WorldWideScience

Sample records for modified dye molecule

  1. Photophysical Behavior of Modified Xanthenic Dyes Embedded into Silsesquioxane Hybrid Films: Application in Photooxidation of Organic Molecules

    Directory of Open Access Journals (Sweden)

    Carolina V. Waiman

    2017-01-01

    Full Text Available Polymeric materials based on a bridged silsesquioxane with pendant dodecyl chains were synthesized and modified with different xanthenic dyes with the aim of developing a material with potential application in photooxidation of organic compounds. The employed dyes constitute a family of novel xanthenic chromophores with outstanding properties as singlet oxygen photosensitizers. The hybrid matrix was chosen for its enhanced properties such as flexibility and chemical resistance. The employed dyes were easily incorporated into the hybrid polymer obtaining homogeneous, transparent, and low-refractive-index materials. The polymeric films were characterized using UV-Vis absorption, fluorescence, and laser flash photolysis techniques. The ability of these materials to produce singlet oxygen was tested following the photooxidation of 9,10-dimethylanthracene which is a well-known chemical trap for singlet oxygen. High photooxidation efficiencies were observed for these materials, which present the advantage of being easily removed/collected from the solution where photooxidation takes place. While photobleaching of the incorporated dyes is commonly observed in the solution, it takes place very slowly when dyes are embedded in the hybrid matrix. These properties bode well for the potential use of these materials in novel wastewater purification strategies.

  2. Improved Dye Stability in Single-Molecule Fluorescence Experiments

    Science.gov (United States)

    EcheverrÍa Aitken, Colin; Marshall, R. Andrew; Pugi, Joseph D.

    Complex biological systems challenge existing single-molecule methods. In particular, dye stability limits observation time in singlemolecule fluorescence applications. Current approaches to improving dye performance involve the addition of enzymatic oxygen scavenging systems and small molecule additives. We present an enzymatic oxygen scavenging system that improves dye stability in single-molecule experiments. Compared to the currently-employed glucose-oxidase/catalase system, the protocatechuate-3,4-dioxygenase system achieves lower dissolved oxygen concentration and stabilizes single Cy3, Cy5, and Alexa488 fluorophores. Moreover, this system possesses none of the limitations associated with the glucose oxidase/catalase system. We also tested the effects of small molecule additives in this system. Biological reducing agents significantly destabilize the Cy5 fluorophore as a function of reducing potential. In contrast, anti-oxidants stabilize the Cy3 and Alexa488 fluorophores. We recommend use of the protocatechuate-3,4,-dioxygenase system with antioxidant additives, and in the absence of biological reducing agents. This system should have wide application to single-molecule fluorescence experiments.

  3. Electroluminescence from completely horizontally oriented dye molecules

    Energy Technology Data Exchange (ETDEWEB)

    Komino, Takeshi [Education Center for Global Leaders in Molecular System for Devices, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Center for Organic Photonics and Electronics Research, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Japan Science and Technology Agency, ERATO, Adachi Molecular Exciton Engineering Project, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Sagara, Yuta [Center for Organic Photonics and Electronics Research, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Tanaka, Hiroyuki [Center for Organic Photonics and Electronics Research, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan); Oki, Yuji [Japan Science and Technology Agency, ERATO, Adachi Molecular Exciton Engineering Project, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Department of Electronics, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Nakamura, Nozomi [Center for Organic Photonics and Electronics Research, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Fujimoto, Hiroshi [Center for Organic Photonics and Electronics Research, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Fukuoka i" 3-Center for Organic Photonics and Electronics Research (i3-OPERA), Fukuoka 819-0388 (Japan); and others

    2016-06-13

    A complete horizontal molecular orientation of a linear-shaped thermally activated delayed fluorescent guest emitter 2,6-bis(4-(10Hphenoxazin-10-yl)phenyl)benzo[1,2-d:5,4-d′] bis(oxazole) (cis-BOX2) was obtained in a glassy host matrix by vapor deposition. The orientational order of cis-BOX2 depended on the combination of deposition temperature and the type of host matrix. Complete horizontal orientation was obtained when a thin film with cis-BOX2 doped in a 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP) host matrix was fabricated at 200 K. The ultimate orientation of guest molecules originates from not only the kinetic relaxation but also the kinetic stability of the deposited guest molecules on the film surface during film growth. Utilizing the ultimate orientation, a highly efficient organic light-emitting diode with the external quantum efficiency of 33.4 ± 2.0% was realized. The thermal stability of the horizontal orientation of cis-BOX2 was governed by the glass transition temperature (T{sub g}) of the CBP host matrix; the horizontal orientation was stable unless the film was annealed above T{sub g}.

  4. Nanospectroscopy of thiacyanine dye molecules adsorbed on silver nanoparticle clusters

    Science.gov (United States)

    Ralević, Uroš; Isić, Goran; Anicijević, Dragana Vasić; Laban, Bojana; Bogdanović, Una; Lazović, Vladimir M.; Vodnik, Vesna; Gajić, Radoš

    2018-03-01

    The adsorption of thiacyanine dye molecules on citrate-stabilized silver nanoparticle clusters drop-cast onto freshly cleaved mica or highly oriented pyrolytic graphite surfaces is examined using colocalized surface-enhanced Raman spectroscopy and atomic force microscopy. The incidence of dye Raman signatures in photoluminescence hotspots identified around nanoparticle clusters is considered for both citrate- and borate-capped silver nanoparticles and found to be substantially lower in the former case, suggesting that the citrate anions impede the efficient dye adsorption. Rigorous numerical simulations of light scattering on random nanoparticle clusters are used for estimating the electromagnetic enhancement and elucidating the hotspot formation mechanism. The majority of the enhanced Raman signal, estimated to be more than 90%, is found to originate from the nanogaps between adjacent nanoparticles in the cluster, regardless of the cluster size and geometry.

  5. Magnetically modified spent grain for dye removal

    Czech Academy of Sciences Publication Activity Database

    Šafařík, Ivo; Horská, Kateřina; Šafaříková, Miroslava

    2011-01-01

    Roč. 53, č. 1 (2011), s. 78-80 ISSN 0733-5210 R&D Projects: GA MŠk OC09052; GA MPO 2A-1TP1/094 Institutional research plan: CEZ:AV0Z60870520 Keywords : Spent grain * Magnetic fluid * Adsorption * Dyes Subject RIV: GM - Food Processing Impact factor: 2.073, year: 2011

  6. Green dyeing process of modified cotton fibres using natural dyes extracted from Tamarix aphylla (L.) Karst. leaves.

    Science.gov (United States)

    Baaka, Noureddine; Mahfoudhi, Adel; Haddar, Wafa; Mhenni, Mohamed Farouk; Mighri, Zine

    2017-01-01

    This research work involves an eco-friendly dyeing process of modified cotton with the aqueous extract of Tamarix aphylla leaves. During this process, the dyeing step was carried out on modified cotton by several cationising agents in order to improve its dyeability. The influence of the main dyeing conditions (dye bath pH, dyeing time, dyeing temperature, salt addition) on the performances of this dyeing process were studied. The dyeing performances of this process were appreciated by measuring the colour yield (K/S) and the fastness properties of the dyed samples. The effect of mordant type with different mordanting methods on dyeing quality was also studied. The results showed that mordanting gave deeper shades and enhanced fastness properties. In addition, environmental indicators (BOD 5 , COD and COD/BOD 5 ) were used to describe potential improvements in the biodegradability of the dyebath wastewater. Further, HPLC was used to identify the major phenolic compounds in the extracted dye.

  7. Organic dyes removal using magnetically modified rye straw

    Energy Technology Data Exchange (ETDEWEB)

    Baldikova, Eva, E-mail: baldie@email.cz [Department of Nanobiotechnology, Institute of Nanobiology and Structural Biology of GCRC, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic); Safarikova, Mirka [Department of Nanobiotechnology, Institute of Nanobiology and Structural Biology of GCRC, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic); Safarik, Ivo, E-mail: ivosaf@yahoo.com [Department of Nanobiotechnology, Institute of Nanobiology and Structural Biology of GCRC, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic); Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic)

    2015-04-15

    Rye straw, a very low-cost material, was employed as a biosorbent for two organic water-soluble dyes belonging to different dye classes, namely acridine orange (acridine group) and methyl green (triarylmethane group). The adsorption properties were tested for native and citric acid–NaOH modified rye straw, both in nonmagnetic and magnetic versions. The adsorption equilibrium was reached in 2 h and the adsorption isotherms data were analyzed using the Langmuir model. The highest values of maximum adsorption capacities were 208.3 mg/g for acridine orange and 384.6 mg/g for methyl green. - Highlights: • Rye derivatives can be considered as efficient adsorbents for organic dyes. • Magnetic modification of straw by microwave-synthesized magnetic iron oxides. • Citric acid–NaOH modification increased the maximum adsorption capacities.

  8. Dyes adsorption on magnetically modified Chlorella vulgaris cells

    Czech Academy of Sciences Publication Activity Database

    Šafaříková, Miroslava; Pona, B. M. R.; Mosiniewicz-Szablewska, E.; Weyda, František; Šafařík, Ivo

    2008-01-01

    Roč. 17, č. 4 (2008), s. 486-492 ISSN 1018-4619 R&D Projects: GA MŠk OC 108; GA MPO 2A-1TP1/094 Institutional research plan: CEZ:AV0Z60870520; CEZ:AV0Z50070508 Keywords : Chlorella vulgaris * magnetically modified cells * dyes Subject RIV: EI - Biotechnology ; Bionics Impact factor: 0.463, year: 2008

  9. Photonics of dyes molecules in reverse micellar solution

    International Nuclear Information System (INIS)

    Ibragimova, M.R.; Laurinas, V.Ch.

    2001-01-01

    Spectral luminescent characteristics of the dye acridine orange and eosin has been studied in reverse micellar solutions of sodium bis(2-ethyl-hexyl)sulfosuccinate. It was shown that the increase of the nucleus volume of reverse micelles. (author)

  10. Single-molecule studies of oligomer extraction and uptake of dyes in poly(dimethylsiloxane) films.

    Science.gov (United States)

    Lange, Jeffrey J; Collinson, Maryanne M; Culbertson, Christopher T; Higgins, Daniel A

    2009-12-15

    Single-molecule microscopic methods were used to probe the uptake, mobility, and entrapment of dye molecules in cured poly(dimethylsiloxane) (PDMS) films as a function of oligomer extraction. The results are relevant to the use of PDMS in microfluidic separations, pervaporation, solid-phase microextraction, and nanofiltration. PDMS films were prepared by spin-casting dilute solutions of Sylgard 184 onto glass coverslips, yielding approximately 1.4 microm thick films after curing. Residual oligomers were subsequently extracted from the films by "spin extraction". In this procedure, 200 microL aliquots of isopropyl alcohol were repeatedly dropped onto the film surface and spun off at 2000 rpm. Samples extracted 5, 10, 20, and 40 times were investigated. Dye molecules were loaded into these films by spin-casting nanomolar dye solutions onto the films. Both neutral perylene diimide (N,N'-bis(butoxypropyl)perylene-3,4,9,10-tetracarboxylic diimide) and cationic rhodamine 6G (R6G) dyes were employed. The films were imaged by confocal fluorescence microscopy. The images obtained depict nonzero populations of fixed and mobile molecules in all films. Cross-correlation methods were used to quantitatively determine the population of fixed molecules in a given region, while a Bayesian burst analysis was used to obtain the total population of molecules. The results show that the total amount of dye loaded increases with increased oligomer extraction, while the relative populations of fixed and mobile molecules decrease and increase, respectively. Bulk R6G data also show greater dye loading with increased oligomer extraction.

  11. Entrapment of dye molecules within submicron silver particles

    Energy Technology Data Exchange (ETDEWEB)

    Yosef, Itzik; Avnir, David, E-mail: david@chem.ch.huji.ac.il [Hebrew University of Jerusalem, Institute of Chemistry (Israel)

    2011-09-15

    We describe a method for the preparation of metal-organic composites submicron particles. Specifically, the preparation of silver particle-clusters 150-200 nm in size, doped with an organic dye Congo-red, is reported. The use of sodium citrate coupled with sodium hypophosphite facilitated the formation of these particle-clusters, which were fully characterized by TEM analysis, Zeta potential and size measurements, scanning electron microscopy, UV-Vis measurements, and thermogravimetric analysis. The latter reveals a catalytic action of the metal on the thermal oxidative decomposition of the entrapped dye. The use of these particles to obtain dense thin metallic films was demonstrated by the coating of ITO glass.

  12. Amino Acid-Assisted Incorporation of Dye Molecules within Calcite Crystals.

    Science.gov (United States)

    Marzec, Bartosz; Green, David C; Holden, Mark A; Coté, Alexander S; Ihli, Johannes; Khalid, Saba; Kulak, Alexander; Walker, Daniel; Tang, Chiu; Duffy, Dorothy M; Kim, Yi-Yeoun; Meldrum, Fiona C

    2018-05-23

    Biomineralisation processes invariably occur in the presence of multiple organic additives, which act in combination to give exceptional control over structures and properties. However, few synthetic studies have investigated the cooperative effects of soluble additives. This work addresses this challenge and focuses on the combined effects of amino acids and coloured dye molecules. The experiments demonstrate that strongly coloured calcite crystals only form in the presence of Brilliant Blue R (BBR) and four of the seventeen soluble amino acids, as compared with almost colourless crystals using the dye alone. The active amino acids are identified as those which themselves effectively occlude in calcite, suggesting a mechanism where they can act as chaperones for individual molecules or even aggregates of dyes molecules. These results provide new insight into crystal-additive interactions and suggest a novel strategy for generating materials with target properties. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Selective adsorption and release of cationic organic dye molecules on mesoporous borosilicates

    International Nuclear Information System (INIS)

    Paul, Manidipa; Pal, Nabanita; Bhaumik, Asim

    2012-01-01

    Mesoporous materials can play a pivotal role as a host material for delivery application to a specific part of a system. In this work we explore the selective adsorption and release of cationic organic dye molecules such as safranine T (ST) and malachite green (MG) on mesoporous borosilicate materials. The mesoporous silica SBA-15 and borosilicate materials (MBS) were prepared using non-ionic surfactant Pluronic P123 as template via evaporation induced self-assembly (EISA) method. After template removal the materials show high surface areas and in some cases ordered mesopores of dimensions ca. 6–7 nm. High surface area, mesoporosity and the presence of heteroatom (boron) help this mesoporous borosilicate material to adsorb high amount of cationic dye molecules at its surface from the respective aqueous solutions. Furthermore, the mesoporous borosilicate samples containing higher percentage adsorbed dyes show excellent release of ST or MG dye in simulated body fluid (SBF) solution at physiological pH = 7.4 and temperature 310 K. The adsorption and release efficiency of mesoporous borosilicate samples are compared with reference boron-free mesoporous pure silica material to understand the nature of adsorbate–adsorbent interaction at the surfaces. - Graphical abstract: Highly ordered 2D-hexagonal mesoporous borosilicate materials have been synthesized by using Pluronic P123 as template. The materials show very good adsorption and release of organic cationic dye molecules under physiological conditions. Highlights: ► Highly ordered 2D-hexagonal mesoporous borosilicate. ► Nonionic Pluoronic P123 templated mesoporous material. ► Adsorption of organic dyes at the mesopore surface. ► Controlled release of dyes under physiological pH and temperature. ► Release of safranine T (ST) and malachite green (MG) dyes in simulated body fluids.

  14. Fluorescence quenching of dye molecules near gold nanoparticles: radiative and nonradiative effects

    NARCIS (Netherlands)

    Dulkeith, E.; Morteani, A.C.; Niedereichholz, T.; Klar, T.A.; Feldman, J.; Levi, S.; van Veggel, F.C.J.M.; Reinhoudt, David; Möller, M.; Gittins, D.I.

    2002-01-01

    The radiative and nonradiative decay rates of lissamine dye molecules, chemically attached to differently sized gold nanoparticles, are investigated by means of time-resolved fluorescence experiments. A pronounced fluorescence quenching is observed already for the smallest nanoparticles of 1  nm

  15. Melamine-formaldehyde microcapsules filled sappan dye modified polypropylene composites: encapsulation and thermal properties

    Science.gov (United States)

    Phanyawong, Suphitcha; Siengchin, Suchart; Parameswaranpillai, Jyotishkumar; Asawapirom, Udom; Polpanich, Duangporn

    2018-01-01

    Sappan dye, a natural dye extracted from sappan wood is widely used in cosmetics, textile dyeing and as food additives. However, it was recognized that natural dyes cannot withstand high temperature. In this study, a protective coating of melamine-formaldehyde shell material was applied over the sappan dye to improve its thermal stability. The percentage of sappan dye used in the microencapsulation was 30, 40, 50, 60 and 70 wt%. The color, shape, size, and thermal stability of sappan dye microcapsules were investigated. It was found that increasing amount of sappan dye content in the microcapsules decreased the particle size. Thermal analysis reveals that the melamine-formaldehyde resin served as an efficient protective shell for sappan dye. Besides, 30 wt% sappan dye microcapsules with different weight percent (1, 3 and 5 wt%) of sappan dye was used as modifier for polypropylene (PP). All the prepared composites are red in color which supports the thermal stability of the microcapsules. The changes in crystallinity and melting behavior of PP by the addition of microcapsules were studied in detail by differential scanning calorimetry. Thermogravimetric studies showed that the thermal stability of PP composites increased by the addition of microcapsules.

  16. Modified dynamical equation for dye doped nematic liquid crystals

    Energy Technology Data Exchange (ETDEWEB)

    Manohar, Rajiv, E-mail: rajlu1@rediffmail.co [Liquid Crystal Research Lab, Physics Department, University of Lucknow, Lucknow 226007 (India); Misra, Abhishek Kumar; Srivastava, Abhishek Kumar [Liquid Crystal Research Lab, Physics Department, University of Lucknow, Lucknow 226007 (India)

    2010-04-15

    Dye doped liquid crystals show changed dielectric properties in comparison to pure liquid crystals. These changes are strongly dependent on the concentration of dye. In the present work we have measured dielectric properties of standard nematic liquid crystals E-24 and its two guest host mixtures of different concentrations with Anthraquinone dye D5. The experimental results are fitted using linear response and in the light of this we have proposed some modifications in the dynamical equation for the nematic liquid crystals by introducing two new variables as dye concentration coefficients. The limitations of the proposed equation in high temperature range have also been discussed. With the help of the proposed dynamical equation for the guest-host liquid crystals (GHLCs) it is possible to predict the various parameters like rotational viscosity, dielectric anisotropy and relaxation time for GHLCs at other concentrations of dye in liquid crystals theoretically.

  17. Modified coal fly ash as low cost adsorbent for removal reactive dyes from batik industry

    Directory of Open Access Journals (Sweden)

    Taufiq Agus

    2018-01-01

    Full Text Available The removal of reactive dyes on modified coal fly ash has been investigated during a series of batch adsorption experiments. Physical characteristics of modified coal fly ash was characterized by Brunauer Emmett Teller (BET surface area analysis, X-ray powder diffraction (XRD, Fourier transform infrared spectrophotometer (FT-IR, and scanning electron microscope (SEM. The effects of operational parameters such as initial dye concentration (50–200 mg/L, solution pH (4–10 and adsorbent dosage (50–200 mg/L were studied. The adsorption experiments indicated that modified coal fly ash was effective in removing of Remazol Blue. The percentage removal of dyes increased while the modified fly ash dosage increased. The percentage removal of dyes increased with decreased initial concentration of the dye and also increased with amount of adsorbent used. The optimum of removal of dyes was found to be 94% at initial dye concentration 50 g/mL, modified fly ash dosage 250 g/mL, and pH of 2.0.

  18. Dye molecules as single-photon sources and large optical nonlinearities on a chip

    International Nuclear Information System (INIS)

    Hwang, J; Hinds, E A

    2011-01-01

    We point out that individual organic dye molecules, deposited close to optical waveguides on a photonic chip, can act as single-photon sources. A thin silicon nitride strip waveguide is expected to collect 28% of the photons from a single dibenzoterrylene molecule. These molecules can also provide large, localized optical nonlinearities, which are enough to discriminate between one photon or two through a differential phase shift of 2 0 per photon. This new atom-photon interface may be used as a resource for processing quantum information.

  19. A simple method to prepare magnetic modified beer yeast and its application for cationic dye adsorption.

    Science.gov (United States)

    Yu, Jun-Xia; Wang, Li-Yan; Chi, Ru-An; Zhang, Yue-Fei; Xu, Zhi-Gao; Guo, Jia

    2013-01-01

    The purpose of this research is to use a simple method to prepare magnetic modified biomass with good adsorption performances for cationic ions. The magnetic modified biomass was prepared by two steps: (1) preparation of pyromellitic dianhydride (PMDA) modified biomass in N, N-dimethylacetamide solution and (2) preparation of magnetic PMDA modified biomass by a situ co-precipitation method under the assistance of ultrasound irradiation in ammonia water. The adsorption potential of the as-prepared magnetic modified biomass was analyzed by using cationic dyes: methylene blue and basic magenta as model dyes. Optical micrograph and x-ray diffraction analyses showed that Fe(3)O(4) particles were precipitated on the modified biomass surface. The as-prepared biosorbent could be recycled easily by using an applied magnetic field. Titration analysis showed that the total concentration of the functional groups on the magnetic PMDA modified biomass was calculated to be 0.75 mmol g(-1) by using the first derivative method. The adsorption capacities (q(m)) of the magnetic PMDA modified biomass for methylene blue and basic magenta were 609.0 and 520.9 mg g(-1), respectively, according to the Langmuir equation. Kinetics experiment showed that adsorption could be completed within 150 min for both dyes. The desorption experiment showed that the magnetic sorbent could be used repeatedly after regeneration. The as-prepared magnetic modified sorbent had a potential in the dyeing industry wastewater treatment.

  20. New compositions of cadmium selenium nanoparticles and dye molecules with cyclodextrin inclusion complexes

    International Nuclear Information System (INIS)

    Asimov, M.M.; Anufrik, S.S.; Tarkovsky, V.V.; Sazonko, H.H.

    2013-01-01

    Spectroscopic properties of new heterogeneous multicolor compositions based on cadmium selenium (CdSe/ZnS) nano crystal and inclusion complexes of dye molecule with cyclodextrin are presented. Spectral fluorescence of proposed compositions investigated in thin films. Signals from multicolor fluorescence of proposing compositions may be combined to definite spectral codes that could be used for tracking or verification of different objects. Calibration bar of signal within spectral codes guarantee high reliability in practical application of proposed multicolor compositions. Express analysis the size of nanoparticles during their synthesis and purification by spectroscopic methods is suggested. Application of Cyclodextrin molecules as target delivery systems is considered. (authors)

  1. Nanoimprinted distributed feedback dye laser sensor for real-time imaging of small molecule diffusion

    DEFF Research Database (Denmark)

    Vannahme, Christoph; Dufva, Martin; Kristensen, Anders

    2014-01-01

    Label-free imaging is a promising tool for the study of biological processes such as cell adhesion and small molecule signaling processes. In order to image in two dimensions of space current solutions require motorized stages which results in low imaging frame rates. Here, a highly sensitive...... distributed feedback (DFB) dye laser sensor for real-time label-free imaging without any moving parts enabling a frame rate of 12 Hz is presented. The presence of molecules on the laser surface results in a wavelength shift which is used as sensor signal. The unique DFB laser structure comprises several areas...

  2. Removal of dyes by adsorption on magnetically modified activated sludge

    Czech Academy of Sciences Publication Activity Database

    Maděrová, Z.; Baldíková, E.; Pospíšková, K.; Šafařík, Ivo; Šafaříková, Miroslava

    2016-01-01

    Roč. 13, č. 7 (2016), s. 1653-1664 ISSN 1735-1472 Institutional support: RVO:60077344 Keywords : biosorption * dyes * magnetic adsorbent * magnetic modification * microwave-assisted synthesis Subject RIV: DJ - Water Pollution ; Quality Impact factor: 1.915, year: 2016

  3. Organic dyes removal using magnetically modified rye straw

    Czech Academy of Sciences Publication Activity Database

    Baldíková, E.; Šafaříková, Miroslava; Šafařík, Ivo

    2015-01-01

    Roč. 180, APR 2015 (2015), s. 181-185 ISSN 0304-8853 R&D Projects: GA ČR GA13-13709S Institutional support: RVO:67179843 Keywords : Rye straw * Adsorbent * Dyes removal * Magnetic modification Subject RIV: CC - Organic Chemistry Impact factor: 2.357, year: 2015

  4. In Situ Mapping of the Molecular Arrangement of Amphiphilic Dye Molecules at the TiO 2 Surface of Dye-Sensitized Solar Cells

    KAUST Repository

    Voïtchovsky, Kislon

    2015-05-27

    © 2015 American Chemical Society. Amphiphilic sensitizers are central to the function of dye-sensitized solar cells. It is known that the cell\\'s performance depends on the molecular arrangement and the density of the dye on the semiconductor surface, but a molecular-level picture of the cell-electrolyte interface is still lacking. Here, we present subnanometer in situ atomic force microscopy images of the Z907 dye at the surface of TiO2 in a relevant liquid. Our results reveal changes in the conformation and the lateral arrangement of the dye molecules, depending on their average packing density on the surface. Complementary quantitative measurements on the ensemble of the film are obtained by the quartz-crystal microbalance with dissipation technique. An atomistic picture of the dye coverage-dependent packing, the effectiveness of the hydrophobic alkyl chains as blocking layer, and the solvent accessibility is obtained from molecular dynamics simulations. (Figure Presented).

  5. Magnetically modified spent coffee grounds for dyes removal

    Czech Academy of Sciences Publication Activity Database

    Šafařík, Ivo; Horská, Kateřina; Svobodová, Barbora; Šafaříková, Miroslava

    2012-01-01

    Roč. 234, č. 2 (2012), s. 345-350 ISSN 1438-2377 R&D Projects: GA MŠk OC09052; GA MPO 2A-1TP1/094 Institutional research plan: CEZ:AV0Z60870520 Keywords : coffee grounds * magnetic fluid * adsorption * dyes * magnetic solid-phase extraction Subject RIV: GM - Food Processing Impact factor: 1.436, year: 2012

  6. Chitosan and chemically modified chitosan beads for acid dyes sorption

    Institute of Scientific and Technical Information of China (English)

    AZLAN Kamari; WAN SAIME Wan Ngah; LAI KEN Liew

    2009-01-01

    The capabilities of chitosan and chitosan-EGDE (ethylene glycol diglycidyl ether) beads for removing Acid Red 37 (AR 37) and Acid Blue 25 (AB 25) from aqueous solution were examined. Chitosan beads were cross-linked with EGDE to enhance its chemical resistance and mechanical strength. Experiments were performed as a function of pH, agitation period and concentration of AR 37 and AB 25. It was shown that the adsorption capacities of chitosan were comparatively higher than chitosan-EGDE for both acid dyes. This is mainly because cross-linking using EGDE reduces the major adsorption sites -NH3+ on chitosan. Langmuir isotherm model showed best conformity compared to Freundlich and BET. The kinetic experimental data agreed very well to the pseudo second-order kinetic model. The desorption study revealed that after three cycles of adsorption and desorption by NaOH and HCl, both adsorbents retained their promising adsorption abilities. FT-IR analysis proved that the adsorption of acid dyes onto chitosan-based adsorbents was a physical adsorption. Results also showed that chitosan and chitosan-EGDE beads were favourable adsorbers and could be employed as low-cost alternatives for the removal of acid dyes in wastewater treatment.

  7. Strength of interactions between immobilized dye molecules and sol-gel matrices.

    Science.gov (United States)

    Ismail, Fanya; Schoenleber, Monika; Mansour, Rolan; Bastani, Behnam; Fielden, Peter; Goddard, Nicholas J

    2011-02-21

    In this paper we present a new theory to re-examine the immobilization technique of dye doped sol-gel films, define the strength and types of possible bonds between the immobilized molecule and sol-gel glass, and show that the immobilized molecule is not free inside the pores as was previously thought. Immobilizing three different pH sensitive dyes with different size and functional groups inside the same sol-gel films revealed important information about the nature of the interaction between the doped molecule and the sol-gel matrix. The samples were characterized by means of ultraviolet-visible spectrophotometer (UV-VIS), thermal gravimetric analysis (TGA), mercury porosimetry (MP), nuclear magnetic resonance spectroscopy ((29)Si NMR) and field-emission environmental scanning electron microscopy (ESEM-FEG). It was found that the doped molecule itself has a great effect on the strength and types of the bonds. A number of factors were identified, such as number and types of the functional groups, overall charge, size, pK(a) and number of the silanol groups which surround the immobilized molecule. These results were confirmed by the successful immobilization of bromocresol green (BCG) after a completely polymerized sol-gel was made. The sol-gel consisted of 50% tetraethoxysilane (TEOS) and 50% methyltriethoxysilane (MTEOS) (w/w). Moreover, the effect of the immobilized molecule on the structure of the sol-gel was studied by means of a leaky waveguide (LW) mode for doped films made before and after polymerization of the sol-gel.

  8. Performance engineering of dye sensitized solar cells (DSSC) using Ag modified titania as photoanode

    Science.gov (United States)

    Nair, Ranjith G.; Mathan Kumar, P.; Samdarshi, S. K.

    2018-01-01

    Present work reports the fabrication of silver (Ag) modified titania photoanode as an efficient photoanode for Dye Sensitized Solar Cell (DSSC). Pristine and Ag modified Titania nanomaterials were prepared using sol gel method. The structural analyses confirm the high crystallinity of the samples with crystallite size distribution in nanorange. TEM micrograph confirms that the synthesized nanomaterials are in uniform size. A red shift is observed in the UV DRS spectra compared to pristine Titania and which confirm the incorporation of Ag inside titania. A prototype DSSC was fabricated using the pristine and modified Titania as photoanode, Ruthenium dye as sensitizer, I-/I-3 as redox electrolyte and platinum counter electrode. The cell with Ag modified titania photoanode showed 15 times enhanced photoconversion efficiency (PCE) than the pristine one. This improved performance of the Ag modified DSSC can be ascribed to reduced recombination and improved charge carrier transport of electrons/holes at the interfaces.

  9. Adsorption of Reactive Red Dye from Wastewater Using Modified Citrulluscolosynthis Ash

    Directory of Open Access Journals (Sweden)

    Mohammadreza Rezaei Kahkha

    2016-07-01

    Full Text Available Dye-bearing wastes pose serious risks to and leave harmful effects on the environment. Increasing wastewater color intensity leads to reduced light reaching the aquatic environment, which adversely affects the life and growth of aquatic plants and invertebrates. Among the many methods available for dye removal from wastewater, membrane separation, oxidation, coagulation, and anaerobic treatment are more common but they are all costly and involve complex processes. Biosorption, in contrast, enjoys both ease of application and simple design so that it is widely used for removing dyes, heavy metals, and phenolic compounds from both water and wastewater. In this paper, the ability of citrulluscolosynthis ash as a bioadsorbent for the removal of reactive red dye is investigated for the first time. Sodium hydroxide is also used to modify the plant ash surface which expectedly enhances its dye removal efficiency. Measurements and removal levels are determined using a UV-vis spectrophotometer. Finally, the effects of pH, adsorbent dosage, dye concentration, and reaction time on dye removal efficiency are also explored. Results show that the optimum conditions to achieve maximum dye removal are as follows: A pH level of 2, an adsorbant dosage of 1.75 g l-1, an initial concentration equal to 90 mg L-1, and A reaction time of 70 min. Adsorption isotherm is found to obey the Ferundlich isotherm. Also, an adsorption capacity of 36 mg g‒1 is achieved under the best conditions. It may thus be concluded that modified citrulluscolosynthis ash can be used as an effective adsorbent to treat colored wastewaters.

  10. Combination of Small Molecule Microarray and Confocal Microscopy Techniques for Live Cell Staining Fluorescent Dye Discovery

    Directory of Open Access Journals (Sweden)

    Attila Bokros

    2013-08-01

    Full Text Available Discovering new fluorochromes is significantly advanced by high-throughput screening (HTS methods. In the present study a combination of small molecule microarray (SMM prescreening and confocal laser scanning microscopy (CLSM was developed in order to discover novel cell staining fluorescent dyes. Compounds with high native fluorescence were selected from a 14,585-member library and further tested on living cells under the microscope. Eleven compartment-specific, cell-permeable (or plasma membrane-targeted fluorochromes were identified. Their cytotoxicity was tested and found that between 1–10 micromolar range, they were non-toxic even during long-term incubations.

  11. Dyes adsorption blue vegetable and blue watercolor by natural zeolites modified with surfactants

    International Nuclear Information System (INIS)

    Jardon S, C. C.; Olguin G, M. T.; Diaz N, M. C.

    2009-01-01

    In this work was carried out the dyes removal blue vegetable and blue watercolor of aqueous solutions, to 20 C, at different times and using a zeolite mineral of Parral (Chihuahua, Mexico) modified with hexadecyl trimethyl ammonium bromide or dodecyl trimethyl ammonium bromide. The zeolite was characterized before and after of its adaptation with NaCl and later with HDTMABr and DTMABr. For the materials characterization were used the scanning electron microscopy of high vacuum; elementary microanalysis by X-ray spectroscopy of dispersed energy and X-ray diffraction techniques. It was found that the surfactant type absorbed in the zeolite material influences on the adsorption process of the blue dye. Likewise, the chemical structure between the vegetable blue dye and the blue watercolor, determines the efficiency of the color removal of the water, by the zeolites modified with the surfactants. (Author)

  12. Determining the exact number of dye molecules attached to colloidal CdSe/ZnS quantum dots in Förster resonant energy transfer assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, Uwe; Jimenez de Aberasturi, Dorleta; Vázquez-González, Margarita; Carrillo-Carrion, Carolina; Niebling, Tobias; Parak, Wofgang J.; Heimbrodt, Wolfram, E-mail: Wolfram.Heimbrodt@physik.uni-marburg.de [Department of Physics and Material Sciences Center, Philipps-University Marburg, Renthof 5, D-35032 Marburg (Germany)

    2015-01-14

    Semiconductor quantum dots functionalized with organic dye molecules are important tools for biological sensor applications. Energy transfer between the quantum dot and the attached dyes can be utilized for sensing. Though important, the determination of the real number of dye molecules attached per quantum dot is rather difficult. In this work, a method will be presented to determine the number of ATTO-590 dye molecules attached to CdSe/ZnS quantum dots based on time resolved spectral analysis. The energy transfer from the excited quantum dot to the attached ATTO-590 dye leads to a reduced lifetime of the quantum dot's excitons. The higher the concentration of dye molecules, the shorter the excitonic lifetime becomes. However, the number of dye molecules attached per quantum dot will vary. Therefore, for correctly explaining the decay of the luminescence upon photoexcitation of the quantum dot, it is necessary to take into account the distribution of the number of dyes attached per quantum dot. A Poisson distribution of the ATTO-590 dye molecules not only leads to excellent agreement between experimental and theoretical decay curves but also additionally yields the average number of dye molecules attached per quantum dot. In this way, the number of dyes per quantum dot can be conveniently determined.

  13. Efficiency Improvement of Some Agricultural Residue Modified Materials for Textile Dyes Absorption

    Science.gov (United States)

    Boonsong, P.; Paksamut, J.

    2018-03-01

    In this work, the adsorption efficiency was investigated of some agricultural residue modified materials as natural bio-adsorbents which were rice straw (Oryza sativa L.) and pineapple leaves (Ananas comosus (L.) Merr.) for the removal of textile dyes. Reactive dyes were used in this research. The improvement procedure of agricultural residue materials properties were alkali-acid modification with sodium hydroxide solution and hydrochloric acid solution. Adsorption performance has been investigated using batch experiments. Investigated adsorption factors consisted of adsorbent dose, contact time, adsorbent materials and pH of solution. The results were found that rice straw had higher adsorption capacity than pineapple leaves. The increasing of adsorption capacity depends on adsorbent dose and contact time. Moreover, the optimum pH for dye adsorption was acidic range because lowering pH increased the positively charges on the adsorbent surface which could be attacked by negatively charge of acid dyes. The agricultural residue modified materials had significant dye removal efficiency which these adsorbents could be used for the treatment of textile effluent in industries.

  14. Ground state analysis of magnetic nanographene molecules with modified edge

    International Nuclear Information System (INIS)

    Gorjizadeh, Narjes; Ota, Norio; Kawazoe, Yoshiyuki

    2013-01-01

    Highlights: ► Graphene molecules can become ferromagnetic by edge modifications. ► Dihydrogenation of one zigzag edge of rectangular flakes make them ferromagnetic. ► Triangular flakes become high-spin state by dehydrogenization of one zigzag edge. - Abstract: We study spin states of edge modified nanographene molecules with rectangular and triangular shapes by first principle calculations using density functional theory (DFT) and Hartree–Fock (HF) methods with Møller–Plesset (MP) correlation energy correction at different levels. Anthracene (C 14 H 10 ) and phenalenyl (C 13 H 9 ), which contain three benzene rings combined in two different ways, can be considered as fragments of a graphene sheet. Carbon-based ferromagnetic materials are of great interest both in fundamental science and technological potential in organic spintronics devices. We show that non-magnetic rectangular molecules such as C 14 H 10 can become ferromagnetic with high-spin state as the ground state by dihydrogenization of one of the zigzag edges, while triangular molecules such as C 13 H 9 become ferromagnetic with high-spin state by dehydrogenization of one of the zigzag edges

  15. Dyes removal of textile wastewater onto surfactant modified zeolite from coal ash and evaluation of the toxic effects

    International Nuclear Information System (INIS)

    Ferreira, Patricia Cunico

    2015-01-01

    Zeolites synthesized from fly and bottom ashes and modified with hexadecyltrimethylammonium (HDTMA) were used as adsorbent to remove dyes - Solophenyl Navy (SN) and Solophenyl Turquoise (ST) and their hydrolysed forms Solophenyl Navy Hydrolysed (SNH) and Solophenyl Turquoise Hydrolysed (STH), from simulated textile wastewater. The HDTMA-modified fly zeolite (ZMF) and HDTMA-modified bottom zeolite (ZMB) were characterized by different techniques, as X-ray fluorescence spectrometry, X-ray diffraction and scanning electron microscopy, etc. The ZMF and ZMB presented negative charge probably due to the formation of a partial bilayer of HDTMA on exchangeable active sites on the external surface of unmodified zeolite. Initial dye concentration, contact time and equilibrium adsorption were evaluated. The adsorption kinetic for SN, ST, SNH and STH onto the zeolites followed the pseudo second-order model. The equilibrium time was 20 min for SN and ST and 30 min for SNH and STH, respectively. Langmuir, Freundlich and Temkin models were applied to describe the adsorption isotherms. Adsorption of the dyes were best described by the Langmuir model, with exception to SN/ZPM, SNH/ZPM and SNH/ZLM systems that followed Freundlich model. The maximum adsorption capacities were 3,64; 3,57; 2,91 e 4,93 for SN, ST, SNH e STH by ZLM, respectively and 0,235; 0,492; 1,26 e 1,86 by ZPM, in this order. The best performance for hydrolyzed dyes has been attributed to reduction of the size of dyes molecules during the hydrolysis process. Acute toxicity of the dyes to a different organism were evaluated by different test-organisms. Waterflea, Ceriodaphnia dubia showed EC50 value of 1,25; 54,5; 0,78 and 2,56 mgL -1 for SN, ST, SNH and STH, respectively. The plant Lemna minor showed EC50 values of 18,9; 69,4; 10,9 and 70,9 mgL -1 for SN, ST, SNH and STH, respectively. Midges larvae of Chironomus tepperi showed EC50 values of 119 and 440 mgL -1 for SN and ST, respectively. Regarding the adsorption

  16. Electrochemical Treatment of Wastewater Containing Mixed Reactive Dyes Using Carbon Nanotube Modified Cathode Electrodes

    Directory of Open Access Journals (Sweden)

    Nader Djafarzadeh

    2016-11-01

    Full Text Available Nowadays, advanced electrochemical oxidation processes are promising methods for the treatment of wastewaters containing organic dyes. One of these methods is the Electro-Fenton (EF technique in which an electrical current is applied to the cathode and anode electrodes to promote electrochemical reactions that generate hydroxyl radicals which mineralize organic pollutants and remove them from wastewater. To carry out the Electro-Fenton process iIn this work, the carbon paper (CP electrode was initially modified with carbon nanotubes (CNT to produce the CP-CNT electrode which was used as the cathode to remove a mixture of organic dyestuff (containing Reactive Blue 69, Reactive Red 195, and Reactive Yellow 84 from wastewaters. Comparison of the two types of cathode electrodes (i.e., CNT and the modified CP-CNT showed that the CP-CNT outperformed the CP electrode. The EF process was employed to treat 500 ml of a mixture of dyes (50 mg/L of each dye containing sodium soulfate and Fe+3 ions. The results revealed that the highest color removal efficiency was achieved when a current of 300 mA was applied for 210 min. COD measurments were used to calculate the effective current and power consumption. It was found that the 300 mA current applied over a period of 210 min yielded the highest effective current and the lowest power consumption. The amount of dyes mineralized by the EF process in the dye solution indicated that 78% of the initial COD had been removed under the above conditions. It may be concluded that the Electro-Fenton process can be successfully used for the treatment of wastewaters containing mixtures of dye pollutants. Cathode electrode type, electrical current, and electrolysis duration were identified as the parameters affecting the process.

  17. Single-Photon Source for Quantum Information Based on Single Dye Molecule Fluorescence in Liquid Crystal Host

    International Nuclear Information System (INIS)

    Lukishova, S.G.; Knox, R.P.; Freivald, P.; McNamara, A.; Boyd, R.W.; Stroud, Jr. C.R.; Schmid, A.W.; Marshall, K.L.

    2006-01-01

    This paper describes a new application for liquid crystals: quantum information technology. A deterministically polarized single-photon source that efficiently produces photons exhibiting antibunching is a pivotal hardware element in absolutely secure quantum communication. Planar-aligned nematic liquid crystal hosts deterministically align the single dye molecules which produce deterministically polarized single (antibunched) photons. In addition, 1-D photonic bandgap cholesteric liquid crystals will increase single-photon source efficiency. The experiments and challenges in the observation of deterministically polarized fluorescence from single dye molecules in planar-aligned glassy nematic-liquid-crystal oligomer as well as photon antibunching in glassy cholesteric oligomer are described for the first time

  18. Computational design of molecules for dye sensitized solar cells and nano electronics

    DEFF Research Database (Denmark)

    Ørnsø, Kristian Baruël

    sensitized solar cell (DSSC) in terms of a loss-less level alignment quality. This scoring only takes into account a simplified absorption spectrum of the dye in combination with the alignment between the molecular levels, the semi-conductor conduction band edge and the redox mediator. To improve on this...... a molecular junction, is by controlling the junction geometry. This is achieved by designing a molecule with two sets of anchor groups, which bind to gold with significantly different strengths. Hence, it is proposed that the geometry can be controlled by chemical passivisation of one type of anchor group....... Using a simple computational model, this experimental hypothesis is verified and the change in conductance upon changing junction geometry is reproduced....

  19. Resonant Pump-dump Quantum Control of Solvated Dye Molecules with Phase Jumps

    Science.gov (United States)

    Konar, Arkaprabha; Lozovoy, Vadim; Dantus, Marcos

    2014-03-01

    Quantum coherent control of two photon and multiphoton excitation processes in atomic and condensed phase systems employing phase jumps has been well studied and understood. Here we demonstrate coherent quantum control of a two photon resonant pump-dump process in a complex solvated dye molecule. Phase jump in the frequency domain via a pulse shaper is employed to coherently enhance the stimulated emission by an order of magnitude when compared to transform limited pulses. Red shifted stimulated emission from successive low energy Stokes shifted excited states leading to narrowband emission are observed upon scanning the pi step across the excitation spectrum. A binary search space routine was also employed to investigate the effects of other types of phase jumps on stimulated emission and to determine the optimum phase that maximizes the emission. Understanding the underlying mechanism of this kind of enhancement will guide us in designing pulse shapes for enhancing stimulated emission, which can be further applied in the field of imaging.

  20. A Research Module for the Organic Chemistry Laboratory: Multistep Synthesis of a Fluorous Dye Molecule.

    Science.gov (United States)

    Slade, Michael C; Raker, Jeffrey R; Kobilka, Brandon; Pohl, Nicola L B

    2014-01-14

    A multi-session research-like module has been developed for use in the undergraduate organic teaching laboratory curriculum. Students are tasked with planning and executing the synthesis of a novel fluorous dye molecule and using it to explore a fluorous affinity chromatography separation technique, which is the first implementation of this technique in a teaching laboratory. Key elements of the project include gradually introducing students to the use of the chemical literature to facilitate their searching, as well as deliberate constraints designed to force them to think critically about reaction design and optimization in organic chemistry. The project also introduces students to some advanced laboratory practices such as Schlenk techniques, degassing of reaction mixtures, affinity chromatography, and microwave-assisted chemistry. This provides students a teaching laboratory experience that closely mirrors authentic synthetic organic chemistry practice in laboratories throughout the world.

  1. Other origins for the fluorescence modulation of single dye molecules in open-circuit and short-circuit devices.

    Science.gov (United States)

    Teguh, Jefri S; Kurniawan, Michael; Wu, Xiangyang; Sum, Tze Chien; Yeow, Edwin K L

    2013-01-07

    Fluorescence intensity modulation of single Atto647N dye molecules in a short-circuit device and a defective device, caused by damaging an open-circuit device, is due to a variation in the excitation light focus as a result of the formation of an alternating electric current.

  2. Solution-Processed Organic Solar Cells from Dye Molecules: An Investigation of Diketopyrrolopyrrole:Vinazene Heterojunctions

    KAUST Repository

    Walker, Bright

    2012-01-25

    Although one of the most attractive aspects of organic solar cells is their low cost and ease of fabrication, the active materials incorporated into the vast majority of reported bulk heterojunction (BHJ) solar cells include a semiconducting polymer and a fullerene derivative, classes of materials which are both typically difficult and expensive to prepare. In this study, we demonstrate that effective BHJs can be fabricated from two easily synthesized dye molecules. Solar cells incorporating a diketopyrrolopyrrole (DPP)-based molecule as a donor and a dicyanoimidazole (Vinazene) acceptor function as an active layer in BHJ solar cells, producing relatively high open circuit voltages and power conversion efficiencies (PCEs) up to 1.1%. Atomic force microscope images of the films show that active layers are rough and apparently have large donor and acceptor domains on the surface, whereas photoluminescence of the blends is incompletely quenched, suggesting that higher PCEs might be obtained if the morphology could be improved to yield smaller domain sizes and a larger interfacial area between donor and acceptor phases. © 2011 American Chemical Society.

  3. Chemically Modified Polyvinyl Chloride for Removal of Thionine Dye (Lauth’s Violet

    Directory of Open Access Journals (Sweden)

    Helena Ma A. M. M. S. Ali

    2017-11-01

    Full Text Available The chemical modification of hydrophobic polymer matrices is an alternative way to elchange their surface properties. The introduction of sulfonic groups in the polymer changes the surface properties such as adhesion, wettability, catalytic ability, and adsorption capacity. This work describes the production and application of chemically modified polyvinyl chloride (PVC as adsorbent for dyes removal. Chemical modification of PVC was evaluated by infrared spectroscopy and elemental analysis, which indicated the presence of sulfonic groups on PVC. The chemically modified PVC (PVCDS showed an ion exchange capacity of 1.03 mmol−1, and efficiently removed the thionine dye (Lauth’s violet from aqueous solutions, reaching equilibrium in 30 min. The adsorption kinetics was better adjusted for a pseudo second order model. This result indicates that the adsorption of thionine onto PVCDS occurs by chemisorption. Among the models for the state of equilibrium, SIPS and Langmuir exhibited the best fit to the experimental results and PVCDS showed high adsorption capacities (370 mg−1. Thus, it is assumed that the system presents homogeneous characteristics to the distribution of active sites. The modification promoted the formation of surface characteristics favorable to the dye adsorption by the polymer.

  4. Behaviors and mechanism of acid dyes sorption onto diethylenetriamine-modified native and enzymatic hydrolysis starch

    International Nuclear Information System (INIS)

    Wang Zuohua; Xiang Bo; Cheng Rumei; Li Yijiu

    2010-01-01

    In this paper, different starches were modified by diethylenetriamine. The native starch reacted with diethylenetriamine giving CAS, whereas the enzymatic hydrolysis starch was modified by diethylenetriamine producing CAES. Adsorption capacities of CAES for four acid dyes, namely, Acid orange 7 (AO7), Acid orange 10 (AO10), Acid green 25 (AG25) and Acid red 18 (AR18) have been determined to be 2.521, 1.242, 1.798 and 1.570 mmol g -1 , respectively. In all cases, CAES has exhibited higher sorption ability than CAS, and the increment for these dyes took the sequence of AO7 (0.944 mmol g -1 ) > AO10 (0.592 mmol g -1 ) > AR18 (0.411 mmol g -1 ) > AG25 (0.047 mmol g -1 ). Sorption kinetics and isotherms analysis showed that these sorption processes were better fitted to pseudo-second-order equation and Langmuir equation. Chemical sorption mechanisms were confirmed by studying the effects of pH, ionic strength and hydrogen bonding. Thermodynamic parameters of these dyes onto CAES and CAS were also observed and it indicated that these sorption processes were exothermic and spontaneous in nature.

  5. Hydrothermally modified fly ash for heavy metals and dyes removal in advanced wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Visa, Maria, E-mail: maria.visa@unitbv.ro; Chelaru, Andreea-Maria, E-mail: andreea.chelaru1@yahoo.com

    2014-06-01

    Fly ash resulted from coal burning is a waste that can be used in wastewater treatment for removal of dyes and heavy metals by adsorption. Class “F” fly ash (FA), collected from the Central Heat and Power (CHP) Plant Brasov (Romania), with oxides composition SiO{sub 2}/Al{sub 2}O{sub 3} over 2.4 was used for obtaining a new substrate with good adsorption capacity for dyes and heavy metals from wastewater. A new material was obtained from modified fly ash with NaOH and hexadecyltrimethylammonium bromide (HTAB) a cationic surfactant. Contact time, optimum amount of substrate and the pH corresponding to 50 mL solution of pollutants were the parameters optimized for obtaining the maximum efficiency in the adsorption process. The optimized adsorption parameters were further used in thermodynamic and kinetic studies of the adsorption processes. The adsorption kinetic mechanisms, and the substrate capacities are further discussed correlated with the surface structure (XRD), composition (EDS, FTIR), and morphology (SEM, AFM). The results indicate that the novel nano-substrate composite with fly ash modified can be used as an efficient and low cost adsorbent for simultaneous removal of dyes and heavy metals, the resulted water respects the discharge regulations.

  6. Hydrothermally modified fly ash for heavy metals and dyes removal in advanced wastewater treatment

    International Nuclear Information System (INIS)

    Visa, Maria; Chelaru, Andreea-Maria

    2014-01-01

    Fly ash resulted from coal burning is a waste that can be used in wastewater treatment for removal of dyes and heavy metals by adsorption. Class “F” fly ash (FA), collected from the Central Heat and Power (CHP) Plant Brasov (Romania), with oxides composition SiO 2 /Al 2 O 3 over 2.4 was used for obtaining a new substrate with good adsorption capacity for dyes and heavy metals from wastewater. A new material was obtained from modified fly ash with NaOH and hexadecyltrimethylammonium bromide (HTAB) a cationic surfactant. Contact time, optimum amount of substrate and the pH corresponding to 50 mL solution of pollutants were the parameters optimized for obtaining the maximum efficiency in the adsorption process. The optimized adsorption parameters were further used in thermodynamic and kinetic studies of the adsorption processes. The adsorption kinetic mechanisms, and the substrate capacities are further discussed correlated with the surface structure (XRD), composition (EDS, FTIR), and morphology (SEM, AFM). The results indicate that the novel nano-substrate composite with fly ash modified can be used as an efficient and low cost adsorbent for simultaneous removal of dyes and heavy metals, the resulted water respects the discharge regulations.

  7. Adsorptioin performance of modified nkalagu bentonite in dye removal: kinetics, equilibrium, thermodynamics and structureal properties of the modified samples

    International Nuclear Information System (INIS)

    Ajemba, R.O.

    2015-01-01

    The adsorption performance of modified Nkalagu bentonite in removing Congo red (CR) from solution was investigated. The raw bentonite was modified by three different physicochemical methods: thermal activation (TA), acid activation (AA), and combined acid and thermal activation (ATA). The Congo red adsorption increased with increase in contact time, initial dye concentration, adsorbent dosage, temperature, and pH change. The results of the kinetics analysis of the adsorption data revealed that adsorption follows pseudo second-order kinetics. Analysis of the equilibrium data showed that Langmuir isotherm provided a better fit to the data. Evaluation of the thermodynamic parameters revealed that adsorption process is spontaneous and endothermic. The results from this study suggest that a combination of thermal and acid activation is an effective modification method to improve adsorption capacity of bentonite and makes the bentonite as low-cost adsorbent for removal of water pollutants. (author)

  8. Removal of Reactive Orange 16 Dye from Aqueous Solution by Using Modified Kenaf Core Fiber

    Directory of Open Access Journals (Sweden)

    Maytham Kadhim Obaid

    2016-01-01

    Full Text Available Evaluated removal of reactive orange 16 (RO16 dye from aqueous solution was studied in batch mode by using kenaf core fiber as low-cost adsorbents. In this attempt, kenaf core fiber with size 0.25–1 mm was treated by using (3-chloro-2-hydroxypropyl trimethylammonium chloride (CHMAC as quaternization agent. Then effective parameters include adsorbent dose, pH, and contact time and initial dye concentration on adsorption by modified kenaf core fiber was investigated. In addition, isotherms and kinetics adsorption studies were estimated for determination of the equilibrium adsorption capacity and reactions dynamics, respectively. Results showed that the best dose of MKCF was 0.1 g/100 mL, the maximum removal of RO16 was 97.25 at 30°C, pH = 6.5, and agitation speed was 150 rpm. The results also showed that the equilibrium data were represented by Freundlich isotherm with correlation coefficients R2=0.9924, and the kinetic study followed the pseudo-second-order kinetic model with correlation coefficients R2=0.9997 for Co=100 mg/L. Furthermore, the maximum adsorption capacity was 416.86 mg/g. Adsorption through kenaf was found to be very effective for the removal of the RO16 dye.

  9. Removal of blue 1 dye of aqueous solutions with a modified clay with iron chloride

    International Nuclear Information System (INIS)

    Hernandez H, K. A.

    2012-01-01

    At the present time, several technologies have been proposed to remove dyes from water, adsorption is one of the most feasible methods and adsorbents with different properties, such as activated carbon, zeolites, clays and hydrogels among others. In this work, the sorption behavior of blue 1 dye by a natural clay from a site located in the Center-East of Mexico, and other modified with iron chloride were determined. The materials were characterized by X-ray diffraction to analyze its crystal structure, by scanning electron microscopy and elemental microanalysis of energy dispersive X-ray spectrometry to determine the composition and morphology, and the zero point charges were also determined to know the charge distribution on the surface of the clay. The ph effect, contact time, dye concentration and temperature were the parameters considered in this study. The results showed that clay does not suffer any important changes in its structure after the chemical treatments (modification with ferric chloride and contact with blue 1 solutions). The ph influences lightly the adsorption of the dye with natural clay, but the same effect is not observed in the ferric modified clay among the factor ph 6 and 8. The equilibrium time and the sorption capacity for natural clay were 48 hours and 6.16 mg/g, while for the ferric clay were 24 hours and 14.22 mg/g. Adsorption kinetics results were best adjusted to the pseudo first and pseudo second order models. Adsorption isotherms were best adjusted to the Langmuir model, indicating that both clays have a homogeneous surface. Thermodynamic parameters (E, ΔS and ΔG and ΔH) were calculated for the dye adsorption by the natural clay using data of the adsorption kinetics at temperatures between 20 and 50 C, indicating that the adsorption process is exothermic. For the case of ferric clay, it was not possible to calculate these thermodynamic parameters because the adsorption capacities were similar in the range of selected

  10. Textile Dye Removal from Aqueous Solution using Modified Graphite Waste/Lanthanum/Chitosan Composite

    Science.gov (United States)

    Kusrini, E.; Wicaksono, B.; Yulizar, Y.; Prasetyanto, EA; Gunawan, C.

    2018-03-01

    We investigated various pre-treatment processes of graphite waste using thermal, mechanical and chemical methods. The aim of this work is to study the performance of modified graphite waste/lanthanum/chitosan composite (MG) as adsorbent for textile dye removal from aqueous solution. Effect of graphite waste resources, adsorbent size and lanthanum concentration on the dye removal were studied in batch experiments. Selectivity of MG was also investigated. Pre-heated graphite waste (NMG) was conducted at 80°C for 1 h, followed by mechanical crushing of the resultant graphite to 75 μm particle size, giving adsorption performance of ˜58%, ˜67%, ˜93% and ˜98% of the model dye rhodamine B (concentration determined by UV-vis spectroscopy at 554 nm), methyl orange (464 nm), methylene blue (664 nm) and methyl violet (580 nm), respectively from aqueous solution. For this process, the system required less than ˜5 min for adsorbent material to be completely saturated with the adsorbate. Further chemical modification of the pre-treated graphite waste (MG) with lanthanum (0.01 – V 0.03 M) and chitosan (0.5% w/w) did not improve the performance of dye adsorption. Under comparable experimental conditions, as those of the ‘thermal-mechanical-pre-treated-only’ (NMG), modification of graphite waste (MG) with 0.03 M lanthanum and 0.5% w/w chitosan resulted in ˜14%, ˜47%, ˜72% and ˜85% adsorption of rhodamine B, methyl orange, methylene blue and methyl violet, respectively. Selective adsorption of methylene blue at most to ˜79%, followed by methyl orange, methyl violet and rhodamine B with adsorption efficiency ˜67, ˜38, and ˜9% sequentially using MG with 0.03 M lanthanum and 0.5% w/w chitosan.

  11. 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.

  12. Pre-concentration and determination of tartrazine dye from aqueous solutions using modified cellulose nanosponges.

    Science.gov (United States)

    Shiralipour, Roohollah; Larki, Arash

    2017-01-01

    In this study, a new absorbent based on cellulose nanosponges modified with methyltrioctylammonium chloride (aliquat 336) was prepared and used for pre-concentration, removal and determination of tartrazine dye, using UV-vis spectrophotometry. This adsorbent was fully characterized using various instrumental techniques such as SEM, FTIR and XRD spectra. The pre-concentration and removal procedures were studied in column and batch modes, respectively. The effects of parameters such as pH of the aqueous medium, methyltrioctylammounium chloride dose, adsorbent amount, desorbing conditions and interfering ions on the adsorption of tartrazine were investigated and optimized. The fitting experimental data with conventional isotherm models revealed that the adsorption followed the Brunauer-Emmett-Teller (BET) model and the maximum adsorption capacity for tartrazine was 180mg/g with modified nanosponges. Under the optimized conditions, the calibration curve was linear over the range of 2-300ng/mL and the limit of detection was 0.15ng/mL. The relative standard deviation (RSD) for 20 and 100ng/mL of tartrazine were 3.1% and 1.5%, respectively. The proposed method was applied for pre-concentration and determination of tartrazine dye in different water samples. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Removal of Disperse Blue 56 and Disperse Red 135 dyes from aqueous dispersions by modified montmorillonite nanoclay

    Directory of Open Access Journals (Sweden)

    Ahmadishoar Javad

    2017-01-01

    Full Text Available In this study modified montmorillonite was used as an adsorbent for the removal of two selected disperse dyes i.e., Disperse Blue 56 (DB and Disperse Red 135 (DR from dye dispersions. The adsorption equilibrium data of dyes adsorption were investigated by using Nernst, Freundlich and Langmuir isotherm models. The adsorption kinetics was analyzed by using different models including pseudo-first-order, pseudo-second-order, Elovich and Intraparticle diffusion model. The Freundlich isotherm was found to be the most appropriate model for describing the sorption of the dyes on modified nanoclay. The best fit to the experimental results was obtained by using the pseudo-second-order kinetic equation, which satisfactorily described the process of dye adsorption. Although different kinetic models may control the rate of the adsorption process, the results indicated that the main rate limiting step was the intraparticle diffusion. The results showed that the proposed modified montmorillonite could be used as an effective adsorbent for the removal of disperse dyes even from highly concentrated dispersions.

  14. PALS investigations of matrix Vycor glass doped with molecules of luminescent dye and silver nanoparticles. Discrepancies from the ETE model

    Directory of Open Access Journals (Sweden)

    Gorgol Marek

    2015-12-01

    Full Text Available A thermal stability of three materials: undoped reference Vycor glass, glass filled with ROT-305 red dye, and silver nanoparticles was investigated by positron annihilation lifetime spectroscopy (PALS in a broad temperature range (from 93 to 473 K. The attempt of pore size calculations from the ortho-positronium lifetime data was performed using the extended Tao-Eldrup (ETE model. Below room temperature, a significant decrease in lifetime values of the longest-lived component was found for all the samples. This effect could not be explained by thermal shrinkage of the material and is probably caused by interaction of o-Ps with a Vycor glass matrix. The greatest discrepancy from the ETE model predictions was observed for the reference glass. Doping the base material with dye molecules and silver nanoparticles resulted in similar small decrease in this discrepancy. After reheating the samples to the room temperature, the PALS components returned to the initial values. In the temperature range of 293–473 K, quite good agreement between PALS results and the ETE model predictions was observed for the reference glass and the glass incorporated with dye molecules. The observed small discrepancy in this range could possibly be partly explained by thermal expansion of the material. For the glass doped with silver nanoparticles, a significant change in PALS parameters was observed in the temperature range from 403 to 473 K.

  15. Evaluation of the adsorbent properties of a zeolite rock modified for the removal of the azo dyes as water pollutants

    International Nuclear Information System (INIS)

    Torres P, J.

    2005-01-01

    At the moment some investigations which make reference to the removal of dyes for diverse adsorbent materials; as well as the factors that influence in the sorption process, considering the type so much of dye as those characteristics of the adsorbent material. In this work were investigated those adsorbent properties of a zeolite rock coming from San Luis Potosi State for the removal of azo dyes, using as peculiar cases the Red 40 (Red Allura) and the Yellow 5 (Tartrazine); for it were determined kinetic parameters and the sorption isotherms, as well as the sorption mechanisms involved in each case, between the dyes and the zeolite rock. In this work also it was considered the characterization before and after to removal of color from the water, through advanced analytical techniques such as the scanning electron microscopy of high vacuum (SEM), elementary microanalysis (EDS) and X-ray diffraction (XRD). The experimental part of the work fundamentally consisted, in the conditioning with a NaCl solution and later on the modification with HDTMA-Br of the natural zeolite rock, for then to put it in contact with solutions of the dyes R-40 and A-5, varying so much the contact times as the concentrations; the quantification of sodium in the liquid phase after the modification of the zeolite rock to determine the capacity of external cation exchange (CICE) it was carried out by means of the atomic absorption spectroscopy technique (EAA), and the quantification of the surfactant and the dyes in the liquid phase, it was carried out by means of the UV-vis spectrophotometry technique. It was found that the kinetic model that better it describes the process of sorption of R-40 and A-5 for the modified zeolite rock with HDTMA-Br, leaving of monocomponent and bi component solutions, it is the pseudo- second order. Inside of the obtained results for the sorption isotherms, as much the dye R-40 as the dye A-5 its presented a better adjustment to the Langmuir model. In what refers

  16. ABTS-Modified Silica Nanoparticles as Laccase Mediators for Decolorization of Indigo Carmine Dye

    Directory of Open Access Journals (Sweden)

    Youxun Liu

    2015-01-01

    Full Text Available Efficient reuse and regeneration of spent mediators are highly desired for many of the laccases’ biotechnology applications. This investigation demonstrates that a redox mediator 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS covalently attached to silica nanoparticles (SNPs effectively mediated dye decolorization catalyzed by laccase. Characteristics of ABTS-modified silica nanoparticles (ABTS-SNPs were researched by scanning electron microscopy and Fourier-transformed infrared spectroscopy. When ABTS and ABTS-SNPs were used as laccase mediators, the decolorization yields of 96 and 95% were, respectively, obtained for indigo carmine dye. The results suggest that ABTS immobilized on SNPs can be used as laccase mediators as they retain almost the same efficiency as the free ABTS. The oxidized ABTS-SNPs were regenerated by their reduction reaction with ascorbic acid. Decolorization efficiency of regenerated ABTS-SNPs and their initial forms were found to be almost equivalent. Six reuse cycles for spent ABTS-SNPs were run for the treatment of indigo carmine, providing decolorization yields of 96–77%. Compared with free mediator, the immobilized mediators have the advantage of being easily recovered, regenerated, and reused making the whole process environmentally friendly.

  17. Energy transfer dynamics from individual semiconductor nanoantennae to dye molecules with implication to light-harvesting nanosystems

    Science.gov (United States)

    Shan, Guangcun; Hu, Mingjun; Yan, Ze; Li, Xin; Huang, Wei

    2018-03-01

    Semiconductor nanocrystals can be used as nanoscale optical antennae to photoexcite individual dye molecules in an ensemble via energy transfer mechanism. The theoretical framework developed by Förster and others describes how electronic excitation migrates in the photosynthetic apparatus of plants, algae, and bacteria from light absorbing pigments to reaction centers where light energy is utilized for the eventual conversion into chemical energy. Herein we investigate the effect of the average donor-acceptor spacing on the time-resolved fluorescence intensity and dynamics of single donor-acceptor pairs with the dye acceptor concentration decreasing by using quantum Monte-Carlo simulation of FRET dynamics. Our results validated that the spatial disorder controlling the microscopic energy transfer rates accounts for the scatter in donor fluorescence lifetimes and intensities, which provides a new design guideline for artificial light-harvesting nanosystems.

  18. Enhanced performance of dye-sensitized solar cells using gold nanoparticles modified fluorine tin oxide electrodes

    International Nuclear Information System (INIS)

    Zhang Dingwen; Shen Jie; Huang Sumei; Wang Milton; Brolo, Alexandre G; Li Xiaodong

    2013-01-01

    We have investigated plasmon-assisted energy conversion in dye-sensitized solar cells (DSCs) applying gold nanoparticles (NPs) modified fluorine tin oxide (FTO) electrodes. A series of Au NPs with different sizes (15-80 nm) were synthesized and immobilized onto FTO glass slides. Photoanodes were prepared on these Au modified FTO substrates using P25 TiO 2 powders and by the screen-printing method. The size effects of Au NPs on the photovoltaic performance of the formed DSCs were investigated systematically. Structural and photoelectrochemical properties of the formed photoanodes were examined by field emission scanning electron microscopy and electrochemical impedance spectroscopy. It was found that the energy conversion efficiency of the DSC was highly dependent on the Au particle size. When the particle size was not greater than 60 nm, the DSC based on the Au NP-FTO composite electrode showed a higher short-circuit current density and better photovoltaic (PV) performance than the cell based on the bare FTO. The best cell was achieved using 25 nm sized Au NPs modified FTO. It exhibited a conversion efficiency of 6.69%, which was 15% higher than that of DSCs without Au NPs. The related PV performance enhancement mechanisms, photoelectrochemical processes and surface-plasmon resonances in DSCs with Au nanostructures are analysed and discussed.

  19. Utilization of chemically modified citrus reticulata peels for biosorptive removal of acid yellow-73 dye from water

    International Nuclear Information System (INIS)

    Rehman, R.; Salman, M.; Mahmud, T.; Kanwal, F.; Zaman, W.

    2013-01-01

    Textile effluents contain several varieties of natural and synthetic dyes, which are non-biodegradable. Acid Yellow-73 is one of them. In this research work, adsorptive removal of this dye was investigated using chemically modified Citrus reticulata peels, in batch mode. It was noted that adsorption of dye on Citrus reticulata peels increased by increasing contact time and decreased in basic pH conditions. Langmuir and Freundlich isothermal models were followed by equilibrium data, but the first isotherm fitted the data better, showing that chemisorption occurred more as compared to physiosorption, showing maximum adsorption capacity 96.46 mg.g-1.L-1. The thermodynamic study showed that adsorption of Acid Yellow-73 on chemically modified Citrus reticulata peels was favorable in nature, following pseudo-second order kinetics. (author)

  20. Ultra-small dye-doped silica nanoparticles via modified sol-gel technique

    Science.gov (United States)

    Riccò, R.; Nizzero, S.; Penna, E.; Meneghello, A.; Cretaio, E.; Enrichi, F.

    2018-05-01

    In modern biosensing and imaging, fluorescence-based methods constitute the most diffused approach to achieve optimal detection of analytes, both in solution and on the single-particle level. Despite the huge progresses made in recent decades in the development of plasmonic biosensors and label-free sensing techniques, fluorescent molecules remain the most commonly used contrast agents to date for commercial imaging and detection methods. However, they exhibit low stability, can be difficult to functionalise, and often result in a low signal-to-noise ratio. Thus, embedding fluorescent probes into robust and bio-compatible materials, such as silica nanoparticles, can substantially enhance the detection limit and dramatically increase the sensitivity. In this work, ultra-small fluorescent silica nanoparticles (NPs) for optical biosensing applications were doped with a fluorescent dye, using simple water-based sol-gel approaches based on the classical Stöber procedure. By systematically modulating reaction parameters, controllable size tuning of particle diameters as low as 10 nm was achieved. Particles morphology and optical response were evaluated showing a possible single-molecule behaviour, without employing microemulsion methods to achieve similar results. [Figure not available: see fulltext.

