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Sample records for azo compounds

  1. Azo compounds as a family of organic electrode materials for alkali-ion batteries.

    Science.gov (United States)

    Luo, Chao; Borodin, Oleg; Ji, Xiao; Hou, Singyuk; Gaskell, Karen J; Fan, Xiulin; Chen, Ji; Deng, Tao; Wang, Ruixing; Jiang, Jianjun; Wang, Chunsheng

    2018-02-27

    Organic compounds are desirable for sustainable Li-ion batteries (LIBs), but the poor cycle stability and low power density limit their large-scale application. Here we report a family of organic compounds containing azo group (N=N) for reversible lithiation/delithiation. Azobenzene-4,4'-dicarboxylic acid lithium salt (ADALS) with an azo group in the center of the conjugated structure is used as a model azo compound to investigate the electrochemical behaviors and reaction mechanism of azo compounds. In LIBs, ADALS can provide a capacity of 190 mAh g -1 at 0.5 C (corresponding to current density of 95 mA g -1 ) and still retain 90%, 71%, and 56% of the capacity when the current density is increased to 2 C, 10 C, and 20 C, respectively. Moreover, ADALS retains 89% of initial capacity after 5,000 cycles at 20 C with a slow capacity decay rate of 0.0023% per cycle, representing one of the best performances in all organic compounds. Superior electrochemical behavior of ADALS is also observed in Na-ion batteries, demonstrating that azo compounds are universal electrode materials for alkali-ion batteries. The highly reversible redox chemistry of azo compounds to alkali ions was confirmed by density-functional theory (DFT) calculations. It provides opportunities for developing sustainable batteries.

  2. The in situ generation and reactive quench of diazonium compounds in the synthesis of azo compounds in microreactors.

    Science.gov (United States)

    Akwi, Faith M; Watts, Paul

    2016-01-01

    In this paper, a micro-fluidic optimized process for the continuous flow synthesis of azo compounds is presented. The continuous flow synthesis of Sudan II azo dye was used as a model reaction for the study. At found optimal azo coupling reaction temperature and pH an investigation of the optimum flow rates of the reactants for the diazotization and azo coupling reactions in Little Things Factory-MS microreactors was performed. A conversion of 98% was achieved in approximately 2.4 minutes and a small library of azo compounds was thus generated under these reaction conditions from couplers with aminated or hydroxylated aromatic systems. The scaled up synthesis of these compounds in PTFE tubing (i.d. 1.5 mm) was also investigated, where good reaction conversions ranging between 66-91% were attained.

  3. The in situ generation and reactive quench of diazonium compounds in the synthesis of azo compounds in microreactors

    Directory of Open Access Journals (Sweden)

    Faith M. Akwi

    2016-09-01

    Full Text Available In this paper, a micro-fluidic optimized process for the continuous flow synthesis of azo compounds is presented. The continuous flow synthesis of Sudan II azo dye was used as a model reaction for the study. At found optimal azo coupling reaction temperature and pH an investigation of the optimum flow rates of the reactants for the diazotization and azo coupling reactions in Little Things Factory-MS microreactors was performed. A conversion of 98% was achieved in approximately 2.4 minutes and a small library of azo compounds was thus generated under these reaction conditions from couplers with aminated or hydroxylated aromatic systems. The scaled up synthesis of these compounds in PTFE tubing (i.d. 1.5 mm was also investigated, where good reaction conversions ranging between 66–91% were attained.

  4. Kinetics of molybdenum(6) complexation with o,o'-dihydroxyazo compounds or heterocyclic azo compounds in the presence of hydroxylamine

    International Nuclear Information System (INIS)

    Kochelaeva, G.A.; Degtyarev, M.Yu.; Ivanov, V.M.; Prokhorova, G.V.; Figurovskaya, V.N.

    1999-01-01

    The kinetics of complexation in the system molybdenum(6)-azo compound-hydroxylamine was studied. Azo compounds of the types o,o'-dihydroxyazo compounds, such as Lyumogallion IREA and Magneson IREA, and heterocyclic azo compounds, such as 4-(2-pyridylazo)resorcinol and 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol, were studied. The formation of mixed-ligand complexes with the ratio of component 1 : 1 : 1 was detected. Rate constants, activation energies, and stability constants of the forming compounds were evaluated. It was concluded that the reagents under study are promising for the analytical chemistry of molybdenum [ru

  5. Synthesis, biological activity and computational studies of novel azo-compounds

    International Nuclear Information System (INIS)

    Ashraf, J.; Murtaza, S.; Mughal, E.U.; Sadiq, A.

    2017-01-01

    In the present protocol, we report the synthesis and characterization of some novel azo-compounds starting from 4-methoxyaniline and 4-aminophenazone, which were diazotized at low temperature. 4-nitrophenol, 2-aminobenzoic acid, benzamide, 4-aminobenzoic acid, resorcinol, o-bromonitrobenzene and 2-nitroaniline were used as active aromatic coupling compounds for the second step. The synthesized compounds were investigated for their potential antibacterial activities by using disc diffusion method against Escherichia coli, Shigellasonnei, Streptococcus pyrogenes, Staphylococcus aureus and Neisseria gonorrhoeae strains. They were also subjected to antioxidant activities by using DPPH method. Results revealed that the compounds of 4-methoxyaniline and 4-aminophenazone showed good antibacterial activity against all strains, where as some azo-compounds have moderate to good antioxidant activities. Furthermore, these compounds were studied by computational analysis. (author)

  6. Reversible Redox Chemistry of Azo Compounds for Sodium-Ion Batteries.

    Science.gov (United States)

    Luo, Chao; Xu, Gui-Liang; Ji, Xiao; Hou, Singyuk; Chen, Long; Wang, Fei; Jiang, Jianjun; Chen, Zonghai; Ren, Yang; Amine, Khalil; Wang, Chunsheng

    2018-03-05

    Sustainable sodium-ion batteries (SSIBs) using renewable organic electrodes are promising alternatives to lithium-ion batteries for the large-scale renewable energy storage. However, the lack of high-performance anode material impedes the development of SSIBs. Herein, we report a new type of organic anode material based on azo group for SSIBs. Azobenzene-4,4'-dicarboxylic acid sodium salt is used as a model to investigate the electrochemical behaviors and reaction mechanism of azo compound. It exhibits a reversible capacity of 170 mAh g -1 at 0.2C. When current density is increased to 20C, the reversible capacities of 98 mAh g -1 can be retained for 2000 cycles, demonstrating excellent cycling stability and high rate capability. The detailed characterizations reveal that azo group acts as an electrochemical active site to reversibly bond with Na + . The reversible redox chemistry between azo compound and Na ions offer opportunities for developing long-cycle-life and high-rate SSIBs. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. SYNTHESIS OF AZO COMPOUNDS DERIVATIVE FROM EUGENOL AND ITS APPLICATION AS A TITRATION INDICATOR

    Directory of Open Access Journals (Sweden)

    Bambang Purwono

    2010-06-01

    Full Text Available The synthesis of azo compounds from eugenol has been carried out by diazotation reaction. The diazonium salt was produced by reaction of aniline and sodium nitrite in acid condition at 0-5 °C temperature to yield benzenediazonium chloride salt. The salt was then reacted with eugenol to produce the azo derivatives. The azo product was analyzed by IR, 1H-NMR, dan GC-MS spectrometer. The results showed that the reaction of benzenediazonium chloride with eugenol gave 4-allyl-2-methoxy-6-hydroxyazobenzene in 34.27% yield for 30 minutes reaction. The derivative of azo compound was dissolved in ethanol and then the color changing was observed in range of pH 9.8-11.1 from yellow to red. Application for titration indicator for acetic acid titrated with sodium hydroxide showed error less than 3.20% compared with phenol phtaline indicator.   Keywords: Eugenol, Azo compound, titration indicator

  8. The in situ generation and reactive quench of diazonium compounds in the synthesis of azo compounds in microreactors

    OpenAIRE

    Faith M. Akwi; Paul Watts

    2016-01-01

    Summary In this paper, a micro-fluidic optimized process for the continuous flow synthesis of azo compounds is presented. The continuous flow synthesis of Sudan II azo dye was used as a model reaction for the study. At found optimal azo coupling reaction temperature and pH an investigation of the optimum flow rates of the reactants for the diazotization and azo coupling reactions in Little Things Factory-MS microreactors was performed. A conversion of 98% was achieved in approximately 2.4 min...

  9. Azo compound degradation kinetics and halonitromethane formation kinetics during chlorination.

    Science.gov (United States)

    Fu, Jing; Wang, Xiaomao; Bai, Weiliang; Yang, Hongwei; Xie, Yuefeng F

    2017-05-01

    The chlorination of azo compounds can produce halonitromethanes (HNMs), which have attracted increasing concern due to their high genotoxicity. By impacting the speciation of chlorine and azo compounds, pH impacts apparent second-order rate constants of Methyl Orange (MO, 27.5-1.4 × 10 3  M -1  s -1 ), Acid Orange II (AO, 16.7-99.3 M -1  s -1 ), and Acid Red 1 (AR 1, 3.7-72.5 M -1  s -1 ) (pH range 6.3-9.0). The two-compartment first-order model successfully described the chloropicrin (TCNM) formation kinetics, suggesting that both fast- and slow-reacting precursors of TCNM are generated from the chlorination of azo compounds. The ratios between fast and slow formation rate constants for MO and AO were 15.6-5.4 × 10 2 , while that of AR 1 was 9.8-19.4 (pH range 6.5-9.0). The fraction of the fast-reacting TCNM precursors decreased with increasing pH for MO and AO; while that for AR 1 decreased when pH increased from 6.5 to 8.0, and then increased when pH increased from 8.0 to 9.0. The impact of pH on TCNM formation was also precursor-specific. The highest molar yields of TCNM predicted from the model in this study were 2.4%, 2.5%, and 1.5% for MO, AO, and AR 1, respectively. The study demonstrates that azo compounds are important HNM precursors, and pose a potential threat to drinking water safety. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Voltammetric determination of zirconium using azo compounds

    International Nuclear Information System (INIS)

    Orshulyak, O.O.; Levitskaya, G.D.

    2008-01-01

    The optimum conditions for zirconium complexation with azo compounds are found. The applicability of Eriochrome Red B, Calcon, and Calcion to the voltammetric determination of zirconium, total Zr(IV) and Hf(IV), and Zr(IV) in the presence of Zn(II), Cu(II), Cd(II), Ni(II), or Ti(IV) is demonstrated. The developed procedures are used to determine zirconium in a terbium alloy and in an alloy for airplane wheel drums [ru

  11. Dendritic azo compounds as a new type amorphous molecular material with quick photoinduced surface-relief-grating formation ability

    Science.gov (United States)

    He, Yaning; Gu, Xinyu; Guo, Miaocai; Wang, Xiaogong

    2008-09-01

    A series of dendritic azobenzene-containing compounds have been synthesized as a new type amorphous molecular material, which can show quick surface-relief-grating (SRG) formation ability upon light irradiation. For the synthesis, the dendritic precursor tris(2-(ethyl(phenyl)amino)ethyl)benzene-1,3,5-tricarboxylate and tris(3,5-bis(2-(ethyl(phenyl)amino)ethoxy)benzyl)benzene-1,3,5-tricarboxylate were prepared by esterification reactions between 1,3,5-benzenetricarbonyl chloride and N-ethyl- N-hydroxyethyl-aniline and 3,5-bis[2-( N-ethylanilino)ethoxy] benzylalcohol. The precursors were, respectively reacted with the diazonium salts of 4-nitroaniline, 4-aminobenzoic acid, and 4-aminobenzonitrile to introduce different types of donor-acceptor azo chromophores at the peripheral positions. The structure and properties of the dendritic azo compounds were characterized by the spectroscopic methods and thermal analysis. The surface-relief-grating (SRG) formation behavior of the dendritic azo compounds was studied by exposing the spin-coated thin films to an interference pattern of laser beams (532 nm) at modest intensity (100 mW/cm 2). The results show that the azo compounds can form stable amorphous glasses in a broad temperature range. The glass transition temperatures ( Tgs) depend on the backbone structures and the type of the peripheral azo chromophors. The type of the electron withdrawing groups in the p-positions of the terminal azobenzene units shows a significant influence on the SRG inscription rate. For the compounds containing the same type azo chromophores, the SRG inscription rate is also affected by the backbone structure.

  12. Anaerobic azo dye reduction

    OpenAIRE

    Zee, van der, F.P.

    2002-01-01

    Azo dyes, aromatic moieties linked together by azo (-N=N-) chromophores, represent the largest class of dyes used in textile-processing and other industries. The release of these compounds into the environment is undesirable, not only because of their colour, but also because many azo dyes and their breakdown products are toxic and/or mutagenic to life. To remove azo dyes from wastewater, a biological treatment strategy based on anaerobic reduction of the azo dye...

  13. Tunable Cascade Reaction of Aryl Diazonium Salts and Trialkylamine: Synthesis of Monofluorinated Arylhydrazones and gem-Difluorinated Azo Compounds.

    Science.gov (United States)

    Guo, Rui; Zhang, Zhengjuan; Shi, Feng; Tang, Pingping

    2016-03-04

    The first example of a mild and tunable cascade reaction of aryl diazonium salts and trialkylamine in the presence of Selectfluor to prepare monofluorinated arylhydrazones and gem-difluorinated azo compounds without metal has been explored. In the presence of H2O, the monofluorinated arylhydrazones were observed in moderate to good yield. In the absence of H2O, the gem-difluorinated azo compounds were obtained. The fluorinated arylhydrazones were utilized to synthesize fluorinated pyrazoles and other nitrogen-containing compounds.

  14. The mechanism and kinetics of the electrochemical cleavage of azo bond of 2-hydroxy-5-sulfophenyl-azo-benzoic acids

    International Nuclear Information System (INIS)

    Mandic, Zoran; Nigovic, Biljana; Simunic, Branimir

    2004-01-01

    The electrochemical reduction of 2-hydroxy-5-[(4-sulfophenyl)azo]benzoic acid, 2-hydroxy-5-[(3-sulfophenyl)azo]benzoic acid, 2-hydroxy-5-[(2-sulfophenyl)azo]benzoic acid and 2-hydroxy-5-azo-benzoic acid has been carried out in aqueous solutions at glassy carbon electrode using cyclic voltammetry and chronoamperometry. The position of sulfo substituent relative to azo bridge as well as pH of the solution have significant impact on the electrochemical behavior of these compounds. It has been proposed that these compounds are reduced predominantly as hydrazone tautomers resulting in corresponding hydrazo compounds. The overall electrochemical reduction follows DISP2 mechanism, ultimately leading to the 5-amino salicylic acid and sulfanilic acid. The rate determining step is the homogenous redox reaction between intermediate hydrazo compound and 5-amino salicylic acid quinoneimine. The mechanism is proposed in which activated complex of 5-amino salicylic acid quinoneimine and intermediate hydrazo compound is formed with the simultaneous loss of one proton

  15. Synthesis, spectroscopic, and molecular structure characterizations of some azo derivatives of 2-hydroxyacetophenone

    Science.gov (United States)

    Albayrak, Çiğdem; Gümrükçüoğlu, İsmail E.; Odabaşoğlu, Mustafa; İskeleli, Nazan Ocak; Ağar, Erbil

    2009-08-01

    Some novel azo compounds were prepared by the reaction of 2-hydroxyacetophenone with aniline and its substituted derivatives. The structures of synthesized azo compounds were determined by IR, UV-Vis, 1H NMR and 13C NMR spectroscopic techniques and the structures of some of these compounds were also determined by X-ray diffraction studies. Structural analysis using IR in solid state shows that the azo form is favoured in the azo compounds whereas UV-Vis analysis of the azo compounds in solution has shown that there is a azo and ionic form. The azo compounds in the basic solvents dimethylformamide (DMF) and dimethylsulfoxide (DMSO) are both azo and ionic form while these compounds in ethyl alcohol (EtOH) and chloroform (CHCl 3) are only azo form.

  16. Anaerobic azo dye reduction

    NARCIS (Netherlands)

    Zee, van der F.P.

    2002-01-01

    Azo dyes, aromatic moieties linked together by azo (-N=N-) chromophores, represent the largest class of dyes used in textile-processing and other industries. The release of these compounds into the environment is undesirable, not only because of their colour, but also

  17. Biological wastewater treatment of azo dyes

    Energy Technology Data Exchange (ETDEWEB)

    Shaul, G.M.; Dempsey, C.R.; Dostal, K.A. (Environmental Protection Agency, Cincinnati, OH (USA))

    1988-09-01

    EPA Water Engineering Research Laboratory, Office of Research and Development, undertook a study to determine the fate of specific water soluble azo dye compounds in the activated sludge process (ASP). The study was approached by dosing the feed to the pilot ASP systems with various water soluble azo dyes and by monitoring each dye compound through the system, analyzing both liquid and sludge samples. The fate of the parent dye compound was assessed via mass balance calculations. These data could determine if the compound was removed by adsorption, apparent biodegradation, or not removed at all. The paper presents results for 18 dye compounds tested from June 1985 through August 1987. The study was conducted at EPAs Test and Evaluation Facility in Cincinnati, Ohio. The objective of this study was to determine the partitioning of water soluble azo dyes in the ASP.

  18. Integrated and sequential anaerobic/aerobic biodegradation of azo dyes

    NARCIS (Netherlands)

    Tan, N.G.C.

    2001-01-01

    Azo dyes constitute a major class of environmental pollutants accounting for 60 to 70% of all dyes and pigments used. These compounds are characterized by aromatic moieties linked together with azo groups (-N=N-). The release of azo dyes into the environment is a concern due to coloration

  19. Fullerene-catalyzed reduction of azo derivatives in water under UV irradiation

    KAUST Repository

    Guo, Yong; Li, Wengang; Yan, Jingjing; Moosa, Basem; Amad, Maan H.; Werth, Charles; Khashab, Niveen M.

    2012-01-01

    Metal-free fullerene (C60) was found to be an effective catalyst for the reduction of azo groups in basic aqueous solution under UV irradiation in the presence of NaBH4. Use of NaBH4 by itself is not sufficient to reduce the azo dyes without the assistance of a metal catalyst such as Pd and Ag. Experimental and theoretical results suggest that C 60 catalyzes this reaction by using its vacant orbital to accept the electron in the bonding orbital of azo dyes, which leads to the activation of the N=N bond. UV irradiation increases the ability of C60 to interact with electron-donor moieties in azo dyes. Filling a vacancy: Experimental and theoretical methods have been combined to show that C60-catalyzed reductions of azo compounds form aromatic amines under UV irradiation (see scheme). The obtained results show that C60 acts as an electron acceptor to catalyze the reduction of azo compounds, and the role of UV irradiation is to increase the ability of C60 to interact with electron-donor moieties in azo compounds. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Fullerene-catalyzed reduction of azo derivatives in water under UV irradiation

    KAUST Repository

    Guo, Yong

    2012-09-27

    Metal-free fullerene (C60) was found to be an effective catalyst for the reduction of azo groups in basic aqueous solution under UV irradiation in the presence of NaBH4. Use of NaBH4 by itself is not sufficient to reduce the azo dyes without the assistance of a metal catalyst such as Pd and Ag. Experimental and theoretical results suggest that C 60 catalyzes this reaction by using its vacant orbital to accept the electron in the bonding orbital of azo dyes, which leads to the activation of the N=N bond. UV irradiation increases the ability of C60 to interact with electron-donor moieties in azo dyes. Filling a vacancy: Experimental and theoretical methods have been combined to show that C60-catalyzed reductions of azo compounds form aromatic amines under UV irradiation (see scheme). The obtained results show that C60 acts as an electron acceptor to catalyze the reduction of azo compounds, and the role of UV irradiation is to increase the ability of C60 to interact with electron-donor moieties in azo compounds. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Chromatographic methods for determination of metals as chelate compounds with heterocyclic azo reagents

    International Nuclear Information System (INIS)

    Basova, E.M.; Bol'shova, T.A.; Shpigun, O.A.; Ivanov, V.M.

    1993-01-01

    Methods for separation and concentration of transition metals as well as cadmium in form of chelates with heterocyclic azo compounds namely, PAN(1-(2-pyridylaso)-2-naphthol), PAR(4-(2-pyridylazo)-resorcin), Br-PAAP (2-(5-bromine-2-pyridylazo)-5-diethyl aminophenol) are considered. The Br-PAAP reagent is the most sensitive and widely-applied one in extraction and highly-efficient liquid chromatography. Methods of sorption concentration with subsequent element determination directly on the sorbent without microelements separation or destruction are the most promissing ones

  2. Synthesis and antibacterial activity of novel Pyrazolo [3, 4-B] quinoline based heterocyclic azo compounds and their dyeing performance

    International Nuclear Information System (INIS)

    Thaokar, Sanjay F.; Patel, Dinesh M.; Patel, Manish P.; Patel, Ranjan G.

    2007-01-01

    3-Amino-6-methyl-1H- pyrazolo [3, 4-B] quinoline was synthesized in good yield. Monoazo compounds were prepared using this intermediate as diazo component with various heterocyclic coupling components. All the azo compounds were characterized by their percentage yield, melting point, elemental analysis, UV-visible spectra, IR-spectra and dyeing performance on nylon and polyester fibres and by their antibacterial activity against gram positive and gram negative bacteria. (author)

  3. Synthesis, electrochemical, spectrophotometric and potentiometric studies of two azo-compounds derived from 4-amino-2-methylquinoline in ethanolic-aqueous buffered solutions

    Energy Technology Data Exchange (ETDEWEB)

    El-Attar, Mona A.; Ghoneim, Mohamed M. [Analytical Chemistry Research Unit, Chemistry Department, Tanta University (Egypt); Ismail, Iqbal M., E-mail: maema.2011@yahoo.com [Chemistry Department, Faculty of Science, King Abdul Aziz University, Jeddah (Saudi Arabia)

    2012-08-15

    Two azo-compounds, 2-methyl-4-(5-amino-2-hydroxy-phenylazo)-quinoline (2) and 2-methyl-4-(2-hydroxy-5-nitrophenylazo)-quinoline, derived from 4-amino-2-methylquinoline were synthesized. Their chemical structures were characterized and confirmed by means of elemental chemical analysis, infrared (IR) spectroscopy, {sup 1}H nuclear magnetic resonance (NMR) and mass spectrometry (MS). The electrochemical behavior of the starting compound (4-amino-2-methylquinoline) and of the two synthesized azo-derivatives was studied at the mercury electrode in the B-R universal buffer at various pH values (2-11.5) containing 40% (v/v) ethanol using dc-polarography, cyclic voltammetry and controlled-potential coulometry. Their electrode reaction pathways were elucidated and discussed. The dissociation constants (pKa) of the examined compounds, stability constants and stoichiometry of their complexes in solution with some transition metal ions (Co(II), Ni(II), Cu(II), La(III) and UO{sup 2+}{sub 2}) were determined. (author)

  4. Acid-Base Properties of Azo Dyes in Solution Studied Using Spectrophotometry and Colorimetry

    Science.gov (United States)

    Snigur, D. V.; Chebotarev, A. N.; Bevziuk, K. V.

    2018-03-01

    Colorimetry and spectrophotometry with chemometric data processing were used to study the acid-base properties of azo dyes in aqueous solution. The capabilities of both methods were compared. Ionization constants of all the functional groups of the azo compounds studied could be determined relative to the change in the specific color difference depending on the acidity of the medium. The colorimetric functions of ion-molecular forms of azo compounds used as an analytical signal allow us to obtain complete information on the acid-base equilibrium in a wide acidity range.

  5. Dielectric Properties of Azo Polymers: Effect of the Push-Pull Azo Chromophores

    Directory of Open Access Journals (Sweden)

    Xuan Zhang

    2018-01-01

    Full Text Available The relationship between the structure and the dielectric properties of the azo polymers was studied. Four azo polymers were synthesized through the azo-coupling reaction between the same precursor (PAZ and diazonium salts of 4-aminobenzoic acid ethyl ester, 4-aminobenzonitrile, 4-nitroaniline, and 2-amino-5-nitrothiazole, respectively. The precursor and azo polymers were characterized by 1H NMR, FT-IR, UV-vis, GPC, and DSC. The dielectric constant and dielectric loss of the samples were measured in the frequency range of 100 Hz–200 kHz. Due to the existence of the azo chromophores, the dielectric constant of the azo polymers increases compared with that of the precursor. In addition, the dielectric constant of the azo polymers increases with the increase of the polarity of the azo chromophores. A random copolymer (PAZ-NT-PAZ composed of the azo polymer PAZ-NT and the precursor PAZ was also prepared to investigate the content of the azo chromophores on the dielectric properties of the azo polymers. It showed that the dielectric constant increases with the increase of the azo chromophores. The results show that the dielectric constant of this kind of azo polymers can be controlled by changing the structures and contents of azo chromophores during the preparation process.

  6. AZO-Ag-AZO transparent electrode for amorphous silicon solar cells

    International Nuclear Information System (INIS)

    Theuring, Martin; Vehse, Martin; Maydell, Karsten von; Agert, Carsten

    2014-01-01

    Metal-based transparent electrodes can be fabricated at low temperatures, which is crucial for various substrate materials and solar cells. In this work, an oxide-metal-oxide (OMO) transparent electrode based on aluminum zinc oxide (AZO) and silver is compared to AZO layers, fabricated at different temperatures and indium tin oxides. With the OMO structure, a sheet resistance of 7.1/square and a transparency above 80% for almost the entire visible spectrum were achieved. The possible application of such electrodes on a textured solar cell was demonstrated on the example of a rough ZnO substrate. An OMO structure is benchmarked in a n-i-p amorphous silicon solar cell against an AZO front contact fabricated at 200 °C. In the experiment, the OMO electrode shows a superior performance with an efficiency gain of 30%. - Highlights: • Multilayer transparent electrode based on aluminum zinc oxide (AZO) and Ag • Comparison of AZO-Ag-AZO transparent electrode to AZO and indium tin oxide • Performance of AZO-Ag-AZO transparent electrodes on textured surfaces • Comparison of amorphous silicon solar cells with different transparent electrodes

  7. Ferroelectric Nematic and Ferrielectric Smectic Mesophases in an Achiral Bent-Core Azo Compound.

    Science.gov (United States)

    Kumar, Jitendra; Prasad, Veena

    2018-03-22

    Here, we report the observation of ferroelectric nematic and ferrielectric smectic mesophases in an achiral bent-core azo compound consisting of nonsymmetrical molecules with a lateral fluoro substitution on one of the wings. These mesophases are enantiotropic in nature with fairly low transition temperatures and wide mesophase ranges. The liquid crystalline properties of this compound are investigated using polarizing optical microscope, differential scanning calorimeter, X-ray diffraction, and electro-optical studies. As revealed by X-ray diffraction measurements, the nematic mesophase is composed of skewed cybotactic clusters and, in the smectic mesophase, the molecules are tilted with respect to the layer normal. The polar order in these mesophases was confirmed by the electro-optical switching and dielectric spectroscopy measurements. The dielectric study in the nematic mesophase shows a single relaxation process at low frequency ( f interest is the fact that the smectic phase exhibits a field induced ferrielectric state, which can be exploited for designing of the potential optical devices due to multistate switching.

  8. Re-evaluation of azo dyes as food additives

    DEFF Research Database (Denmark)

    Pratt, Iona; Larsen, John Christian; Mortensen, Alicja

    2013-01-01

    additives to be assessed by the Scientific Committee on Food, many years ago, (ii) because of concern regarding possible health effects of artificial colours arising since the original evaluations.Concerns includedbehavioural effects in children, allergic reactions, genotoxicity and possible carcinogenicity......Aryl azo compounds are widely used as colorants (azo dyes) in a wide range of products including textiles, leather, paper, cosmetics, pharmaceuticals and food.As part of its systematic re-evaluation of food additives, the European Food Safety Authority (EFSA) has carried out new risk assessments...

  9. (azo anils and oxalate ion) copper(ii)

    African Journals Online (AJOL)

    B. S. Chandravanshi

    transition metal complexes compared to corresponding free ligands may be attributed to structural symmetry of ... C H, N contents in synthesized azo anils ligands and in Cu(II) complexes were found using. CHNS technique (Costech international-4100). Metal contents in synthesized complexes were. Compounds. Color.

  10. Chlorine disinfection of dye wastewater: Implications for a commercial azo dye mixture

    International Nuclear Information System (INIS)

    Vacchi, Francine Inforçato; Albuquerque, Anjaina Fernandes; Vendemiatti, Josiane Aparecida; Morales, Daniel Alexandre; Ormond, Alexandra B.; Freeman, Harold S.; Zocolo, Guilherme Julião; Zanoni, Maria Valnice Boldrin; Umbuzeiro, Gisela

    2013-01-01

    Azo dyes, the most widely used family of synthetic dyes, are often employed as colorants in areas such as textiles, plastics, foods/drugs/cosmetics, and electronics. Following their use in industrial applications, azo dyes have been found in effluents and various receiving waters. Chemical treatment of effluents containing azo dyes includes disinfection using chlorine, which can generate compounds of varying eco/genotoxicity. Among the widely known commercial azo dyes for synthetic fibers is C.I. Disperse Red 1. While this dye is known to exist as a complex mixture, reports of eco/genotoxicity involve the purified form. Bearing in mind the potential for adverse synergistic effects arising from exposures to chemical mixtures, the aim of the present study was to characterize the components of commercial Disperse Red 1 and its chlorine-mediated decoloration products and to evaluate their ecotoxicity and mutagenicity. In conducting the present study, Disperse Red 1 was treated with chlorine gas, and the solution obtained was analyzed with the aid of LC–ESI-MS/MS to identify the components present, and then evaluated for ecotoxicity and mutagenicity, using Daphnia similis and Salmonella/microsome assays, respectively. The results of this study indicated that chlorination of Disperse Red 1 produced four chlorinated aromatic compounds as the main products and that the degradation products were more ecotoxic than the parent dye. These results suggest that a disinfection process using chlorine should be avoided for effluents containing hydrophobic azo dyes such commercial Disperse Red 1. -- Highlights: ► Aqueous solutions of Disperse Red 1 were treated with chlorine. ► The chlorination products of Disperse Red 1 were identified using LC–ESI-MS/MS. ► Daphnia and Salmonella/microsome were employed for eco/genotoxicity testing. ► The chlorinated dye was more mutagenic than the dye itself. ► Chlorination should be avoided in effluents containing azo-dyes.

  11. Syntheses of Azo-Imine Derivatives from Vanillin as an Acid Base Indicator

    Directory of Open Access Journals (Sweden)

    Bambang Purwono

    2013-05-01

    Full Text Available Preparations of azo, imine and azo-imine derivatives from vanillin as an indicator of acid-base titration have been carried out. The azo derivative of 4-hydroxy-3-methoxy-5-(phenylazobenzaldehyde 2 was produced by diazotitation reaction of vanillin in 37.04% yield. The azo product was then refluxed with aniline in ethanol to yield azo-imine derivatives, 2-methoxy-6-(phenylazo-4-((phenyliminomethylphenol 1 in 82.21% yield. The imine derivative, 2-methoxy-4-((phenyliminomethyl-phenol 3 was obtained by refluxing of vanillin and aniline mixture in ethanol solvent and produced 82.17% yield. The imine product was then reacted with benzenediazonium chloride salt. However, the products indicated hydrolyzed product of 4-hydroxy-3-methoxy-5-(phenylazobenzaldehyde 2 in 22.15% yield. The 2-methoxy-4-((phenyliminomethylphenol 2 could be used as an indicator for titration of NaOH by H2C2O4 with maximum concentration of H2C2O4 0.1 M while the target compound 1 could be used as titration indicator for titration of NaOH with H2C2O4 with same result using phenolphthalein indicator.

  12. 40 CFR 721.2577 - Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Copper complex of (substituted... Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine salt... substances identified generically as copper complex of (substituted sulfonaphthyl azo substituted phenyl...

  13. Azo dye reduction by mesophilic and thermophilic anaerobic consortia

    NARCIS (Netherlands)

    Santos, dos A.B.; Madrid, de M.P.; Stams, A.J.M.; Lier, van J.B.; Cervantes, F.J.

    2005-01-01

    The reduction of the azo dye model compounds Reactive Red 2 (RR2) and Reactive Orange 14 (RO14) by mesophilic (30 C) and thermophilic (55 C) anaerobic consortia was studied in batch assays. The contribution of fermentative and methanogenic microorganisms in both temperatures was evaluated in the

  14. Chlorine disinfection of dye wastewater: Implications for a commercial azo dye mixture

    Energy Technology Data Exchange (ETDEWEB)

    Vacchi, Francine Inforcato; Albuquerque, Anjaina Fernandes; Vendemiatti, Josiane Aparecida; Morales, Daniel Alexandre [Faculdade de Tecnologia, Universidade Estadual de Campinas, Limeira, SP, 13484-332 (Brazil); Ormond, Alexandra B.; Freeman, Harold S. [Department of Textile Engineering, Chemistry, and Science, North Carolina State University, Raleigh, NC 27695-8301 (United States); Zocolo, Guilherme Juliao; Zanoni, Maria Valnice Boldrin [Departamento de Quimica Analitica, Universidade Estadual Paulista Julio de Mesquita Filho, Instituto de Quimica de Araraquara, Araraquara, SP 14801-970 (Brazil); Umbuzeiro, Gisela, E-mail: giselau@ft.unicamp.br [Faculdade de Tecnologia, Universidade Estadual de Campinas, Limeira, SP, 13484-332 (Brazil)

    2013-01-01

    Azo dyes, the most widely used family of synthetic dyes, are often employed as colorants in areas such as textiles, plastics, foods/drugs/cosmetics, and electronics. Following their use in industrial applications, azo dyes have been found in effluents and various receiving waters. Chemical treatment of effluents containing azo dyes includes disinfection using chlorine, which can generate compounds of varying eco/genotoxicity. Among the widely known commercial azo dyes for synthetic fibers is C.I. Disperse Red 1. While this dye is known to exist as a complex mixture, reports of eco/genotoxicity involve the purified form. Bearing in mind the potential for adverse synergistic effects arising from exposures to chemical mixtures, the aim of the present study was to characterize the components of commercial Disperse Red 1 and its chlorine-mediated decoloration products and to evaluate their ecotoxicity and mutagenicity. In conducting the present study, Disperse Red 1 was treated with chlorine gas, and the solution obtained was analyzed with the aid of LC-ESI-MS/MS to identify the components present, and then evaluated for ecotoxicity and mutagenicity, using Daphnia similis and Salmonella/microsome assays, respectively. The results of this study indicated that chlorination of Disperse Red 1 produced four chlorinated aromatic compounds as the main products and that the degradation products were more ecotoxic than the parent dye. These results suggest that a disinfection process using chlorine should be avoided for effluents containing hydrophobic azo dyes such commercial Disperse Red 1. -- Highlights: Black-Right-Pointing-Pointer Aqueous solutions of Disperse Red 1 were treated with chlorine. Black-Right-Pointing-Pointer The chlorination products of Disperse Red 1 were identified using LC-ESI-MS/MS. Black-Right-Pointing-Pointer Daphnia and Salmonella/microsome were employed for eco/genotoxicity testing. Black-Right-Pointing-Pointer The chlorinated dye was more mutagenic

  15. Novel zinc(II)phthalocyanines bearing azo-containing schiff base: Determination of pKa values, absorption, emission, enzyme inhibition and photochemical properties

    Science.gov (United States)

    Kantar, Cihan; Mavi, Vildan; Baltaş, Nimet; İslamoğlu, Fatih; Şaşmaz, Selami

    2016-10-01

    Azo-containing schiff bases are well known and there are many studies about their various properties in literature. However, phthalocyanines bearing azo-containing schiff bases, their spectral, analytical and biological properties are unknown. Therefore, new zinc (II) phthalocyanines bearing azo-containing schiff base were synthesized and investigated to determine pKa values, absorption, emission, enzyme inhibition and photochemical properties. Emission spectra were reported and large Stokes shift values were determined for all compounds, indicating that all molecules exhibit excited state intramolecular proton transfer. These phthalocyanines were the first examples of phthalocyanine showing excited state intramolecular proton transfer. Singlet oxygen quantum yields of zinc (II) phthalocyanines were determined. pKa values and indicator properties of all compounds were investigated by potentiometry. All compounds were assayed for inhibitory activity against bovine milk xanthine oxidase and acetylcholinesterase enzyme in vitro. Compound 2 showed the high inhibitory effect against xanthine oxidase (IC50 = 0.24 ± 0.01 μM). However, phthalocyanine compounds did not show enzyme inhibitor behavior.

  16. Adsorptive stripping voltammetric behaviour of copper complexes of some heterocyclic azo compounds.

    Science.gov (United States)

    Farias, P A; Ferreira, S L; Ohara, A K; Bastos, M B; Goulart, M S

    1992-10-01

    Controlled adsorptive accumulation of copper complexed with TAN, TAC, TAR and TAM (heterocyclic azo-compounds) on a static mercury drop electrode provides the basis for the direct stripping measurement of this element in the nanomolar concentration level. The ligand TAN exhibited great sensitivity and better separation of the peak current of the ligand in relation to the complex. The reduction current of adsorbed complex ions of copper is measured by linear scan cathodic stripping voltammetry, preceded by a period of accumulation of a few minutes. The peak potential is at approximately -0.37 V vs. Ag/AgCl. Optimal experimental parameters were found to be a TAN concentration of 1 x 10(-5)M, an accumulation potential of -0.22 V, and a solution pH of 3.7 (acetate buffer). The detection limit is 0.8nM after a 5-min accumulation with a stirred solution, and the response is linear up to 50 mug/l. Many common cations and anions do not interfere in the determination of copper. The interference of titanium is eliminated by addition of fluoride ion. Results are reported for a fresh water sample.

  17. Synthesis and characterization of 5-amino-2-((3-hydroxy-4-((3-hydroxyphenyl phenyl diazenyl phenol and its Cu(II complex – a strategy toward developing azo complexes for reduction of cytotoxicity

    Directory of Open Access Journals (Sweden)

    Durba Ganguly

    2014-12-01

    Full Text Available A major drawback of azo compounds is their associated toxicity, often carcinogenic, which is related to the reduction of the azo bond. This study intends to re-investigate this behavior by studying 5-amino-2-((3-hydroxy-4-((3-hydroxyphenyl phenyl diazenyl phenol (AHPD, a compound containing two azo bonds. Interaction of AHPD and its dimeric Cu(II complex with bacterial strains Escherichia coli and Staphylococcus aureus revealed the complex was less toxic. Reductive cleavage of the azo bond in AHPD and the complex followed using cytochrome c reductase (a model azo-reductase as well as azo-reductase enzymes obtained from bacterial cell extracts. Degradation of the azo bond was less in the complex allowing us to correlate the observed cytotoxicity. Cyclic voltammetry on AHPD and the complex support observations of enzyme assay experiments. These were particularly useful in realizing the formation of amines as an outcome of the reductive cleavage of azo bonds in AHPD that could not be identified through an enzyme assay. Results suggest that complex formation of azo compounds could be a means to control the formation of amines responsible for cytotoxicity. Studies carried out on bacterial cells for mere simplicity bear significance for multicellular organisms and could be important for human beings involved with the preparation and utilization of azo dyes.

  18. Synthesis and evaluation of mutual azo prodrug of 5-aminosalicylic acid linked to 2-phenylbenzoxazole-2-yl-5-acetic acid in ulcerative colitis

    Directory of Open Access Journals (Sweden)

    Jilani JA

    2013-07-01

    Full Text Available Jamal A Jilani,1 Maha Shomaf,2 Karem H Alzoubi3 1Department of Medicinal Chemistry and Pharmacognosy, Jordan University of Science and Technology, Irbid, Jordan; 2Department of Pathology, Jordan University, Amman, Jordan; 3Department of Clinical Pharmacy, Jordan University of Science and Technology, Irbid, Jordan Abstract: In this study, the syntheses of 4-aminophenylbenzoxazol-2-yl-5-acetic acid, (an analogue of a known nonsteroidal anti-inflammatory drug [NSAID] and 5-[4-(benzoxazol-2-yl-5-acetic acidphenylazo]-2-hydroxybenzoic acid (a novel mutual azo prodrug of 5-aminosalicylic acid [5-ASA] are reported. The structures of the synthesized compounds were confirmed using infrared (IR, hydrogen-1 nuclear magnetic resonance (1H NMR, and mass spectrometry (MS spectroscopy. Incubation of the azo compound with rat cecal contents demonstrated the susceptibility of the prepared azo prodrug to bacterial azoreductase enzyme. The azo compound and the 4-aminophenylbenzoxazol-2-yl-5-acetic acid were evaluated for inflammatory bowel diseases, in trinitrobenzenesulfonic acid (TNB-induced colitis in rats. The synthesized diazo compound and the 4-aminophenylbenzoxazol-2-yl-5-acetic acid were found to be as effective as 5-aminosalicylic acid for ulcerative colitis. The results of this work suggest that the 4-aminophenylbenzoxazol-2-yl-5-acetic acid may represent a new lead for treatment of ulcerative colitis. Keywords: benzoxazole acetic acid, azo prodrug, colon drug delivery

  19. Research on Synthesis of New Azo Calix[4]arene and its Dyeing Properties

    Directory of Open Access Journals (Sweden)

    Tang Jun

    2015-01-01

    Full Text Available With the raw materials of calix[4]arene, benzocaine, tricaine and procaine hydrochloride, three new azo calix[4]arene derivatives—6a, 6b and 6c are synthesized by diazotization–coupling reaction of an aromatic amine, with its yield of 83%, 81% and 83% respectively. The structural characterization is in a way of IR, 1H NMR and elemental analysis. This paper investigates the spectral properties of azo calix[4]arene derivatives under different solution pH conditions through the UV–visible spectroscopy, and researches the dyeing properties through the dyeing curve, color yield test and fastness test. The results show that, with the increase of pH value, the azo calix[4]arene derivatives—6a, 6b and 6c form azo–hydrazone tautomeric isomers with the maximum absorption peak redshift; the dyeing effect of the compound is good, of which the dye–uptake rate of the compound 6a is as high as 78%; the surface depth of color yield is 2.798, and the dry and wet rubbing fastness and the soaping fastness are respectively 4, which is a better disperse dye.

  20. Synthesis and reactions of cyclovalence isomers of azo-keto-carbenes

    International Nuclear Information System (INIS)

    Rettenbacher, A.S.

    2001-09-01

    -exocyclic azomethine imines was worked out, which results from the so far unknown intramolecular reaction of azo-nitrogen atoms on carbenoids (rhodium-stabilized carbenes). Work up and isolation of the different reaction products turned out not to be without difficulty. Most of the novel and in solution partly unstable compounds that were characterized in this thesis would not have been isolable in the conventional manner (chemical separation processes, column chromatography). However, this has been managed by employing the radial chromatography upon optimizing some parameters; apparently, this is a not widely known chromatographic separation method that enables fast separations with high efficiency. To clarify the question, why only certain azomethine imines react with special dipolarophiles, quantum-mechanical calculations of the reactants' frontier orbitals have been carried out; this resulted in a satisfactory concordance with the FMO theory by Fukui. Likewise, molecular calculations rationalize the observed stereo- and regioselectivity as well as the kinetic and thermodynamic reaction control in the course of cycloaddition reactions of azomethine imines. (author)

  1. Solar photoassisted advanced oxidation process of azo dyes.

    Science.gov (United States)

    Prato-Garcia, D; Buitrón, G

    2009-01-01

    Advanced oxidation processes assisted with natural solar radiation in CPC type reactors (parabolic collector compound), was applied for the degradation of three azo dyes: acid orange (AO7), acid red 151 (AR151) and acid blue 113 (AB113). Fenton, Fenton like and ferrioxalate-type complexes showed to be effective for degrade the azo linkage and moieties in different extensions. Initially, the best dose of reagents (Fe(3 + )-H(2)O(2)) was determined through a factorial experimental design, next, using response surface methodologies, the reagent consumption was reduced up to 40%, maintaining in all cases high decolourisation percentages (>98%) after 60 min. of phototreatment. In this work, it was also studied the effect of concentration changes of the influent between 100-300 mg/L and the operation of the photocatalytic process near neutral conditions (pH 6.0-6.5) by using ferrioxalate type complex (FeOx).

  2. Synthesis of azo pyridone dyes

    Directory of Open Access Journals (Sweden)

    Mijin Dušan Ž.

    2011-01-01

    Full Text Available Over 50% of all colorants which are used nowdays are azo dyes and pigments, and among them arylazo pyridone dyes (and pigments have became of interest in last several decades due to the high molar extinction coefficient, and the medium to high light and wet fastness properties. They find application generally as disperse dyes. The importance of disperse dyes increased in the 1970s and 1980s due to the use of polyester and nylon as the main synthetic fibers. Also, disperse dyes were used rapidly since 1970 in inks for the heat-transfer printing of polyester. The main synthetic route for the preparation of azo dyes is coupling reaction between an aromatic diazo compound and a coupling component. Of all dyes manufactured, about 60% are produced by this reaction. Arylazo pyridone dyes can be prepared from pyridone moiety as a coupling component, where substituent can be on nitrogen, and diazonim salts which can be derived from different substituted anilines or other heterocyclic derivatives. In addition, arylazo dyes containing pyridone ring can be prepared from arylazo diketones or arylazo ketoesters (obtained by coupling β-diketones or β-ketoesters with diazonim salts by condensation with cyanoacetamide. Disazo dyes can be prepared by tetrazotizing a dianiline and coupling it with a pyridone or by diazotizing aniline and coupling it with a dipyridone. Trisazo dyes can be also prepared by diazotizing of aniline and coupling it with a tripyridone or by hexazotizing a trianiline and coupling it with a pyridone. The main goal of this paper is to give a brief review on the synthesis of arylazo pyridone dyes due to the lack of such reviews. In addition, some properties of arylazo pyridone dyes as light fastness and azo-hydrazon tautomerism are disccused.

  3. Dye-sensitized solar cell based on AZO/Ag/AZO multilayer transparent conductive oxide film

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Jin-He; Li, Ying [School of Materials Science and Engineering, Shanghai University, 149 Yanchang Road, Shanghai 200072 (China); Duong, Thanh-Tung; Choi, Hyung-Jin [Department of Materials Engineering, Chungnam National University, Daeduk Science Town, 305-764 Daejeon (Korea, Republic of); Yoon, Soon-Gil, E-mail: sgyoon@cnu.ac.kr [Department of Materials Engineering, Chungnam National University, Daeduk Science Town, 305-764 Daejeon (Korea, Republic of)

    2013-04-15

    Highlights: ► AZO/Ag/AZO (AAA) multilayer was used for working electrode of DSSC cell. ► The 100 nm-thick Nb-doped TiO{sub 2} layer showed a good blocking effect. ► The DSSC cell by AAA TCO material showed the highest efficiency of about 3.25%. -- Abstract: Niobium-doped TiO{sub 2} blocking layer and Al-doped ZnO (AZO)/Ag/AZO (AAA) TCO layers were grown onto glass substrate using pulsed laser deposition (PLD) and direct current (dc)/radio-frequency (rf) sputtering at room temperature, respectively for dye-sensitized solar cell (DSSC) applications. The 100 nm-thick NTO layer showed a blocking effect for the oxygen diffusion into AAA layer and for the recombination of the electrons. The DSSC cell composed of the NTO (100 nm)/AAA (400 nm) showed the highest photo-electrical efficiency of about 3.25%. An insertion of aluminum foil between serrated clip and AAA (100 nm) TCO improved a photo-conversion efficiency of the DSSC.

  4. Dye-sensitized solar cell based on AZO/Ag/AZO multilayer transparent conductive oxide film

    International Nuclear Information System (INIS)

    Qi, Jin-He; Li, Ying; Duong, Thanh-Tung; Choi, Hyung-Jin; Yoon, Soon-Gil

    2013-01-01

    Highlights: ► AZO/Ag/AZO (AAA) multilayer was used for working electrode of DSSC cell. ► The 100 nm-thick Nb-doped TiO 2 layer showed a good blocking effect. ► The DSSC cell by AAA TCO material showed the highest efficiency of about 3.25%. -- Abstract: Niobium-doped TiO 2 blocking layer and Al-doped ZnO (AZO)/Ag/AZO (AAA) TCO layers were grown onto glass substrate using pulsed laser deposition (PLD) and direct current (dc)/radio-frequency (rf) sputtering at room temperature, respectively for dye-sensitized solar cell (DSSC) applications. The 100 nm-thick NTO layer showed a blocking effect for the oxygen diffusion into AAA layer and for the recombination of the electrons. The DSSC cell composed of the NTO (100 nm)/AAA (400 nm) showed the highest photo-electrical efficiency of about 3.25%. An insertion of aluminum foil between serrated clip and AAA (100 nm) TCO improved a photo-conversion efficiency of the DSSC

  5. AZO/Au/AZO tri-layer thin films for the very low resistivity transparent electrode applications

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Chien-Hsun [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China); Wu, Hung-Wei, E-mail: hwwu@mail.ksu.edu.tw [Department of Computer and Communication, Kun Shan University, Tainan 71003, Taiwan (China); Huang, Jow-Lay [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China); Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 81148, Taiwan (China); Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan 70101, Taiwan (China)

    2014-08-01

    Highlights: • High-quality Al-doped ZnO (AZO)/Au/AZO transparent conducting oxide films. • AZO films (30 nm) made by RF sputtering; ion sputtering for Au film (5–20 nm). • Effects of Au thickness on optical and electrical properties were analyzed. • The resistivity of 9 × 10{sup −5} Ω cm and the transmittance of 86.2% of the multilayer films were obtained in this study. - Abstract: Aluminum-doped ZnO (AZO)/gold/AZO tri-layer structures with very low resistivity and high transmittance are prepared by simultaneous RF magnetron sputtering (for AZO) and ion sputtering (for Au). The properties of the tri-layer films are investigated at different Au layer thicknesses (5–20 nm). The effects of Au layer thickness and the role of Au on the transmission properties of the tri-layer films were investigated. The very low resistivity of 1.01 × 10{sup −5} Ω cm, mobility of 27.665 cm{sup 2} V{sup −1} s{sup −1}, and carrier concentration of 4.563 × 10{sup 22} cm{sup −3} were obtained at an Au layer thickness of 20 nm. The peak transmittance of 86.18% at 650-nm wavelength was obtained at an Au layer thickness of 8 nm. These results show the films to be a good candidate for high-quality electrode scheme in various display applications.

  6. Structural and optical properties of ZnO nanostructures electrochemically synthesized on AZO/Ag/AZO-multilayer-film-coated polyethersulfone substrates

    International Nuclear Information System (INIS)

    Oh, Dohyun; Yoo, Chanho; No, Youngsoo; Kim, Suyoun; Kim, Taewhan; Cho, Woonjo; Kim, Jinyoung

    2012-01-01

    ZnO nanostructures were formed on Al-doped ZnO (AZO)/Ag/AZO-multilayer-film-coated flexible polyethersulfone (PES) substrates at low temperature by using an electrochemical deposition method. The resistivity of the AZO/Ag/AZO multilayer films decreased with increasing thickness of the Ag film. X-ray diffraction patterns for the ZnO nanostructures showed that the crystal structure of the ZnO was hexagonal wurtzite and that the orientation was along the c-axis perpendicular to the substrate. Scanning electron microscopy images showed that the ZnO nanostructures grown at current densities of - 1.0 and - 1.5 mA/cm 2 were ZnO nanorods with diameters of 150 nm and ZnO nanoflowers with a planar dimension, respectively. Photoluminescence spectra showed that the band-edge emission peak of the ZnO nanostructures dominantly appeared in the ultraviolet region. These results showed that ZnO nanorods and nanoflowers with high quality were synthesized on AZO/Ag/AZO-multilayer-film-coated PES substrates.

  7. Degradation of azo dyes by environmental microorganisms and helminths

    Energy Technology Data Exchange (ETDEWEB)

    Kingthom Chung; Stevens, S.E. Jr. (Memphis State Univ., TN (United States). Dept. of Biology)

    1993-11-01

    The degradation of azo dyes by environmental microorganisms, fungi, and helminths is reviewed. Azo dyes are used in a wide variety of products and can be found in the effluent of most sewage treatment facilities. Substantial quantities of these dyes have been deposited in the environment, particularly in streams and rivers. Azo dyes were shown to affect microbial activities and microbial population sizes in the sediments and in the water columns of aquatic habitats. Only a few aerobic bacteria have been found to reduce azo dyes under aerobic conditions, and little is known about the process. A substantial number of anaerobic bacteria capable of azo dye reduction have been reported. The enzyme responsible for azo dye reduction has been partially purified, and characterization of the enzyme is proceeding. The nematode Ascaris lumbricoides and the cestode Moniezia expanza have been reported to reduce azo dyes anaerobically. Recently the fungus Phanerochaete chrysoporium was reported to mineralize azo dyes via a peroxidation-mediated pathway. A possible degradation pathway for the mineralization of azo dye is proposed and future research needs are discussed.

  8. The structural and electro-optical characteristics of AZO/Cr:Cu/AZO transparent conductive film

    International Nuclear Information System (INIS)

    Lin, Tien-Chai; Huang, Wen-Chang; Tsai, Fu-Chun

    2015-01-01

    A novel triple-layered transparent conductive film, AZO/Cr:Cu/AZO (ACCA), was presented in the paper. The structural and electro-optical properties of the ACCA film were discussed. The thickness of the middle metal layer was constant and those of the AZO layers were varied. The ACCA film shows an obvious ZnO (002) c-axis preferential growth. No diffraction peaks related to Cr and Cu were observed through x-ray diffraction analysis. The middle Cr:Cu layer showed a thickness of 8.16 nm with a continuous and amorphous structure by the observation of a high-resolution transmission electron microscopy (HR-TEM). For the electro-optical characteristic, a best figure of merit (FOM) value of 3.54 × 10 −3 Ω −1 with a corresponding transmittance of 85% was obtained at the thickness of 116 nm of ACCA film. The high FOM value of the film is due to the improvement of conductivity and small sacrifices of transparency. - Highlights: • A novel triple-layered transparent conductive film, AZO/Cr:Cu/AZO is developed. • Chromium is added to copper to reduce the oxidation–reduction reaction. • The film has a FOM of 3.54 × 10 −3 Ω −1 with a corresponding transmittance of 85%. • The Cr:Cu layer shows a continuous and amorphous structure

  9. The structural and electro-optical characteristics of AZO/Cr:Cu/AZO transparent conductive film

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Tien-Chai [Department of Electrical Engineering, Kun Shan University, No. 195, Kun-Da Road, Yung-Kang Dist., Tainan 71003, Taiwan, ROC (China); Huang, Wen-Chang, E-mail: wchuang@mail.ksu.edu.tw [Department of Electro-Optical Engineering, Kun Shan University, No. 195, Kun-Da Road, Yung-Kang Dist., Tainan 71003, Taiwan, ROC (China); Tsai, Fu-Chun [Department of Electro-Optical Engineering, Kun Shan University, No. 195, Kun-Da Road, Yung-Kang Dist., Tainan 71003, Taiwan, ROC (China)

    2015-08-31

    A novel triple-layered transparent conductive film, AZO/Cr:Cu/AZO (ACCA), was presented in the paper. The structural and electro-optical properties of the ACCA film were discussed. The thickness of the middle metal layer was constant and those of the AZO layers were varied. The ACCA film shows an obvious ZnO (002) c-axis preferential growth. No diffraction peaks related to Cr and Cu were observed through x-ray diffraction analysis. The middle Cr:Cu layer showed a thickness of 8.16 nm with a continuous and amorphous structure by the observation of a high-resolution transmission electron microscopy (HR-TEM). For the electro-optical characteristic, a best figure of merit (FOM) value of 3.54 × 10{sup −3} Ω{sup −1} with a corresponding transmittance of 85% was obtained at the thickness of 116 nm of ACCA film. The high FOM value of the film is due to the improvement of conductivity and small sacrifices of transparency. - Highlights: • A novel triple-layered transparent conductive film, AZO/Cr:Cu/AZO is developed. • Chromium is added to copper to reduce the oxidation–reduction reaction. • The film has a FOM of 3.54 × 10{sup −3} Ω{sup −1} with a corresponding transmittance of 85%. • The Cr:Cu layer shows a continuous and amorphous structure.

  10. Electrical circuit model of ITO/AZO/Ge photodetector.

    Science.gov (United States)

    Patel, Malkeshkumar; Kim, Joondong

    2017-10-01

    In this data article, ITO/AZO/Ge photodetector was investigated for electrical circuit model. Due to the double (ITO and AZO) transparent metal-oxide films (DOI:10.1016/j.mssp.2016.03.007) (Yun et al., 2016) [1], the Ge heterojunction device has a better interface quality due to the AZO layer with a low electrical resistance due to the ITO layer (Yun et al., 2015) [2]. The electrical and interfacial benefitted ITO/AZO/Ge heterojunction shows the quality Schottky junction. In order to investigate the device, the ITO/AZO/Ge heterojunction was analyzed by R-C circuit model using the impedance spectroscopy.

  11. Electrical circuit model of ITO/AZO/Ge photodetector

    Directory of Open Access Journals (Sweden)

    Malkeshkumar Patel

    2017-10-01

    Full Text Available In this data article, ITO/AZO/Ge photodetector was investigated for electrical circuit model. Due to the double (ITO and AZO transparent metal-oxide films (DOI:10.1016/j.mssp.2016.03.007 (Yun et al., 2016 [1], the Ge heterojunction device has a better interface quality due to the AZO layer with a low electrical resistance due to the ITO layer (Yun et al., 2015 [2]. The electrical and interfacial benefitted ITO/AZO/Ge heterojunction shows the quality Schottky junction. In order to investigate the device, the ITO/AZO/Ge heterojunction was analyzed by R–C circuit model using the impedance spectroscopy.

  12. Evidence for significantly enhancing reduction of Azo dyes in Escherichia coli by expressed cytoplasmic Azoreductase (AzoA) of Enterococcus faecalis.

    Science.gov (United States)

    Feng, J; Heinze, T M; Xu, H; Cerniglia, C E; Chen, H

    2010-05-01

    Although cytoplasmic azoreductases have been purified and characterized from various bacteria, little evidence demonstrating that these azoreductases are directly involved in azo dye reduction in vivo is known. In order to evaluate the contribution of the enzyme to azo dye reduction in vivo, experiments were conducted to determine the effect of a recombinant cytoplasmic azoreductase (AzoA) from Enterococcus faecalis expressed in Escherichia coli on the rate of metabolism of Methyl Red, Ponceau BS and Orange II. The intact cells that contained IPTG induced AzoA had a higher rate of dye reduction with increases of 2 (Methyl Red), 4 (Ponceau BS) and 2.6 (Orange II)-fold compared to noninduced cells, respectively. Metabolites of Methyl Red isolated from induced cultures were identified as N,N-dimethyl-p-phenylenediamine and 2-aminobenzoic acid through liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) analyses. In conclusion, our data demonstrate that AzoA from Ent. faecalis is capable of increasing the reduction of azo dyes in intact E. coli cells and that cytoplasmic azoreductase is involved in bacterial dye degradation in vivo.

  13. The Hydractinia echinata Test-System. III: Structure-Toxicity Relationship Study of Some Azo-, Azo-Anilide, and Diazonium Salt Derivatives

    Directory of Open Access Journals (Sweden)

    Sergiu Adrian Chicu

    2014-07-01

    Full Text Available Structure-toxicity relationships for a series of 75 azo and azo-anilide dyes and five diazonium salts were developed using Hydractinia echinata (H. echinata as model species. In addition, based on these relationships, predictions for 58 other azo-dyes were made. The experimental results showed that the measured effectiveness Mlog(1/MRC50 does not depend on the number of azo groups or the ones corresponding to metobolites, but it is influenced by the number of anilide groups, as well as by the substituents’ positions within molecules. The conformational analysis pointed out the intramolecular hydrogen bonds, especially the simple tautomerization of quinoidic (STOH or aminoidic (STNH2 type. The effectiveness is strongly influenced by the “push-pull” electronic effect, specific to two hydroxy or amino groups separated by an azo moiety (double alternate tautomery, (DAT, to the –COOH or –SO3H groups which are located in ortho or para position with respect to the azo group. The levels of the lipophylic/hydrophilic, electronic and steric equilibriums, pointed out by the Mlog(1/MRC50 values, enabled the calculation of their average values Clog(1/MRC50 (“Köln model”, characteristic to one derivative class (class isotoxicity. The azo group reduction and the hydrolysis of the amido/peptidic group are two concurrent enzymatic reactions, which occur with different reaction rates and mechanisms. The products of the partial biodegradation are aromatic amines. No additive or synergic effects are noticed among them.

  14. Antimicrobial azobenzene compounds and their potential use in biomaterials

    Science.gov (United States)

    Sessa, L.; Concilio, S.; Iannelli, P.; De Santis, F.; Porta, A.; Piotto, S.

    2016-04-01

    We recently synthesized a class of active compounds with azobenzene structure [1] and lowest in silico toxicity values. The antimicrobial activity of these molecules and their thermal stability are very promising and indicate that they may have interesting and therapeutically significant applications. This work aims to develop new materials with antibacterial and antifungal activity inserting different percentages of synthetic antimicrobial azo compounds in commercial polymer matrices. We realized thin films using solvent casting and melt compounding techniques. The obtained materials retained the proprieties of the pure matrices. This means that azo dye dissolved in the matrix does not influence the thermal behavior and the morphology of the material. Tested films exhibited the capability to inhibit biofilms formation of S. aureus and C. albicans. Spectrophotometric investigation of the azo compound released from the polymer matrices confirmed that the realized materials might be interesting for biomedical tools, antibacterial surfaces, and films for active packaging.

  15. Aerobic decolourization of two reactive azo dyes under varying ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-02-01

    Feb 1, 2010 ... Azo dyes generally resist aerobic microbial degra- dation, only organisms with specialized azo dye reducing enzymes were found to degrade azo dyes under fully aerobic ... textile mill, in sterile plastic bottles. Isolation of ...

  16. Density functional theory study of adsorption geometries and electronic structures of azo-dye-based molecules on anatase TiO2 surface for dye-sensitized solar cell applications.

    Science.gov (United States)

    Prajongtat, Pongthep; Suramitr, Songwut; Nokbin, Somkiat; Nakajima, Koichi; Mitsuke, Koichiro; Hannongbua, Supa

    2017-09-01

    Structural and electronic properties of eight isolated azo dyes (ArNNAr', where Ar and Ar' denote the aryl groups containing benzene and naphthalene skeletons, respectively) were investigated by density functional theory (DFT) based on the B3LYP/6-31G(d,p) and TD-B3LYP/6-311G(d,p) methods The effect of methanol solvent on the structural and electronic properties of the azo dyes was elucidated by employing a polarizable continuum model (PCM). Then, the azo dyes adsorbed onto the anatase TiO 2 (101) slab surface through a carboxyl group. The geometries and electronic structures of the adsorption complexes were determined using periodic DFT based on the PWC/DNP method. The calculated adsorption energies indicate that the adsorbed dyes preferentially take configuration of the bidentate bridging rather than chelating or monodentate ester-type geometries. Furthermore, the azo compounds having two carboxyl groups are coordinated to the TiO 2 surface more preferentially through the carboxyl group connecting to the benzene skeleton than through that connecting to the naphthalene skeleton. The dihedral angles (Φ B-N ) between the benzene- and naphthalene-skeleton moieties are smaller than 10° for the adsorbed azo compounds containing one carboxyl group. In contrast, Φ B-N > 30° are obtained for the adsorbed azo compounds containing two carboxyl groups. The almost planar conformations of the former appear to strengthen both π-electrons conjugation and electronic coupling between low-lying unoccupied molecular orbitals of the azo dyes and the conduction band of TiO 2 . On the other hand, such coupling is very weak for the latter, leading to a shift of the Fermi level of TiO 2 in the lower-energy direction. The obtained results are useful to the design and synthesize novel azo-dye-based molecules that give rise to higher photovoltaic performances of the dye-sensitized solar cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Characterization of AZO and Ag based films prepared by RF magnetron sputtering

    International Nuclear Information System (INIS)

    Miao, Dagang; Jiang, Shouxiang; Zhao, Hongmei; Shang, Songmin; Chen, Zhuoming

    2014-01-01

    Highlights: • Highly infrared reflective AZO and Ag based films were prepared. • Ag showed better crystallization on AZO film than on glass substrate. • Infrared reflection rate was inversely proportional to the film sheet resistance. • Film with infrared reflection of 97% in FIR region was acquired. - Abstract: Ag, AZO/Ag, Ag/AZO and AZO/Ag/AZO films were prepared on glass substrates by radio frequency (RF) magnetron sputtering technology. The prepared films were systematically investigated by X-ray Diffraction (XRD), Atomic Force Microscopy (AFM), UV–visible spectrophotometer, a four-point probe system and Fourier Transform Infrared Spectroscopy. The results indicated that Ag inner layer starts forming a continuous film at the thickness of 10 nm and Ag layer presents superior crystallization on AZO substrate than that on glass substrate. The continuous Ag inner layer film provided the highest average visible transmittance of 85.4% (AZO/Ag/AZO). The lowest sheet resistance of 3.21 Ω/sq and the highest infrared reflection rate of 97% in FIR region can be obtained on AZO/Ag (15 nm)/AZO film. The high infrared reflection property of the AZO/Ag/AZO coating makes it a promising candidate for solar control films

  18. Comparison of carrier transport mechanism under UV/Vis illumination in an AZO photodetector and an AZO/p-Si heterojunction photodiode produced by spray pyrolysis

    International Nuclear Information System (INIS)

    Shasti, M.; Mortezaali, A.; Dariani, R. S.

    2015-01-01

    In this study, Aluminum doped Zinc Oxide (AZO) layer is deposited on p-type silicon (p-Si) by spray pyrolysis method to fabricate ultraviolet-visible (UV/Vis) photodetector as Al doping process can have positive effect on the photodetector performance. Morphology, crystalline structure, and Al concentration of AZO layer are investigated by SEM, XRD, and EDX. The goal of this study is to analyze the mechanism of carrier transport by means of current-voltage characteristics under UV/Vis illumination in two cases: (a) electrodes connected to the surface of AZO layer and (b) electrodes connected to cross section of heterojunction (AZO/p-Si). Measurements indicate that the AZO/p-Si photodiode exhibits a higher photocurrent and lower photoresponse time under visible illumination with respect to AZO photodetector; while under UV illumination, the above result is inversed. Besides, the internal junction field of AZO/p-Si heterojunction plays an important role on this mechanism

  19. Comparison of carrier transport mechanism under UV/Vis illumination in an AZO photodetector and an AZO/p-Si heterojunction photodiode produced by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Shasti, M.; Mortezaali, A., E-mail: mortezaali@alzahra.ac.ir; Dariani, R. S. [Department of Physics, Alzahra University, Tehran 1993893973 (Iran, Islamic Republic of)

    2015-01-14

    In this study, Aluminum doped Zinc Oxide (AZO) layer is deposited on p-type silicon (p-Si) by spray pyrolysis method to fabricate ultraviolet-visible (UV/Vis) photodetector as Al doping process can have positive effect on the photodetector performance. Morphology, crystalline structure, and Al concentration of AZO layer are investigated by SEM, XRD, and EDX. The goal of this study is to analyze the mechanism of carrier transport by means of current-voltage characteristics under UV/Vis illumination in two cases: (a) electrodes connected to the surface of AZO layer and (b) electrodes connected to cross section of heterojunction (AZO/p-Si). Measurements indicate that the AZO/p-Si photodiode exhibits a higher photocurrent and lower photoresponse time under visible illumination with respect to AZO photodetector; while under UV illumination, the above result is inversed. Besides, the internal junction field of AZO/p-Si heterojunction plays an important role on this mechanism.

  20. Highly transparent conductive AZO/Zr50Cu50/AZO films in wide range of visible and near infrared wavelength grown by pulsed laser deposition

    Directory of Open Access Journals (Sweden)

    Jingyun Cheng

    Full Text Available Novel AZO/Zr50Cu50/AZO tri-layer transparent conductive films with excellent transmittance in both visible and near infrared region were successfully prepared by pulsed laser deposition on glass substrates. The electrical and optical properties were investigated at various Zr50Cu50 thicknesses. As the AZO thickness was fixed at 50 nm and Zr50Cu50 thickness was varied between 1 and 18 nm, it was found that AZO (50 nm/Zr50Cu50/AZO (50 nm tri-layer films exhibited good conductivity and high transmittance in both visible and near infrared wavelength. Additionally, both the electrical and optical properties of AZO (50 nm/Zr50Cu50 (2 nm/AZO (50 nm tri-layer films were found to be sensitive to the growth temperature. In this work, the lowest sheet resistance (43 Ω/□ and relatively high transmittance (∼80% in the range of 400–2000 nm were achieved while the growth temperature was 350 °C. Furthermore, the AZO (50 nm/Zr50Cu50 (2 nm/AZO (50 nm thin film deposited at 350 °C exhibits the highest figure of merit of 1.42 × 10−3 Ω−1, indicating that the multilayer is promising for coated glasses and thin film solar cells. Keywords: Transparent conductive oxide, AZO, Zr50Cu50, Electrical and optical properties, Visible and near infrared transmittance

  1. Modification of azo dyes by lactic acid bacteria.

    Science.gov (United States)

    Pérez-Díaz, I M; McFeeters, R F

    2009-08-01

    The ability of Lactobacillus casei and Lactobacillus paracasei to modify the azo dye, tartrazine, was recently documented as the result of the investigation on red coloured spoilage in acidified cucumbers. Fourteen other lactic acid bacteria (LAB) were screened for their capability to modify the food colouring tartrazine and other azo dyes of relevance for the textile industry. Most LAB modified tartrazine under anaerobic conditions, but not under aerobic conditions in modified chemically defined media. Microbial growth was not affected by the presence of the azo dyes in the culture medium. The product of the tartrazine modification by LAB was identified as a molecule 111 daltons larger than its precursor by liquid chromatography-mass spectrometry. This product had a purple colour under aerobic conditions and was colourless under anaerobic conditions. It absorbed light at 361 and 553 nm. LAB are capable of anabolizing azo dyes only under anaerobic conditions. IMPACT AND SIGNIFICANCE OF THE STUDY: Although micro-organisms capable of reducing the azo bond on multiple dyes have been known for decades, this is the first report of anabolism of azo dyes by food related micro-organisms, such as LAB.

  2. Antiferroelectric phase in liquid crystalline compounds with azo group in their molecular core

    Czech Academy of Sciences Publication Activity Database

    Kašpar, Miroslav; Novotná, Vladimíra; Hamplová, Věra; Podoliak, Natalia; Nonnenmacher, D.; Giesselmann, F.; Glogarová, Milada

    2011-01-01

    Roč. 38, č. 3 (2011), s. 309-315 ISSN 0267-8292 R&D Projects: GA AV ČR IAA100100911; GA AV ČR(CZ) GA202/09/0047 Grant - others:German Czech bilateral program(DE) D4-CZ5/2010-2011; GA UK(CZ) SVV-2011-263303 Institutional research plan: CEZ:AV0Z10100520 Keywords : liquid crystals * antiferroelectricity * azo linkage group * photosensitivity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.858, year: 2011

  3. Preparation and Properties of Flexible AZO@C Nanofibers

    Directory of Open Access Journals (Sweden)

    MA Hui

    2018-01-01

    Full Text Available A new type of environmental-friendly flexible nanofibers of aluminum doped zinc oxide (AZO coated carbon (AZO@C was successfully prepared by using polyvinyl alcohol (PVA as raw materials. The as-spun PVA nanofibers were prepared via electrospinning and its water resistance was greatly improved after heat-treatment. Then, the PVA nanofibers with a layer of zinc aluminum hydroxide on the surface were synthesized by hydrothermal method. Thereafter, new AZO@C composite nanofibers was produced after sintering at 500℃ to the carbonization of PVA nanofibers and the dehydration of zinc aluminum hydroxide to form AZO nanoparticles. The structure and properties of the samples were characterized by Fourier-transform infrared spectrometer (FT-IR, thermal gravimetric analyzer (TGA and scanning electron microscope (SEM. The average diameter of the AZO@C nanofibers is (320±45nm. The photocatalytic property of the resultant composite fibers is demonstrated by degrading methyl orange under solar light.

  4. Characteristics of indium-free GZO/Ag/GZO and AZO/Ag/AZO multilayer electrode grown by dual target DC sputtering at room temperature for low-cost organic photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ho-Kyun; Kim, Han-Ki [Department of Display Materials Research Center, Materials Research Center for Information Displays (MRCID), Kyung Hee University, 1 Seocheon-dong, Youngin-si, Gyeonggi-do 446-701 (Korea); Kang, Jae-Wook [Department of Material Processing, Korea Institute of Materials Science(KIMS), 66 Sangnam-dong, Changwon-si, Gyeongnam 641-831 (Korea); Na, Seok-In; Kim, Don-Yu. [Heeger Center for Advanced Materials, Department of Materials Science and Engineering, Gwangju Institute of Science and Technology, 1 Oryoung-dong, Gwangju 500-712 (Korea)

    2009-11-15

    We compared the electrical, optical, structural and surface properties of indium-free Ga-doped ZnO (GZO)/Ag/GZO and Al-doped ZnO (AZO)/Ag/AZO multilayer electrodes deposited by dual target direct current sputtering at room temperature for low-cost organic photovoltaics. It was shown that the electrical and optical properties of the GZO/Ag/GZO and AZO/Ag/AZO multilayer electrodes could be improved by the insertion of an Ag layer with optimized thickness between oxide layers, due to its very low resistivity and surface plasmon effect. In addition, the Auger electron spectroscopy depth profile results for the GZO/Ag/GZO and AZO/Ag/AZO multilayer electrodes showed no interfacial reaction between the Ag layer and GZO or AZO layer, due to the low preparation temperature and the stability of the Ag layer. Moreover, the bulk heterojunction organic solar cell fabricated on the multilayer electrodes exhibited higher power conversion efficiency than the organic solar cells fabricated on the single GZO or AZO layer, due to much lower sheet resistance of the multilayer electrode. This indicates that indium-free GZO/Ag/GZO and AZO/Ag/AZO multilayer electrodes are a promising low-cost and low-temperature processing electrode scheme for low-cost organic photovoltaics. (author)

  5. Structural evolution, electrical and optical properties of AZO films ...

    Indian Academy of Sciences (India)

    Administrator

    Aluminum-doped zinc oxide (AZO) target was fabricated using AZO ... All AZO films show c-axis preferred orientation and hexagonal structure. With increasing film thick- ness from 153 to 1404 nm, the crystallinity was improved and the angle of (002) peak was close to ... For observing grain boundary and size, the target was.

  6. Azo dye decolorization assisted by chemical and biogenic sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Prato-Garcia, Dorian [Laboratory for Research on Advanced Processes for Water Treatment, Unidad Académica Juriquilla, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Blvd. Juriquilla 3001, Querétaro 76230 (Mexico); Cervantes, Francisco J. [División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa de San José 2055, San Luis Potosí 78216 (Mexico); Buitrón, Germán, E-mail: gbuitronm@ii.unam.mx [Laboratory for Research on Advanced Processes for Water Treatment, Unidad Académica Juriquilla, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Blvd. Juriquilla 3001, Querétaro 76230 (Mexico)

    2013-04-15

    Highlights: ► Azo dyes were reduced efficiently by chemical and biogenic sulfide. ► Biogenic sulfide was more efficient than chemical sulfide. ► There was no competition between dyes and sulfate for reducing equivalents. ► Aromatic amines barely affected the sulfate-reducing process. -- Abstract: The effectiveness of chemical and biogenic sulfide in decolorizing three sulfonated azo dyes and the robustness of a sulfate-reducing process for simultaneous decolorization and sulfate removal were evaluated. The results demonstrated that decolorization of azo dyes assisted by chemical sulfide and anthraquinone-2,6-disulfonate (AQDS) was effective. In the absence of AQDS, biogenic sulfide was more efficient than chemical sulfide for decolorizing the azo dyes. The performance of sulfate-reducing bacteria in attached-growth sequencing batch reactors suggested the absence of competition between the studied azo dyes and the sulfate-reducing process for the reducing equivalents. Additionally, the presence of chemical reduction by-products had an almost negligible effect on the sulfate removal rate, which was nearly constant (94%) after azo dye injection.

  7. Ion irradiation of AZO thin films for flexible electronics

    Energy Technology Data Exchange (ETDEWEB)

    Boscarino, Stefano; Torrisi, Giacomo; Crupi, Isodiana [IMM-CNR and Dipartimento di Fisica e Astronomia, Università di Catania, via S. Sofia 64, 95123 Catania (Italy); Alberti, Alessandra [CNR-IMM, via Strada VIII 5, 95121 Catania (Italy); Mirabella, Salvatore; Ruffino, Francesco [IMM-CNR and Dipartimento di Fisica e Astronomia, Università di Catania, via S. Sofia 64, 95123 Catania (Italy); Terrasi, Antonio, E-mail: antonio.terrasi@ct.infn.it [IMM-CNR and Dipartimento di Fisica e Astronomia, Università di Catania, via S. Sofia 64, 95123 Catania (Italy)

    2017-02-01

    Highlights: • Evidence of electrical good quality AZO ultra thin films without thermal annealing. • Evidence of the main role of Oxygen vs. structural parameters in controlling the electrical performances of AZO. • Evidence of the role of the ion irradiation in improving the electrical properties of AZO ultra thin films. • Synthesis of AZO thin films on flexible/plastic substrates with good electrical properties without thermal processes. - Abstract: Aluminum doped Zinc oxide (AZO) is a promising transparent conductor for solar cells, displays and touch-screen technologies. The resistivity of AZO is typically improved by thermal annealing at temperatures not suitable for plastic substrates. Here we present a non-thermal route to improve the electrical and structural properties of AZO by irradiating the TCO films with O{sup +} or Ar{sup +} ion beams (30–350 keV, 3 × 10{sup 15}–3 × 10{sup 16} ions/cm{sup 2}) after the deposition on glass and flexible polyethylene naphthalate (PEN). X-ray diffraction, optical absorption, electrical measurements, Rutherford Backscattering Spectrometry and Atomic Force Microscopy evidenced an increase of the crystalline grain size and a complete relief of the lattice strain upon ion beam irradiation. Indeed, the resistivity of thin AZO films irradiated at room temperature decreased of two orders of magnitude, similarly to a thermal annealing at 400 °C. We also show that the improvement of the electrical properties does not simply depend on the strain or polycrystalline domain size, as often stated in the literature.

  8. UV-visible-DAD and 1H-NMR spectroscopy data fusion for studying the photodegradation process of azo-dyes using MCR-ALS.

    Science.gov (United States)

    Fernández, Cristina; Pilar Callao, M; Larrechi, M Soledad

    2013-12-15

    The photodegradation process of three azo-dyes - Acid Orange 61, Acid Red 97 and Acid Brown 425 - was monitored simultaneously by ultraviolet-visible spectroscopy with diode array detector (UV-vis-DAD) and (1)H-nuclear magnetic resonance ((1)H-NMR). Multivariate curve resolution-alternating least squares (MCR-ALS) was applied to obtain the concentration and spectral profile of the chemical compounds involved in the process. The analysis of the H-NMR data suggests there are more intermediate compounds than those obtained with the UV-vis-DAD data. The fusion of UV-vis-DAD and the (1)H-NMR signal before the multivariate analysis provides better results than when only one of the two detector signals was used. It was concluded that three degradation products were present in the medium when the three azo-dyes had practically degraded. This study is the first application of UV-vis-DAD and (1)H-NMR spectroscopy data fusion in this field and illustrates its potential as a quick method for evaluating the evolution of the azo-dye photodegradation process. © 2013 Elsevier B.V. All rights reserved.

