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Sample records for dye chemistry

  1. The Chemistry of Plant and Animal Dyes.

    ERIC Educational Resources Information Center

    Sequin-Frey, Margareta

    1981-01-01

    Provides a brief history of natural dyes. Chemical formulas are provided for flavonoids, luteolin, genistein, brazilin, tannins, terpenes, naphthoquinone, anthraquinone, and dyes with an alkaloid structure. Also discusses chemical background of different dye processes. (CS)

  2. The Chemistry of Vat Dyes. Palette of Color Monograph Series.

    ERIC Educational Resources Information Center

    Epp, Dianne N.

    From prehistoric times people have been fascinated with color; from cave paintings to the latest computers, color has been a constant companion. Textiles are made more beautiful by the alteration or application of colorants. This teaching resource investigates vat dyes, a colorant class which includes the oldest dyes known as well as important…

  3. The Chemistry of Natural Dyes. Palette of Color Monograph Series.

    ERIC Educational Resources Information Center

    Epp, Dianne N.

    From prehistoric times people have been fascinated with color; from cave paintings to the latest computers, color has been a constant companion. Textiles and craft items are made more beautiful by the alteration or application of colorants. This teaching resource investigates dyes obtained from natural sources, such as plants and animals. These…

  4. Linear Dichroism of Cyanine Dyes in Stretched Polyvinyl Alcohol Films: A Physical Chemistry Laboratory Experiment.

    ERIC Educational Resources Information Center

    Natarajan, L. V.; And Others

    1983-01-01

    Provides background information, procedures, and results of an undergraduate physical chemistry experiment on the polarization of absorption spectra of cyanine dyes in stretched polyvinyl alcohol films. The experiment gives a simple demonstration of the concept of linear dichromism and the validity of the TEM method used in the analyses. (JN)

  5. Role of the surface chemistry of activated carbons in dye removal from aqueous solution

    NASA Astrophysics Data System (ADS)

    Zhou, Hua-lei; Zhen, Wen-juan; Zhu, Qian; Wu, Xiao-bin; Chang, Zhi-dong; Li, Wen-jun

    2015-07-01

    Commercial activated carbons were modified by a series of chemical or physical treatments using H2O2, NH3, and heating under N2 flow without notably changing their pore structures. The resultant carbons were characterized by N2 adsorption and Bohem titration and then used to remove Ponceau 4R, methyl orange and brilliant blue from aqueous solutions. Surface chemistry was found to play a significantly different role in removing these three compounds. The removal of anionic Ponceau 4R increases with increasing carbon surface basicity due to the predominant dispersive interaction mechanism. In contrast, surface chemistry has little effect on the removal of anionic methyl orange, which can be explained by two parallel mechanisms involving electrostatic and dispersive interactions due to the basic amine group in a dye molecule. The influence of surface chemistry on the removal of amphoteric brilliant blue dye can also be ignored due to a weak interaction between the carbons and dye molecules, which is resulted from strong cohesive energy from electrostatic forces inside amphoteric dye molecules.

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

    PubMed Central

    2014-01-01

    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. PMID:24501431

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

    PubMed

    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.

  8. Applying Statistics in the Undergraduate Chemistry Laboratory: Experiments with Food Dyes

    NASA Astrophysics Data System (ADS)

    Thomasson, Kathryn A.; Lofthus-Herschman, Sheila; Humbert, Michelle; Kulevsky, Norman

    1998-02-01

    Simple experiments have been developed using visible spectroscopy to introduce students to statistical analysis of data. Students in chemistry often gain their first substantial experience with statistics in undergraduate chemistry laboratories (Quantitative Analysis and Physical Chemistry). Simple experiments using Beer's Law of absorption spectroscopy help introduce students to applying statistics. We have chosen two food coloring dyes found in many household items: FD and C Red #40 and FD and C Blue #1. To learn to evaluate their data, the students determine the concentration of a solution at a variety of confidence limits, and treat their data for suspicious values using the Q-test. Other experiments can be done to learn the concept of pooled variance. For example, students compare solutions they make themselves to determine if they are the same to what confidence level. Furthermore, Beer's Law can be used to teach linear least squares fitting by using a serial dilution of a colored compound and measuring absorbance for each concentration. Finally, by using common household substances and a simple analysis technique, students find that statistics can be considerably less threatening, and in some cases even fun.

  9. A ``plasmonic cuvette'': dye chemistry coupled to plasmonic interferometry for glucose sensing

    NASA Astrophysics Data System (ADS)

    Siu, Vince S.; Feng, Jing; Flanigan, Patrick W.; Palmore, G. Tayhas R.; Pacifici, Domenico

    2014-06-01

    A non-invasive method for the detection of glucose is sought by millions of diabetic patients to improve personal management of blood glucose over a lifetime. In this work, the synergistic advantage of combining plasmonic interferometry with an enzyme-driven dye assay yields an optical sensor capable of detecting glucose in saliva with high sensitivity and selectivity. The sensor, coined a "plasmonic cuvette," is built around a nano-scale groove-slit-groove (GSG) plasmonic interferometer coupled to an Amplex-red/Glucose-oxidase/Glucose (AR/GOx/Glucose) assay. The proposed device is highly sensitive, with a measured intensity change of 1.7×105%/m (i.e., one order of magnitude more sensitive than without assay) and highly specific for glucose sensing in picoliter volumes, across the physiological range of glucose concentrations found in human saliva (20-240 μm). Real-time glucose monitoring in saliva is achieved by performing a detailed study of the underlying enzyme-driven reactions to determine and tune the effective rate constants in order to reduce the overall assay reaction time to ˜2 min. The results reported suggest that by opportunely choosing the appropriate dye chemistry, a plasmonic cuvette can be turned into a general, real-time sensing scheme for detection of any molecular target, with high sensitivity and selectivity, within extremely low volumes of biological fluid (down to femtoliters). Hereby, we present the results on glucose detection in artificial saliva as a notable and clinically relevant case study.

  10. Extraction and Quantitation of FD&C Red Dye #40 from Beverages Containing Cranberry Juice: A College-Level Analytical Chemistry Experiment

    ERIC Educational Resources Information Center

    Rossi, Henry F., III; Rizzo, Jacqueline; Zimmerman, Devon C.; Usher, Karyn M.

    2012-01-01

    A chemical separation experiment can be an interesting addition to an introductory analytical chemistry laboratory course. We have developed an experiment to extract FD&C Red Dye #40 from beverages containing cranberry juice. After extraction, the dye is quantified using colorimetry. The experiment gives students hands-on experience in using solid…

  11. Adsorption of a Textile Dye on Commercial Activated Carbon: A Simple Experiment to Explore the Role of Surface Chemistry and Ionic Strength

    ERIC Educational Resources Information Center

    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. Ground and excited state chemistry of some hydrophilic thiazine dyes for possible photogalvanic applications

    SciTech Connect

    Burton, W.C.