  1. Two-Sided Surface Oxidized Cellulose Membranes Modified with PEI: Preparation, Characterization and Application for Dyes Removal

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2017-09-01

    Full Text Available Porous regenerated cellulose (RC membranes were prepared with cotton linter pulp as a raw material. These membranes were first oxidized on both sides by a modified (2,2,6,6-tetramethylpiperidin-1-yloxyl (TEMPO oxidation system using a controlled oxidation reaction technique. Then, the oxidized RC membranes were functionalized with polyethylenimine (PEI via the glutaraldehyde crosslinking method to obtain bifunctional (carboxyl and amino porous RC membranes, as revealed by Fourier transform infrared spectroscopy (FT-IR, elemental analysis and zeta potential measurement. The scanning electron microscopy (SEM and the tests of the mechanical properties and permeability characteristics of modified RC membranes demonstrated that the porous structure and certain mechanical properties could be retained. The adsorption performance of the modified membranes towards dyes was subsequently investigated. The modified membranes displayed good adsorption capacities, rapid adsorption equilibrium and removal efficiencies towards both anionic (xylenol orange (XO and cationic (methylene blue (MB dyes, making them suitable bioadsorbents for wastewater treatment.

  2. Adsorption of a reactive dye on chemically modified activated carbons--influence of pH.

    Science.gov (United States)

    Orfão, J J M; Silva, A I M; Pereira, J C V; Barata, S A; Fonseca, I M; Faria, P C C; Pereira, M F R

    2006-04-15

    The surface chemistry of a commercial activated carbon with a slightly basic nature was modified by appropriate treatments in order to obtain two additional samples, respectively with acidic and basic properties, without changing its textural parameters significantly. Different techniques (N2 adsorption at 77 K, temperature programmed desorption, and determination of acidity, basicity, and pH at the point of zero charge) were used to characterize the adsorbents. Kinetic and equilibrium adsorption data of a selected textile reactive dye (Rifafix Red 3BN, C.I. reactive red 241) on the mentioned materials were obtained at the pH values of 2, 7, and 12. The kinetic curves are fitted using the second-order model. The respective rate constants seem to diminish progressively with the initial concentration for the more diluted solutions tested, reaching a constant value at higher concentrations, which depends on the experimental system under consideration (adsorbent and pH). In general, the Langmuir model provides the best fit for the equilibrium data. The different uptakes obtained are discussed in relation to the surface chemical properties of the adsorbents. It is shown that the adsorption of the reactive (anionic) dye on the basic sample (prepared by thermal treatment under H2 flow at 700 degrees C) is favored. This conclusion is explained on the basis of the dispersive and electrostatic interactions involved. Moreover, it is also shown that the optimal adsorption condition for all the activated carbons tested corresponds to solution pH values not higher than the pH(pzc) of the adsorbents, which may be interpreted by taking into account the electrostatic forces present.

  3. In Situ Mapping of the Molecular Arrangement of Amphiphilic Dye Molecules at the TiO 2 Surface of Dye-Sensitized Solar Cells

    KAUST Repository

    Voï tchovsky, Kislon; Ashari-Astani, Negar; Tavernelli, Ivano; Té treault, Nicolas; Rothlisberger, Ursula; Stellacci, Francesco; Grä tzel, Michael; Harms, Hauke A.

    2015-01-01

    © 2015 American Chemical Society. Amphiphilic sensitizers are central to the function of dye-sensitized solar cells. It is known that the cell's performance depends on the molecular arrangement and the density of the dye on the semiconductor surface

  4. Modified Multiwalled Carbon Nanotubes for Treatment of Some Organic Dyes in Wastewater

    Directory of Open Access Journals (Sweden)

    M. I. Mohammed

    2014-01-01

    Full Text Available In Iraq, a large quantity of basic orange and methyl violet dyes contaminated wastewater from textile industries is discharged into Tigris River. So the aim of this work is to found an efficient and fast technique that can be applied directly for removal of such dyes from the wastewater before discharging into river. Accordingly, CNTs as a new approach prepared by CCVD technique were purified, functionalized, and used as adsorption material to remove dyes from wastewater. The effect of pH, contact time, CNTs dosage, and dyes concentration on removal of pollutants was studied. The removal percentage of both dyes was proportional to the contact time, CNTs dosage, and pH and inversely proportional to the dyes concentration. The results show that the equilibrium time was 20 and 30 min for basic orange and methyl violet dyes, respectively, and the maximum removal percentage for all dyes concentrations was at pH = 8.5 and CNTs dosage of 0.25 g/L and 0.3 g/L for methyl violet and basic orange dye, respectively. The adsorption isotherm shows that the correlation coefficient of Freundlich model was higher than Langmuir model for both dyes, indicating that the Freundlich model is more appropriate to describe the adsorption characteristics of organic pollutants.

  5. Multilayer Choline Phosphate Molecule Modified Surface with Enhanced Cell Adhesion but Resistance to Protein Adsorption.

    Science.gov (United States)

    Chen, Xingyu; Yang, Ming; Liu, Botao; Li, Zhiqiang; Tan, Hong; Li, Jianshu

    2017-08-22

    Choline phosphate (CP), which is a new zwitterionic molecule, and has the reverse order of phosphate choline (PC) and could bind to the cell membrane though the unique CP-PC interaction. Here we modified a glass surface with multilayer CP molecules using surface-initiated atom-transfer radical polymerization (SI-ATRP) and the ring-opening method. Polymeric brushes of (dimethylamino)ethyl methacrylate (DMAEMA) were synthesized by SI-ATRP from the glass surface. Then the grafted PDMAEMA brushes were used to introduce CP groups to fabricate the multilayer CP molecule modified surface. The protein adsorption experiment and cell culture test were used to evaluate the biocompatibility of the modified surfaces by using human umbilical veinendothelial cells (HUVECs). The protein adsorption results demonstrated that the multilayer CP molecule decorated surface could prevent the adsorption of fibrinogen and serum protein. The adhesion and proliferation of cells were improved significantly on the multilayer CP molecule modified surface. Therefore, the biocompatibility of the material surface could be improved by the modified multilayer CP molecule, which exhibits great potential for biomedical applications, e.g., scaffolds in tissue engineering.

  6. Effects of modified TiO{sub 2} photoanode on the photoelectrochemical properties of dye sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Shengli, E-mail: luvictory@hotmail.com [School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou 310023 (China); Sun, Sam-Shajing [Ph.D. Program in Materials Science and Engineering and Center for Materials Research, Norfolk State University, Norfolk, VA 23504 (United States); Geng, Rui [School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou 310023 (China); College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310000 (China); Gao, Jianrong [College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310000 (China)

    2015-08-31

    The study of nanoporous TiO{sub 2} electrodes modified by magnesium and manganese acetates in dye sensitized solar cells was reported. The formation and composition of modified electrodes were characterized by X-ray photoelectron spectroscopy and X-ray diffraction, revealing that MgO and Mn(OH)O were formed after magnesium acetate and manganese acetate treatments. Sunlight absorbance was also enhanced after such modification as supported by UV–vis spectra. The effects of modification include the increase of the dye adsorption, open-circuit voltage, short-circuit current density, and photoelectric conversion efficiency of the fabricated devices. The mechanisms of electron transfer, charge recombination, and electron lifetime were investigated by dark current and electrochemical impedance spectroscopy. - Highlights: • A simple dip coating process was used to modify the TiO{sub 2} electrode surface. • The loaded dye was increased and the lifetime of electrons in TiO{sub 2} was extended. • DSSC efficiency of 5.3% based on magnesium acetate modified TiO{sub 2} was obtained.

  7. Preparation of tetraethylenepentamine modified magnetic graphene oxide for adsorption of dyes from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Xiaosheng [Hubei Normal University (China); Tang, Ping; Liu, Liangliang, E-mail: liuliangliang@caas.cn [Chinese Academy of Agricultural Sciences, Changsha (China)

    2018-05-01

    In this study, tetraethylenepentamine modified magnetic graphene oxide nanomaterial (TMGO) was prepared and characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and vibration sample magnetometer (VSM). All the characterizations proved that the modification and preparation of TMGO were successful. The TMGO nanomaterial was used in the adsorption of Acid Red 18 (AR) in aqueous solution. The parameters like pH of solution, adsorption kinetics and isotherms were all investigated. The results indicated that the TMGO nanomaterial had satisfied adsorption ability and the maximum adsorption capacity was 524.2 mg g{sup -}'1 at 45 °C and pH 6. The adsorption capacity remained at 91.8% of the initial value after five cycles. The adsorption process with AR was found through fitting the pseudo-second-order kinetics equations and the Freundlich adsorption model. The experimental results demonstrated that the TMGO nanomaterial could be rapidly extracted from the medium and had a good adsorption ability to remove dyes in wastewater. (author)

  8. COMPARATIVE STUDIES OF PHYSICAL CHARACTERISTICS OF RAW AND MODIFIED SAWDUST FOR THEIR USE AS ADSORBENTS FOR REMOVAL OF ACID DYE

    Directory of Open Access Journals (Sweden)

    Jivan Singh

    2011-05-01

    Full Text Available The present paper aims to investigate the physical characteristics of sawdust relative to its use as an adsorbent for removal of an acid dye (Orange G from aqueous solutions. The raw sawdust was sieved to have a uniform size and was activated by sulphuric acid by refluxing the content at 60 oC for 4 h. Surface morphology and surface functional groups of both raw and modified sawdust samples were investigated by Scanning Electron Microscope (SEM, Energy Dispersive X-ray Analysis (EDX, Fourier Transformation Infrared (FTIR, and elemental analysis. All these analyses displayed significant change in the structure of the sawdust. The data obtained from batch adsorption experiments for the removal of the selected dye confirmed that adsorption characteristics of the modified sawdust were better than those of raw sawdust.

  9. Identification of a cytotoxic molecule in heat-modified citrus pectin.

    Science.gov (United States)

    Leclere, Lionel; Fransolet, Maude; Cambier, Pierre; El Bkassiny, Sandy; Tikad, Abdellatif; Dieu, Marc; Vincent, Stéphane P; Van Cutsem, Pierre; Michiels, Carine

    2016-02-10

    Modified forms of citrus pectin possess anticancer properties. However, their mechanism of action and the structural features involved remain unclear. Here, we showed that citrus pectin modified by heat treatment displayed cytotoxic effects in cancer cells. A fractionation approach was used aiming to identify active molecules. Dialysis and ethanol precipitation followed by HPLC analysis evidenced that most of the activity was related to molecules with molecular weight corresponding to low degree of polymerization oligogalacturonic acid. Heat-treatment of galacturonic acid also generated cytotoxic molecules. Furthermore, heat-modified galacturonic acid and heat-fragmented pectin contained the same molecule that induced cell death when isolated by HPLC separation. Mass spectrometry analyses revealed that 4,5-dihydroxy-2-cyclopenten-1-one was one cytotoxic molecule present in heat-treated pectin. Finally, we synthesized the enantiopure (4R,5R)-4,5-dihydroxy-2-cyclopenten-1-one and demonstrated that this molecule was cytotoxic and induced a similar pattern of apoptotic-like features than heat-modified pectin. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Improvement of the electrochromic response of a low-temperature sintered dye-modified porous electrode using low-resistivity indium tin oxide nanoparticles

    International Nuclear Information System (INIS)

    Watanabe, Yuichi; Suemori, Kouji; Hoshino, Satoshi

    2016-01-01

    An indium tin oxide (ITO) nanoparticle-based porous electrode sintered at low temperatures was investigated as a transparent electrode for electrochromic displays (ECDs). The electrochromic (EC) response of the dye-modified ITO porous electrode sintered at 150 °C, which exhibited a generally low resistivity, was markedly superior to that of a conventional dye-modified TiO 2 porous electrode sintered at the same temperature. Moreover, the EC characteristics of the dye-modified ITO porous electrode sintered at 150 °C were better than those of the high-temperature (450 °C) sintered conventional dye-modified TiO 2 porous electrode. These improvements in the EC characteristics of the dye-modified ITO porous electrode are attributed to its lower resistivity than that of the TiO 2 porous electrodes. In addition to its sufficiently low resistivity attained under the sintering conditions required for flexible ECD applications, the ITO porous film had superior visible-light transparency and dye adsorption capabilities. We conclude that the process temperature, resistivity, optical transmittance, and dye adsorption capability of the ITO porous electrode make it a promising transparent porous electrode for flexible ECD applications.

  11. The Adsorption Geometry and Electronic Structure of Organic Dye Molecule on TiO2(101 Surface from First Principles Calculations

    Directory of Open Access Journals (Sweden)

    Niu Mang

    2017-01-01

    Full Text Available Using density functional theory (DFT, we have investigated the structural and electronic properties of dye-sensitized solar cells (DSSCs comprised of I-doped anatase TiO2(101 surface sensitized with NKX-2554 dye. The calculation results indicate that the cyanoacrylic acid anchoring group in NKX-2554 has a strong binding to the TiO2(101 surface. The dissociative and bidentate bridging type was found to be the most favorable adsorption configuration. On the other hand, the incorporations of I dopant can reduce the band gap of TiO2 photoanode and improve the of NKX-2554 dye, which can improve the visible-light absorption of anatase TiO2 and can also facilitate the electron injection from the dye molecule to the TiO2 substrate. As a result, the I doping can significantly enhance the incident photon-to-current conversion efficiency (IPCE of DSSCs.

  12. Towards the coupling of single photons from dye molecules to a photonic waveguide

    Science.gov (United States)

    Polisseni, Claudio; Kho, Kiang Wei; Major, Kyle; Grandi, Samuele; Boisser, Sebastien; Hwang, Jaesuk; Clark, Alex; Hinds, Edward

    Single photons are very attractive for quantum information processing given their long coherence time and their ability to carry information in many degrees of freedom. A current challenge is the efficient generation of single photons in a photonic chip in order to scale up the complexity of quantum operations. We have proposed that a dibenzoterrylene (DBT) molecule inside an anthracene (AC) crystal could couple lifetime-limited indistinguishable single photons into a photonic waveguide if deposited in its vicinity. In this talk I describe the recent progress towards the realization of this proposal. A new method has been developed for evaporating AC and DBT to produce crystals that are wide and thin. The crystals are typically several microns across and have remarkably uniform thickness, which we control between 20 and 150 nm. The crystal growth is carried out in a glove bag in order to exclude oxygen, which improves the photostability of the DBT molecules by orders of magnitude. We image the fluorescence of single DBT molecules using confocal microscopy and analyse the polarization of this light to determine the alignment of the molecules. I will report on our efforts to control the alignement of the molecules by aligning the host matrix with the substrate.

  13. Reactive Pad-Steam Dyeing of Cotton Fabric Modified with Cationic P(St-BA-VBT Nanospheres

    Directory of Open Access Journals (Sweden)

    Kuanjun Fang

    2018-05-01

    Full Text Available The Poly[Styrene-Butyl acrylate-(P-vinylbenzyl trimethyl ammonium chloride] P(St-BA-VBT nanospheres with N+(CH33 functional groups were successfully prepared and applied to modify cotton fabrics using a pad-dry process. The obtained cationic cotton fabrics were dyed with pad-steam dyeing with reactive dye. The results show that the appropriate concentration of nanospheres was 4 g/L. The sodium carbonate of 25 g/L and steaming time of 3 min were suitable for dyeing cationic cotton with 25 g/L of C.I. Reactive Blue 222. The color strength and dye fixation rates of dyed cationic cotton fabrics increased by 39.4% and 14.3% compared with untreated fabrics. Moreover, sodium carbonate and steaming time were reduced by 37.5% and 40%, respectively. The rubbing and washing fastness of dyed fabrics were equal or higher 3 and 4–5 grades, respectively. Scanning electron microscopy (SEM images revealed that the P(St-BA-VBT nanospheres randomly distributed and did not form a continuous film on the cationic cotton fiber surfaces. The X-ray photoelectron spectroscopy (XPS analysis further demonstrated the presence of cationic nanospheres on the fiber surfaces. The cationic modification did not affect the breaking strength of cotton fabrics.

  14. The modified connection formulae for the rotational transition cross sections in diatomic molecules for slow collisions

    International Nuclear Information System (INIS)

    Ostrovsky, V.N.; Ustimov, V.I.

    1984-01-01

    The formulae connecting the cross sections for various rotational transitions in diatomic molecules colliding with atomic particles are valid in the framework of the sudden approximation. In order to extend the applicability domain of these formulae to the slow-collision region a semi-empirical correction factor is introduced with an exponential dependence on the translation rotation energy transfer and on the inverse collision velocity. The modified connection formulae are applied to the rotational transitions in an HD molecule colliding with an H 2 molecule. (author)

  15. Preparation of surface modified zinc oxide nanoparticle with high capacity dye removal ability

    International Nuclear Information System (INIS)

    Mahmoodi, Niyaz Mohammad; Najafi, Farhood

    2012-01-01

    Highlights: ► Amine-functionalized zinc oxide nanoparticle (AFZON) was synthesized. ► Isotherm and kinetics data followed Langmuir isotherm and pseudo-second order kinetic model, respectively. ► Q 0 of ZON for AB25, DR23 and DR31 was 20, 12 and 15 mg/g, respectively. ► Q 0 of AFZON for AB25, DR23 and DR31 was 1250, 1000 and 1429 mg/g, respectively. ► AFZON was regenerated at pH 12. -- Abstract: In this paper, the surface modification of zinc oxide nanoparticle (ZON) by amine functionalization was studied to prepare high capacity adsorbent. Dye removal ability of amine-functionalized zinc oxide nanoparticle (AFZON) and zinc oxide nanoparticle (ZON) was also investigated. The physical characteristics of AFZON were studied using Fourier transform infrared (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD). Acid Blue 25 (AB25), Direct Red 23 (DR23) and Direct Red 31 (DR31) were used as model compounds. The effect of operational parameters such as dye concentration, adsorbent dosage, pH and salt on dye removal was evaluated. The isotherm and kinetic of dye adsorption were studied. The maximum dye adsorption capacity (Q 0 ) was 20 mg/g AB25, 12 mg/g DR23 and 15 mg/g DR31 for ZON and 1250 mg/g AB25, 1000 mg/g DR23 and 1429 mg/g DR31 for AFZON. It was found that dye adsorption followed Langmuir isotherm. Adsorption kinetic of dyes was found to conform to pseudo-second order kinetics. Dye desorption tests (adsorbent regeneration) showed that the maximum dye release of 90% AB25, 86% for DR23 and 90% for DR31 were achieved in aqueous solution at pH 12. Based on the data of the present investigation, it can be concluded that the AFZON being an adsorbent with high dye adsorption capacity might be a suitable alternative to remove dyes from colored aqueous solutions.

  16. Reuse of effluent from dyeing process of polyamide fibers modified by double barrier discharge (DBD) plasma

    OpenAIRE

    Oliveira, Fernando Ribeiro; Steffens, F.; Souto, A. Pedro; Zille, Andrea

    2016-01-01

    Published online: 27 Feb 2015 Low-temperature plasma technology becomes more and more attractive compared with traditional wet processes in textile preparation and finishing due to its high efficiency and low environmental impact. The objective of this study was to investigate the influence of dielectric barrier discharge plasma treatment on the trichromic dyeing process of polyamide 6.6 (PA66) and the reuse of the generated effluents for new dyeing processes. Chemical and physical charact...

  17. Equilibrium, kinetics and thermodynamics studies of textile dyes adsorption on modified Tunisian clay

    Directory of Open Access Journals (Sweden)

    naghmouchi nahed

    2016-04-01

    Full Text Available The adsorption capacity of two anionic textile dyes (RR120 and BB150 on DMSO intercalated Tunisian raw clay was investigated with respect to contact time, initial dye concentration, pH and Temperature. The equilibrium data were fitted into Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherms. The kinetic parameters were calculated using pseudo-first order, pseudo second-order, intra-particle diffusion and Elovich kinetic models. The thermodynamic parameters (DH°, DS° and DG° of the adsorption process were also evaluated.

  18. Visible light assisted photodegradation of halocarbons on the dye modified TiO{sub 2} surface using visible light

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Debabrata; Dasgupta, Shimanti [Chemistry Section, Central Mechanical Engineering Research Institute, Durgapur 713209 (India); N Rao, Nageswar [Wastewater Technology Division, National Environmental Engineering Research Institute, Nagpur 400020 (India)

    2006-05-05

    Visible light assisted photodegradation of various halocarbons, viz. chloro-phenols, trichloroethylene, 1,2-dichloroethane and 1,4-dichlorobenzene, has been achieved on the surface of dye-modified TiO{sub 2} semiconductor. Thionine, eosinY, rhodamineB, methyleneblue, nileblueA and safranineO were used for the modification of TiO{sub 2} semiconductor photocatalyst. After 5h of irradiation with a 150W Xenon lamp, over 55-72% degradation of pollutants has been achieved. A working mechanism involving excitation of surface adsorbed dye, followed by charge injection into the TiO{sub 2} conduction band and formation of reactive {sup *}O{sub 2}{sup -}/{sup *}HO{sub 2} radicals, is proposed for the degradation of the enlisted organics to carbon dioxide. Efficacy of the photocatalytic system towards halocarbon degradation has been discussed in regard to excited state redox properties of the dyes selected for this study. Formation of {sup *}O{sub 2}{sup -} radical has been substantiated by using a chemiluminescent probe luminol. (author)

  19. Photoelectrocatalytic degradation of indanthrene blue dye using Ti/Ru-based electrodes prepared by a modified Pechini method

    Energy Technology Data Exchange (ETDEWEB)

    Pupo, Marilia M.S.; Costa, Lucas S. da; Figueiredo, Aile C.; Eguiluz, Katlin I. B.; Salazar-Banda, Giancarlo R., E-mail: gianrsb@gmail.com [Universidade Tiradentes, Aracaju, SE (Brazil). Instituto de Tecnologia e Pesquisa. Programa de Pos-Graduacao em Engenharia de Processos; Silva, Ronaldo S. da [Universidade Federal de Sergipe, Sao Cristovao, SE (Brazil). Departamento de Fisica. Laboratorio de Materiais Ceramicos Avancados; Cunha, Frederico G.C. [Universidade Federal de Sergipe, Sao Cristovao, SE (Brazil). Departamento de Fisica

    2013-03-15

    Photoelectrodes were used to treat synthetic textile wastewater contaminated with indanthrene blue dye. Two media of treatment were used (NaCl and Na{sub 2}SO{sub 4}), with variations on temperature, pH, current density, dye and chloride concentration. A modified Pechini method was applied to obtain Ti/Ru-based electrodes (Ti, Ru, Ti{sub 0.5}Ru{sub 0.5}, Ti{sub 0.75}Ru{sub 0.25} and Ti{sub 0.25}Ru{sub 0.75}) containing anatase TiO{sub 2} nanoparticles and a color degradation analysis was done. Physical (atomic force microscopy and X-ray diffractometry) and electrochemical characterizations (cyclic voltammetry) were considered. The condition that yielded highest color removal for the system presented 0.05 mol L-1 NaCl, 100 mA cm-2, 35 Degree-Sign C and pH 7, independent of the dye concentration for the Ti{sub 0.25}Ru{sub 0.75} electrode. (author)

  20. Bio-active molecules modified surfaces enhanced mesenchymal stem cell adhesion and proliferation

    International Nuclear Information System (INIS)

    Mobasseri, Rezvan; Tian, Lingling; Soleimani, Masoud; Ramakrishna, Seeram; Naderi-Manesh, Hossein

    2017-01-01

    Surface modification of the substrate as a component of in vitro cell culture and tissue engineering, using bio-active molecules including extracellular matrix (ECM) proteins or peptides derived ECM proteins can modulate the surface properties and thereby induce the desired signaling pathways in cells. The aim of this study was to evaluate the behavior of human bone marrow mesenchymal stem cells (hBM-MSCs) on glass substrates modified with fibronectin (Fn), collagen (Coll), RGD peptides (RGD) and designed peptide (R-pept) as bio-active molecules. The glass coverslips were coated with fibronectin, collagen, RGD peptide and R-peptide. Bone marrow mesenchymal stem cells were cultured on different substrates and the adhesion behavior in early incubation times was investigated using scanning electron microscopy (SEM) and confocal microscopy. The MTT assay was performed to evaluate the effect of different bio-active molecules on MSCs proliferation rate during 24 and 72 h. Formation of filopodia and focal adhesion (FA) complexes, two steps of cell adhesion process, were observed in MSCs cultured on bio-active molecules modified coverslips, specifically in Fn coated and R-pept coated groups. SEM image showed well adhesion pattern for MSCs cultured on Fn and R-pept after 2 h incubation, while the shape of cells cultured on Coll and RGD substrates indicated that they might experience stress condition in early hours of culture. Investigation of adhesion behavior, as well as proliferation pattern, suggests R-peptide as a promising bio-active molecule to be used for surface modification of substrate in supporting and inducing cell adhesion and proliferation. - Highlights: • Bioactive molecules modified surface is a strategy to design biomimicry scaffold. • Bi-functional Tat-derived peptide (R-pept) enhanced MSCs adhesion and proliferation. • R-pept showed similar influences to fibronectin on FA formation and attachment.

  1. Magnetically modified Posidonia oceanica biomass as an adsorbent for organic dyes removal

    Czech Academy of Sciences Publication Activity Database

    Šafařík, Ivo; Ashoura, N.; Maděrová, Z.; Pospíšková, K.; Baldíková, E.; Šafaříková, Miroslava

    2016-01-01

    Roč. 17, č. 2 (2016), s. 351-358 ISSN 1108-393X Institutional support: RVO:60077344 Keywords : Posidonia oceanica * Neptune balls * magnetic biomass * organic dyes * adsorbent Subject RIV: DJ - Water Pollution ; Quality Impact factor: 1.683, year: 2016

  2. Ultrafast vibronic dynamics of dye molecules studied by the induced grating method

    International Nuclear Information System (INIS)

    Liu, C.H.; Troeger, P.; Laubereau, A.

    1985-08-01

    Previous work on transient polarization spectroscopy applying the induced grating technique concentrated on the time scale > 10 -11 s. Only one earlier study on a shorter time scale showed the occurrence of the so-called coherence peak without a detailed explanation for this phenomena. We report new theoretical and experimental data on a polarization effect that occurs in the nonlinear Rayleigh scattering of delayed probing pulses from induced population gratings. The periodic population changes are generated by two synchronized pumping pulses of the same frequency. Model calculations are presented, which carefully evaluate the orientational distribution and give quantitative information on the scattering signal for various polarization conditions. The scattering mechanism for the coherence peak is explained as a two step process with one photon absorption and emission process; it depends on the vibronic relaxation of the terminating level in the excited electronic state. Experimental results are reported for the vibrational and orientational relaxation times. For example values of tausub(v)=0.2+-0.2 ps and tausub(v)=0.8+-0.3 ps are measured respectively for Rhodamine 6G in ethanol and phenoxazone 9 in dioxane. Our three-beam transient grating technique under general polarization conditions can be used for the study of a variety of dynamic processes of molecules in the excited electronic or ground state. An important advantage compared to nonlinear absorption or induced dichroism techniques is that the scattering method avoids undesirable background signals. (author)

  3. Reconstruction of calmodulin single-molecule FRET states, dye interactions, and CaMKII peptide binding by MultiNest and classic maximum entropy

    Science.gov (United States)

    DeVore, Matthew S.; Gull, Stephen F.; Johnson, Carey K.

    2013-08-01

    We analyzed single molecule FRET burst measurements using Bayesian nested sampling. The MultiNest algorithm produces accurate FRET efficiency distributions from single-molecule data. FRET efficiency distributions recovered by MultiNest and classic maximum entropy are compared for simulated data and for calmodulin labeled at residues 44 and 117. MultiNest compares favorably with maximum entropy analysis for simulated data, judged by the Bayesian evidence. FRET efficiency distributions recovered for calmodulin labeled with two different FRET dye pairs depended on the dye pair and changed upon Ca2+ binding. We also looked at the FRET efficiency distributions of calmodulin bound to the calcium/calmodulin dependent protein kinase II (CaMKII) binding domain. For both dye pairs, the FRET efficiency distribution collapsed to a single peak in the case of calmodulin bound to the CaMKII peptide. These measurements strongly suggest that consideration of dye-protein interactions is crucial in forming an accurate picture of protein conformations from FRET data.

  4. Reconstruction of Calmodulin Single-Molecule FRET States, Dye-Interactions, and CaMKII Peptide Binding by MultiNest and Classic Maximum Entropy.

    Science.gov (United States)

    Devore, Matthew S; Gull, Stephen F; Johnson, Carey K

    2013-08-30

    We analyze single molecule FRET burst measurements using Bayesian nested sampling. The MultiNest algorithm produces accurate FRET efficiency distributions from single-molecule data. FRET efficiency distributions recovered by MultiNest and classic maximum entropy are compared for simulated data and for calmodulin labeled at residues 44 and 117. MultiNest compares favorably with maximum entropy analysis for simulated data, judged by the Bayesian evidence. FRET efficiency distributions recovered for calmodulin labeled with two different FRET dye pairs depended on the dye pair and changed upon Ca 2+ binding. We also looked at the FRET efficiency distributions of calmodulin bound to the calcium/calmodulin dependent protein kinase II (CaMKII) binding domain. For both dye pairs, the FRET efficiency distribution collapsed to a single peak in the case of calmodulin bound to the CaMKII peptide. These measurements strongly suggest that consideration of dye-protein interactions is crucial in forming an accurate picture of protein conformations from FRET data.

  5. Structure of deformable diatomic molecules: a modified n-butane liquid

    International Nuclear Information System (INIS)

    Jang, Seanea; Kim, Soonchul; Lee, Songhi

    2005-01-01

    The density functional approximation for polyatomic molecules, which is based on the bridge function of the intermolecular interaction, was developed and applied to investigate the thermodynamic and the structural properties of deformable diatomic molecules. The Percus trick was employed to calculate the uniform structure of modified n-butane. The calculated static correlation functions were used to predict the density behaviors of a modified n-butane liquid at liquid-solid interfaces. The theoretical results show that (i) at low densities, the hypernetted-chain (HNC) equation compares with the density functional approximation based on the bridge function and that (ii) the relative population between the gauche and the trans states strongly affects the liquid structure at liquid-solid interfaces.

  6. Adsorption of and acidic dye from aqueous solution by surfactant modified bentonite

    International Nuclear Information System (INIS)

    Bouberka, Z.; Khenifi, A.; Belkaid, N.; Ait Mahamed, H.; Haddou, B.; Derriche, Z.

    2009-01-01

    The aim of this paper is to study the adsorption of an acidic dye S. Y. 4 GL (i.e: Supranol yellow 4GL) from aqueous solution on inorgano-organo clay. Bentonite is a kind of natural clay with good exchanging ability. By exchanging its inter lamellar cations with Cetyltrimethylammonium bromide (CTAB) and hydroxy aluminic or chromium poly cations, the properties of natural bentonite can be greatly improved. (Author)

  7. Observation of microwave conductivity in copper iodide films and relay effect in the dye molecules attached to CuI photocathode

    International Nuclear Information System (INIS)

    Sirimanne, Prasad M.; Soga, Tetsuo; Kunst, Marinus

    2005-01-01

    Microwave conductivity and two channels of recombination process were observed in the CuI films. Spin orbital splitting resulted in split in the valence band of CuI. The dye molecules attached to the CuI film act as an electron mediator in addition to the sensitization process under back wall-mode illumination. - Graphical abstract: Transient microwave-photoconductivity of CuI film

  8. 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.

  9. Wavelength and coherence effects on the growth mechanism of silicon nanopillars and their use in the modification of spontaneous lifetime emission of BODIPY dye molecules

    Energy Technology Data Exchange (ETDEWEB)

    Acikgoz, Sabriye [Bogazici University, Department of Physics, Istanbul (Turkey); Karamanoglu Mehmetbey University, Department of Material Science and Engineering, Karaman (Turkey); Bilen, Bukem; Saygili, Asli C.; Aktas, Gulen; Inci, Mehmet Naci [Bogazici University, Department of Physics, Istanbul (Turkey); Sanyal, Amitav [Bogazici University, Department of Chemistry, Istanbul (Turkey)

    2012-09-15

    Silicon nanopillars are grown by an electrochemical anodization of p-type silicon wafers at low current densities in a hydrofluoric acid solution. CW, white light, and various UV pulsed lasers are employed as illumination sources in sample preparation to study wavelength and coherence effects on the growth mechanism of the nanopillars. Coherence is observed to be the foundation of regularity in obtaining conical shapes. The pillar size is found to be almost linearly proportional to the employed illumination wavelength during their growth. BODIPY dye molecules are chemically attached to these silicon nanopillars and the radiative decay rates are investigated by means of a time-resolved fluorescence experiment. The decay rate of the dye molecules embedded in the vicinity of various size pillar tips is significantly affected due to different apex angles of the conical nature. It is demonstrated that the pillar size and the separation between pillars can be adjusted if one uses a coherent light source with an appropriate wavelength during the course of fabrication process. Since change in the decay rate is due to tips of the pillars only, separation of a few micrometers between pillar tips allows one to directly monitor a dye, which is embedded to the tip of a single nanopillar, via a confocal microscopic method for the spontaneous lifetime measurements, without having needed to any extra efforts for an in situ imaging process. It is observed that as the pillar size gets smaller, the inhibition in the spontaneous lifetime of BODIPY is more pronounced. In addition, a more regular pillar structure yields nonvarying decay rates of the dye molecules throughout the silicon sample. (orig.)

  10. 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.

  11. Inter-Dye Distance Distributions Studied by a Combination of Single-Molecule FRET-Filtered Lifetime Measurements and a Weighted Accessible Volume (wAV Algorithm

    Directory of Open Access Journals (Sweden)

    Henning Höfig

    2014-11-01

    Full Text Available Förster resonance energy transfer (FRET is an important tool for studying the structural and dynamical properties of biomolecules. The fact that both the internal dynamics of the biomolecule and the movements of the biomolecule-attached dyes can occur on similar timescales of nanoseconds is an inherent problem in FRET studies. By performing single-molecule FRET-filtered lifetime measurements, we are able to characterize the amplitude of the motions of fluorescent probes attached to double-stranded DNA standards by means of flexible linkers. With respect to previously proposed experimental approaches, we improved the precision and the accuracy of the inter-dye distance distribution parameters by filtering out the donor-only population with pulsed interleaved excitation. A coarse-grained model is employed to reproduce the experimentally determined inter-dye distance distributions. This approach can easily be extended to intrinsically flexible proteins allowing, under certain conditions, to decouple the macromolecule amplitude of motions from the contribution of the dye linkers.

  12. ELECTRO-DEGRADATION OF REACTIVE BLUE DYES USING CYLINDER MODIFIED ELECTRODE: Ti/β-PbO2 AS DIMENSIONALLY STABLE ANODE

    Directory of Open Access Journals (Sweden)

    Aris Mukimin

    2010-12-01

    Full Text Available A cylinder modified electrode of the β-PbO2 was fabricated by anodic electro-deposition method on titanium substrate. The PbO2 layer prepared from high acid solution (pH: 0.3 that contains a mixed of 0.5 M Pb(NO32, 1 M HNO3, and 0,02 M NaF. The physicochemical properties of the PbO2 electrode were analyzed by using Energy Dispersive X-Ray Analysis and X-Ray Diffraction. The analyses have shown that oxide layer has an O/Pb ratio about 1.6 and the PbO impurities are formed in the surface layer besides the β-PbO2. The modified electrode was used as anode paired stainless cathode in the electro-degradation of reactive blue dye. The results of the electro-catalytic oxidation process of the dye solution were expressed in terms of the remaining intensity dye and chemical oxygen demand (COD values. The modified electrode has removal efficiency of the reactive blue dye at voltage of 7 V, pH of 7, concentration NaCl of 2 g/L, initial dye concentration of 100 mg/L with simple and short time operations.

  13. 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.

  14. 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.

  15. Enhancing adsorption capacity of toxic malachite green dye through chemically modified breadnut peel: equilibrium, thermodynamics, kinetics and regeneration studies.

    Science.gov (United States)

    Chieng, Hei Ing; Lim, Linda B L; Priyantha, Namal

    2015-01-01

    Breadnut skin, in both its unmodified (KS) and base-modified (BM-KS) forms, was investigated for its potential use as a low-cost adsorbent for the removal of toxic dye, malachite green (MG). Characterization of the adsorbents was carried out using scanning electron microscope, X-ray fluorescence and Fourier transform infra-red spectroscopy. Batch adsorption experiments, carried out under optimized conditions, for the adsorption of MG were fitted using five isotherm models (Langmuir, Freundlich, Dubinin-Radushkevich, Temkin and Sips) and six error functions to determine the best-fit model. The adsorption capacity was greatly enhanced when breadnut skin was chemically modified with NaOH, leading to an adsorption capacity of 353.0 mg g(-1), that was far superior to most reported adsorbents for the removal of MG. Thermodynamics studies indicated that the adsorption of MG was spontaneous on KS and BM-KS, and the reactions were endothermic and exothermic, respectively. Kinetics studies showed that both followed the pseudo-second order. Regeneration experiments on BM-KS indicated that its adsorption capacity was still maintained at>90% even after five cycles. It can be concluded that NaOH-modified breadfruit skin has great potential to be utilized in real-life application as a low-cost adsorbent for the removal of MG in wastewater treatment.

  16. 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.

  17. Dynamical Orientation of Large Molecules on Oxide Surfaces and its Implications for Dye-Sensitized Solar Cells

    KAUST Repository

    Brennan, Thomas P.

    2013-11-12

    A dual experimental-computational approach utilizing near-edge X-ray absorption fine structure (NEXAFS) spectroscopy and density functional theory-molecular dynamics (DFT-MD) is presented for determining the orientation of a large adsorbate on an oxide substrate. A system of interest in the field of dye-sensitized solar cells is studied: an organic cyanoacrylic acid-based donor-π-acceptor dye (WN1) bound to anatase TiO2. Assessment of nitrogen K-edge NEXAFS spectra is supported by calculations of the electronic structure that indicate energetically discrete transitions associated with the two π systems of the C-N triple bond in the cyanoacrylic acid portion of the dye. Angle-resolved NEXAFS spectra are fitted to determine the orientation of these two orbital systems, and the results indicate an upright orientation of the adsorbed dye, 63 from the TiO2 surface plane. These experimental results are then compared to computational studies of the WN1 dye on an anatase (101) TiO2 slab. The ground state structure obtained from standard DFT optimization is less upright (45 from the surface) than the NEXAFS results. However, DFT-MD simulations, which provide a more realistic depiction of the dye at room temperature, exhibit excellent agreement - within 2 on average - with the angles determined via NEXAFS, demonstrating the importance of accounting for the dynamic nature of adsorbate-substrate interactions and DFT-MD\\'s powerful predictive abilities. © 2013 American Chemical Society.

  18. Dynamical Orientation of Large Molecules on Oxide Surfaces and its Implications for Dye-Sensitized Solar Cells

    KAUST Repository

    Brennan, Thomas P.; Tanskanen, Jukka T.; Bakke, Jonathan R.; Nguyen, William H.; Nordlund, Dennis; Toney, Michael F.; McGehee, Michael D.; Sellinger, Alan; Bent, Stacey F.

    2013-01-01

    A dual experimental-computational approach utilizing near-edge X-ray absorption fine structure (NEXAFS) spectroscopy and density functional theory-molecular dynamics (DFT-MD) is presented for determining the orientation of a large adsorbate on an oxide substrate. A system of interest in the field of dye-sensitized solar cells is studied: an organic cyanoacrylic acid-based donor-π-acceptor dye (WN1) bound to anatase TiO2. Assessment of nitrogen K-edge NEXAFS spectra is supported by calculations of the electronic structure that indicate energetically discrete transitions associated with the two π systems of the C-N triple bond in the cyanoacrylic acid portion of the dye. Angle-resolved NEXAFS spectra are fitted to determine the orientation of these two orbital systems, and the results indicate an upright orientation of the adsorbed dye, 63 from the TiO2 surface plane. These experimental results are then compared to computational studies of the WN1 dye on an anatase (101) TiO2 slab. The ground state structure obtained from standard DFT optimization is less upright (45 from the surface) than the NEXAFS results. However, DFT-MD simulations, which provide a more realistic depiction of the dye at room temperature, exhibit excellent agreement - within 2 on average - with the angles determined via NEXAFS, demonstrating the importance of accounting for the dynamic nature of adsorbate-substrate interactions and DFT-MD's powerful predictive abilities. © 2013 American Chemical Society.

  19. Dyes adsorption blue vegetable and blue watercolor by natural zeolites modified with surfactants;Adsorcion de colorantes azul vegetal y azul acuarela por zeolitas naturales modificadas con surfactantes

    Energy Technology Data Exchange (ETDEWEB)

    Jardon S, C. C.; Olguin G, M. T. [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Diaz N, M. C., E-mail: teresa.olguin@inin.gob.m [Instituto Tecnologico de Toluca, Av. Instituto Tecnologico s/n, Ex-Rancho la Virgen, 52140 Metepec, Estado de Mexico (Mexico)

    2009-07-01

    In this work was carried out the dyes removal blue vegetable and blue watercolor of aqueous solutions, to 20 C, at different times and using a zeolite mineral of Parral (Chihuahua, Mexico) modified with hexadecyl trimethyl ammonium bromide or dodecyl trimethyl ammonium bromide. The zeolite was characterized before and after of its adaptation with NaCl and later with HDTMABr and DTMABr. For the materials characterization were used the scanning electron microscopy of high vacuum; elementary microanalysis by X-ray spectroscopy of dispersed energy and X-ray diffraction techniques. It was found that the surfactant type absorbed in the zeolite material influences on the adsorption process of the blue dye. Likewise, the chemical structure between the vegetable blue dye and the blue watercolor, determines the efficiency of the color removal of the water, by the zeolites modified with the surfactants. (Author)

  20. Use of Fricke solution modified with dyes for dosimetry in phototherapeutic treatments

    International Nuclear Information System (INIS)

    Almeida, Mayara Gabriella Oliveira de; Nascimento, Rizia Keila; Vieira, Rafaela Etelvina de Amorim; Souza, Vivianne Lucia Bormann

    2014-01-01

    Dyes and pigments (photosensitizers) are characterized by their ability to absorb visible light, and to participate in photochemical reactions. These colors are used in medicine in the dose recommended for use in photodynamic therapy (PDT). There are lasers that can meet most of the phototherapeutic agents and are capable of providing light of considerable power with precision on the injured tissue. The use of light emitting diodes (LEDs) have become feasible, thus reducing the cost of the procedures. The Dosimetry Laboratory Chemistry of the CRCN-NE/Brazilian CNEN has worked with some likely dye use in phototherapy treatments, including: methylene blue, malachite green and toluidine blue. A volume of 2.6 ml of the dosimeters was transferred to test tubes and these were irradiated with LED 24, 48, 72 and 96 acrylic simulator 110 mm x 110 mm x 80 mm at a distance of 6.5 cm from reading light source of the irradiated samples was performed on a spectrophotometer. Having obtaining excellent correlations (above 0.97) to the dosimeter calibration curves. Suggests that the dosimeter can be applied to perform a quality control in photodynamic therapy. However, further experiments should be performed before a wide application of this technique. A volume of 2.6 ml of the dosimeters was transferred to test tubes and these were irradiated with LED 24, 48, 72 and 96 acrylic simulator 110 mm x 110 mm x 80 mm at a distance of 6.5 cm from reading light source of the irradiated samples was performed on a spectrophotometer. Having obtaining excellent correlations (above 0.97) to the dosimeter calibration curves. Suggests that the dosimeter can be applied to perform a quality control in photodynamic therapy. However, further experiments should be performed before a wide application of this technique

  1. Influence of silver nanoparticles on relaxation processes and efficiency of dipole – dipole energy transfer between dye molecules in polymethylmethacrylate films

    Energy Technology Data Exchange (ETDEWEB)

    Bryukhanov, V V; Borkunov, R Yu; Tsarkov, M V [Immanuel Kant Baltic Federal University, Kaliningrad (Russian Federation); Konstantinova, E I; Slezhkin, V A [Kaliningrad State Technical University, Kaliningrad (Russian Federation)

    2015-10-31

    The fluorescence and phosphorescence of dyes in thin polymethylmethacrylate (PMMA) films in the presence of ablated silver nanoparticles has been investigated in a wide temperature range by methods of femtosecond and picosecond laser photoexcitation. The fluorescence and phosphorescence times, as well as spectral and kinetic characteristics of rhodamine 6G (R6G) molecules in PMMA films are measured in a temperature range of 80 – 330 K. The temperature quenching activation energy of the fluorescence of R6G molecules in the presence of ablated silver nanoparticles is found. The vibrational relaxation rate of R6G in PMMA films is estimated, the efficiency of the dipole – dipole electron energy transfer between R6G and brilliant green molecules (enhanced by plasmonic interaction with ablated silver nanoparticles) is analysed, and the constants of this energy transfer are determined. (nanophotonics)

  2. Influence of silver nanoparticles on relaxation processes and efficiency of dipole – dipole energy transfer between dye molecules in polymethylmethacrylate films

    International Nuclear Information System (INIS)

    Bryukhanov, V V; Borkunov, R Yu; Tsarkov, M V; Konstantinova, E I; Slezhkin, V A

    2015-01-01

    The fluorescence and phosphorescence of dyes in thin polymethylmethacrylate (PMMA) films in the presence of ablated silver nanoparticles has been investigated in a wide temperature range by methods of femtosecond and picosecond laser photoexcitation. The fluorescence and phosphorescence times, as well as spectral and kinetic characteristics of rhodamine 6G (R6G) molecules in PMMA films are measured in a temperature range of 80 – 330 K. The temperature quenching activation energy of the fluorescence of R6G molecules in the presence of ablated silver nanoparticles is found. The vibrational relaxation rate of R6G in PMMA films is estimated, the efficiency of the dipole – dipole electron energy transfer between R6G and brilliant green molecules (enhanced by plasmonic interaction with ablated silver nanoparticles) is analysed, and the constants of this energy transfer are determined. (nanophotonics)

  3. Enhancement of sorption capacity of cocoa shell biomass modified with non-thermal plasma for removal of both cationic and anionic dyes from aqueous solution.

    Science.gov (United States)

    Takam, Brice; Acayanka, Elie; Kamgang, Georges Y; Pedekwang, Merlin T; Laminsi, Samuel

    2017-07-01

    Removal of cationic dye, Azur II, and anionic dye, Reactive Red 2 (RR-2) from aqueous solutions, has been successfully achieved by using a modified agricultural biomaterial waste: cocoa shell husk (Theobroma cacao) treated by gliding arc plasma (CPHP). The biomass in its natural form CPHN and modified form CPHP was characterized by infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and point of zero charge (pH pzc ). Experimental variables such as initial pH, contact time, and temperature were optimized for adsorptive characteristics of CPHN and CPHP. The results show that the removal of the Azur II dye was favorable in the basic pH region (pH 10) while the Reactive Red 2 dye was favorable in the acidic pH region (pH 2). The minimum equilibrium time for Azur II and RR-2 dye was obtained after 40 and 240 min, respectively. The adsorption kinetics and isotherm data obtained were best described by a pseudo-second-order kinetic rate model and a combination of Langmuir-Freundlich isotherm models. This work indicates that the plasma-treated raw materials are good alternative multi-purpose sorbents for the removal of many coexisting pollutants from aqueous solutions.

  4. Polyoxometalate-modified TiO2 nanotube arrays photoanode materials for enhanced dye-sensitized solar cells

    Science.gov (United States)

    Liu, Ran; Sun, Zhixia; Zhang, Yuzhuo; Xu, Lin; Li, Na

    2017-10-01

    In this work, we prepared for the first time the TiO2 nanotube arrays (TNAs) photoanode with polyoxometalate(POMs)-modified TiO2 electron-transport layer for improving the performance of zinc phthalocyanine(ZnPc)-sensitized solar cells. The as-prepared POMs/TNAs/ZnPc composite photoanode exhibited higher photovoltaic performances than the TNAs/ZnPc photoanode, so that the power conversion efficiency of the solar cell device based on the POMs/TNAs/ZnPc photoanode displayed a notable improvement of 45%. These results indicated that the POMs play a key role in reducing charge recombination in phthalocyanine-sensitized solar cells, together with TiO2 nanotube arrays being helpful for electron transport. The mechanism of the performance improvement was demonstrated by the measurements of electrochemical impedance spectra and open-circuit voltage decay curves. Although the resulting performance is still below that of the state-of-the-art dye-sensitized solar cells, this study presents a new insight into improving the power conversion efficiency of phthalocyanine-sensitized solar cells via polyoxometalate-modified TiO2 nanotube arrays photoanode.

  5. Encapsulation of dye molecules into mesoporous polymer resin and mesoporous polymer-silica films by an evaporation-induced self-assembly method

    Energy Technology Data Exchange (ETDEWEB)

    Chi Yue; Li Nan; Tu Jinchun; Zhang Yujie [School of Material Science and Engineering, Key Laboratory of Automobile Materials of Ministry of Education, Jilin University, Changchun 130012 (China); Li Xiaotian, E-mail: xiaotianli@jlu.edu.c [School of Material Science and Engineering, Key Laboratory of Automobile Materials of Ministry of Education, Jilin University, Changchun 130012 (China); Shao Changlu, E-mail: clshao@nenu.edu.c [Center for Advanced Optoelectronic Functional Materials Research, Northeast Normal University, Changchun 130024 (China)

    2010-03-15

    Polymer resin and polymer-silica films with highly ordered mesostructure have been used as host materials to encapsulate DCM (4-(dicyanomethylene) -2-methyl-6-(4-dimethylaminostyryl)-4h-pyran), a kind of fluorescent dye, through evaporation-induced self-assembly method (EISA). After encapsulation, the composites show significant blue-shift in photoluminescence (PL) spectra. Particularly, by changing the excitation wavelength, the samples show different emission bands. These phenomena are related to the mesostructure and the positions of DCM molecules in the host.

  6. Enhanced Photocatalytic Degradation of Methyl Orange Dye under the Daylight Irradiation over CN-TiO₂ Modified with OMS-2.

    Science.gov (United States)

    Hassan, Mohamed Elfatih; Chen, Jing; Liu, Guanglong; Zhu, Duanwei; Cai, Jianbo

    2014-12-12

    In this study, CN-TiO₂ was modified with cryptomelane octahedral molecular sieves (OMS-2) by the sol-gel method based on the self-assembly technique to enhance its photocatalytic activity under the daylight irradiation. The synthesized samples were characterized by X-ray diffraction (XRD), UV-vis spectroscopy, Fourier transform infrared spectroscopy (FT-IR) and porosimeter analysis. The results showed that the addition of OMS-2 in the sol lead to higher Brunauer-Emmett-Teller (BET) surface area, pore volume, porosity of particle after heat treatment and the specific surface area, porosity, crystallite size and pore size distribution could be controlled by adjusting the calcination temperature. Compared to the CN-TiO₂-400 sample, CN-TiO₂/OMS-2-400 exhibited greater red shift in absorption edge of samples in visible region due to the OMS-2 coated. The enhancement of photocatalytic activity of CN-TiO₂/OMS-2 composite photocatalyst was subsequently evaluated for the degradation of the methyl orange dye under the daylight irradiation in water. The results showed that the methyl orange dye degradation rate reach to 37.8% for the CN-TiO₂/OMS-2-400 sample under the daylight irradiation for 5 h, which was higher than that of reference sample. The enhancement in daylight photocatalytic activities of the CN-TiO₂/OMS samples could be attributed to the synergistic effects of OMS-2 coated, larger surface area and red shift in adsorption edge of the prepared sample.

  7. A Zinc Porphyrin Sensitizer Modified with Donor and Acceptor Groups for Dye-ensitized Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Lee, See Woo; Sarker, K. Ashis; Hong, Jong Dal [Incheon National University, Incheon (Korea, Republic of)

    2014-09-15

    In this article, we have designed and synthesized a novel donor-π-acceptor (D-π-A) type porphyrin-based sensitizer (denoted UI-5), in which a carboxyl anchoring group and a 9,9-dimethyl fluorene were introduced at the meso-positions of porphyrin ring via phenylethynyl and ethynyl bridging units, respectively. Long alkoxy chains in ortho-positions of the phenyls were supposed to reduce the degree of dye aggregation, which tends to affect electron injection yield in a photovoltaic cell. The cyclic voltammetry was employed to determine the band gap of UI-5 to be 1.41 eV based on the HOMO and LUMO energy levels, which were estimated by the onset oxidation and reduction potentials. The incident monochromatic photon-to-current conversion efficiency of the UI-5 DSSC assembled with double-layer (20 nm-sized TiO{sub 2}/400 nm-sized TiO{sub 2}) film electrodes appeared lower upon overall ranges of the excitation wavelengths, but exhibited a higher value over the NIR ranges (λ = 650-700 nm) compared to the common reference sensitizer N719. The UI-5-sensitized cell yielded a relatively poor device performance with an overall conversion efficiency of 0.74% with a short circuit photocurrent density of 3.05 mA/cm2, an open circuit voltage of 0.54 mV and a fill factor of 0.44 under the standard global air mass (AM 1.5) solar conditions. However, our report about the synthesis and the photovoltaic characteristics of a porphyrin-based sensitizer in a D-π-A structure demonstrated a significant complex relationship between the sensitizer structure and the cell performance.

  8. Dyes removal of textile wastewater onto surfactant modified zeolite from coal ash and evaluation of the toxic effects; Remocao de corantes de efluente textil por zeolita de cinzas de carvao modificada por surfactante e avaliacao dos efeitos toxicos

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Patricia Cunico

    2015-07-01

    Zeolites synthesized from fly and bottom ashes and modified with hexadecyltrimethylammonium (HDTMA) were used as adsorbent to remove dyes - Solophenyl Navy (SN) and Solophenyl Turquoise (ST) and their hydrolysed forms Solophenyl Navy Hydrolysed (SNH) and Solophenyl Turquoise Hydrolysed (STH), from simulated textile wastewater. The HDTMA-modified fly zeolite (ZMF) and HDTMA-modified bottom zeolite (ZMB) were characterized by different techniques, as X-ray fluorescence spectrometry, X-ray diffraction and scanning electron microscopy, etc. The ZMF and ZMB presented negative charge probably due to the formation of a partial bilayer of HDTMA on exchangeable active sites on the external surface of unmodified zeolite. Initial dye concentration, contact time and equilibrium adsorption were evaluated. The adsorption kinetic for SN, ST, SNH and STH onto the zeolites followed the pseudo second-order model. The equilibrium time was 20 min for SN and ST and 30 min for SNH and STH, respectively. Langmuir, Freundlich and Temkin models were applied to describe the adsorption isotherms. Adsorption of the dyes were best described by the Langmuir model, with exception to SN/ZPM, SNH/ZPM and SNH/ZLM systems that followed Freundlich model. The maximum adsorption capacities were 3,64; 3,57; 2,91 e 4,93 for SN, ST, SNH e STH by ZLM, respectively and 0,235; 0,492; 1,26 e 1,86 by ZPM, in this order. The best performance for hydrolyzed dyes has been attributed to reduction of the size of dyes molecules during the hydrolysis process. Acute toxicity of the dyes to a different organism were evaluated by different test-organisms. Waterflea, Ceriodaphnia dubia showed EC50 value of 1,25; 54,5; 0,78 and 2,56 mgL{sup -1} for SN, ST, SNH and STH, respectively. The plant Lemna minor showed EC50 values of 18,9; 69,4; 10,9 and 70,9 mgL{sup -1} for SN, ST, SNH and STH, respectively. Midges larvae of Chironomus tepperi showed EC50 values of 119 and 440 mgL{sup -1} for SN and ST, respectively. Regarding

  9. Thermodynamic characteristics of the adsorption of organic molecules on modified MCM-41 adsorbents

    Science.gov (United States)

    Gus'kov, V. Yu.; Sukhareva, D. A.; Salikhova, G. R.; Karpov, S. I.; Kudasheva, F. Kh.; Roessner, F.; Borodina, E. V.

    2017-07-01

    The adsorption of a number of organic molecules on samples of MCM-41 adsorbent modified with dichloromethylphenylsilane and subsequently treated with sulfuric acid (MDCS) and N-trimethoxysilylpropyl- N, N, N-trimethylammonium chloride (MNM) is studied. Specific retention volumes equal to the Henry constant are determined by means of inverse gas chromatography at infinite dilution. The thermodynamic characteristics of adsorption, the dispersive and specific components of the Helmholtz energy of adsorption, and the increment of the methyl group to the heat of adsorption are calculated. It is shown that the grafting of aminosilane and phenylsilane groups enhances the forces of dispersion and reduces specific interactions. A greater drop in polarity is observed for MDCS than for MNM, due to the stronger polarity of amoinosilane; the enthalpy factor makes the main contribution to the adsorption of organic compounds on the investigated adsorbents. It is found that the MNM sample is capable of the irreversible adsorption of alcohols.

  10. Localization microscopy of DNA in situ using Vybrant{sup ®} DyeCycle™ Violet fluorescent probe: A new approach to study nuclear nanostructure at single molecule resolution

    Energy Technology Data Exchange (ETDEWEB)

    Żurek-Biesiada, Dominika [Laboratory of Cell Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków (Poland); Szczurek, Aleksander T. [Institute of Molecular Biology (IMB), Ackermannweg 4, 55128 Mainz (Germany); Prakash, Kirti [Institute of Molecular Biology (IMB), Ackermannweg 4, 55128 Mainz (Germany); Institute for Pharmacy and Molecular Biotechnology (IPMB), University of Heidelberg, Im Neuenheimer Feld 364, D-69120 Heidelberg (Germany); Mohana, Giriram K. [Institute of Molecular Biology (IMB), Ackermannweg 4, 55128 Mainz (Germany); Lee, Hyun-Keun [Institute of Molecular Biology (IMB), Ackermannweg 4, 55128 Mainz (Germany); Department of Physics, University of Mainz (JGU), Staudingerweg 7, 55128 Mainz (Germany); Roignant, Jean-Yves [Institute of Molecular Biology (IMB), Ackermannweg 4, 55128 Mainz (Germany); Birk, Udo J. [Institute of Molecular Biology (IMB), Ackermannweg 4, 55128 Mainz (Germany); Department of Physics, University of Mainz (JGU), Staudingerweg 7, 55128 Mainz (Germany); Dobrucki, Jurek W., E-mail: jerzy.dobrucki@uj.edu.pl [Laboratory of Cell Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków (Poland); Cremer, Christoph, E-mail: c.cremer@imb-mainz.de [Institute of Molecular Biology (IMB), Ackermannweg 4, 55128 Mainz (Germany); Institute for Pharmacy and Molecular Biotechnology (IPMB), University of Heidelberg, Im Neuenheimer Feld 364, D-69120 Heidelberg (Germany); Department of Physics, University of Mainz (JGU), Staudingerweg 7, 55128 Mainz (Germany)

    2016-05-01

    Higher order chromatin structure is not only required to compact and spatially arrange long chromatids within a nucleus, but have also important functional roles, including control of gene expression and DNA processing. However, studies of chromatin nanostructures cannot be performed using conventional widefield and confocal microscopy because of the limited optical resolution. Various methods of superresolution microscopy have been described to overcome this difficulty, like structured illumination and single molecule localization microscopy. We report here that the standard DNA dye Vybrant{sup ®} DyeCycle™ Violet can be used to provide single molecule localization microscopy (SMLM) images of DNA in nuclei of fixed mammalian cells. This SMLM method enabled optical isolation and localization of large numbers of DNA-bound molecules, usually in excess of 10{sup 6} signals in one cell nucleus. The technique yielded high-quality images of nuclear DNA density, revealing subdiffraction chromatin structures of the size in the order of 100 nm; the interchromatin compartment was visualized at unprecedented optical resolution. The approach offers several advantages over previously described high resolution DNA imaging methods, including high specificity, an ability to record images using a single wavelength excitation, and a higher density of single molecule signals than reported in previous SMLM studies. The method is compatible with DNA/multicolor SMLM imaging which employs simple staining methods suited also for conventional optical microscopy. - Highlights: • Super-resolution imaging of nuclear DNA with Vybrant Violet and blue excitation. • 90nm resolution images of DNA structures in optically thick eukaryotic nuclei. • Enhanced resolution confirms the existence of DNA-free regions inside the nucleus. • Optimized imaging conditions enable multicolor super-resolution imaging.

  11. Adsorption of a cationic dye molecule on polystyrene microspheres in colloids: effect of surface charge and composition probed by second harmonic generation.

    Science.gov (United States)

    Eckenrode, Heather M; Jen, Shih-Hui; Han, Jun; Yeh, An-Gong; Dai, Hai-Lung

    2005-03-17

    Nonlinear optical probe, second harmonic generation (SHG), of the adsorption of the dye molecule malachite green (MG), in cationic form at pH polystyrene microspheres in aqueous solution is used to study the effect of surface charge and composition on molecular adsorption. Three types of polystyrene microspheres with different surface composition are investigated: (1) a sulfate terminated, anionic surface, (2) a neutral surface without any functional group termination, and (3) an amine terminated, cationic surface. The cationic dye was found to adsorb at all three surfaces, regardless of surface charge. The adsorption free energies, DeltaG's, measured for the three surfaces are -12.67, -12.39, and -10.46 kcal/mol, respectively, with the trend as expected from the charge interactions. The adsorption density on the anionic surface, where attractive charge-charge interaction dominates, is determined by the surface negative charge density. The adsorption densities on the neutral and cationic surfaces are on the other hand higher, perhaps as a result of a balance between minimizing repulsive charge interaction and maximizing attractive molecule-substrate and intermolecular interactions. The relative strength of the SH intensity per molecule, in combination of a model calculation, reveals that the C(2) axis of the MG molecule is nearly perpendicular to the surface on the anionic surface and tilts away from the surface norm when the surface is neutral and further away when cationic. Changing the pH of the solution may alter the surface charge and subsequently affect the adsorption configuration and SH intensity.

  12. One Novel Multiple-Target Plasmid Reference Molecule Targeting Eight Genetically Modified Canola Events for Genetically Modified Canola Detection.

    Science.gov (United States)

    Li, Zhuqing; Li, Xiang; Wang, Canhua; Song, Guiwen; Pi, Liqun; Zheng, Lan; Zhang, Dabing; Yang, Litao

    2017-09-27

    Multiple-target plasmid DNA reference materials have been generated and utilized as good substitutes of matrix-based reference materials in the analysis of genetically modified organisms (GMOs). Herein, we report the construction of one multiple-target plasmid reference molecule, pCAN, which harbors eight GM canola event-specific sequences (RF1, RF2, MS1, MS8, Topas 19/2, Oxy235, RT73, and T45) and a partial sequence of the canola endogenous reference gene PEP. The applicability of this plasmid reference material in qualitative and quantitative PCR assays of the eight GM canola events was evaluated, including the analysis of specificity, limit of detection (LOD), limit of quantification (LOQ), and performance of pCAN in the analysis of various canola samples, etc. The LODs are 15 copies for RF2, MS1, and RT73 assays using pCAN as the calibrator and 10 genome copies for the other events. The LOQ in each event-specific real-time PCR assay is 20 copies. In quantitative real-time PCR analysis, the PCR efficiencies of all event-specific and PEP assays are between 91% and 97%, and the squared regression coefficients (R 2 ) are all higher than 0.99. The quantification bias values varied from 0.47% to 20.68% with relative standard deviation (RSD) from 1.06% to 24.61% in the quantification of simulated samples. Furthermore, 10 practical canola samples sampled from imported shipments in the port of Shanghai, China, were analyzed employing pCAN as the calibrator, and the results were comparable with those assays using commercial certified materials as the calibrator. Concluding from these results, we believe that this newly developed pCAN plasmid is one good candidate for being a plasmid DNA reference material in the detection and quantification of the eight GM canola events in routine analysis.

  13. A small azide-modified thiazole-based reporter molecule for fluorescence and mass spectrometric detection

    Directory of Open Access Journals (Sweden)

    Stefanie Wolfram

    2014-10-01

    Full Text Available Molecular probes are widely used tools in chemical biology that allow tracing of bioactive metabolites and selective labeling of proteins and other biomacromolecules. A common structural motif for such probes consists of a reporter that can be attached by copper(I-catalyzed 1,2,3-triazole formation between terminal alkynes and azides to a reactive headgroup. Here we introduce the synthesis and application of the new thiazole-based, azide-tagged reporter 4-(3-azidopropoxy-5-(4-bromophenyl-2-(pyridin-2-ylthiazole for fluorescence, UV and mass spectrometry (MS detection. This small fluorescent reporter bears a bromine functionalization facilitating the automated data mining of electrospray ionization MS runs by monitoring for its characteristic isotope signature. We demonstrate the universal utility of the reporter for the detection of an alkyne-modified small molecule by LC–MS and for the visualization of a model protein by in-gel fluorescence. The novel probe advantageously compares with commercially available azide-modified fluorophores and a brominated one. The ease of synthesis, small size, stability, and the universal detection possibilities make it an ideal reporter for activity-based protein profiling and functional metabolic profiling.

  14. CaSnO 3 obtained by modified Pechini method applied in the photocatalytic degradation of an azo dye

    Directory of Open Access Journals (Sweden)

    G. L. Lucena

    Full Text Available Abstract Pure forms of alkaline-earth stannates with perovskite structure (ASnO3, A= Ca2+, Sr2+, Ba2+ have been used as photocatalysts. In this work, CaSnO3 perovskite sample was synthesized by a modified Pechini method at 800 ºC and characterized by X-ray diffraction (XRD, UV-visible spectroscopy, infrared spectroscopy and Raman spectroscopy. The photocatalytic degradation of remazol golden yellow (RNL dye under UV radiation was evaluated. The XRD pattern showed that the synthesis method favored the orthorhombic CaSnO3 crystallization. According to the Raman spectrum, a material with high short-range order was obtained despite of the relatively low synthesis temperature, compared to the solid-state reaction one. The highest photocatalytic activity was attained at pH 3, which presented 51% discoloration and improved activity of 35% compared to discoloration solely due to adsorption (absence of radiation. The point of zero charge (PZC and the photocatalytic results indicated that a direct mechanism prevailed at pH 3, whereas an indirect mechanism prevailed at pH 6.

  15. Quantitative Structure-Retention Relationships (QSRR) for Chromatographic Separation of Disazo and Trisazo 4,4'-Diaminobenzanilide-based Dyes

    OpenAIRE

    Funar-Timofei, Simona; Fabian, Walter M. F.; Simu, Georgeta M.; Suzukic, Takahiro

    2006-01-01

    For a series of 23 disazo and trisazo 4,4'-diaminobenzanilide-based direct dye molecules, thechromatographic mobilities, extrapolated to modifier-free conditions (RM0 values), were determinedfrom reverse-phase thin-layer chromatography (RP-TLC) experiments. Traditional and rational QSAR/QSPR modelling techniques have been applied to find a quantitative structure-retention relationship (QSRR) for the dyes. Molecular dye structures were energy minimized by both molecular mechanics and quantum c...

  16. Application of zein-modified magnetite nanoparticles in dispersive magnetic micro-solid-phase extraction of synthetic food dyes in foodstuffs.

    Science.gov (United States)

    Jangju, Azam; Farhadi, Khalil; Hatami, Mehdi; Amani, Samireh; Esma-Ali, Farzan; Moshkabadi, Aisan; Hajilari, Fatemeh

    2017-03-01

    A simple method for the simultaneous and trace analysis of four synthetic food azo dyes including carmoisine, ponceau 4R, sunset yellow, and allura red from some foodstuff samples was developed by combining dispersive μ-solid-phase extraction and high-performance liquid chromatography with diode array detection. Zein-modified magnetic Fe 3 O 4 nanoparticles were prepared and used for μ-solid-phase extraction of trace amounts of mentioned food dyes. The prepared modified magnetic nanoparticles were characterized by scanning electron microscopy and FTIR spectroscopy. The factors affecting the extraction of the target analytes such as pH, amount of sorbent, extraction time, type and volume of the desorption eluent, and desorption time were investigated. Under the optimized conditions, the method provided good repeatability with relative standard deviations lower than 5.8% (n = 9). Limit of detection values ranged between 0.3 and 0.9 ng/mL with relatively high enrichment factors (224-441). Comparing the obtained results indicated that Fe 3 O 4 nanoparticles modified by zein biopolymer show better analytical application than bare magnetic nanoparticles. The proposed method was also applied for the determination of target synthetic food dyes in foodstuff samples such as carbonated beverage, snack, and candy samples. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Dynamic response of physisorbed hydrogen molecules on lanthanide-modified zirconia nanoparticles

    International Nuclear Information System (INIS)

    Loong, C.K.; Trouw, F.; Ozawa, Masakuni; Suzuki, Suguru

    1997-01-01

    Ultrafine lanthanide (Ln = Ce and Nd)-modified zirconia powders synthesized by a coprecipitation method exhibit high surface areas and adsorption sites that are essential for catalytic applications. We report a study of the surface chemistry of Ce 0.1 Zr 0.9 O 2 and Nd 0.1 Zr 0.9 O 1.95 powders. First, the specific surface area and porosity are characterized by nitrogen isotherm-adsorption measurements. Second, the motion of hydrogen molecules physisorbed on Ce- and Nd-doped zirconias is studied by inelastic neutron scattering. Nitrogen adsorption-desorption isotherm measurements yield a BET surface area (26.1 m 2 /g) and mesopore size (∼5 nm radius) in Ce 0.1 Zr 0.9 O 2 as compared to those (72.3 m 2 /g and ∼3 nm) in Nd 0.1 Zr 0.9 O 1.95 . The vibrational densities of states of H 2 on Ce 0.1 Zr 0.9 O 2 and Nd 0.1 Zr 0.9 O 1.95 were measured at 20 K over the 0-200 meV energy range for three hydrogen coverage. The spectra for both samples consist of two parts: a sharp peak at ∼14.5 meV and a broad component extending beyond 200 meV. The sharp peak corresponds to transitions from the J=0 to J=1 rotational states of bulk hydrogen molecules, and its intensity decreases with decreasing H 2 coverage. The broad component corresponds to overdamped motion of surface adsorbed hydrogen molecules. The major difference in the latter component between the Ce- and Nd-doped samples is an excess of intensities in the 5-14 meV region in Nd 0.1 Zr 0.9 O 1.95 . The confined motion of adsorbed H 2 on the different micropore and mesopore surfaces of Ce 0.1 Zr 0.9 O 2 and Nd 0.1 Zr 0.9 O 1.95 is discussed

  18. The local microenvironment surrounding dansyl molecules attached to controlled pore glass in pure and alcohol-modified supercritical carbon dioxide.

