochemical synthesis of electroconducting polymers
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Gvozdenović Milica M., Jugović Branimir Z., Stevanović Jasmina S., and Grgur Branimir N.
- Subjects
electrochemical synthesis ,anode ,polyaniline ,polypyrrole ,Chemical technology ,TP1-1185 - Abstract
Electroconducting polymers from the group of synthetic metals are extensively investigated due to numerous properties perspective in practical application. These materials may be synthesized by both chemical and electrochemical procedures. Chemical synthesis is suitable when bulk quantities of the polymer are needed and up to date it presents dominant commercial method of producing electroconducting polymers. Nevertheless, electrochemical synthesis has its advantages; it avoids usage of oxidants since conducting polymeric material is obtained at anode upon application of positive potential, leading to increased purity. On the other hand, since the polymer is deposited onto electrode, further electrochemical characterization is facilitated. Owing to actuality of the research in the field this texts aims to describe important aspects of electrochemical synthesis of electroconducting polymers, with special emphasis to polyaniline and polypyrrole. [Projekat Ministarstva nauke Republike Srbije, br. 172046]
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- 2014
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23. Treatment of waste sulfuric acid copper electrolyte
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Marković Radmila, Stevanović Jasmina, Gvozdenović Milica, and Jakšić Jelena M.
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anode ,electrolyte refining ,waste electrolyte ,copper ,nickel ,Mining engineering. Metallurgy ,TN1-997 - Abstract
The aim of this paper was to investigate the possibility of using the copper anodes with high nickel content for electrolytic treatment of waste sulfuric acid copper electrolyte. Nickel content in each anode was about 10 wt. %. Lead, antimony, and tin content was within the limits ranged from 0.1 to 1.4 wt. %. Copper mass content in anodes was in the range from 86 to 90 wt. %, and was mathematical deference to 100 wt. %. Electrolytic processing was done in galvanostatic conditions at the current density of 250 A/m2, electrolyte temperature of 63 ± 2 ° C, duration of each test of 72 h. The mass of each anode was about 7 kg. The waste sulfuric acid electrolyte with concentration of 30 g dm3 Cu2+ ions and 225 g/dm3 SO4 2- ions was used as the working solution. Changing the anode mass, changing the content of copper and nickel ions in the working solution and the mass of obtained cathode deposit were the subject of discussion in this paper. The difference in weight of anode at the beginning and end of the process confirmed that the anodes are dissolved during the process. A significant reduction of Cu2+ ions concentration was achieved as well as an increase in concentration of Ni2+ ions in the working solution. Mass of cathode deposit, obtained during electrolytic refining of anode with the smallest impurity content, was greater than the mass of dissolved correspondent anode for about 2%. Mass of cathode deposit, obtained by refining the anode with the content of Pb + Sn + Sb from 1.5 to 3.5 wt. %, was less than the mass of dissolved correspondent anode by about 2 %.
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- 2014
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24. Uniaxial tension of drying sieves
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Bojić Nada V., Nikolić Ružica R., Jugović Branimir Z., Jugović Zvonimir S., and Gvozdenović Milica M.
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drying sieve ,thermo stabilization ,joining spiral ,tensile forces ,Chemical technology ,TP1-1185 - Abstract
Although the literature contains numerous studies that have been developed to describe the nonlinear behavior of drying sieves' operation, there are no papers in this which report deeper investigation of the drying sieve behavior when exposed to tension and thermo stabilization. The aim of this paper is to provide insight into the elastoplastic behavior of the thermo stabilized and not stabilized sieves subjected to the tensile force. Within this work both theoretical and experimental investigations were performed. The sieves were joined by using a spiral. In separate experiments tests of wire base and weft of the weave mesh were performed, both for thermo stabilized and not thermo stabilized sieves, sieves joining and the sieve thermo stabilization itself. It was established that the thermo stabilization of sieves provides for stability of sieves' dimensions and that open thermo stabilized drying sieve exhibits better mechanical properties and exploitation characteristics then the sieves joining. [Projekat Ministarstva nauke Republike Srbije, br. ON174004: Micromechanics criteria of damage and fracture and br. TR 32036: Development of software for solving the coupled multi-physical problems]
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- 2013
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25. Partitioning of cellulolytic activity in the polyethylene glycol/dextran two-phase systems
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Antov Mirjana G., Jugović Branimir Z., Gvozdenović Milica M., and Knežević-Jugović Zorica D.
- Subjects
aqueous two-phase system ,cellulolytic activity ,partitioning ,purification ,Technology (General) ,T1-995 - Abstract
This study is concerned with the partitioning of cellulolytic activity in the polyethylene glycol/dextran two-phase systems. In the system of 10% (w/w) polyethylene glycol 1500/5% (w/w) dextran 500,000/80% (w/w) crude enzyme at the pH 5, 100%, yield of cellulolytic activity from Penicillium sp. in the top phase was achieved in a single extraction step. Addition of KH2PO4 to this system at a concentration of 15 mmol/L improved the purification factor in the top phase for cellulolytic activity from crude preparation to a value of 2.6, although it had an adverse effect on the yield in the same phase. [Projekat Ministarstva nauke Republike Srbije, br. 46010]
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- 2012
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26. Electrochemical synthesis and corrosion behavior of thin polyaniline film on mild steel, copper and aluminum
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Elkais Ali Ramadan, Gvozdenović Milica M., Jugović Branimir Z., Trišović Tomislav Lj., Maksimović Miodrag M., and Grgur Branimir N.
- Subjects
polyaniline ,mild steel ,copper ,aluminum ,corrosion ,Chemical technology ,TP1-1185 - Abstract
The electrochemical synthesis of polyaniline (PANI) on mild steel, aluminum and copper from the sodium benzoate solutions has been investigated. It has been shown that thin, highly adherent, polyaniline films on the investigated metals could be obtained by anodic oxidation with current densities in the range of 0.5 and 1.5 mA cm-2. The corrosion behavior of mild steel, aluminum and copper with polyaniline coating in 0.5 mol dm3 NaCl (pH 3) solutions, has been investigated by polarization technique. The corrosion current densities, porosity and protection efficiency was determined. It has been shown that polyaniline coating provided corrosion protection of all mentioned metals.