    1982-08-01

    The research was designed to study the ground and excited state properties of hydrophilic analogues of the thiazine dye, thionine. The analogues were prepared by substituting ..beta..-hydroxyethyl or N-methylpiperazine groups onto the thiazine chromophore. Positive charges were introduced into the analogues containing the N-methylpiperazine groups by methylation of the N-methyl nitrogen atom of the piperazine ring. After purification and characterization of the analogues, ground state properties such as water solubility and aggregation were studied. Excited state studies involved determination of triplet state lifetimes (tau), and triplet state rate constants for, self quenching, (k/sub SQ/), ferrous quenching (k/sub Q/), and bromide and iodide (k/sub Br/ and K/sub I/) quenching. Oxidation and decay of the photoproducts, semireduced dyes and leuco dyes, was also studied.

  13. Cycloruthenated sensitizers: improving the dye-sensitized solar cell with classical inorganic chemistry principles.

    PubMed

    Robson, Kiyoshi C D; Bomben, Paolo G; Berlinguette, Curtis P

    2012-07-14

    A divergence from the conventional approach to chromophore design has led to the establishment of many exciting new benchmarks for the dye-sensitized solar cell (DSSC), including the first documented power conversion efficiency in excess of 12% at 1 sun illumination [Yella et al., Science 2011, 334, 629]. Paramount to these advances is the deviation from polypyridyl ruthenium dyes bearing NCS(-) ligands, such as [Ru(dcbpy)(2)(NCS)(2)] (N3; dcbpy = 4,4'-dicarboxy-2,2'-bipyridine). While metal-free and porphyrin dyes have demonstrated much promise, the discovery that the NCS(-) ligands of N3 can be replaced by anionic, chelating cyclometalating ligands without compromising device efficiencies has ushered in a new era of ruthenium dye development. A particularly appealing feature of this class of dyestuff is that they offer acute control of the frontier molecular orbitals to enable the precise attenuation of both the ground and excited state redox potentials through judicious chemical modification of the aryl ring. This Perspective summarizes very recent developments in the field, and demonstrates how the new and rapidly expanding class of Ru-based sensitizers provides a conduit for enhancing the performance (and potentially the stability) of the DSSC.

  14. Accuracy of color prediction of anthraquinone dyes in methanol solution estimated from first principle quantum chemistry computations.

    PubMed

    Cysewski, Piotr; Jeliński, Tomasz

    2013-10-01

    The electronic spectrum of four different anthraquinones (1,2-dihydroxyanthraquinone, 1-aminoanthraquinone, 2-aminoanthraquinone and 1-amino-2-methylanthraquinone) in methanol solution was measured and used as reference data for theoretical color prediction. The visible part of the spectrum was modeled according to TD-DFT framework with a broad range of DFT functionals. The convoluted theoretical spectra were validated against experimental data by a direct color comparison in terms of CIE XYZ and CIE Lab tristimulus model color. It was found, that the 6-31G** basis set provides the most accurate color prediction and there is no need to extend the basis set since it does not improve the prediction of color. Although different functionals were found to give the most accurate color prediction for different anthraquinones, it is possible to apply the same DFT approach for the whole set of analyzed dyes. Especially three functionals seem to be valuable, namely mPW1LYP, B1LYP and PBE0 due to very similar spectra predictions. The major source of discrepancies between theoretical and experimental spectra comes from L values, representing the lightness, and the a parameter, depicting the position on green→magenta axis. Fortunately, the agreement between computed and observed blue→yellow axis (parameter b) is very precise in the case of studied anthraquinone dyes in methanol solution. Despite discussed shortcomings, color prediction from first principle quantum chemistry computations can lead to quite satisfactory results, expressed in terms of color space parameters.

  15. Sawdust Derivative for Environmental Application: Chemistry, Functionalization and Removal of textile dye from aqueous solution.

    PubMed

    Pinto, Thais F; Bezerra, Cícero W B; Silva, Domingos S A; Silva, Edson C DA; Vieira, Adriana P; Airoldi, Claudio; Melo, Júlio C P DE; Silva, Hildo A S; Santana, Sirlane A A

    2016-09-01

    The adsorption of Violet Remazol 5R (VR 5) on wood sawdust modified with succinic anhydride (SSA) as a function of contact time, pH, and initial dye concentrations was investigated using a batch technique under ambient conditions. The SSA obtained was confirmed by IR spectroscopy, thermogravimetry and 13C NMR, and degrees of substitution (DS) were calculated. A study on the effect of the pH on the adsorption of VR 5 showed that the optimum pH was 2.0. The interactions were assayed with respect to the pseudo-first-order and pseudo-second-order kinetic models, and were found to follow closely the pseudo-second-order. The isotherm was adjusted to the Langmuir, the Freundlich and the Temkin sorption models. SSA is a promising material for the removal of dye textile from aqueous solutions, and under conditions studied the removal percentage achieved was 51.7%.

  16. Precolumbian Chemistry.

    ERIC Educational Resources Information Center

    Robinson, Janet Bond

    1995-01-01

    Describes the content and development of a curriculum that provides an approach to descriptive chemistry and the history of technology through consideration of the pottery, metallurgy, pigments, dyes, agriculture, and medicine of pre-Columbian people. (DDR)

  17. The Chemistry of Formazan Dyes: Synthesis and Characterization of a Stable Verdazyl Radical and a Related Boron-Containing Heterocycle

    ERIC Educational Resources Information Center

    Berry, David E.; Hicks, Robin G.; Gilroy, Joe B.

    2009-01-01

    This experiment describes the synthesis and characterization of a formazan dye, and its subsequent conversion to a stable verdazyl radical and a boron-nitrogen heterocycle (boratatetrazine). Each of these compounds is intensely colored and is prepared and handled under aerobic conditions, which often surprises students as free radicals are…

  18. Application of Near‐IR Absorption Porphyrin Dyes Derived from Click Chemistry as Third‐Order Nonlinear Optical Materials

    PubMed Central

    Mi, Yongsheng; Liang, Pengxia; Cao, Hui; He, Wanli

    2015-01-01

    Abstract Recently, third‐order nonlinear properties of porphyrins and porphyrin polymers and coordination compounds have been extensively studied in relation to their use in photomedicine and molecular photonics. A new functionalized porphyrin dye containing electron‐rich alkynes was synthesized and further modified by formal [2+2] click reactions with click reagents tetracyanoethylene (TCNE) and 7, 7, 8, 8‐tetracyanoquinodimethane (TCNQ). The photophysical properties of these porphyrin dyes, as well as the click reaction, were studied by UV/Vis spectroscopy. In particular, third‐order nonlinear optical properties of the dyes, which showed typical d‐π‐A structures, were characterized by Z‐scan techniques. In addition, the self‐assembly properties were investigated through the phase‐exchange method, and highly organized morphologies were observed by scanning electron microscopy (SEM). The effects of the click post‐functionalization on the properties of the porphyrins were studied, and these functionalized porphyrin dyes represent an interesting set of candidates for optoelectronic device components. PMID:27308215

  19. A review of the chemistry and uses of crocins and crocetin, the carotenoid natural dyes in saffron, with particular emphasis on applications as colorants including their use as biological stains.