    Science.gov (United States)

    Page, Phillip M; McCarty, Taylor A; Munson, Chase A; Bright, Frank V

    2008-06-01

    We report on the local microenvironment surrounding a free dansyl probe, dansyl attached to controlled pore glass (D-CPG), and dansyl molecules attached to trimethylsilyl-capped CPG (capped D-CPG) in pure and alcohol-modified supercritical CO2. These systems were selected to provide insights into the local microenvironment surrounding a reactive agent immobilized at a silica surface in contact with pure and cosolvent-modified supercritical CO2. Local surface-bound dansyl molecule solvation on the CPG surface depends on the dansyl molecule surface loading, the surface chemistry (uncapped versus capped), the bulk fluid density, and the alcohol gas phase absolute acidity. At high dansyl loadings, the surface-bound dansyl molecules are largely "solvated" by other dansyl molecules and these molecules are not affected significantly by the fluid phase. When the dansyl surface loading decreases, dansyl molecules can be accessed/solvated/wetted by the fluid phase. However, at the lowest dansyl loadings studied, the dansyl molecules are in a fluid inaccessible/restrictive environment and do not sense the fluid phase to any significant degree. In uncapped D-CPG, one can poise the system such that the local concentration of an environmentally less responsible cosolvent (alcohol) in the immediate vicinity of surface-immobilized dansyl molecules can approach 100% even though the bulk solution contains orders of magnitude less of this less environmentally responsible cosolvent. In capped C-CPG, the surface excess is attenuated in comparison to that of uncapped D-CPG. The extent of this cosolvent surface excess is discussed in terms of the dansyl surface loading, the local density fluctuations, the cosolvent and surface silanol gas phase acidities, and the silica surface chemistry. These results also have implications for cleanings, extractions, heterogeneous reactions, separations, and nanomaterial fabrication using supercritical fluids.

  19. Fixation of some chemically modified reactive dye during gamma irradiation of cotton fabrics in presence of vinyl and acrylic monomers

    International Nuclear Information System (INIS)

    Zohdy, M.H.; El-Naggar, A.M.; Abdallah, W.A.

    1999-01-01

    The radiation grafting of vinyl sulfone dye having an activated double bond in presence of styrene monomer or its mixtures with ethyl acrylate onto cotton fabric has been investigated. The chemical reaction of the vinyl sulfone form with peroxy radicals on cotton fabric through covalent bonding is tested by extracting the dyed samples in 50% aqueous DMF solution. It was found that the presence of styene monomer in the dyeing solution is essential for the reaction or grafting of the vinyl sulfone dye. However, when a constant styrene concentration of 5% was used in the dye bath, the color strength expressed as K/S was found to increase by increasing the dye concentration. The results showed that the color strength obtained in case of using 10% ethyl acrylate is much lower than in the case of using the same concentration of styrene monomer. A solvent composition of equal ratios of methanol and water has been proven to be suitable to produce the highest improvement in the color strength. The irradiation dose was found to play an important role in initiating the reaction of the vinyl sulfone dye

  20. for aqueous dye lasers

    Indian Academy of Sciences (India)

    2014-02-12

    Feb 12, 2014 ... inclusion complex of RhB with the container molecule cucurbit[7]uril (CB[7]). Keywords. Temperature-dependent fluorescence; Rhodamine B; cucurbit[7]uril; host–guest complex; dye laser. PACS Nos 36.20.kd; 83.60.pq; 87.64.kv. 1. Introduction. Rhodamine B (RhB) is an efficient and photostable laser dye ...

  1. Theoretical study on the application of double-donor branched organic dyes in dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yan-Hong; Liu, Rui-Rui [Gansu Key Laboratory of Polymer Materials, College of Chemistry and Chemical Engineering, Key Laboratory of Eco-environment-related Polymer Materials, Ministry of Education, Northwest Normal University, Lanzhou, 730070, Gansu (China); Zhu, Kai-Li [College of Chemistry and Life Science, Gansu Normal University for Nationalities, Hezuo, 747000, Gansu (China); Song, Yan-Lin [Gansu Key Laboratory of Polymer Materials, College of Chemistry and Chemical Engineering, Key Laboratory of Eco-environment-related Polymer Materials, Ministry of Education, Northwest Normal University, Lanzhou, 730070, Gansu (China); Geng, Zhi-Yuan, E-mail: zhiyuangeng@126.com [Gansu Key Laboratory of Polymer Materials, College of Chemistry and Chemical Engineering, Key Laboratory of Eco-environment-related Polymer Materials, Ministry of Education, Northwest Normal University, Lanzhou, 730070, Gansu (China)

    2016-09-15

    A novel organic dye with 2D-A structure has been designed and calculated whereby density functional theory (DFT) and time-dependent density functional theory (TD-DFT) for dye-sensitized solar cells. The double-donor branched dye which was consisted of two separated light-harvesting moieties was beneficial to photocurrent generation. First, we discussed the effects of different donor chains on photoelectric performance in the dye molecule, using the DTP-B8 which was a previously reported structure as the reference. Only to conclude that the suitable length can achieve the satisfactory efficiency. Secondly, to modify and sift potential sensitizers further, three series of dyes (BC-series, CB-series and CC-series) were designed and characterized. The increased molar extinction coefficient and the red-shifted λ{sub max} was attributed to an increasing in electron conjunction. This work presented a new route to design sensitizers that provide two channels for donating more electrons and improve the final efficiency. It is expected to provide some theoretical guidance on designing and synthetizing high efficiency photosensitive dye in the future experiments. - Highlights: • A novel organic dye with 2D-A structure was designed and characterized. • The double-donor branched dye was consisted of two separated light-harvesting paths. • The double-donor branched dye was beneficial to photocurrent generation. • The molar extinction coefficient was greatly improved in this novel structure. • Four promising candidates have been screened out.

  2. 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.

  3. 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.

  4. Insight into the effects of modifying chromophores on the performance of quinoline-based dye-sensitized solar cells

    Science.gov (United States)

    Mao, Mao; Wang, Jian-Bo; Liu, Xiu-Lin; Wu, Guo-Hua; Fang, Xia-Qin; Song, Qin-Hua

    2018-02-01

    A series of organic dyes based on quinoline as an electron-deficient π-linker, were designed and synthesized for dye sensitized solar cells (DSSC) application. These push-pull conjugated dyes, sharing same anchoring group with distinctive electron-rich donating groups such as N,N-diethyl (DEA-Q), 3,6-dimethoxy carbazole (CBZ-Q), bis(4-butoxyphenyl)amine (BPA-Q), were synthesized by Riley oxidation of sbnd CH3 followed by Knoevenagel condensation of the corresponding aldehyde precursors 2a-c with cyanoacrylic acid. The optical, electrochemical, theoretical calculation and photovoltaic properties with these three dyes were systematically investigated. Compared to DEA-Q and CBZ-Q, BPA-Q possesses better light harvesting properties with regard to extended conjugate length, red-shifted intramolecular charge transfer band absorption and broaden light-responsive IPCE spectrum, resulting in a greater short circuit photocurrent density output. BPA-Q also has improved open-circuit voltage due to the apparent large charge recombination resistance. Consequently, assembled with iodine redox electrolytes, the device with BPA-Q achieved the best overall conversion efficiency value of 3.07% among three dyes under AM 1.5G standard conditions. This present investigation demonstrates the importance of various N-substituent chromophores in the prevalent D-π-A type organic sensitizers for tuning the photovoltaic performance of their DSSCs.

  5. Small Molecule Modifiers of the microRNA and RNA Interference Pathway

    OpenAIRE

    Deiters, Alexander

    2009-01-01

    Recently, the RNA interference (RNAi) pathway has become the target of small molecule inhibitors and activators. RNAi has been well established as a research tool in the sequence-specific silencing of genes in eukaryotic cells and organisms by using exogenous, small, double-stranded RNA molecules of approximately 20 nucleotides. Moreover, a recently discovered post-transcriptional gene regulatory mechanism employs microRNAs (miRNAs), a class of endogenously expressed small RNA molecules, whic...

  6. Adsorption of Procion Blue MX-R dye from aqueous solutions by lignin chemically modified with aluminium and manganese

    International Nuclear Information System (INIS)

    Adebayo, Matthew A.; Prola, Lizie D.T.; Lima, Eder C.; Puchana-Rosero, M.J.; Cataluña, Renato; Saucier, Caroline; Umpierres, Cibele S.; Vaghetti, Julio C.P.; Silva, Leandro G. da; Ruggiero, Reinaldo

    2014-01-01

    Graphical abstract: - Highlights: • Complexes of carboxy-methylated lignin with Al and Mn were used as adsorbents. • The optimum adsorption conditions were achieved at pH 2 and 298 K. • Maximum adsorption capacities are 73.52 mg g −1 (CML-Al) and 55.16 mg g −1 (CML-Mn). • CML-Al could remove ca. 95.83% of dye-contaminated industrial effluents. • CML-Al and CML-Mn are effective for treatment of simulated dye-house effluents. - Abstract: A macromolecule, CML, was obtained by purifying and carboxy-methylating the lignin generated from acid hydrolysis of sugarcane bagasse during bioethanol production from biomass. The CMLs complexed with Al 3+ (CML-Al) and Mn 2+ (CML-Mn) were utilised for the removal of a textile dye, Procion Blue MX-R (PB), from aqueous solutions. CML-Al and CML-Mn were characterised using Fourier transform infrared spectroscopy (FTIR), scanning differential calorimetry (SDC), scanning electron microscopy (SEM) and pH PZC . The established optimum pH and contact time were 2.0 and 5 h, respectively. The kinetic and equilibrium data fit into the general order kinetic model and Liu isotherm model, respectively. The CML-Al and CML-Mn have respective values of maximum adsorption capacities of 73.52 and 55.16 mg g −1 at 298 K. Four cycles of adsorption/desorption experiments were performed attaining regenerations of up to 98.33% (CML-Al) and 98.08% (CML-Mn) from dye-loaded adsorbents, using 50% acetone + 50% of 0.05 mol L −1 NaOH. The CML-Al removed ca. 93.97% while CML-Mn removed ca. 75.91% of simulated dye house effluents

  7. Adsorption of Procion Blue MX-R dye from aqueous solutions by lignin chemically modified with aluminium and manganese

    Energy Technology Data Exchange (ETDEWEB)

    Adebayo, Matthew A. [Institute of Chemistry, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, Postal Box 15003, 91501-970 Porto Alegre, RS (Brazil); Department of Chemical Sciences, Ajayi Crowther University, PMB 1066 Oyo, Oyo State (Nigeria); Prola, Lizie D.T. [Institute of Chemistry, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, Postal Box 15003, 91501-970 Porto Alegre, RS (Brazil); Lima, Eder C., E-mail: eder.lima@ufrgs.br [Institute of Chemistry, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, Postal Box 15003, 91501-970 Porto Alegre, RS (Brazil); Puchana-Rosero, M.J.; Cataluña, Renato; Saucier, Caroline; Umpierres, Cibele S.; Vaghetti, Julio C.P. [Institute of Chemistry, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, Postal Box 15003, 91501-970 Porto Alegre, RS (Brazil); Silva, Leandro G. da; Ruggiero, Reinaldo [Institute of Chemistry, Federal University of Uberlândia (UFU), AV. João Naves de Ávila 2121 block 1D—Campus Santa Mônica, 38400-902 Uberlândia, MG (Brazil)

    2014-03-01

    Graphical abstract: - Highlights: • Complexes of carboxy-methylated lignin with Al and Mn were used as adsorbents. • The optimum adsorption conditions were achieved at pH 2 and 298 K. • Maximum adsorption capacities are 73.52 mg g{sup −1} (CML-Al) and 55.16 mg g{sup −1} (CML-Mn). • CML-Al could remove ca. 95.83% of dye-contaminated industrial effluents. • CML-Al and CML-Mn are effective for treatment of simulated dye-house effluents. - Abstract: A macromolecule, CML, was obtained by purifying and carboxy-methylating the lignin generated from acid hydrolysis of sugarcane bagasse during bioethanol production from biomass. The CMLs complexed with Al{sup 3+} (CML-Al) and Mn{sup 2+} (CML-Mn) were utilised for the removal of a textile dye, Procion Blue MX-R (PB), from aqueous solutions. CML-Al and CML-Mn were characterised using Fourier transform infrared spectroscopy (FTIR), scanning differential calorimetry (SDC), scanning electron microscopy (SEM) and pH{sub PZC}. The established optimum pH and contact time were 2.0 and 5 h, respectively. The kinetic and equilibrium data fit into the general order kinetic model and Liu isotherm model, respectively. The CML-Al and CML-Mn have respective values of maximum adsorption capacities of 73.52 and 55.16 mg g{sup −1} at 298 K. Four cycles of adsorption/desorption experiments were performed attaining regenerations of up to 98.33% (CML-Al) and 98.08% (CML-Mn) from dye-loaded adsorbents, using 50% acetone + 50% of 0.05 mol L{sup −1} NaOH. The CML-Al removed ca. 93.97% while CML-Mn removed ca. 75.91% of simulated dye house effluents.

  8. Thermodynamics of organic molecule adsorption on sorbents modified with 5-hydroxy-6-methyluracil by inverse gas chromatography.

    Science.gov (United States)

    Gus'kov, Vladimir Yu; Gainullina, Yulia Yu; Ivanov, Sergey P; Kudasheva, Florida Kh

    2014-08-22

    The thermodynamic features of organic molecule adsorption from the gaseous phase of sorbents modified with 5-hydroxy-6-methyluracil (HMU) were studied. Molar internal energy and entropy of adsorption variation analyses showed that with every type surface, except for silica gel, layers of supramolecular structure have cavities equal in size with the ones revealed in HMU crystals by X-ray diffraction. Adsorption thermodynamics on HMU-modified sorbents depended on the amount of impregnated HMU and on the polarity, but not the porosity, of the initial sorbent. Polarity of the modified surface increased as a function of HMU quantity and initial sorbent mean pore size, but become appreciably lower if the initial surface is capable of hydrogen bonding. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Multifunctional stannum oxide compact bilayer modified by europium and erbium respectively doped ytterbium fluoride for high-performance dye-sensitized solar cell

    International Nuclear Information System (INIS)

    Yue, Jingyi; Xiao, Yaoming; Li, Yanping; Han, Gaoyi

    2017-01-01

    Graphical abstract: Multifunctional SnO 2 compact bilayer respectively modified by YbF 3 :Eu 3+ (SYEu) and YbF 3 :Er 3+ (SYEr) demonstrates three functions: 1) reducing the recombination rate of electron-hole pairs, 2) improving the utilization of sunlight, and 3) enhancing the long-term stability of the photovoltaic device. Display Omitted -- Highlights: •Multifunctional SYEu/SYEr compact bilayer is designed and fabricated. •The compact bilayer exhibits a reduced electron recombination rate. •The compact bilayer shows enhanced UV and IR light response via light-conversions. •The double layer has no significant influence on arising quenching effect. -- Abstract: Multifunctional stannum oxide compact bilayer modified by europium and erbium respectively doped ytterbium fluoride (SYEu/SYEr) is designed and prepared by a convenient and low-cost spin-coating approach for dye-sensitized solar cell. The most important three functions of the compact bilayer are reducing the recombination rate of electrons as a barrier layer, enlarging the utilization of sunlight as a luminescence material both with down- and up- conversions, and enhancing the long-term stability of the device as a defender of the dye. Besides, the construction of double layer with down- and up- conversion functions has no significant influence on giving rise to quenching effect. Furthermore, these findings offer potential applications for photovoltaic device with a wide range response of sunlight via the variation in rare-earth species and cell structures.

  10. 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

  11. Modifying TiO{sub 2} surface architecture by oxygen plasma to increase dye sensitized solar cell efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Rajmohan, Gayathri Devi [Institute for Frontier Materials, Deakin University, Geelong Waurn Ponds, Victoria 3216 (Australia); Dai, Xiujuan J., E-mail: jane.dai@deakin.edu.au [Institute for Frontier Materials, Deakin University, Geelong Waurn Ponds, Victoria 3216 (Australia); Tsuzuki, Takuya; Lamb, Peter R. [Institute for Frontier Materials, Deakin University, Geelong Waurn Ponds, Victoria 3216 (Australia); Plessis, Johan du [School of Applied Sciences, RMIT University, GPO Box 2476 V, Melbourne, Victoria 3001 (Australia); Huang, Fuzhi; Cheng, Yi-Bing [Department of Materials Engineering, Monash University, Melbourne, Victoria 3800 (Australia)

    2013-10-31

    Oxygen plasma treatment of TiO{sub 2} films has been used to improve the efficiency of dye sensitized solar cells. Both a commercial TiO{sub 2} sample and a TiO{sub 2} thin film synthesized by a sol-gel technique were treated using a custom built inductively coupled plasma apparatus. X-ray photoelectron spectroscopy revealed that oxygen-plasma treatment increased the number of oxygen functional groups (hydroxyl groups) and introduced some Ti{sup 3+} species on the surface of TiO{sub 2}. A sample solar cell with plasma treated TiO{sub 2} showed an overall solar-to-electricity conversion efficiency of 4.3%, about a 13% increase over untreated TiO{sub 2}. The photon conversion efficiency for the plasma treated TiO{sub 2} was 34% higher than untreated TiO{sub 2}. This enhanced cell-performance is partly due to increased dye adsorption from an increase in surface oxygen functional groups and also may be partly due to Ti{sup 3+} states on the surface of TiO{sub 2}. - Highlights: • Oxygen plasma is used to generate hydroxyl groups on the surface of TiO{sub 2} • Parallel study was conducted using a spin coated TiO{sub 2} and a Commercial TiO{sub 2} film. • The plasma functionalization caused increased dye uptake. • Some species in Ti{sup 3+} state are also generated after oxygen plasma. • Dye sensitised solar cell with functionalised electrode showed improved efficiency.

  12. Implementation of chitosan inductively modified by γ-rays copolymerization with acrylamide in the decontamination of aqueous basic dye solution

    Directory of Open Access Journals (Sweden)

    R.O. Aly

    2017-02-01

    Full Text Available The modification induced by gamma rays for the natural polymer, chitosan, was established using the monomer acrylamide. The hydrogel obtained was characterized using Fourier transform infrared spectroscopy and the thermal properties were investigated by thermogravimetric analysis (TGA. The effect of absorbed dose (kGy and chitosan:acrylamide ratio on the gel % was studied. The impact of the polymerization variables was observed on the swelling % of the prepared hydrogel with water. The highest equilibrium degree of swelling of the prepared chitosan–AAm hydrogel, 380 g/g was predicted at 75% AAm and absorbed dose of 10 kGy for 97.7% gel. The removal of the basic blue dye (Astrazone Blue BG-200% from aqueous solutions was discussed. The adsorption capacity of basic dye on chitosan–AAm increased from 24.5 to 47.2 mg/g by increasing pH from 4.0 to 9.0. The effect of pH, absorbed dose, chitosan:AAm ratio and the concentration of the dye on the effectiveness of the adsorption process was studied.

  13. High performance dye-sensitized solar cells using graphene modified fluorine-doped tin oxide glass by Langmuir–Blodgett technique

    Energy Technology Data Exchange (ETDEWEB)

    Roh, Ki-Min [Rare Metals Research Center, Korea Institute of Geoscience and Mineral Resources, Daejeon 305-350 (Korea, Republic of); Jo, Eun-Hee; Chang, Hankwon [Rare Metals Research Center, Korea Institute of Geoscience and Mineral Resources, Daejeon 305-350 (Korea, Republic of); Nanomaterials Science and Engineering Major, University of Science and Technology, Daejeon 305-350 (Korea, Republic of); Han, Tae Hee [Department of Organic and Nano Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Jang, Hee Dong, E-mail: hdjang@kigam.re.kr [Rare Metals Research Center, Korea Institute of Geoscience and Mineral Resources, Daejeon 305-350 (Korea, Republic of); Nanomaterials Science and Engineering Major, University of Science and Technology, Daejeon 305-350 (Korea, Republic of)

    2015-04-15

    Since the introduction of dye-sensitized solar cells (DSSCs) with low fabrication cost and high power conversion efficiency, extensive studies have been carried out to improve the charge transfer rate and performance of DSSCs. In this paper, we present DSSCs that use surface modified fluorine-doped tin oxide (FTO) substrates with reduced graphene oxide (r-GO) sheets prepared using the Langmuir–Blodgett (LB) technique to decrease the charge recombination at the TiO{sub 2}/FTO interface. R-GO sheets were excellently attached on FTO surface without physical deformations such as wrinkles; effects of the surface coverage of r-GO on the DSSC performance were also investigated. By using graphene modified FTO substrates, the resistance at the interface of TiO{sub 2}/FTO was reduced and the power conversion efficiency was increased to 8.44%. - Graphical abstract: DSSCs with graphene modified FTO glass were fabricated with the Langmuir Blodgett technique. GO sheets were transferred to FTO at various surface pressures in order to change the surface density of graphene and the highest power conversion efficiency of the DSSC was 8.44%. - Highlights: • By LB technique, r-GO sheets were coated on FTO without physical deformation. • DSSCs were fabricated with, r-GO modified FTO substrates. • With surface modification by r-GO, the interface resistance of DSSC decreased. • Maximum PCE of the DSSC was increased up to 8.44%.

  14. Immobilization of sericin molecules via amorphous carbon plasma modified-polystyrene dish for serum-free culture

    International Nuclear Information System (INIS)

    Tunma, Somruthai; Song, Doo-Hoon; Kim, Si-Eun; Kim, Kyoung-Nam; Han, Jeon-Geon; Boonyawan, Dheerawan

    2013-01-01

    In this study, we focused on sericin hydrolysates, originating from silkworm used in serum-free human bone marrow-derived mesenchymal stem cells (hBM-MSCs) culture. We reported the effect of a covalent linkage between a bioactive protein molecule and polystyrene dish surface via a carbon intermediate layer which can slow down the release rate of protein compounds into the phosphate buffer saline (PBS) solution. Films of amorphous carbon (a-C) and functionalized-carbon were deposited on PS culture dish surfaces by using a DC magnetron sputtering system and RF PECVD system. We found that a-C based-films can increase the hydrophilicity and biocompatibility of polystyrene (PS) dishes, especially a-C films and a-C:N 2 films showed good attachment of hBM-MSCs at 24 h. However, in the case of silica surface (a-C:SiO x films), the cells showed a ragged and unattached boundary resulting from the presence of surface silanol groups. For the UV–vis absorbance, all carbon modified-PS dishes showed a lower release rate of sericin molecules into PBS solution than PS control. This revealed that the functionalized carbon could be enhanced by specific binding properties with given molecules. The carbon-coated PS dishes grafting with sericin protein were used in a serum-free condition. We also found that hBM-MSCs have higher percentage of proliferated cells at day 7 for the modified dishes with carbon films and coated with sericin than the PS control coated with sericin. The physical film properties were measured by atomic force microscopy (AFM), scanning electron microscope (SEM) and contact angle measurement. The presence of -NH 2 groups of sericin compounds on the PS dish was revealed by Fourier transform infrared spectroscopy (FTIR). The stability of covalent bonds of sericin molecules after washing out ungrafted sericin was confirmed by X-ray photoelectron spectroscopy (XPS).

  15. Immobilization of sericin molecules via amorphous carbon plasma modified-polystyrene dish for serum-free culture

    Science.gov (United States)

    Tunma, Somruthai; Song, Doo-Hoon; Kim, Si-Eun; Kim, Kyoung-Nam; Han, Jeon-Geon; Boonyawan, Dheerawan

    2013-10-01

    In this study, we focused on sericin hydrolysates, originating from silkworm used in serum-free human bone marrow-derived mesenchymal stem cells (hBM-MSCs) culture. We reported the effect of a covalent linkage between a bioactive protein molecule and polystyrene dish surface via a carbon intermediate layer which can slow down the release rate of protein compounds into the phosphate buffer saline (PBS) solution. Films of amorphous carbon (a-C) and functionalized-carbon were deposited on PS culture dish surfaces by using a DC magnetron sputtering system and RF PECVD system. We found that a-C based-films can increase the hydrophilicity and biocompatibility of polystyrene (PS) dishes, especially a-C films and a-C:N2 films showed good attachment of hBM-MSCs at 24 h. However, in the case of silica surface (a-C:SiOx films), the cells showed a ragged and unattached boundary resulting from the presence of surface silanol groups. For the UV-vis absorbance, all carbon modified-PS dishes showed a lower release rate of sericin molecules into PBS solution than PS control. This revealed that the functionalized carbon could be enhanced by specific binding properties with given molecules. The carbon-coated PS dishes grafting with sericin protein were used in a serum-free condition. We also found that hBM-MSCs have higher percentage of proliferated cells at day 7 for the modified dishes with carbon films and coated with sericin than the PS control coated with sericin. The physical film properties were measured by atomic force microscopy (AFM), scanning electron microscope (SEM) and contact angle measurement. The presence of sbnd NH2 groups of sericin compounds on the PS dish was revealed by Fourier transform infrared spectroscopy (FTIR). The stability of covalent bonds of sericin molecules after washing out ungrafted sericin was confirmed by X-ray photoelectron spectroscopy (XPS).

  16. Immobilization of sericin molecules via amorphous carbon plasma modified-polystyrene dish for serum-free culture

    Energy Technology Data Exchange (ETDEWEB)

    Tunma, Somruthai [The Graduate School, Chiang Mai University, 239 Huay Kaew Road, Muang District, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics (ThEP), 239 Huay Kaew Road, Muang District, Chiang Mai 50200 (Thailand); Song, Doo-Hoon [Research Center for Orofacial Hard Tissue Regeneration, College of Dentistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Kim, Si-Eun; Kim, Kyoung-Nam [Research Center for Orofacial Hard Tissue Regeneration, College of Dentistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Department and Research Institute of Dental Biomaterials and Bioengineering, College of Dentistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Han, Jeon-Geon [Center for Advanced Plasma Surface Technology, Sungkyunkwan University, 300 Chunchun-dong, Jangan-gu, Suwon 440-746 (Korea, Republic of); Boonyawan, Dheerawan [Thailand Center of Excellence in Physics (ThEP), 239 Huay Kaew Road, Muang District, Chiang Mai 50200 (Thailand); Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, 239 Huay Kaew Road, Muang District, Chiang Mai 50200 (Thailand)

    2013-10-15

    In this study, we focused on sericin hydrolysates, originating from silkworm used in serum-free human bone marrow-derived mesenchymal stem cells (hBM-MSCs) culture. We reported the effect of a covalent linkage between a bioactive protein molecule and polystyrene dish surface via a carbon intermediate layer which can slow down the release rate of protein compounds into the phosphate buffer saline (PBS) solution. Films of amorphous carbon (a-C) and functionalized-carbon were deposited on PS culture dish surfaces by using a DC magnetron sputtering system and RF PECVD system. We found that a-C based-films can increase the hydrophilicity and biocompatibility of polystyrene (PS) dishes, especially a-C films and a-C:N{sub 2} films showed good attachment of hBM-MSCs at 24 h. However, in the case of silica surface (a-C:SiO{sub x} films), the cells showed a ragged and unattached boundary resulting from the presence of surface silanol groups. For the UV–vis absorbance, all carbon modified-PS dishes showed a lower release rate of sericin molecules into PBS solution than PS control. This revealed that the functionalized carbon could be enhanced by specific binding properties with given molecules. The carbon-coated PS dishes grafting with sericin protein were used in a serum-free condition. We also found that hBM-MSCs have higher percentage of proliferated cells at day 7 for the modified dishes with carbon films and coated with sericin than the PS control coated with sericin. The physical film properties were measured by atomic force microscopy (AFM), scanning electron microscope (SEM) and contact angle measurement. The presence of -NH{sub 2} groups of sericin compounds on the PS dish was revealed by Fourier transform infrared spectroscopy (FTIR). The stability of covalent bonds of sericin molecules after washing out ungrafted sericin was confirmed by X-ray photoelectron spectroscopy (XPS).

  17. Electric-field-modified Feshbach resonances in ultracold atom–molecule collision

    International Nuclear Information System (INIS)

    Cheng Dong; Li Ya; Feng Eryin; Huang Wuying

    2017-01-01

    We present a detailed analysis of near zero-energy Feshbach resonances in ultracold collisions of atom and molecule, taking the He–PH system as an example, subject to superimposed electric and magnetic static fields. We find that the electric field can induce Feshbach resonance which cannot occur when only a magnetic field is applied, through couplings of the adjacent rotational states of different parities. We show that the electric field can shift the position of the magnetic Feshbach resonance, and change the amplitude of resonance significantly. Finally, we demonstrate that, for narrow magnetic Feshbach resonance as in most cases of ultracold atom–molecule collision, the electric field may be used to modulate the resonance, because the width of resonance in electric field scale is relatively larger than that in magnetic field scale. (paper)

  18. Effect of Modified Pectin Molecules on the Growth of Bone Cells

    NARCIS (Netherlands)

    Kokkonen, H.E.; Ilvesaro, J.M.; Morra, M.; Schols, H.A.; Tuukkanen, J.

    2007-01-01

    The aim of this study was to investigate molecular candidates for bone implant nanocoatings, which could improve biocompatibility of implant materials. Primary rat bone cells and murine preosteoblastic MC3T3-E1 cells were cultured on enzymatically modified hairy regions (MHR-A and MHR-B) of apple

  19. Evaluation of the adsorbent properties of a zeolite rock modified for the removal of the azo dyes as water pollutants; Evaluacion de las propiedades adsorbentes de una roca zeolitica modificada para la remocion de colorantes azoicos como contaminantes del agua

    Energy Technology Data Exchange (ETDEWEB)

    Torres P, J

    2005-07-01

    At the moment some investigations which make reference to the removal of dyes for diverse adsorbent materials; as well as the factors that influence in the sorption process, considering the type so much of dye as those characteristics of the adsorbent material. In this work were investigated those adsorbent properties of a zeolite rock coming from San Luis Potosi State for the removal of azo dyes, using as peculiar cases the Red 40 (Red Allura) and the Yellow 5 (Tartrazine); for it were determined kinetic parameters and the sorption isotherms, as well as the sorption mechanisms involved in each case, between the dyes and the zeolite rock. In this work also it was considered the characterization before and after to removal of color from the water, through advanced analytical techniques such as the scanning electron microscopy of high vacuum (SEM), elementary microanalysis (EDS) and X-ray diffraction (XRD). The experimental part of the work fundamentally consisted, in the conditioning with a NaCl solution and later on the modification with HDTMA-Br of the natural zeolite rock, for then to put it in contact with solutions of the dyes R-40 and A-5, varying so much the contact times as the concentrations; the quantification of sodium in the liquid phase after the modification of the zeolite rock to determine the capacity of external cation exchange (CICE) it was carried out by means of the atomic absorption spectroscopy technique (EAA), and the quantification of the surfactant and the dyes in the liquid phase, it was carried out by means of the UV-vis spectrophotometry technique. It was found that the kinetic model that better it describes the process of sorption of R-40 and A-5 for the modified zeolite rock with HDTMA-Br, leaving of monocomponent and bi component solutions, it is the pseudo- second order. Inside of the obtained results for the sorption isotherms, as much the dye R-40 as the dye A-5 its presented a better adjustment to the Langmuir model. In what refers

  20. Engineering of Porphyrin Molecules for Use as Effective Cathode Interfacial Modifiers in Organic Solar Cells of Enhanced Efficiency and Stability.

    Science.gov (United States)

    Tountas, Marinos; Verykios, Apostolis; Polydorou, Ermioni; Kaltzoglou, Andreas; Soultati, Anastasia; Balis, Nikolaos; Angaridis, Panagiotis A; Papadakis, Michael; Nikolaou, Vasilis; Auras, Florian; Palilis, Leonidas C; Tsikritzis, Dimitris; Evangelou, Evangelos K; Gardelis, Spyros; Koutsoureli, Matroni; Papaioannou, George; Petsalakis, Ioannis D; Kennou, Stella; Davazoglou, Dimitris; Argitis, Panagiotis; Falaras, Polycarpos; Coutsolelos, Athanassios G; Vasilopoulou, Maria

    2018-06-06

    In the present work, we effectively modify the TiO 2 electron transport layer of organic solar cells with an inverted architecture using appropriately engineered porphyrin molecules. The results show that the optimized porphyrin modifier bearing two carboxylic acids as the anchoring groups and a triazine electron-withdrawing spacer significantly reduces the work function of TiO 2 , thereby reducing the electron extraction barrier. Moreover, the lower surface energy of the porphyrin-modified substrate results in better physical compatibility between the latter and the photoactive blend. Upon employing porphyrin-modified TiO 2 electron transport layers in PTB7:PC 71 BM-based organic solar cells we obtained an improved average power conversion efficiency up to 8.73%. Importantly, porphyrin modification significantly increased the lifetime of the devices, which retained 80% of their initial efficiency after 500 h of storage in the dark. Because of its simplicity and efficacy, this approach should give tantalizing glimpses and generate an impact into the potential of porphyrins to facilitate electron transfer in organic solar cells and related devices.

  1. Adsorption behavior of modified Iron stick yam skin with Polyethyleneimine as a potential biosorbent for the removal of anionic dyes in single and ternary systems at low temperature.

    Science.gov (United States)

    Zhang, Yan-Zhuo; Li, Jun; Zhao, Jing; Bian, Wei; Li, Yun; Wang, Xiu-Jie

    2016-12-01

    The skin of Iron stick yam (ISY) was modified with Polyethyleneimine (ISY@PEI) and evaluated for use as a potential biosorbent to remove the anionic dyes Sunset yellow (SY), Lemon yellow (LY), and Carmine (CM) from wastewater under low temperature conditions (5-15°C) in single and ternary dye systems. Both in the single and ternary systems, experimental data showed that adsorption capacity reached the highest value at 5°C, and adsorption capacity decreased when the temperature increased (10-50°C). The equilibrium data fitted very well to the Langmuir model and the extended Langmuir isotherm, for the single and ternary systems, respectively. The maximum adsorption capability was 138.92, 476.31, and 500.13mg/g for LY, SY, and CM, respectively, in a single system and 36.63, 303.31, and 294.12mg/g for LY, SY, and CM, respectively, in a ternary system. The adsorption followed pseudo-second-order kinetics. The thermodynamic parameters indicated that it was a spontaneous and exothermic process. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Decolourisation of dye solutions by oxidation with H2O2 in the presence of modified activated carbons

    International Nuclear Information System (INIS)

    Santos, V.P.; Pereira, M.F.R.; Faria, P.C.C.; Orfao, J.J.M.

    2009-01-01

    The decolourisation of dye solutions by oxidation with H 2 O 2 , using activated carbon as catalyst, is studied. For this purpose, three different samples, mainly differing in the respective surface chemistries, were prepared and characterized. Moreover, this work involved three pH levels, corresponding to acid, neutral and alkaline solutions, and six dyes belonging to several classes. The catalytic decolourisation tests were performed in a laboratorial batch reactor. Adsorption on activated carbon and non-catalytic peroxidation kinetic experiments were also carried out in the same reactor, in order to compare the efficiencies of the three processes. The non-catalytic reaction is usually inefficient and, typically, adsorption presents a low level of decolourisation. In these cases, the combination of activated carbon with hydrogen peroxide may significantly enhance the process, since the activated carbon catalyses the decomposition of H 2 O 2 into hydroxyl radicals, which are very reactive. Based on the experiments with the different activated carbon samples, which have similar physical properties, it is proved that the surface chemistry of the catalyst plays a key role, being the basic sample the most active. This is discussed considering the involvement of the free electrons on the graphene basal planes of activated carbon as active centres for the catalytic reaction. Additionally, it is shown that the decolourisation is enhanced at high pH values, and a possible explanation for this observation, based on the proposed mechanism, is given

  3. A detailed study on the working mechanism of a heteropoly acid modified TiO2 photoanode for efficient dye-sensitized solar cells.

    Science.gov (United States)

    Jiang, Yanxia; Yang, Yulin; Qiang, Liangsheng; Fan, Ruiqing; Li, Liang; Ye, Tengling; Na, Yong; Shi, Yan; Luan, Tianzhu

    2015-03-14

    A novel heteropolyacid (HPA) K6SiW11O39Ni(H2O)·xH2O (SiW11Ni) modified TiO2 has been successfully synthesized and introduced into the photoanode of dye-sensitized solar cells (DSSCs). The performance of the cell with the HPA-modified photoanode (SiW11Ni/TiO2), mixed with P25 powder in the ratio of 2 : 8, is better than the cell with a pristine P25 photoanode. An increase of 31% in the photocurrent and 22% improvement in the conversion efficiency are obtained. The effect of the heteropolyacid was well studied by UV-vis spectroscopy, spectro-electrochemical spectroscopy, dark current, intensity-modulated photocurrent spectroscopy and intensity-modulated photovoltage spectroscopy, open-circuit voltage decay and electrochemical impedance spectroscopy. The results show that the interfacial layer modified by SiW11Ni can enhance the injection and transport of electrons, and then retard the recombination of electrons, which results in a longer electron lifetime. What's more, the introduction of SiW11Ni can simultaneously broaden the absorption in the visible region, eventually leading to an efficient increase in energy conversion efficiency.

  4. Dye@bio-MOF-1 Composite as a Dual-Emitting Platform for Enhanced Detection of a Wide Range of Explosive Molecules.

    Science.gov (United States)

    Wang, Chen; Tian, Li; Zhu, Wei; Wang, Shiqiang; Wang, Peng; Liang, Yun; Zhang, Wanlin; Zhao, Hongwei; Li, Guangtao

    2017-06-14

    By incorporating a cationic dye within a metal-organic framework (MOF) through an ion-exchange process, a responsive dye@bio-MOF-1 composite has been synthesized, serving as a dual-emitting platform for enhanced detection of different kinds of nitro-explosives, especially nitroalkanes, nitramines, and nitrate esters. The dye@bio-MOF-1 composite was constructed with free amines on their well-defined cavities, which is essential for the capture of explosives into their confined nanospace. It was observed that the encapsulation of explosives into the constructed dye@bio-MOF-1 composite could dramatically alter the luminescent properties of the dyes as well as the MOF skeletons owing to the size exclusivity and confinement-induced effect. For nitroaromatics, the dye@bio-MOF-1 composite exhibits turn-off responses via fluorescence quenching. Unexpectedly, the composite shows unique turn-on responses for aliphatic nitro-organics via confinement-induced enhancement, demonstrating enhanced ability to detecting different kinds of explosives selectively in aqueous solution. Furthermore, the dye@bio-MOF-1 film was facilely fabricated, making the chemical sensing more convenient and easier to realize the discrimination of the targeted explosives. The dual tunable responses indicate that dye@bio-MOF-1 composites are favorable materials for molecular sensing. On the basis of the host-guest properties of the constructed dye@bio-MOF-1 composite, our work can be further extended to sensing specific analytes with remarkable turn-on sensing properties, in particular those difficult to recognize with conventional methods.

  5. Modifying factors of the cellular concentration of photolyase molecules in Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Fukui, A.; Laskowski, W.

    1984-01-01

    The effects of preillumination with photoreactivating light flashes before UV-irradiation on the number of photoreactivable complexes consisting of UV-induced DNA-damages and active photolyase molecules (Nsub(PREact), on the fluence decrements ΔDsub(PRE), that are obtained from two UV-survival curves without and with 1 flash photoreactivation and proportional to Nsub(PREact) were determined in haploid Saccharomyces cerevisiae cells. ΔDsub(PRE) increased by preillumination from 0.115 J m -2 to 0.460 Jm -2 and from 0.376 Jm -2 to 0.494 Jm -2 in cells in logarithmic growth phase and in stationary growth phase, respectively. ΔDsub(PRE) in log-cells that were preilluminated before and after resuspension in buffer at 40 0 C for 60 min was larger than ΔDsub(PRE) in log-cells preilluminated only after resuspension in buffer. (author)

  6. Simulation of fluorescence resonance energy transfer experiments: effect of the dyes on protein folding

    International Nuclear Information System (INIS)

    Allen, Lucy R; Paci, Emanuele

    2010-01-01

    Fluorescence resonance energy transfer is a powerful technique which is often used to probe the properties of proteins and complex macromolecules. The technique relies on relatively large fluorescent dyes which are engineered into the molecule of interest. In the case of small proteins, these dyes may affect the stability of the protein, and modify the folding kinetics and the folding mechanisms which are being probed. Here we use atomistic simulation to investigate the effect that commonly used fluorescent dyes have on the folding of a four-helix bundle protein. We show that, depending on where the dyes are attached, their effect on the kinetic and thermodynamic properties of the protein may be significant. We find that, while the overall folding mechanism is not affected by the dyes, they can destabilize, or even stabilize, intermediate states.

  7. Synthesis and characterization of reactive dye-cassava mesocarp ...

    African Journals Online (AJOL)

    The synthesis of triazine based reactive dyes was carried out. The resultant dyes were characterized by thin layers chromatography, molecular weight, infrared and ultra- violet spectroscopy, and used in dyeing cassava mesocarp to produce dye modified cellulosic substrates. The dyed substrates were tested for dye fixation, ...

  8. Phenotype-Based Screening of Small Molecules to Modify Plant Cell Walls Using BY-2 Cells.

    Science.gov (United States)

    Okubo-Kurihara, Emiko; Matsui, Minami

    2018-01-01

    The plant cell wall is an important and abundant biomass with great potential for use as a modern recyclable resource. For effective utilization of this cellulosic biomass, its ability to degrade efficiently is key point. With the aim of modifying the cell wall to allow easy decomposition, we used chemical biological technology to alter its structure. As a first step toward evaluating the chemicals in the cell wall we employed a phenotype-based approach using high-throughput screening. As the plant cell wall is essential in determining cell morphology, phenotype-based screening is particularly effective in identifying compounds that bring about alterations in the cell wall. For rapid and reproducible screening, tobacco BY-2 cell is an excellent system in which to observe cell morphology. In this chapter, we provide a detailed chemical biological methodology for studying cell morphology using tobacco BY-2 cells.

  9. One-Body Potential Theory of Molecules and Solids Modified Semiempirically for Electron Correlation

    International Nuclear Information System (INIS)

    March, N.H.

    2010-08-01

    The study of Cordero, March and Alonso (CMA) for four spherical atoms, Be,Ne,Mg and Ar, semiempirically fine-tunes the Hartree-Fock (HF) ground-state electron density by inserting the experimentally determined ionization potentials. The present Letter, first of all, relates this approach to the very recent work of Bartlett 'towards an exact correlated orbital theory for electrons'. Both methods relax the requirement of standard DFT that a one-body potential shall generate the exact ground-state density, though both work with high quality approximations. Unlike DFT, the CMA theory uses a modified HF non-local potential. It is finally stressed that this potential generates also an idempotent Dirac density matrix. The CMA approach is thereby demonstrated to relate, albeit approximately, to the DFT exchange-correlation potential. (author)

  10. Self-assembled gold nanoparticles modified ITO electrodes: The monolayer binder molecule effect

    Energy Technology Data Exchange (ETDEWEB)

    Ballarin, Barbara; Cassani, Maria Cristina; Scavetta, Erika; Tonelli, Domenica [Dipartimento di Chimica Fisica ed Inorganica, Universita di Bologna, V.le Risorgimento 4, 40136 Bologna, INSTM, UdR Bologna (Italy)

    2008-11-15

    The fabrication of gold attached organosilane-coated indium tin oxide Au{sub NPs}-MPTMS/ITO and Au{sub NPs}-APTES/ITO electrodes [MPTMS 3-(mercaptopropyl)-trimethoxysilane, APTES = 3-(aminopropyl)-triethoxysilane, ITO = indium tin oxide] was carried out making use of a well-known two-step procedure and the role played by the -SH and -NH{sub 2} functional groups in the two electrodes has been examined and compared using different techniques. Information about particle coverage and inter-particle spacing has been obtained using transmission electron microscopy (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM) whereas, bulk surface properties have been probed with UV-vis spectroscopy, CV and electrochemical impedance spectroscopy (EIS). The catalytic activity of the two electrodes has been evaluated studying the electrooxidation of methanol in alkaline conditions. The results obtained show that the NH{sub 2} functionality in the APTES binder molecule favours the formation of isle-like Au nanoparticle aggregates that lead to both a higher electron transfer and electrocatalytic activity. (author)

  11. Role of solvent environments in single molecule conductance used insulator-modified mechanically controlled break junctions

    Science.gov (United States)

    Muthusubramanian, Nandini; Maity, Chandan; Galan Garcia, Elena; Eelkema, Rienk; Grozema, Ferdinand; van der Zant, Herre; Kavli Institute of Nanoscience Collaboration; Department of Chemical Engineering Collaboration

    We present a method for studying the effects of polar solvents on charge transport through organic/biological single molecules by developing solvent-compatible mechanically controlled break junctions of gold coated with a thin layer of aluminium oxide using plasma enhanced atomic layer deposition (ALD). The optimal oxide thickness was experimentally determined to be 15 nm deposited at ALD operating temperature of 300°C which yielded atomically sharp electrodes and reproducible single-barrier tunnelling behaviour across a wide conductance range between 1 G0 and 10-7 G0. The insulator protected MCBJ devices were found to be effective in various solvents such as deionized water, phosphate buffered saline, methanol, acetonitrile and dichlorobenzene. The yield of molecular junctions using such insulated electrodes was tested by developing a chemical protocol for synthesizing an amphipathic form of oligo-phenylene ethynylene (OPE3-PEO) with thioacetate anchoring groups. This work has further applications in studying effects of solvation, dipole orientation and other thermodynamic interactions on charge transport. Eu Marie Curie Initial Training Network (ITN). MOLECULAR-SCALE ELECTRONICS: ``MOLESCO'' Project Number 606728.

  12. Simultaneous removal of binary mixture of Brilliant Green and Crystal Violet using derivative spectrophotometric determination, multivariate optimization and adsorption characterization of dyes on surfactant modified nano-γ-alumina

    Science.gov (United States)

    Zolgharnein, Javad; Bagtash, Maryam; Shariatmanesh, Tahere

    2015-02-01

    The present study deals with the simultaneous removal of Brilliant Green (BG) and Crystal Violet (CV) by surfactant-modified alumina. The utilization of alumina nanoparticles with an anionic surfactant (sodium dodecyl sulfate (SDS)) as a novel and efficient adsorbent is successfully carried out to remove two cationic dyes from aqueous solutions in binary batch systems. A first-order derivative spectrophotometric method is developed for the simultaneous determination of BG and CV in binary solutions. The linear concentration range and limits of detection for the simultaneous determination of BG and CV were found to be: 1-20, 1-15 mg/L, 0.3 and 0.5 mg/L, respectively. The influence of various parameters, such as contact time, initial concentration of dyes and sorbent mass on the dye adsorption is investigated. A response surface methodology achieved through performing the Box-Behnken design is utilized to optimize the removal of dyes by surfactant-modified nanoparticle alumina through a batch adsorption process. The proposed quadratic model resulting from the Box-Behnken design approach fitted very well with the experimental data. The optimal conditions for dye removal were contact time t = 50 min, sorbent dose = 0.036 g, CBG (Initial BG concentration) = 215 mg/L and CCV (Initial CV concentration) = 170 mg/L. Furthermore, FT-IR analysis, the isotherms and kinetics of adsorption were also explored.

  13. Enhancing sensitivity of SERRS nanoprobes by modifying heptamethine cyanine-based reporter molecules

    Directory of Open Access Journals (Sweden)

    Yunfei Zhang

    2016-07-01

    Full Text Available Surface enhanced resonance Raman scattering (SERRS is a physical phenomenon that occurs when the energy of incident light is close to that of electronic excitation of reporter molecules (RMs attached on substrates. SERRS has showed great promise in healthcare applications such as tumor diagnosis, image-guided tumor surgery and real-time evaluation of therapeutic response due to its ultra-sensitivity, manipulating convenience and easy accessibility. As the most widely used organic near-infrared (NIR fluorophore, heptamethine cyanines possess the electronic excitation energy that is close to the plasmon absorption energy of the gold nano-scaffolds, which results in the extraordinary enhancement of the SERRS signal. However, the effect of heptamethine cyanine structure and the gold nanoparticle morphology to the SERRS intensity are barely investigated. This work developed a series of SERRS nanoprobes in which two heptamethine cyanine derivatives (IR783 and IR780 were used as the RM and three gold nanoparticles (nanorod, nanosphere and nanostar were used as the substrates. Interestingly, even though IR780 and IR783 possess very similar chemical structure, SERRS signal produced by IR780 was determined as 14 times higher than that of IR783 when the RM concentration was 6.5 × 10−6M. In contrast, less than 4.0 fold SERRS signal intensity increase was measured by changing the substrate morphologies. Above experimental results indicate that finely tuning the chemical structure of the heptamethine cyanine could be a feasible way to develop robust SERRS probes to visualize tumor or guide tumor resection with high sensitivity and target to background ratio.

  14. The removal of Tartrazine dye by modified Alumina with sodium dodecyl sulfate from aqueous solutions: equilibrium and thermodynamic studies

    Directory of Open Access Journals (Sweden)

    A. Parchebaf Jadid

    2017-11-01

    Full Text Available Edible colors are materials which in the case of adding to food and drinks cause transferring color to them. Most of these colors are not acceptable in terms of applying in human food and underlies various diseases like gastrointestinal disorders, renal, liver and blood toxicity. The goal of this study was investigating the efficiency of improved alumina by sodium dodecyl sulfate (SDS in eliminating Tartrazine from aqueous environments. In this research, the impact of effective parameters such as initial concentration of Tartrazine, time, pH, alumina dose and SDS value were studied in order to approach an optimal condition for eliminating the color. Also, absorption behavior was evaluated by Freundlich and Langmuir isotherms. The highest efficiency of Tartrazine elimination in the solution resulted in optimal pH of 2, the amount of adsorbent 1.5 g/L, 16 min duration and value 0.04 SDS g/l which was obtained for dye concentration 5 mg/L about 94.13%. Also, results suggested that Tartrazine absorption follows Langmuir isotherm (R2 = 0.9867. Obtained results from thermodynamic studies such as Gibbs free energy (-5.728 Kj/mol and enthalpy (-85.86 Kj/mol and entropy (-271.102 J/mol.K also suggested that the absorption process was exothermic. The results of this research suggested that improved alumina by sodium dodecyl sulfate had a relative good capability in Tartrazine elimination from aqueous environments. Thus

  15. Adsorption studies of a water soluble dye, Reactive Red MF-3B, using sonication-surfactant-modified attapulgite clay

    International Nuclear Information System (INIS)

    Huang Jianhua; Liu Yuanfa; Jin Qingzhe; Wang Xingguo; Yang Jun

    2007-01-01

    The removal of water-soluble Reactive Red MF-3B from aqueous media by sonication-surfactant-modified attapulgite clay was studied in a batch system. The surfactant used was octodecyl trimethyl ammonium chloride (OTMAC). Adsorbent characterizations were investigated using X-ray diffraction, infrared spectroscopy, and surface area analysis. The effects of pH, contact time, initial solute concentration, adsorbent dose, and temperature on the adsorption of Reactive Red MF-3B onto modified clay were investigated. On the basis of kinetic studies, specific rate constants involved in the processes were calculated and second-order adsorption kinetics was observed in the case. Film diffusion was found to be the rate-limiting step. Reactive Red MF-3B adsorption was found to increase with increase temperature. The Reactive Red MF-3B equilibrium adsorption data were fitted to Freundlich and Langmuir isotherm models, the former being found to provide the better fit of the experimental data. Thermodynamic parameters were calculated. From the results it can be concluded that the surfactant-modified clay could be a good adsorbent for treating Reactive Red MF-3B-contaminated waters

  16. Laser Dyes

    Indian Academy of Sciences (India)

    amplification or generation of coherent light waves in the UV,. VIS, and near IR region. .... ciency in most flashlamp pumped dye lasers. It is used as reference dye .... have led to superior laser dyes with increased photostabilities. For instance ...

  17. 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.

  18. Solar Hydrogen Production Coupled with the Degradation of a Dye Pollutant Using TiO2 Modified with Platinum and Nafion

    Directory of Open Access Journals (Sweden)

    Jungwon Kim

    2014-01-01

    Full Text Available The simultaneous production of molecular hydrogen (H2 and degradation of rhodamine B (RhB was successfully achieved using TiO2 modified with platinum and nafion (Pt/TiO2/Nf under visible light (λ>420 nm. Pt/TiO2/Nf exhibited high activity for H2 production in the presence of RhB and EDTA as a photosensitizer (also an organic dye pollutant and an electron donor, respectively. However, the activity of TiO2 modified with either platinum or nafion for H2 production was negligible under the same experimental conditions. The negatively charged nafion layer enhances the adsorption of cationic RhB and pulls protons, a source of hydrogen, to the surface of TiO2 through electrostatic attraction. On the other hand, platinum deposits on TiO2 can act as an electron sink and a temporary electron reservoir for the reduction of protons. With the production of H2, RhB was gradually degraded through N-deethylation, which was confirmed by the spectral blue shift of the maximum absorption wavelength (λmax from 556 to 499 nm (corresponding to the λmax of rhodamine 110. With Pt/TiO2/Nf employed at [RhB]=20 μM (0.6 μmol, approximately 70 μmol of H2 was produced and RhB and its intermediates were completely removed over a 12 h period. A detailed reaction mechanism was discussed.

  19. Photocatalytic, antimicrobial activities of biogenic silver nanoparticles and electrochemical degradation of water soluble dyes at glassy carbon/silver modified past electrode using buffer solution.

    Science.gov (United States)

    Khan, Zia Ul Haq; Khan, Amjad; Shah, Afzal; Chen, Yongmei; Wan, Pingyu; Khan, Arif Ullah; Tahir, Kamran; Muhamma, Nawshad; Khan, Faheem Ullah; Shah, Hidayat Ullah

    2016-03-01

    In the present research work a novel, nontoxic and ecofriendly procedure was developed for the green synthesis of silver nano particle (AgNPs) using Caruluma edulis (C. edulis) extract act as reductant as well as stabilizer agents. The formation of AgNPs was confirmed by UV/Vis spectroscopy. The small and spherical sizes of AgNPs were conformed from high resolution transmission electron microscopy (HRTEM) analysis and were found in the range of 2-10nm, which were highly dispersion without any aggregation. The crystalline structure of AgNPs was conformed from X-ray diffraction (XRD) analysis. For the elemental composition EDX was used and FTIR helped to determine the type of organic compounds in the extract. The potential electrochemical property of modified silver electrode was also studied. The AgNPs showed prominent antibacterial motion with MIC values of 125 μg/mL against Bacillus subtilis and Staphylococcus aureus while 250 μg/mL against Escherichia coli. High cell constituents' release was exhibited by B. subtilis with 2 × MIC value of silver nanoparticles. Silver nanoparticles also showed significant DPPH free radical scavenging activity. This research would have an important implication for the synthesis of more efficient antimicrobial and antioxidant agent. The AgNP modified electrode (GC/AgNPs) exhibited an excellent electro-catalytic activity toward the redox reaction of phenolic compounds. The AgNPs were evaluated for electrochemical degradation of bromothymol blue (BTB) dyes which showed a significant activity. From the strong reductive properties it is obvious that AgNPs can be used in water sanitization and converting some organic perilous in to non-hazardous materials. The AgNPs showed potential applications in the field of electro chemistry, sensor, catalyst, nano-devices and medical. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Bleaching and diffusion dynamics in optofluidic dye lasers

    DEFF Research Database (Denmark)

    Gersborg-Hansen, Morten; Balslev, Søren; Mortensen, Asger

    2007-01-01

    The authors have investigated the bleaching dynamics that occur in optofluidic dye lasers where the liquid laser dye in a microfluidic channel is locally bleached due to optical pumping. They find that for microfluidic devices, the dye bleaching may be compensated through diffusion of dye molecules...

  1. Surface-Enhanced Raman Spectroscopy of Dye and Thiol Molecules Adsorbed on Triangular Silver Nanostructures: A Study of Near-Field Enhancement, Localization of Hot-Spots, and Passivation of Adsorbed Carbonaceous Species

    Directory of Open Access Journals (Sweden)

    Manuel R. Gonçalves

    2012-01-01

    Full Text Available Surface-enhanced Raman spectroscopy (SERS of thiols and dye molecules adsorbed on triangular silver nanostructures was investigated. The SERS hot-spots are localized at the edges and corners of the silver triangular particles. AFM and SEM measurements permit to observe many small clusters formed at the edges of triangular particles fabricated by nanosphere lithography. Finite-element calculations show that near-field enhancements can reach values of more than 200 at visible wavelengths, in the gaps between small spherical particles and large triangular particles, although for the later no plasmon resonance was found at the wavelengths investigated. The regions near the particles showing strong near-field enhancement are well correlated with spatial localization of SERS hot-spots done by confocal microscopy. Silver nanostructures fabricated by thermal evaporation present strong and fast fluctuating SERS activity, due to amorphous carbon contamination. Thiols and dye molecules seem to be able to passivate the undesired SERS activity on fresh evaporated silver.

  2. Surface-Enhanced Raman Spectroscopy of Dye and Thiol Molecules Adsorbed on Triangular Silver Nano structures: A Study of Near-Field Enhancement, Localization of Hot-Spots, and Passivation of Adsorbed Carbonaceous Species

    International Nuclear Information System (INIS)

    Goncalves, M.R.; Marti, O.; Fabian Enderle, F.

    2012-01-01

    Surface-enhanced Raman spectroscopy (SERS) of thiols and dye molecules adsorbed on triangular silver nanostructures was investigated. The SERS hot-spots are localized at the edges and corners of the silver triangular particles. AFM and SEM measurements permit to observe many small clusters formed at the edges of triangular particles fabricated by nanosphere lithography. Finite-element calculations show that near-field enhancements can reach values of more than 200 at visible wavelengths, in the gaps between small spherical particles and large triangular particles, although for the later no plasmon resonance was found at the wavelengths investigated. The regions near the particles showing strong near-field enhancement are well correlated with spatial localization of SERS hot-spots done by confocal microscopy. Silver nanostructures fabricated by thermal evaporation present strong and fast fluctuating SERS activity, due to amorphous carbon contamination. Thiols and dye molecules seem to be able to passivate the undesired SERS activity on fresh evaporated silver. excitation: by far-field illumination of metal nanostructures or rough metal Raman scattering cross-section of gold-palladium target Temporal Fluctuation in SERS Temporal and spectral fluctuations.

  3. Smectite flocculation structure modified by Al13 macro-molecules--as revealed by the transmission X-ray microscopy (TXM).

    Science.gov (United States)

    Zbik, Marek S; Martens, Wayde N; Frost, Ray L; Song, Yen-Fang; Chen, Yi-Ming; Chen, Jian-Hua

    2010-05-01

    The aggregate structure which occurs in aqueous smectitic suspensions is responsible for poor water clarification, difficulties in sludge dewatering and the unusual rheological behaviour of smectite rich soils. These macroscopic properties are dictated by the 3D structural arrangement of smectite finest fraction within flocculated aggregates. Here, we report results from a relatively new technique, transmission X-ray microscopy (TXM), which makes it possible to investigate the internal structure and 3D tomographic reconstruction of the smectite clay aggregates modified by Al(13) Keggin macro-molecule [Al(13)(O)(4)(OH)(24)(H(2)O)(12)](7+). Three different treatment methods were shown resulted in three different micro-structural environments of the resulting flocculation. In case of smectite sample prepared in Methods 1 and 3 particles fall into the primary minimum where Van der Waals forces act between FF oriented smectite flakes and aggregates become approach irreversible flocculation. In case of sample prepared using Method 2, particles contacting by edges (EE) and edge to face (EF) orientation fell into secondary minimum and weak flocculation resulted in severe gelation and formation of the micelle-like texture in fringe superstructure, which was first time observed in smectite based gel. Copyright 2010 Elsevier Inc. All rights reserved.

  4. Photoactive curcumin-derived dyes with surface anchoring moieties used in ZnO nanoparticle-based dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Ganesh, T.; Kim, Jong Hoon; Yoon, Seog Joon; Kil, Byung-Ho; Maldar, N.N.; Han, Jin Wook; Han, Sung-Hwan

    2010-01-01

    Photoactive, eco-friendly and high molar extinction coefficient, curcumin-derived dyes (BCMoxo and BCtCM) have been explored in ZnO nanoparticles (NPs)-based dye-sensitized solar cells (DSSCs). The boron complex curcumin dyes modified with di-carboxylic anchor groups (BCtCM) provided surface attachment with a strong UV-vis region absorption than the dye molecule without anchor groups (BCMoxo). Photoanodes primed with poly-dispersive ZnO NPs (∼80-50 nm) specifically devised for these dyes and optimized for the critical thickness, sensitization time and concentration using a solvent-free ionic electrolyte so as to get current density as high as 1.66 mA/cm 2 under 80 mW/cm 2 irradiation. Therefore, a successful conversion of visible light into electricity by using these curcumin-derived dyes (natural derived photoactive molecules) as photosensitizer in DSSCs would be a great interest in future studies for enhancing further conversion efficiencies.

  5. Photoactive curcumin-derived dyes with surface anchoring moieties used in ZnO nanoparticle-based dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Ganesh, T.; Kim, Jong Hoon; Yoon, Seog Joon; Kil, Byung-Ho; Maldar, N.N. [Inorganic Nano-Materials Laboratory, Department of Chemistry, Hanyang University, Sung-Dong-Ku, Haengdang-dong 17, Seoul (Korea, Republic of); Han, Jin Wook, E-mail: jwhan@hanyang.ac.kr [Inorganic Nano-Materials Laboratory, Department of Chemistry, Hanyang University, Sung-Dong-Ku, Haengdang-dong 17, Seoul (Korea, Republic of); Han, Sung-Hwan, E-mail: shhan@hanyang.ac.kr [Inorganic Nano-Materials Laboratory, Department of Chemistry, Hanyang University, Sung-Dong-Ku, Haengdang-dong 17, Seoul (Korea, Republic of)

    2010-09-01

    Photoactive, eco-friendly and high molar extinction coefficient, curcumin-derived dyes (BCMoxo and BCtCM) have been explored in ZnO nanoparticles (NPs)-based dye-sensitized solar cells (DSSCs). The boron complex curcumin dyes modified with di-carboxylic anchor groups (BCtCM) provided surface attachment with a strong UV-vis region absorption than the dye molecule without anchor groups (BCMoxo). Photoanodes primed with poly-dispersive ZnO NPs ({approx}80-50 nm) specifically devised for these dyes and optimized for the critical thickness, sensitization time and concentration using a solvent-free ionic electrolyte so as to get current density as high as 1.66 mA/cm{sup 2} under 80 mW/cm{sup 2} irradiation. Therefore, a successful conversion of visible light into electricity by using these curcumin-derived dyes (natural derived photoactive molecules) as photosensitizer in DSSCs would be a great interest in future studies for enhancing further conversion efficiencies.

  6. An easy and effective method for the intercalation of hydrophobic natural dye into organo-montmorillonite for improved photostability

    Science.gov (United States)

    Taguchi, Taiga; Kohno, Yoshiumi; Shibata, Masashi; Tomita, Yasumasa; Fukuhara, Choji; Maeda, Yasuhisa

    2018-05-01

    β-carotene (BC) is one of the naturally occurring dyes belonging to the carotenoids group. Although it is more environmentally friendly and better suited for humans compared with synthetic dyes, it destabilizes with light and heat, easily losing its color under irradiation. Extended application of BC are therefore limited. The aim of this study is to improve the stability of BC by intercalation into the montmorillonite layers modified with a cationic surfactant, by a simple mixing and minimal solvent use. The physical mixing of small quantities of concentrated BC/hexane solutions with organo-modified montmorillonite successfully resulted in the composite material. The length and the number of alkyl chains of the surfactant used for the organic modification influenced the stability enhancement of the incorporated dye. The improved stability of the dye molecules incorporated in the interlayer space was found to be due to restricted contact with atmospheric oxygen.

  7. Investigation into Photoconductivity in Single CNF/TiO2-Dye Core–Shell Nanowire Devices

    Directory of Open Access Journals (Sweden)

    Rochford Caitlin

    2010-01-01

    Full Text Available Abstract A vertically aligned carbon nanofiber array coated with anatase TiO2 (CNF/TiO2 is an attractive possible replacement for the sintered TiO2 nanoparticle network in the original dye-sensitized solar cell (DSSC design due to the potential for improved charge transport and reduced charge recombination. Although the reported efficiency of 1.1% in these modified DSSC’s is encouraging, the limiting factors must be identified before a higher efficiency can be obtained. This work employs a single nanowire approach to investigate the charge transport in individual CNF/TiO2 core–shell nanowires with adsorbed N719 dye molecules in dark and under illumination. The results shed light on the role of charge traps and dye adsorption on the (photo conductivity of nanocrystalline TiO2 CNF’s as related to dye-sensitized solar cell performance.

  8. BODIPYs for Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Klfout, Hafsah; Stewart, Adam; Elkhalifa, Mahmoud; He, Hongshan

    2017-11-22

    BODIPY, abbreviation of boron-dipyrromethene, is one class of robust organic molecules that has been used widely in bioimaging, sensing, and logic gate design. Recently, BODIPY dyes have been explored for dye-sensitized solar cells (DSCs). Studies demonstrate their potential as light absorbers for the conversion of solar energy to electricity. However, their photovoltaic performance is inferior to many other dyes, including porphyrin dyes. In this review, several synthetic strategies of BODIPY dyes for DSCs and their further functionalization are described. The photophysical properties of dye molecules and their photovoltaic performances in DSCs are summarized. We aim to provide readers a clear picture of the field and expect to shed light on the next generation of BODIPY dyes for their applications in solar energy conversion.

  9. Modified magnetite nanoparticles with cetyltrimethylammonium bromide as superior adsorbent for rapid removal of the disperse dyes from wastewater of textile companies

    Directory of Open Access Journals (Sweden)

    Ali Asghar Rajabi

    2016-01-01

    Full Text Available This paper reports application of cetyltrimethylammonium bromide (CTAB coated magnetite nanoparticles (Fe3O4 NPs as a novel adsorbent for removal of two types of disperse dyes, including disperse red 167, and disperse blue 183, from wastewater of textile companies. The effect of parameters including type of surfactant, pH of solution, surfactant concentration, and amount of salt, was investigated and optimized. The obtained results showed that the ratio of initial dye concentration to CTAB amounts has critical effect on removal processes so that removal efficiencies higher than 95% can be achieved even at high concentration of dyes as high as 500 mg l-1 when the ratio is optimum. Removal of dyes is very fast, and equilibrium is reached at times less than 10 min even for high concentration of the dyes. Very high adsorbent capacity (as high as 2000 mg g-1 was yielded for maximum tested concentration of the dyes (500 mg g-1. The obtained result was confirmed by thermogravimetric analysis data. This study showed that CTAB coated Fe3O4 NPs is a very efficient adsorbent for removal of dyes from wastewater of textile companies and has high capacity under optimum conditions.

  10. Optimized adsorption of sulfonated phthalocyanines on ZnO electrodes and their characterization in dye- sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Falgenhauer, Jane; Loewenstein, Thomas; Schlettwein, Derck [Institute of Applied Physics, Justus-Liebig-University Giessen (Germany)

    2010-07-01

    Phthalocyanines belong to the most stable industrial dyes and show some of the highest molar extinction coefficients in the visible range. ZnO is known as a wide band gap semiconductor material which can be conveniently prepared as a porous electrode from solution-based processes. Sulfonated phthalocyanines were adsorbed at such electrodeposited porous ZnO thin films to work as a photosensitizer in a dye sensitized solar cell (DSSC). The adsorption solution of the phthalocyanine was modified in its composition and by adding different detergents in different concentrations. The adsorption solutions and the sensitized ZnO films were investigated by UV/Vis spectroscopy to characterize the aggregation of the dye molecules. Most of the detergents used could minimize the aggregation of the dye molecules in the adsorption solution without hindering the adsorption of the phthalocyanine on the ZnO surface. The photoelectrochemical characteristics of the resulting test cells were determined using a standard liquid electrolyte. The efficiency of the cells did not reach the expected level and reasons for this are discussed based on film morphology, amount of adsorbed dye molecules, competition by detergent adsorption, the optical absorbance of the dyes in the film and aggregate formation.

  11. Increased charge transfer of Poly (ethylene oxide) based electrolyte by addition of small molecule and its application in dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Muthuraaman, B.; Will, Geoffrey; Wang, Hongxia; Moonie, Paul; Bell, John

    2013-01-01

    A Poly (ethylene oxide) based polymer electrolyte impregnated with 2-Mercapto benzimidazole was comprehensively characterized by XRD, UV–visible spectroscopy, FTIR as well as electrochemical impedance spectroscopy. It was found that the crystallization of PEO was dramatically reduced and the ionic conductivity of the electrolyte was increased 4.5 fold by addition of 2-Mercapto benzimidazole. UV–visible and FTIR spectroscopes indicated the formation of charge transfer complex between 2-Mercapto benzimidazole and iodine of the electrolyte. Dye-sensitized solar cells with the polymer electrolytes were assembled. It was found that both the photocurrent density and photovoltage were enhanced with respect to the DSC without 2-Mercapto benzimidazole, leading to a 60% increase of the performance of the cell.