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- 2011
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27. Influence of chloride ion concentration on initial corrosion of AZ63 magnesium alloy
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Grgur, Branimir, Grgur, Branimir, Jugović, Branimir, Gvozdenović, Milica M., Grgur, Branimir, Grgur, Branimir, Jugović, Branimir, and Gvozdenović, Milica M.
- Abstract
The initial corrosion behavior of AZ63 magnesium alloy was investigated in 1, 3, 5 and 7 wt.% NaCl solutions by means of corrosion potential, linear polarization, electrochemical impedance spectroscopy, and polarization measurements, during exposure in the corrosion media. Results show that the increase in chloride concentration provokes an increase in the corrosion rate. Based on the obtained kinetics parameters the mechanisms of anodic dissolution and hydrogen evolution reactions were discussed, and kinetic models were proposed. It is concluded that anodic dissolution proceeds under Temkin conditions and hydrogen evolution reaction depends on the surface coverage of Mg(OH)2 species.
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- 2022
28. Corrosion behavior of copper in 3 % NaCl with addition of cynarae extract
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Jokić, Bojan, Jokić, Bojan, Gvozdenović, Milica, Jovanović, Marijana, Jugović, Branimir, Grgur, Branimir, Jokić, Bojan, Jokić, Bojan, Gvozdenović, Milica, Jovanović, Marijana, Jugović, Branimir, and Grgur, Branimir
- Abstract
In this work, corrosion behavior of cooper in corrosion media consisted of aerated aqueous electrolyte of 3% NaCl with addition of different amount of cynarae extract as green corrosion inhibitor, is presented. Techniques used in this study involved open circuit measurements, evaluation of charge transfer resistance and corrosion current density during exposure to corrosion environment. Also, electrochemical impedance spectroscopy measurements are presented. Potentiodymamic polarization curves were also used for the evaluation of the corrosion current density and corrosion potential of coper in corrosion media. Based on these results, it was concluded that the satisfactory results of corrosion inhibition exceeding 70 % were obtained with small amount of only 37*10-2 of mas. % of cynarae extract, based on open circuit behavior which involved decrease of the open circuit potentials of copper in the presence of cynarae extract it was concluded that this extract served as cathodic inhibitor., Koroziono ponašanje bakra u aerisanom vodenom rastvoru 3% NaCl bez i sa dodatkom različite količine ekstrakta cynarae (artičoka) je ispitano u cilju evaluacije inhibicije korozije bakra i mogućnosti primene ekstrakta cynarae kao zelenog inhibitora korozije. Za evaluaciju efikasnosti zaštite korišćene su uobičajene eksperimntalne tehnike praćenja potencija otvorenog kola, otpornosti prenosa naelektrisanja i struje korozije u vremenu kao i spektroskopija elektrohemijske impedancije. Ustanovljeno je da veoma male količine ovog inhibitora od svega 37*10-2 mas. % pružaju zadovoljavajuću zaštitu od korozije u 3% NaCl. Na osnovu smanjenja potencijala otvorenog kola bakra u prisustvu ekstrakta cynarae, ustanovljeno je da je inhibitor katodnog tipa.
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- 2022
29. Electrical properties of electrochemically co-polymerized aniline and sulphanilic acid
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Novaković, Nikola, Novaković, Nikola, Petrović, Miloš, Jugović, Branimir, Grgur, Branimir, Gvozdenović, Milica, Novaković, Nikola, Novaković, Nikola, Petrović, Miloš, Jugović, Branimir, Grgur, Branimir, and Gvozdenović, Milica
- Abstract
Electrochemical synthesis of poly(aniline-co-(sulfanilic acid)) was performed on a graphite electrode with constant current densities from an aqueous electrolyte containing 1.0 mol dm-3 H2SO4 and 0.25 mol dm-3 monomers with different ratios of aniline and sulfanilic acid. Optimal conditions for copolymerization were set to the current density of 0.75 mA cm-2 and the electrolyte containing 0.15 mol dm-3 aniline and 0.10 mol dm-3 sulfanilic acid. Electrochemical characterization of the poly(aniline-co-(sulfanilic acid)) electrode was performed using cyclic voltammetry and galvanostatic charge/discharge techniques. Electrical properties such as specific power and specific energy at different discharge currents were also determined. Based on the Ragon plot, it was observed that the poly(aniline-co-(sulfanilic acid)) electrode exhibited battery features at low discharge currents. In contrast, it was possible to achieve specific power of supercapacitors at high discharge currents. Moreover, after 4000 cycles of charge/discharge poly(aniline-co-(sulfanilic acid)), capacity retention exceeding 90 % was obtained., Elektrohemijska kopolimerizacija anilina i sulfanilne kiseline ostvarena je u galvanostatskim uslovima različitim gustinama struje na grafitnoj elektrodi. Kao elektrolit korišćen je vodeni rastvor 1.0 mol dm-3 H2SO4 sa dodatkom 0.25 mol dm-3 monomera različitog odnosa anilina i sulfanilne kiseline. Izabrani su optimalni uslovi za sintezu u pogledu gustine struje polimerizacije od 0.75 mA cm-2 i sastava elektrolita koji je sadržavao 0.15 mol dm-3 anilina i 0.10 mol dm-3 sulfanilne kiseline. Za elektrohemijsku karakterizaciju elektrode na bazi kopolimera anilina i sulfanilne kiseline korišćene su tehnike ciklične voltametrije i snimanja hronopotenciometrijskih krivih punjenja/pražnjenja. Na osnovu krivih pražnjenja procenjene su električne karakteristike ove elektrode: specifična energija i specifična snaga. Na osnovu Ragonovog dijagrama pokazano je da elektroda na bazi kopolimera anilina i sulfanilne kiseline poseduje baterijska svojstva pri niskim strujama pražnjenja, dok se pri visokim strujama pražnjenja ponaša kao elektroda superkondenzatora. Takođe, ova elektroda je nakon 4000 ciklusa punjenja i pražnjenja zadržala preko 90 % početnog kapaciteta.