  9. Understanding effects of chemical structure on azo dye decolorization characteristics by Aeromonas hydrophila

    Energy Technology Data Exchange (ETDEWEB)

    Hsueh, Chung-Chuan [Department of Chemical and Materials Engineering, National I-Lan University, I-Lan 260, Taiwan (China); Chen, Bor-Yann, E-mail: bychen@niu.edu.tw [Department of Chemical and Materials Engineering, National I-Lan University, I-Lan 260, Taiwan (China); Yen, Chia-Yi [Department of Chemical and Materials Engineering, National I-Lan University, I-Lan 260, Taiwan (China)

    2009-08-15

    This novel comparative study tended to disclose how the molecular structures present in seven azo dyes including two types of azo dyes (i.e., naphthol type azo dyes - Reactive Black 5 (RB 5), Reactive Blue 171 (RB 171), Reactive Green 19 (RG19), Reactive Red 198 (RR198), Reactive Red 141 (RR141) and non-naphthol type azo dyes - Direct Yellow 86 (DY86), Reactive Yellow 84 (RY84)) affected color removal capability of Aeromonas hydrophila. Generally speaking, the decolorization rate of naphthol type azo dye with hydroxyl group at ortho to azo bond was faster than that of non-naphthol type azo dye without hydroxyl group, except of RG19. The azo dyes with electron-withdrawing groups (e.g., sulfo group in RR198, RB5 and RR141) would be easier to be decolorized than the azo dyes with the electron-releasing groups (e.g., -NH-triazine in RB171 and RG19). In addition, the azo dyes containing more electron-withdrawing groups (e.g., RR198, RB5 and RR141) showed significantly faster rate of decolorization. The azo dyes with electron-withdrawing groups (e.g., sulfo group) at para and ortho to azo bond (e.g., RR198, RB5 and RR141) could be more preferred for color removal than those at meta (e.g., DY86 and RY84). The former azo dyes with para and ortho sulfo group provided more effective resonance effects to withdraw electrons from azo bond, causing azo dyes to be highly electrophilic for faster rates of reductive biodecolorization. However, since the ortho substituent caused steric hindrance near azo linkage(s), azo dyes with para substituent could be more favorable (e.g., SO{sub 2}(CH{sub 2}){sub 2}SO{sub 4}{sup -} in RR198 and RB5) than those with ortho substituent (e.g., sulfo group at RR141) for decolorization. Thus, the ranking of the position for the electron-withdrawing substituent in azo dyes to escalate decolorization was para > ortho > meta. This study suggested that both the positions of substituents on the aromatic ring and the electronic characteristics of

  10. Radiation degradation and hemolytic toxicity evaluation of mono azo reactive dyes

    International Nuclear Information System (INIS)

    Saeed, Q.U.; Bhatti, I.A.; Ashraf, A.

    2017-01-01

    Monoazo reactive dyes have been synthesized and subjected to degradation before their application. Advanced oxidation process has been recognized as a promising radiation technology for the remediation of hazardous organic compounds. Radiation induced degradation of two mono azo reactive dyes have been tried at different absorbed dose, 5 kGy,10 kGy and 15 kGy. Aqueous solutions of these dyes were treated with gamma radiation using Cs 137 radiation source at Nuclear Institute of Agriculture and Biology (NIAB) Faisalabad. Dyes were evaluated spectrophotometrically by UV-visible and fourier transform infra red (FT-IR) spectroscopic techniques before and after irradiation to analyse their percentage decolorization and degradation. Maximum percentage decolorization of 93% and 63% was achieved for mono azo dyes D1 and D2 at 15 kGy absorbed dose. Toxicity study of these dyes was also tested by haemolytic activity assay. Percentage haemolytic activity of untreated dyes was found within permissible limit showing non toxicity of dye solutions. (author)

  11. Effects of reduction products of ortho-hydroxyl substituted azo dyes on biodecolorization of azo dyes

    International Nuclear Information System (INIS)

    Liu Guangfei; Wang Jing; Lu Hong; Jin Ruofei; Zhou Jiti; Zhang Long

    2009-01-01

    The mediated effects of reduction products of some ortho-hydroxyl substituted azo dyes on biodecolorization were investigated. The results indicated that the addition of reduction products could effectively accelerate dye decolorization by Shigella sp. QRZ-1. The best accelerating effect was obtained with the addition of reduction products of Acid Red 14 (AR14), resulting in an over 3-fold increase in decolorization efficiency of many azo dyes. In sequencing batch reactor experiments, the accelerating effect of reduction products of AR14 was more obvious (1.5-fold) during the startup of the system. When the dye concentration was increased to 500 mg L -1 , the accelerated decolorization efficiency was still maintained around 95%. The presence of AR14 in the feed enhanced the decolorization performance of anaerobic sludge, indicating that the strategy may be beneficial for practical application. 1-Naphthol-2-amino-4-sulfonic acid, which is one of the reduction products of AR14, may function as redox mediator to speed up azo dye biodecolorization.

  12. UV-vis, IR and 1H NMR spectroscopic studies of some mono- and bis-azo-compounds based on 2,7-dihydroxynaphthalene and aniline derivatives

    Science.gov (United States)

    Issa, Raafat M.; Fayed, Tarek A.; Awad, Mohammed K.; El-Kony, Sanaa M.

    2005-12-01

    The absorption spectra of mono- and bis-azo-derivatives obtained by coupling the diazonium salts of aromatic amines and 2,7-dihydroxynaphthalene have been studied in six organic solvents. The different absorption bands have been assigned and the effect of solvents on the charge transfer band is also discussed. The diagnostic IR spectral bands and 1H NMR signals are assigned and discussed in relation to molecular structure. Also, semi-empirical molecular orbital calculations using the atom superposition and electron delocalization molecular orbital (ASED-MO) theory have been performed to investigate the molecular and electronic structures of these compounds. According to these calculations, an intramolecular hydrogen bonding is essential for stabilization of such molecules.

  13. Synthesis, Characterisation and DFT Calculations of Azo-Imine Dyes

    Directory of Open Access Journals (Sweden)

    Sevil Özkınalı

    2017-11-01

    Full Text Available In this study, azo dyes containing an imine group were synthesised by coupling p-hydroxybenzylidene aniline with the diazonium salts of p-toluidine, 4-aminophenol, aniline, p-chloroaniline, p-fluoroaniline, and p-nitroaniline. The compounds were characterised by melting point, elemental, UV-Vis and IR analyses as well as 1H-NMR and 13C-NMR spectroscopies. Moreover, the experimental data were supplemented with density functional theory (DFT calculations. The experimental data on FT-IR and UV–Vis spectra of the compounds were compared with theoretical results. The DFT calculations were performed to obtain the ground state geometries of the compounds using the B3LYP hybrid functional level with 6-311++g(2d,2p basis set. Frontier molecular orbital energies, band gap energies and some chemical reactivity parameters, such as chemical hardness and electronegativity, were calculated and compared with experimental values. A significant correlation was observed between the dipole moment and polarities of the solvents and the absorption wavelength of the compounds.

  14. Effects of reduction products of ortho-hydroxyl substituted azo dyes on biodecolorization of azo dyes

    Energy Technology Data Exchange (ETDEWEB)

    Liu Guangfei [Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental and Biological Science and Technology, Dalian University of Technology, Linggong Road No. 2, Dalian 116024 (China); Wang Jing, E-mail: wangjingbio@yahoo.cn [Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental and Biological Science and Technology, Dalian University of Technology, Linggong Road No. 2, Dalian 116024 (China); Lu Hong; Jin Ruofei; Zhou Jiti; Zhang Long [Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental and Biological Science and Technology, Dalian University of Technology, Linggong Road No. 2, Dalian 116024 (China)

    2009-11-15

    The mediated effects of reduction products of some ortho-hydroxyl substituted azo dyes on biodecolorization were investigated. The results indicated that the addition of reduction products could effectively accelerate dye decolorization by Shigella sp. QRZ-1. The best accelerating effect was obtained with the addition of reduction products of Acid Red 14 (AR14), resulting in an over 3-fold increase in decolorization efficiency of many azo dyes. In sequencing batch reactor experiments, the accelerating effect of reduction products of AR14 was more obvious (1.5-fold) during the startup of the system. When the dye concentration was increased to 500 mg L{sup -1}, the accelerated decolorization efficiency was still maintained around 95%. The presence of AR14 in the feed enhanced the decolorization performance of anaerobic sludge, indicating that the strategy may be beneficial for practical application. 1-Naphthol-2-amino-4-sulfonic acid, which is one of the reduction products of AR14, may function as redox mediator to speed up azo dye biodecolorization.

  15. 40 CFR 721.2097 - Azo chromium complex dyestuff preparation (generic name).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Azo chromium complex dyestuff... New Uses for Specific Chemical Substances § 721.2097 Azo chromium complex dyestuff preparation... substance identified generically as an azo chromium complex dyestuff preparation (PMN P-95-240) is subject...

  16. High-Quality AZO/Au/AZO Sandwich Film with Ultralow Optical Loss and Resistivity for Transparent Flexible Electrodes.

    Science.gov (United States)

    Zhou, Hua; Xie, Jing; Mai, Manfang; Wang, Jing; Shen, Xiangqian; Wang, Shuying; Zhang, Lihua; Kisslinger, Kim; Wang, Hui-Qiong; Zhang, Jinxing; Li, Yu; Deng, Junhong; Ke, Shanming; Zeng, Xierong

    2018-05-09

    Transparent flexible electrodes are in ever-growing demand for modern stretchable optoelectronic devices, such as display technologies, solar cells, and smart windows. Such sandwich-film-electrodes deposited on polymer substrates are unattainable because of the low quality of the films, inducing a relatively large optical loss and resistivity as well as a difficulty in elucidating the interference behavior of light. In this article, we report a high-quality AZO/Au/AZO sandwich film with excellent optoelectronic performance, e.g., an average transmittance of about 81.7% (including the substrate contribution) over the visible range, a sheet resistance of 5 Ω/sq, and a figure-of-merit (FoM) factor of ∼55.1. These values are well ahead of those previously reported for sandwich-film-electrodes. Additionally, the interference behaviors of light modulated by the coat and metal layers have been explored with the employment of transmittance spectra and numerical simulations. In particular, a heater device based on an AZO/Au/AZO sandwich film exhibits high performance such as short response time (∼5 s) and uniform temperature field. This work provides a deep insight into the improvement of the film quality of the sandwich electrodes and the design of high-performance transparent flexible devices by the application of a flexible substrate with an atomically smooth surface.

  17. Light sensitive polymer obtained by dispersion of azo-functionalized POSS nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Miniewicz, A., E-mail: andrzej.miniewicz@pwr.edu.pl [Advanced Materials Engineering and Modelling, Faculty of Chemistry, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland); Tomkowicz, M.; Karpinski, P.; Sznitko, L. [Advanced Materials Engineering and Modelling, Faculty of Chemistry, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland); Mossety-Leszczak, B. [Faculty of Chemistry, Rzeszow University of Technology, Al. Powstancow Warszawy 12, 35-959 Rzeszow (Poland); Dutkiewicz, M. [Faculty of Chemistry, Adam Mickiewicz University of Poznan, Umultowska 89 B, 61-614 Poznan (Poland)

    2015-07-29

    Highlights: • Nanocomposite material PMMA containing azo-functionalized POSS has been prepared. • Surface topographies of prepared films are porous and dependent on azo-POSS content. • Photo-induced optical anisotropies both static and dynamic have been characterized. - Abstract: Hybrid inorganic–organic nanoparticles based on cubic siloxane cage (RSiO{sub 3/2}){sub 8}, known as polyhedral oligosilsesquioxane (POSS), have been functionalized by eight groups of azo-benzene mesogens and dispersed in poly(methyl methacrylate) PMMA matrix. Presence of azo-benzene units adds an important light-driven functionality to the system due to their photoisomerization resulting in refractive index and/or absorption changes of the whole system. The polymer films containing various concentrations of azo-POSS nanoparticles show remarkable changes of surface morphology being either transparent (at low POSS concentration) or highly scattering (at high POSS concentration) for visible light. Surface structures were examined by optical microscopy as well as by atomic force microscopy (AFM). Results of photoinduced alignment are discussed in the framework of light-induced modification of the aliphatic chains containing azo-benzene photoisomerizing moieties and self-organization process.

  18. Light sensitive polymer obtained by dispersion of azo-functionalized POSS nanoparticles

    International Nuclear Information System (INIS)

    Miniewicz, A.; Tomkowicz, M.; Karpinski, P.; Sznitko, L.; Mossety-Leszczak, B.; Dutkiewicz, M.

    2015-01-01

    Highlights: • Nanocomposite material PMMA containing azo-functionalized POSS has been prepared. • Surface topographies of prepared films are porous and dependent on azo-POSS content. • Photo-induced optical anisotropies both static and dynamic have been characterized. - Abstract: Hybrid inorganic–organic nanoparticles based on cubic siloxane cage (RSiO 3/2 ) 8 , known as polyhedral oligosilsesquioxane (POSS), have been functionalized by eight groups of azo-benzene mesogens and dispersed in poly(methyl methacrylate) PMMA matrix. Presence of azo-benzene units adds an important light-driven functionality to the system due to their photoisomerization resulting in refractive index and/or absorption changes of the whole system. The polymer films containing various concentrations of azo-POSS nanoparticles show remarkable changes of surface morphology being either transparent (at low POSS concentration) or highly scattering (at high POSS concentration) for visible light. Surface structures were examined by optical microscopy as well as by atomic force microscopy (AFM). Results of photoinduced alignment are discussed in the framework of light-induced modification of the aliphatic chains containing azo-benzene photoisomerizing moieties and self-organization process

  19. Analytical procedures for the determination of disperse azo dyes

    Energy Technology Data Exchange (ETDEWEB)

    Betowski, L.D.; Jones, T.L. (Environmental Protection Agency, Las Vegas, NV (USA)); Munslow, W.; Nunn, N.J. (Lockheed Engineering and Management Services Co., Las Vegas, NV (USA))

    1988-09-01

    Disperse Blue 79 is the most widely-used azo dye in the US. Its economic importance for the dye industry and textile industry is very great. Because of its use and potential for degradation to aromatic amines, this compound has been chosen for testing by the Interagency Testing Committee. The authors laboratory has been developing methods for the analytical determination of Disperse Blue 79 and any possible degradation products in wastewater. This work has been taking place in conjunction with the study of the fate of azo dyes in the wastewater treatment processes by the Water Engineering Research Laboratory of the US EPA in Cincinnati. There were various phases for this analytical development. The first step involved purifying the commercial material or presscake to obtain a standard for quantitative determination. A combination of HPLC, TLC and mass spectrometric methods was used to determine purity after extraction and column cleanup. Phase two involved the extraction of the dye from the matrices involved. The third phase was the actual testing of Disperse Blue 79 in the waste activated sludge system and anaerobic digester. Recovery of the dye and any degradation products at each sampling point (e.g., secondary effluent, waste activated sludge) was the goal of this phase.

  20. Fabrication of AZO TCO Films by RF-sputtering and Their Physical Properties

    Directory of Open Access Journals (Sweden)

    Jang T.S.

    2016-01-01

    Full Text Available We report on the fabrication of Al-doped ZnO (AZO transparent-conductive oxide (TCO films on glass substrates by RF-sputtering, their physical properties, and the effect of thermal annealing on the AZO TCO films. The AZO films on glass substrates have a preferred orientation of the c-axis, irrespective of deposition conditions, which means that the AZO films have textured structures along the c-axis. The film thickness and surface roughness in the AZO films are proportional to plasma power and deposition time, while they are inverse-proportional to working gas ratio and working pressure. The AZO films have the optical transmittance over 80 % in the wavelength range of 400 – 1000 nm, irrespective of deposition conditions. The plasma power and the deposition time relatively give a large influence on the optical transmittance, compared to the working gas ratio and the working pressure. The AZO films deposited at room temperature have poor electrical properties, while the thermal annealing under Ar ambient significantly improves the electrical conductivity of the AZO films: an as-deposited sample has an electrical resistivity of 87 Wcm and an electron concentration of 1.3´1017 cm−3, while the annealed sample has an electrical resistivity of 3.7´10-2 Wcm and an electron concentration of 1.2´1020 cm−3.

  1. Effect of the nature of p-substituents in benzene ring of azo compounds based on chromotropic acid on their reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Savvin, S B; Dedkova, V P; Azarashvili, M A; Likhonina, E A

    1988-08-01

    Effect of acceptor and donor substituents in a reagent on degree of contrast and selectivity of spectrophotometric beryllium determination as well as other elements was considered taking derivatives of orthanilic-azo-chromotropic acid as an example. The optimal pH region of aminoorthanilic-azo-chromotropic acid interaction with Be 5-6.5; the optimal wavelength is 640 nm. The solution colour changes from violet-red to blue during complex formation. Selectivity increases after addition of masking substances. Be determination on the background of 4-fold Cu and VO/sup 2+/ amounts 8-fold Al amounts, 2-fold Zn amounts is possible in the presence of 5-fold EDTA amounts unsubstituted reagent is characterized by the lowest degree of contrast and selectivity of reactions with metals.

  2. Degradação redutiva de azo-corantes utilizando-se ferro metálico Reductive degradation of azo-dyes by metallic iron

    Directory of Open Access Journals (Sweden)

    Cláudio Lima de Souza

    2006-03-01

    Full Text Available Corantes azo são extensivamente utilizados em processos de tingimento de fibras têxteis, sendo caracterizados por elevada resistência frente a processos aeróbios de biodegradação e, por conseqüência, persistência nos processos convencionais de tratamento de resíduos. Neste trabalho reporta-se a degradação redutiva de corantes azo, utilizando-se ferro metálico. Em condições experimentais otimizadas (pH 7 e 10 g de lã de aço comercial a completa descoloração do corante modelo (preto reativo 5 foi conseguida em um sistema contínuo, operando com tempos de retenção de 6 min. Nestas condições, o ferro solubilizado alcança concentrações compatíveis com os limites impostos pela atual legislação brasileira (12 mg L-1. Trata-se de um resultado bastante promissor, principalmente levando-se em consideração o caráter recalcitrante dos azo corantes e a simplicidade do sistema proposto.Azo dyes are extensively used in textile dying processes and are characterized by extreme resistance to biodegradation and consequently persistence during conventional wastewater treatment processes. In this work the reductive degradation of azo dyes was studied using zero-valent iron. At optimized experimental conditions (pH 7 and 10 g of commercial iron wool complete decolorization of the model dye (reactive black 5 was afforded in a continuous system operating with hydraulic retention time of 6 min. At these conditions the released total soluble iron reaches a concentration compatible with the limits imposed by the current Brazilian legislation (12 mg L-1. That is a very promising result, mainly taking into account the high recalcitrant character of azo dyes and the simplicity of the proposed system.

  3. Azo biphenyl polyurethane: Preparation, characterization and application for optical waveguide switch

    Science.gov (United States)

    Jiang, Yan; Da, Zulin; Qiu, Fengxian; Yang, Dongya; Guan, Yijun; Cao, Guorong

    2018-01-01

    Azo waveguide polymers are of particular interest in the design of materials for applications in optical switch. The aim of this contribution was the synthesis and thermo-optic waveguide switch properties of azo biphenyl polyurethanes. A series of monomers and azo biphenyl polyurethanes (Azo BPU1 and Azo BPU2) were synthesized and characterized by FT-IR, UV-Vis spectroscopy and 1H NMR. The physical and mechanical properties of thin polymer films were measured. The refractive index and thermo-optic coefficient (dn/dT) of polymer films were investigated for TE (transversal electric) polarizations by ATR technique. The transmission loss of film was measured using the Charge Coupled Device digital imaging devices. The results showed the Azo BPU2 containing chiral azobenzene chromophore had higher dn/dT and lower transmission loss. Subsequently, a 1 × 2 Y-branch and 2 × 2 Mach-Zehnder optical switches based on the prepared polymers were designed and simulated. The results showed that the power consumption of all switches was less than 1.0 mW. Compared with 1 × 2 Y-branch optical switch, the 2 × 2 Mach-Zehnder optical switches based on the same polymer have the faster response time, which were about only 1.2 and 2.0 ms, respectively.

  4. Synthesis, Characterization and Photoinduction of Optical Anisotropy in Liquid Crystalline Diblock Azo-Copolymers

    DEFF Research Database (Denmark)

    Forcén, P; Oriol, L; Sánchez, C

    2007-01-01

    Diblock copolymers with polymethyl methacrylate and side chain liquid crystalline WC) azopolymethacrylate blocks were synthesized by atom transfer radical polymerization (ATRP). The azobeazene content in these copolymers ranges from 52 to 7 wt %. For an azo conteat dowri to 20% they exhibit a LC...... anisotropy induced in these films by illumination with linearly polarized 488 nm light was studied and the resuits compared with those of the azo homopolymer and of a random copolymer with a similar composition. The formation of azo aggregates inside the azo blocks is strongly reduced in going from...... the homopolymer to the copolymers. Photoinduced azo orientation perpendicular to the 488 nm light polarization was found in aH the polymers. The orientational order parameter is very similar in the homopolymer and in the block copolymers with an azo content down to 20 wt %, while it is much lower in the random...

  5. Ion irradiation of AZO thin films for flexible electronics

    Science.gov (United States)

    Boscarino, Stefano; Torrisi, Giacomo; Crupi, Isodiana; Alberti, Alessandra; Mirabella, Salvatore; Ruffino, Francesco; Terrasi, Antonio

    2017-02-01

    Aluminum doped Zinc oxide (AZO) is a promising transparent conductor for solar cells, displays and touch-screen technologies. The resistivity of AZO is typically improved by thermal annealing at temperatures not suitable for plastic substrates. Here we present a non-thermal route to improve the electrical and structural properties of AZO by irradiating the TCO films with O+ or Ar+ ion beams (30-350 keV, 3 × 1015-3 × 1016 ions/cm2) after the deposition on glass and flexible polyethylene naphthalate (PEN). X-ray diffraction, optical absorption, electrical measurements, Rutherford Backscattering Spectrometry and Atomic Force Microscopy evidenced an increase of the crystalline grain size and a complete relief of the lattice strain upon ion beam irradiation. Indeed, the resistivity of thin AZO films irradiated at room temperature decreased of two orders of magnitude, similarly to a thermal annealing at 400 °C. We also show that the improvement of the electrical properties does not simply depend on the strain or polycrystalline domain size, as often stated in the literature.

  6. Enhanced optical and electrical properties of Ni inserted ITO/Ni/AZO tri-layer structure for photoelectric applications

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, M. Melvin David; Kim, Hyunki [Department of Electrical Engineering, Incheon National University, Incheon 406772 (Korea, Republic of); Park, Yun Chang [Measurement and Analysis Division, National Nanofab Center (NNFC), Daejeon 305-806 (Korea, Republic of); Kim, Joondong, E-mail: joonkim@incheon.ac.kr [Department of Electrical Engineering, Incheon National University, Incheon 406772 (Korea, Republic of)

    2015-05-15

    Highlights: • Ni-embedding transparent conductor effectively reduces the resistivity. • Ni insertion improves the carrier mobility and collection efficiencies. • ITO/Ni/AZO is effective to improve photo-responses compared to ITO/AZO. - Abstract: A thin Ni layer of 5 nm thickness was deposited in between indium-tin-oxide (ITO) and aluminum-doped-zinc oxide (AZO) layers of 50 nm thickness each. The Ni inserting tri-layer structure (ITO/Ni/AZO) showed lower resistivity of 5.51 × 10{sup −4} Ωcm which is nearly 20 times lesser than 97.9 × 10{sup −4} Ωcm of bilayer structure (ITO/AZO). A thin Ni layer in between ITO and AZO enhanced the carrier concentration, mobility and photoresponse behaviors so that figure of merit (FOM) value of ITO/Ni/AZO device was greater than that of ITO/AZO device. ITO/Ni/AZO structure showed improved quantum efficiencies over a broad range of wavelengths (∼350–950 nm) compared to that of ITO/AZO bilayer structure, resulting in enhanced photoresponses. These results show that the optical, electrical and photoresponse properties of ITO/AZO structure could be enhanced by inserting Ni layer of 5 nm thickness in between ITO and AZO layers.

  7. Organic heterostructures deposited by MAPLE on AZO substrate

    Science.gov (United States)

    Socol, M.; Preda, N.; Stanculescu, A.; Breazu, C.; Florica, C.; Stanculescu, F.; Iftimie, S.; Girtan, M.; Popescu-Pelin, G.; Socol, G.

    2017-09-01

    Organic heterostructures based on poly(3-hexylthiophene) (P3HT) and fullerene (C60) as blends or multilayer were deposited on Al:ZnO (AZO) by Matrix-Assisted Pulsed Laser Evaporation (MAPLE) technique. The AZO layers were obtained by Pulsed Laser Deposition (PLD) on glass substrate, the high quality of the films being reflected by the calculated figure of merit. The organic heterostructures were investigated from morphological, optical and electrical point of view by atomic force microscopy (AFM), UV-vis spectroscopy, photoluminescence (PL) and current-voltage (I-V) measurements, respectively. The increase of the C60 content in the blend heterostructure has as result a high roughness. Compared with the multilayer heterostructure, those based on blends present an improvement in the electrical properties. Under illumination, the highest current value was recorded for the heterostructure based on the blend with the higher C60 amount. The obtained results showed that MAPLE is a useful technique for the deposition of the organic heterostructures on AZO as transparent conductor electrode.

  8. FIA-Spectrophotometric Method for Determination of Nitrite in Meat Products: An Experiment Exploring Color Reduction of an Azo-Compound

    Science.gov (United States)

    Penteado, Jose C.; Angnes, Lucio; Masini, Jorge C.; Oliveira, Paulo C. C.

    2005-01-01

    This article describes the reaction between nitrite and safranine O. This sensitive reaction is based on the disappearance of color of the reddish-orange azo dye, allowing the determination of nitrite at the mg mL-1 level. A factorial optimization of parameters was carried out and the method was applied for the quantification of nitrite in…

  9. Ordered ZnO/AZO/PAM nanowire arrays prepared by seed-layer-assisted electrochemical deposition

    International Nuclear Information System (INIS)

    Shen, Yu-Min; Pan, Chih-Huang; Wang, Sheng-Chang; Huang, Jow-Lay

    2011-01-01

    An Al-doped ZnO (AZO) seed layer is prepared on the back side of a porous alumina membrane (PAM) substrate by spin coating followed by annealing in a vacuum at 400 °C. Zinc oxide in ordered arrays mediated by a high aspect ratio and an ordered pore array of AZO/PAM is synthesized. The ZnO nanowire array is prepared via a 3-electrode electrochemical deposition process using ZnSO 4 and H 2 O 2 solutions at a potential of − 1 V (versus saturated calomel electrode) and temperatures of 65 and 80 °C. The microstructure and chemical composition of the AZO seed layer and ZnO/AZO/PAM nanowire arrays are characterized by field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), and energy-dispersive X-ray spectroscopy (EDS). Results indicate that the ZnO/AZO/PAM nanowire arrays were assembled in the nanochannel of the porous alumina template with diameters of 110–140 nm. The crystallinity of the ZnO nanowires depends on the AZO seed layer during the annealing process. The nucleation and growth process of ZnO/AZO/PAM nanowires are interpreted by the seed-layer-assisted growth mechanism.

  10. The effect of lactate unit number in compounds with azo group in the molecular core

    Czech Academy of Sciences Publication Activity Database

    Novotná, Vladimíra; Hamplová, Věra; Kašpar, Miroslav; Podoliak, Natalia; Bubnov, Alexej; Glogarová, Milada; Nonnenmacher, D.; Giesselmann, F.

    2011-01-01

    Roč. 38, č. 5 (2011), s. 649-655 ISSN 0267-8292 R&D Projects: GA AV ČR IAA100100911; GA AV ČR(CZ) GA202/09/0047; GA ČR(CZ) GAP204/11/0723 Grant - others:RFASI(RU) 02.740.11.5166; Společný projekt AV ČR-DAAD SNR(CZ) D4-CZ5/2010-2011; GA UK(CZ) SVV-2011-263303 Institutional research plan: CEZ:AV0Z10100520 Keywords : liquid crystals * ferroelectricity * chirality * azo group * antiferroelectricity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.858, year: 2011 http://dx.doi.org/10.1080/02678292.2011.565426

  11. Decolourization and degradation of azo Dye, Synozol Red HF6BN ...

    African Journals Online (AJOL)

    Decolourization and degradation of azo Dye, Synozol Red HF6BN, by Pleurotus ostreatus. Sidra Ilyas, Skinder Sultan Sultan, Abdul Rehman. Abstract. The present paper focuses on the use of fungus, Pleurotus ostreatus, to decolorize and degrade azo dye, Synazol Red HF6BN. Decolorization study showed that P.

  12. Evaluation of biodecolorization of the textile azo dye by halophilic archaea

    Directory of Open Access Journals (Sweden)

    Masoomeh Selseleh Hassan-Kiadehi

    2017-09-01

    Discussion and conclusion: In conclusion, our results indicate that halophilic archaea have very high potential to decolorize azo dyes. Regarding high amounts of salts in textile wastewaters, using such microorganisms which can tolerate the harsh environment in order to decolorize azo dyes, could be a new approach in this field.

  13. Oxidation using quaternary ammonium polyhalides VII. Oxidation of primary amines and hydrazo compounds by use of benzyltrimethylammonium tribromide

    OpenAIRE

    Nishida, Akiko; Kohro, Noriaki; Fujisaki, Shizuo; Kajigaeshi, Shoji

    1990-01-01

    The reactions of primary amines and hydrazo compounds with benzyltrimethylammonium tribromide in aqueous sodium hydroxide or in water gave the corresponding nitriles and azo compounds in satisfactory yields, respectively.

  14. Effect of AZO on GO-NO-GO radiation indicator

    International Nuclear Information System (INIS)

    Hasan Sham; Taiman Kadni; Noriah Mod Ali

    2002-01-01

    The purpose of the study is to evaluate the effect of Azo group dyes as an radiation indicator. Dimethyl Yellow, Alizarin Red, Congo Red, Methyl Violet and Bromophenol Blue dyes were used to compare the capability of each dye to change colour in response to radiation. Sensitivity of single and incorporated dyes were identified by exposing them to 5-50 kGy gamma radiation. The result shows that the Azo group is more sensitive to radiation compare to other groups. (Author)

  15. A novel ITO/AZO/SiO2/p-Si frame SIS heterojunction fabricated by magnetron sputtering

    International Nuclear Information System (INIS)

    He, Bo; Wang, HongZhi; Li, YaoGang; Ma, ZhongQuan; Xu, Jing; Zhang, QingHong; Wang, ChunRui; Xing, HuaiZhong; Zhao, Lei; Rui, YiChuan

    2013-01-01

    Highlights: •Because the ITO/AZO double films lead to a great decrease of the lateral resistance. •The photon current can easily flow through top film entering the Cu front contact. •High photocurrent is obtained under a reverse bias. -- Abstract: The novel ITO/AZO/SiO 2 /p-Si SIS heterojunction has been fabricated by low temperature thermal oxidation an ultrathin silicon dioxide and RF sputtering deposition ITO/AZO double films on p-Si (1 0 0) polished substrate. The microstructural, optical and electrical properties of the ITO/AZO antireflection films were characterized by XRD, SEM, UV–VIS spectrophotometer, four point probe and Hall effect measurement, respectively. The results show that ITO/AZO films are of good quality. And XPS was carried out on the ultrathin SiO 2 film. The heterojunction shows strong rectifying behavior under a dark condition, which reveals that formation of a diode between AZO and p-Si. The ideality factor and the saturation current of this diode is 2.7 and 8.68 × 10 −5 A, respectively. High photocurrent is obtained under a reverse bias when the crystalline quality of ITO/AZO double films is good enough to transmit the light into p-Si. We can see that under reverse bias conditions the photocurrent of ITO/AZO/SiO 2 /p-Si SIS heterojunction is much higher than the photocurrent of AZO/SiO 2 /p-Si SIS heterojunction. Because the high quality crystallite and the good conductivity of ITO film which prepared by magnetron-sputtering on AZO film lead to a great decrease of the lateral resistance. The photon induced current can easily flow through ITO layer entering the Cu front contact. Thus, high photocurrent is obtained under a reverse bias

  16. Spectroscopic, thermal, catalytic and biological studies of Cu(II) azo dye complexes

    Science.gov (United States)

    El-Sonbati, A. Z.; Diab, M. A.; El-Bindary, A. A.; Shoair, A. F.; Hussein, M. A.; El-Boz, R. A.

    2017-08-01

    New complexes of copper(II) with azo compounds of 5-amino-2-(aryl diazenyl)phenol (HLn) are prepared and investigated by elemental analyses, molar conductance, IR, 1H NMR, UV-Visible, mass, ESR spectra, magnetic susceptibility measurements and thermal analyses. The complexes have a square planar structure and general formula [Cu(Ln)(OAc)]H2O. Study the catalytic activities of Cu(II) complexes toward oxidation of benzyl alcohol derivatives to carbonyl compounds were tested using H2O2 as the oxidant. The intrinsic binding constants (Kb) of the ligands (HLn) and Cu(II) complexes (1-4) with CT-DNA are determined. The formed compounds have been tested for biological activity of antioxidants, antibacterial against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria and yeast Candida albicans. Antibiotic (Ampicillin) and antifungal against (Colitrimazole) and cytotoxic compounds HL1, HL2, HL3 and complex (1) showed moderate to good activity against S. aureus, E. coli and Candida albicans, and also to be moderate on antioxidants and toxic substances. Molecular docking is used to predict the binding between the ligands with the receptor of breast cancer (2a91).

  17. CYP-450 isoenzymes catalyze the generation of hazardous aromatic amines after reaction with the azo dye Sudan III.

    Science.gov (United States)

    Zanoni, Thalita Boldrin; Lizier, Thiago M; Assis, Marilda das Dores; Zanoni, Maria Valnice B; de Oliveira, Danielle Palma

    2013-07-01

    This work describes the mutagenic response of Sudan III, an adulterant food dye, using Salmonella typhimurium assay and the generation of hazardous aromatic amines after different oxidation methods of this azo dye. For that, we used metabolic activation by S9, catalytic oxidation by ironporphyrin and electrochemistry oxidation in order to simulate endogenous oxidation conditions. The oxidation reactions promoted discoloration from 65% to 95% of Sudan III at 1 × 10(-4)molL(-1) and generation of 7.6 × 10(-7)molL(-1) to 0.31 × 10(-4)molL(-1) of aniline, o-anisidine, 2-methoxi-5-methylaniline, 4-aminobiphenyl, 4,4'-oxydianiline; 4,4'-diaminodiphenylmethane and 2,6-dimethylaniline. The results were confirmed by LC-MS-MS experiments. We also correlate the mutagenic effects of Sudan III using S. typhimurium with the strain TA1535 in the presence of exogenous metabolic activation (S9) with the metabolization products of this compound. Our findings clearly indicate that aromatic amines are formed due to oxidative reactions that can be promoted by hepatic cells, after the ingestion of Sudan III. Considering that, the use of azo compounds as food dyestuffs should be carefully controlled. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. The effect of dioctyl sodium sulphosuccinate on tartrazine azo reduction by intestinal bacteria.

    Science.gov (United States)

    Allan, R J; Roxon, J J

    1977-03-01

    1. Washed whole-cell suspensions of Proteus vulgaris and micro-organisms from rat faeces, reductively cleave the azo bond of the food dye tartrazine under anaerobic conditions. 2. Dioctyl sodium sulphosuccinate, a common faecal softening laxative, when added to incubations in vitro at concentrations greater than 0.005%, increases tartrazine azo reduction in P. vulgaris whole-cell suspensions. 3. By contrast, concentrations of dioctyl sodium sulphosuccinate greater than 0.005% when added to incubations in vitro of rat faecal preparations, resulted in an inhibition of tartrazine azo reduction.

  19. Synthesis and Characterization of a New Heterocyclic Azo Pigment

    International Nuclear Information System (INIS)

    Asniza, M.; Issam, A.M.; Khalil, H.P.S.A.

    2011-01-01

    A new heterocyclic coupling agent has been produced from the reaction of maleic anhydride and p-aminophenol, namely N-(4-hexahydrophenol)maleimide. The coupling agent underwent azo coupling reaction with aromatic amine, which is p-aminophenol to produce a new heterocyclic azo pigment. The pigment was then subjected to solubility, hiding power and light fastness test. Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet/ Visible (UV/Vis) Spectroscopy, and Nuclear Magnetic Resonance Spectroscopy ( 1 H-NMR, 13 C-NMR) were used to obtain the characteristics and structural features of the pigment. (author)

  20. [The decolorization and biodegrading metabolism of azo dyes by Pseudomonas S-42].

    Science.gov (United States)

    Liu, Z P; Yang, H F

    1989-12-01

    Pseudomonas S-42 was capable of decolorizing azo dyes such as Diamira Brilliant Orange RR(DBO-RR), Direct Brown M (DBM), Eriochrome Brown R(EBR) and so on. The cell suspension, cell-free extract and purified enzyme of Pseud. S-42 could decolorize azo dyes under similar conditions: the optimum pH and temperature laid 7.0 and 37 degrees C respectively. The efficiencies of decolorizing of DBO-RR, DBM, EBR by intact cells stood more than 90%. When the cell concentration was 15 mg(wet)/ml and the reaction time was 5 hours, the decolorizing activity for above three azo dyes by intact cells were 1.75, 2.4, 0.95 micrograms dye/mg cell, respectively. Cell-free extract and purified enzyme could well express the decolorizing activity only under the anaerobic condition and added NADH. Purified enzyme belongs to azoreductase, its molecular weight is about 34,000-2000 daltons, and its Vmax and Km for DBO-RR are 13 mumol.mg protein-1.min-1 and 54 mumol/L. The results of the detection of the biodegrading products of DBO-RR by spectrophotometric and NaNO2 reactional methods showed that the biodegradation of azo dyes was initiated by the reduction cleavage of azo bonds. It was hypothesized that biodegrading metabolism pathway of DBO-RR by Pseudomonas S-42.

  1. Ohmic contacts on n-type β-Ga2O3 using AZO/Ti/Au

    Directory of Open Access Journals (Sweden)

    Patrick H. Carey IV

    2017-09-01

    Full Text Available AZO interlayers between n-Ga2O3 and Ti/Au metallization significantly enhance Ohmic contact formation after annealing at ≥ 300°C. Without the presence of the AZO, similar anneals produce only rectifying current-voltage characteristics. Transmission Line Measurements of the Au/Ti/AZO/Ga2O3 stacks showed the specific contact resistance and transfer resistance decreased sharply from as-deposited values with annealing. The minimum contact resistance and specific contact resistance of 0.42 Ω-mm and 2.82 × 10-5 Ω-cm2 were achieved after a relatively low temperature 400°C annealing. The conduction band offset between AZO and Ga2O3 is 0.79 eV and provides a favorable pathway for improved electron transport across this interface.

  2. Ohmic contacts on n-type β-Ga2O3 using AZO/Ti/Au

    Science.gov (United States)

    Carey, Patrick H.; Yang, Jiancheng; Ren, F.; Hays, David C.; Pearton, S. J.; Jang, Soohwan; Kuramata, Akito; Kravchenko, Ivan I.

    2017-09-01

    AZO interlayers between n-Ga2O3 and Ti/Au metallization significantly enhance Ohmic contact formation after annealing at ≥ 30 0°C. Without the presence of the AZO, similar anneals produce only rectifying current-voltage characteristics. Transmission Line Measurements of the Au/Ti/AZO/Ga2O3 stacks showed the specific contact resistance and transfer resistance decreased sharply from as-deposited values with annealing. The minimum contact resistance and specific contact resistance of 0.42 Ω-mm and 2.82 × 10-5 Ω-cm2 were achieved after a relatively low temperature 40 0°C annealing. The conduction band offset between AZO and Ga2O3 is 0.79 eV and provides a favorable pathway for improved electron transport across this interface.

  3. Reduction of azo dyes by flavin reductase from Citrobacter freundii A1

    Directory of Open Access Journals (Sweden)

    Mohd Firdaus Abdul-Wahab

    2012-12-01

    Full Text Available Citrobacter freundii A1 isolated from a sewage treatment facility was demonstrated to be able to effectively decolorize azo dyes as pure and mixed culture. This study reports on the investigation on the enzymatic systems involved. An assay performed suggested the possible involvement of flavin reductase (Fre as an azo reductase. A heterologouslyexpressed recombinant Fre from C. freundii A1 was used to investigate its involvement in the azo reduction process. Three model dyes were used, namely Acid Red 27 (AR27, Direct Blue 15 (DB15 and Reactive Black 5 (RB5. AR27 was found to be reduced the fastest by Fre, followed by RB5, and lastly DB15. Redox mediators nicotinamide adenine dinucleotide (NADH and riboflavin enhance the reduction, suggesting the redox activity of the enzyme. The rate and extent of reduction of the model dyes correlate well with the reduction potentials (Ep. The data presented here strongly suggest that Fre is one of the enzymes responsible for azo reduction in C. freundii A1, acting via an oxidation-reduction reaction.

  4. Metabolism of azo dyes by human skin microbiota.

    Science.gov (United States)

    Stingley, Robin L; Zou, Wen; Heinze, Thomas M; Chen, Huizhong; Cerniglia, Carl E

    2010-01-01

    Reduction of Methyl Red (MR) and Orange II (Or II) by 26 human skin bacterial species was monitored by a rapid spectrophotometric assay. The analysis indicated that skin bacteria, representing the genera Staphylococcus, Corynebacterium, Micrococcus, Dermacoccus and Kocuria, were able to reduce MR by 74-100 % in 24 h, with only three species unable to reduce completely the dye in that time. Among the species tested, only Corynebacterium xerosis was unable to reduce Or II to any degree by 24 h, and only Staphylococcus delphini, Staphylococcus sciuri subsp. sciuri and Pseudomonas aeruginosa were able to reduce completely this dye within 24 h. MR reduction started with early-exponential growth in Staphylococcus aureus and Staphylococcus epidermidis, and around late-exponential/early-stationary growth in P. aeruginosa. Reduction of Or II, Ponceau S and Ponceau BS started during late-exponential/early-stationary growth for all three species. Using liquid chromatography/electrospray ionization mass spectrometry analyses, MR metabolites produced by Staph. aureus, Staph. epidermidis and P. aeruginosa were identified as N,N-dimethyl-p-phenylenediamine and 2-aminobenzoic acid. Searches of available genomic and proteomic data revealed that at least four of the staphylococci in this study, Staphylococcus haemolyticus, Staph. epidermidis, Staphylococcus cohnii and Staphylococcus saprophyticus, have hypothetical genes with 77, 76, 75 and 74 % sequence identity to azo1 encoding an azoreductase from Staph. aureus and hypothetical proteins with 82, 80, 72 and 74 % identity to Azo1, respectively. In addition, Staphylococcus capitis has a protein with 79 % identity to Azo1. Western analysis detected proteins similar to Azo1 in all the staphylococci tested, except Staph. delphini, Staph. sciuri subsp. sciuri and Staphylococcus auricularis. The data presented in this report will be useful in the risk assessment process for evaluation of public exposure to products containing these dyes.

  5. Low resistance and transparent Ag/AZO ohmic contact to p-GaN

    International Nuclear Information System (INIS)

    Han, T.; Wang, T.; Gan, X. W.; Wu, H.; Shi, Y.; Liu, C.

    2014-01-01

    Silver (Ag)/ aluminum-doped zinc oxide (AZO) films were deposited on p-GaN by using electron beam evaporation. After the annealing process, current -voltage (I-V) measurements were carried out to determine the characteristic of the contacts. The Ag/AZO films annealed at 600 .deg. C were found to present an ohmic contact behavior. The specific contact resistance was calculated to be 9.76 x 10 -4 Ωcm 2 and the transmittance was over 80% for visibly light. The atomic force microscope was used to measure the aggregation of Ag grains which may have been the main factor in the formation of the Ag/AZO ohmic contact to p-GaN.

  6. Enhanced performance of a-IGZO thin-film transistors by forming AZO/IGZO heterojunction source/drain contacts

    International Nuclear Information System (INIS)

    Zou, Xiao; Fang, Guojia; Wan, Jiawei; Liu, Nishuang; Long, Hao; Wang, Haolin; Zhao, Xingzhong

    2011-01-01

    A low-cost Al-doped ZnO (AZO) thin film was deposited by radio-frequency magnetron sputtering with different Ar/O 2 flow ratios. The optical and electrical properties of an AZO film were investigated. A highly conductive AZO film was inserted between the amorphous InGaZnO (a-IGZO) channel and the metal Al electrode to form a heterojunction source/drain contact, and bottom-gate amorphous a-IGZO thin-film transistors (TFTs) with a high κ HfON gate dielectric were fabricated. The AZO film reduced the source/drain contact resistivity down to 79 Ω cm. Enhanced device performance of a-IGZO TFT with Al/AZO bi-layer S/D electrodes (W/L = 500/40 µm) was achieved with a saturation mobility of 13.7 cm 2 V −1 s −1 , a threshold voltage of 0.6 V, an on-off current ratio of 4.7 × 10 6 , and a subthreshold gate voltage swing of 0.25 V dec −1 . It demonstrated the potential application of the AZO film as a promising S/D contact material for the fabrication of the high performance TFTs

  7. Reversible photocontrol of molecular assemblies of metal complex containing azo-amphiphiles

    International Nuclear Information System (INIS)

    Einaga, Yasuaki; Mikami, Rie; Akitsu, Takashiro; Li, Guangming

    2005-01-01

    Photo-controllable molecular systems, [M(en) 2 ][Pt(en) 2 Cl 2 ](1) 4 (M 2+ =Pt 2+ , Pd 2+ and en=ethylenediamine), have been designed by the self-assembly of chloride-bridged platinum/palladium complexes and photochromic amphiphiles of the azobenzene derivative, 4-[4-(N-methyl-N-n-dodecylamino)phenylazo]benzene sulfonic acid (designated as compound 1). Reversible structural changes caused by cis-trans photoisomerization of azo groups in compound 1 were observed by alternating illumination of UV and visible light. Visible illumination resulted in the formation of the plate-like structures, whereas UV illumination resulted in fragmentation of the assembling structures. Reversible changes were observed in the electronic states of the chloride-bridged platinum/palladium complexes; the plate-like structures exhibited charge transfer absorption of chloride-bridged platinum complexes and delocalized Pt(II)/Pt(IV) states, while the fragments of the separated complexes exhibited no charge transfer bands. As a consequence, we have discovered that the reversible structural changes in this system could be controlled by photoillumination

  8. Diphenyl (4′-(Aryldiazenylbiphenyl-4-ylamino(pyridin-3-ylmethylphosphonates as Azo Disperse Dyes for Dyeing Polyester Fabrics

    Directory of Open Access Journals (Sweden)

    Mohamed F. Abdel-Megeed

    2013-01-01

    Full Text Available Diphenyl (4′-aminobiphenyl-4-ylamino(pyridin-3-ylmethylphosphonate (1 was synthesized in 88% yield from reaction of pyridine-3-carboxaldehyde with benzidine and triphenylphosphite in the presence of titanium tetrachloride as a catalyst. Diazotization of 1 gave the corresponding diazonium salt 2 which was coupled with several hydroxyl or amino compounds to give the corresponding azo dyes 3–8 in 82–88% yields after crystallization. The dyes produced were applied to polyesters as disperse dyes and their fastness properties were elevated.

  9. Strong guided mode resonant local field enhanced visible harmonic generation in an azo-polymer resonant waveguide grating.

    Science.gov (United States)

    Lin, Jian Hung; Tseng, Chun-Yen; Lee, Ching-Ting; Young, Jeff F; Kan, Hung-Chih; Hsu, Chia Chen

    2014-02-10

    Guided mode resonance (GMR) enhanced second- and third-harmonic generation (SHG and THG) is demonstrated in an azo-polymer resonant waveguide grating (RWG), comprised of a poled azo-polymer layer on top of a textured SU8 substrate with a thin intervening layer of TiO2. Strong SHG and THG outputs are observed by matching either in-coming fundamental- or out-going harmonic-wavelength to the GMR wavelengths of the azo-polymer RWG. Without the azo-polymer coating, pure TiO2 RWGs, do not generate any detectable SHG using a fundamental beam peak intensity of 2 MW/cm(2). Without the textured TiO2 layer, a planar poled azo-polymer layer results in 3650 times less SHG than the full nonlinear RWG structure under identical excitation conditions. Rigorous coupled-wave analysis calculations confirm that this enhancement of the nonlinear conversion is due to strong local electric fields that are generated at the interfaces of the TiO2 and azo-polymer layers when the RWG is excited at resonant wavelengths associated with both SHG and THG conversion processes.

  10. AZO/Ag/AZO anode for resonant cavity red, blue, and yellow organic light emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Gentle, A. R., E-mail: angus.gentle@uts.edu.au; Smith, G. B. [School of Mathematical and Physical Sciences and Institute of Nanoscale Technology, University of Technology Sydney, P.O. Box 123, Broadway, New South Wales 2007 (Australia); Yambem, S. D.; Burn, P. L.; Meredith, P. [Centre for Organic Photonics and Electronics, School of Chemistry and Molecular Biosciences and School of Mathematics and Physics, The University of Queensland, St Lucia, Queensland 4072 (Australia)

    2016-06-28

    Indium tin oxide (ITO) is the transparent electrode of choice for organic light-emitting diodes (OLEDs). Replacing ITO for cost and performance reasons is a major drive across optoelectronics. In this work, we show that changing the transparent electrode on red, blue, and yellow OLEDs from ITO to a multilayer buffered aluminium zinc oxide/silver/aluminium zinc oxide (AZO/Ag/AZO) substantially enhances total output intensity, with better control of colour, its constancy, and intensity over the full exit hemisphere. The thin Ag containing layer induces a resonant cavity optical response of the complete device. This is tuned to the emission spectra of the emissive material while minimizing internally trapped light. A complete set of spectral intensity data is presented across the full exit hemisphere for each electrode type and each OLED colour. Emission zone modelling of output spectra at a wide range of exit angles to the normal was in excellent agreement with the experimental data and hence could, in principle, be used to check and adjust production settings. These multilayer transparent electrodes show significant potential for both eliminating indium from OLEDs and spectrally shaping the emission.

  11. Polyazidopyrimidines: High Energy Compounds and Precursors to Carbon Nanotubes (Postprint)

    National Research Council Canada - National Science Library

    Ye, Chengfeng; Gao, Haixiang; Boatz, Jerry A; Drake, Gregory W; Twamley, Brendan; Shreeve, Jean'ne M

    2006-01-01

    ...). The compound 4,4',6,6'-tetra(azido)azo-1,3,5-triazine (2), has a heat of formation of 2171 (6164 kJ kg -1) (Fig. 1). Recently it was demonstrated that 1 and 2 were good precursors to nano carbon nitride materials...

  12. Experimental Study on Fabrication of AZO Transparent Electrode for Organic Solar Cell Using Selective Low-Temperature Atomic Layer Deposition

    International Nuclear Information System (INIS)

    Kim, Kicheol; Song, Gensoo; Kim, Hyungtae; Yoo, Kyunghoon; Kang, Jeongjin; Hwang, Junyoung; Lee, Sangho; Kang, Kyungtae; Kang, Heuiseok; Cho, Youngjune

    2013-01-01

    AZO (aluminum-doped zinc oxide) is one of the best candidate materials to replace Into (indium tin oxide) for TKOs (transparent conductive oxides) used in flat panel displays, organic light-emitting diodes (OLDS), and organic solar cells (OCSS). In the present study, to apply an AZO thin film to the transparent electrode of an organic solar cell, a low temperature selective atomic layer deposition (ALD) process was adopted to deposit an AZO thin film on a flexible polyethylene-naphthanate (Pen) substrate. The reactive gases for the ALD process were di-ethyl-zinc (De) and tri-methylaluminum (Tma) as precursors and H 2 O as an oxidant. The structural, electrical, and optical characteristics of the AZO thin film were evaluated. From the measured results of the electrical and optical characteristics of the AZO thin films deposited on the Pen substrates by Ald, it was shown that the Azo thin film appeared to be comparable to a commercially used Into thin film, which confirmed the feasibility of AZO as a TCO for flexible organic solar cells in the near future

  13. Polyazido Pyrimidines: High Energy Compounds and Precursors to Carbon Nanotubes (PREPRINT)

    National Research Council Canada - National Science Library

    Ye, Chengfeng; Gao, Haoxiang; Twamley, Brendan; Shreeve, Jean'ne M; Drake, Gregory W; Boatz, Jerry A

    2006-01-01

    ...). The compound 4,4',6,6'-tetra(azido)azo-1,3,5-triazine (2), has a heat of formation of 2171 (6164 kJ kg -1). Recently it was demonstrated that 1 and 4 were good precursors to nano carbon nitride materials...

  14. Photocatalytic fluoroalkylation reactions of organic compounds

    OpenAIRE

    Barata Vallejo, Sebastian; Bonesi, Sergio Mauricio; Postigo, Jose Alberto

    2017-01-01

    Photocatalytic methods for fluoroalkyl-radical generation provide more convenient alternatives to the classical perfluoroalkyl-radical (Rf) production through chemical initiators, such as azo or peroxide compounds or the employment of transition metals through a thermal electron transfer (ET) initiation process. The mild photocatalytic reaction conditions tolerate a variety of functional groups and, thus, are handy to the late-stage modification of bioactive molecules. Transition metal-photoc...

  15. Optimization of AZO films prepared on flexible substrates

    Indian Academy of Sciences (India)

    Administrator

    grey relational analysis, the optimization of these deposition process parameters for AZO thin films with multiple characteristics ... bias voltage, annealing temperature and plasma treatment deposition time (Pei et ... water and dried in nitrogen.

  16. Transparent conducting AZO and ITO films produced by pulsed laser ablation at 355 nm

    DEFF Research Database (Denmark)

    Thestrup, B.; Schou, Jørgen

    1999-01-01

    Thin films of aluminium-doped zinc oxide (AZO) and indium tin oxide (ITO) were deposited on glass substrates by laser ablation in an oxygen environment. The electrical and optical properties of films grown at various oxygen pressures were compared. With no substrate heating, highly transparent...... and conducting films were obtained with oxygen pressures between 15 and 23 mTorr for both materials. We obtained a specific resistivity of 1.8 x 10(-3) Omega cm for AZO and 1.1 x 10(-3) Omega cm for ITO. By heating the substrate to 160 degrees C or 200 degrees C, the resistivity was further reduced to 1.1 x 10......(-3) Omega cm for AZO and 3.9 x 10(-4) Omega cm for ITO. The average transmission of visible light (450-750 MI) was between 82% and 98% in most cases. The results suggest that AZO is a promising alternative to ITO....

  17. Computational models for structure-hydrophobicity relationships of 4-carboxyl-2,6-dinitrophenyl azo hydroxynaphthalenes.

    Science.gov (United States)

    Idowu, Olakunle S; Adegoke, Olajire A; Idowu, Abiola; Olaniyi, Ajibola A

    2007-01-01

    Some phenyl azo hydroxynaphthalene dyes (e.g., sunset yellow) are certified as approved colorants for food, cosmetics, and drug formulations. The hydrophobicity of 4 newly synthesized azo dyes of the phenyl azo hydroxynaphthalene class was investigated, as a training set, with the goal of developing models for quantitative structure-property relationships (QSPR). Retention behavior of the molecules reversed-phase thin-layer chromatography (RPTLC) was investigated using liquid paraffin-coated silica gel as the stationary phase. Mobile phases consisted of aqueous mixtures of methanol, acetone, and dimethylformamide (DMF). Basic hydrophobicity parameter (Rmw), specific hydrophobic surface area (S), and isocratic chromatographic hydrophobicity index (phio) were computed from the chromatographic data. The hydrophobicity index (Rm) decreased linearly with increasing concentration of organic modifiers. Extrapolated Rmw values obtained by using DMF and acetone differ significantly from the value obtained by using methanol as organic modifier [P dyes and may also play useful roles in computer-assisted molecular discovery of nontoxic azo dyes.

  18. Influence of various thickness metallic interlayers on opto-electric and mechanical properties of AZO thin films on PET substrates

    Science.gov (United States)

    Chang, R. C.; Li, T. C.; Lin, C. W.

    2012-02-01

    Various thickness metallic interlayers to improve the opto-electric and mechanical properties of aluminum-doped zinc oxide (AZO) thin films deposited on flexible polyethylene terephtalate (PET) substrates are studied. The effects of the interlayers on the resistance and transmittance of the AZO thin films are discussed. The result shows that the metallic interlayers effectively improve the electric resistance but reduce the optical transmittance of the AZO thin films. These phenomena become more obvious as the interlayer thickness increases. However, the AZO with an aluminum interlayer still behaves an acceptable transmittance. Moreover, mechanical tests indicate that the aluminum interlayer increases the hardness and modulus, and reduce the residual stress of the AZO thin films. In contrast, the silver and copper interlayers decrease the AZO's mechanical properties. Comparing to those without any interlayer, the results show that the best interlayer is the 6 nm thick aluminum film.

  19. Studies on Dyeing Performance of Novel Acid Azo Dyes and Mordent Acid Azo Dyes Based on 2,4-Dihydroxybenzophenone

    Directory of Open Access Journals (Sweden)

    Bharat C. Dixit

    2009-01-01

    Full Text Available Novel acid azo and mordent acid azo dyes have been prepared by the coupling of diazo solution of different aminonaphthol sulphonic acids and aromatic amino acids with 2,4-dihydroxybenzophenone. The resultant dyes were characterized by elemental analysis as well as IR and 1H NMR spectral studies. The UV-visible spectral data have also been discussed in terms of structure property relationship. The dyeing assessments of all the dyes were evaluated on wool and silk textile fibers. The dyeing of chrome pretreated wool and silk have also been monitored. The result shows that better hue was obtained on mordented fiber. Results of bactericidal studies of chrome pretreated fibers revealed that the toxicity of mordented dyes against bacteria is fairly good. Dyeing on wool and silk fibers resulted in yellowish pink to reddish brown colourations having excellent light fastness and washing fastness.

  20. Extending the scope of amantadine drug by incorporation of phenolic azo Schiff bases as potent selective inhibitors of carbonic anhydrase II, drug likeness and binding analysis.

    Science.gov (United States)

    Channar, Pervaiz Ali; Saeed, Aamer; Shahzad, Danish; Larik, Fayaz Ali; Hassan, Mubashir; Raza, Hussain; Abbas, Qamar; Seo, Sung-Yum

    2018-05-16

    A series of Amantadine based azo Schiff base dyes 6a-6e have been synthesized and characterized by 1 H NMR and 13 C NMR and evaluated for their in vitro carbonic anhydrase II inhibition activity and antioxidant activity. All of the synthesized showed excellent carbonic inhibition. Compound 6b was found to be the most potent derivative in the series, the IC 50 of 6b was found to be 0.0849 ± 0.00245μM (standard Acetazolamide IC 50 =0.9975±0.049μM). The binding interactions of the most active analogs were confirmed through molecular docking studies. Docking studies showed 6b is interacting by making two hydrogen bonds w at His93 and Ser1 residues respectively. All compounds showed a good drug score and followed Lipinski's rule. In summary, our studies have shown that these amantadine derived phenolic azo Schiff base derivatives are a new class of carbonic anhydrase II inhibitors. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  1. Effect of dye structure and redox mediators on anaerobic azo and anthraquinone dye reduction

    Directory of Open Access Journals (Sweden)

    Mayara Carantino Costa

    2012-01-01

    Full Text Available We investigated the biological decolourisation of dyes with different molecular structures. The kinetic constant values (k1 achieved with azo dye Reactive Red 120 were 7.6 and 10.1 times higher in the presence of RM (redox mediators AQDS and riboflavin, respectively, than the assays lacking RM. The kinetic constant achieved with the azo dye Congo Red was 42 times higher than that obtained with the anthraquinone dye Reactive Blue 4. The effect of RM on dye reduction was more evident for azo dyes resistant to reductive processes, and ineffective for anthraquinone dyes because of the structural stability of the latter.

  2. Inductively coupled hydrogen plasma processing of AZO thin films for heterojunction solar cell applications

    International Nuclear Information System (INIS)

    Zhou, H.P.; Xu, S.; Zhao, Z.; Xiang, Y.

    2014-01-01

    Highlights: • A high-density plasma reactor of inductively coupled plasma source is used in this work. • The conductivity and transmittance can be enhanced simultaneously in the hydrogen process. • The formation of additional donors and passivation due to the hydrogen plasma processing. • The photovoltaic improvement due to the improved AZO layer and hetero-interface quality in the solar cells. - Abstract: Al-doped ZnO (AZO) thin films deposited by means of RF magnetron sputtering were processed in a low frequency inductively coupled plasma of H 2 , aiming at heterojunction (HJ) solar cell applications. A variety of characterization results show that the hydrogen plasma processing exerts a significant influence on the microstructures, electrical and optical properties of the AZO films. The incorporation of hydrogen under the optimum treatment simultaneously promoted the transmittance and conductivity due to the hydrogen associated passivation effect on the native defects and the formation of shallow donors in the films, respectively. A p-type c-Si based HJ solar cell with a front AZO contact was also treated in as-generated non-equilibrium hydrogen plasma and the photovoltaic performance of the solar cell was prominently improved. The underlying mechanism was discussed in terms of the beneficial impacts of high-density hydrogen plasma on the properties of AZO itself and the hetero-interfaces involved in the HJ structure (interface defect and energy band configuration)

  3. Electroluminescence enhancement for near-ultraviolet light emitting diodes with graphene/AZO-based current spreading layers

    DEFF Research Database (Denmark)

    Lin, Li; Ou, Yiyu; Zhu, Xiaolong

    LEDs) have attracted significant research interest due to their intensive applications in various areas where indium tin oxide (ITO) is one of the most widely employed transparent conductive materials for NUV LEDs. Compared to ITO, indium-free aluminum-doped zinc oxide (AZO) has similar electrical......Near-ultraviolet light emitting diodes with different aluminum-doped zinc oxide-based current spreading layers were fabricated and electroluminescence (EL) was compared. A 170% EL enhancement was achieved by using a graphene-based interlayer. GaN-based near-ultraviolet light emitting diodes (NUV...... with a new type of current spreading layer (CSL) which combines AZO and a single-layer graphene (SLG) as an effective transparent CSL [1]. In the present work, LEDs with solo AZO CSL in Fig.1(a) and SLG/Ni/AZO-based CSL in Fig.1(b) were both fabricated for EL comparison. Standard mesa fabrication including...

  4. Structure Modification of an Active Azo-Compound as a Route to New Antimicrobial Compounds

    Directory of Open Access Journals (Sweden)

    Simona Concilio

    2017-05-01

    Full Text Available Some novel (phenyl-diazenylphenols 3a–g were designed and synthesized to be evaluated for their antimicrobial activity. A previously synthesized molecule, active against bacteria and fungi, was used as lead for modifications and optimization of the structure, by introduction/removal or displacement of hydroxyl groups on the azobenzene rings. The aim of this work was to evaluate the consequent changes of the antimicrobial activity and to validate the hypothesis that, for these compounds, a plausible mechanism could involve an interaction with protein receptors, rather than an interaction with membrane. All newly synthesized compounds were analyzed by 1H-NMR, DSC thermal analysis and UV-Vis spectroscopy. The in vitro minimal inhibitory concentrations (MIC of each compound was determined against Gram-positive and Gram-negative bacteria and Candida albicans. Compounds 3b and 3g showed the highest activity against S. aureus and C. albicans, with remarkable MIC values of 10 µg/mL and 3 µg/mL, respectively. Structure-activity relationship studies were capable to rationalize the effect of different substitutions on the phenyl ring of the azobenzene on antimicrobial activity.

  5. Use of Titanium Dioxide Photocatalysis on the Remediation of Model Textile Wastewaters Containing Azo Dyes

    Directory of Open Access Journals (Sweden)

    Josino Costa Moreira

    2011-12-01

    Full Text Available The photocatalytic degradation of two commercial textile azo dyes, namely C.I Reactive Black 5 and C.I Reactive Red 239, has been studied. TiO2 P25 Degussa was used as catalyst and photodegradation was carried out in aqueous solution under artificial irradiation with a 125 W mercury vapor lamp. The effects of the amount of TiO2 used, UV-light irradiation time, pH of the solution under treatment, initial concentration of the azo dye and addition of different concentrations of hydrogen peroxide were investigated. The effect of the simultaneous photodegradation of the two azo dyes was also investigated and we observed that the degradation rates achieved in mono and bi-component systems were identical. The repeatability of photocatalytic activity of the photocatalyst was also tested. After five cycles of TiO2 reuse the rate of colour lost was still 77% of the initial rate. The degradation was followed monitoring the change of azo dye concentration by UV-Vis spectroscopy. Results show that the use of an efficient photocatalyst and the adequate selection of optimal operational parameters may easily lead to a complete decolorization of the aqueous solutions of both azo dyes.

  6. Comparative study on reaction selectivity of azo dye decolorization by Pseudomonas luteola

    International Nuclear Information System (INIS)

    Hsueh, C.-C.; Chen, B.-Y.

    2007-01-01

    This study is to inspect how the variation of molecular structures and functional groups present in our model azo dyes (i.e., Congo red, Eriochrome black T (EBT), methyl orange, and methyl red) affects biodecolorization capability of Pseudomonas luteola. The most viable decolorization was found at pH 7-9 and the optimal cellular age for the most effective decolorization was 7 days after static incubation in dye-free cultures. In decolorization, the maximal absorption wavelength in UV-vis spectra for the different dye-containing cultures shifted from visible light range towards the ultraviolet visible range. Methyl red was not decolorized in contrast to methyl orange, Congo red, and Eriochrome black T. The sulfonic group para to azo bond (-N=N-) in methyl orange was a strong electron-withdrawing group through resonance to cause an enhancement of color removal to be easily biodecolorized. As a charged carboxyl group on methyl red is at ortho position (i.e., in the proximity) to azo bond, this led to a complete inhibition to decolorization. However, decolorization of Congo red and EBT in the absence of charged group (e.g., hydroxy or amino group) near azo bond was not completely repressed like methyl red. Thus, the presence of electron-withdrawing groups as the substituents on azo dyes enhanced decolorization capability for biodegradability. In addition, Monod kinetic model provided better predictions to all dye decolorization at initial short periods of time due to negligible intermediate formed at initial short time duration, but significant intermediate accumulation took place at longer period of time. In contrast, the decolorization performances of methyl orange at 400 ppm and EBT at 230 ppm were significantly less than those predicted from the Monod kinetic model likely due to accumulated intermediates exceeding the threshold levels for feedback inhibition

  7. Effect of silver nanoparticles on photo-induced reorientation of azo groups in polymer films

    International Nuclear Information System (INIS)

    Zhou Jingli; Yang Jianjun; Sun Youyi; Zhang Douguo; Shen Jing; Zhang Qijin; Wang Keyi

    2007-01-01

    A series of polymer films containing azo groups and silver nanoparticles were prepared. Photo-induced reorientation of the film was conducted under irradiation of polarized light with wavelength at 365 nm, 442 nm and 532 nm, respectively. The influence of the concentration of dopant silver on the reorientation of the azo groups was studied. An enhancement of about 50% for the reorientation rate and about 70% for the reorientation amplitude was achieved. From a comparison of the enhancement obtained by irradiating with three different light sources, it was realized that the mechanism for enhancement of reorientation of azo groups is due to plasmon resonance of silver nanoparticles doped in the polymer films

  8. Impact of self-assembled monolayer assisted surface dipole modulation of PET substrate on the quality of RF-sputtered AZO film

    Energy Technology Data Exchange (ETDEWEB)

    Vo, Thieu Thi Tien [Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China); Faculty of Chemical Engineering and Food Technology, Ba Ria-Vung Tau University, Vung Tau (Viet Nam); Mahesh, K.P.O. [Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China); Lin, Pao-Hung [Department of Electronic and Computer Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China); Tai, Yian, E-mail: ytai@mail.ntust.edu.tw [Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China)

    2017-05-01

    Highlights: • We use SAMs functionalizing the PET substrates to generate different surface dipoles. • We deposited AZO film on pristine and SAMs-modified PET substrate. • The positive dipole moment of PET surface promotes the crystallinity of AZO film. • The negative dipole moment of PET surface deteriorates the crystallinity of AZO film. • The electrical properties of AZO/PET changes upon the variation of the crystallinity. - Abstract: In this study, we fabricated the electron donating/withdrawing group functionalized organosilane self-assembled monolayers (SAMs) on transparent polyethylene terephthalate (PET) flexible substrate followed by the deposition of aluminum doped zinc oxide (AZO) using RF magnetron sputtering at room temperature. The effect of different SAMs on transparent PET substrates and AZO films were studied by contact angle (CA), X-ray photoelectron spectroscopy (XPS), Atomic force microscopy (AFM), X-ray diffraction (XRD), Field-Emission scanning electron microscope (FE-SEM), Hall measurement and UV–vis spectroscopy (UV–vis). The results presented that the surface dipole (i.e. electron-donating/withdrawing) of different SAMs functionalized PET substrates affected the quality of the AZO films which deposited on top of them. The crystallinity, the charge mobility, and the carrier concentration of the AZO improved when the film was deposited on the PET functionalized with electron donating group, which was possibly due to favored interaction between electron donating group and Al ions.

  9. Impact of self-assembled monolayer assisted surface dipole modulation of PET substrate on the quality of RF-sputtered AZO film

    International Nuclear Information System (INIS)

    Vo, Thieu Thi Tien; Mahesh, K.P.O.; Lin, Pao-Hung; Tai, Yian

    2017-01-01

    Highlights: • We use SAMs functionalizing the PET substrates to generate different surface dipoles. • We deposited AZO film on pristine and SAMs-modified PET substrate. • The positive dipole moment of PET surface promotes the crystallinity of AZO film. • The negative dipole moment of PET surface deteriorates the crystallinity of AZO film. • The electrical properties of AZO/PET changes upon the variation of the crystallinity. - Abstract: In this study, we fabricated the electron donating/withdrawing group functionalized organosilane self-assembled monolayers (SAMs) on transparent polyethylene terephthalate (PET) flexible substrate followed by the deposition of aluminum doped zinc oxide (AZO) using RF magnetron sputtering at room temperature. The effect of different SAMs on transparent PET substrates and AZO films were studied by contact angle (CA), X-ray photoelectron spectroscopy (XPS), Atomic force microscopy (AFM), X-ray diffraction (XRD), Field-Emission scanning electron microscope (FE-SEM), Hall measurement and UV–vis spectroscopy (UV–vis). The results presented that the surface dipole (i.e. electron-donating/withdrawing) of different SAMs functionalized PET substrates affected the quality of the AZO films which deposited on top of them. The crystallinity, the charge mobility, and the carrier concentration of the AZO improved when the film was deposited on the PET functionalized with electron donating group, which was possibly due to favored interaction between electron donating group and Al ions.

  10. Using chemical wet-etching methods of textured AZO films on a-Si:H solar cells for efficient light trapping

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Guo-Sheng; Li, Chien-Yu; Huang, Kuo-Chan; Houng, Mau-Phon, E-mail: mphoung@eembox.ncku.edu.tw

    2015-06-15

    In this paper, Al-doped ZnO (AZO) films are deposited on glasses substrate by RF magnetron sputtering. The optical, electrical and morphological properties of AZO films textured by wet-etching with different etchants, H{sub 3}PO{sub 4}, HCl, and HNO{sub 3} are studied. It is found that the textured structure could enhance the light scattering and light trapping ability of amorphous silicon solar cells. The textured AZO film etched with HNO{sub 3} exhibits optimized optical properties (T% ≧ 80% over entire wavelength, haze ratio > 40% at 550 nm wavelength) and excellent electrical properties (ρ = 5.86 × 10{sup −4} Ωcm). Scanning electron microscopy and Atomic force microscopy are used to observe surface morphology and average roughness of each textured AZO films. Finally, the textured AZO films etched by H{sub 3}PO{sub 4}, HCl and HNO{sub 3} were applied to front electrode layer for p–i–n amorphous silicon solar cells. The highest conversion efficiency of amorphous silicon solar cell fabricated on HNO{sub 3}-etched AZO film was 7.08% with open-circuit voltage, short-circuit current density and fill factor of 895 mV, 14.92 mA/cm{sup 2} and 0.56, respectively. It shows a significantly enhancement in the short-circuit current density and conversion efficiency by 16.2% and 20.2%, respectively, compared with the solar cell fabricated on as-grown AZO film. - Highlights: • The textured surface enhances light scattering and light trapping ability. • The HNO{sub 3}-etched AZO film exhibits excellent optical and electrical properties. • The efficiency of a-Si:H solar cell fabricated on HNO{sub 3}-etched AZO film was 7.08%. • The short-circuit current density enhances to 16.2%. • The conversion efficiency enhances to 20.2%.

  11. Using chemical wet-etching methods of textured AZO films on a-Si:H solar cells for efficient light trapping

    International Nuclear Information System (INIS)

    Lin, Guo-Sheng; Li, Chien-Yu; Huang, Kuo-Chan; Houng, Mau-Phon

    2015-01-01

    In this paper, Al-doped ZnO (AZO) films are deposited on glasses substrate by RF magnetron sputtering. The optical, electrical and morphological properties of AZO films textured by wet-etching with different etchants, H 3 PO 4 , HCl, and HNO 3 are studied. It is found that the textured structure could enhance the light scattering and light trapping ability of amorphous silicon solar cells. The textured AZO film etched with HNO 3 exhibits optimized optical properties (T% ≧ 80% over entire wavelength, haze ratio > 40% at 550 nm wavelength) and excellent electrical properties (ρ = 5.86 × 10 −4 Ωcm). Scanning electron microscopy and Atomic force microscopy are used to observe surface morphology and average roughness of each textured AZO films. Finally, the textured AZO films etched by H 3 PO 4 , HCl and HNO 3 were applied to front electrode layer for p–i–n amorphous silicon solar cells. The highest conversion efficiency of amorphous silicon solar cell fabricated on HNO 3 -etched AZO film was 7.08% with open-circuit voltage, short-circuit current density and fill factor of 895 mV, 14.92 mA/cm 2 and 0.56, respectively. It shows a significantly enhancement in the short-circuit current density and conversion efficiency by 16.2% and 20.2%, respectively, compared with the solar cell fabricated on as-grown AZO film. - Highlights: • The textured surface enhances light scattering and light trapping ability. • The HNO 3 -etched AZO film exhibits excellent optical and electrical properties. • The efficiency of a-Si:H solar cell fabricated on HNO 3 -etched AZO film was 7.08%. • The short-circuit current density enhances to 16.2%. • The conversion efficiency enhances to 20.2%

  12. Effect of Reactive Black 5 azo dye on soil processes related to C and N cycling

    Directory of Open Access Journals (Sweden)

    Khadeeja Rehman

    2018-05-01

    Full Text Available Azo dyes are one of the largest classes of synthetic dyes being used in textile industries. It has been reported that 15–50% of these dyes find their way into wastewater that is often used for irrigation purpose in developing countries. The effect of azo dyes contamination on soil nitrogen (N has been studied previously. However, how does the azo dye contamination affect soil carbon (C cycling is unknown. Therefore, we assessed the effect of azo dye contamination (Reactive Black 5, 30 mg kg−1 dry soil, bacteria that decolorize this dye and dye + bacteria in the presence or absence of maize leaf litter on soil respiration, soil inorganic N and microbial biomass. We found that dye contamination did not induce any change in soil respiration, soil microbial biomass or soil inorganic N availability (P > 0.05. Litter evidently increased soil respiration. Our study concludes that the Reactive Black 5 azo dye (applied in low amount, i.e., 30 mg kg−1 dry soil contamination did not modify organic matter decomposition, N mineralization and microbial biomass in a silty loam soil.

  13. Decolorization of azo dyes (Direct Blue 151 and Direct Red 31 by moderately alkaliphilic bacterial consortium

    Directory of Open Access Journals (Sweden)

    Sylvine Lalnunhlimi

    2016-03-01

    Full Text Available Abstract Removal of synthetic dyes is one of the main challenges before releasing the wastes discharged by textile industries. Biodegradation of azo dyes by alkaliphilic bacterial consortium is one of the environmental-friendly methods used for the removal of dyes from textile effluents. Hence, this study presents isolation of a bacterial consortium from soil samples of saline environment and its use for the decolorization of azo dyes, Direct Blue 151 (DB 151 and Direct Red 31 (DR 31. The decolorization of azo dyes was studied at various concentrations (100–300 mg/L. The bacterial consortium, when subjected to an application of 200 mg/L of the dyes, decolorized DB 151 and DR 31 by 97.57% and 95.25% respectively, within 5 days. The growth of the bacterial consortium was optimized with pH, temperature, and carbon and nitrogen sources; and decolorization of azo dyes was analyzed. In this study, the decolorization efficiency of mixed dyes was improved with yeast extract and sucrose, which were used as nitrogen and carbon sources, respectively. Such an alkaliphilic bacterial consortium can be used in the removal of azo dyes from contaminated saline environment.

  14. Novel bio-electro-Fenton technology for azo dye wastewater treatment using microbial reverse-electrodialysis electrolysis cell

    DEFF Research Database (Denmark)

    Li, Xiaohu; Jin, Xiangdan; Zhao, Nannan

    2017-01-01

    Development of sustanaible technologies for treatment of azo dyes containing wastewaters has long been of great interest. In this study, we proposed an innovative concept of using microbial reverse-electrodialysis electrolysis cell (MREC) based Fenton process to treat azo dye wastewater. In such ......Development of sustanaible technologies for treatment of azo dyes containing wastewaters has long been of great interest. In this study, we proposed an innovative concept of using microbial reverse-electrodialysis electrolysis cell (MREC) based Fenton process to treat azo dye wastewater....... In such MREC-Fenton integrated process, the production of H2O2 which is the key reactant of fenton-reaction was driven by the electrons harvested from the exoelectrogens and salinity-gradient between sea water and fresh water in MREC. Complete decolorization and mineralization of 400 mg L-1 Orange G...

  15. Novel colorimetric sensors for cyanide based on azo-hydrazone tautomeric skeletons.

    Science.gov (United States)

    Adegoke, Olajire A; Adesuji, Temitope E; Thomas, Olusegun E

    2014-07-15

    The monoazo dyes, 4-carboxyl-2, 6-dinitrophenylazohydroxynaphthalenes dyes (AZ-01, AZ-03 and AZ-04), were evaluated as a highly selective colorimetric chemosensor for cyanide ion. The recognition of cyanide ion gave an obvious colour change from light yellow to brownish red and upon dilution with acetone produced a purple to lilac colour. Optimum conditions for the reaction between the azo dyes and cyanide ion were established at 30°C for 5 min, and different variables affecting the reaction were carefully studied and optimised. Under the optimum conditions, linear relationships between the CN(-) concentrations and light absorption were established. Using these azo-hydrazone molecular switch entities, excellent selectivity towards the detection of CN(-) in aqueous solution over miscellaneous competitive anions was observed. Such selectivity mainly results from the possibility of nucleophilic attack on the azo-hydrazone chemosensors by cyanide anions in aqueous system, which is not afforded by other competing anions. The cyanide chemosensor method described here should have potential application as a new family probes for detecting cyanide in aqueous solution. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. ADSORPSI-DESORPSI ZAT WARNA AZO JENIS REMAZOL BLACK B MENGGUNAKAN MEMBRAN POLIELEKTROLIT (PEC KITOSAN-PEKTIN

    Directory of Open Access Journals (Sweden)

    Ni Putu Sri Ayuni

    2016-08-01

    Full Text Available Abstrak Sekitar 2-50% dari zat warna azo yang digunakan selama proses pencelupan ini tidak mengikat serat dan langsung dilepaskan ke lingkungan melalui instalasi pengolahan limbah. Hal ini perlu dilakukan pengolahan limbah cair yang mengandung zat warna azo jenis Remazol Black B sebelum dibuang ke lingkungan. Penelitian ini bertujuan untuk mengetahui kondisi optimum membran PEC kitosan-pektin yang dapat digunakan untuk mengadsorpsi zat warna azo jenis Remazol Black B .Untuk memperoleh kondisi optimum akan dilakukan adsorpsi zat warna azo jenis Remazol Black B dengan variasi waktu kontak (5-150 menit, pH (5-9 dan konsentrasi larutan zat warna azo jenis Remazol Black B (5, 10, 15, 20, dan 25 mg/L. Untuk mengetahui karakteristik zat warna jenis Remazol Black B oleh membran PEC kitosan-pektin di analisis dengan persamaan isoterm adsorpsi Langmuir dan isoterm adsorpsi Freundlich sedangkan daya adsorpsi maksimum dari membran PEC kitosan pektin ditentukan dari kurva berdasarkan karakteristik membran yang diperoleh. Hasil penelitian menunjukkan bahwa adsorpsi zat warna azo jenis Remazol Black B terjadi pada kondisi optimum dengan pH 5, waktu 120 menit dan konsentrasi larutan zat warna azo jenis Remazol Black B 10 mg/L (62,75 %. Pola adsorpsi mengikuti pola adsorpsi isoterm Freundlich dengan daya adsorpsi maksimum 0,02 (mg/g. Untuk efisiensi desorpsi maksimal diperoleh pada larutan NaCl 1 M (11,17 % Kata Kunci: adsorpsi, membran polielektrolit kitosan pektin, Remazol Black B Abstract Azo dyes produced approximately 2-50% from dying process were thrown through effluent to the environment without any treatment. The objective of this research were to know the optimum condition of PEC chitosan pectin membrane using to adsorp Remazol Black B with various contact time (5-150 min, pH (5-9 and Remazol Black B concentration (5, 10, 15, 20, dan 25 mg/L. Adsorption charactheristic of Remazol Black B by PEC chitosan pectin membrane were determined by Langmuir and

  17. Atomic-Layer-Deposited AZO Outperforms ITO in High-Efficiency Polymer Solar Cells

    KAUST Repository

    Kan, Zhipeng

    2018-05-11

    Tin-doped indium oxide (ITO) transparent conducting electrodes are widely used across the display industry, and are currently the cornerstone of photovoltaic device developments, taking a substantial share in the manufacturing cost of large-area modules. However, cost and supply considerations are set to limit the extensive use of indium for optoelectronic device applications and, in turn, alternative transparent conducting oxide (TCO) materials are required. In this report, we show that aluminum-doped zinc oxide (AZO) thin films grown by atomic layer deposition (ALD) are sufficiently conductive and transparent to outperform ITO as the cathode in inverted polymer solar cells. Reference polymer solar cells made with atomic-layer-deposited AZO cathodes, PCE10 as the polymer donor and PC71BM as the fullerene acceptor (model systems), reach power conversion efficiencies of ca. 10% (compared to ca. 9% with ITO-coated glass), without compromising other figures of merit. These ALD-grown AZO electrodes are promising for a wide range of optoelectronic device applications relying on TCOs.