  12. Synthesis of functionalized MgAl-layered double hydroxides via modified mussel inspired chemistry and their application in organic dye adsorption.

    Science.gov (United States)

    Zhao, Jiao; Huang, Qiang; Liu, Meiying; Dai, Yanfeng; Chen, Junyu; Huang, Hongye; Wen, Yuanqing; Zhu, Xiaoli; Zhang, Xiaoyong; Wei, Yen

    2017-11-01

    In this paper, a novel strategy for the preparation of poly(levodopa) functionalized MgAl-layered double hydroxide (PDOPA-f-LDH) was developed based on the modified mussel inspired chemistry. The utilization of PDOPA-f-LDH for the removal of methylene blue (MB) from aqueous solution was also examined. Taken advantage of the self-polymerization of levodopa (DOPA) in alkaline solution and the strong affinity of catechol groups to the substrate surface, the LDH was covered homogeneously by a layer of polymer coating of DOPA, leading to the functionalization toward LDH. The structure, surface morphology, thermostability and elemental composition of as-prepared PDOPA-f-LDH were investigated by the transmission electron microscope, scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy. Besides, the surface charge of the PDOPA-f-LDH was also investigated using zeta potential. The effects of various parameters, including contact time, initial MB concentration, solution pH and temperature, on the adsorption of MB onto PDOPA-f-LDH were systematically investigated. Results show that the adsorption capacity of functionalized LDH at 25°C could reach up to 102mg/g, which is much higher than that of pure LDH in the same experimental conditions. The adsorption kinetics and isotherm of MB adsorption were studied in batch experiments. The pseudo-second-order model is found to be the best to describe the adsorption kinetics. The isotherm result shows that the Freundlich isotherm is the better-fit-isotherm model to represent the equilibrium data. The values of thermodynamic parameters, including enthalpy change ΔH 0 , entropy change ΔS 0 and Gibbs free energy change ΔG 0 , were also determined. All the ΔG 0 values are negative; the ΔH 0 and ΔS 0 values of PDOPA-f-LDH were -7.824kJmol -1 and -0.01562kJmol -1 K -1 , respectively. And the activation energy of system (E a ) is calculated as 24.69k

  13. Differential Expression of Osteo-Modulatory Molecules in Periodontal Ligament Stem Cells in Response to Modified Titanium Surfaces

    Directory of Open Access Journals (Sweden)

    So Yeon Kim

    2014-01-01

    Full Text Available This study assessed differential gene expression of signaling molecules involved in osteogenic differentiation of periodontal ligament stem cells (PDLSCs subjected to different titanium (Ti surface types. PDLSCs were cultured on tissue culture polystyrene (TCPS, and four types of Ti discs (PT, SLA, hydrophilic PT (pmodPT, and hydrophilic SLA (modSLA with no osteoinductive factor and then osteogenic activity, including alkaline phosphatase (ALP activity, mRNA expression of runt-related gene 2, osterix, FOSB, FRA1, and protein levels of osteopontin and collagen type IA, were examined. The highest osteogenic activity appeared in PDLSCs cultured on SLA, compared with the TCPS and other Ti surfaces. The role of surface properties in affecting signaling molecules to modulate PDLSC behavior was determined by examining the regulation of Wnt pathways. mRNA expression of the canonical Wnt signaling molecules, Wnt3a and β-catenin, was higher on SLA and modSLA than on smooth surfaces, but gene expression of the calcium-dependent Wnt signaling molecules Wnt5a, calmodulin, and NFATc1 was increased significantly on PT and pmodPT. Moreover, integrin α2/β1, sonic hedgehog, and Notch signaling molecules were affected differently by each surface modification. In conclusion, surface roughness and hydrophilicity can affect differential Wnt pathways and signaling molecules, targeting the osteogenic differentiation of PDLSCs.

  14. Strong interaction between dye molecule and electromagnetic field localized around 1 Nm3 at gaps of nanoparticle dimers by plasmon resonance

    Science.gov (United States)

    Itoh, Tamitake; Yamamoto, Yuko S.

    2017-11-01

    Electronic transition rates of a molecule located at a crevasse or a gap of a plasmonic nanoparticle (NP) dimer are largely enhanced up to the factor of around 106 due to electromagnetic (EM) coupling between plasmonic and molecular electronic resonances. The coupling rate is determined by mode density of the EM fields at the crevasse and the oscillator strength of the local electronic resonance of a molecule. The enhancement by EM coupling at a gap of plasmonic NP dimer enables us single molecule (SM) Raman spectroscopy. Recently, this type of research has entered a new regime wherein EM enhancement effects cannot be treated by conventional theorems, namely EM mechanism. Thus, such theorems used for the EM enhancement effect should be re-examined. We here firstly summarize EM mechanism by using surface-enhanced Raman scattering (SERS), which is common in EM enhancement phenomena. Secondly, we focus on recent two our studies on probing SM fluctuation by SERS within the spatial resolution of sub-nanometer scales. Finally, we discuss the necessity of re-examining the EM mechanism with respect to two-fold breakdowns of the weak coupling assumption: the breakdown of Kasha's rule induced by the ultra-fast plasmonic de-excitation and the breakdown of the weak coupling by EM coupling rates exceeding both the plasmonic and molecular excitonic dephasing rates.

  15. Removal of blue 1 dye of aqueous solutions with a modified clay with iron chloride; Remocion de colorante azul 1 de soluciones acuosas con una arcilla modificada con cloruro de hierro

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez H, K. A.

    2012-07-01

    At the present time, several technologies have been proposed to remove dyes from water, adsorption is one of the most feasible methods and adsorbents with different properties, such as activated carbon, zeolites, clays and hydrogels among others. In this work, the sorption behavior of blue 1 dye by a natural clay from a site located in the Center-East of Mexico, and other modified with iron chloride were determined. The materials were characterized by X-ray diffraction to analyze its crystal structure, by scanning electron microscopy and elemental microanalysis of energy dispersive X-ray spectrometry to determine the composition and morphology, and the zero point charges were also determined to know the charge distribution on the surface of the clay. The ph effect, contact time, dye concentration and temperature were the parameters considered in this study. The results showed that clay does not suffer any important changes in its structure after the chemical treatments (modification with ferric chloride and contact with blue 1 solutions). The ph influences lightly the adsorption of the dye with natural clay, but the same effect is not observed in the ferric modified clay among the factor ph 6 and 8. The equilibrium time and the sorption capacity for natural clay were 48 hours and 6.16 mg/g, while for the ferric clay were 24 hours and 14.22 mg/g. Adsorption kinetics results were best adjusted to the pseudo first and pseudo second order models. Adsorption isotherms were best adjusted to the Langmuir model, indicating that both clays have a homogeneous surface. Thermodynamic parameters (E, {Delta}S and {Delta}G and {Delta}H) were calculated for the dye adsorption by the natural clay using data of the adsorption kinetics at temperatures between 20 and 50 C, indicating that the adsorption process is exothermic. For the case of ferric clay, it was not possible to calculate these thermodynamic parameters because the adsorption capacities were similar in the range of

  16. An in vitro tag-and-modify protein sample generation method for single-molecule fluorescence resonance energy transfer.

    Science.gov (United States)

    Hamadani, Kambiz M; Howe, Jesse; Jensen, Madeleine K; Wu, Peng; Cate, Jamie H D; Marqusee, Susan

    2017-09-22

    Biomolecular systems exhibit many dynamic and biologically relevant properties, such as conformational fluctuations, multistep catalysis, transient interactions, folding, and allosteric structural transitions. These properties are challenging to detect and engineer using standard ensemble-based techniques. To address this drawback, single-molecule methods offer a way to access conformational distributions, transient states, and asynchronous dynamics inaccessible to these standard techniques. Fluorescence-based single-molecule approaches are parallelizable and compatible with multiplexed detection; to date, however, they have remained limited to serial screens of small protein libraries. This stems from the current absence of methods for generating either individual dual-labeled protein samples at high throughputs or protein libraries compatible with multiplexed screening platforms. Here, we demonstrate that by combining purified and reconstituted in vitro translation, quantitative unnatural amino acid incorporation via AUG codon reassignment, and copper-catalyzed azide-alkyne cycloaddition, we can overcome these challenges for target proteins that are, or can be, methionine-depleted. We present an in vitro parallelizable approach that does not require laborious target-specific purification to generate dual-labeled proteins and ribosome-nascent chain libraries suitable for single-molecule FRET-based conformational phenotyping. We demonstrate the power of this approach by tracking the effects of mutations, C-terminal extensions, and ribosomal tethering on the structure and stability of three protein model systems: barnase, spectrin, and T4 lysozyme. Importantly, dual-labeled ribosome-nascent chain libraries enable single-molecule co-localization of genotypes with phenotypes, are well suited for multiplexed single-molecule screening of protein libraries, and should enable the in vitro directed evolution of proteins with designer single-molecule conformational

  17. Quantum dot-dye hybrid systems for energy transfer applications

    International Nuclear Information System (INIS)

    Ren, Ting

    2010-01-01

    In this thesis, we focus on the preparation of energy transfer-based quantum dot (QD)-dye hybrid systems. Two kinds of QD-dye hybrid systems have been successfully synthesized: QD-silica-dye and QD-dye hybrid systems. In the QD-silica-dye hybrid system, multishell CdSe/CdS/ZnS QDs were adsorbed onto monodisperse Stoeber silica particles with an outer silica shell of thickness 2-24 nm containing organic dye molecules (Texas Red). The thickness of this dye layer has a strong effect on the total sensitized acceptor emission, which is explained by the increase in the number of dye molecules homogeneously distributed within the silica shell, in combination with an enhanced surface adsorption of QDs with increasing dye amount. Our conclusions were underlined by comparison of the experimental results with Monte-Carlo simulations, and by control experiments confirming attractive interactions between QDs and Texas Red freely dissolved in solution. New QD-dye hybrid system consisting of multishell QDs and organic perylene dyes have been synthesized. We developed a versatile approach to assemble extraordinarily stable QD-dye hybrids, which uses dicarboxylate anchors to bind rylene dyes to QD. This system yields a good basis to study the energy transfer between QD and dye because of its simple and compact design: there is no third kind of molecule linking QD and dye; no spacer; and the affinity of the functional group to the QD surface is strong. The FRET signal was measured for these complexes as a function of both dye to QD ratio and center-to-center distance between QD and dye by controlling number of covered ZnS layers. Data showed that fluorescence resonance energy transfer (FRET) was the dominant mechanism of the energy transfer in our QD-dye hybrid system. FRET efficiency can be controlled by not only adjusting the number of dyes on the QD surface or the QD to dye distance, but also properly choosing different dye and QD components. Due to the strong stability, our QD-dye

  18. Quantum dot-dye hybrid systems for energy transfer applications

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Ting

    2010-07-01

    In this thesis, we focus on the preparation of energy transfer-based quantum dot (QD)-dye hybrid systems. Two kinds of QD-dye hybrid systems have been successfully synthesized: QD-silica-dye and QD-dye hybrid systems. In the QD-silica-dye hybrid system, multishell CdSe/CdS/ZnS QDs were adsorbed onto monodisperse Stoeber silica particles with an outer silica shell of thickness 2-24 nm containing organic dye molecules (Texas Red). The thickness of this dye layer has a strong effect on the total sensitized acceptor emission, which is explained by the increase in the number of dye molecules homogeneously distributed within the silica shell, in combination with an enhanced surface adsorption of QDs with increasing dye amount. Our conclusions were underlined by comparison of the experimental results with Monte-Carlo simulations, and by control experiments confirming attractive interactions between QDs and Texas Red freely dissolved in solution. New QD-dye hybrid system consisting of multishell QDs and organic perylene dyes have been synthesized. We developed a versatile approach to assemble extraordinarily stable QD-dye hybrids, which uses dicarboxylate anchors to bind rylene dyes to QD. This system yields a good basis to study the energy transfer between QD and dye because of its simple and compact design: there is no third kind of molecule linking QD and dye; no spacer; and the affinity of the functional group to the QD surface is strong. The FRET signal was measured for these complexes as a function of both dye to QD ratio and center-to-center distance between QD and dye by controlling number of covered ZnS layers. Data showed that fluorescence resonance energy transfer (FRET) was the dominant mechanism of the energy transfer in our QD-dye hybrid system. FRET efficiency can be controlled by not only adjusting the number of dyes on the QD surface or the QD to dye distance, but also properly choosing different dye and QD components. Due to the strong stability, our QD-dye

  19. Modeling the efficiency of Förster resonant energy transfer from energy relay dyes in dye-sensitized solar cells

    KAUST Repository

    Hoke, Eric T.

    2010-02-11

    Förster resonant energy transfer can improve the spectral breadth, absorption and energy conversion efficiency of dye sensitized solar cells. In this design, unattached relay dyes absorb the high energy photons and transfer the excitation to sensitizing dye molecules by Förster resonant energy transfer. We use an analytic theory to calculate the excitation transfer efficiency from the relay dye to the sensitizing dye accounting for dynamic quenching and relay dye diffusion. We present calculations for pores of cylindrical and spherical geometry and examine the effects of the Förster radius, the pore size, sensitizing dye surface concentration, collisional quenching rate, and relay dye lifetime. We find that the excitation transfer efficiency can easily exceed 90% for appropriately chosen dyes and propose two different strategies for selecting dyes to achieve record power conversion efficiencies. © 2010 Optical Society of America.

  20. A NIR-remote controlled upconverting nanoparticle: an improved tool for living cell dye-labeling

    International Nuclear Information System (INIS)

    Zheng, Bin; Gong, Xiaoqun; Wang, Hanjie; Wang, Sheng; Chang, Jin; Wang, Huiquan; Li, Wei; Tan, Jian

    2015-01-01

    In living cells, due to the selective permeability and complicated cellular environment, the uptake efficiency and fluorescence decay of organic dyes during dye-labeling may be influenced, which may eventually result in poor fluorescent imaging. In this work, a protocol of UCNs@mSiO_2-(FA and Azo) core–shell nanocarriers was designed and prepared successfully. The core–shell nanocarriers were assembled from two parts, including a mesoporous silica shell surface modified by folate (FA) and azobenzene (Azo), and an upconverting nanocrystal (UCN) core. The mesoporous silica shell is used for loading organic dyes and conjugating folate which helps to enhance the cellular uptake of nanocarriers. The UCN core works as a transducer to convert near infrared (NIR) light to local UV and visible light to activate a back-and-forth wagging motion of azobenzene molecules on the surface, while the azobenzene acts as a molecular impeller for propelling the release of organic dyes. The nanocarriers of loading organic dyes can maintain the stability of the fluorescent imaging effect better than free organic dyes. The experimental results show that with the help of the nanoparticle, cell uptake efficiency of the model dyes of rhodamine and 4′, 6-diamidino-2-phenylindole (DAPI) was significantly improved. The release of dyes can only be triggered by NIR light exposure and their quantity is highly dependent on the duration of NIR light exposure, thus realizing NIR-regulated dye release spatiotemporally. Our work may open a novel avenue for precisely controlling UCN-based living cell imaging in biotechnology and diagnostics, as well as studying cell dynamics, cell–cell interactions, and tissue morphogenesis. (paper)

  1. Electrical properties of SAM-modified ITO surface using aromatic small molecules with double bond carboxylic acid groups for OLED applications

    International Nuclear Information System (INIS)

    Can, Mustafa; Havare, Ali Kemal; Aydın, Hasan; Yagmurcukardes, Nesli; Demic, Serafettin; Icli, Sıddık; Okur, Salih

    2014-01-01

    Graphical abstract: - Highlights: • We report that the performance of OLED consist of aromatic small molecules with double bond carboxylic acid groups on ITO surface. • The OLED devices were tested in terms of electrical and optical characteristics. • The I–V results show that OLEDs with SAM-modified ITO surface have lower turn on voltages than OLED configurations without SAMs. - Abstract: 5-[(3-Methylphenyl)(phenyl)amino]isophthalic acid (5-MePIFA) and 5-(diphenyl)amino]isophthalic acid (5-DPIFA) organic molecules were synthesized to form self-assembled monolayer on indium tin oxide (ITO) anode to enhance hole transport from ITO to organic hole transport layers such as TPD. The modified surface was characterized by scanning tunneling microscopy (STM). The change in the surface potential was measured by Kelvin probe force microscopy (KPFM). Our Kelvin probe force microscopy (KPFM) measurements showed that the surface potentials increased more than 100 mV with reference to bare indium tin-oxide. The results show that the threshold voltage on OLEDs with modified ITO is lowered significantly compared to OLEDs with unmodified ITO. The hole mobility of TPD has been estimated using space–charge-limited current measurements (SCLC)

  2. Electrical properties of SAM-modified ITO surface using aromatic small molecules with double bond carboxylic acid groups for OLED applications

    Energy Technology Data Exchange (ETDEWEB)

    Can, Mustafa [Izmir Katip Celebi University, Faculty of Engineering, Department of Engineering Sciences, Çiğli, Izmir (Turkey); Havare, Ali Kemal [Toros University, Faculty of Engineering, Electric and Electronic Department, Mersin (Turkey); Aydın, Hasan; Yagmurcukardes, Nesli [Izmir Institute of Technology, Material Science and Engineering, Izmir (Turkey); Demic, Serafettin [Izmir Katip Celebi University, Faculty of Engineering, Department of Material Science and Engineering, Çiğli, Izmir (Turkey); Icli, Sıddık [Ege University, Solar Energy Institute, Izmir (Turkey); Okur, Salih, E-mail: salih.okur@ikc.edu.tr [Izmir Katip Celebi University, Faculty of Engineering, Department of Material Science and Engineering, Çiğli, Izmir (Turkey)

    2014-09-30

    Graphical abstract: - Highlights: • We report that the performance of OLED consist of aromatic small molecules with double bond carboxylic acid groups on ITO surface. • The OLED devices were tested in terms of electrical and optical characteristics. • The I–V results show that OLEDs with SAM-modified ITO surface have lower turn on voltages than OLED configurations without SAMs. - Abstract: 5-[(3-Methylphenyl)(phenyl)amino]isophthalic acid (5-MePIFA) and 5-(diphenyl)amino]isophthalic acid (5-DPIFA) organic molecules were synthesized to form self-assembled monolayer on indium tin oxide (ITO) anode to enhance hole transport from ITO to organic hole transport layers such as TPD. The modified surface was characterized by scanning tunneling microscopy (STM). The change in the surface potential was measured by Kelvin probe force microscopy (KPFM). Our Kelvin probe force microscopy (KPFM) measurements showed that the surface potentials increased more than 100 mV with reference to bare indium tin-oxide. The results show that the threshold voltage on OLEDs with modified ITO is lowered significantly compared to OLEDs with unmodified ITO. The hole mobility of TPD has been estimated using space–charge-limited current measurements (SCLC)

  3. Two photon absorption energy transfer in the light-harvesting complex of photosystem II (LHC-II) modified with organic boron dye

    Science.gov (United States)

    Chen, Li; Liu, Cheng; Hu, Rui; Feng, Jiao; Wang, Shuangqing; Li, Shayu; Yang, Chunhong; Yang, Guoqiang

    2014-07-01

    The plant light-harvesting complexes of photosystem II (LHC-II) play important roles in collecting solar energy and transferring the energy to the reaction centers of photosystems I and II. A two photon absorption compound, 4-(bromomethyl)-N-(4-(dimesitylboryl)phenyl)-N-phenylaniline (DMDP-CH2Br), was synthesized and covalently linked to the LHC-II in formation of a LHC-II-dye complex, which still maintained the biological activity of LHC-II system. Under irradiation with femtosecond laser pulses at 754 nm, the LHC-II-dye complex can absorb two photons of the laser light effectively compared with the wild type LHC-II. The absorbed excitation energy is then transferred to chlorophyll a with an obvious fluorescence enhancement. The results may be interesting and give potentials for developing hybrid photosystems.

  4. The removal of reactive dyes from aqueous solutions using chemically modified mesoporous silica in the presence of anionic surfactant-The temperature dependence and a thermodynamic multivariate analysis

    International Nuclear Information System (INIS)

    Cestari, Antonio R.; Vieira, Eunice F.S.; Vieira, Glaucia S.; Costa, Luiz P. da; Tavares, Andrea M.G.; Loh, Watson; Airoldi, Claudio

    2009-01-01

    The three-parameter Sips adsorption model was successfully employed to modeled equilibrium adsorption data of a yellow and a red dye onto a mesoporous aminopropyl-silica, in the presence of the surfactant sodium dodecylbenzenesulfonate (DBS) from 25 to 55 deg. C. The results were evaluated in relation to the previously reported surface tension measurements. The presence of curvatures of the vant Hoff plots suggested the presence of non-zero heat capacities terms (Δ ads C p ). For the yellow dye, it is observed that the values of Δ ads H are almost all positive and they decrease in endothermicity, in the absence and in the presence of DBS, from 25 to 55 deg. C. For the red dye, there is an increase in endothermicity in relation to the temperature increase. The negative Δ ads G values indicate spontaneous adsorption processes. Almost all adsorption entropy values (Δ ads S) were positive. This suggests that entropy is a driving force of adsorption. The adsorption thermodynamic parameters were also evaluated using a new 2 3 full factorial design analysis. The multivariate polynomial modelings indicated that the thermodynamic parameters are also affected by important interactive effects of the experimental factors and not by the temperature changes alone

  5. The removal of reactive dyes from aqueous solutions using chemically modified mesoporous silica in the presence of anionic surfactant-The temperature dependence and a thermodynamic multivariate analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cestari, Antonio R. [Laboratory of Materials and Calorimetry, Departamento de Quimica/CCET, Universidade Federal de Sergipe, CEP 49100-000, Sao Cristovao, Sergipe (Brazil)], E-mail: cestari@ufs.br; Vieira, Eunice F.S.; Vieira, Glaucia S.; Costa, Luiz P. da; Tavares, Andrea M.G. [Laboratory of Materials and Calorimetry, Departamento de Quimica/CCET, Universidade Federal de Sergipe, CEP 49100-000, Sao Cristovao, Sergipe (Brazil); Loh, Watson; Airoldi, Claudio [Universidade Estadual de Campinas, Instituto de Quimica, CP 6154, 13083-970, Campinas, Sao Paulo (Brazil)

    2009-01-15

    The three-parameter Sips adsorption model was successfully employed to modeled equilibrium adsorption data of a yellow and a red dye onto a mesoporous aminopropyl-silica, in the presence of the surfactant sodium dodecylbenzenesulfonate (DBS) from 25 to 55 deg. C. The results were evaluated in relation to the previously reported surface tension measurements. The presence of curvatures of the vant Hoff plots suggested the presence of non-zero heat capacities terms ({delta}{sub ads}C{sub p}). For the yellow dye, it is observed that the values of {delta}{sub ads}H are almost all positive and they decrease in endothermicity, in the absence and in the presence of DBS, from 25 to 55 deg. C. For the red dye, there is an increase in endothermicity in relation to the temperature increase. The negative {delta}{sub ads}G values indicate spontaneous adsorption processes. Almost all adsorption entropy values ({delta}{sub ads}S) were positive. This suggests that entropy is a driving force of adsorption. The adsorption thermodynamic parameters were also evaluated using a new 2{sup 3} full factorial design analysis. The multivariate polynomial modelings indicated that the thermodynamic parameters are also affected by important interactive effects of the experimental factors and not by the temperature changes alone.

  6. Diffusion dynamics in micro-fluidic dye lasers

    DEFF Research Database (Denmark)

    Gersborg-Hansen, Morten; Balslev, Søren; Mortensen, Niels Asger

    2007-01-01

    We have investigated the bleaching dynamics that occur in opto-fluidic dye lasers, where the liquid laser dye in a channel is locally bleached due to optical pumping. Our studies suggest that for micro-fluidic devices, the dye bleaching may be compensated through diffusion of dye molecules alone....... By relying on diffusion rather than convection to generate the necessary dye replenishment, our observation potentially allows for a significant simplification of opto-fluidic dye laser device layouts, omitting the need for cumbersome and costly external fluidic handling or on-chip micro-fluidic pumping...

  7. Dye linked conjugated homopolymers: using conjugated polymer electroluminescence to optically pump porphyrin-dye emission

    DEFF Research Database (Denmark)

    Nielsen, K.T.; Spanggaard, H.; Krebs, Frederik C

    2004-01-01

    . Electroluminescent devices of the homopolymer itself and of the zinc-porphyrin containing polymer were prepared and the nature of the electroluminescence was characterized. The homopolymer segments were found to optically pump the emission of the zinc-porphyrin dye moities. The homopolymer exhibits blue......Zinc-porphyrin dye molecules were incorporated into the backbone of a conjugated polymer material by a method, which allowed for the incorporation of only one zinc-porphyrin dye molecule into the backbone of each conjugated polymer molecule. The electronic properties of the homopolymer were...

  8. Magnetic field effects in dye-sensitized solar cells controlled by different cell architecture.

    Science.gov (United States)

    Klein, M; Pankiewicz, R; Zalas, M; Stampor, W

    2016-07-21

    The charge recombination and exciton dissociation are generally recognized as the basic electronic processes limiting the efficiency of photovoltaic devices. In this work, we propose a detailed mechanism of photocurrent generation in dye-sensitized solar cells (DSSCs) examined by magnetic field effect (MFE) technique. Here we demonstrate that the magnitude of the MFE on photocurrent in DSSCs can be controlled by the radius and spin coherence time of electron-hole (e-h) pairs which are experimentally modified by the photoanode morphology (TiO2 nanoparticles or nanotubes) and the electronic orbital structure of various dye molecules (ruthenium N719, dinuclear ruthenium B1 and fully organic squaraine SQ2 dyes). The observed MFE is attributed to magnetic-field-induced spin-mixing of (e-h) pairs according to the Δg mechanism.

  9. Design and construction of liquid lasers using organic dyes

    International Nuclear Information System (INIS)

    Hariri, Akbar.

    1984-01-01

    Organic dye solution show great promise of obtaining tunable coherent light over the uv, visible and near infrared portion of spectrum. In this paper we describe various pumping schemes of dye molecules. Design, construction and performance of a pulsed dye laser, transversely pumped by a nitrogen laser and wall-ablation flash lamp-pumped dye lasers are the particular examples which are presented in detail

  10. FRET structure with non-radiative acceptor provided by dye-linker-glass surface complex and single-molecule photodynamics by TIRFM-polarized imaging

    International Nuclear Information System (INIS)

    Tani, Toshiro; Mashimo, Kei; Suzuki, Tetsu; Horiuchi, Hiromi; Oda, Masaru

    2008-01-01

    We present our recent study of microscopic single-molecule imaging on the artificial complex of tetramethylrhodamine linked with a propyl chain onto silica glass surface, i.e. an asymmetric fluorescence resonance energy transfer (FRET) structure with non-radiative acceptor. In the synthesis of the complex, we used a mixture of two kinds of isomers to introduce rather small photodynamic difference among them. This isomeric structure change will provide more or less a distinctive photophysical change in e.g. non-radiative relaxation rate. Our recent observation at room temperatures, so far, shows that such contributions can be discriminated in the histograms of the fluorescent spot intensities; broad but distinctive multi-components appear. To identify the isomeric difference as a cause of structures, some configurational assumptions are necessary. One such basic prerequisite is that the transition dipoles of the chromophores should be oriented almost parallel to the glass surface. In order to make clear the modeling, we also provide preliminary experiments on the polarization dependence of the imaging under rotating polarization in epi-illumination

  11. CW organic dye laser

    International Nuclear Information System (INIS)

    Tuccio, S.A.; Peterson, O.G.

    1975-01-01

    A method and apparatus for producing continuous emission from a lasing medium comprising organic dye molecules in solution are described. Continuous emission is accomplished by flowing the medium through a focused optical cavity while simultaneously producing a population inversion in that portion of the medium flowing in close proximity to the focal point of the cavity. The population inversion is produced by pumping the medium longitudinally, along the optical axis of the cavity, preferably by the focused output of a continuous-wave argon laser. Sufficient thermal energy is continuously dissipated from the medium to maintain the optical homogeneity thereof at or above the quality required for continuous emission

  12. A modified gradient approach for the growth of low-density InAs quantum dot molecules by molecular beam epitaxy

    Science.gov (United States)

    Sharma, Nandlal; Reuter, Dirk

    2017-11-01

    Two vertically stacked quantum dots that are electronically coupled, so called quantum dot molecules, are of great interest for the realization of solid state building blocks for quantum communication networks. We present a modified gradient approach to realize InAs quantum dot molecules with a low areal density so that single quantum dot molecules can be optically addressed. The individual quantum dot layers were prepared by solid source molecular beam epitaxy depositing InAs on GaAs(100). The bottom quantum dot layer has been grown without substrate rotation resulting in an In-gradient across the surface, which translated into a density gradient with low quantum dot density in a certain region of the wafer. For the top quantum dot layer, separated from the bottom quantum dot layer by a 6 nm thick GaAs barrier, various InAs amounts were deposited without an In-gradient. In spite of the absence of an In-gradient, a pronounced density gradient is observed for the top quantum dots. Even for an In-amount slightly below the critical thickness for a single dot layer, a density gradient in the top quantum dot layer, which seems to reproduce the density gradient in the bottom layer, is observed. For more or less In, respectively, deviations from this behavior occur. We suggest that the obvious influence of the bottom quantum dot layer on the growth of the top quantum dots is due to the strain field induced by the buried dots.

  13. Fluorescence study of some xanthine dyes under stepped laser excitation

    International Nuclear Information System (INIS)

    Chirkova, L.V.; Ketsle, G.A.; Ermagambetov, K.T.

    1996-01-01

    Paper is devoted to definition of triplet state in molecules of xanthine dyes and study of intramolecular energy circulation. Stepped two-quanta excitation of dyes has been carried out with help of experimental unit. Intensive luminescence activated by excitation of triplet molecules of dyes within triplet-triplet band with wave length of 1060 nm was registered for eosin. Given luminescence spectrally coincides with fast fluorescence. 5 refs., 6 figs

  14. Event-specific qualitative and quantitative detection of five genetically modified rice events using a single standard reference molecule.

    Science.gov (United States)

    Kim, Jae-Hwan; Park, Saet-Byul; Roh, Hyo-Jeong; Shin, Min-Ki; Moon, Gui-Im; Hong, Jin-Hwan; Kim, Hae-Yeong

    2017-07-01

    One novel standard reference plasmid, namely pUC-RICE5, was constructed as a positive control and calibrator for event-specific qualitative and quantitative detection of genetically modified (GM) rice (Bt63, Kemingdao1, Kefeng6, Kefeng8, and LLRice62). pUC-RICE5 contained fragments of a rice-specific endogenous reference gene (sucrose phosphate synthase) as well as the five GM rice events. An existing qualitative PCR assay approach was modified using pUC-RICE5 to create a quantitative method with limits of detection correlating to approximately 1-10 copies of rice haploid genomes. In this quantitative PCR assay, the square regression coefficients ranged from 0.993 to 1.000. The standard deviation and relative standard deviation values for repeatability ranged from 0.02 to 0.22 and 0.10% to 0.67%, respectively. The Ministry of Food and Drug Safety (Korea) validated the method and the results suggest it could be used routinely to identify five GM rice events. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Enhanced performance of dye-sensitized solar cells with layered structure graphitic carbon nitride and reduced graphene oxide modified TiO2 photoanodes

    Science.gov (United States)

    Lv, Huiru; Hu, Haihua; Cui, Can; Lin, Ping; Wang, Peng; Wang, Hao; Xu, Lingbo; Pan, Jiaqi; Li, Chaorong

    2017-11-01

    TiO2/reduced graphene oxide (TiO2/rGO) composite has been widely exploited as the photoanode material for high efficient dye-sensitized solar cells (DSSCs). However, the power conversion efficiency (PCE) is limited due to the charge recombination between the rGO and electrolyte. In this paper, we incorporate 5.5 wt% layered structure graphitic carbon nitride (g-C3N4) and 0.25 wt% rGO into TiO2 nanoparticle (NP) film to form a triple-component TiO2/rGO/g-C3N4 (TGC) photoanode for DSSCs. The TGC photoanode significantly increased the dye absorption and thus to improve the light harvesting efficiency. Furthermore, the electrochemical impedance spectroscopy (EIS) analysis of the DSSCs based on TGC photoanode demonstrates that the incorporation of the rGO and g-C3N4 into TiO2 effectively accelerates the electron transfer and reduces the charge recombination. As a result, the DSSCs based on TGC film show PCE of 5.83%, enhanced by 50.1% compared with that of pure TiO2 photoanodes. This result strongly suggests a facile strategy to improve the photovoltaic performance of DSSCs.

  16. Properties of excited singular states of the anthraquinone dye in the Langmuir-Blodgett films

    International Nuclear Information System (INIS)

    Baratova, A.A.; Ibraev, N.Kh.

    2004-01-01

    The spectral luminescence properties of the anthraquinone dye solution and the Langmuir-Blodgett films have been investigated. The nature of the absorption centers is determined from the spectral characteristics. The conclusion about probable spatial configuration of the dye molecule in the dye molecule in monolayer on water surface is made. (author)

  17. Nano-dyeing

    Directory of Open Access Journals (Sweden)

    Ning Cui-Juan

    2016-01-01

    Full Text Available Dyeing nanofibers is a frontier of both modern textile engineering and nanotechnology. This paper suggest a feasible method for dyeing nanofibers with a natural red (Roselle Calyx by bubble electrospinning. Reactive dye (Red S3B and acid dye (Red 2B were also used in the experiment for comparison. The dyeing process was finished during the spinning process.

  18. Use of Fricke solution modified with dyes for dosimetry in phototherapeutic treatments; Uso da solucao Fricke modificada com corantes para futura dosimetria em tratamentos fototerapeuticos

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Mayara Gabriella Oliveira de; Nascimento, Rizia Keila; Vieira, Rafaela Etelvina de Amorim; Souza, Vivianne Lucia Bormann, E-mail: mayaradqf@hotmail.com, E-mail: riziakeila@hotmail.com, E-mail: rafaelarodriguesss@hotmail.com, E-mail: vlsouza@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife (Brazil)

    2014-07-01

    Dyes and pigments (photosensitizers) are characterized by their ability to absorb visible light, and to participate in photochemical reactions. These colors are used in medicine in the dose recommended for use in photodynamic therapy (PDT). There are lasers that can meet most of the phototherapeutic agents and are capable of providing light of considerable power with precision on the injured tissue. The use of light emitting diodes (LEDs) have become feasible, thus reducing the cost of the procedures. The Dosimetry Laboratory Chemistry of the CRCN-NE/Brazilian CNEN has worked with some likely dye use in phototherapy treatments, including: methylene blue, malachite green and toluidine blue. A volume of 2.6 ml of the dosimeters was transferred to test tubes and these were irradiated with LED 24, 48, 72 and 96 acrylic simulator 110 mm x 110 mm x 80 mm at a distance of 6.5 cm from reading light source of the irradiated samples was performed on a spectrophotometer. Having obtaining excellent correlations (above 0.97) to the dosimeter calibration curves. Suggests that the dosimeter can be applied to perform a quality control in photodynamic therapy. However, further experiments should be performed before a wide application of this technique. A volume of 2.6 ml of the dosimeters was transferred to test tubes and these were irradiated with LED 24, 48, 72 and 96 acrylic simulator 110 mm x 110 mm x 80 mm at a distance of 6.5 cm from reading light source of the irradiated samples was performed on a spectrophotometer. Having obtaining excellent correlations (above 0.97) to the dosimeter calibration curves. Suggests that the dosimeter can be applied to perform a quality control in photodynamic therapy. However, further experiments should be performed before a wide application of this technique.

  19. Thermodynamics properties study of diatomic molecules with q-deformed modified Poschl-Teller plus Manning Rosen non-central potential in D dimensions using SUSYQM approach

    Science.gov (United States)

    Suparmi, A.; Cari, C.; Pratiwi, B. N.

    2016-04-01

    D-dimensional Dirac equation of q-deformed modified Poschl-Teller plus Manning Rosen non-central potential was solved using supersymmetric quantum mechanics (SUSY QM). The relativistic energy spectra were analyzed by using SUSY QM and shape invariant properties from radial part of D dimensional Dirac equation and the angular quantum numbers were obtained from angular part of D dimensional Dirac equation. The SUSY operators was used to generate the D dimensional relativistic wave functions both for radial and angular parts. In the non-relativistic limit, the relativistic energy equation was reduced to the non-relativistic energy. In the classical limit, the partition function of vibrational, the specific heat of vibrational, and the mean energy of vibrational of some diatomic molecules were calculated from the equation of non-relativistic energy with the help of error function and Mat-lab 2011.

  20. Sorption Characteristics of Mixed Molecules of Glutaraldehyde from Water on Mesoporous Acid-Amine Modified Low-Cost Activated Carbon: Mechanism, Isotherm, and Kinetics

    Directory of Open Access Journals (Sweden)

    Mukosha Lloyd

    2015-01-01

    Full Text Available The environmental discharge of inefficiently treated waste solutions of the strong biocide glutaraldehyde (GA from hospitals has potential toxic impact on aquatic organisms. The adsorption characteristics of mixed polarized monomeric and polymeric molecules of GA from water on mesoporous acid-amine modified low-cost activated carbon (AC were investigated. It was found that the adsorption strongly depended on pH and surface chemistry. In acidic pH, the adsorption mechanism was elaborated to involve chemical sorption of mainly hydroxyl GA monomeric molecules on acidic surface groups, while in alkaline pH, the adsorption was elaborated to involve both chemical and physical sorption of GA polymeric forms having mixed functional groups (aldehyde, carboxyl, and hydroxyl on acidic and amine surface groups. The optimum pH of adsorption was about 12 with significant contribution by cooperative adsorption, elucidated in terms of hydrogen bonding and aldol condensation. Freundlich and Dubinin-Radushkevich models were fitted to isotherm data. The adsorption kinetics was dependent on initial concentration and temperature and described by the Elovich model. The adsorption was endothermic, while the intraparticle diffusion model suggested significant contribution by film diffusion. The developed low-cost AC could be used to supplement the GA alkaline deactivation process for efficient removal of residual GA aquatic toxicity.

  1. The molecular ordering phenomenon in dye-doped nematic liquid crystals

    International Nuclear Information System (INIS)

    Prakash Yadav, Satya; Pandey, Kamal Kumar; Kumar Misra, Abhishek; Kumar Tripathi, Pankaj; Manohar, Rajiv

    2011-01-01

    The experimental results of this work point out the role of the guest dye molecules in the molecular ordering of nematic liquid crystals. We have discussed the changes in the energies of interactions between rod-like nematic molecules and anthraquinone dye by considering the presence of steric and dipole-dipole interactions in the dye-doped system. The concentration of the dye plays an important role in the determination of molecular ordering in such dye-doped systems. Below a certain concentration of dye (known as the critical concentration), where the interaction between the dye molecules can be neglected, the addition of dye molecules introduces some disorder into the system in the form of domain formation. Above this critical concentration, this disorder is small.

  2. The molecular ordering phenomenon in dye-doped nematic liquid crystals

    Energy Technology Data Exchange (ETDEWEB)

    Prakash Yadav, Satya; Pandey, Kamal Kumar; Kumar Misra, Abhishek; Kumar Tripathi, Pankaj; Manohar, Rajiv, E-mail: rajiv.manohar@gmail.com [Liquid Crystal Research Laboratory, Physics Department, University of Lucknow, Lucknow-226007 (India)

    2011-03-15

    The experimental results of this work point out the role of the guest dye molecules in the molecular ordering of nematic liquid crystals. We have discussed the changes in the energies of interactions between rod-like nematic molecules and anthraquinone dye by considering the presence of steric and dipole-dipole interactions in the dye-doped system. The concentration of the dye plays an important role in the determination of molecular ordering in such dye-doped systems. Below a certain concentration of dye (known as the critical concentration), where the interaction between the dye molecules can be neglected, the addition of dye molecules introduces some disorder into the system in the form of domain formation. Above this critical concentration, this disorder is small.

  3. Natural dyes as photosensitizers for dye-sensitized solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Sancun; Wu, Jihuai; Huang, Yunfang; Lin, Jianming [Institute of Materials Physical Chemistry, Huaqiao University, Quanzhou, Fujian 362021 (China)

    2006-02-15

    The dye-sensitized solar cells (DSC) were assembled by using natural dyes extracted from black rice, capsicum, erythrina variegata flower, rosa xanthina, and kelp as sensitizers. The I{sub SC} from 1.142mA to 0.225mA, the V{sub OC} from 0.551V to 0.412V, the fill factor from 0.52 to 0.63, and P{sub max} from 58{mu}W to 327{mu}W were obtained from the DSC sensitized with natural dye extracts. In the extracts of natural fruit, leaves and flower chosen, the black rice extract performed the best photosensitized effect, which was due to the better interaction between the carbonyl and hydroxyl groups of anthocyanin molecule on black rice extract and the surface of TiO{sub 2} porous film. The blue-shift of absorption wavelength of the black rice extract in ethanol solution on TiO{sub 2} film and the blue-shift phenomenon from absorption spectrum to photoaction spectrum of DSC sensitized with black rice extract are discussed in the paper. Because of the simple preparation technique, widely available and low cheap cost natural dye as an alternative sensitizer for dye-sensitized solar cell is promising. (author)

  4. Performance variation from triphenylamine- to carbazole-triphenylamine-rhodaniline-3-acetic acid dyes in dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chien-Hsin, E-mail: yangch@nuk.edu.tw [Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 811, Taiwan (China); Lin, Wen-Churng [Department of Environmental Engineering, Kun Shan University, Tainan 710, Taiwan (China); Wang, Tzong-Liu; Shieh, Yeong-Tarng; Chen, Wen-Janq; Liao, Shao-Hong; Sun, Yu-Kuang [Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 811, Taiwan (China)

    2011-10-17

    Highlights: {yields} We synthesized an organic dye of carbazole-rhodaniline-3-acetic acid-triphenylamine. {yields} A dye-sensitized solar cell is fabricated using this dye with efficiency of 4.64%. {yields} Carbazole donor in the dye molecule provides electron in increasing efficiency. {yields} Two rhodaniline-3-acetic acids play a key role in increasing efficiency. {yields} AC impedance proves this dye's effect on enhancing charge transfer in TiO{sub 2}. - Abstract: Organic dyes have been synthesized which contain an extra-electron donor (carbazole) and electron acceptors (rhodaniline-3-acetic acid) on triphenylamines (TPA). Photophysical, electrochemical, and theoretical computational methods have categorized these compounds. Nanocrystalline TiO{sub 2}-based dye-sensitized solar cells (DSSCs) are fabricated using these dye molecules as light-harvesting sensitizers. The overall efficiency of sensitized cells has 4.64% relative to a cis-di(thiocyanato)-bis(2,2'-bipyridyl)-4,4'-dicarboxylate ruthenium (II) (N3 dye)-sensitized device (7.83%) fabricated and measured under the same conditions. Carbazole-electron donation in the dye molecules plays a key role in the increased efficiency. Two rhodaniline-3-acetic acid groups appear to help convey the charge transfer from the excited dye molecules to the conduction band of TiO{sub 2}, leading to a higher efficiency of devices using such a dye. Electrochemical impedance supports this dye's effect on enhancing charge transfer in TiO{sub 2} (e{sup -}). Computations on this dye compound also indicate the larger charge transfer efficiency in the electronically excited state.

  5. Hair dye poisoning

    Science.gov (United States)

    Hair tint poisoning ... Different types of hair dye contain different harmful ingredients. The harmful ingredients in permanent dyes are: Naphthylamine Other aromatic amino compounds Phenylenediamines Toluene ...

  6. How to prevent dimerization of laser dyes in water? Simulation and organic synthesis

    International Nuclear Information System (INIS)

    Dare-Doyen, S.

    2000-01-01

    Xanthenes are widely used as laser dyes in ethanol medium because their photophysical properties there are excellent. On the other hand, when they are dissolved in water, their fluorescence is almost zero on account of the dimerization phenomenon (aggregation of two molecules) which is specific in water although the interaction between the two molecules (these dyes are mainly cations) be repulsive. The first part of this work deals with the dimerization study of two dyes, the 6G rhodamine and the 6G pyronine. Molecular dynamics simulation results (AMBER software) have been compared with those of the NMR; thus it has been possible to describe the geometry of the 6G rhodamine dimer and to identify two structures present in equal quantities for the 6G pyronine dimer. It has been demonstrated that the role of water is essential in the aggregation mechanism; this role can be understood as resulting of the hydrophobic effect. The second part of this work concerns the synthesis of rhodamines which are soluble but not able to dimerize in water at the running concentrations of the laser dyes. At first, aminophenol precursors having hydrophilic ionic groups on modifiable sites have been synthesized without changing their photophysical properties. The synthesis sequence of the 3-(2-alkylamino-4-hydroxyphenyl)propionic acids has not given the waited products but N-(3'-hydroxyphenyl)amino-alkylsulfonic acids have been obtained. Their condensation with the phthalic anhydride has led to dyes of a charge -2 at a pH of 5 in water and which have photophysical properties similar to those of the rhodamine 575 in ethanol and laser emission properties in the emission spectral range of the rhodamine 6G in ethanol. This synthesis work has then led to the preparation of two laser dyes usable in water. (author) [fr

  7. Dye-Sensitized Approaches to Photovoltaics

    Science.gov (United States)

    Grätzel, Michael

    2008-03-01

    Sensitization of wide band-gap semiconductors to photons of energy less than the band-gap is a key step in two technically important processes - panchromatic photography and photoelectrochemical solar cells. In both cases the photosensitive species is not the semiconductor - silver halide or metal oxide - but rather an electrochemically active dye. The gap between the highest occupied molecular level (HOMO) and the lowest unoccupied molecular level (LUMO) is less than the band-gap of the semiconductor with which it is associated. It can therefore absorb light of a wavelength longer than that to which the semiconductor itself is sensitive. The electrochemical process is initiated when the dye molecule relaxes from its photoexcited level by electron injection into the semiconductor, which therefore acts as a photoanode. If the dye is in contact with a redox electrolyte, the negative charge represented by the lost electron can be recovered from the reduced state of the redox system, which in return is regenerated by charge transfer from a cathode. An external load completes the electrical circuit. The system therefore represents a conversion of the energy of absorbed photons into an electrical current by a regenerative device in every functional respect analogous to a solid-state photovoltaic cell. As in any engineering system, choice of materials, their optimization and their synergy are essential to efficient operation. While a semiconductor-electrolyte contact is analogous to a Schottky contact, in that a barrier is established between two materials of different conduction mechanism, with the possibility of optical absorption, charge carrier pair generation and separation, it should be remembered that the photogenerated valence band hole in the semiconductor represents a powerful oxidizing agent. Given that the band-gap is related to the strength and therefore the stability of chemical bonding within the semiconductor, for narrow-gap materials the most likely

  8. Ultrasound for low temperature dyeing of wool with acid dye.

    Science.gov (United States)

    Ferrero, F; Periolatto, M

    2012-05-01

    The possibility of reducing the temperature of conventional wool dyeing with an acid levelling dye using ultrasound was studied in order to reach exhaustion values comparable to those obtained with the standard procedure at 98 °C, obtaining dyed samples of good quality. The aim was to develop a laboratory method that could be transferred at industrial level, reducing both the energy consumption and fiber damage caused by the prolonged exposure to high temperature without the use of polluting auxiliary agents. Dyeings of wool fabrics were carried out in the temperature range between 60 °C and 80 °C using either mechanical or ultrasound agitation of the bath and coupling the two methods to compare the results. For each dyeing, the exhaustion curves of the dye bath were determined and the better results of dyeing kinetics were obtained with ultrasound coupled with mechanical stirring. Hence the corresponding half dyeing times, absorption rate constants according to Cegarra-Puente modified equation and ultrasonic efficiency were calculated in comparison with mechanical stirring alone. In the presence of ultrasound the absorption rate constants increased by at least 50%, at each temperature, confirming the synergic effect of sonication on the dyeing kinetics. Moreover the apparent activation energies were also evaluated and the positive effect of ultrasound was ascribed to the pre-exponential factor of the Arrhenius equation. It was also shown that the effect of ultrasound at 60 °C was just on the dye bath, practically unaffecting the wool fiber surface, as confirmed by the results of SEM analysis. Finally, fastness tests to rubbing and domestic laundering yielded good values for samples dyed in ultrasound assisted process even at the lower temperature. These results suggest the possibility, thanks to the use of ultrasound, to obtain a well equalized dyeing on wool working yet at 60°C, a temperature process strongly lower than 98°C, currently used in industry

  9. Electrohemical properties of carbon nanotube paste electrodes modified with redox cationic dyes=Propriedades eletroquímicas de eletrodos a base de pasta de nanotubo de carbono modificados com corantes redox catiônicos

    Directory of Open Access Journals (Sweden)

    Arnaldo César Pereira

    2012-07-01

    Full Text Available The present work describes the electrochemical behavior of methylene blue and toluidine blue as electron mediators adsorbed in the multiwall carbon nanotubes paste. Based on midpoint potential and separation of cathodic and anodic peaks (ΔE, it was not observed interaction of different eletrolytes with the cationic dyes by an ion exchange reaction and, as a consequence, absence of leaching of cationic dyes to the solution phase. The kinetics of electron transfer on the surface electrode was not sufficiently fast showing a fairly resistence of carbon nanotube paste modified with the mediators. The midpoint potential and ΔE also were insentive to the pH range (4-8, confirming the protective effect of carbon nanotubes matrix, owing to strong interaction of between the latter and the nitrogen of nitrogen of cationic dyes with carbon nanotube matrix, minimizing the proton interaction under cationic dye. This result is very important for sensor/biosensor preparation, because the eletrooxidation behavior of the analyte will be only affected by its formal potencial shifting. Carbon nanotubes proved to be an efficient solid matrix for the adsorption of mediator electron in comparison to the electrochemical behavior of free cationic dyes in solution phase.O presente trabalho descreve o comportamento eletroquímico de azul de metileno e azul de toluidina como mediadores de elétrons adsorvidos em pasta de nanotubo de carbono multiparede. Com base no potencial médio e na separação de pico catódico e anódico (ΔE, não foi observada interação de diferentes eletrólitos com os corantes catiônicos por meio de reação de troca iônica e, como consequência, ausência de lixiviação dos corantes para solução. A cinética de transferência de elétron na superfície do eletrodo não foi suficientemente rápida, mostrando razoável resistência da pasta de nanotubo de carbono modificada com os mediadores. O potencial médio e ΔE também foram insens

  10. Enriching PMMA nanospheres with adjustable charges as novel templates for multicolored dye-PMMA nanocomposites

    International Nuclear Information System (INIS)

    Wang Xumei; Xu Shuping; Xu Weiqing; Liang Chongyang; Li Hongrui; Sun Fei

    2011-01-01

    Multicolored fluorescent dye loaded PMMA nanospheres were synthesized by the electrostatic adsorption of dye molecules on the charged PMMA nanospheres, whose charges were adjusted by choosing different initiators. The charged PMMA nanospheres have a wider capacity and advantage for combining the charged dyes. The fluorescent dye-PMMA composite nanospheres possess the advantages of higher brightness, longer lifetime and stronger resistance to photobleaching relative to dye molecules. Dye leakage remained lower than 5% over one week. These fluorescent nanospheres have been used in biological labels in cell imaging. They can easily stain blood cancer cells without further surface modification.

  11. Molecules for Fluorescence Detection of Specific Chemicals

    Science.gov (United States)

    Fedor, Steve

    2008-01-01

    A family of fluorescent dye molecules has been developed for use in on-off fluorescence detection of specific chemicals. By themselves, these molecules do not fluoresce. However, when exposed to certain chemical analytes in liquid or vapor forms, they do fluoresce (see figure). These compounds are amenable to fixation on or in a variety of substrates for use in fluorescence-based detection devices: they can be chemically modified to anchor them to porous or non-porous solid supports or can be incorporated into polymer films. Potential applications for these compounds include detection of chemical warfare agents, sensing of acidity or alkalinity, and fluorescent tagging of proteins in pharmaceutical research and development. These molecules could also be exploited for use as two-photon materials for photodynamic therapy in the treatment of certain cancers and other diseases. A molecule in this family consists of a fluorescent core (such as an anthracene or pyrene) attached to two end groups that, when the dye is excited by absorption of light, transfer an electron to the core, thereby quenching the fluorescence. The end groups can be engineered so that they react chemically with certain analytes. Upon reaction, electrons on the end groups are no longer available for transfer to the core and, consequently, the fluorescence from the core is no longer quenched. The chemoselectivity of these molecules can be changed by changing the end groups. For example, aniline end groups afford a capability for sensing acids or acid halides (including those contained in chemical warfare agents). Pyridine or bipyridyl end groups would enable sensing of metal ions. Other chemicals that can be selectively detected through suitable choice of end groups include glucose and proteins. Moreover, the fluorescent cores can be changed to alter light-absorption and -emission characteristics: anthracene cores fluoresce at wavelengths around 500 nm, whereas perylene cores absorb and emit at

  12. Broad band exciplex dye lasers

    International Nuclear Information System (INIS)

    Dienes, A.; Shank, C.V.; Trozzolo, A.M.

    1975-01-01

    The disclosure is concerned with exciplex dye lasers, i.e., lasers in which the emitting species is a complex formed only from a constituent in an electronically excited state. Noting that an exciplex laser, favorable from the standpoint of broad tunability, results from a broad shift in the peak emission wavelength for the exciplex relative to the unreacted species, a desirable class resulting in such broad shift is described. Preferred classes of laser media utilizing specified resonant molecules are set forth. (auth)

  13. Uniform silica nanoparticles encapsulating two-photon absorbing fluorescent dye

    International Nuclear Information System (INIS)

    Wu Weibing; Liu Chang; Wang Mingliang; Huang Wei; Zhou Shengrui; Jiang Wei; Sun Yueming; Cui Yiping; Xu Chunxinag

    2009-01-01

    We have prepared uniform silica nanoparticles (NPs) doped with a two-photon absorbing zwitterionic hemicyanine dye by reverse microemulsion method. Obvious solvatochromism on the absorption spectra of dye-doped NPs indicates that solvents can partly penetrate into the silica matrix and then affect the ground and excited state of dye molecules. For dye-doped NP suspensions, both one-photon and two-photon excited fluorescence are much stronger and recorded at shorter wavelength compared to those of free dye solutions with comparative overall dye concentration. This behavior is possibly attributed to the restricted twisted intramolecular charge transfer (TICT), which reduces fluorescence quenching when dye molecules are trapped in the silica matrix. Images from two-photon laser scanning fluorescence microscopy demonstrate that the dye-doped silica NPs can be actively uptaken by Hela cells with low cytotoxicity. - Graphical abstract: Water-soluble silica NPs doped with a two-photon absorbing zwitterionic hemicyanine dye were prepared. They were found of enhanced one-photon and two-photon excited fluorescence compared to free dye solutions. Images from two-photon laser scanning fluorescence microscopy demonstrate that the dye-doped silica NPs can be actively uptaken by Hela cells.

  14. 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...

  15. Synthesis of dye linked conducting block copolymers, dye linked conducting homopolymers and preliminary application to photovoltaics

    DEFF Research Database (Denmark)

    Krebs, Frederik C; Hagemann, O.; Jørgensen, M.

    2004-01-01

    A synthetic approach to the synthesis of a large super molecule composed of two chemically different conducting polymer blocks with, respectively, high and low lying electronic energy levels linked through a porphyrin dye molecule is presented. The synthetic strategies to these molecular architec...

  16. Feasibility analysis of color removal from textile dyeing wastewater in a fixed-bed column system by surfactant-modified zeolite (SMZ)

    International Nuclear Information System (INIS)

    Ozdemir, Ozgur; Turan, Mustafa; Turan, Abdullah Zahid; Faki, Aysegul; Engin, Ahmet Baki

    2009-01-01

    In this study, the ability of surfactant-modified zeolite (SMZ) to remove color from real textile wastewater was investigated. Tests were performed in a fixed-bed column reactor and the surface of natural zeolite was modified with a quaternary amine surfactant hexadecyltrimethylammonium bromide (HTAB). The zeolite bed that was modified at 1 g L -1 HTAB concentration and HTAB flow rate of 0.015 L min -1 showed good performance in removing color. Effects of wastewater color intensity, flow rates and bed heights were also studied. Wastewater was diluted several times in the ratios of 25%, 50% and 75% in order to assess the influence of wastewater strength. The breakthrough curves of the original and diluted wastewaters are dispersed due to the fact that breakthrough came late at lower color intensities and saturation of the bed appeared faster at higher color intensities. The column had a 3-cm diameter and four different bed heights of 12.5, 25, 37.5 and 50 cm, which treated 5.25, 19.50, 35.25 and 51 L original textile wastewater, respectively, at the breakthrough time at a flow rate of 0.025 L min -1 . The theoretical service times evaluated from bed depth service time (BDST) approach for different column variables. The calculated and theoretical values of the exchange zone height were found with a difference of 27%. The various design parameters obtained from fixed-bed experimental studies showed good correlation with corresponding theoretical values, under different bed heights. The regeneration of the SMZ was also evaluated using a solution consisting of 30 g L -1 NaCl and 1.5 g L -1 NaOH at pH 12 and temperature 30 o C. Twice-regenerated SMZ showed the best performance compared with the others while first- and thrice-regenerated perform lower than the original SMZ.

  17. Dye-sensitized solar cells using natural dyes as sensitizers from Malaysia local fruit `Buah Mertajam'

    Science.gov (United States)

    Hambali, N. A. M. Ahmad; Roshidah, N.; Hashim, M. Norhafiz; Mohamad, I. S.; Saad, N. Hidayah; Norizan, M. N.

    2015-05-01

    We experimentally demonstrate the high conversion efficiency, low cost, green technology and easy to fabricate dye-sensitized solar cells (DSSCs) using natural anthocyanin dyes as sensitizers. The DSSCs was fabricated by using natural anthocyanin dyes which were extracted from different parts of the plants inclusive `Buah Mertajam', `Buah Keriang Dot', `Bunga Geti', Hibiscus, Red Spinach and Henna. The natural anthocyanin dyes that found in flower, leaves and fruits were extracted by the simple procedures. This anthocyanin dye is used to replace the expensive chemical synthetic dyes due to its ability to effectively attach into the surface of Titanium dioxide (TiO2). A natural anthocyanin dyes molecule adsorbs to each particle of the TiO2 and acts as the absorber of the visible light. A natural anthocyanin dye from Buah Mertajam shows the best performance with the conversion efficiency of 5.948% and fill factor of 0.708 followed by natural anthocyanin dyes from `Buah Keriang Dot', `Bunga Geti', Hibiscus, Red Spinach and Henna. Buah Mertajam or scientifically known as eriglossum rubiginosum is a local Malaysia fruit.

  18. Solid-state mAbs and ADCs subjected to heat-stress stability conditions can be covalently modified with buffer and excipient molecules.

    Science.gov (United States)

    Valliere-Douglass, John F; Lewis, Patsy; Salas-Solano, Oscar; Jiang, Shan

    2015-02-01

    We report that a unique type of chemical modification occurs on lyophilized proteins. Freeze-dried mAbs and antibody-drug conjugates (ADCs) can be covalently modified with buffer and excipient molecules on the side chains of Glu, Asp, Thr, and Ser amino acids when subjected to temperature stress. The reaction occurs primarily via condensation of common buffers and excipients such as histidine, tris, trehalose and sucrose, with Glu and Asp carboxylates in the primary sequence of proteins. The reaction was also found to proceed through condensation of carboxylate containing buffers such as citrate, with Thr and Ser hydroxyls in the primary sequence of proteins. Based on the mass of the covalent adducts observed on mAbs and ADCs, it is apparent that the reaction produces water as a product and is thus favored in a low moisture environments such as a lyophilized protein cake. Herein, we present the evidence for the covalent modification of proteins drawn from case studies of in-depth characterization of heat-stressed mAbs and ADCs in the solid state. We also demonstrate how common charge variant assays such as imaged capillary isoelectric focusing and mass spectrometry can be used to monitor this specific class of protein modification. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  19. Photoinduced electron transfer in some photosensitive molecules ...

    Indian Academy of Sciences (India)

    Unknown

    redox reactions of substrates like biological molecules,11,12 dyes,13,14 alcohols15,16 etc. Colloidal ... state which is characterised by a phenomenon of dual fluorescence. In the present ... The dried solid was transferred to quartz cell under vacuum ... Recently Grätzel et al34 have developed the dye-sensitized meso-.

  20. Tuning luminescence intensity of RHO6G dye using silver ...

    Indian Academy of Sciences (India)

    Wintec

    Wang and Kerker (1982) found that due to interaction of metal and dye in core shell particles splitting of extinction bands occurs. En- hancement also has been reported due to such interaction. Quenching of the luminescence of dye molecules ad- sorbed on a smooth Ag surface was observed by Ritchie and Burstein (1981).

  1. Tunable Microfluidic Dye Laser

    DEFF Research Database (Denmark)

    Olsen, Brian Bilenberg; Helbo, Bjarne; Kutter, Jörg Peter

    2003-01-01

    We present a tunable microfluidic dye laser fabricated in SU-8. The tunability is enabled by integrating a microfluidic diffusion mixer with an existing microfluidic dye laser design by Helbo et al. By controlling the relative flows in the mixer between a dye solution and a solvent......, the concentration of dye in the laser cavity can be adjusted, allowing the wavelength to be tuned. Wavelength tuning controlled by the dye concentration was demonstrated with macroscopic dye lasers already in 1971, but this principle only becomes practically applicable by the use of microfluidic mixing...

  2. Isothermal, kinetic and thermodynamic studies on basic dye sorption ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-12-15

    Dec 15, 2009 ... The isothermal data correlated with the Langmuir model better than the. Freundlich model. ... there were two intra-particle diffusion steps in the dye sorption processes. .... rated monolayer of sorbate molecule on the sorbent.

  3. Probing the Effects of Templating on the UV and Visible Light Photocatalytic Activity of Porous Nitrogen-Modified Titania Monoliths for Dye Removal.

    Science.gov (United States)

    Nursam, Natalita M; Wang, Xingdong; Tan, Jeannie Z Y; Caruso, Rachel A

    2016-07-13

    Porous nitrogen-modified titania (N-titania) monoliths with tailored morphologies were prepared using phase separation and agarose gel templating techniques. The doping and templating process were simultaneously carried out in a one-pot step using alcohol amine-assisted sol-gel chemistry. The amount of polymer used in the monoliths that were prepared using phase separation was shown to affect both the physical and optical properties: higher poly(ethylene glycol) content increased the specific surface area, porosity, and visible light absorption of the final materials. For the agarose-templated monoliths, the infiltration conditions affected the monolith morphology. A porous monolith with high surface area and the least shrinkage was obtained when the N containing alkoxide precursor was infiltrated into the agarose scaffolds at 60 °C. The effect of the diverse porous morphologies on the photocatalytic activity of N-titania was studied for the decomposition of methylene blue (MB) under visible and UV light irradiation. The highest visible light activity was achieved by the agarose-templated N-titania monolith, in part due to higher N incorporation. This sample also showed better UV activity, partly because of the higher specific surface area (up to 112 m(2) g(-1)) compared to the phase separation-induced monoliths (up to 103 m(2) g(-1)). Overall, agarose-templated, porous N-titania monoliths provided better features for effectively removing the MB contaminant.

  4. A Double-Stimuli-Responsive Fluorescent Center for Monitoring of Food Spoilage based on Dye Covalently Modified EuMOFs: From Sensory Hydrogels to Logic Devices.

    Science.gov (United States)

    Xu, Xiao-Yu; Lian, Xiao; Hao, Ji-Na; Zhang, Chi; Yan, Bing

    2017-10-01

    Unsafe food is a huge threat to human health and the economy, and detecting food spoilage early is an ongoing and imperative need. Herein, a simple and effective strategy combining a fluorescence sensor and one-to-two logic operation is designed for monitoring biogenic amines, indicators of food spoilage. Sensors (methyl red@lanthanide metal-organic frameworks (MR@EuMOFs)) are created by covalently modifying MR into NH 2 -rich EuMOFs, which have a high quantum yield (48%). A double-stimuli-responsive fluorescence center is produced via energy transfer from the ligands to Eu 3+ and MR. Portable sensory hydrogels are obtained by dispersing and solidifying MR@EuMOFs in water-phase sodium salt of carboxy methyl cellulose (CMC-Na). The hydrogels exhibit a color transition upon "smelling" histamine (HI) vapor. This transition and shift in the MR-based emission peak are closely related to the HI concentration. Using the HI concentration as the input signal and the two fluorescence emissions as output signals, an advanced analytical device based on a one-to-two logic gate is constructed. The four output combinations, NOT (0, 1), YES (1, 0), PASS 1 (1, 1), and PASS 0 (0, 0), allow the direct analysis of HI levels, which can be used for real-time food-freshness evaluation. The novel strategy suggested here may be a new application for a molecular logic system in the sensing field. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Chemistry of Natural Dyes

    Indian Academy of Sciences (India)

    scientific principles, and the interaction between the dye and the dyed material is ... Dyes are classified based on their structure, source, method of application .... the right source that gives not only beautiful tones, but colourfast shades as well.

  6. Modified Nanodiamonds for Detoxification

    Science.gov (United States)

    Gibson, Natalie Marie

    essential for interacting with charged molecules, like OTA. Furthermore, the increased ZPs lead to improved colloidal stabilities over a wide range of pH, which is important for their interaction in the GI tract. While the dyes and OTA illustrated primarily electrostatic adsorption mechanisms, neutrally charged AfB1's adsorption was predominantly based upon the aggregate size of the ND substrate. In addition to mycotoxins, fluorescent dyes, including propidium iodide, pyranine and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), were initially utilized during methodological development. Fluorescent dye investigations helped assesses the adsorption mechanisms of NDs and demonstrated the significance of electrostatic interactions. Beyond electrostatic adsorption mechanisms, surface functional groups were also responsible for the amount of dye adsorbed, as was also true in OTA adsorption. Therefore, surface characterization was carried out for several ND samples by FTIR, TOF-SIMS and TDMS analysis. Final results of our studies show that our modified NDs perform better than yeast cells walls and other NDs but comparable to activated charcoal in the adsorption of AfB1, and outperform clay minerals in OTA studies. Moreover, it was demonstrated that adsorption can be maintained in a wide range of pH, thereby, increasing the possibility of NDs use in mycotoxins enterosorbent applications.

  7. 3D-QSPR Method of Computational Technique Applied on Red Reactive Dyes by Using CoMFA Strategy

    OpenAIRE

    Mahmood, Uzma; Rashid, Sitara; Ali, S. Ishrat; Parveen, Rasheeda; ul-Haq, Zaheer; Ambreen, Nida; Khan, Khalid Mohammed; Perveen, Shahnaz; Voelter, Wolfgang

    2011-01-01

    Cellulose fiber is a tremendous natural resource that has broad application in various productions including the textile industry. The dyes, which are commonly used for cellulose printing, are ?reactive dyes? because of their high wet fastness and brilliant colors. The interaction of various dyes with the cellulose fiber depends upon the physiochemical properties that are governed by specific features of the dye molecule. The binding pattern of the reactive dye with cellulose fiber is called ...

  8. Extension lifetime for dye-sensitized solar cells through multiple dye adsorption/desorption process

    Science.gov (United States)

    Chiang, Yi-Fang; Chen, Ruei-Tang; Shen, Po-Shen; Chen, Peter; Guo, Tzung-Fang

    2013-03-01

    In this study, we propose a novel concept of extending the lifetime of dye-sensitized solar cells (DSCs) and reducing the costs of re-conditioning DSCs by recycling the FTO/TiO2 substrates. The photovoltaic performances of DSCs using substrates with various cycles of dye uptake and rinse off history are tested. The results show that dye adsorption and Voc are significantly increased under multiple dye adsorption/desorption process and resulted in the improvement of power conversion efficiency. Moreover, the dyeing kinetics is faster after multiple recycling processes, which is favorable for the industrial application. With surface analysis and charge transport characteristics, we also demonstrate the optimal functionality of TiO2/dye interface for the improved Voc and efficiency. The results confirm that the improved performances are due to increased dye loading and dense packing of dye molecules. Our results are beneficial for the understanding on the extension of DSCs lifetime after long-term operation in the application of DSC modules. This approach may also be applied in the replacement of newly synthesized photosensitizes to the active cells.

  9. MOLECULAR VALIDATED MODEL FOR ADSORPTION OF PROTONATED DYE ON LDH

    Directory of Open Access Journals (Sweden)

    B. M. Braga

    Full Text Available Abstract Hydrotalcite-like compounds are anionic clays of scientific and technological interest for their use as ion exchange materials, catalysts and modified electrodes. Surface phenomenon are important for all these applications. Although conventional analytical methods have enabled progress in understanding the behavior of anionic clays in solution, an evaluation at the atomic scale of the dynamics of their ionic interactions has never been performed. Molecular simulation has become an extremely useful tool to provide this perspective. Our purpose is to validate a simplified model for the adsorption of 5-benzoyl-4-hydroxy-2-methoxy-benzenesulfonic acid (MBSA, a prototype molecule of anionic dyes, onto a hydrotalcite surface. Monte Carlo simulations were performed in the canonical ensemble with MBSA ions and a pore model of hydrotalcite using UFF and ClayFF force fields. The proposed molecular model has allowed us to reproduce experimental data of atomic force microscopy. Influences of protonation during the adsorption process are also presented.

