Polyaniline nanostructures synthesizedby the dopant-free oxidative polymerization of aniline

Istraživanja u ovoj doktorskoj disertaciji obuhvataju: sinteze nanostruktura polianilina (PANI) oksidativnom hemijskom polimerizacijom anilina (ANI) sa amonijum peroksidisulfatom (APS) u razliĉitim sistemima bez dodatka kiseline i templata, u uslovima opadajućeg pH, karakterizaciju sintetisanih PANI razliĉitim fiziĉkohemijskim metodama i prouĉavanje mehanizma sinteze i formiranja PANI nanostruktura u ispitivanim sistemima. Sinteze PANI su uraĊene korišćenjem jednostavnih, ekonomiĉnih i ekološki prihvatljivih procedura i supstancija. Akcenat je bio na korišćenju što manjeg broja hemikalija za odgovarajuće sintetiĉke procedure. Pored oksidacionog sredstva (APS) i monomera (ANI), u reakcione sisteme su ukljuĉeni razliĉiti organski rastvaraĉi, hidrolizovani kolagen (biološki materijal), ili FeSO4 (katalizator). Idealan molski odnos APS i ANI od 1,25 za sintezu elektroprovodnog oblika PANI, emeraldin soli, je upotrebljen u svim sintezama. Varirani su sledeći uslovi: poĉetna pH vrednost, dužina trajanja sinteze, uslovi mešanja reakcione smeše i organski rastvaraĉi. Rezultati dobijeni u okviru ove doktroske teze se mogu podeliti u sledećih pet celina: 1) Oksidacija ANI vršena je pomoću APS u sistemima bez dodatka kiseline i templata u kojima su koncentracije oba reaktanta bile niske (CANI = 0,02 i 0,05 M). Reakcija je praćena merenjem temperature i pH. Karakteristike polimerizacije i sintetisanih PANI uporeĊivane su sa analognim sintezama u koncentrovanim sistemima (CANI = 0,1 i 0,2 M). Skenirajućom elektronskom mikroskopijom (SEM) je utvrĊeno da se nanostrukturni PANI sulfat/hidrogen sulfat, sintetisan pri niskim koncentracijama reaktanata, sastoji od mreže nanoštapića i nanogranula. Molekulska struktura sintetisanih i dedopiranih PANI uzoraka, ispitivana elementarnom analizom, infracrvenom spektroskopijom sa furijeovom transformacijom (FTIR), ramanskom, ultraljubiĉastom-vidljivom (UV-Vis) i elektronskom paramagnetnom rezonantnom (EPR) spektroskopijom, je znaĉajno drugaĉija u poreĊenju sa molekulskom strukturom nanostrukturnih PANI sulfata/hidrogen sulfata sintetisanih u koncentrovanim...The research in this Ph.D. thesis includes: synthesis of nanostructured polyaniline (PANI) by the chemical oxidative polymerization of aniline (ANI) with ammonium peroxydisulfate (APS) in different systems with the use of dopant-free template-free falling-pH method, characterization of the synthesized PANI by various physicochemical methods and the study of the mechanism of synthesis and the formation of PANI nanostructures in investigated systems. Syntheses of PANI were performed using simple, cost-effective and environmentally friendly procedures and substances. The emphasis was on using not as many chemicals for the proper synthetic procedure. Besides the oxidant (APS) and monomer (ANI), in the reaction mixtures were included various organic solvents, hydrolyzed collagen (a biological system) or FeSO4 (catalysator). The optimal molar ratio of the ANI and APS of 1.25 for the electroconductive emeraldin salt form of PANI syntheses was used in all synthetic procedures. The initial pH value, the length of the synthesis, stirring conditions of the reaction mixture and the organic solvents were varied. The results obtained within this thesis can be divided into the following five sections: 1) The oxidation of ANI with APS was conducted in diluted aqueous systems (CANI = 0,02 i 0,05 M) without added acid and template (dilute dopant-free template-free method). The reaction was monitored by measuring the temperature and pH. The characteristics of the polymerization and the synthesized PANI were compared to analog synthesis in concentrated systems (CANI = 0,1 i 0,2 M). Scanning electron microscopy (SEM) revealed that nanostructured PANI sulfate/hydrogen sulfate, synthesized in low concentration conditions, consists of a network of nanorods and nanogranules.The molecular structure of PANI sulfate/hydrogen sulfate prepared in diluted ANI solutions considerably different in comparison to the structure of PANI sulfate/hydrogen sulfate prepared in concentrated aqueous ANI was discovered by elemental analysis, Fourier transform infrared spectroscopic (FTIR), Raman, ultra-violet (UV–Vis) and electron paramagnetic resonance (EPR) spectroscopic studies. The..

