40 research outputs found
Characteristics of the citrate-based zinc-polyaniline secondary cell with supercapattery behavior
The electrochemical characteristics of zincāpolyaniline (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 60ā40 mW h g-1 and the specific power of 150ā350 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
Elektrohemijska sinteza elektroprovodnih polimera
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 necessary and up to date it presents dominant commercial method of producing electroconducting polymers. Nevertheless, the 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 text aims to describe important aspects of electrochemical synthesis of electroconducting polymers, with special emphasis to polyaniline and polypyrrole.Tradicionalno shvatanje o polimerima kao odliÄnim izolatorima izmenjeno je sedamdesetih godina proÅ”log veka kada su nauÄnici uspeli da sintetizuju poiliacetilen Äija je provodljivost bila bliska metalnoj. Ova Äinjenica ukazala je na novo svojstvo polimernih materijala i lansirala potpuno novo multidisciplinarno nauÄno polje, popularno nazvano, sintetiÄki metali. Iako je danas pojmom elektroprovodnih polimera obuhvaÄena velika grupa jedinjenja koja su klasifikovana prema prirodi prenosioca naelektrisanja, naziv elektroprovodni polimeri se najÄeÅ”Äe koristi u literaturi upravo za polimerne materijala iz grupe sintetiÄkih metala koji poseduju elektronsku provodljivost kao posledicu specifiÄnosti molekulske strukture. Pored zahteva molekulske structure, koja podrazumeva konjugovani sistem dvostrukih veza, za provodljivost elektroprovodnih polimera neophodno je dopovanje. Termin dopovanje, iako preuzet iz terminologije klasiÄnih neorganskih poluprovodnika, podrazumeva u mnogome drugaÄiji proces. Dopovanje elektroprovodnih polimera podrazumeva oksidaciju tokom koje se, u cilju održavanja elektroneutralnosti polimernog lanca, uvodi stehiometrijska koliÄina jona (anjona). Terminom dopovanje obuhvaÄena je i protonacija polimernog lanca kiselinom, u sluÄaju polianilina, a nedavno je potvrÄena i u sluÄaju polipirola. Kako je, na ovaj naÄin, uvedena velika koliÄina jona izmenjenja je polazna struktura elektroprovodnog polimera, tako da svojstva nastalog materijala zavise u velikoj meri od svojstava dopanta. Iako su na poÄetku razvoja ove oblasti, elektroprovodni polimeri bili sintetizovani hemijskim postupcima, sticanjem uvida u mehanizam hemijske sinteze koja podrazumeva oksidativnu radikalnu polimerizaciju, postalo je jasno da se ovi materijali mogu dobiti i elektrohemijskim postupcima. Elektrohemijska sinteza ima prednosti, poÅ”to se polimer dobija oksidacijom na elektrodama (anodama), Äime je izbegnuta upotreba oksidacinog sredstva i omoguÄena veÄa ÄistoÄa proizvoda. Sa druge strane, elektroprovodni polimer je u veÄini sluÄajeva dobijen u obliku prevlake na elektrodi, pa je njegova dalja karakterizacija elektrohemijskim tenikama olakÅ”ana. Interesovanje za oblst sinteze elektroprovodnih polimera ne jenjava, pa je ovaj tekst posveÄen osnovnim principima elektrohemijskih postupaka sinteze sa posebnim osvrtom na najpopularnije elektroprovodne polimere, polianilin i polipirol
The use of anodic linear sweep voltammetery analysis (ALSV) for characterization the copper anodes used for sulphur acidic waste solution treatment
This paper addresses on investigation the possibility of electrolytic treatment the sulphur acidic waste solution, obtained in the conventional electrolytic copper refining process. The copper anodes with non-standard nickel, lead, tin and antimony content were specially prepared for the refining process. Nickel content of all anodes was approximately 7.5 mass %, and the content of lead, tin and antimony was varied. Results, obtained using the standard electrochemical techniques, have indicated that the anodes could be used under the same conditions as well as in the conventional copper refining process
Electrochemical Water Treatment Devices
Paper published in 43rd International October Conference on Mining and Metallurgy - IOC 2011, October 12-15, 2011, Kladovo, Serbia: Proceedings, Bor : Technical Faculty, 2011
Analyzing the corrosion characteristics of anodes used for the sulphur acidic waste water treatment