  10. Ultrasound-assisted dyeing of cellulose acetate.

    Science.gov (United States)

    Udrescu, C; Ferrero, F; Periolatto, M

    2014-07-01

    The possibility of reducing the use of auxiliaries in conventional cellulose acetate dyeing with Disperse Red 50 using ultrasound technique was studied as an alternative to the standard procedure. Dyeing of cellulose acetate yarn was carried out by using either mechanical agitation alone, with and without auxiliaries, or coupling mechanical and ultrasound agitation in the bath where the temperature range was maintained between 60 and 80 °C. The best results of dyeing kinetics were obtained with ultrasound coupled with mechanical agitation without auxiliaries (90% of bath exhaustion value at 80 °C). Hence the corresponding half dyeing times, absorption rate constants according to Cegarra-Puente modified equation and ultrasound efficiency were calculated confirming the synergic effect of sonication on the dyeing kinetics. Moreover the apparent activation energies were also evaluated and the positive effect of ultrasound added to mechanical agitation was evidenced by the lower value (48 kJ/mol) in comparison with 112 and 169 kJ/mol for mechanical stirring alone with auxiliaries and without, respectively. Finally, the fastness tests gave good values for samples dyed with ultrasound technique even without auxiliaries. Moreover color measurements on dyed yarns showed that the color yield obtained by ultrasound-assisted dyeing at 80 °C of cellulose acetate without using additional chemicals into the dye bath reached the same value yielded by mechanical agitation, but with remarkably shorter time. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. uv dye lasers

    International Nuclear Information System (INIS)

    Abakumov, G.A.; Fadeev, V.V.; Khokhlov, R.V.; Simonov, A.P.

    1975-01-01

    The most important property of visible dye lasers, that is, continuous wavelength tuning, stimulated the search for dyes capable to lase in uv. They were found in 1968. Now the need for tunable uv lasers for applications in spectroscopy, photochemistry, isotope separation, remote air and sea probing, etc. is clearly seen. A review of some recent advances in uv dye lasers is reviewed

  12. Single molecules and nanotechnology

    CERN Document Server

    Vogel, Horst

    2007-01-01

    This book focuses on recent advances in the rapidly evolving field of single molecule research. These advances are of importance for the investigation of biopolymers and cellular biochemical reactions, and are essential to the development of quantitative biology. Written by leading experts in the field, the articles cover a broad range of topics, including: quantum photonics of organic dyes and inorganic nanoparticles their use in detecting properties of single molecules the monitoring of single molecule (enzymatic) reactions single protein (un)folding in nanometer-sized confined volumes the dynamics of molecular interactions in biological cells The book is written for advanced students and scientists who wish to survey the concepts, techniques and results of single molecule research and assess them for their own scientific activities.

  13. 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.

  14. Hair dye contact allergy

    DEFF Research Database (Denmark)

    Søsted, Heidi; Rastogi, Suresh Chandra; Andersen, Klaus Ejner

    2004-01-01

    Colouring of hair can cause severe allergic contact dermatitis. The most frequently reported hair dye allergens are p-phenylenediamine (PPD) and toluene-2,5-diamine, which are included in, respectively, the patch test standard series and the hairdressers series. The aim of the present study...... was to identify dye precursors and couplers in hair dyeing products causing clinical hair dye dermatitis and to compare the data with the contents of these compounds in a randomly selected set of similar products. The patient material comprised 9 cases of characteristic clinical allergic hair dye reaction, where...... exposure history and patch testing had identified a specific hair dye product as the cause of the reaction. The 9 products used by the patients were subjected to chemical analysis. 8 hair dye products contained toluene-2,5-diamine (0.18 to 0.98%). PPD (0.27%) was found in 1 product, and m-aminophenol (0...

  15. Single-molecule conductance of a chemically modified, π-extended tetrathiafulvalene and its charge-transfer complex with F4TCNQ

    Directory of Open Access Journals (Sweden)

    Raúl García

    2015-06-01

    Full Text Available We describe the synthesis and single-molecule electrical transport properties of a molecular wire containing a π-extended tetrathiafulvalene (exTTF group and its charge-transfer complex with F4TCNQ. We form single-molecule junctions using the in situ break junction technique using a homebuilt scanning tunneling microscope with a range of conductance between 10 G0 down to 10−7 G0. Within this range we do not observe a clear conductance signature of the neutral parent molecule, suggesting either that its conductance is too low or that it does not form a stable junction. Conversely, we do find a clear conductance signature in the experiments carried out on the charge-transfer complex. Due to the fact we expected this species to have a higher conductance than the neutral molecule, we believe this supports the idea that the conductance of the neutral molecule is very low, below our measurement sensitivity. This idea is further supported by theoretical calculations. To the best of our knowledge, these are the first reported single-molecule conductance measurements on a molecular charge-transfer species.

  16. Investigation of the lasing of dyes under copper vapor laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Danilova, V I; Kopylova, T N; Maier, G V; Masarnovskii, L V; Soldatov, A N; Sukhanov, V B

    1980-10-01

    The lasing characteristics of dyes pumped by copper vapor laser radiation are investigated in order to determine the optimal energetic parameters of the dye-laser system. Expressions are derived for the yields of stimulated emission from dye molecules, and it is shown that the most effective means of improving the lasing characteristics of rhodamine dye solutions is by the modification of intermolecular interactions, in part by the use of multicomponent solutions. Results are then presented of experimental measurements of the emission intensities of combinations of rhodamine dyes irradiated by the 5106-A line of a copper vapor laser. An increase in the lasing efficiency of the acceptor molecule is found for all the dye pairs investigated, with even greater emission intensities observed for multicomponent dye mixtures when the mixtures were pumped transversely. Under longitudinal pumping, improvements in lasing efficiency were obtained only for mixtures of rhodamine 6 Zh with cresil violet.

  17. WATERLESS DYEING [REVIEW

    Directory of Open Access Journals (Sweden)

    DEVRENT Nalan

    2015-05-01

    Full Text Available The textile industry is believed to be one of the biggest consumers of water. Water consumption and exhaustion in dyeing textile materials in conventional methods is an important environmental problem. The cost of waste water treatment will cause a prominent problem in the future as it does today. Increasing consideration of ecologic consequences of industrial processes as well as legislation enforcing the avoidance of environmental problems have caused a reorientation of thinking and promoted projects for replacement of conventional technologies. One of these new technologies is dyeing in supercritical fluids. Dyeing with supercritical carbon dioxide is a favourable concept considering the value of water as a natural resource and the cost of waste water treatment. This dyeing method offers many advantages over conventional aqueous dyeing: During this dyeing process no water is used, therefore there is no waste water problem, no other chemicals are required; the carbon dioxide can be recycled; the dystuff which is not adsorbed on the substrate can be collected and reused; The necessary energy consumption in this process is relatively lower than is needed to heat water in conventional methods of dyeing. Due to unnecessary of drying process, it helps to save both energy and time; and dyeing cycle is shorter compared with traditional methods. In addition carbon dioxide is non-toxic and non-flammable. Supercritical fluid, supercritical dyeing, disperse dyestuffs, solid-fluid equilibrium

  18. QSPR study of absorption maxima of organic dyes for dye-sensitized solar cells based on 3D descriptors

    Science.gov (United States)

    Xu, Jie; Zhang, Hui; Wang, Lei; Liang, Guijie; Wang, Luoxin; Shen, Xiaolin; Xu, Weilin

    2010-07-01

    A quantitative structure-property relationship (QSPR) study was performed for the prediction of the absorption maxima ( λmax) of organic dyes for dye-sensitized solar cells (DSSCs). The entire set of 70 dyes was divided into a training set of 53 dyes and a test set of 17 dyes according to Kennard and Stones algorithm. Three-dimensional (3D) descriptors were calculated to represent the dye molecules. A ten-descriptor model, with a squared correlation coefficient ( R2) of 0.9543 and a standard error of estimation ( s) of 14.7 nm, was produced by using the stepwise multilinear regression analysis (MLRA) on the training set. The reliability of the proposed model was further illustrated using various evaluation techniques: leave-one-out cross-validation procedure, randomization tests, and validation through the external test set. All descriptors involved in the model were derived solely from the chemical structure of the dye molecules, which makes the model very useful to estimate the λmax of dyes before they are actually synthesized.

  19. Synthesis and spectroscopic properties of silica-dye-semiconductor nanocrystal hybrid particles.

    Science.gov (United States)

    Ren, Ting; Erker, Wolfgang; Basché, Thomas; Schärtl, Wolfgang

    2010-12-07

    We prepared silica-dye-nanocrystal hybrid particles and studied the energy transfer from semiconductor nanocrystals (= donor) to organic dye molecules (= acceptor). Multishell CdSe/CdS/ZnS semiconductor nanocrystals were adsorbed onto monodisperse Stöber silica particles with an outer silica shell of thickness 2-23 nm containing organic dye molecules (Texas Red). The thickness of this dye layer has a strong effect on the energy transfer efficiency, which is explained by the increase in the number of dye molecules homogeneously distributed within the silica shell, in combination with an enhanced surface adsorption of nanocrystals with increasing dye amount. Our conclusions were underlined by comparison of the experimental results with numerically calculated FRET efficiencies and by control experiments confirming attractive interaction between the nanocrystals and Texas Red freely dissolved in solution.

  20. Comparative Studies on Dyeability with Direct, Acid and Reactive Dyes after Chemical Modification of Jute with Mixed Amino Acids Obtained from Extract of Waste Soya Bean Seeds

    Science.gov (United States)

    Bhaumik, Nilendu Sekhar; Konar, Adwaita; Roy, Alok Nath; Samanta, Ashis Kumar

    2017-12-01

    Jute fabric was treated with mixed natural amino acids obtained from waste soya bean seed extract for chemical modification of jute for its cataionization and to enhance its dyeability with anionic dyes (like direct, reactive and acid dye) as well enabling soya modified jute for salt free dyeing with anionic reactive dyes maintaining its eco-friendliness. Colour interaction parameters including surface colour strength were assessed and compared for both bleached and soya-modified jute fabric for reactive dyeing and compared with direct and acid dye. Improvement in K/S value (surface colour strength) was observed for soya-modified jute even in absence of salt applied in dye bath for reactive dyes as well as for direct and acid dyes. In addition, reactive dye also shows good dyeability even in acid bath in salt free conditions. Colour fastness to wash was evaluated for bleached and soya-modified jute fabric after dyeing with direct, acid and reactive dyes are reported. Treatment of jute with soya-extracted mixed natural amino acids showed anchoring of some amino/aldemine groups on jute cellulosic polymer evidenced from Fourier Transform Infra-Red (FTIR) Spectroscopy. This amino or aldemine group incorporation in bleached jute causes its cationization and hence when dyed in acid bath for reactive dye (instead of conventional alkali bath) showed dye uptake for reactive dyes. Study of surface morphology by Scanning Electron Microscopy (SEM) of said soya-modified jute as compared to bleached jute was studied and reported.

  1. Covalent attachment of pyridine-type molecules to glassy carbon surfaces by electrochemical reduction of in situ generated diazonium salts. Formation of ruthenium complexes on ligand-modified surfaces

    International Nuclear Information System (INIS)

    Yesildag, Ali; Ekinci, Duygu

    2010-01-01

    In this study, pyridine, quinoline and phenanthroline molecules were covalently bonded to glassy carbon (GC) electrode surfaces for the first time using the diazonium modification method. Then, the complexation ability of the modified films with ruthenium metal cations was investigated. The derivatization of GC surfaces with heteroaromatic molecules was achieved by electrochemical reduction of the corresponding in situ generated diazonium salts. X-ray photoelectron spectroscopy (XPS) was used to confirm the attachment of heteroaromatic molecules to the GC surfaces and to determine the surface concentration of the films. The barrier properties of the modified GC electrodes were studied in the presence of redox probes such as Fe(CN) 6 3- and Ru(NH 3 ) 6 3+ by cyclic voltammetry. Additionally, the presence of the resulting organometallic films on the surfaces was verified by XPS after the chemical transformation of the characterized ligand films to the ruthenium complex films. The electrochemical behavior of these films in acetonitrile solution was investigated using voltammetric methods, and the surface coverage of the organometallic films was determined from the reversible metal-based Ru(II)/Ru(III) oxidation waves.

  2. Covalent attachment of pyridine-type molecules to glassy carbon surfaces by electrochemical reduction of in situ generated diazonium salts. Formation of ruthenium complexes on ligand-modified surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Yesildag, Ali [Department of Chemistry, Faculty of Sciences, Atatuerk University, 25240 Erzurum (Turkey); Ekinci, Duygu, E-mail: dekin@atauni.edu.t [Department of Chemistry, Faculty of Sciences, Atatuerk University, 25240 Erzurum (Turkey)

    2010-09-30

    In this study, pyridine, quinoline and phenanthroline molecules were covalently bonded to glassy carbon (GC) electrode surfaces for the first time using the diazonium modification method. Then, the complexation ability of the modified films with ruthenium metal cations was investigated. The derivatization of GC surfaces with heteroaromatic molecules was achieved by electrochemical reduction of the corresponding in situ generated diazonium salts. X-ray photoelectron spectroscopy (XPS) was used to confirm the attachment of heteroaromatic molecules to the GC surfaces and to determine the surface concentration of the films. The barrier properties of the modified GC electrodes were studied in the presence of redox probes such as Fe(CN){sub 6}{sup 3-} and Ru(NH{sub 3}){sub 6}{sup 3+} by cyclic voltammetry. Additionally, the presence of the resulting organometallic films on the surfaces was verified by XPS after the chemical transformation of the characterized ligand films to the ruthenium complex films. The electrochemical behavior of these films in acetonitrile solution was investigated using voltammetric methods, and the surface coverage of the organometallic films was determined from the reversible metal-based Ru(II)/Ru(III) oxidation waves.

  3. 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

  4. Extraction of dye

    African Journals Online (AJOL)

    Dyes of natural origins are great for color appreciation as any variation in the concentration of dye, mordant, type of water, soil and climate give variations in ... Grey scale and blue dyed silk were used for color fastness rating. ..... Down to Earth.

  5. Optical study of planar waveguides based on oxidized porous silicon impregnated with laser dyes

    Energy Technology Data Exchange (ETDEWEB)

    Chouket, A. [Unite de recherche de Spectroscopie Raman, Departement de Physique, Faculte des Sciences de Tunis, Elmanar 2092, Tunis (Tunisia); Charrier, J. [Laboratoire d' Optronique CNRS-UMR FOTON 6082, Universite de Rennes 1, ENSSAT-6 rue de Kerampont, BP 80518, 22305 Lannion Cedex (France); Elhouichet, H. [Unite de recherche de Spectroscopie Raman, Departement de Physique, Faculte des Sciences de Tunis, Elmanar 2092, Tunis (Tunisia)], E-mail: habib.elhouichet@fst.rnu.tn; Oueslati, M. [Unite de recherche de Spectroscopie Raman, Departement de Physique, Faculte des Sciences de Tunis, Elmanar 2092, Tunis (Tunisia)

    2009-05-15

    Oxidized porous silicon optical planar waveguides were elaborated and impregnated with rhodamine B and rhodamine 6G. The waveguiding, absorption, and photoluminescence properties of these impregnated waveguides were studied. Successful impregnation of the structure with laser dyes is shown from photoluminescence and reflectivity measurements. Furthermore, the reflectivity spectra prove the homogenous incorporation of both dye molecules inside the pores of the matrices. The refractive indices of waveguide layers were determined before and after dye impregnation to indicate the conservation of guiding conditions. The optical losses in the visible wavelengths are studied as a function of dye concentration. The dye absorption is the main reason for these losses.

  6. Plasma surface functionalization and dyeing kinetics of Pan-Pmma copolymers

    OpenAIRE

    Labay, C.; Canal, C.; Rodríguez, C.; Caballero, G.; Canal, J.M.

    2013-01-01

    Fiber surface modification with air corona plasma has been studied through dyeing kinetics under isothermal conditions at 30 °C on an acrylic-fiber fabric with a cationic dye (CI Basic Blue 3) analyzing the absorption, desorption and fixing on the surface of molecules having defined cationic character. The initial dyeing rate in the first 60 s indicates an increase of 58.3% in the dyeing rate due to the effect of corona plasma on the acrylic fiber surface. At the end of the dyeing process...

  7. Pulse radiolysis of ethanolic solutions of rhodamine dyes

    International Nuclear Information System (INIS)

    Kartasheva, L.I.; Kucherenko, E.A.; Kozlov, A.S.; Pikaev, A.K.

    1983-01-01

    The primary products of radiolytical transformations of rhodamine 6G, rhodamine B, rhodamine 3B and rhodamine 110 in ethanolic solutions were studied by pulse radiolysis method under various conditions. It was found that the semireduced form of a dye was the only intermediate product of such transformations in ethanolic solutions of all dyes. It was shown that this species was formed by interaction of the dye with esub(s) - and CH 3 CHOH. The properties of this species were investigated and the rate constants of respective reactions for each dye were determined. It was found that nature and position of a substituent in the molecule of the dye have an effect on the rate of formation of the semi-reduced form. (author)

  8. Triphenylamine based organic dyes for dye sensitized solar cells: A theoretical approach

    Energy Technology Data Exchange (ETDEWEB)

    Mohankumar, V.; Pandian, Muthu Senthil; Ramasamy, P., E-mail: ramasamyp@ssn.edu.in [SSN Research Centre, SSN College of Engineering, Chennai-603110, Tamilnadu (India)

    2016-05-23

    The geometry, electronic structure and absorption spectra for newly designed triphenylamine based organic dyes were investigated by density functional theory (DFT) and time dependent density functional theory (TD-DFT) with the Becke 3-Parameter-Lee-Yang-parr(B3LYP) functional, where the 6-31G(d,p) basis set was employed. All calculations were performed using the Gaussian 09 software package. The calculated HOMO and LUMO energies show that charge transfer occurs in the molecule. Ultraviolet–visible (UV–vis) spectrum was simulated by TD-DFT in gas phase. The calculation shows that all of the dyes can potentially be good sensitizers for DSSC. The LUMOs are just above the conduction band of TiO{sub 2} and their HOMOs are under the reduction potential energy of the electrolytes (I{sup −}/I{sub 3}{sup −}) which can facilitate electron transfer from the excited dye to TiO{sub 2} and charge regeneration process after photo oxidation respectively. The simulated absorption spectrum of dyes match with solar spectrum. Frontier molecular orbital results show that among all the three dyes, the “dye 3” can be used as potential sensitizer for DSSC.

  9. Novel diyne-bridged dyes for efficient dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Jing-Kun, E-mail: fjk@njust.edu.cn [Department of Chemistry, School of Chemical Engineering, Nanjing University of Science and Technology, Xiaolingwei Street No. 200, Nanjing, 210094 (China); Sun, Tengxiao [Department of Chemistry, School of Chemical Engineering, Nanjing University of Science and Technology, Xiaolingwei Street No. 200, Nanjing, 210094 (China); Tian, Yi [Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577 (Japan); Zhang, Yingjun, E-mail: ZhangYingjun@hec.cn [HEC Pharm Group, HEC R& D Center, Dongguan, 523871 (China); Jin, Chuanfei [HEC Pharm Group, HEC R& D Center, Dongguan, 523871 (China); Xu, Zhimin; Fang, Yu; Hu, Xiangyu; Wang, Haobin [Department of Chemistry, School of Chemical Engineering, Nanjing University of Science and Technology, Xiaolingwei Street No. 200, Nanjing, 210094 (China)

    2017-07-01

    Three new metal free organic dyes (FSD101-103) were synthesized to investigate the influence of diyne unit on dye molecules. FSD101 and FSD102 with diyne unit and FSD103 with monoyne unit were applied as sensitizers in the dye-sensitized solar cells (DSSCs). The optical and electrochemical properties, theoretical studies, and photovoltaic parameters of DSSCs sensitized by these dyes were systematically investigated. By replacing the monoyne unit with a diyne unit, FSD101 exhibited broader absorption spectrum, lower IP, higher EA, lower band gap energy, higher oscillator strength, more efficient electron injection ability, broader IPCE response range and higher τ{sub e} in comparison with FSD103. Hence, DSSC sensitized by FSD101 showed higher J{sub sc} and V{sub oc} values, and demonstrated a power conversion efficiency of 3.12%, about 2-fold as that of FSD103 (1.55%). FSD102 showed similar results as FSD101, with a power conversion efficiency of 2.98%, despite a stronger electron withdraw cyanoacrylic acid group was introduced. This may be due to the lower efficiency of the electron injection from dye to TiO{sub 2} and lower τ{sub e} of FSD102 than that of FSD101. These results indicate that the performance of DSSCs can be significantly improved by introducing a diyne unit into this type of organic dyes. - Highlights: • Diyne-bridge was introduced into dye molecules by a transition-metal-free protocol. • Power conversion efficiency grows from 1.55% to 3.12% by replacing monoyne unit with diyne unit. • FSD101 with diyne unit shows the highest electron lifetime resulting in a higher V{sub oc}.

  10. Fluorescent nanohybrids based on asymmetrical cyanine dyes decorated carbon nanotubes

    OpenAIRE

    Çavuşlar, Özge; Cavuslar, Ozge

    2015-01-01

    In this thesis, we focused on imparting new optical properties to carbon nanotubes (CNTs) to allow their optical detection and visualization in biomedical applications. We investigated the interactions of CNTs and DNA wrapped CNTs with asymmetrical cyanine dye molecules to study the applicability of resulting hybrid materials to fluorescent based systems. When CNTs interacted with asymmetrical cyanine dyes, they constructed a light absorbing nanoarray. However, the fluorescence emission of th...

  11. Analysis of photoisomerizable dyes using laser absorption and fluorescence techniques

    International Nuclear Information System (INIS)

    Duchowicz, R.; Di Paolo, R.E.; Scaffardi, L.; Tocho, J.O.

    1992-01-01

    The attention of the present report has been directed mainly to the description of laser-based techniques developed in order to obtain kinetic and spectroscopic properties of polymethine cyanine dyes in solution. Special attention was dedicated to photoisomerizable molecules where the absorption spectra of both isomers are strongly overlapped. As an example, measurements of two different dyes of laser technological interest, DTCI and DODCI were performed. The developed methods provide a complete quantitative description of photophysical processes. (author). 14 refs, 6 figs

  12. Kinetics of leather dyeing pretreated with enzymes: role of acid protease.

    Science.gov (United States)

    Kanth, Swarna Vinodh; Venba, Rajangam; Jayakumar, Gladstone Christopher; Chandrababu, Narasimhan Kannan

    2009-04-01

    In the present investigation, kinetics of dyeing involving pretreatment with acid protease has been presented. Application of acid protease in dyeing process resulted in increased absorption and diffusion of dye into the leather matrix. Enzyme treatment at 1% concentration, 60 min duration and 50 degrees C resulted in maximum of 98% dye exhaustion and increased absorption rate constants. The final exhaustion (C(infinity)) for the best fit of CI Acid Black 194 dye has been 98.5% with K and r2 values from the modified Cegarra-Puente isotherm as 0.1033 and 0.0631. CI Acid Black 194 being a 2:1 metal complex acid dye exhibited higher absorption rate than the acid dye CI Acid Black 210. A reduction in 50% activation energy calculated from Arrhenius equation has been observed in enzyme assisted dyeing process of both the dyes that substantiates enhanced dye absorption. The absorption rate constant calculated with modified Cegarra-Puente equation confirm higher rate constants and faster kinetics for enzyme assisted dyeing process. Enzyme treated leather exhibited richness of color and shade when compared with control. The present study substantiates the essential role of enzyme pretreatment as an eco-friendly leather dyeing process.

  13. Interactions of Fluorescein Dye with Spherical and Star Shaped Gold Nanoparticles.

    Science.gov (United States)

    Pal, Gopa Dutta; Paul, Somnath; Bardhan, Munmun; Ganguly, Tapan

    2018-04-01

    UV-vis absorption, FT-IR, steady state fluorescence and fluorescence lifetime measurements were made on Fluorescein dye (Fl dye) molecules in presence of gold nanoparticles of different morphologies: spherical gold nanoparticles (GNP) and star shaped gold nanoparticles (GNS). The experimental observations demonstrate that Fl dye molecules form dimers when adsorbed on nanosurface of spherical gold particles. On the other hand possibly due to lack of adsorption on the surface of GNS the dye molecules were unable to form dimers. The projected tips on the surface of GNS may possibly hinder the dyes to adsorb on the surface of this nanoparticle. From the spectral analysis and measurements of thermodynamic parameters it is inferred that two different types of ground state interactions occur between Fl-dye-GNP and Fl dye-GNS systems. Both the observed negative values of the thermodynamic parameters ΔH and ΔS in the case of the former system predict the possibility of occurrences of hydrogen bonding interactions between two neighboring Fl dye molecules when adsorbed on the nanosurface of GNP. On the other hand in Fl dye-GNS system electrostatic interactions appear to occur, as evidenced from negative ΔH and positive value of ΔS, between the positive charges residing on the tips of the nanoparticles and anionic form of Fl dye. It has been concluded that as the adsorption of organic dyes on solid surfaces is prerequisite for the degradation of dye pollutants, the present experimental observations demonstrate that GNP could be used as a better candidate than GNS in degradation mechanism of the xanthenes dyes.

  14. Formation of Ultracold Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Cote, Robin [Univ. of Connecticut, Storrs, CT (United States)

    2016-01-28

    Advances in our ability to slow down and cool atoms and molecules to ultracold temperatures have paved the way to a revolution in basic research on molecules. Ultracold molecules are sensitive of very weak interactions, even when separated by large distances, which allow studies of the effect of those interactions on the behavior of molecules. In this program, we have explored ways to form ultracold molecules starting from pairs of atoms that have already reached the ultracold regime. We devised methods that enhance the efficiency of ultracold molecule production, for example by tuning external magnetic fields and using appropriate laser excitations. We also investigates the properties of those ultracold molecules, especially their de-excitation into stable molecules. We studied the possibility of creating new classes of ultra-long range molecules, named macrodimers, thousand times more extended than regular molecules. Again, such objects are possible because ultra low temperatures prevent their breakup by collision. Finally, we carried out calculations on how chemical reactions are affected and modified at ultracold temperatures. Normally, reactions become less effective as the temperature decreases, but at ultracold temperatures, they can become very effective. We studied this counter-intuitive behavior for benchmark chemical reactions involving molecular hydrogen.

  15. Direct thermal dyes

    Science.gov (United States)

    Ehlinger, Edward

    1990-07-01

    Direct thermal dyes are members of a class of compounds referred to in the imaging industry as color formers or leuco dyes. The oldest members of that class have simple triarylmethane structures, and have been employed for years in various dyeing applications. More complex triarylmethane compounds, such as phthalides and fluorans, are now used in various imaging systems to produce color. Color is derived from all of these compounds via the same mechanism, on a molecular level. That is, an event of activation produces a highly resonating cationic system whose interaction with incident light produces reflected light of a specific color. The activation event in the case of a direct thermal system is the creation of a melt on the paper involving dye and an acidic developer. The three major performance parameters in a thermal system are background color, image density, and image stability. The three major dye physical parameters affecting thermal performance are chemical constituency, purity, and particle size. Those dyes having the best combination of characteristics which can also be manufactured economically dominate the marketplace. Manufacturing high performance dyes for the thermal market involves multi-step, convergent reaction sequences performed on large scale. Intermediates must be manufactured at the right time, and at the right quality to be useful.

  16. Dyes for displays

    Science.gov (United States)

    Claussen, U.

    1984-01-01

    The improvement of contrast and visibility of LCD by two different means was undertaken. The two methods are: (1) development of fluorescent dyes to increase the visibility of fluorescent activated displays (FLAD); and (2) development of dichroic dyes to increase the contrast of displays. This work was done in close cooperation with the electronic industry, where the newly synthesized dyes were tested. The targets for the chemical synthesis were selected with the help of computer model calculations. A marketable range of dyes was developed. Since the interest of the electronic industries concerning FLAD was low, the investigations were stopped. Dichroic dyes, especially black mixtures with good light fastness, order parameter, and solubility in nematic phases were developed. The application of these dyes is restricted to indoor use because of an increase of viscosity below -10 C. Applications on a technical scale, e.g., for the automotive industry, will be possible if the displays work at temperatures down to -40 C. This problem requires a complex optimization of the dye/nematic phase system.

  17. Dyeing of Polyester with Disperse Dyes: Part 2. Synthesis and Dyeing Characteristics of Some Azo Disperse Dyes for Polyester Fabrics

    Directory of Open Access Journals (Sweden)

    Alya M. Al-Etaibi

    2016-06-01

    Full Text Available The goal of this study was to utilize carrier for accelerating the rate of dyeing not only to enhance dyeing of polyester fabrics dyed with disperse dyes 3a,b, but also to save energy. Both the color strength expressed as dye uptake and the fastness properties of the dyed fabrics were evaluated.

  18. Plasma surface functionalization and dyeing kinetics of Pan-Pmma copolymers

    Science.gov (United States)

    Labay, C.; Canal, C.; Rodríguez, C.; Caballero, G.; Canal, J. M.

    2013-10-01

    Fiber surface modification with air corona plasma has been studied through dyeing kinetics under isothermal conditions at 30 °C on an acrylic-fiber fabric with a cationic dye (CI Basic Blue 3) analyzing the absorption, desorption and fixing on the surface of molecules having defined cationic character. The initial dyeing rate in the first 60 s indicates an increase of 58.3% in the dyeing rate due to the effect of corona plasma on the acrylic fiber surface. At the end of the dyeing process, the plasma-treated fabrics absorb 24.7% more dye, and the K/S value of the acrylic fabric increases by 8.8%. With selected dyestuff molecules, new techniques can be designed to amplify the knowledge about plasma-treated surface modifications of macromolecules.

  19. Spectral sensitization of TiO2 by new hemicyanine dyes in dye solar cell yielding enhanced photovoltage: Probing chain length effect on performance

    International Nuclear Information System (INIS)

    Fadadu, Kishan B.; Soni, Saurabh S.

    2013-01-01

    Graphical abstract: New hemicyanine dyes based on indolenine moiety were utilized as light harvesting materials in dye sensitized solar cell. Chain lengths of the molecules were varied in order to study its effect of chain length on the performance of DSSC. Electron transfer kinetic of the solar cell was studied and it was found that the chain length changes the electron transfer kinetic. We have achieved remarkable photovoltage and overall performance of DSSC. Highlights: ► New hemicyanine dyes based on indolenine moiety were utilized as light harvesting materials in dye sensitized solar cell. ► Chain lengths of the molecules were varied in order to study its effect of chain length on the performance of DSSC. ► Electron transfer kinetic of the solar cell was studied and it was found that the chain length changes the electron transfer kinetic. -- Abstract: New hemicyanine dyes having indole nucleus with different alkyl chain length were synthesized and characterized using 1 H NMR and mass spectroscopy. These dyes were used to sensitize the TiO 2 film in dye sensitized solar cell. Nanocrystalline dye solar cells were fabricated and characterized using various electrochemical techniques. It has been found that the alkyl chain length present in the dye molecules greatly affects the overall performance of dye solar cell. Molecules having longer alkyl chain are having better sensitizers which enhance V oc to significant extent. Chain length dependent performance was further investigated using Tafel polarization and impedance method. Hemicyanine dye having hexyl chain has outperformed by attaining 2.9% solar to electricity conversion efficiency

  20. Compact quantum dots for single-molecule imaging.

    Science.gov (United States)

    Smith, Andrew M; Nie, Shuming

    2012-10-09

    Single-molecule imaging is an important tool for understanding the mechanisms of biomolecular function and for visualizing the spatial and temporal heterogeneity of molecular behaviors that underlie cellular biology (1-4). To image an individual molecule of interest, it is typically conjugated to a fluorescent tag (dye, protein, bead, or quantum dot) and observed with epifluorescence or total internal reflection fluorescence (TIRF) microscopy. While dyes and fluorescent proteins have been the mainstay of fluorescence imaging for decades, their fluorescence is unstable under high photon fluxes necessary to observe individual molecules, yielding only a few seconds of observation before complete loss of signal. Latex beads and dye-labeled beads provide improved signal stability but at the expense of drastically larger hydrodynamic size, which can deleteriously alter the diffusion and behavior of the molecule under study. Quantum dots (QDs) offer a balance between these two problematic regimes. These nanoparticles are composed of semiconductor materials and can be engineered with a hydrodynamically compact size with exceptional resistance to photodegradation (5). Thus in recent years QDs have been instrumental in enabling long-term observation of complex macromolecular behavior on the single molecule level. However these particles have still been found to exhibit impaired diffusion in crowded molecular environments such as the cellular cytoplasm and the neuronal synaptic cleft, where their sizes are still too large (4,6,7). Recently we have engineered the cores and surface coatings of QDs for minimized hydrodynamic size, while balancing offsets to colloidal stability, photostability, brightness, and nonspecific binding that have hindered the utility of compact QDs in the past (8,9). The goal of this article is to demonstrate the synthesis, modification, and characterization of these optimized nanocrystals, composed of an alloyed HgxCd1-xSe core coated with an

  1. Tuberculosis Therapy Modifies the Cytokine Profile, Maturation State, and Expression of Inhibitory Molecules on Mycobacterium tuberculosis-Specific CD4+ T-Cells.

    Directory of Open Access Journals (Sweden)

    Kapil K Saharia

    Full Text Available Little is known about the expression of inhibitory molecules cytotoxic T-lymphocyte antigen-4 (CTLA-4 and programmed-death-1 (PD-1 on Mycobacterium tuberculosis (Mtb-specific CD4 T-cells and how their expression is impacted by TB treatment.Cryopreserved PBMCs from HIV-TB co-infected and TB mono-infected patients with untreated and treated tuberculosis (TB disease were stimulated for six hours with PPD and stained. Using polychromatic flow cytometry, we characterized the differentiation state, cytokine profile, and inhibitory molecule expression on PPD-specific CD4 T-cells.In our HIV-TB co-infected cohort, TB treatment increased the proportion of PPD-specific CD4 T-cells co-producing IFN-γ+IL-2+TNF-α+ and IFN-γ+IL-2+ (p = 0.0004 and p = 0.0002, respectively while decreasing the proportion of PPD-specific CD4 T-cells co-producing IFN-γ+MIP1-β+TNF-α+ and IFN-γ+MIP1-β+. The proportion of PPD-specific CD4 T-cells expressing an effector memory phenotype decreased (63.6% vs 51.6%, p = 0.0015 while the proportion expressing a central memory phenotype increased (7.8% vs. 21.7%, p = 0.001 following TB treatment. TB treatment reduced the proportion of PPD-specific CD4 T-cells expressing CTLA-4 (72.4% vs. 44.3%, p = 0.0005 and PD-1 (34.5% vs. 29.2%, p = 0.03. Similar trends were noted in our TB mono-infected cohort.TB treatment alters the functional profile of Mtb-specific CD4 T-cells reflecting shifts towards a less differentiated maturational profile and decreases PD-1 and CTLA-4 expression. These could serve as markers of reduced mycobacterial burden. Further study is warranted.

  2. Kinetics and mechanism of azo dye destruction in advanced oxidation processes

    International Nuclear Information System (INIS)

    Wojnarovits, L.; Palfi, T.; Takacs, E.

    2007-01-01

    The kinetics and mechanism of dye destruction in advanced oxidation processes is discussed on the example of Apollofix Red (Ar-28) radiolysis in aqueous solution. When the reactive intermediate reacts with the color bearing part of the molecule causing with nearly 100% efficiency destruction of the conjugation, the dose dependence, or time dependence of color disappearance is linear. In this case, spectrophotometry can be used to follow-up dye decomposition. Linear dependence was observed when hydrated electrons or hydrogen atoms reacted with the dye. In hydroxyl radical reactions some colored products form with spectra similar to those of the starting dye molecules. For that reason, spectrophotometry gives false result about the intact dye molecule concentration. Analysis by the HPLC reveals logarithmic time dependence in agreement with a theoretical model developed

  3. Molecule nanoweaver

    Science.gov (United States)

    Gerald, II; Rex, E [Brookfield, IL; Klingler, Robert J [Glenview, IL; Rathke, Jerome W [Homer Glen, IL; Diaz, Rocio [Chicago, IL; Vukovic, Lela [Westchester, IL

    2009-03-10

    A method, apparatus, and system for constructing uniform macroscopic films with tailored geometric assemblies of molecules on the nanometer scale. The method, apparatus, and system include providing starting molecules of selected character, applying one or more force fields to the molecules to cause them to order and condense with NMR spectra and images being used to monitor progress in creating the desired geometrical assembly and functionality of molecules that comprise the films.

  4. Influence of the Debye length on the interaction of a small molecule-modified Au nanoparticle with a surface-bound bioreceptor.

    Science.gov (United States)

    Bukar, Natalia; Zhao, Sandy Shuo; Charbonneau, David M; Pelletier, Joelle N; Masson, Jean-Francois

    2014-05-18

    We report that a shorter Debye length and, as a consequence, decreased colloidal stability are required for the molecular interaction of folic acid-modified Au nanoparticles (Au NPs) to occur on a surface-bound receptor, human dihydrofolate reductase (hDHFR). The interaction measured using surface plasmon resonance (SPR) sensing was optimal in a phosphate buffer at pH 6 and ionic strength exceeding 300 mM. Under these conditions, the aggregation constant of the Au NPs was approximately 10(4) M(-1) s(-1) and the Debye length was below 1 nm, on the same length scale as the size of the folate anion (approximately 0.8 nm). Longer Debye lengths led to poorer SPR responses, revealing a reduced affinity of the folic acid-modified Au NPs for hDHFR. While high colloidal stability of Au NPs is desired in most applications, these conditions may hinder molecular interactions due to Debye lengths exceeding the size of the ligand and thus preventing close interactions with the surface-bound molecular receptor.

  5. Toward a general mixed quantum/classical method for the calculation of the vibronic ECD of a flexible dye molecule with different stable conformers: Revisiting the case of 2,2,2-trifluoro-anthrylethanol.

    Science.gov (United States)

    Cerezo, Javier; Aranda, Daniel; Avila Ferrer, Francisco J; Prampolini, Giacomo; Mazzeo, Giuseppe; Longhi, Giovanna; Abbate, Sergio; Santoro, Fabrizio

    2018-06-01

    We extend a recently proposed mixed quantum/classical method for computing the vibronic electronic circular dichroism (ECD) spectrum of molecules with different conformers, to cases where more than one hindered rotation is present. The method generalizes the standard procedure, based on the simple Boltzmann average of the vibronic spectra of the stable conformers, and includes the contribution of structures that sample all the accessible conformational space. It is applied to the simulation of the ECD spectrum of (S)-2,2,2-trifluoroanthrylethanol, a molecule with easily interconvertible conformers, whose spectrum exhibits a pattern of alternating positive and negative vibronic peaks. Results are in very good agreement with experiment and show that spectra averaged over all the sampled conformational space can deviate significantly from the simple average of the contributions of the stable conformers. The present mixed quantum/classical method is able to capture the effect of the nonlinear dependence of the rotatory strength on the molecular structure and of the anharmonic couplings among the modes responsible for molecular flexibility. Despite its computational cost, the procedure is still affordable and promises to be useful in all cases where the ECD shape arises from a subtle balance between vibronic effects and conformational variety. © 2018 Wiley Periodicals, Inc.

  6. Vibrational spectroscopy of photosensitizer dyes for organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Perez Leon, C.

    2005-11-18

    Ruthenium(II) complexes containing polypyridyl ligands are intensely investigated as potential photosensitizers in organic solar cells. Of particular interest is their use in dye-sensitized solar cells based on nanocrystalline films of TiO{sub 2}. Functional groups of the dye allow for efficient anchoring on the semiconductor surface and promote the electronic communication between the donor orbital of the dye and the conduction band of the semiconductor. In the present work a new dye, [Ru(dcbpyH{sub 2}){sub 2}(bpy-TPA{sub 2})](PF6{sub )2}, and the well known (Bu{sub 4}N){sub 2}[Ru(dcbpyH){sub 2}(NCS){sub 2}] complex were spectroscopically characterized. The electronic transitions of both dyes showed solvatochromic shifts due to specific interactions of the ligands with the solvent molecules. The surface-enhanced Raman (SER) spectra of the dyes dissolved in water, ethanol, and acetonitrile were measured in silver and gold colloidal solutions. The results demonstrate that the dyes were adsorbed on the metallic nanoparticles in different ways for different solvents. It was also found that in the gold colloid, the aqueous solutions of both dyes did not produce any SERS signal, whereas in ethanolic solution the SERS effect was very weak. Deprotonation, H-bonding, and donor-acceptor interactions seem to determine these different behaviors. Our results indicate the important role of the charge transfer mechanism in SERS. The adsorption of the dye on two different TiO{sub 2} substrates, anatase paste films and anatase nanopowder, was also studied to clarify the role of the carboxylate groups in the anchoring process of the dyes on the semiconductor surface. The recorded spectra indicate a strong dependence of the anchoring configuration on the morphology of the semiconductor. (orig.)

  7. Photocatalytic degradation of reactive black-5 dye using TiO2 ...

    Indian Academy of Sciences (India)

    sons, considerable attention has been focused on complete oxidation of organic ... Figure 1. Molecular structure of the RB-5 dye (Reactive black 5 (RB 5) dye: molec- ular weight: 991·8 .... by collision with ground state molecules. The optimum ...

  8. Structure and linear spectroscopic properties of near IR polymethine dyes

    International Nuclear Information System (INIS)

    Webster, Scott; Padilha, Lazaro A.; Hu Honghua; Przhonska, Olga V.; Hagan, David J.; Van Stryland, Eric W.; Bondar, Mikhail V.; Davydenko, Iryna G.; Slominsky, Yuriy L.; Kachkovski, Alexei D.

    2008-01-01

    We performed a detailed experimental investigation and quantum-chemical analysis of a new series of near IR polymethine dyes with 5-butyl-7,8-dihydrobenzo[cd]furo[2,3-f]indolium terminal groups. We also synthesized and studied two neutral dyes, squaraine and tetraone, with the same terminal groups and performed a comparison of the spectroscopic properties of this set of 'near IR' dyes (polymethine, squaraine, and tetraone) with an analogous set of 'visible' dyes with simpler benzo[e]indolium terminal groups. From these measurements, we find that the dyes with dihydrobenzo[cd]furo[2,3-f]indolium terminal groups are characterized by a remarkably large shift ∼300 nm (∼200 nm for tetraone) of their absorption bands towards the red region. We discuss the difference in electronic structure for these molecules and show that the 'near IR' dyes are characterized by an additional weak fluorescence band from the higher lying excited states connected with the terminal groups. Absorption spectra for the longest polymethines are solvent-dependent and are characterized by a broadening of the main band in polar solvents, which is explained by ground state symmetry breaking and reduced charge delocalization within the polymethine chromophore. The results of these experiments combined with the agreement of quantum chemical calculations moves us closer to a predictive capability for structure-property relations in cyanine-like molecules

  9. Optical properties of anthocyanin dyes on TiO2 as photosensitizers for application of dye-sensitized solar cell (DSSC)

    Science.gov (United States)

    Ahliha, A. H.; Nurosyid, F.; Supriyanto, A.; Kusumaningsih, T.

    2018-03-01

    Dye-sensitized solar cell (DSSC) is one of the alternative energy that can convert light energy into electrical energy. The component of DSSC consists of FTO substrates, TiO2, electrolyte, dye sensitizer, and counter electrode. This study aim was to determine the effect of optical properties of anthocyanin dyes on efficiency of DSSC. The dye sensitizer used can be extracted from anthocyanin pigments such as dragon fruit, black rice, and red cabbage. The red cabbage sensitizer shows lower absorbance value in the visible range (450-580 nm), than dragon fruit and black rice. The chemical structure of each dye molecules has an R group (carbonyl and hydroxyl) that forms a bond with the oxide layer. Red cabbage dye cell has the highest efficiency, 0.06% then dragon fruit and black rice, 0.02% and 0.03%.

  10. Dye gain gold NW array of surface plasmon polariton waveguide

    Directory of Open Access Journals (Sweden)

    Jun Zhu

    Full Text Available Plasmon lasers can support ultrasmall mode confinement and ultrafast dynamics with device feature sizes below the diffraction limit. At present in the single visible light frequency, the optical gain method of constraint SPP on metal nanowires structure reported less. We design the gold nanowire array structure, consisting of PMMA and R6G dye molecules as gain, by 488 nm pump in the middle of the nanowires position for wide range of light, use symmetry broken overcome that momentum does not match the photonic and SPP energy conversion. Theoretical analysis shows that dyes provide coherent optical feedback, resulting in nanowires face will observe laser properties of surface plasmons. Feature analysis: the incident light and pump joint strength is greater than the sum of strength which is the incident light, pump respectively. Under the effect of dye molecules gain effective, length of SPP transmission can increase 1 µm. The results achieved in a single optical frequency of stimulated radiation, application of dye optical gain can achieve continuous gain effect. This is for the future development of plasma amplifier and the wavelength laser. Keywords: SPP, Stimulated radiation, Gold nanowires array, Dye molecules

  11. Radiation induced degradation of dyes-An overview

    International Nuclear Information System (INIS)

    Rauf, M.A.; Ashraf, S. Salman

    2009-01-01

    Synthetic dyes are a major part of our life. Products ranging from clothes to leather accessories to furniture all depend on extensive use of organic dyes. An unfortunate side effect of extensive use of these chemicals is that huge amounts of these potentially carcinogenic compounds enter our water supplies. Various advanced oxidation processes (AOPs) including the use of high-energy radiation have been developed to degrade these compounds. In this review, dye decoloration and degradation as a result of its exposure to high energy radiation such as gamma radiation and pulsed electron beam are discussed in detail. The role of various transient species such as ·H, ·OH and e aq - are taken into account as reported by various researchers. Literature citations in this area show that e aq - is very effective in decolorization but is less active in the further degradation of the products formed. The degradation of the dyes is initiated exclusively by ·OH attack on electron-rich sites of the dye molecules. Additionally, various parameters that affect the efficiency of radiation induced degradation of dyes, such as effect of radiation dose, oxygen, pH, hydrogen peroxide, added ions and dye classes are also reviewed and summarized. Lastly, pilot plant application of radiation for wastewater treatment is briefly discussed.

  12. Molecular modification of coumarin dyes for more efficient dye sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-de-Armas, Rocio; San-Miguel, Miguel A.; Oviedo, Jaime; Sanz, Javier Fdez. [Department of Physical Chemistry, University of Seville, Seville (Spain)

    2012-05-21

    In this work, new coumarin based dyes for dye sensitized solar cells (DSSC) have been designed by introducing several substituent groups in different positions of the NKX-2311 structure. Two types of substitutions have been considered: the introduction of three electron-donating groups (-OH, -NH{sub 2}, and -OCH{sub 3}) and two different substituents with steric effect: -CH{sub 2}-CH{sub 2}-CH{sub 2}- and -CH{sub 2}-HC=CH-. The electronic absorption spectra (position and width of the first band and absorption threshold) and the position of the LUMO level related to the conduction band have been used as theoretical criteria to evaluate the efficiency of the new dyes. The introduction of a -NH{sub 2} group produces a redshift of the absorption maximum position and the absorption threshold, which could improve the cell efficiency. In contrast, the introduction of -CH{sub 2}-CH{sub 2}-CH{sub 2}- does not modify significantly the electronic structure of NKX-2311, but it might prevent aggregation. Finally, -CH{sub 2}-HC=CH- produces important changes both in the electronic spectrum and in the electronic structure of the dye, and it would be expected as an improvement of cell efficiency for these dyes.

  13. Treatment of dyeing wastewater including reactive dyes (Reactive ...

    African Journals Online (AJOL)

    Fungal growth was not observed at pH 2. Maximum fungal decolourisation ocurred at pH 3 for anionic reactive dyes (RR, RBB, RB) and pH 6 for cationic MB dye. The fungal dye bioremoval was associated with the surface charge of the fungus due to electrostatic interactions. Growing R. arrhizus strain decolourised 100% of ...

  14. Hair cosmetics: dyes.

    Science.gov (United States)

    Guerra-Tapia, A; Gonzalez-Guerra, E

    2014-11-01

    Hair plays a significant role in body image, and its appearance can be changed relatively easily without resort to surgical procedures. Cosmetics and techniques have therefore been used to change hair appearance since time immemorial. The cosmetics industry has developed efficient products that can be used on healthy hair or act on concomitant diseases of the hair and scalp. Dyes embellish the hair by bleaching or coloring it briefly, for temporary periods of longer duration, or permanently, depending on the composition of a dye (oxidative or nonoxidative) and its degree of penetration of the hair shaft. The dermatologist's knowledge of dyes, their use, and their possible side effects (contact eczema, cancer, increased porosity, brittleness) can extend to an understanding of cosmetic resources that also treat hair and scalp conditions. Copyright © 2013 Elsevier España, S.L.U. and AEDV. All rights reserved.

  15. Synthesis and characterisation of new laser dyes

    International Nuclear Information System (INIS)

    Scala-Valero, Claudine

    1997-01-01

    Rhodamines are very efficient laser dyes for the red part of the visible spectrum: their fluorescence quantum efficiencies are about hundred per cent. However, their conversion efficiencies in dye amplifier are about fifty per cent, due to the presence of S n electronic level which is responsible of the re-absorption of a part of photons. In this research thesis, the author aims at trying to move this S n level out of the stimulated emission bandwidth. Models have been developed to propose new structures derived from rhodamines and theoretically possessing the desired properties. The so-recommended molecules have then been synthesised and characterised in terms of absorption and fluorescence spectra, of quantum efficiency, and of fluorescence lifetime. Two modifications are proposed for the rhodamine 6G structure, either by grafting methyl substitutes, or by grafting variously substituted amines. The searched result is obtained with the second modification [fr

  16. Hair Dye and Hair Relaxers

    Science.gov (United States)

    ... For Consumers Consumer Information by Audience For Women Hair Dye and Hair Relaxers Share Tweet Linkedin Pin it More sharing ... products. If you have a bad reaction to hair dyes and relaxers, you should: Stop using the ...

  17. Irradiation treatment of textile dyes: Apollofix-red

    International Nuclear Information System (INIS)

    Wojnarovits, L.; Palfi, T.; Takacs, E.

    2004-01-01

    The UV-VIS absorption spectra of azo dyes in aqueous solutions strongly overlap with the spectra of intermediates produced in reaction with the intermediates of water radiolysis. This overlap complicates the investigation of reaction mechanisms. The paper describes a method for the separation of the two spectra on the example of Apollofix-Red, a triazine and H-acid containing dye. The reactivity of water radiolysis intermediates (e aq - , OH, H, O 2 /HO 2 ) with the dye is also discussed. The most intensive decolouration was found in the reaction of e aq - and H which is due to the fast reaction of these intermediates with the -N=N-azo group of the unreacted molecule and their slow reaction with the transformed molecules. (author)

  18. Dye filled security seal

    International Nuclear Information System (INIS)

    Wilson, D.C.

    1982-01-01

    A security seal for providing an indication of unauthorized access to a sealed object includes an elongate member to be entwined in the object such that access is denied unless the member is removed. The elongate member has a hollow, pressurizable chamber extending throughout its length that is filled with a permanent dye under greater than atmospheric pressure. Attempts to cut the member and weld it together are revealed when dye flows through a rupture in the chamber wall and stains the outside surface of the member

  19. Interaction of dyes CD–1 and SD–1 with the surface of oligodimethysiloxane

    Science.gov (United States)

    Chausov, D. N.

    2018-03-01

    We carried out the modeling orientation of the dyes CD–1 and SD–1 relative to the surface of oligodimethysiloxane using the atom–atom potentials method. We have discovered the dependence of the interaction energy in dyes molecules on the angles which characterizes their orientation relative to the surface of the oligodimethysiloxane crystal. It was found out that the obtained energy value of interaction with the surface can explain weak adhesive qualities of the dyes and the orientation type relative to the surface. We identified the break– loose force for the dyes on the oligodimethysiloxane crystal surface.

  20. LASERS, ACTIVE MEDIA: The aqueous-polyelectrolyte dye solution as an active laser medium

    Science.gov (United States)

    Akimov, A. I.; Saletskii, A. M.

    2000-11-01

    The spectral, luminescent, and lasing properties of aqueous solutions of a cationic dye rhodamine 6G with additions of anion polyelectrolytes — polyacrylic and polymethacrylic acids — are studied. It is found that the energy and spectral properties of lasing of these solutions depend on the ratio of concentrations of polyelectrolyte and molecules. It is also found that the lasing parameters of aqueous-polyelectrolyte dye solutions can be controlled by changing the structure of the molecular system. The variation in the structure of aqueous-polyelectrolyte dye solutions of rhodamine 6G resulted in an almost five-fold increase in the lasing efficiency compared to that in aqueous dye solutions.

  1. Degradation chemistry of N719 and Z-907 dyes at elevated temperatures

    DEFF Research Database (Denmark)

    Lund, Torben; Nguyen, Hoang Thai; Phuong, Nguyen Tuyet

    2009-01-01

    Degradation chemistry of N719 and Z-907 dyes at elevated temperatures.   Torben Lunda, Phuong Tuyet Nguyena and Hoang Thai Nguyenb aDepartment of Science, Systems and Models, Roskilde University, DK-4000, Denmark bDepartment of Chemistry, University of Sciences, HoChiMinh City, Vietnam......      The popular dye sensitized solar cell dyes N719 and Z-907 are in general accepted to be very stable under solar cell conditions below 45 ºC.1 The dyes, however, may undergo thiocyanate ligand substitution reactions with the DSC solvent and additive molecules at elevated temperatures (80-100 º...

  2. Molecule Matters

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 4. Molecule Matters – van der Waals Molecules - History and Some Perspectives on Intermolecular Forces. E Arunan. Feature Article Volume 14 Issue 4 April 2009 pp 346-356 ...

  3. First principles DFT study of dye-sensitized CdS quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Kalpna; Singh, Kh. S. [Department of Physics, D. J. College, Baraut -250611, U.P. (India); Kishor, Shyam, E-mail: shyam387@gmail.com [Department of Chemistry, J. V. College, Baraut -250611, U.P. (India); Josefesson, Ida; Odelius, Michael [Fysikum, Albanova University Center, Stockholm University, S-106 91 Stockholm (Sweden); Ramaniah, Lavanya M. [High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai-400085 (India)

    2014-04-24

    Dye-sensitized quantum dots (QDs) are considered promising candidates for dye-sensitized solar cells. In order to maximize their efficiency, detailed theoretical studies are important. Here, we report a first principles density functional theory (DFT) investigation of experimentally realized dye - sensitized QD / ligand systems, viz., Cd{sub 16}S{sub 16}, capped with acetate molecules and a coumarin dye. The hybrid B3LYP functional and a 6−311+G(d,p)/LANL2dz basis set are used to study the geometric, energetic and electronic properties of these clusters. There is significant structural rearrangement in all the clusters studied - on the surface for the bare QD, and in the positions of the acetate / dye ligands for the ligated QDs. The density of states (DOS) of the bare QD shows states in the band gap, which disappear on surface passivation with the acetate molecules. Interestingly, in the dye-sensitised QD, the HOMO is found to be localized mainly on the dye molecule, while the LUMO is on the QD, as required for photo-induced electron injection from the dye to the QD.

  4. OPTIMIZATION OF DYEING PARAMETERS TO DYE COTTON WITH CARROT EXTRACTION

    Directory of Open Access Journals (Sweden)

    MIRALLES Verónica

    2017-05-01

    Full Text Available Natural dyes derived from flora and fauna are believed to be safe because of non-toxic, non-carcinogenic and biodegradable nature. Furthermore, natural dyes do not cause pollution and waste water problems. Natural dyes as well as synthetic dyes need the optimum parameters to get a good dyeing. On some occasions, It is necessary the use of mordants to increase the affinity between cellulose fiber and natural dye, but there are other conditions to optimize in the dyeing process, like time, temperature, auxiliary porducts, etc. In addition, the optimum conditions are different depends on the type of dye and the fiber nature. The aim of this work is the use of carrot extract to dye cotton fabric by exhaustion at diverse dyeing conditions. Diffferent dyeing processes were carried out to study the effect of pH condition and the temperature, using 7, 6 and 4 pH values and 95 ºC and 130ºC for an hour. As a result some images of dyed samples are shown. Moreover, to evaluate the colour of each sample CIELAB parameters are analysed obtained by reflexion spectrophotometre. The results showed that the temperature used has an important influence on the colour of the dyed sample.

  5. Degradation characteristic of monoazo, diazo and anthraquinone dye by UV / H2O2 process

    Science.gov (United States)

    Abidin, Che Zulzikrami Azner; Fahmi, Muhammad Ridwan; Fazara, Md Ali Umi; Nadhirah, Siti Nurfatin

    2014-10-01

    In this study, the degradation characteristic of monoazo, diazo and anthraquinone dye by UV / H2O2 process was evaluated based on the trend of color, chemical oxygen demand (COD) and total organic carbon (TOC) removal. Three types of dyes consist of monoazo, diazo and anthraquinone dyes were used to compare the degradation mechanism of the dyes. The UV / H2O2 experiments were conducted in a laboratory scale cylindrical glass reactor operated in semi-batch mode. The UV/Vis characterization of monoazo, diazo and anthraquinone dye indicated that the rapid degradation of the dyes by UV / H2O2 process is meaningful with respect to decolourization, as a result of the azo bonds and substitute antraquinone chromophore degradation. However, this process is not efficient for aromatic amines removal. The monoazo MO was difficult to be decolorized than diazo RR120 dye, which imply that number of sulphonic groups in the dye molecules determines the reactivity with hydroxyl radical. The increased in COD removal is the evidence for oxidation and decreased in carbon content of dye molecules. TOC removal analysis shows that low TOC removal of monoazo MO and diazo RR120, as compared to anthraquinone RB19 may indicate an accumulation of by-products that are resistant to the H2O2 photolysis.

  6. Decoloration and degradation of Reactive Red-120 dye by electron beam irradiation in aqueous solution

    International Nuclear Information System (INIS)

    Paul, Jhimli; Rawat, K.P.; Sarma, K.S.S.; Sabharwal, S.

    2011-01-01

    The decoloration and degradation of aqueous solution of the reactive azo dye viz. Reactive Red-120 (RR-120) was carried out by electron beam irradiation. The change in decoloration percentage, removal of chemical oxygen demand (COD) and total organic carbon (TOC), solution pH and five-day biochemical oxygen demand (BOD 5 ) were investigated with respect to the applied dose. However, the concentration of the dye in the solution showed a great influence on all these observables. During the radiolysis process, it was found that the decoloration of dye was caused by the destruction of the chromophore group of the dye molecule, whereas COD and TOC removal were depended on the extent of mineralization of the dye. The decrease in pH during the radiolysis process indicated the fragmentation of the large dye molecule into smaller organic components mostly like smaller organic acids. The BOD 5 /COD ratio of the unirradiated dye solution was in the range of 0.1-0.2, which could be classified as non-biodegradable wastewater. However, the BOD 5 /COD ratio increased upon irradiation and it indicated the transformation of non-biodegradable dye solution into biodegradable solution. This study showed that electron beam irradiation could be a promising method for treatment of textile wastewater containing RR-120 dye.

  7. Degradation characteristic of monoazo, diazo and anthraquinone dye by UV/H2O2 process

    International Nuclear Information System (INIS)

    Abidin, Che Zulzikrami Azner; Fahmi, Muhammad Ridwan; Fazara, Md Ali Umi; Nadhirah, Siti Nurfatin

    2014-01-01

    In this study, the degradation characteristic of monoazo, diazo and anthraquinone dye by UV/H 2 O 2 process was evaluated based on the trend of color, chemical oxygen demand (COD) and total organic carbon (TOC) removal. Three types of dyes consist of monoazo, diazo and anthraquinone dyes were used to compare the degradation mechanism of the dyes. The UV/H 2 O 2 experiments were conducted in a laboratory scale cylindrical glass reactor operated in semi-batch mode. The UV/Vis characterization of monoazo, diazo and anthraquinone dye indicated that the rapid degradation of the dyes by UV/H 2 O 2 process is meaningful with respect to decolourization, as a result of the azo bonds and substitute antraquinone chromophore degradation. However, this process is not efficient for aromatic amines removal. The monoazo MO was difficult to be decolorized than diazo RR120 dye, which imply that number of sulphonic groups in the dye molecules determines the reactivity with hydroxyl radical. The increased in COD removal is the evidence for oxidation and decreased in carbon content of dye molecules. TOC removal analysis shows that low TOC removal of monoazo MO and diazo RR120, as compared to anthraquinone RB19 may indicate an accumulation of by-products that are resistant to the H 2 O 2 photolysis

  8. Microfluidic Dye Lasers

    DEFF Research Database (Denmark)

    Kristensen, Anders; Balslev, Søren; Gersborg-Hansen, Morten

    2006-01-01

    A technology for miniaturized, polymer based lasers, suitable for integration with planar waveguides and microfluidic networks is presented. The microfluidic dye laser device consists of a microfluidic channel with an embedded optical resonator. The devices are fabricated in a thin polymer film...

  9. (MTT) dye reduction assay.

    African Journals Online (AJOL)

    to inhibit proliferation of HeLa cells was determined using the 3443- dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) dye reduction assay. Extracts from roots of Agathisanthemum bojeri, Synaptolepis kirkii and Zanha africana and the leaf extract of Physalis peruviana at a concentration of 10 pg/ml inhibited cell ...

  10. Levitated droplet dye laser

    DEFF Research Database (Denmark)

    Azzouz, H.; Alkafadiji, L.; Balslev, Søren

    2006-01-01

    a high quality optical resonator. Our 750 nL lasing droplets consist of Rhodamine 6G dissolved in ethylene glycol, at a concentration of 0.02 M. The droplets are optically pumped at 532 nm light from a pulsed, frequency doubled Nd:YAG laser, and the dye laser emission is analyzed by a fixed grating...

  11. Dye laser principles with applications

    CERN Document Server

    Duarte, Frank J; Liao, Peter F; Kelley, Paul

    1990-01-01

    A tutorial introduction to the field of dye lasers, Dye Laser Principles also serves as an up-to-date overview for those using dye lasers as research and industrial tools. A number of the issues discussed in this book are pertinent not only to dye lasers but also to lasers in general. Most of the chapters in the book contain problem sets that expand on the material covered in the chapter.Key Features* Dye lasers are among the most versatile and successful laser sources currently available in use Offering both pulsed and continuous-wave operation and tunable from the near ultraviole

  12. Adsorption behavior of natural anthocyanin dye on mesoporous silica

    Science.gov (United States)

    Kohno, Yoshiumi; Haga, Eriko; Yoda, Keiko; Shibata, Masashi; Fukuhara, Choji; Tomita, Yasumasa; Maeda, Yasuhisa; Kobayashi, Kenkichiro

    2014-01-01

    Because of its non-toxicity, naturally occurring anthocyanin is potentially suitable as a colorant for foods and cosmetics. To the wider use of the anthocyanin, the immobilization on the inorganic host for an easy handling as well as the improvement of the stability is required. This study is focused on the adsorption of significant amount of the natural anthocyanin dye onto mesoporous silica, and on the stability enhancement of the anthocyanin by the complexation. The anthocyanin has successfully been adsorbed on the HMS type mesoporous silica containing small amount of aluminum. The amount of the adsorbed anthocyanin has been increased by modifying the pore wall with n-propyl group to make the silica surface hydrophobic. The light fastness of the adsorbed anthocyanin has been improved by making the composite with the HMS samples containing aluminum, although the degree of the improvement is not so large. It has been proposed that incorporation of the anthocyanin molecule deep inside the mesopore is required for the further enhancement of the stability.

  13. Atkins' molecules

    CERN Document Server

    Atkins, Peters

    2003-01-01

    Originally published in 2003, this is the second edition of a title that was called 'the most beautiful chemistry book ever written'. In it, we see the molecules responsible for the experiences of our everyday life - including fabrics, drugs, plastics, explosives, detergents, fragrances, tastes, and sex. With engaging prose Peter Atkins gives a non-technical account of an incredible range of aspects of the world around us, showing unexpected connections, and giving an insight into how this amazing world can be understood in terms of the atoms and molecules from which it is built. The second edition includes dozens of extra molecules, graphical presentation, and an even more accessible and enthralling account of the molecules themselves.

  14. Interstellar Molecules

    Science.gov (United States)

    Solomon, Philip M.

    1973-01-01

    Radioastronomy reveals that clouds between the stars, once believed to consist of simple atoms, contain molecules as complex as seven atoms and may be the most massive objects in our Galaxy. (Author/DF)

  15. Characteristics of dye-sensitized solar cells using natural dye

    Energy Technology Data Exchange (ETDEWEB)

    Furukawa, Shoji, E-mail: furukawa@cse.kyutech.ac.j [Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka-shi, Fukuoka-ken 820-8502 (Japan); Iino, Hiroshi; Iwamoto, Tomohisa; Kukita, Koudai; Yamauchi, Shoji [Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka-shi, Fukuoka-ken 820-8502 (Japan)

    2009-11-30

    Dye-sensitized solar cells are expected to be used for future clean energy. Recently, most of the researchers in this field use Ruthenium complex as dye in the dye-sensitized solar cells. However, Ruthenium is a rare metal, so the cost of the Ruthenium complex is very high. In this paper, various dye-sensitized solar cells have been fabricated using natural dye, such as the dye of red-cabbage, curcumin, and red-perilla. As a result, it was found that the conversion efficiency of the solar cell fabricated using the mixture of red-cabbage and curcumin was about 0.6% (light source: halogen lamp), which was larger than that of the solar cells using one kind of dye. It was also found that the conversion efficiency was about 1.0% for the solar cell with the oxide semiconductor film fabricated using polyethylene glycol (PEG) whose molecular weight was 2,000,000 and red-cabbage dye. This indicates that the cost performance (defined by [conversion efficiency]/[cost of dye]) of the latter solar cell (dye: red-cabbage) is larger by more than 50 times than that of the solar cell using Ruthenium complex, even if the effect of the difference between the halogen lamp and the standard light source is taken into account.

  16. Controlled synthesis of Fe{sub 2}O{sub 3} modified Ag-{sub 010}BiVO{sub 4} heterostructures with enhanced photoelectrochemical activity toward the dye degradation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Junqi, E-mail: sfmlab@163.com; Zhou, Jian; Hao, Hongjuan; Li, Weijie

    2017-03-31

    Highlights: • Z-scheme system and n-n heterogeneous were constructed on the (010) and (110) facet. • The n-n-Z system realizes the wide absorption range, high charge-separation and strong redox ability. • The PEC performance of the Fe{sub 2}O{sub 3} modified Ag-BiVO{sub 4} was enhanced than that of the pure BiVO{sub 4}. - Abstract: Crystal facet dependence is an important approach for optimizing the performance of photocatalyst. In consideration that there is a close correlation between the photoelectric conversion efficiencies and crystal facet, the monoclinic bismuth vanadate (m-BiVO{sub 4}) with (010) and (110) crystal facets has drawn attention. We designed the Ag nanoparticles modified the (010) facet of the BiVO{sub 4} (Ag-{sub 010}BiVO{sub 4}) and then the Ag-{sub 010}BiVO{sub 4} heterogeneous nanostructure was modified by the Fe{sub 2}O{sub 3} nanoparticles. In the Fe{sub 2}O{sub 3} modified Ag-{sub 010}BiVO{sub 4}, the (110) facet of the BiVO{sub 4} was only modified by the Fe{sub 2}O{sub 3} nano-particles to construct the n-n heterojunction structure. Simultaneously, the Z-scheme system was fabricated on the (010) facet of the BiVO{sub 4}, where was modified by the Ag and Fe{sub 2}O{sub 3} nano-particles. We investigated its photoelectrochemical (PEC) and photocatalytic activities by the measurement of the electrochemical performance and degradation of methyl orange (MO). The Ag species in the system is only treated as the solid state electron mediator. As was expected, the Fe{sub 2}O{sub 3} modified Ag-{sub 010}BiVO{sub 4} heterojunction structure exhibited the highest photocurrent density and the smallest impedance. Besides, the Fe{sub 2}O{sub 3} modified Ag-{sub 010}BiVO{sub 4} heterojunction structure exhibited excellent redox ability and the MO could be degraded 92% after 150 min. It is worth noting that the outstanding performance should be attributed to the synergistic effect of n-n and Z-scheme system in the different facets, which

  17. Influence of annealing temperature and organic dyes as sensitizers on sol–gel derived TiO{sub 2} films

    Energy Technology Data Exchange (ETDEWEB)

    Rani, Mamta; Abbas, Saeed J.; Tripathi, S.K., E-mail: surya@pu.ac.in

    2014-09-15

    Highlights: • Preparation of rice shaped TiO{sub 2} nanorods with anatase structure by sol–gel method. • Effect of post deposition annealing on structural properties of TiO{sub 2} is studied. • Unlike individual dye, absorption of Cocktail dye with TiO{sub 2} nanorods is broader. • Cocktail dye sensitized TiO{sub 2} film has more photosensitivity than EY, RB, AO. • Increase in photosensitivity up to optimum temperature is due to hole passivation. - Abstract: Five different organic dyes and reported cocktail dye composed of these dyes are used as sensitizer for titanium dioxide (TiO{sub 2}). Rice shaped (TiO{sub 2}) nanorods are prepared by using sol–gel method. The films annealed at 673 K and above are crystalline with anatase structure. The effect of post annealing temperature is studied on various structural parameters. Cocktail dye shows broader absorption with TiO{sub 2} nanorods in visible region compared with five dyes. Maximum photosensitivity is obtained with RhB dye, followed by FGF and cocktail dye sensitized TiO{sub 2} films. Increase in photosensitivity is due to passivating some hole traps on the surface up to some optimum temperature, above which photosensitivity decreases due to a higher photo activation energy compared to dark conductivity in low temperature region and also may be due to damage of the dye molecule. This work may prove its worth for understanding the electron transport in dye sensitized nanodevices.