  18. Atomic-Layer-Deposited AZO Outperforms ITO in High-Efficiency Polymer Solar Cells

    KAUST Repository

    Kan, Zhipeng; Wang, Zhenwei; Firdaus, Yuliar; Babics, Maxime; Alshareef, Husam N.; Beaujuge, Pierre

    2018-01-01

    Tin-doped indium oxide (ITO) transparent conducting electrodes are widely used across the display industry, and are currently the cornerstone of photovoltaic device developments, taking a substantial share in the manufacturing cost of large-area modules. However, cost and supply considerations are set to limit the extensive use of indium for optoelectronic device applications and, in turn, alternative transparent conducting oxide (TCO) materials are required. In this report, we show that aluminum-doped zinc oxide (AZO) thin films grown by atomic layer deposition (ALD) are sufficiently conductive and transparent to outperform ITO as the cathode in inverted polymer solar cells. Reference polymer solar cells made with atomic-layer-deposited AZO cathodes, PCE10 as the polymer donor and PC71BM as the fullerene acceptor (model systems), reach power conversion efficiencies of ca. 10% (compared to ca. 9% with ITO-coated glass), without compromising other figures of merit. These ALD-grown AZO electrodes are promising for a wide range of optoelectronic device applications relying on TCOs.

  19. TiO2/beads as a photocatalyst for the degradation of X3B azo dye

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The feasibility of photocatalytic degradation of X3B azo dye by TiO2/beads photocatalyst was studied. The effects of parameters such as the amount of TiO2/beads, airflow, as well as the concentrations of H2O2, Fe3+, Mg2+ and Na+ on the photocatalytic degradation of X3B azo dye were also studied. The results showed that 25 mg/dm3 X3B azo dye can be photocatalytically degraded completely by 30 min illumination with a 375W medium pressure mercury lamp. Adding a small amount of H2O2 or Fe3+, the efficiencies of photocatalytic degradation of X3B azo dye were increased rapidly. The mechanisms of the reaction and the role of the additives were also investigated. After 120 hours TiO2/beads showed no significant loss of the photocatalytic activity.

  20. Novel acid mono azo dye compound: Synthesis, characterization, vibrational, optical and theoretical investigations of 2-[(E)-(8-hydroxyquinolin-5-yl)-diazenyl]-4,5-dimethoxybenzoic acid

    Science.gov (United States)

    Saçmacı, Mustafa; Çavuş, Hatice Kanbur; Arı, Hatice; Şahingöz, Recep; Özpozan, Talat

    2012-11-01

    Novel acid mono azo dye, 2-[(E)-(8-hydroxyquinolin-5yl)-diazenyl]-4,5-dimethoxybenzoic acid (HQD), was synthesized by coupling diazonium salt solution of 2-amino-4,5-dimethoxybenzoic acid (DMA) with 8-hydroxyquinoline (HQ). This dye was characterized by UV-vis, IR & Raman, 1H and 13C NMR spectroscopic techniques and elemental analysis. The normal coordinate analysis of HQD was also performed to assign each band in vibrational spectra. DFT (B3LYP and B3PW91) calculations were employed to optimize the geometry, to interpret NMR spectra, to calculate and to determine the stable tautomeric structure of the compound. Natural Bond Orbital (NBO) analysis was performed to investigate intramolecular interactions. The vibrational spectral data obtained from solid phase IR & Raman spectra were assigned based on the results of the theoretical calculations. UV-vis spectroscopic technique was employed to obtain the optical band gap of HQD. The analysis of the optical absorption data revealed the existence of direct and indirect transitions in the optical band gaps. The optical band gaps of HQD have been found 1.95 and 1.90 eV for direct and indirect transitions, respectively.

  1. Synthesis and antitumor evaluation of thiophene based azo dyes incorporating pyrazolone moiety

    Directory of Open Access Journals (Sweden)

    Moustafa A. Gouda

    2016-03-01

    Full Text Available A series of thiophene incorporating pyrazolone moieties 5a–f and 6a–c were synthesized via diazo coupling of diazonium salt of 3-substituted-2-amino-4,5,6,7-tetrahydrobenzo[b]thiophenes 1a–c with 3-methyl-1H-pyrazol-5(4H-one, 3-methyl-1-phenyl-1H-pyrazol-5(4H-one or 3-amino-1H-pyrazol-5(4H-one, respectively. Newly synthesized dyes were applied to polyester fabric as disperse dyes in which their color measurements and fastness properties were evaluated. These dyes showed generally red to blue shifted color with high extinction coefficient in comparison with aniline-based azo dyes. The antitumor activity of the synthesized dyes was evaluated. The results showed clearly that most of them exhibited good activity and compounds 5c and 5d exhibited moderate activity.

  2. Synthesis and characterization of azo-guanidine based alcoholic media naked eye DNA sensor

    Science.gov (United States)

    Hashmat, Uzma; Yousaf, Muhammad; Lal, Bhajan; Ullah, Shafiq; Holder, Alvin A.; Badshah, Amin

    2016-01-01

    DNA sensing always has an open meadow of curiosity for biotechnologists and other researchers. Recently, in this field, we have introduced an emerging class of molecules containing azo and guanidine functionalities. In this study, we have synthesized three new compounds (UA1, UA6 and UA7) for potential application in DNA sensing in alcoholic medium. The synthesized materials were characterized by elemental analysis, FTIR, UV-visible, 1H NMR and 13C NMR spectroscopies. Their DNA sensing potential were investigated by UV-visible spectroscopy. The insight of interaction with DNA was further investigated by electrochemical (cyclic voltammetry) and hydrodynamic (viscosity) studies. The results showed that compounds have moderate DNA binding properties, with the binding constants range being 7.2 × 103, 2.4 × 103 and 0.2 × 103 M−1, for UA1, UA6 and UA7, respectively. Upon binding with DNA, there was a change in colour (a blue shift in the λmax value) which was observable with a naked eye. These results indicated the potential of synthesized compounds as DNA sensors with detection limit 1.8, 5.8 and 4.0 ng µl−1 for UA1, UA6 and UA7, respectively. PMID:28018613

  3. Ozonation of azo dyes (Orange II and Acid Red 27) in saline media

    International Nuclear Information System (INIS)

    Silva, Alessandra C.; Pic, Jean Stephane; Sant'Anna, Geraldo L.; Dezotti, Marcia

    2009-01-01

    Ozonation of two azo dyes was investigated in a monitored bench scale bubble column reactor (8.5-L), varying liquid media salt content (0, 1, 40 and 100 g L -1 , NaCl). In experiments with Orange II pH was varied (5, 7.5 and 9) but ozonation of Acid Red 27 was performed at pH 7.5. Ozone self-decomposition rate-constant increased with salt concentration. Color removal was very effective and fast achieved under all experimental conditions. For the two azo dyes tested, more than 98% of color intensity was removed in 30-min ozonation assays. However, only partial mineralization of azo dyes (45%-Orange II; 20%-Acid Red 27) was attained in such experiments. The degree of mineralization (TOC removal) was negatively affected by salt concentration. Biodegradation assays conducted by respirometry revealed the inhibitory effect of dye degradation products formed during ozonation.

  4. Methods for the analysis of azo dyes employed in food industry--A review.

    Science.gov (United States)

    Yamjala, Karthik; Nainar, Meyyanathan Subramania; Ramisetti, Nageswara Rao

    2016-02-01

    A wide variety of azo dyes are generally added for coloring food products not only to make them visually aesthetic but also to reinstate the original appearance lost during the production process. However, many countries in the world have banned the use of most of the azo dyes in food and their usage is highly regulated by domestic and export food supplies. The regulatory authorities and food analysts adopt highly sensitive and selective analytical methods for monitoring as well as assuring the quality and safety of food products. The present manuscript presents a comprehensive review of various analytical techniques used in the analysis of azo dyes employed in food industries of different parts of the world. A brief description on the use of different extraction methods such as liquid-liquid, solid phase and membrane extraction has also been presented. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Characterization of Predominant Reductants in an Anaerobic Leachate-Contaminated Aquifer by Nitroaromatic Probe Compounds

    DEFF Research Database (Denmark)

    Rügge, Kirsten; Hofstetter, Thomas B.; Haderlein, Stefan B.

    1998-01-01

    The biogeochemical processes controlling the reductive transformation of contaminants in an anaerobic aquifer were inferred from the relative reactivity patterns of redox-sensitive probe compounds. The fate of five nitroaromatic compounds (NACs) was monitored under different redox conditions in a...... results suggest that Fe(ll) associated with ferric iron minerals is a highly reactive reductant in anaerobic aquifers, which may also determine the fate of other classes of reducible contaminants such as halogenated solvents, azo compounds, sulfoxides, chromate, or arsenate....

  6. Role of brown-rot fungi in the bioremoval of azo dyes under different conditions

    Directory of Open Access Journals (Sweden)

    Naeem Ali

    2010-12-01

    Full Text Available The present study is vital to the understanding of bioremediation of structurally different azo dyes by some unusual Brown-rot fungi. Bioremoval of each dye (20 mg l-1 was tested in two different culture media under static and shaking conditions by taking inocula from different fungi. Fungal strains showed varying dyes removal abilities, though considerable high in case of Acid Red (AR 151(di-azo as compared to Orange (Or II (mono-azo. With an exception of Aspergillus tereus SA3, all the fungal isolates showed higher removal of dyes in SDB. Under static condition, the maximum decolorizing fungal strains were; Aspergillus flavus SA2 (67% and Alternaria spp. SA4 (57% in AR 151, while Penicillium spp. (34 and 33 % in Orange II, in SDB and STE, respectively. Bioremoval of dyes was considerably increased when experiments were shifted from static to shaking mode. It was specifically increased (% in; AR 151 (255 with Penicillium spp., Or II with A. flavus SA2 (112 and Alternaria spp. (111. The primary mechanism of dyes removal proved to be fungal biosorption. However, reduction of dyes (onto fungal with formation of their products (α. naphthol, sulphalinic acid and aniline furthermore revealed that dyes (specifically azo were actually biodegraded.

  7. Biodegradation of azo dyes in cocultures of anaerobic granular sludge with aerobic aromatic amine degrading enrichment cultures

    NARCIS (Netherlands)

    Tan, N.C.G.; Prenefeta-Boldú, F.X.; Opsteeg, J.L.; Lettinga, G.; Field, J.A.

    1999-01-01

    A prerequisite for the mineralization (complete biodegradation) of many azo dyes is a combination of reductive and oxidative steps. In this study, the biodegradation of two azo dyes, 4-phenylazophenol (4-PAP) and Mordant Yellow 10 (4-sulfophenylazo-salicylic acid; MY10), was evaluated in batch

  8. Thermal stability and degradation behavior of novel wholly aromatic azo polyamide-hydrazides

    International Nuclear Information System (INIS)

    Al-Ghamdia, R.F.; Fahmib, M.M.; Mohamed, N.A.

    2005-01-01

    Thermal stability and degradation behavior of a series of novel wholly aromatic azo polyamide-hydrazides have been investigated in nitrogen and in air atmospheres using differential scanning ealorimetry, thermogravimetry, infrared spectroscopy and elemental analysis. The influences of controlled structural variations and molecular weight on the thermal stability and degradation behavior of this series of polymers have also been studied. The structural differences were achieved by varying the content of para- and meta substituted phenylene rings incorporated within this series. The polymers were prepared by a low temperature solution polycondensation reaction of p aminosalicylic acid hydrazide and an equimolar amount of 4,4-azo dibenzoyl chloride [4,4 ADBC] or 3,3-azo dibenzoyl chloride [3,3ADBC] or mixtures of various molar ratios of 4,4ADBC and 3,3ADBC in anhydrous N,N- dimethyl acetamide [DMAc] containing lithium chloride as a solvent at -10 degree C. The results clearly reveal that these polymers are characterized by high thermal stability. Their weight loss occurred in three distinctive steps. The first was small and assigned to the evaporation of absorbed moisture. The second was appreciable and was attributed to the cyclo dehydration reaction of the hydrazide groups into 1,3,4-oxadiazole rings by losing water, combined with elimination of azo groups by losing molecular nitrogen. This is not a true degradation but rather a thermo-chemical transformation reaction of the azo polyamide-hydrasdes into the corresponding polyamide-l,3,4-oxadiazoles. The third was relatively severe and sharp, particularly in air, and corresponded to the decomposition of the resulting polyamide-l, 3,4-oxadiazoles. In both degradation atmospheres, the improved resistance to high temperatures was always associated with increased content of para- phenylene moieties of the investigated polymer. Further, with exception of 160-200 degree C temperature range, where the lower molecular weight

  9. Synthesis and characterization of near-IR absorbing metal-free and zinc(II phthalocyanines modified with aromatic azo groups

    Directory of Open Access Journals (Sweden)

    Mukaddes Özçeşmeci

    2015-05-01

    Full Text Available Metal-free and zinc(II phthalocyanine complexes bearing peripheral (E-4-((2-hydroxynaphthalen-1-yldiazenyl units have been synthesized. Novel phthalonitrile derivative required for the preparation of phthalocyanine complexes was prepared by coupling 4-aminophthalonitrile and 2-naphthol. The structures of these new compounds were characterized by using elemental analyses, proton nuclear magnetic resonance, fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, fluorescence spectroscopy and mass spectrometry. In the UV-Vis spectra a broad absorption band appears for phthalocyanine complexes at around 450–500 nm resulting from azo-group introduced onto the phthalocyanine ring. The photophysical properties of metal-free and zinc(II phthalocyanines were studied in tetrahydrofuran.

  10. Comparison study of transparent RF-sputtered ITO/AZO and ITO/ZnO bilayers for near UV-OLED applications

    Science.gov (United States)

    Rezaie, Mahdiyar Nouri; Manavizadeh, Negin; Abadi, Ehsan Mohammadi Nasr; Nadimi, Ebrahim; Boroumand, Farhad Akbari

    2017-01-01

    Hybrid inorganic/organic light-emitting diodes have attracted much attention in the field of luminescent electronics due to the desired incorporation of high optoelectronic features of inorganic materials with the processability and variety of organic polymers. To generate and emit a near ultraviolet (N-UV) ray, wide band gap semiconductors can be applied in the organic light-emitting diodes (OLEDs). In this paper, zinc oxide (ZnO) and aluminum-doped ZnO (AZO) thin films are deposited by radio frequency (RF) sputtering above the ITO electrode and poly [2-methoxy-5-(2-ethyl-hexyloxy)-1,4-phenylene-vinylene] (MEH-PPV) conjugated polymer is utilized as a complementary p-type semiconductor in OLED structure. The impact of ZnO and AZO thickness on the structural, electrical, optical and morphological properties of ITO/AZO and ITO/ZnO bilayers are scrutinized and compared. Results show that with the enlargement of both ZnO and AZO film thickness, the physical properties are gradually improved resulting in the better quality of transparent conducting thin film. The average electrical resistivity of 8.4 × 10-4 and 1.1 × 10-3 Ω-cm, average sheet resistance of 32.9 and 42.3 Ω/sq, average transmittance of 88.3 and 87.3% and average FOM of 1.0 × 104 and 7.4 × 103 (Ω-cm)-1 are obtained for ITO/AZO and ITO/ZnO bilayers, respectively. Moreover, comparing the results indicates that the strain and the stress within the ITO/AZO bilayer are decreased nearly 19% with respect to ITO/ZnO bilayer which yield higher quality of crystal. Consequently, the physical properties of ITO/AZO bilayer is found to be superior regarding ITO/ZnO bilayer. For fabricated UV-OLEDs, the turn-on voltages, the characteristic energy (Et) and the total concentration of traps (Nt) for the devices with the structures of ITO/ZnO/MEH-PPV/Al and ITO/AZO/MEH-PPV/Al are obtained 12 and 14 V, 0.108 and 0.191 eV, 9.33 × 1016 and 5.22 × 1016 cm-3, respectively. Furthermore, according to the electroluminescence

  11. Low-temperature-fabricated ZnO, AZO, and SnO{sub 2} nanoparticle-based dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hong Hee; Park, Cheolmin; Choi, Wonkook; Cho, Sungjae; Moon, Byungjoon; Son, Dongick [Korea Institute of Science and Technology, Seoul (Korea, Republic of); Yonsei University, Seoul (Korea, Republic of)

    2014-11-15

    The authors investigated the microstructural and the electrical properties of ZnO, AZO, and SnO{sub 2} based dye-sensitized solar cells (DSSCs) fabricated using a low-temperature-processed (200 .deg. C) dyesensitized ZnO, AZO, and SnO{sub 2} nanoparticle thin film and a Pt catalyst deposited on ITO/glass by RF magnetron sputtering. A hydropolymer containing PEG (poly ethylene glycol) and PEO (poly ethylene oxide) is used to make uniformly-distributed ZnO, AZO, and SnO{sub 2} nanoparticle layer which forms a nano porous ZnO, AZO, and SnO{sub 2} network after heat treatment. The layer is then dye sensitized and sandwiched between two electrodes in an electrolyte to make a DSSC device. The highest measured parameters, the short-circuit current density (J{sub sc}), the open circuit potential (V{sub oc}), the fill factor (FF), and power conversion efficiency (η), of the DSSC fabricated wander optimized conditions were observed to be 5.10 mA/cm{sup 2}, 0.61 V, 0.46, and 1.43%, respectively.

  12. Mechanism of azo dye degradation in Advanced Oxidation Processes: Degradation of Sulfanilic Acid Azochromotrop and its parent compounds in aqueous solution by ionizing radiation

    International Nuclear Information System (INIS)

    Palfi, Tamas; Wojnarovits, Laszlo; Takacs, Erzsebet

    2011-01-01

    Mechanistic studies were made on hydroxyl radical and hydrated electron reaction with Sulfanilic Acid Azochromotrop (SPADNS) as model azo dye in dilute aqueous solution. SPADNS contains 4,5-dihydroxynaphthalene-2,7-disulfonic acid part and 4-sulfophenylazo group. To establish the details of the reaction mechanism the reactions of two simpler molecules without 4-sulfophenylazo part were also studied: one of them contained one (in position 4, II), the other two (in positions 4 and 5, III) -OH groups. Hydroxyl radicals react with these molecules with radical addition to the naphthalene-2,7-disulfonic acid part. The adduct hydroxycyclohexadienyl type radical decays in radical-radical reactions, or undergoes a (pH dependent) water elimination to yield naphthoxy radical. The radical decay takes place on the ms timescale. Degradation efficiencies are 0.6-0.8. Hydrated electron in the case of the two simpler molecules reacts with the rings, while in the case of dye with the azo bond. Electron scavenging is followed by protonation, this reaction in the case of II and III yields cyclohexadienyl, while with the dye hydrazo radical. The efficiency of degradation with II and III is 0.2-0.6, while for SPADNS it is close to 1.

  13. Decolorization of azo dye and generation of electricity by microbial fuel cell with laccase-producing white-rot fungus on cathode

    International Nuclear Information System (INIS)

    Lai, Chi-Yung; Wu, Chih-Hung; Meng, Chui-Ting; Lin, Chi-Wen

    2017-01-01

    Highlights: • A laccase-producing fungus on cathode of MFC was used to enhance degradation of azo dye. • Laccase-producing fungal cathodes performed better than laccase-free control cathodes. • A maximum power density of 13.38 mW/m"2 and an >90% decolorization of acid orange 7 were obtained. • Growing a fungal culture with continuous laccase production improved MFC’s electricity generation. - Abstract: Wood-degrading white-rot fungi produce many extracellular enzymes, including the multi-copper oxidative enzyme laccase (EC 1.10.3.2). Laccase uses atmospheric oxygen as the electron acceptor to catalyze a one-electron oxidation reaction of phenolic compounds and therefore has the potential to simultaneously act as a cathode catalyst in a microbial fuel cell (MFC) and degrade azo dye pollutants. In this study, the laccase-producing white-rot fungus Ganoderma lucidum BCRC 36123 was planted on the cathode surface of a single-chamber MFC to degrade the azo dye acid orange 7 (AO7) synergistically with an anaerobic microbial community in the anode chamber. In a batch culture, the fungus used AO7 as the sole carbon source and produced laccase continuously, reaching a maximum activity of 20.3 ± 0.3 U/L on day 19 with a 77% decolorization of the dye (50 mg/L). During MFC operations, AO7 in the anolyte diffused across a layer of polyvinyl alcohol-hydrogel that separated the cathode membrane from the anode chamber, and served as a carbon source to support the growth of, and production of laccase by, the fungal mycelium that was planted on the cathode. In such MFCs, laccase-producing fungal cathodes outperformed laccase-free controls, yielding a maximum open-circuit voltage of 821 mV, a closed-circuit voltage of 394 mV with an external resistance of 1000 Ω, a maximum power density of 13.38 mW/m"2, a maximum current density of 33 mA/m"2, and a >90% decolorization of AO7. This study demonstrates the feasibility of growing a white-rot fungal culture with continuous

  14. Structural, optical and nonlinear optical studies of AZO thin film prepared by SILAR method for electro-optic applications

    Science.gov (United States)

    Edison, D. Joseph; Nirmala, W.; Kumar, K. Deva Arun; Valanarasu, S.; Ganesh, V.; Shkir, Mohd.; AlFaify, S.

    2017-10-01

    Aluminium doped (i.e. 3 at%) zinc oxide (AZO) thin films were prepared by simple successive ionic layer adsorption and reaction (SILAR) method with different dipping cycles. The structural and surface morphology of AZO thin films were studied by using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The optical parameters such as, transmittance, band gap, refractive index, extinction coefficient, dielectric constant and nonlinear optical properties of AZO films were investigated. XRD pattern revealed the formation of hexagonal phase ZnO and the intensity of the film was found to increase with increasing dipping cycle. The crystallite size was found to be in the range of 29-37 nm. Scanning Electron Microscope (SEM) images show the presence of small sized grains, revealing that the smoothest surface was obtained at all the films. The EDAX spectrum of AZO conforms the presence of Zn, O and Al. The optical transmittance in the visible region is high 87% and the band gap value is 3.23 eV. The optical transmittance is decreased with respect to dipping cycles. The room temperature PL studies revealed that the AZO films prepared at (30 cycles) has good film quality with lesser defect density. The third order nonlinear optical parameters were also studied using Z-scan technique to know the applications of deposited films in nonlinear devices. The third order nonlinear susceptibility value is found to be 1.69 × 10-7, 3.34 × 10-8, 1.33 × 10-7and 2.52 × 10-7 for AZO films deposited after 15, 20, 25 and 30 dipping cycles.

  15. Influence of mass transfer and chemical reaction on ozonation of azo dyes

    Energy Technology Data Exchange (ETDEWEB)

    Choi, I.S.; Wiesmann, U. [Dept. of Environmental Engineering, Technical Univ. of Berlin, Berlin (Germany)

    2003-07-01

    Azo dyes can be only mineralised by chemical oxidation. In this paper the oxidation of reactive black 5 (RB 5) and reactive orange 96 (RO 96) with concentrations between 35 and 5700 mgL{sup -1} (RB 5) and between 20 and 2050 mgL{sup -1} (RO 96) is investigated. A lab scale bubble column was used, which was gassed by a mixture of O{sub 2} and O{sub 3}. The oxidation rate was influenced by mass transfer for all dye concentrations used. For lower dye concentrations mass transfer alone was decisive for reaction rate showing an enhancement factor of E {approx} 1. However, in the region of higher dye concentrations, the slope of the decreasing ozone concentration inside the liquid boundary layer increases more and more with increasing dye concentration as a result of a chemical oxidation. Therefore, the enhancement factor depends on the kind and concentration of the azo dyes. For RB 5 as an diazo dye an enhancement factor of E = 9 was observed for 3800 mgL{sup -1}, RO 96 as a mono azo dye with a remarkable higher chemical oxidation rate shows an E = 17 already for 2050 mgL{sup -1}. (orig.)

  16. Electrochemical characterization of azo dye (E)-1-(4-((4-(phenylamino)phenyl)diazenyl)phenyl)ethanone (DPA)

    International Nuclear Information System (INIS)

    Surucu, Ozge; Abaci, Serdar; Seferoğlu, Zeynel

    2016-01-01

    Highlights: • Electrochemical characterization of azo dye DPA was performed. • Pencil graphite electrode was used as working electrode. • Cyclic voltammetry was used to determine the effect of scan rate and pH. • Chronoamperometry was used to determine diffusion constant. • Square wave voltammetry verified the results of cyclic voltammetry. - Abstract: An enormous range of possible dyes are available, especially as the starting molecules are readily available and cheap. As other dye classes become less viable from either an environmental or economic reasons, azo dyes come to the forefront. Therefore, electrochemical characterization of a novel synthesized azo dye (E)-1-(4-((4-(phenylamino) phenyl)diazenyl)phenyl)ethanone was achieved for the first time. Cyclic voltammetry, chronoamperometry and square wave voltammetry techniques were used to investigate the electrochemical behavior and electrocatalytic effect of azo dye (E)-1-(4-((4-(phenylamino) phenyl)diazenyl)phenyl)ethanone at pencil graphite electrode. Cyclic voltammograms were utilized to determine the effect of scan rate and pH on the peak current and peak potential. Chronoamperometry technique was used to determine diffusion constant, D and the type of adsorption isotherms. The kinetics parameters which were the apparent electron transfer rate constant, k s and charge transfer coefficient, α were calculated. Square wave voltammetry was used to verify responses of cyclic voltammetry technique.

  17. Growth of KOH etched AZO nanorods and investigation of its back scattering effect in thin film a-Si solar cell

    Science.gov (United States)

    Sharma, Jayasree Roy; Mitra, Suchismita; Ghosh, Hemanta; Das, Gourab; Bose, Sukanta; Mandal, Sourav; Mukhopadhyay, Sumita; Saha, Hiranmay; Barua, A. K.

    2018-02-01

    In order to increase the stabilized efficiencies of thin film silicon (TFS) solar cells it is necessary to use better light management techniques. Texturization by etching of sputtered aluminum doped zinc oxide (Al:ZnO or AZO) films has opened up a variety of promises to optimize light trapping schemes. RF sputtered AZO film has been etched by potassium hydroxide (KOH). A systematic study of etching conditions such as etchant concentration, etching time, temperature management etc. have been performed in search of improved electrical and optical performances of the films. The change in etching conditions has exhibited a noticeable effect on the structure of AZO films for which the light trapping effect differs. After optimizing the etching conditions, nanorods have been found on the substrate. Hence, nanorods have been developed only by chemical etching, rather than the conventional development method (hydrothermal method, sol-gel method, electrolysis method etc.). The optimized etched substrate has 82% transmittance, moderate haze in the visible range and sheet resistance ∼13 (Ω/□). The developed nanorods (optimized etched substrate) provide better light trapping within the cell as the optical path length has been increased by using the nanorods. This provides an effect on carrier collection as well as the efficiency in a-Si solar cells. Finite difference time domain (FDTD) simulations have been performed to observe the light trapping by AZO nanorods formed on sputtered AZO films. For a p-i-n solar cell developed on AZO nanorods coated with sputtered AZO films, it has been found through simulations that, the incident light is back scattered into the absorbing layer, leading to an increase in photogenerated current and hence higher efficiency. It has been found that, the light that passes through the nanorods is not getting absorbed and maximum amount of light is back scattered towards the solar cell.

  18. Preparation, spectral, X-ray powder diffraction and computational studies and genotoxic properties of new azo-azomethine metal chelates

    Science.gov (United States)

    Bitmez, Şirin; Sayin, Koray; Avar, Bariş; Köse, Muhammet; Kayraldız, Ahmet; Kurtoğlu, Mükerrem

    2014-11-01

    A new tridentate azo-azomethine ligand, N‧-[{2-hydroxy-5-[(4-nitrophenyl)diazenyl]phenyl}methylidene]benzohydrazidemonohydrate, (sbH·H2O) (1), is prepared by condensation of benzohydrazide and 2-hydroxy-5-[(4-nitrophenyl)diazenyl]benzaldehyde (a) with treatment of a solution of diazonium salt of p-nitroaniline and 2-hydroxybenzaldehyde in EtOH. The five coordination compounds, [Co(sb)2]·4H2O (2), [Ni(sb)2]·H2O (3), [Cu(sb)2]·4H2O (4), [Zn(sb)2]·H2O (5) and [Cd(sb)2]·H2O (6) are prepared by reacting the Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) ions with the ligand. The structures of the compounds are elucidated from the elemental analyses data and spectroscopic studies. It is found the ligand acts as a tridentate bending through phenolic and carbonyl oxygens and nitrogen atom of the Cdbnd Nsbnd group similar to the most of salicylaldimines. Comparison of the infrared spectra of the ligand and its metal complexes confirm that azo-Schiff base behaves as a monobasic tridentate ligand towards the central metal ion with an ONO donor sequence. Upon complexation with the ligand, the Cd(II), and Zn(II) ions form monoclinic structures, while Co(II), Cu(II) and Ni(II) ions form orthorhombic structures. Quantum chemical calculations are performed on tautomers and its metal chelates by using DFT/B3LYP method. Most stable tautomer is determined as tautomer (1a). The geometrical parameters of its metal chelates are obtained as theoretically. The NLO properties of tautomer (1a) and its metal complexes are investigated. Finally, the ligand and its metal complexes are assessed for their genotoxicity.

  19. An Improved Method for Removal of Azo Dye Orange II from Textile Effluent Using Albumin as Sorbent

    Directory of Open Access Journals (Sweden)

    Tadashi Ohashi

    2012-11-01

    Full Text Available Azo dyes are generally resistant to biodegradation due to their complex structures. Acid orange II is one of the most widely used dyes in the textile industry. The influence of bovine serum albumin (BSA in different concentrations, pH, and time of contact on Orange II was investigated using kinetics and adsorption-isotherm experiments. The results showed that the maximum colour removed from dye/albumin was 99.50% and that a stable dye-protein complex had been formed at pH 3.5 and in a proportion of 1:3 (v/v, respectively. The synthetic effluent did not show toxicity to the microcrustacean Artemia salina, and showed a CL50 equal to 97 µg/mL to azo dye orange II. Additionally, the methodology was effective in removing the maximum of orange II using BSA by adsorption at pH 3.5 which mainly attracted ions to the azo dye during the adsorption process. This suggests that this form of treatment is economical and easy to use which potentially could lead to bovine serum albumin being used as a sorbent for azo dyes.

  20. Isolation and screening of azo dye decolorizing bacterial isolates from dye-contaminated textile wastewater

    Directory of Open Access Journals (Sweden)

    Shahid Mahmood

    2011-04-01

    Full Text Available Azo dyes are released into wastewater streams without any pretreatment and pollute water and soilenvironments. To prevent contamination of our vulnerable resources, removal of these dye pollutants is of greatimportance. For this purpose, wastewater samples were collected from dye-contaminated sites of Faisalabad. About200 bacterial isolates were isolated through enrichment and then tested for their potential to remove RemazolBlack-B azo dye in liquid medium. Five bacterial isolates capable of degrading Remazol Black-B azo dye efficientlywere screened through experimentation on modified mineral salt medium. Isolate SS1 (collected from wastewater ofSupreme Textile Industry was able to completely remove the Remazol Black-B dye from the liquid medium in 18 h.Further, the isolate showed the best performance at the dye concentration of 100 mg L-1 medium (pH 7 and attemperature 35oC. Similarly, yeast extract proved to be the best carbon source for decolorization purpose. Theresults imply that the isolate SS1 could be used for the removal of the reactive dyes from textile effluents.

  1. Azo group containing compounds: investigation of the decay mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Franzke, D; Kritzenberger, J; Kunz, T [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    We investigated compounds containing the N=N-X (X=S,P,N{sub 3}) group which are potential candidates for microstructuring by photoresist technology or by photoablation. To elucidate the mechanism of thermal decomposition and photolysis we used infrared and UV spectroscopy, respectively, in solution as well as in the solid state. In this article we describe photolytic and thermolytic properties of one representative molecule for each of three substance classes: diazosulfides, azophosphonates and pentazadienes. (author) 4 figs., 4 refs.

  2. The influence of target erosion grade in the optoelectronic properties of AZO coatings growth by magnetron sputtering

    International Nuclear Information System (INIS)

    Zubizarreta, C.; G-Berasategui, E.; Ciarsolo, I.; Barriga, J.; Gaspar, D.; Martins, R.; Fortunato, E.

    2016-01-01

    Graphical abstract: - Highlights: • High quality AZO films deposited at low temperature by RF magnetron sputtering. • Transmittance values of 84% and resistivity of 1.9 × 10"−"3 Ω cm were obtained. • Stable optoelectronic and structural properties during whole life of the target. • RF MS: robust and reliable for the industrial manufacture of AZO frontal electrode. - Abstract: Aluminum-doped zinc oxide (AZO) transparent conductor coating has emerged as promising substitute to tin-doped indium oxide (ITO) as electrode in optoelectronic applications such as photovoltaics or light emitting diodes (LEDs). Besides its high transmission in the visible spectral region and low resistivity, AZO presents a main advantage over other candidates such as graphene, carbon nanotubes or silver nanowires; it can be deposited using the technology industrially implemented to manufacture ITO layers, the magnetron sputtering (MS). This is a productive, reliable and green manufacturing technique. But to guarantee the robustness, reproducibility and reliability of the process there are still some issues to be addressed, such as the effect and control of the target state. In this paper a thorough study of the influence of the target erosion grade in developed coatings has been performed. AZO films have been deposited from a ceramic target by RF MS. Structure, optical transmittance and electrical properties of the produced coatings have been analyzed as function of the target erosion grade. No noticeable differences have been found neither in optoelectronic properties nor in the structure of the coatings, indicating that the RF MS is a stable and consistent process through the whole life of the target.

  3. All-fiber maskless lithographic technology to form microcircular interference pattern on Azo polymer film

    Science.gov (United States)

    Kim, Junki; Jung, Yongmin; Oh, Kyunghwan; Chun, Chaemin; Hong, Jeachul; Kim, Dongyu

    2005-03-01

    We report a novel all-fiber, maskless lithograpic technology to form various concentric grating patterns for micro zone plate on azo polymer film. The proposed technology is based on the interference pattern out of the cleaved end of a coreless silica fiber (CSF)-single mode fiber (SMF) composite. The light guided along SMF expands into the CSF segment to generate various circular interference patterns depending on the length of CSF. Interference patterns are experimentally observed when the CSF length is over a certain length and the finer spacing between the concentric rings are obtained for a longer CSF. By using beam propagation method (BPM) package, we could further investigated the concentric interference patterns in terms of intensity distribution and fringe spacing as a function of CSF length. These intereference patterns are directly projected over azo polymer film and their intensity distrubution formed surface relief grating (SRG) patterns. Compared to photoresist films azo polymer layers produce surface relief grating (SRG), where the actual mass of layer is modulated rather than refractive index. The geometric parameters of the CSF length as well as diameter and the spacing between the cleaved end of a CSF and azo polymer film, were found to play a major role to generate various concentric structures. With the demonstration of the circular SRG patterns, we confirmed that the proposed technique do have an ample potential to fabricate micro fresnel zone plate, that could find applications in lens arrays for optical beam formings as well as compact photonic devices.

  4. Influence of chemical structures on biodegradation of azo dyes by ...

    African Journals Online (AJOL)

    Influence of chemical structures on biodegradation of azo dyes by Pseudomonas sp. NA Oranusi, CJ Ogugbue. Abstract. No Abstract. Global Journal of Environmental Sciences Vol. 5(1) 2006: 19-25. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  5. Azo coupling of 4-nitrophenyldiazonium chloride with aliphatic nucleophiles: an integrated organic synthesis and X-ray crystallography experiment; Acoplamento de cloreto de 4-nitrofenildiazonio com nucleofilos alifaticos: experimento integrado de sintese organica e cristalografia de raios X

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Silvio; Marques, Monique F.; Rocha, Valeria, E-mail: silviodc@ufba.br [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Instituto de Quimica; Lariucci, Carlito; Vencato, Ivo [Universidade Federal de Goiania (UFG), GO (Brazil). Instituto de Fisica

    2013-11-01

    This article describes an undergraduate experiment for the synthesis of p-nitrophenyldiazonium chloride and its coupling with acetylacetone and two enaminones, 4-phenylamino-pent-3-en-2-one and 4-amino-pent-3-en-2-one, in an adaptation of a previously reported synthetic protocol. The azo dyes 4-(E)-phenylamino-3-[(E)-2-(4-nitrophenylazo)]-3-penten-2-one and 4-(E)-amino-3-[(E)-2-(4-nitrophenylazo)]-3-penten-2-one were obtained, and the solid state structure of this latter azo compound was characterized by single crystal X-ray diffraction studies. This two-week integrated laboratory approach involves simple synthetic experiments and microwave chemistry in the organic laboratory plus crystallography analysis, suitable for novice students on undergraduate experimental chemistry courses. (author)

  6. Influence of Ag doping on structural, optical, and photoluminescence properties of nanostructured AZO films by sol–gel technique

    International Nuclear Information System (INIS)

    Khan, Firoz; Baek, Seong-Ho; Kim, Jae Hyun

    2014-01-01

    Graphical abstract: The optical band gap of the Ag–AZO film first decreased to a value of ∼3.31 eV for a 1% Ag/Zn atomic ratio from a value of ∼3.69 for undoped AZO film. For higher values (beyond a 1% Ag/Zn atomic ratio) of Ag doping, the values of Eg started to increase and finally attained a value of ∼3.66 eV for an Ag/Zn 3% atomic ratio. The photoluminescence (PL) studies showed that the relative PL intensity of the Ag–AZO films in blue (IB) and green (IG) regions increased with Ag doping. The PL positions of these peaks were blue shifted with increased Ag content up to an Ag/Zn atomic ratio of 3%. The increase in IB and IG is due to the charge difference between Ag + and Zn 2+ , whereas shifting of the PL positions is due to the size of Ag + and Zn 2+ ions. -- Highlights: • The optical band gap of the Ag–AZO film is tuned with Ag doping. • The PL intensity of the Ag–AZO film in visible region is increased with Ag doping. • The PL positions of these peaks were blue shifted with increased Ag content. • The increase in I B and I G is due to the charge difference between Ag + and Zn 2+ . • The shifting of the PL positions is due to the size of Ag + and Zn 2+ ions. -- Abstract: The effects of Ag doping on the structural, electrical, optical, and photoluminescence properties of sol-gel derived Al rich zinc oxide (Ag–AZO) films are studied. The Al/Zn atomic ratio was constant (∼20%) in all the films, whereas the Ag/Zn atomic ratio varied from 0% to 3%. All the films were highly transparent in the 400–1200 nm wavelength range. The XRD results and surface morphologies of the films confirmed that the grain size increased with Ag doping. The optical band gap (E g ) of the Ag–AZO film first decreased to a value of ∼3.31 eV for a 1% Ag/Zn atomic ratio from a value of ∼3.69 for undoped AZO film. For higher values (beyond a 1% Ag/Zn atomic ratio) of Ag doping, the values of E g started to increase and finally attained a value of ∼3.66 e

  7. Sensitive spectrophotometric determination of aceclofenac following azo dye formation with 4-carboxyl-2,6-dinitrobenzene diazonium ion.

    Science.gov (United States)

    Aderibigbe, Segun A; Adegoke, Olajire A; Idowu, Olakunle S; Olaleye, Sefiu O

    2012-01-01

    The study is a description of a sensitive spectrophotometric determination of aceclofenac following azo dye formation with 4-carboxyl-2,6-dinitrobenzenediazonium ion (CDNBD). Spot test and thin layer chromatography revealed the formation of a new compound distinct from CDNBD and aceclofenac. Optimization studies established a reaction time of 5 min at 30 degrees C after vortex mixing the drug/CDNBD for 10 s. An absorption maximum of 430 nm was selected as analytical wavelength. A linear response was observed over 1.2-4.8 μg/mL of aceclofenac with a correlation coefficient of 0.9983 and the drug combined with CDNBD at stoichiometric ratio of 2 : 1. The method has a limit of detection of 0.403 μg/mL, limit of quantitation of 1.22 μg/mL and is reproducible over a three day assessment. The method gave Sandell's sensitivity of 3.279 ng/cm2. Intra- and inter-day accuracies (in terms of errors) were less than 6% while precisions were of the order of 0.03-1.89% (RSD). The developed spectrophotometric method is of equivalent accuracy (p > 0.05) with British Pharmacopoeia, 2010 potentiometric method. It has the advantages of speed, simplicity, sensitivity and more affordable instrumentation and could found application as a rapid and sensitive analytical method of aceclofenac. It is the first described method by azo dye derivatization for the analysis of aceclofenac in bulk samples and dosage forms.

  8. Synthesis, characterization and dyeing assessment of novel acid azo dyes and mordent acid azo dyes based on 2-hydroxy-4-methoxybenzophenone on wool and silk fabrics

    Directory of Open Access Journals (Sweden)

    DHIRUBHAI J. DESAI

    2010-05-01

    Full Text Available Novel acid mono azo and mordent acid mono azo dyes were synthesised by the coupling of diazonium salt solution of different aromatic amines with 2-hydroxy-4-methoxybenzophenone. The resulting dyes were characterized by spectral techniques, i.e., elemental analysis, IR, 1H-NMR and UV–visible spectroscopy. The dyeing performance of all the dyes was evaluated on wool and silk fabrics. The dyeing of chrome pre-treated wool and silk fabrics showed better hues on mordented fabrics. Dyeing of wool and silk fabrics resulted in pinkish blue to red shades with very good depth and levelness. The dyed fabrics showed excellent to very good light, washing, perspiration, sublimation and rubbing fastness. The results of antibacterial studies of chrome pre-treated fabrics revealed that the toxicity of mordented dyes against Escherichia coli, Staphylococcus aureus, Salmonella typhi, Bacillus subtilis bacteria was fairly good.

  9. The influence of target erosion grade in the optoelectronic properties of AZO coatings growth by magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Zubizarreta, C., E-mail: cristina.zubizarreta@tekniker.es [IK4-Tekniker, Research Centre, c/ Iñaki Goenaga, 5, 20600 Eibar, Guipuzkoa (Spain); G-Berasategui, E.; Ciarsolo, I.; Barriga, J. [IK4-Tekniker, Research Centre, c/ Iñaki Goenaga, 5, 20600 Eibar, Guipuzkoa (Spain); Gaspar, D.; Martins, R.; Fortunato, E. [i3N/CENIMAT, Department of Materials Science, Faculty of Science and Technology, Universidade NOVA de Lisboa (Portugal)

    2016-09-01

    Graphical abstract: - Highlights: • High quality AZO films deposited at low temperature by RF magnetron sputtering. • Transmittance values of 84% and resistivity of 1.9 × 10{sup −3} Ω cm were obtained. • Stable optoelectronic and structural properties during whole life of the target. • RF MS: robust and reliable for the industrial manufacture of AZO frontal electrode. - Abstract: Aluminum-doped zinc oxide (AZO) transparent conductor coating has emerged as promising substitute to tin-doped indium oxide (ITO) as electrode in optoelectronic applications such as photovoltaics or light emitting diodes (LEDs). Besides its high transmission in the visible spectral region and low resistivity, AZO presents a main advantage over other candidates such as graphene, carbon nanotubes or silver nanowires; it can be deposited using the technology industrially implemented to manufacture ITO layers, the magnetron sputtering (MS). This is a productive, reliable and green manufacturing technique. But to guarantee the robustness, reproducibility and reliability of the process there are still some issues to be addressed, such as the effect and control of the target state. In this paper a thorough study of the influence of the target erosion grade in developed coatings has been performed. AZO films have been deposited from a ceramic target by RF MS. Structure, optical transmittance and electrical properties of the produced coatings have been analyzed as function of the target erosion grade. No noticeable differences have been found neither in optoelectronic properties nor in the structure of the coatings, indicating that the RF MS is a stable and consistent process through the whole life of the target.

  10. Interfacial electronic structure of C{sub 60}/ZnPc/AZO on photoemission spectroscopy for organic photovoltaic applications

    Energy Technology Data Exchange (ETDEWEB)

    Heo, Nari; Kim, Yoonsu; Jung, Yunwoo; Cheon, Suyoung; Cho, Soohaeng [Department of Physics, Yonsei University, Wonju 220-710 (Korea, Republic of); Cho, Sang Wan, E-mail: dio8027@yonsei.ac.kr [Department of Physics, Yonsei University, Wonju 220-710 (Korea, Republic of); Park, Soohyung; Yi, Yeonjin [Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749 (Korea, Republic of); Smith, Kevin E. [Department of Physics, Boston University, 590 Commonwealth Ave, Boston, MA 02215 (United States)

    2016-10-20

    Highlights: • The electronic structure of a bilayer on AZO has been evaluated by UPS and XPS. • The energy difference between the ZnPc HOMO and the C{sub 60} LUMO was determined. • The result is discussed in terms of the work function and resistivity of each TCO. - Abstract: The interfacial electronic structure of a bilayer of fullerene (C{sub 60}) and zinc phthalocyanine (ZnPc) grown on aluminum-doped zinc oxide (AZO) substrates has been evaluated by X-ray and ultraviolet photoemission spectroscopy. The energy difference between the highest occupied molecular orbital (HOMO) level of the ZnPc layer and the lowest unoccupied molecular orbital (LUMO) level of the C{sub 60} layer (E{sup D}{sub HOMO} − E{sup A}{sub LUMO}) was determined and compared to that grown on an indium tin oxide (ITO) substrate. The E{sup D}{sub HOMO} − E{sup A}{sub LUMO} value of the heterojunction on AZO was 1.4 eV, while that on ITO was 1.1 eV. This result is discussed in terms of the differences of the work function and resistivity of each transparent conductive oxide. We also obtained complete energy level diagrams of C{sub 60}/ZnPc/AZO and C{sub 60}/ZnPc/ITO.

  11. Influence of a Crosslinker Containing an Azo Group on the Actuation Properties of a Photoactuating LCE System

    Directory of Open Access Journals (Sweden)

    Lukas B. Braun

    2016-12-01

    Full Text Available Photoactuating liquid crystalline elastomers (LCE are promising candidates for an application as artificial muscles in microdevices. In this work, we demonstrate that by optimizing (1 the illumination conditions and (2 the mixture of azo monomer and azo crosslinker, thick films of an all-azo LCE can be prepared, which show a strong length change without bending during photoactuation. This becomes possible by working with white light (about 440 nm, whose absorption is low, leading to a large penetration depth. By adding an azo crosslinker to a previously prepared system, several improvements of the actuation properties—like a stronger photoactuation at lower operational temperatures—could be achieved. In addition, films of different crosslinker concentrations and thicknesses were produced by photopolymerization at varying temperatures within a magnetic field, and their thermo- and photoresponsive behavior was investigated. An extraordinarily strong maximal thermal actuation of 46% and—by exposure to white light at 70 °C—a photoresponsive change in length of up to 40% in just about 13 s could be obtained. Even densely crosslinked samples were still able to photoactuate remarkably. Isothermal back-deformation could either be achieved by irradiation with red light (7 min or by keeping the film in the dark (13 min.

  12. High-energy, stable and recycled molecular solar thermal storage materials using AZO/graphene hybrids by optimizing hydrogen bonds.

    Science.gov (United States)

    Luo, Wen; Feng, Yiyu; Qin, Chengqun; Li, Man; Li, Shipei; Cao, Chen; Long, Peng; Liu, Enzuo; Hu, Wenping; Yoshino, Katsumi; Feng, Wei

    2015-10-21

    An important method for establishing a high-energy, stable and recycled molecular solar heat system is by designing and preparing novel photo-isomerizable molecules with a high enthalpy and a long thermal life by controlling molecular interactions. A meta- and ortho-bis-substituted azobenzene chromophore (AZO) is covalently grafted onto reduced graphene oxide (RGO) for solar thermal storage materials. High grafting degree and close-packed molecules enable intermolecular hydrogen bonds (H-bonds) for both trans-(E) and cis-(Z) isomers of AZO on the surface of nanosheets, resulting in a dramatic increase in enthalpy and lifetime. The metastable Z-form of AZO on RGO is thermally stabilized with a half-life of 52 days by steric hindrance and intermolecular H-bonds calculated using density functional theory (DFT). The AZO-RGO fuel shows a high storage capacity of 138 Wh kg(-1) by optimizing intermolecular H-bonds with a good cycling stability for 50 cycles induced by visible light at 520 nm. Our work opens up a new method for making advanced molecular solar thermal storage materials by tuning molecular interactions on a nano-template.

  13. ZnO nanorods/AZO photoanode for perovskite solar cells fabricated in ambient air

    Science.gov (United States)

    La Ferrara, Vera; De Maria, Antonella; Rametta, Gabriella; Della Noce, Marco; Vittoria Mercaldo, Lucia; Borriello, Carmela; Bruno, Annalisa; Delli Veneri, Paola

    2017-08-01

    ZnO nanorods are a good candidate for replacing standard photoanodes, such as TiO2, in perovskite solar cells and in principle superseding the high performances already obtained. This is possible because ZnO nanorods have a fast electron transport rate due to their large surface area. An array of ZnO nanorods is grown by chemical bath deposition starting from Al-doped ZnO (AZO) used both as a seed layer and as an efficient transparent anode in the visible spectral range. In particular, in this work we fabricate methylammonium lead iodide (CH3NH3PbI3) perovskite solar cells using glass/AZO/ZnO nanorods/perovskite/Spiro-OMeTAD/Au as the architecture. The growth of ZnO nanorods has been optimized by varying the precursor concentrations, growth time and solution temperature. All the fabrication process and photovoltaic characterizations have been carried out in ambient air and the devices have not been encapsulated. Power conversion efficiency as high as 7.0% has been obtained with a good stability over 20 d. This is the highest reported value to the best of our knowledge and it is a promising result for the development of perovskite solar cells based on ZnO nanorods and AZO.

  14. Aerobic decolourization of two reactive azo dyes under varying ...

    African Journals Online (AJOL)

    Bacillus cereus isolated from dye industrial waste, that is, effluent and soil samples was screened for its ability to decolourize two reactive azo dye – cibacron black PSG and cibacron red P4B under aerobic conditions at pH 7 and incubated at 35°C over a five day period. Different carbon and nitrogen sources were used for ...

  15. Reductive decolourisation of azo dyes by mesophilic and thermophilic methanogenic consortia

    NARCIS (Netherlands)

    Cervantes, F.J.; Santos, dos A.B.; Madrid, de M.P.; Stams, A.J.M.; Lier, van J.B.

    2005-01-01

    The contribution of acidogenic bacteria and methanogenic archaea on the reductive decolourisation of azo dyes was assessed in anaerobic granular sludge. Acidogenic bacteria appeared to play an important role in the decolourising processes when glucose was provided as an electron donor; whereas

  16. Efeitos dos parâmetros operacionais na fotodegradação do azo corante direct red 23 na interface dióxido de titânio/água Effects of operational parameters on the photodegradation of direct red 23 azo dye at the titanium dioxide/water interface

    Directory of Open Access Journals (Sweden)

    Débora Nobile Clausen

    2007-01-01

    Full Text Available The decolorization and degradation of direct red 23 azo dye have been investigated in aqueous suspension of titanium dioxide under artificial irradiation. The effects of some operational parameters such as azo dye concentration, catalyst loading, and solution pH were investigated at 30.0 ºC and optimized values were obtained. The first-order kinetic model was used to discuss the results. The UV-Vis spectra changes showed that the azo dye sample, collected after 6 h irradiation, was 98% decolorized while the residual total carbon was 97.9% degraded, indicating simultaneous photodecolorization and degradation.

  17. Aerobic Biodegradation Characteristic of Different Water-Soluble Azo Dyes

    Directory of Open Access Journals (Sweden)

    Shixiong Sheng

    2017-12-01

    Full Text Available This study investigated the biodegradation performance and characteristics of Sudan I and Acid Orange 7 (AO7 to improve the biological dye removal efficiency in wastewater and optimize the treatment process. The dyes with different water-solubility and similar molecular structure were biologically treated under aerobic condition in parallel continuous-flow mixed stirred reactors. The biophase analysis using microscopic examination suggested that the removal process of the two azo dyes is different. Removal of Sudan I was through biosorption, since it easily assembled and adsorbed on the surface of zoogloea due to its insolubility, while AO7 was biodegraded incompletely and bioconverted, the AO7 molecule was decomposed to benzene series and inorganic ions, since it could reach the interior area of zoogloea due to the low oxidation-reduction potential conditions and corresponding anaerobic microorganisms. The transformation of NH3-N, SO42− together with the presence of tryptophan-like components confirm that AO7 can be decomposed to non-toxic products in an aerobic bioreactor. This study provides a theoretical basis for the use of biosorption or biodegradation mechanisms for the treatment of different azo dyes in wastewater.

  18. Self-assembled graphene/azo polyelectrolyte multilayer film and its application in electrochemical energy storage device.

    Science.gov (United States)

    Wang, Dongrui; Wang, Xiaogong

    2011-03-01

    Graphene/azo polyelectrolyte multilayer films were fabricated through electrostatic layer-by-layer (LbL) self-assembly, and their performance as electrochemical capacitor electrode was investigated. Cationic azo polyelectrolyte (QP4VP-co-PCN) was synthesized through radical polymerization, postpolymerization azo coupling reaction, and quaternization. Negatively charged graphene nanosheets were prepared by a chemically modified method. The LbL films were obtained by alternately dipping a piece of the pretreated substrates in the QP4VP-co-PCN and nanosheet solutions. The processes were repeated until the films with required numbers of bilayers were obtained. The self-assembly and multilayer surface morphology were characterized by UV-vis spectroscopy, AFM, SEM, and TEM. The performance of the LbL films as electrochemical capacitor electrode was estimated using cyclic voltammetry. Results show that the graphene nanosheets are densely packed in the multilayers and form random graphene network. The azo polyelectrolyte cohesively interacts with the nanosheets in the multilayer structure, which prevents agglomeration of graphene nanosheets. The sheet resistance of the LbL films decreases with the increase of the layer numbers and reaches the stationary value of 1.0 × 10(6) Ω/square for the film with 15 bilayers. At a scanning rate of 50 mV/s, the LbL film with 9 bilayers shows a gravimetric specific capacitance of 49 F/g in 1.0 M Na(2)SO(4) solution. The LbL films developed in this work could be a promising type of the electrode materials for electric energy storage devices.

  19. Phosphorus-containing azo compounds as analytical reagents for beryllium

    International Nuclear Information System (INIS)

    Lisenko, N.F.; Dolzhnikova, E.N.; Petrova, G.S.; Tsvetkov, E.N.; Vsesoyuznyj Nauchno-Issledovatel'skij Inst. Khimicheskikh Reaktivov i Osobo Chistykh Veshchestv, Moscow; AN SSSR, Moscow. Inst. Ehlementoorganicheskikh Soedinenij)

    1979-01-01

    The interaction of beryllium with six new azocompounds based on chromotropic or R-acids and o-aminophenyl-phenylphosphonic acids is studied. A sharp difference in the detection limit for beryllium by the two groups of compounds is found. Azoderivatives based on chromotropic acid are promising agent for beryllium due to sufficiently high selectivity. The introduction of the methyl-group into the o-position of the phosphorus-containing group improves the analytical properties of agents. Techniques are developed for the determination of beryllium in bronze, sewage water and in an artificial mixture using a sodium salt of 1.8-dioxi-2 [2' - (oxi- (o-methylphenyl)-phosphenyl)-phenilazo]-naphtalene-3.6-disulfoacid

  20. DECOLORIZATION OF AZO DYES AND MINERALIZATION OF PHENANTHRENE BY TRAMETES SP. AS03 ISOLATED FROM INDONESIAN MANGROVE FOREST

    Directory of Open Access Journals (Sweden)

    Asep Hidayat

    2014-04-01

    Full Text Available Textile industry contributes the most disposals of synthetic dyes, and about 40% of textile dyes has been generating high amount of colored wastewater. Polycyclic aromatic hydrocarbons (PAHs, such as phenanthrene, is a group of organic compounds, that structurally comprised of two or more benzene rings, which persist in air, water, and soil. The organic pollutants of dyes and PAHs have adversely effects the food chain and are potentially toxic, mutagenic, and carcinogenic to the environment. The objective of this research is to screen and investigate the potential fungus from mangrove forest to degrade azo dyes and phenanthrene.  In this study, fungi were collected from mangrove forest in Riau Province – Sumatra – Indonesia. Previously, Trametes sp. AS03 is one of the fungi isolated from mangrove forest in Riau Province, that was able to decolorize Remazol Brilliant Blue R (RBBR. The capability of Trametes sp. AS03 to decolorize four azo dyes, Remazol B. Violet (V5, Levafix Orange E3GA (Or64, Levafix B. Red E-6BA (R159, and Sumifix S. Scarlet 2GF (R222, were further evaluated. The result shows that Trametes sp. AS03 decolorized 91, 60, 48, and 31 of V5, R222, R159, and Or64, respectively. By showing its capability to decolorize some of the dyes, Trametes sp. AS03 was used to break down phenanthrene. AS03 degraded more than 70% of phenanthrene in 15 days.

  1. AZO Thin Films by Sol-Gel Process for Integrated Optics

    Directory of Open Access Journals (Sweden)

    Azzedine Boudrioua

    2013-07-01

    Full Text Available Undoped and aluminum-doped zinc oxide (AZO thin films are prepared by the sol-gel process. Zinc acetate dihydrate, ethanol, and monoethanolamine are used as precursor, solvent, and stabilizer, respectively. In the case of AZO, aluminum nitrate nonahydrate is added to the precursor solution with an atomic percentage equal to 1 and 2 at.% Al. The multi thin layers are deposited by spin-coating onto glass substrates, and are transformed into ZnO upon annealing at 550 °C. Films display a strong preferential orientation, with high values for the Texture Coefficients (TC of the (002 direction (TC(002 ≈ 3. The structural, morphological, and optical properties of the thin films as a function of aluminum content have been investigated using X-Ray Diffraction (XRD, Atomic Force Microscopy (AFM, and Scanning Electronic Microscopy (SEM. Waveguiding properties of the thin films have been also studied using m-lines spectroscopy. The results indicate that the films are monomodes at 632.8 nm with optical propagation optical losses estimated around 1.6 decibel per cm (dB/cm.

  2. Adsorption of aromatic compounds from the biodegradation of azo dyes on activated carbon

    Science.gov (United States)

    Faria, P. C. C.; Órfão, J. J. M.; Figueiredo, J. L.; Pereira, M. F. R.

    2008-03-01

    The adsorption of three selected aromatic compounds (aniline, sulfanilic acid and benzenesulfonic acid) on activated carbons with different surface chemical properties was investigated at different solution pH. A fairly basic commercial activated carbon was modified by means of chemical treatment with HNO 3, yielding an acid activated carbon. The textural properties of this sample were not significantly changed after the oxidation treatment. Equilibrium isotherms of the selected compounds on the mentioned samples were obtained and the results were discussed in relation to their surface chemistry. The influence of electrostatic and dispersive interactions involved in the uptake of the compounds studied was evaluated. The Freundlich model was used to fit the experimental data. Higher uptakes are attained when the compounds are present in their molecular form. In general, adsorption was disfavoured by the introduction of oxygen-containing groups on the surface of the activated carbon.

  3. Simultaneous detection and removal of radioisotopes with modified alginate beads containing an azo-based probe using RGB coordinates

    International Nuclear Information System (INIS)

    Jo, Ara; Jang, Geunseok; Namgung, Ho; Kim, Choongho; Kim, Daigeun; Kim, Yujun; Kim, Jongho; Lee, Taek Seung

    2015-01-01

    Highlights: • Modified alginate with azo-based probe (ABO) was synthesized by a reaction between sodium alginate and azo-based probe (BO2). • BO2 was found to be a good probe molecule for radioisotopes using colorimetric analysis. • Detection of Co 2+ and Sr 2+ was mainly carried out via interaction between BO2 and metal ions. • Simultaneous removal of radioisotopes was assessed by the ion-exchange of carboxylate groups in sodium alginate. • The alginate beads with dual functions of detection and removal of metal ions are successfully accomplished. - Abstract: We prepared alginate beads that were modified with an azo-based probe molecule to monitor simultaneously the removal (by alginate) and probing (by the azo-probe molecule) of radioisotopes such as cobalt, strontium, and cesium ions. As an azo-probe molecule, Basic Orange 2 (BO2) was immobilized to the alginate bead. The BO2 in aqueous solution exhibited a slight red shift in absorption with a change in color from orange to dark orange upon addition of cobalt and strontium ions. In contrast, the color of BO2 did not change upon exposure to cesium ions. Thus, the covalently embedded BO2 in alginate beads could adsorb cobalt and strontium ions resulting in recognizable color change of the beads, which was induced by the formation of a complex between BO2 and metal ions. The color changes of the beads in the presence of metal ions were determined quantitatively using RGB color coordinate values. In addition to effectively removing metal ions, the colorimetric coordinate method provides a convenient and simple sensing technique for naked-eye metal ion detection.

  4. Picric acid sensing and capture by a sterically encumbered azo ...

    Indian Academy of Sciences (India)

    Dhananjayan Kaleeswaran

    2018-01-25

    Jan 25, 2018 ... above observations in mind, here we demonstrate how the presence of bulky ... can affect the azo-polymerization process, PNACs sens- ing ability and CO2 uptake ... on a JEOL model JSM-7600F electron microscope, operat- ing at the .... i PrTAPB is flanked by two isopropyl groups and hence results in a ...

  5. Transport behaviors of anionic azo dyes at interface between surfactant-modified flax shives and aqueous solution: Synchrotron infrared and adsorption studies

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wenxia [MOE Key Laboratory of Resources and Environmental Systems Optimization, Institute for Energy, Environment and Sustainability Research, UR-NCEPU, North China Electric Power University, Beijing, 102206 (China); Huang, Guohe, E-mail: huang@iseis.org [MOE Key Laboratory of Resources and Environmental Systems Optimization, Institute for Energy, Environment and Sustainability Research, UR-NCEPU, North China Electric Power University, Beijing, 102206 (China); An, Chunjiang; Xin, Xiaying [Institute for Energy, Environment and Sustainable Communities, University of Regina, Regina, S4S 0A2 (Canada); Zhang, Yan [MOE Key Laboratory of Resources and Environmental Systems Optimization, Institute for Energy, Environment and Sustainability Research, UR-NCEPU, North China Electric Power University, Beijing, 102206 (China); Liu, Xia [Canadian Light Source, Saskatoon, S7N 2V3 (Canada)

    2017-05-31

    Highlights: • Surfactant modified flax shives for removing anionic azo dyes. • The equilibrium and kinetic studies for the adsorption of anionic azo dyes. • The migration patterns of dye pollutants at flax shive-water interface. • New insights from synchrotron infrared-assisted characterization. • Potential as biomass adsorbent for the removal of dyes from wastewater. - Abstract: From the viewpoint of sustainability, biomass adsorbent has a high potential in pollution control and there is an emerging interest to investigate the behaviors of pollutants at the interface between biomass adsorbent and solution. This study investigated the performance of cetyltrimethylammonium bromide surfactant-modified flax shives (MFS) for removal of anionic azo dyes from aqueous solution. The equilibrium and kinetic analysis for the adsorption of Acid Orange 7 (AO-7), Acid Red 18 (AR-18) and Acid Black 1 (AB-1) on MFS were conducted. The surface of MFS was characterized by synchrotron infrared and SEM analysis. The absorbed amount of three anionic azo dyes varied with the change of adsorbent dosage, pH and ionic strength. The adsorption isotherm data well fit to the Langmuir model. The adsorption process followed the pseudo-second-order kinetics and the liquid film diffusion models. Thermodynamic studies indicated that the adsorption of three anionic azo dyes was spontaneous. The adsorption of AR-18 and AB-1 onto MFS was endothermic while the adsorption of AO-7 was exothermic. The results can help better understand the behaviors of organic pollutants at biomass adsorbent-water interface. They also present the potential of using MFS as a suitable adsorbent for the removal of anionic azo dyes from wastewater.

  6. Transport behaviors of anionic azo dyes at interface between surfactant-modified flax shives and aqueous solution: Synchrotron infrared and adsorption studies

    International Nuclear Information System (INIS)

    Wang, Wenxia; Huang, Guohe; An, Chunjiang; Xin, Xiaying; Zhang, Yan; Liu, Xia

    2017-01-01

    Highlights: • Surfactant modified flax shives for removing anionic azo dyes. • The equilibrium and kinetic studies for the adsorption of anionic azo dyes. • The migration patterns of dye pollutants at flax shive-water interface. • New insights from synchrotron infrared-assisted characterization. • Potential as biomass adsorbent for the removal of dyes from wastewater. - Abstract: From the viewpoint of sustainability, biomass adsorbent has a high potential in pollution control and there is an emerging interest to investigate the behaviors of pollutants at the interface between biomass adsorbent and solution. This study investigated the performance of cetyltrimethylammonium bromide surfactant-modified flax shives (MFS) for removal of anionic azo dyes from aqueous solution. The equilibrium and kinetic analysis for the adsorption of Acid Orange 7 (AO-7), Acid Red 18 (AR-18) and Acid Black 1 (AB-1) on MFS were conducted. The surface of MFS was characterized by synchrotron infrared and SEM analysis. The absorbed amount of three anionic azo dyes varied with the change of adsorbent dosage, pH and ionic strength. The adsorption isotherm data well fit to the Langmuir model. The adsorption process followed the pseudo-second-order kinetics and the liquid film diffusion models. Thermodynamic studies indicated that the adsorption of three anionic azo dyes was spontaneous. The adsorption of AR-18 and AB-1 onto MFS was endothermic while the adsorption of AO-7 was exothermic. The results can help better understand the behaviors of organic pollutants at biomass adsorbent-water interface. They also present the potential of using MFS as a suitable adsorbent for the removal of anionic azo dyes from wastewater.

  7. Decolorization of two azo dyes using marine Lysobacter sp. T312D9

    Directory of Open Access Journals (Sweden)

    Khouloud M. I. B.

    2013-01-01

    Full Text Available Aims: Novel azo dye-degrading bacterium T312D9 strain has been isolated from Abou Quir Gulf, Alexandria, Egypt. Methodology and Results: The identification of the isolate by 16S rRNA gene sequencing revealed to be Lysobacter sp. This marine ecofriendly isolate was exploited for its ability to degrade two synthetic azo dyes considered as detrimental pollutants from industrial effluents: congo red and methyl red. Using different dye concentrations showed the highest metabolic activity for complete degradation obtained from 100 to 500 mg/L within 30 h under static condition, also, sustaining higher dye loading of 1 g/L was carried out. The significant induction of enzymes NADH - 2,6-dichloroindophenol (NADH-DCIP reductase and tyrosinaseindicated their prominent role in dye degradation. The biodegradation of two azo dyes were analyzed by gas chromatographicmass spectrum analysis (GC-MS and Fourier transform infrared spectroscopy (FTIR before and after treatment. Toxicity study revealed the much less toxic nature of the metabolites produced after complete decolorization. Conclusion, significance and impact of study: Lysobacter sp T312D9 represent an inexpensive and promising marine bacteria for removal of both methyl and congo red. High sustainable metabolic activity for biodegradation under static condition. NADHDCIPreductase and tyrosinase were significantly induced during biodegradation of dyes. The obtained metabolites revealed to beless toxic in nature which offers a practical biological treatment.

  8. Spectroscopic and theoretical study of the "azo"-dye E124 in condensate phase: evidence of a dominant hydrazo form.

    Science.gov (United States)

    Almeida, Mariana R; Stephani, Rodrigo; Dos Santos, Hélio F; de Oliveira, Luiz Fernando C

    2010-01-14

    Spectroscopic techniques, including Raman, IR, UV/vis, and NMR were used to characterize the samples of the azo dye Ponceau 4R (also known as E124, New Coccine; Cochineal Red; C.I. no. 16255; Food Red No. 102), which is 1,3-naphthalenedisulfonic acid, 7-hydroxy-8-[(4-sulfo-1-naphthalenyl) azo] trisodium salt in aqueous solution and solid state. In addition, first principle calculations were carried out for the azo (OH) and hydrazo (NH) tautomers in order to assist in the assignment of the experimental data. The two intense bands observed in the UV/vis spectrum, centered at 332 and 507 nm, can be compared to the calculated values at 296 and 474 nm for azo and 315 and 500 nm for hydrazo isomer, with the latter in closer agreement to the experiment. The Raman spectrum is quite sensitive to tautomeric equilibrium; in solid state and aqueous solution, three bands were observed around 1574, 1515, and 1364 cm(-1), assigned to mixed modes including deltaNH + betaCH + nuCC, deltaNH + nuC horizontal lineO + nuC horizontal lineN + betaCH and nuCC vibrations, respectively. These assignments are predicted only for the NH species centered at 1606, 1554, and 1375 cm(-1). The calculated Raman spectrum for the azo (OH) tautomer showed two strong bands at 1468 (nuN = N + deltaOH) and 1324 cm(-1) (nuCC + nuC-N), which were not obtained experimentally. The (13)C NMR spectrum showed a very characteristic peak at 192 ppm assigned to the carbon bound to oxygen in the naphthol ring; the predicted values were 165 ppm for OH and 187 for NH isomer, supporting once again the predominance of NH species in solution. Therefore, all of the experimental and theoretical results strongly suggest the food dye Ponceau 4R or E124 has a major contribution of the hydrazo structure instead of the azo form as the most abundant in condensate phase.

  9. 40 CFR Appendix B to Part 414 - Complexed Metal-Bearing Waste Streams

    Science.gov (United States)

    2010-07-01

    ... 414—Complexed Metal-Bearing Waste Streams Chromium Azo dye intermediates/Substituted diazonium salts + coupling compounds Vat dyes Acid dyes Azo dyes, metallized/Azo dye + metal acetate Acid dyes, Azo...

  10. Abatement of Azo Dye from Wastewater Using Bimetal-Chitosan

    Directory of Open Access Journals (Sweden)

    Ghorban Asgari

    2013-01-01

    Full Text Available We introduce a new adsorbent, bimetallic chitosan particle (BCP that is successfully synthesized and applied to remove the orange II dye from wastewater. The effects of pH, BCP quantity, and contact time are initially verified on the basis of the percentage of orange II removed from the wastewater. Experimental data reveal that the Cu/Mg bimetal and chitosan have a synergistic effect on the adsorption process of the adsorbate, where the dye adsorption by Cu/Mg bimetal, chitosan alone, and bimetal-chitosan is 10, 49, and 99.5%, respectively. The time required for the complete decolorization of orange II by 1 mg/L of BCP is 10 min. The Langmuir model is the best fit for the experimental data, which attains a maximum adsorption capacity of 384.6 mg/g. The consideration of the kinetic behavior indicates that the adsorption of orange II onto the BCP fits best with the pseudo-second-order and Elovich models. Further, the simulated azo dye wastewater can be effectively treated using a relatively low quantity of the adsorbent, 1 mg/L, within a short reaction time of 20 min. Overall, the use of BCP can be considered a promising method for eliminating the azo dye from wastewater effectively.

  11. Separation of thorium, uranium and rare-earth elements with 2-[(2-arsenophenyl)-azo]-1,8-dihydroxy-7-[(2,4,6-tribromophenyl)azo]-naphthalene-3,6-disulfonic acid by capillary electrophoresis

    International Nuclear Information System (INIS)

    Liu, Bi-feng; Liu, Liang-bin; Cheng, Jie-ke

    1998-01-01

    The separation of thorium, uranium and rare-earth elements (RE) as their 2-[(2-arsenophenyl)-azo]-1,8-dihydroxy-7-[(2,4,6-tribromophenyl)azo]-naphthalene-3,6-disulfonic acid complexes by capillary electrophoresis with direct UV-Vis detection is presented in this paper. The influences of pH value and concentration of electrolyte, voltage and surfactant on separation were investigated and optimized. Under the selected conditions (30mM NaAc-HCl buffer containing 0.5mM cetyltrimethylammonium bromide and 0.2mM chelating reagent, pH 4.30, 12KV, 635nm as detection wavelength), the coexisted ions were separated within 4min, and limits of detection of 37, 39, 199μgl -1 for RE, thorium, uranium with a linear dynamic range of over 2 orders of magnitude were achieved, respectively

  12. Evaluation of the structural, optical and electrical properties of AZO thin films prepared by chemical bath deposition for optoelectronics

    Science.gov (United States)

    Kumar, K. Deva Arun; Valanarasu, S.; Rosario, S. Rex; Ganesh, V.; Shkir, Mohd.; Sreelatha, C. J.; AlFaify, S.

    2018-04-01

    Aluminum doped zinc oxide (AZO) thin films for electrode applications were deposited on glass substrates using chemical bath deposition (CBD) method. The influence of deposition time on the structural, morphological, and opto-electrical properties of AZO films were investigated. Structural studies confirmed that all the deposited films were hexagonal wurtzite structure with polycrystalline nature and exhibited (002) preferential orientation. There is no other impurity phases were detected for different deposition time. Surface morphological images shows the spherically shaped grains are uniformly arranged on to the entire film surface. The EDS spectrum confirms the presence of Zn, O and Al elements in deposited AZO film. The observed optical transmittance is high (87%) in the visible region, and the calculated band gap value is 3.27 eV. In this study, the transmittance value is decreased with increasing deposition time. The room temperature PL spectrum exposed that AZO thin film deposited at (60 min) has good optical quality with less defect density. The minimum electrical resistivity and maximum carrier concentration values were observed as 8.53 × 10-3(Ω cm) and 3.53 × 1018 cm-3 for 60 min deposited film, respectively. The obtained figure of merit (ϕ) value 3.05 × 10-3(Ω/sq)- 1 is suggested for an optoelectronic device.

  13. Synthesis, characterization and biological profile of metal and azo-metal complexes of embelin

    Directory of Open Access Journals (Sweden)

    R. Aravindhan

    2014-12-01

    Full Text Available The present study emphasizes synthesis and bioprofiling of embelin, embelin-metal (EM and embelin-azo-metal (EAM complexes in detail. EM complexes were prepared using pure embelin and d-block transition elements, namely Mn, Fe, Co, Ni, Cu, and Zn. Similarly, EAM complexes were synthesized using phenyl azo-embelin with the said transition metals. Embelin, EM, and EAM complexes were subjected to ultra violet visible spectroscopy, Fourier transform infrared spectroscopy, nuclear magnetic resonance, electrospray ionization mass spectrometry, thermogravimetric analysis, carbon hydrogen nitrogen sulfur analysis. With regard to bioprofiling, the test complexes were studied for the antioxidant and antimicrobial activities. Results revealed that the prepared EM and EAM complexes form octahedral complexes with embelin with the yield in the range of 45–75%. All the instrumental analyses authenticate the interaction of metals with bidentate embelin through its enolic and quinonic oxygen atoms as [M(Emb2(H2O2]H2O and [M(Emb-Azo2(H2O2]. The antioxidant profile studies suggested that upon complexation with metals, the free radical scavenging activity of embelin reduced significantly. But, with regard to antimicrobial activity, cobalt and nickel embelin complexes displayed>80% growth inhibition in comparison with embelin alone. The hemolytic activity studies suggested that both embelin and the metal complexes are non-hemolytic. The reason for the reduction in antioxidant and an increase in antimicrobial activities were discussed in detail.

  14. Photocatalytic oxidation of a reactive azo dye and evaluation of the ...

    African Journals Online (AJOL)

    The purpose of this study was to investigate the photocatalytic oxidation of a reactive azo dye and determine the improvement in the biodegradability when photocatalytic oxidation was used as a pretreatment step prior to biological treatment. The results obtained from the experiments adding H2O2/TiO2 show that the ...

  15. Decolorization of Remazol Black-B azo dye in soil by fungi

    Directory of Open Access Journals (Sweden)

    Azeem Khalid*, Sadia Batool, Muhammad Tariq Siddique, Zilli Huma Nazli, Riffat Bibi, Shahid Mahmood and Muhammad Arshad

    2011-04-01

    Full Text Available Textile industry is known to release huge amount of dyes in the water and soil environments during the dyeingprocess. The present study was planned with the aim to remove azo dye toxicants from the soil using fungal strains.The fungi were isolated by using Remazol Black-B azo dye as the sole source of C and N. Ten isolates were initiallyselected for testing their decolorization potential in the liquid medium. Three most effective strains were used tostudy the decolorization of Remazol Black-B in soil. The strain S4 was found to be very effective in removing thedye Remazol Black-B from liquid medium as well as in soil suspension. More than 95% decolorization by the strainS4 was observed in soil under optimal incubation conditions. Overall, the dye decolorization was maximum at 100mg dye kg-1 soil at pH 7-8 under static conditions. Glucose, moisture and aeration also affected the decolorizationefficacy of the fungal strain in soil. This study implies that fungi could be used for bioremediation of dyecontaminatedsites.

  16. Perspectives d'amélioration du conseil prévisionnel de fertilisation azotée à la parcelle en Wallonie par l'utilisation du logiciel AzoFert®

    Directory of Open Access Journals (Sweden)

    Abras, M.

    2013-01-01

    Full Text Available Prospects for improving the provisional nitrogen fertilization recommendation at field scale in Wallonia using the AzoFert® software. The French software AzoFert® for nitrogen fertilization recommendation is currently under adaptation and validation for soil and climatic conditions in Wallonia by the CRA-W within the INTERREG IV project "SUN" (Sustainable Use of Nitrogen. This adaptation has raised the need for a change of values in the parameter tables and catalogs relating to meadow residues, crop residues, catch crop practices, crops, organic amendments and soil type. Data from 25 trials of increasing nitrogen fertilizer rates conducted by CRA-W between 1996 and 2011 in cereal, potato and vegetable crops located on loam and sandy loam soil were used to validate the AzoFert® software adapted for Wallonia. The difference between nitrogen rates recommended on the one hand by AzoFert® or Azobil® (software currently used in the reference lab for Nitrate [Requasud] at CRA-W and the optimal dose of nitrogen fertilizer assessed in each trial on the other hand shows that, in most cases, AzoFert® gives a recommendation closer to the optimum than Azobil®. The nitrogen uptake measured in the plants collected in the unfertilized control plot also shows a higher correlation with nitrogen supply from the soil assessed by AzoFert® than for plants assessed by Azobil®. The more accurate estimate of the mineralization of organic sources, probably linked to the dynamic soil nitrogen supply approach integrated into AzoFert®, may explain the gain in the greater accuracy of the AzoFert® recommendation in comparison with that of Azobil®.

  17. FACILE SYNTHESIS OF 1-NAPHTHOL AZO DYES WITH NANO ...

    African Journals Online (AJOL)

    Preferred Customer

    a highly efficient and one pot synthesis of azo dyes based on 1-naphthol under ... known and were identified by comparison of their physical and spectroscopic data with those of ... δ: 16.15 (s, 1H), 8.41 (d, J = 7.6 Hz, 1 H), 8.33 (d, J = 8.8 Hz, 2H), 7.8 (d, .... 86. 81. 77. 70. 65. N2. + IO4. -. O2N. 2d. 96. 93. 90. 85. 79. 73. 69.