    PubMed

    Bathaie, S Z; Farajzade, A; Hoshyar, R

    2014-08-01

    The perennial flowering plant, saffron crocus (Crocus sativus L.), is the source of the most expensive spice in the world. The dried stigmas of saffron flowers are the source of a natural dye, saffron, which has been used from ancient times for dyeing silk and fabric rugs, and for painting; it also has been used for cooking and in medicine. The yellow compounds present in the dye include crocins, which are 20-carbon water soluble glycosyl derivatives of the carotenoid, crocetin, and the dicarboxylic acid itself. We review the chemistry of these compounds and discuss various applications of saffron as a natural dye. We review in particular the use of saffron or its constituents in histopathologic techniques.

  20. Interfacing click chemistry with automated oligonucleotide synthesis for the preparation of fluorescent DNA probes containing internal xanthene and cyanine dyes.

    PubMed

    Astakhova, I Kira; Wengel, Jesper

    2013-01-14

    Double-labeled oligonucleotide probes containing fluorophores interacting by energy-transfer mechanisms are essential for modern bioanalysis, molecular diagnostics, and in vivo imaging techniques. Although bright xanthene and cyanine dyes are gaining increased prominence within these fields, little attention has thus far been paid to probes containing these dyes internally attached, a fact which is mainly due to the quite challenging synthesis of such oligonucleotide probes. Herein, by using 2'-O-propargyl uridine phosphoramidite and a series of xanthenes and cyanine azide derivatives, we have for the first time performed solid-phase copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) click labeling during the automated phosphoramidite oligonucleotide synthesis followed by postsynthetic click reactions in solution. We demonstrate that our novel strategy is rapid and efficient for the preparation of novel oligonucleotide probes containing internally positioned xanthene and cyanine dye pairs and thus represents a significant step forward for the preparation of advanced fluorescent oligonucleotide probes. Furthermore, we demonstrate that the novel xanthene and cyanine labeled probes display unusual and very promising photophysical properties resulting from energy-transfer interactions between the fluorophores controlled by nucleic acid assembly. Potential benefits of using these novel fluorescent probes within, for example, molecular diagnostics and fluorescence microscopy include: Considerable Stokes shifts (40-110 nm), quenched fluorescence of single-stranded probes accompanied by up to 7.7-fold light-up effect of emission upon target DNA/RNA binding, remarkable sensitivity to single-nucleotide mismatches, generally high fluorescence brightness values (FB up to 26), and hence low limit of target detection values (LOD down to <5 nM).

  1. Effect of Dye and Conjugation Chemistry on the Biodistribution Profile of Near-Infrared-Labeled Nanobodies as Tracers for Image-Guided Surgery.

    PubMed

    Debie, Pieterjan; Van Quathem, Jannah; Hansen, Inge; Bala, Gezim; Massa, Sam; Devoogdt, Nick; Xavier, Catarina; Hernot, Sophie

    2017-03-09

    Advances in optical imaging technologies have stimulated the development of near-infrared (NIR) fluorescently labeled targeted probes for use in image-guided surgery. As nanobodies have already proven to be excellent candidates for molecular imaging, we aimed in this project to design NIR-conjugated nanobodies targeting the tumor biomarker HER2 for future applications in this field and to evaluate the effect of dye and dye conjugation chemistry on their pharmacokinetics during development. IRDye800CW or IRdye680RD were conjugated either randomly (via lysines) or site-specifically (via C-terminal cysteine) to the anti-HER2 nanobody 2Rs15d. After verification of purity and functionality, the biodistribution and tumor targeting of the NIR-nanobodies were assessed in HER2-positive and -negative xenografted mice. Site-specifically IRDye800CW- and IRdye680RD-labeled 2Rs15d as well as randomly labeled 2Rs15d-IRDye680RD showed rapid tumor accumulation and low nonspecific uptake, resulting in high tumor-to-muscle ratios at early time points (respectively 6.6 ± 1.0, 3.4 ± 1.6, and 3.5 ± 0.9 for HER2-postive tumors at 3 h p.i., while <1.0 for HER2-negative tumors at 3 h p.i., p < 0.05). Contrarily, using the randomly labeled 2Rs15d-IRDye800CW, HER2-positive and -negative tumors could only be distinguished after 24 h due to high nonspecific signals. Moreover, both randomly labeled 2Rs15d nanobodies were not only cleared via the kidneys but also partially via the hepatobiliary route. In conclusion, near-infrared fluorescent labeling of nanobodies allows rapid, specific, and high contrast in vivo tumor imaging. Nevertheless, the fluorescent dye as well as the chosen conjugation strategy can affect the nanobodies' properties and consequently have a major impact on their pharmacokinetics.

  2. Products of Photodegradation for Coumarin Laser Dyes.

    DTIC Science & Technology

    1983-10-31

    WORDS (CM0110m.em ote. Side U m....*0 mid 140蔾OF WeeMok mINIINI) C.~. coumarin laser dyes ,.laser dye photodegradation , dye photolysis mechanisms...oŕ PRODUCTS OF PHOTODEGRADATION FOR COUMI3N LASER DYES Guil ord Jones, I ,* W. R. Berguark, and W. R. Jacokson Department of Chemistry...documented.’ The products of photodegradation for a single coumarin dye have been identified in the early report of Winters. Handel- berg, and Mohr

  3. Fluorescent porous film modified polymer optical fiber via "click" chemistry: stable dye dispersion and trace explosive detection.

    PubMed

    Ma, Jiajun; Lv, Ling; Zou, Gang; Zhang, Qijin

    2015-01-14

    In this paper, we report a facile strategy to fabricate fluorescent porous thin film on the surface of U-bent poly(methyl methacrylate) optical fiber (U-bent POF) in situ via "click" polymerization for vapor phase sensing of explosives. Upon irradiation of evanescent UV light transmitting within the fiber under ambient condition, a porous film (POSS-thiol cross-linking film, PTCF) is synthesized on the side surface of the fiber by a thiol-ene "click" reaction of vinyl-functionalized polyhedral oligomeric silsesquioxanes (POSS-V8) and alkane dithiols. When vinyl-functionalized porphyrin, containing four allyl substituents at the periphery, is added into precursors for the polymerization, fluorescence porphyrin can be covalently bonded into the cross-linked network of PTCF. This "fastened" way reduces the aggregation-induced fluorescence self-quenching of porphyrin and enhances the physicochemical stability of the porous film on the surface of U-bent POF. Fluorescent signals of the PTCF/U-bent POF probe made by this method exhibit high fluorescence quenching toward trace TNT and DNT vapor and the highest fluorescence quenching efficiency is observed for 1, 6-hexanedimercaptan-based film. In addition, because of the presence of POSS-V8 with multi cross-linkable groups, PTCF exhibits well-organized pore network and stable dye dispersion, which not only causes fast and sensitive fluorescence quenching against vapors of nitroaromatic compounds, but also provides a repeatability of the probing performance.