  18. Organic Semiconductors based on Dyes and Color Pigments.

    Science.gov (United States)

    Gsänger, Marcel; Bialas, David; Huang, Lizhen; Stolte, Matthias; Würthner, Frank

    2016-05-01

    Organic dyes and pigments constitute a large class of industrial products. The utilization of these compounds in the field of organic electronics is reviewed with particular emphasis on organic field-effect transistors. It is shown that for most major classes of industrial dyes and pigments, i.e., phthalocyanines, perylene and naphthalene diimides, diketopyrrolopyrroles, indigos and isoindigos, squaraines, and merocyanines, charge-carrier mobilities exceeding 1 cm(2) V(-1) s(-1) have been achieved. The most widely investigated molecules due to their n-channel operation are perylene and naphthalene diimides, for which even values close to 10 cm(2) V(-1) s(-1) have been demonstrated. The fact that all of these π-conjugated colorants contain polar substituents leading to strongly quadrupolar or even dipolar molecules suggests that indeed a much larger structural space shows promise for the design of organic semiconductor molecules than was considered in this field traditionally. In particular, because many of these dye and pigment chromophores demonstrate excellent thermal and (photo-)chemical stability in their original applications in dyeing and printing, and are accessible by straightforward synthetic protocols, they bear a particularly high potential for commercial applications in the area of organic electronics. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. 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.

  20. Tunable ultraviolet solid-state dye laser based on MPMMA doped with pyrromethene 597

    International Nuclear Information System (INIS)

    Jiang, Y G; Fan, R W; Xia, Y Q; Chen, D Y

    2011-01-01

    Solid-state dye sample based on modified polymethyl methacrylate (MPMMA) co-doped with pyrromethene 597 (PM597), and coumarin 460 (C460) were prepared. A frequency-doubled pulsed Nd:YAG laser is used to pump solid-state dye sample, and the narrow linewidth dye laser of 94.4 mJ was obtained at 582 nm in an oscillator-amplifier configuration. Using a beta-BaB 2 O 4 (BBO) crystal to frequency double the dye laser into ultraviolet (UV), a tuning range from 279 to 305 nm was demonstrated from a single doped PM597 dye. To the best of our knowledge, the UV tuning range is the best under the same condition so far. The conversion slope efficiency from solid dye laser to UV laser was 8.9% and the highest UV laser output energy reached 6.94 mJ at 291 nm

  1. Consumer available permanent hair dye products cause major allergic immune activation in an animal model

    DEFF Research Database (Denmark)

    Bonefeld, C M; Larsen, J M; Dabelsteen, S

    2010-01-01

    Background p-Phenylenediamine (PPD) and related substances are ingredients of more than two-thirds of oxidative (permanent) hair dyes currently used. Although PPD is a potent skin sensitizer in predictive assays, the extent to which permanent hair dyes sensitize humans has been questioned due...... to the in-use conditions, e.g. the presence of couplers in the hair dye gel and rapid oxidation using a developer. Objectives To study the skin sensitizing potential of permanent hair dyes in mice. Methods Two different permanent hair dye products containing PPD were studied in CBA mice using a modified......-cell proliferation within the draining lymph nodes. Treatment with the mixture induced at least 20% more skin inflammation, cytokine production and CD4+ T-cell activation compared with the colour gel alone. Conclusions Consumer available PPD-containing permanent hair dyes can be potent and rapid immune activators...

  2. Photo-catalytic Removal of Methyl Orange Dye by Polyaniline ...

    African Journals Online (AJOL)

    Photo-catalytic Removal of Methyl Orange Dye by Polyaniline Modified ZnO using Visible Radiation. ... The as-synthesized nano-ZnO, PANI and PANI/ZnO nanocomposite were characterized by X-ray diffraction (XRD), FT-IR, and UV-Vis spectroscopy. The UV–visible spectroscopy studies showed that the absorption peak ...

  3. Adsorption of Remazol Black B dye on Activated Carbon Felt

    Directory of Open Access Journals (Sweden)

    Donnaperna Lucio

    2008-11-01

    Full Text Available The adsorption of Remazol Black B (anionic dye on a microporous activated carbon felt is investigated from its aqueous solution. The surface chemistry of activated carbon is studied using X-ray microanalysis, "Boehm" titrations and pH of PZC measurements which indicates that the surface oxygenated groups are mainly acidic in nature. The kinetics of Remazol Black B adsorption is observed to be pH dependent and governed by the diffusion of the dye molecules. The experimental data can be explained by "intra-particle diffusion model". For Remazol Black B, the Khan model is best suited to simulate the adsorption isotherms.

  4. Mechanism of radiation destruction of dyes in polymers

    International Nuclear Information System (INIS)

    Belichenko, A.S.; Dyumaev, K.M.; Maslyukov, A.P.; Matyushin, G.A.; Nechitailo, V.S.

    1991-01-01

    Considering the experimental results, it might be expected that the mechanism of radiation destruction of dyed polymers by UV-and γ-irradiation should also be associated with a chemical reaction between dye molecules and oxyradicals which appear either on destruction of polymer macromolecules or on oxidation of macroradicals by the oxygen dissolved in the matrix. Thus, the radiation stability of dyes should depend on the rate of formation of primary radicals in the polymer under the action of UV- and γ-irradiation. As has been demostrated, this rate can be influenced by 'resonant' low-molecular additives which perform oscillative cross-relaxation. (author) 8 refs.; 2 figs

  5. 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.

  6. Biological decolorization of xanthene dyes by anaerobic granular biomass.

    Science.gov (United States)

    Apostol, Laura Carmen; Pereira, Luciana; Pereira, Raquel; Gavrilescu, Maria; Alves, Maria Madalena

    2012-09-01

    Biodegradation of a xanthene dyes was investigated for the first time using anaerobic granular sludge. On a first screening, biomass was able to decolorize, at different extents, six azo dye solutions: acid orange 7, direct black 19, direct blue 71, mordant yellow 10, reactive red 2 and reactive red 120 and two xanthene dyes--Erythrosine B and Eosin Y. Biomass concentration, type of electron donor, induction of biomass with dye and mediation with activated carbon (AC) were variables studied for Erythrosine B (Ery) as model dye. Maximum color removal efficiency was achieved with 4.71 g VSS L⁻¹, while the process rates were independent of the biomass concentration above 1.89 g VSS L⁻¹. No considerable effects were observed when different substrates were used as electron donors (VFA, glucose or lactose). Addition of Ery in the incubation period of biomass led to a fivefold increase of the decolorization rate. The rate of Ery decolorization almost duplicated in the presence of commercial AC (0.1 g L⁻¹ AC₀). Using different modified AC samples (from the treatment of AC₀), a threefold higher rate was obtained with the most basic one, AC(H₂), as compared with non-mediated reaction. Higher rates were obtained at pH 6.0. Chemical reduction using Na₂S confirmed the recalcitrant nature of this dye. The results attest that decolorization of Ery is essentially due to enzymatic and adsorption phenomena.

  7. Adhesion molecules

    CERN Document Server

    Preedy, Victor R

    2016-01-01

    This book covers the structure and classification of adhesion molecules in relation to signaling pathways and gene expression. It discusses immunohistochemical localization, neutrophil migration, and junctional, functional, and inflammatory adhesion molecules in pathologies such as leukocyte decompression sickness and ischemia reperfusion injury. Highlighting the medical applications of current research, chapters cover diabetes, obesity, and metabolic syndrome; hypoxia; kidney disease; smoking, atrial fibrillation, and heart disease, the brain and dementia; and tumor proliferation. Finally, it looks at molecular imaging and bioinformatics, high-throughput technologies, and chemotherapy.

  8. An overview of nanomaterials applied for removing dyes from wastewater.

    Science.gov (United States)

    Cai, Zhengqing; Sun, Youmin; Liu, Wen; Pan, Fei; Sun, Peizhe; Fu, Jie

    2017-07-01

    Organic dyes are one of the most commonly discharged pollutants in wastewaters; however, many conventional treatment methods cannot treat them effectively. Over the past few decades, we have witnessed rapid development of nanotechnologies, which offered new opportunities for developing innovative methods to treat dye-contaminated wastewater with low price and high efficiency. The large surface area, modified surface properties, unique electron conduction properties, etc. offer nanomaterials with excellent performances in dye-contaminated wastewater treatment. For examples, the agar-modified monometallic/bimetallic nanoparticles have the maximum methylene blue adsorption capacity of 875.0 mg/g, which are several times higher than conventional adsorbents. Among various nanomaterials, the carbonaceous nanomaterials, nano-sized TiO 2 , and graphitic carbon nitride (g-C 3 N 4 ) are considered as the most promising nanomaterials for removing dyes from water phase. However, some challenges, such as high cost and poor separation performance, still limit their engineering application. This article reviewed the recent advances in the nanomaterials used for dye removal via adsorption, photocatalytic degradation, and biological treatment. The modification methods for improving the effectiveness of nanomaterials are highlighted. Finally, the current knowledge gaps of developing nanomaterials on the environmental application were discussed, and the possible further research direction is proposed.

  9. Interaction Between Cyanine Dye IR-783 and Polystyrene Nanoparticles in Solution.

    Science.gov (United States)

    Zhang, Yunzhi; Xu, Hui; Casabianca, Leah B

    2018-05-17

    The interactions between small molecule drugs or dyes and nanoparticles are important to the use of nanoparticles in medicine. Noncovalent adsorption of dyes on nanoparticle surfaces is also important to the development of nanoparticle dual-use imaging contrast agents. In the present work, solution-state NMR is used to examine the noncovalent interaction between a near-infrared cyanine dye and the surface of polystyrene nanoparticles in solution. Using 1D proton NMR, we can approximate the number of dye molecules that associate with each nanoparticle for different sized nanoparticles. Saturation-Transfer Difference (STD)-NMR was also used to show that protons near the positively-charged nitrogen in the dye are more strongly associated with the negatively-charged nanoparticle surface than protons near the negatively-charged sulfate groups of the dye. The methods described here can be used to study similar drug or dye molecules interacting with the surface of organic nanoparticles. This article is protected by copyright. All rights reserved.

  10. Single Molecule Study of Photoconversion and Spectral Heterogeneities of Fluorophores

    DEFF Research Database (Denmark)

    Liao, Zhiyu

    of conformational changes and dynamics. The photophysical properties of organic dyes directly determine the quality of the experiments. So the better understanding of the photophysical properties of organic dyes, the better we are able to design the experiments and interpret the data, especially in single molecule...... important criteria for a good fluorophore. Improving the photostability of organic dyes by designing the structure is always a difficult task for organic chemists. It requires a comprehensive understanding of the mechanism of the photobleaching behavior of fluorophores. It is the aim of this work...... to understand the mechanisms of photobleaching behaviors of organic dyes, terrylene diimide (TDI) and amino-trioxatriangulenium dye (A3-TOTA+). Photobleaching is usually seen as permanent loss of fluorescence. In this work, we show that organic fluorophores can be converted into another chemical compound after...

  11. Photovoltaic cells based on ternary P3HT:PCBM:polymethine dye active layer transparent in the visible range of light

    Energy Technology Data Exchange (ETDEWEB)

    Bliznyuk, Valery N., E-mail: vblizny@clemson.edu [Department of Materials Science and Engineering, Clemson University, Clemson, SC, 29634 (United States); Gasiorowski, Jacek [Semiconductor Physics, Technische Universität Chemnitz, D-09107 Chemnitz (Germany); Ishchenko, Alexander A.; Bulavko, Gennadiy V. [Institute of Organic Chemistry, National Academy of Sciences of Ukraine, 5 Murmanskaya str., Kiev 02660 (Ukraine); Rahaman, Mahfujur [Semiconductor Physics, Technische Universität Chemnitz, D-09107 Chemnitz (Germany); Hingerl, Kurt [Center for Interface and Nanoanalytics, Johannes Kepler University, Linz 4040 (Austria); Zahn, Dietrich R.T. [Semiconductor Physics, Technische Universität Chemnitz, D-09107 Chemnitz (Germany); Sariciftci, Niyazi S. [Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, Johannes Kepler University, Linz 4040 (Austria)

    2016-12-15

    Highlights: • Addition of a polymethine dye to P3HT:PCBM bulk-heterojunction (BHJ) films leads to a compositionally induced transparency in the system. • Variation of the complex refractive index in binary and ternary BHJ films has been studied with spectroscopic ellipsometry. • Power conversion efficiency of ternary BHJ solar cells is determined by the dye composition and photodoping. - Abstract: Optical and photovoltaic properties were studied for ternary photovoltaic cells containing a traditional donor-acceptor bulk-heterojunction (BHJ) active layer modified with polymethine dye molecules in a broad range of compositions and wavelengths. An effect of composition induced optical transparency, due to the strong modification of the density of states, was observed for symmetrical compositions with approximately equal amount of components. Based on our spectroscopic ellipsometry and atomic force microscopy (AFM) studies we can suggest that the variation of the refractive index, which is significantly reduced in the visible range for ternary systems, is involved in the physical mechanism of the phenomenon. Despite of an addition of the IR absorbing component (which allows broadening of the absorption band to up to 800 nm) no improvement in the power conversion efficiency (PCE) is observed in comparison to the binary BHJ system (P3HT:PCBM). Nevertheless, we believe that further advance of the efficiency will be possible if the energy levels will be chemically designed to avoid formation of charge traps at the BHJ interface during light excitation. Such fine adjustment of the system should become possible with a proper choice of polymer:dye composition due to a high versatility of the polymethine dyes demonstrated in previous studies.

  12. Excitation energy transfer from dye molecules to doped graphene

    Indian Academy of Sciences (India)

    Recently, we have reported theoretical studies on the rate of energy transfer ... Dirac cone approximation and hence our conclusions are of qualitative nature. 2. .... make another change of variable to r given by r = ki q/2 to get. G1 (q) = Aq2.

  13. Dye lasers in atomic spectroscopy

    International Nuclear Information System (INIS)

    Lange, W.; Luther, J.; Steudel, A.

    1974-01-01

    The properties of dye lasers which are relevant to atomic spectroscopy are discussed. Several experiments made possible by tunable dye lasers are discussed. Applications of high spectral density dye lasers are covered in areas such as absorption spectroscopy, fluorescence spectroscopy, photoionization and photodetachment, and two- and multi-photon processes. Applications which take advantage of the narrow bandwidth of tunable dye lasers are discussed, including saturation spectroscopy, fluorescence line narrowing, classic absorption and fluorescence spectroscopy, nonoptical detection of optical resonances, heterodyne spectroscopy, and nonlinear coherent resonant phenomena. (26 figures, 180 references) (U.S.)

  14. Molecule Matters

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 16; Issue 12. Molecule Matters - Dinitrogen. A G Samuelson J Jabadurai. Volume 16 Issue 12 ... Author Affiliations. A G Samuelson1 J Jabadurai1. Department of Inroganic and Physical Chemistry, Indian Institute of Science, Bangalore 560 012, India.

  15. Molecule Matters

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 11; Issue 9. Molecule Matters - A Chromium Compound with a Quintuple Bond. K C Kumara Swamy. Feature Article Volume 11 Issue 9 September 2006 pp 72-75. Fulltext. Click here to view fulltext PDF. Permanent link:

  16. Adsorption of the diazo dye Direct Red 23 onto a zinc oxide surface: A spectroscopic study

    Science.gov (United States)

    Lucilha, Adriana Campano; Bonancêa, Carlos Eduardo; Barreto, Wagner José; Takashima, Keiko

    2010-01-01

    The adsorption of the diazo dye Direct Red 23 onto a zinc oxide surface at 30 °C in the dark was investigated. The color reduction was monitored by spectrophotometry at 503 nm. The FTIR and Raman spectra of the Direct Red 23 adsorption as a function of ZnO concentration were registered. From the PM3 semi-empirical calculations of the atomic charge density and dipole moment of the Direct Red 23 molecule, it was demonstrated that the azo dye molecule may be adsorbed onto the ZnO surface through molecule geometry modifications, enhancing the interfacial area causing a variation in the bonding frequencies.

  17. Selective nonspecific solvation under dielectric saturation and fluorescence spectra of dye solutions in binary solvents.

    Science.gov (United States)

    Bakhshiev, N G; Kiselev, M B

    1991-09-01

    The influence of selective nonspecific solvation on the fluorescence spectra of three substitutedN-methylphthalimides in a binary solvent system consisting of a nonpolar (n-heptane) and a polar (pyridine) component has been studied under conditions close to dielectric saturation. The substantially nonlinearity of the effect is confirmation that the spectral shifts of fluorescence bands depend on the number of polar solvent molecules involved in solvating the dye molecule. The measured fluorescence spectral shifts determined by substituting one nonpolar solvent molecula with a polar one in the proximity of the dye molecule agree quantitatively with the forecasts of the previously proposed semiempirical theory which describes this nonlinear solvation phenomenon.

  18. Tuning the photovoltage of dye-sensitized solar cells based on electrodeposited ZnO

    Energy Technology Data Exchange (ETDEWEB)

    Oekermann, Torsten [Institute of Physical Chemistry and Electrochemistry, Leibniz Universitaet Hannover, Callinstrasse 3- 3A, 30167 Hannover (Germany); Peter, Laurence [Department of Chemistry, University of Bath, Bath BA2 7AY (United Kingdom); Yoshida, Tsukasa [Graduate School of Engineering, Gifu University, Yanagido 1-1, Gifu 501-1193 (Japan)

    2007-07-01

    Nanoporous, fully crystalline ZnO films can be prepared by cathodic electrodeposition from aqueous solutions of Zn salts under the influence of structure-directing agents such as surfactants. Dye-sensitized solar cells (DSSC) based on such films have emerged as a possible alternative for nanocrystalline TiO2-based DSSC due to the very high porosity and good electron transport properties of the films. In this study, we have investigated the influence of the sensitizer dye molecules on the photovoltage of the ZnO-based DSSC. Impedance measurements show that the adsorbed dye molecules lead to a shift of the flatband potential of the ZnO. Electron pushing or withdrawing effects of the dye molecules and protonation or deprotonation of the ZnO surface are discussed as possible explanations. The shifts in the flatband potential partly explain the differences in the photovoltages caused by different dyes, however, differences in the electron injection efficiency and the blocking of electron back reaction by the dye molecules have to be taken into account, too, for a complete description.

  19. 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.

  20. Bright photoactivatable fluorophores for single-molecule imaging.

    Science.gov (United States)

    Grimm, Jonathan B; English, Brian P; Choi, Heejun; Muthusamy, Anand K; Mehl, Brian P; Dong, Peng; Brown, Timothy A; Lippincott-Schwartz, Jennifer; Liu, Zhe; Lionnet, Timothée; Lavis, Luke D

    2016-12-01

    Small-molecule fluorophores are important tools for advanced imaging experiments. We previously reported a general method to improve small, cell-permeable fluorophores which resulted in the azetidine-containing 'Janelia Fluor' (JF) dyes. Here, we refine and extend the utility of these dyes by synthesizing photoactivatable derivatives that are compatible with live-cell labeling strategies. Once activated, these derived compounds retain the superior brightness and photostability of the JF dyes, enabling improved single-particle tracking and facile localization microscopy experiments.

  1. Dye Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Di Wei

    2010-03-01

    Full Text Available Dye sensitized solar cell (DSSC is the only solar cell that can offer both the flexibility and transparency. Its efficiency is comparable to amorphous silicon solar cells but with a much lower cost. This review not only covers the fundamentals of DSSC but also the related cutting-edge research and its development for industrial applications. Most recent research topics on DSSC, for example, applications of nanostructured TiO2, ZnO electrodes, ionic liquid electrolytes, carbon nanotubes, graphene and solid state DSSC have all been included and discussed.

  2. Dye solar cell research

    CSIR Research Space (South Africa)

    Cummings, F

    2009-11-01

    Full Text Available Cummings Energy and Processes Materials Science and Manufacturing Council for Scientific and Industrial Research P.O. Box 395 Pretoria 0001, South Africa 27 November 2009 CONTENT head2rightBackground head2rightCSIR Dye Solar Cell Research head2... rightCollaborations and Links © CSIR 2007 www.csir.co.za head2rightAcknowledgements BACKGROUND head2rightSA is dry: Annual rainfall average of 450 mm compared with a world average of 860 mm head2rightOn upside, we have some...

  3. Use of dyes in cariology.

    Science.gov (United States)

    van de Rijke, J W

    1991-04-01

    The property of dyes to enhance contrast by their colour can be used in clinical dentistry and in investigations in vitro or in vivo. They have been used for indication of affected dental tissues, improvement of diagnostic methods, enhancement of patient awareness and information about specific processes. The development of particular dye systems, aimed at clinical application, is often laborious because of toxic effects, lack of specificity, irreversible staining or difficulties with removal of the dye. Clinically used dyes are often visually observed, which means a qualitative assessment of the staining, while quantification of the staining, if performed at all, is confined mostly to laboratory experiments. In this paper the application of dyes, arranged according to their specific purpose in cariology, is discussed, and a brief historical overview is given of the development of two particular dye applications for which commercial dye systems are now available. If certain requirements are met, dyes can be of great help in detection and quantification when used with several diagnostic methods.

  4. Advanced treatments for the removal of a textile dye

    International Nuclear Information System (INIS)

    Almazan S, P. T.

    2016-01-01

    In this work, the remove a dye from aqueous solution and the treatment of textile wastewater using natural and iron and copper modified materials and advanced oxidation by Fenton and photo-Fenton heterogeneous processes are presented. Clay and activated carbon were modified using Fe and Cu electrodes at ph values of 7 and 2 respectively. The materials were characterized by scanning electronic microscopy (Sem), electron X-ray dispersive spectroscopy (EDS), X-ray diffraction and specific area (Bet), the optimum ph for clay modifications with Fe and Cu was 7, whereas for copper modified activated carbon was 2, because de elemental analysis indicated that under the above conditions the content of evaluated metals is highest. The specific area for natural and iron and copper modified clay samples was 5.97, 131.30 and 78.44 m"2/g, whereas for natural and copper modified activated carbon at ph 2 was 654.85 and 647.61 m"2/g. Dye and wastewater used in this study were obtained from a laundry where jeans are manufactured in Almoloya del Rio in Mexico State. Dye was characterized by infrared spectrophotometry and UV-Vis and it was compared with a standard of potassium indigo trisulfonate and it was observed that both spectra were identical, whereby the dye used in this study is an indigo dye with a maximum absorption band at 591 nm. The characterization of wastewater shows a low biodegradability index (0.25) indicating the presence of non-biodegradability organic matter, and a high concentration of phosphorous was found (93.7 mg/L). A compound parabolic concentrator (CPC-2D) was built to concentrate UV radiation from sunlight and applied in photo-Fenton heterogeneous process obtaining concentrated UV-A and UV-B radiation of 54.29±0.71 and 1.65±0.37 W/m"2 respectively. Iron modified clay (Mt-Fe-7) and copper modified activated carbon (Ac-Cu-2) was used as catalyst in the photo-Fenton process with hydrogen peroxide. The results show that using 1.5 g of catalyst, a

  5. Natural dyeing and UV protection of plasma treated cotton

    Science.gov (United States)

    Gorjanc, Marija; Mozetič, Miran; Vesel, Alenka; Zaplotnik, Rok

    2018-03-01

    Raw cotton fabrics have been exposed to low-pressure non-equilibrium gaseous plasma to improve the adsorption of natural dyes as well as ultraviolet (UV) protection factor. Plasma created in a glass tube by an electrodeless radiofrequency (RF) discharge was created either in oxygen or ammonia at the pressure of 50 Pa to stimulate formation of oxygen and nitrogen groups, respectively. The type and concentration of functional groups was determined by X-ray photoelectron spectroscopy (XPS) and morphological modifications by scanning electron microscopy (SEM). The colour yield for curcumin dye was improved significantly for samples treated with ammonia plasma what was explained by bonding of the dye to surface of amino groups. Contrary, the yield decreased when oxygen plasma treatment was applied due to the negatively charged surface that repels the negatively charged dye molecules. The effect was even more pronounced when using green tea extract as the colouring agent. The colour difference between the untreated and ammonia plasma treated sample increased linearly with plasma treatment time reaching the factor of 3.5 for treatment time of 300 s. The ultraviolet protection factor (UPF) was over 50 indicating excellent protection due to improved adsorption of the dye on the ammonia plasma treated samples.

  6. Phosphate cellulose with metaphosphoric acid for dye removal

    International Nuclear Information System (INIS)

    Silva, S.C.C.; Silva, F.C.; Lima, L.C.B.; Santos, M.R.M.C.; Osajima, J.A.; Silva Filho, E.C. da

    2014-01-01

    The chemical modification of cellulose is a suitable method used for producing value-added products, making them more efficient and selective for certain applications such as adsorption of dye. Thus the aim of this study was to modify the natural cellulose with metaphosphoric acid, characterized it through the techniques of FTIR and "3"1P NMR and applies it in the adsorption of brilliant green dye, evaluating the kinetic models of pseudo first-order and pseudo second-order and the theoretical models of the Langmuir, Freundlich and Temkin isotherms. The characterizations demonstrated the effectiveness of the modification, the maximum adsorption capacity was 150.0 mg g-1, adjusting better to the kinetic model of pseudo-second order and the theoretical model of Temkin, with the adsorbent showing efficient for removal of brilliant green dye. (author)

  7. Deposition of organic dyes for dye-sensitized solar cell by using matrix-assisted pulsed laser evaporation

    Directory of Open Access Journals (Sweden)

    Chih-Ping Yen

    2016-08-01

    Full Text Available The deposition of various distinct organic dyes, including ruthenium complex N3, melanin nanoparticle (MNP, and porphyrin-based donor-π-acceptor dye YD2-o-C8, by using matrix-assisted pulsed laser evaporation (MAPLE for application to dye-sensitized solar cell (DSSC is investigated systematically. It is found that the two covalently-bonded organic molecules, i.e., MNP and YD2-o-C8, can be transferred from the frozen target to the substrate with maintained molecular integrity. In contrast, N3 disintegrates in the process, presumably due to the lower bonding strength of metal complex compared to covalent bond. With the method, DSSC using YD2-o-C8 is fabricated, and an energy conversion efficiency of 1.47% is attained. The issue of the low penetration depth of dyes deposited by MAPLE and the possible resolution to it are studied. This work demonstrates that MAPLE could be an alternative way for deposition of organic dyes for DSSC.

  8. Molecular design of new hydrazone dyes for dye-sensitized solar cells: Synthesis, characterization and DFT study

    KAUST Repository

    Al-Sehemi, Abdullah G.

    2012-07-01

    Three new sensitizers 2-{4-[2-(4-Nitrobenzylidene)hydrazino)]phenyl} ethylene-1,1,2-tricarbonitrile (NBHPET), 2-{4-[2-p-Chlorobenzylidenehydrazino] phenyl}- ethylene-1,1,2-tri carbonitrile (CBHPET) and 2-{4-[2-p- Bromobenzylidenehydrazino] phenyl}ethylene-1,1,2-tricarbonitrile (BBHPET) have been synthesized. The dyes showed pronounced solvatochromic effects as the polarity of the solvents increased. The structures have been optimized at B3LYP/6-31G(d) level of theory. The torsion in E-isomer is smaller than Z-isomer and azo isomers. The highest occupied molecular orbitals are delocalized on whole molecule while lowest unoccupied molecular orbitals are distributed on the tricarbonitrile. The lowest unoccupied molecular orbital energies are above the conduction band of titanium dioxide, highest occupied molecular orbitals of the dyes are below the redox couple of new synthesized dyes and small energy gap revealed these dyes would be better sensitizers for dye-sensitized solar cells. © 2012 Elsevier B.V. All rights reserved.

  9. Deposition of organic dyes for dye-sensitized solar cell by using matrix-assisted pulsed laser evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Yen, Chih-Ping [Department of Physics, National Taiwan University, Taipei 106, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Yu, Pin-Feng [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Department of Physics, National Chung Cheng University, Chiayi 621, Taiwan (China); Wang, Jyhpyng [Department of Physics, National Taiwan University, Taipei 106, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Department of Physics, National Central University, Taoyuan 320, Taiwan (China); Lin, Jiunn-Yuan [Department of Physics, National Chung Cheng University, Chiayi 621, Taiwan (China); Chen, Yen-Mu [SuperbIN Co., Ltd., Taipei 114, Taiwan (China); Chen, Szu-yuan, E-mail: sychen@ltl.iams.sinica.edu.tw [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Department of Physics, National Central University, Taoyuan 320, Taiwan (China)

    2016-08-15

    The deposition of various distinct organic dyes, including ruthenium complex N3, melanin nanoparticle (MNP), and porphyrin-based donor-π-acceptor dye YD2-o-C8, by using matrix-assisted pulsed laser evaporation (MAPLE) for application to dye-sensitized solar cell (DSSC) is investigated systematically. It is found that the two covalently-bonded organic molecules, i.e., MNP and YD2-o-C8, can be transferred from the frozen target to the substrate with maintained molecular integrity. In contrast, N3 disintegrates in the process, presumably due to the lower bonding strength of metal complex compared to covalent bond. With the method, DSSC using YD2-o-C8 is fabricated, and an energy conversion efficiency of 1.47% is attained. The issue of the low penetration depth of dyes deposited by MAPLE and the possible resolution to it are studied. This work demonstrates that MAPLE could be an alternative way for deposition of organic dyes for DSSC.

  10. Ultrafast photodynamics of the indoline dye D149 adsorbed to porous ZnO in dye-sensitized solar cells.

    Science.gov (United States)

    Rohwer, Egmont; Richter, Christoph; Heming, Nadine; Strauch, Kerstin; Litwinski, Christian; Nyokong, Tebello; Schlettwein, Derck; Schwoerer, Heinrich

    2013-01-14

    We investigate the ultrafast dynamics of the photoinduced electron transfer between surface-adsorbed indoline D149 dye and porous ZnO as used in the working electrodes of dye-sensitized solar cells. Transient absorption spectroscopy was conducted on the dye in solution, on solid state samples and for the latter in contact to a I(-)/I(3)(-) redox electrolyte typical for dye-sensitized solar cells to elucidate the effect of each component in the observed dynamics. D149 in a solution of 1:1 acetonitrile and tert-butyl alcohol shows excited-state lifetimes of 300±50 ps. This signature is severely quenched when D149 is adsorbed to ZnO, with the fastest component of the decay trace measured at 150±20 fs due to the charge-transfer mechanism. Absorption bands of the oxidized dye molecule were investigated to determine regeneration times which are in excess of 1 ns. The addition of the redox electrolyte to the system results in faster regeneration times, of the order of 1 ns. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Treatment of wastewater dyeing agent by photocatalytic process in solar reactor

    OpenAIRE

    Zahraa, O.; Maire, S.; Evenou, F.; Hachem, C.; Pons, M. N.; Alinsafi, A.; Bouchy, M.

    2006-01-01

    The photocatalytic decolorization of industrial textile dyes has been studied. The treatment was carried out on a solar reactor consisting in a flat active plane, tilted so as to face the sun and to allow the trickling of the water to be treated. Alternatively the reactor could be irradiated by an artificial source. After checking the system using salicylic acid, a conventional model molecule, the photocatalytic decolorization of Orange II, Yellow Drimarene, and Black Drimarene dyes was inves...

  12. Influence of mordants in the colour of natural dyes: theoretical predictions and experimental results

    OpenAIRE

    Costa, Cristina; Estêvão Candeias, A. J.; Palace Carvalho, A. J.; Prates Ramalho, J. P.

    2007-01-01

    Arraiolos tapestries are probably one of the richest artistic Portuguese expressions in terms of textile production and a cultural heritage that urges to preserve. The richness of colours displayed by some of the Arraiolos tapestries denotes the likely use of a wide variety of dyes. The different light-fastness of dyes combined with the use of different types of mordants can also explain the appearance of pale shades and fading in some tapestries due to different molecule interact...

  13. Degradation characteristic of monoazo, diazo and anthraquinone dye by UV/H{sub 2}O{sub 2} process

    Energy Technology Data Exchange (ETDEWEB)

    Abidin, Che Zulzikrami Azner, E-mail: zulzikrami@unimap.edu.my, E-mail: drfahmi@unimap.edu.my, E-mail: umifazara@unimap.edu.my, E-mail: fatinnadhirah89@gmail.com; Fahmi, Muhammad Ridwan, E-mail: zulzikrami@unimap.edu.my, E-mail: drfahmi@unimap.edu.my, E-mail: umifazara@unimap.edu.my, E-mail: fatinnadhirah89@gmail.com; Fazara, Md Ali Umi, E-mail: zulzikrami@unimap.edu.my, E-mail: drfahmi@unimap.edu.my, E-mail: umifazara@unimap.edu.my, E-mail: fatinnadhirah89@gmail.com; Nadhirah, Siti Nurfatin, E-mail: zulzikrami@unimap.edu.my, E-mail: drfahmi@unimap.edu.my, E-mail: umifazara@unimap.edu.my, E-mail: fatinnadhirah89@gmail.com [School of Environmental Engineering, University Malaysia Perlis (UniMAP), Kompleks Pusat Pengajian Jejawi 3, 02600 Arau, Perlis (Malaysia)

    2014-10-24

    In this study, the degradation characteristic of monoazo, diazo and anthraquinone dye by UV/H{sub 2}O{sub 2} process was evaluated based on the trend of color, chemical oxygen demand (COD) and total organic carbon (TOC) removal. Three types of dyes consist of monoazo, diazo and anthraquinone dyes were used to compare the degradation mechanism of the dyes. The UV/H{sub 2}O{sub 2} experiments were conducted in a laboratory scale cylindrical glass reactor operated in semi-batch mode. The UV/Vis characterization of monoazo, diazo and anthraquinone dye indicated that the rapid degradation of the dyes by UV/H{sub 2}O{sub 2} process is meaningful with respect to decolourization, as a result of the azo bonds and substitute antraquinone chromophore degradation. However, this process is not efficient for aromatic amines removal. The monoazo MO was difficult to be decolorized than diazo RR120 dye, which imply that number of sulphonic groups in the dye molecules determines the reactivity with hydroxyl radical. The increased in COD removal is the evidence for oxidation and decreased in carbon content of dye molecules. TOC removal analysis shows that low TOC removal of monoazo MO and diazo RR120, as compared to anthraquinone RB19 may indicate an accumulation of by-products that are resistant to the H{sub 2}O{sub 2} photolysis.

  14. Enhancement of Electron Transfer Efficiency in Solar Cells Based on PbS QD/N719 Dye Cosensitizers

    Directory of Open Access Journals (Sweden)

    Yanyan Gao

    2012-01-01

    Full Text Available Cosensitized solar cells (CSSCs have recently become an active subject in the field of sensitized solar cells (SSCs due to their increasing electronic utilization. However, because of the dye molecules, layer must be single, dye-SSCs cannot be co-sensitized with two different dyes to form two different molecules layer. But it is possible to be cosensitized with quantum dots (QDs and dyes. Here we designed novel photoanode architecture, namely, PbS QDs and N719 dyes are used as co-sensitizers of the TiO2 mesoporous film. The experimental result shows that PbS QDs/N719 dyes co-sensitized structure can make PbS QDs and N719 dyes mutual improvement. Taking the advantage of PbS not only achieved higher transfer efficiency of photo-excited electron, but also achieved obviously wider range and higher intensity of absorption. The PbS QDs which have been deposited on the TiO2 film was coated by N719 dyes, which can effectively prevent PbS QDs from corroding by I-/I3-electrolyte and light. As we expected, the solar energy-conversion efficiency which is showed by CSSCs fabricated following these photoanodes is relatively higher than the PbS QDs or N719 dyes, single-sensitized solar cells under the illumination of one sun.

  15. Exciplex formation in blended spin-cast films of fluorene-linked dyes and bisphthalimide quenchers.

    Science.gov (United States)

    Stewart, David J; Dalton, Matthew J; Swiger, Rachel N; Cooper, Thomas M; Haley, Joy E; Tan, Loon-Seng

    2013-05-16

    Spin-cast films of dyes (donor-π-donor, donor-π-acceptor, and acceptor-π-acceptor type, where the donor is Ph2N-, the acceptor is 2-benzothiazoyl, and the π-linker is 9,9-diethylfluorene) blended with nonconjugated bisphthalimides were prepared. Upon visible-light excitation of the dyes, quenching of the excited state occurs by exciplex formation between dye and bisphthalimide molecules or, in some cases, by excimer formation or aggregation-induced emission between two dye molecules. The extent of exciplex formation is dependent on the driving force, which can be calculated using the energy difference between the lowest unoccupied molecular orbitals (LUMOs) of the dyes and bisphthalimides. The results show that complete exciplex formation occurs when this driving force is greater than 0.57 eV whereas partial exciplex formation occurs when the driving force is between 0.28 and 0.57 eV. The exciplex emission energies can also be predicted by calculating the difference between the LUMO level of the bisphthalimide and the highest occupied molecular orbital (HOMO) of the dye. These calculated values, which were obtained from the electrochemically determined energy levels, showed good agreement with the observed emission energies. The exciplex lifetimes were found to be significantly longer than the lifetimes of the lone dyes. These exciplexes formed from nonlinked donors and acceptors in the solid state might have potential uses in nonlinear photonics.

  16. Photodynamic dye adsorption and release performance of natural zeolite

    OpenAIRE

    Hovhannisyan, Vladimir; Dong, Chen-Yuan; Chen, Shean-Jen

    2017-01-01

    Clinoptilolite type of zeolite (CZ) is a promising material for biomedicine and pharmaceutics due to its non-toxicity, thermal stability, expanded surface area, and exceptional ability to adsorb various atoms and organic molecules into micropores. Using multiphoton microscopy, we demonstrated that individual CZ particles produce two-photon excited luminescence and second harmonic generation signal at femtosecond laser excitation, and adsorb photo-dynamically active dyes such as hypericin and ...

  17. Single molecule tracking

    Science.gov (United States)

    Shera, E. Brooks

    1988-01-01

    A detection system is provided for identifying individual particles or molecules having characteristic emission in a flow train of the particles in a flow cell. A position sensitive sensor is located adjacent the flow cell in a position effective to detect the emissions from the particles within the flow cell and to assign spatial and temporal coordinates for the detected emissions. A computer is then enabled to predict spatial and temporal coordinates for the particle in the flow train as a function of a first detected emission. Comparison hardware or software then compares subsequent detected spatial and temporal coordinates with the predicted spatial and temporal coordinates to determine whether subsequently detected emissions originate from a particle in the train of particles. In one embodiment, the particles include fluorescent dyes which are excited to fluoresce a spectrum characteristic of the particular particle. Photones are emitted adjacent at least one microchannel plate sensor to enable spatial and temporal coordinates to be assigned. The effect of comparing detected coordinates with predicted coordinates is to define a moving sample volume which effectively precludes the effects of background emissions.

  18. Redox properties of phenosafranine at zeolite-modified electrodes-Effect of surface modification and solution pH

    International Nuclear Information System (INIS)

    Easwaramoorthi, S.; Natarajan, P.

    2008-01-01

    Redox properties of cationic dye phenosafranine (3,7-diamino-5-phenylphenazenium chloride) (PS + ) were studied at zeolite-modified electrodes using Zeolite-Y and NaZSM-5. The peak current and peak potential of phenosafranine-adsorbed zeolite were found to be influenced by the pH of the electrolyte solution. Observation of a second redox couple is suggested to be due to formation of new species at low concentration from the reduced phenosafranine at the zeolite-modified electrodes. Titanium dioxide nanoparticles encapsulated in the cavities of the zeolite or anchored on the external surface of the zeolite do not seem to affect the redox properties of adsorbed PS + . When the cyclic voltammograms are recorded immediately after the electrode is immersed into the solution, the redox potential of PS + is found to be sensitive to the nature of the zeolite surface. The peak potential shifts towards positive region under continuous cycles as the surface hydroxyl groups get protonated in acidic electrolyte solution thereby forcing the movement of dye molecules from the zeolite surface to the zeolite electrode solution interface. The electron transfer rate constants for the adsorbed dye at the electrode are calculated to be 2.5 ± 0.2 s -1 and 3.5 ± 0.2 s -1 for the zeolite-Y electrode and the ZSM-5 electrode, respectively by the Laviron equation

  19. Hybrid molecule/superconductor assemblies

    International Nuclear Information System (INIS)

    McDevitt, J.T.; Haupt, S.G.; Riley, D.R.; Zhao, J.; Zhou, J.P., Jones, C.

    1993-01-01

    The fabrication of electronic devices from molecular materials has attracted much attention recently. Schottky diodes, molecular transistors, metal-insulator-semiconductor diodes, MIS field effect transistors and light emitting diodes have all been prepared utilizing such substances. The active elements in these devices have been constructed by depositing the molecular phase onto the surface of a metal, semiconductor or insulating substrate. With the recent discovery of high temperature superconductivity, new opportunities now exist for the study of molecule/superconductor interactions as well as for the construction of novel hybrid molecule/superconductor devices. In this paper, methods for preparing the initial two composite molecule/semiconductor devices will be reported. Consequently, light sensors based on dye-coated superconductor junctions as well as molecular switches fashioned from conductive polymer coated superconductor junctions as well as molecular switches fashioned from conductive polymer coated superconductor microbridges will be discussed. Moreover, molecule/superconductor energy and electron transfer phenomena will be illustrated also for the first time

  20. Role of hydrogen-bonding and photoinduced electron transfer (PET) on the interaction of resorcinol based acridinedione dyes with Bovine Serum Albumin (BSA) in water

    International Nuclear Information System (INIS)

    Kumaran, Rajendran; Vanjinathan, Mahalingam; Ramamurthy, Perumal

    2015-01-01

    Resorcinol based acridinedione (ADDR) dyes are a class of laser dyes and have structural similarity with purine derivatives, nicotinamide adenine dinucleotide (NADH) analogs. These dyes are classified into photoinduced electron transfer (PET) and non-photoinduced electron transfer dyes, and the photophysical properties of family of these dyes exhibiting PET behavior are entirely different from that of non-PET dyes. The PET process in ADDR dyes is governed by the solvent polarity such that an ADDR dye exhibits PET process through space in an aprotic solvent like acetonitrile and does not exhibit the same in protic solvents like water and methanol. A comparison on the fluorescence emission, lifetime and nature of interaction of various ADDR dyes with a large globular protein like Bovine Serum Albumin (BSA) was carried out in aqueous solution. The interaction of PET based ADDR dyes with BSA in water is found to be largely hydrophobic, but hydrogen-bonding interaction of BSA with dye molecule influences the fluorescence emission of the dye and shifts the emission towards red region. Fluorescence spectral studies reveal that the excited state properties of PET based ADDR dyes are largely influenced by the addition of BSA. The microenvironment around the dye results in significant change in the fluorescence lifetime and emission. Fluorescence enhancement with a red shift in the emission results after the addition of BSA to ADDR dyes containing free amino hydrogen in the 10th position of basic acridinedione dye. The amino hydrogen (N–H) in the 10th position of ADDR dye is replaced by methyl group (N–CH 3 ), a significant decrease in the fluorescence intensity with no apparent shift in the emission maximum was observed after the addition of BSA. The nature of interaction between ADDR dyes with BSA is hydrogen-bonding and the dye remains unbound even at the highest concentration of BSA. Circular Dichroism (CD) studies show that the addition of dye to BSA results in a

  1. Development of AVLIS dye laser system

    International Nuclear Information System (INIS)

    Sugiyama, Akira; Nakayama, Tsuyoshi; Kato, Masaaki; Arisawa, Takashi

    1995-01-01

    CVL pumped single mode dye laser was performed. It was found that pressure tuning has some excellent feature in comparison to mechanical tuning in dye laser frequency control. For evaluation of dye laser amplifier, two-dimensional rate equation was proposed. Calculated data by this equation agreed with experimental data in large diameter input dye laser beam condition. (author)

  2. THE DYEING PROCESS OF KNITTED FABRICS AT DIFFERENT TEMPERATURES USING ULTRASOUND

    Directory of Open Access Journals (Sweden)

    MITIC Jelena

    2014-05-01

    Full Text Available The dyeing of knitted fabrics made from 100 % cellulose using on-line procedure vinyl sulfonic reactive dye, with or without ultrasound energy, is carried out in this paper. The impact of temperature has been observed. The dye exhaustion is monitored using the method of absorption spectrophotometry, and the quality control of the coloration is monitored using color measurements. The acting of ultrasound on coloration consistency, as well as on some mechanical characteristics has also been examined. All examples of the ultrasound dyeing process show greater dye exhaustion in comparison to the conventional procedure. In addition, all the samples, which have been dyed with the ultrasound energy at 40°C, are significantly darker and have deeper color in comparison with the referent sample. The temperature has a great influence on kinetic energy of the dye molecules, and therefore on the diffusion processes in the dyeing system. The exhaustion chart indicates that when the temperature is lower the exhaustion degree drops. However, all the samples dyed with the ultrasound energy have bigger exhaustion. Besides that, ultrasound energy contributes to warming up the processing environment, so the additional warm up with the electricity is unnecessary, unlike the conventional way of dyeing. Since the reactive dyes chemically connect themselves with the cellulose substrate and in that way form covalent connection, the dyed fabrics have good washing consistency. Analysis results indicate that the consistencies are identical regardless the applied dyeing procedure. In other words, the dyeing method using the ultrasound energy produces the dyed fabric of the same quality. After analyzing the results of breaking force and elongation at break of knitted fabrics, it is noticeable that there is no degradation of previously mentioned knitted fabrics features (horizontally and vertically during the ultrasound wave’s activity.

  3. Selective laser photolysis of simple molecules

    International Nuclear Information System (INIS)

    Golnabi, Hossein.

    1984-01-01

    A two-photon technique is reported for the measurement of relative cross section for the photolysis of simple molecules into particular product channels. In this method two independently tunable dye lasers were used to sequentially dissociate molecules of Cs 2 and Cs-Kr for the wavelengths in the range 420 to 660 nm, and then to excite the resulting products to determine the relative cross sections for the photolysis of Cs 2 and Cs-kr into each of the lowest four of the energetically possible product states

  4. A novel biosorbent for dye removal: Extracellular polymeric substance (EPS) of Proteus mirabilis TJ-1

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Zhiqiang [State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment of Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China); Laboratoire de Sciences Analytiques (UMR CNRS 5180), Universite Claude Bernard Lyon 1, Universite de Lyon, 69622 Villeurbanne Cedex (France); Xia Siqing [State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment of Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China)], E-mail: siqingxia@mail.tongji.edu.cn; Wang Xuejiang; Yang Aming; Xu Bin; Chen Ling; Zhu Zhiliang; Zhao Jianfu [State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment of Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China); Jaffrezic-Renault, Nicole; Leonard, Didier [Laboratoire de Sciences Analytiques (UMR CNRS 5180), Universite Claude Bernard Lyon 1, Universite de Lyon, 69622 Villeurbanne Cedex (France)

    2009-04-15

    This paper deals with the extracellular polymeric substance (EPS) of Proteus mirabilis TJ-1 used as a novel biosorbent to remove dye from aqueous solution in batch systems. As a widely used and hazardous dye, basic blue 54 (BB54) was chosen as the model dye to examine the adsorption performance of the EPS. The effects of pH, initial dye concentration, contact time and temperature on the sorption of BB54 to the EPS were examined. At various initial dye concentrations (50-400 mg/L), the batch sorption equilibrium can be obtained in only 5 min. Kinetic studies suggested that the sorption followed the internal transport mechanism. According to the Langmuir model, the maximum BB54 uptake of 2.005 g/g was obtained. Chemical analysis of the EPS indicated the presence of protein (30.9%, w/w) and acid polysaccharide (63.1%, w/w). Scanning electron microscopy (SEM) images showed that the EPS with a crystal-linear structure was whole enwrapped by adsorbed dye molecules. FTIR spectrum result revealed the presence of adsorbing groups such as carboxyl, hydroxyl and amino groups in the EPS. High-molecular weight of the EPS with more binding-sites and stronger van der Waals forces together with its specific construct leads to the excellent performance of dye adsorption. The EPS shows potential board application as a biosorbent for both environmental protection and dye recovery.

  5. The influence of local electric fields on photoinduced absorption in dye-sensitized solar cells.

    Science.gov (United States)

    Cappel, Ute B; Feldt, Sandra M; Schöneboom, Jan; Hagfeldt, Anders; Boschloo, Gerrit

    2010-07-07

    The dye-sensitized solar cell (DSC) challenges conventional photovoltaics with its potential for low-cost production and its flexibility in terms of color and design. Transient absorption spectroscopy is widely used to unravel the working mechanism of DSCs. A surprising, unexplained feature observed in these studies is an apparent bleach of the ground-state absorption of the dye, under conditions where the dye is in the ground state. Here, we demonstrate that this feature can be attributed to a change of the local electric field affecting the absorption spectrum of the dye, an effect related to the Stark effect first reported in 1913. We present a method for measuring the effect of an externally applied electric field on the absorption of dye monolayers adsorbed on flat TiO(2) substrates. The measured signal has the shape of the first derivative of the absorption spectra of the dyes and reverses sign along with the reversion of the direction of the change in dipole moment upon excitation relative to the TiO(2) surface. A very similar signal is observed in photoinduced absorption spectra of dye-sensitized TiO(2) electrodes under solar cell conditions, demonstrating that the electric field across the dye molecules changes upon illumination. This result has important implications for the analysis of transient absorption spectra of DSCs and other molecular optoelectronic devices and challenges the interpretation of many previously published results.

  6. Bioaccumulation versus adsorption of reactive dye by immobilized growing Aspergillus fumigatus beads

    International Nuclear Information System (INIS)

    Wang, B.-E.; Hu Yongyou

    2008-01-01

    The removal of reactive brilliant blue KN-R using growing Aspergillus fumigatus (abbr. A. fumigatus) immobilized on carboxymethylcellulose (CMC) beads with respect to initial dye concentration was investigated. Bioaccumulation was the dominant mechanism of the dye removal. According to the UV-vis spectra and the results of three sets of experiments, it could be concluded that the bioaccumulation using immobilized growing A. fumigatus beads was achieved by metabolism-dependent accumulation and metabolism-independent adsorption (15-23% proportion of overall dye removal), which included biosorption by mycelia entrapped in them and adsorption on immobilization matrix. The transmission electron microscope (TEM) images showed the intracellular structures of mycelia and the toxicity of dye. It was found that the fungus had a considerable tolerance to reactive brilliant blue KN-R at initial dye concentrations of <114.7 mg/l. Though at high initial dye concentrations the growth of mycelia was inhibited significantly by the dye molecules in the growth medium, the bioaccumulation capacity was not markedly affected and the maximum bioaccumulation capacity was 190.5 ± 2.0 mg/g at an initial dye concentration of 374.4 mg/l. The bioaccumulation rates were not constant over the contact time

  7. Configuration of organic dye excimers in nanoporous SiO2 matrices

    International Nuclear Information System (INIS)

    Sorokin, A.V.; Gnap, B.A.; Bespalova, I.I.; Yefimova, S.L.; Malyukin, Yu.V.

    2016-01-01

    The effect of cyanine dye 3,3′-dioctadecyloxacarbocyanine perchlorate (DiO) and benzimidazole dye 4-dimethylamino-1,8-naphthoylene-1′,2′-benzimidazole (DNBI) accumulation in nanoporous silica matrices on the dyes luminescence properties has been studied. For both dyes, ground state dimer formation with perpendicular transition dipoles at high dye concentrations has been considered as a result of restricted geometry of the nanoscale pores. The dimer excitation leads to excimer formation revealing by appearance of new long-wavelength luminescence band and shortening the dye luminescence lifetime. In the excimer luminescence excitation spectra two additional bands have been observed, one of which is bathochromically shifted relatively to the absorption band and another one is hypsocromically shifted. Using the Kasha exciton model it was shown that the excimers possess oblique transition dipoles configuration. - Highlights: • Organic dye molecules are efficiently accumulated in nanoporous silica matrices. • Restricted geometry of SiO 2 nanopores provokes excimerization of both cyanine and benzimidazole dyes. • The excimers reveal configuration of oblique dimers. • The excimers are originated from ground state dimers with a perpendicular arrangement of transition dipoles.

  8. A novel biosorbent for dye removal: Extracellular polymeric substance (EPS) of Proteus mirabilis TJ-1

    International Nuclear Information System (INIS)

    Zhang Zhiqiang; Xia Siqing; Wang Xuejiang; Yang Aming; Xu Bin; Chen Ling; Zhu Zhiliang; Zhao Jianfu; Jaffrezic-Renault, Nicole; Leonard, Didier

    2009-01-01

    This paper deals with the extracellular polymeric substance (EPS) of Proteus mirabilis TJ-1 used as a novel biosorbent to remove dye from aqueous solution in batch systems. As a widely used and hazardous dye, basic blue 54 (BB54) was chosen as the model dye to examine the adsorption performance of the EPS. The effects of pH, initial dye concentration, contact time and temperature on the sorption of BB54 to the EPS were examined. At various initial dye concentrations (50-400 mg/L), the batch sorption equilibrium can be obtained in only 5 min. Kinetic studies suggested that the sorption followed the internal transport mechanism. According to the Langmuir model, the maximum BB54 uptake of 2.005 g/g was obtained. Chemical analysis of the EPS indicated the presence of protein (30.9%, w/w) and acid polysaccharide (63.1%, w/w). Scanning electron microscopy (SEM) images showed that the EPS with a crystal-linear structure was whole enwrapped by adsorbed dye molecules. FTIR spectrum result revealed the presence of adsorbing groups such as carboxyl, hydroxyl and amino groups in the EPS. High-molecular weight of the EPS with more binding-sites and stronger van der Waals forces together with its specific construct leads to the excellent performance of dye adsorption. The EPS shows potential board application as a biosorbent for both environmental protection and dye recovery

  9. Treatment of dye house effluents

    International Nuclear Information System (INIS)

    Waheed, S.; Ashraf, C.M.

    1999-01-01

    Environmental considerations play an increasingly important role in processing of textiles. For textile, limits on particular substances have been and are being laid down either by law or as a result of the demands of clothing manufactures. One of the most complex areas in textile processing is textile printing and dyeing. Here, virtually all dye classes are used. In some printing processes such as reactive printing, many of products used end up in the wastewater. A study of the optimisation of wastewater treatment systems and the systematic management of water and the problems of dyeing are reviewed in this article. (author)

  10. OMG: Open Molecule Generator.

    Science.gov (United States)

    Peironcely, Julio E; Rojas-Chertó, Miguel; Fichera, Davide; Reijmers, Theo; Coulier, Leon; Faulon, Jean-Loup; Hankemeier, Thomas

    2012-09-17

    Computer Assisted Structure Elucidation has been used for decades to discover the chemical structure of unknown compounds. In this work we introduce the first open source structure generator, Open Molecule Generator (OMG), which for a given elemental composition produces all non-isomorphic chemical structures that match that elemental composition. Furthermore, this structure generator can accept as additional input one or multiple non-overlapping prescribed substructures to drastically reduce the number of possible chemical structures. Being open source allows for customization and future extension of its functionality. OMG relies on a modified version of the Canonical Augmentation Path, which grows intermediate chemical structures by adding bonds and checks that at each step only unique molecules are produced. In order to benchmark the tool, we generated chemical structures for the elemental formulas and substructures of different metabolites and compared the results with a commercially available structure generator. The results obtained, i.e. the number of molecules generated, were identical for elemental compositions having only C, O and H. For elemental compositions containing C, O, H, N, P and S, OMG produces all the chemically valid molecules while the other generator produces more, yet chemically impossible, molecules. The chemical completeness of the OMG results comes at the expense of being slower than the commercial generator. In addition to being open source, OMG clearly showed the added value of constraining the solution space by using multiple prescribed substructures as input. We expect this structure generator to be useful in many fields, but to be especially of great importance for metabolomics, where identifying unknown metabolites is still a major bottleneck.

  11. OMG: Open Molecule Generator

    Directory of Open Access Journals (Sweden)

    Peironcely Julio E

    2012-09-01

    Full Text Available Abstract Computer Assisted Structure Elucidation has been used for decades to discover the chemical structure of unknown compounds. In this work we introduce the first open source structure generator, Open Molecule Generator (OMG, which for a given elemental composition produces all non-isomorphic chemical structures that match that elemental composition. Furthermore, this structure generator can accept as additional input one or multiple non-overlapping prescribed substructures to drastically reduce the number of possible chemical structures. Being open source allows for customization and future extension of its functionality. OMG relies on a modified version of the Canonical Augmentation Path, which grows intermediate chemical structures by adding bonds and checks that at each step only unique molecules are produced. In order to benchmark the tool, we generated chemical structures for the elemental formulas and substructures of different metabolites and compared the results with a commercially available structure generator. The results obtained, i.e. the number of molecules generated, were identical for elemental compositions having only C, O and H. For elemental compositions containing C, O, H, N, P and S, OMG produces all the chemically valid molecules while the other generator produces more, yet chemically impossible, molecules. The chemical completeness of the OMG results comes at the expense of being slower than the commercial generator. In addition to being open source, OMG clearly showed the added value of constraining the solution space by using multiple prescribed substructures as input. We expect this structure generator to be useful in many fields, but to be especially of great importance for metabolomics, where identifying unknown metabolites is still a major bottleneck.

  12. Teaching Old Dyes New Tricks: Biological Probes Built from Fluoresceins and Rhodamines.

    Science.gov (United States)

    Lavis, Luke D

    2017-06-20

    Small-molecule fluorophores, such as fluorescein and rhodamine derivatives, are critical tools in modern biochemical and biological research. The field of chemical dyes is old; colored molecules were first discovered in the 1800s, and the fluorescein and rhodamine scaffolds have been known for over a century. Nevertheless, there has been a renaissance in using these dyes to create tools for biochemistry and biology. The application of modern chemistry, biochemistry, molecular genetics, and optical physics to these old structures enables and drives the development of novel, sophisticated fluorescent dyes. This critical review focuses on an important example of chemical biology-the melding of old and new chemical knowledge-leading to useful molecules for advanced biochemical and biological experiments.

  13. Survery on Actual Conditions of Food Dyes

    OpenAIRE

    佐藤, ひろみ

    1981-01-01

    Many food dyes are widely used as food additives in Japan, and many investigations have been pointed the problems of safety of these food dyes used in Japanese food. There are two types of commercial food dyes, one is synthetic dyes and the other is natural dyes.Recently Japanese food is not stained so colourfully, but it is stained faintly in colour near to natural food by using of mixed synthetic dyes. On their hand, many consumers have a tendency to prefer natural food dyes because they ha...

  14. Effect of auxiliary group for p-type organic dyes in NiO-based dye-sensitized solar cells: The first principal study

    Science.gov (United States)

    Li, Juan; Zhang, Shijie; Shao, Di; Yang, Zhenqing; Zhang, Wansong

    2018-03-01

    Auxiliary acceptor groups play a crucial role in D-A-π-A structured organic dyes. In this paper, we designed three D-A-π-A structured organic molecules based on the prototype dye QT-1, named ME18-ME20, and further investigated their electronic and optical properties with density functional theory (DFT) and time-dependent DFT (TDDFT). The calculated results indicate that the scope and intensity of dyes' absorption spectra have some outstanding changes by inserting auxiliary groups. ME20 has not only 152 nm redshifts to long wave orientation, but also 78% increased oscillator strength compared to QT-1, and its absorption spectrum broadens region even up to 1400 nm. Then, we studied the reason that the effect of the introduced different auxiliary acceptor groups in these dyes through their ground states geometries and energy levels, electron transfer and recombination rate.

  15. Molecule Matters van der Waals Molecules

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 12. Molecule Matters van der Waals Molecules - Noble Gas Clusters are London Molecules! E Arunan. Feature Article Volume 14 Issue 12 December 2009 pp 1210-1222 ...

  16. Preparation of fluorescent-dye-labeled cDNA from RNA for microarray hybridization.

    Science.gov (United States)

    Ares, Manuel

    2014-01-01

    This protocol describes how to prepare fluorescently labeled cDNA for hybridization to microarrays. It consists of two steps: first, a mixture of anchored oligo(dT) and random hexamers is used to prime amine-modified cDNA synthesis by reverse transcriptase using a modified deoxynucleotide with a reactive amine group (aminoallyl-dUTP) and an RNA sample as a template. Second, the cDNA is purified and exchanged into bicarbonate buffer so that the amine groups in the cDNA react with the dye N-hydroxysuccinimide (NHS) esters, covalently joining the dye to the cDNA. The dye-coupled cDNA is purified again, and the amount of dye incorporated per microgram of cDNA is determined.

  17. Hair Dyes and Cancer Risk

    Science.gov (United States)

    ... http://www.fda.gov/aboutfda/centersoffices/officeoffoods/cfsan/default.htm . Selected References Huncharek M, Kupelnick B. Personal use of hair dyes and the risk of bladder cancer: results of a meta-analysis. ...

  18. Si Functionalization With Dye Molecular as Light-Harvesting Material

    International Nuclear Information System (INIS)

    Nurul Aqidah Mohd Sinin; Mohd Adib Ibrahim; Mohd Asri Mat Teridi; Norasikin Ahmad Ludin; Suhaila Sepeai; Kamaruzzaman Sopian

    2015-01-01

    The surface plays an important role in thin silicon solar cells, especially with regard to the surface state and interface electronic properties that influence the electron and hole to recombine. In order to keep the recombination loss at a tolerable minimum and avoid an unacceptably large efficiency loss when moving towards thinner silicon materials, the surface must be electronically well passivated. Passivation is the most significant step for the functionalization of silicon. In this study, Si functionalization with a dye molecule might increase the absorption of light that acts as light-harvesting material on the silicon surface. Two types of dye molecular were used; DiL (λ_p_e_a_k = 549 nm) and DiO (λ_p_e_a_k = 484 nm). Both dyes were deposited using a spin-coating technique. These dye layers on the silicon surface were characterized using a Kelvin probe (KP) and photoluminescence (PL) spectroscopy. A different mechanism of slow charge trapping and detrapping was observed using KP measurement. A lifetime decay was observed that indicated a slow process of charge detrapping, owing to light trapping inside the dye/ SiNW interface, with a slow process for an equilibrium to establish between the surface states and the space charge region. An average lifetime of the entire fluorescence decay process was recorded at about 1.24 ns (DiO) and 0.22 ns (DiL), using PL spectroscopy. We show conclusively that these two types of dye can be used as light absorbers, in order to improve the surface properties of the silicon. (author)

  19. On the degradability of printing and dyeing wastewater by wet air oxidation.

    Science.gov (United States)

    Hu, X; Lei, L; Chen, G; Yue, P L

    2001-06-01

    A modified first-order kinetics model was used to study the wet air oxidation of printing and dyeing wastewater. The model simulations are in good agreement with experimental data. The results indicate that a certain fraction of organic pollutants in the printing and dyeing wastewater could not be removed even at elevated temperature and prolonged reaction time. The ratio of degradable organic matter is found independent of temperature and can be improved by using a catalyst.

  20. Photophysical properties, photodegradation characteristics, and lasing action for coumarin dye C540A in polymeric media

    Science.gov (United States)

    Jones, Guilford, II; Huang, Zhennian; Pacheco, Dennis P., Jr.; Russell, Jeffrey A.

    2004-07-01

    Tunable solid-state dye lasers operating in the blue-green spectral region are attractive for a variety of applications. An important consideration in assessing the viability of this technology is the service life of the gain medium, which is presently limited by dye photodegradation. In this study, solid polymeric samples consisting of the coumarin dye C540A in modified PMMA were subjected to controlled photodegradation tests. The excitation laser was a flashlamp-pumped dye laser operating at 440 nm with a pulse duration of 1 μs. A complementary set of data was obtained for dye in solution phase for comparison purposes. Photophysical properties of C540A in water solution of polymethacrylic acid (PMAA) have been investigated with a view to assess the suitability of the sequestering polymer (PMAA) as an effective additive to facilitate use of a water medium for highly efficient blue-green dye lasers. Lasing action of C540A in aqueous PMAA has been realized using flashlamp-pumped laser system, yielding excellent laser efficiencies superior to that achieved in ethanolic solutions with the same dye. Laser characterization of dye in media included measurement of laser threshold, slope efficiency, pulse duration and output wavelength.

  1. Electronic spectral study of interaction of electron donor – acceptor dyes in the ground and excited state with a metal ion. Effect of molecular structure of the dye

    International Nuclear Information System (INIS)

    Sardar, Sanjib Kr; Mandal, Prasun K.; Bagchi, Sanjib

    2014-01-01

    Interaction of manganese (II) ion with electron donor (D)–acceptor (A) dyes having symmetric D–A–D configuration of chromophores (ketocyanine dye) and the corresponding parent merocyanines (D–A configuration) in acetonitrile has been compared by monitoring the electronic absorption, and steady state and time resolved fluorescence characteristics of the dyes. Absorption spectral studies point to the formation of a 1:1 metal ion–dye (S 0 -state) complex. Equilibrium constant (K 0 ) and other thermodynamic parameters for complex formation have been determined for all the systems. Symmetric ketocyanine dyes (D–A–D) form stronger complex than the corresponding dye with D–A configuration. Quenching of fluorescence is caused due to complex formation with the cation. However, for very low concentration of salts, where complex formation is insignificant, an enhancement of fluorescence intensity takes place due to addition of salt. The absorption band of the dye undergoes a slight blue shift in the same concentration range of the metal ion. Fluorescence life time of the excited state also increases with an increase in salt concentration in that concentration range. Results have been explained in terms of formation of a weak association complex where one or more cations replace equivalent solvent molecules in the cybotatic region around the dye. The binding constant of the association complex involving cation and the dye (S 1 -state) has been determined. While the value of the binding constant is higher for a symmetric D–A–D dye relative to that for the corresponding dye with D–A configuration, the extent of fluorescence enhancement for the latter is larger. Values of decay constant for the different photophysical processes have been calculated. Formation of association complex in the S 1 -state is characterised by a slower nonradiative decay of S 1 -state of the dyes. -- Highlights: • A ketocyanine dye forms 1:1 complex with metal ions. • Slight

  2. The use of supramolecular chemistry in dye delivery systems

    International Nuclear Information System (INIS)

    Merckel, Daniel Andrew Sturton

    2002-01-01

    This thesis reports an investigation into supramolecular recognition of the sulfate/ sulfonate oxoanionic group, a moiety present in the majority of reactive dyes. In the first section the problems associated with the use of reactive dyes in dyeing cotton fabrics together with a literature review of supramolecular approaches to anion recognition are discussed. Drawing on the current literature concerning anion recognition (in particular the recognition of phosphates), the main body of the thesis concerns the design and synthesis of several series ofC-shaped (tweezer) and tripodal potential sulfate/ sulfonate receptors. These receptors incorporate the H-bond donor groups guanidine and thiourea and to a lesser extent urea and amide functionalities. In addition the behaviour of potential tweezer-like receptor molecules based on s-triazine (derived from cyanuric chloride) has also been investigated. The sulfate/ sulfonate and related phosphonate association properties of these potential receptors have been studied. Particular emphasis has been placed on the solid-state supramolecular structures formed by these complexes as determined by single crystal X-ray structural studies, and several novel and revealing examples have been analysed in detail. NMR titration binding studies have also been undertaken in order to investigate the complexation behaviour of several receptors with ''model dye'' phosphonates and sulfonates in solution. In addition a number of single crystal X-ray crystallographic studies were undertaken for other members of the Grossel research group during the course of this work, and the results of these structural studies are also reported. (author)

  3. 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.

  4. Diffusion driven optofluidic dye lasers encapsulated into polymer chips

    DEFF Research Database (Denmark)

    Wienhold, Tobias; Breithaupt, Felix; Vannahme, Christoph

    2012-01-01

    Lab-on-a-chip systems made of polymers are promising for the integration of active optical elements, enabling e.g. on-chip excitation of fluorescent markers or spectroscopy. In this work we present diffusion operation of tunable optofluidic dye lasers in a polymer foil. We demonstrate that these ......Lab-on-a-chip systems made of polymers are promising for the integration of active optical elements, enabling e.g. on-chip excitation of fluorescent markers or spectroscopy. In this work we present diffusion operation of tunable optofluidic dye lasers in a polymer foil. We demonstrate...... that these first order distributed feedback lasers can be operated for more than 90 min at a pulse repetition rate of 2 Hz without fluidic pumping. Ultra-high output pulse energies of more than 10 μJ and laser thresholds of 2 μJ are achieved for resonator lengths of 3 mm. By introducing comparatively large on......-chip dye solution reservoirs, the required exchange of dye molecules is accomplished solely by diffusion. Polymer chips the size of a microscope cover slip (18 × 18 mm2) were fabricated in batches on a wafer using a commercially available polymer (TOPAS® Cyclic Olefin Copolymer). Thermal imprinting...

  5. Photophysical studies of PET based acridinedione dyes with globular protein: Bovine serum albumin

    International Nuclear Information System (INIS)

    Rajendran, Kumaran; Perumal, Ramamurthy

    2010-01-01

    Interaction of acridinedione dyes with model transport proteins, bovine serum albumin (BSA) in aqueous solution were investigated by fluorescence spectral studies. A fluorescence enhancement was observed on the addition of BSA to photoinduced electron transfer (PET) based acridinedione dyes, which posses C 6 H 4 (p-OCH 3 ) in the 9th position of the basic acridinedione ring. On the contrary, the addition of BSA to non-PET based acridinedione dyes with methyl or phenyl substitution in the 9th position does not result in any fluorescence enhancement. The enhancement in the fluorescence intensity is attributed to the suppression of PET process through space between -OCH 3 group and the acridinedione moiety is elucidated by steady state fluorescence measurements. The fluorescence anisotropy value (r) of 0.40 reveals that the motion of the dye molecule is highly constrained and is largely confined to the rigid microenvironment of the protein molecule. The binding constant (K) was found to be in the order of 6.0x10 3 [M] -1 , which implies the existence of hydrophobic interaction between the PET based dye and BSA. Time resolved fluorescence lifetime measurements reveal that the PET based acridinedione dye preferably binds in the hydrophobic interior of BSA.