  18. A New Nano Silica Gel Supported by Thionyl Chloride as a Solid Acid for the Efficient Diazotization of Aniline Derivatives: Application and Synthesis of Azo Dyes

    Directory of Open Access Journals (Sweden)

    Mohammad Mirjalili

    2012-01-01

    Full Text Available A new nano silicagel supported by thionyl chloride as a solid acid was synthesized and used as a increasing the production yield of dye to affect the efficient diazotization of arylamines. The diazonium salts thus obtained were coupled, using standard experimental procedures, to anilines and naphthols to afford the requisite azo dyes in good yield. The diazotization and subsequent azo-coupling generated the related azo dyes at low temperature in short reaction times with a simple experimental procedure.

  19. Thermal and Optical Modulation of the Carrier Mobility in OTFTs Based on an Azo-anthracene Liquid Crystal Organic Semiconductor.

    Science.gov (United States)

    Chen, Yantong; Li, Chao; Xu, Xiuru; Liu, Ming; He, Yaowu; Murtaza, Imran; Zhang, Dongwei; Yao, Chao; Wang, Yongfeng; Meng, Hong

    2017-03-01

    One of the most striking features of organic semiconductors compared with their corresponding inorganic counterparts is their molecular diversity. The major challenge in organic semiconductor material technology is creating molecular structural motifs to develop multifunctional materials in order to achieve the desired functionalities yet to optimize the specific device performance. Azo-compounds, because of their special photoresponsive property, have attracted extensive interest in photonic and optoelectronic applications; if incorporated wisely in the organic semiconductor groups, they can be innovatively utilized in advanced smart electronic applications, where thermal and photo modulation is applied to tune the electronic properties. On the basis of this aspiration, a novel azo-functionalized liquid crystal semiconductor material, (E)-1-(4-(anthracen-2-yl)phenyl)-2-(4-(decyloxy)phenyl)diazene (APDPD), is designed and synthesized for application in organic thin-film transistors (OTFTs). The UV-vis spectra of APDPD exhibit reversible photoisomerizaton upon photoexcitation, and the thin films of APDPD show a long-range orientational order based on its liquid crystal phase. The performance of OTFTs based on this material as well as the effects of thermal treatment and UV-irradiation on mobility are investigated. The molecular structure, stability of the material, and morphology of the thin films are characterized by thermal gravimetric analysis (TGA), polarizing optical microscopy (POM), (differential scanning calorimetry (DSC), UV-vis spectroscopy, atomic force microscopy (AFM), and scanning tunneling microscopy (STM). This study reveals that our new material has the potential to be applied in optical sensors, memories, logic circuits, and functional switches.

  20. Alkoxyl- and carbon-centered radicals as primary agents for degrading non-phenolic lignin-substructure model compounds.

    Science.gov (United States)

    Ohashi, Yasunori; Uno, Yukiko; Amirta, Rudianto; Watanabe, Takahito; Honda, Yoichi; Watanabe, Takashi

    2011-04-07

    Lignin degradation by white-rot fungi proceeds via free radical reaction catalyzed by oxidative enzymes and metabolites. Basidiomycetes called selective white-rot fungi degrade both phenolic and non-phenolic lignin substructures without penetration of extracellular enzymes into the cell wall. Extracellular lipid peroxidation has been proposed as a possible ligninolytic mechanism, and radical species degrading the recalcitrant non-phenolic lignin substructures have been discussed. Reactions between the non-phenolic lignin model compounds and radicals produced from azo compounds in air have previously been analysed, and peroxyl radical (PR) is postulated to be responsible for lignin degradation (Kapich et al., FEBS Lett., 1999, 461, 115-119). However, because the thermolysis of azo compounds in air generates both a carbon-centred radical (CR) and a peroxyl radical (PR), we re-examined the reactivity of the three radicals alkoxyl radical (AR), CR and PR towards non-phenolic monomeric and dimeric lignin model compounds. The dimeric lignin model compound is degraded by CR produced by reaction of 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH), which under N(2) atmosphere cleaves the α-β bond in 1-(4-ethoxy-3-methoxyphenyl)-2-(2-methoxyphenoxy)-1,3-propanediol to yield 4-ethoxy-3-methoxybenzaldehyde. However, it is not degraded by the PR produced by reaction of Ce(4+)/tert-BuOOH. In addition, it is degraded by AR produced by reaction of Ti(3+)/tert-BuOOH. PR and AR are generated in the presence and absence of veratryl alcohol, respectively. Rapid-flow ESR analysis of the radical species demonstrates that AR but not PR reacts with the lignin model compound. Thus, AR and CR are primary agents for the degradation of non-phenolic lignin substructures.

  1. Synthesis, characterization and photoinduction of optical anisotropy in liquid crystalline diblock azo-copolymers

    NARCIS (Netherlands)

    Forcen, P.; Oriol, L.; Sanchez, S.; Alcala, R.; Hvilsted, S.; Jankova, K.; Loos, J.

    2007-01-01

    Diblock copolymers with polymethyl methacrylate and side chain liquid crystalline (LC) azopolymethacrylate blocks were synthesized by atom transfer radical polymerization (ATRP). The azobenzene content in these copolymers ranges from 52 to 7 wt %. For an azo content down to 20% they exhibit a LC

  2. Synthesis and characterization of Mg-based amorphous alloys and their use for decolorization of Azo dyes

    International Nuclear Information System (INIS)

    Iqbal, M; Wang, W H

    2014-01-01

    Mg-based alloys are light weight and have wide range of applications in the automotive industry. These alloys are widely used because of their very attractive physical and mechanical properties and corrosion resistance. The properties and applications can be further improved by changing the nature of materials from crystalline to amorphous. In this study, melt spun ribbons (MSRs) of Mg 70 Zn 25 Ca 5 Mg 68 Zn 27 Ca 5 alloys were prepared by melt spinning technique by using 3-4N pure metals. Characterization of the samples was done by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and energy dispersive x-ray analyzer (EDAX). Microstructural investigations were conducted by using scanning electron microscopy (SEM), atomic force microscopy (AFM) as well as optical and stereo scan microscopy techniques. DSC results showed multistage crystallization. Activation energy was found to be 225 kJ/mol by Kissinger method indicating good thermal stability against crystallization. XRD, DSC, SEM and EDS (energy dispersive spectroscopy) results are agreed very well. In order to study decolorization, the MSRs of Mg 70 Zn 25 Ca 5 Mg 68 Zn 27 Ca 5 alloys were treated repeatedly with various azo dyes at room temperature. In order to compare the results, MSRs of amorphous Zr- and Ni-based metallic glasses were also treated. Reaction of MSRs with azo dyes results in their decolorization in a few hours. Decolorization of azo dyes takes place by introducing amorphous MSRs which results in breaking the -N=N- bonds that exist in dye contents. It is concluded that Mg-based alloys are useful for paint and dye industries and will be beneficial to control water pollution. Comparison of results showed that Mg-based alloys are more efficient than Zr- and Ni-based amorphous alloys for decolorization of azo dyes

  3. The oxidation of acid azo dye AY 36 by a manganese oxide containing mine waste

    International Nuclear Information System (INIS)

    Clarke, Catherine E.; Kielar, Filip; Johnson, Karen L.

    2013-01-01

    Highlights: ► This study looks at the oxidative breakdown of the amine containing dye acid yellow 36 by a Mn oxide containing mine waste. ► The oxidation proceeds by successive one electron transfers between the dye molecule and the Mn oxide minerals. ► The initial decolorization of the dye is rapid, but does not involve the cleavage of the azo bond. -- Abstract: The oxidative breakdown of acid azo dye acid yellow 36 (AY 36) by a Mn oxide containing mine tailings is demonstrated. The oxidation reaction is pH dependent with the rate of decolorization increasing with decreasing pH. The oxidation reaction mechanism is initiated at the amino moiety and proceeds via successive, one electron transfers from the dye to the Mn oxide minerals. The reaction pathway involves the formation of a number of colorless intermediate products, some of which hydrolyze in a Mn oxide-independent step. Decolorization of the dye is rapid and is observed before the cleavage of the azo-bond, which is a slower process. The terminal oxidation products were observed to be p-benzoquinone and 3-hydroxybenzenesulfonate. The reaction order of the initial decolorization was determined to be pseudo fractional order with respect to pH and pseudo first order with respect to dye concentration and Mn tailings’ surface area

  4. Total aerobic destruction of azo contaminants with nanoscale zero-valent copper at neutral pH: promotion effect of in-situ generated carbon center radicals.

    Science.gov (United States)

    Dong, Guohui; Ai, Zhihui; Zhang, Lizhi

    2014-12-01

    In this study, nanoscale zero-valent copper (nZVC) was synthesized with a facile solvothermal method and used for the aerobic removal of azo contaminants at neutral pH for the first time. We found that both Cu(I) and OH generated during the nZVC induced molecular oxygen activation process accounted for the rapid total destruction of azo contaminants in the nZVC/Air system, where nZVC could activate molecular oxygen to produce H2O2, and also release Cu(I) to break the -NN- bond of azo contaminants via the sandmeyer reaction for the generation of carbon center radicals. The in-situ generated carbon center radicals would then react with OH produced by the Cu(I) catalyzed decomposition of H2O2, resulting in the generation of low molecular weight organic acids and their subsequent mineralization. The indispensible role of Cu(I) catalyzed sandmeyer reaction and the promotion effect of in-situ generated carbon center radicals on the rapid total destruction of azo contaminants in the nZVC/Air system were confirmed by gas chromatography-mass spectrometry analysis. This study can deepen our understanding on the degradation of organic pollutant with molecular oxygen activated by zero valent metal, and also provide a new method to remove azo contaminants at neutral pH. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Heterogeneous fenton degradation of azo dyes catalyzed by modified polyacrylonitrile fiber fe complexes: QSPR (quantitative structure peorperty relationship) study.

    Science.gov (United States)

    Li, Bing; Dong, Yongchun; Ding, Zhizhong

    2013-07-01

    The amidoximated polyacrylonitrile (PAN) fiber Fe complexes were prepared and used as the heterogeneous Fenton catalysts for the degradation of 28 anionic water soluble azo dyes in water under visible irradiation. The multiple linear regression (MLR) method was employed to develop the quantitative structure property relationship (QSPR) model equations for the decoloration and mineralization of azo dyes. Moreover, the predictive ability of the QSPR model equations was assessed using Leave-one-out (LOO) and cross-validation (CV) methods. Additionally, the effect of Fe content of catalyst and the sodium chloride in water on QSPR model equations were also investigated. The results indicated that the heterogeneous photo-Fenton degradation of the azo dyes with different structures was conducted in the presence of the amidoximated PAN fiber Fe complex. The QSPR model equations for the dye decoloration and mineralization were successfully developed using MLR technique. MW/S (molecular weight divided by the number of sulphonate groups) and NN=N (the number of azo linkage) are considered as the most important determining factor for the dye degradation and mineralization, and there is a significant negative correlation between MW/S or NN=N and degradation percentage or total organic carbon (TOC) removal. Moreover, LOO and CV analysis suggested that the obtained QSPR model equations have the better prediction ability. The variation in Fe content of catalyst and the addition of sodium chloride did not alter the nature of the QSPR model equations.

  6. Novel 2-phenyl-3-{4’-[N-(4”-aminophenylcarbamoyl]-phenyl}-quinazoline-4(3Hone-6-sulphonic acidbased mono azo reactive dyes

    Directory of Open Access Journals (Sweden)

    DIVYESH R. PATEL

    2011-02-01

    Full Text Available A series of new heterocyclic mono azo reactive dyes 7a–m were prepared by diazotization of 2-phenyl-3-{4’-[N-(4”-aminophenylcarbamoyl]-phenyl}-quinazoline-4(3H-one-6-sulphonic acid (3 and coupling with various cyanurated coupling components 6a–m and their dyeing performance on silk, wool and cotton fibres was assessed. These dyes were found to give a variety of colour shades with very good depth and levelness on the fibres. All the compounds were identified by conventional method (IR and 1H-NMR and elemental analyses. The percentage dye bath exhaustion on different fibres was reasonably good and acceptable. The dyed fibre showed moderate to very good fastness to light, washing and rubbing.

  7. Synthesis and spectral studies of some novel coumarin based disperse azo dyes

    International Nuclear Information System (INIS)

    Amjad, R.; Khan, S.R.; Naeem, M.

    2009-01-01

    Synthesis of some novel coumarin based azo dyes was carried out by diazotization of heterocyclic amines using nitrosyl sulphuric acid and then coupling them with 7-hydroxy-4-methyl Coumarin. The synthesized dyes when applied on polyester fibers showed moderate to good light fastness and very good to excellent fastness to washing, rubbing, perspiration and sublimation. (author)

  8. Radiation resistance of organic azo dyes in aqueous solutions

    International Nuclear Information System (INIS)

    Khabarov, V.N.; Kozlov, L.L.

    1987-01-01

    The resistance to the action of the ionizing radiation of aqueous and aqueous-alcoholic solutions of organic mono- and diazo dyes was studied. The radiation chemical yield of decolorization of the dye, determined from the kinetic decolorization curves served as a quantitative criterion of the radiation resistance. The influence of pH, addition of ethanol, hydroquinone, thiourea, glucose and oxygen on the radiation resistance of the azo dyes was studied. An attempt was made to relate the efficiency of radiation decolorization to the chemical nature of the dye

  9. KINETIC BEHAVIOR OF SOME AZO DYES DECOLORIZATION BY VARIATION OF ZINC OXIDE AND TITANIUM DIOXIDE CONCENTRATIONS

    Directory of Open Access Journals (Sweden)

    Wallace J. C. da Silva

    Full Text Available The decolorization of three monoazo dyes (acid orange 7, direct orange 34, and methyl orange, one diazo dye (direct yellow 86 and one tetraazo dye (direct red 80 were mediated by n-type semiconductors as ZnO and TiO2 under pseudo-first order conditions at 30 ºC. The decolorization rate constants of these azo dyes were determined, varying the semiconductor concentration for the majority of them from 1.0 to 10.0 g L-1. In general, the highest rate constants were displayed for ZnO. This work elucidates that the decolorization capacity depends on the charge, structure, and adsorption of the azo dye on the semiconductor surface as well as the agglomeration of the photocatalyst particles.

  10. Simultaneous Decolorization and Biohydrogen Production from Xylose by Klebsiella oxytoca GS-4-08 in the Presence of Azo Dyes with Sulfonate and Carboxyl Groups

    Science.gov (United States)

    Cao, Ming-yue; Wang, Peng-tao; Wang, Shi; Yue, Ying-rong; Yuan, Wen-duo; Qiao, Wei-chuan; Wang, Fei

    2017-01-01

    ABSTRACT Biohydrogen production from the pulp and paper effluent containing rich lignocellulosic material could be achieved by the fermentation process. Xylose, an important hemicellulose hydrolysis product, is used less efficiently as a substrate for biohydrogen production. Moreover, azo dyes are usually added to fabricate anticounterfeiting paper, which further increases the complexity of wastewater. This study reports that xylose could serve as the sole carbon source for a pure culture of Klebsiella oxytoca GS-4-08 to achieve simultaneous decolorization and biohydrogen production. With 2 g liter−1 of xylose as the substrate, a maximum xylose utilization rate (URxyl) and a hydrogen molar yield (HMY) of 93.99% and 0.259 mol of H2 mol of xylose−1, respectively, were obtained. Biohydrogen kinetics and electron equivalent (e− equiv) balance calculations indicated that methyl red (MR) penetrates and intracellularly inhibits both the pentose phosphate pathway and pyruvate fermentation pathway, while methyl orange (MO) acted independently of the glycolysis and biohydrogen pathway. The data demonstrate that biohydrogen pathways in the presence of azo dyes with sulfonate and carboxyl groups were different, but the azo dyes could be completely reduced during the biohydrogen production period in the presence of MO or MR. The feasibility of hydrogen production from industrial pulp and paper effluent by the strain if the xylose is sufficient was also proved and was not affected by toxic substances which usually exist in such wastewater, except for chlorophenol. This study offers a promising energy-recycling strategy for treating pulp and paper wastewaters, especially for those containing azo dyes. IMPORTANCE The pulp and paper industry is a major industry in many developing countries, and the global market of pulp and paper wastewater treatment is expected to increase by 60% between 2012 and 2020. Such wastewater contains large amounts of refractory contaminants, such

  11. Antimicrobial polymer films for food packaging

    Science.gov (United States)

    Concilio, S.; Piotto, S.; Sessa, L.; Iannelli, P.; Porta, A.; Calabrese, E. C.; Galdi, M. R.; Incarnato, L.

    2012-07-01

    New antimicrobial polymeric systems were realized introducing new antimicrobial azo compounds in PP and LDPE matrices. The polymeric materials containing different percentage of azo compounds were mold-casted and the obtained film were tested in vitro against Gram+ and Gram- bacteria and fungi. These results hold promise for the fabrication of bacteria-resistant polymer films by means of simple melt processing with antimicrobial azo-dyes.

  12. The influence of target erosion grade in the optoelectronic properties of AZO coatings growth by magnetron sputtering

    Science.gov (United States)

    Zubizarreta, C.; G-Berasategui, E.; Ciarsolo, I.; Barriga, J.; Gaspar, D.; Martins, R.; Fortunato, E.

    2016-09-01

    Aluminum-doped zinc oxide (AZO) transparent conductor coating has emerged as promising substitute to tin-doped indium oxide (ITO) as electrode in optoelectronic applications such as photovoltaics or light emitting diodes (LEDs). Besides its high transmission in the visible spectral region and low resistivity, AZO presents a main advantage over other candidates such as graphene, carbon nanotubes or silver nanowires; it can be deposited using the technology industrially implemented to manufacture ITO layers, the magnetron sputtering (MS). This is a productive, reliable and green manufacturing technique. But to guarantee the robustness, reproducibility and reliability of the process there are still some issues to be addressed, such as the effect and control of the target state. In this paper a thorough study of the influence of the target erosion grade in developed coatings has been performed. AZO films have been deposited from a ceramic target by RF MS. Structure, optical transmittance and electrical properties of the produced coatings have been analyzed as function of the target erosion grade. No noticeable differences have been found neither in optoelectronic properties nor in the structure of the coatings, indicating that the RF MS is a stable and consistent process through the whole life of the target.

  13. Analysis of electrode microbial communities in an up-flow bioelectrochemical system treating azo dye wastewater

    International Nuclear Information System (INIS)

    Cui, Min-Hua; Cui, Dan; Gao, Lei; Cheng, Hao-Yi; Wang, Ai-Jie

    2016-01-01

    Bioelectrochemical system (BES) is a rapidly developing technology covering contamination remediation, resource recovery and power generation. Electrode biofilms play a key role in BES operation. In this work, a single chamber up-flow bioelectrochemical system (UBES) was assembled with two preinoculated anodes and two raw cathodes for azo dye wastewater treatment. Microbial community structures of these electrodes after long-term operation (more than 200 days) were carried out by high-throughput Illumina 16S rRNA gene MiSeq sequencing platform. Microorganisms belonging to Enterobacter, Desulfovibrio and Enterococcus, which are capable of bidirectional extracellular electron transfer, were found to be the dominant members in all biofilms. Neither the polarity nor the position of the electrodes obviously altered the microbial community structures. This study provides a feasible strategy to build electrode active biofilms in a BES for azo dye wastewater treatment and gives great inspirations to bring this technology closer to application.

  14. Isolation and Characterization of Paracoccus sp. GSM2 Capable of Degrading Textile Azo Dye Reactive Violet 5

    Directory of Open Access Journals (Sweden)

    Mallikarjun C. Bheemaraddi

    2014-01-01

    Full Text Available A potential bacterial strain GSM2, capable of degrading an azo dye Reactive Violet 5 as a sole source of carbon, was isolated from textile mill effluent from Solapur, India. The 16S rDNA sequence and phenotypic characteristics indicated an isolated organism as Paracoccus sp. GSM2. This strain exhibited complete decolorization of Reactive Violet 5 (100 mg/L within 16 h, while maximally it could decolorize 800 mg/L of dye within 38 h with 73% decolorization under static condition. For color removal, the most suitable pH and temperature were pH 6.0–9.0 and 25–40°C, respectively. The isolate was able to decolorize more than 70% of five structurally different azo dyes within 38 h. The isolate is salt tolerant as it can bring out more than 90% decolorization up to a salt concentration of 2% (w/v. UV-Visible absorption spectra before and after decolorization suggested that decolorization was due to biodegradation and was further confirmed by FT-IR spectroscopy. Overall results indicate the effectiveness of the strain GSM2 explored for the treatment of textile industry effluents containing various azo dyes. To our knowledge, this could be the first report on biodegradation of Reactive Violet 5 by Paracoccus sp. GSM2.

  15. Descoloração redutiva de corantes azo e o efeito de mediadores redox na presença do aceptor de elétrons sulfato Reductive decolourisation of azo dyes and the effect of redox mediators in the presence of the electron acceptor sulfate

    Directory of Open Access Journals (Sweden)

    Mayara Carantino Costa

    2010-01-01

    Full Text Available We investigated the impact of sulphate and the redox mediator Anthraquinone-2,6-disulfonate (AQDS on the decolorization of the azo dyes Congo Red (CR and Reactive Black 5 (RB5. In anaerobic reactors free of extra sulphate dosage, the color removal efficiency decreased drastically when the external electron donor ethanol was removed. In presence of an extra dosage of sulphate, CR decolourisations were 47.8% (free of AQDS and 96.5% (supplemented with AQDS. The decolourisations achieved in both reactors with RB5 were lower than the ones found with CR. Finally, the biogenic sulphide contribution on azo dye reduction was negligiable.

  16. Decolorization of direct poly azo dye with nanophotocatalytic UV/NiO process

    Directory of Open Access Journals (Sweden)

    Ali Assadi

    2012-01-01

    Full Text Available Aims: The aim of the present study is to investigate the efficiency of ultraviolet/ nickel oxide (UV/NiO system as one form of advanced oxidation processes (AOP for decolorization of red poly azo. Materials and Methods: This study was conducted as a laboratory scale in a batch mode. Ultraviolet radiation was provided by a low pressure (11 W UV lamp. Effects of various factors including pH, different irradiation durations, different concentration of nickel oxide, and initial dye concentration were evaluated. Results: The results of the UV/NiO system′s assessment showed that UV light alone cannot remove DR 80 dye. Nickel oxide is an effective catalyst in the decolorization of dye with the nanophotocatalytic process. The decolorization efficiency increases with decreasing pH value and the optimum pH value is 4. Fainally, the highest removal efficiency achieved by UV/NiO process for DR 80 dye with concentrations of 25 mg/l and 50 mg/l was 94.3% and 82.2%, respectively. UV/NiO-based decolorization process follows pseudo-second-order reaction kinetics. Conclusions: From the findings of the present study, it can be concluded that UV/NiO process is an effective technique for decolorization of poly azo dye, DR 80, in aqueous solutions.

  17. Adsorption of the reactive azo dyes onto NH4Cl-induced activated carbon

    Directory of Open Access Journals (Sweden)

    Sakine Shekoohiyan

    2016-03-01

    Full Text Available Background: The efficacy of NH4Cl-induced activated carbon (NAC was examined in order to adsorb RR198, an azo reactive model dye, from an aqueous solution. Methods: The effects of pH (3 to 10, adsorbent dose (0.1 to 1.2 g/L, dye concentration and contact time on the adsorption efficiency were investigated. Results: The results showed that the removal of dye was highest at a solution pH of 7 and a powder dose of 1.1 g/L. The 85.9%, 72.6% and 65.4% removal of RR198 was obtained for a concentration of 25, 50 and 100 mg/L, respectively, at a relatively short contact time of 30 minutes, and at optimum pH and NAC concentrations of 1 g/L. The experimental data for kinetic analysis illustrated a best fit to the pseudo-second-order model. The study data on equilibrium were modeled using Langmuir, Freundlich and Dubinin–Radushkevich models; the Langmuir equation provided the best fit for the data. Conclusion: Therefore, the NAC appears to be an efficient and appropriate adsorbent for the removal of reactive azo dyes from waste streams.

  18. Synthesis, characterization, thermal

    Directory of Open Access Journals (Sweden)

    Selma Bal

    2017-09-01

    Full Text Available This work explains the synthesis of a new azo-Schiff base compound, derived from condensation between N-ethylcarbazole-3-carbaldehyde and 1,3-diaminopropane, followed by azo coupling reaction with the diazonium salt of 2-amino-4-methyl phenol. The newly synthesized azo-Schiff base was further reacted with the acetate salts of Copper, Cobalt and Nickel to give three coordination compounds. All synthesized compounds have been characterized through spectral analysis. The coordination compounds have been examined for their thermal and catalytic features. Good and moderate yields were obtained for the oxidation of styrene and cyclohexene. Thermal features of the ligand and its complexes have been explained and the results obtained have supported the proposed structures.

  19. Serendipitous discovery of light-induced (In Situ) formation of an Azo-bridged dimeric sulfonated naphthol as a potent PTP1B inhibitor.

    Science.gov (United States)

    Bongard, Robert D; Lepley, Michael; Thakur, Khushabu; Talipov, Marat R; Nayak, Jaladhi; Lipinski, Rachel A Jones; Bohl, Chris; Sweeney, Noreena; Ramchandran, Ramani; Rathore, Rajendra; Sem, Daniel S

    2017-05-31

    Protein tyrosine phosphatases (PTPs) like dual specificity phosphatase 5 (DUSP5) and protein tyrosine phosphatase 1B (PTP1B) are drug targets for diseases that include cancer, diabetes, and vascular disorders such as hemangiomas. The PTPs are also known to be notoriously difficult targets for designing inihibitors that become viable drug leads. Therefore, the pipeline for approved drugs in this class is minimal. Furthermore, drug screening for targets like PTPs often produce false positive and false negative results. Studies presented herein provide important insights into: (a) how to detect such artifacts, (b) the importance of compound re-synthesis and verification, and (c) how in situ chemical reactivity of compounds, when diagnosed and characterized, can actually lead to serendipitous discovery of valuable new lead molecules. Initial docking of compounds from the National Cancer Institute (NCI), followed by experimental testing in enzyme inhibition assays, identified an inhibitor of DUSP5. Subsequent control experiments revealed that this compound demonstrated time-dependent inhibition, and also a time-dependent change in color of the inhibitor that correlated with potency of inhibition. In addition, the compound activity varied depending on vendor source. We hypothesized, and then confirmed by synthesis of the compound, that the actual inhibitor of DUSP5 was a dimeric form of the original inhibitor compound, formed upon exposure to light and oxygen. This compound has an IC 50 of 36 μM for DUSP5, and is a competitive inhibitor. Testing against PTP1B, for selectivity, demonstrated the dimeric compound was actually a more potent inhibitor of PTP1B, with an IC 50 of 2.1 μM. The compound, an azo-bridged dimer of sulfonated naphthol rings, resembles previously reported PTP inhibitors, but with 18-fold selectivity for PTP1B versus DUSP5. We report the identification of a potent PTP1B inhibitor that was initially identified in a screen for DUSP5, implying common

  20. The contribution of fermentative bacteria and methanogenic archaea to azo dye reduction by a thermophilic anaerobic consortium

    NARCIS (Netherlands)

    Santos, dos A.B.; Cervantes, F.J.; Madrid, de M.P.; Bok, de F.A.M.; Stams, A.J.M.; Lier, van J.B.

    2006-01-01

    The contribution of fermentative bacteria and methanogenic archaea to azo dye reduction by a thermophilic anaerobic consortium was studied. Additionally, the effects of different electron-donating substrates and the redox mediator riboflavin on dye reduction were assessed by using either a

  1. Azo dye removal in a membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor

    International Nuclear Information System (INIS)

    Cui, Dan; Guo, Yu-Qi; Cheng, Hao-Yi; Liang, Bin; Kong, Fan-Ying; Lee, Hyung-Sool; Wang, Ai-Jie

    2012-01-01

    Highlights: ► A membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor was developed. ► Alizarin Yellow R as the mode of azo dyes was efficiently converted to p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA). ► PPD and 5-ASA were further oxidized in a bio-contact oxidation reactor. ► The mechanism of UBER for azo dye removal was discussed. - Abstract: Azo dyes that consist of a large quantity of dye wastewater are toxic and persistent to biodegradation, while they should be removed before being discharged to water body. In this study, Alizarin Yellow R (AYR) as a model azo dye was decolorized in a combined bio-system of membrane-free, continuous up-flow bio-catalyzed electrolysis reactor (UBER) and subsequent aerobic bio-contact oxidation reactor (ABOR). With the supply of external power source 0.5 V in the UBER, AYR decolorization efficiency increased up to 94.8 ± 1.5%. Products formation efficiencies of p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA) were above 90% and 60%, respectively. Electron recovery efficiency based on AYR removal in cathode zone was nearly 100% at HRTs longer than 6 h. Relatively high concentration of AYR accumulated at higher AYR loading rates (>780 g m −3 d −1 ) likely inhibited acetate oxidation of anode-respiring bacteria on the anode, which decreased current density in the UBER; optimal AYR loading rate for the UBER was 680 g m −3 d −1 (HRT 2.5 h). The subsequent ABOR further improved effluent quality. Overall the Chroma decreased from 320 times to 80 times in the combined bio-system to meet the textile wastewater discharge standard II in China.

  2. Azo dye removal in a membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Dan; Guo, Yu-Qi; Cheng, Hao-Yi; Liang, Bin; Kong, Fan-Ying [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No. 202 Haihe Road, Harbin 150090 (China); Lee, Hyung-Sool [Department of Civil and Environmental Engineering, University of Waterloo, 200 University Avenue West Waterloo, Ontario, Canada N2L 3G1 (Canada); Wang, Ai-Jie, E-mail: waj0578@hit.edu.cn [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No. 202 Haihe Road, Harbin 150090 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer A membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor was developed. Black-Right-Pointing-Pointer Alizarin Yellow R as the mode of azo dyes was efficiently converted to p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA). Black-Right-Pointing-Pointer PPD and 5-ASA were further oxidized in a bio-contact oxidation reactor. Black-Right-Pointing-Pointer The mechanism of UBER for azo dye removal was discussed. - Abstract: Azo dyes that consist of a large quantity of dye wastewater are toxic and persistent to biodegradation, while they should be removed before being discharged to water body. In this study, Alizarin Yellow R (AYR) as a model azo dye was decolorized in a combined bio-system of membrane-free, continuous up-flow bio-catalyzed electrolysis reactor (UBER) and subsequent aerobic bio-contact oxidation reactor (ABOR). With the supply of external power source 0.5 V in the UBER, AYR decolorization efficiency increased up to 94.8 {+-} 1.5%. Products formation efficiencies of p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA) were above 90% and 60%, respectively. Electron recovery efficiency based on AYR removal in cathode zone was nearly 100% at HRTs longer than 6 h. Relatively high concentration of AYR accumulated at higher AYR loading rates (>780 g m{sup -3} d{sup -1}) likely inhibited acetate oxidation of anode-respiring bacteria on the anode, which decreased current density in the UBER; optimal AYR loading rate for the UBER was 680 g m{sup -3} d{sup -1} (HRT 2.5 h). The subsequent ABOR further improved effluent quality. Overall the Chroma decreased from 320 times to 80 times in the combined bio-system to meet the textile wastewater discharge standard II in China.

  3. Case study of the sonochemical decolouration of textile azo dye Reactive Black 5

    International Nuclear Information System (INIS)

    Vajnhandl, Simona; Le Marechal, Alenka Majcen

    2007-01-01

    The decolouration and mineralization of reactive dye C.I. Reactive Black 5, a well-known representative of non-biodegradable azo dyes, by means of ultrasonic irradiation at 20, 279 and 817 kHz has been investigated with emphasis on the effect of various parameters on decolouration and degradation efficiency. Characterization of the used ultrasound systems was performed using calorimetric measurements and oxidative species monitoring using Fricke and iodine dosimeter. Experiments were carried out with low frequency probe type, and a high-frequency plate type transducer at 50, 100 and 150 W of acoustic power and within the 5-300 mg/L initial dye concentration range. Decolouration, as well as radical production, increased with increasing frequency, acoustic power, and irradiation time. Any increase in initial dye concentration results in decreased decolouration rates. Sonochemical decolouration was substantially depressed by the addition of 2-methyl-2-propanol as a radical scavenger, which suggests radical-induced reactions in the solution. Acute toxicity to marine bacteria Vibrio fischeri was tested before and after ultrasound irradiation. Under the conditions employed in this study, no toxic compounds were detected after 6 h of irradiation. Mineralization of the dye was followed by TOC measurements. Relatively low degradation efficiency (50% after 6 h of treatment) indicates that ultrasound is rather inefficient in overall degradation, when used alone

  4. Synthesis and Evaluation of Changes Induced by Solvent and Substituent in Electronic Absorption Spectra of New Azo Disperse Dyes Containig Barbiturate Ring

    Directory of Open Access Journals (Sweden)

    Hooshang Hamidian

    2013-01-01

    Full Text Available Six azo disperse dyes were prepared by diazotizing 4-amino hippuric acid and coupled with barbituric acid and 2-thiobarbituric acid. Then, the products were reacted with aromatic aldehyde, sodium acetate, and acetic anhydride, and oxazolone derivatives were formed. Characterization of the dyes was carried out by using UV-Vis, FT-IR, 1H NMR and 13C NMR, and mass spectroscopic techniques. The solvatochromic behavior of azo disperse dyes was evaluated in various solvents. The effects of substituents of aromatic aldehyde, barbiturate, and thiobarbiturate ring on the color of dyes were investigated.

  5. Degradation of azo dyes by sequential Fenton's oxidation and aerobic biological treatment

    International Nuclear Information System (INIS)

    Tantak, Nilesh P.; Chaudhari, Sanjeev

    2006-01-01

    A two stage sequential Fenton's oxidation followed by aerobic biological treatment train was used to achieve decolorization and to enhance mineralization of azo dyes, viz. Reactive Black 5 (RB5), Reactive Blue 13 (RB13), and Acid Orange 7 (AO7). In the first stage, Fenton's oxidation process was used while in the second stage aerobic sequential batch reactors (SBRs) were used as biological process. Study was done to evaluate effect of pH on Fenton's oxidation process. Results reveal that pH 3 was optimum pH for achieving decolorization and dearomatization of dyes by Fenton's process. Degradation of dye was assessed by COD reduction and reduction in aromatic amines (naphthalene chromophores) which was measured by reduction in absorbance at 200 nm. More than 95% of color was removed with Fenton's oxidation process in all dyes. In overall treatment train 81.95, 85.57, and 77.83% of COD reduction was achieved in RB5, RB13, and AO7 dyes, respectively. In the Fenton's oxidation process 56, 24.5, and 80% reduction in naphthalene group was observed in RB5, RB13, and AO7, respectively, which further increased to 81.34, 68.73, and 92% after aerobic treatment. Fenton's oxidation process followed by aerobic SBRs treatment sequence seems to be viable method for achieving significant degradation of azo dye

  6. Synthesized TiO{sub 2}/ZSM-5 composites used for the photocatalytic degradation of azo dye: Intermediates, reaction pathway, mechanism and bio-toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Kefu; Hu, Xin-Yan [College of the Environment and Ecology, Xiamen University, Xiamen (China); Chen, Bor-Yann; Hsueh, Chung-Chuan [Department of Chemical and Materials Engineering, National I-Lan University, I-Lan, Taiwan (China); Zhang, Qian [Department of Environmental Engineering, National Taiwan University, Taipei, Taiwan (China); Wang, Jiajie; Lin, Yu-Jung [College of the Environment and Ecology, Xiamen University, Xiamen (China); Chang, Chang-Tang, E-mail: ctchang73222@gmail.com [Department of Environmental Engineering, National I-Lan University, I-Lan, Taiwan (China)

    2016-10-15

    Highlights: • The major photo-catalytic degradation pathway of azo-dye was elaborated according to the identification of by-products from GC–MS and IC analysis. • Comparative assessment on characteristics of abiotic and biotic dye decolorization was analyzed. • EDTA (hole scavengers) and t-BuOH (radical scavengers) were used to determine the main active oxidative species in the system. • The toxicity effects of degradation intermediates of Reactive Black 5 (RB5) on the cellular respiratory activity were assessed. - Abstract: In this study, a one-step solid dispersion method was used to synthesize titanium dioxide (TiO{sub 2})/Zeolite Socony Mobil-5 (ZSM-5) composites with substantially reduced time and energy consumption. A degradation efficiency of more than 95% was achieved within 10 min using 50% PTZ (synthesized TiO{sub 2}/ZSM-5 composites with TiO{sub 2} contents of 50 wt% loaded on ZSM-5) at pH 7 and 25 °C. The possible degradation pathway of azo-dye Reactive Black 5 (RB5) was investigated using gas chromatography–mass spectrometry and ion chromatography (IC). The bonds between the N atoms and naphthalene groups are likely attacked first and cleaved by hydroxyl radicals, ultimately resulting in the decolorization and mineralization of the azo dye. A comparative assessment of the characteristics of abiotic and biotic dye decolorization was completed. In addition, the toxicity effects of the degradation intermediates of azo-dye RB5 on cellular respiratory activity were analyzed. The bio-toxicity results showed that the decay rate constants of CO{sub 2} production from the azo-dye RB5 samples at different degradation times increased initially and subsequently decreased, indicating that intermediates of higher toxicity could adhere to the catalyst surface and gradually destroyed by further photocatalytic oxidation. Additionally, EDTA (hole scavengers) and t-BuOH (radical scavengers) were used to detect the main active oxidative species in the system

  7. Biodecolorization of the azo dye Reactive Red 2 by a halotolerant enrichment culture.

    Science.gov (United States)

    Beydilli, M Inan; Pavlostathis, Spyros G

    2007-11-01

    The decolorization of the azo dye Reactive Red 2 (RR2) under anoxic conditions was investigated using a mesophilic (35 degrees C) halotolerant enrichment culture capable of growth at 100 g/L sodium chloride (NaCl). Batch decolorization assays were conducted with the unacclimated halotolerant culture, and dye decolorization kinetics were determined as a function of the initial dye, biomass, carbon source, and an externally added oxidation-reduction mediator (anthraquinone-2,6-disulphonic acid) concentrations. The maximum biomass-normalized RR2 decolorization rate by the halotolerant enrichment culture under batch, anoxic incubation conditions was 26.8 mg dye/mg VSSxd. Although RR2 decolorization was inhibited at RR2 concentrations equal to and higher than 300 mg/L, the halotolerant culture achieved a 156-fold higher RR2 decolorization rate compared with a previously reported, biomass-normalized RR2 decolorization rate by a mixed mesophilic (35 degrees C) methanogenic culture in the absence of NaCl. Decolorization kinetics at inhibitory RR2 levels were described based on the Haldane model (Haldane, 1965). Five repetitive dyeing/decolorization cycles performed using the halotolerant culture and the same RR2 dyebath solution demonstrated the feasibility of biological renovation and reuse of commercial-strength spent reactive azo dyebaths.

  8. Linearly and circularly polarized laser photoinduced molecular order in azo dye doped polymer films

    Directory of Open Access Journals (Sweden)

    Saad Bendaoud

    2017-01-01

    Full Text Available Photo-induced behavior of Azo Disperse one (AZD1 doped Poly(Methyl MethAcrylate (PMMA using both linear and circular polarized light is studied. The anisotropy is not erased by the circular polarization light. The circular polarization light combined with relatively long lifetime of the cis state in azo dye doped polymers activate all transverse directions of the angular hole burning through the spot in the film inducing anisotropy. Under circular polarized light, there is no orientation perpendicularly to the helex described by the rotating electric field vector, trans molecules reorients in the propagation direction of the pump beam. The polarization state of the probe beam after propagation through the pumped spot depends strongly on the angle of incidence of both pump and probe beams on the input face. In the case where circular polarized pump and probe beams are under the same angle of incidence, the probe beam “sees” anisotropic film as if it is isotropic. Results of this work shows the possibility to reorient azobenzene-type molecules in two orthogonal directions using alternately linearly and circularly polarized beams.

  9. Impacto dos mediadores redox na remoção de cor de corantes azo e antraquinônico por lodo granular anaeróbio sob condições mesofílicas e termofílicas Impact of redox mediators on colour removal of azo and anthraquinone dyes by anaerobic granular sludge under mesophilic and thermophilic conditions

    Directory of Open Access Journals (Sweden)

    André Bezerra dos Santos

    2007-03-01

    Full Text Available Investigou-se o efeito de diferentes mediadores redox (MR na remoção de cor de corantes azo e antraquinônico pelo uso de lodo granular anaeróbio sob condições mesofílicas (30ºC e termofílicas (55ºC. Comprovou-se em experimento em batelada que a adição de concentrações catalíticas de MR pode ter um efeito marcante nas taxas de descoloração do corante azo Reactive Red 2 (RR2, mas o mesmo comportamento não pode ser obtido com o corante antraquinônico Reactive Blue 5 (RB5. Entretanto, com ambos os corantes, o simples aumento da temperatura de incubação para condições termofílicas fez acelerar consideravelmente os processos de descoloração, comparados com condições mesofílicas. Por exemplo, a constante de primeira ordem "k" da redução dos corantes RR2 e RB5, foi aumentada em 6,2 e 11 vezes, respectivamente, à 55ºC quando comparado com 30ºC. Por fim, comprovou-se em experimentos de fluxo contínuo, a boa performance do tratamento termofílico na descoloração redutiva de corantes azo.The effect of different redox mediators (RM on colour removal of azo and anthraquinone dyes was investigated with anaerobic granular sludge under mesophilic (30ºC and thermophilic (55ºC conditions. Batch experiments revealed that an addition of catalytic concentrations of RM provided a remarkable effect on the decolourisation rates of the azo dye Reactive Red 2 (RR2, but the same effect could not be obtained with the anthraquinone dye Reactive Blue 5 (RB5. Nevertheless, for both dyes, the temperature increase to thermophilic conditions was an effective strategy to considerably accelerate the decolourisation process compared to mesophilic conditions. For instance, the first-order rate constant "k" of RR2 and RB5 reduction, was increased in 6.2 and 11-fold, respectively, at 55ºC in comparison with 30ºC. Such an effect of the temperature on the reductive decolourisation of azo dye was also verified in continuous flow experiments.

  10. Radiolysis of organic triphenylmethane, anthraquinone, xanthene, oxazine, thiazine and azo dyes in polymeric films

    International Nuclear Information System (INIS)

    Khabarov, V.N.; Kozlov, L.L.; Molin, A.A.; Mekhanic, T.V.

    1988-01-01

    Effect of air oxygen and temperature (77 - 323 K) on decolorization radiation-chemical processes of triphenylmethane, anthraquinone, xanthene, oxazine, thiazine and azo dyes in different polymeric matrices is investigated. Radiation decolorization rate for the majority of dyes increases at the irradiation in O 2 presence, which is, presumably, connected with the dye oxidation by the singlet oxygen. The organic dyes manifest the most radiation resistance in polyethyleneterephthalate and polystyrene films

  11. Efficient degradation of Azo dyes by a newly isolated fungus Trichoderma tomentosum under non-sterile conditions.

    Science.gov (United States)

    He, Xiao-Ling; Song, Chao; Li, Yuan-Yuan; Wang, Ning; Xu, Lei; Han, Xin; Wei, Dong-Sheng

    2018-04-15

    A fast-growing fungus with remarkable ability to degrade several azo dyes under non-sterile conditions was isolated and identified. This fungus was identified as Trichoderma tomentosum. Textile effluent of ten-fold dilution could be decolorized by 94.9% within 72h before optimization. Acid Red 3R model wastewater with a concentration of 85.5mgL -1 could be decolorized by 99.2% within the same time after optimization. High-level of manganese peroxidase and low-level of lignin peroxidase activities were detected during the process of decolorization from the culture supernatant, indicating the possible involvement of two enzymes in azo dye decolorization. No aromatic amine products were detected from the degradation products of Acid Red 3R by gas chromatography-mass spectrometry (GC/MS) analysis, indicating the possible involvement of a special symmetrical oxidative degradation pathway. Phytotoxicity assay confirmed the lower toxicity toward the test plant seeds of the degradation products when compared to the original dye. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Efficient azo dye decolorization in a continuous stirred tank reactor (CSTR) with built-in bioelectrochemical system.

    Science.gov (United States)

    Cui, Min-Hua; Cui, Dan; Gao, Lei; Cheng, Hao-Yi; Wang, Ai-Jie

    2016-10-01

    A continuous stirred tank reactor with built-in bioelectrochemical system (CSTR-BES) was developed for azo dye Alizarin Yellow R (AYR) containing wastewater treatment. The decolorization efficiency (DE) of the CSTR-BES was 97.04±0.06% for 7h with sludge concentration of 3000mg/L and initial AYR concentration of 100mg/L, which was superior to that of the sole CSTR mode (open circuit: 54.87±4.34%) and the sole BES mode (without sludge addition: 91.37±0.44%). The effects of sludge concentration and sodium acetate (NaAc) concentration on azo dye decolorization were investigated. The highest DE of CSTR-BES for 4h was 87.66±2.93% with sludge concentration of 12,000mg/L, NaAc concentration of 2000mg/L and initial AYR concentration of 100mg/L. The results in this study indicated that CSTR-BES could be a practical strategy for upgrading conventional anaerobic facilities against refractory wastewater treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Nonlinear optical parameters of nanocrystalline AZO thin film measured at different substrate temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Jilani, Asim, E-mail: asim.jilane@gmail.com [Centre of Nanotechnology, King Abdulaziz University, Jeddah (Saudi Arabia); Abdel-wahab, M.Sh [Centre of Nanotechnology, King Abdulaziz University, Jeddah (Saudi Arabia); Materials Science and Nanotechnology Department, Faculty of Postgraduate Studies for Advanced Sciences, Beni -Suef University, Beni-Suef (Egypt); Al-ghamdi, Attieh A. [Centre of Nanotechnology, King Abdulaziz University, Jeddah (Saudi Arabia); Dahlan, Ammar sadik [Department of architecture, faculty of environmental design, King Abdulaziz University, Jeddah (Saudi Arabia); Yahia, I.S. [Department of Physics, Faculty of Science, King Khalid University, P.O. Box 9004, Abha (Saudi Arabia); Nano-Science & Semiconductor Labs, Department of Physics, Faculty of Education, Ain Shams University, Roxy, 11757 Cairo (Egypt)

    2016-01-15

    The 2.2 wt% of aluminum (Al)-doped zinc oxide (AZO) transparent and preferential c-axis oriented thin films were prepared by using radio frequency (DC/RF) magnetron sputtering at different substrate temperature ranging from room temperature to 200 °C. For structural analysis, X-ray Diffraction (XRD) and Atomic Force Electron Microscope (AFM) was used for morphological studies. The optical parameters such as, optical energy gap, refractive index, extinction coefficient, dielectric loss, tangent loss, first and third order nonlinear optical properties of transparent films were investigated. High transmittance above 90% and highly homogeneous surface were observed in all samples. The substrate temperature plays an important role to get the best transparent conductive oxide thin films. The substrate temperature at 150 °C showed the growth of highly transparent AZO thin film. Energy gap increased with the increased in substrate temperature of Al doped thin films. Dielectric constant and loss were found to be photon energy dependent with substrate temperature. The change in substrate temperature of Al doped thin films also affect the non-liner optical properties of thin films. The value of χ{sup (3)} was found to be changed with the grain size of the thin films that directly affected by the substrate temperature of the pure and Al doped ZnO thin films.

  14. Decolorization of azo dyes Orange G using hydrodynamic cavitation coupled with heterogeneous Fenton process.

    Science.gov (United States)

    Cai, Meiqiang; Su, Jie; Zhu, Yizu; Wei, Xiaoqing; Jin, Micong; Zhang, Haojie; Dong, Chunying; Wei, Zongsu

    2016-01-01

    The present work demonstrates the application of the combination of hydrodynamic cavitation (HC) and the heterogeneous Fenton process (HF, Fe(0)/H2O2) for the decolorization of azo dye Orange G (OG). The effects of main affecting operation conditions such as the inlet fluid pressure, initial concentration of OG, H2O2 and zero valent iron (ZVI), the fixed position of ZVI, and medium pH on decolorization efficiency were discussed with guidelines for selection of optimum parameters. The results revealed that the acidic conditions are preferred for OG decolorizaiton. The decolorization rate increased with increasing H2O2 and ZVI concentration and decreased with increasing OG initial concentration. Besides, the decolorization rate was strongly dependent on the fixed position of ZVI. The analysis results of degradation products using liquid chromatography-ESI-TOF mass spectrometry revealed that the degradation mechanism of OG proceeds mainly via reductive cleavage of the azo linkage due to the attack of hydroxyl radical. The present work has conclusively established that the combination of HC and HF can be more energy efficient and gives higher decolorization rate of OG as compared with HC and HF alone. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Ultrasound enhanced activation of peroxydisulfate by activated carbon fiber for decolorization of azo dye.

    Science.gov (United States)

    Huang, Tianyin; Zhang, Ke; Qian, Yajie; Fang, Cong; Chen, Jiabin

    2018-02-20

    Activated carbon fiber (ACF) has become an emerging activator for peroxydisulfate (PDS) to generate sulfate radical (SO 4 •- ). However, the relative low activation efficiency and poor contaminant mineralization limited its widespread application. Herein, ultrasound (US) was introduced to the ACF activated PDS system, and the synergistic effect of US and ACF in PDS activation and the enhancement of contaminant mineralization were investigated. The synergistic effect of US and ACF was observed in the PDS activation to decolorize orange G (OG). The decolorization efficiency increased with increasing ACF loading and US power, and PDS/OG ratio from 1 to 40. The activation energy was determined to be 24.065 kJ/mol. The radical-induced decolorization of OG took place on the surface of ACF, and both SO 4 •- and hydroxyl radical ( • OH) contributed to OG decolorization. The azo bond and naphthalene ring on OG were destructed to other aromatic intermediates and finally mineralized to CO 2 and H 2 O. The introduction of US in the ACF/PDS system significantly enhanced the mineralization of OG. The combination of US and PDS was highly efficient to activate PDS to decolorize azo dyes. Moreover, the introduction of US remarkably improved the contaminant mineralization.

  16. Antimicrobial Activity of Some Synthetic Compounds on Fungi Associated with Post Harvest Rot of Red Pepper (Capsicum annum

    Directory of Open Access Journals (Sweden)

    Matthew O. KOLAWOLE

    2012-11-01

    Full Text Available Rhizopus sp, Mucor sp, Collectotrichum capsici and Geotrichum candidum were isolated but pathogenic test revealed that Collectotrichum capsici and Geotrichum candidum were the most pathogenic of all the isolates. Ni2+ + Azo has the highest inhibitory effect, closely followed by Ni2+ + PAN while Copper (II complex of Thiourea has the lowest inhibitory effect. However, 10mg/ml concentration proved to be the most effective when radial mycelial growth of the test fungi was measured. The inhibitory effects of each complex on the isolates increases with increase in incubation period. There is the feasibility of using synthetic associated with the symptoms. The three synthetic compounds, Copper (II complex of Thiourea, Ni2+ + compounds as preservatives for harvested red pepper.

  17. Effect of addition of heavy metal ion on decolouration and degradation of azo dye in aqueous solution by gamma irradiation combined with ozone

    International Nuclear Information System (INIS)

    Lee, M.J.; Jin, J.H.; Nho, Y.C.; Arai, H.

    1998-01-01

    In decomposition of azo dyes solution by simultaneous application of gamma-ray and ozone treatment, the effect of addition of heavy metal ion upon decolouration and decomposition was studied. Cupric ion was used as a heavy metal ion. For the aqueous solution with and without addition of cupric ion, the degree of decolouration of 552 nm, the changes of pH, the reduction of TOC and BOD were measured as function of dose under condition of fixed concentration of ozone. It appeared that the addition of cupric ion played a positive role in decomposition of azo dye solution, but played a negative role in decolouration

  18. Synthesis, characterization and photoluminescence properties of ...

    Indian Academy of Sciences (India)

    Further, TEM image of azo-GO indicates some dark spots on the GO sheets due to azo functionalization. AFM ... Introduction. Photochromic compounds, which can easily undergo ... change in optical properties and morphologies.9,10.

  19. Styrene and Azo-Styrene Based Colorimetric Sensors for Highly Selective Detection of Cyanide

    OpenAIRE

    Prestiani, Agustina Eka; Purwono, Bambang

    2017-01-01

    A novel styrene (1) and azo-styrene (2) based chemosensor from vanillin has been successfully synthesized. Sensor 1 was obtained by one step Knoevenagel condensation of Ultrasound method and sensor 2 by coupling diazo and Knoevenagel condensation reaction. Both of sensors showed high sensitivity and selectivity to detect CN- in aqueous media, even the presence of other anions, such as F-, Cl-, Br-, I-, CO32-, SO42-, H2PO4-, and AcO-. Colorimetric sensing of sensor 1 is inclined to be deproton...

  20. pI-Control in comparative fluorescence gel electrophoresis (CoFGE) using amphoteric azo dyes

    Czech Academy of Sciences Publication Activity Database

    Hanneken, M.; Šlais, Karel; König, S.

    2015-01-01

    Roč. 8, SEP (2015), s. 36-39 ISSN 2212-9685 Institutional support: RVO:68081715 Keywords : comparative fluorescence gel * electrophoresis * protein grid * azo dyes Subject RIV: CB - Analytical Chemistry, Separation http://ac.els-cdn.com/S2212968515000094/1-s2.0-S2212968515000094-main.pdf?_tid=7c92fa40-56e6-11e5-b36a-00000aab0f01&acdnat=1441798543_19612c0d7466780944bc4ae22173da92

  1. Radiolysis of organic triphenylmethane, anthraquinone, xanthene, oxazine, thiazine, and azo dyes in polymers films

    International Nuclear Information System (INIS)

    Khabarov, V.N.; Kozlov, L.L.; Molin, A.A.; Mekhanik, T.V.

    1989-01-01

    The effect of the oxygen in the air and the temperature on radiochemical processes of decolorization of triphenylmethane, anthraquinone, xanthene, oxazine, thiazine, and azo dyes in polymer matrices of different chemical natures was studied. The rate of radiation decolorization for most of the dyes increases in irradiation in the presence of O 2 , which is hypothetically due to oxidation of the dye by singlet oxygen. The organic dyes exhibit the highest radiation stability in polyethylene terephthalate and polystyrene films

  2. Potential of the aquatic fern Azolla filiculoides in biodegradation of an azo dye: modeling of experimental results by artificial neural networks.

    Science.gov (United States)

    Khataee, A R; Movafeghi, A; Vafaei, F; Lisar, S Y Salehi; Zarei, M

    2013-01-01

    The potential of an aquatic fern, Azolla filiculoides, in phytoremediation of a mono azo dye solution, C.I. Acid Blue 92 (AB92), was studied. The effects of operational parameters such as reaction time, initial dye concentration, fern fresh weight, pH, temperature and reusability of the fern on biodegradation efficiency were investigated. The intermediate compounds produced by biodegradation process were analyzed using GC-MS analysis. An artificial neural network (ANN) model was developed to predict the biodegradation efficiency. The findings indicated that ANN provides reasonable predictive performance (R2 = 0.961). The effects of AB92 solutions (10 and 20 mg L(-1)) on growth, chlorophylls and carotenoids content, activity of antioxidant enzymes such as superoxide dismutase, peroxidase and catalase and formation of malondialdehyde were analyzed. AB92 generally showed inhibitory effects on the growth. Moreover, photosynthetic pigments in the fronds significantly decreased in the treatments. An increase was detected for lipid peroxidation and antioxidant enzymes activity, suggesting that AB92 caused reactive oxygen species production in Azolla fronds, which were scavenged by induced activities of antioxidant enzymes.

  3. Radiation Treatment of Wastewater Containing Pharmaceutical Compounds

    International Nuclear Information System (INIS)

    Takács, E.; Wojnárovits, L.; Homlok, R.; Illés, E.; Csay, T.; Szabó, L.; Rácz, G.

    2012-01-01

    High-energy ionizing radiation induced degradation of maleic acid, fumaric acid and 20 aromatic molecules was investigated in air saturated aqueous solutions. Hydroxyl radicals were generated water radiolysis. The decomposition was followed by chemical oxygen demand (COD) and total organic carbon content (TOC) measurements. Up to ∼50% decrease of COD the dose dependence was linear. By the ratio of the decrease of COD and the amount of reactive radiolysis intermediates introduced into the solution the oxidation efficiencies were calculated. Efficiencies around 0.5-1 (O 2 molecule built in products/OH) found for most of the compounds show that the one-electron-oxidant OH induces 2-4 electron oxidations. The high oxidation rates were explained by OH addition to unsaturated bonds and subsequent reactions of the dissolved O 2 with organic radicals. In amino substituted molecules or in Acid Red 1 azo dye, O 2 cannot compete efficiently with the unimolecular transformation of organic radicals and the efficiency is lower (0.2-0.5). (author)

  4. Synthesis, Spectral, Thermogravimetric, XRD, Molecular Modelling and Potential Antibacterial Studies of Dimeric Complexes with Bis Bidentate ON–NO Donor Azo Dye Ligands

    Directory of Open Access Journals (Sweden)

    Bipin Bihari Mahapatra

    2013-01-01

    Full Text Available The dimeric complexes of Co(II, Ni(II, Cu(II, Zn(II, Cd(II, and Hg(II with two new symmetrical ON–NO donor bis bidentate (tetradentate azo dye ligands, LH2 = 4,4′-bis(4′-hydroxyquinolinolinylazodiphenylsulphone, and L′H2 = 4,4′-bis(acetoacetanilideazodiphenylsulphone have been synthesized. The metal complexes have been characterised by elemental analytical, conductance, magnetic susceptibility, IR, electronic spectra, ESR, NMR, thermogravimetry, X-ray diffraction (powder pattern spectra, and molecular modelling studies. The Co(II and Ni(II complexes are found to be octahedral, Cu(II complexes are distorted octahedral, and a tetrahedral stereochemistry has been assigned to Zn(II, Cd(II, and Hg(II complexes. The thermogravimetric study indicates that compounds are quite stable. The energy optimized structures are proposed using the semiempirical ZINDO/1 quantum mechanical calculations. The potential antibacterial study of the ligands and some metal complexes has been made with one gram positive bacteria Staphylococcus aureus and one gram negative bacteria E. coli which gives encouraging results. Both the Co(II complexes are found to possess monoclinic crystal system.

  5. Preparation and morphological and optical characterization of azo-polymer-based SiO2 sonogel hybrid composites

    International Nuclear Information System (INIS)

    Morales-Saavedra, Omar G; Ontiveros-Barrera, Fernando G; Torres-Zúñiga, Vicente; Guadalupe-Bañuelos, José; Ortega-Martínez, Roberto; Rivera, Ernesto; García, Tonatiuh

    2009-01-01

    The well-established catalyst-free sonogel route was successfully implemented to fabricate highly pure, optically active, solid state polymeric azo- dye/SiO 2 -based hybrid composites. Bulk samples exhibit controllable geometrical shapes and monolithic structure with variable dopant concentrations. Since the implemented azo-dye chromophores exhibit a push–pull structure, hybrid film samples were spin-coated on ITO-covered glass substrates; molecular alignment was then performed via electrical poling in order to explore the quadratic nonlinear optical performance of this kind of composite. Comprehensive morphological, spectroscopic and optical characterization of the samples were performed with several experimental techniques: atomic force microscopy, x-ray diffraction and infrared, Raman, photoluminescent and ultraviolet–visible spectroscopies. The linear refractive indices of both bulk and thin film samples were measured according to the Brewster angle technique and a numerical analysis of the transmission spectral data, respectively. Regardless of the low glass transition temperatures of the studied polymers, some hybrid film samples were able to display stable nonlinear optical activity such as second harmonic generation. Results show that the chromophores were satisfactorily embedded into the highly pure SiO 2 sonogel network without significant guest–host molecular interactions, thus preserving their optical properties and producing sol–gel hybrid glasses suitable for optical applications

  6. Synthesis of mutual azo prodrugs of anti-inflammatory agents and peptides facilitated by α-aminoisobutyric acid.

    Science.gov (United States)

    Kennedy, David A; Vembu, Nagarajan; Fronczek, Frank R; Devocelle, Marc

    2011-12-02

    Reported is the synthesis of azo mutual prodrugs of the nonsteroidal anti-inflammatory agents (NSAIDs) 4-aminophenylacetic acid (4-APAA) or 5-aminosalicylic acid (5-ASA) with peptides, including an antibiotic peptide temporin analogue modified at the amino terminal by an α-aminoisobutyric acid (Aib) residue. These prodrugs are designed for colonic delivery of two agents to treat infection and inflammation by the bacterial pathogen Clostridium difficile . © 2011 American Chemical Society

  7. Iron promotion of the TiO2 photosensitization process towards the photocatalytic oxidation of azo dyes under solar-simulated light irradiation

    International Nuclear Information System (INIS)

    Castro, Camilo A.; Centeno, Aristobulo; Giraldo, Sonia A.

    2011-01-01

    Highlights: → Azo dye photooxidation occurs under strict combination of ultraviolet and visible irradiation of Fe-TiO 2 . → Fe 3+ enhances the TiO 2 photooxidation of azo dyes while decreases that of phenol. → UV irradiation leads to a decrease in photooxidation activity of Fe-TiO 2 photocatalysts. - Abstract: The photocatalytic oxidation of the azo dye Orange-II (Or-II) using Fe loaded TiO 2 (Fe-TiO 2 ) was studied under ultraviolet (UV), visible (vis) and simultaneous UV-vis irradiations using a solar light simulator. Photocatalysts were characterized by means of XRD, SEM-EDX, FTIR and DRS. Fe 3+ species, identified in XPS analyses, were responsible of the increased absorption of visible light. Moreover, DRS analyses showed a decrease in the bandgap due to Fe 3+ loading. Photocatalystic tests proved that Fe modification enhanced the TiO 2 photocatalytic activity towards Or-II photodegradation under simultaneous UV-vis irradiation. Even so, the performance of the Fe-TiO 2 samples towards the photodegradation of phenol, under UV irradiation, was lower than TiO 2 suggesting the recombination of the UV photogenerated electron-hole pair. Therefore, results evidence a Fe 3+ promotion of the electron caption in the photosensitization process of TiO 2 by Or-II acting as a sensitizer. Such process leads to the Or-II photooxidation under UV-vis irradiation by losing energy in electron transferring processes to sensitize TiO 2 , and, the formation of reactive oxygen species promoted by the injected electron to the TiO 2 conduction band.

  8. Azo dyes degradation using TiO2-Pt/graphene oxide and TiO2-Pt/reduced graphene oxide photocatalysts under UV and natural sunlight irradiation

    Science.gov (United States)

    Rosu, Marcela-Corina; Coros, Maria; Pogacean, Florina; Magerusan, Lidia; Socaci, Crina; Turza, Alexandru; Pruneanu, Stela

    2017-08-01

    The photocatalytic degradation of azo dyes with different structures (amaranth, sunset yellow and tartrazine) using TiO2-Pt nanoparticles (TPt), TiO2-Pt/graphene oxide (TPt-GO) and TiO2-Pt/reduced graphene oxide (TPt-rGO) composites were investigated in the presence of UV and natural sunlight irradiation. The composites were prepared by a combined chemical-thermal method and characterized by Transmission Electron Microscopy (TEM), X-ray powder diffraction (XRD), Infrared (FTIR) and UV-Vis spectroscopy. The modification of TiO2-Pt with graphene oxide shifted its optical absorption edge towards the visible region and increased its photocatalytic activity under UV and natural sunlight irradiation. The efficiency of catalysts on azo dyes degradation (in similar conditions) reached high values (above 99%) under sunlight conditions, proving the remarkable photocatalytic activities of obtained composites. TPt-GO nanocomposite exhibited higher photoactivity than TPt or TPt-rGO, demonstrating degradation efficiencies of 99.56% for amaranth, 99.15% for sunset yellow and 96.23% for tartrazine. The dye photodegradation process follows a pseudo-first-order kinetic with respect to the Langmuir-Hinshelwood reaction mechanism. A direct dependence between azo dyes degradation rate and chemical structure of dyes has been observed.

  9. Cancer risk assessment of azo dyes and aromatic amines from tattoo bands, folders of paper, toys, bed clothes, watch straps and ink

    NARCIS (Netherlands)

    Zeilmaker MJ; van Kranen HJ; van Veen MP; Janus J; LBM

    2000-01-01

    Dit rapport beschrijft een schatting voor het risico op kanker dat verbonden is aan het gebruik van tatoe bandjes, kinderspeelpapier, speelgoed, beddengoed, lederen horlogebandjes en inkt waarin kankerverwekkende azo kleurstoffen aangetroffen zijn. In genoemde producten zijn benzidine en de

  10. Photoresponsive smart surface of LC azo-dendrimer: photomanipulation of topological structures and real-time imaging at a nano-scale

    Science.gov (United States)

    Araoka, Fumito; Eremin, Alexey; Aya, Satoshi; Lee, Guksik; Ito, Atsuki; Nadasi, Hajnalka; Sebastian, Nerea; Ishikawa, Ken; Haba, Osamu; Stannarius, Ralf; Yonetake, Koichiro; Takezoe, Hideo

    2017-02-01

    In this paper, we review some results on our recent studies on photo-induced phenomena of liquid crystals (LCs) by means of interfaces decorated with a photo-responsive azobenzene dendrimer (azo-dendrimer). The azo-dendrimer molecules doped in a LC are spontaneously segregated from bulk and adsorbed onto substrate/LC or solvent/LC interfaces, and their photo-isomerization can bring about the so-called anchoring transition, i.e. reversible switching between homeotropic and planar alignment states of the bulk LC, when exposed to UV/VIS light. In addition to photoinduced anchoring transition in a LC cell, several interesting photo-induced phenomena through the azo-dendrimerdecorated interfaces have been reported, such as photo-induced transformation of the interior topological structures of nematic, cholesteric and smectic droplets, photo-mechanical motion of the micro particles dispersed in a nematic matrix, and optical assistance of the athermal anchoring transition with the aid of a perfluoropolymer surface. In addition to such phenomena, we also discuss the conditions of such photo-responsive interfaces in terms of the polar anchoring energy at the interface upon photo-isomerization under illumination of UV and/or VIS lights. The anisotropy of the polar anchoring energy was evaluated experimentally by means of Polarization Microscopy (POM), Dielectric Spectroscopy (DS), Second Harmonic Generation (SHG), and Attenuated Total Reflection Fourier Transform Infrared (ATR-IR) Spectroscopy, and theoretically based on the simple Rapini-Papoular model. We also demonstrate the continuous bulk orientation change by the photo-dynamic process through the fine control of the polar anchoring energy. Besides, the state-of-the-art video-rate atomic force microscopy (ν-AFM) was carried out to visualize the dynamics of such interfaces at a nano-meter scale.

  11. Optical, thermal and combustion properties of self-colored polyamide nanocomposites reinforced with azo dye surface modified ZnO nanoparticles

    Science.gov (United States)

    Hajibeygi, Mohsen; Shabanian, Meisam; Omidi-Ghallemohamadi, Mehrdad; Khonakdar, Hossein Ali

    2017-09-01

    New self-colored aromatic-polyamide (PA) nanocomposites containing azo and naphthalene chromophores were prepared with azo-dye surface-modified ZnO nanoparticles (SMZnO) using solution method in dimethylformamide. The X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) results showed the uniform distribution for ZnO nanoparticles in the PA matrix. The UV-vis spectra of PA/ZnO nanocomposites (PANC) showed a blue shift as well as reduction in absorbance intensities and the photoluminescence studies revealed that the increasing intensities of the violet emission in SMZnO loading. From thermo gravimetric analysis (TGA), the temperature at 10% mass loss (T10) increased from 291.8 °C to 387.6 °C for PANC containing 8 mass% of SMZnO, as well as the char yield enhanced significantly, which was about 23.5% higher than the neat PA. The peak heat release rate resulted from microscale combustion calorimeter (MCC), by 8 mass% loading of SMZnO, decreased about 56.9% lower than the neat PA.

  12. Physiological characterization of Enterococcus faecalis during azoreductase activity

    OpenAIRE

    Punj, Sumit; John, Gilbert H.

    2011-01-01

    Azo dyes are widely used in the food, pharmaceutical, paper, and textile industries. Some azo dyes are known to produce carcinogenic compounds upon reductive cleavage of the azo bond (N=N) by intestinal flora. There is not much information available on the effect of these dyes on the physiology of the gut microflora as well as their kinetics of reduction in different environments. The azoreductase activity of Enterococcus faecalis, an important opportunistic intestinal pathogen, was tested us...

  13. Conformation of the azo bond and its influence on the molecular and crystal structures, IR and Raman spectra, and electron properties of 6-methyl-3,5-dinitro-2-[(E)-phenyldiazenyl]pyridine - Quantum chemical DFT calculations

    Science.gov (United States)

    Michalski, J.; Bryndal, I.; Lorenc, J.; Hermanowicz, K.; Janczak, J.; Hanuza, J.

    2018-02-01

    The crystal and molecular structures of 6-methyl-3,5-dinitro-2-[(E)-phenyldiazenyl]pyridine have been determined by X-ray diffraction and quantum chemical DFT calculations. The crystal is monoclinic, space group Cc (No. 9) with Z = 4 with the unit cell parameters: a = 12.083(7), b = 12.881(6), c = 8.134(3) Å and β = 97.09(5)°. The azo-bridge appears in the trans conformation in which C2-N2-N2‧-C1‧ torsion angle takes a value - 178.6(3)°, whereas the dihedral angle between the planes of the phenyl and pyridine rings is 3.5(2)°. The IR and Raman spectra measured in the temperature range 80-350 K and quantum chemical calculations with the use of B3LYP/6-311G(2d,2p) approach confirmed the trans configuration of the azo-bridge as the most stable energetically and allowed determination of the energy other virtual structures. The observed effects were used in the discussion of vibrational dynamics of the studied compound. The energy gap between cis and trans conformers equals to 1.054 eV (0.03873 Hartree). The electron absorption and emission spectra have been measured and analyzed on the basis of DFT calculations. The life time of the excited state is 12 μs and the Stokes shift is close to 5470 cm- 1.

  14. Microbial dynamics during azo dye degradation in a UASB reactor supplied with yeast extract.

    Science.gov (United States)

    Silva, S Q; Silva, D C; Lanna, M C S; Baeta, B E L; Aquino, S F

    2014-01-01

    The present work aimed to investigate the microbial dynamics during the anaerobic treatment of the azo dye blue HRFL in bench scale upflow anaerobic sludge bed (UASB) reactor operated at ambient temperature. Sludge samples were collected under distinct operational phases, when the reactor were stable (low variation of color removal), to assess the effect of glucose and yeast extract as source of carbon and redox mediators, respectively. Reactors performance was evaluated based on COD (chemical oxygen demand) and color removal. The microbial dynamics were investigated by PCR-DGGE (Polimerase Chain Reaction - Denaturing Gradient of Gel Electrophoresis) technique by comparing the 16S rDNA profiles among samples. The results suggest that the composition of microorganisms changed from the beginning to the end of the reactor operation, probably in response to the presence of azo dye and/or its degradation byproducts. Despite the highest efficiency of color removal was observed in the presence of 500 mg/L of yeast extract (up to 93%), there were no differences regarding the microbial profiles that could indicate a microbial selection by the yeast extract addition. On the other hand Methosarcina barkeri was detected only in the end of operation when the best efficiencies on color removal occurred. Nevertheless the biomass selection observed in the last stages of UASB operation is probably a result of the washout of the sludge in response of accumulation of aromatic amines which led to tolerant and very active biomass that contributed to high efficiencies on color removal.

  15. Removal of anionic azo dyes from aqueous solution by functional ionic liquid cross-linked polymer

    International Nuclear Information System (INIS)

    Gao, Hejun; Kan, Taotao; Zhao, Siyuan; Qian, Yixia; Cheng, Xiyuan; Wu, Wenli; Wang, Xiaodong; Zheng, Liqiang

    2013-01-01

    Highlights: • Equilibrium, kinetic and thermodynamic of adsorption of dyes onto PDVB-IL was investigated. • PDVB-IL has a high adsorption capacity to treat dyes solution. • Higher adsorption capacity is due to the functional groups of PDVB-IL. • Molecular structure of dyes influences the adsorption capacity. -- Abstract: A novel functional ionic liquid based cross-linked polymer (PDVB-IL) was synthesized from 1-aminoethyl-3-vinylimidazolium chloride and divinylbenzene for use as an adsorbent. The physicochemical properties of PDVB-IL were investigated by Fourier transform infrared spectroscopy, scanning electron microscopy and thermogravimetric analysis. The adsorptive capacity was investigated using anionic azo dyes of orange II, sunset yellow FCF, and amaranth as adsorbates. The maximum adsorption capacity could reach 925.09, 734.62, and 547.17 mg/g for orange II, sunset yellow FCF and amaranth at 25 °C, respectively, which are much better than most of the other adsorbents reported earlier. The effect of pH value was investigated in the range of 1–8. The result shows that a low pH value is found to favor the adsorption of those anionic azo dyes. The adsorption kinetics and isotherms are well fitted by a pseudo second-order model and Langmuir model, respectively. The adsorption process is found to be dominated by physisorption. The introduction of functional ionic liquid moieties into cross-linked poly(divinylbenzene) polymer constitutes a new and efficient kind of adsorbent

  16. Equilibrium and thermodynamics of azo dyes biosorption onto Spirulina platensis

    Directory of Open Access Journals (Sweden)

    G. L. Dotto

    2013-03-01

    Full Text Available The equilibrium and thermodynamics of azo dye (tartrazine and allura red biosorption onto Spirulina platensis biomass were investigated. The equilibrium curves were obtained at 298, 308, 318 and 328 K, and four isotherm models were fitted the experimental data. Biosorption thermodynamic parameters (ΔG, ΔH and ΔS were estimated. The results showed that the biosorption was favored by a temperature decrease. For both dyes, the Sips model was the best to represent the equilibrium experimental data (R²>0.99 and ARE<5.0% and the maximum biosorption capacities were 363.2 and 468.7 mg g-1 for tartrazine and allura red, respectively, obtained at 298 K. The negative values of ΔG and ΔH showed that the biosorption of both dyes was spontaneous, favorable and exothermic. The positive values of ΔS suggested that the system disorder increases during the biosorption process.

  17. Cancer risk assessment of azo dyes and aromatic amines from tattoo bands, folders of paper, toys, bed clothes, watch straps and ink

    NARCIS (Netherlands)

    Zeilmaker MJ; Kranen HJ van; Veen MP van; Janus J; LBM

    2000-01-01

    A quantitative assessment was performed to estimate the cancer risk to individuals using tattoo bands, folders of paper, toys, bed clothes, watch straps and ink which are coloured with azo dyes. In these products benzidine and the benzidine related amines o-anisidine, 2,4-toluenediamine,

  18. BF3.SiO2: an efficient catalyst for the synthesis of azo dyes at room temperature

    Directory of Open Access Journals (Sweden)

    Bi Bi Fatemeh Mirjalili

    2012-07-01

    Full Text Available A rapid one-pot method has been developed for the synthesis of azo dyes via ‎sequential diazotization–diazo coupling of aromatic amines with coupling agents at room ‎temperature in the presence of BF3.SiO2 as acidic catalyst. The obtained aryl diazonium salts bearing silica supported boron tri-flouride counter ion‎ was sufficiently stable to be kept at room ‎temperature in the dry state.‎

  19. Acid azo dye remediation in anoxic-aerobic-anoxic microenvironment under periodic discontinuous batch operation: bio-electro kinetics and microbial inventory.

    Science.gov (United States)

    Venkata Mohan, S; Suresh Babu, P; Naresh, K; Velvizhi, G; Madamwar, Datta

    2012-09-01

    Functional behavior of anoxic-aerobic-anoxic microenvironment on azo dye (C.I. Acid black 10B) degradation was evaluated in a periodic discontinuous batch mode operation for 26 cycles. Dye removal efficiency and azo-reductase activity (30.50 ± 1 U) increased with each feeding event until 13th cycle and further stabilized. Dehydrogenase activity also increased gradually and stabilized (2.0 ± 0.2 μg/ml) indicating the stable proton shuttling between metabolic intermediates providing higher number of reducing equivalents towards dye degradation. Voltammetric profiles showed drop in redox catalytic currents during stabilized phase also supports the consumption of reducing equivalents towards dye removal. Change in Tafel slopes, polarization resistance and other bioprocess parameters correlated well with the observed dye removal and biocatalyst behavior. Microbial community analysis documented the involvement of specific organism pertaining to aerobic and facultative functions with heterotrophic and autotrophic metabolism. Integrating anoxic microenvironment with aerobic operation might have facilitated effective dye mineralization due to the possibility of combining redox functions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Enhancing the electrochemical oxidation of acid-yellow 36 azo dye using boron-doped diamond electrodes by addition of ferrous ion

    International Nuclear Information System (INIS)

    Villanueva-Rodriguez, M.; Hernandez-Ramirez, A.; Peralta-Hernandez, J.M.; Bandala, Erick R.; Quiroz-Alfaro, Marco A.

    2009-01-01

    This work shows preliminary results on the electrochemical oxidation process (EOP) using boron-doped diamond (BDD) electrode for acidic yellow 36 oxidation, a common azo dye used in textile industry. The study is centred in the synergetic effect of ferrous ions and hydroxyl free radicals for improving discoloration of azo dye. The assays were carried out in a typical glass cell under potentiostatic conditions. On experimental conditions, the EOP was able to partially remove the dye from the reaction mixture. The reaction rate increased significantly by addition of Fe 2+ (1 mM as ferrous sulphate) to the system and by (assumed) generation of ferrate ion [Fe(VI)] over BDD electrode. Ferrate is considered as a highly oxidizing reagent capable of removing the colorant from the reaction mixture, in synergistic action with the hydroxyl radicals produced on the BDD surface. Further increases in the Fe 2+ concentration lead to depletion of the reaction rate probably due to the hydroxyl radical scavenging effect of Fe 2+ excess in the system.

  1. Radiation Treatment of Wastewater Containing Pharmaceutical Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Takács, E.; Wojnárovits, L.; Homlok, R.; Illés, E.; Csay, T.; Szabó, L.; Rácz, G. [Centre for Energy Research, Institute of Isotopes, Hungarian Academy of Sciences, Budapest (Hungary)

    2012-07-01

    High-energy ionizing radiation induced degradation of maleic acid, fumaric acid and 20 aromatic molecules was investigated in air saturated aqueous solutions. Hydroxyl radicals were generated water radiolysis. The decomposition was followed by chemical oxygen demand (COD) and total organic carbon content (TOC) measurements. Up to ∼50% decrease of COD the dose dependence was linear. By the ratio of the decrease of COD and the amount of reactive radiolysis intermediates introduced into the solution the oxidation efficiencies were calculated. Efficiencies around 0.5-1 (O{sub 2} molecule built in products/OH) found for most of the compounds show that the one-electron-oxidant OH induces 2-4 electron oxidations. The high oxidation rates were explained by OH addition to unsaturated bonds and subsequent reactions of the dissolved O{sub 2} with organic radicals. In amino substituted molecules or in Acid Red 1 azo dye, O{sub 2} cannot compete efficiently with the unimolecular transformation of organic radicals and the efficiency is lower (0.2-0.5). (author)

  2. 125I-labeled crosslinking reagent that is hydrophilic, photoactivatable, and cleavable through an azo linkage

    International Nuclear Information System (INIS)

    Denny, J.B.; Blobel, G.

    1984-01-01

    A radioactive crosslinking reagent, N-[4-(p-azido-m-[ 125 I]iodophenylazo)benzoyl]-3-aminopropyl-N'-oxysulfosuccinimide ester, has been synthesized. The reagent is photoactivatable, water-soluble, cleavable through an azo linkage, and labeled with 125 I at the carrier-free specific activity of 2000 Ci/mmol. Any protein derivatized with the reagent is thus converted into an 125 I-labeled photoaffinity probe. Crosslinks are formed following photolysis with 366-nm light, and cleavage by sodium dithionite results in the donation of radioactivity to the distal partner in crosslinked complexes. The newly labeled proteins are then analyzed by gel electrophoresis and autoradiography. The compound was prepared by iodination of N-[4-(p-aminophenylazo)benzoyl]-3-aminopropionic acid using carrier-free Na 125 I and chloramine-T, followed by azide formation and conversion to the water-soluble sulfosuccinimide ester. As a model system, protein A-Sepharose was derivatized with the reagent under subdued light. Each derivatized protein A molecule contained only one crosslinker. The derivatized protein A-Sepharose was then photolyzed in the presence of human serum and subsequently treated with sodium dithionite. Analysis of the serum by gel electrophoresis revealed that 1.1% of the radioactive label originally present on the protein A-Sepharose was transferred to the heavy chain of IgG, which was the most intensely labeled protein in the gel. The next most intensely labeled protein was IgG light chain, which incorporated radioactivity that was lower by a factor of 3.6 than that of the heavy chain. 36 references, 3 figures

  3. Decolourisations and biodegradations of model azo dye solutions using a sequence batch reactor, followed by ultrafiltration

    DEFF Research Database (Denmark)

    Korenak, J.; Ploder, J.; Trček, J.