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- 2022
30. Electrochemical and Electrical Performances of High Energy Storage Polyaniline Electrode with Supercapattery Behavior
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Gojgić, Jelena, Gojgić, Jelena, Petrović, Miloš, Jugović, Branimir, Jokić, Bojan, Grgur, Branimir, Gvozdenović, Milica, Gojgić, Jelena, Gojgić, Jelena, Petrović, Miloš, Jugović, Branimir, Jokić, Bojan, Grgur, Branimir, and Gvozdenović, Milica
- Abstract
Polyaniline (PANI), due to its highly reversible electrochemistry with superior energy storage and delivery characteristics, is considered as an electrode material in batteries, capacitors, and hybrid systems. We used a facile electrochemical synthesis for the formation of the PANI electrode using galvanostatic polymerization of aniline on the graphite electrode at the current density of 2.0 mA cm−2 from the aqueous electrolyte containing 0.25 mol dm−3 aniline and 1.0 mol dm−3 H2SO4. Electrochemical and electrical characterization suggested excellent energy storage features of the PANI electrode in a three-electrode system with specific energy up to 53 Wh kg−1 and specific power up to 7600 W kg−1. After 2000 successive charge/discharge cycles at 9.5 Ag−1, the PANI electrode retained 95% of the initial capacity, with practically unaltered Coulombic efficiency of nearly 98%, providing a good base for future studies and practical applications.
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- 2022
31. Capacitive properties of electrochemically synthesized polyaniline on graphite electrode
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Gojgić, Jelena, Gojgić, Jelena, Petrović, Miloš, Jugović, Branimir, Grgur, Branimir, Jokić, Bojan, Gvozdenović, Milica, Gojgić, Jelena, Gojgić, Jelena, Petrović, Miloš, Jugović, Branimir, Grgur, Branimir, Jokić, Bojan, and Gvozdenović, Milica
- Abstract
Intrinsically conducting polymers, especially polyaniline (PANI), are widely investigated in the field of energy storage and conversion due to the highly reversible electrochemistry of doping/dedoping. These reactions are responsible for PANI’s high capacitance, often reported as pseudocapacitance. In this work, PANI electrodes were obtained by electrochemical polymerization of aniline monomer, with different polymerization charges ranging between 0.125 and 1.0 mA cm-2, on a graphite electrode, at the constant current density of 2.0 mA cm-2. The electrolyte used in this study consisted of 1.0 mol dm-3 H2SO4 and 0.2 mol dm-3 aniline. Electrochemical characterization of the PANI electrode involved cyclic voltammetry, chronopotentiometric charge/discharge and electrochemical impedance spectroscopy at constant potentials. Specific capacitance was determined from these techniques following the procedure for pseudocapacitive electrodes. After 250 cycles of charge/discharge with the current density of 10 mA cm-2, only 7 % of the capacitance was lost, indicating good stability of PANI that likely originates from its structure comprising a shared divalent sulfate ion between two monomer units., Elektroprovodni polimeri, prvenstveno polianilin (PANI), su intenzivno proučavani u oblasti konverzije i skladištenja električne energije, zahvaljujući visokoj reverzibilnosti reakcije dopovanja/dedopovanje. Ove reakcije su odgovorne za visoku specifičnu kapacitivnost PANI koja se često u literaturi označava kao pseudokapacitivnost. U ovom radu, elektrode na bazi PANI dobijene su oksidativnom elektrohemijskom polimerizacijom anilina različitim kapacitetima polimerizacije u opsegu od 0,125 do 1,0 mA cm-2 na elektrodi od grafita u galvanostatskim uslovima gustinom struje od 2,0 mA cm-2. Kao elektrolit korišćen je vodeni rastvor 1,0 mol dm-3 H2SO4 uz dodatak 0,2 mol dm-3 anilina. Za elektrohemijsku karakterizaciju elektrode na bazi PANI korišćene su tehnike ciklične voltametrije, hronopotenciometrijskog snimanja krivih punjenja/pražnjenja i spektroskopija elektrohemijske impedanse na konstantnom potencijalu. Specifična kapacitivnost PANI elektrode određivana je na način uobičajen za pseudokapacitivne elektrode. Na osnovu 250 sukcesivnih ciklusa punjenja i pražnjenja gustinom struje od 10 mA cm-2, utvrđeno je gubitak kapacitivnosti od svega 7%, što se verovatno može dovesti u vezu sa povećanom stabilnošću PANI usled strukture koja podrazumeva deljenje dvovalentnog sulfatnog jona između dve jedinice monomera.
- Published
- 2022
32. Electrochemically synthesized polyaniline as support for lipase immobilization
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Bezbradica, Dejan, Jugović, Branimir, Gvozdenović, Milica, Jakovetić, Sonja, and Knežević-Jugović, Zorica
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- 2011
- Full Text
- View/download PDF
33. Electrochemical synthesis and characterization of polyaniline thin film and polyaniline powder
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Elkais, Ali Ramadan, Gvozdenović, Milica M., Jugović, Branimir Z., Stevanović, Jasmina S., Nikolić, Nebojša D., and Grgur, Branimir N.
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- 2011
- Full Text
- View/download PDF
34. The effect of the concentration of the reacting ion on the control of the electrodeposition process
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Živković Predrag M., Nikolić Nebojša D., Gvozdenović Milica, and Popov Konstantin I.