Design of an amino-functionalized chelating macroporous copolymer poly(GMA-co-EGDMA) for the sorption of Cu(II) ions

Polymer-based, highly porous nanocomposites with functionalized ligands attached to the core structure are extremely efficient in the detection, removal and recovery of metals through the process of sorption. Quantum-chemical models could be helpful for sorption process analyses. The sorption of Cu(II) ions by amino-functionalized chelating macroporous copolymers poly(GMA-co-EGDMA)-amine and sorption selectivity of the subject copolymers, ethylenediamine (en), diethylenetriamine (dien) and triethylenetetramine (trien), were successfully modelled by quantum chemical calculations. Considering the crystal structures from CSD and experimental conditions during the formation of metal complexes, the most frequent mononuclear complexes are those with the tetradentate teta ligand, while binuclear complexes are formed when the metal ion is in large excess. Although the en-copolymer was the most effective functionalized one, higher maximum sorption capacities (Qmax) were observed for the dien- and trien-copolymers, due to their abilities to form binuclear complexes. The enthalpy term has the greatest contribution to the total Gibbs energy change of reaction for the formation of mononuclear Cu(II) complexes (ΔGaq), while the solvation energy of the reaction has the greatest contribution in the formation of binuclear complexes. The results of the study indicate that small amines with the ability to form binuclear complex are the best choice for functionalization of the considered copolymer

Supplementary data for article: Rakić, A. A.; Vukomanović, M.; Trifunović, S.; Travas-Sejdic, J.; Chaudhary, O. J.; Horský, J.; Ćirić-Marjanović, G. Solvent Effects on Dopant-Free PH-Falling Polymerization of Aniline. Synthetic Metals 2015, 209, 279–296. https://doi.org/10.1016/j.synthmet.2015.07.031

Supplementary material for: [https://doi.org/10.1016/j.synthmet.2015.07.031]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1996

Supplementary data for article: Rakić, A. A.; Vukomanović, M.; Trifunović, S.; Travas-Sejdic, J.; Chaudhary, O. J.; Horský, J.; Ćirić-Marjanović, G. Solvent Effects on Dopant-Free PH-Falling Polymerization of Aniline. Synthetic Metals 2015, 209, 279–296. https://doi.org/10.1016/j.synthmet.2015.07.031

Supplementary material for: [https://doi.org/10.1016/j.synthmet.2015.07.031]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1996

Synthesis, Crystal Structure, Theoretical Calculations, Antibacterial Activity, Electrochemical Behavior, and Molecular Docking of Ni(II) and Cu(II) Complexes with Pyridoxal-Semicarbazone

New Ni (II) and Cu (II) complexes with pyridoxal-semicarbazone were synthesized and their structures were solved by X-ray crystallography. This analysis showed the bis-ligand octahedral structure of [Ni(PLSC-H)2]·H2O and the dimer octahedral structure of [Cu(PLSC)(SO4)(H2O)]2·2H2O. Hirshfeld surface analysis was employed to determine the most important intermolecular interactions in the crystallographic structures. The structures of both complexes were further examined using density functional theory and natural bond orbital analysis. The photocatalytic decomposition of methylene blue in the presence of both compounds was investigated. Both compounds were active toward E. coli and S. aureus, with a minimum inhibition concentration similar to that of chloramphenicol. The obtained complexes led to the formation of free radical species, as was demonstrated in an experiment with dichlorofluorescein-diacetate. It is postulated that this is the mechanistic pathway of the antibacterial and photocatalytic activities. Cyclic voltammograms of the compounds showed the peaks of the reduction of metal ions. A molecular docking study showed that the Ni(II) complex exhibited promising activity towards Janus kinase (JAK), as a potential therapy for inflammatory diseases, cancers, and immunologic disorders

Enzymatic oligomerization and polymerization of arylamines: state of the art and perspectives