  4. Aqueous dispersible graphene/Pt nanohybrids by green chemistry: application as cathodes for dye-sensitized solar cells.

    PubMed

    Kim, Young-Gon; Akbar, Zico Alaia; Kim, Dong Young; Jo, Seong Mu; Jang, Sung-Yeon

    2013-03-01

    Aqueous dispersible nanohybrids (NHBs) of graphene nanosheets (GNSs) and Pt nanoparticles (Pt-NPs) were synthesized through the one-pot reduction of their precursors using an environmentally benign chemical, vitamin C. The concurrent reduction of the precursors, which includes graphene oxide (GO) to GNS and H2PtCl6 to Pt(0), was facile and efficient to yield GNS/Pt-NHBs in which face-centered cubic (fcc) crystalline Pt-NPs with average diameters of ~5 nm were robustly attached on the surface of the GNSs. The conversion yield during Pt reduction was fairly high (∼90%) and the Pt content within the NHBs was easily controllable. The resulting stable aqueous colloidal dispersion of GNS/Pt-NHBs was successfully fabricated as thin films without using any binder by the electro-spray method at room temperature, and the fabricated samples were used as counter electrodes (CEs) for dye-sensitized solar cells (DSSCs). The electrocatalytic activity of the NHBs for I(-)/I3(-) redox couples in conventional DSSCs was investigated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analysis. Doping of GNSs with small amounts of Pt-NPs (<10 wt %) could dramatically enhance the redox kinetics. The enhanced electrocatalytic activity of the GNS/Pt-NHBs was reflected in the performance of the DSSCs. The power conversion efficiency of optimized DSSCs using the NHB-CEs was 8.91% (VOC: 830 mV, JSC: 15.56 mAcm(-2), and FF: 69%), which is comparable to that of devices using the state-of-the-art Pt-based CEs (8.85%).

  5. Green chemistry methods in sulfur dyeing: application of various reducing D-sugars and analysis of the importance of optimum redox potential.

    PubMed

    Blackburn, Richard S; Harvey, Anna

    2004-07-15

    The importance of sulfur dyeing of cellulosic fibers, particularly cotton, is realized economically throughout the dyeing industry. At the present time, dyeing with sulfur dyes requires the use of various auxiliaries, many of which have adverse effects on the environment. The most damaging of these is the reducing agent sodium sulfide, required to reduce the dye molecules to a water-soluble leuco form to enable adsorption and diffusion into the fiber. In this study, attempts have been made to replace the sodium sulfide used within the sulfur dyeing process with a variety of environmentally friendly reducing sugars. The redox potential of various hexose and pentose monosaccharides and reducing disaccharides was recorded and compared. Subsequently, cotton was dyed with the world's most important sulfur dye, C. I. Sulfur Black 1, using the reducing sugars under alkaline conditions, and compared to dyeings secured by employing commercial sulfide reducing agents. It was observed that reducing sugars gave comparable, and in many cases superior, color strength and wash fastness results, with respect to the commercial sulfide-based reducing agents, which still account for the vast majority of sulfur dyeing processes and that pose significant environmental concern. Employment of reducing sugars in sulfur dyeing could provide a sustainable, nontoxic, biodegradable, cost-effective alternative to sodium polysulfide and sodium hydrogen sulfide. Comparison of the redox potential of reducing sugars against the color strength of the dyeings secured demonstrated that there was an optimum redox potential of around -650 mV for maximum color strength achieved. The same redox potential also conferred the lowest color loss upon washing. These observations were attributed to reduction of the polymeric dye molecules to an optimum size for fiber affinity and diffusion into the fiber, but which would also confer maximum wash fastness upon oxidation.

  6. The importance of dye chemistry and TiCl4 surface treatment in the behavior of Al2O3 recombination barrier layers deposited by atomic layer deposition in solid-state dye-sensitized solar cells.

    PubMed

    Brennan, Thomas P; Bakke, Jonathan R; Ding, I-Kang; Hardin, Brian E; Nguyen, William H; Mondal, Rajib; Bailie, Colin D; Margulis, George Y; Hoke, Eric T; Sellinger, Alan; McGehee, Michael D; Bent, Stacey F

    2012-09-21

    Atomic layer deposition (ALD) was used to fabricate Al(2)O(3) recombination barriers in solid-state dye-sensitized solar cells (ss-DSSCs) employing an organic hole transport material (HTM) for the first time. Al(2)O(3) recombination barriers of varying thickness were incorporated into efficient ss-DSSCs utilizing the Z907 dye adsorbed onto a 2 μm-thick nanoporous TiO(2) active layer and the HTM spiro-OMeTAD. The impact of Al(2)O(3) barriers was also studied in devices employing different dyes, with increased active layer thicknesses, and with substrates that did not undergo the TiCl(4) surface treatment. In all instances, electron lifetimes (as determined by transient photovoltage measurements) increased and dark current was suppressed after Al(2)O(3) deposition. However, only when the TiCl(4) treatment was eliminated did device efficiency increase; in all other instances efficiency decreased due to a drop in short-circuit current. These results are attributed in the former case to the similar effects of Al(2)O(3) ALD and the TiCl(4) surface treatment whereas the insulating properties of Al(2)O(3) hinder charge injection and lead to current loss in TiCl(4)-treated devices. The impact of Al(2)O(3) barrier layers was unaffected by doubling the active layer thickness or using an alternative ruthenium dye, but a metal-free donor-π-acceptor dye exhibited a much smaller decrease in current due to its higher excited state energy. We develop a model employing prior research on Al(2)O(3) growth and dye kinetics that successfully predicts the reduction in device current as a function of ALD cycles and is extendable to different dye-barrier systems.

  7. Dye Painting!

    ERIC Educational Resources Information Center

    Johnston, Ann

    This resource provides practical instructions for applying color and design directly to fabric. Basic information about the dye painting process is given. The guide addresses the technical aspects of fabric dye and color use and offers suggestions for fabric manipulation and dye application in order to achieve various design effects. This…

  8. Enhanced adsorption of the cationic dyes in the spherical CuO/meso-silica nano composite and impact of solution chemistry.

