Branimir Z. Jugović

Electrochemical synthesis of electroconducting polymers

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]

Behaviour of non-standard composition copper bearing anodes from the copper refining process

This paper addresses on investigation the possibility of electrolytic treatment the sulphur acidic waste solution, obtained in the conventional electrolytic copper refining process. Beside the high copper concentration, the high concentration of other metals, in this case nickel, is the main characteristic of these waste solutions. Due to this fact, the copper bearing 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. The preliminary results, obtained using the standard electrochemical techniques, have indicated that the copper bearing anodes could be used under the same conditions as well as in the conventional copper refining process. The measurements in constant galvanostatic pulse have pointed out that the all chemical elements from copper bearing anodes were dissolved and only copper was deposited onto the cathode. It was also pointed out that Ni concentration in the base working electrolyte (sulphur acidic waste solution), after 72 h of process, increased to 102 mass% at T(1)=63+/-2 degrees C and up to 122 mass% at T(1)=73+/-2 degrees C, while arsenic concentration decreased to a minimum value.

Dewatering of sludge obtained by neutralisation from sulfuric-acid waste solutions

The aim of this paper was to investigate the possibility of removing the liquid phase from the sludge using the mechanical dewatering methods. The sludge was obtained by neutralization of sulfuric acid waste solution from the process of copper electrolysis, using 1M Ca (OH)2 with and without addition of FeCl3 and AlCl3 as coagulants. Classical method of filtration by gravity and vacuum filtration method were used for tests of sludge dewatering process in the laboratory conditions. Solution volume, amount of sample, dewatering duration was measured during the experiments. The obtained results, presented in this paper, showed that using the vacuum filtration method, high of sludge sample was reduced for 75%, which is almost three times higher value compared to the results obtained using the gravity filtration. Data relating to the time of filtration, using different methods, show that in application of vacuum filtration method the dewatering time is almost 200 times faster compared to the time dewatering with gravity filtration. The shortest settling time was registered for the sludge that was obtained by neutralization process without coagulants addition.

The influence of m-aminobenzoic acid on electrochemical synthesis and behavior of poly(aniline-co-( m -aminobenzoic acid)

Poly(aniline-co-(m-aminobenzoic acid)) was synthesized electrochemically at graphite electrode under galvanostatic conditions. Aqueous electrolyte for synthesis was consisted of HCl and different amount of aniline and m-aminobenzoic acid. The presence of the meta positioned carboxylic group in m-aminobenzoic acid influenced higher co-polymerization potential, different morphology and electrochemical behavior of copolymers compared to polyaniline. Electrochemical activity is achieved by proton exchange in neutral environment that can result in a faster charge/discharge process, which is in the case of PANI limited by slow anion exchange, making this material promising for consideration in super-capacitors and in biological system.