- Subjects
polarization curve equation ,concentration dependence ,Chemistry ,QD1-999 - Abstract
The effect of the concentration of the reacting ion on the nature of the control of the electrodeposition process was investigated by digital simulation of the polarization curve using the Newman form of the polarization curve equation and the Levich dependence of the limiting diffusion current density under natural convection conditions. A simple method for the determination of the exchange current density from polarization measurements is also proposed. The agreement with experiments was correct.
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- 2009
- Full Text
- View/download PDF
35. Električna svojstva elektrohemijski kopolimerizovanog anilina i sulfanilne kiseline
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Novaković, Nikola, Petrović, Miloš, Jugović, Branimir, Grgur, Branimir, and Gvozdenović, Milica
- Subjects
electrochemical synthesis ,poly(aniline-co-(sulfanilic acid)) ,Ragone plot ,specific power ,specific energy - Abstract
Electrochemical synthesis of poly(aniline-co-(sulfanilic acid)) was performed on a graphite electrode with constant current densities from an aqueous electrolyte containing 1.0 mol dm-3 H2SO4 and 0.25 mol dm-3 monomers with different ratios of aniline and sulfanilic acid. Optimal conditions for copolymerization were set to the current density of 0.75 mA cm-2 and the electrolyte containing 0.15 mol dm-3 aniline and 0.10 mol dm-3 sulfanilic acid. Electrochemical characterization of the poly(aniline-co-(sulfanilic acid)) electrode was performed using cyclic voltammetry and galvanostatic charge/discharge techniques. Electrical properties such as specific power and specific energy at different discharge currents were also determined. Based on the Ragon plot, it was observed that the poly(aniline-co-(sulfanilic acid)) electrode exhibited battery features at low discharge currents. In contrast, it was possible to achieve specific power of supercapacitors at high discharge currents. Moreover, after 4000 cycles of charge/discharge poly(aniline-co-(sulfanilic acid)), capacity retention exceeding 90 % was obtained. Elektrohemijska kopolimerizacija anilina i sulfanilne kiseline ostvarena je u galvanostatskim uslovima različitim gustinama struje na grafitnoj elektrodi. Kao elektrolit korišćen je vodeni rastvor 1.0 mol dm-3 H2SO4 sa dodatkom 0.25 mol dm-3 monomera različitog odnosa anilina i sulfanilne kiseline. Izabrani su optimalni uslovi za sintezu u pogledu gustine struje polimerizacije od 0.75 mA cm-2 i sastava elektrolita koji je sadržavao 0.15 mol dm-3 anilina i 0.10 mol dm-3 sulfanilne kiseline. Za elektrohemijsku karakterizaciju elektrode na bazi kopolimera anilina i sulfanilne kiseline korišćene su tehnike ciklične voltametrije i snimanja hronopotenciometrijskih krivih punjenja/pražnjenja. Na osnovu krivih pražnjenja procenjene su električne karakteristike ove elektrode: specifična energija i specifična snaga. Na osnovu Ragonovog dijagrama pokazano je da elektroda na bazi kopolimera anilina i sulfanilne kiseline poseduje baterijska svojstva pri niskim strujama pražnjenja, dok se pri visokim strujama pražnjenja ponaša kao elektroda superkondenzatora. Takođe, ova elektroda je nakon 4000 ciklusa punjenja i pražnjenja zadržala preko 90 % početnog kapaciteta.
- Published
- 2022
36. Kapacitivna svojstva elekrode na bazi elektrohemijski formiranog polianilina
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Gojgić, Jelena, Petrović, Miloš, Jugović, Branimir, Grgur, Branimir, Jokić, Bojan, and Gvozdenović, Milica
- Subjects
specific capacitance ,discharge curves ,electrochemical polymerization ,polyaniline - Abstract
Intrinsically conducting polymers, especially polyaniline (PANI), are widely investigated in the field of energy storage and conversion due to the highly reversible electrochemistry of doping/dedoping. These reactions are responsible for PANI’s high capacitance, often reported as pseudocapacitance. In this work, PANI electrodes were obtained by electrochemical polymerization of aniline monomer, with different polymerization charges ranging between 0.125 and 1.0 mA cm-2, on a graphite electrode, at the constant current density of 2.0 mA cm-2. The electrolyte used in this study consisted of 1.0 mol dm-3 H2SO4 and 0.2 mol dm-3 aniline. Electrochemical characterization of the PANI electrode involved cyclic voltammetry, chronopotentiometric charge/discharge and electrochemical impedance spectroscopy at constant potentials. Specific capacitance was determined from these techniques following the procedure for pseudocapacitive electrodes. After 250 cycles of charge/discharge with the current density of 10 mA cm-2, only 7 % of the capacitance was lost, indicating good stability of PANI that likely originates from its structure comprising a shared divalent sulfate ion between two monomer units. Elektroprovodni polimeri, prvenstveno polianilin (PANI), su intenzivno proučavani u oblasti konverzije i skladištenja električne energije, zahvaljujući visokoj reverzibilnosti reakcije dopovanja/dedopovanje. Ove reakcije su odgovorne za visoku specifičnu kapacitivnost PANI koja se često u literaturi označava kao pseudokapacitivnost. U ovom radu, elektrode na bazi PANI dobijene su oksidativnom elektrohemijskom polimerizacijom anilina različitim kapacitetima polimerizacije u opsegu od 0,125 do 1,0 mA cm-2 na elektrodi od grafita u galvanostatskim uslovima gustinom struje od 2,0 mA cm-2. Kao elektrolit korišćen je vodeni rastvor 1,0 mol dm-3 H2SO4 uz dodatak 0,2 mol dm-3 anilina. Za elektrohemijsku karakterizaciju elektrode na bazi PANI korišćene su tehnike ciklične voltametrije, hronopotenciometrijskog snimanja krivih punjenja/pražnjenja i spektroskopija elektrohemijske impedanse na konstantnom potencijalu. Specifična kapacitivnost PANI elektrode određivana je na način uobičajen za pseudokapacitivne elektrode. Na osnovu 250 sukcesivnih ciklusa punjenja i pražnjenja gustinom struje od 10 mA cm-2, utvrđeno je gubitak kapacitivnosti od svega 7%, što se verovatno može dovesti u vezu sa povećanom stabilnošću PANI usled strukture koja podrazumeva deljenje dvovalentnog sulfatnog jona između dve jedinice monomera.