    PubMed

    Liang, Zhijie; Zhao, Zhiwei; Sun, Tianyi; Shi, Wenxin; Cui, Fuyi

    2017-01-01

    In this study, the spherical mesoporous silica (meso-silica MCM-41) and that inorganically modified with CuO (CuO/MCM-41 nano composite) were synthesized and characterized. It was demonstrated that CuO were successfully loaded in the synthesized nano composite CuO/MCM-41. Importantly, the loaded CuO had a significant enhancement effect on the adsorption of Crystal violet and Methylene blue. Adsorption kinetic of the tested cationic dyes in the synthesized materials fitted the pseudo-second-order kinetic model and Weber's intra-particle diffusion model well. According to the Langmuir isotherm model, the maximum adsorption capacities (Qmax) of the CuO/MCM-41 towards Crystal violet and Methylene blue increased to 52.9 and 87.8mg/g, while those of the pure MCM-41 were 46.2 and 65.7mg/g, respectively. Due to the surface charge of CuO and the protonation of the dye molecules, the electrostatic forces between the loaded CuO and the organic cationic dyes contributed to the enhancement effect. Additionally, the presented results indicated that the adsorption of the cationic dyes in the CuO/MCM-41 depended on pH and ion strength of the solution but insignificantly on the coexisted humic acid due to the mesoporous character of CuO/MCM-41 nano composite.

  9. Chemistry for Artists and Art Buffs.

    ERIC Educational Resources Information Center

    Denio, Allen A.

    1979-01-01

    This course provides an attractive introduction to chemistry for a group of students who would normally avoid traditional chemistry courses. Topics include color, pigments, metals, ceramics, glass, paints, plastics, fibers, and dyes. (BB)

  10. Investigation of the azo-hydrazone tautomeric equilibrium in an azo dye involving the naphthalene moiety by UV-vis spectroscopy and quantum chemistry

    NASA Astrophysics Data System (ADS)

    Ünal, Arslan; Eren, Bilge; Eren, Erdal

    2013-10-01

    Photophysical properties of the azo-hydrazone tautomerism of Eriochrome Blue Black B (1-(1-hydroxy-2-naphthylazo)-2-naphthol-4-sulphonic acid) in DMF, MeCN and water were investigated using UV-visible spectroscopy and quantum chemical calculations. The optimized molecular structure parameters, relative energies, mole fractions, electronic absorption spectra and HOMO-LUMO energies for possible stable tautomeric forms of EBB were theoretically calculated by using hybrid density functional theory, (B3LYP) methods with 6-31G(d) basis set level and polarizable continuum model (PCM) for solvation effect. The effects of varying pH-, dye concentration-, solvent-, temperature-, and time-dependences on the UV-vis spectra of Eriochrome Blue Black B were also investigated experimentally. The calculations showed that the dye exhibited acid-base, azo-hydrazone and aggregate equilibria in DMF solution, while the most probably preferred form in MeCN solution was azo form. Thermodynamic parameters of dimerization reaction in DMF solution proved that entropy was the driving force of this reaction.

  11. Energy-transfer-based wavelength-shifting DNA probes with "clickable" cyanine dyes.

    PubMed

    Holzhauser, Carolin; Rubner, Moritz M; Wagenknecht, Hans-Achim

    2013-05-01

    The insertion of cyanine dye azides as energy donor dyes via postsynthetic "click"-type cycloaddition chemistry with e.g. a new thiazole orange azide combined with thiazole red yields dual emitting DNA probes with good fluorescence readout properties.

  12. Dye Painting with Fiber Reactive Dyes

    ERIC Educational Resources Information Center

    Benjamin-Murray, Betsy

    1977-01-01

    In her description of how to use dyes directly onto fabrics the author lists materials to be used, directions for mixing dyes, techniques for applying dyes, references for additional reading and sources for dye materials. Preceding the activity with several lessons in design and other textile techniques with the dye process will ensure a…

  13. Surface functionalized SiO2 nanoparticles with cationic polymers via the combination of mussel inspired chemistry and surface initiated atom transfer radical polymerization: Characterization and enhanced removal of organic dye.

    PubMed

    Huang, Qiang; Liu, Meiying; Mao, Liucheng; Xu, Dazhuang; Zeng, Guangjian; Huang, Hongye; Jiang, Ruming; Deng, Fengjie; Zhang, Xiaoyong; Wei, Yen

    2017-03-28

    Monodispersed SiO2 particles functionalized with cationic polymers poly-((3-acrylamidopropyl)trimethylammonium chloride) (PAPTCl) were prepared using mussel inspired surface modification strategy and surface initiated atom transfer radical polymerization (SI-ATRP). Fourier transform infrared spectroscopy, transmission electron microscope, thermogravimetric analysis, X-ray photoelectron spectroscopy, and zeta potential were employed to characterize these SiO2 samples. The adsorption performance of the functionalized SiO2 (donated as SiO2-PDA-PAPTCl) towards anionic organic dye Congo red (CR) was investigated to evaluate their potential environmental applications. We demonstrated that the surface of SiO2 particles can be successfully functionalized with cationic PAPTCl. The adsorption capability of as-prepared SiO2 was found to increases from 28.70 and 106.65mg/g after surface grafted with cationic polymers. The significant enhancement in the adsorption capability of SiO2-PDA-PAPTCl is mainly attributed to the introduction of cationic polymers. More importantly, this strategy is expected to be promising for fabrication of many other functional polymer nanocomposites for environmental applications due to the universality of mussel inspired chemistry and well designability and good monomer adaptability of SI-ATRP.

  14. JCE Resources for Chemistry and Art.

    ERIC Educational Resources Information Center

    Jacobsen, Erica K.

    2001-01-01

    Includes an annotated bibliography of articles featured in this journal on art, dyes, glass, pottery and ceramics, interdisciplinary courses in art and chemistry, light and color, metalwork, and music. (YDS)

  15. Dye laser amplifier

    DOEpatents

    Moses, Edward I.

    1992-01-01

    An improved dye laser amplifier is disclosed. The efficiency of the dye lr amplifier is increased significantly by increasing the power of a dye beam as it passes from an input window to an output window within the dye chamber, while maintaining the intensity of the dye beam constant.

  16. Dye laser amplifier

    DOEpatents

    Moses, E.I.

    1992-12-01

    An improved dye laser amplifier is disclosed. The efficiency of the dye laser amplifier is increased significantly by increasing the power of a dye beam as it passes from an input window to an output window within the dye chamber, while maintaining the intensity of the dye beam constant. 3 figs.

  17. Charge and Energy Transfer in the Metal-free Indoline Dyes for Dye-sensitized Solar Cells

    NASA Astrophysics Data System (ADS)

    Diao, Li-ying; Gu, Wen-xiang; Chen, Yue-hui; Ma, Feng-cai

    2006-06-01

    Metal-free indoline dyes for dye-sensitized solar cells were studied by employing quantum chemistry methods. Comparative study of the properties of both ground and excited states of metal-free indoline dyes for dye- sensitized solar cells revealed: (i) as the number of rhodanine rings increases, the energy difference between HOMO and LUMO decreases and there is a red shift in the absorption spectrum with the binding energy increased, and the transition dipole moment decreased; (ii) Based on an analysis of charge differential density, we observed that the charge and energy are transfered from the phenylethenyl to the indoline and rhodanine rings; (iii) The electron-hole coherences are mainly on the indoline and rhodanine rings, and the exciton sizes are 30 and 40 atoms for indoline dyes with one and two rhodanline rings, respectively. These results serve as a good example of computer-aided design in metal-free indoline dyes for dye-sensitized solar cells.