    2018-01-01

    RNA gene and ITS1-5.8S rDNA-ITS2 sequence analysis, respectively. Serratia marcescens and Klebsiella oxytoca were the most common bacteria with the highest number present during the aerobic and anaerobic phases of the bioprocess. In addition, a high number of Elizabethkingia miricola, Morganella morganii......, Comamonas testosteroni, Trichosporon sp. and Galactomyces sp. were detected. Taken together, our results demonstrated that the sequencing batch reactor system combined with ultrafiltration is an efficient technique for treatment of wastewater containing azo dye. Moreover, the ultrafiltration effectively...

  4. Biosurfactant production from Pseudomonas taiwanensis L1011 and its application in accelerating the chemical and biological decolorization of azo dyes.

    Science.gov (United States)

    Liu, Cong; You, Yanting; Zhao, Ruofei; Sun, Di; Zhang, Peng; Jiang, Jihong; Zhu, Aihua; Liu, Weijie

    2017-11-01

    Dye dispersion and the interaction efficiency between azoreductases and dye molecules are rate-limiting steps for the decolorization of azo dyes. In this study, a biosurfactant-producing strain, Pseudomonas taiwanensis L1011, was isolated from crude oil. To increase the yield of the biosurfactant BS-L1011 from P. taiwanensis L1011, culture conditions were optimized including temperature, initial pH, carbon source, nitrogen source and C/N ratio. A maximum yield of 1.12g/L of BS-L1011 was obtained using D-mannitol as carbon source and yeast extract/urea as compound nitrogen source with C/N ratio of 10/4, pH 7.0 and 28°C. BS-L1011 exhibited a low critical micelle concentration (CMC) of 10.5mg/L and was able to reduce the surface tension of water to 25.8±0.1 mN/m. BS-L1011 was stable over a wide range of temperatures, pH values and salt concentrations. The biosurfactant is reported for the first time to accelerate chemical decolorization of Congo red by sodium hypochlorite, and biological decolorization of Amaranth by Bacillus circulans BWL1061, thus showing a potential in the treatment of dyeing wastewater. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Structure and reactivity of thiazolium azo dyes: UV-visible, resonance Raman, NMR, and computational studies of the reaction mechanism in alkaline solution.

    Science.gov (United States)

    Abbott, Laurence C; Batchelor, Stephen N; Moore, John N

    2013-03-07

    UV-visible absorption, resonance Raman, and (1)H NMR spectroscopy, allied with density functional theory (DFT) calculations, have been used to study the structure, bonding, and alkaline hydrolysis mechanism of the cationic thiazloium azo dye, 2-[2-[4-(diethylamino)phenyl]diazenyl]-3-methyl-thiazolium (1a), along with a series of six related dyes with different 4-dialkylamino groups and/or other phenyl ring substituents (2a-c, 3a-c) and the related isothiazolium azo dye, 5-[2-[4-(dimethylamino)phenyl]diazenyl]-2-methyl-isothiazolium (4). These diazahemicyanine dyes are calculated to have a similar low-energy structure that is cis, trans at the (iso)thiazolium-azo group, and for which the calculated Raman spectra provide a good match with the experimental data; the calculations on these structures are used to assign and discuss the transitions giving rise to the experimental spectra, and to consider the bonding and its variation between the dyes. UV-visible, Raman, and NMR spectra recorded from minutes to several weeks after raising the pH of an aqueous solution of 1a to ca. 11.5 show that the dominant initial step in the reaction is loss of diethylamine to produce a quinonimine (ca. hours), with subsequent reactions occurring on longer time scales (ca. days to weeks); kinetic analyses give a rate constant of 2.6 × 10(-2) dm(3) mol(-1) s(-1) for reaction of 1a with OH(-). UV-visible spectra recorded on raising the pH of the other dyes in solution show similar changes that are attributed to the same general reaction mechanism, but with different rate constants for which the dependence on structure is discussed.

  6. DMol3/COSMO-RS prediction of aqueous solubility and reactivity of selected Azo dyes: Effect of global orbital cut-off and COSMO segment variation

    CSIR Research Space (South Africa)

    Wahab, OO

    2018-01-01

    Full Text Available Aqueous solubility and reactivity of four azo dyes were investigated by DMol3/COSMO-RS calculation to examine the effects of global orbital cut-off and COSMO segment variation on the accuracies of theoretical solubility and reactivity. The studied...

  7. Degradation of a mono sulfonated azo dye by an integrated bio sorption and anaerobic system

    International Nuclear Information System (INIS)

    Goncalves, L. C.; Campos, R.; Pinheiro, H. M.; Lopes, A.; Ferra, M. I.

    2009-01-01

    A simulated textile effluent containing a mono sulphonated azo dye was fed to an anaerobic bioreactor in which a natural adsorbent, spent brewery grains (SBG), was incorporated. SABG is a by-product of the brewing industry and could act as adsorbent as well an electron shuttle (lignin fraction) in the dye degradation mechanism. Furthermore, it can also work as a conditioner for the anaerobic biomass. The influence of the dye (Acid Orange 7, AO7) concentration (60 and 150 mg/L) and the presence of SBG in the performance of upflow anaerobic sludge blanket reactor (UASB) was evaluated. (Author)

  8. Degradation of a mono sulfonated azo dye by an integrated bio sorption and anaerobic system

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, L. C.; Campos, R.; Pinheiro, H. M.; Lopes, A.; Ferra, M. I.

    2009-07-01

    A simulated textile effluent containing a mono sulphonated azo dye was fed to an anaerobic bioreactor in which a natural adsorbent, spent brewery grains (SBG), was incorporated. SABG is a by-product of the brewing industry and could act as adsorbent as well an electron shuttle (lignin fraction) in the dye degradation mechanism. Furthermore, it can also work as a conditioner for the anaerobic biomass. The influence of the dye (Acid Orange 7, AO7) concentration (60 and 150 mg/L) and the presence of SBG in the performance of upflow anaerobic sludge blanket reactor (UASB) was evaluated. (Author)

  9. Waste Plant Material as a Potential Adsorbent of a Selected Azo Dye

    Directory of Open Access Journals (Sweden)

    Tomczak Elwira

    2017-06-01

    Full Text Available This paper discusses the adsorption of Direct Orange 26 azo dye on sunflower husk - an agricultural waste product. During the study, sorption kinetics and equilibrium as well as sorption capacity of the husk were investigated. The adsorption kinetics was analyzed using pseudo-first and pseudo-second order equations, which indicated a chemical sorption mechanism. The sorption equilibrium was approximated with the two-parameter Freundlich and Langmuir equations and the three-parameter Redlich-Peterson equation. The main experiments were carried out in a laboratory adsorption column under different process conditions. Experimental data were interpreted with the Thomas model, based on the volumetric flow rate, initial composition of the feed solution and mass of the adsorbent. The results of modeling the adsorption equilibrium, adsorption kinetics and adsorption dynamics were evaluated statistically.

  10. Degradation of the azo dye Acid Red 1 by anodic oxidation and indirect electrochemical processes based on Fenton's reaction chemistry. Relationship between decolorization, mineralization and products

    International Nuclear Information System (INIS)

    Florenza, Xavier; Solano, Aline Maria Sales; Centellas, Francesc; Martínez-Huitle, Carlos Alberto

    2014-01-01

    Highlights: • Degradation of Acid Red 1 by anodic oxidation, electro-Fenton and photoelectro-Fenton • Quicker and similar decolorization by electro-Fenton and photoelectro-Fenton due to oxidation with ● OH in the bulk • Almost total mineralization by photoelectro-Fenton with Pt or BDD due to fast photolysis of products by UVA light • Detection of 11 aromatic products, 15 hydroxylated compounds, 13 desulfonated derivatives and 7 carboxylic acids • Release of NH 4 + , NO 3 − and SO 4 2− ions, and generation of persistent N-products of low molecular mass - Abstract: Solutions of 236 mg dm −3 Acid Red 1 (AR1), an azo dye widely used in textile dying industries, at pH 3.0 have been comparatively treated by anodic oxidation with electrogenerated H 2 O 2 (AO-H 2 O 2 ), electro-Fenton (EF) and photoelectro-Fenton (PEF) at constant current density (j). Assays were performed with a stirred tank reactor equipped with a Pt or boron-doped diamond (BDD) anode and an air-diffusion cathode for H 2 O 2 generation from O 2 reduction. The main oxidizing agents were hydroxyl radicals produced at the anode from water oxidation in all methods and in the bulk from Fenton's reaction between generated H 2 O 2 and 0.5 mmol dm −3 Fe 2+ in EF and PEF. For each anode, higher oxidation power was found in the sequence AO-H 2 O 2 < EF < PEF. The oxidation ability of the BDD anode was always superior to that of Pt. Faster and similar decolorization efficiency was achieved in EF and PEF owing to the quicker destruction of aromatics with hydroxyl radicals produced in the bulk. The PEF process with BDD was the most potent method yielding almost total mineralization due to the additional rapid photolysis of recalcitrant intermediates like Fe(III)-carboxylate complexes under UVA irradiation. The increase in j always enhanced the decolorization and mineralization processes because of the greater production of hydroxyl radicals, but decreases the mineralization current efficiency

  11. New fluorescent azo-Schiff base Cu(II) and Zn(II) metal chelates; spectral, structural, electrochemical, photoluminescence and computational studies

    Science.gov (United States)

    Purtas, Fatih; Sayin, Koray; Ceyhan, Gokhan; Kose, Muhammet; Kurtoglu, Mukerrem

    2017-06-01

    A new Schiff base containing azo chromophore group obtained by condensation of 2-hydroxy-4-[(E)-phenyldiazenyl]benzaldehyde with 3,4-dimethylaniline (HL) are used for the syntheses of new copper(II) and zinc(II) chelates, [Cu(L)2], and [Zn(L)2], and characterized by physico-chemical and spectroscopic methods such as 1H and 13C NMR, IR, UV.-Vis. and elemental analyses. The solid state structure of the ligand was characterized by single crystal X-ray diffraction study. X-ray diffraction data was then used to calculate the harmonic oscillator model of aromaticity (HOMA) indexes for the rings so as to investigate of enol-imine and keto-amine tautomeric forms in the solid state. The phenol ring C10-C15 shows a considerable deviation from the aromaticity with HOMA value of 0.837 suggesting the shift towards the keto-amine tautomeric form in the solid state. The analytical data show that the metal to ligand ratio in the chelates was found to be 1:2. Theoretical calculations of the possible isomers of the ligand and two metal complexes are performed by using B3LYP method. Electrochemical and photoluminescence properties of the synthesized azo-Schiff bases were also investigated.

  12. DFT, FT-IR, FT-Raman and NMR studies of 4-(substituted phenylazo)-3,5-diacetamido-1H-pyrazoles

    Science.gov (United States)

    Kınalı, Selin; Demirci, Serkan; Çalışır, Zühre; Kurt, Mustafa; Ataç, Ahmet

    2011-05-01

    We present a detailed analysis of the structural and vibrational spectra of some novel azo dyes. 2-(Substituted phenylazo)malononitriles were synthesized by the coupling reaction of the diazonium salts, which were prepared with the use of various aniline derivatives with malononitrile, and then 4-(substituted phenylazo)-3,5-diamino-1H-pyrazole azo dyes were obtained via the ring closure of the azo compounds with hydrazine monohydrate. The experimental and theoretical vibrational spectra of azo dyes were studied. The structural and spectroscopic analysis of the molecules were carried out by using Becke's three-parameters hybrid functional (B3LYP) and density functional harmonic calculations. The 1H nuclear magnetic resonance (NMR) chemical shifts of the azo dye molecules were calculated using the gauge-invariant-atomic orbital (GIAO) method. The calculated vibrational wavenumbers and chemical shifts were compared with the experimental data of the molecules.

  13. TiO2/Ag modified penta-bismuth hepta-oxide nitrate and its adsorption performance for azo dye removal

    Institute of Scientific and Technical Information of China (English)

    Eshraq Ahmed Abdullah; Abdul Halim Abdullah; Zulkarnain Zainal; Mohd Zobir Hussein; Tan Kar Ban

    2012-01-01

    A modified hydrophilic penta-bismuth hepta-oxide nitrate (Bi5O7NO3) surface was synthesized via a precipitation method using TiO2 and Ag as modified agents.The synthesized product was characterized by different analytical techniques.The removal efficiency was evaluated using mono- and di-sulphonated azo dyes as model pollutants.Different kinetic,isotherm and diffusion models were chosen to describe the adsorption process.X-ray photoelectron spectroscopy (XPS) results revealed no noticeable differences in the chemical states of modified adsorbent when compared to pure Bi5O7NO3; however,the presence of hydrophilic centres such as TiO2 and Ag developed positively charged surface groups and improved its adsorption performance to a wide range of azo dyes.Dyes removal was found to be a function of adsorbent dosage,initial dye concentration,solution pH and temperature.The reduction of Langrnuir 1,2-mixed order kinetics to the second or first-order kinetics could be successfully used to describe the adsorption of dyes onto the modified adsorbent.Mass transfer can be described by intra-particle diffusion at a certain stage,but it was not the rate limiting step that controlled the adsorption process.Homogenous behavior of adsorbent surface can be explored by applying Langmuir isotherm to fit the adsorption data.

  14. Analysis of photoinduced birefringence in azo-dye doped films by a fast imaging technique

    International Nuclear Information System (INIS)

    Marino, Iari-Gabriel; Lottici, Pier Paolo

    2010-01-01

    In photo-birefringent films, the relationship ρ(I) between optical retardation ρ and pump irradiance I may be obtained with imaging techniques applied within a pump-probe setup. However, measurement of ρ(I) are reported only at long irradiation times and low time-resolution. In this paper we describe a polariscopic imaging technique with higher sensitivity (by a factor of ∼ 30), where the probe beam is focused on the entrance pupil of the camera ('Maxwellian view'). The technique is applied to an azo-dye doped polymeric film, obtaining the continuous ρ(I) curve after irradiation times from 10 ms to 240 ms. Exponential functions are fitted against the experimental data both as a function of time and irradiance.

  15. Fe{sub 3}O{sub 4}@Nico-Ag magnetically recyclable nanocatalyst for azo dyes reduction

    Energy Technology Data Exchange (ETDEWEB)

    Kurtan, U., E-mail: ukurtan@fatih.edu.tr; Amir, Md.; Baykal, A.

    2016-02-15

    Graphical abstract: - Highlights: • Fe{sub 3}O{sub 4}@Nico@Ag magnetic recyclable nanocatalyst (MRC) is more effective for the reduction of azo dyes consisting of MB and MO. • It could be reused several times without significant loss in catalytic activity. • Fe{sub 3}O{sub 4}@Nico@Ag (MRCs) has been successively used for colour reduction of MO, MB, EY, RhB and their mixtures. - Abstract: In this study, we report the successful synthesis of Fe{sub 3}O{sub 4}@Nico-Ag nanocomposite as magnetically recyclable nanocatalyst (MRCs) via reflux process at 80 °C for 5 h followed by reduction of Ag{sup +}. FeCl{sub 3}·6H{sub 2}O, FeCl{sub 2}·4H{sub 2}O, AgNO{sub 3} as starting reactants and nicotinic acid as linker. The structure, morphology, thermal behaviour and magnetic properties of the product were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive spectrometry (EDX), thermal gravimetry (TG) and vibrating sample magnetometry (VSM), respectively. The catalytic activity of product for various azo dyes such as methylene blue (MB), methyl orange (MO), Rhodamine B (RhB) and eosin Y (EY) and their double mixtures were studied. It was found that Fe{sub 3}O{sub 4}@Nico-Ag MRCs is an efficient catalyst and can also rapidly separated from the reaction medium using magnet without considerable loss in its catalytic activity and used several times. Fe{sub 3}O{sub 4}@Nico-Ag MRCs has potential for the treatment of industrial dye pollutants.

  16. A REVIEW ON EFFICACIOUS METHODS TO DECOLORIZE REACTIVE AZO DYE

    Directory of Open Access Journals (Sweden)

    Jagadeesan Vijayaraghavan

    2013-01-01

    Full Text Available This paper deals with the intensive review of reactive azo dye, Reactive Black 5. Various physicochemical methods namely photo catalysis, electrochemical, adsorption, hydrolysis and biological methods like microbial degradation, biosorption and bioaccumulation have been analyzed thoroughly along with the merits and demerits of each method. Among these various methods, biological treatment methods are found to be the best for decolorization of Reactive Black 5. With respect to dye biosorption, microbial biomass (bacteria, fungi, microalgae, etc, and outperformed macroscopic materials (seaweeds, crab shell, etc. are used for decolorization process. The use of living organisms may not be an option for the continuous treatment of highly toxic organic/inorganic contaminants. Once the toxicant concentration becomes too high or the process operated for a long time, the amount of toxicant accumulated will reach saturation. Beyond this point, an organism's metabolism may be interrupted, resulting in death of the organism. This scenario is not existed in the case of dead biomass, which is flexible to environmental conditions and toxicant concentrations. Thus, owing to its favorable characteristics, biosorption has received much attention in recent years.

  17. Phycoremediation of industrial wastewater containing azo compounds

    OpenAIRE

    Parin D. Shah; Dipti Galani; M S. Rao

    2000-01-01

    This paper summarizes the state-of-the-art biological wastewater treatment technique that uses eukaryotic microalgae as well as several prokaryotic photosynthetic cyanobacteria. Micro algae are known to remove dyes by bioadsorption (sorption of dye molecules over the surface of algal cells), biodegradation and bioconversion (diffusion of dye molecules into the algal cells and subsequent conversion). This paper mainly focuses on biodegradation abilities of microalgae for t...

  18. Hollow Palladium Nanoparticles Facilitated Biodegradation of an Azo Dye by Electrically Active Biofilms

    KAUST Repository

    Kalathil, Shafeer; Chaudhuri, Rajib Ghosh

    2016-01-01

    Dye wastewater severely threatens the environment due to its hazardous and toxic effects. Although many methods are available to degrade dyes, most of them are far from satisfactory. The proposed research provides a green and sustainable approach to degrade an azo dye, methyl orange, by electrically active biofilms (EABs) in the presence of solid and hollow palladium (Pd) nanoparticles. The EABs acted as the electron generator while nanoparticles functioned as the electron carrier agents to enhance degradation rate of the dye by breaking the kinetic barrier. The hollow Pd nanoparticles showed better performance than the solid Pd nanoparticles on the dye degradation, possibly due to high specific surface area and cage effect. The hollow cavities provided by the nanoparticles acted as the reaction centers for the dye degradation.

  19. Hollow Palladium Nanoparticles Facilitated Biodegradation of an Azo Dye by Electrically Active Biofilms

    KAUST Repository

    Kalathil, Shafeer

    2016-08-04

    Dye wastewater severely threatens the environment due to its hazardous and toxic effects. Although many methods are available to degrade dyes, most of them are far from satisfactory. The proposed research provides a green and sustainable approach to degrade an azo dye, methyl orange, by electrically active biofilms (EABs) in the presence of solid and hollow palladium (Pd) nanoparticles. The EABs acted as the electron generator while nanoparticles functioned as the electron carrier agents to enhance degradation rate of the dye by breaking the kinetic barrier. The hollow Pd nanoparticles showed better performance than the solid Pd nanoparticles on the dye degradation, possibly due to high specific surface area and cage effect. The hollow cavities provided by the nanoparticles acted as the reaction centers for the dye degradation.

  20. Hollow Palladium Nanoparticles Facilitated Biodegradation of an Azo Dye by Electrically Active Biofilms

    Directory of Open Access Journals (Sweden)

    Shafeer Kalathil

    2016-08-01

    Full Text Available Dye wastewater severely threatens the environment due to its hazardous and toxic effects. Although many methods are available to degrade dyes, most of them are far from satisfactory. The proposed research provides a green and sustainable approach to degrade an azo dye, methyl orange, by electrically active biofilms (EABs in the presence of solid and hollow palladium (Pd nanoparticles. The EABs acted as the electron generator while nanoparticles functioned as the electron carrier agents to enhance degradation rate of the dye by breaking the kinetic barrier. The hollow Pd nanoparticles showed better performance than the solid Pd nanoparticles on the dye degradation, possibly due to high specific surface area and cage effect. The hollow cavities provided by the nanoparticles acted as the reaction centers for the dye degradation.

  1. DFT Study of the Structure, Reactivity, Natural Bond Orbital and Hyperpolarizability of Thiazole Azo Dyes

    Directory of Open Access Journals (Sweden)

    Osman I. Osman

    2017-02-01

    Full Text Available The structure, reactivity, natural bond orbital (NBO, linear and nonlinear optical (NLO properties of three thiazole azo dyes (A, B and C were monitored by applying B3LYP, CAM-B3LYP and ωB97XD functionals with 6-311++G** and aug-cc-pvdz basis sets. The geometrical parameters,dipolemoments,HOMO-LUMO(highest occupied molecular orbital,lowest unoccupied molecular orbital energy gaps, absorption wavelengths and total hyperpolarizabilities were investigated in carbon tetrachloride (CCl4 chloroform (CHCl3, dichloromethane (CH2Cl2 and dimethlysulphoxide (DMSO. The donor methoxyphenyl group deviates from planarity with the thiazole azo moiety by ca. 38◦; while the acceptor dicyanovinyl, indandione and dicyanovinylindanone groups diverge by ca. 6◦. The HOMOs for the three dyes are identical. They spread over the methoxyphenyl donor moiety, the thiazole and benzene rings as π-bonding orbitals. The LUMOs are shaped up by the nature of the acceptor moieties. The LUMOs of the A, B and C dyes extend over the indandione, malononitrile and dicyanovinylindanone acceptor moieties, respectively, as π-antibonding orbitals. The HOMO-LUMO splittings showed that Dye C is much more reactive than dyes A and B. Compared to dyes A and B, Dye C yielded a longer maximum absorption wavelength because of the stabilization of its LUMOs relative to those of the other two. The three dyes show solvatochromism accompanied by significant increases in hyperpolarizability. The enhancement of the total hyperpolarizability of C compared to those of A and B is due to the cumulative action of the long π-conjugation of the indanone ring and the stronger electron-withdrawing ability of the dicyanovinyl moiety that form the dicyanovinylindanone acceptor group. These findings are facilitated by a natural bond orbital (NBO technique. The very high total hyperpolarizabilities of the three dyes define their potent nonlinear optical (NLO behaviour.

  2. Effect of an azo dye (DR1) on the dielectric parameters of a nematic liquid crystal system

    International Nuclear Information System (INIS)

    Ozder, S.; Okutan, M.; Koeysal, O.; Goektas, H.; San, S.E.

    2007-01-01

    The dielectric parameters and relaxation properties of azo dye (DR1) doped E7 and pure E7 liquid crystal (LC) have been investigated in a wide frequency range of 10 k-10 MHz through the dielectric spectroscopy method at room temperature. Dielectric anisotropy (Δε) property of the LC changes from the positive type to negative type and dielectric anisotropy values decrease with doping of DR1. The relaxation frequency f r of E7 and E7/DR1 LC was calculated by means of Cole-Cole plots. Influence of bias voltage on the dielectric parameters has also been investigated

  3. Isolation, Screening and Development of Local Bacterial Consortia With Azo Dyes Decolourising Capability

    Directory of Open Access Journals (Sweden)

    Khadijah, O.

    2009-01-01

    Full Text Available A total of 1540 bacterial isolates were isolated and screened for their ability to degrade selected azo dyes. Of these, nine isolates were chosen for further studies based on their ability to degrade a wide spectrum of dyes efficiently and rapidly. Several microbial consortia were developed and tested for their effectiveness. Overall the consortia were able to degrade 70 - 100% colour within 72 hours compared to 60 – 97% colour removed by individual isolates. A microbial consortium labelled C15 showed good growth in agitation culture but the colour removal was best in static culture with 80 - 100% colour removed in less than 72 hours. Based on the 16S rRNA sequencing, two of the bacterial isolates in C15 belong to the Chryseobacterium genus while the other one belongs to Flavobacterium genus.

  4. Synthesis and spectroscopic characterization of gallic acid and some of its azo complexes

    Science.gov (United States)

    Masoud, Mamdouh S.; Hagagg, Sawsan S.; Ali, Alaa E.; Nasr, Nessma M.

    2012-04-01

    A series of gallic acid and azo gallic acid complexes were prepared and characterized by elemental analysis, IR, electronic spectra and magnetic susceptibility. The complexes were of different geometries: Octahedral, Tetrahedral and Square Planar. ESR was studied for copper complexes. All of the prepared complexes were of isotropic nature. The thermal analyses of the complexes were studied by DTA and DSC techniques. The thermodynamic parameters and the thermal transitions, such as glass transitions, crystallization and melting temperatures for some ligands and their complexes were evaluated and discussed. The entropy change values, ΔS#, showed that the transition states are more ordered than the reacting complexes. The biological activities of some ligands and their complexes are tested against Gram positive and Gram negative bacteria. The results showed that some complexes have a well considerable activity against different organisms.

  5. Enhanced degradation of azo dye alizarin yellow R in a combined process of iron-carbon microelectrolysis and aerobic bio-contact oxidation.

    Science.gov (United States)

    Liang, Bin; Yao, Qian; Cheng, Haoyi; Gao, Shuhong; Kong, Fanying; Cui, Dan; Guo, Yuqi; Ren, Nanqi; Lee, Duu-Jong; Wang, Aijie

    2012-06-01

    With the aim of enhanced degradation of azo dye alizarin yellow R (AY) and further removal of the low-strength recalcitrant matter (LsRM) of the secondary effluent as much as possible, our research focused on the combination of aerobic bio-contact oxidation (ABO) with iron/carbon microelectrolysis (ICME) process. The combined ABO (with effective volume of 2.4 l) and ICME (with effectively volume of 0.4 l) process were studied with relatively short hydraulic retention time (HRT) of 4 or 6 h. At the HRT of 6 h with the reflux ratio of 1 and 2, the AY degradation efficiency in the final effluent was >96.5%, and the total organic carbon (TOC) removal efficiency were 69.86% and 79.44%, respectively. At the HRT of 4 h and the reflux ratio of 2, TOC removal efficiency and AY degradation efficiency were 73.94% and 94.89%, respectively. The ICME process obviously enhanced the total AY removal and the generated micromolecule acids and aldehydes then that wastewater backflow to the ABO where they were further biodegraded. The present research might provide the potential options for the advanced treatment azo dyes wastewater with short HRT and acceptable running costs.

  6. Biodegradation of carcinogenic textile azo dyes using bacterial isolates of mangrove sediment

    Directory of Open Access Journals (Sweden)

    Guru Prasad Srinivasan

    2014-02-01

    Full Text Available Objective: To evaluate the biodegrading property against carcinogenic azo dyes using bacterial isolates of mangrove sediment. Methods: The bacterial isolates were subjected to submerged fermentation and their growth kinetics were studied. The potential strain was characterized using 16S rDNA sequencing. Results: In the present study, dye degrading bacterial colonies were isolated from the mangrove sediment samples of Parangipettai estuarine area, Tamil Nadu. Of the 30 morphologically different strains isolated, 5 showed antagonistic property. The growth kinetics of the two strains, P1 and G1, which showed potent activity were calculated. One particular isolate (P1 showing promising dye degrading potential in the submerged fermentation was further characterized. The strain was identified as Paenibacillus sp. by 16S rDNA sequencing. Conclusions: This study reveals the less explored microflora of mangrove sediments. The novel strain may further be analyzed and used in the treatment of effluent from dye industry so as to reduce the impact of carcinogenic contaminants.

  7. Decolorization of the azo dye Acid Orange 51 by laccase produced in solid culture of a newly isolated Trametes trogii strain

    OpenAIRE

    Daâssi, Dalel; Zouari-Mechichi, Héla; Frikha, Fakher; Martínez, María Jesús; Nasri, M.; Mechichi, Tahar

    2013-01-01

    This study concerns the decolorization and detoxification of the azo dye Acid Orange 51 (AO51) by crude laccase from Trametes trogii produced in solid culture using sawdust as support media. A three-level Box?Behnken factorial design with four factors (enzyme concentration, 1-hydroxybenzotriazole (HBT) concentration, dye concentration and reaction time) combined with response surface methodology was applied to optimize AO51 decolorization. A mathematical model was developed showing the effect...

  8. Azo dye removal in a membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor.

    Science.gov (United States)

    Cui, Dan; Guo, Yu-Qi; Cheng, Hao-Yi; Liang, Bin; Kong, Fan-Ying; Lee, Hyung-Sool; Wang, Ai-Jie

    2012-11-15

    Azo dyes that consist of a large quantity of dye wastewater are toxic and persistent to biodegradation, while they should be removed before being discharged to water body. In this study, Alizarin Yellow R (AYR) as a model azo dye was decolorized in a combined bio-system of membrane-free, continuous up-flow bio-catalyzed electrolysis reactor (UBER) and subsequent aerobic bio-contact oxidation reactor (ABOR). With the supply of external power source 0.5 V in the UBER, AYR decolorization efficiency increased up to 94.8±1.5%. Products formation efficiencies of p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA) were above 90% and 60%, respectively. Electron recovery efficiency based on AYR removal in cathode zone was nearly 100% at HRTs longer than 6 h. Relatively high concentration of AYR accumulated at higher AYR loading rates (>780 gm(-3) d(-1)) likely inhibited acetate oxidation of anode-respiring bacteria on the anode, which decreased current density in the UBER; optimal AYR loading rate for the UBER was 680 gm(-3) d(-1) (HRT 2.5 h). The subsequent ABOR further improved effluent quality. Overall the Chroma decreased from 320 times to 80 times in the combined bio-system to meet the textile wastewater discharge standard II in China. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Low-Cost Biodegradation and Detoxification of Textile Azo Dye C.I. Reactive Blue 172 by Providencia rettgeri Strain HSL1

    Directory of Open Access Journals (Sweden)

    Harshad Lade

    2015-01-01

    Full Text Available Present study focuses on exploitation of agricultural waste wheat bran (WB as growth medium for degradation of textile azo dye C.I. Reactive Blue 172 (RB 172 using a single bacterium P. rettgeri strain HSL1 (GenBank accession number JX853768.1. The bacterium was found to completely decolorize 50 mg L−1 of dye RB 172 within 20 h at 30 ± 0.2°C under microaerophilic incubation conditions. Additionally, significant reduction in COD (85% and TOC (52% contents of dye decolorized medium was observed which suggested its mineralization. Induction in the activities of azoreductase (159% and NADH-DCIP reductase (88% provided an evidence for reductive cleavage of dye RB 172. The HPLC, FTIR, and GC-MS analysis of decolorized products confirmed the degradation of dye into various metabolites. The proposed metabolic pathway for biodegradation of RB 172 has been elucidated which showed the formation of 2 intermediate metabolites, namely, 4-(ethenylsulfonyl aniline and 1-amino-1-(4-aminophenyl propan-2-one. The acute and phytotoxicity evaluation of degraded metabolites suggests that bacterial strain favors the detoxification of dye RB 172. Thus, WB could be utilized as a low-cost growth medium for the enrichment of bacteria and their further use for biodegradation of azo dyes and its derivatives containing wastes into nontoxic form.

  10. Synthesis and application of new mordent and disperse azo dyes based on 2,4-dihydroxybenzophenone

    Directory of Open Access Journals (Sweden)

    BHARAT C. DIXIT

    2007-02-01

    Full Text Available Novel mordent and disperse azo dyes were prepared by the coupling of various diazo solutions of aromatic amines with 2,4-ihydroxybenzophenone. The resultant dyes were characterized by elemental analyses as well as IR and NMR spectral studies. The UV-visible spectral data have also been iscussed in terms of structural property relationship. The dyeing assessment of all the dyeswas evaluated on wool and polyester textile fibers. The dyeing of chrome treated (i.e., chrome mordented wool and polyesters was also monitored. The results show that a better hue was obtained on mordented fibers. The results of the anti-bacterial properties of the chrome dyes revealed that the toxicity of these dyes against bacteria is fairly good.

  11. Application of Acidic Treated Pumice as an Adsorbent for the Removal of Azo Dye from Aqueous Solutions:kinetic, Equilibrium and Thermodynamic Studies

    Directory of Open Access Journals (Sweden)

    Saied Bashiri

    2012-11-01

    Full Text Available Colored effluents are one of the important environment pollution sources since they contain unused dye compounds which are toxic and less-biodegradable. In this work removal of Acid Red 14 and Acid Red 18 azo dyes was investigated by acidic treated pumice stone as anefficient adsorbent at various experimental conditions. Removal of dye increased with increase in contact time and initial dye concentration, while decreased for increment in solution temperature and pH. Results of the equilibrium study showed that the removal ofAR14 and AR18 followed Freundlich (r2>0.99 and Langmuir (r2>0.99 isotherm models.Maximum sorption capacities were 3.1 and 29.7 mg/g for AR 14 and AR18, namely significantly higher than those reported in the literature, even for activated carbon. Fitting of experimental data onto kinetic models showed the relevance of the pseudo-second order (r2>0.99 and intra-particle diffusion (r2>0.98 models for AR14 and AR18, respectively. For both dyes, the values of external mass transfer coefficient decreased for increasing initial dye concentrations, showing increasing external mass transfer resistance at solid/liquid layer.Desorption experiments confirmed the relevance of pumice stone for dye removal, since the pH regeneration method showed 86% and 89 % regeneration for AR14 and AR18,respectively.

  12. Application of acidic treated pumice as an adsorbent for the removal of azo dye from aqueous solutions: kinetic, equilibrium and thermodynamic studies

    Directory of Open Access Journals (Sweden)

    Samarghandi Mohammad

    2012-11-01

    Full Text Available Abstract Colored effluents are one of the important environment pollution sources since they contain unused dye compounds which are toxic and less-biodegradable. In this work removal of Acid Red 14 and Acid Red 18 azo dyes was investigated by acidic treated pumice stone as an efficient adsorbent at various experimental conditions. Removal of dye increased with increase in contact time and initial dye concentration, while decreased for increment in solution temperature and pH. Results of the equilibrium study showed that the removal of AR14 and AR18 followed Freundlich (r2>0.99 and Langmuir (r2>0.99 isotherm models. Maximum sorption capacities were 3.1 and 29.7 mg/g for AR 14 and AR18, namely significantly higher than those reported in the literature, even for activated carbon. Fitting of experimental data onto kinetic models showed the relevance of the pseudo-second order (r2>0.99 and intra-particle diffusion (r2>0.98 models for AR14 and AR18, respectively. For both dyes, the values of external mass transfer coefficient decreased for increasing initial dye concentrations, showing increasing external mass transfer resistance at solid/liquid layer. Desorption experiments confirmed the relevance of pumice stone for dye removal, since the pH regeneration method showed 86% and 89% regeneration for AR14 and AR18, respectively.

  13. Biofilm inhibition formation of clinical strains of Pseudomonas aeruginosa mutans, photocatalytic activity of azo dye and GC-MS analysis of leaves of Lagerstroemia speciosa.

    Science.gov (United States)

    Sai Saraswathi, V; Kamarudheen, Neethu; Bhaskara Rao, K V; Santhakumar, K

    2017-04-01

    The investigation was conducted to analyse the bioactive compounds from the leaf extracts of L. speciosa by GC-MS. The extracts were screened for antibacterial and antibiofilm activities against potential clinical strains. The bioactive compounds from the leaves of L. speciosa were extracted by soxhlet continuous extraction method and their chemical composition was analysed by Gas Chromatography-Mass Spectroscopy (GC-MS). The antibacterial activity was evaluated against clinical strain like Staphylococcus aureus, Escherichia coli, P. aeruginosa and Salmonella typhi by well diffusion technique. We also screened for antibacterial property against common food borne pathogens namely Listeria monocytogenes and Bacillus cereus at varied concentration 250μml -1 to 1000μml -1 . Thereafter antibiofilm assay was carried out at from 250 to 1000μg/ml against P. aeruginosa (high biofilm forming pathogen) clinical strain by cover slip technique and the morphology of the pathogen was observed using Scanning Electron Microscopy-(SEM). It was observed that diverse class of secondary metabolites were found by GC-MS analysis for all the extracts upon the continuous extraction. It was found that only minimum inhibition was seen in alcoholic extract for antibacterial activity, whereas all other extracts showed negligible activity. P. aeruginosa biofilm inhibited to 93.0±2% and 91±2% at higher concentration (1000μg/ml) for methanolic and ethanolic extract respectively. Absence of extracellular matrix structure and the surface cracking of biofilm were viewed by SEM, which confirmed the antibiofilm activity. Hence this study reveals that L. speciosa showed significant antibiofilm activity against P. aeruginosa due to the phytoconstituents present in the leaf extracts which was well documented in the alcoholic extracts by GC-MS analysis. The methanolic and ethanolic extract showed good photocatalytic activity of 77.44% and 96.66% against azo dye degradation respectively. Further

  14. A Novel Preparation Method of Two Polymer Dyes with Low Cytotoxicity

    Directory of Open Access Journals (Sweden)

    Dongjun Lv

    2017-02-01

    Full Text Available A new preparation method of polymer dyes was developed to improve both the grafting degree of the azo dyes onto O-carboxymethyl chitosan (OMCS and the water solubility of prepared polymer dyes. Firstly, the coupling compound of two azo edible colorants, sunset yellow (SY and allura red (AR, was grafted onto OMCS, and then coupled with their diazonium salt. The chemical structure of prepared polymer dyes was determined by Fourier transform-infrared spectroscopy and 1H-NMR, and the results showed that the two azo dyes were successfully grafted onto OMCS. The grafting degree onto OMCS and the water solubility of polymer dyes were tested, and the results showed that they were both improved as expected. The UV-vis spectra analysis results showed that the prepared polymer dyes showed similar color performance with the original azo dyes. Eventually, the cytotoxicity of prepared polymer dyes was tested and compared with the original azo dyes by a cytotoxicity test on human liver cell lines LO2, and the results showed that their grafting onto OMCS significantly reduced the cytotoxicity.

  15. The influence of Triton X-100 surfactant on the morphology and properties of zinc sulfide nanoparticles for applications in azo dyes degradation

    Energy Technology Data Exchange (ETDEWEB)

    Dumbrava, Anca, E-mail: adumbrava@univ-ovidius.ro [Department of Chemistry and Chemical Engineering, Ovidius University of Constanta, 124 Mamaia Blvd., Constanta 900527 (Romania); Berger, Daniela, E-mail: danaberger01@yahoo.com [University Politehnica of Bucharest, Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, Polizu Street 1-7, Bucharest 011061 (Romania); Prodan, Gabriel [Electron Microscopy Laboratory, Ovidius University of Constanta, 124 Mamaia Blvd., Constanta 900527 (Romania); Matei, Cristian [University Politehnica of Bucharest, Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, Polizu Street 1-7, Bucharest 011061 (Romania); Moscalu, Florin [Department of Physics, Ovidius University of Constanta, 124 Mamaia Blvd., Constanta 900527 (Romania); Diacon, Aurel [University Politehnica of Bucharest, Department of Bioresources and Polymer Science, Polizu Street 1-7, Bucharest 011061 (Romania)

    2017-06-01

    Herein we report the synthesis, by two different routes, of ZnS nanoparticles capped with Triton X-100 (TX), which were characterized by X-ray diffraction, transmission electron microscopy, high resolution electron microscopy, selected area electron diffraction, energy dispersive X-ray spectroscopy, FTIR spectroscopy, UV–visible spectroscopy, photoluminescence spectroscopy, and surface area measurements. The TX-capped ZnS nanopowders have a very good photocatalytic activity and high specific surface area, depending on the synthesis route; e.g. an azo dye solution is almost complete photobleached in only 60 min (a photocatalytic activity of 97.79%) using TX-capped ZnS nanopowder, with specific surface area of 191 m{sup 2}/g, and further a photocatalytic activity of 99.75% was achieved in 120 min. Based on the photocatalytic results, the ZnS nanopowders can be considered suitable catalysts for a green, very efficient and quick strategy for removing of organic pollutants from wastewaters. - Highlights: • Triton X-100 was used as surfactant in ZnS nanopowders synthesis by two methods. • Triton X-capped ZnS nanoparticles with high specific surface area were synthesized. • A very high capacity for bleaching an azo dye solution was evidenced. • Some of ZnS powders properties were crucially modified by the synthesis technique.

  16. The influence of Triton X-100 surfactant on the morphology and properties of zinc sulfide nanoparticles for applications in azo dyes degradation

    International Nuclear Information System (INIS)

    Dumbrava, Anca; Berger, Daniela; Prodan, Gabriel; Matei, Cristian; Moscalu, Florin; Diacon, Aurel

    2017-01-01

    Herein we report the synthesis, by two different routes, of ZnS nanoparticles capped with Triton X-100 (TX), which were characterized by X-ray diffraction, transmission electron microscopy, high resolution electron microscopy, selected area electron diffraction, energy dispersive X-ray spectroscopy, FTIR spectroscopy, UV–visible spectroscopy, photoluminescence spectroscopy, and surface area measurements. The TX-capped ZnS nanopowders have a very good photocatalytic activity and high specific surface area, depending on the synthesis route; e.g. an azo dye solution is almost complete photobleached in only 60 min (a photocatalytic activity of 97.79%) using TX-capped ZnS nanopowder, with specific surface area of 191 m 2 /g, and further a photocatalytic activity of 99.75% was achieved in 120 min. Based on the photocatalytic results, the ZnS nanopowders can be considered suitable catalysts for a green, very efficient and quick strategy for removing of organic pollutants from wastewaters. - Highlights: • Triton X-100 was used as surfactant in ZnS nanopowders synthesis by two methods. • Triton X-capped ZnS nanoparticles with high specific surface area were synthesized. • A very high capacity for bleaching an azo dye solution was evidenced. • Some of ZnS powders properties were crucially modified by the synthesis technique.

  17. Mycoremediation of congo red dye by filamentous fungi

    OpenAIRE

    Bhattacharya, Sourav; Das, Arijit; G, Mangai.; K, Vignesh.; J, Sangeetha.

    2011-01-01

    Azo, anthroquinone and triphenylmethane dyes are the major classes of synthetic colourants, which are difficult to degrade and have received considerable attention. Congo red, a diazo dye, is considered as a xenobiotic compound, and is recalcitrant to biodegradative processes. Nevertheless, during the last few years it has been demonstrated that several fungi, under certain environmental conditions, are able to transfer azo dyes to non toxic products using laccases. The aim of this work was t...

  18. Use of 4-Amino-Naphtalene sulfonic acid as a the sole carbon, nitrogen and sulphur source, by a microbial community

    International Nuclear Information System (INIS)

    Velasquez-Garcia, A.; Salazar-Huerta, A.; Cobos-Casconcelos de los, D.; Santoyo-Tepole, F.; Juarez-Ramirez, C.; Ruiz-Ordaz, N.; Galindez-Mayer, J.

    2009-01-01

    Sulphonated aromatic amines are toxic compounds widely used in chemical synthesis of pharmaceuticals, pesticides and azo dyes. They also generated by degradation of many ozo compounds. Sulphonated amines are readily soluble in water, thus causing damage when discharged to aquatic environments. (Author)

  19. Novel salicylazo polymers for colon drug delivery: dissolving polymers by means of bacterial degradation.

    Science.gov (United States)

    Saphier, Sigal; Karton, Yishai

    2010-02-01

    Novel azo polymers were prepared for colonic drug delivery with a release mechanism based on structural features of azo derivatives designed for rapid bacterial degradation leading to soluble polymers. Two Salicylazo derivatives were prepared and conjugated as side chains at different ratios to methacrylic acid-methyl methacrylate copolymers (Eudragits). The azo compounds were designed to have a hydrophilic and a hydrophobic part on opposite sides of the azo bond. Upon reduction of the azo bonds, the hydrophobic part is released, resulting in a more water soluble polymer. The solubility of the polymeric films was studied relative to Eudragit S known to dissolve toward the end of the small intestine. One of the two azo derivatives prepared gave rise to polymers, which showed reduced solubility relative to Eudragit S. These polymers were subjected to reduction tests in anaerobic rat cecal suspensions by following the release of the hydrophobic product. Reduction rate was found to be rapid, comparable to that of Sulfasalazine. Studies on the azopolymeric films in anaerobic rat cecal suspensions, showed that these polymers dissolve faster than in sterilized suspensions. Solid dosage forms may be coated with these polymers to provide an efficient delivery system to the colon with a rapid release mechanism. (c) 2009 Wiley-Liss, Inc. and the American Pharmacists Association.

  20. Adsorption mechanism and kinetics of azo dye chemicals on oxide nanotubes: a case study using porous CeO_2 nanotubes

    International Nuclear Information System (INIS)

    Wu, Junshu; Wang, Jinshu; Du, Yucheng; Li, Hongyi; Jia, Xinjian

    2016-01-01

    Metal oxide nanotubes are believed to be promising materials with adsorption functionality for water purification due to their synergistic effect of the overall microscale morphology for easy separation and nanoscale surface characters providing enough surface active absorption sites. This work shows the synthesis of uniform hierarchical porous CeO_2 nanotubes via nanowire-directed templating method and describes the adsorption behavior of CeO_2 nanotubes for a typical azo dye Congo red which has resistance to oxidation and decoloration in natural conditions. Fourier transform infrared spectroscopy spectra provided the evidence that Congo red was successfully coated on the surface of CeO_2 nanotubes by both bidentate-type bridge link of Ce"4"+ cations from sulfonate SO_3"− groups and the electrostatic attraction between the protonated surface generated by oxygen vacancies and dissociated sulfonate groups. The adsorption kinetic data fitted well to the pseudo-second-order kinetic equation, whereas the Langmuir isotherm equation exhibited better correlation with the experimental data. The calculated maximum adsorption capacity from the isothermal model was 362.32 mg/g. In addition, the prepared CeO_2 nanotubes exhibited good recyclability and reusability as highly efficient adsorbents for Congo red removal after regeneration. These favorable performances enable the obtained CeO_2 nanotubes to be promising materials for dye removal from aqueous solution.Graphical AbstractCeO_2 nanotubes composed of crystallized nanoparticles exhibit well adsorption ability for a typical azo dye Congo red.

  1. New azo coupling reactions for visible spectrophotometric determination of salbutamol in bulk and pharmaceutical preparations

    International Nuclear Information System (INIS)

    Dhahir, S. A.

    2011-01-01

    The purpose of the present study was to develop a new, simple, cheap, fast, accurate, and sensitive colorimetric methods that can be used for the determination of salbutamol sulphate drug in pure from as well as in pharmaceutical formulations. The method is based on the reaction 2-chloro-4-nitroaniline with nitrite in acid medium to form diazonium ion, which is coupled with of salbutamol in basic medium to form azo dyes, showing yellow color and absorption maxima at 463 nm. Beer's law is obeyed in the concentration of 4-48μg/ml. The molar absorptivity and san dell's sensitivity are 5.27x103 L mole-1 cm-1, 0.015 μgcm-2, respectively. The optimum reaction conditions and other analytical parameters were evaluated. (author).

  2. Fenton oxidative decolorization of the azo dye Direct Blue 15 in aqueous solution

    DEFF Research Database (Denmark)

    Sun, Jian-Hui; Shi, Shao-Hui; Lee, Yi-Fan

    2009-01-01

    In this paper, the application of Fenton oxidation process for the decolorization of an azo dye Direct Blue 15 (DB15) in aqueous solution was investigated. The effect of initial pH, dosage of H2O2, H2O2/Fe2+ and H2O2/dye ratios and the reaction temperature on the decolorization efficiency...... = 60: 1 and temperature = 30 degrees C. Under the optimal conditions, 4.7 x 10(-5) mol/L of the DB15 aqueous solution can be completely decolorized by Fenton oxidation within 50-min reaction time and the decolorization kinetic rate constant k was determined as 0.1694 min(-1). Additionally increasing...... the reaction temperature from 20 to 40 degrees C showed a positive effect on the decolorization efficiency of DB15. The present study can provide guidance to relational industry operators and planners to effectively treat the DB15 contaminated wastewater by Fenton oxidation process. (C) 2009 Elsevier B. V. All...

  3. Roentgenographic and derivatographic investigation of gallium and indium complexes with azo compounds on the base of pyrogallol

    International Nuclear Information System (INIS)

    Gambarov, D.G.; Rzaev, R.Z.; Musaev, F.N.; Musaeva, A.N.; Chyragov, F.M.

    1985-01-01

    Seven complexes of gallium and indium with N-donor ligands obtained on the base of pyrogallol are synthesized. Their chemical composition is established. Nitrogen-containing ligands and their complexes are investigated by the methods of roentgenographic and thermogravimetric analyses. It is shown that gallium and indium complexes are amorphous compounds. An assumption is made on the thermolysis character that complexes have a similar structure: structural complex nucleus constitutes a six-term chelate ring. Para-substitutors in the ligand do not participate in complexing, possibly they participate in H-bonds formation. It is established by spectrophotometric methods that in solutions stoichiometric ratio metal: ligand is the same as in the solid phase

  4. Roentgenographic and derivatographic investigation of gallium and indium complexes with azo compounds on the base of pyrogallol

    Energy Technology Data Exchange (ETDEWEB)

    Gambarov, D G; Rzaev, R Z; Musaev, F N; Musaeva, A N; Chyragov, F M

    1985-01-01

    Seven complexes of gallium and indium with N-donor ligands obtained on the base of pyrogallol are synthesized. Their chemical composition is established. Nitrogen-containing ligands and their complexes are investigated by the methods of roentgenographic and thermogravimetric analyses. It is shown that gallium and indium complexes are amorphous compounds. An assumption is made on the thermolysis character that complexes have a similar structure: structural complex nucleus constitutes a six-term chelate ring. Para-substitutors in the ligand do not participate in complexing, possibly they participate in H-bonds formation. It is established by spectrophotometric methods that in solutions stoichiometric ratio metal: ligand is the same as in the solid phase.

  5. Deciphering effects of functional groups and electron density on azo dyes degradation by graphene loaded TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qian [College of Chemical Engineering, HuaQiao University, Xiamen 361021 (China); Liang, Xiao [School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093 (China); Chen, Bor-Yann [Department of Chemical and Materials Engineering, National I-Lan University, 26047, Taiwan (China); Chang, Chang-Tang, E-mail: ctchang@niu.edu.tw [Department of Environmental Engineering, National I-Lan University, 26047, Taiwan (China)

    2015-12-01

    Highlights: • The degradation pathways of RB5, RB171 and RR198 have been identified. • The favorable bond to be broken under photo degradation was deciphered in this research. • The breakages of the bonds were due to the electron density changes around the bonds. • The hydroxyl radicals as the main oxidized species were confirmed by positive hole trapper and ESR. - Abstract: This study tended to decipher the mechanism of photo degradation of azo dyes, which bond was favorable to be broken for application of wastewater decolorization. That is, from chemical structure perspective, the critical substituents to affect electron donor/acceptor for dye degradation would be identified in this research. The model reactive blacks (RB5), reactive blue 171 (RB171) and reactive red 198 (RR198) were degraded by graphene loaded TiO{sub 2}, indicating how the electron withdrawing and releasing groups affect azo dye degradability. The byproducts and intermediate products were analyzed by ultraviolet–visible spectroscopy (UV–vis), gas chromatography–mass spectrometry (GC–MS) and ion chromatography (IC). Furthermore, the radicals involved in the reaction were found by electron paramagnetic resonance (ESR) to confirm the main oxidized species of hydroxyl radicals rather than the light generated positive holes. The finding revealed that the breakages of the bonds were due to the electron density changes around the bonds. This principle can be applicable not only for RB5 degradation, but also for reactive blue 171 (RB171), reactive red 198 (RR198) and some other textile dyes.

  6. ISOLATION AND CHARACTERIZATION OF A MOLYBDENUM-REDUCING AND AZO-DYE DECOLORIZING SERRATIA MARCESCENS STRAIN NENI-1 FROM INDONESIAN SOIL

    Directory of Open Access Journals (Sweden)

    Neni Gusmanizar

    2016-01-01

    Full Text Available Heavy metals and organic xenobiotics including dyes are important industrial components with their usage amounting to the millions of tonnes yearly. Their presence in the environment is a serious pollution issue globally. Bioremediation of these pollutants using microbes with multiple detoxification capacity is constantly being sought. In this work we screen the ability of a molybdenum-reducing bacterium isolated from contaminated soil to decolorize various azo and triphenyl methane dyes. The bacterium reduces molybdate to molybdenum blue (Mo-blue optimally at pH 6.0, and temperatures of between 25 and 40oC. Glucose was the best electron donor for supporting molybdate reduction followed by sucrose, trehalose, maltose, d-sorbitol, dmannitol, d-mannose, myo-inositol, glycerol and salicin in descending order. Other requirements include a phosphate concentration of between 5.0 and 7.5 mM and a molybdate concentration between 10 and 20 mM. The absorption spectrum of the Moblue produced was similar to previous Mo-reducing bacterium, and closely resembles a reduced phosphomolybdate. Molybdenum reduction was inhibited by copper, silver and mercury at 2 ppm by 43.8%, 42.3% and 41.7%, respectively. We screen for the ability of the bacterium to decolorize various dyes. The bacterium was able to decolorize the dye Congo Red. Biochemical analysis resulted in a tentative identification of the bacterium as Serratia marcescens strain Neni-1. The ability of this bacterium to detoxify molybdenum and decolorize azo dye makes this bacterium an important tool for bioremediation.

  7. Synthesis, structure and study of azo-hydrazone tautomeric equilibrium of 1,3-dimethyl-5-(arylazo)-6-amino-uracil derivatives

    Science.gov (United States)

    Debnath, Diptanu; Roy, Subhadip; Li, Bing-Han; Lin, Chia-Her; Misra, Tarun Kumar

    2015-04-01

    Azo dyes, 1,3-dimethyl-5-(arylazo)-6-aminouracil (aryl = -C6H5 (1), -p-CH3C6H4 (2), -p-ClC6H4 (3), -p-NO2C6H4 (4)) were prepared and characterized by UV-vis, FT-IR, 1H NMR, 13C NMR spectroscopic techniques and single crystal X-ray crystallographic analysis. In the light of spectroscopic analysis it evidences that of the tautomeric forms, the azo-enamine-keto (A) form is the predominant form in the solid state whereas in different solvents it is the hydrazone-imine-keto (B) form. The study also reveals that the hydrazone-imine-keto (B) form exists in an equilibrium mixture with its anionic form in various organic solvents. The solvatochromic and photophysical properties of the dyes in various solvents with different hydrogen bonding parameter were investigated. The dyes exhibit positive solvatochromic property on moving from polar protic to polar aprotic solvents. They are fluorescent active molecules and exhibit high intense fluorescent peak in some solvents like DMSO and DMF. It has been demonstrated that the anionic form of the hydrazone-imine form is responsible for the high intense fluorescent peak. In addition, the acid-base equilibrium in between neutral and anionic form of hydrazone-imine form in buffer solution of varying pH was investigated and evaluated the pKa values of the dyes by making the use of UV-vis spectroscopic methods. The determined acid dissociation constant (pKa) values increase according to the sequence of 2 > 1 > 3 > 4.

  8. Reaction of the antitumor antibiotic olivomycin I with aryl diazonium salts. Synthesis, cytotoxic and antiretroviral potency of 5-aryldiazenyl-6-O-deglycosyl derivatives of olivomycin I.

    Science.gov (United States)

    Tevyashova, Anna N; Olsufyeva, Eugenia N; Turchin, Konstantin F; Balzarini, Jan; Bykov, Eugenyi E; Dezhenkova, Lyubov G; Shtil, Alexander A; Preobrazhenskaya, Maria N

    2009-07-15

    The azo coupling of the antibiotic olivomycin I (1) with aryl diazonium tetrafluoroborates produced 5-aryldiazenyl-6-O-deglycosyl derivatives of 1. The structures of new compounds were confirmed by (1)H NMR and mass spectrometry analysis. A quantum-chemical study was performed to analyze the possible directions of electrophilic substitution of 1 and the easiness of 6-O-disaccharide hydrolysis in the course of azo coupling. The antiproliferative and anti-retroviral activities of novel derivatives were studied.

  9. Removal of Azo Dye from Synthetic Wastewater Using Immobilized Nano-Diatomite Within Calcium Alginate

    Directory of Open Access Journals (Sweden)

    AA Khodabandelou

    2016-03-01

    Full Text Available Introduction: The presence of organic dyes, discharged by textile industries, in aqueous environments can cause detrimental effects on aquatic life and subsequently human health. Therefore, the decolorization of aquatic environments is mandatory to protect the environment. For this reason, in the present study, nano-sized diatomite was immobilized within calcium alginate as a nanocomposite adsorbent for removing organic azo dye (Direct blue 15 from aqueous solutions.  Methods: First of all, Iranian diatomite was grinded in a planetary ball mill equipped with tungsten carbide cup for 20 h to achieve nanoparticles of the diatomite. For the immobilization of nanostructured diatomite, a 2% sodium alginate solution was used. Scanning electron microscopy (SEM, X-ray diffraction (XRD and Fourier transform infra-red (FT-IR spectroscopy were used to characterize immobilized nano-diatomite. Fifty milliliter Erlenmeyer flasks were used as batch flow mode experimental reactors. Working solutions were prepared by the dilution of stock solution (1 g/L to desired concentrations. The effect of different operational parameters including contact time, initial pH, adsorbent dosage and initial dye concentration along with kinetic and isotherm of the adsorption were evaluated. After each experiment, the residual concentration of the dyes was measured spectrophotometrically. Results: As results, the adsorption of organic dye increased with increasing contact time and adsorbent dosage, while increasing initial dye concentrations resulted in decreasing the adsorption. The adsorption of DB-15 was favored at basic PH. The immobilization of diatomite led to enhancing the adsorption of  DB-15 compared to diatomite alone. According to the obtained correlation coefficient, the adsorption of DB-15 obeyed pseudo-second order kinetic model and Langmuir isotherm model. The maximum adsorption capacity of diatomite/alginate nanocomposite for the adsorption of DB-15 were found

  10. Azoreductase and dye detoxification activities of Bacillus velezensis strain AB.

    Science.gov (United States)

    Bafana, Amit; Chakrabarti, Tapan; Devi, Sivanesan Saravana

    2008-01-01

    Azo dyes are known to be a very important and widely used class of toxic and carcinogenic compounds. Although lot of research has been carried out for their removal from industrial effluents, very little attention is given to changes in their toxicity and mutagenicity during the treatment processes. Present investigation describes isolation of a Bacillus velezensis culture capable of degrading azo dye Direct Red 28 (DR28). Azoreductase enzyme was isolated from it, and its molecular weight was found to be 60 kDa. The enzyme required NADH as cofactor and was oxygen-insensitive. Toxicity and mutagenicity of the dye during biodegradation was monitored by using a battery of carefully selected in vitro tests. The culture was found to degrade DR28 to benzidine and 4-aminobiphenyl, both of which are potent mutagens. However, on longer incubation, both the compounds were degraded further, resulting in reduction in toxicity and mutagenicity of the dye. Thus, the culture seems to be a suitable candidate for further study for both decolourization and detoxification of azo dyes, resulting in their safe disposal.

  11. Fast response dry-type artificial molecular muscles with [c2]daisy chains

    Science.gov (United States)

    Iwaso, Kazuhisa; Takashima, Yoshinori; Harada, Akira

    2016-06-01

    Hierarchically organized myosin and actin filaments found in biological systems exhibit contraction and expansion behaviours that produce work and force by consuming chemical energy. Inspired by these naturally occurring examples, we have developed photoresponsive wet- and dry-type molecular actuators built from rotaxane-based compounds known as [c2]daisy chains (specifically, [c2]AzoCD2 hydrogel and [c2]AzoCD2 xerogel). These actuators were prepared via polycondensation between four-armed poly(ethylene glycol) and a [c2]daisy chain based on α-cyclodextrin as the host component and azobenzene as a photoresponsive guest component. The light-induced actuation arises from the sliding motion of the [c2]daisy chain unit. Ultraviolet irradiation caused the gels to bend towards the light source. The response of the [c2]AzoCD2 xerogel, even under dry conditions, is very fast (7° every second), which is 10,800 times faster than the [c2]AzoCD2 hydrogel (7° every 3 h). In addition, the [c2]AzoCD2 xerogel was used as a crane arm to lift an object using ultraviolet irradiation to produce mechanical work.

  12. New self-assembled material based on Ru nanoparticles and 4-sulfocalix[4]arene as an efficient and recyclable catalyst for reduction of brilliant yellow azo dye in water: a new model catalytic reaction

    Energy Technology Data Exchange (ETDEWEB)

    Rambabu, Darsi; Pradeep, Chullikkattil P.; Dhir, Abhimanew, E-mail: abhimanew@iitmandi.ac.in [Indian Institute of Technology (India)

    2016-12-15

    New self-assembled material (Ru@SC) with ruthenium nanoparticles (Ru NPs) and 4-sulfocalix[4]arene (SC) is synthesized in water at room temperature. Ru@SC is characterized by thermal gravimetric analysis, FT-IR, powder x-ray diffraction, TEM and SEM analysis. The size of Ru nanoparticles in the self-assembly is approximately 5 nm. The self-assembled material Ru@SC shows an efficient catalytic reduction of toxic ‘brilliant yellow’ (BY) azo dye. The reduced amine products were successfully separated and confirmed by single-crystal XRD, NMR and UV-Vis spectroscopy. Ru@SC showed a better catalytic activity in comparison with commercial catalysts Ru/C (ruthenium on charcoal 5 %) and Pd/C (palladium on charcoal 5 and 10 %). The catalyst also showed a promising recyclability and heterogeneous nature as a catalyst for reduction of ‘BY’ azo dye.

  13. Spectrophotometric determination of sildenafil citrate in pure form and in pharmaceutical formulation using some chromotropic acid azo dyes

    Science.gov (United States)

    Issa, Y. M.; El-Hawary, W. F.; Youssef, A. F. A.; Senosy, A. R.

    2010-04-01

    Two simple and highly sensitive spectrophotometric methods were developed for the quantitative determination of the drug sildenafil citrate (SC), Viagra, in pure form and in pharmaceutical formulations, through ion-associate formation reactions (method A) with mono-chromotropic acid azo dyes, chromotrope 2B (I) and chromotrope 2R (II) and ion-pair reactions (method B) with bi-chromotropic acid azo dyes, 3-phenylazo-6-o-carboxyphenylazo-chromotropic acid (III), bis-3,6-(o-hydroxyphenylazo)-chromotropic acid (IV), bis-3,6-(p-N,N-dimethylphenylazo)-chromotropic acid (V) and 3-phenylazo-6-o-hydroxyphenylazo-chromotorpic acid (VI). The reaction products, extractable in methylene chloride, were quantitatively measured at 540, 520, 540, 570, 600 and 575 nm using reagents, I-VI, respectively. The reaction conditions were studied and optimized. Beer's plots were linear in the concentration ranges 3.3-87.0, 3.3-96.0, 5.0-115.0, 2.5-125.0, 8.3-166.7 and 0.8-15.0 μg mL -1 with corresponding molar absorptivities 1.02 × 10 4, 8.34 × 10 3, 6.86 × 10 3, 5.42 × 10 3, 3.35 × 10 3 and 2.32 × 10 4 L mol -1 cm -1 using reagents I-VI, respectively. The limits of detection and Sandell's sensitivities were calculated. The methods were successfully applied to the analysis of commercial tablets (Vigoran) and the recovery study reveals that there is no interference from the common excipients that are present in tablets. Statistical comparison of the results was performed with regard to accuracy and precision using Student's t- and F-tests at 95% confidence level. There is no significant difference between the reported and proposed methods with regard to accuracy and precision.

  14. Photoassisted Electrochemical Treatment of Azo and Phtalocyanine Reactive Dyes in the Presence of Surfactants

    Science.gov (United States)

    Sala, Mireia; López-Grimau, Víctor; Gutiérrez-Bouzán, Carmen

    2016-01-01

    An electrochemical treatment (EC) was applied at different intensities to degrade the chromophoric groups of dyes C.I. Reactive Black 5 (RB5) and C.I. Reactive Blue 7 (Rb7) until uncolored species were obtained. Decolorization rate constants of the azo dye RB5 were higher than the phtalocyanine Rb7 ones. In addition, the EC treatment was more efficient at higher intensities, but these conditions significantly increased the generation of undesirable by-products such as chloroform. The combination of EC with UV irradiation (UVEC) drastically minimized the generation of chloroform. The photo-assisted electrochemical treatment was also able to achieve decolorization values of 99%. Finally, mixtures of dyes and surfactants were treated by EC and UVEC. In the presence of surfactants, the decolorization kinetic of dyes was slowed due to the competitive reactions of surfactants degradation. Both methods achieved total decolorization and in both cases, the generation of haloforms was negligible. PMID:28773335

  15. Characterization of an azo-calix[4]arene-based optical sensor for Europium (III) ions

    International Nuclear Information System (INIS)

    Echabaane, M.; Rouis, A.; Bonnamour, I.; Ouada, H. Ben

    2012-01-01

    Selective and sensitive optical sensor membranes (optodes) were elaborated to detect cations in aqueous solutions. The sensing films are based on chromogenic calix[4]arene derivatives. The optode membranes were studied using UV/Vis absorption spectroscopy measurements. The sensitivity of the optode has been tested for Pb 2+ , Cd 2+ , Mg 2+ and Eu 3+ ions at pH 6.8. The results showed a good selectivity response towards Eu 3+ . Low selectivity coefficients were observed for Cd 2+ and Mg 2+ where Pb 2+ can be considered as interfering ions. The characteristics of this optode such as response time, regeneration, reproducibility and lifetime are discussed. - Highlights: ► We report optical sensing studies of chromogenic calixarene derivatives. ► We investigate optical interaction between azo-calix[4]arene and Eu 3+ . ► We study sensitivity and selectivity of optode films. ► We describe characteristics of optode films for determination of europium traces.

  16. Electrochemical characteriztion of the bioanode during simultaneous azo dye decolorization and bioelectricity generation in an air-cathode single chambered microbial fuel cell

    International Nuclear Information System (INIS)

    Sun Jian; Hu Yongyou; Hou Bin

    2011-01-01

    To achieve high power output based on simultaneously azo dye decolorization using microbial fuel cell (MFC), the bioanode responses during decolorization of a representative azo dye, Congo red, were investigated in an air-cathode single chambered MFC using representative electrochemical techniques. It has been found that the maximum stable voltage output was delayed due to slowly developed anode potential during Congo red decolorization, indicating that the electrons recovered from co-substrate are preferentially transferred to Congo red rather than the bioanode of the MFC and Congo red decolorization is prior to electricity generation. Addition of Congo red had a negligible effect on the Ohmic resistance (R ohm ) of the bioanode, but the charge-transfer resistance (R c ) and the diffusion resistance (R d ) were significantly influenced. The R c and R d firstly decreased then increased with increase of Congo red concentration, probably due to the fact that the Congo red and its decolorization products can act as electron shuttle for conveniently electrons transfer from bacteria to the anode at low concentration, but result in accelerated consumption of electrons at high concentration. Cyclic voltammetry results suggested that Congo red was a more favorable electron acceptor than the bioanode of the MFC. Congo red decolorization did not result in a noticeable decrease in peak catalytic current until Congo red concentration up to 900 mg l -1 . Long-term decolorization of Congo red resulted in change in catalytic active site of anode biofilm.

  17. Enzyme-mediated bacterial biodegradation of an azo dye (C.I. Acid blue 113): reuse of treated dye wastewater in post-tanning operations.

    Science.gov (United States)

    Senthilvelan, T; Kanagaraj, J; Panda, R C

    2014-11-01

    "Dyeing" is a common practice used to color the hides during the post-tanning operations in leather processing generating plenty of wastewater. The waste stream containing dye as pollutant is severely harmful to living beings. An azo dye (C.I. Acid Blue 113) has been biodegraded effectively by bacterial culture mediated with azoreductase enzyme to reduce the pollution load in the present investigation. The maximum rate of dye degradation was found to be 96 ± 4 and 92 ± 4 % for the initial concentrations of 100 and 200 mg/l, respectively. The enzyme activity was measured using NADH as a substrate. Fourier transform infrared spectroscopy (FT-IR) analysis was confirmed that the transformation of azo linkage could be transformed into N2 or NH3 or incorporated into complete biomass. Breaking down of dye molecules to various metabolites (such as aniline, naphthalene-1,4-diamine, 3-aminobenzenesulfonic acid, naphthalene-1-sulfonic acid, 8-aminonaphthalene-1-sulfonic acid, 5,8-diaminonaphthalene-1-sulfonic acid) was confirmed by gas chromatography and mass spectra (GC-MS) and mass (electrospray ionization (ESI)) spectra analysis. The treated wastewater could be reused for dyeing operation in the leather processing, and the properties of produced leather were evaluated by conventional methods that revealed to have improved dye penetration into the grain layer of experimental leather sample and resulted in high levelness of dyeing, which helps to obtain the desired smoothness and soft leather properties.

  18. Adsorption mechanism and kinetics of azo dye chemicals on oxide nanotubes: a case study using porous CeO{sub 2} nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Junshu; Wang, Jinshu, E-mail: wangjsh@bjut.edu.cn; Du, Yucheng; Li, Hongyi; Jia, Xinjian [Beijing University of Technology, School of Materials Science and Engineering (China)

    2016-07-15

    Metal oxide nanotubes are believed to be promising materials with adsorption functionality for water purification due to their synergistic effect of the overall microscale morphology for easy separation and nanoscale surface characters providing enough surface active absorption sites. This work shows the synthesis of uniform hierarchical porous CeO{sub 2} nanotubes via nanowire-directed templating method and describes the adsorption behavior of CeO{sub 2} nanotubes for a typical azo dye Congo red which has resistance to oxidation and decoloration in natural conditions. Fourier transform infrared spectroscopy spectra provided the evidence that Congo red was successfully coated on the surface of CeO{sub 2} nanotubes by both bidentate-type bridge link of Ce{sup 4+} cations from sulfonate SO{sub 3}{sup −} groups and the electrostatic attraction between the protonated surface generated by oxygen vacancies and dissociated sulfonate groups. The adsorption kinetic data fitted well to the pseudo-second-order kinetic equation, whereas the Langmuir isotherm equation exhibited better correlation with the experimental data. The calculated maximum adsorption capacity from the isothermal model was 362.32 mg/g. In addition, the prepared CeO{sub 2} nanotubes exhibited good recyclability and reusability as highly efficient adsorbents for Congo red removal after regeneration. These favorable performances enable the obtained CeO{sub 2} nanotubes to be promising materials for dye removal from aqueous solution.Graphical AbstractCeO{sub 2} nanotubes composed of crystallized nanoparticles exhibit well adsorption ability for a typical azo dye Congo red.

  19. Evaluation on the Photosensitivity of 2,2′-Azobis(2,4-DimethylValeronitrile with UV

    Directory of Open Access Journals (Sweden)

    Yi Yang

    2017-12-01

    Full Text Available Azo compounds have high exothermic characteristics and low thermal stability, which have caused many serious thermal accidents around the world. In general, different locations (e.g., equatorial or polar regions have different UV intensities. If the azo compound exists in an inappropriately stored or transported condition, the decrease in thermal stability may cause a thermal hazard or ageing. 2,2′-Azobis(2,4-dimethylvaleronitrile (ADVN is investigated with respect to the thermal stability affected by UV exposure at 0, 6, 12, and 24 h. When ADVN is exposed to 24 h of UV (100 mW/m2 and 254 nm, T0 is not only advanced, but the mass loss is also increased during the main decomposition stage. In addition, the apparent activation energy and integral procedural decomposition temperature (IPDT of ADVN exposed to 24 h of UV is calculated by kinetic models. Therefore, the prevention mechanism, thermal characteristics, and kinetic parameters are established in our study. We should isolate UV contacting ADVN under any situations, avoiding ADVN being aged or leading to thermal runaway. This study provided significant information for a safer process under changing UV exposure times for ADVN. Furthermore, the research method may serve as an important benchmark for handling potentially hazardous chemicals, such as azo compounds described herein.

  20. Facile synthesis of 1-naphthol azo dyes with nano SiO2/HIO4 under solvent-free conditions

    Directory of Open Access Journals (Sweden)

    A.R. Pourali

    2013-09-01

    Full Text Available Nano-silica supported periodic acid (nano-SPIA has been utilized as a heterogeneous reagent for a highly efficient and one pot synthesis of azo dyes based on 1-naphthol under solvent-free conditions at room temperature. This method has some advantages, the reaction workup is very easy and the catalyst can be easily separated from the reaction mixture and one-pot procedure. The related products have been obtained in good to excellent yields, high purity and short reaction times. The structures of the products have been characterized by several techniques using UV-Vis, FT-IR, 1H NMR, 13C NMR and mass spectra.DOI: http://dx.doi.org/10.4314/bcse.v27i3.13

  1. Efficiency of Polymeric Membrane Graphene Oxide-TiO2 for Removal of Azo Dye

    Directory of Open Access Journals (Sweden)

    Elahe Dadvar

    2017-01-01

    Full Text Available Achieving the desired standard of drinking water quality has been one of the concerns across water treatment plants in the developing countries. Processes such as grid chamber, coagulation, sedimentation, clarification, filtration, and disinfection are typically used in water purification plants. Among these methods, unit filtration which employs polymers is one of the new technologies. There have been many studies about the use of semiconductive TiO2 with graphene oxide (GO on the base of different polymeric membranes for the removal of azo dyes, especially methylene blue (MB. Polymeric GO-TiO2 membranes have high photocatalytic, antifouling property and permeate the flux removal of organic pollutants. The aim of this study was to investigate the characteristics of different polymeric membranes such as anionic perfluorinated polymer (Nafion, cellulose acetate, polycarbonate (PC, polysulfone fluoride (PSF, and polyvinylidene fluoride (PVDF. The result of this study showed that the GO-TiO2 membrane can be used in the field of water treatment and will be used for the removal of polycyclic aromatic hydrocarbons (PAHs from wastewater.

  2. Electrochemical and optical properties of new soluble dithienylpyrroles based on azo dyes

    International Nuclear Information System (INIS)

    Cihaner, Atilla; Algi, Fatih

    2009-01-01

    Two dithienylpyrroles based on azo dyes, namely 2,5'-dimethyl-[4-(2,5-di-thiophen-2-yl-pyrrol-1-yl)-phenyl]azobenzene (SNS-AB2) and 2,5'-dimethyloxy-[4-(2,5-di-thiophen-2-yl-pyrrol-1-yl)-phenyl]azobenzene (SNS-AB3), were synthesized and their corresponding polymers (PSNS-AB2 and PSNS-AB3) were successfully obtained via electropolymerization. The monomers have lower oxidation potentials (0.75 V and 0.80 V vs. Ag/AgCl for SNS-AB2 and SNS-AB3, respectively) when compared to their analogous. Both monomers exhibited photoisomerism properties under irradiation at 360 nm. During the irradiation process, for example, the color of SNS-AB3 changes from yellow to greenish yellow. The electroactive polymer films have well defined and reversible redox couples with a good cycle stability in both aqueous and organic solutions. The polymer films also exhibited electrochromic behaviors; color changes from yellowish green to dark green for the PSNS-AB2 (λ max = 435 nm and E g = 2.31 eV) and from mustard color to green for PSNS-AB3 (λ max = 430 nm and E g = 2.34 eV). Furthermore, the soluble polymers demonstrated different hues of yellow and green colors

  3. Green synthesis of palladium nanoparticles with carboxymethyl cellulose for degradation of azo-dyes

    Energy Technology Data Exchange (ETDEWEB)

    Li, Gang; Li, Yun; Wang, Zhengdong; Liu, Huihong, E-mail: huihongliu@126.com

    2017-02-01

    Palladium nanoparticles (PdNPs) were synthesized through friendly environmental method using PdCl{sub 2} and carboxymethyl cellulose (CMC) in an aqueous solution (pH 6) at controlled water bath (80 °C) for 30 min. CMC functioned as both reducing and stabilizing agent. The characterization through high resolution-transmission electron microscopic (HRTEM) and X-ray Fluorescence Spectrometry (XRF) inferred that the as-synthesized PdNPs were spherical in shape with a face cubic crystal (FCC) structure. The results from dynamic light scattering (DLS) suggested the PdNPs had the narrow size distribution with an average size of 2.5 nm. The negative zeta potential (−52.6 mV) kept the as-synthesized PdNPs stable more than one year. The PdNPs showed the excellent catalytic activity by reducing degradation of azo-dyes, such as p-Aminoazobenzene, acid red 66, acid orange 7, scarlet 3G and reactive yellow 179, in the present of sodium borohydride. - Highlights: • Green synthesis of palladium nanoparticles using carboxymethyl cellulose. • The synthesis of palladium nanoparticles were performed easily. • Carboxymethyl cellulose acts as both reducing and stabilization agents. • The as-synthesized palladium nanoparticles show excellent catalytic activity.

  4. Comparison of three combined sequencing batch reactor followed by enhanced Fenton process for an azo dye degradation: Bio-decolorization kinetics study

    Energy Technology Data Exchange (ETDEWEB)

    Azizi, A., E-mail: armina_84@yahoo.com [Civil and Environmental Engineering Department, Amirkabir University of Technology, Hafez Ave., Tehran15875-4413 (Iran, Islamic Republic of); Alavi Moghaddam, M.R., E-mail: alavim@yahoo.com [Civil and Environmental Engineering Department, Amirkabir University of Technology, Hafez Ave., Tehran15875-4413 (Iran, Islamic Republic of); Maknoon, R., E-mail: rmaknoon@yahoo.com [Civil and Environmental Engineering Department, Amirkabir University of Technology, Hafez Ave., Tehran15875-4413 (Iran, Islamic Republic of); Kowsari, E., E-mail: kowsarie@aut.ac.ir [Department of Chemistry, Amirkabir University of Technology, Hafez Ave., Tehran 15875-4413 (Iran, Islamic Republic of)

    2015-12-15

    Highlights: • Three combined advanced SBR and enhanced Fenton process as post treatment was compared. • Higher biomass concentration, dye, COD and metabolites removal was presented together. • Pseudo zero and pseudo first-order bio-decolorization kinetics were observed in all SBRs. • High reduction of AR18 to intermediate metabolites was monitored by HPLC. - Abstract: The purpose of this research was to compare three combined sequencing batch reactor (SBR) – Fenton processes as post-treatment for the treatment of azo dye Acid Red 18 (AR18). Three combined treatment systems (CTS1, CTS2 and CTS3) were operated to investigate the biomass concentration, COD removal, AR18 dye decolorization and kinetics study. The MLSS concentration of CTS2 reached 7200 mg/L due to the use of external feeding in the SBR reactor of CTS2. The COD concentration remained 273 mg/L and 95 mg/L (initial COD = 3270 mg/L) at the end of alternating anaerobic–aerobic SBR with external feeding (An-A MSBR) and CTS2, respectively, resulting in almost 65% of Fenton process efficiency. The dye concentration of 500 mg/L was finally reduced to less than 10 mg/L in all systems indicating almost complete AR18 decolorization, which was also confirmed by UV–vis analysis. The dye was removed following two successive parts as parts 1 and 2 with pseudo zero-order and pseudo first-order kinetics, respectively, in all CTSs. Higher intermediate metabolites degradation was obtained using HPLC analysis in CTS2. Accordingly, a combined treatment system can be proposed as an appropriate and environmentally-friendly system for the treatment of the azo dye AR18 in wastewater.

  5. Post-treatment of anaerobically degraded azo dye Acid Red 18 using aerobic moving bed biofilm process: Enhanced removal of aromatic amines

    International Nuclear Information System (INIS)

    Hosseini Koupaie, E.; Alavi Moghaddam, M.R.; Hashemi, S.H.