The literature concerning the oxidative oligomerization and polymerization of various arylamines, e.g., aniline, substituted anilines, aminonaphthalene and its derivatives, catalyzed by oxidoreductases, such as laccases and peroxidases, in aqueous, organic, and mixed aqueous organic monophasic or biphasic media, is reviewed. An overview of template-free as well as template-assisted enzymatic syntheses of oligomers and polymers of arylamines is given. Special attention is paid to mechanistic aspects of these biocatalytic processes. Because of the nontoxicity of oxidoreductases and their high catalytic efficiency, as well as high selectivity of enzymatic oligomerizations/polymerizations under mild conditions-using mainly water as a solvent and often resulting in minimal byproduct formation-enzymatic oligomerizations and polymerizations of arylamines are environmentally friendly and significantly contribute to a "green'' chemistry of conducting and redox-active oligomers and polymers. Current and potential future applications of enzymatic polymerization processes and enzymatically synthesized oligo/polyarylamines are discussed

Polyaniline nanostructures synthesizedby the dopant-free oxidative polymerization of aniline

Istraživanja u ovoj doktorskoj disertaciji obuhvataju: sinteze nanostruktura polianilina (PANI) oksidativnom hemijskom polimerizacijom anilina (ANI) sa amonijum peroksidisulfatom (APS) u razliĉitim sistemima bez dodatka kiseline i templata, u uslovima opadajućeg pH, karakterizaciju sintetisanih PANI razliĉitim fiziĉkohemijskim metodama i prouĉavanje mehanizma sinteze i formiranja PANI nanostruktura u ispitivanim sistemima. Sinteze PANI su uraĊene korišćenjem jednostavnih, ekonomiĉnih i ekološki prihvatljivih procedura i supstancija. Akcenat je bio na korišćenju što manjeg broja hemikalija za odgovarajuće sintetiĉke procedure. Pored oksidacionog sredstva (APS) i monomera (ANI), u reakcione sisteme su ukljuĉeni razliĉiti organski rastvaraĉi, hidrolizovani kolagen (biološki materijal), ili FeSO4 (katalizator). Idealan molski odnos APS i ANI od 1,25 za sintezu elektroprovodnog oblika PANI, emeraldin soli, je upotrebljen u svim sintezama. Varirani su sledeći uslovi: poĉetna pH vrednost, dužina trajanja sinteze, uslovi mešanja reakcione smeše i organski rastvaraĉi. Rezultati dobijeni u okviru ove doktroske teze se mogu podeliti u sledećih pet celina: 1) Oksidacija ANI vršena je pomoću APS u sistemima bez dodatka kiseline i templata u kojima su koncentracije oba reaktanta bile niske (CANI = 0,02 i 0,05 M). Reakcija je praćena merenjem temperature i pH. Karakteristike polimerizacije i sintetisanih PANI uporeĊivane su sa analognim sintezama u koncentrovanim sistemima (CANI = 0,1 i 0,2 M). Skenirajućom elektronskom mikroskopijom (SEM) je utvrĊeno da se nanostrukturni PANI sulfat/hidrogen sulfat, sintetisan pri niskim koncentracijama reaktanata, sastoji od mreže nanoštapića i nanogranula. Molekulska struktura sintetisanih i dedopiranih PANI uzoraka, ispitivana elementarnom analizom, infracrvenom spektroskopijom sa furijeovom transformacijom (FTIR), ramanskom, ultraljubiĉastom-vidljivom (UV-Vis) i elektronskom paramagnetnom rezonantnom (EPR) spektroskopijom, je znaĉajno drugaĉija u poreĊenju sa molekulskom strukturom nanostrukturnih PANI sulfata/hidrogen sulfata sintetisanih u koncentrovanim...The research in this Ph.D. thesis includes: synthesis of nanostructured polyaniline (PANI) by the chemical oxidative polymerization of aniline (ANI) with ammonium peroxydisulfate (APS) in different systems with the use of dopant-free template-free falling-pH method, characterization of the synthesized PANI by various physicochemical methods and the study of the mechanism of synthesis and the formation of PANI nanostructures in investigated systems. Syntheses of PANI were performed using simple, cost-effective and environmentally friendly procedures and substances. The emphasis was on using not as many chemicals for the proper synthetic procedure. Besides the oxidant (APS) and monomer (ANI), in the reaction mixtures were included various organic solvents, hydrolyzed collagen (a biological system) or FeSO4 (catalysator). The optimal molar ratio of the ANI and APS of 1.25 for the electroconductive emeraldin salt form of PANI syntheses was used in all synthetic procedures. The initial pH value, the length of the synthesis, stirring conditions of the reaction mixture and the organic solvents were varied. The results obtained within this thesis can be divided into the following five sections: 1) The oxidation of ANI with APS was conducted in diluted aqueous systems (CANI = 0,02 i 0,05 M) without added acid and template (dilute dopant-free template-free method). The reaction was monitored by measuring the temperature and pH. The characteristics of the polymerization and the synthesized PANI were compared to analog synthesis in concentrated systems (CANI = 0,1 i 0,2 M). Scanning electron microscopy (SEM) revealed that nanostructured PANI sulfate/hydrogen sulfate, synthesized in low concentration conditions, consists of a network of nanorods and nanogranules.The molecular structure of PANI sulfate/hydrogen sulfate prepared in diluted ANI solutions considerably different in comparison to the structure of PANI sulfate/hydrogen sulfate prepared in concentrated aqueous ANI was discovered by elemental analysis, Fourier transform infrared spectroscopic (FTIR), Raman, ultra-violet (UV–Vis) and electron paramagnetic resonance (EPR) spectroscopic studies. The..