  6. Single molecule studies of solvent-dependent diffusion and entrapment in poly(dimethylsiloxane) thin films.

    Science.gov (United States)

    Lange, Jeffrey J; Culbertson, Christopher T; Higgins, Daniel A

    2008-12-15

    Single molecule microscopic and spectroscopic methods are employed to probe the mobility and physical entrapment of dye molecules in dry and solvent-loaded poly(dimethylsiloxane) (PDMS) films. PDMS films of approximately 220 nm thickness are prepared by spin casting dilute solutions of Sylgard 184 onto glass coverslips, followed by low temperature curing. A perylene diimide dye (BPPDI) is used to probe diffusion and molecule-matrix interactions. Two classes of dye-loaded samples are investigated: (i) those incorporating dye dispersed throughout the films ("in film" samples) and (ii) those in which the dye is restricted primarily to the PDMS surface ("on film" samples). Experiments are performed under dry nitrogen and at various levels of isopropyl alcohol (IPA) loading from the vapor phase. A PDMS-coated quartz-crystal microbalance is employed to monitor solvent loading and drying of the PDMS and to ensure equilibrium conditions are achieved. Single molecules are shown to be predominantly immobile under dry conditions and mostly mobile under IPA-saturated conditions. Quantitative methods for counting the fluorescent spots produced by immobile single molecules in optical images of the samples demonstrate that the population of mobile molecules increases nonlinearly with IPA loading. Even under IPA saturated conditions, the population of fixed molecules is found to be greater than zero and is greatest for "in film" samples. Fluorescence correlation spectroscopy is used to measure the apparent diffusion coefficient for the mobile molecules, yielding a mean value of D = 1.4(+/-0.4) x 10(-8) cm(2)/s that is virtually independent of IPA loading and sample class. It is concluded that a nonzero population of dye molecules is physically entrapped within the PDMS matrix under all conditions. The increase in the population of mobile molecules under high IPA conditions is attributed to the filling of film micropores with solvent, rather than by incorporation of molecularly

  7. [1]Benzothieno[3,2-b]benzothiophene-Based Organic Dyes for Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Capodilupo, Agostina L; Fabiano, Eduardo; De Marco, Luisa; Ciccarella, Giuseppe; Gigli, Giuseppe; Martinelli, Carmela; Cardone, Antonio

    2016-04-15

    Three new metal-free organic dyes with the [1]benzothieno[3,2-b]benzothiophene (BTBT) π-bridge, having the structure donor-π-acceptor (D-π-A) and labeled as 19, 20 and 21, have been designed and synthesized for application in dye-sensitized solar cells (DSSC). Once the design of the π-acceptor block was fixed, containing the BTBT as the π-bridge and the cyanoacrylic group as the electron acceptor and anchoring unit, we selected three donor units with different electron-donor capacity, in order to assemble new chromophores with high molar extinction coefficients (ε), whose absorption features well reflect the good performance of the final DSSC devices. Starting with the 19 dye, which shows a molar extinction coefficient ε of over 14,000 M(-1) cm(-1) and takes into account the absorption maximun at the longer wavelength, the substitution of the BFT donor unit with the BFA yields a great enhancement of absorptivity (molar extinction coefficient ε > 42,000 M(-1) cm(-1)), until reaching the higher value (ε > 69,000 M(-1) cm(-1)) with the BFPhz donor unit. The good general photovoltaic performances obtained with the three dyes highlight the suitable properties of electron-transport of the BTBT as the π-bridge in organic chromophore for DSSC, making this very cheap and easy to synthesize molecule particularly attractive for efficient and low-cost photovoltaic devices.

  8. Scanning probe microscopy studies on the adsorption of selected molecular dyes on titania

    Directory of Open Access Journals (Sweden)

    Jakub S. Prauzner-Bechcicki

    2016-11-01

    Full Text Available Titanium dioxide, or titania, sensitized with organic dyes is a very attractive platform for photovoltaic applications. In this context, the knowledge of properties of the titania–sensitizer junction is essential for designing efficient devices. Consequently, studies on the adsorption of organic dyes on titania surfaces and on the influence of the adsorption geometry on the energy level alignment between the substrate and an organic adsorbate are necessary. The method of choice for investigating the local environment of a single dye molecule is high-resolution scanning probe microscopy. Microscopic results combined with the outcome of common spectroscopic methods provide a better understanding of the mechanism taking place at the titania–sensitizer interface. In the following paper, we review the recent scanning probe microscopic research of a certain group of molecular assemblies on rutile titania surfaces as it pertains to dye-sensitized solar cell applications. We focus on experiments on adsorption of three types of prototypical dye molecules, i.e., perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA, phtalocyanines and porphyrins. Two interesting heteromolecular systems comprising molecules that are aligned with the given review are discussed as well.

  9. In-situ investigation of adsorption of dye and coadsorbates on TiO 2 films using QCM-D, fluorescence and AFM techniques

    KAUST Repository

    Harms, Hauke A.; Té treault, Nicolas; Voitchovsky, Kislon; Stellacci, Francesco; Grä tzel, Michael

    2013-01-01

    Simultaneous adsorption of dye molecules and coadsorbates is important for the fabrication of high-efficiency dyesensitized solar cells, but its mechanism is not well understood. Herein, we use a quartz crystal microbalance with dissipation

  10. 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.

  11. 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

  12. Radiation degradation-adsorption treatment of some toxic dyes present in wastewater

    International Nuclear Information System (INIS)

    El-Kelesh, N.A.; Dessouki, A.M.; Amer, S.I.

    2002-01-01

    The radiolysis or three toxic dyes, viz. Reactive Yellow 3, Reactive Black 39, and Basic Blue 26, was investigated as a function of the dye concentration, pH, irradiation dose and dose rate. The radiolytic degradation was more pronounced with Reactive yellow 3 and Reactive Black 39 than with Basic Blue 26. The degree of degradation could be increased by combining the irradiation procedure with the conventional treatment, such as addition of oxygen or hydrogen peroxide; addition of nitrogen, on the other hand, resulted in no change. A pH drop was observed and tentatively attributed to the degradation of the dye molecules to lower molecular weight compounds such as organic acids. The primary radiolysis products as well as the secondary products are responsible for the degradation of the dye chromophore. Experiments with the adsorption or exchange of the dyes on GAC, some ion exchange resins and polymeric membranes were carried out to find that the polymeric membranes have the highest adsorption capacity for the pollutants except the basic dye. The combined treatment by irradiation and adsorption resulted in a complete removal of the toxic dyes in question

  13. Peripheral Hole Acceptor Moieties on an Organic Dye Improve Dye‐Sensitized Solar Cell Performance

    Science.gov (United States)

    Hao, Yan; Gabrielsson, Erik; Lohse, Peter William; Yang, Wenxing; Johansson, Erik M. J.; Hagfeldt, Anders

    2015-01-01

    Investigation of charge transfer dynamics in dye‐sensitized solar cells is of fundamental interest and the control of these dynamics is a key factor for developing more efficient solar cell devices. One possibility for attenuating losses through recombination between injected electrons and oxidized dye molecules is to move the positive charge further away from the metal oxide surface. For this purpose, a metal‐free dye named E6 is developed, in which the chromophore core is tethered to two external triphenylamine (TPA) units. After photoinduced electron injection into TiO2, the remaining hole is rapidly transferred to a peripheral TPA unit. Electron–hole recombination is slowed down by 30% compared to a reference dye without peripheral TPA units. Furthermore, it is found that the added TPA moieties improve the electron blocking effect of the dye, retarding recombination of electrons from TiO2 to the cobalt‐based electrolyte. PMID:27722076

  14. Treatment of wastewater dyeing agent by photocatalytic process in solar reactor

    Directory of Open Access Journals (Sweden)

    O. Zahraa

    2006-01-01

    Full Text Available The photocatalytic decolorization of industrial textile dyes has been studied. The treatment was carried out on a solar reactor consisting in a flat active plane, tilted so as to face the sun and to allow the trickling of the water to be treated. Alternatively the reactor could be irradiated by an artificial source. After checking the system using salicylic acid, a conventional model molecule, the photocatalytic decolorization of Orange II, Yellow Drimarene, and Black Drimarene dyes was investigated. Artificial and solar irradiation gave comparable results although the heating by the sun reduced the amount of adsorption. The kinetics agrees with the Langmuir-Hinshelwood model and a discrepancy between adsorption constants deduced from the kinetic and adsorption experiments was interpreted by considering various types of adsorption sites. Orange II and Drimarene dyes decolorization kinetics are opposite limiting cases of the above model, as being of order 0 and 1 with respect to the dye, respectively.

  15. Henna (Lawsonia inermis L. Dye-Sensitized Nanocrystalline Titania Solar Cell

    Directory of Open Access Journals (Sweden)

    Khalil Ebrahim Jasim

    2012-01-01

    Full Text Available Low-cost solar cells have been the subject of intensive research activities for over half century ago. More recently, dye-sensitized solar cells (DSSCs emerged as a new class of low-cost solar cells that can be easily prepared. Natural-dye-sensitized solar cells (NDSSCs are shown to be excellent examples of mimicking photosynthesis. The NDSSC acts as a green energy generator in which dyes molecules adsorbed to nanocrystalline layer of wide bandgap semiconductor material harvest photons. In this paper we investigate the structural, optical, electrical, and photovoltaic characterization of two types of natural dyes, namely, the Bahraini Henna and the Yemeni Henna, extracted using the Soxhlet extractor. Solar cells from both materials were prepared and characterized. It was found that the levels of open-circuit voltage and short-circuit current are concentration dependent. Further suggestions to improve the efficiency of NDSSC are discussed.

  16. Henna (Lawsonia inermis L.) Dye-Sensitized Nanocrystalline Titania Solar Cell

    International Nuclear Information System (INIS)

    Jasim, Kh.E.; Al-Dallal, Sh.; Hassan, A.M.

    2012-01-01

    Low-cost solar cells have been the subject of intensive research activities for over half century ago. More recently, dye-sensitized solar cells (DSSCs) emerged as a new class of low-cost solar cells that can be easily prepared. Natural-dye-sensitized solar cells (NDSSCs) are shown to be excellent examples of mimicking photosynthesis. The NDSSC acts as a green energy generator in which dyes molecules adsorbed to nanocrystalline layer of wide bandgap semiconductor material harvest photons. In this paper we investigate the structural, optical, electrical, and photovoltaic characterization of two types of natural dyes, namely, the Bahraini Henna and the Yemeni Henna, extracted using the Soxhlet extractor. Solar cells from both materials were prepared and characterized. It was found that the levels of open-circuit voltage and short-circuit current are concentration dependent. Further suggestions to improve the efficiency of NDSSC are discussed

  17. Dye Giant Absorption and Light Confinement Effects in Porous Bragg Microcavities

    DEFF Research Database (Denmark)

    Oliva-Ramírez, Manuel; Gil-Rostra, Jorge; Simonsen, Adam C.

    2018-01-01

    This work presents a simple experimental procedure to probe light confinement effects in photonic structures. Two types of porous 1D Bragg microcavities with two resonant peaks in the reflection gap were prepared by physical vapor deposition at oblique angle configurations and then infiltrated...... with dye solutions of increasing concentrations. The unusual position shift and intensity drop of the transmitted resonant peak observed when it was scanned through the dye absorption band have been accounted for by the effect of the light trapped at their optical defect layer. An experimentally observed...... giant absorption of the dye molecules and a strong anomalous dispersion in the refractive index of the solution are claimed as the reasons for the observed variations in the Bragg microcavity resonant feature. Determining the giant absorption of infiltrated dye solutions is proposed as a general...

  18. Efficiency-limiting processes in cyclopentadithiophene-bridged donor-acceptor-type dyes for solid-state dye-sensitized solar cells

    KAUST Repository

    Hinkel, Felix

    2018-01-26

    The charge generation and recombination processes in three novel push-pull photosensitizers for dye-sensitized solar cells (DSSCs) are studied by ps–μs transient absorption (TA) and quasi-steady-state photoinduced absorption (PIA) spectroscopy. The three cyclopentadithiophene-based photosensitizer dye molecules exhibit comparably low power conversion efficiencies ranging from 0.8% to 1.7% in solid-state DSSCs. We find that the photocurrents increase in the presence of Li-salt additives. Both TA and PIA measurements observe long-lived dye cations created by electron injection from the dyes’ excited state for two dyes from the series. However, the third dye shows significantly lower performance as a consequence of the less efficient electron injection even after the addition of Li-salts and faster electron-hole recombination on the ns-μs time scale. In essence, the prerequisites for this class of donor-π bridge-acceptor photosensitizers to reach higher charge generation efficiencies are a combination of strong dipole moments and fine tuning of the electronic landscape at the titania-dye interface by Li-salt addition.

  19. Insights into the Mechanism of a Covalently Linked Organic Dye-Cobaloxime Catalyst System for Dye-Sensitized Solar Fuel Devices.

    Science.gov (United States)

    Pati, Palas Baran; Zhang, Lei; Philippe, Bertrand; Fernández-Terán, Ricardo; Ahmadi, Sareh; Tian, Lei; Rensmo, Håkan; Hammarström, Leif; Tian, Haining

    2017-06-09

    A covalently linked organic dye-cobaloxime catalyst system based on mesoporous NiO is synthesized by a facile click reaction for mechanistic studies and application in a dye-sensitized solar fuel device. The system is systematically investigated by photoelectrochemical measurements, density functional theory, time-resolved fluorescence, transient absorption spectroscopy, and photoelectron spectroscopy. The results show that irradiation of the dye-catalyst on NiO leads to ultrafast hole injection into NiO from the excited dye, followed by a fast electron transfer process to reduce the catalyst. Moreover, the dye adopts different structures with different excited state energies, and excitation energy transfer occurs between neighboring molecules on the semiconductor surface. The photoelectrochemical experiments also show hydrogen production by this system. The axial chloride ligands of the catalyst are released during photocatalysis to create the active sites for proton reduction. A working mechanism of the dye-catalyst system on the photocathode is proposed on the basis of this study. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  20. Efficiency-limiting processes in cyclopentadithiophene-bridged donor-acceptor-type dyes for solid-state dye-sensitized solar cells

    KAUST Repository

    Hinkel, Felix; Kim, Yoojin M.; Zagraniarsky, Yulian; Schlü tter, Florian; Andrienko, Denis; Mü llen, Klaus; Laquai, Fré dé ric

    2018-01-01

    The charge generation and recombination processes in three novel push-pull photosensitizers for dye-sensitized solar cells (DSSCs) are studied by ps–μs transient absorption (TA) and quasi-steady-state photoinduced absorption (PIA) spectroscopy. The three cyclopentadithiophene-based photosensitizer dye molecules exhibit comparably low power conversion efficiencies ranging from 0.8% to 1.7% in solid-state DSSCs. We find that the photocurrents increase in the presence of Li-salt additives. Both TA and PIA measurements observe long-lived dye cations created by electron injection from the dyes’ excited state for two dyes from the series. However, the third dye shows significantly lower performance as a consequence of the less efficient electron injection even after the addition of Li-salts and faster electron-hole recombination on the ns-μs time scale. In essence, the prerequisites for this class of donor-π bridge-acceptor photosensitizers to reach higher charge generation efficiencies are a combination of strong dipole moments and fine tuning of the electronic landscape at the titania-dye interface by Li-salt addition.

  1. Changes in inorganic matrices of dye sensitized solar cells during preparation

    Energy Technology Data Exchange (ETDEWEB)

    Graaf, Harald; Baumgaertel, Thomas; Luettich, Franziska; Kehr, Mirko [Institute of Physics, University of Technology Chemnitz (Germany); Maedler, Carsten [Institute of Physics, University of Technology Chemnitz (Germany); Department of Physics, Boston University, Boston, MA (United States); Oekermann, Thorsten [Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover (Germany)

    2010-07-01

    Dye-sensitized solar cells (DSSC) containing zinc oxide (ZnO) as the inorganic semiconductor and organic dye molecules as the sensitizer are well known devices with high efficiency. Such DSSC are prepared by electrochemical deposition of an aqueous zinc salt solution including organic molecules as templates. The template is desorbed in a second step to obtain a porous ZnO network. As a final step the sensitizing organic molecules were re-adsorped from solution. Within these different processing steps the structure of the ZnO can be influenced. We will discuss the growth mechanism during film deposition e.g. due to different template molecules. Also the crystal structure changes accompanying the desorption process, which is performed in an alkaline aqueous solution. Different techniques as X-ray investigations, optical absorption and scanning probe methods are used to identify the variations in different cells and within the production process.

  2. The impact of UV irradiation on the radical initiating capacity of dissolved dyes

    International Nuclear Information System (INIS)

    Vig, A.; Czilik, M.; Rusznak, I.

    2002-01-01

    Complete text of publication follows. Kinetics of photodecomposition of three model dyes dissolved in isopropanol-water mixture has been determined after exposure to UV radiation in the range from 360 through 400 nm and from 220 through 400 nm, respectively. It has been disclosed earlier that photodecomposition of the dissolved dyes was decelerated initially by the presence of the dissolved oxygen in the system. The presence of a radical initiator, AIBN was indispensable for arriving at the decomposition of the irradiated dye solution in the range from 360 through 400 nm. The equation of W i D = [O 2 ]/τ D was used for the calculation of radical initiating rate of the irradiated dye molecule on the isopropanol (W i D (mol/l x s)), where [O 2 ] (mol/l) is the dissolved oxygen concentration in the system and τ D (s) is duration of the induction period of the photodestruction of the dissolved dye. The equation is valid only for photodecomposition which are not chain reaction. The photodegradation of dissolved dyes was also other then chain reaction, consequently the above equation could be applied in the study too. The average radical initiating rate of the dyes applied in this study was in the order of magnitude equal to that of AIBN. The number of cycles between the first radical formation and the last regeneration of the dye molecule could be calculated in bath systems (in the presence and absence of oxygen, respectively): K = W i D /W D , where K is the number of cycles, W D (mol/l x s) is the initial rate of the decomposition of the dissolved dyed. The number of cycles in the oxygen containing systems significantly exceeded those obtained in the oxygen systems because W D was markedly higher in the latter system than in the former one

  3. Organic synthetic dye degradation by modified pinhole discharge

    Czech Academy of Sciences Publication Activity Database

    Božic' Lončaric', A.; Koprivanac, N.; Šunka, Pavel; Člupek, Martin; Babický, Václav

    2004-01-01

    Roč. 54, suppl.C (2004), C958-C963 ISSN 0011-4626. [Symposium on Plasma Physics and Technology /21st/. Praha, 14.06.2004-17.06.2004] R&D Projects: GA ČR GA202/02/1026 Keywords : organic synthetic Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.292, year: 2004

  4. Highly efficient volume hologram multiplexing in thick dye-doped jelly-like gelatin.

    Science.gov (United States)

    Katarkevich, Vasili M; Rubinov, Anatoli N; Efendiev, Terlan Sh

    2014-08-01

    Dye-doped jelly-like gelatin is a thick-layer self-developing photosensitive medium that allows single and multiplexed volume phase holograms to be successfully recorded using pulsed laser radiation. In this Letter, we present a method for multiplexed recording of volume holograms in a dye-doped jelly-like gelatin, which provides significant increase in their diffraction efficiency. The method is based on the recovery of the photobleached dye molecule concentration in the hologram recording zone of gel, thanks to molecule diffusion from other unexposed gel areas. As an example, an optical recording of a multiplexed hologram consisting of three superimposed Bragg gratings with mean values of the diffraction efficiency and angular selectivity of ∼75% and ∼21', respectively, is demonstrated by using the proposed method.

  5. Metal-free indoline dye sensitized solar cells based on nanocrystalline Zn{sub 2}SnO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Lihua [Institute of New Energy Technology and Nano-Materials, Fuzhou University, Fuzhou, Fujian 350002 (China); Jiang, Lilong; Wei, Mingding [Institute of New Energy Technology and Nano-Materials, Fuzhou University, Fuzhou, Fujian 350002 (China); National Engineering Research Center for Chemical Fertilizer Catalyst, Fuzhou University, Fuzhou, Fujian 350002 (China)

    2010-02-15

    Zn{sub 2}SnO{sub 4} nanocrystals were synthesized and first used as the electrode materials for the metal-free indoline dyes sensitized solar cells (DSSCs). The highest efficiency of 3.08% was achieved for a D131 DSSC. This might be attributed to the fact that the D131 dye has a greater positive oxidation potential, which can lead to rapid dye regeneration, avoiding the geminate charge recombination between oxidized dye molecules and injected electrons in the Zn{sub 2}SnO{sub 4} film. The efficiency can be improved significantly using a mixture solution of D131 and N719 dyes for which an efficiency of 3.6% was obtained. (author)

  6. Assessment of the banana pseudostem as a low-cost biosorbent for the removal of reactive blue 5G dye.

    Science.gov (United States)

    Módenes, Aparecido N; Espinoza-Quiñones, Fernando R; Geraldi, Claudinéia A Q; Manenti, Diego R; Trigueros, Daniela E G; Oliveira, Ana Paula de; Borba, Carlos E; Kroumov, Alexander D

    2015-01-01

    In this work, the removal of reactive blue 5G (RB5G) dye using the drying biomass of banana pseudostem (BPS) was investigated. The characterization of BPS particles was performed. Improvement in the RB5G dye removal performance at the following sorption conditions was evidenced: pH 1, 30°C sorption temperature and 40 rpm shaking, regardless of the particle size range. Kinetic RB5G dye sorption data obtained at better conditions fit well in an Elovich model. A combined Langmuir-BET isotherm model provides a good representation of the RB5G dye equilibrium sorption data, which shows the evidence of a physical sorption process on the BPS surface. Based on the results, the removal of RB5G dye molecules by BPS is based on a physical sorption process.

  7. Design of new metal-free dyes for dye-sensitized solar cells: A first-principles study

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Xiong; Zhou, Le; Li, Yawei [Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871 (China); Sun, Qiang, E-mail: sunqiang@pku.edu.cn [Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871 (China); Center for Applied Physics and Technology, Peking University, Beijing 100871 (China); Jena, Puru [Department of Physics, Virginia Commonwealth University, Richmond, VA 23284 (United States)

    2012-08-06

    Five new metal-free dyes with acceptor–π–donor (A–π–D) structure are studied using first-principles calculation based on density functional theory. Benzothiadiazole (BTD) and triphenylamine (TPA) were chosen, respectively, as an acceptor and a donor with 4-(dicyanomethylene)-2-methyl-6-(4-dimethylamino-styryl)-4H-pyran (DCM) as a π linker. The linker was further modified by -CH=CH- resulting in a red-shift with improved absorption spectra caused by the smaller energy gap and the increased orbital hybridization. The designed dyes are found to exhibit wide absorption spectra, high molar extinction coefficients, desirable orbital distributions, and good energy levels alignment, and hence can have potential applications in dye-sensitized solar cells. -- Highlights: ► New metal-free dyes with A–π–D architecture. ► With wide absorption spectra and high molar extinction coefficients. ► With desirable orbital distribution and good energy levels alignment.

  8. Adsorption characteristics of brilliant green dye on kaolin

    International Nuclear Information System (INIS)

    Nandi, B.K.; Goswami, A.; Purkait, M.K.

    2009-01-01

    Experimental investigations were carried out to adsorb toxic brilliant green dye from aqueous medium using kaolin as an adsorbent. Characterization of kaolin is done by measuring: (i) particle size distribution using particle size analyzer, (ii) BET surface area using BET surface analyzer, and (iii) structural analysis using X-ray diffractometer. The effects of initial dye concentration, contact time, kaolin dose, stirring speed, pH and temperature were studied for the adsorption of brilliant green in batch mode. Adsorption experiments indicate that the extent of adsorption is strongly dependent on pH of solution. Free energy of adsorption (ΔG 0 ), enthalpy (ΔH 0 ) and entropy (ΔS 0 ) changes are calculated to know the nature of adsorption. The calculated values of ΔG 0 at 299 K and 323 K indicate that the adsorption process is spontaneous. The estimated values of ΔH 0 and ΔS 0 both show the negative sign, which indicate that the adsorption process is exothermic and the dye molecules are organized on the kaolin surface in less randomly fashion than in solution. The adsorption kinetic has been described by first-order, pseudo-second-order and intra-particle-diffusion models. It was observed that the rate of dye adsorption follows pseudo-second-order model for the dye concentration range studied in the present case. Standard adsorption isotherms were used to fit the experimental equilibrium data. It was found that the adsorption of brilliant green on kaolin follows the Langmuir adsorption isotherm

  9. Feasibility of solar-pumped dye lasers

    Science.gov (United States)

    Lee, Ja H.; Kim, Kyung C.; Kim, Kyong H.

    1987-01-01

    Dye laser gains were measured at various pump-beam irradiances on a dye cell in order to evaluate the feasibility of solar pumping. Rhodamine 6G dye was considered as a candidate for the solar-pumped laser because of its high utilization of the solar spectrum and high quantum efficiency. Measurements show that a solar concentration of 20,000 is required to reach the threshold of the dye.

  10. Fluorescence lifetime of emitters with broad homogeneous linewidths modified in opal photonic crystals

    DEFF Research Database (Denmark)

    Nikolaev, Ivan S.; Lodahl, Peter; Vos, Willem L.

    2008-01-01

    We have investigated the dynamics of spontaneous emission from dye molecules embedded in opal photonic crystals. Fluorescence lifetimes of Rhodamine 6G (R6G) dye were measured as a function of both optical frequency and crystal lattice parameter of the polystyrene opals. Due to the broad...

  11. Natural dyes versus lysochrome dyes in cheiloscopy: A comparative evaluation.

    Science.gov (United States)

    Singh, Narendra Nath; Brave, V R; Khanna, Shally

    2010-01-01

    Cheiloscopy is the study of lip prints. Lip prints are genotypically determined and are unique, and stable. At the site of crime, lip prints can be either visible or latent. To develop lip prints for study purpose various chemicals such as lysochrome dyes, fluorescent dyes, etc. are available which are very expensive. Vermilion (Sindoor used by married Indian women) and indigo dye (fabric whitener) are readily available, naturally derived, and cost-effective reagents available in India. To compare the efficacy of sudan black, vermilion, and indigo in developing visible and latent lip prints made on bone china cup, satin fabric, and cotton fabric. Out of 45 Volunteers 15 lip prints were made on bone China cup 15 lip prints on Satin fabric and 15 on Cotton fabric. Sudan black, vermilion and indigo were applied on visible and latent lip prints and graded as good (+,+), fair (+), and poor (-) and statistically evaluated. The vermilion and indigo dye gives comparable results to that of sudan black for developing visible and latent lip prints.

  12. 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.

  13. Intersystem crossing in complex molecules

    International Nuclear Information System (INIS)

    Pappalardo, R.G.

    1980-01-01

    The general question of singlet-triplet intersystem crossing is addressed in the context of large organic molecules, i.e., ''complex'' molecules capable of self-relaxation in the absence of collisions. Examples of spectral properties of such molecules in the vapor phase are discussed, relying on extensive Russian literature in this area. Formal expressions for the relaxation rate in the electronic excited states are derived on the basis of the formalism of collision theory, and are applied to the specific case of intersystem crossing. The derivation of the ''energy-gap'' law for triplet-singlet conversion in aromatic hydrocarbons is briefly outlined. The steep rise of internal conversion rates as a function of excess excitation energy, and its competition with the intersystem crossing process, are reviewed for the case of naphthalene vapor. A general expression for the spin-orbit interaction Hamiltonian in molecular systems is outlined. Experimental observations on singlet-triplet conversion rates and the factors that can drastically affect such rates are discussed, with emphasis on the ''in- ternal'' and ''external'' heavy-atom effects. Basic relations of ESR spectroscopy and magnetophotoselection are reviewed. Technological implications of the singlet-triplet crossing in complex molecules are discussed in the context of chelate lasers, dye lasers and luminescent displays. Effects related to singlet-triplet crossing, and generally to excited-state energy-transfer in biological systems, are exemplified by the role of aromatic amino-acids in the phosphorescence of proteins, by some recent studies of energy-transfer in models of biomembranes, and by the clustering of triplet-energy donor-acceptor pairs in micelles

  14. Simultaneous adsorption of dyes and heavy metals from multicomponent solutions using fly ash

    International Nuclear Information System (INIS)

    Visa, Maria; Bogatu, Cristina; Duta, Anca

    2010-01-01

    In wastewaters originating from dye industry there are amounts of dyes (very common methyl orange, methylene blue-MB) and heavy metals (cadmium, copper, nickel mainly from the organo-metallic dyes). They tend to adsorb in a competitive process and modify the substrate. Advanced removal is usually proposed via adsorption and the use of modified fly ash as a substrate is sustainable solution. The main constituents of fly ash (silica, alumina, iron oxide and un-burned carbon), are the priority compounds which favour the heavy metal adsorption and are active sites in dyes' adsorption processes. The paper studies the effect of MB adsorbed on the fly ash surface on the removal efficiency of cadmium, copper and nickel ionic species from complex, multi-cationic dye solutions. The adsorption efficiency and kinetics are evaluated from the complex, multicomponent systems and possible influences are discussed. High efficiencies are obtained at low heavy metal concentrations (as it is the real case for the dyes industry) whereas at medium values, competitive processes lower the individual efficiencies of copper, nickel or cadmium from mixtures.

  15. Photo-electrocatalytic hydrogen generation at dye-sensitised electrodes functionalised with a heterogeneous metal catalyst

    International Nuclear Information System (INIS)

    Hoogeveen, Dijon A.; Fournier, Maxime; Bonke, Shannon A.; Fang, Xi-Ya; Mozer, Attila J.; Mishra, Amaresh; Bäuerle, Peter; Simonov, Alexandr N.; Spiccia, Leone

    2016-01-01

    Dye-sensitised photocathodes promoting hydrogen evolution are usually coupled to a catalyst to improve the reaction rate. Herein, we report on the first successful integration of a heterogeneous metal particulate catalyst, viz., Pt aggregates electrodeposited from acidic solutions on the surface of a NiO-based photocathode sensitised with a p-type perylenemonoimid-sexithiophene-triphenylamine dye (PMI-6T-TPA). The platinised dye-NiO electrodes generate photocurrent density of ca −0.03 mA cm −2 (geom.) with 100% faradaic efficiency for the H 2 evolution at 0.059 V vs. reversible hydrogen electrode under 1 sun visible light irradiation (AM1.5G, 100 mW cm −2 , λ > 400 nm) for more than 10 hours in 0.1 M H 2 SO 4 (aq.). The Pt-free dye-NiO and dye-free Pt-modified NiO cathodes show no photo-electrocatalytic hydrogen evolution under these conditions. The performance of these Pt-modified PMI-6T-TPA-based photoelectrodes compares well to that of previously reported dye-sensitised photocathodes for H 2 evolution.

  16. Removal of Reactive Anionic Dyes from Binary Solutions by Adsorption onto Quaternized Kenaf Core Fiber

    Directory of Open Access Journals (Sweden)

    Intidhar Jabir Idan

    2017-01-01

    Full Text Available The most challenging mission in wastewater treatment plants is the removal of anionic dyes, because they are water-soluble and produce very shining colours in the water. In this regard, kenaf core fiber (KCF was chemically modified by the quaternized agent (3-chloro-2-hydroxypropyltrimethylammonium chloride to increase surface area and change the surface properties in order to improve the removing reactive anionic dyes from binary aqueous solution. The influencing operating factors like dye concentration, pH, adsorbent dosage, and contact time were examined in a batch mode. The results indicate that the percentage of removal of Reactive Red-RB (RR-RB and Reactive Black-5 (RB-5 dyes from binary solution was increased with increasing dyes concentrations and the maximum percentage of removal reached up to 98.4% and 99.9% for RR-RB and RB-5, respectively. Studies on effect of pH showed that the adsorption was not significantly influenced by pH. The equilibrium analyses explain that, in spite of the extended Langmuir model failure to describe the data in the binary system, it is better than the Jain and Snoeyink model in describing the adsorption behavior of binary dyes onto QKCF. Also, the pseudo-second-order model was better to represent the adsorption kinetics for RR-RB and RB-5 dyes on QKCF.

  17. Monodispersed Zinc Oxide Nanoparticle-Dye Dyads and Triads

    Energy Technology Data Exchange (ETDEWEB)

    Gladfelter, Wayne L. [Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Chemistry; Blank, David A. [Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Chemistry; Mann, Kent R. [Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Chemistry

    2017-06-22

    The overall energy conversion efficiency of photovoltaic cells depends on the combined efficiencies of light absorption, charge separation and charge transport. Dye-sensitized solar cells are photovoltaic devices in which a molecular dye absorbs light and uses this energy to initiate charge separation. The most efficient dye-sensitized solar cells (DSSCs) use nanocrystal titanium dioxide films to which are attached ruthenium complexes. Numerous studies have provided valuable insight into the dynamics of these and analogous photosystems, but the lack of site homogeneity in binding dye molecules to metal oxide films and nanocrystals (NCs) is a significant impediment to extracting fundamental details about the electron transfer across the interface. Although zinc oxide is emerging as a potential semiconducting component in DSSCs, there is less known about the factors controlling charge separation across the dye/ZnO interface. Zinc oxide crystallizes in the wurtzite lattice and has a band gap of 3.37 eV. One of the features that makes ZnO especially attractive is the remarkable ability to control the morphology of the films. Using solution deposition processes, one can prepare NCs, nanorods and nanowires having a variety of shapes and dimensions. This project solved problems associated with film heterogeneity through the use of dispersible sensitizer/ZnO NC ensembles. The overarching goal of this research was to study the relationship between structure, energetics and dynamics in a set of synthetically controlled donor-acceptor dyads and triads. These studies provided access to unprecedented understanding of the light absorption and charge transfer steps that lie at the heart of DSSCs, thus enabling significant future advances in cell efficiencies. The approach began with the construction of well-defined dye-NC dyads that were sufficiently dispersible to allow the use of state of the art pulsed laser spectroscopic and kinetic methods to understand the charge transfer

  18. Enhancing the performance of dye-sensitized solar cells by incorporating nanomica in gel electrolytes☆

    KAUST Repository

    Lai, Yi-Hsuan; Lin, Chia-Yu; Chen, Jian-Ging; Wang, Chun-Chieh; Huang, Kuan-Chieh; Liu, Ken-Yen; Lin, King-Fu; Lin, Jiang-Jen; Ho, Kuo-Chuan

    2010-01-01

    Gel-type dye-sensitized solar cells (DSSCs) were fabricated with 5.0 wt% polyvinyidene fluoride-co-hexafluoro propylene (PVDF-HFP) in methoxy propionitrile (MPN) as gel polymer electrolyte (GPE), 1-butyl-3-methylimidazolium iodide (BMII)/iodine (I2) as redox couple, 4-tertiary butyl pyridine (TBP) and guanidine thiocyanate as additives. The incorporation of alkyl-modified nanomica (AMNM) in the PVDF-HFP gel electrolytes caused the reduction of crystallization of PVDF-HFP, which was confirmed by X-ray diffraction (XRD) analysis. The short-circuit current density (JSC) of the cell increased due to the decrease of diffusion resistance, as judged by the electrochemical impedance spectra (EIS) analysis, while the open-circuit voltage (VOC) remained almost the same. As the loading of AMNM in the PVDF-HFP gel electrolyte was increased to 3.0 wt%, the JSC and power conversion efficiency (η) of the cells increased from 8.3 to 13.6 mA/cm2 and 3.5% to 5.7%, respectively. However, the JSC decreased as the loading of AMNM exceeded 3.0 wt%. At higher AMNM loadings, nanomica acted as a barrier interface between the electrolyte and the dye molecules to hinder electron transfer, and thus reducing the cell's photocurrent density. Furthermore, the DSSCs fabricated by dispersing polymethyl methacrylate (PMMA) microspheres in the TiO2 electrode with the GPE containing 3.0 wt% AMNM improved the η to 6.70%. The TiO2 films would exhibit larger porosity by blending with PMMA, leading the penetration of GPEs into the porous TiO2 easier, thus improving the contact between the dye-adsorbed TiO2 surfaces and the GPEs, as characterized by EIS. Moreover, the η of gel-type DSSCs with a 25 μm thickness of surlyn reached 7.96% as compared with 6.70% for the DSSCs with a 60 μm surlyn. © 2009 Elsevier B.V. All rights reserved.

  19. Enhancing the performance of dye-sensitized solar cells by incorporating nanomica in gel electrolytes☆

    KAUST Repository

    Lai, Yi-Hsuan

    2010-04-01

    Gel-type dye-sensitized solar cells (DSSCs) were fabricated with 5.0 wt% polyvinyidene fluoride-co-hexafluoro propylene (PVDF-HFP) in methoxy propionitrile (MPN) as gel polymer electrolyte (GPE), 1-butyl-3-methylimidazolium iodide (BMII)/iodine (I2) as redox couple, 4-tertiary butyl pyridine (TBP) and guanidine thiocyanate as additives. The incorporation of alkyl-modified nanomica (AMNM) in the PVDF-HFP gel electrolytes caused the reduction of crystallization of PVDF-HFP, which was confirmed by X-ray diffraction (XRD) analysis. The short-circuit current density (JSC) of the cell increased due to the decrease of diffusion resistance, as judged by the electrochemical impedance spectra (EIS) analysis, while the open-circuit voltage (VOC) remained almost the same. As the loading of AMNM in the PVDF-HFP gel electrolyte was increased to 3.0 wt%, the JSC and power conversion efficiency (η) of the cells increased from 8.3 to 13.6 mA/cm2 and 3.5% to 5.7%, respectively. However, the JSC decreased as the loading of AMNM exceeded 3.0 wt%. At higher AMNM loadings, nanomica acted as a barrier interface between the electrolyte and the dye molecules to hinder electron transfer, and thus reducing the cell\\'s photocurrent density. Furthermore, the DSSCs fabricated by dispersing polymethyl methacrylate (PMMA) microspheres in the TiO2 electrode with the GPE containing 3.0 wt% AMNM improved the η to 6.70%. The TiO2 films would exhibit larger porosity by blending with PMMA, leading the penetration of GPEs into the porous TiO2 easier, thus improving the contact between the dye-adsorbed TiO2 surfaces and the GPEs, as characterized by EIS. Moreover, the η of gel-type DSSCs with a 25 μm thickness of surlyn reached 7.96% as compared with 6.70% for the DSSCs with a 60 μm surlyn. © 2009 Elsevier B.V. All rights reserved.

  20. Quirks of dye nomenclature. 1. Evans blue.

    Science.gov (United States)

    Cooksey, C J

    2014-02-01

    The history, origin, identity, chemistry and use of Evans blue dye are described along with the first application to staining by Herbert McLean Evans in 1914. In the 1930s, the dye was marketed under the name, Evans blue dye, which was profoundly more acceptable than the ponderous chemical name.

  1. Thousand-fold enhancement of single-molecule fluorescence near a single gold nanorod

    NARCIS (Netherlands)

    Yuan, H.; Khatua, S.; Zijlstra, P.; Yorulmaz, M.; Orrit, M.

    2013-01-01

    Single molecules: Large enhancements of single-molecule fluorescence up to 1100 times by using synthesized gold nanorods are reported (see picture). This high enhancement is achieved by selecting a dye with its adsorption and emission close to the surface plasmon resonance of the gold nanorods

  2. Synthesis, Characterization, and Application of Gold Nanoparticles in Green Nanochemistry Dye-Sensitized Solar Cells

    Science.gov (United States)

    2012-06-01

    dendrimers . The NPs were found to have discrete absorption and fluorescence from the UV spectrum to near infrared. Bauer et al. (6) and McFarland et al...of TiO2 nanoparticles, and are transported to the electrode. An I - /I3 - is used as a redox couple to replenish electrons to the dye molecules

  3. Molecule Matters van der Waals Molecules

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 7. Molecule Matters van der Waals Molecules - Rg•••HF Complexes are Debye Molecules! E Arunan. Feature Article Volume 15 Issue 7 July 2010 pp 667-674. Fulltext. Click here to view fulltext PDF. Permanent link:

  4. Assessment of dye distribution in sensitized solar cells by microprobe techniques

    Energy Technology Data Exchange (ETDEWEB)

    Barreiros, M.A., E-mail: alexandra.barreiros@lneg.pt [Laboratório Nacional de Energia e Geologia, LEN/UES, Estrada do Paço do Lumiar, 22, 1649-038 Lisboa (Portugal); Corregidor, V. [IPFN, Instituto Superior Técnico, Universidade de Lisboa, E.N. 10, 2686-953 Sacavém (Portugal); Alves, L.C. [C2TN, Campus Tecnológico e Nuclear, Instituto Superior Técnico, Universidade de Lisboa, E.N. 10, 2686-953 Sacavém (Portugal); Guimarães, F. [Laboratório Nacional de Energia e Geologia, LGM/UCTM, Rua da Amieira, Apartado 1089, 4466-901 S. Mamede de Infesta (Portugal); Mascarenhas, J.; Torres, E.; Brites, M.J. [Laboratório Nacional de Energia e Geologia, LEN/UES, Estrada do Paço do Lumiar, 22, 1649-038 Lisboa (Portugal)

    2015-04-01

    Dye sensitized solar cells (DSCs) have received considerable attention once this technology offers economic and environmental advantages over conventional photovoltaic (PV) devices. The PV performance of a DSC relies on the characteristics of its photoanode, which typically consists of a nanocrystalline porous TiO{sub 2} film, enabled with a large adsorptive surface area. Dye molecules that capture photons from light during device operation are attached to the film nanoparticles. The effective loading of the dye in the TiO{sub 2} electrode is of paramount relevance for controlling and optimizing solar cell parameters. Relatively few methods are known today for quantitative evaluation of the total dye adsorbed on the film. In this context, microprobe techniques come out as suitable tools to evaluate the dye surface distribution and depth profile in sensitized films. Electron Probe Microanalysis (EPMA) and Ion Beam Analytical (IBA) techniques using a micro-ion beam were used to quantify and to study the distribution of the Ru organometallic dye in TiO{sub 2} films, making use of the different penetration depth and beam sizes of each technique. Different 1D nanostructured TiO{sub 2} films were prepared, morphologically characterized by SEM, sensitized and analyzed by the referred techniques. Dye load evaluation in different TiO{sub 2} films by three different techniques (PIXE, RBS and EPMA/WDS) provided similar results of Ru/Ti mass fraction ratio. Moreover, it was possible to assess dye surface distribution and its depth profile, by means of Ru signal, and to visualize the dye distribution in sample cross-section through X-ray mapping by EPMA/EDS. PIXE maps of Ru and Ti indicated an homogeneous surface distribution. The assessment of Ru depth profile by RBS showed that some films have homogeneous Ru depth distribution while others present different Ru concentration in the top layer (2 μm thickness). These results are consistent with the EPMA/EDS maps obtained.

  5. Bifacial dye-sensitized solar cells: A strategy to enhance overall efficiency based on transparent polyaniline electrode

    OpenAIRE

    Wu, Jihuai; Li, Yan; Tang, Qunwei; Yue, Gentian; Lin, Jianming; Huang, Miaoliang; Meng, Lijian

    2014-01-01

    Dye-sensitized solar cell (DSSC) is a promising solution to global energy and environmental problems because of its clean, low-cost, high efficiency, good durability, and easy fabrication. However, enhancing the efficiency of the DSSC still is an important issue. Here we devise a bifacial DSSC based on a transparent polyaniline (PANI) counter electrode (CE). Owing to the sunlight irradiation simultaneously from the front and the rear sides, more dye molecules are excited and more ...

  6. Organofunctionalized Amazon smectite for dye removal from aqueous medium-Kinetic and thermodynamic adsorption investigations

    Energy Technology Data Exchange (ETDEWEB)

    Guerra, Denis L., E-mail: denis@cpd.ufmt.br [Universidade Federal de Mato Grosso, DRM-UFMT, Mato Grosso, Brasil 78060 900 (Brazil); Silva, Weber L.L. [Universidade Federal de Mato Grosso, DRM-UFMT, Mato Grosso, Brasil 78060 900 (Brazil); Oliveira, Helen C.P. [Universidade Estadual do Norte Fluminense, UENF, Rio de Janeiro, Brasil 28013 602 (Brazil); Viana, Rubia R. [Universidade Federal de Mato Grosso, DRM-UFMT, Mato Grosso, Brasil 78060 900 (Brazil); Airoldi, Claudio [Chemistry Institute, State University of Campinas, P.O. Box 6154, 13084-971 Campinas, Sao Paulo (Brazil)

    2011-02-15

    The objective of this study is to examine the adsorption behavior of Sumifix Brilliant Orange 3R textile dye from aqueous solution on smectite sample, an abundant Amazon clay. The original smectite clay mineral has been collected from Amazon region, Brazil. The compound 2-aminomethylpyridine was anchored onto smectite surface by heterogeneous route. The ability of these materials to remove the Sumifix Brilliant Orange 3R textile dye from aqueous solution was followed by a series of adsorption isotherms, using a batchwise process. The maximum number of moles adsorbed was determined to be 1.26 and 2.07 mmol g{sup -1} for natural and modified clay samples, respectively. The energetic effects caused by dye cations adsorption were determined through calorimetric titrations. Thermodynamics indicated the existence of favorable conditions for such dye-nitrogen interactions.

  7. Organofunctionalized Amazon smectite for dye removal from aqueous medium--kinetic and thermodynamic adsorption investigations.

    Science.gov (United States)

    Guerra, Denis L; Silva, Weber L L; Oliveira, Helen C P; Viana, Rúbia R; Airoldi, Claudio

    2011-02-15

    The objective of this study is to examine the adsorption behavior of Sumifix Brilliant Orange 3R textile dye from aqueous solution on smectite sample, an abundant Amazon clay. The original smectite clay mineral has been collected from Amazon region, Brazil. The compound 2-aminomethylpyridine was anchored onto smectite surface by heterogeneous route. The ability of these materials to remove the Sumifix Brilliant Orange 3R textile dye from aqueous solution was followed by a series of adsorption isotherms, using a batchwise process. The maximum number of moles adsorbed was determined to be 1.26 and 2.07 mmol g(-1) for natural and modified clay samples, respectively. The energetic effects caused by dye cations adsorption were determined through calorimetric titrations. Thermodynamics indicated the existence of favorable conditions for such dye-nitrogen interactions. Copyright © 2010. Published by Elsevier B.V.

  8. Removal of methyl violet dye by adsorption onto N-benzyltriazole derivatized dextran

    DEFF Research Database (Denmark)

    Cho, Eunae; Tahir, Muhammad Nazir; Kim, Hwanhee

    2015-01-01

    In this work, N-benzyltriazole derivatized dextran was evaluated for its potential as a novel carbohydrate-based adsorbent for the removal of methyl violet dye from water. The modified dextran was synthesized by a click reaction of pentynyl dextran and benzyl azide, and the structure...... was characterized by nuclear magnetic resonance spectroscopy, elemental analysis, and scanning electron microscopy. Dextran was substituted with a triazole-linked benzyl group. For decolorization of the dye effluent, adsorption is a very effective treatment; here, the driving force is based on hydrogen bonding, pi...... stacking, and electrostatic interaction between the methyl violet dye and the N-benzyltriazole derivatized dextran. Batch experiments were carried out to investigate the required contact time and the effects of pH, initial dye concentrations, and temperature. The experimental data were analyzed...

  9. Organofunctionalized Amazon smectite for dye removal from aqueous medium-Kinetic and thermodynamic adsorption investigations

    International Nuclear Information System (INIS)

    Guerra, Denis L.; Silva, Weber L.L.; Oliveira, Helen C.P.; Viana, Rubia R.; Airoldi, Claudio

    2011-01-01

    The objective of this study is to examine the adsorption behavior of Sumifix Brilliant Orange 3R textile dye from aqueous solution on smectite sample, an abundant Amazon clay. The original smectite clay mineral has been collected from Amazon region, Brazil. The compound 2-aminomethylpyridine was anchored onto smectite surface by heterogeneous route. The ability of these materials to remove the Sumifix Brilliant Orange 3R textile dye from aqueous solution was followed by a series of adsorption isotherms, using a batchwise process. The maximum number of moles adsorbed was determined to be 1.26 and 2.07 mmol g -1 for natural and modified clay samples, respectively. The energetic effects caused by dye cations adsorption were determined through calorimetric titrations. Thermodynamics indicated the existence of favorable conditions for such dye-nitrogen interactions.

  10. Single molecule DNA detection with an atomic vapor notch filter

    Energy Technology Data Exchange (ETDEWEB)

    Uhland, Denis; Rendler, Torsten; Widmann, Matthias; Lee, Sang-Yun [University of Stuttgart and Stuttgart Research Center of Photonic Engineering (SCoPE) and IQST, 3rd Physics Institute, Stuttgart (Germany); Wrachtrup, Joerg; Gerhardt, Ilja [University of Stuttgart and Stuttgart Research Center of Photonic Engineering (SCoPE) and IQST, 3rd Physics Institute, Stuttgart (Germany); Max Planck Institute for Solid State Research, Stuttgart (Germany)

    2015-12-01

    The detection of single molecules has facilitated many advances in life- and material-science. Commonly the fluorescence of dye molecules is detected, which are attached to a non-fluorescent structure under study. For fluorescence microscopy one desires to maximize the detection efficiency together with an efficient suppression of undesired laser leakage. Here we present the use of the narrow-band filtering properties of hot atomic sodium vapor to selectively filter the excitation light from the red-shifted fluorescence of dye labeled single-stranded DNA molecules. A statistical analysis proves an enhancement in detection efficiency of more than 15% in a confocal and in a wide-field configuration. (orig.)

  11. Adsorption of a Textile Dye on Commercial Activated Carbon: A Simple Experiment to Explore the Role of Surface Chemistry and Ionic Strength

    Science.gov (United States)

    Martins, Angela; Nunes, Nelson

    2015-01-01

    In this study, an adsorption experiment is proposed using commercial activated carbon as adsorbent and a textile azo dye, Mordant Blue-9, as adsorbate. The surface chemistry of the activated carbon is changed through a simple oxidation treatment and the ionic strength of the dye solution is also modified, simulating distinct conditions of water…

  12. 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.

  13. Effective NH2-grafting on attapulgite surfaces for adsorption of reactive dyes

    International Nuclear Information System (INIS)

    Xue, Ailian; Zhou, Shouyong; Zhao, Yijiang; Lu, Xiaoping; Han, Pingfang

    2011-01-01

    Highlights: → We prepared a new amine functionalized adsorbent derived from clay-based material. → Attapulgite surface was modified with 3-aminopropyltriethoxysilane. → Some modification parameters affecting the adsorption potential were investigated. → Enhance the attapulgite adsorptive capacity for reactive dyes from aqueous solutions. - Abstract: The amine moiety has an important function in many applications, including, adsorption, catalysis, electrochemistry, chromatography, and nanocomposite materials. We developed an effective adsorbent for aqueous reactive dye removal by modifying attapulgite with an amino-terminated organosilicon (3-aminopropyltriethoxysilane, APTES). Surface properties of the APTES-modified attapulgite were characterized by the Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption-desorption. We evaluated the impact of solvent, APTES concentration, water volume, reaction time, and temperature on the surface modification. NH 2 -attapulgite was used to remove reactive dyes in aqueous solution and showed very high adsorption rates of 99.32%, 99.67%, and 96.42% for Reactive Red 3BS, Reactive Blue KE-R and Reactive Black GR, respectively. These powerful dye removal effects were attributed to strong electrostatic interactions between reactive dyes and the grafted NH 2 groups.

  14. Cyanidin-Based Novel Organic Sensitizer for Efficient Dye-Sensitized Solar Cells: DFT/TDDFT Study

    Directory of Open Access Journals (Sweden)

    Kalpana Galappaththi

    2017-01-01

    Full Text Available Cyanidin is widely considered as a potential natural sensitizer in dye-sensitized solar cells due to its promising electron-donating and electron-accepting abilities and cheap availability. We consider modifications of cyanidin structure in order to obtain broader UV-Vis absorption and hence to achieve better performance in DSSC. The modified molecule consists of cyanidin and the benzothiadiazolylbenzoic acid group, where the benzothiadiazolylbenzoic acid group is attached to the cyanidin molecule by replacing one hydroxyl group. The resulting structure was then computationally simulated by using the Spartan’10 software package. The molecular geometries, electronic structures, absorption spectra, and electron injections of the newly designed organic sensitizer were investigated in this work through density functional theory (DFT and time-dependent density functional theory (TDDFT calculations using the Gaussian’09W software package. Furthermore, TDDFT computational calculations were performed on cyanadin and benzothiadiazolylbenzoic acid separately, as reference. The computational studies on the new sensitizer have shown a reduced HOMO-LUMO gap; bathochromic and hyperchromic shifts of absorption spectra range up to near-infrared region revealing its enhanced ability to sensitize DSSCs.

  15. Thermal ion-molecule reactions in oxygen-containing molecules

    International Nuclear Information System (INIS)

    Kumakura, Minoru

    1981-02-01

    The energetics of ions and the thermal ion-molecule reactions in oxygen-containing molecules have been studied with a modified time-of-flight mass spectrometer. It was found that the translational energy of ion can be easily obtained from analysis of the decay curve using the time-of-flight mass spectrometer. The condensation-elimination reactions proceeded via cross- and homo-elimination mechanism in which the nature of intermediate-complex could be correlated with the nature of reactant ion. It was elucidated that behavior of poly-atomic oxygen-containing ions on the condensation-elimination reactions is considerably influenced by their oxonium ion structures having functional groups. In addition, the rate constants of the condensation-elimination reactions have affected with the energy state of reactant ion and the dipole moment and/or the polarizability of neutral molecule. It was clarified that the rate constants of the ion-molecule clustering reactions in poly-atomic oxygen-containing molecules such as cyclic ether of six member rings are very large and the cluster ions are stable owing to the large number of vibrational degree of freedom in the cluster ions. (author)

  16. Photoelectrochemical studies of dye-sensitized solar cells using organic dyes

    Energy Technology Data Exchange (ETDEWEB)

    Marinado, Tannia

    2009-10-15

    The dye-sensitized solar cell (DSC) is a promising efficient low-cost molecular photovoltaic device. One of the key components in DSCs is the dye, as it is responsible for the capture of sunlight. State-of-the-art DSC devices, based on ruthenium dyes, show record efficiencies of 10-12 %. During the last decade, metal-free organic dyes have been extensively explored as sensitizers for DSC application. The use of organic dyes is particularly attractive as it enables easy structural modifications, due to fairly short synthetic routes and reduced material cost. Novel dye should in addition to the light-harvesting properties also be compatible with the DSC components. In this thesis, a series of new organic dyes are investigated, both when integrated in the DSC device and as individual components. The evaluation methods consisted of different electrochemical and photoelectrochemical techniques. Whereas the light-harvesting properties of the dyes were fairly easily improved, the behavior of the dye integrated in the DSC showed less predictable photovoltaic results. The dye series studied in Papers II and IV revealed that their dye energetics limited vital electron-transfer processes, the dye regeneration (Paper II) and injection quantum yield (Paper IV). Further, in Papers III-VI, it was observed that different dye structures seemed to alter the interfacial electron recombination with the electrolyte. In addition to the dye structure sterics, some organic dyes appear to enhance the interfacial recombination, possibly due to specific dye-redox acceptor interaction (Paper V). The impact of dye sterical modifications versus the use of coadsorbent was explored in Paper VI. The dye layer properties in the presence and absence of various coadsorbents were further investigated in Paper VII. The core of this thesis is the identification of the processes and properties limiting the performance of the DSC device, aiming at an overall understanding of the compatibility between the

  17. Radiative characteristics of CVL pumped dye laser

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, Uichi; Ishiguro, Takahide

    1987-09-01

    This paper describes the radiative characteristics of CVL pumped dye laser. It is compared YAG-SH (530 nm) with CVL (511, 578 nm) and CVL (511 nm) for pumping source. Influence of solvent in dye laser power was examined. The present experimental results show that efficiency of CVL (511 nm) pumped dye laser was most high. When the dye solution is at a standstill, the efficiency of dye laser with water and Sodium Lauryl Sulfate (S.L.S., 2 %wt.) was most high among the four kinds of solvent. In the condition of dye solution flow, the water and S.L.S. or ethylene glycol was useful solvent for dye laser.

  18. Radiative characteristics of CVL pumped dye laser

    International Nuclear Information System (INIS)

    Kubo, Uichi; Ishiguro, Takahide.

    1987-01-01

    This paper describes the radiative characteristics of CVL pumped dye laser. It is compared YAG-SH (530 nm) with CVL (511, 578 nm) and CVL (511 nm) for pumping source. Influence of solvent in dye laser power was examined. The present experimental results show that efficiency of CVL (511 nm) pumped dye laser was most high. When the dye solution is at a standstill, the efficiency of dye laser with water and Sodium Lauryl Sulfate (S.L.S., 2 %wt.) was most high among the four kinds of solvent. In the condition of dye solution flow, the water and S.L.S. or Ethylene Glycol was useful solvent for dye laser. (author)

  19. Influence of styryl dyes on blood erythrocytes

    Science.gov (United States)

    Nizomov, Negmat; Barakaeva, Mubaro; Kurtaliev, Eldar N.; Rahimov, Sherzod I.; Khakimova, Dilorom P.; Khodjayev, Gayrat; Yashchuk, Valeriy N.

    2008-08-01

    It was studied the influence of F, Sbt, Sil, Sbo monomer and homodimer Dst-5, Dst-10, Dbt-5, Dbt-10, Dil-10, Dbo-10 styryl dyes on blood erythrocytes of white rats. It was shown that the homodimer styryl dyes Dst-5, Dbt-5 and Dbo-10 decrease the erythrocytes quantity by 1.5-2 times more as compared with monomer dyes Sbt and Sbo. The main cause of dyes different action is the different oxidation degree of intracellular hemoglobin evoked by these dyes. It was established that the observed effects was connected with different penetration of these dyes through membrane of erythrocytes and with interaction of these dyes with albumin localized in membranes of cells.

  20. Exploiting quantum interference in dye sensitized solar cells

    DEFF Research Database (Denmark)

    Maggio, Emanuele; Solomon, Gemma C.; Troisi, Alessandro

    2014-01-01

    A strategy to hinder the charge recombination process in dye sensitized solar cells is developed in analogy with similar approaches to modulate charge transport across nanostructures. The system studied is a TiO2 (anatase)-chromophore interface, with an unsaturated carbon bridge connecting the two...... of the possible tunnelling path. Calculations carried out on realistic molecules at the DFT level of theory show how the recombination lifetime can be modulated by changes in the electron-withdrawing (donating) character of the groups connected to the cross-conjugated bridge. Tight binding calculations...

  1. New Components for Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Stefano Caramori

    2010-01-01

    Full Text Available Dye-Sensitized Solar Cells (DSSCs are among the most promising solar energy conversion devices of new generation, since coupling ease of fabrication and low cost offer the possibility of building integration in photovoltaic windows and facades. Although in their earliest configuration these systems are close to commercialization, fundamental studies are still required for developing new molecules and materials with more desirable properties as well as improving our understanding of the fundamental processes at the basis of the functioning of photoactive heterogeneous interfaces. In this contribution, some recent advances, made in the effort of improving DSSC devices by finding alternative materials and configurations, are reviewed.

  2. Atomic-Scale Control of Electron Transport through Single Molecules

    DEFF Research Database (Denmark)

    Wang, Y. F.; Kroger, J.; Berndt, R.

    2010-01-01

    Tin-phthalocyanine molecules adsorbed on Ag(111) were contacted with the tip of a cryogenic scanning tunneling microscope. Orders-of-magnitude variations of the single-molecule junction conductance were achieved by controllably dehydrogenating the molecule and by modifying the atomic structure...

  3. Characteristics of a Broadband Dye Laser Using Pyrromethene and Rhodamine Dyes

    Science.gov (United States)

    Tedder, Sarah A.; Danehy, Paul M.; Wheeler, Jeffrey L.

    2011-01-01

    A broadband dye laser pumped by a frequency-doubled Nd:YAG laser with a full-width half-maximum (FWHM) from 592 to 610 nm was created for the use in a dual-pump broadband CARS system called WIDECARS. The desired broadband dye laser was generated with a mixture of Pyrromethene dyes as an oscillator gain medium and a spectral selective optic in the oscillator cavity. A mixture of Rhodamine dyes were used in the amplifier dye cell. To create this laser a study was performed to characterize the spectral behavior of broadband dye lasers created with Rhodamine dyes 590, 610, and 640, Pyrromethene dyes 597 and 650 as well as mixture of these dyes.

  4. Octane-Assisted Reverse Micellar Dyeing of Cotton with Reactive Dyes

    Directory of Open Access Journals (Sweden)

    Alan Yiu-lun Tang

    2017-12-01

    Full Text Available In this study, we investigated the computer colour matching (CCM of cotton fabrics dyed with reactive dye using the octane-assisted reverse micellar approach. The aim of this study is to evaluate the colour quality and compare the accuracy between CCM forecasting and simulated dyeing produced by conventional water-based dyeing and octane-assisted reverse micellar dyeing. First, the calibration of dyeing databases for both dyeing methods was established. Standard samples were dyed with known dye concentrations. Computer colour matching was conducted by using the colour difference formula of International Commission on Illumination (CIE L*a*b*. Experimental results revealed that the predicted concentrations were nearly the same as the expected known concentrations for both dyeing methods. This indicates that octane-assisted reverse micellar dyeing system can achieve colour matching as good as the conventional water-based dyeing system. In addition, when comparing the colour produced by the conventional water-based dyeing system and the octane-assisted reverse micellar dyeing system, the colour difference (ΔE is ≤1, which indicates that the reverse micellar dyeing system could be applied for industrial dyeing with CCM.

  5. Tunable lasers in isotope separation: a colorful view of a dye chemist

    International Nuclear Information System (INIS)

    Hammond, P.R.

    1977-01-01

    Some of the problems to be encountered in the possible large scale use of dye lasers in an isotope separation plant are discussed.The effect of laser dye deterioration on performance is examined algebraically in terms of disappearance of dye molecules and the appearance of a new, single chemical product having absorption in the fluorescence band for a single pass through a transversely pumped amplifier. Loss of output, defined as ''quantum yield of laser deterioration'', Q/sub L/, is related to the true quantum yield of molecular destruction of the dye Q/sub M/, and other known parameters. 6-Diethylamino 3-keto fluoran, an example of an oxygen tricyclic merocyanine, is described. It was first reported in the pre-1900 German literature under the name of Chromogen Red B and it is an ineffective lasing dye on account of low fluorescence quantum yield. The techniques for measurement and the excited state absorption cross-sections are reported for the dyes rhodamine 6G fluoroborate in alcohol, rhodamine B basic solution in trifluoroethanol and kiton red S in trifluoroethanol

  6. 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.

  7. Measurement of liquid sheet using laser tagging method by photochromic dye

    Science.gov (United States)

    Rosli, Nurrina Binti; Amagai, Kenji

    2014-12-01

    Liquid atomization system has been extensively applied as the most significant process in many industrial fields. In the internal combustion engine, the combustion phenomenon is strongly influenced by the spray characteristics of the fuel given by the atomization process. In order to completely understand the whole atomization process, a detail investigation of relations between the liquid jet characteristics and the breakup phenomenon is required. In this study, a non-intrusive method called as laser tagging method by photochromic dye has been developed with aim to study the breakup process of liquid sheet in detail, covering from the behavior in film until disintegrated into ligament and droplets. The laser tagging method by photochromic dye is based on a shift in the absorption spectrum of photochromic dye molecules tagged by ultraviolet laser. The shift results a color change at the tagged region of liquid containing the dye. In this study, the motions of the dye traces were analyzed as the liquid surface velocity. As a result, liquid sheet was found to keep its velocity constantly in film before suddenly increase around broken point. However, it then decreased after broken into droplets. By forming a set of four points of dye traces on the liquid sheet, the change of relative position of the set enabled the measurement of deformation and rotational motion of the liquid sheet. As a result, the normal strain of the liquid sheet parallel to the flow direction depended on the flow behavior of ligament formation.

  8. Artificial evolution of coumarin dyes for dye sensitized solar cells.

    Science.gov (United States)

    Venkatraman, Vishwesh; Abburu, Sailesh; Alsberg, Bjørn Kåre

    2015-11-07

    The design and discovery of novel molecular structures with optimal properties has been an ongoing effort for materials scientists. This field has in general been dominated by experiment driven trial-and-error approaches that are often expensive and time-consuming. Here, we investigate if a de novo computational design methodology can be applied to the design of coumarin-based dye sensitizers with improved properties for use in Grätzel solar cells. To address the issue of synthetic accessibility of the designed compounds, a fragment-based assembly is employed, wherein the combination of chemical motifs (derived from the existing databases of structures) is carried out with respect to user-adaptable set of rules. Rather than using computationally intensive density functional theory (DFT)/ab initio methods to screen candidate dyes, we employ quantitative structure-property relationship (QSPR) models (calibrated from empirical data) for rapid estimation of the property of interest, which in this case is the product of short circuit current (Jsc) and open circuit voltage (Voc). Since QSPR models have limited validity, pre-determined applicability domain criteria are used to prevent unacceptable extrapolation. DFT analysis of the top-ranked structures provides supporting evidence of their potential for dye sensitized solar cell applications.

  9. COMPARATIVE STUDY OF TWO DYEING METHODS USING REACTIVE DYE

    Directory of Open Access Journals (Sweden)

    HINOJOSA Belén

    2016-05-01

    Full Text Available Environment preservation is a common worry not only for people but for companies as well. Industry is more and more concern about the necessity of developing new and more respectful processes. Dye is one of the most important processes in the textile industry but it is also considered as no too safe regarding environment issues. This process uses large amounts of water and generates big volumes of wastewater. Following this issue, new regulations and laws emerge to control the waste generated. This leads to the companies and increased costs in terms of wastewater treatments and high water consumption. In this research we compare two systems on garment finishing application, the conventional bath process and the new Ecofinish system that is able to save water and product. To compare these processes, we carried out a reactive dyeing using both systems in order to determine the quality differences in the final product. For this purpose, the samples have been tested to washing and rubbing fastness, according to UNE EN ISO 105 C10 and UNE- EN ISO 105 X12 standards, respectively. This study confirms that this system achieves water savings and reduces the wastewater produced, getting a good dyeing. This process can be considered as an alternative to the conventional one.

  10. Modified cyanobacteria

    Science.gov (United States)

    Vermaas, Willem F J.

    2014-06-17

    Disclosed is a modified photoautotrophic bacterium comprising genes of interest that are modified in terms of their expression and/or coding region sequence, wherein modification of the genes of interest increases production of a desired product in the bacterium relative to the amount of the desired product production in a photoautotrophic bacterium that is not modified with respect to the genes of interest.

  11. Biochemical study of some environmental pollutants dyes Part II: disperse dyes

    International Nuclear Information System (INIS)

    Shakra, S.; Ahmed, F.A.; Fetyan, N.A.

    2005-01-01

    This work was aimed to develop a method for removal of the dyes color from the textile wastewater that is well be much less costly than the other chemical or physical methods used. It therefore included: 1. Preparation of three disperses dyes. 2. Isolation of dyes degradable microorganisms from wastewater effluents and soil after adding 200 ppm of each dye individually. 3. Decolorisation and biodegradation of the dyes in liquid culture of the isolated bacteria (Bacillus thuringiensis). 4. Identification of the probable byproducts by different instruments. 5. Toxicity assessment of the dyes and their biodegraded products

  12. Solution Processed Silver Nanoparticles in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Marko Berginc

    2014-01-01

    Full Text Available A plasmonic effect of silver nanoparticles (Ag NPs in dye-sensitized solar cells (DSSCs is studied. The solutions of silver nitrate in isopropanol, ethylene glycol, or in TiO2 sol were examined as possible precursors for Ag NPs formation. The solutions were dip-coated on the top of the porous TiO2 layer. The results of optical measurements confirmed the formation of Ag NPs throughout the porous TiO2 layer after the heat treatment of the layers above 100°C. Heat treatment at 220°C was found to be optimal regarding the formation of the Ag NPs. The porous TiO2 layers with Ag NPs have been evaluated also in DSSC by measuring current-voltage characteristics and the external quantum efficiency of the cells. In addition, the amount of adsorbed dye has been determined to prove the plasmonic effect in the cells. The I-V characterization of the DSSCs revealed an increase of the short circuit current in the presence of Ag NPs although the amount of the attached dye molecules decreased. These results confirm that the performance enhancement is related to the plasmonic effect. However, neither a thin sol-gel TiO2 layer nor poly(4-vinylpyridine shells provide effective protection for the long term stability of the Ag NPs against the corrosion of I3-/I- based electrolyte.

  13. Electronic-excitation energy transfer in heterogeneous dye solutions under laser excitation

    International Nuclear Information System (INIS)

    Levshin, L.V.; Mukushev, B.T.; Saletskii, A.M.

    1995-01-01

    An experimental study has been made of electronic-excitation energy transfer (EEET) among dye molecules of different types for different exciting-fight wavelengths and temperatures. Upon selective laser excitation of the donor, the inhomogeneous broadening of molecular levels increases the probability of EEET from the donor to acceptor molecules. The efficiency of this process is directly proportional to the acceptor molecule concentration and is temperature dependent. The EEET is accompanied by the spectral migration of energy among donor molecules, which reduces the fluorescence quantum efficiency of the donor. Increasing the frequency of the exciting light decreases in the donor fluorescence quantum efficiency. An increase in the acceptor molecule concentration results in a decrease of the spectral migration of excitation in the donor molecule system. 5 refs., 5 figs

  14. Spectroscopic and impedance studies of reverse biased degraded dye solar cells

    CSIR Research Space (South Africa)

    Le Roux, Lukas J

    2011-03-01

    Full Text Available The work that is presented here is focused on the results that were obtained during studies of the performance of Dye Solar Cells under certain reverse bias conditions. This reverse voltage could permanently modify or damage a cell...