    2011-01-01

    Highlights: → Biofilm process was applied as post-treatment of anaerobically degraded an azo dye. → More than 65% of the dye total metabolites was completely mineralized. → Based on HPLC analysis, more than 80% of 1-naphthylamine-4-sulfonate was removed. → Inhibition of biofilm growth was increased with increasing the initial dye concentration. → Considerable porous morphology was observed in the SEM photographs of the biofilm. - Abstract: The application of aerobic moving bed biofilm process as post-treatment of anaerobically degraded azo dye Acid Red 18 was investigated in this study. The main objective of this work was to enhance removal of anaerobically formed the dye aromatic metabolites. Three separate sequential treatment systems were operated with different initial dye concentrations of 100, 500 and 1000 mg/L. Each treatment system consisted of an anaerobic sequencing batch reactor (An-SBR) followed by an aerobic moving bed sequencing batch biofilm reactor (MB-SBBR). Up to 98% of the dye decolorization and more than 80% of the COD removal occurred anaerobically. The obtained results suggested no significant difference in COD removal as well as the dye decolorization efficiency using three An-SBRs receiving different initial dye concentrations. Monitoring the dye metabolites through HPLC suggested that more than 80% of anaerobically formed 1-naphthylamine-4-sulfonate was completely removed in the aerobic biofilm reactors. Based on COD analysis results, at least 65-72% of the dye total metabolites were mineralized during the applied treatment systems. According to the measured biofilm mass and also based on respiration-inhibition test results, increasing the initial dye concentration inhibited the growth and final mass of the attached-growth biofilm in MB-SBBRs.

  6. Synthesis, spectroscopic and TD-DFT quantum mechanical study of azo-azomethine dyes. A laser induced trans-cis-trans photoisomerization cycle.

    Science.gov (United States)

    Georgiev, Anton; Kostadinov, Anton; Ivanov, Deyan; Dimov, Deyan; Stoyanov, Simeon; Nedelchev, Lian; Nazarova, Dimana; Yancheva, Denitsa

    2018-03-05

    This paper describes the synthesis, spectroscopic characterization and quantum mechanical calculations of three azo-azomethine dyes. The dyes were synthesized via condensation reaction between 4-(dimethylamino)benzaldehyde and three different 4-aminobenzene azo dyes. Quantum chemical calculations on the optimized molecular geometry and electron densities of the trans (E) and cis (Z) isomers and their vibrational frequencies have been computed by using DFT/B3LYP density-functional theory with 6-311++G(d,p) basis set in vacuo. The thermodynamic parameters such as total electronic energy E (RB3LYP), enthalpy H 298 (sum of electronic and thermal enthalpies), free Gibbs energy G 298 (sum of electronic and thermal free Gibbs energies) and dipole moment μ were computed for trans (E) and cis (Z) isomers in order to estimate the ΔE trans→cis , Δμ trans→cis, ΔH trans→cis , ΔG trans→cis and ΔS trans→cis values. After molecular geometry optimization the electronic spectra have been obtained by TD-DFT calculations at same basis set and correlated with the spectra of vapour deposited nanosized films of the dyes. The NBO analysis was performed in order to understand the intramolecular charge transfer and energy of resonance stabilization. Solvatochromism was investigated by UV-VIS spectroscopy in five different organic solvents with increasing polarity. The dynamic photoisomerization experiments have been performed in DMF by pump lasers λ=355nm (mostly E→Z) and λ=491nm (mostly Z→E) in spectral region 300nm - 800nm at equal concentrations and times of illumination in order to investigate the photodynamical trans-cis-trans properties of the CHN and NN chromophore groups of the dyes. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Effect of food azo dye tartrazine on learning and memory functions in mice and rats, and the possible mechanisms involved.

    Science.gov (United States)

    Gao, Yonglin; Li, Chunmei; Shen, Jingyu; Yin, Huaxian; An, Xiulin; Jin, Haizhu

    2011-08-01

    Tartrazine is an artificial azo dye commonly used in human food and pharmaceutical products. The present study was conducted to evaluate the toxic effect of tartrazine on the learning and memory functions in mice and rats. Animals were administered different doses of tartrazine for a period of 30 d and were evaluated by open-field test, step-through test, and Morris water maze test, respectively. Furthermore, the biomarkers of the oxidative stress and pathohistology were also measured to explore the possible mechanisms involved. The results indicated that tartrazine extract significantly enhanced active behavioral response to the open field, increased the escape latency in Morris water maze test and decreased the retention latency in step-through tests. The decline in the activities of catalase, glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) as well as a rise in the level of malonaldehyde (MDA) were observed in the brain of tartrazine-treated rats, and these changes were associated with the brain from oxidative damage. The dose levels of tartrazine in the present study produced a few adverse effects in learning and memory functions in animals. The mechanisms might be attributed to promoting lipid peroxidation products and reactive oxygen species, inhibiting endogenous antioxidant defense enzymes and the brain tissue damage. Tartrazine is an artificial azo dye commonly used in human food and pharmaceutical products. Since the last assessment carried out by the Joint FAO/WHO Expert Committee on Food Additives in 1964, many new studies have been conducted. However, there is a little information about the effects on learning and memory performance. The present study was conducted to evaluate the toxic effect of tartrazine on the learning and memory functions in animals and its possible mechanism involved. Based on our results, we believe that more extensive assessment of food additives in current use is warranted. © 2011 Institute of Food

  8. Voltammetric analysis of N-containing drugs using the hanging galinstan drop electrode (HGDE).

    Science.gov (United States)

    Channaa, H; Surmann, P

    2009-03-01

    The electrochemical behaviour of several N-containing voltammetric active drugs such as 1,4-benzodiazepines (chlordiazepoxide, nitrazepam and diazepam) as well as one nitro-compound (nitrofurantoin) and one azo-compound (phenazopyridine) is described using a new kind of liquid electrode, the hanging galinstan drop electrode. Concentrations of 10(-5) - 10(-8) mol L(-1) are generally measurable. Differential pulse and adsorptive stripping voltammograms are recorded in different supporting electrolytes, like 0.1 M KNO3, acetate buffer solution pH = 4.6 and phosphate buffer solution pH = 7.0. The effects of varying the starting potentials, U(start) for DPV and accumulation times, t(acc) for AdSV are considered. Briefly, it is shown that the novel galinstan electrode is suitable for reducing several functional groups in organic substances, here presented for N-oxide-, azomethine-, nitro- and azo-groups.

  9. [Decolorization of the azo dye reactive red X-3B by an Al-Cu bimetallic system].

    Science.gov (United States)

    Fan, Jin-hong; Ma, Lu-ming; Wang, Hong-wu; Wu, De-li

    2008-06-01

    The decoloration mechanism and kinetics of the azo dye reactive red X-3B by an Al-Cu bimetallic system were investigated by measuring the dye removal, the TOC removal and the aniline concentration, and by adding EDTA as control experiments. The results showed the colority removal rate of X-3B reached 83% in the near neutral pH medium for 30 min and 96.4% for 120 min, in which, about 34% was due to the X-3B reduced to aniline, and about 20% and 30% was due to the flocculating of aluminum ions and surface adsorption of aluminum-fillings respectively. The decolorization of dyeing wastewater is a gradual reaction process, which first adsorbs a large number of dyeing ingredients and then carries out inner electrolysis reduction, improved effectively by the flocculating action of aluminum ions. The decolorization reaction appears to be a pseudo first-order reaction and increases with rising temperature.

  10. Photocatalytic oxidation of aromatic amines using MnO2@g-C3N4

    Data.gov (United States)

    U.S. Environmental Protection Agency — An efficient and direct oxidation of aromatic amines to aromatic azo-compounds has been achieved using a MnO2@g-C3N4 catalyst under visible light as a source of...

  11. Sodium Perborate Oxidation of an Aromatic Amine

    Science.gov (United States)

    Juestis, Laurence

    1977-01-01

    Describes an experiment involving the oxidation of aromatic primary amines to the corresponding azo compound; suggests procedures for studying factors that influence the yield of such a reaction, including the choice of solvent and the oxidant-amine ratio. (MLH)

  12. Synthesis, characterization, thermal properties and theoretical investigation on Bis(guanidinium) 4,4‧- Azo-1H-1,2,4-triazol-5-one

    Science.gov (United States)

    Cao, Wen-li; Guo, Jia-jia; Chen, Xiang; Ding, Zi-mei; Xu, Kang-zhen; Song, Ji-rong; Fan, An; Huang, Jie

    2017-11-01

    Bis(guanidinium) 4,4‧-Azo-1H-1,2,4-triazol-5-one [G2(ZTO)] was synthesized and characterized by X-ray single crystal diffraction, elemental analyzer and Fourier Transform Infrared (FT-IR) spectrometer. The result from X-ray single crystal diffraction indicates that G2(ZTO) crystallizes in the monoclinic space group P2(1)/c with parameters of a = 4.779(2) Å, b = 9.081(4) Å, c = 14.676(6) Å, α = 90.00°, β = 92.43(7)°, γ = 90.00°, V = 636.4(5) Å3, Z = 2, μ(Mo Kα) = 0.131, F(000) = 328, S = 1.071, Dc = 1.640 g·cm-3, R1 = 0.0510 and wR2 = 0.1389. Interestingly enough, its structure does not contain crystallization water, which is a unique characteristic in this material. Besides, the molecular geometry of the compound was optimized by using Density Functional Theory (DFT) method at B3LYP/6-31G (d, p) level in the ground state, revealing that the obtained geometric parameters are in accordance with the X-ray result of the structure. The experimental vibrational spectrum was compared with the calculated spectrum. Besides, molecular electrostatic potential (MEP) of G2(ZTO) was computed with the same method in gas phase, theoretically. The thermal properties of this compound were investigated by DSC, TG/DTG and micro-DSC methods. The results manifest that its thermal behavior can be divided into two main decomposition stages, the first intense decomposition peak temperature is 248.11 °C at the heating rate of 10 °C·min-1, which is higher than that of RDX (219 °C) but slightly lower than that of G(ZTO)·H2O (252.08 °C). The constant-volume combustion heat (ΔcU) of G2(ZTO), G(ZTO)·H2O and ZTO were determined and then the enthalpy of formation were calculated. The results show that G2(ZTO) possesses the highest standard molar enthalpy of formation, which may be explained by the fact that G2(ZTO) contains no water and possesses the highest nitrogen content in all guanidine salts. Moreover, the apparent activation energy (E), thermal stability and safety

  13. Degradation of direct azo dye by Cucurbita pepo free and immobilized peroxidase.

    Science.gov (United States)

    Boucherit, Nabila; Abouseoud, Mahmoud; Adour, Lydia

    2013-06-01

    Enzymatic decolourization of the azo dye, Direct Yellow (DY106) by Cucurbita pepo (courgette) peroxidase (CP) is a complex process, which is greatly affected by pH, temperature, enzyme activity and the concentrations of H2O2 and dye. Courgette peroxidase was extracted and its performance was evaluated by using the free-CP (FCP) and immobilized-CP (ICP) forms in the decolourization of DY106. Immobilization of peroxidase in calcium alginate beads was performed according to a strategy aiming to minimize enzyme leakage and keep its activity at a maximum value by optimizing sodium alginate content, enzyme loading and calcium chloride concentration. The initial conditions at which the highest DY106 decolourization yield was obtained were found at pH 2, temperature 20 degrees C, H2O2 dose 1 mmol/L (FCP) and 100 mmol/L (ICP). The highest decolourization rates were obtained for dye concentrations 50 mg/L (FCP) and 80 mg/L (ICP). Under optimal conditions, the FCP was able to decolorize more than 87% of the dye within 2 min. While with ICP, the decolourization yield was 75% within 15 min. The decolourization and removal of DY106 was proved by UV-Vis analysis. Fourier transform infrared (FT-IR) spectroscopy analysis was also performed on DY106 and enzymatic treatment precipitated byproduct.

  14. Incorporation of Kojic Acid-Azo Dyes on TiO2 Thin Films for Dye Sensitized Solar Cells Applications

    Directory of Open Access Journals (Sweden)

    Carolynne Zie Wei Sie

    2017-01-01

    Full Text Available Sensitization of heavy metal free organic dyes onto TiO2 thin films has gained much attention in dye sensitized solar cells (DSSCs. A series of new kojic acid based organic dyes KA1–4 were synthesized via nucleophilic substitution of azobenzene bearing different vinyl chains A1–4 with kojyl chloride 4. Azo dyes KA1–4 were characterized for photophysical properties employing absorption spectrometry and photovoltaic characteristic in TiO2 thin film. The presence of vinyl chain in A1–4 improved the photovoltaic performance from 0.20 to 0.60%. The introduction of kojic acid obtained from sago waste further increases the efficiency to 0.82–1.54%. Based on photovoltaic performance, KA4 achieved the highest solar to electrical energy conversion efficiency (η = 1.54% in the series.

  15. Removal of azo and anthraquinone reactive dyes from industrial wastewaters using MgO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Moussavi, Gholamreza, E-mail: Moussavi@modares.ac.ir [Department of Environmental Health, School of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Mahmoudi, Maryam [Department of Environmental Health, School of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)

    2009-09-15

    In the present investigation, a porous MgO powder was synthesized and tested for the removal of dyes from aqueous solution. The size of the MgO particles was in the range of 38-44 nm, with an average specific surface area of 153.7 m{sup 2}/g. Adsorption of reactive blue 19 and reactive red 198 was conducted to model azo and anthraquinone dyes at various MgO dosages, dye concentrations, solution pHs and contact times in a batch reactor. Experimental results indicate that the prepared MgO powder can remove more than 98% of both dyes under optimum operational conditions of a dosage of 0.2 g, pH 8 and a contact time of 5 min for initial dye concentrations of 50-300 mg/L. The isotherm evaluations revealed that the Langmuir model attained better fits to the experimental equilibrium data than the Freundlich model. The maximum predicted adsorption capacities were 166.7 and 123.5 mg of dye per gram of adsorbent for RB 19 and RR 198, respectively. In addition, adsorption kinetic data followed a pseudo-second-order rate for both tested dyes.

  16. Synthesis of MoO3 nanoparticles for azo dye degradation by catalytic ozonation

    International Nuclear Information System (INIS)

    Manivel, Arumugam; Lee, Gang-Juan; Chen, Chin-Yi; Chen, Jing-Heng; Ma, Shih-Hsin; Horng, Tzzy-Leng; Wu, Jerry J.

    2015-01-01

    Highlights: • Synthesis of one-dimensional MoO 3 nanostructures using hydrothermal, microwave, and sonochemical methods. • Sonochemical synthesized MoO 3 presents the best efficiency for the dye removal by catalytic ozonation. • Efficient environmental remediation process. - Abstract: One-dimensional molybdenum trioxide nanostructures were prepared in three different approaches, including thermal, microwave, and sonochemical methods. The physicochemical properties of the obtained MoO 3 nanoparticles were investigated by diffused reflectance spectroscopy, X-ray diffraction analysis, field emission scanning electron microscopy, high resolution transmission electron microscopy, and Brunauer–Emmett–Teller surface area analysis. Among the methods as investigated, sonochemical synthesis gave well-dispersed fine MoO 3 nanoparticles compared with the other approaches. All the synthesized MoO 3 nanostructures were examined for the catalytic ozonation to degrade azo dye in aqueous environment. Different performances were obtained for the catalyst prepared in different methods and the catalytic efficiencies were found to be the order of sonochemical, microwave, and then thermal methods. The sonochemical MoO 3 catalyst allowed the total dye removal within 20 min and its good performance was justified according to their higher surface area with higher number of active sites that provide effective dye interaction for better degradation

  17. ESTUDIO CINÉTICO DE LA FOTODEGRADACIÓN DEL NARANJA DE METILO EN PRESENCIA DE TiO2: EFECTO DE LA FUENTE DE RADIACIÓN U.V., CONCENTRACIÓN DEL AZO-COLORANTE Y DEL CATALIZADOR

    Directory of Open Access Journals (Sweden)

    Juan M. Hernández

    2012-01-01

    Full Text Available En este trabajo se estudió la degradación fotocatalítica de soluciones acuosas de naranja de metilo con óxido de titanio (Degussa P-25 iluminado con luz ultravioleta artificial y/o solar. Se realizaron experimentos para investigar el efecto de variables de operación tales como fuente de radiación U.V., concentración del azo- colorante y concentración del catalizador. Los resultados mostraron que la velocidad de degradación se vio afectada por parámetros experimentales tales como la concentración del colorante y/o la concentración del catalizador. La cinética de degradación cambia cuando se difiere en la fuente de radiación U.V., siendo de orden 0.5 en el caso de la radiación U.V. proporcionada por una lámpara de 150 W y de orden cero cuando se utilizó radiación U.V. solar. La degradación del azo-compuesto alcanzó el 100% en todos los casos.

  18. Stable triazenes derived from 2-alkylaminonaphthalenes and 5-nitrobenzo[c]-1,2-thiazole-3-diazonium hydrogensulfate

    Czech Academy of Sciences Publication Activity Database

    Přikryl, J.; Macháček, V.; Jansa, Petr; Svobodová, M.; Růžička, A.; Nachtigall, Petr; Černý, A.

    -, č. 19 (2008), s. 3272-3278 ISSN 1434-193X R&D Projects: GA MŠk LC512 Institutional research plan: CEZ:AV0Z40550506 Keywords : azo compounds * diazonium s * triazenes Subject RIV: CC - Organic Chemistry Impact factor: 3.016, year: 2008

  19. Role of surfactant derived intermediates in the efficacy and mechanism for radiation chemical degradation of a hydrophobic azo dye, 1-phenylazo-2-naphthol

    Energy Technology Data Exchange (ETDEWEB)

    Das, Laboni [Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Chatterjee, Suchandra [Food Technology Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Naik, Devidas B. [Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Adhikari, Soumyakanti, E-mail: asoumya@barc.gov.in [Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2015-11-15

    Highlights: • Demonstration of the role of surfactant in the degradation of the hydrophobic dye. • First direct observation of the formation of “hydrazyl radical-parent” adduct. • Similar products obtained in the reaction of e{sup −}{sub aq} and ·OH radical in TX-100 medium. • Significant reduction in cytotoxicity of irradiated dye in aqueous–organic medium. • New mechanistic pathway could be delineated. - Abstract: A combined methodology involving gamma and pulse radiolysis, product analysis and toxicity studies has been adopted to comprehend the degradation process of a model hydrophobic azo dye, 1-phenylazo-2-naphthol, emphasizing the role of the surfactant, which is an integral part of textile waste. Two new and important findings are underlined in this article. The first is the direct attestation of the hydrazyl radical-parent adduct, formed in the reaction of the dye with e{sup −}{sub aq} followed by protonation and subsequent addition to the unreacted dye molecule. This has been confirmed from concentration dependent studies. Secondly, we have clearly shown that in the reaction of hydroxyl radical with the dye in Triton X-100 media, the initially produced TX radicals cause reductive degradation of the dye. Identification and detailed analysis of HPLC and GCMS data reveals that similar products are formed in both the reactions of e{sup −}{sub aq} and ·OH radicals. Moreover, the cytotoxicity of 10{sup −4} mol dm{sup −3} dye was found to be reduced significantly after irradiation. Thus, the present study not only depicts new pathways for the degradation of hydrophobic azo dye, but also demonstrates the role of a surfactant in the entire process.

  20. Compósitos de poli(álcool vinílico contendo hidroxissais lamelares de zinco, intercalados com corantes aniônicos azo (tropaeolina 0 e tropaeolina 00 Poly(vinyl alcohol composites containing layered hydroxide salts, intercalated with anionic azo dyes (tropaeolin 0 and tropaeolin 0

    Directory of Open Access Journals (Sweden)

    Marlon Luiz Neves da Silva

    2013-01-01

    Full Text Available Hidroxissais lamelares de zinco foram intercalados com corantes aniônicos azo, obtendo-se pigmentos de coloração laranja. Os materiais foram caracterizados por difração de raios X (XRD, espectroscopia vibracional na região do infravermelho com transformada de Fourier (FTIR, análise térmica (TGA/DTA/DSC e espectroscopia fotoeletrônica de raios X (XPS. Após caracterização, os pigmentos lamelares foram dispersos em uma matriz de poli(álcool vinílico - PVA, em concentrações variáveis, em relação à massa de PVA. Filmes homogêneos, transparentes e coloridos foram obtidos pelo método de "casting" úmido e mantidos em dessecador em umidade controlada de 65 % por uma semana e avaliados quanto às suas propriedades mecânicas. Devido às diferentes polaridades dos ânions intercalados, diferentes comportamentos foram observados para os pigmentos quando utilizados como cargas em PVA. Esse trabalho abre uma frente de pesquisas na utilização de hidroxissais lamelares intercalados com corantes aniônicos, como cargas alternativas em materiais compósitos poliméricos.Layered zinc hydroxide salts were intercalated with anionic azo dyes, obtaining orange pigments. The materials were characterized by X-ray diffraction (XRD, Fourier Transform Infrared spectroscopy (FTIR, thermal analysis (TGA/DTA/DSC and X-ray photoelectron spectroscopy (XPS. After characterization, the layered pigments were dispersed into a matrix of poly(vinyl alcohol - PVA, in variable concentrations, in relation to the PVA mass. Homogeneous, transparent and colorful films were obtained by wet casting method and kept in a desiccator at 65% of humidity for one week and evaluated in relation to their mechanical properties. Owing to the different intercalated anions polarities, different behaviors were observed for both pigments when used as fillers in PVA. This work opens a research front in the utilization of layered hydroxide salt intercalated with anionic dyes, as

  1. Synthesis, Structural Characterization and Antimicrobial Activity of Cu(II and Fe(III Complexes Incorporating Azo-Azomethine Ligand

    Directory of Open Access Journals (Sweden)

    Mohammad Azam

    2018-04-01

    Full Text Available We are reporting a novel azo-azomethine ligand, HL and its complexes with Cu(II and Fe(III ions. The ligand and its complexes are characterized by various physico-chemical techniques using C,H,N analyses, FT-IR, 1H-NMR, ESI-MS and UV-Vis studies. TGA analyses reveal complexes are sufficiently stable and undergo two-step degradation processes. The redox behavior of the complexes was evaluated by cyclic voltammetry. Furthermore, the ligand and its complexes were tested for antimicrobial activity against bacterial and fungal strains by determining inhibition zone, minimal inhibitory concentration (MIC and minimal bactericidal concentration (MBC. The complexes showed moderate antimicrobial activity when tested against Gram +ve and Gram −ve bacterial strains. To obtain insights into the structure of ligand, DFT studies are recorded. The results obtained are quite close to the experimental results. In addition, the energy gap, chemical hardness, softness, electronegativity, electrophilic index and chemical potential were calculated using HOMO, LUMO energy value of ligand.

  2. Aerobic sludge granulation for simultaneous anaerobic decolorization and aerobic aromatic amines mineralization for azo dye wastewater treatment.

    Science.gov (United States)

    Yan, Lawrence K Q; Fung, Ka Y; Ng, Ka M

    2018-06-01

    In this study, the capability of using aerobic granules to undergo simultaneous anaerobic decolorization and aerobic aromatic amines degradation was demonstrated for azo dye wastewater treatment. An integrated acclimation-granulation process was devised, with Mordant Orange 1 as the model pollutant. Performance tests were carried out in a batch column reactor to evaluate the effect of various operating parameters. The optimal condition was to use 1.0-1.7 mm (1.51 ± 0.33 mm) granules, 5 g/L biomass, and 4000 mg/L organics as nutrient; and supplement the wastewater with 1  mg/L dissolved oxygen. This led to a dye mineralization of 61 ± 2%, an anaerobic dye removal of 88 ± 1%, and an aerobic aromatic amines removal of 70 ± 3% within 48 h. This study showed that simultaneous anaerobic/aerobic process by aerobic granules could be a possible alternative to the conventional activated sludge process.

  3. Extractive and spectrophotometric determination of U (VI) using 5-(3-phenolyl azo)-2-hydroxy-4-ethoxy propiophenone oxime (PHEPO)

    International Nuclear Information System (INIS)

    Subrahmanyam, P.; Krishnapriya, B.; Rekha, D.; Reddy Prasad, P.; Chiranjeevi, P.

    2007-01-01

    A simple spectrophotometric method for the determination of U (VI) using 5-(3-phenolyl azo)-2-hydroxy-4-ethoxy propiophenone oxime (PHEPO) is developed. The reagent PHEPO was synthesized and used for extraction of uranium. At pH 8.5-10.0 uranium forms a purple colored complex with PHEPO which was then quantitatively extracted in chloroform showing maximum absorbance at wavelength of 380nm. The proposed method obeys Beer's law in the range of 1.2-19.0ppm. molar absorptivity and Sandelson's sensitivity of extracted species were calculated to be 1.750 x 104 lmol-1 cm-1 and 8.5 x 10-5 mg cm-2 respectively. The method was applied for the determination of uranium in synthetic and plant samples. It was found that the newly developed method is competent to those of standard methods. (author)

  4. Effects of Electrical Stimulation on the Degradation of Azo Dye in Three-Dimensional Biofilm Electrode Reactors

    Directory of Open Access Journals (Sweden)

    Xian Cao

    2017-04-01

    Full Text Available Three-dimensional biofilm electrode reactors (3D-BERs were constructed to degrade the azo dye Reactive Brilliant Red (RBR X-3B. The 3D-BERs with different influent concentrations and external voltages were individually studied to investigate their influence on the removal of X-3B. Experimental results showed that 3D-BERs have good X-3B removal efficiency; even when the influent concentration was 800 mg/L, removal efficiency of 73.4% was still achieved. In addition, the X-3B removal efficiency stabilized shortly after the influent concentration increased. In 3D-BERs, the average X-3B removal efficiency increased from 52.8% to 85.4% when the external voltage rose from 0 to 2 V. We further identified the intermediate products via UV-Vis and gas chromatography-mass spectrometry (GC-MS analyses, and discussed the potential mechanism of degradation. After the conjugate structure of X-3B was destroyed, all of the substances generated mainly consisted of lower-molecular-weight organics.

  5. Strength-controllable graphene oxide amphiprotic aerogels as highly efficient carrier for anionic and cationic azo molecules

    Science.gov (United States)

    Xiong, Jiaqing; Jiao, Chenlu; Xu, Sijun; Tao, Jin; Zhang, Desuo; Lin, Hong; Chen, Yuyue

    2015-06-01

    Ice-bath self-assembly was employed to fabricate the GO/AP-MCC/CS aerogel based on natural materials. The components are amphiprotic microcrystalline cellulose (AP-MCC), chitosan (CS), and graphene oxide (GO), which act as the main framework, auxiliary framework and adhesive, respectively. The results of characterization determines the components form the GO/AP-MCC/CS aerogel according to chemical interactions. The mechanical properties depend largely on the mass ratio of AP-MCC/CS, which can be regulated by controlling the contents of AP-MCC and CS. The resultant GO/AP-MCC/CS aerogel was observed possessing three-dimensional (3D) interpenetrating porous networks with wrinkled structure on the inner wall, which provide a good encapsulation capacity for the guest molecules. As expected, owing to the amphiprotic properties and large specific surface area, GO/AP-MCC/CS aerogel exhibits high-efficiency load capacity for both anionic (CR) and cationic azo molecules (MB), which can reach up to about 132.2 mg/g for CR and 123.2 mg/g for MB, respectively.

  6. Optimization of integrated chemical-biological degradation of a reactive azo dye using response surface methodology

    International Nuclear Information System (INIS)

    Sudarjanto, Gatut; Keller-Lehmann, Beatrice; Keller, Jurg

    2006-01-01

    The integrated chemical-biological degradation combining advanced oxidation by UV/H 2 O 2 followed by aerobic biodegradation was used to degrade C.I. Reactive Azo Red 195A, commonly used in the textile industry in Australia. An experimental design based on the response surface method was applied to evaluate the interactive effects of influencing factors (UV irradiation time, initial hydrogen peroxide dosage and recirculation ratio of the system) on decolourisation efficiency and optimizing the operating conditions of the treatment process. The effects were determined by the measurement of dye concentration and soluble chemical oxygen demand (S-COD). The results showed that the dye and S-COD removal were affected by all factors individually and interactively. Maximal colour degradation performance was predicted, and experimentally validated, with no recirculation, 30 min UV irradiation and 500 mg H 2 O 2 /L. The model predictions for colour removal, based on a three-factor/five-level Box-Wilson central composite design and the response surface method analysis, were found to be very close to additional experimental results obtained under near optimal conditions. This demonstrates the benefits of this approach in achieving good predictions while minimising the number of experiments required

  7. Spatial variation of electrode position in bioelectrochemical treatment system: Design consideration for azo dye remediation.

    Science.gov (United States)

    Yeruva, Dileep Kumar; Shanthi Sravan, J; Butti, Sai Kishore; Annie Modestra, J; Venkata Mohan, S

    2018-05-01

    In the present study, three bio-electrochemical treatment systems (BET) were designed with variations in cathode electrode placement [air exposed (BET1), partially submerged (BET2) and fully submerged (BET3)] to evaluate azo-dye based wastewater treatment at three dye loading concentrations (50, 250 and 500 mg L -1 ). Highest dye decolorization (94.5 ± 0.4%) and COD removal (62.2 ± 0.8%) efficiencies were observed in BET3 (fully submerged electrodes) followed by BET1 and BET2, while bioelectrogenic activity was highest in BET1 followed by BET2 and BET3. It was observed that competition among electron acceptors (electrode, dye molecules and intermediates) critically regulated the fate of bio-electrogenesis to be higher in BET1 and dye removal higher in BET3. Maximum half-cell potentials in BET3 depict higher electron acceptance by electrodes utilized for dye degradation. Study infers that spatial positioning of electrodes in BET3 is more suitable towards dye remediation, which can be considered for scaling-up/designing a treatment plant for large-scale industrial applications. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Optical characterization and blu-ray recording properties of metal(II) azo barbituric acid complex films

    Energy Technology Data Exchange (ETDEWEB)

    Li, X.Y. [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)], E-mail: xyli@siom.ac.cn; Wu, Y.Q. [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Key Lab of Functional Inorganic Material Chemistry (Heilongjiang University), Ministry of Education, Haerbin 150080 (China)], E-mail: yqwu@siom.ac.cn; Gu, D.D.; Gan, F.X. [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2009-02-25

    Smooth thin films of nickel(II), cobalt(II) and zinc(II) complexes with azo barbituric acid were prepared by the spin-coating method. Absorption spectra of the thin films on K9 glass substrates in 300-700 nm wavelength region were measured. Optical constants (complex refractive index N = n + ik) of the thin films prepared on single-crystal silicon substrates in 275-695 nm wavelength region were investigated on rotating analyzer-polarizer type of scanning ellipsometer, and dielectric constant {epsilon} ({epsilon} = {epsilon}{sub 1} + i{epsilon}{sub 2}) as well as absorption coefficient {alpha} of thin films were calculated at 405 nm. In addition, static optical recording properties of the cobalt(II) complex thin film with an Ag reflective layer was carried out using a 406.7 nm blue-violet laser and a high numerical aperture (NA) of 0.90. Clear recording marks with high reflectivity contrast (>60%) at proper laser power and pulse width were obtained, and the size of recording mark was as small as 250 nm. The results indicate that these metal(II) complexes are promising organic recording medium for the blu-ray optical storage system.

  9. Synthesis of silver nanoparticles using bacterial exopolysaccharide and its application for degradation of azo-dyes

    Directory of Open Access Journals (Sweden)

    Chinnashanmugam Saravanan

    2017-09-01

    Full Text Available In this study, the synthesis and characterization of exopolysaccharide-stabilized sliver nanoparticles (AgNPs was carried out for the degradation of industrial textile dyes. Characterization of AgNPs was done using surface plasmon spectra using UV–Vis spectroscopy, X-ray diffraction (XRD and Raman spectroscopy. The morphological nature of AgNPs was determined through transmission electron microscopy (TEM, scanning electron microscopy (SEM and atomic force microscopy (AFM, which indicated that the AgNPs were spherical in shape, with an average size of 35 nm. The thermal behaviour of AgNPs revealed that it is stable up to 437.1 °C and the required energy is 808.2J/g in TGA-DTA analysis. Ability of EPS stabilized AgNPs for degradation of azo dyes such as Methyl orange (MO and Congo red (CR showed that EPS stabilized AgNPs were found to be efficient in facilitating the degradation process of industrial textile dyes. The electron transfer takes place from reducing agent to dye molecule via nanoparticles, resulting in the destruction of the dye chromophore structure. This makes EPS-AgNPs a suitable, cheap and environment friendly candidate for biodegradation of harmful textile dyes.

  10. Biodegradation mechanisms and kinetics of azo dye 4BS by a microbial consortium.

    Science.gov (United States)

    He, Fang; Hu, Wenrong; Li, Yuezhong

    2004-10-01

    A microbial consortium consisting of a white-rot fungus 8-4* and a Pseudomonas 1-10 was isolated from wastewater treatment facilities of a local dyeing house by enrichment, using azo dye Direct Fast Scarlet 4BS as the sole source of carbon and energy, which had a high capacity for rapid decolorization of 4BS. To elucidate the decolorization mechanisms, decolorization of 4BS was compared between individual strains and the microbial consortium under different treatment processes. The microbial consortium showed a significant improvement on dye decolorization rates under either static or shaking culture, which might be attributed to the synergetic reaction of single strains. From the curve of COD values and the UV-visible spectra of 4BS solutions before and after decolorization cultivation with the microbial consortium, it was found that 4BS could be mineralized completely, and the results had been used for presuming the degrading pathway of 4BS. This study also examined the kinetics of 4BS decolorization by immobilized microbial consortium. The results demonstrated that the optimal decolorization activity was observed in pH range between four and 9, temperature range between 20 and 40 degrees C and the maximal specific decolorization rate occurred at 1,000 mg l(-1) of 4BS. The proliferation and distribution of microbial consortium were also microscopically observed, which further confirmed the decolorization mechanisms of 4BS.

  11. EFFECT OF ULTRAVIOLET LIGHT ON THE PROPERTIES OF DYED COTTON CELLULOSE

    Directory of Open Access Journals (Sweden)

    ROSU Liliana

    2016-05-01

    Full Text Available Textile dyes have been reported of causing various stages of contact dermatitis. Reactive dyes are widely applied in dyeing cellulose fiber based textiles (100% cotton, skin fibers (hemp, flax, regenerated cellulose (cellulose acetate, viscose, protein fibers (natural silk, wool. The human body comes in contact daily with such compounds. This aspect is important for elucidating their biological effects on the human body, in correlation with physico-chemical properties. Dyes are chemical compounds containing chromophore and auxochrome groups. Authors herein report results concerning the influence of UV irradiation with λ > 300 nm on the structure and properties of different colored textiles. Subjects to study were textiles painted with four azo-triazine based dyes which were exposed to 100 h UV irradiation time and irradiation dose values up to 3500 J cm-2. The five azo dyes were: reactive orange 13, reactive red 183, reactive yellow 143, reactive blue 204 and reactive red 2. Structural modifications as a result of irradiation were undertaken by UV-Vis spectroscopy. It was observed that during UV exposure there occurred partial dyes detachment from the textiles, accompanied by glucosidic units and dye photodecomposition by C–N bond scission and degradation of aromatic entities and azo based chromophores. Color modifications were also investigated. Color differences significantly increased with the irradiation dose for all the studied samples.

  12. All-Nonvacuum-Processed CIGS Solar Cells Using Scalable Ag NWs/AZO-Based Transparent Electrodes.

    Science.gov (United States)

    Wang, Mingqing; Choy, Kwang-Leong

    2016-07-06

    With record cell efficiency of 21.7%, CIGS solar cells have demonstrated to be a very promising photovoltaic (PV) technology. However, their market penetration has been limited due to the inherent high cost of the cells. In this work, to lower the cost of CIGS solar cells, all nonvacuum-processed CIGS solar cells were designed and developed. CIGS absorber was prepared by the annealing of electrodeposited metallic layers in a chalcogen atmosphere. Nonvacuum-deposited Ag nanowires (NWs)/AZO transparent electrodes (TEs) with good transmittance (92.0% at 550 nm) and high conductivity (sheet resistance of 20 Ω/□) were used to replace the vacuum-sputtered window layer. Additional thermal treatment after device preparation was conducted at 220 °C for a few of minutes to improve both the value and the uniformity of the efficiency of CIGS pixel cell on 5 × 5 cm substrate. The best performance of the all-nonvacuum-fabricated CIGS solar cells showed an efficiency of 14.05% with Jsc of 34.82 mA/cm(2), Voc of 0.58 V, and FF of 69.60%, respectively, which is comparable with the efficiency of 14.45% of a reference cell using a sputtered window layer.

  13. Analytical techniques combined with chemometrics for authentication and determination of contaminants in condiments

    NARCIS (Netherlands)

    Reinholds, Ingars; Bartkevics, Vadims; Silvis, Isabelle C.J.; Ruth, van Saskia M.; Esslinger, Susanne

    2015-01-01

    Spices and herbs play an important role as flavorings, colorants, and also as bioactive compounds used in medicine and cosmetics. The presence of common contaminants, e.g., mycotoxins, pesticide residues, heavy metals, and the adulterants, e.g., azo dyes, filth and extraneous matter have been

  14. 2035-IJBCS-Article-J O Otutu

    African Journals Online (AJOL)

    hp

    the heterocyclic amines in the synthesis of azo dyes, has come under focus. The attraction of the heterocycles stems from their significance in medicine, agriculture, industry and academic research and teaching. The interesting and often intriguing structural and electronic properties of heterocyclic compounds often naturally ...

  15. Applicability of an improved Trolox equivalent antioxidant capacity (TEAC) assay for evaluation of antioxidant capacity measurements of mixtures

    NARCIS (Netherlands)

    Berg, R. van den; Haenen, G.R.M.M.; Berg, H. van den; Bast, A.

    1999-01-01

    The TEAC (Trolox equivalent antioxidant capacity) assay is based on scavenging of 2,2'-azinobis-(3- ethylbenzothiazoline-6-sulfonate) radical anions (ABTS(.-)). In this report we describe a modification based on pre-generation of the ABTS radical anions with a thermolabile azo compound, 2,2'-azobis-

  16. Synthesis of dark brown single-walled carbon nanotubes and their

    Indian Academy of Sciences (India)

    We report here a simple and effective approach to the covalent attachment of single-walled carbon nanotubes (SWCNTs) and azo compounds. The functionalized SWCNTs prepared (through a radical mechanism) have been used for a diazonium coupling reaction. The results showed that the chemical method used has ...

  17. Synthesis of dark brown single-walled carbon nanotubes and their ...

    Indian Academy of Sciences (India)

    Abstract. We report here a simple and effective approach to the covalent attachment of single-walled carbon nanotubes (SWCNTs) and azo compounds. The functionalized SWCNTs prepared (through a radical mecha- nism) have been used for a diazonium coupling reaction. The results showed that the chemical method ...

  18. Photocatalytic oxidation of aromatic amines using MnO2@g ...

    Science.gov (United States)

    An efficient and direct oxidation of aromatic amines to aromatic azo-compounds has been achieved using a MnO2@g-C3N4 catalyst under visible light as a source of energy at room temperature Prepared for submission to the journal, Advanced Materials Letters.

  19. Enhanced accumulation and visible light-assisted degradation of azo dyes in poly(allylamine hydrochloride)-modified mesoporous silica spheres

    International Nuclear Information System (INIS)

    Tao Xia; Liu Bing; Hou Qian; Xu Hui; Chen Jianfeng

    2009-01-01

    A new route for the economic and efficient treatment of azo dye pollutants is reported, in which surface-modified organic-inorganic hybrid mesoporous silica (MS) spheres were chosen as microreactors for the accumulation and subsequent photodegradation of pollutants in defined regions. The surface-modified silica materials were prepared by anchoring the polycationic species such as poly(allylamine hydrochloride) on MS spheres via a simple wet impregnation method. The as-synthesized spheres with well-defined porous structures exhibited 15 times of accumulating capacity for orange II and Congo red compared to that of the pure MS spheres. Diffuse reflectance UV-vis spectroscopy and confocal laser scanning microscopy demonstrated that the accumulated orange II and CR in defined MS spheres were rapidly degraded in the presence of Fenton reagent under visible radiation. Kinetics analysis in recycling degradation showed that the as-synthesized materials might be utilized as environment-friendly preconcentrators/microreactors for the remediation of dye wastewater

  20. Chemical speciation and equilibria of some nucleic acid compounds and their iron(III) complexes

    Science.gov (United States)

    Masoud, Mamdouh S.; Abd El-Kaway, Marwa Y.; Hindawy, Ahmed M.; Soayed, Amina A.

    The pH effect on electronic absorption spectra of some biologically active nucleic acid constituents have been studied at room temperature and the mechanism of ionization was explained. These compounds are of two categories (pyrimidines: [barbital; 5,5'-diethyl-barbituric acid], [SBA; 4,6-dihydroxy-2-mercapto-pyrimidin], [NBA; 5-nitro-2,4,6(1H,3H,5H)-pyrimidine trione] and [TU; 2,3-dihydro-2-thioxo-pyrimidin-4(1H)-one]) and (purines: [adenine; 6-amino purine], its [Schiff bases derived from adenine-acetylacetone; (Z)-4-(7H-purin-6-ylimino)pentan-2-one) and adenine-salicylaldehyde; 2-((7H-purin-6-ylimino) methyl) phenol] and its [Azo derived from adenine-resorcinol; 4-((7H-purin-6-yl)-diazenyl) benzene-1,3-diol]. The phenomena of tautomerization assigned different tautomers. Different spectrophotometric methods are applied to evaluate the pK's values that explained with their molecular structures. The interaction of Fe3+ with some selected pyrimidines (barbital, NBA and SBA) was explained using familiar six spectrophotometric methods. The data typified the existence of different absorbing species with the different stoichiometries 1:1, 1:2, 1:3 and 2:3. The stability constant of the complexes was computed. More approach was deduced to assign the existence of different species applying the distribution diagrams.

  1. Rapid isolation of a facultative anaerobic electrochemically active bacterium capable of oxidizing acetate for electrogenesis and azo dyes reduction.

    Science.gov (United States)

    Shen, Nan; Yuan, Shi-Jie; Wu, Chao; Cheng, Yuan-Yuan; Song, Xiang-Ning; Li, Wen-Wei; Tong, Zhong-Hua; Yu, Han-Qing

    2014-05-01

    In this study, 27 strains of electrochemically active bacteria (EAB) were rapidly isolated and their capabilities of extracellular electron transfer were identified using a photometric method based on WO3 nanoclusters. These strains caused color change of WO3 from white to blue in a 24-well agar plate within 40 h. Most of the isolated EAB strains belonged to the genera of Aeromonas and Shewanella. One isolate, Pantoea agglomerans S5-44, was identified as an EAB that can utilize acetate as the carbon source to produce electricity and reduce azo dyes under anaerobic conditions. The results confirmed the capability of P. agglomerans S5-44 for extracellular electron transfer. The isolation of this acetate-utilizing, facultative EBA reveals the metabolic diversity of environmental bacteria. Such strains have great potential for environmental applications, especially at interfaces of aerobic and anaerobic environments, where acetate is the main available carbon source.

  2. Electrochemical methods for monitoring of environmental carcinogens.

    Science.gov (United States)

    Barek, J; Cvacka, J; Muck, A; Quaiserová, V; Zima, J

    2001-04-01

    The use of modern electroanalytical techniques, namely differential pulse polarography, differential pulse voltammetry on hanging mercury drop electrode or carbon paste electrode, adsorptive stripping voltammetry and high performance liquid chromatography with electrochemical detection for the determination of trace amounts of carcinogenic N-nitroso compounds, azo compounds, heterocyclic compounds, nitrated polycyclic aromatic hydrocarbons and aromatic and heterocyclic amines is discussed. Scope and limitations of these methods are described and some practical applications based on their combination with liquid-liquid or solid phase extraction are given.

  3. Colorful and transparent poly(vinyl alcohol) composite films filled with layered zinc hydroxide salts, intercalated with anionic orange azo dyes (methyl orange and orange II)

    International Nuclear Information System (INIS)

    Neves da Silva, Marlon Luiz; Marangoni, Rafael; Cursino, Ana Cristina Trindade; Schreiner, Wido Herwig; Wypych, Fernando

    2012-01-01

    Highlights: ► Zinc hydroxide salts were successfully intercalated with anionic orange azo dyes. ► The anionic dye was co-intercalated with hydrated chloride anions. ► The orange materials were used as fillers for poly(vinyl alcohol). ► Transparent, homogeneous, colorful PVA films were obtained by wet casting. ► Some composites stored at lower humidity exhibited improved mechanical properties. - Abstract: Layered zinc hydroxide salts (zinc LHS) were intercalated with anionic orange azo dyes, namely methyl orange (MO) and orange II (OII), and co-intercalated with hydrated chloride anions. After characterization by X-ray diffraction (XRD), thermal analysis (TGA/DTA), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS), the materials were used as fillers for poly(vinyl alcohol) (PVA). Colorful transparent films were obtained by wet casting, revealing good dispersion of the material into the polymer. In the case of zinc LHS/OII, PVA was intercalated between the zinc LHS layers. Evaluation of the mechanical properties of the PVA composite films revealed that the layered colorful materials were able to increase the mechanical properties of the PVA films only when the films were stored under lower relative humidity. As expected, films with higher water content displayed reduced tensile strength and modulus because of the plasticizing effect of water. As for the films stored at 43% relative humidity, more pronounced improvement of modulus was observed for 1 and 4% zinc LHS/OII, and enhanced tensile strength was achieved for 0.5 and 1% zinc LHS/OII. This effect can be attributed to better dispersion of the layered filler and its better adhesion to the PVA matrix.

  4. Performance and microbial community structures of hydrolysis acidification process treating azo and anthraquinone dyes in different stages.

    Science.gov (United States)

    Liu, Na; Xie, Xuehui; Yang, Bo; Zhang, Qingyun; Yu, Chengzhi; Zheng, Xiulin; Xu, Leyi; Li, Ran; Liu, Jianshe

    2017-01-01

    In this study, performance of hydrolysis acidification process treating simulated dyeing wastewater containing azo and anthraquinone dyes in different stages was investigated. The decolorization ratio, COD Cr removal ratio, BOD 5 /COD Cr value, and volatile fatty acids (VFAs) production were almost better in stage 1 than that in stage 2. Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GC-MS) confirmed the biodegradation of Reactive Black 5 (RB5) and Remazol Brilliant Blue R (RBBR) in hydrolysis acidification process. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analyses revealed that significant difference of microbial community structures existed in stage 1 and 2. The dominant species in stage 1 was related to Bacteroidetes group, while the dominant species in stage 2 was related to Bacteroidetes and Firmicutes groups. From the results, it could be speculated that different dyes' structures might have significant influence on the existence and function of different bacterial species, which might supply information for bacteria screening and acclimation in the treatment of actual dyeing wastewater.

  5. Extraction, Analytical and Advanced Methods for Detection of Allura Red AC (E129 in Food and Beverages Products

    Directory of Open Access Journals (Sweden)

    Shafiquzzaman eSiddiquee

    2016-05-01

    Full Text Available Allura Red AC (E129 is an azo dye that widely used in drinks, juices, bakery, meat and sweets products. High consumption of Allura Red has claimed an adverse effects of human health including allergies, food intolerance, cancer, multiple sclerosis, attention deficit hyperactivity disorder (ADHD, brain damage, nausea, cardiac disease and asthma due to the reaction of aromatic azo compounds (R = R' = aromatic. Several countries have banned and strictly controlled the uses of Allura Red in food and beverage products. This review paper is critically summarized on the available analytical and advanced methods for determination of Allura Red and also concisely discussed on the acceptable daily intake (ADI, toxicology and extraction methods.

  6. Photoresists for Microlithography

    Indian Academy of Sciences (India)

    otherwise and listening to music both Indian and western: classical and modem. S V Eswaran has worked on lac resin, heterocycles and ... These free positions can undergo azo coupling reac- tion in the unexposed part with the photo active component, viz. the diazo compound. The consequent increase in IIl:olecular.

  7. Optimization of integrated chemical-biological degradation of a reactive azo dye using response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Sudarjanto, Gatut [Advanced Wastewater Management Centre, The University of Queensland, Qld 4072 (Australia); Keller-Lehmann, Beatrice [Advanced Wastewater Management Centre, The University of Queensland, Qld 4072 (Australia); Keller, Jurg [Advanced Wastewater Management Centre, The University of Queensland, Qld 4072 (Australia)]. E-mail: j.keller@awmc.uq.edu.au

    2006-11-02

    The integrated chemical-biological degradation combining advanced oxidation by UV/H{sub 2}O{sub 2} followed by aerobic biodegradation was used to degrade C.I. Reactive Azo Red 195A, commonly used in the textile industry in Australia. An experimental design based on the response surface method was applied to evaluate the interactive effects of influencing factors (UV irradiation time, initial hydrogen peroxide dosage and recirculation ratio of the system) on decolourisation efficiency and optimizing the operating conditions of the treatment process. The effects were determined by the measurement of dye concentration and soluble chemical oxygen demand (S-COD). The results showed that the dye and S-COD removal were affected by all factors individually and interactively. Maximal colour degradation performance was predicted, and experimentally validated, with no recirculation, 30 min UV irradiation and 500 mg H{sub 2}O{sub 2}/L. The model predictions for colour removal, based on a three-factor/five-level Box-Wilson central composite design and the response surface method analysis, were found to be very close to additional experimental results obtained under near optimal conditions. This demonstrates the benefits of this approach in achieving good predictions while minimising the number of experiments required.

  8. Poly(methylmethacrylate) grafted chitosan: An efficient adsorbent for anionic azo dyes

    International Nuclear Information System (INIS)

    Singh, V.; Sharma, A.K.; Tripathi, D.N.; Sanghi, R.

    2009-01-01

    Present study reports on peroxydisulfate/ascorbic acid initiated synthesis of Chitosan-graft-poly(methylmethacrylate) (Ch-g-PMMA) and its characterization by FTIR, XRD and 13 C NMR. The copolymer remained water insoluble even under highly acidic conditions and was evaluated to be an efficient adsorbent for the three anionic azo dyes (Procion Yellow MX, Remazol Brilliant Violet and Reactive Blue H5G) over a wide pH range of 4-10 being most at pH 7. The adsorbent was also found efficient in decolorizing the textile industry wastewater and was much more efficient than the parent chitosan. Equilibrium sorption experiments were carried out at different pH and initial dye concentration values. The experimental equilibrium data for each adsorbent-dye system were successfully fitted to the Langmuir and Freundlich sorption isotherms. Based on Langmuir model Q max for yellow, violet and blue dyes was 250, 357 and 178, respectively. Thermodynamic parameters of the adsorption processes such as ΔG o , ΔH o , and ΔS o were calculated. The negative values of free energy reflected the spontaneous nature of adsorption. The adsorption kinetic data of all the three dyes could be well represented by pseudo-second-order model with the correlation coefficients (R 2 ) being 0.9922, 0.9997 and 0.9862, for direct yellow, reactive violet and blue dye, respectively with rate constants 0.91 x 10 -4 , 1.82 x 10 -4 and 1.05 x 10 -4 g mg -1 min -1 , respectively. At pH 7, parent chitosan also showed pseudo-second-order kinetics. The temperature dependence of dye uptake and the pseudo-second-order kinetics of the adsorption indicated that chemisorption is the rate-limiting step that controls the process

  9. Modern Electrochemical Methods for Monitoring of Chemical Carcinogens

    Directory of Open Access Journals (Sweden)

    J. Zima

    2005-04-01

    Full Text Available This contribution is based on our presentation at the 1st International Symposiumon Sensor Science, Paris, 16-20 June 2003. It presents recent results regarding theelectrochemical determination of submicromolar and nanomolar concentrations of variouscarcinogenic substances (nitrated polycyclic aromatic hydrocarbons, heterocycliccompounds, azo compounds, aromatic amino compounds, etc. using both traditional(classical dropping mercury electrode, static mercury drop electrode, hanging mercury dropelectrode and non-traditional types of electrodes (solid amalgam electrodes, carbon pasteelectrodes, platinum tubular electrodes.

  10. Enhancement of the optical response in a biodegradable polymer/azo-dye film by the addition of carbon nanotubes

    International Nuclear Information System (INIS)

    Costanzo, Guadalupe Díaz; Ledesma, Silvia; Ribba, Laura; Goyanes, Silvia

    2014-01-01

    A new biodegradable photoresponsive material was developed using poly(lactic acid) (PLA) as the matrix material and Disperse Orange 3 (DO3) as photoisomerizable azo-dye. It was observed that the addition of multi-walled carbon nanotubes (MWCNTs) leads to a new phenomenon consisting of an enhancement of the optical anisotropy in a wide range of temperatures. In particular, the optical anisotropy increases 100% at room temperature. Moreover, the material containing MWCNTs shows a faster optical response that is evidenced as an increase in the growth rate of optical anisotropy. Spectroscopic data is provided to study the interaction among DO3, MWCNTs and PLA. The enhancement of optical anisotropy obtained with the addition of MWCNTs was related to the glass transition temperature (T g ) of each material. Maximum optical anisotropy was obtained 15 °C below the T g for both materials. Results are interpreted in terms of the interactions among DO3, MWCNTs and PLA and the packing density of the dye into the polymer chains. (paper)

  11. Estudo da descoloração e degradação de corantes azo mediante processo oxidativo avançado: UV/H2O2

    OpenAIRE

    Adailton Alves

    2009-01-01

    Este estudo teve como objetivo o uso de Processos Oxidativos Avançados (POA\\'s), para a descoloração e degradação dos corantes azo (Congo Red) e (Acid Yellow 42) em solução aquosa, sendo realizado em escala de bancada (processo batelada), utilizando-se reator tubular. Utililizou-se o Processo Oxidativo Avançado UV/H2O2, avaliando a influência dos seguintes fatores: concentração dos corantes, pH, temperatura, concentração do H2O2, concentração do NaCl e concentração do Na2SO4. Para a otimizaçã...

  12. Gas-phase acylation of aminopropyl-silica gel in the synthesis of some chemically bonded silica materials for analytical applications

    International Nuclear Information System (INIS)

    Basiuk, Vladimir; Khil'chevskaya, E.G.

    1991-01-01

    Gas-phase acylation of aminopropyl-silica gel with aliphatic dicarboxylic (succinic, adipic and sebacic) and 4-aminobenzoic acids is proposed as a rapid and efficient one-step method for the synthesis of carboxyalkyl- and 4-aminophenylamidopropyl-silica gels, usually used as zwitterion exchangers for liquid chromatography and matrices for multi-step syntheses of silica-bound aromatic azo reagents for the sorption and chromatographic separation of metal ions. Acylation degrees of 59-90% are achieved after 0.5 h. IR spectra of the acylation products and near-UV-visible spectra for bonded aromatic azo compounds, based on 4-aminobenzamidopropyl-silica gel, are presented. Some positive and negative aspects of the gas-phase acylation are discussed. (author). 34 refs.; 2 figs.; 2 tabs

  13. A Sensitive Determination of Carbofuran by Spectrophotometer using 4, 4-azo-bis-3, 3′5, 5′-tetra bromoaniline in various Environmental Samples

    Directory of Open Access Journals (Sweden)

    O. Bhargavi

    2006-01-01

    Full Text Available A simple and sensitive spectrophotometric technique was developed for the determination of carbofuran in its formulations, water and grain samples. The method was based on the alkaline hydrolyzed product of carbofuran phenol interacted with diazonium salt of 4,4-azo-bis-3,3′5,5′-tetra bromo aniline. The maximum absorbance of the red coloured derivative was measured at 470 nm. The beer’s law was obeyed in the concentration range of 0.1-16.0 µg/mL. The interference of the non target species were studied on the determination of carbofuran which increases the selectivity of the method. The present method was successfully applied for the determination of carbofuran in its formulations, water and grain samples.

  14. Study of structure and properties of oxide electrode materials (Fe3O4, AZO, SRO) and their device applications

    Science.gov (United States)

    Olga, Chichvarina

    Ferroelectric thin film capacitor heterostructures have attracted considerable attention in the last decade because of their potential applications in piezoelectric sensors, actuators, power generators and non-volatile memory devices. Strongly correlated all-perovskite oxide heterojunctions are of a particular interest, as their material properties (electronic, structural, magnetic and optical, etc.) can be tuned via doping, interface effect, applied electrical field, and formation of two-dimensional electron gas (2DEG), etc. The right selection of electrode material for this type of capacitor-like structures may modify and enhance the performance of a device, as the electrode/barrier layer interfaces can significantly influence its macroscopic properties. Although there is a number of reports on the effect of electrode interfaces on the properties of PZT capacitors deposited on SRO buffered STO substrate, very little is known about Fe3O4/PZT and AZO/PZT electrode interfaces. This thesis comprises two parts. In the first part we present a systematic study of the structural, transport, magnetic and optical properties of oxide thin films: AZO, Fe3O4 and SRO. These monolayers were fabricated via pulsed laser deposition technique on quartz, MgO and STO substrates respectively. The second part of this thesis elucidates the behaviour of these three oxides as electrode components in PZT/SRO/STO heteroepitaxial structures. The highlights of the work are summarized below: 1) Zinc-blende (ZB) phase of ZnO was predicted to possess higher values of conductivity and higher doping efficiency compared to its wurzite counterpart and thus has greater chances of facilitating the fabrication of ZnO-electrode-based devices. However, zinc-blende is a metastable phase, and it is challenging to obtain single-phase ZB. To tackle this challenge we tuned parameters such-as film thickness, substrate and annealing effect, and achieved a ZB phase of Ti-doped ZnO, ZB-(Zn1-xTix)O thin film. An

  15. Use of active consortia of constructed ternary bacterial cultures via mixture design for azo-dye decolorization enhancement

    International Nuclear Information System (INIS)

    Chen, B.-Y.; Wang, M.-Y.; Lu, W.-B.; Chang, J.-S.

    2007-01-01

    This first-attempt study used constructed bacterial consortia containing Escherichia coli DH5α (a weak decolorizer) and its UV-irradiated mutants (E. coli UVT1 and UV68; strong decolorizers) via equilateral triangle diagram and mixture experimental design to assess color removal during species evolution. The results showed that although strain DH5α was not an effective decolorizer, its presence might still played a significant role in affecting optimal color removal capabilities of mixed consortia (e.g., E. coli DH5α, UVT1 and UV68) for two model azo dyes; namely, reactive red 22 (RR22) and reactive black 5 (RB5). Contour analysis of ternary systems also clearly showed that decolorization of RR22 and RB5 by DH5α-containing active mixed consortia was more effective than mono-cultures of the stronger decolorizer alone (e.g., UVT1). The optimal composition of the mixed consortium (UV68, UVT1, DH5α) achieving the highest specific decolorization rate was (13%:58%:29%) and (0%:74%:26%) for decolorization of RR22 and RB5, respectively, with initial total cell density fixed at OD 600 = 3.5 ± 0.28

  16. Adsorption of Azo-Dye Orange II from Aqueous Solutions Using a Metal-Organic Framework Material: Iron- Benzenetricarboxylate

    Science.gov (United States)

    Rojas García, Elizabeth; López Medina, Ricardo; May Lozano, Marcos; Hernández Pérez, Isaías; Valero, Maria J.; Maubert Franco, Ana M.

    2014-01-01

    A Metal-Organic Framework (MOF), iron-benzenetricarboxylate (Fe(BTC)), has been studied for the adsorptive removal of azo-dye Orange II from aqueous solutions, where the effect of various parameters was tested and isotherm and kinetic models were suggested. The adsorption capacities of Fe(BTC) were much higher than those of an activated carbon. The experimental data can be best described by the Langmuir isotherm model (R2 > 0.997) and revealed the ability of Fe(BTC) to adsorb 435 mg of Orange II per gram of adsorbent at the optimal conditions. The kinetics of Orange II adsorption followed a pseudo-second-order kinetic model, indicating the coexistence of physisorption and chemisorption, with intra-particle diffusion being the rate controlling step. The thermodynamic study revealed that the adsorption of Orange II was feasible, spontaneous and exothermic process (−25.53 kJ·mol−1). The high recovery of the dye showed that Fe(BTC) can be employed as an effective and reusable adsorbent for the removal of Orange II from aqueous solutions and showed the economic interest of this adsorbent material for environmental purposes. PMID:28788289

  17. Adsorption of Azo-Dye Orange II from Aqueous Solutions Using a Metal-Organic Framework Material: Iron- Benzenetricarboxylate

    Directory of Open Access Journals (Sweden)

    Elizabeth Rojas García

    2014-12-01

    Full Text Available A Metal-Organic Framework (MOF, iron-benzenetricarboxylate (Fe(BTC, has been studied for the adsorptive removal of azo-dye Orange II from aqueous solutions, where the effect of various parameters was tested and isotherm and kinetic models were suggested. The adsorption capacities of Fe(BTC were much higher than those of an activated carbon. The experimental data can be best described by the Langmuir isotherm model (R2 > 0.997 and revealed the ability of Fe(BTC to adsorb 435 mg of Orange II per gram of adsorbent at the optimal conditions. The kinetics of Orange II adsorption followed a pseudo-second-order kinetic model, indicating the coexistence of physisorption and chemisorption, with intra-particle diffusion being the rate controlling step. The thermodynamic study revealed that the adsorption of Orange II was feasible, spontaneous and exothermic process (−25.53 kJ·mol−1. The high recovery of the dye showed that Fe(BTC can be employed as an effective and reusable adsorbent for the removal of Orange II from aqueous solutions and showed the economic interest of this adsorbent material for environmental purposes.

  18. The Role of Crystallization Parameters for the Synthesis of Germanosilicate with UTL Topology

    Czech Academy of Sciences Publication Activity Database

    Shvets, O. V.; Zukal, Arnošt; Kasian, N.; Žilková, Naděžda; Čejka, Jiří

    2008-01-01

    Roč. 14, č. 32 (2008), s. 10134-10140 ISSN 0947-6539 R&D Projects: GA AV ČR 1QS400400560; GA ČR GA203/08/0604 Institutional research plan: CEZ:AV0Z40400503 Keywords : azo compounds * germanium * microporous materials Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 5.454, year: 2008

  19. Light scattering effect of ITO:Zr/AZO films deposited on periodic textured glass surface morphologies for silicon thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, Shahzada Qamar [Sungkyunkwan University, Department of Energy Science, Suwon (Korea, Republic of); COMSATS Institute of Information Technology, Department of Physics, Lahore (Pakistan); Kwon, Gi Duk; Kim, Sunbo; Balaji, Nagarajan; Shin, Chonghoon; Kim, Sangho; Khan, Shahbaz; Pribat, Didier [Sungkyunkwan University, Department of Energy Science, Suwon (Korea, Republic of); Ahn, Shihyun; Le, Anh Huy Tuan; Park, Hyeongsik; Raja, Jayapal; Lee, Youn-Jung [Sungkyunkwan University, College of Information and Communication Engineering, Suwon (Korea, Republic of); Razaq, Aamir [COMSATS Institute of Information Technology, Department of Physics, Lahore (Pakistan); Velumani, S. [Sungkyunkwan University, College of Information and Communication Engineering, Suwon (Korea, Republic of); Department of Electrical Engineering (SEES), Mexico City (Mexico); Yi, Junsin [Sungkyunkwan University, Department of Energy Science, Suwon (Korea, Republic of); Sungkyunkwan University, College of Information and Communication Engineering, Suwon (Korea, Republic of)

    2015-09-15

    Various SF{sub 6}/Ar plasma-textured periodic glass surface morphologies for high transmittance, haze ratio and low sheet resistance of ITO:Zr films are reported. The SF{sub 6}/Ar plasma-textured glass surface morphologies were changed from low aspect ratio to high aspect ratio with the increase in RF power from 500 to 600 W. The micro- and nano-size features of textured glass surface morphologies enhanced the haze ratio in visible as well as NIR wavelength region. Micro-size textured features also influenced the sheet resistance and electrical characteristics of ITO:Zr films due to step coverage. The ITO:Zr/AZO bilayer was used as front TCO electrode for p-i-n amorphous silicon thin film solar cells with current density-voltage characteristics as: V{sub oc} = 875 mV, FF = 70.90 %, J{sub sc} = 11.31 mA/cm{sup 2}, η = 7.02 %. (orig.)

  20. Effect of acid orange 7 on nitrification process

    Energy Technology Data Exchange (ETDEWEB)

    He, Yongjie (ManTech Environmental Tech., Inc., Dayton, OH (United States)); Bishop, P.L. (Univ. of Cincinnati, OH (United States). Dept. of Civil and Environmental Engineering)

    The effect of Acid Orange 7 (AO7), an azo dye commonly used in textile, pharmaceutical, food, and cosmetic industries, on the nitrification process is studied using completely stirred tank reactors (CSTR) and batch treatment systems. Azo dyes are of concern because many of the dyes or their metabolic intermediates are carcinogenic. AO7 biodegradation is found to be essentially complete when solids retention times (SRT) are maintained above 7.5 days, but systems with lower SRTs are unstable. It is shown that AO7 inhibits all stages of the nitrification process. Nitrite oxidizers are found to be more sensitive to AO7 than ammonium oxidizers. The results of kinetic studies indicate that the inhibition of ammonium oxidation is typified by noncompetitive inhibition; the presence of AO7 decreases the maximum substrate utilization rate and very slightly increases K[sub s], the half-saturation constant. AO7 is found to be less toxic to nitrification than some metal and phenolic compounds, but more toxic than some common organic compounds such as formalin, methanol, or acetone.

  1. Properties of transparent and conductive Al:ZnO/Au/Al:ZnO multilayers on flexible PET substrates

    International Nuclear Information System (INIS)

    Dimopoulos, T.; Bauch, M.; Wibowo, R.A.; Bansal, N.; Hamid, R.; Auer, M.; Jäger, M.; List-Kratochvil, E.J.W.

    2015-01-01

    Highlights: • Transparent, low resistive AZO/Au/AZO layers were sputtered on PET substrates. • AZO/Au/AZO has higher figure of merit than ITO for specific Au thicknesses. • The resistance of AZO/Au/AZO is stable against repetitive substrate bending. • AZO/Au/AZO electrode performance is comparable to ITO in light emitting diodes. - Abstract: We investigate the structural, electrical and optical properties of transparent electrodes, consisting of Al-doped ZnO (AZO) and ultrathin Au layers, sputtered on polyethylene terephthalate (PET). These electrodes are relevant for optoelectronic devices and thin film photovoltaics. When deposited on AZO, Au films as thin as 3 nm form electrically conductive, meandering structures, whereas uniform Au films are obtained from a thickness of 5 nm. The sheet resistance decreases with Au thickness, reaching 7 Ω for 11 nm-thick Au. AZO/Au/AZO trilayers combine lowest resistance with highest transparency, while their resistance stability against bending fatigue is superior to the Sn-doped In 2 O 3 (ITO) electrode. The figure of merit of AZO/Au/AZO is larger than of ITO for Au thickness equal to or larger than 9 nm. To demonstrate the applicability of the AZO/Au/AZO transparent electrode, simple organic light emitting diodes were fabricated and tested in comparison to PET/ITO standard substrates

  2. Properties of transparent and conductive Al:ZnO/Au/Al:ZnO multilayers on flexible PET substrates

    Energy Technology Data Exchange (ETDEWEB)

    Dimopoulos, T., E-mail: theodoros.dimopoulos@ait.ac.at [AIT-Austrian Institute of Technology, Energy Department, Photovoltaic Systems, Giefinggasse 2, 1210, Vienna (Austria); Bauch, M.; Wibowo, R.A.; Bansal, N. [AIT-Austrian Institute of Technology, Energy Department, Photovoltaic Systems, Giefinggasse 2, 1210, Vienna (Austria); Hamid, R. [AIT-Austrian Institute of Technology, Mobility Department, Electric Drive Technologies, Giefinggasse 2, 1210, Vienna (Austria); Auer, M.; Jäger, M. [NanoTecCenter Weiz Forschungsgesellschaft mbH, Franz-Pichler Straße 32, A-8160 Weiz (Austria); List-Kratochvil, E.J.W. [NanoTecCenter Weiz Forschungsgesellschaft mbH, Franz-Pichler Straße 32, A-8160 Weiz (Austria); Institute of Solid State Physics, Graz University of Technology, Petersgasse 16, A-8010 Graz (Austria)

    2015-10-15

    Highlights: • Transparent, low resistive AZO/Au/AZO layers were sputtered on PET substrates. • AZO/Au/AZO has higher figure of merit than ITO for specific Au thicknesses. • The resistance of AZO/Au/AZO is stable against repetitive substrate bending. • AZO/Au/AZO electrode performance is comparable to ITO in light emitting diodes. - Abstract: We investigate the structural, electrical and optical properties of transparent electrodes, consisting of Al-doped ZnO (AZO) and ultrathin Au layers, sputtered on polyethylene terephthalate (PET). These electrodes are relevant for optoelectronic devices and thin film photovoltaics. When deposited on AZO, Au films as thin as 3 nm form electrically conductive, meandering structures, whereas uniform Au films are obtained from a thickness of 5 nm. The sheet resistance decreases with Au thickness, reaching 7 Ω for 11 nm-thick Au. AZO/Au/AZO trilayers combine lowest resistance with highest transparency, while their resistance stability against bending fatigue is superior to the Sn-doped In{sub 2}O{sub 3} (ITO) electrode. The figure of merit of AZO/Au/AZO is larger than of ITO for Au thickness equal to or larger than 9 nm. To demonstrate the applicability of the AZO/Au/AZO transparent electrode, simple organic light emitting diodes were fabricated and tested in comparison to PET/ITO standard substrates.

  3. Azo dyes decomposition on new nitrogen-modified anatase TiO2 with high adsorptivity

    International Nuclear Information System (INIS)

    Janus, M.; Choina, J.; Morawski, A.W.

    2009-01-01

    New vis active photocatalyst was obtained by the modification of commercial anatase TiO 2 (Police, Poland) in pressure reactor in an ammonia water atmosphere at 100 o C for 4 h. The photocatalytic activity of new material was tested during three azo dyes decomposition: monoazo (Reactive Read), diazo (Reactive Black) and poliazodye (Direct Green). Obtained photocatalyst had new bands at 1430-1440 cm -1 attributed to the bending vibrations of NH 4 + and at 1535 cm -1 associated with NH 2 groups or NO 2 and NO. UV-vis/DR spectra of photocatalyst had also insignificant decrease in visible region. Fluorescence technique was used for studying the amount of hydroxyl radicals produced on TiO 2 surface during visible light irradiation. The hydroxyl radicals produced react with coumarin present in the solution to form 7-hydroxycoumarin which has fluorescent capacity. Photocatalytic activity of modified TiO 2 was compared with commercial titanium dioxide P25 (Degussa, Germany). The photocatalytic activity of TiO 2 /N was higher than that of unmodified material and P25 under visible light irradiation. The ability for dye adsorption (Reactive Red) on photocatalyst surface was also tested. Unmodified TiO 2 and P25 has isotherm of adsorption by Freundlich model, and nitrogen-modified TiO 2 by Langmuir model. The presence of nitrogen at the surface of TiO 2 significantly increased adsorption capacity of TiO 2 as well as OH· radicals formation under visible radiation.

  4. Photocatalytic degradation of an azo-dye on TiO2/activated carbon composite material.

    Science.gov (United States)

    Andriantsiferana, C; Mohamed, E F; Delmas, H

    2014-01-01

    A sequential adsorption/photocatalytic regeneration process to remove tartrazine, an azo-dye in aqueous solution, has been investigated. The aim ofthis work was to compare the effectiveness of an adsorbent/photocatalyst composite-TiO2 deposited onto activated carbon (AC) - and a simple mixture of powders of TiO2 and AC in same proportion. The composite was an innovative material as the photocatalyst, TiO2, was deposited on the porous surface ofa microporous-AC using metal-organic chemical vapour deposition in fluidized bed. The sequential process was composed of two-batch step cycles: every cycle alternated a step of adsorption and a step of photocatalytic oxidation under ultra-violet (365 nm), at 25 degreeC and atmospheric pressure. Both steps, adsorption and photocatalytic oxidation, have been investigated during four cycles. For both materials, the cumulated amounts adsorbed during four cycles corresponded to nearly twice the maximum adsorption capacities qmax proving the photocatalytic oxidation to regenerate the adsorbent. Concerning photocatalytic oxidation, the degree of mineralization was higher with the TiO2/AC composite: for each cycle, the value of the total organic carbon removal was 25% higher than that obtained with the mixture powder. These better photocatalytic performances involved better regeneration than higher adsorbed amounts for cycles 2, 3 and 4. Better performances with this promising material - TiO2 deposited onto AC - compared with TiO2 powder could be explained by the vicinity of photocatalytic and AC adsorption sites.

  5. Improved biodegradation of synthetic azo dye by horseradish peroxidase cross-linked on nano-composite support.

    Science.gov (United States)

    Sun, Huaiyan; Jin, Xinyu; Long, Nengbing; Zhang, Ruifeng

    2017-02-01

    A ZnO nanowires/macroporous SiO 2 composite was used as support to immobilize horseradish peroxidase (HRP) by in-situ cross-linking method. Using diethylene glycol diglycidyl ether (DDE) as a long-chained cross-linker, it was adsorbed on the surface of ZnO nanowires before reaction with HRPs, the resulted composite was quite different from the traditional cross-linking enzyme aggregates (CLEAs) on both structure and catalytic performance. The immobilized HRP showed high activity in the decolorization of azo dyes. The effect of various conditions such as the loading amount of HRP, solution pH, temperature, contact time and concentration of dye were optimized on the decolorization. The decolorization percentage of Acid Blue 113 and Acid black 10 BX reached as high as 95.4% and 90.3%, respectively. The immobilized HRP gave the highest decolorization rate under dye concentration as 50mg/L and reaction time of 35min. The immobilized HRP exhibited much better resistance to temperature and pH inactivation than free HRP. The storage stability and reusability were greatly improved through the immobilization, from the decolorization of Acid blue 113 it was found that 80.4% of initial efficiency retained after incubation at 4°C for 60 days, and that 79.4% of decolorization efficiency retained after 12 cycles reuse. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Capacidad de Remoción de los Residuos de la Fermentación Cervecera Modificados por Óxidos de Hierro Frente a un Colorante Azo Bifuncional Reactivo de la Industria Textil

    OpenAIRE

    Tapia Montesinos, María Alejandra

    2017-01-01

    Los procesos de la industria textil se encuentran entre los más nocivos para el medio ambiente, ya que producen grandes cantidades de aguas residuales coloreadas muy contaminadas. En el presente trabajo se emplearon los residuos de la fermentación cervecera para determinar el residuo con mayor porcentaje de remoción del colorante azo bifuncional reactivo (Synozol Red K3BS), siendo el de mejor rendimiento el bagazo de grano de tamaño de partícula entre 75 – 150 μm (99.29% de ...

  7. Studies on unusually reactive metal powders. Preparation of new organometallic and organic compounds including potential new catalysts. Final report, July 1, 1980-December 31, 1984

    International Nuclear Information System (INIS)

    Rieke, R.D.

    1985-06-01

    This research project was involved with the preparation and study of highly reactive metal powders prepared by the reduction of metal salts with alkali metals. Studies concentrated on nickel, copper, cadmium, uranium, iron, and magnesium. The nickel powders have been found to react rapidly with benzylic halides, and the resulting organonickel complexes yield dibenzyl. Aryl halides react rapidly with the nickel powders to produce biaryl compounds in high yields. Benzylic halides react with the nickel powders in the presence of acylhalides to produce benzyl ketones in high yields. Reactions of ROCOCOC1 and benzylic halides with nickel powders yield benzyl ketones. These reactions proceed with a wide variety of substituents on the phenyl ring of the benzylic halides. Highly reactive uranium has been prepared, and found to react with a variety of oxygen containing substrates, such as nitrobenzene to yield azo benzene. Highly reactive magnesium has opened up a totally new area of low temperature Grignard chemistry. The preparation of highly reactive copper has allowed the direct preparation of organocopper species directly from organic halides. 16 refs., 6 tabs

  8. FACTORS AFFECTING THE REMOVAL OF A BASIC AND AN AZO DYE FROM ARTIFICIAL SOLUTIONS BY ADSORPTION USING ACTIVATED CARBON

    Directory of Open Access Journals (Sweden)

    H Albroomi

    2014-10-01

    Full Text Available Decolourisation of wastewater, particularly from textile industries, is one of the major environmental concerns these days. Current methods for removing dyes from wastewater are costly and cannot effectively be used to treat wide range of such wastewater. This work describes the use of commercial available granular activated carbon (GAC as an efficient adsorbent material for dyes removal. Aqueous solutions of various basic dye Methylene Blue (MB and azo-dye Tartrazine with concentrations 5-20 mg l–1 and 10-100 mg l–1, respectively, were shaken with certain amount of GAC to determine the adsorption capacity and removal efficiencies. The effects of adsorbent dose, initial pH, initial dye concentration, agitation speed and contact time on dyes removal efficiencies have been studied. Maximum dye concentration was removed from the solution within 60-90 min after the beginning of every experiment. Adsorption parameters were found to fit well into Langmuir and Freundlich adsorption isotherms models with correlation coefficient (R2 > 0.99 in the concentration range of MB and TZ studied.

  9. Microwave-enhanced UV/H2O2 degradation of an azo dye (tartrazine): optimization, colour removal, mineralization and ecotoxicity.

    Science.gov (United States)

    Parolin, Fernanda; Nascimento, Ulisses Magalhães; Azevedo, Eduardo Bessa

    2013-01-01

    This study optimizes two factors, pH and initial [H2O2], in the ultraviolet (UV)/H2O2/microwave (MW) process through experimental design and assesses the effect of MWs on the colour removal of an azo-dye (tartrazine) solution that was favoured by an acidic pH. The estimated optimal conditions were: initial [H2O2] = 2.0 mmol L(-1) and pH = 2.6, at 30 +/- 2 degrees C. We obtained colour removals of approximately 92% in 24 min of irradiation (EDL, 244.2 W), following zero order kinetics: k = (3.9 +/- 0.52) x 10(-2) a.u. min(-1) and R2 = 0.989. Chemical and biological oxygen demand were significantly removed. On the other hand, the carbon content, biodegradability and ecotoxicity (Lactuca sativa) remained approximately the same. The UV/H2O2/MW process was shown to be eight times faster than other tested processes (MW, H2O2, H2O2/MW, and UV/MW).

  10. Triphenyl{(E-4-[4-(phenyldiazenylphenyl]-4H-1,2,4-triazol-1-yl}boron

    Directory of Open Access Journals (Sweden)

    Daisuke Urakami

    2009-10-01

    Full Text Available In the title compound, C32H26BN5 or [(C14H11N5B(C6H53], the B atom is approximately tetrahedrally coordinated. The diazo unit is in a trans conformation, which is generally more stable than a cis one for aromatic azo compounds. The crystal structure features very weak C—H...π interactions. The dihedral angles between the central benzene ring and the terminal rings in the heterocycle are 62.64, 73.54 and 61.60°.

  11. Preparation, characterization of a ceria loaded carbon nanotubes nanocomposites photocatalyst and degradation of azo dye Acid Orange 7

    Directory of Open Access Journals (Sweden)

    Wen Tao

    2016-06-01

    Full Text Available A ceria loaded carbon nanotubes (CeO2/CNTs nanocomposites photocatalyst was prepared by chemical precipitation, and the preparation conditions were optimized using an orthogonal experiment method. HR-TEM, XRD, UV-Vis/DRS, TGA and XPS were used to characterize the photocatalyst. Nitrogen adsorption-desorption was employed to determine the BET specific surface area. The results indicated that the photocatalyst has no obvious impurities. CeO2 was dispersed on the carbon nanotubes with a good loading effect and high loading efficiency without agglomeration. The catalyst exhibits a strong ability to absorb light in the ultraviolet region and some ability to absorb light in the visible light region. The CeO2/CNTs nanocomposites photocatalyst was used to degrade azo dye Acid Orange 7 (40 mg/L. The optical decolorization rate was 66.58% after xenon lamp irradiation for 4 h, which is better than that of commercial CeO2 (43.13%. The results suggested that CeO2 loading on CNTs not only enhanced the optical decolorization rate but also accelerated the separation of CeO2/CNTs and water.

  12. Synthesis, structure and solvatochromic properties of some novel 5-arylazo-6-hydroxy-4-phenyl-3-cyano-2-pyridone dyes

    Directory of Open Access Journals (Sweden)

    Alimmari Adel

    2012-07-01

    Full Text Available Abstract Background A series of some novel arylazo pyridone dyes was synthesized from the corresponding diazonium salt and 6-hydroxy-4-phenyl-3-cyano-2-pyridone using a classical reaction for the synthesis of the azo compounds. Results The structure of the dyes was confirmed by UV-vis, FT-IR, 1H NMR and 13C NMR spectroscopic techniques and elemental analysis. The solvatochromic behavior of the dyes was evaluated with respect to their visible absorption properties in various solvents. Conclusions The azo-hydrazone tautomeric equilibration was found to depend on the substituents as well as on the solvent. The geometry data of the investigated dyes were obtained using DFT quantum-chemical calculations. The obtained calculational results are in very good agreement with the experimental data.