Polyaniline nanostructures synthesizedby the dopant-free oxidative polymerization of aniline

Istraživanja u ovoj doktorskoj disertaciji obuhvataju: sinteze nanostruktura polianilina (PANI) oksidativnom hemijskom polimerizacijom anilina (ANI) sa amonijum peroksidisulfatom (APS) u razliĉitim sistemima bez dodatka kiseline i templata, u uslovima opadajućeg pH, karakterizaciju sintetisanih PANI razliĉitim fiziĉkohemijskim metodama i prouĉavanje mehanizma sinteze i formiranja PANI nanostruktura u ispitivanim sistemima. Sinteze PANI su uraĊene korišćenjem jednostavnih, ekonomiĉnih i ekološki prihvatljivih procedura i supstancija. Akcenat je bio na korišćenju što manjeg broja hemikalija za odgovarajuće sintetiĉke procedure. Pored oksidacionog sredstva (APS) i monomera (ANI), u reakcione sisteme su ukljuĉeni razliĉiti organski rastvaraĉi, hidrolizovani kolagen (biološki materijal), ili FeSO4 (katalizator). Idealan molski odnos APS i ANI od 1,25 za sintezu elektroprovodnog oblika PANI, emeraldin soli, je upotrebljen u svim sintezama. Varirani su sledeći uslovi: poĉetna pH vrednost, dužina trajanja sinteze, uslovi mešanja reakcione smeše i organski rastvaraĉi. Rezultati dobijeni u okviru ove doktroske teze se mogu podeliti u sledećih pet celina: 1) Oksidacija ANI vršena je pomoću APS u sistemima bez dodatka kiseline i templata u kojima su koncentracije oba reaktanta bile niske (CANI = 0,02 i 0,05 M). Reakcija je praćena merenjem temperature i pH. Karakteristike polimerizacije i sintetisanih PANI uporeĊivane su sa analognim sintezama u koncentrovanim sistemima (CANI = 0,1 i 0,2 M). Skenirajućom elektronskom mikroskopijom (SEM) je utvrĊeno da se nanostrukturni PANI sulfat/hidrogen sulfat, sintetisan pri niskim koncentracijama reaktanata, sastoji od mreže nanoštapića i nanogranula. Molekulska struktura sintetisanih i dedopiranih PANI uzoraka, ispitivana elementarnom analizom, infracrvenom spektroskopijom sa furijeovom transformacijom (FTIR), ramanskom, ultraljubiĉastom-vidljivom (UV-Vis) i elektronskom paramagnetnom rezonantnom (EPR) spektroskopijom, je znaĉajno drugaĉija u poreĊenju sa molekulskom strukturom nanostrukturnih PANI sulfata/hidrogen sulfata sintetisanih u koncentrovanim...The research in this Ph.D. thesis includes: synthesis of nanostructured polyaniline (PANI) by the chemical oxidative polymerization of aniline (ANI) with ammonium peroxydisulfate (APS) in different systems with the use of dopant-free template-free falling-pH method, characterization of the synthesized PANI by various physicochemical methods and the study of the mechanism of synthesis and the formation of PANI nanostructures in investigated systems. Syntheses of PANI were performed using simple, cost-effective and environmentally friendly procedures and substances. The emphasis was on using not as many chemicals for the proper synthetic procedure. Besides the oxidant (APS) and monomer (ANI), in the reaction mixtures were included various organic solvents, hydrolyzed collagen (a biological system) or FeSO4 (catalysator). The optimal molar ratio of the ANI and APS of 1.25 for the electroconductive emeraldin salt form of PANI syntheses was used in all synthetic procedures. The initial pH value, the length of the synthesis, stirring conditions of the reaction mixture and the organic solvents were varied. The results obtained within this thesis can be divided into the following five sections: 1) The oxidation of ANI with APS was conducted in diluted aqueous systems (CANI = 0,02 i 0,05 M) without added acid and template (dilute dopant-free template-free method). The reaction was monitored by measuring the temperature and pH. The characteristics of the polymerization and the synthesized PANI were compared to analog synthesis in concentrated systems (CANI = 0,1 i 0,2 M). Scanning electron microscopy (SEM) revealed that nanostructured PANI sulfate/hydrogen sulfate, synthesized in low concentration conditions, consists of a network of nanorods and nanogranules.The molecular structure of PANI sulfate/hydrogen sulfate prepared in diluted ANI solutions considerably different in comparison to the structure of PANI sulfate/hydrogen sulfate prepared in concentrated aqueous ANI was discovered by elemental analysis, Fourier transform infrared spectroscopic (FTIR), Raman, ultra-violet (UV–Vis) and electron paramagnetic resonance (EPR) spectroscopic studies. The..