This paper addresses on investigation the possibility of electrolytic treatment the sulphur acidic waste solution, obtained in the conventional electrolytic copper refining process. The copper anodes with non-standard nickel, lead, tin and antimony content were specially prepared for the refining process. Nickel content of all anodes was approximately 7.5 mass %, and the content of lead, tin and antimony was varied. It was observed, that anodes with O2 content lower than 200 ppm, were not passivated. Results, obtained using the standard electrochemical techniques, have indicated that the anodes with non-standard chemical composition could be used under the same conditions as well as in the conventional copper refining process
Electrochemical characterization of polyaniline electrode for use in electrochemical power sources
Polyaniline (PANI) electrode was formed by electrochemical synthesis on graphite under galvanostatic condition at current density of 2.0 mA cm-2 from aqueous solution of 1.0 mol dm-3 HCl and 0.25 mol dm-3 aniline. Electrochemical characterization of the PANI electrode was performed in 0.5 mol dm-3 HCl using cyclic voltammetry and galvanostatic measurements. The overall charge capacity of the PANI electrode was estimated to be 0.154 mA h cm-2, corresponding to 25 % of the theoretical mass of PANI available for the dopant exchange. It was observed that during initial cyclization at low pH, the extent of PANI degradation products was insignificant and practically had no influence on the charge/discharge characteristics of the PANI electrode
Characteristics of polyaniline lead - dioxide power sources
Polyaniline (PANI) anode, electrochemically synthesized on graphite electrode from sulfuric acid solution, and electrochemically formed thin film lead dioxide cathode, were investigated for possible applications as electrode materials in PANI | H2SO4 | PbO2 aqueous based rechargeable power sources. The stimulation of charge/discharge characteristics of the cell, based on half cell reactions investigations, was evaluated. Charging of the cell would occur in the voltage range of 1.2 and 1.7 V, while discharge would occur in the range of 1.3 and 1 V
Electrochemical characterization of polyaniline electrode for use in electrochemical power sources
Polyaniline (PANI) electrode was formed by electrochemical synthesis on graphite under galvanostatic condition at current density of 2.0 mA cm-2 from aqueous solution of 1.0 mol dm-3 HCl and 0.25 mol dm-3 aniline. Electrochemical characterization of the PANI electrode was performed in 0.5 mol dm-3 HCl using cyclic voltammetry and galvanostatic measurements. The overall charge capacity of the PANI electrode was estimated to be 0.154 mA h cm-2, corresponding to 25 % of the theoretical mass of PANI available for the dopant exchange. It was observed that during initial cyclization at low pH, the extent of PANI degradation products was insignificant and practically had no influence on the charge/discharge characteristics of the PANI electrode
Characteristics of polyaniline lead - dioxide power sources
Polyaniline (PANI) anode, electrochemically synthesized on graphite electrode from sulfuric acid solution, and electrochemically formed thin film lead dioxide cathode, were investigated for possible applications as electrode materials in PANI | H2SO4 | PbO2 aqueous based rechargeable power sources. The stimulation of charge/discharge characteristics of the cell, based on half cell reactions investigations, was evaluated. Charging of the cell would occur in the voltage range of 1.2 and 1.7 V, while discharge would occur in the range of 1.3 and 1 V
Polipirol | cink Äelija sa vodenim rastvorom elektrolita i svojstvima superkapabaterije
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 āsupercapaterryā behavior.Elektroda na bazi polipirola (PPY) dobijena je elektrohemijskom oksidativnom polimerizacijom na grafitnoj elektrodi u uslovima konstantne gustine struje. Kao elektrolit za sintezu, koriÅ”Äen je vodeni rastvor 0,1 mol dm-3 pirola i 1,0 mol dm-3 HCl. Formirana je elektrohemijska Äelija u kojoj je elektroda na bazi PPY koriÅ”Äena 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 elektriÄnih parametara ove Äelije bazirana je na elektrohemijskim eksperimentima. UtvrÄeno je da je proces punjenja/pražnjenja zavisio od struje punjenja/pražnjenja, punejnje Äelije zapoÄinje na naponu izmeÄu 0,5 i 0,7 V, a zavrÅ”ava se na naponu od oko 1,3 V. Procenjene vrednosti energije bile su izmeÄu 46 i 68 W h kg-1, dok se za specifiÄnu snagu dobijaju vrednosti izmeÄu 125 i 380 W kg-1, Å”to ukazuje na superkapabaterijska svojstva Zn|PPY Äelije