  13. Kinetic and equilibrium study of adsorption of di-azo dyes on commercial activated carbon

    International Nuclear Information System (INIS)

    Hyali, E.A.S.A.; Abady, T.G.A.

    2013-01-01

    This research work is concerned with studying the adsorption of a number of di-azo dyes on commercial activated carbon (CAC). The synthesized dyes vary in their structures by the central parts. which are either ortho, meta or para phenvlene diamine. This variation affects the linearity of molecules, their spatial arrangement and electron movement throughout the molecule by resonance. Factors a fleeting adsorption process, such as the efiect of contact time, initial concentration, p1-I of the adsorption medium, adsorbent dose, effect of solvent and temperature were studied. The results indicated that, the adsorption process is fast in the first 10 mm, then gradually decreased with time and approaches maximum within 70-80 min for all the studied dyes. The increase of initial concentration and temperature decreased the adsorption efficiency. The results also shows that, the adsorption is found to be more efficient at low Ph value. The increase of the adsorbent dose increases the adsorption efficiency and decreases its capacity. The variation of solvent (ethanol-water ratio) indicates that the decrease of dielectric constant lowers the adsorption efficiency. The study included application of three adsorption isotherms, Freundlich, Langmuir and Tempkin on the experimental data of the studied systems. The results indicated that, Freundlich isotherm fits better the adsorption data. Kinetic analysis of the adsorption data was also conducted by employing 4 kinetic models; pseudo first order and pseudo second order, Elovich and intra particle diffusion equations. The results obtained conclude that, the studied systems follow the Pseudo second order model. (author)

  14. Decolorization and detoxification of Synozol red HF-6BN azo dye, by Aspergillus niger and Nigrospora sp

    Directory of Open Access Journals (Sweden)

    Sidra Ilyas

    2013-01-01

    Full Text Available In the present investigation the fungi, Aspergillus niger and Nigrospora sp. were employed for decolorization of Synazol red HF-6BN. Decolorization study showed that Aspergillus niger and Nigrospora sp. were able to decolorize 88% and 96% Synazol red 6BN, respectively, in 24 days. It was also studied that 86% and 90% Synazol red containing of dye effluent was decolorized by Aspergillus niger and Nigrospora sp. after 28 days of incubation at room temperature. A fungal-based protein with relative molecular mass of 70 kDa was partially purified and examined for enzymatic characteristics. The enzyme exhibited highest activity at temperature ranging from 40-50[degree sign]C and at pH=6.0. The enzyme activity was enhanced in the presence of metal cations. High performance liquid chromatography analysis confirmed that these fungal strains are capable to degrade Synazol red dye into metabolites. No zones of inhibition on agar plates and growth of Vigna radiata in the presence of dye extracted sample, indicated that the fungal degraded dye metabolites are nontoxic to beneficial micro-flora and plant growth. Aspergillus niger and Nigrospora sp. have promising potential in color removal from textile wastewater-containing azo dyes.

  15. Azo polymers with electronical push and pull structures prepared via RAFT polymerization and its photoinduced birefringence behavior

    Directory of Open Access Journals (Sweden)

    2008-08-01

    Full Text Available Two methacrylate monomers containing azo and electronical push and pull structure, e.g. 2-Methyl-acrylic-acid-2-{[4-(4-cyano-phenylazo-3-methyl-phenyl]-ethyl-amino-ethyl ester (MACP with cyano substituted and 2-Methylacrylic-acid-2-{ethyl-[4-(4-methoxy-phenylazo-3-methyl-phenyl]-amino}-ethyl ester (MAMP with methoxy substituted, were synthesized and polymerized using 2-cyanoprop-2-yl dithiobenzoate (CPDB as chain transfer agent and 2,2'-azobisisobutyronitrile (AIBN as initiator. The results showed that the polymerization displayed characteristics of ‘living’/controlled free radical polymerization. Thus, the obtained polymers, polyMACP (pMACP and polyMAMP (pMAMP, had controlled molecular weights and narrow molecular weights distribution. The chain extension experiments of pMACP and pMAMP using styrene as the second monomer were successfully carried out. The photo-induced trans-cis-trans isomerization kinetic of pMACP and pMAMP in chloroform solution were described. Marked differences in rate for the trans-cis and cis-trans isomerization of pMACP and pMAMP were observed in chloroform solution due to the different electronic effects in these two polymers. Photoinduced birefringence and surface relief grating (SRG of the pMACP and pMAMP were investigated in thin film state.

  16. Synthesis and optical properties of azo -dye-attached novel second-order NLO polymers with high thermal stability

    Science.gov (United States)

    Ushiwata, Takami; Okamoto, Etsuya; Komatsu, Kyoji; Kaino, Toshikuni

    2001-06-01

    Novel second order nonlinear optical (NLO) polymethacrylate or polyacrylate polymers with high glass transition temperatures containing an azo dye attached as side-chain have been prepared using a new approach from polymethacrylic acid or polyacrylic acid as starting materials. Glass transition temperatures of 150 approximately 170 degree Celsius were obtained for Disperse red 1 dye attached polymethacrylic acid. These are attributed to the hydrogen bonding between the residual carboxyl groups in the starting polymers. Poled films by corona poling exhibited large NLO susceptibilities, (chi) (2)33 up to 53 pm/V at a wavelength of 1.3 micrometer. Due to the high glass transition temperatures of the polymers, long-term stability of the optical nonlinearity at 100 degrees Celsius was observed for 200 hrs or more. However residual carboxyl groups caused absorbance decrease mainly by hydrolysis of the ester bonds of the polymers investigated by UV-Vis absorption measurement. The stability of induced polar order of the NLO polymer was enhanced by using aminoalkyl chromophore and imidizing it thermally to introduce imide structure into the polymer main-chain. This imidized polymer exhibited (chi) (2)33 of 45 pm/V at a wavelength of 1.3 micrometer and maintained about 90% of the initial value after 230 hrs or more at 100 degrees Celsius.

  17. The Comparative Study on the Rapid Decolorization of Azo, Anthraquinone and Triphenylmethane Dyes by Anaerobic Sludge

    Directory of Open Access Journals (Sweden)

    Daizong Cui

    2016-10-01

    Full Text Available An anaerobic sludge (AS, capable of decolorizing a variety of synthetic dyes, was acclimated and is reported here. The sludge presented a much better dye decolorizing ability than that of different individual strains. A broad spectrum of dyes could be decolorized by the sludge. Continuous decolorization tests showed that the sludge exhibited the ability to decolorize repeated additions of dye. The chemical oxygen demand (COD removal rate of the dye wastewater reached 52% after 12 h of incubation. Polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE profiles revealed that the microbial community changed as a result of varying initial concentrations of dyes. Phylogenetic analysis indicated that microbial populations in the sludge belonged to the phyla Acidobacteria, Firmicutes, Bacteroidetes, Chloroflexi and Proteobacteria. The degradation products of the three types of dye were identified. For azo dyes, the anaerobic sludge converted Methyl Orange to N,N-dimethylbenzene-1,4-diamine and 4-aminobenzenesulfonic acid; for triphenylmethane dyes, after Malachite Green was decolorized, the analyzed products were found to be a mixture of N,N-dimethylbenzenamine, 3-dimethyl-aminophenol and 4-dimethylaminobenzophenone; for anthraquinone dyes, two products (acetophenone and 2-methylbenzoic acid were observed after Reactive Blue 19 decolorization. Together, these results suggest that the anaerobic sludge has promising potential for use in the treatment of industrial wastewater containing various types of dyes.

  18. The Comparative Study on the Rapid Decolorization of Azo, Anthraquinone and Triphenylmethane Dyes by Anaerobic Sludge.

    Science.gov (United States)

    Cui, Daizong; Zhang, Hao; He, Rubao; Zhao, Min

    2016-10-28

    An anaerobic sludge (AS), capable of decolorizing a variety of synthetic dyes, was acclimated and is reported here. The sludge presented a much better dye decolorizing ability than that of different individual strains. A broad spectrum of dyes could be decolorized by the sludge. Continuous decolorization tests showed that the sludge exhibited the ability to decolorize repeated additions of dye. The chemical oxygen demand (COD) removal rate of the dye wastewater reached 52% after 12 h of incubation. Polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE) profiles revealed that the microbial community changed as a result of varying initial concentrations of dyes. Phylogenetic analysis indicated that microbial populations in the sludge belonged to the phyla Acidobacteria, Firmicutes, Bacteroidetes, Chloroflexi and Proteobacteria. The degradation products of the three types of dye were identified. For azo dyes, the anaerobic sludge converted Methyl Orange to N , N -dimethylbenzene-1,4-diamine and 4-aminobenzenesulfonic acid; for triphenylmethane dyes, after Malachite Green was decolorized, the analyzed products were found to be a mixture of N , N -dimethylbenzenamine, 3-dimethyl-aminophenol and 4-dimethylaminobenzophenone; for anthraquinone dyes, two products (acetophenone and 2-methylbenzoic acid) were observed after Reactive Blue 19 decolorization. Together, these results suggest that the anaerobic sludge has promising potential for use in the treatment of industrial wastewater containing various types of dyes.

  19. Visual monitoring of solid-phase extraction using chromogenic fluorous synthesis supports.

    Science.gov (United States)

    Blackburn, Christopher

    2012-03-12

    Reductive aminations and further transformations of an azo dye and fluorous tagged aldehyde are described. The intensely colored 2,4-dialkoxybenzyl protected amines undergo Fmoc-based peptide coupling, Suzuki reactions, and sulfonamide formation with product isolation facilitated by visual monitoring of fluorous solid phase extraction. Target compounds are released from the supports in high yields and purities by treatment with trifluoroacetic acid (TFA).

  20. Decolorizing of azo dye Reactive red 24 aqueous solution using exfoliated graphite and H2O2 under ultrasound irradiation.

    Science.gov (United States)

    Li, Mei; Li, Ji-Tai; Sun, Han-Wen

    2008-07-01

    At its natural pH (6.95), the decolorization of Reactive red 24 in ultrasound, ultrasound/H2O2, exfoliated graphite, ultrasound/exfoliated graphite, exfoliated graphite/H2O2 and ultrasound/exfoliated graphite/H2O2 systems were compared. An enhancement was observed for the decolorization in ultrasound/exfoliated graphite/H2O2 system. The effect of solution pH, H2O2 and exfoliated graphite dosages, and temperature on the decolorization of Reactive red 24 was investigated. The sonochemical treatment in combination with exfoliated graphite/H2O2 showed a synergistic effect for the decolorization of Reactive red 24. The results indicated that under proper conditions, there was a possibility to remove Reactive red 24 very efficient from aqueous solution. The decolorization of other azo dyes (Reactive red 2, Methyl orange, Acid red 1, Acid red 73, Acid red 249, Acid orange 7, Acid blue 113, Acid brown 75, Acid green 20, Acid yellow 42, Acid mordant brown 33, Acid mordant yellow 10 and Direct green 1) was also investigated, at their natural pH.

  1. Activated carbon modified with 4-(8-hydroxyquinoline-azo)benzamidine for selective solid-phase extraction and preconcentration of trace lead from environmental samples

    International Nuclear Information System (INIS)

    Tian, H.; Chang, X.; Hu, Z.; Yang, K.; He, Q.; Zhang, L.; Tu, Z.

    2010-01-01

    Activated carbon was chemically modified with 4-(8-hydroxyquinoline-azo)benzamidine and used for separation and preconcentration of trace amounts of Pb(II) in environmental samples by solid-phase extraction prior to the measurement by inductively coupled plasma atomic emission spectrometry. The effects of pH, shaking time, eluent concentration and volume, sample flow rate and potential interfering ions were studied. Under the optimum conditions, the enrichment factor was 100, the detection limits is 0. 43 ng mL -1 , and the relative standard deviations are <2. 1% (n = 8). The adsorption capacity of the sorbent is 53. 58 mg of lead(II) per gram of the material. The sorbent was successfully applied to the preconcentration of trace Pb(II) in the reference materials GBW 08301 (river sediment) and GBW 08302 (Tibet soil). The recovery of lead(II) from Yellow river water, Huangshui water, and tap water is in range of 99. 3-101. 6%. (author)

  2. Treatment of a non-azo dye aqueous solution by CWAO in continuous reactor using a Ni catalyst derived from hydrotalcite-like precursor.

    Science.gov (United States)

    Vallet, Ana; Besson, Michèle; Ovejero, Gabriel; García, Juan

    2012-08-15

    Catalytic wet air oxidation (CWAO) of a Basic Yellow 11 (BY11) aqueous solution, chosen as a model of a hardly biodegradable non-azo dye was carried out in a continuous-flow trickle-bed reactor, using nickel supported over hydrotalcite precursor calcined at 550°C. An increase in the reaction temperature (120-180°C), and a decrease in dye concentration (1000-3000 ppm) or liquid flow rate (0.1-0.7 mL min(-1)) enhanced the CWAO performance in a 30 and 19% for the variation of the temperature and concentration respectively. After a small leaching observed within the first hours, the catalyst proved to be very stable during the 65-day reaction. The CWAO process was found to be very efficient, achieving BY11 conversion up to 95% and TOC conversion up to 85% at 0.1 mL min(-1) and 180°C under 5 MPa air. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. The effects of halide ions on the radiation-induced decoloration of azo and anthraquinone dyes in N2O-saturated aqueous solutions

    International Nuclear Information System (INIS)

    Suzuki, Nobutake; Tokunaga, Okihiro; Washino, Masamitsu

    1978-01-01

    The radiation-induced decoloration of azo and anthraquinone dyes was studied in N 2 O-saturated aqueous solutions containing halide ions. In the N 2 O-saturated solutions, the decoloration yield, G(-Dye), increased markedly upon the addition of Br - and I - , which are efficient scavengers of the OH radical. In the nitrogen-saturated solutions, however, the G(-Dye) decreased upon the addition of Br - and I - . Such an increase in the G(-Dye) upon the addition of Br - and I - in the N 2 O-saturated solutions is mainly attributable to the attacks of the halide radical anions, Br 2 - and I 2 - , on the ring structure of the dyes. On the other hand, the G(-Dye) was not changed upon the addition of Cl - in the N 2 O-saturated solution. This may be attributable to the very slow rate of the formation of Cl 2 - in a neutral solution. (auth.)

  4. Novas tendências no tratamento de efluentes têxteis New tendencies on textile effluent treatment

    Directory of Open Access Journals (Sweden)

    Airton Kunz

    2002-02-01

    Full Text Available Textile effluents, when not correctly treated, cause a high impact to the environment. The main recalcitrant compounds present in textile effluent are represented by the synthetic dyes, used during the fibber dying process. Among others, the azo dyes are considered the most harmful due to its mutagenic and carcinogenic character. In the present work we reported a revision study on the new tendencies for remediation of textile effluents, mainly to degrade the recalcitrant compounds. For this purpose, chemical, physical, photochemical, biological and combined processes were investigated.

  5. Poly(acrylamide) functionalized chitosan: An efficient adsorbent for azo dyes from aqueous solutions

    International Nuclear Information System (INIS)

    Singh, Vandana; Sharma, Ajit Kumar; Sanghi, Rashmi

    2009-01-01

    In the present communication we report on the optimization of persulfate/ascorbic acid initiated synthesis of chitosan-graft-poly(acrylamide) (Ch-g-PAM) and its application in the removal of azo dyes. The optimum yield of the copolymer was obtained using 16 x 10 -2 M acrylamide, 3.0 x 10 -2 M ascorbic acid, 2.4 x 10 -3 M K 2 S 2 O 8 and 0.1 g chitosan in 25 mL of 5% aqueous formic acid at 45 ± 0.2 o C. Ch-g-PAM remained water insoluble even under highly acidic conditions and could efficiently remove Remazol violet and Procion yellow dyes from the aqueous solutions over a pH range of 3-8 in contrast to chitosan (Ch) which showed pH dependent adsorption. The adsorption data of the Ch-g-PAM and Ch for both the dyes were modeled by Langmuir and Freundlich isotherms where the data fitted better to Langmuir isotherms. To understand the adsorption behavior of Ch-g-PAM, adsorption of Remazol violet on to the copolymer was optimized and the kinetic and thermodynamic studies were carried out taking Ch as reference. Both Ch-g-PAM and Ch followed pseudo-second-order adsorption kinetics. The thermodynamic study revealed a positive heat of adsorption (ΔH o ), a positive ΔS o and a negative ΔG o , indicating spontaneous and endothermic nature of the adsorption of RV dye on to the Ch-g-PAM. The Ch-g-PAM was found to be very efficient in removing color from real industrial wastewater as well, though the interfering ions present in the wastewater slightly hindered its adsorption capacity. The data from regeneration efficiencies for ten cycles evidenced the high reusability of the copolymer in the treatment of waste water laden with even high concentrations of dye.

  6. Organic solvent-free air-assisted liquid-liquid microextraction for optimized extraction of illegal azo-based dyes and their main metabolite from spices, cosmetics and human bio-fluid samples in one step.

    Science.gov (United States)

    Barfi, Behruz; Asghari, Alireza; Rajabi, Maryam; Sabzalian, Sedigheh

    2015-08-15

    Air-assisted liquid-liquid microextraction (AALLME) has unique capabilities to develop as an organic solvent-free and one-step microextraction method, applying ionic-liquids as extraction solvent and avoiding centrifugation step. Herein, a novel and simple eco-friendly method, termed one-step air-assisted liquid-liquid microextraction (OS-AALLME), was developed to extract some illegal azo-based dyes (including Sudan I to IV, and Orange G) from food and cosmetic products. A series of experiments were investigated to achieve the most favorable conditions (including extraction solvent: 77μL of 1-Hexyl-3-methylimidazolium hexafluorophosphate; sample pH 6.3, without salt addition; and extraction cycles: 25 during 100s of sonication) using a central composite design strategy. Under these conditions, limits of detection, linear dynamic ranges, enrichment factors and consumptive indices were in the range of 3.9-84.8ngmL(-1), 0.013-3.1μgmL(-1), 33-39, and 0.13-0.15, respectively. The results showed that -as well as its simplicity, fastness, and use of no hazardous disperser and extraction solvents- OS-AALLME is an enough sensitive and efficient method for the extraction of these dyes from complex matrices. After optimization and validation, OS-AALLME was applied to estimate the concentration of 1-amino-2-naphthol in human bio-fluids as a main reductive metabolite of selected dyes. Levels of 1-amino-2-naphthol in plasma and urinary excretion suggested that this compound may be used as a new potential biomarker of these dyes in human body. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Evaluation of Fenton Process in Removal of Direct Red 81

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Baghapour

    2016-01-01

    Full Text Available Background: Dyes are visible materials and are considered as one of the hazardous components that make up the industrial waste. Dye compounds in natural water, even in very low concentrations, will lead to environmental problems. Azo dyes are compounds with one or more –N=N– groups and are used in textile industry. Because of its low price, solubility, and stability, azo dyes are widely used in the textile industry. Direct Red 81 (DR81 is one of the azo dyes, which is removed from bodies of water, using various methods. This study aimed to assess DR81 dye removal by Fenton oxidation and the effects of various parameters on this process. Methods: Decolorization tests by Fenton oxidation were performed at dye concentrations of 50, 500, 100 and 1000 mg/L; hydrogen peroxide concentrations of 0, 10, 30, 60 and 120 mg/L; iron (II sulfate heptahydrate concentrations of 0, 3, 5, 20 and 50 mg/L; and pH levels of 3, 5, 7 and 10 for durations of 5, 10, 20, 30, 60 and 180 minutes. Results: The optimal condition occurred at a dye concentration of 20 mg/L, hydrogen peroxide concentration of 120 mg/L, bivalent iron concentration of 100 mg/L, pH of 3, and duration of 30 minutes. Under such conditions, the maximum dye removal rate was 88.98%. Conclusion: The results showed that DR81 could be decomposed and removed by Fenton oxidation. In addition, the removal of Direct Red 81 (DR81 depends on several factors such as dye concentration, reaction time, concentrations of hydrogen peroxide and iron, and pH

  8. Simultaneous determination of ten illegal azo dyes in feed by ultra-high performance liquid chromatography tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Piątkowska Marta

    2017-09-01

    Full Text Available Introduction: The paper presents the method of simultaneous determination of 10 illegal azo dyes in feed by ultra-high performance liquid chromatography coupled with tandem mass spectrometry technique. Material and Methods: The dyes were extracted with hexane, evaporated to dryness, and analysed. Separation was achieved in 7 min in a gradient elution using acetonitrile (A and 0.1% formic acid (B as a mobile phase. Results: The validation results showed the repeatability of the method, which was evaluated at three levels (50, 500, and 5,000 μg/kg. All the matrix calibration curves for the working ranges were linear (R2 0.9904 to 1.0, the repeatability was between 2.1% and 24%, and recoveries ranged from 77.9% to 120%. The LOD and LOQ were at 1-2 and 5-10 μg/kg for different dyes, respectively. Furthermore, the method was applied in the homogeneity tests of the in-house prepared feed containing Sudan I at the levels of 0.5, 5, and 50 mg/kg. Conclusions: A sensitive, selective, and fast multiresidue method was successfully developed and validated. Its robustness was confirmed by the analysis of an experimental feed containing Sudan I.

  9. Electric Characteristic Enhancement of an AZO/Si Schottky Barrier Diode with Hydrogen Plasma Surface Treatment and AlxOx Guard Ring Structure

    Directory of Open Access Journals (Sweden)

    Chien-Yu Li

    2018-01-01

    Full Text Available In this study, the design and fabrication of AZO/n-Si Schottky barrier diodes (SBDs with hydrogen plasma treatment on silicon surface and AlxOx guard ring were presented. The Si surface exhibited less interface defects after the cleaning process following with 30 w of H2 plasma treatment that improved the switching properties of the following formed SBDs. The rapid thermal annealing experiment also held at 400 °C to enhance the breakdown voltage of SBDs. The edge effect of the SBDs was also suppressed with the AlxOx guard ring structure deposited by the atomic layer deposition (ALD at the side of the SBDs. Experimental results show that the reverse leakage current was reduced and the breakdown voltage increased with an addition of the AlxOx guard ring. The diode and fabrication technology developed in the study were applicable to the realization of SBDs with a high breakdown voltage (>200 V, a low reverse leakage current density (≤72 μA/mm2@100 V, and a Schottky barrier height of 1.074 eV.

  10. Electric Characteristic Enhancement of an AZO/Si Schottky Barrier Diode with Hydrogen Plasma Surface Treatment and AlxOx Guard Ring Structure

    Science.gov (United States)

    Li, Chien-Yu; Cheng, Min-Yu; Houng, Mau-Phon; Yang, Cheng-Fu; Liu, Jing

    2018-01-01

    In this study, the design and fabrication of AZO/n-Si Schottky barrier diodes (SBDs) with hydrogen plasma treatment on silicon surface and AlxOx guard ring were presented. The Si surface exhibited less interface defects after the cleaning process following with 30 w of H2 plasma treatment that improved the switching properties of the following formed SBDs. The rapid thermal annealing experiment also held at 400 °C to enhance the breakdown voltage of SBDs. The edge effect of the SBDs was also suppressed with the AlxOx guard ring structure deposited by the atomic layer deposition (ALD) at the side of the SBDs. Experimental results show that the reverse leakage current was reduced and the breakdown voltage increased with an addition of the AlxOx guard ring. The diode and fabrication technology developed in the study were applicable to the realization of SBDs with a high breakdown voltage (>200 V), a low reverse leakage current density (≤72 μA/mm2@100 V), and a Schottky barrier height of 1.074 eV. PMID:29316726

  11. Azo dyes decomposition on new nitrogen-modified anatase TiO{sub 2} with high adsorptivity

    Energy Technology Data Exchange (ETDEWEB)

    Janus, M., E-mail: mjanus@ps.pl [Szczecin University of Technology, Department of Sanitary Engineering, al. Piastow 50, 70-310 Szczecin (Poland); Szczecin University of Technology, Institute of Chemical and Environment Engineering, Department of Water Technology and Environment Engineering, ul. Pulaskiego 10, 70-322 Szczecin (Poland); Choina, J.; Morawski, A.W. [Szczecin University of Technology, Institute of Chemical and Environment Engineering, Department of Water Technology and Environment Engineering, ul. Pulaskiego 10, 70-322 Szczecin (Poland)

    2009-07-15

    New vis active photocatalyst was obtained by the modification of commercial anatase TiO{sub 2} (Police, Poland) in pressure reactor in an ammonia water atmosphere at 100 {sup o}C for 4 h. The photocatalytic activity of new material was tested during three azo dyes decomposition: monoazo (Reactive Read), diazo (Reactive Black) and poliazodye (Direct Green). Obtained photocatalyst had new bands at 1430-1440 cm{sup -1} attributed to the bending vibrations of NH{sub 4}{sup +} and at 1535 cm{sup -1} associated with NH{sub 2} groups or NO{sub 2} and NO. UV-vis/DR spectra of photocatalyst had also insignificant decrease in visible region. Fluorescence technique was used for studying the amount of hydroxyl radicals produced on TiO{sub 2} surface during visible light irradiation. The hydroxyl radicals produced react with coumarin present in the solution to form 7-hydroxycoumarin which has fluorescent capacity. Photocatalytic activity of modified TiO{sub 2} was compared with commercial titanium dioxide P25 (Degussa, Germany). The photocatalytic activity of TiO{sub 2}/N was higher than that of unmodified material and P25 under visible light irradiation. The ability for dye adsorption (Reactive Red) on photocatalyst surface was also tested. Unmodified TiO{sub 2} and P25 has isotherm of adsorption by Freundlich model, and nitrogen-modified TiO{sub 2} by Langmuir model. The presence of nitrogen at the surface of TiO{sub 2} significantly increased adsorption capacity of TiO{sub 2} as well as OH{center_dot} radicals formation under visible radiation.

  12. Isolation of quercetin from the methanolic extract of Lagerstroemia speciosa by HPLC technique, its cytotoxicity against MCF-7 cells and photocatalytic activity.

    Science.gov (United States)

    Sai Saraswathi, V; Saravanan, D; Santhakumar, K

    2017-06-01

    The flavonoids present in the leaves of Lagerstroemia speciosa were extracted, characterized by spectral methods and studied for its cytotoxicity activity against MCF-cell lines and photocatalytic activity against azo dye. Direct and sequential soxhlet extraction was performed and its concentrated crude extract was subjected to high performance liquid chromatography. The yield obtained by the isolated compound (MEI-quercetin) from leaves of L. speciosa was found to be 1.8g from the methanolic extract. The phytochemical analysis and the Rf value of the isolated flavonoid was found to be 3.59. The isolated compound was characterized by Infrared Spectroscopy, NMR and Mass. Based on the characterization, the structure was elucidated as quercetin - a flavonoid. The isolated compound showed the significant in vitro cytotoxicity activity against MCF-7 cell lines at 500μg/ml when compared to the crude extract. Among the various concentrations (25, 50, 100, 250, and 500μg/ml), at higher concentration the cell viability was pronounced and also compared with that of the control. It was first time to report that the isolated flavonoid showed photocatalytic against azo dye-methyl orange. The dye degradation was monitored by UV-Vis spectrophotometry. The isolated compound showed dye degradation of 91.66% with the crude extract 82.47% at 160min. Hence in the present findings, the photocatalytic degradation of MO dye under UV irradiation was investigated over isolated compound of L. speciosa. Hence we expect that this can be used to treat the waste water in near future based on the photocatalytic technique. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Synthesis, characterization and degradation activity of Methyl orange Azo dye using synthesized CuO/α-Fe2O3 nanocomposite

    Directory of Open Access Journals (Sweden)

    Mohsen Mehdipour Ghazi

    2017-04-01

    Full Text Available This study investigated the photo-degradation of methyl orange (MO as a type of azo dye using a CuO/α-Fe2O3 nanocomposite. A CuO/α-Fe2O3 powder with a crystalline size in the range of 27-49 nm was successfully prepared using simple co-precipitation along with a sonication method. The characterization of the synthesized sample was done via XRD, FE-SEM, EDS, FTIR and DRS analyses. The Tauc equation revealed that the band gap of the nano composite in the direct mood was 2.05 ev, which is in the visible light range. The effect of operating factors containing dye concentration, photocatalyst dosage and pH on dye degradation efficiency was measured. Response Surface Method (RSM was employed to specify the parameter effects. The photocatalytic activity of the CuO/α-Fe2O3 nanocomposite was evaluated by degradation of MO under visible light irradiation. The results showed that the pH value played a very effective role in the dye degradation process efficiency. Also, the photocatalytic degradation of MO obtained was equal to 88.47% in the optimal values.

  14. Preparation of an anionic azo pigment-pillared layered double hydroxide and the thermo- and photostability of the resulting intercalated material

    Science.gov (United States)

    Guo, Shengchang; Li, Dianqing; Zhang, Weifeng; Pu, Min; Evans, David G.; Duan, Xue

    2004-12-01

    A large anionic pigment has been intercalated into a layered double hydroxide (LDH) host by ion-exchange of an Mg/Al LDH-nitrate precursor with a solution of C.I. Pigment Red 48:2 (the calcium salt of 4-((5-chloro-4-methyl-2-sulfophenyl)azo)-3-hydroxy-2-naphthalene-carboxylic acid), in ethane-1,2-diol. After intercalation of the pigment, the interlayer distance in the LDH increases from 0.86 to 1.72 nm. Infrared spectra and TG-DTA curves reveal the presence of a complex system of supramolecular host-guest interactions. The UV-visible diffuse reflectance spectra of C.I. Pigment Red 48:2 show marked changes after heating at 200 °C and above, whereas there are no significant changes in the spectra of the intercalated pigment after heating at temperatures up to 300 °C, showing that the thermostability is markedly enhanced by intercalation in the LDH host. The pigment-intercalated LDHs exhibits much higher photostability to UV light than the pristine pigment, in the case of both the pure solids and their composites with polypropylene, as shown by measurement of CIE 1976 L*a*b* color difference ( ΔE) values.

  15. Thermal Effect on the Structural, Electrical, and Optical Properties of In-Line Sputtered Aluminum Doped Zinc Oxide Films Explored with Thermal Desorption Spectroscopy

    Directory of Open Access Journals (Sweden)

    Shang-Chou Chang

    2014-01-01

    Full Text Available This work investigates the thermal effect on the structural, electrical, and optical properties of aluminum doped zinc oxide (AZO films. The AZO films deposited at different temperatures were measured using a thermal desorption system to obtain their corresponding thermal desorption spectroscopy (TDS. In addition to obtaining information of thermal desorption, the measurement of TDS also has the effect of vacuum annealing on the AZO films. The results of measuring TDS imply part of the doped aluminum atoms do not stay at substituted zinc sites in AZO films. The (002 preferential direction of the AZO films in X-ray diffraction spectra shifts to a lower angle after measurement of TDS. The grain size grows and surface becomes denser for all AZO films after measurement of TDS. The carrier concentration, mobility, and average optical transmittance increase while the electrical resistivity decreases for AZO films after measurement of TDS. These results indicate that the AZO films deposited at 200°C are appropriate selections if the AZO films are applied in device fabrication of heat-produced process.

  16. Synthesis and antimicrobial activities of novel 1,4-benzothiazine derivatives

    Directory of Open Access Journals (Sweden)

    Vijay V. Dabholkar

    2016-09-01

    Full Text Available A series of 2H,4H-2-[3,5-dimethyl-4-(substituted phenyl azo pyrazol-1-yl] carbonyl methyl-3-oxo-1,4-benzothiazine derivatives have been synthesized by the reaction of 2H,4H-2-hydrazino carbonyl methyl-3-oxo-1,4-benzothiazine with acetyl acetone derivatives using ultrasound in lesser time with higher yields. All the synthesized compounds were investigated for their antibacterial activities. The result indicated that the compounds show convincing activities against Gram-positive bacteria (Bacillus subtilis and Streptococcus lactis when compared with standard drug (ampicillin trihydrate. These compounds were also synthesized by conventional method and their structures have been elucidated on the basis of spectral analyses and chemical reactions.

  17. Optothermal Switching of Cholesteric Liquid Crystals: A Study of Azobenzene Derivatives and Laser Wavelengths

    Directory of Open Access Journals (Sweden)

    Tai-Chieh Huang

    2015-09-01

    Full Text Available The laser-initiated thermal (optothermal switching of cholesteric liquid crystals (CLCs is characterized by using different azobenzene (Azo derivatives and laser wavelengths. Under 405-nm laser irradiation, Azo-doped CLCs undergo phase transition from cholesteric to isotropic. No cis-to-trans photoisomerization occurs when the 405-nm laser irradiation is blocked because only a single laser is used. The fast response of Azo-doped CLCs under the on–off switching of the 405-nm laser occurs because of the optothermal effect of the system. The 660-nm laser, which cannot be used as irradiation to generate the trans–cis photoisomerization of Azo, is used in Anthraquinone (AQ-Azo-doped CLCs to examine the optothermal effect of doped Azo. The results show that the LC-like Azo derivative bearing two methyl groups ortho to the Azo moiety (A4 can greatly lower the clearing temperature and generate large amount of heat in AQ-A4-doped CLCs.

  18. Isotopically modified compounds

    International Nuclear Information System (INIS)

    Kuruc, J.

    2009-01-01

    In this chapter the nomenclature of isotopically modified compounds in Slovak language is described. This chapter consists of following parts: (1) Isotopically substituted compounds; (2) Specifically isotopically labelled compounds; (3) Selectively isotopically labelled compounds; (4) Non-selectively isotopically labelled compounds; (5) Isotopically deficient compounds.

  19. Using Polarized Spectroscopy to Investigate Order in Thin-Films of Ionic Self-Assembled Materials Based on Azo-Dyes

    Science.gov (United States)

    Ahmad, Mariam; Andersen, Frederik; Brend Bech, Ári; Bendixen, H. Krestian L.; Nawrocki, Patrick R.; Bloch, Anders J.; Bora, Ilkay; Bukhari, Tahreem A.; Bærentsen, Nicolai V.; Carstensen, Jens; Chima, Smeeah; Colberg, Helene; Dahm, Rasmus T.; Daniels, Joshua A.; Dinckan, Nermin; El Idrissi, Mohamed; Erlandsen, Ricci; Førster, Marc; Ghauri, Yasmin; Gold, Mikkel; Hansen, Andreas; Hansen, Kenn; Helmsøe-Zinck, Mathias; Henriksen, Mathias; Hoffmann, Sophus V.; Hyllested, Louise O. H.; Jensen, Casper; Kallenbach, Amalie S.; Kaur, Kirandip; Khan, Suheb R.; Kjær, Emil T. S.; Kristiansen, Bjørn; Langvad, Sylvester; Lund, Philip M.; Munk, Chastine F.; Møller, Theis; Nehme, Ola M. Z.; Nejrup, Mathilde Rove; Nexø, Louise; Nielsen, Simon Skødt Holm; Niemeier, Nicolai; Nikolajsen, Lasse V.; Nøhr, Peter C. T.; Skaarup Ovesen, Jacob; Paustian, Lucas; Pedersen, Adam S.; Petersen, Mathias K.; Poulsen, Camilla M.; Praeger-Jahnsen, Louis; Qureshi, L. Sonia; Schiermacher, Louise S.; Simris, Martin B.; Smith, Gorm; Smith, Heidi N.; Sonne, Alexander K.; Zenulovic, Marko R.; Winther Sørensen, Alma; Vogt, Emil; Væring, Andreas; Westermann, Jonas; Özcan, Sevin B.

    2018-01-01

    Three series of ionic self-assembled materials based on anionic azo-dyes and cationic benzalkonium surfactants were synthesized and thin films were prepared by spin-casting. These thin films appear isotropic when investigated with polarized optical microscopy, although they are highly anisotropic. Here, three series of homologous materials were studied to rationalize this observation. Investigating thin films of ordered molecular materials relies to a large extent on advanced experimental methods and large research infrastructure. A statement that in particular is true for thin films with nanoscopic order, where X-ray reflectometry, X-ray and neutron scattering, electron microscopy and atom force microscopy (AFM) has to be used to elucidate film morphology and the underlying molecular structure. Here, the thin films were investigated using AFM, optical microscopy and polarized absorption spectroscopy. It was shown that by using numerical method for treating the polarized absorption spectroscopy data, the molecular structure can be elucidated. Further, it was shown that polarized optical spectroscopy is a general tool that allows determination of the molecular order in thin films. Finally, it was found that full control of thermal history and rigorous control of the ionic self-assembly conditions are required to reproducibly make these materials of high nanoscopic order. Similarly, the conditions for spin-casting are shown to be determining for the overall thin film morphology, while molecular order is maintained. PMID:29462883

  20. Using Polarized Spectroscopy to Investigate Order in Thin-Films of Ionic Self-Assembled Materials Based on Azo-Dyes

    Directory of Open Access Journals (Sweden)

    Miguel R. Carro-Temboury Martin Kühnel

    2018-02-01

    Full Text Available Three series of ionic self-assembled materials based on anionic azo-dyes and cationic benzalkonium surfactants were synthesized and thin films were prepared by spin-casting. These thin films appear isotropic when investigated with polarized optical microscopy, although they are highly anisotropic. Here, three series of homologous materials were studied to rationalize this observation. Investigating thin films of ordered molecular materials relies to a large extent on advanced experimental methods and large research infrastructure. A statement that in particular is true for thin films with nanoscopic order, where X-ray reflectometry, X-ray and neutron scattering, electron microscopy and atom force microscopy (AFM has to be used to elucidate film morphology and the underlying molecular structure. Here, the thin films were investigated using AFM, optical microscopy and polarized absorption spectroscopy. It was shown that by using numerical method for treating the polarized absorption spectroscopy data, the molecular structure can be elucidated. Further, it was shown that polarized optical spectroscopy is a general tool that allows determination of the molecular order in thin films. Finally, it was found that full control of thermal history and rigorous control of the ionic self-assembly conditions are required to reproducibly make these materials of high nanoscopic order. Similarly, the conditions for spin-casting are shown to be determining for the overall thin film morphology, while molecular order is maintained.

  1. Degradation efficiency and mechanism of azo dye RR2 by a novel ozone aerated internal micro-electrolysis filter.

    Science.gov (United States)

    Zhang, Xian-Bing; Dong, Wen-Yi; Sun, Fei-Yun; Yang, Wei; Dong, Jiao

    2014-07-15

    A newly designed ozone aerated internal micro-electrolysis filter (OIEF) was developed to investigate its degradation efficiencies and correlated reaction mechanisms of RR2 dye. Complete decolorization and 82% TOC removal efficiency were stably achieved in OIEF process. Based on the comprehensive experimental results, an empirical equation was proposed to illustrate the effects of initial dye concentration and ozone dosage rate on color removal. The results indicated that OIEF process could be operated at wide pH range without significant treatment efficiencies change, while the optimum pH for RR2 dye degradation was 9.0. There were 15, 8 and 6 kinds of identified intermediates during ozonation, IE and OIEF treatment processes, respectively. Less identified intermediates and their lower concentrations in OIEF may attribute to its rather excellent mineralization performance. It was found that ozonation, Fe(2+)/Fe(3+) catalyzed ozonation, the redox reactions of electro-reduction and electro-oxidation are the most important mechanisms in OIEF process. The catalytic effect of Fe(2+)/Fe(3+) would induce mutual conversion between dissolved Fe(2+) and Fe(3+), and then decrease the dissolution rate of ZVI. The excellent treatment performance proved that the OIEF process is one promising technology applied for reactive azo dyes and other refractory wastewater treatment. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Using Polarized Spectroscopy to Investigate Order in Thin-Films of Ionic Self-Assembled Materials Based on Azo-Dyes.

    Science.gov (United States)

    Kühnel, Miguel R Carro-Temboury Martin; Ahmad, Mariam; Andersen, Frederik; Bech, Ári Brend; Bendixen, H Krestian L; Nawrocki, Patrick R; Bloch, Anders J; Bora, Ilkay; Bukhari, Tahreem A; Bærentsen, Nicolai V; Carstensen, Jens; Chima, Smeeah; Colberg, Helene; Dahm, Rasmus T; Daniels, Joshua A; Dinckan, Nermin; Idrissi, Mohamed El; Erlandsen, Ricci; Førster, Marc; Ghauri, Yasmin; Gold, Mikkel; Hansen, Andreas; Hansen, Kenn; Helmsøe-Zinck, Mathias; Henriksen, Mathias; Hoffmann, Sophus V; Hyllested, Louise O H; Jensen, Casper; Kallenbach, Amalie S; Kaur, Kirandip; Khan, Suheb R; Kjær, Emil T S; Kristiansen, Bjørn; Langvad, Sylvester; Lund, Philip M; Munk, Chastine F; Møller, Theis; Nehme, Ola M Z; Nejrup, Mathilde Rove; Nexø, Louise; Nielsen, Simon Skødt Holm; Niemeier, Nicolai; Nikolajsen, Lasse V; Nøhr, Peter C T; Orlowski, Dominik B; Overgaard, Marc; Ovesen, Jacob Skaarup; Paustian, Lucas; Pedersen, Adam S; Petersen, Mathias K; Poulsen, Camilla M; Praeger-Jahnsen, Louis; Qureshi, L Sonia; Ree, Nicolai; Schiermacher, Louise S; Simris, Martin B; Smith, Gorm; Smith, Heidi N; Sonne, Alexander K; Zenulovic, Marko R; Sørensen, Alma Winther; Sørensen, Karina; Vogt, Emil; Væring, Andreas; Westermann, Jonas; Özcan, Sevin B; Sørensen, Thomas Just

    2018-02-15

    Three series of ionic self-assembled materials based on anionic azo-dyes and cationic benzalkonium surfactants were synthesized and thin films were prepared by spin-casting. These thin films appear isotropic when investigated with polarized optical microscopy, although they are highly anisotropic. Here, three series of homologous materials were studied to rationalize this observation. Investigating thin films of ordered molecular materials relies to a large extent on advanced experimental methods and large research infrastructure. A statement that in particular is true for thin films with nanoscopic order, where X-ray reflectometry, X-ray and neutron scattering, electron microscopy and atom force microscopy (AFM) has to be used to elucidate film morphology and the underlying molecular structure. Here, the thin films were investigated using AFM, optical microscopy and polarized absorption spectroscopy. It was shown that by using numerical method for treating the polarized absorption spectroscopy data, the molecular structure can be elucidated. Further, it was shown that polarized optical spectroscopy is a general tool that allows determination of the molecular order in thin films. Finally, it was found that full control of thermal history and rigorous control of the ionic self-assembly conditions are required to reproducibly make these materials of high nanoscopic order. Similarly, the conditions for spin-casting are shown to be determining for the overall thin film morphology, while molecular order is maintained.

  3. Detection of Azo Dyes in Curry Powder Using a 1064-nm Dispersive Point-Scan Raman System

    Directory of Open Access Journals (Sweden)

    Sagar Dhakal

    2018-04-01

    Full Text Available Curry powder is extensively used in Southeast Asian dishes. It has been subject to adulteration by azo dyes. This study used a newly developed 1064 nm dispersive point-scan Raman system for detection of metanil yellow and Sudan-I contamination in curry powder. Curry powder was mixed with metanil yellow and (separately with Sudan-I, at concentration levels of 1%, 3%, 5%, 7%, and 10% (w/w. Each sample was packed into a nickel-plated sample container (25 mm × 25 mm × 1 mm. One Raman spectral image of each sample was acquired across the 25 mm × 25 mm surface area. Intensity threshold value was applied to the spectral images of Sudan-I mixtures (at 1593 cm−1 and metanil yellow mixtures (at 1147 cm−1 to obtain binary detection images. The results show that the number of detected adulterant pixels is linearly correlated with the sample concentration (R2 = 0.99. The Raman system was further used to obtain a Raman spectral image of a curry powder sample mixed together with Sudan-I and metanil yellow, with each contaminant at equal concentration of 5% (w/w. The multi-component spectra of the mixture sample were decomposed using self-modeling mixture analysis (SMA to extract pure component spectra, which were then identified as matching those of Sudan-I and metanil yellow using spectral information divergence (SID values. The results show that the 1064 nm dispersive Raman system is a potential tool for rapid and nondestructive detection of multiple chemical contaminants in the complex food matrix.

  4. Enhanced azo dye removal in a continuously operated up-flow anaerobic filter packed with henna plant biomass

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Jingang, E-mail: hjg@hdu.edu.cn [Institute of Environmental Science and Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China); Wu, Mengke; Chen, Jianjun; Liu, Xiuyan; Chen, Tingting [Institute of Environmental Science and Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Wen, Yue [State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China); Tang, Junhong; Xie, Zhengmiao [Institute of Environmental Science and Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China)

    2015-12-15

    Highlights: • Henna stem mixed with ceramic media in UAF enhanced the removal of AO7. • Bio-reduction was the main AO7 removal pathway in henna-added UAF. • Adsorption and endogenous reduction were the main removal pathways in the control. • Henna played a multiple role in providing electron donors and redox mediator. - Abstract: Effects of henna plant biomass (stem) packed in an up-flow anaerobic bio-filter (UAF) on an azo dye (AO7) removal were investigated. AO7 removal, sulfanilic acid (SA) formation, and pseudo first-order kinetic constants for these reactions (k{sub AO7} and k{sub SA}) were higher in the henna-added UAF (R2) than in the control UAF without henna (R1). The maximum k{sub AO7} in R1 and R2 were 0.0345 and 0.2024 cm{sup −1}, respectively, on day 18; the corresponding molar ratios of SA formation to AO7 removal were 0.582 and 0.990. Adsorption and endogenous bio-reduction were the main AO7 removal pathways in R1, while in R2 bio-reduction was the dominant. Organics in henna could be released and fermented to volatile fatty acids, acting as effective electron donors for AO7 reduction, which was accelerated by soluble and/or fixed lawsone. Afterwards, the removal process weakened over time, indicating the demand of electron donation and lawsone-releasing during the long-term operation of UAF.

  5. Insight about electrical properties of low-temperature solution-processed Al-doped ZnO nanoparticle based layers for TFT applications

    Energy Technology Data Exchange (ETDEWEB)

    Diallo, Abdou Karim; Gaceur, Meriem; Fall, Sadiara; Didane, Yahia; Ben Dkhil, Sadok; Margeat, Olivier, E-mail: margeat@cinam.univ-mrs.fr; Ackermann, Jörg; Videlot-Ackermann, Christine, E-mail: videlot@cinam.univ-mrs.fr

    2016-12-15

    Highlights: • Al-doped ZnO (AZO) nanoparticles. • Impact of dispersion state and solid state on electrical properties. • Extrinsic doping with Al for high conducting AZO nanoparticle based layers. • Low-temperature operating nanoparticulate AZO TFTs. - Abstract: Aluminium-doped zinc oxide nanoparticles (NPs) with controlled Al doping contents (AZO{sub x} with x = 0–0.8 at% of Al) were explored as new oxide semiconductor materials to study the impact of doping on both solution and solid states. Polycrystalline AZO{sub x} thin films were produced by spin-coating the dispersions following by a thermal post-treatment at low-temperature (80 °C or 150 °C). The coated AZO{sub x} films were employed as active layer in thin-film transistors. Morphology and microstructure were studied by scanning electron microscopy and X-ray diffraction. The impact on the device performances (mobility, conductivity, charge carrier density) of Al-doping content together with the solution state was examined. Spin-coated films delivered an electron mobility up to 3 × 10{sup −2} cm{sup 2}/Vs for the highest Al-doping ratio AZO{sub 0.8}. Despite highly different morphologies, extrinsic doping with aluminium significantly increases the conductivity of low temperature solution-processed AZO{sub x} NPs series based layers by several orders of magnitude from AZO{sub 0} to AZO{sub 0.8}.

  6. Photoassisted electrochemical recirculation system with boron-doped diamond anode and carbon nanotubes containing cathode for degradation of a model azo dye

    International Nuclear Information System (INIS)

    Vahid, Behrouz; Khataee, Alireza

    2013-01-01

    In this research work, a photoassisted electrochemical system under recirculation mode and with UV irradiation was designed for treatment of C.I. Acid Blue 92 (AB92) as a model anionic azo dye in aqueous solution. Degradation experiments were carried out with boron-doped diamond (BDD) anode and carbon nanotubes-polytetrafluoroethylene (CNTs-PTFE) cathode in the presence of sulfate as an electrolyte. A comparative study of AB92 degradation by photolysis, electrochemical oxidation and photoassisted electrochemical processes after 45 min of treatment demonstrated that degradation efficiency was 27.89, 37.65 and 95.86%, respectively. Experimental data revealed that the degradation rate of AB92 in all of the processes obeyed pseudo-first-order kinetics and application of photoassisted electrochemical system reduced electrical energy per order (E EO ), considerably. Degradation efficiency of photoassisted electrochemical process enhanced by increasing applied current and flow rate values, but vice versa trend was observed for initial dye concentration and an optimum amount of 6 was obtained for initial pH. The TOC measurement results demonstrated that 93.24% of organic substrates were mineralized after 120 min of photoassisted electrochemical process and GC–Mass analysis was performed for identification of degradation intermediates

  7. The effect of NCS- on the radiation-induced decoloration of azo and anthraquinone dyes in N2O-saturated aqueous solutions

    International Nuclear Information System (INIS)

    Suzuki, Nobutake; Hotta, Hiroshi

    1977-01-01

    The radiation-induced decoloration of azo and anthraquinone dyes was studied in N 2 O-saturated aqueous solutions containing NCS - . In the N 2 O-saturated solutions, the decoloration yield, G(-Dye), increased markedly upon the addition of NCS - , which is an efficient scavenger of the OH radical-that is, from 1.46 up to 2.10 for Acid Red 265 and from 0.51 up to 1.51 for Acid Blue 40 upon the addition of 1 mM NCS - . In the nitrogen-saturated solutions, however, the G(-Dye) decreased upon the addition of NCS - . It is concluded that the increase in the G(-Dye) upon the addition of NCS - in the N 2 O-saturated solutions is mainly attributable to the attack of the radical anion (NCS) 2 - on the ring structure of the dyes. This radical anion is formed through the following path: NCS - +OH → NCS+OH - and NCS+NCS - reversible (NCS) 2 - . At low NCS - concentrations, the G(-Dye) decreased for Acid Red 265 and increased for Acid Blue 40. This may be attributable to the larger reactivity of (NCS) 2 - on Acid Blue 40 than on Acid Red 265. (auth.)

  8. Superhydrophobic and anti-reflective ZnO nanorod-coated FTO transparent conductive thin films prepared by a three-step method

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bao-jia, E-mail: li_bjia@126.com [School of Materials Science and Engineering, Jiangsu University, Zhenjiang, 212013 (China); Jiangsu Provincial Key Laboratory of Center for Photon Manufacturing Science and Technology, Jiangsu University, Zhenjiang, 212013 (China); Huang, Li-jing; Ren, Nai-fei [Jiangsu Provincial Key Laboratory of Center for Photon Manufacturing Science and Technology, Jiangsu University, Zhenjiang, 212013 (China); School of Mechanical Engineering, Jiangsu University, Zhenjiang, 212013 (China); Kong, Xia; Cai, Yun-long; Zhang, Jie-lu [Jiangsu Tailong Reduction Box Co. Ltd., Taixing, 225400 (China)

    2016-07-25

    A ZnO nanorod-coated FTO film was prepared by sputtering an AZO layer on FTO glass, thermal annealing of the AZO/FTO film, and hydrothermal growth of ZnO nanorods at 70 °C on the annealed AZO/FTO film using zinc foils as zinc source. Two other ZnO nanorod-coated FTO films were also prepared by hydrothermal growths of ZnO nanorods on the FTO glass and the unannealed AZO/FTO film respectively for comparison purpose. The results were observed in detail using X-ray diffraction, scanning electron microscopy, water contact/sliding angle measurement, spectrophotometry and four-point probe measurement. The ZnO nanorods on the annealed AZO/FTO film were found to exhibit denser distribution and better orientation than those on the FTO glass and the unannealed AZO/FTO film. As a result, the ZnO nanorod-coated annealed AZO/FTO film demonstrated superhydrophobicity, high transparency and low reflectance in the visible range. Also this film had the lowest sheet resistance of 4.0 Ω/sq, implying its good electrical conductivity. This investigation provides a valuable reference for developing multifunctional transparent conductive films. - Highlights: • ZnO nanorod-coated annealed AZO/FTO film was obtained by a three-step method. • FTO and unannealed AZO/FTO films were also used as substrates for comparison. • ZnO nanorods on the annealed AZO/FTO film were denser and more vertically-oriented. • The ZnO nanorod-coated annealed AZO/FTO film (Z/TA-FTO) had superhydrophobicity. • The Z/TA-FTO exhibited high transparency, low reflectance and good conductivity.

  9. Textured surface structures formed using new techniques on transparent conducting Al-doped zinc oxide films prepared by magnetron sputtering

    International Nuclear Information System (INIS)

    Minami, Tadatsugu; Miyata, Toshihiro; Uozaki, Ryousuke; Sai, Hitoshi; Koida, Takashi

    2016-01-01

    Surface-textured Al-doped ZnO (AZO) films formed using two new techniques based on magnetron sputtering deposition were developed by optimizing the light scattering properties to be suitable for transparent electrode applications in thin-film silicon solar cells. Scrambled egg-like surface-textured AZO films were prepared using a new texture formation technique that post-etched pyramidal surface-textured AZO films prepared under deposition conditions suppressing c-axis orientation. In addition, double surface-textured AZO films were prepared using another new texture formation technique that completely removed, by post-etching, the pyramidal surface-textured AZO films previously prepared onto the initially deposited low resistivity AZO films; simultaneously, the surface of the low resistivity films was slightly etched. However, the obtained very high haze value in the range from the near ultraviolet to visible light in the scrambled egg-like surface-textured AZO films did not contribute significantly to the obtainable photovoltaic properties in the solar cells fabricated using the films. Significant light scattering properties as well as a low sheet resistance could be achieved in the double surface-textured AZO films. In addition, a significant improvement of external quantum efficiency in the range from the near ultraviolet to visible light was achieved in superstrate-type n-i-p μc-Si:H solar cells fabricated using a double surface-textured AZO film prepared under optimized conditions as the transparent electrode. - Highlights: • Double surface-textured AZO films prepared using a new texture formation technique • Extensive light scattering properties with low sheet resistance achieved in the double surface-textured AZO films • Improved external quantum efficiency of μc-Si:H solar cells using a double surface-textured AZO film

  10. Textured surface structures formed using new techniques on transparent conducting Al-doped zinc oxide films prepared by magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Minami, Tadatsugu [Optoelectronic Device System R& D Center, Kanazawa Institute of Technology, Nonoichi, Ishikawa 921-8501 (Japan); Miyata, Toshihiro, E-mail: tmiyata@neptune.kanazawa-it.ac.jp [Optoelectronic Device System R& D Center, Kanazawa Institute of Technology, Nonoichi, Ishikawa 921-8501 (Japan); Uozaki, Ryousuke [Optoelectronic Device System R& D Center, Kanazawa Institute of Technology, Nonoichi, Ishikawa 921-8501 (Japan); Sai, Hitoshi; Koida, Takashi [Research Center for Photovoltaics, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan)

    2016-09-01

    Surface-textured Al-doped ZnO (AZO) films formed using two new techniques based on magnetron sputtering deposition were developed by optimizing the light scattering properties to be suitable for transparent electrode applications in thin-film silicon solar cells. Scrambled egg-like surface-textured AZO films were prepared using a new texture formation technique that post-etched pyramidal surface-textured AZO films prepared under deposition conditions suppressing c-axis orientation. In addition, double surface-textured AZO films were prepared using another new texture formation technique that completely removed, by post-etching, the pyramidal surface-textured AZO films previously prepared onto the initially deposited low resistivity AZO films; simultaneously, the surface of the low resistivity films was slightly etched. However, the obtained very high haze value in the range from the near ultraviolet to visible light in the scrambled egg-like surface-textured AZO films did not contribute significantly to the obtainable photovoltaic properties in the solar cells fabricated using the films. Significant light scattering properties as well as a low sheet resistance could be achieved in the double surface-textured AZO films. In addition, a significant improvement of external quantum efficiency in the range from the near ultraviolet to visible light was achieved in superstrate-type n-i-p μc-Si:H solar cells fabricated using a double surface-textured AZO film prepared under optimized conditions as the transparent electrode. - Highlights: • Double surface-textured AZO films prepared using a new texture formation technique • Extensive light scattering properties with low sheet resistance achieved in the double surface-textured AZO films • Improved external quantum efficiency of μc-Si:H solar cells using a double surface-textured AZO film.

  11. Effect of atomic layer deposited Al2O3:ZnO alloys on thin-film silicon photovoltaic devices

    Science.gov (United States)

    Abdul Hadi, Sabina; Dushaq, Ghada; Nayfeh, Ammar

    2017-12-01

    In this work, we present the effects of the Al2O3:ZnO ratio on the optical and electrical properties of aluminum doped ZnO (AZO) layers deposited by atomic layer deposition, along with AZO application as the anti-reflective coating (ARC) layer and in heterojunction configurations. Here, we report complex refractive indices for AZO layers with different numbers of aluminum atomic cycles (ZnO:Al2O3 = 1:0, 39:1, 19:1, and 9:1) and we confirm their validity by fitting models to experimental data. Furthermore, the most conductive layer (ZnO:Al2O3 = 19:1, conductivity ˜4.6 mΩ cm) is used to fabricate AZO/n+/p-Si thin film solar cells and AZO/p-Si heterojunction devices. The impact of the AZO layer on the photovoltaic properties of these devices is studied by different characterization techniques, resulting in the extraction of recombination and energy band parameters related to the AZO layer. Our results confirm that AZO 19:1 can be used as a low cost and effective conductive ARC layer for solar cells. However, AZO/p-Si heterojunctions suffer from an insufficient depletion region width (˜100 nm) and recombination at the interface states, with an estimated potential barrier of ˜0.6-0.62 eV. The work function of AZO (ZnO:Al2O3 = 19:1) is estimated to be in the range between 4.36 and 4.57 eV. These material properties limit the use of AZO as an emitter in Si solar cells. However, the results imply that AZO based heterojunctions could have applications as low-cost photodetectors or photodiodes, operating under relatively low reverse bias.

  12. Low-temperature, solution-processed aluminum-doped zinc oxide as electron transport layer for stable efficient polymer solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Qianqian [College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101 (China); Bao, Xichang, E-mail: baoxc@qibebt.ac.cn [Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101 (China); Yu, Jianhua [College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Zhu, Dangqiang [Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101 (China); Zhang, Qian [College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Gu, Chuantao [Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101 (China); Dong, Hongzhou [College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Yang, Renqiang [Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101 (China); Dong, Lifeng, E-mail: DongLifeng@qust.edu.cn [College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Department of Physics, Hamline University, St. Paul, MN 55104 (United States)

    2016-04-30

    A simple low-temperature solution-processed zinc oxide (ZnO) and aluminum-doped ZnO (AZO) were synthesized and investigated as an electron transport layer (ETL) for inverted polymer solar cells. A solar cell with a blend of poly(4,8-bis-alkyloxy-benzo[1,2-b:4,5-b′] dithiophene-alt-alkylcarbonyl-thieno [3,4-b] thiophene) and (6,6)-phenyl-C71-butyric acid methyl ester as an active layer and AZO as ETL demonstrates a high power conversion efficiency (PCE) of 7.36% under the illumination of AM 1.5G, 100 mW/cm{sup 2}. Compared to the cells with ZnO ETL (PCE of 6.85%), the PCE is improved by 7.45% with the introduction of an AZO layer. The improved PCE is ascribed to the enhanced short circuit current density, which results from the electron transport property of the AZO layer. Moreover, AZO is a more stable interfacial layer than ZnO. The PCE of the solar cells with AZO as ETL retain 85% of their original value after storage for 120 days, superior to the 39% of cells with ZnO ETL. The results above indicate that a simple low-temperature solution-processed AZO film is an efficient and economical ETL for high-performance inverted polymer solar cells. Due to its environmental friendliness, good electrical properties, and simple preparation approach, AZO has the potential to be applied in high-performance, large-scale industrialization of solar cells and other electronic devices. - Highlights: • ZnO and AZO were synthesized by a simple low-temperature solution-processed method. • AZO films show high transmittance and conductivity. • The photovoltaic performance can be improved with AZO as ETL. • AZO-based devices demonstrate excellent stability, with 85% retained after 120 days.

  13. Study on the electrical and optical properties of Ag/Al-doped ZnO coatings deposited by electron beam evaporation

    International Nuclear Information System (INIS)

    Sahu, D.R.; Lin, S.-Y.; Huang, J.-L.

    2007-01-01

    A layer of silver was deposited onto the surface of glass substrates, coated with AZO (Al-doped ZnO), to form Ag/AZO film structures, using e-beam evaporation techniques. The electrical and optical properties of AZO, Ag and Ag/AZO film structures were studied. The deposition of Ag layer on the surface of AZO films resulted in lowering the effective electrical resistivity with a slight reduction of their optical transmittance. Ag (11 nm)/AZO (25 nm) film structure, with an accuracy of ±0.5 nm for the thickness shows a sheet resistance as low as 5.6 ± 0.5 Ω/sq and a transmittance of about 66 ± 2%. A coating consisting of AZO (25 nm)/Ag (11 nm)/AZO (25 nm) trilayer structure, exhibits a resistance of 7.7 ± 0.5 Ω/sq and a high transmittance of 85 ± 2%. The coatings have satisfactory properties of low resistance, high transmittance and highest figure of merit for application in optoelectronics devices including flat displays, thin films transistors and solar cells as transparent conductive electrodes

  14. Significant improvement in performances of LiNi0.5Mn1.5O4 through surface modification with high ordered Al-doped ZnO electro-conductive layer

    International Nuclear Information System (INIS)

    Sun, Hongdan; Xia, Bingbo; Liu, Weiwei; Fang, Guoqing; Wu, Jingjing; Wang, Haibo; Zhang, Ruixue; Kaneko, Shingo; Zheng, Junwei; Wang, Hongyu; Li, Decheng

    2015-01-01

    Graphical abstract: Al-doped ZnO (AZO)-coated LiNi 0.5 Mn 1.5 O 4 (LNMO) was prepared by sol–gel method. AZO-coated LNMO electrode shows excellent rate capability and a remarkable improvement in the cyclic performance at a high rate at elevated temperature. - Highlights: • Al-doped ZnO (AZO)-coated LiNi 0.5 Mn 1.5 O 4 (LNMO) was prepared by a traditional sol–gel method. • Al-doped ZnO (AZO) layer grown on the surface of LNMO is high ordered. • At a high rate of 10 C, the discharge capacity of the AZO-coated LNMO electrode can reach 114 mAh g −1 . • Al-doped ZnO (AZO) modification improved cyclic performance of LNMO at high temperatures. - Abstract: Al-doped ZnO (AZO)-coated LiNi 0.5 Mn 1.5 O 4 (LNMO) was prepared by sol–gel method. Transmission electron microscopy (TEM) analysis indicates that AZO layer grown on the surface of LNMO is high ordered. The results of electrochemical performance measurements reveal that the AZO-coated LNMO electrode displays the best rate capability compared with the bare LNMO and ZnO-coated LNMO, even at a high rate of 10 C. The discharge capacity of the AZO-coated LNMO electrode can still reach 114.3 mAh g −1 , about 89% of its discharge capacity at 0.1 C. Moreover, AZO-coated LNMO electrode shows a remarkable improvement in the cyclic performance at a high rate at elevated temperature due to the protective effect of AZO coating layer. The electrode delivers a capacity of 120.3 mAh g −1 with the capacity retention of 95% at 5 C in 50 cycles at 50 °C. The analysis of electrochemical impedance spectra (EIS) indicates that AZO-coated LNMO possesses the lowest charge transfer resistance compared to the bare LNMO and ZnO-coated LNMO, which may be responsible for improved rate capability

  15. Significant improvement in performances of LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} through surface modification with high ordered Al-doped ZnO electro-conductive layer

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Hongdan; Xia, Bingbo [College of Physics, Optoelectronics and Energy & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006 (China); Key Laboratory of Lithium Ion Battery Materials of Jiangsu Province, Institute of Chemical Power Sources, Soochow University, Suzhou 215006 (China); Liu, Weiwei [Changzhou Institute of Energy Storage Materials & Devices, Changzhou 213000 (China); Fang, Guoqing; Wu, Jingjing; Wang, Haibo; Zhang, Ruixue [College of Physics, Optoelectronics and Energy & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006 (China); Key Laboratory of Lithium Ion Battery Materials of Jiangsu Province, Institute of Chemical Power Sources, Soochow University, Suzhou 215006 (China); Kaneko, Shingo [Key Laboratory of Lithium Ion Battery Materials of Jiangsu Province, Institute of Chemical Power Sources, Soochow University, Suzhou 215006 (China); Zheng, Junwei [College of Physics, Optoelectronics and Energy & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006 (China); Key Laboratory of Lithium Ion Battery Materials of Jiangsu Province, Institute of Chemical Power Sources, Soochow University, Suzhou 215006 (China); Wang, Hongyu [Changzhou Institute of Energy Storage Materials & Devices, Changzhou 213000 (China); Li, Decheng, E-mail: lidecheng@suda.edu.cn [College of Physics, Optoelectronics and Energy & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006 (China); Key Laboratory of Lithium Ion Battery Materials of Jiangsu Province, Institute of Chemical Power Sources, Soochow University, Suzhou 215006 (China)

    2015-03-15

    Graphical abstract: Al-doped ZnO (AZO)-coated LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} (LNMO) was prepared by sol–gel method. AZO-coated LNMO electrode shows excellent rate capability and a remarkable improvement in the cyclic performance at a high rate at elevated temperature. - Highlights: • Al-doped ZnO (AZO)-coated LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} (LNMO) was prepared by a traditional sol–gel method. • Al-doped ZnO (AZO) layer grown on the surface of LNMO is high ordered. • At a high rate of 10 C, the discharge capacity of the AZO-coated LNMO electrode can reach 114 mAh g{sup −1}. • Al-doped ZnO (AZO) modification improved cyclic performance of LNMO at high temperatures. - Abstract: Al-doped ZnO (AZO)-coated LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} (LNMO) was prepared by sol–gel method. Transmission electron microscopy (TEM) analysis indicates that AZO layer grown on the surface of LNMO is high ordered. The results of electrochemical performance measurements reveal that the AZO-coated LNMO electrode displays the best rate capability compared with the bare LNMO and ZnO-coated LNMO, even at a high rate of 10 C. The discharge capacity of the AZO-coated LNMO electrode can still reach 114.3 mAh g{sup −1}, about 89% of its discharge capacity at 0.1 C. Moreover, AZO-coated LNMO electrode shows a remarkable improvement in the cyclic performance at a high rate at elevated temperature due to the protective effect of AZO coating layer. The electrode delivers a capacity of 120.3 mAh g{sup −1} with the capacity retention of 95% at 5 C in 50 cycles at 50 °C. The analysis of electrochemical impedance spectra (EIS) indicates that AZO-coated LNMO possesses the lowest charge transfer resistance compared to the bare LNMO and ZnO-coated LNMO, which may be responsible for improved rate capability.

  16. Al-doped ZnO/Ag grid hybrid transparent conductive electrodes fabricated using a low-temperature process

    Energy Technology Data Exchange (ETDEWEB)

    An, Ha-Rim; Oh, Sung-Tag [Department of Materials Science and Engineering, Seoul National University of Science and Technology, Seoul 139-743 (Korea, Republic of); Kim, Chang Yeoul [Future Convergence Ceramic Division, Korea Institute Ceramic Engineering and Technology (KICET), Seoul 233-5 (Korea, Republic of); Baek, Seong-Ho [Energy Research Division, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 711-873 (Korea, Republic of); Park, Il-Kyu, E-mail: ikpark@ynu.ac.kr [Department of Electronic Engineering, Yeungnam University, Gyeongbuk 712-749 (Korea, Republic of); Ahn, Hyo-Jin, E-mail: hjahn@seoultech.ac.kr [Department of Materials Science and Engineering, Seoul National University of Science and Technology, Seoul 139-743 (Korea, Republic of)

    2014-12-05

    Highlights: • Al-doped ZnO/Ag transparent conductive electrode is fabricated at low temperature. • Performance of the hybrid transparent conductive electrode affected by the structure. • The performance enhancement mechanism is suggested. - Abstract: Al-doped ZnO (AZO)/Ag grid hybrid transparent conductive electrode (TCE) structures were fabricated at a low temperature by using electrohydrodynamic jet printing for the Ag grids and atomic layer deposition for the AZO layers. The structural investigations showed that the AZO/Ag grid hybrid structures consisted of Ag grid lines formed by Ag particles and the AZO layer covering the inter-spacing between the Ag grid lines. The Ag particles comprising the Ag grid lines were also capped by thin AZO layers, and the coverage of the AZO layers was increased with increasing the thickness of the AZO layer. Using the optimum thickness of AZO layer of 70 nm, the hybrid TCE structure showed an electrical resistivity of 5.45 × 10{sup −5} Ω cm, an optical transmittance of 80.80%, and a figure of merit value of 1.41 × 10{sup −2} Ω{sup −1}. The performance enhancement was suggested based on the microstructural investigations on the AZO/Ag grid hybrid structures.

  17. (E-4-[(4-Nitrophenyldiazenyl]phenyl anthracene-9-carboxylate

    Directory of Open Access Journals (Sweden)

    François Léonard

    2008-12-01

    Full Text Available In the title compound, C27H17N3O4, the azo group displays a trans conformation and the dihedral angles between the central benzene ring and the pendant anthracene and nitrobenzene rings are 82.94 (7 and 7.30 (9°, respectively. In the crystal structure, weak C—H...O hydrogen bonds, likely associated with a dipole moment present on the molecule, help to consolidate the packing.

  18. Decolorization of Mordant red 73 azo dye in water using H2O2/UV and photo-Fenton treatment.

    Science.gov (United States)

    Elmorsi, Taha M; Riyad, Yasser M; Mohamed, Zeinhom H; Abd El Bary, Hassan M H

    2010-02-15

    Decolorization of the Mordant red 73 (MR73) azo dye in water was investigated in laboratory-scale experiments using UV/H(2)O(2) and photo-Fenton treatments. Photodegradation experiments were carried out in a stirred batch photoreactor equipped with a low-pressure mercury lamp as UV source at 254 nm. The effect of operating parameters such as pH, [H(2)O(2)](,) [dye] and the presence of inorganic salts (NaNO(3), NaCl and Na(2)CO(3)) were also investigated. The results indicated that complete dye decolorization was obtained in less than 60 min under optimum conditions. Furthermore, results showed that dye degradation was dependent upon pH, [H(2)O(2)] and initial dye concentration. The presence of chloride ion led to large decreases in the photodegradation rate of MR73 while both nitrate and carbonate ions have a slight effect. The photo-Fenton treatment, in the presence of Fe powder as a source of Fe(2+) ions, was highly efficient and resulted in 99% decolorization of the dye in 15 min. Mineralization of MR73 dye was investigated by determining chemical oxygen demand (COD). In a 3h photoperiod "65%" of the dye was mineralized by the H(2)O(2)/UV process, while the photo-Fenton treatment was more efficient producing 85% mineralization over the same 3-h period.

  19. Adsorption of heavy metal ions and azo dyes by crosslinked nanochelating resins based on poly(methylmethacrylate-co-maleic anhydride

    Directory of Open Access Journals (Sweden)

    M. Ghaemy

    2014-03-01

    Full Text Available Chelating resins are suitable materials for the removal of heavy metals in water treatments. A copolymer, Poly(MMA-co-MA, was synthesized by radical polymerization of maleic anhydride (MA and methyl methacrylate (MMA, characterized and transformed into multifunctional nanochelating resin beads (80–150 nm via hydrolysis, grafting and crosslink reactions. The resin beads were characterized by swelling studies, field emission scanning electron microscopy (FESEM and Fourier transform infrared spectroscopy (FTIR. The main purpose of this work was to determine the adsorption capacity of the prepared resins (swelling ratio ~55% towards metal ions such as Hg2+, Cd2+, Cu2+ from water at three different pH values (3, 6 and 9. Variations in pH and types of metal ions have not significantly affected the chelation capacity of these resins. The maximum chelation capacity of one of the prepared resin beads (Co-g-AP3 for Hg2+ was 63, 85.8 and 71.14 mg/g at pH 3, 6 and 9, respectively. Approximately 96% of the metal ions could be desorbed from the resin. Adsorption capacity of these resins towards three commercial synthetic azo dyes was also investigated. The maximum adsorption of dye AY42 was 91% for the resin Co-g-AP3 at room temperature. This insures the applicability of the synthesized resins for industrial applications.

  20. Photophysical behavior of layer-by-layer electrostatic self-assembled film of azo dye Chromotrope-2R and a polycation

    Energy Technology Data Exchange (ETDEWEB)

    Hansda, Chaitali [Department of Physics, Jadavpur University, Jadavpur, Kolkata 700032 (India); Department of Physics, The University of Burdwan, Golapbag, Burdwan 713104 (India); Dutta, Bipan [Department of Physics, Sammilani Mahavidyalaya, Baghajatin Station, E.M. Bypass, Kolkata 700075 (India); Chakraborty, Utsav; Singha, Tanmoy [Department of Physics, Jadavpur University, Jadavpur, Kolkata 700032 (India); Hussain, Syed Arshad; Bhattacharjee, Debajyoti [Department of Physics, Tripura University, Suryamaninagar 799022, Tripura West (India); Paul, Sharmistha [West Bengal State Council of Science and Technology, Vigyan Chetana Bhavan, Sector-I, Salt Lake, Kolkata 700064 (India); Paul, Pabitra Kumar, E-mail: pabitra_tu@yahoo.co.in [Department of Physics, Jadavpur University, Jadavpur, Kolkata 700032 (India)

    2016-10-15

    This communication reports the fabrication of layer-by-layer electrostatic self-assembled films of an azo dye Chromotrope-2R (CH2R) and a Polycation poly(allylamine hydrochloride) (PAH) onto solid substrate. UV–vis absorption and steady state fluorescence emission spectroscopy successfully confirm the incorporation of dye molecules onto the PAH coated quartz substrate. The adsorption behavior of CH2R onto PAH backbone in LbL films highly depends upon the variation of the microenvironment namely pH of the dye solution from which the film was fabricated. PAH layer onto quartz substrate was able to swell sufficiently in the dye solution at very high pH. The Density functional theory was also utilized here to explain the origin of various spectral transitions from the ground electronic states for both in neutral and anionic form of CH2R. In LbL films the more closure association of dye molecules causes their aggregations which are reflected in their absorption and steady state fluorescence emission spectra when compared to those of pure dye solution. Atomic force microscopic images of LbL films assembled from CH2R aqueous solution at different pH clearly reveal the change in the surface morphology of the films and different degree of association of dye molecules in LbL films deposited at various pH of CH2R.

  1. Photophysical behavior of layer-by-layer electrostatic self-assembled film of azo dye Chromotrope-2R and a polycation

    International Nuclear Information System (INIS)

    Hansda, Chaitali; Dutta, Bipan; Chakraborty, Utsav; Singha, Tanmoy; Hussain, Syed Arshad; Bhattacharjee, Debajyoti; Paul, Sharmistha; Paul, Pabitra Kumar

    2016-01-01

    This communication reports the fabrication of layer-by-layer electrostatic self-assembled films of an azo dye Chromotrope-2R (CH2R) and a Polycation poly(allylamine hydrochloride) (PAH) onto solid substrate. UV–vis absorption and steady state fluorescence emission spectroscopy successfully confirm the incorporation of dye molecules onto the PAH coated quartz substrate. The adsorption behavior of CH2R onto PAH backbone in LbL films highly depends upon the variation of the microenvironment namely pH of the dye solution from which the film was fabricated. PAH layer onto quartz substrate was able to swell sufficiently in the dye solution at very high pH. The Density functional theory was also utilized here to explain the origin of various spectral transitions from the ground electronic states for both in neutral and anionic form of CH2R. In LbL films the more closure association of dye molecules causes their aggregations which are reflected in their absorption and steady state fluorescence emission spectra when compared to those of pure dye solution. Atomic force microscopic images of LbL films assembled from CH2R aqueous solution at different pH clearly reveal the change in the surface morphology of the films and different degree of association of dye molecules in LbL films deposited at various pH of CH2R.

  2. Wet chemical etching of Al-doped ZnO film deposited by RF magnetron sputtering method on textured glass substrate for energy application

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Ki Hwan; Nam, Sang Hun; Jung, Won Suk; Lee, Yong Min; Yang, Hee Su; Boo, Jin Hyo [Dept. of Chemistry, Sungkyunkwan University, Suwon (Korea, Republic of)

    2015-03-15

    The etching of glasses in aqueous hydrofluoric acid (HF) solutions is applied in many technological fields. Particularly, the textured transparent conductive oxide materials on the glass substrate etched by HF were used to improve the current density of solar cells. In this study, the textured glass substrate has been etched by solution and the Al-doped ZnO (AZO) thin films have been prepared on this textured glass substrates by RF magnetron sputtering method. After the AZO film deposition, the surface of AZO has been etched by hydrochloric acid with different concentration and etching time. Etched AZO thin films had higher haze ratio and sheet resistance than bare AZO glass. Increases in the root-mean-square surface roughness of AZO films enhanced from 53.78 to 84.46 nm the haze ratio in above 700 nm wavelength. Our process could be applicable in texturing glass and etching AZO surface to fabricate solar cell in industrial scale. We also carried out fabricating an organic solar-cell device. Energy conversion efficiency improvement of 123% was obtained with textured AZO-based solar-cell device compared with that of nontextured solar-cell device.

  3. Monopolar Electro-Coagulation Process for Azo Dye C.I. Acid Red 18 Removal from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Ghasem Azarian

    2014-12-01

    Full Text Available The discharge of wastewaters containing an untreated dye results in aesthetic problems and an increase in gases solubility, which causes light transmission inhibition into water bodies. In spite of advantages of physicochemical and biological methods, these processes produce huge amounts of sludge, toxic by-products and require several oxidant chemicals. By contrast, electrochemical processes because of their high versatility, high efficiency and eco-friendly properties are more acceptable. In the present study, the removal of azo dye Acid Red 18 and chemical oxygen demand (COD from synthetic wastewater by monopolar (EC process was investigated and key parameters such as operating time, current density (CD, initial pH and energy, and electrode consumption were optimized. It was found that the process had a very good efficiency in the removal of both COD and color; for the iron electrode, the maximum amounts of color and COD removal were 99.5% and 59.0%, respectively. An operating time of 45 min, pH of 7 and CD of 1.2 mA/cm2 was selected as the optimized condition. The optimization of variables is extremely crucial as it results in a decrease in costs, energy and electrode consumption. Overall, the iron electrode used less energy than the aluminum electrode and was more acceptable for use in this process due to economical reasons. The findings of UV/vis spectra illustrated that the structures of this dye were removed by the process. In comparison with traditional methods such as aerobic and anaerobic systems, the EC process is a suitable alternative for the treatment of wastewaters containing dye pollutants.