  18. Determination of minimum enzymatic decolorization time of reactive dye solution by spectroscopic & mathematical approach.

    PubMed

    Celebi, Mithat; Ozdemir, Zafer Omer; Eroglu, Emre; Altikatoglu, Melda; Guney, Ibrahim

    2015-02-01

    Synthetic dyes are very important for textile dyeing, paper printing, color photography and petroleum products. Traditional methods of dye removal include biodegradation, precipitation, adsorption, chemical degradation, photo degradation, and chemical coagulation. Dye decolorization with enzymatic reaction is an important issue for several research field (chemistry, environment) In this study, minimum decolorization time of Remazol Brilliant Blue R dye with Horseradish peroxidase enzyme was calculated using with mathematical equation depending on experimental data. Dye decolorization was determined by monitoring the absorbance decrease at the specific maximum wavelength for dye. All experiments were carried out with different initial dye concentrations of Remazol Brilliant Blue R at 25 degrees C constant temperature for 30 minutes. The development of the least squares estimators for a nonlinear model brings about complications not encountered in the case of the linear model. Decolorization times for completely removal of dye were calculated according to equation. It was shown that mathematical equation was conformed exponential curve for dye degradation.

  19. Just Dyeing to Find Out.

    ERIC Educational Resources Information Center

    Monhardt, Becky Meyer

    1996-01-01

    Presents a multidisciplinary unit on natural dyes designed to take advantage of the natural curiosity of middle school students. Discusses history of dyes, natural dyes, preparation of dyes, and the dyeing process. (JRH)

  20. Primary Photoprocesses in Dyes and Other Complex Molecules.

    DTIC Science & Technology

    1978-10-31

    photobiology are given . -~~~~~ 3.2 Reports and Manuscripts in Preparation TR— l3. A Study of the Photodegradation of the Blue—Green Laser Dye , AC3F , A...the contract a preliminary study of the photodegradation of the laser dye , AC3F [Blue—Green Dye Laser Development , Annual Report F4—75 , NELC F233 b...I AD—A0b2 568 WASHINGTON STATE UNIV PULLMAN DEPT OF CHEMISTRY FFG 713 ‘c — F, PRIMARY PHOTOPROCESSES IN DYES AND OTHER COMPLEX MOLECULES. (U) OCT 78

  1. The Chemistry of Photographic Color Dye Formation

    ERIC Educational Resources Information Center

    Kahn, Bruce E.

    2004-01-01

    A laboratory activity that can be used at a number of levels from high school to college is discussed. This activity can be used to teach chemical concepts such as oxidation and reduction, stoichiometry, acids and bases, pH, nucleophilic reactions, conjugation, leaving groups, complexation, solubility, and reversibility.

  2. A Colorful Solubility Exercise for Organic Chemistry

    ERIC Educational Resources Information Center

    Shugrue, Christopher R.; Mentzen, Hans H., II; Linton, Brian R.

    2015-01-01

    A discovery chemistry laboratory has been developed for the introductory organic chemistry student to investigate the concepts of polarity, miscibility, solubility, and density. The simple procedure takes advantage of the solubility of two colored dyes in a series of solvents or solvent mixtures, and the diffusion of colors can be easily…

  3. The Chemistry of Color Photography

    ERIC Educational Resources Information Center

    Guida, Wayne C.; Raber, Douglas J.

    1975-01-01

    Presents several topics in color photography which can serve as an introduction of scientific concepts into the classroom, such as: photochemistry (energy transport), organic chemistry (dye formation), physics (nature of light), psychology (color perception), and engineering (isolation of different chemical processes within layers of the film).…

  4. Textile Chemistry for the Artist.

    ERIC Educational Resources Information Center

    Butler, Sara; Malott, Sally

    1981-01-01

    Focuses on the chemistry of fibers commonly used by artists. Presents information regarding the reactions of these fibers to dyes, bleaches, solvents, and other selected agents of design. Tables provide a classification of natural and manufactured fibers, characteristics, chemical formulas and reactions of selected fibers, and characteristics of…

  5. Bimanes and Related Heterocycles as Laser Dyes

    DTIC Science & Technology

    1991-01-10

    34Pyrroniethene-BF2 Complexes as Laser Dyes: 1.", Heteroatomn Chemistry, 1990, 1,389. Statement of the Problem: (see Reprints) Summary: (see Reprints...pyrromethene-BF 2 complexes (P-BF 2) by reference to rhodamine 6G (RE 100). The complexes 5 and 6 were the first dyes to surpass rhodamine 60 and are now the...benzyl)bimane 6 was prepared from other quasiaromatic cyclic amides and hydrazides . 3-methyl-4-benzyl-4-chloro-2-pyrazolin-5-one 10b A strong

  6. Investigation of hair dye deposition, hair color loss, and hair damage during multiple oxidative dyeing and shampooing cycles.

    PubMed

    Zhang, Guojin; McMullen, Roger L; Kulcsar, Lidia

    2016-01-01

    Color fastness is a major concern for consumers and manufacturers of oxidative hair dye products. Hair dye loss results from multiple wash cycles in which the hair dye is dissolved by water and leaches from the hair shaft. In this study, we carried out a series of measurements to help us better understand the kinetics of the leaching process and pathways associated with its escape from the fiber. Hair dye leaching kinetics was measured by suspending hair in a dissolution apparatus and monitoring the dye concentration in solution (leached dye) with an ultraviolet-visible spectrophotometer. The physical state of dye deposited in hair fibers was evaluated by a reflectance light microscopy technique, based on image stacking, allowing enhanced depth of field imaging. The dye distribution within the fiber was monitored by infrared spectroscopic imaging of hair fiber cross sections. Damage to the ultrafine structure of the hair cuticle (surface, endocuticle, and cell membrane complex) and cortex (cell membrane complex) was determined in hair cross sections and on the hair fiber surface with atomic force microscopy. Using differential scanning calorimetry, we investigated how consecutive coloring and leaching processes affect the internal proteins of hair. Further, to probe the surface properties of hair we utilized contact angle measurements. This study was conducted on both pigmented and nonpigmented hair to gain insight into the influence of melanin on the hair dye deposition and leaching processes. Both types of hair were colored utilizing a commercial oxidative hair dye product based on pyrazole chemistry.

  7. Benzidine Dyes Action Plan

    EPA Pesticide Factsheets

    This Action Plan addresses the use of benzidine-based dyes and benzidine congener-based dyes, both metalized and non-metalized, in products that would result in consumer exposure, such as for use to color textiles.

  8. Collaborative Physical Chemistry Projects Involving Computational Chemistry

    NASA Astrophysics Data System (ADS)

    Whisnant, David M.; Howe, Jerry J.; Lever, Lisa S.