  15. Synthesis, characterization and dyeing behavior of heterocyclic acid dyes and mordent acid dyes on wool and silk fabrics

    Directory of Open Access Journals (Sweden)

    Patel Hitendra M.

    2012-01-01

    Full Text Available Novel heterocyclic acid and mordent acid dyes were synthesized by the coupling of diazonium salt solution of different aromatic amines with 2- butyl-3-(4-hydroxybenzoylbenzofuran. The resulting heterocyclic acid dyes were characterized by spectral techniques, i.e., elemental analysis, IR, 1HNMR, 13C-NMR spectral studies and UV- visible spectroscopy. The dyeing performance of all the heterocyclic acid 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.

  16. Fate of Colored Smoke Dyes

    Science.gov (United States)

    1992-01-01

    4.13] have been applied to their estimation. This approach has the advantages of sensitivity and of not requiring high purity and known structures...Chrom absorbance detector, and an Alltech Econosil C-18 (10 micrometer) column (4.6 mm X 25 cm with guard column). The mobile phase, HPLC-grade methanol...water partition coefficient or vice versa. The HPLC method is of similar precision and has the advantage that known structure and purity of the dye are

  17. Dataset on analysis of dyeing property of natural dye from Thespesia populnea bark on different fabrics

    Directory of Open Access Journals (Sweden)

    Kuchekar Mohini

    2018-02-01

    Full Text Available The natural dyes separated from plants are of gaining interest as substitutes for synthetic dyes in food and cosmetics. Thespesia populnea (T. populnea is widely grown plant and used in the treatment of various diseases. This study was aimed to separate natural dye from T. populnea bark and analysis of its dyeing property on different fabrics. In this investigation pharmacognostic study was carried out. The pharmacognostic study includes morphological study, microscopical examination, proximate analysis along with the phytochemical study. The dyeing of different fabric was done with a natural dye extracted from T. populnea bark. The fabrics like cotton, butter crep, polymer, chiken, lone, ulene and tarakasa were dye with plant extract. The various evaluation parameters were studied. It includes effect of washing with water, effect of soap, effect of sunlight, effect of alum, effect of Cupric sulphate, microscopical study of fabrics and visual analysis of dyeing by common people were studied. In results, natural dye isolated from T. populnea bark could be used for dyeing fabrics with good fastness properties. The studies reveals that, the dyeing property of fabrics after washing with water and soap, exposed to sunlight does not get affected. It was observed that cotton and tarakasa stains better as compared with other fabrics. It was concluded that the ethanolic extract having good dyeing property. Keywords: Plant, Thespesia populnea, Bark, Natural dye, Fabrics

  18. Fluorescent labeling of NASBA amplified tmRNA molecules for microarray applications

    Directory of Open Access Journals (Sweden)

    Kaplinski Lauris

    2009-05-01

    Full Text Available Abstract Background Here we present a novel promising microbial diagnostic method that combines the sensitivity of Nucleic Acid Sequence Based Amplification (NASBA with the high information content of microarray technology for the detection of bacterial tmRNA molecules. The NASBA protocol was modified to include aminoallyl-UTP (aaUTP molecules that were incorporated into nascent RNA during the NASBA reaction. Post-amplification labeling with fluorescent dye was carried out subsequently and tmRNA hybridization signal intensities were measured using microarray technology. Significant optimization of the labeled NASBA protocol was required to maintain the required sensitivity of the reactions. Results Two different aaUTP salts were evaluated and optimum final concentrations were identified for both. The final 2 mM concentration of aaUTP Li-salt in NASBA reaction resulted in highest microarray signals overall, being twice as high as the strongest signals with 1 mM aaUTP Na-salt. Conclusion We have successfully demonstrated efficient combination of NASBA amplification technology with microarray based hybridization detection. The method is applicative for many different areas of microbial diagnostics including environmental monitoring, bio threat detection, industrial process monitoring and clinical microbiology.

  19. Development of Carbocyanine Dyes for PRMT Inhibition and Imaging

    Science.gov (United States)

    Sinha, Sarmistha Halder; Owens, Eric A.; Feng, You; Yang, Yutao; Xie, Yan; Tu, Yaping; Henary, Maged; Zheng, Yujun George

    2014-01-01

    Summary Protein arginine methylation regulates multiple biological processes. Deregulation of protein arginine methyltransferase (PRMT) activities has been observed in many disease phenotypes. Small molecule probes that target PRMTs with strong affinity and selectivity can be used as valuable tools to dissect biological mechanisms of arginine methylation and establish the role of PRMT proteins in a disease process. In this work, we report synthesis and evaluation of a class of carbocyanine compounds containing indolium, benz[e]indolium or benz[c,d]indolium heterocyclic moieties that bind to the predominant arginine methyltransferase PRMT1 and inhibit its methyltransferase activity at low micromolar potencies. In particular, the developed molecules have long wavelength colorimetric and fluorometric photoactivities, which can be used for optical and near-infrared fluorescence imaging in cells or biological tissues. Together, these new chemical probes have potential application in PRMT studies both as enzyme inhibitors and as fluorescent dyes for microscope imaging. PMID:22749641

  20. Magnetic polymer microcapsules loaded with Nile Red fluorescent dye

    Science.gov (United States)

    Bartel, Marta; Wysocka, Barbara; Krug, Pamela; Kępińska, Daria; Kijewska, Krystyna; Blanchard, Gary J.; Kaczyńska, Katarzyna; Lubelska, Katarzyna; Wiktorska, Katarzyna; Głowala, Paulina; Wilczek, Marcin; Pisarek, Marcin; Szczytko, Jacek; Twardowski, Andrzej; Mazur, Maciej

    2018-04-01

    Fabrication of multifunctional smart vehicles for drug delivery is a fascinating challenge of multidisciplinary research at the crossroads of materials science, physics and biology. We demonstrate a prototypical microcapsule system that is capable of encapsulating hydrophobic molecules and at the same time reveals magnetic properties. The microcapsules are prepared using a templated synthesis approach where the molecules to be encapsulated (Nile Red) are present in the organic droplets that are suspended in the polymerization solution which also contains magnetic nanoparticles. The polymer (polypyrrole) grows on the surface of organic droplets encapsulating the fluorescent dye in the core of the formed microcapsule which incorporates the nanoparticles into its wall. For characterization of the resulting structures a range of complementary physicochemical methodology is used including optical and electron microscopy, magnetometry, 1H NMR and spectroscopy in the visible and X-ray spectral ranges. Moreover, the microcapsules have been examined in biological environment in in vitro and in vivo studies.

  1. Removal of dyes from textile wastewater by using nanofiltration polyetherimide membrane

    Science.gov (United States)

    Karisma, Doni; Febrianto, Gabriel; Mangindaan, Dave

    2017-12-01

    Followed by rapid development of the textile industries since 19th century the dyeing technology is thriving ever since. However, its progress is followed by lack of responsibility and knowledge in treating the dye-containing wastewater. There are some emerging technologies in treating such kind of wastewater, where membrane technology is one of those technologies that has uniqueness in the performance of separating dyes from wastewater, accompanied with small amount of energy. The development of membrane technology is one of several eco-engineering developments for sustainability in water resource management. However, there are a lot of rooms for improvement for this membrane technology, especially for the application in treating textile wastewater in Indonesia. Based on the demand in Indonesia for clean water and further treatment of dye-containing wastewater, the purpose of this research is to fabricate nanofiltration (NF) membranes to accommodate those problems. Furthermore, the fabricated NF membrane will be modified by interfacial polymerization to impart a new selective layer on top of NF membrane to improve the performance of the separation of the dyes from dye-containing wastewater. This research was conducted into two phases of experiments. In the first phase the formulation of polymeric dope solution of PEI/Acetone/NMP (N-methyl-pyrollidone), using the variation of 15/65/20, 16/64/20, and 17/63/20. This research show that many areas still can be explored in textile wastewater treatment using membrane in Indonesia.

  2. Dye removal from textile wastewater using bioadsorbent

    International Nuclear Information System (INIS)

    Gardazi, S.M.H.

    2014-01-01

    Textile industries throughout the world produce huge quantities of dyes and pigments annually. Effluents from textile industries are dye wastewater, and disposal of these wastes to freshwater bodies causes damage to the environment. Among the treatment technologies, adsorption is an attractive and viable option, provided that the sorbent is inexpensive and readily available for use. In this study, a typical basic dye, methylene blue, in wastewater was treated using Melia azedarach sawdust. The effects of contact time, adsorbent amount and particle size were investigated on the removal efficiency of adsorbent for methylene blue. Complete removal of the dye were attained at higher adsorbent dose of 3 g/L with 50 mg/L initial dye concentration. The maximum adsorption was at 240 minutes, whereas more than 90% removal with 105 meu m particle size of 1 g/L adsorbent for same initial dye concentration. The experimental data best fits with 2 Langmuir adsorption isotherm (R= 0.991). (author)

  3. 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.

  4. Laser inactivation of periodontal bacteria using photosensitizing dyes

    Science.gov (United States)

    Golding, Paul S.; Maddocks, L.; King, Terence A.; Drucker, D. B.

    1996-12-01

    We demonstrate the killing of the oral bacteria Prevotella nigrescens using a photosensitizer and light from a 10 Hz, frequency doubled, Q-switched Nd:YAG pumped dye laser, with modified oscillator to increase output power. This system produced light at wavelengths close to 620 nm, the absorption maximum of the photosensitizing agent, malachite green isothiocyanate, a wavelength that is not significantly absorbed by tissue. A bacterial reduction of 97.5 percent was achieved at an energy density of 0.67 J/cm2 and exposure times of 300 seconds.

  5. Panchromatic Response in Solid-State Dye-Sensitized Solar Cells Containing Phosphorescent Energy Relay Dyes

    KAUST Repository

    Yum, Jun-Ho; Hardin, Brianâ E.; Moon, Soo-Jin; Baranoff, Etienne; Nà ¼ esch, Frank; McGehee, Michaelâ D.; Grà ¤ tzel, Michael; Nazeeruddin, Mohammadâ K.

    2009-01-01

    Running relay: Incorporating an energyrelay dye (ERD) into the hole transporter of a dye-sensitized solar cell increased power-conversion efficiency by 29% by extending light harvesting into the blue region. In the operating mechanism (see picture

  6. Time dependent – density functional theory characterization of organic dyes for dye-sensitized solar cells

    KAUST Repository

    Hilal, Rifaat; Aziz, Saadullah G.; Osman, Osman I.; Bredas, Jean-Luc

    2017-01-01

    We aim at providing better insight into the parameters that govern the intramolecular charge transfer (ICT) and photo-injection processes in dyes for dye-sensitised solar cells (DSSC). Density functional theory (DFT) and time-dependent DFT (TD

  7. Incorporating Multiple Energy Relay Dyes in Liquid Dye-Sensitized Solar Cells

    KAUST Repository

    Yum, Jun-Ho; Hardin, Brian E.; Hoke, Eric T.; Baranoff, Etienne; Zakeeruddin, Shaik M.; Nazeeruddin, Mohammad K.; Torres, Tomas; McGehee, Michael D.; Grä tzel, Michael

    2011-01-01

    Panchromatic response is essential to increase the light-harvesting efficiency in solar conversion systems. Herein we show increased light harvesting from using multiple energy relay dyes inside dye-sensitized solar cells. Additional photoresponse

  8. Increased light harvesting in dye-sensitized solar cells with energy relay dyes

    KAUST Repository

    Hardin, Brian E.; Hoke, Eric T.; Armstrong, Paul B.; Yum, Jun-Ho; Comte, Pascal; Torres, Tomá s; Fré chet, Jean M. J.; Nazeeruddin, Md Khaja; Grä tzel, Michael; McGehee, Michael D.

    2009-01-01

    Conventional dye-sensitized solar cells have excellent charge collection efficiencies, high open-circuit voltages and good fill factors. However, dye-sensitized solar cells do not completely absorb all of the photons from the visible and near

  9. Increased light harvesting in dye-sensitized solar cells with energy relay dyes

    KAUST Repository

    Hardin, Brian E.

    2009-06-21

    Conventional dye-sensitized solar cells have excellent charge collection efficiencies, high open-circuit voltages and good fill factors. However, dye-sensitized solar cells do not completely absorb all of the photons from the visible and near-infrared domain and consequently have lower short-circuit photocurrent densities than inorganic photovoltaic devices. Here, we present a new design where high-energy photons are absorbed by highly photoluminescent chromophores unattached to the titania and undergo Förster resonant energy transfer to the sensitizing dye. This novel architecture allows for broader spectral absorption, an increase in dye loading, and relaxes the design requirements for the sensitizing dye. We demonstrate a 26% increase in power conversion efficiency when using an energy relay dye (PTCDI) with an organic sensitizing dye (TT1). We estimate the average excitation transfer efficiency in this system to be at least 47%. This system offers a viable pathway to develop more efficient dye-sensitized solar cells.

  10. 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.

  11. 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.

  12. Quantitative structure-activity relationship analysis of substituted arylazo pyridone dyes in photocatalytic system: Experimental and theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Dostanić, J., E-mail: jasmina@nanosys.ihtm.bg.ac.rs [University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Department of Catalysis and Chemical Engineering, Njegoševa 12, 11000 Belgrade (Serbia); Lončarević, D. [University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Department of Catalysis and Chemical Engineering, Njegoševa 12, 11000 Belgrade (Serbia); Zlatar, M. [University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Department of Chemistry, Njegoševa 12, 11000 Belgrade (Serbia); Vlahović, F. [University of Belgrade, Innovation center of the Faculty of Chemistry, 11000 Belgrade (Serbia); Jovanović, D.M. [University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Department of Catalysis and Chemical Engineering, Njegoševa 12, 11000 Belgrade (Serbia)

    2016-10-05

    Highlights: • Electronic effects of para substituted arylazo pyridone dyes. • Linear relationship between Hammett σ{sub p} constants and dyes photoreactivity. • The photocatalytic reactions facilitated by el.-acceptors and retarded by el.-donors. • Fukui functions to analyze the reactivity on concurrent sites within a molecule. • Hydroxyl radicals sustain attack from two reaction sites, depending on a substituent type. - Abstract: A series of arylazo pyridone dyes was synthesized by changing the type of the substituent group in the diazo moiety, ranging from strong electron-donating to strong electron-withdrawing groups. The structural and electronic properties of the investigated dyes was calculated at the M062X/6-31 + G(d,p) level of theory. The observed good linear correlations between atomic charges and Hammett σ{sub p} constants provided a basis to discuss the transmission of electronic substituent effects through a dye framework. The reactivity of synthesized dyes was tested through their decolorization efficiency in TiO{sub 2} photocatalytic system (Degussa P-25). Quantitative structure-activity relationship analysis revealed a strong correlation between reactivity of investigated dyes and Hammett substituent constants. The reaction was facilitated by electron-withdrawing groups, and retarded by electron-donating ones. Quantum mechanical calculations was used in order to describe the mechanism of the photocatalytic oxidation reactions of investigated dyes and interpret their reactivities within the framework of the Density Functional Theory (DFT). According to DFT based reactivity descriptors, i.e. Fukui functions and local softness, the active site moves from azo nitrogen atom linked to benzene ring to pyridone carbon atom linked to azo bond, going from dyes with electron-donating groups to dyes with electron-withdrawing groups.

  13. Quantitative structure-activity relationship analysis of substituted arylazo pyridone dyes in photocatalytic system: Experimental and theoretical study

    International Nuclear Information System (INIS)

    Dostanić, J.; Lončarević, D.; Zlatar, M.; Vlahović, F.; Jovanović, D.M.

    2016-01-01

    Highlights: • Electronic effects of para substituted arylazo pyridone dyes. • Linear relationship between Hammett σ_p constants and dyes photoreactivity. • The photocatalytic reactions facilitated by el.-acceptors and retarded by el.-donors. • Fukui functions to analyze the reactivity on concurrent sites within a molecule. • Hydroxyl radicals sustain attack from two reaction sites, depending on a substituent type. - Abstract: A series of arylazo pyridone dyes was synthesized by changing the type of the substituent group in the diazo moiety, ranging from strong electron-donating to strong electron-withdrawing groups. The structural and electronic properties of the investigated dyes was calculated at the M062X/6-31 + G(d,p) level of theory. The observed good linear correlations between atomic charges and Hammett σ_p constants provided a basis to discuss the transmission of electronic substituent effects through a dye framework. The reactivity of synthesized dyes was tested through their decolorization efficiency in TiO_2 photocatalytic system (Degussa P-25). Quantitative structure-activity relationship analysis revealed a strong correlation between reactivity of investigated dyes and Hammett substituent constants. The reaction was facilitated by electron-withdrawing groups, and retarded by electron-donating ones. Quantum mechanical calculations was used in order to describe the mechanism of the photocatalytic oxidation reactions of investigated dyes and interpret their reactivities within the framework of the Density Functional Theory (DFT). According to DFT based reactivity descriptors, i.e. Fukui functions and local softness, the active site moves from azo nitrogen atom linked to benzene ring to pyridone carbon atom linked to azo bond, going from dyes with electron-donating groups to dyes with electron-withdrawing groups.

  14. Hair dye poisoning and the developing world

    Directory of Open Access Journals (Sweden)

    Sampathkumar Krishnaswamy

    2009-01-01

    Full Text Available Hair dye poisoning has been emerging as one of the important causes of intentional self harm in the developing world. Hair dyes contain paraphenylene-diamine and a host of other chemicals that can cause rhabdomyolysis, laryngeal edema, severe metabolic acidosis and acute renal failure. Intervention at the right time has been shown to improve the outcome. In this article, we review the various manifestations, clinical features and treatment modalities for hair dye poisoning.

  15. Spectroscopic study of the interaction of styrylcyanine dyes Sbo, Sil and their derivatives with bovine serum albumin.

    Science.gov (United States)

    Kurtaliev, Eldar N

    2011-07-01

    The spectral-luminescent characteristics of newly synthesized styrylcyanine dyes on the base of dyes Sbo ((E)-2-(4-(dimethylamino)styryl)-3-methylbenzo[d]oxazol-3-ium iodide) and Sil ((E)-2-(4-(dimethylamino)styryl)-1,3,3-trimethyl-3H-indolium perchlorate) in aqueous solutions without and in the presence of bovine serum albumin (BSA) were studied. It was established that the absorption spectra of dyes Tol-6, Dbo-10 and Dil-10 with increasing amount of BSA appear new bands with λ(max)=505 nm, λ(max)=512 nm and λ(max)=566 nm, respectively, whose intensity increases in proportion to the amount of albumin. The intensity of the glow of the main band of fluorescence in the presence of BSA sharply increases. The binding constant (K) and the number of binding sites (N) of studied dyes with BSA were determined. The dependence of binding constants with BSA on the dipole moment of dye molecules was determined, which indicates that besides electrostatic forces of attraction between molecules styrylcyanine dyes with BSA, hydrophobic interactions are essential. © Springer Science+Business Media, LLC 2011

  16. Solubilization of Hydrophobic Dyes in Surfactant Solutions

    Directory of Open Access Journals (Sweden)

    Ali Reza Tehrani-Bagha

    2013-02-01

    Full Text Available In this paper, the use of surfactants for solubilization of hydrophobic organic dyes (mainly solvent and disperse dyes has been reviewed. The effect of parameters such as the chemical structures of the surfactant and the dye, addition of salt and of polyelectrolytes, pH, and temperature on dye solubilization has been discussed. Surfactant self-assemble into micelles in aqueous solution and below the concentration where this occurs—the critical micelle concentration (CMC—there is no solubilization. Above the CMC, the amount of solubilized dye increases linearly with the increase in surfactant concentration. It is demonstrated that different surfactants work best for different dyes. In general, nonionic surfactants have higher solubilization power than anionic and cationic surfactants. It is likely that the reason for the good performance of nonionic surfactants is that they allow dyes to be accommodated not only in the inner, hydrocarbon part of the micelle but also in the headgroup shell. It is demonstrated that the location of a dye in a surfactant micelle can be assessed from the absorption spectrum of the dye-containing micellar solution.

  17. Micro-Cavity Fluidic Dye Laser

    DEFF Research Database (Denmark)

    Helbo, Bjarne; Kristensen, Anders; Menon, Aric Kumaran

    2003-01-01

    We have successfully designed, fabricated and characterized a micro-cavity fluidic dye laser with metallic mirrors, which can be integrated with polymer based lab-on-a-chip microsystems without further processing steps. A simple rate-equation model is used to predict the average pumping power...... threshold for lasing as function of cavity-mirror reflectance, laser dye concentration and cavity length. The laser device is characterized using the laser dye Rhodamine 6G dissolved in ethanol. Lasing is observed, and the influence of dye concentration is investigated....

  18. Ultrasonic assisted dyeing: dyeing of acrylic fabrics C.I. Astrazon Basic Red 5BL 200%.

    Science.gov (United States)

    Kamel, M M; Helmy, H M; Mashaly, H M; Kafafy, H H

    2010-01-01

    The dyeing of acrylic fabrics using C.I. Astrazon Basic Red 5BL 200% has been studied with both conventional and ultrasonic techniques. The effect of dye concentration, dye bath pH, ultrasonic power, dyeing time and temperature were studied and the resulting shades obtained by dyeing with both techniques were compared. Colour strength values obtained were found to be higher with ultrasonic than with conventional heating. The results of fastness properties of the dyed fabrics were studied. X-ray and Scanning Electron Microscope SEM were carried out on dyed samples using both methods of dyeing to find out an explanation for the better dyeability of acrylic fabrics with (US) method. Dyeing kinetics of acrylic fabrics using C.I. Astrazon Basic Red 5BL 200% using conventional and ultrasonic conditions were compared. The time/dye-uptake isotherms are revealing the enhanced dye-uptake in the second phase of dyeing. The values of dyeing rate constant, half-time of dyeing and standard affinity and ultrasonic efficiency have been calculated and discussed.

  19. High Excitation Transfer Efficiency from Energy Relay Dyes in Dye-Sensitized Solar Cells

    KAUST Repository

    Hardin, Brian E.; Yum, Jun-Ho; Hoke, Eric T.; Jun, Young Chul; Péchy, Peter; Torres, Tomás; Brongersma, Mark L.; Nazeeruddin, Md. Khaja; Grätzel, Michael; McGehee, Michael D.

    2010-01-01

    The energy relay dye, 4-(Dicyanomethylene)-2-methyl-6-(4- dimethylaminostyryl)-4H-pyran (DCM), was used with a near-infrared sensitizing dye, TT1, to increase the overall power conversion efficiency of a dye-sensitized solar cell (DSC) from 3

  20. Photostability of low cost dye-sensitized solar cells based on natural and synthetic dyes

    Science.gov (United States)

    Abdou, E. M.; Hafez, H. S.; Bakir, E.; Abdel-Mottaleb, M. S. A.

    2013-11-01

    This paper deals with the use of some natural pigments as well as synthetic dyes to act as sensitizers in dye-sensitized solar cells (DSSCs). Anthocyanin dye extracted from rosella (Hibiscus sabdariffa L.) flowers, the commercially available textile dye Remazole Red RB-133 (RR) and merocyanin-like dye based on 7-methyl coumarin are tested. The photostability of the three dyes is investigated under UV-Vis light exposure. The results show a relatively high stability of the three dyes. Moreover, the photostability of the solid dyes is studied over the TiO2 film electrodes. A very low decolorization rates are recorded as; rate constants k = 1.6, 2.1 and 1.9 × 10-3 min-1 for anthocyanin, RR and coumarin dyes, respectively. The stability results favor selecting anthocyanin as a promising sensitizer candidate in DSSCs based on natural products. Dyes-sensitized solar cells are fabricated and their conversion efficiency (η) is 0.27%, 0.14% and 0.001% for the anthocyanin, RR and coumarin dyes, respectively. Moreover, stability tests of the sealed cells based on anthocyanin and RR dyes are done under continuous light exposure of 100 mW cm-2, reveals highly stable DSSCs.

  1. Acid-base indicator properties of dyes from local plants I: Dyes from ...

    African Journals Online (AJOL)

    DR. MIKE HORSFALL

    Acid-base indicator properties of dyes from local plants I: Dyes from Basella alba. (Indian spinach) and ... solution, which change colour immediately after the equivalence point has .... The pH ranges over which the dyes change colour were ...

  2. Goat anti-rabbit IgG conjugated fluorescent dye-doped silica nanoparticles for human breast carcinoma cell recognition.

    Science.gov (United States)

    Chen, Min-Yan; Chen, Ze-Zhong; Wu, Ling-Ling; Tang, Hong-Wu; Pang, Dai-Wen

    2013-11-12

    We report an indirect method for cancer cell recognition using photostable fluorescent silica nanoprobes as biological labels. The dye-doped fluorescent silica nanoparticles were synthesized using the water-in-oil (W/O) reverse microemulsion method. The silica matrix was produced by the controlled hydrolysis of tetraethylorthosilicate (TEOS) in water nanodroplets with the initiation of ammonia (NH3·H2O). Fluorescein isothiocyanate (FITC) or rhodamine B isothiocyanate conjugated with dextran (RBITC-Dextran) was doped in silica nanoparticles (NPs) with a size of 60 ± 5 nm as a fluorescent signal element by covalent bonding and steric hindrance, respectively. The secondary antibody, goat anti-rabbit IgG, was conjugated on the surface of the PEG-terminated modified FITC-doped or RBITC-Dextran-doped silica nanoparticles (PFSiNPs or PBSiNPs) by covalent binding to the PEG linkers using the cyanogen bromide method. The concentrations of goat anti-rabbit IgG covering the nanoprobes were quantified via the Bradford method. In the proof-of-concept experiment, an epithelial cell adhesion molecule (EpCAM) on the human breast cancer SK-Br-3 cell surface was used as the tumor marker, and the nanoparticle functionalized with rabbit anti-EpCAM antibody was employed as the nanoprobe for cancer cell recognition. Compared with fluorescent dye labeled IgG (FITC-IgG and RBITC-IgG), the designed nanoprobes display dramatically increased stability of fluorescence as well as photostability under continuous irradiation.

  3. Rationalization of dye uptake on titania slides for dye-sensitized solar cells by a combined chemometric and structural approach.

    Science.gov (United States)

    Gianotti, Valentina; Favaro, Giada; Bonandini, Luca; Palin, Luca; Croce, Gianluca; Boccaleri, Enrico; Artuso, Emma; van Beek, Wouter; Barolo, Claudia; Milanesio, Marco

    2014-11-01

    A model photosensitizer (D5) for application in dye-sensitized solar cells has been studied by a combination of XRD, theoretical calculations, and spectroscopic/chemometric methods. The conformational stability and flexibility of D5 and molecular interactions between adjacent molecules were characterized to obtain the driving forces that govern D5 uptake and grafting and to infer the most likely arrangement of the molecules on the surface of TiO2. A spectroscopic/chemometric approach was then used to yield information about the correlations between three variables that govern the uptake itself: D5 concentration, dispersant (chenodeoxycholic acid; CDCA) concentration, and contact time. The obtained regression model shows that large uptakes can be obtained at high D5 concentrations in the presence of CDCA with a long contact time, or in absence of CDCA if the contact time is short, which suggests how dye uptake and photovoltaic device preparation can be optimized. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Computational screening of functionalized zinc porphyrins for dye sensitized solar cells

    DEFF Research Database (Denmark)

    Ørnsø, Kristian Baruël; García Lastra, Juan Maria; Thygesen, Kristian Sommer

    2013-01-01

    separation, and high output voltage. Here we demonstrate an extensive computational screening of zinc porphyrins functionalized with electron donating side groups and electron accepting anchoring groups. The trends in frontier energy levels versus side groups are analyzed and a no-loss DSSC level alignment...... quality is estimated. Out of the initial 1029 molecules, we find around 50 candidates with level alignment qualities within 5% of the optimal limit. We show that the level alignment of five zinc porphyrin dyes which were recently used in DSSCs with high efficiencies can be further improved by simple side......An efficient dye sensitized solar cell (DSSC) is one possible solution to meet the world's rapidly increasing energy demands and associated climate challenges. This requires inexpensive and stable dyes with well-positioned frontier energy levels for maximal solar absorption, efficient charge...

  5. Dye-Affinity Nanofibrous Membrane for Adsorption of Lysozyme: Preparation and Performance Evaluation

    Directory of Open Access Journals (Sweden)

    Steven Sheng-Shih Wang

    2018-01-01

    Full Text Available Polyacrylonitrile (PAN nanofibrous membrane was prepared by an electrospinning technique. After heat treatment and alkaline hydrolysis, the weak ion exchange membrane was grafted with chitosan molecule and then covalently immobilized with a Cibacron Blue F3GA (CB. Fibre diameter, porosity and pore size of the membrane and immobilized dye density were characterized. Furthermore, the membrane was applied to evaluate the binding performance of lysozyme under various operating parameters (pH, chitosan mass per volume ratio, dye concentration, ionic strength and temperature in batch mode. The experimental results were directly applied to purify lysozyme from chicken egg white by membrane chromatography. The results showed that the capture efficiency, recovery yield and purification factor were 90 and 87 %, and 47-fold, respectively, in a single step. The binding capacity remained consistent after five repeated cycles of adsorption-desorption operations. This work demonstrates that the dye-affinity nanofibrous membrane holds great potential for purification of lysozyme from real feedstock.

  6. 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 ...

  7. 3D-QSPR method of computational technique applied on red reactive dyes by using CoMFA strategy.

    Science.gov (United States)

    Mahmood, Uzma; Rashid, Sitara; Ali, S Ishrat; Parveen, Rasheeda; Zaheer-Ul-Haq; Ambreen, Nida; Khan, Khalid Mohammed; Perveen, Shahnaz; Voelter, Wolfgang

    2011-01-01

    Cellulose fiber is a tremendous natural resource that has broad application in various productions including the textile industry. The dyes, which are commonly used for cellulose printing, are "reactive dyes" because of their high wet fastness and brilliant colors. The interaction of various dyes with the cellulose fiber depends upon the physiochemical properties that are governed by specific features of the dye molecule. The binding pattern of the reactive dye with cellulose fiber is called the ligand-receptor concept. In the current study, the three dimensional quantitative structure property relationship (3D-QSPR) technique was applied to understand the red reactive dyes interactions with the cellulose by the Comparative Molecular Field Analysis (CoMFA) method. This method was successfully utilized to predict a reliable model. The predicted model gives satisfactory statistical results and in the light of these, it was further analyzed. Additionally, the graphical outcomes (contour maps) help us to understand the modification pattern and to correlate the structural changes with respect to the absorptivity. Furthermore, the final selected model has potential to assist in understanding the characteristics of the external test set. The study could be helpful to design new reactive dyes with better affinity and selectivity for the cellulose fiber.

  8. Spectral-fluorescent study of the interaction of the polymethine dye probe Cyan 2 with chondroitin-4-sulfate

    Science.gov (United States)

    Tatikolov, Alexander S.; Akimkin, Timofey M.; Panova, Ina G.; Yarmoluk, Sergiy M.

    2017-04-01

    The noncovalent interaction of the polymethine dye probe 3,3‧,9-trimethylthiacarbocyanine iodide (Cyan 2) with chondroitin-4-sulfate (C4S) in buffer solutions with different pH and in water in the absence of buffers has been studied by spectral-fluorescent methods. It has been shown that in all media studied, at relatively high concentrations, the dye is bound to C4S mainly as a monomer, which is accompanied by a steep rise of fluorescence (the intermediate formation of dye aggregates on the biopolymer is also observed). From the dependence of the fluorescence quantum yield on the concentration of C4S, the parameters of binding of the dye monomer to C4S were obtained: the effective binding constant K, the number of the monomeric C4S units n per one dye monomer bound to C4S, and the fluorescence quantum yield of the bound dye monomer Φfb. The dependence of Φfb (and K) on pH of the medium is not monotonic: it has a minimum in the region of neutral pH and a growth in the regions of acid and basic pH. This can be explained by changing the charge of a C4S macromolecule as a function of pH and related conformational alterations in the biopolymer, which can affect the rigidity of a dye molecule and the energy of its interaction with the biopolymer.

  9. Simulation of the adsorption capacity of polar organic compounds and dyes from water onto activated carbons: Model development and validation

    Directory of Open Access Journals (Sweden)

    Warisa Bunmahotama

    2018-03-01

    Full Text Available A model approach is developed to simulate the adsorption isotherms of low-molecular-weight polar organic compounds (LMWPOCs, halogenated LMWPOCs, and dye molecules onto activated carbons (AC. The models were based on the Dubinin–Astakhov equation, with the limiting pore volume of adsorbent estimated from the pore size distribution data, and the adsorption affinity of the adsorbate described by the molecular connectivity index. The models were used to simulate the adsorption data of 87 LMWPOCs onto six ACs, 25 halogenated LMWPOCs onto two ACs and 22 dyes onto three ACs. The developed models follow the experimental data fairly well, with errors of 49, 33 and 43% for the tested LMWPOCs, halogenated LMWPOCs, and dyes, respectively. This study shows that the developed model approach may provide a simple means for the estimation of adsorption capacity for LMWPOCs and dyes onto ACs in water.

  10. Thermally and optically tunable lasing properties from dye-doped holographic polymer dispersed liquid crystal in capillaries

    Science.gov (United States)

    Chen, Maozhou; Dai, Haitao; Wang, Dongshuo; Yang, Yue; Luo, Dan; Zhang, Xiaodong; Liu, Changlong

    2018-03-01

    In this paper, we investigated tunable lasing properties from the dye-doped holographic polymer dispersed liquid crystal (HPDLC) gratings in capillaries with thermal and optical manners. The thermally tunable range of the lasing from the dye-doped HPDLC reached 8.60 nm with the temperature ranging from 23 °C to 50 °C. The optically tunable laser emission was achieved by doping azo-dye in HPDLC. The transition of azo-dye from trans- to cis-state could induce the reorientation of LC molecules after UV light irradiation, which resulted in the variation of refractive index contrast of LC-rich/polymer-rich layer in HPDLC. Experimentally, the emission wavelength of lasing showed a blueshift (about 2 nm) coupled with decreasing output intensities. The tunable laser based on HPDLC may enable more applications in laser displays, optical communication, biosensors, etc.

  11. Diffusion Of Indigo Molecules Inside The Palygorskite Clay Channels

    OpenAIRE

    Dejoie , Catherine; Martinetto , Pauline; Dooryhee , Eric; Van Eslande , Elsa; Blanc , Sylvie; Bordat , Patrice; Brown , Ross; Porcher , Florence; Anne , Michel

    2011-01-01

    International audience; The search for durable dyes led several past civilizations to develop artificial pigments. Maya Blue (MB), manufactured in pre-Columbian Mesoamerica, is one of the best known examples of an organic-inorganic hybrid material. Its durability is due to the unique association of indigo molecule and palygorskite, a particular fibrous clay occurring in Yucatan. Despite 50 years of sustained interest, the microscopic structure of MB and its relation to the durability remain o...

  12. Utilization of magnetically responsive cereal by-product for organic dye removal

    Czech Academy of Sciences Publication Activity Database

    Baldíková, Eva; Politi, D.; Maděrová, Zdeňka; Pospíšková, K.; Sidiras, D.; Šafaříková, Miroslava; Šafařík, Ivo

    2016-01-01

    Roč. 96, č. 6 (2016), s. 2204-2214 ISSN 0022-5142 R&D Projects: GA ČR GA13-13709S Grant - others:GA MŠk(CZ) LO1305 Institutional support: RVO:67179843 Keywords : modified rice straw * aqueous-solution * methylene-blue * wheat-straw * activated carbon * cost adsorbents * crystal violet * anionic dyes * adsorption * acid * barley straw * magnetic modification * magnetic adsorbent * microwave-assisted synthesis * organic dyes Subject RIV: GC - Agronomy Impact factor: 2.463, year: 2016

  13. Spin-Dependent Transport through Chiral Molecules Studied by Spin-Dependent Electrochemistry

    Science.gov (United States)

    2016-01-01

    Conspectus Molecular spintronics (spin + electronics), which aims to exploit both the spin degree of freedom and the electron charge in molecular devices, has recently received massive attention. Our recent experiments on molecular spintronics employ chiral molecules which have the unexpected property of acting as spin filters, by way of an effect we call “chiral-induced spin selectivity” (CISS). In this Account, we discuss new types of spin-dependent electrochemistry measurements and their use to probe the spin-dependent charge transport properties of nonmagnetic chiral conductive polymers and biomolecules, such as oligopeptides, L/D cysteine, cytochrome c, bacteriorhodopsin (bR), and oligopeptide-CdSe nanoparticles (NPs) hybrid structures. Spin-dependent electrochemical measurements were carried out by employing ferromagnetic electrodes modified with chiral molecules used as the working electrode. Redox probes were used either in solution or when directly attached to the ferromagnetic electrodes. During the electrochemical measurements, the ferromagnetic electrode was magnetized either with its magnetic moment pointing “UP” or “DOWN” using a permanent magnet (H = 0.5 T), placed underneath the chemically modified ferromagnetic electrodes. The spin polarization of the current was found to be in the range of 5–30%, even in the case of small chiral molecules. Chiral films of the l- and d-cysteine tethered with a redox-active dye, toludin blue O, show spin polarizarion that depends on the chirality. Because the nickel electrodes are susceptible to corrosion, we explored the effect of coating them with a thin gold overlayer. The effect of the gold layer on the spin polarization of the electrons ejected from the electrode was investigated. In addition, the role of the structure of the protein on the spin selective transport was also studied as a function of bias voltage and the effect of protein denaturation was revealed. In addition to

  14. Dye Sensitized Solar Cell, DSSC

    Directory of Open Access Journals (Sweden)

    Pongsatorn Amornpitoksuk

    2003-07-01

    Full Text Available A dye sensitized solar cell is a new type of solar cell. The operating system of this solar cell type is similar to plant’s photosynthesis process. The sensitizer is available for absorption light and transfer electrons to nanocrystalline metal oxide semiconductor. The ruthenium(II complexes with polypyridyl ligands are usually used as the sensitizers in solar cell. At the present time, the complex of [Ru(2,2',2'’-(COOH3- terpy(NCS3] is the most efficient sensitizer. The total photon to current conversion efficiency was approximately 10% at AM = 1.5.

  15. Incorporating Multiple Energy Relay Dyes in Liquid Dye-Sensitized Solar Cells

    KAUST Repository

    Yum, Jun-Ho

    2011-01-05

    Panchromatic response is essential to increase the light-harvesting efficiency in solar conversion systems. Herein we show increased light harvesting from using multiple energy relay dyes inside dye-sensitized solar cells. Additional photoresponse from 400-590 nm matching the optical window of the zinc phthalocyanine sensitizer was observed due to Förster resonance energy transfer (FRET) from the two energy relay dyes to the sensitizing dye. The complementary absorption spectra of the energy relay dyes and high excitation transfer efficiencies result in a 35% increase in photovoltaic performance. © 2011 Wiley-VCH Verlag GmbH& Co. KGaA.

  16. Characteristics of dye Rhoeo spathacea in dye sensitizer solar cell (DSSC)

    Science.gov (United States)

    Sumardiasih, Sri; Obina, Wilfrida M.; Cari; Supriyanto, Agus; Septiawan, Trio Y.; Khairuddin

    2017-01-01

    Dye-sensitized solar cell (DSSC) is a device that converts solar energy into electrical energy. The magnitude of the efficiency of DSSC is mainly based on the amount of dye absorbed by the surface of TiO2. In this work, used natural dye extracted from leaves Rhoeo spathacea. The dye partially used to immerse of TiO2 as working electrodes, and the rest are directly mixed TiO2 paste to obtain dye titanium dioxide.The paste TiO2 and dye titanium dioxide coated onto the fluorine-doped tin oxide (FTO) glass plate by spin coating method. The absorbance spectra of the dye, dye titanium dioxide and TiO2 were obtained by UV-Vis spectroscopy. The conductivity of the dye, dye titanium dioxide, and TiO2 was measured by two point probe El-Kahfi 100. The DSSC based on dye titanium dioxide that stirring for 5 hours the highest efficiency of 0,0520 % whereas those based on TiO2 immersed for 36 hours showed achieved 0,0501 % obtained from I-V characterization.

  17. Characteristics of dye Rhoeo spathacea in dye sensitizer solar cell (DSSC)

    International Nuclear Information System (INIS)

    Sumardiasih, Sri; Obina, Wilfrida M.; Cari; Supriyanto, Agus; Septiawan, Trio Y.; Khairuddin

    2017-01-01

    Dye-sensitized solar cell (DSSC) is a device that converts solar energy into electrical energy. The magnitude of the efficiency of DSSC is mainly based on the amount of dye absorbed by the surface of TiO 2 . In this work, used natural dye extracted from leaves Rhoeo spathacea. The dye partially used to immerse of TiO 2 as working electrodes, and the rest are directly mixed TiO 2 paste to obtain dye titanium dioxide.The paste TiO 2 and dye titanium dioxide coated onto the fluorine-doped tin oxide (FTO) glass plate by spin coating method. The absorbance spectra of the dye, dye titanium dioxide and TiO 2 were obtained by UV-Vis spectroscopy. The conductivity of the dye, dye titanium dioxide, and TiO 2 was measured by two point probe El-Kahfi 100. The DSSC based on dye titanium dioxide that stirring for 5 hours the highest efficiency of 0,0520 % whereas those based on TiO 2 immersed for 36 hours showed achieved 0,0501 % obtained from I-V characterization. (paper)

  18. Improving the Performance of Gold-Nanoparticle-Doped Solid-State Dye Laser Using Thermal Conversion Effect

    Science.gov (United States)

    An, N. T. M.; Lien, N. T. H.; Hoang, N. D.; Hoa, D. Q.

    2018-04-01

    Energy transfer between spherical gold nanoparticles with size of more than 15 nm and molecules of organic dye 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4 H-pyran (DCM) has been studied. Such radiative energy transfer led to high local temperature, giving rise to a bleaching effect that resulted in rapid degradation of the laser medium. Gold nanoparticles were dispersed at concentrations from 5 × 109 particles/mL to 5 × 1010 particles/mL in DCM polymethylmethacrylate polymer using a radical polymerization process with 2,2'-azobis(isobutyronitrile) (AIBN) as initiator. Using the fast thermoelectric cooling method, the laser medium stability was significantly improved. The output stability of a distributed feedback dye laser pumped by second-harmonic generation from a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser was investigated. Moreover, bidirectional energy transfer between gold nanoparticles and dye molecules was observed.

  19. The use of ionic salt dyes as amorphous, thermally stable emitting layers in organic light-emitting diodes

    Science.gov (United States)

    Chondroudis, Konstantinos; Mitzi, David B.

    2000-01-01

    The conversion of two neutral dye molecules (D) to ionic salts (H2N-D-NH2ṡ2HX) and their utilization as emitting layers in organic light-emitting diodes (OLEDs) is described. The dye salts, AEQTṡ2HCl and APTṡ2HCl, can be deposited as amorphous films using conventional evaporation techniques. X-ray diffraction and scanning electron microscopy analysis, coupled with thermal annealing studies, demonstrate the resistance of the films to crystallization. This stability is attributed to strong ionic forces between the relatively rigid molecules. OLEDs incorporating such salts for emitting layers exhibit better thermal stability compared with devices made from the corresponding neutral dyes (H2N-D-NH2). These results suggest that ionic salts may more generally enable the formation of thermally stable, amorphous emitting, and charge transporting layers.

  20. Theoretical study of indoline dyes for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Ham, Ho Wan; Kim, Young Sik

    2010-01-01

    Indoline dye sensitizers were designed and studied theoretically to increase molar extinction coefficients in the visible to near infrared region for solar-cell devices. To gain insight into dye sensitizers' structural, electronic, and optical properties, DFT/TDDFT calculations were performed on a series of dye sensitizers derived from the D149. The good agreement between the experimental and TDDFT calculated absorption spectra of the D149 sensitizer allowed us to provide a detailed assessment of the main spectral features of a series of dye sensitizers. Increase in the conjugation length resulted in a more red-shifted spectral response and less positive oxidation potential than that of the D149. The dye with the dimethylfluorene group showed stronger absorption bands due to a large dipole moment. The calculated dipoles for the dye series correlate well with the observed strong absorption bands of the electronic spectra. These results provided useful clues for the molecular engineering of efficient organic dye sensitizers.

  1. High Excitation Transfer Efficiency from Energy Relay Dyes in Dye-Sensitized Solar Cells

    KAUST Repository

    Hardin, Brian E.

    2010-08-11

    The energy relay dye, 4-(Dicyanomethylene)-2-methyl-6-(4- dimethylaminostyryl)-4H-pyran (DCM), was used with a near-infrared sensitizing dye, TT1, to increase the overall power conversion efficiency of a dye-sensitized solar cell (DSC) from 3.5% to 4.5%. The unattached DCM dyes exhibit an average excitation transfer efficiency (EÌ?TE) of 96% inside TT1-covered, mesostructured TiO2 films. Further performance increases were limited by the solubility of DCM in an acetonitrile based electrolyte. This demonstration shows that energy relay dyes can be efficiently implemented in optimized dye-sensitized solar cells, but also highlights the need to design highly soluble energy relay dyes with high molar extinction coefficients. © 2010 American Chemical Society.

  2. Low-threshold conical microcavity dye lasers

    DEFF Research Database (Denmark)

    Grossmann, Tobias; Schleede, Simone; Hauser, Mario

    2010-01-01

    element simulations confirm that lasing occurs in whispering gallery modes which corresponds well to the measured multimode laser-emission. The effect of dye concentration on lasing threshold and lasing wavelength is investigated and can be explained using a standard dye laser model....

  3. A comparative study of carbocyanine dyes measured with TOF-SIMS and other mass spectrometric techniques

    International Nuclear Information System (INIS)

    Adriaensen, L.; Vangaever, F.; Gijbels, R.

    2004-01-01

    A series of cationic, zwitterionic and anionic carbocyanine dyes have been measured with TOF-SIMS under Ga + bombardment. In contrast to the cationic dyes, which give very intense molecular ion and characteristic fragment signals in the positive mode, the anionic dyes produce only a few fragment signals of low intensity. Even in the negative mode no molecular ions of the anionic dyes are seen in the recorded spectra. Actually, none of the studied molecules produces negative SIMS spectra containing molecular information. A comparative study was made between TOF-SIMS and other mass spectrometric techniques, namely, fast atom bombardment (FAB), electro spray ionization (ESI) and matrix assisted laser desorption ionization (MALDI). The measurements show that MALDI, ESI as well as FAB all give rise to spectra containing molecular ion signals, either in the positive, in the negative or in both modes. Unlike with TOF-SIMS, this observation also applies to the anionic dyes. Characteristic fragments of the dyes are present in all the recorded spectra. However, TOF-SIMS appears to induce more fragment ions in comparison with the other techniques. ESI, for instance, produces hardly any molecular fragments. Finally, the kind of fragment ions recorded depends upon the technique used, though some signals are produced by various techniques. For these carbocyanine dyes there is no clear correlation between the mass spectra obtained with TOF-SIMS and spectra obtained with the other techniques. This points to different desorption/ionization mechanisms, and makes it difficult, in practice, to make predictions on the feasibility of TOF-SIMS, starting from results of the other MS techniques

  4. Natural Dye-Sensitized Solar Cell Based on Nanocrystalline TiO2

    International Nuclear Information System (INIS)

    Jasim, K.E.

    2012-01-01

    During the last quarter of the twentieth century there have been intensive research activities looking for green sources of energy. The main aim of the green generators or converters of energy is to replace the conventional (fossil) energy sources, hence reducing further accumulation of the green house gasses GHGs. Conventional silicon and III-V semiconductor solar cell based on crystalline bulk, quantum well and quantum dots structure or amorphous and thin film structures provided a feasible solution. However, natural dye sensitized solar cells NDSSC are a promising class of photovoltaic cells with the capability of generating green energy at low production cost since no vacuum systems or expensive equipment are required in their fabrication. Also, natural dyes are abundant, easily extracted and safe materials. In NDSSC, once dye molecules exposed to light they become oxidized and transfer electrons to a nano structured layer of wide bandgap semiconductors such as TiO 2 . The generated electrons are drawn outside the cell through ohmic contact to a load. In this paper we review the structure and operation principles of the dye sensitized solar cell DSSC. We discuss preparation procedures, optical and electrical characterization of the NDSSC using local dyes extracted from Henna (Lawsonia inermis L.), pomegranate, cherries and Bahraini raspberries (Rubus spp.). These natural organic dyes are potential candidates to replace some of the man-made dyes used as sensitizer in many commercialized photoelectrochemical cells. Factors limiting the operation of the DSSC are discussed. NDSSCs are expected to be a favored choice in the building-integrated photovoltaic (BIPV) due to their robustness, therefore, requiring no special shielding from natural events such as tree strikes or hails. (author)

  5. Observing single molecule chemical reactions on metal nanoparticles.

    Energy Technology Data Exchange (ETDEWEB)

    Emory, S. R. (Steven R.); Ambrose, W. Patrick; Goodwin, P. M. (Peter M); Keller, Richard A.

    2001-01-01

    We report the study of the photodecomposition of single Rhodamine 6G (R6G) dye molecules adsorbed on silver nanoparticles. The nanoparticles were immobilized and spatially isolated on polylysine-derivatized glass coverslips, and confocal laser microspectroscopy was used to obtain surface-enhanced Raman scattering (SERS) spectra from individual R6G molecules. The photodecomposition of these molecules was observed with 150-ms temporal resolution. The photoproduct was identified as graphitic carbon based on the appearance of broad SERS vibrational bands at 1592 cm{sup -1} and 1340 cm{sup -1} observed in both bulk and averaged single-molecule photoproduct spectra. In contrast, when observed at the single-molecule level, the photoproduct yielded sharp SERS spectra. The inhomogeneous broadening of the bulk SERS spectra is due to a variety of photoproducts in different surface orientations and is a characteristic of ensemble-averaged measurements of disordered systems. These single-molecule studies indicate a photodecomposition pathway by which the R6G molecule desorbs from the metal surface, an excited-state photoreaction occurs, and the R6G photoproduct(s) readsorbs to the surface. A SERS spectrum is obtained when either the intact R6G or the R6G photoproduct(s) are adsorbed on a SERS-active site. This work further illustrates the power of single-molecule spectroscopy (SMS) to reveal unique behaviors of single molecules that are not discernable with bulk measurements.

  6. In-situ investigation of adsorption of dye and coadsorbates on TiO 2 films using QCM-D, fluorescence and AFM techniques

    KAUST Repository

    Harms, Hauke A.

    2013-09-11

    Simultaneous adsorption of dye molecules and coadsorbates is important for the fabrication of high-efficiency dyesensitized solar cells, but its mechanism is not well understood. Herein, we use a quartz crystal microbalance with dissipation technique (QCM-D) to study dynamically and quantitatively the sensitization of TiO2 in situ. We investigate dye loading for a ruthenium(II) polypyridyl complex (Z907), of a triphenylamine-based D-π-A dye (Y123), and of a ullazine sensitizer (JD21), as well as the simultaneous adsorption of the latter two with the coadsorbate chenodeoxycholic acid. By combining the QCM-D technique with fluorescence measurements, we quantify molar ratios between the dye and coadsorbate. Furthermore, we will present first studies using liquid-phase AFM on the adsorbed dye monolayer, thus obtaining complementary microscopic information that may lead to understanding of the adsorption mechanism on the molecular scale. © 2013 SPIE.

  7. Dye Sensitizers for Photodynamic Therapy

    Directory of Open Access Journals (Sweden)

    Harold S. Freeman

    2013-03-01

    Full Text Available Photofrin® was first approved in the 1990s as a sensitizer for use in treating cancer via photodynamic therapy (PDT. Since then a wide variety of dye sensitizers have been developed and a few have been approved for PDT treatment of skin and organ cancers and skin diseases such as acne vulgaris. Porphyrinoid derivatives and precursors have been the most successful in producing requisite singlet oxygen, with Photofrin® still remaining the most efficient sensitizer (quantum yield = 0.89 and having broad food and drug administration (FDA approval for treatment of multiple cancer types. Other porphyrinoid compounds that have received approval from US FDA and regulatory authorities in other countries include benzoporphyrin derivative monoacid ring A (BPD-MA, meta-tetra(hydroxyphenylchlorin (m-THPC, N-aspartyl chlorin e6 (NPe6, and precursors to endogenous protoporphyrin IX (PpIX: 1,5-aminolevulinic acid (ALA, methyl aminolevulinate (MAL, hexaminolevulinate (HAL. Although no non-porphyrin sensitizer has been approved for PDT applications, a small number of anthraquinone, phenothiazine, xanthene, cyanine, and curcuminoid sensitizers are under consideration and some are being evaluated in clinical trials. This review focuses on the nature of PDT, dye sensitizers that have been approved for use in PDT, and compounds that have entered or completed clinical trials as PDT sensitizers.

  8. Optimization of nanoparticle structure for improved conversion efficiency of dye solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, Norani Muti, E-mail: noranimuti-mohamed@petronas.com.my [Centre of Innovative Nanostructure and Nanodevices, Universiti Teknologi PETRONAS, Seri Iskandar, 31750 Tronoh, Perak (Malaysia); Zaine, Siti Nur Azella, E-mail: ct.azella@gmail.com.my [Fundamental and Applied Sciences Department, Universiti Teknologi PETRONAS, Seri Iskandar, 31750 Tronoh, Perak (Malaysia)

    2014-10-24

    Heavy dye loading and the ability to contain the light within the thin layer (typically ∼12 μm) are the requirement needed for the photoelectrode material in order to enhance the harvesting efficiency of dye solar cell. This can be realized by optimizing the particle size with desirable crystal structure. The paper reports the investigation on the dependency of the dye loading and light scattering on the properties of nanostructured photoelectrode materials by comparing 4 different samples of TiO{sub 2} in the form of nanoparticles and micron-sized TiO{sub 2} aggregates which composed of nanocrystallites. Their properties were evaluated by using scanning electron microscopy, X-ray diffraction and UVVis spectroscopy while the performance of the fabricated test cells were measured using universal photovoltaic test system (UPTS) under 1000 W/cm{sup 2} intensity of radiation. Nano sized particles provide large surface area which allow for greater dye adsorption but have no ability to retain the incident light in the TiO{sub 2} film. In contrast, micron-sized particles in the form of aggregates can generate light scattering allowing the travelling distance of the light to be extended and increasing the interaction between the photons and dye molecules adsorb on TiO{sub 2}nanocrystallites. This resulted in an improvement in the conversion efficiency of the aggregates that demonstrates the close relation between light scattering effect and the structure of the photolectrode film.

  9. Adsorption of dyes onto activated carbon cloth: using QSPRs as tools to approach adsorption mechanisms.

    Science.gov (United States)

    Metivier-Pignon, Hélène; Faur, Catherine; Le Cloirec, Pierre

    2007-01-01

    The present study aimed to investigate the adsorption of dyes onto activated carbon cloths. Kinetics and isotherms were studied based on results of batch reactors to constitute databases for the adsorption rates and capacities of 22 commercial dyes. Added to a qualitative analysis of experimental results, quantitative structure property relationships (QSPRs) were used to determine the structural features that influence most adsorption processes. QSPRs consisted of multiple linear regressions correlating adsorption parameters with molecular connectivity indices (MCIs) as molecular descriptors. Results related to adsorption kinetics showed that the size of molecules was the significant feature, the high order MCIs involved in QSPRs indicating the influence of a critical size on adsorption rate. Improved statistical fits were obtained when the database was divided according to the chemical classes of dyes. As regards to adsorption isotherms, their particular form led to the use of saturation capacity as the adsorption parameter. By contrast with adsorption kinetics, molecular overcrowding seemed to be of less influence on adsorption equilibrium. In this case, MCIs included in the QSPR were more related to details of the molecular structure. The robustness of the QSPR assessed for azo dyes was studied for the other dyes. Although the small size of the database limited predictive ability, features relevant to the influence of the database composition on QSPRs have been highlighted.

  10. Modification of wool protein fiber with plasma and dendrimer: Effects on dyeing with cochineal.

    Science.gov (United States)

    Sajed, Toktam; Haji, Aminoddin; Mehrizi, Mohammad Khajeh; Nasiri Boroumand, Majid

    2018-02-01

    In this study, plasma treatment and a poly(propylene imine) dendrimer were employed to improve the dyeability of wool fibers with cochineal natural dye. FESEM, EDX, AFM and FTIR techniques were employed to investigate the effects of these treatments on chemical and physical properties of wool fibers. The etching of the surface layer of wool fibers and increased roughness after plasma treatment was confirmed by FESEM and AFM images. EDX and FTIR analyses confirmed the creation of oxygen-containing groups and attachment of dendrimer molecules on wool fibers after plasma and dendrimer treatments respectively. The effects of different dyeing parameters on dye absorption and the applicability of different isotherm and kinetic models on the dyeing process were investigated. The results showed that the kinetics of absorption of cochineal on raw, plasma-treated and dendrimer-treated fibers was best fitted with the pseudo-second-order model and the isotherms of the dyeing processes followed the Freundlich model. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Evaluation on ecological stability and biodegradation of dyeing wastewater pre-treated by electron beam

    International Nuclear Information System (INIS)

    Lee, M.J.; Park, C.K.; Yoo, D.H.; Lee, J.K.; Lee, B.J.; Han, B.S.; Kim, J.K.; Kim, Y.R.

    2005-01-01

    Biological treatment of dye wastewater pre-treated by electron beam has been performed in order to evaluate the biodegradation and ecological stability of effluent. In the process of electron-beam treatment of wastewater there are utilized chemical transformations of pollutants induced by ionizing radiation. Partial decomposition of pollutant takes place as well as transformations of pollutant molecules that result in improving subsequent purification stages like as biological processing. Dyeing wastewater contains many kind of pollutants which are difficult to be decomposed completely by microorganisms. In this study, biodegradation with dyeing wastewater pre-treated by electron beams was observed. On the other hand, consideration on public acceptance in terms of ecological stability of biological effluent pre-treated by electron beams was given in this study. The results of laboratory investigations on biodegradation and ecological stability of effluent showed that biodegradation of dye wastewater pre-treated by electron beam was enhanced compared to unirradiated one. In the initial stage of biological oxidation regardless of different HRT, dye wastewater pre-treated by electron beam could be oxidized easily compare to without treated one. More number of survived daphnia magna could be observed in the biological effluent pre-treated by electron beam. This means that biological effluent pre-treated by electron beam can be said 'it is safe on the ecological system'

  12. Design of butterfly type organic dye sensitizers with double electron donors: The first principle study

    Science.gov (United States)

    Yang, Zhenqing; Shao, Di; Li, Juan; Tang, Lian; Shao, Changjin

    2018-05-01

    In this work, we designed a series of butterfly type organic dyes, named ME07-ME13 by introducing such as triphenylamine, phenothiazine, coumarin groups etc. as electron donors and further investigated their absorption spectra using density functional theory (DFT) and time-dependent DFT (TDDFT). All designed dyes cover the entire visible absorption spectrum from 300 to 800 nm. It's fascinating that ME13 molecule has two absorption peak and the molar coefficient of two absorption peaks are above 4.645 × 104 M-1·cm-1. The light absorption area of ME13 exhibits an increment of 16.5-19.1% compared to ME07-ME12. Furthermore, we performed a detailed analysis on their geometrical and electronic properties, including molecular structures, energy levels, light harvesting efficiency (LHE), driving force (ΔGinject), regeneration (ΔGregen),electron dipole moments (μnormal), intermolecular electron transfer and dye/(TiO2)38 system electron transitions. The results of calculation reveal that double coumarin donors in ME13 are promising functional groups for butterfly type organic dye sensitizers. It is expected that the design of double donors can provide a new strategy and guidance for the investigation in high efficiency dye-sensitized devices.

  13. Impact of quenching failure of Cy dyes in differential gel electrophoresis.

    Directory of Open Access Journals (Sweden)

    Weiqun Wang

    Full Text Available BACKGROUND: Differential gel electrophoresis (DIGE is a technology widely used for protein expression analysis. It is based on labelling with fluorescent Cy dyes. In comparative fluorescence gel electrophoresis experiments, however, unspecific labelling using N-hydroxy-succinimide-ester-based labelling protocols was recently detected. Cross-talk was observed due to failure of the quenching process. Here, the impact of this effect for DIGE experiments was investigated. METHODOLOGY/PRINCIPAL FINDINGS: Experiments to test quenching efficiency were performed in replicate using Escherichia coli lysate. Parameters such as the amount of dye and quencher were varied. Labelling and quenching were reversed in one experiment. Differences in protein spot volumes due to limited quenching were determined. For some spots twice the volume was detected underscoring the importance of proper control of silencing of active dye. CONCLUSIONS/SIGNIFICANCE: It could be demonstrated that uncontrolled labelling increased protein spot volume, even doubling it in some cases. Moreover, proteins responded differently to the protocol. Such unpredictable and unspecific processes are not acceptable in protein regulation studies so that it is necessary to validate the correct amount of quencher for individual samples before the DIGE experiment is performed. Increase of the concentration of lysine, which is used as quencher, from 10 mM to 2500 mM, was sufficient to silence the dye. Alternatively, active dye molecules can be removed by filtration.

  14. Molecular reorientation of dye doped nematic liquid crystals in the laser illumination

    International Nuclear Information System (INIS)

    San, S. E.; Koeysal, O.; Ecevit, F. N.

    2002-01-01

    In this study it is investigated how dye doped nematic liquid crystals reorient under the illumination of laser beam whose wavelength is appropriate to absorbance characteristics of the doping dye. Nematic liquid crystal E7 is used with anthraquinone dye 1% wt/wt in the preparation of the sample and this material is filled in homegenously aligned measurement cell having 15 μm thickness. Mechanism of molecular reorientation includes the absorbance effects of the energy of laser by doping dye and this reorientation causes the refractive index of the material to be changed. There are potential application possibilities of such molecular reorientation based effects in nonlinear optics such as real time holography whose basis is grating diffraction that is observed and investigated in the frame of fundamentals of molecule light interaction mechanisms. Experimental analyses allowed finding characteristic values of diffraction signals depending on physical parameters of set up for a dye doped liquid crystal system and this system provided a 20 % diffraction efficiency under the optimum circumstances

  15. Investigation of processes of interaction relativistic electrons with the solutions of organic dyes

    International Nuclear Information System (INIS)

    Buki, A.Yu.; Gokov, S.P.; Kazarinov, Yu.G.; Kalenik, S.A.; Kasilov, V.I.; Kochetov, S.S.; Makhnenko, P.L.; Mel'nitskiy, I.V.; Tverdohvalov, A.V.; Tsyatsko, V.V.; Shopen, O.A.

    2014-01-01

    Investigation of the processes of interaction of ionizing radiation with complex organic objects can solve a number of fundamental and applied problems in radiation physics, chemistry and biology. In this work we investigated the dose dependence (dose range 1...5MRad) optical density relative concentrations of water, alcohol and glycerine solution following organic dyes: methylene blue - C 16 H 18 N 3 SCl and methyl orange - C 14 H 14 N 3 O 3 SNa, irradiated with an electron beam with an energy of 16MeV. In the analysis of absorption spectra, it was found that water solutions of dyes have less resistance to radiation as compared with the alcohol and glycerol. Also, all solutions of methyl orange less radiation resistant than the methylene blue solution. Analysis of the spectra showed that these relationships are close to linear in the range of doses. To understand the physical and chemical processes occurring in the interaction of relativistic electrons with the studied organic objects were performed the computer simulations of the energy spectra of ions formed due to breaking the chemical bonds of molecules of dye solutions using the program SRIM-2010. The analysis showed that radiation - stimulated chemical processes play a major role in the destruction of the source of organic dye molecules. The remaining processes (interaction of electrons and nuclei, the cascade processes) accounts for about 10% of all molecular breaks.

  16. Variations in thermo-optical properties of neutral red dye with laser ablated gold nanoparticles

    Science.gov (United States)

    Prakash, Anitha; Pathrose, Bini P.; Mathew, S.; Nampoori, V. P. N.; Radhakrishnan, P.; Mujeeb, A.

    2018-05-01

    We have investigated the thermal and optical properties of neutral red dye incorporated with different weight percentage of gold nanoparticles prepared by laser ablation method. Optical absorption studies confirmed the production of spherical nanoparticles and also the interactions of the dye molecules with gold nanoparticles. The quenching of fluorescence and the reduction in the lifetime of gold incorporated samples were observed and was due to the non-radiative energy transfer between the dye molecules and gold nanoparticles. Dual beam thermal lens technique has been employed to measure the heat diffusion in neutral red with various weight percentage of gold nano sol dispersed in ethanol. The significant outcome of the experiment is that, the overall heat diffusion is slower in the presence of gold nano sol compared to that of dye alone sample. Brownian motion is suggested to be the main mechanism of heat transfer under the present conditions. The thermal diffusivity variations of samples with respect to different excitation power of laser were also studied.

  17. Coulombic interactions on the deposition and rotational mobility distributions of dyes in polyelectrolyte multilayer thin films.

    Science.gov (United States)

    Li, Ye; Yip, Wai Tak

    2004-12-07

    We employed negatively charged fluorescein (FL), positively charged rhodamine 6G (R6G), and neutral Nile Red (NR) as molecular probes to investigate the influence of Coulombic interaction on their deposition into and rotational mobility inside polyelectrolyte multilayer (PEM) films. The entrapment efficiency of the dyes reveals that while Coulombic repulsion has little effect on dye deposition, Coulombic attraction can dramatically enhance the loading efficiency of dyes into a PEM film. By monitoring the emission polarization of single dye molecules in polyethylenimine (PEI) films, the percentages of mobile R6G, NR, and FL were determined to be 87 +/- 4%, 76 +/- 5%, and 68 +/- 3%, respectively. These mobility distributions suggest that cationic R6G enjoys the highest degree of rotational freedom, whereas anionic FL shows the least mobility because of Coulombic attraction toward cationic PEI. Regardless of charges, this high percentage of mobile molecules is in stark contrast to the 5-40% probe mobility reported from spun-cast polymer films, indicating that our PEI films contain more free volume and display richer polymer dynamics. These observations demonstrate the potential of using isolated fluorescent probes to interrogate the internal structure of a PEM film at a microscopic level.

  18. Tunability of optofluidic distributed feedback dye lasers

    DEFF Research Database (Denmark)

    Gersborg-Hansen, Morten; Kristensen, Anders

    2007-01-01

    We investigate the tunability of optofluidic distributed feedback (DFB) dye lasers. The lasers rely on light-confinement in a nano-structured polymer film where an array of nanofluidic channels constitutes a third order Bragg grating DFB laser resonator with a central phase-shift. The lasers...... are operated by filling the DFB laser resonator with a dye solution by capillary action and optical pumping with a frequency doubled Nd: YAG laser. The low reflection order of the DFB laser resonator yields low out-of-plane scattering losses as well as a large free spectral range (FSR), and low threshold...... fluences down to similar to 7 mu J/mm2 are observed. The large FSR facilitates wavelength tuning over the full gain spectrum of the chosen laser dye and we demonstrate 45 nm tunability using a single laser dye by changing the grating period and dye solution refractive index. The lasers are straight...

  19. Modification on C217 by auxiliary acceptor toward efficient sensitiser for dye-sensitised solar cells: a theoretical study

    Science.gov (United States)

    Zhao, Caibin; Jin, Lingxia; Ge, Hongguang; Guo, Xiaohua; Zhang, Qiang; Wang, Wenliang

    2018-02-01

    In this work, to develop efficient organic dye sensitisers, a series of novel donor-acceptor-π-acceptor metal-free dyes were designed based on the C217 dye by means of modifying different auxiliary acceptors, and their photovoltaic performances were theoretically investigated with systematic density functional theory calculations coupled with the incoherent charge-hopping model. Results showed that the designed dyes possess lower highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels as well as narrower HOMO-LUMO gaps compared to C217, which indicate their higher light-harvesting efficiency. In addition, using the (TiO2)38 cluster and bidentate bridging model, we predicted that the photoelectric conversion efficiency (PCE) for the C217 dye is as high as 9.92% under air mass (AM) 1.5 illumination (100 mW.cm-2), which is in good agreement with its experimental value (9.60%-9.90%). More interestingly, the cell sensitised by the dye 7 designed in this work exhibits a middle-sized open-circuit voltage of 0.737 V, large short-circuit photocurrent density of 21.16 mAˑcm-2 and a fill factor of 0.801, corresponding to a quite high PCE of 12.49%, denoting the dye 7 is a more promising sensitiser candidate than the C217, and is worth further experimental study.

  20. Uptake of Retinoic Acid-Modified PMMA Nanoparticles in LX-2 and Liver Tissue by Raman Imaging and Intravital Microscopy.

    Science.gov (United States)

    Yildirim, Turgay; Matthäus, Christian; Press, Adrian T; Schubert, Stephanie; Bauer, Michael; Popp, Jürgen; Schubert, Ulrich S

    2017-10-01

    A primary amino-functionalized methyl methacrylate-based statistical copolymer is covalently coupled with retinoic acid (RA) and a fluorescent dye (DY590) in order to investigate the feasibility of the RA containing polymeric nanoparticles for Raman imaging studies and to study the possible selectivity of RA for hepatic stellate cells via intravital microscopy. Cationic nanoparticles are prepared by utilizing the nanoprecipitation method using modified polymers. Raman studies show that RA functional nanoparticles can be detectable in all tested cells without any need of additional label. Moreover, intravital microscopy indicates that DY590 is eliminated through the hepatobiliary route but not if used as covalently attached tracing molecule for nanoparticles. However, it is a suitable probe for sensitive detection of polymeric nanoparticles. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.