  4. Kinetics of decolorization of azo dye by bipolar pulsed barrier discharge in a three-phase discharge plasma reactor

    International Nuclear Information System (INIS)

    Zhang Ruobing; Zhang Chi; Cheng Xingxin; Wang Liming; Wu Yan; Guan Zhicheng

    2007-01-01

    Removal of amaranth, a commercial synthetic azo dye widely used in the dye and food industry, was examined as a possible remediation technology for treating dye-contaminated water. Effects of various parameters such as gas flow rate, solution conductivity, pulse repetition frequency, etc., on decolorization kinetics were investigated. Experimental results show that an aqueous solution of 24 mg/l dye is 81.24% decolorized following 30 min plasma treatment for a 50 kV voltage and 0.75 m 3 /h gas flow rate. Decolorization reaction of amaranth in the plasma reactor is a pseudo first order reaction. Rate constant (k) of decolorization increases quickly with increasing the applied voltage, pulse repetition frequency and the gas flow rate. However, when the applied voltage is beyond 50 kV and increases further, increase rate of k decreases. In addition, k decreases quickly when the solution conductivity increases from 200 to 1481 μS/cm. The decolorization reaction has a high rate constant (k = 0.0269 min -1 ) when the solution pH is beyond 10. Rate constant k decreases with the decrease of pH and reaches minimum at a pH of about 5 (k min = 0.01603 min -1 ), then increases to 0.02105 min -1 when pH decreases to 3.07. About 15% of the initial TOC can be degraded only in about 120 min non-thermal plasma treatment

  5. Kinetics of decolorization of azo dye by bipolar pulsed barrier discharge in a three-phase discharge plasma reactor.

    Science.gov (United States)

    Zhang, Ruobing; Zhang, Chi; Cheng, XingXin; Wang, Liming; Wu, Yan; Guan, Zhicheng

    2007-04-02

    Removal of amaranth, a commercial synthetic azo dye widely used in the dye and food industry, was examined as a possible remediation technology for treating dye-contaminated water. Effects of various parameters such as gas flow rate, solution conductivity, pulse repetition frequency, etc., on decolorization kinetics were investigated. Experimental results show that an aqueous solution of 24 mg/l dye is 81.24% decolorized following 30 min plasma treatment for a 50 kV voltage and 0.75 m(3)/h gas flow rate. Decolorization reaction of amaranth in the plasma reactor is a pseudo first order reaction. Rate constant (k) of decolorization increases quickly with increasing the applied voltage, pulse repetition frequency and the gas flow rate. However, when the applied voltage is beyond 50 kV and increases further, increase rate of k decreases. In addition, k decreases quickly when the solution conductivity increases from 200 to 1481 microS/cm. The decolorization reaction has a high rate constant (k=0.0269 min(-1)) when the solution pH is beyond 10. Rate constant k decreases with the decrease of pH and reaches minimum at a pH of about 5 (k(min)=0.01603 min(-1)), then increases to 0.02105 min(-1) when pH decreases to 3.07. About 15% of the initial TOC can be degraded only in about 120 min non-thermal plasma treatment.

  6. Pressurized polyol synthesis of Al-doped ZnO nanoclusters with high electrical conductivity and low near-infrared transmittance

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ho-Nyun; Shin, Chi-Ho [Surface Technology R& BD Group, Korea Institute of Industrial Technology (KITECH), Incheon 406-840 (Korea, Republic of); Hwang, Duck Kun [Department of Corporate Diagnosis, Small and Medium Business Corporation, Seoul 150-718 (Korea, Republic of); Kim, Haekyoung [School of Materials Science and Engineering, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Oh, Kyeongseok [Department of Chemical and Environmental Technology, Inha Technical College, Incheon 402-752 (Korea, Republic of); Kim, Hyun-Jong, E-mail: hjkim23@kitech.re.kr [Surface Technology R& BD Group, Korea Institute of Industrial Technology (KITECH), Incheon 406-840 (Korea, Republic of)

    2015-09-25

    Highlights: • Low-temperature pressurized polyol method synthesized Al-doped ZnO nanoclusters. • Reaction time affected the doping efficiency, resistivity, and NIR transmittance. • The near-IR blocking efficiency of Al-doped ZnO (AZO) nanoclusters reached 85%. • AZO nanocluster coatings could be used for heat reflectors or artificial glasses. - Abstract: In this study, a novel pressurized polyol method is proposed to synthesize aluminum-doped ZnO (AZO) nanoclusters without utilizing additional thermal treatment to avoid the merging of nanoclusters. The size of the AZO nanoclusters range from 100 to 150 nm with a resistivity of 204 Ω cm. The AZO nanoclusters primarily consist of approximately 10-nm nanocrystals that form a spherically clustered morphology. A two-stage growth model has been proposed based on the results of scanning electron microscopy and transmission electron microscopy images, nanocluster sizes, and X-ray diffraction patterns. The primary AZO nanocrystals first nucleate under pressurized conditions and then spontaneously aggregate into larger nanoclusters. Optically, the AZO nanoclusters exhibit a significant decrease in the near-infrared (NIR) transmittance compared to pure ZnO nanoparticles. The NIR blocking efficiency of AZO nanoclusters reached 85%. Moreover, the doping efficiency, resistivity, and NIR transmittance of AZO nanoclusters are influenced by the reaction time in the pressurized polyol solution. On the other hand, the reaction time has no effect on the particle size and crystallinity. An optically transparent coating for the AZO nanoclusters, which consisted of iso-propanol solvent and ultraviolet-curable acrylic binder, was also demonstrated.

  7. (Bio)transformation of 2,4-dinitroanisole (DNAN) in soils

    Energy Technology Data Exchange (ETDEWEB)

    Olivares, Christopher I., E-mail: olivarec@email.arizona.edu [Department of Chemical and Environmental Engineering, University of Arizona, P.O. Box 210011, Tucson, AZ 85721 (United States); Abrell, Leif [Department of Soil, Water & Environmental Science, University of Arizona, P.O. Box 210011, Tucson, AZ 85721 (United States); Department of Chemistry & Biochemistry, University of Arizona, P.O. Box 210011, Tucson, AZ 85721 (United States); Khatiwada, Raju; Chorover, Jon [Department of Soil, Water & Environmental Science, University of Arizona, P.O. Box 210011, Tucson, AZ 85721 (United States); Sierra-Alvarez, Reyes; Field, Jim A. [Department of Chemical and Environmental Engineering, University of Arizona, P.O. Box 210011, Tucson, AZ 85721 (United States)

    2016-03-05

    Highlights: • DNAN anaerobic transformation was faster than aerobic conversion. • Anaerobic DNAN conversion rate correlated well with soil organic carbon (≤2.07%). • H{sub 2} added as electron donor enhanced DNAN biotransformation. • DNAN nitroreduction lead to monomer products which coupled to form azo dimers. • Anaerobic transformation pathway and azo dimer formation mechanism were proposed. - Abstract: Recent studies have begun to assess the environmental fate and toxicity of 2,4-dinitroanisole (DNAN), an insensitive munition compound of interest to defense agencies. Aerobic and anaerobic DNAN biotransformation in soils was evaluated in this study. Under aerobic conditions, there was little evidence of transformation; most observed removal was attributed to adsorption and subsequent slow chemical reactions. Under anaerobic conditions, DNAN was reductively (bio)transformed and the rate of the transformation was positively correlated with soil organic carbon (OC) up to a threshold of 2.07% OC. H{sub 2} addition enhanced the nitroreduction rate compared to endogenous treatments lacking H{sub 2}. Heat-killed treatments provided rates similar to the endogenous treatment, suggesting that abiotic factors play a role in DNAN reduction. Ten (bio)transformation products were detected by high-resolution mass spectrometry. The proposed transformation pathway involves reduction of DNAN to aromatic amines, with putative reactive nitroso-intermediates coupling with the amines to form azo dimers. Secondary reactions include N-alkyl substitution, O-demethylation (sometimes followed by dehydroxylation), and removal of an N-containing group. Globally, our results suggest that the main reaction DNAN undergoes in anaerobic soils is nitroreduction to 2-methoxy-5-nitroaniline (MENA) and 2,4-diaminoanisole (DAAN), followed by anaerobic coupling reactions yielding azo-dimers. The dimers were subsequently subject to further (bio)transformations.

  8. Sanskrit Compound Processor

    Science.gov (United States)

    Kumar, Anil; Mittal, Vipul; Kulkarni, Amba

    Sanskrit is very rich in compound formation. Typically a compound does not code the relation between its components explicitly. To understand the meaning of a compound, it is necessary to identify its components, discover the relations between them and finally generate a paraphrase of the compound. In this paper, we discuss the automatic segmentation and type identification of a compound using simple statistics that results from the manually annotated data.

  9. Journal of Chemical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Further, iPrTAPB-Azo-COP has also been utilized for capture of carbon dioxide as the azo-COP is enriched with CO2-philic nitrogen atoms apart from its microporosity. Since the azo (–N=N-) linkages are masked by the bulky isopropyl groups, iPrTAPB-Azo-COP exhibits a CO2 uptake of 6.5 and 19.4 wt% at 1 bar and 30 bar ...

  10. Characterization of pore-expanded amino-functionalized mesoporous silicas directly synthesized with dimethyldecylamine and its application for decolorization of sulphonated azo dyes

    International Nuclear Information System (INIS)

    Yang Hong; Feng Qiyan

    2010-01-01

    With dimethyldecylamine (DMDA) as the expander, a new kind of pore-expanded amino-functionalized mesoporous silicas (PEAFMS) was directly synthesized under mild alkali condition. The characteristics of PEAFMS sample demonstrated that the presence of DMDA markedly augmented the average pore diameter (19.04 nm) and strongly enhanced its decolorization ability. Subsequently, acid mordant dark yellow GG (YGG) and reactive red violet X-2R (RVX) were chosen to assess its adsorption capacity for sulphonated azo dyes. The effect of initial pH was investigated and the decolorization mechanism was illuminated. Three isotherms were conducted and the goodness of fit increased as the following order: Freundlich < Langmuir < Redlich-Peterson. The maximum adsorption capacities of YGG and RVX onto PEAFMS were 1.967 and 0.957 mmol/g, respectively. Adsorption kinetic processes were better predicted by the pseudo-second-order rate equation than the pseudo-first-order one. Adsorption thermodynamic results suggested that the adsorption behavior of both dyes onto PEAFMS was spontaneous with the chemical nature. In addition, the regeneration of PEAFMS was proved to be feasible using NaOH as the strippant. After five cycles, PEAFMS still possessed a favorable adsorption capacity for dyes. It is safely concluded that PEAFMS could be a potential adsorbent for the dye removal from wastewater.

  11. AFM study of advanced composite materials for organic photovoltaic cells with active layer based on P3HT:PCBM and chiral photosensitive liquid crystalline dopants

    Czech Academy of Sciences Publication Activity Database

    Iwan, A.; Sikora, A.; Hamplová, Věra; Bubnov, Alexej

    2015-01-01

    Roč. 42, č. 7 (2015), s. 964-972 ISSN 0267-8292 R&D Projects: GA MŠk 7AMB13PL041; GA ČR GA13-14133S; GA MŠk(CZ) LD14007; GA MŠk 7AMB13PL038 Grant - others:AVČR(CZ) M100101204 Institutional support: RVO:68378271 Keywords : AFM * chiral liquid crystal * organic solar cells * azo compounds * photovoltaic s Subject RIV: JJ - Other Materials Impact factor: 2.244, year: 2015

  12. Biochemical and molecular characterization of an azoreductase from Staphylococcus aureus, a tetrameric NADPH-dependent flavoprotein

    Science.gov (United States)

    Chen, Huizhong; Hopper, Sherryll L.; Cerniglia, Carl E.

    2018-01-01

    Azo dyes are a predominant class of colourants used in tattooing, cosmetics, foods and consumer products. A gene encoding NADPH-flavin azoreductase (Azo1) from the skin bacterium Staphylococcus aureus ATCC 25923 was identified and overexpressed in Escherichia coli. RT-PCR results demonstrated that the azo1 gene was constitutively expressed at the mRNA level in S. aureus. Azo1 was found to be a tetramer with a native molecular mass of 85 kDa containing four non-covalently bound FMN. Azo1 requires NADPH, but not NADH, as an electron donor for its activity. The enzyme was resolved to dimeric apoprotein by removing the flavin prosthetic groups using hydrophobic-interaction chromatography. The dimeric apoprotein was reconstituted on-column and in free stage with FMN, resulting in the formation of a fully functional native-like tetrameric enzyme. The enzyme cleaved the model azo dye 2-[4-(dimethylamino)phenylazo]benzoic acid (Methyl Red) into N,N-dimethyl-p-phenylenediamine and 2-aminobenzoic acid. The apparent Km values for NADPH and Methyl Red substrates were 0·;074 and 0·057 mM, respectively. The apparent Vmax was 0·4 µM min−1 (mg protein)−1. Azo1 was also able to metabolize Orange II, Amaranth, Ponceau BS and Ponceau S azo dyes. Azo1 represents the first azoreductase to be identified and characterized from human skin microflora. PMID:15870453

  13. Study on the enhanced and stable field emission behavior of a novel electrosprayed Al-doped ZnO bilayer film

    KAUST Repository

    Mahmood, Khalid; Munir, Rahim; Swain, Bhabani Sankar; Han, Gill Sang; Kim, Byeong Jo; Jung, Hyun Suk

    2014-01-01

    A novel electrosprayed bilayer film composed of an over-layer (L 2) of aluminium-doped ZnO (AZO) nanoflakes (NF-AZO) and a under-layer (L1) of AZO nanocrystallites structure (NC-AZO) named BL:NF/NC-AZO is studied as an excellent field-emitter. The XRD pattern demonstrated that the doped bilayer film has preferential growth along the c-axis with hexagonal wurtzite structure and the (0 0 2) peak shifted toward the larger angle side after doping. The lowest turn-on field of ∼2.8 V μm-1, highest emission current density of 1.95 mA cm-2 is obtained for BL:NF/NC-AZO under the field of 6.8 V μm-1 and as well as the highest field enhancement factor (β) is estimated to be 4370 ± 3, compared to pure ZnO bilayer film (BL:NF/NC-ZnO) and also better than NC-AZO film and possesses the excellent long term stability of emission current. The PL intensity of doped ZnO bilayer film is very much stronger than pure ZnO bilayer structure. The superior field emission properties are attributed to the better morphologies, Al-doping and better crystallinity of bilayer AZO films. © 2014 The Royal Society of Chemistry.

  14. Annealing effects on the optical and morphological properties of ZnO nanorods on AZO substrate by using aqueous solution method at low temperature.

    Science.gov (United States)

    Hang, Da-Ren; Islam, Sk Emdadul; Sharma, Krishna Hari; Kuo, Shiao-Wei; Zhang, Cheng-Zu; Wang, Jun-Jie

    2014-01-01

    Vertically aligned ZnO nanorods (NRs) on aluminum-doped zinc oxide (AZO) substrates were fabricated by a single-step aqueous solution method at low temperature. In order to optimize optical quality, the effects of annealing on optical and structural properties were investigated by scanning electron microscopy, X-ray diffraction, photoluminescence (PL), and Raman spectroscopy. We found that the annealing temperature strongly affects both the near-band-edge (NBE) and visible (defect-related) emissions. The best characteristics have been obtained by employing annealing at 400°C in air for 2 h, bringing about a sharp and intense NBE emission. The defect-related recombinations were also suppressed effectively. However, the enhancement decreases with higher annealing temperature and prolonged annealing. PL study indicates that the NBE emission is dominated by radiative recombination associated with hydrogen donors. Thus, the enhancement of NBE is due to the activation of radiative recombinations associated with hydrogen donors. On the other hand, the reduction of visible emission is mainly attributed to the annihilation of OH groups. Our results provide insight to comprehend annealing effects and an effective way to improve optical properties of low-temperature-grown ZnO NRs for future facile device applications.

  15. Synthesis, characterization and biological activities of some azo derivatives of aminothiadiazole derived from nicotinic and isonicotinic acids

    Directory of Open Access Journals (Sweden)

    Ivan Hameed R. Tomi

    2014-11-01

    Full Text Available In this study we synthesized the new compounds containing bis-1,3,4-thiadiazole 3(A–Dn from many reaction steps (cyclization, diazotization and etherification respectively. The compounds have been characterized by melting point, FT-IR and 1H NMR data. All the synthesized compounds have been evaluated in vitro for their antimicrobial activities against several microbes like: Escherichia coli, Klebsiellia pneumonia, Pseudomonas aeruginosa, Serratia marscens and Staphylococcus aureus and show that some of these compounds have very good antibacterial activity.

  16. Batch and fixed-bed adsorption of tartrazine azo-dye onto activated carbon prepared from apricot stones

    Science.gov (United States)

    Albroomi, H. I.; Elsayed, M. A.; Baraka, A.; Abdelmaged, M. A.

    2017-07-01

    This work describes the potential of utilizing prepared activated carbon from apricot stones as an efficient adsorbent material for tartrazine (TZ) azo-dye removal in a batch and dynamic adsorption system. The results revealed that activated carbons with well-developed surface area (774 m2/g) and pore volume (1.26 cm3/g) can be manufactured from apricot stones by H3PO4 activation. In batch experiments, effects of the parameters such as initial dye concentration and temperature on the removal of the dye were studied. Equilibrium was achieved in 120 min. Adsorption capacity was found to be dependent on the initial concentration of dye solution, and maximum adsorption was found to be 76 mg/g at 100 mg/L of TZ. The adsorption capacity at equilibrium ( q e) increased from 22.6 to 76 mg/g with an increase in the initial dye concentrations from 25 to 100 mg/L. The thermodynamic parameters such as change in free energy (Δ G 0), enthalpy (Δ H 0) and entropy (Δ S 0) were determined and the positive value of (Δ H) 78.1 (K J mol-1) revealed that adsorption efficiency increased with an increase in the process temperature. In fixed-bed column experiments, the effect of selected operating parameters such as bed depth, flow rate and initial dye concentration on the adsorption capacity was evaluated. Increase in bed height of adsorption columns leads to an extension of breakthrough point as well as the exhaustion time of adsorbent. However, the maximum adsorption capacities decrease with increases of flow rate. The breakthrough data fitted well to bed depth service time and Thomas models with high coefficient of determination, R 2 ≥ 94.

  17. Conducting polypyrrole films as a potential tool for electrochemical treatment of azo dyes in textile wastewaters

    Energy Technology Data Exchange (ETDEWEB)

    Haque, Md. Mominul [Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW 2109 (Australia); Smith, Warren T. [Samadha Pacifica Pty Ltd, Woonona, NSW 2517 (Australia); Wong, Danny K.Y., E-mail: Danny.Wong@mq.edu.au [Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW 2109 (Australia)

    2015-02-11

    Highlights: • Anion exchange property of polypyrrole films exploited in developing a treatment method for Acid Red 1. • An environmentally friendly treatment method for Acid Red 1 without generating any toxic by-products. • Acid Red 1 is anodically entrapped and cathodically liberated at polypyrrole films. • Analytical characteristics of Acid Red 1-entrapped polypyrrole films. - Abstract: In this paper, we demonstrate conducting polypyrrole films as a potential green technology for electrochemical treatment of azo dyes in wastewaters using Acid Red 1 as a model analyte. These films were synthesised by anodically polymerising pyrrole in the presence of Acid Red 1 as a supporting electrolyte. In this way, the anionic Acid Red 1 is electrostatically attracted to the cationic polypyrrole backbone formed to maintain electroneutrality, and is thus entrapped in the film. These Acid Red 1-entrapped polypyrrole films were characterised by electrochemical, microscopic and spectroscopic techniques. Based on a two-level factorial design, the solution pH, Acid Red 1 concentration and polymerisation duration were identified as significant parameters affecting the entrapment efficiency. The entrapment process will potentially aid in decolourising Acid Red 1-containing wastewaters. Similarly, in a cathodic process, electrons are supplied to neutralise the polypyrrole backbone, liberating Acid Red 1 into a solution. In this work, following an entrapment duration of 480 min in 2000 mg L{sup −1} Acid Red 1, we estimated 21% of the dye was liberated after a reduction period of 240 min. This allows the recovery of Acid Red 1 for recycling purposes. A distinctive advantage of this electrochemical Acid Red 1 treatment, compared to many other techniques, is that no known toxic by-products are generated in the treatment. Therefore, conducting polypyrrole films can potentially be applied as an environmentally friendly treatment method for textile effluents.

  18. Porphyrin Co(III-Nitrene Radical Mediated Pathway for Synthesis of o-Aminoazobenzenes

    Directory of Open Access Journals (Sweden)

    Monalisa Goswami

    2018-05-01

    Full Text Available Azobenzenes are versatile compounds with a range of applications, including dyes and pigments, food additives, indicators, radical reaction initiators, molecular switches, etc. In this context, we report a general method for synthesizing o-aminoazobenzenes using the commercially available cobalt(II tetraphenyl porphyrin [CoII(TPP]. The net reaction is a formal dimerization of two phenyl azides with concomitant loss of two molecules of dinitrogen. The most commonly used methodology to synthesize azobenzenes is based on the initial diazotization of an aromatic primary amine at low temperatures, which then reacts with an electron rich aromatic nucleophile. As such, this limits the synthesis of azobenzenes with an amine functionality. In contrast, the method we report here relies heavily on the o-amine moiety and retains it in the product. The reaction is metal catalyzed and proceeds through a porphyrin Co(III-nitrene radical intermediate, which is known to form on activation of organic azides at the cobalt center. The synthesized o-aminoazobenzenes are bathochromatically shifted, as compared to azobenzenes without amine substituents. Based on the crystal structure of one of the products, strong H-bonding between the N-atom of the azo functionality and the H of the NH2 substituent is shown to stabilize the trans isomeric form of the product. The NH2 substituents offers possibilities for further functionalization of the synthesized azo compounds.

  19. Structural, absorption, and molecular properties of o,o'-dihydroxyazo resorcinol dyes bearing an acryloyloxy group

    Science.gov (United States)

    Özkınalı, Sevil; Çavuş, M. Serdar; Ceylan, Abdullah; Gür, Mahmut

    2017-12-01

    To the best of our knowledge, this is the first study reporting the synthesis and characterization of o,o‧-dihydroxyazo dyes bearing an acryloyl group. The o,o‧-dihydroxyazo dyes were synthesized through coupling of resorcinol with the diazonium salts of 2-amino-4-methylphenol, 2-aminophenol, 2-amino-4-chlorophenol, and 2-amino-4-nitrophenol. Their acryloyl derivatives were synthesized using metallic sodium and acryloyl chloride under an inert atmosphere. Characterization of the compounds was conducted using infrared (IR), ultraviolet-visible (UV-vis), proton nuclear magnetic resonance (1H NMR), and carbon nuclear magnetic resonance (13C NMR) spectroscopic methods. The tautomerism of the synthesized compounds' was also evaluated. The results were compared with theoretical results obtained by density functional theory (DFT). The DFT calculations were performed to obtain ground-state optimized geometries and calculate the relevant electronic and chemical reactivity parameters. Furthermore, possible tautomers deduced from the UV-vis spectra were investigated using theoretical calculations. Both the IR and NMR spectral data showed that azo tautomers predominate in the solid state and DMSO solvent. The effects of pH, solvent, and substituent on the predominant tautomers were further investigated through UV-vis spectroscopy. The results indicate that hydrazone tautomers were dominant at pH 12 in dimethylformamide (DMF), whereas azo tautomers were dominant at pH 2 in EtOH or CHCl3.

  20. Effect of light and sweeteners on color in an amaretto-type liqueur.

    Science.gov (United States)

    Castañeda-Olivares, F; Pless, R C; González-Jasso, E

    2010-01-01

    Studies on the color loss in an amaretto-type liqueur under controlled light conditions showed a clear dependence of the decoloration rate on the light intensity, and complete color stability in the absence of light. The principal sweetener used in the preparation of the liqueur strongly affected the rate of color loss under irradiation, color stability being much greater for the formulations containing sucrose or no added sweetener instead of fructose 42. These differences were more pronounced in experiments conducted with chemically well-defined mixtures that contained either of the 2 azo dyes used in the coloration of the amaretto, tartrazine, and Allura Red, and various alternative sweeteners, in 28% (v/v) ethanol solution: D-fructose and, to a lesser extent, D-glucose, at concentrations of 14% (w/v), were effective in bringing about photodecoloration, while no color loss was detected in the presence of sucrose, or in the absence of any added sugar. The results are interpreted in terms of a redox reaction of reducing sugars with the diarylazo compounds, the function of the light being the conversion of the azo compound from the predominant trans configuration to the cis configuration, which on geometric grounds lends itself better to a concerted, cyclical redox reaction with the reducing sugar. © 2010 Institute of Food Technologists®

  1. Bioelectricity Generation and Bioremediation of an Azo-Dye in a Microbial Fuel Cell Coupled Activated Sludge Process

    Science.gov (United States)

    Khan, Mohammad Danish; Abdulateif, Huda; Ismail, Iqbal M.; Sabir, Suhail; Khan, Mohammad Zain

    2015-01-01

    Simultaneous bioelectricity generation and dye degradation was achieved in the present study by using a combined anaerobic-aerobic process. The anaerobic system was a typical single chambered microbial fuel cell (SMFC) which utilizes acid navy blue r (ANB) dye along with glucose as growth substrate to generate electricity. Four different concentrations of ANB (50, 100, 200 and 400 ppm) were tested in the SMFC and the degradation products were further treated in an activated sludge post treatment process. The dye decolorization followed pseudo first order kinetics while the negative values of the thermodynamic parameter ∆G (change in Gibbs free energy) shows that the reaction proceeds with a net decrease in the free energy of the system. The coulombic efficiency (CE) and power density (PD) attained peak values at 10.36% and 2,236 mW/m2 respectively for 200 ppm of ANB. A further increase in ANB concentrations results in lowering of cell potential (and PD) values owing to microbial inhibition at higher concentrations of toxic substrates. Cyclic voltammetry studies revealed a perfect redox reaction was taking place in the SMFC. The pH, temperature and conductivity remain 7.5–8.0, 27(±2°C and 10.6–18.2 mS/cm throughout the operation. The biodegradation pathway was studied by the gas chromatography coupled with mass spectroscopy technique, suggested the preferential cleavage of the azo bond as the initial step resulting in to aromatic amines. Thus, a combined anaerobic-aerobic process using SMFC coupled with activated sludge process can be a viable option for effective degradation of complex dye substrates along with energy (bioelectricity) recovery. PMID:26496083

  2. Evaluation of three reagent dosing strategies in a photo-Fenton process for the decolorization of azo dye mixtures

    International Nuclear Information System (INIS)

    Prato-Garcia, D.; Buitrón, Germán

    2012-01-01

    Highlights: ► Dosing strategies for a photo-Fenton process were evaluated. ► The dosing strategy had no effect of on the decolorization. ► The type of strategy influenced SUVA index, toxicity reduction and biodegradability. ► A continuous reagents supply was found to be the most adequate strategy. ► Decolorization as well as a less toxic and biodegradable effluent was produced. - Abstract: Three reagent dosing strategies used in the solar photo-assisted decolorization of a mixture of sulfonated dyes consisting of acid blue 113, acid orange 7 and acid red 151 were evaluated. Results demonstrated that the dosing strategy influenced both reagent consumption and the biodegradability and toxicity of the effluent. In one strategy (E 1 ), the Fenton's reactants were dosed in a punctual mode, while in the other two strategies (E 2 an E 3 ), the reactants were dosed continuously. In the E 2 strategy the reactants were dosed by varying the duration of the injection time. In the E 3 strategy, the reactants were dosed during 60 min at a constant rate, but with different concentrations. All cases showed that feeding the reactor between 40% and 60% of the maximal dose was sufficient to decolorize more than 90% of the mixture of azo dyes. The E 1 strategy was less effective for aromatic content reduction. Conversely, the continuous addition of the reagents (E 2 and E 3 strategies) improved the aromatic content removal. E 3 strategy was substantially more appropriate than E 1 strategy due to improved the effluent quality in two key areas: toxicity and biodegradability.

  3. A Novel MS-Cleavable Azo Cross-Linker for Peptide Structure Analysis by Free Radical Initiated Peptide Sequencing (FRIPS)

    Science.gov (United States)

    Iacobucci, Claudio; Hage, Christoph; Schäfer, Mathias; Sinz, Andrea

    2017-10-01

    The chemical cross-linking/mass spectrometry (MS) approach is a growing research field in structural proteomics that allows gaining insights into protein conformations. It relies on creating distance constraints between cross-linked amino acid side chains that can further be used to derive protein structures. Currently, the most urgent task for designing novel cross-linking principles is an unambiguous and automated assignment of the created cross-linked products. Here, we introduce the homobifunctional, amine-reactive, and water soluble cross-linker azobisimidoester (ABI) as a prototype of a novel class of cross-linkers. The ABI-linker possesses an innovative modular scaffold combining the benefits of collisional activation lability with open shell chemistry. This MS-cleavable cross-linker can be efficiently operated via free radical initiated peptide sequencing (FRIPS) in positive ionization mode. Our proof-of-principle study challenges the gas phase behavior of the ABI-linker for the three amino acids, lysine, leucine, and isoleucine, as well as the model peptide thymopentin. The isomeric amino acids leucine and isoleucine could be discriminated by their characteristic side chain fragments. Collisional activation experiments were conducted via positive electrospray ionization (ESI) on two Orbitrap mass spectrometers. The ABI-mediated formation of odd electron product ions in MS/MS and MS3 experiments was evaluated and compared with a previously described azo-based cross-linker. All cross-linked products were amenable to automated analysis by the MeroX software, underlining the future potential of the ABI-linker for structural proteomics studies. [Figure not available: see fulltext.

  4. Effects of substrate heating and vacuum annealing on optical and electrical properties of alumina-doped ZnO films deposited by DC magnetron sputtering

    Science.gov (United States)

    Tang, Chien-Jen; Wang, Chun-Yuan; Jaing, Cheng-Chung

    2011-10-01

    Alumina-doped zinc oxide (AZO) films have wide range of applications in optical and optoelectronic devices. AZO films have advantage in high transparency, high stability to hydrogen plasma and low cost to alternative ITO film. AZO film was prepared by direct-current (DC) magnetron sputtering from ceramic ZnO:Al2O3 target. The AZO films were compared in two different conditions. The first is substrate heating process, in which AZO film was deposited by different substrate temperature, room temperature, 150 °C and 250 °C. The second is vacuum annealing process, in which AZO film with deposited at room temperature have been annealed at 250 °C and 450 °C in vacuum. The optical properties, electrical properties, grain size and surface structure properties of the films were studied by UV-VIS-NIR spectrophotometer, Hall effect measurement equipment, x-ray diffraction, and scanning electron microscopy. The resistivity, carrier mobility, carrier concentration, and grain size of AZO films were 1.92×10-3 Ω-cm, 6.38 cm2/Vs, 5.08×1020 #/cm3, and 31.48 nm respectively, in vacuum annealing of 450 °C. The resistivity, carrier mobility, carrier concentration, and grain size of AZO films were 8.72×10-4 Ω-cm, 6.32 cm2/Vs, 1.13×1021 #/cm3, and 31.56 nm, respectively, when substrate temperature was at 250 °C. Substrate heating process is better than vacuum annealed process for AZO film deposited by DC Magnetron Sputtering.

  5. Electrodeposition of silver nanoparticle arrays on transparent conductive oxides

    International Nuclear Information System (INIS)

    Zhang, Dezhong; Tang, Yang; Jiang, Fuguo; Han, Zhihua; Chen, Jie

    2016-01-01

    Highlights: • The sliver nanoparticles' size and the distance between nanoparticles are tunable. - Abstract: In this paper, we present a facile method for the preparation of silver nanoparticles on aluminum-doped zinc oxide (AZO) via electrodeposition techniques at room temperature. The morphology and structure of silver nanoparticles are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), respectively. Due to localized surface plasmon resonances, as-prepared silver nanoparticles on AZO glass exhibited different reflectivity in contrast with bare AZO glass. The weighted reflection of AZO substrate increased from 10.2% to 12.8%. The high reflection property of silver nanoparticle arrays on AZO substrate might be applicable for thin film solar cells and other optoelectronics applications.

  6. Electrodeposition of silver nanoparticle arrays on transparent conductive oxides

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Dezhong; Tang, Yang, E-mail: tangyang@nicenergy.com; Jiang, Fuguo; Han, Zhihua; Chen, Jie

    2016-04-30

    Highlights: • The sliver nanoparticles' size and the distance between nanoparticles are tunable. - Abstract: In this paper, we present a facile method for the preparation of silver nanoparticles on aluminum-doped zinc oxide (AZO) via electrodeposition techniques at room temperature. The morphology and structure of silver nanoparticles are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), respectively. Due to localized surface plasmon resonances, as-prepared silver nanoparticles on AZO glass exhibited different reflectivity in contrast with bare AZO glass. The weighted reflection of AZO substrate increased from 10.2% to 12.8%. The high reflection property of silver nanoparticle arrays on AZO substrate might be applicable for thin film solar cells and other optoelectronics applications.

  7. Microchemical Plant in a Liquid Droplet: Plasmonic Liquid Marble for Sequential Reactions and Attomole Detection of Toxin at Microliter Scale.

    Science.gov (United States)

    Han, Xuemei; Koh, Charlynn Sher Lin; Lee, Hiang Kwee; Chew, Wee Shern; Ling, Xing Yi

    2017-11-15

    Miniaturizing the continuous multistep operations of a factory into a microchemical plant offers a safe and cost-effective approach to promote high-throughput screening in drug development and enforcement of industrial/environmental safety. While particle-assembled microdroplets in the form of liquid marble are ideal as microchemical plant, these platforms are mainly restricted to single-step reactions and limited to ex situ reaction monitoring. Herein, we utilize plasmonic liquid marble (PLM), formed by encapsulating liquid droplet with Ag nanocubes, to address these issues and demonstrate it as an ideal microchemical plant to conduct reaction-and-detection sequences on-demand in a nondisruptive manner. Utilizing a two-step azo-dye formation as our model reaction, our microchemical plant allows rapid and efficient diazotization of nitroaniline to form diazonium nitrobenzene, followed by the azo coupling of this intermediate with target aromatic compound to yield azo-dye. These molecular events are tracked in situ via SERS measurement through the plasmonic shell and further verified with in silico investigation. Furthermore, we apply our microchemical plant for ultrasensitive SERS detection and quantification of bisphenol A (BPA) with detection limit down to 10 amol, which is 50 000-fold lower than the BPA safety limit. Together with the protections offered by plasmonic shell against external environments, these collective advantages empower PLM as a multifunctional microchemical plant to facilitate small-volume testing and optimization of processes relevant in industrial and research contexts.

  8. Molecular and excited state properties of isomeric scarlet disperse dyes

    Science.gov (United States)

    Lim, Jihye; Szymczyk, Malgorzata; Mehraban, Nahid; Ding, Yi; Parrillo-Chapman, Lisa; El-Shafei, Ahmed; Freeman, Harold S.

    2018-06-01

    This work was part of an investigation aimed at characterizing the molecular and excited state properties of currently available disperse dyes developed to provide stability to extensive sunlight exposures when adsorbed on poly(ethylene terephthalate) (PET) fibers. Having completed the characterization of yellow, magenta, and cyan disperse dyes for PET-based fabrics used outdoors, our attention turned to the colors designed to enhance the color gamut of a standard 4-member (cyan/yellow/magenta/black) color set. The present study pertained specifically to the characterization of commercially available scarlet dyes. In this regard, HPLC analysis showed that a scarlet product used for PET coloration was mainly a 70/30 mixture of dyes, and the use of HRMS and single crystal X-ray diffraction analyses indicated that these two dyes were azo compounds derived from isomeric pyridine-based couplers which differed in the location of the primary amino (sbnd NH2) and anilino (sbnd NHPh) groups attached to the pyridine ring. One dye structure has the sbnd NHPh group para to the azo group (Sc2), while the other has that group in the ortho position (Sc3). The presence of either ortho substituent provides photostabilization through intramolecular H-bonding with the azo moiety. Further, results from molecular modeling studies showed that the lower excited state oxidation potential of Sc3 relative to that of Sc2 allows Sc3 to function as an energy quencher for the excited state of Sc2 - through thermodynamically favorable electron transfer.

  9. Isolation, cloning and characterization of an azoreductase from the halophilic bacterium Halomonas elongata.

    Science.gov (United States)

    Eslami, Maryam; Amoozegar, Mohammad Ali; Asad, Sedigheh

    2016-04-01

    Azo dyes are a major class of colorants used in various industries including textile, paper and food. These dyes are regarded as pollutant since they are not readily reduced under aerobic conditions. Halomonas elongata, a halophilic bacterium, has the ability to decolorize different mono and di-azo dyes in anoxic conditions. In this study the putative azoreductase gene of H. elongata, formerly annotated as acp, was isolated, heterologously expressed in Escherichia coli, purified and characterized. The gene product, AzoH, was found to have a molecular mass of 22 kDa. The enzyme requires NADH, as an electron donor for its activity. The apparent Km was 63 μM for NADH and 12 μM for methyl red as a mono-azo dye substrate. The specific activity for methyl red was 0.27 μmol min(-1)mg(-1). The optimum enzyme activity was achieved in 50mM sodium phosphate buffer at pH 6. Although increased salinity resulted in reduced activity, AzoH could decolorize azo dye at NaCl concentrations up to 15% (w/v). The enzyme was also shown to be able to decolorize remazol black B as a representative of di-azo dyes. This is the first report describing the sequence and activity of an azo-reducing enzyme from a halophilic bacterium. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Trap-induced charge transfer/transport at energy harvesting assembly

    Science.gov (United States)

    Cho, Seongeun; Paik, Hanjong; Kim, Tae Wan; Park, Byoungnam

    2017-02-01

    Understanding interfacial electronic properties between electron donors and acceptors in hybrid optoelectronic solar cells is crucial in governing the device parameters associated with energy harvesting. To probe the electronic localized states at an electron donor/acceptor interface comprising a representative hybrid solar cell, we investigated the electrical contact properties between Al-doped zinc oxide (AZO) and poly (3-hexylthiophene) (P3HT) using AZO as the source and drain electrodes, pumping carriers from AZO into P3HT. The injection efficiency was evaluated using the transmission line method (TLM) in combination with field effect transistor characterizations. Highly conductive AZO films worked as the source and drain electrodes in the devices for TLM and field effect measurements. A comparable contact resistance difference between AZO/P3HT/AZO and Au/P3HT/Au structures contradicts the fact that a far larger energy barrier exists for electrons and holes between AZO and P3HT compared with between P3HT and Au based on the Schottky-Mott model. It is suggested that band to band tunneling accounts for the contradiction through the initial hop from AZO to P3HT for hole injection. The involvement of the tunneling mechanism in determining the contact resistance implies that there is a high density of electronic traps in the organic side.

  11. Treatment of a non-azo dye aqueous solution by CWAO in continuous reactor using a Ni catalyst derived from hydrotalcite-like precursor

    International Nuclear Information System (INIS)

    Vallet, Ana; Besson, Michèle; Ovejero, Gabriel; García, Juan

    2012-01-01

    Highlights: ► Ni supported over hydrotalcite calcined precursors as catalyst. ► Catalytic wet air oxidation in trickle bed reactor for Basic Yellow 11 removal. ► Dye removal depends on temperature, initial dye concentration and flow rate. ► The catalyst proved to be stable and efficient for the dye degradation. - Abstract: Catalytic wet air oxidation (CWAO) of a Basic Yellow 11 (BY11) aqueous solution, chosen as a model of a hardly biodegradable non-azo dye was carried out in a continuous-flow trickle-bed reactor, using nickel supported over hydrotalcite precursor calcined at 550 °C. An increase in the reaction temperature (120–180 °C), and a decrease in dye concentration (1000–3000 ppm) or liquid flow rate (0.1–0.7 mL min −1 ) enhanced the CWAO performance in a 30 and 19% for the variation of the temperature and concentration respectively. After a small leaching observed within the first hours, the catalyst proved to be very stable during the 65-day reaction. The CWAO process was found to be very efficient, achieving BY11 conversion up to 95% and TOC conversion up to 85% at 0.1 mL min −1 and 180 °C under 5 MPa air.

  12. Photocatalytic Oxidation of Azo Dyes and Oxalic Acid in Batch Reactors and CSTR: Introduction of Photon Absorption by Dyes to Kinetic Models

    Directory of Open Access Journals (Sweden)

    I. Grčić

    2018-04-01

    Full Text Available The possibilities of treating industrial effluents and water purification by advanced oxidation processes have been extensively studied; photocatalysis has emerged as a feasible alternative solution. In order to apply the photocatalytic treatment on a larger scale, relevant modeling approaches are necessary. The scope of this work was to investigate the applicability of recently published kinetic models in different reactor systems (batch and CSTR under UVA or UVC irradiation and in combination with two types of TiO2 catalyst, AEROXIDE® P25 and PC-500 for degradation of azo dyes (C.I. Reactive Violet 2, and C.I. Mordant Yellow 10, oxalic acid and their mixtures. The influences of reactor geometry and irradiation intensities on pollutant oxidation efficiency were examined. The effect of photon absorption by dyes in water matrix was thoroughly studied. Relevant kinetic models were introduced to the mass balance for particular reactor system. Resulting models were sufficient for description of pollutant degradation in batch reactors and CSTR. Experimental results showed 1.15 times higher mineralization extents achieved after 7 cycles in CSTR than in batch photoreactor of similar geometry within the equivalent time-span. The application of CSTR in-series could simplify the photocatalytic water treatment on a larger scale.

  13. Flexible Al-doped ZnO films grown on PET substrates using linear facing target sputtering for flexible OLEDs

    International Nuclear Information System (INIS)

    Jeong, Jin-A; Shin, Hyun-Su; Choi, Kwang-Hyuk; Kim, Han-Ki

    2010-01-01

    We report the characteristics of flexible Al-doped zinc oxide (AZO) films prepared by a plasma damage-free linear facing target sputtering (LFTS) system on PET substrates for use as a flexible transparent conducting electrode in flexible organic light-emitting diodes (OLEDs). The electrical, optical and structural properties of LFTS-grown flexible AZO electrodes were investigated as a function of dc power. We obtained a flexible AZO film with a sheet resistance of 39 Ω/□ and an average transmittance of 84.86% in the visible range although it was sputtered at room temperature without activation of the Al dopant. Due to the effective confinement of the high-density plasma between the facing AZO targets, the AZO film was deposited on the PET substrate without plasma damage and substrate heating caused by bombardment of energy particles. Moreover, the flexible OLED fabricated on the AZO/PET substrate showed performance similar to the OLED fabricated on a ITO/PET substrate in spite of a lower work function. This indicates that LFTS is a promising plasma damage-free and low-temperature sputtering technique for deposition of flexible and indium-free AZO electrodes for use in cost-efficient flexible OLEDs.

  14. Transparent conductive ZnO layers on polymer substrates: Thin film deposition and application in organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Dosmailov, M. [Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria); Leonat, L.N. [Linz Institute for Organic Solar Cells (LIOS)/Institute of Physical Chemistry, Johannes Kepler University Linz, A-4040 Linz (Austria); Patek, J. [Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria); Roth, D.; Bauer, P. [Institute of Experimental Physics, Johannes Kepler University Linz, A-4040 Linz (Austria); Scharber, M.C.; Sariciftci, N.S. [Linz Institute for Organic Solar Cells (LIOS)/Institute of Physical Chemistry, Johannes Kepler University Linz, A-4040 Linz (Austria); Pedarnig, J.D., E-mail: johannes.pedarnig@jku.at [Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria)

    2015-09-30

    Aluminum doped ZnO (AZO) and pure ZnO thin films are grown on polymer substrates by pulsed-laser deposition and the optical, electrical, and structural film properties are investigated. Laser fluence, substrate temperature, and oxygen pressure are varied to obtain transparent, conductive, and stoichiometric AZO layers on polyethylene terephthalate (PET) that are free of cracks. At low fluence (1 J/cm{sup 2}) and low pressure (10{sup −3} mbar), AZO/PET samples of high optical transmission in the visible range, low electrical sheet resistance, and high figure of merit (FOM) are produced. AZO films on fluorinated ethylene propylene have low FOM. The AZO films on PET substrates are used as electron transport layer in inverted organic solar cell devices employing P3HT:PCBM as photovoltaic polymer-fullerene bulk heterojunction. - Highlights: • Aluminum doped and pure ZnO thin films are grown on polyethylene terephthalate. • Growth parameters laser fluence, temperature, and gas pressure are optimized. • AZO films on PET have high optical transmission and electrical conductance (FOM). • Organic solar cells on PET using AZO as electron transport layer are made. • Power conversion efficiency of these OSC devices is measured.

  15. A Designed Room Temperature Multilayered Magnetic Semiconductor

    Science.gov (United States)

    Bouma, Dinah Simone; Charilaou, Michalis; Bordel, Catherine; Duchin, Ryan; Barriga, Alexander; Farmer, Adam; Hellman, Frances; Materials Science Division, Lawrence Berkeley National Lab Team

    2015-03-01

    A room temperature magnetic semiconductor has been designed and fabricated by using an epitaxial antiferromagnet (NiO) grown in the (111) orientation, which gives surface uncompensated magnetism for an odd number of planes, layered with the lightly doped semiconductor Al-doped ZnO (AZO). Magnetization and Hall effect measurements of multilayers of NiO and AZO are presented for varying thickness of each. The magnetic properties vary as a function of the number of Ni planes in each NiO layer; an odd number of Ni planes yields on each NiO layer an uncompensated moment which is RKKY-coupled to the moments on adjacent NiO layers via the carriers in the AZO. This RKKY coupling oscillates with the AZO layer thickness, and it disappears entirely in samples where the AZO is replaced with undoped ZnO. The anomalous Hall effect data indicate that the carriers in the AZO are spin-polarized according to the direction of the applied field at both low temperature and room temperature. NiO/AZO multilayers are therefore a promising candidate for spintronic applications demanding a room-temperature semiconductor.

  16. (E-2-Acetyl-4-[(3-methylphenyldiazenyl]phenol: an X-ray and DFT study

    Directory of Open Access Journals (Sweden)

    Orhan Büyükgüngör

    2010-03-01

    Full Text Available The title compound, C15H14N2O2, an azo dye, displays a trans configuration with respect to the N=N bridge. The dihedral angle between the aromatic rings is 0.18 (14°. There is a strong intramolecular O—H...O hydrogen bond. Geometrical parameters, determined using X-ray diffraction techniques, are compared with those calculated by density functional theory (DFT, using hybrid exchange–correlation functional, B3LYP and semi-empirical (PM3 methods.

  17. Assessment of toxicity and genotoxicity of the reactive azo dyes Remazol Black B and Remazol Orange 3R and effectiveness of electron beam irradiation in the reduction of color and toxic effects

    International Nuclear Information System (INIS)

    Pinheiro, Alessandro de Sa

    2011-01-01

    The textile industries play an important role in national and global economy. But, their activities are considered potentially polluting. The use of large volumes of water and the production of colored wastewater with high organic matter are among the main issues raised, especially during the stage of dyeing and washing of the textile process. The reactive azo dyes are the main colors used in the industry for dyeing of cotton in Brazil and worldwide. Because of its low setting and variations in the fiber production process, about 30% of the initial concentration used in the dyeing baths are lost and will compose the final effluent. These compounds have a low biodegradability, are highly soluble in water and therefore are not completely removed by conventional biological processes. In addition, other processes do not promote degradation but the transference to solid environment. The dyes discarded without treatment in the water body can cause aesthetic modifications, alter photosynthesis and gas solubility, as well as being toxic and genotoxic. The main objectives of this study were to evaluate the toxicity and genotoxicity of two reactive azo dyes (Remazol Black B - RPB and Remazol Orange 3R - R3AR) and the percentage of color and toxicity reduction after the use of electron beam radiation. The acute toxicity assays performed with Vibrio fischeri, Daphnia similis and Biomphalaria glabrata showed different response patterns for dyes. The different chemical forms of dyes were slightly toxic to Vibrio fischeri and only the RPB dye (vinylsulphone) was toxic (EC50 15min = 6,23 mg L-1). In tests with Daphnia similis, the dye RPB was slightly toxic in its pattern form, sulphatoethylsulphone, (CE50 48h = 91,25 mg L -1 ) and showed no toxicity in other chemical forms. However, the RA3R dye was toxic to the dafnids and the vinylsulphone form very toxic (EC50 48h = 0,54 mg L-1). No toxicity was observed in Biomphalaria glabrata assays. Chronic toxicity was assessed with the

  18. Electron shuttles in biotechnology.

    Science.gov (United States)

    Watanabe, Kazuya; Manefield, Mike; Lee, Matthew; Kouzuma, Atsushi

    2009-12-01

    Electron-shuttling compounds (electron shuttles [ESs], or redox mediators) are essential components in intracellular electron transfer, while microbes also utilize self-produced and naturally present ESs for extracellular electron transfer. These compounds assist in microbial energy metabolism by facilitating electron transfer between microbes, from electron-donating substances to microbes, and/or from microbes to electron-accepting substances. Artificially supplemented ESs can create new routes of electron flow in the microbial energy metabolism, thereby opening up new possibilities for the application of microbes to biotechnology processes. Typical examples of such processes include halogenated-organics bioremediation, azo-dye decolorization, and microbial fuel cells. Herein we suggest that ESs can be applied widely to create new microbial biotechnology processes.

  19. A comparative study of quantum yield and electrical energy per order (E(Eo)) for advanced oxidative decolourisation of reactive azo dyes by UV light.

    Science.gov (United States)

    Muruganandham, M; Selvam, K; Swaminathan, M

    2007-06-01

    This paper evaluates the quantum yield and electrical energy per order (E(Eo)) efficiency of Reactive Orange 4 (RO4) and Reactive Yellow 14 (RY14) azo dyes by three advanced oxidation processes (AOPs). Both dyes were completely decolourised by all these processes. The relative decolourisation efficiencies of these processes were in the following order: Fe(2+)/H(2)O(2)/UV>UV/TiO(2)>UV/H(2)O(2). The low efficiency of UV/H(2)O(2) process is mainly due to low UV absorption by hydrogen peroxide at the 365nm. The figure of merit E(Eo) values showed that UV/H(2)O(2) process consumes more electrical energy than the other two processes. The electrical energy consumption is in the following order: UV/H(2)O(2)>UV/TiO(2)>Fe(2+)/H(2)O(2)/UV. At low initial dye concentration higher quantum yield was observed in UV/TiO(2) process, whereas in photo-Fenton process higher quantum yield was observed at high initial dye concentration. The structure of dye molecule also influences the quantum yield and E(Eo) value.

  20. A comparative study of quantum yield and electrical energy per order (E Eo) for advanced oxidative decolourisation of reactive azo dyes by UV light

    International Nuclear Information System (INIS)

    Muruganandham, M.; Selvam, K.; Swaminathan, M.

    2007-01-01

    This paper evaluates the quantum yield and electrical energy per order (E Eo ) efficiency of Reactive Orange 4 (RO4) and Reactive Yellow 14 (RY14) azo dyes by three advanced oxidation processes (AOPs). Both dyes were completely decolourised by all these processes. The relative decolourisation efficiencies of these processes were in the following order: Fe 2+ /H 2 O 2 /UV > UV/TiO 2 > UV/H 2 O 2 . The low efficiency of UV/H 2 O 2 process is mainly due to low UV absorption by hydrogen peroxide at the 365 nm. The figure of merit E Eo values showed that UV/H 2 O 2 process consumes more electrical energy than the other two processes. The electrical energy consumption is in the following order: UV/H 2 O 2 > UV/TiO 2 > Fe 2+ /H 2 O 2 /UV. At low initial dye concentration higher quantum yield was observed in UV/TiO 2 process, whereas in photo-Fenton process higher quantum yield was observed at high initial dye concentration. The structure of dye molecule also influences the quantum yield and E Eo value

  1. Catalytic role of Au-TiO{sub 2} nanocomposite on enhanced degradation of an azo-dye by electrochemically active biofilms: a quantized charging effect

    Energy Technology Data Exchange (ETDEWEB)

    Kalathil, Shafeer; Lee, Jintae; Cho, Moo Hwan, E-mail: mhcho@ynu.ac.kr [Yeungnam University, School of Chemical Engineering (Korea, Republic of)

    2013-01-15

    A green and sustainable approach to azo dye degradation by an electrochemically active biofilm (EAB) with Au-TiO{sub 2} nanocomposite assistance (average size of Au {approx}8 nm) has been developed with high efficiency and mineralization of toxic intermediates. The EAB-Au-TiO{sub 2} system degraded the dye more rapidly than the EAB without the nanocomposite, which indicated the catalytic role of the Au-TiO{sub 2} nanocomposite on the dye degradation. Toxicity measurements showed that the dye wastewater treated by the EAB-Au-TiO{sub 2} system was almost non-toxic while the dye wastewater treated by the EAB without the nanocomposite showed a high toxicity compared to the parent dye. Quantized charging and Fermi level equilibration within the Au-TiO{sub 2} nanocomposite may be attributed to the excellent catalytic activity of the nanocomposite on the dye degradation. A mechanism of the catalytic activity is also proposed. Redox behavior and quantized charging of the nanocomposite were confirmed by cyclic voltammetry (CV) and differential pulse voltammetry (DPV), respectively. The proposed protocol can be effectively utilized in wastewater treatment applications.

  2. Transparent conducting oxide top contacts for organic electronics

    KAUST Repository

    Franklin, Joseph B.

    2014-01-01

    A versatile method for the deposition of transparent conducting oxide (TCO) layers directly onto conjugated polymer thin film substrates is presented. Using pulsed laser deposition (PLD) we identify a narrow window of growth conditions that permit the deposition of highly transparent, low sheet resistance aluminium-doped zinc oxide (AZO) without degradation of the polymer film. Deposition on conjugated polymers mandates the use of low growth temperatures (<200°C), here we deposit AZO onto poly-3-hexylthiophene (P3HT) thin films at 150°C, and investigate the microstructural and electrical properties of the AZO as the oxygen pressure in the PLD chamber is varied (5-75 mTorr). The low oxygen pressure conditions previously optimized for AZO deposition on rigid substrates are shown to be unsuitable, resulting in catastrophic damage of the polymer films. By increasing the oxygen pressure, thus reducing the energy of the ablated species, we identify conditions that allow direct deposition of continuous, transparent AZO films without P3HT degradation. We find that uptake of oxygen into the AZO films reduces the intrinsic charge carriers and AZO films with a measured sheet resistance of approximately 500 Ω □-1 can be prepared. To significantly reduce this value we identify a novel process in which AZO is deposited over a range of oxygen pressures-enabling the deposition of highly transparent AZO with sheet resistances below 50 Ω □-1 directly onto P3HT. We propose these low resistivity films are widely applicable as transparent top-contacts in a range of optoelectronic devices and highlight this by demonstrating the operation of a semi-transparent photovoltaic device. © 2014 The Royal Society of Chemistry. 2014.

  3. Enhanced electrical properties of AZO thin films grown on different substrates by using a facing-target sputtering system with hetero targets

    Science.gov (United States)

    Lee, ChangHyun; Bae, Kang; Jin, IkHyeon; Kim, HwaMin; Sohn, SunYoung

    2015-09-01

    Al-doped ZnO (AZO) films were deposited on glass, polyethylene naphthalate (PEN) and polyethylene terephthalate (PET) at room temperature by using conventional rf-magneton sputtering (CMS) and a facing-target sputtering (FTS) with hetero targets of Al2O3 and ZnO. Their structural, surface morphology, electrical and optical properties were characterized by using X-ray diffractometry (XRD), atomic force microscopy (AFM), Hall-effect measurement and ultravioletvisible spectrophotometry, respectively. The films exhibit highly c-axis preferred orientation and a closely packed nanocrystalline. Structure the FTS-films deposited on plastic substrate are found to receive much less stress due to bombardment of high-energy particles compress to the CMS-films deposited on plastic substrates, during the sputtering process, which can enhance the electrical properties and crystalline quality of the FTS-films compared with those of the CMS-films. The resistivities of the FTS-films are 6.50 × 10-4 Ω·cm on glass, 7.0 × 10-4 Ω·cm on PEN and 7.4 × 10-4 Ω·cm on PET while the values for the CMS-films are 7.6 × 10-4 Ω·cm on glass, 1.20 × 10-3 Ω·cm on PEN and 1.58 × 10-3 Ω·cm on PET.

  4. The Orange Side of Disperse Red 1: Humidity-Driven Color Switching in Supramolecular Azo-Polymer Materials Based on Reversible Dye Aggregation.

    Science.gov (United States)

    Schoelch, Simon; Vapaavuori, Jaana; Rollet, Frédéric-Guillaume; Barrett, Christopher J

    2017-01-01

    Humidity detection, and the quest for low-cost facile humidity-sensitive indicator materials is of great interest for many fields, including semi-conductor processing, food transport and storage, and pharmaceuticals. Ideal humidity-detection materials for a these applications might be based on simple clear optical readout with no power supply, i.e.: a clear color change observed by the naked eye of any untrained observer, since it doesn't require any extra instrumentation or interpretation. Here, the introduction of a synthesis-free one-step procedure, based on physical mixing of easily available commercial materials, for producing a humidity memory material which can be easily painted onto a wide variety of surfaces and undergoes a remarkable color change (approximately 100 nm blue-shift of λ MAX ) upon exposure to various thresholds of levels of ambient humidity is reported. This strong color change, easily visible to as a red-to-orange color switch, is locked in until inspection, but can then be restored reversibly if desired, after moderate heating. By taking advantage of spontaneously-forming reversible 'soft' supramolecular bonds between a red-colored azo dye and a host polymer matrix, a reversible dye 'migration' aggregation appearing orange, and dis-aggregation back to red can be achieved, to function as the sensor. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Diversity of Ligninolytic Enzymes and Their Genes in Strains of the Genus Ganoderma: Applicable for Biodegradation of Xenobiotic Compounds?

    Directory of Open Access Journals (Sweden)

    Giselle Torres-Farradá

    2017-05-01

    Full Text Available White-rot fungi (WRF and their ligninolytic enzymes (laccases and peroxidases are considered promising biotechnological tools to remove lignin related Persistent Organic Pollutants from industrial wastewaters and contaminated ecosystems. A high diversity of the genus Ganoderma has been reported in Cuba; in spite of this, the diversity of ligninolytic enzymes and their genes remained unexplored. In this study, 13 native WRF strains were isolated from decayed wood in urban ecosystems in Havana (Cuba. All strains were identified as Ganoderma sp. using a multiplex polymerase chain reaction (PCR-method based on ITS sequences. All Ganoderma sp. strains produced laccase enzymes at higher levels than non-specific peroxidases. Native-PAGE of extracellular enzymatic extracts revealed a high diversity of laccase isozymes patterns between the strains, suggesting the presence of different amino acid sequences in the laccase enzymes produced by these Ganoderma strains. We determined the diversity of genes encoding laccases and peroxidases using a PCR and cloning approach with basidiomycete-specific primers. Between two and five laccase genes were detected in each strain. In contrast, only one gene encoding manganese peroxidase or versatile peroxidase was detected in each strain. The translated laccases and peroxidases amino acid sequences have not been described before. Extracellular crude enzymatic extracts produced by the Ganoderma UH strains, were able to degrade model chromophoric compounds such as anthraquinone and azo dyes. These findings hold promises for the development of a practical application for the treatment of textile industry wastewaters and also for bioremediation of polluted ecosystems by well-adapted native WRF strains.

  6. Diversity of Ligninolytic Enzymes and Their Genes in Strains of the Genus Ganoderma: Applicable for Biodegradation of Xenobiotic Compounds?

    Science.gov (United States)

    Torres-Farradá, Giselle; Manzano León, Ana M.; Rineau, François; Ledo Alonso, Lucía L.; Sánchez-López, María I.; Thijs, Sofie; Colpaert, Jan; Ramos-Leal, Miguel; Guerra, Gilda; Vangronsveld, Jaco

    2017-01-01

    White-rot fungi (WRF) and their ligninolytic enzymes (laccases and peroxidases) are considered promising biotechnological tools to remove lignin related Persistent Organic Pollutants from industrial wastewaters and contaminated ecosystems. A high diversity of the genus Ganoderma has been reported in Cuba; in spite of this, the diversity of ligninolytic enzymes and their genes remained unexplored. In this study, 13 native WRF strains were isolated from decayed wood in urban ecosystems in Havana (Cuba). All strains were identified as Ganoderma sp. using a multiplex polymerase chain reaction (PCR)-method based on ITS sequences. All Ganoderma sp. strains produced laccase enzymes at higher levels than non-specific peroxidases. Native-PAGE of extracellular enzymatic extracts revealed a high diversity of laccase isozymes patterns between the strains, suggesting the presence of different amino acid sequences in the laccase enzymes produced by these Ganoderma strains. We determined the diversity of genes encoding laccases and peroxidases using a PCR and cloning approach with basidiomycete-specific primers. Between two and five laccase genes were detected in each strain. In contrast, only one gene encoding manganese peroxidase or versatile peroxidase was detected in each strain. The translated laccases and peroxidases amino acid sequences have not been described before. Extracellular crude enzymatic extracts produced by the Ganoderma UH strains, were able to degrade model chromophoric compounds such as anthraquinone and azo dyes. These findings hold promises for the development of a practical application for the treatment of textile industry wastewaters and also for bioremediation of polluted ecosystems by well-adapted native WRF strains. PMID:28588565

  7. Organolanthanoid compounds

    International Nuclear Information System (INIS)

    Schumann, H.

    1984-01-01

    Up to little more than a decade ago organolanthanoid compounds were still a curiosity. Apart from the description of an isolated number of cyclopentadienyl and indenyl derivatives, very few significant contributions had been made to this interesting sector of organometallic chemistry. However, subsequent systematic studies using modern preparative and analytical techniques, together with X-ray single crystal structure determinations, enabled the isolation and characterization of a large number of very interesting homoleptic and heteroleptic compounds in which the lanthanoid is bound to hydrogen, to substituted or unsubstituted cyclopentadienyl groups, to allyl or alkynyl groups, or even to phosphorus ylides, trimethylsilyl, and carbonylmetal groups. These compounds, which are all extremely sensitive to oxygen and water, open up new possibilities in the field of catalysis and have great potential in organic synthesis - as recent studies with pentamethylcyclopentadienyl derivatives, organolanthanoid(II) compounds, and hexamethyllanthanoid complexes have already shown. (orig.) [de

  8. Rapid degradation of azo dye Direct Black BN by magnetic MgFe{sub 2}O{sub 4}-SiC under microwave radiation

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Jia; Yang, Shaogui, E-mail: yangsg@nju.edu.cn; Li, Na; Meng, Lingjun; Wang, Fei; He, Huan; Sun, Cheng

    2016-08-30

    Highlights: • MgFe{sub 2}O{sub 4}-SiC was first successfully synthesized. • MgFe{sub 2}O{sub 4}-SiC attained the maximum absorbing value of 13.32 dB at 2.57 GHz, which reached extremely high RL value at low frequency range. • Fast decolorization and high TOC removal of azo dye Direct Black BN with complicated structure could occur with MgFe{sub 2}O{sub 4}-SiC under MW radiation. • MgFe{sub 2}O{sub 4}-SiC had better MW absorbing property and higher MW catalytic activity than MnFe{sub 2}O{sub 4}-SiC under the same condition. • MgFe{sub 2}O{sub 4}-SiC was of practical use in the wastewater treatment. - Abstract: A novel microwave (MW) catalyst, MgFe{sub 2}O{sub 4} loaded on SiC (MgFe{sub 2}O{sub 4}-SiC), was successfully synthesized by sol-gel method, and pure MgFe{sub 2}O{sub 4} was used as reference. The MgFe{sub 2}O{sub 4} and MgFe{sub 2}O{sub 4}-SiC catalysts were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), N{sub 2} adsorption analyzer (BET specific surface area), X-ray photoelectron spectroscopy (XPS). The electromagnetic parameters of the prepared catalysts were measured by vector network analyzer. The reflection loss (RL) based on the electromagnetic parameters calculated in Matlab showed MgFe{sub 2}O{sub 4}-SiC attained the maximum absorbing value of 13.32 dB at 2.57 GHz, which reached extremely high RL value at low frequency range, revealing the excellent MW absorption property of MgFe{sub 2}O{sub 4}-SiC. MW-induced degradation of Direct Black BN (DB BN) over as-synthesized MgFe{sub 2}O{sub 4}-SiC indicated that degradation efficiency of DB BN (20 mg L{sup −1}) in 5 min reached 96.5%, the corresponding TOC removal was 65%, and the toxicity of DB BN after degradation by MgFe{sub 2}O{sub 4}-SiC obviously decreased. The good stability and applicability of MgFe{sub 2}O{sub 4}-SiC on the degradation process were also discovered. Moreover, the ionic chromatogram during degradation

  9. Aluminum-doped zinc oxide thin films grown on various substrates using facing target sputtering system

    Science.gov (United States)

    Kim, Hwa-Min; Lee, Chang Hyun; Shon, Sun Young; Kim, Bong Hwan

    2017-11-01

    Aluminum-doped zinc oxide (AZO) films were fabricated on various substrates, such as glass, polyethylene naphthalate (PEN), and polyethylene terephthalate (PET), at room temperature using a facing target sputtering (FTS) system with hetero ZnO and Al2O3 targets, and their electrical and optical properties were investigated. The AZO film on glass exhibited compressive stress while the films on the plastic substrates showed tensile stress. These stresses negatively affected the crystalline quality of the AZO films, and it is suggested that the poor crystalline quality of the films may be related to the neutral Al-based defect complexes formed in the films; these complexes act as neutral impurity scattering centers. AZO films with good optoelectronic properties could be formed on the glass and plastic substrates by the FTS technique using the hetero targets. The AZO films deposited on the glass, PEN, and PET substrates showed very low resistivities, of 5.0 × 10-4 Ω cm, 7.0 × 10-4 Ω cm, and 7.4 × 10-4 Ω cm, respectively. Further, the figure merit of the AZO film formed on the PEN substrate in the visible range (400-700 nm) was significantly higher than that of the AZO film on PET and similar to that of the AZO film on glass. Finally, the average transmittances of the films in the visible range (400-700 nm) were 83.16% (on glass), 76.3% (on PEN), and 78.16% (on PET).

  10. Al-doped ZnO seed layer-dependent crystallographic control of ZnO nanorods by using electrochemical deposition

    Energy Technology Data Exchange (ETDEWEB)

    Son, Hyo-Soo; Choi, Nak-Jung [Department of Nano-Optical Engineering, Korea Polytechnic University, Siheung 429-793 (Korea, Republic of); Kim, Kyoung-Bo [Department of Metallurgical and Materials Engineering, Inha Technical College, Incheon 402-752 (Korea, Republic of); Kim, Moojin [Department of Renewable Energy, Jungwon University, Goesan-gun, Chungbuk 367-805 (Korea, Republic of); Lee, Sung-Nam, E-mail: snlee@kpu.ac.kr [Department of Nano-Optical Engineering, Korea Polytechnic University, Siheung 429-793 (Korea, Republic of)

    2016-10-15

    Highlights: • Polar and semipolar ZnO NRs were successfully achieved by hydrothermal synthesis. • Semipolar and polar ZnO NRs were grown on ZnO and AZO/m-sapphire, respectively. • Al % of AZO/m-sapphire enhanced the lateral growth rate of polar ZnO NRs. - Abstract: We investigated the effect of an Al-doped ZnO film on the crystallographic direction of ZnO nanorods (NRs) using electrochemical deposition. From high-solution X-ray diffraction measurements, the crystallographic plane of ZnO NRs grown on (1 0 0) ZnO/m-plane sapphire was (1 0 1). The surface grain size of the (100) Al-doped ZnO (AZO) film decreased with increasing Al content in the ZnO seed layer, implying that the Al dopant accelerated the three-dimensional (3D) growth of the AZO film. In addition, it was found that with increasing Al doping concentration of the AZO seed layer, the crystal orientation of the ZnO NRs grown on the AZO seed layer changed from [1 0 1] to [0 0 1]. With increasing Al content of the nonpolar (1 0 0) AZO seed layer, the small surface grains with a few crystallographic planes of the AZO film changed from semipolar (1 0 1) ZnO NRs to polar (0 0 1) ZnO NRs due to the increase of the vertical [0 0 1] growth rate of the ZnO NRs owing to excellent electrical properties.

  11. Enfermedad por arañazo de gato: Presentación de un caso

    Directory of Open Access Journals (Sweden)

    Ileana Alvarez Lam

    2003-12-01

    Full Text Available La enfermedad por arañazo de gato (EAG es un proceso infeccioso benigno, relativamente frecuente en niños y adolescentes producido por Bartonella henselae. La manifestación más frecuente de la enfermedad es la presencia de una lesión de inoculación seguida de linfadenopatía regional con presencia de fiebre u otros síntomas generales o sin estos. Se reporta el caso de un paciente de 13 años de edad que la afección se inició con adenopatía axilar izquierda y cuadro febril de 37,5 °C - 38,5 °C de 3 días de evolución con aparición más tardía de lesión similar en región interescapular, en la cual se planteaba la posibilidad de un proceso linfoproliferativo. Una vez esclarecida la historia clinicoepidemiológica del paciente se realizaron un grupo de exámenes complementarios y se indicó practicar exéresis de la lesión inicial. El estudio histopatológico mostró una linfadenitis crónica con focos pionecrotizantes compatibles con EAG. Se indicó tratamiento con eritromicina oral durante 10 días con resolución total del cuadro adénico.The cat-scratch disease (CSD is a bening infectious process, relatively common in children and adolescents, produced by Bartonella henselae.The most frequent manifestations of the disease is the presence of an innoculation injury followed by regional lymphoadenopathy with fever or other general symptoms, or without them. A case of a 13-year-old male patient, whose affection began with left axillary adenopathy and febrile picture of 37.5°C-38.5°C of 3 days of evolution with the later appearance of a similar injury in the interscapular region, where a lymphoproliferative process may occur, is presented. Once the clinicoepidemiological history of the patient was determined, a series of complementary tests was made and the exeresis of the initial injury was indicated. The histopathological study showed a chronic lymphadenitis with pyonecrotizing focuses compatible with the cat-scratch disease

  12. Liposome fusion and lipid exchange on ultraviolet irradiation of liposomes containing a photochromic phospholipid

    International Nuclear Information System (INIS)

    Morgan, C.G.; Sandhu, S.S.; Mitchell, A.C.

    1995-01-01

    A photochromic phospholipid, 1,2-bis[4-n-butylphenylazo)phenylbutyroyl]phosphatidylcholine (Bis-Azo PC) has been incorporated inot liposomes of gel- and liquid-crystalline-phase phospholipids. Liposomes of gel-phase phospholipid are stable in the presence of the trans photostationary state Bis-Az0 PC and can encapsulate fluorescent marker dye. On photoisomerization to the cis photostationary state, trapped marker is rapidly released. Liposomes containing Bis-Azo PC can rapidly fuse together after UV isomerization, this process continuing in the dark. Exposure to white light causes reversion of Bis-Azo PC to the trans form and halts dye leakage and vesicle fusion. Both unilamellar and multilamellar liposomes are able to fuse together on UV exposure. On UV photolysis, liposomes containing Bis-Azo PC do not fuse with a large excess of unlabeled liposomes, but transfer of Bis-Azo PC can be demonstrated spectrophotometrically. Vesicles of pure gel-phase lipid containing trapped marker dye but initially no Bis-Azo PC become leaky as a result of this lipid transfer. Liposomes composed of liquid-crystalline-phase phosphatidylcholine-containing Bis-Azo PC neither leak trapped marker nor fuse together on photolysis, nor do liquid-crystalline-phase liposomes, fuse with gel-phase liposomes under these conditions. (Author)

  13. Treatment of an azo dye effluent by peroxi-coagulation and its comparison to traditional electrochemical advanced processes.

    Science.gov (United States)

    do Vale-Júnior, Edilson; da Silva, Djalma R; Fajardo, Ana S; Martínez-Huitle, Carlos A

    2018-04-05

    Peroxi-coagulation (PC) is an interesting new process that has not been widely studied in the literature. This work presents the application of this technology to treat an azo dye synthetic effluent, studying the effect of different parameters including initial pH, current density (j), initial dye concentration and supporting electrolyte. The two former variables significantly affected the colour removal of the wastewater, followed by the initial dye concentration and the kind of electrolyte, in a lesser extent. The optimum operating conditions achieved were initial pH of 3.0, j = 33.3 mA cm -2 , 100 mg L -1 of methyl orange (MO) and Na 2 SO 4 as supporting electrolyte. The performance of PC was also compared to other electrochemical advanced processes, under similar experimental conditions. Results indicate that the kinetic decay of the MO increases in the following order: electrocoagulation (EC) oxidation (EO) with electrogenerated H 2 O 2 oxidant character of the homogenous OH radicals generated by EF and PC approaches. The EO process with production of H 2 O 2 (EO-H 2 O 2 ) is limited by mass transport and the EC, as a separation method, takes longer times to achieve similar removal results. Energy requirements about 0.06 kWh g COD -1 , 0.09 kWh g COD -1 , 0.7 kWh g COD -1 and 0.1 kWh g COD -1 were achieved for PC, EF, EO-H 2 O 2 and EC, respectively. Degradation intermediates were monitored and carboxylic acids were detected for PC and EF processes, being rapidly removed by the former technology. PC emerges as a promising and competitive alternative for wastewaters depollution, among other oxidative approaches. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. The formation of lithium diarylargentates from arylsilver compounds and the corresponding aryllithium compounds

    NARCIS (Netherlands)

    Blenkers, J.; Hofstee, H.K.; Boersma, J.; Kerk, G.J.M. van der

    1979-01-01

    Diarylsilverlithium compounds of the type Ar2AgLi are formed by treating arylsilver compounds with the corresponding aryllithium compounds. Cryoscopy in benzene shows that the Ar2AgLi compounds are associated into dimers. NMR spectroscopic data indicate that only one type of aryl group is present in

  15. The investigation of ZnO:Al2O3/metal composite back reflectors in amorphous silicon germanium thin film solar cells

    Institute of Scientific and Technical Information of China (English)

    Wang Guang-Hong; Zhao Lei; Yan Bao-Jun; Chen Jing-Wei; Wang Ge; Diao Hong-Wei; Wang Wen-Jing

    2013-01-01

    Different aluminum-doped ZnO (AZO)/metal composite thin films,including AZO/Ag/Al,AZO/Ag/nickelchromium alloy (NiCr),and AZO/Ag/NiCr/Al,are utilized as the back reflectors of p-i-n amorphous silicon germanium thin film solar cells.NiCr is used as diffusion barrier layer between Ag and Al to prevent mutual diffusion,which increases the short circuit current density of solar cell.NiCr and NiCr/Al layers are used as protective layers of Ag layer against oxidation and sulfurization,the higher efficiency of solar cell is achieved.The experimental results show that the performance of a-SiGe solar cell with AZO/Ag/NiCr/Al back reflector is best.The initial conversion efficiency is achieved to be 8.05%.

  16. Homogenous smooth sol gel films doped with organic compounds for nonlinear optics

    Energy Technology Data Exchange (ETDEWEB)

    Vasiliu, I.C. [INOE 2000 — National Institute for Optoelectronics, 409 Atomistilor Str., Magurele, Bucharest, RO 077125 (Romania); Ionita, I., E-mail: i_ionita@yahoo.com [UB — University of Bucharest, 405 Atomistilor Str., Magurele, Bucharest, RO 077125 (Romania); Matei, A. [INFLPR — National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor Str., Magurele, Bucharest, RO 077125 (Romania); Elisa, M.; Iordanescu, R.; Feraru, I.; Emandi, A. [INOE 2000 — National Institute for Optoelectronics, 409 Atomistilor Str., Magurele, Bucharest, RO 077125 (Romania)

    2016-02-29

    The demand for protection of various types of optical sensors from laser-beam pulses has resulted in the search for optical limiting devices that have the property of being transparent at low intensity of light (normal light), but no transparent towards high intensity (laser) light. Organic material with nonlinear optical (NLO) properties as reverse saturable absorption and two-photon absorption can be used for optical limiting with the advantage of a very fast response and self-activation. A promising approach in the fabrication of thin films by low cost/easy use deposition methods for second-order nonlinear optics is sol–gel technique. The present paper reports on the sol–gel synthesis of some pyrazolone derivative doped SiO{sub 2}–P{sub 2}O{sub 5} smooth and homogenous films (Root mean square roughness (Rq) = 1.1 nm) using as precursors tetraethylorthosilicate (TEOS) and phosphoric acid (H{sub 3}PO{sub 4}). The structure of the deposited azo-derivatives doped thin films was examined by Fourier transform infrared spectroscopy and atomic force microscopy, while their optical properties of the films by UV–VIS spectroscopy. The nonlinear optical efficiencies due to the interaction of the NLO-active chromophores with the inorganic matrix have a significant influence on the second harmonic generation capabilities that was measured using a femtosecond Ti:Sapphire laser. The properties of the films were investigated and correlated with the concentration of the organic dopant and the thermal treatment temperature. - Highlights: • We obtained pyrazolone derivative doped SiO{sub 2}–P{sub 2}O{sub 5} smooth and homogenous films. • The pyrazolone derivative presents SHG characteristics by itself. • Thin sol gel films doped with organic compounds with NLO properties. • Temperature of thermal treatment and aging time can improve NLO properties of films. • We found that 150 °C and 28 h aging time give the maximum performance in SHG response.

  17. Reaction of congo red in water after irradiation by pulsed intense relativistic electron beam

    International Nuclear Information System (INIS)

    Kikuchi, Takashi; Kondo, Hironobu; Sasaki, Toru; Harada, Nob.; Moriwaki, Hiroshi; Nakanishi, Hiromitsu; Imada, Go

    2011-01-01

    The reaction of congo red, a well-known toxic azo dye, occurred after irradiation by a pulsed intense relativistic electron beam (PIREB). An aquation of congo red was irradiated by PIREB (2 MeV, 0.36 kA, 140 ns). After PIREB irradiation, the solution was measured by electrospray ionization-mass spectrometry and liquid chromatography/mass spectrometry. It was found that congo red underwent a reaction (77% conversion after five shots of PIREB irradiation) and the hydroxylated compounds of the dye were observed as reaction products. (author)

  18. Low operation voltage of GaN-based LEDs with Al-doped ZnO upper contact directly on p-type GaN without insert layer

    Science.gov (United States)

    Chen, P. H.; Chen, Yu An; Chang, L. C.; Lai, W. C.; Kuo, Cheng Huang

    2015-07-01

    Al-doped ZnO (AZO) film was evaporated on double-side polished sapphire, p-GaN layers, n+-InGaN-GaN short-period superlattice (SPS) structures, and GaN-based light-emitting diodes (LEDs) by e-beam. The AZO film on the p-GaN layer after thermal annealing exhibited an extremely high transparency (98% at 450 nm) and a small specific contact resistance of 2.19 × 10-2 Ω cm2, which was almost the same as that of as-deposited AZO on n+-SPS structure. With 20 mA injection current, the forward voltages were 3.30 and 3.27 V, whereas the output powers were 4.32 and 4.07 mW for the LED with AZO on insert n+-SPS upper contact and the LED with AZO on p-GaN upper contact (without insert layer), respectively. The small specific contact resistance and low operation voltage of LED with AZO on p-GaN upper contact was achieved by rapid thermal annealing (RTA) process.

  19. Fabrication of silver nanowires and metal oxide composite transparent electrodes and their application in UV light-emitting diodes

    Science.gov (United States)

    Yan, Xingzhen; Ma, Jiangang; Xu, Haiyang; Wang, Chunliang; Liu, Yichun

    2016-08-01

    In this paper, we prepared the silver nanowires (AgNWs)/aluminum-doped zinc oxide (AZO) composite transparent conducting electrodes for n-ZnO/p-GaN heterojunction light emitting-diodes (LEDs) by drop casting AgNW networks and subsequent atomic layer deposition (ALD) of AZO at 150 °C. The contact resistances between AgNWs were dramatically reduced by pre-annealing in the vacuum chamber before the ALD of AZO. In this case, AZO works not only as the conformal passivation layer that protects AgNWs from oxidation, but also as the binding material that improves AgNWs adhesion to substrates. Due to the localized surface plasmons (LSPs) of the AgNWs resonant coupling with the ultraviolet (UV) light emission from the LEDs, a higher UV light extracting efficiency is achieved from LEDs with the AgNWs/AZO composite electrodes in comparison with the conventional AZO electrodes. Additionally, the antireflective nature of random AgNW networks in the composite electrodes caused a broad output light angular distribution, which could be of benefit to certain optoelectronic devices like LEDs and solar cells.

  20. Photocontrol of Voltage-Gated Ion Channel Activity by Azobenzene Trimethylammonium Bromide in Neonatal Rat Cardiomyocytes.

    Directory of Open Access Journals (Sweden)

    Sheyda R Frolova

    Full Text Available The ability of azobenzene trimethylammonium bromide (azoTAB to sensitize cardiac tissue excitability to light was recently reported. The dark, thermally relaxed trans- isomer of azoTAB suppressed spontaneous activity and excitation propagation speed, whereas the cis- isomer had no detectable effect on the electrical properties of cardiomyocyte monolayers. As the membrane potential of cardiac cells is mainly controlled by activity of voltage-gated ion channels, this study examined whether the sensitization effect of azoTAB was exerted primarily via the modulation of voltage-gated ion channel activity. The effects of trans- and cis- isomers of azoTAB on voltage-dependent sodium (INav, calcium (ICav, and potassium (IKv currents in isolated neonatal rat cardiomyocytes were investigated using the whole-cell patch-clamp technique. The experiments showed that azoTAB modulated ion currents, causing suppression of sodium (Na+ and calcium (Ca2+ currents and potentiation of net potassium (K+ currents. This finding confirms that azoTAB-effect on cardiac tissue excitability do indeed result from modulation of voltage-gated ion channels responsible for action potential.