    2000-02-01

    The physical chemistry classes from three colleges have collaborated on two computational chemistry projects using Quantum CAChe 3.0 and Gaussian 94W running on Pentium II PCs. Online communication by email and the World Wide Web was an important part of the collaboration. In the first project, students used molecular modeling to predict benzene derivatives that might be possible hair dyes. They used PM3 and ZINDO calculations to predict the electronic spectra of the molecules and tested the predicted spectra by comparing some with experimental measurements. They also did literature searches for real hair dyes and possible health effects. In the final phase of the project they proposed a synthetic pathway for one compound. In the second project the students were asked to predict which isomer of a small carbon cluster (C3, C4, or C5) was responsible for a series of IR lines observed in the spectrum of a carbon star. After preliminary PM3 calculations, they used ab initio calculations at the HF/6-31G(d) and MP2/6-31G(d) level to model the molecules and predict their vibrational frequencies and rotational constants. A comparison of the predictions with the experimental spectra suggested that the linear isomer of the C5 molecule was responsible for the lines.

  9. Ultrasonic dyeing of cellulose nanofibers.

    PubMed

    Khatri, Muzamil; Ahmed, Farooq; Jatoi, Abdul Wahab; Mahar, Rasool Bux; Khatri, Zeeshan; Kim, Ick Soo

    2016-07-01

    Textile dyeing assisted by ultrasonic energy has attained a greater interest in recent years. We report ultrasonic dyeing of nanofibers for the very first time. We chose cellulose nanofibers and dyed with two reactive dyes, CI reactive black 5 and CI reactive red 195. The cellulose nanofibers were prepared by electrospinning of cellulose acetate (CA) followed by deacetylation. The FTIR results confirmed complete conversion of CA into cellulose nanofibers. Dyeing parameters optimized were dyeing temperature, dyeing time and dye concentrations for each class of the dye used. Results revealed that the ultrasonic dyeing produced higher color yield (K/S values) than the conventional dyeing. The color fastness test results depicted good dye fixation. SEM analysis evidenced that ultrasonic energy during dyeing do not affect surface morphology of nanofibers. The results conclude successful dyeing of cellulose nanofibers using ultrasonic energy with better color yield and color fastness results than conventional dyeing.

  10. Laser dye stability

    NASA Astrophysics Data System (ADS)

    Fletcher, N.

    1980-06-01

    Lasing characteristics and bleaching of four Eastman Kodak ir dyes have been examined in dimethyl sulfoxide. These ir dyes are shown to improve in performance in the absence of oxygen. Their photochemical stability was found to be comparable to the quinolone laser dyes when exposed to flashlamp excitation. Photodecomposition of the ir dyes under lasing conditions was found to vary between 1.6 and 6×10-10 moles of dye for each joule (electrical) of input energy; in comparison, the photodecomposition values for the better coumarin dyes was 0.2 to 1.0×10-10 moles/J at a concentration of 1.0×10-4 M in ethanol. It was also found that increasing the concentration of these tricarbocyanine dyes gives a marked improvement in the useful lifetime of these solutions as lasing media in the absence of oxygen.

  11. Candies to Dye For: Cooperative, Open-Ended Student Activities To Promote Understanding of Electrophoretic Fractionation.

    ERIC Educational Resources Information Center

    Emry, Randall; Curtright, Robert D.; Wright, Jonathan; Markwell, John

    2000-01-01

    Introduces electrophoresis activities developed for chemistry and biology courses in which students identify the food, drug, and cosmetic identity of the food dyes used in the coating of candies. (YDS)

  12. Electron Donor-Acceptor Quenching and Photoinduced Electron Transfer for Coumarin Dyes.

    DTIC Science & Technology

    1983-10-31

    Mechanism of cousarin photodegradation . Ithe behavior of eoiuma dyes is water ad In aqueous detergent media,. and the effsects of medism aud, additives on...D-i36 345 ELECTRON DONOR-ACCEPTOR UENCHING AND PHOTOINDUCED i/i Ai ELECTRON TRANSFER FOR COUMARIN DYES (U) BOSTON UNIY MR DEPT OF CHEMISTRY G JONES...TYPE OF REPORT & PEIOD COVERED Electron Donor-acceptor Quenching and Photo- Technical, 1/1/82-10/31/82 induced Electron Transfer for Coumarin Dyes S

  13. Synthesis of Laser Dyes

    DTIC Science & Technology

    1988-11-09

    block number) This report describes the progress made in attempts to prepare seven laser dyes. These dyes all have a 2-(L-pyridy.)-1,3- oxazole ...structure one dye, The synthesis of one dye, 2-(Ni-met.hyl-4-pyridiniiumi)pherianthroL9,10-dJ-1,3- oxazole tosylate (I) has been com-pleted. Preliminary...1,3- oxazoles . I~ 20 [IISTRI:’UTIGTJi/AVAILABILITY OF ABSTRACT 21. ABSTRACT SECURITY CLASSIFICATION 0UNITILA-,SIFIEDI.JNLiITED 0 SAME AS RPT El DTIC

  14. Biophysical chemistry.

    PubMed

    Häussinger, Daniel; Pfohl, Thomas

    2010-01-01

    Biophysical chemistry at the Department of Chemistry, University of Basel, covers the NMR analysis of protein-protein interaction using paramagnetic tags and sophisticated microscopy techniques investigating the dynamics of biological matter.

  15. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1983

    1983-01-01

    Presents background information, laboratory procedures, classroom materials/activities, and chemistry experiments. Topics include sublimation, electronegativity, electrolysis, experimental aspects of strontianite, halide test, evaluation of present and future computer programs in chemistry, formula building, care of glass/saturated calomel…

  16. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1976

    1976-01-01

    Described are eight chemistry experiments and demonstrations applicable to introductory chemistry courses. Activities include: measure of lattice enthalpy, Le Chatelier's principle, decarboxylation of soap, use of pocket calculators in pH measurement, and making nylon. (SL)

  17. Chemistry Dashboard

    EPA Pesticide Factsheets

    The Chemistry Dashboard is part of a suite of dashboards developed by EPA to help evaluate the safety of chemicals. The Chemistry Dashboard provides access to a variety of information on over 700,000 chemicals currently in use.

  18. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1972

    1972-01-01

    Thirteen ideas are presented that may be of use to chemistry teachers. Topics covered include vitamin C, industrial chemistry, electrical conductivity, electrolysis, alkali metals, vibration modes infra-red, dynamic equilibrium, and some new demonstrations in gaseous combinations. (PS)

  19. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1982

    1982-01-01

    Presents background information, laboratory procedures, classroom materials/activities, and experiments for chemistry. Topics include superheavy elements, polarizing power and chemistry of alkali metals, particulate carbon from combustion, tips for the chemistry laboratory, interesting/colorful experiments, behavior of bismuth (III) iodine, and…

  20. Aberration corrected STEM to study an ancient hair dyeing formula

    NASA Astrophysics Data System (ADS)

    Patriarche, G.; Van Elslande, E.; Castaing, J.; Walter, P.