Dopant-free interfacial oxidative polymerization of aniline

Polyaniline (PANI) was synthesized by the oxidation of aniline with ammonium peroxydisulfate (APS) as an oxidant in an immiscible organic/aqueous biphasic system, without added acid. An organic phase contained aniline dissolved in chloroform, while the oxidant was dissolved in water. The produced PANIs have conductivities in the range 0.008-0.1 S cm(-1). Their nanogranular morphology was confirmed by scanning electron microscopy (SEM). Molecular structure of synthesized PANIs was investigated by FTIR, Raman, and UV-Vis spectroscopies, and elemental analysis. The influence of mechanical stirring and reaction time on the yield of polymerization, structure, and properties of synthesized PANIs was studied. The differences in the molecular structure, morphology, and conductivity between PANI prepared by dopant-free interfacial polymerization and PAN1 prepared by corresponding polymerization in monophasic aqueous system are discussed. The results are also compared with the literature data on the interfacial polymerizations of aniline with APS in the presence of acids. (C) 2014 Elsevier B.V. All rights reserved

Non-stoichiometric tungsten-carbide-oxide-supported Pt–Ru anode catalysts for PEM fuel cells – From basic electrochemistry to fuel cell performance

Durability and cost of Proton Exchange Membrane fuel cells (PEMFCs) are two major factors delaying their commercialization. Cost is associated with the price of the catalysts, while durability is associated with degradation and poisoning of the catalysts, primarily by CO. This motivated us to develop tungsten-carbide-oxide (WxCyOz) as a new non-carbon based catalyst support for Pt–Ru–based anode PEMFC catalyst. The aim was to improve performance and obtain higher CO tolerance compared to commercial catalysts. The performance of obtained PtRu/WxCyOz catalysts was investigated using cyclic voltammetry, linear scan voltammetry and rotating disk electrode voltammetry. Particular attention was given to the analysis of CO poisoning, to better understand how WxCyOz species can contribute to the CO tolerance of PtRu/WxCyOz. Improved oxidation of COads at low potentials (E 0.5 V vs. RHE) CO removal proceeds dominantly via OH provided from the oxidized metal sites. The obtained catalyst with the best performance (30% PtRu/WxCyOz) was tested as an anode catalyst in PEM fuel cell. When using synthetic reformate as a fuel in PEMFC, there is a significant power drop of 35.3 % for the commercial 30% PtRu/C catalyst, while for the PtRu/WxCyOz anode catalyst this drop is around 16 %