- Published
- 2022
37. Production of Antioxidant Egg White Hydrolysates in a Continuous Stirred Tank Enzyme Reactor Coupled with Membrane Separation Unit
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Jakovetić, Sonja, Luković, Nevena, Jugović, Branimir, Gvozdenović, Milica, Grbavčić, Sanja, Jovanović, Jelena, and Knežević-Jugović, Zorica
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- 2015
- Full Text
- View/download PDF
38. Corrosion behavior of duplex polyaniline/epoxy coating on mild steel in 3% NaCl
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Gvozdenović Milica M., Grgur Branimir N., Kačarević-Popović Zorica M., and Mišković-Stanković Vesna B.
- Subjects
polyaniline ,electro-deposition ,epoxy coatings ,corrosion ,thermal stability ,Chemical technology ,TP1-1185 - Abstract
The corrosion behavior and thermal stability of epoxy coatings electrodeposited on mild steel and on mild steel with electrochemically deposited polyaniline (PANI) film were investigated by electrochemical impedance spectroscopy (EIS) and thermo gravimetric analysis (TGA). The aim of the paper was to present new findings on the corrosion protection of mild steel by a duplex PANI/-epoxy coating in 3% NaCI solution and to determine the effect of thin PANI film on the protective properties of the coating. PANI film was deposited electrochemically on mild steel from an aqueous solution of 0.5 mol dm"3 sodium benzoate and 0.1 mol dm"3 aniline at a constant current density of 1.5 mA cm"2. Non-pigmented epoxy coatings on mild steel and on mild steel with PANI film were obtained by cathodic electrode position at constant voltage and stirring conditions. The resin concentration in the electrode position bath was 10 wt.% solid dispersion in water at pH 5.7. The applied voltage was 250 V, the temperature 26°C and the deposition time 3 min. It was shown that thin PANI film could be used to modify the surface of mild steel prior to epoxy coating deposition, due to the increased corrosion protection of a duplex PANI/epoxy coating comparing to an epoxy coating on mild steel in 3% NaCl solution.
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- 2005
- Full Text
- View/download PDF
39. Synthesis of Aliphatic Esters of Cinnamic Acid as Potential Lipophilic Antioxidants Catalyzed by Lipase B from Candida antarctica
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Jakovetić, Sonja M., Jugović, Branimir Z., Gvozdenović, Milica M., Bezbradica, Dejan I., Antov, Mirjana G., Mijin, Dušan Ž., and Knežević-Jugović, Zorica D.
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- 2013
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40. Copper-Sulfate Pentahydrate as a Product of the Waste Sulfuric Acid Solution Treatment
- Author
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Marković, Radmila, Stevanović, Jasmina, Avramović, Ljiljana, Nedeljković, Dragutin, Jugović, Branimir, Stajić-Trošić, Jasna, and Gvozdenović, Milica
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- 2012
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- View/download PDF
41. Uticaj samodopovanja na elektrohemijsku sintezu i svojstva polianilina
- Author
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Gvozdenović, Milica M., Jugović, Branimir, Jokić, Bojan, Džunuzović, Enis S., and Grgur, Branimir
- Subjects
electrochemical polzmerization ,m-aminobenzoic acid ,self-doping ,aniline - Abstract
Electrochemical synthesis was used to polymerize aniline and copolymerize aniline and m-aminobenzoic from aqueous acidic electrolyte containing aniline and aniline with different amount of m-aminobenzoic acid. These materials were obtained galvanostatically at graphite electrode at current density of 1.0 mA cm-2 from aqueous electrolyte containing 1.0 mol dm-3 HCl and different amount of monomers. The effect of self-doping due to meta positioned carboxylic group was observed in both synthesis parameters, morphology, degree of oxidation and electrochemical behaviour. The presence of m-aminobenzoic acid led higher copolymerization increasing with the increase of amount of m-aminobenzoic acid if comparing to polymerization potential of aniline. Moreover, the copolymer with equal amount of aniline/m-aminobenzoic acid showed electrochemical activity in neutral electrolyte which might be due to possibility of proton exchange process which can be expelled from the copolymer during oxidation process together by insertion of anions, making this material promising for use in electrochemical biosensors. Elektrohemijski postupak korišćen je za polimerizaciju anilina i kopolimerizaciju anilina i m-aminobenzoeve kiseline iz kiselog vodenog rastvora elektrolita sa različitim molskim odnosima anilina i m-aminobezoeve kiseline. Ovi materijali dobijeni su uslovima konstantne gustine struje od 1,0 mA cm-2 iz kiselog vodenog elektrolita koji je sadržavao 1,0 mol dm-3 HCl, anilin i m-aminobenzoevu kiselinu. Uticaj samo-dopovanja koji je posledica prisustva karboskilne grupe u meta položaju ispoljavao se u različitim parametrima sinteze, morfologiji dobijenih materijala, stepenu oksidacije i elektrohemijskom ponašanju. Prisustvo m-aminobenzoeve kiseline uslovilo je veći potencijal sinteze kopolimera u odnosu na polianilin koji je rastao sa porastom udela m-aminobezoeve kiseline. Kopolimer koji je dobijen iz elektrolita sa jednakim molskim odnosom anilina i m-aminobenzoeve kiseline pokazao je elektrohemijsku aktivnost u neutralnom elektrolitu koja može biti posledica razmene protona što ovaj materijal čini perspektivnim za praktičnu primenu u elektrohemijskim biosenzorima.
- Published
- 2021
42. Influence of surface processes on the current-voltage characteristic of organic solar cells
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Gojanović, Jovana, Matavulj, Petar, Gvozdenović, Milica, Ćirović, Nataša, Khalf, Ali Ramadan Ahmed, Gojanović, Jovana, Matavulj, Petar, Gvozdenović, Milica, Ćirović, Nataša, and Khalf, Ali Ramadan Ahmed
- Abstract
Organic solar cells (OSCs) are emerging low-cost, easy production photovoltaics. Their efficiency is strongly affected by the interface physics that needs to be researched. In this thesis, the interface physics of metal/inorganic semiconductor and metal/organic semiconductor contacts is considered. The basic structures and operation principles of OSCs are reviewed and a detailed description of the drift-diffusion model (DDM) used for modeling the OSCs is included. An extensive and detailed literature review of different physical effects that can cause the S-kink appearance in the current density-voltage (J-V) characteristics of OSCs is presented. The original research results on ITO/(poly(3,4‒ethilenedioxythiophene):poly (styrenesulfonate))PEDOT:PSS/(poly(3‒hexylthiophene))P3HT:(1‒(3‒methoxycarbonyl)propyl‒1‒phenyl‒[6,6]‒methanofullerene) PCBM/Al and ITO/PEDOT:PSS/P3HT:(indene‒C60 bisadduct) ICBA/Al solar cells are presented and discussed. The influence of the surface processes on the shape of OSCs’ J-V characteristics has been investigated by DDM. The surface recombination and thermal injection of charge carriers on the anode and cathode are taken into account through boundary conditions. It is deduced that there are two different types of S-shape deviations in OSCs' J-V characteristics, one arises from the reduced surface recombination velocities (SRVs), and the other is attributed to the large (>0.2eV) injection barrier height for electrons. The measured J-V characteristics of ITO/PEDOT:PSS/P3HT:PCBM/Al and ITO/PEDOT:PSS/P3HT:ICBA/Al solar cells are reproduced well by the DDM. It is anticipated that the S-shaped J-V curves of ITO/PEDOT:PSS/P3HT:ICBA/Al solar cells originate from the large electron barrier height on the cathode, rather than by the reduction of the SRVs., Органске соларне ћелије су јефтине фотоволтаичне направе лаке производње. Њихова ефикасност јако зависи од контактне физике на електродним спојевима коју треба истражити. У овој тези, у уводном делу, разматрана је физика на споју метала и неорганског полупроводника, као и на споју метала и органског полупроводника. Представљене су основне структуре и описан је принцип рада органских соларних ћелија (ОСЋ), а дрифт-дифузиони модел (ДДМ) који се користи за моделовање ОСЋ је детаљно размотрен. Саставни део дисертације је и опсежан преглед литературе на тему различитих физичких ефеката који могу проузроковати појаву S-девијације струјно-напонске (I-V) карактеристике ОСЋ. Спроведено је оригнално истраживање на ITO/(poly(3,4‒ethilenedioxythiophene):poly (styrenesulfonate))PEDOT:PSS/(poly(3‒hexylthiophene))P3HT:(1‒(3‒methoxycarbonyl)propyl‒1‒phenyl‒[6,6]‒methanofullerene) PCBM/Al and ITO/PEDOT:PSS/P3HT:(indene‒C60 bisadduct) ICBA/Al соларним ћелијама и добијени резултати су представљени и продискутовани. Утицај површинских процеса на облик I-V карактеристике ОСЋ је испитан помоћу ДДМ. Површинска рекомбинација и термичка инјекција носилаца наелектрисања на аноди и катоди узете су у обзир кроз граничне услове. Закључено је да постоје две различите врсте S-девијације I-V криве ОСЋ. Прва врста потиче од редукованих брзина површинске рекомбинације (БПР) док се друга врста може приписати великој висини инјекционе баријере (>0,2eV) за електроне. Измерене I-V карактеристике ITO/PEDOT:PSS/P3HT:PCBM/Al и ITO/PEDOT:PSS/P3HT:ICBA/Al соларних ћелија су добро репродуковане помоћу ДДМ. Утврђено је да S-девијација I-V кривих ITO/PEDOT:PSS/P3HT:ICBA/Al соларних ћелија потиче од велике висине инјекционе баријере за електроне на катоди, а не од редукованих БПР.
- Published
- 2021
43. Aqueous electrolyte polypyrrole | zinc cell with supercapattery performance
- Author
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Janačković, Marija, Janačković, Marija, Gvozdenović, Milica M., Jugović, Branimir, Grgur, Branimir, Janačković, Marija, Janačković, Marija, Gvozdenović, Milica M., Jugović, Branimir, and Grgur, Branimir
- Abstract
Electrochemical oxidative polymerization at constant current density was used to produce polypyrrole (PPY) at graphite electrode from aqueous acidic electrolyte containing 0,1 mol dm-3 pyrrole and 1,0 mol dm-3 HCl. PPY electrode was than used as cathode while zinc electrode served as anode in electrochemical cell with an aqueous electrolyte containing 2,0 mol dm-3 NH4Cl and 1,1 mol dm-3 ZnCl2. The relevant electrochemical parameters of this cell were evaluated from electrochemical experiments. It was observed that charge of Zn|PPY cell started at voltage between 0,5 and 0,7 V and proceeded up to 1,5 V. Charge/discharge of the cell was dependent on charge/discharge current density with open circuit voltage of the fully discharged cell around 1,3 V. The estimated values of specific energy were between 46 and 68 W h kg-1 while specific power values were between 125 and 380 W kg-1, which suggested that Zn|PPY cell had “supercapaterry” behavior., Elektroda na bazi polipirola (PPY) dobijena je elektrohemijskom oksidativnom polimerizacijom na grafitnoj elektrodi u uslovima konstantne gustine struje. Kao elektrolit za sintezu, korišćen je vodeni rastvor 0,1 mol dm-3 pirola i 1,0 mol dm-3 HCl. Formirana je elektrohemijska ćelija u kojoj je elektroda na bazi PPY korišćena kao katoda dok je anoda bila elektroda od cinka, a elektrolit se sastojao od vodenog rastvora 2,0 mol dm-3 NH4Cl i 1,1 mol dm-3 ZnCl2. Procena relevantnih elektrohemijskih i električnih parametara ove ćelije bazirana je na elektrohemijskim eksperimentima. Utvrđeno je da je proces punjenja/pražnjenja zavisio od struje punjenja/pražnjenja, punejnje ćelije započinje na naponu između 0,5 i 0,7 V, a završava se na naponu od oko 1,3 V. Procenjene vrednosti energije bile su između 46 i 68 W h kg-1, dok se za specifičnu snagu dobijaju vrednosti između 125 i 380 W kg-1, što ukazuje na superkapabaterijska svojstva Zn|PPY ćelije.
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- 2021
44. Kinetics of the mild steel corrosion protection by polypyrrole-oxalate coating in sulfuric acid solution
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Grgur, Branimir N., Živković, Predrag, and Gvozdenović, Milica M.
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- 2006
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45. A kinetic study of d-glucose oxidation by bromine in aqueous solutions
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Grgur, Branimir N., Žugić, Dragana L., Gvozdenović, Milica M., and Trišović, Tomislav Lj.
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- 2006
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46. Redukcija kiseonika na polikristalnim elektrodama zlata, paladijuma i zlata modifikovanog 'ostrvima' paladijuma
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Grgur, Branimir N., Štrbac, Svetlana, Rakočević, Zlatko, Gvozdenović, Milica, Srejić, Irina Lj., Grgur, Branimir N., Štrbac, Svetlana, Rakočević, Zlatko, Gvozdenović, Milica, and Srejić, Irina Lj.
- Abstract
Reakcija redukcije kiseonika je izučavana u kiseloj i baznoj sredini na dobro definisanim polikristalnim elektrodama zlata, Au(poly), paladijuma, Pd(poly), kao i na bimetalnim, Pd/Au(poly), elektrodama. Modifikovane Pd/Au(poly) elektrode su dobijene metodom spontane depozicije paladijuma na Au(poly) supstrat, kod koje se jednostavnim variranjem vremena deponovanja postižu različite pokrivenosti. Površinska morfologija radnih elektroda je ispitivana tehnikom mikroskopije atomskih sila. Istovremenim snimanjem topografskih i faznih slika je dobijen sveobuhvatan uvid u različite karakteristike radnih elektroda. Na taj način, u slučaju Pd(poly) elektrode su zapažene značajne promene na površini do kojih je došlo usled odigravanja reakcija redukcije kiseonika i vodonik-peroksida. U slučaju bimetalnih Pd/Au(poly) elektroda, mikroskopija atomskih sila je pokazala da dolazi do ostrvskog rasta depozita sa pokrivenostima ispod punog monosloja. Elektrohemijska karakterizacija elektroda je vršena u radnim rastvorima tehnikom ciklične voltametrije. Metodom rotirajuće disk elektrode (RDE) je ispitana elektrokatalitička aktivnost osnovnih Au(poly), Pd(poly) i bimetalnih Pd/Au(poly) elektroda za reakciju redukcije kiseonika. Pored toga, ispitivana je i reakcija redukcije vodonik-peroksida, koji se u zavisnosti od mehanizma reakcije redukcije kiseonika može javiti ili kao proizvod ili kao intermedijer. Analizom RDE rezultata se stekao uvid u mogući reakcioni mehanizam za redukciju kiseonika na svim radnim elektrodama. Pokazano je da se na Au(poly) elektrodi redukcija kiseonika odigrava uz izmenu 2e- u kiseloj sredini, dok se u baznoj sredini sa povećanjem potencijala mehanizam reakcije menja iz 2e- u 4e- redukciju. Redukcija kiseonika na Pd(poly) elektrodi se u obe sredine pretežno odigrava 4e- serijskim reakcionim putem u oblasti potencijala gde površina paladijuma nije ili je delimično oksidovana, dok se na površini koja je oksidovana, reakcija odigrava delimično 2e- reakcionim put, Oxygen reduction reaction (ORR) was studied on polycrystalline gold, Au(poly), polycrystalline palladium, Pd(poly) and bimetallic Pd/Au(poly) electrodes in acid and alkaline solutions. Modified Pd/Au(poly) electrodes were obtained by spontaneous deposition of palladium on the Au(poly) substrate, where simple variation of the deposition time results in different coverage. Surface morphology of working electrodes was examined by atomic force microscopy technique. Comprehensive insight into different characteristics of working electrodes has been obtained by simultaneous recording of topographic and phase images. In the case of Pd(poly) electrodes, significant changes on the surface were observed due to the occurrence of oxygen and hydrogen-peroxide reduction reactions. In the case of bimetallic Pd/Au(poly) electrodes, it was concluded that there is an island growth of the deposited Pd, whereby a submonolayer coverage is obtained. Electrochemical characterization of working electrodes was performed in acid and alkaline electrolytes using a cyclic voltammetry technique. Electrocatalytic activity of bare Au(poly), Pd(poly) and bimetallic Pd/Au(poly) electrodes for ORR was examined using the rotating disk electrode (RDE) method. In addition, since hydrogen-peroxide can appear either as a product or as an intermediate during ORR, reduction reaction hydrogen-peroxide was studied. The insight into the possible reaction mechanism for the ORR on all working electrodes was obtained by analyzing the RDE results. ORR proceeds with the exchange of 2e- on the Au(poly) electrode in acid solution, while in the alkaline solution the reaction mechanism changes from 2e- to 4e- reduction with the increase of the potential. On Pd(poly) electrode, in the potential regions where Pd surface is either oxide free or partly oxidized, ORR proceeds mainly through 4e- series pathway in both media, while in the potential region where Pd surface is oxidized, reaction occurs partly through 2e- reduct
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- 2019
47. The initial characteristics of the polypyrrole based aqueous rechargeable batteries with supercapattery characteristics
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Grgur, Branimir, Janačković, Marija, Jugović, Branimir, Gvozdenović, Milica, Grgur, Branimir, Janačković, Marija, Jugović, Branimir, and Gvozdenović, Milica
- Abstract
The electrochemically synthesized polypyrrole (PPy) is investigated as a possible active material of the low-cost aqueous based secondary power sources in combination with zinc, lead oxide, and lead sulfate. The discharge capacity of the polypyrrole in the chloride-based electrolyte (for the Zn|PPy cell) is in the range 110 mAh g −1 of PPy, while in the sulfate-based electrolyte ∼150 mAh g −1 of PPy (for the PbSO 4 |PPy and PPy|PbO 2 cells), which is close to the theoretically calculated values. Electrochemical and electrical parameters, reactions in the cells, specific capacity, specific capacitance, energy, and power, for the Zn|PPy, PPy|PbO 2 and PbSO 4 |PPy cells are determined. In addition, the energy efficiency, for the considered systems is estimated. Obtained values of the specific power and energy, could classified investigated systems as a battery type hybrid superacapacitors or “supercapattery”.
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- 2019
48. Characteristics of the citrate-based zinc-polyaniline secondary cell with supercapattery behaviour
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Grgur, Branimir, Gvozdenović, Milica, Jugović, Branimir, Trišović, Tomislav, Grgur, Branimir, Gvozdenović, Milica, Jugović, Branimir, and Trišović, Tomislav
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The electrochemical characteristics of zinc-polyaniline (PANI) secondary cell in the electrolyte containing 0.8 M Na citrate, 0.3 M NH4Cl and 0.3 M ZnCl2 is investigated. Based on the measurements of potentials and voltage of the cell during charge/discharge for the currents in the range of 18 to 45 mA, the specific electrode capacity of 85 to 55 mA h g(-1), the specific energy of 60-40 mW h g(-1) and the specific power of 150-350 mW g(-1), is determined. Keywords: polyaniline; zinc; batteries; pseudocapacitors; citrates.
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- 2019
49. Electrochemical synthesis and characterization of poly(o-toluidine) as high energy storage material
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Gvozdenović, Milica, Jugović, Branimir, Jokić, Bojan, Džunuzović, Enis, Grgur, Branimir, Gvozdenović, Milica, Jugović, Branimir, Jokić, Bojan, Džunuzović, Enis, and Grgur, Branimir
- Abstract
Poly(o-toluidine) (POT) is electrochemically synthesized on graphite electrode at constant current density of 1.5 mA cm(-2) from aqueous electrolyte of 1.0 mol dm(-3) H2SO4 and 0.25 mol dm(-3) o-toluidine. Electrochemical characterization of POT electrode is performed using cyclic voltammetry, Mot Schottky analysis and galvanostatic measurements at different currents. POT electrode exhibited high energy storage features, with specific energy up to 17.5 Wh kg(-1) and specific power up to 3300 W kg(-1). Cyclic stability exceeding 90% is obtained over 2000 charge/discharge cycles at 13.1 A g(-1) indicating the perspective application of POT electrode as energy storage material.
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- 2019
50. Nanostructured intrinsically conducting polymers formed by electrochemical synthesis
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Gvozdenović, Milica M., Gvozdenović, Milica M., Jugović, Branimir, Grgur, Branimir, Gvozdenović, Milica M., Gvozdenović, Milica M., Jugović, Branimir, and Grgur, Branimir
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Due to unique properties of intrinsically conducting polymers (ICP) such as: electrical conductivity, reversible electrochemistry, optical activity, biocompatibility, environmental and corrosion stability, they still represent a base for both theoretical and practical studies. The mentioned properties open up possibilities for practical application in the field of electrochemical systems for energy storage and conversion, sensors, biosensors, antistatic coatings, magnetic shielding, active corrosion protection etc. Bearing in mind that nanostructurization of materials lead to improvement of physical and chemical properties, there is a growing interest in the development of nanosized ICP. Nanosized ICP can be prepared by both chemical and electrochemical procedures. Although chemical synthesis is a common approach, there are also not a few studies of electrochemical synthesis of ICP. The aim of this paper is to review literature dedicated to electrochemical formation of nanostructured ICP with special attention dedicated to polyaniline and polypyrrole as the most popular ICPs., Interesovanje za elektroprovodne polimere kako u teorijskom tako i praktičnom smislu utemeljeno je u jedinstvenim svojstvima ovih materijala, kao što su: kontrolisana električna provodljivost, reverzibilna oksidacija redukcija (dopovanje/dedopovanje), optička aktivnost, bio-kompatibilnost, korziona postojanost itd. Ova svojstva otvaraju mogućnosti praktične primene u oblasti elektrohemisjkih primarnih i sekundarnih izvora električne energije, elektrohemijskih kondenzatora, senzorima, biosenzorima, aktivnoj zaštiti od korozije. Imajući u vidu da nanostrukturizacija materijala dovodi do značajnog poboljšanja fizičkih i hemijskih svojstava materijala postoji veliko interesovanje za proučavanje nanostruktuirasnih elektroporvodnih polimera. Nanostruktuirani elektroprovodni polimeri mogu se dobiti hemijskim i elektrohemijskim postupcima sinteze. Iako je hemijska sinteza zastupljenija, u literaturi može se naći značajan broj radova posvećen elektrohemisjkom formiranju nanostruktuiranih elektroprovodnih polimera, pa je upravo i ovaj tekst posvećen toj probelmatici, u prvom redu elektrohemisjkom formiranju nanostruktura polianilina i polipirola kao najznačajnijih predstavnika elektroprovodnih polimera.
- Published
- 2016
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