    2014-05-01

    Lead-based chemistry was initiated in ancient Egypt for cosmetic preparation more than 4000 years ago. Here, we study a hair-dyeing recipe using lead salts described in text since Greco-Roman times. We report direct evidence about the shape and distribution of PbS nanocrystals that form within the hair during blackening.

  1. Microencapsulated Fluorescent Dye Penetrant.

    DTIC Science & Technology

    1979-07-01

    Microencapsulated fluorescent dye pentrant materials were evaluated for feasibility as a technique to detect cracks on metal surfaces when applied as...a free flowing dry powder. Various flourescent dye solutions in addition to a commercial penetrant (Zyglo ZL-30) were microencapsulated and tested on

  2. Hair dye poisoning

    MedlinePlus

    ... temporary dyes are: Arsenic Bismuth Denatured alcohol Lead ( lead poisoning ) Mercury Pyrogallol Silver Hair dyes may contain other ... infection. Continued exposure to lead or mercury can lead to permanent brain and nervous system damage. Alternative ... References Lee DC. Hydrocarbons. In: Marx JA, Hockberger ...

  3. Oxazine laser dyes

    DOEpatents

    Hammond, Peter R.; Field, George F.

    1992-01-01

    New oxazine compounds useful as dye laser media in solution, are superiior to prior art materials. The oxazine dyes useful when pumped by the 578.2 nm copper line to operate in the 700-800 nm range are described by formula I ##STR1##

  4. Sweet Chemistry

    NASA Astrophysics Data System (ADS)

    Aurian-Blajeni*, Benedict; Sam, Jonathan; Sisak, Michael

    1999-01-01

    This laboratory exercise is an introduction to spectrophotometry suitable for college freshmen and high school students. It involves food dyes and brown M&M candy. The spectra of "primary" dyes are measured and represented graphically as absorbance vs wavelength to show that minimum absorption of light occurs in the spectral region corresponding to the color of the dye. The spectra of dye combinations illustrate the fact that some common colors are actually mixtures of colors. Finally, the Beer-Lambert law is verified by using the single-wavelength absorbance (620 nm, blue) of mixtures. This project illustrates the absorption of light by substances and its dependence on wavelength, the change of light absorption with the concentration of dissolved substance (Beer-Lambert law), and the explicit correspondence of colors with spectral features. It uses safe chemicals and connects everyday objects and substances with laboratory measurements.

  5. Monolithic dye laser amplifier

    DOEpatents

    Kuklo, T.C.

    1993-03-30

    A fluid dye laser amplifier for amplifying a dye beam by pump beams has a channel structure defining a channel through which a laseable fluid flows and the dye and pump beams pass transversely to one another through a lasing region. The channel structure is formed with two pairs of mutually spaced-apart and mutually confronting glass windows, which are interlocked and make surface-contacts with one another and surround the lasing region. One of the glass window pairs passes the dye beam and the other passes the pump beams therethrough and through the lasing region. Where these glass window pieces make surface-contacts, glue is used to join the pieces together to form a monolithic structure so as to prevent the dye in the fluid passing through the channel from entering the space between the mutually contacting glass window pieces.

  6. Monolithic dye laser amplifier

    DOEpatents

    Kuklo, Thomas C.

    1993-01-01

    A fluid dye laser amplifier for amplifying a dye beam by pump beams has a channel structure defining a channel through which a laseable fluid flows and the dye and pump beams pass transversely to one another through a lasing region. The channel structure is formed with two pairs of mutually spaced-apart and mutually confronting glass windows, which are interlocked and make surface-contacts with one another and surround the lasing region. One of the glass window pairs passes the dye beam and the other passes the pump beams therethrough and through the lasing region. Where these glass window pieces make surface-contacts, glue is used to join the pieces together to form a monolithic structure so as to prevent the dye in the fluid passing through the channel from entering the space between the mutually contacting glass window pieces.

  7. CLUSTER CHEMISTRY

    SciTech Connect

    Muetterties, Earl L.

    1980-05-01

    Metal cluster chemistry is one of the most rapidly developing areas of inorganic and organometallic chemistry. Prior to 1960 only a few metal clusters were well characterized. However, shortly after the early development of boron cluster chemistry, the field of metal cluster chemistry began to grow at a very rapid rate and a structural and a qualitative theoretical understanding of clusters came quickly. Analyzed here is the chemistry and the general significance of clusters with particular emphasis on the cluster research within my group. The importance of coordinately unsaturated, very reactive metal clusters is the major subject of discussion.

  8. Forensic chemistry.

    PubMed

    Bell, Suzanne

    2009-01-01

    Forensic chemistry is unique among chemical sciences in that its research, practice, and presentation must meet the needs of both the scientific and the legal communities. As such, forensic chemistry research is applied and derivative by nature and design, and it emphasizes metrology (the science of measurement) and validation. Forensic chemistry has moved away from its analytical roots and is incorporating a broader spectrum of chemical sciences. Existing forensic practices are being revisited as the purview of forensic chemistry extends outward from drug analysis and toxicology into such diverse areas as combustion chemistry, materials science, and pattern evidence.

  9. Chemistry in the Time of the Pharaohs

    ERIC Educational Resources Information Center

    Loyson, Peter

    2011-01-01

    The Egyptians were known in the ancient world as experts in many applied chemistry fields such as metallurgy, wine and beer making, glass making, paper manufacture, paint pigments, dyes, cosmetics, perfumes, and pharmaceuticals. They made significant developments in the extraction of metals from their ores, especially copper and gold. The…

  10. Adaptation for improving lifetime of dye laser using coumarin dyes

    SciTech Connect

    Fletcher, A.N.

    1984-10-23

    The effective lasing lifetime of laser dyes including coumarin dyes are significantly extended by the use of an inert cover gas for the laser dye solution such as argon in combination with the employment of a glass filter such as Pyrex disposed between the pumping flash lamp and the dye laser cavity capable of absorbing electromagnetic radiation of about 300 nanometers or shorter wavelength.

  11. Dye system for dye laser applications

    DOEpatents

    Hammond, Peter R.

    1991-01-01

    A dye of the DCM family, [2-methyl-6-[2-(1,2,3,4-tetrahydro-1-methyl-6-quinolinyl)ethenyl]-4H-pyran -4-ylidene]-propanedinitrile, dissolved in 2-phenoxyethanol, is non-mutagenic, stable and efficient, particularly in a pumped continuous wave laser system.

  12. Direct thermal dyes

    NASA Astrophysics Data System (ADS)

    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.

  13. Long-lived laser dye

    SciTech Connect

    Fletcher, A.N.

    1986-07-29

    A method is described of obtaining in a flashlamp pumped laser system, a long-lived flashpumped laser dye having a low threshold of lasing and a moderate output comprising the steps of: placing a dye solution comprising a laser dye, the N-methyl tosylate salt of 2-(4-pyridyl)-5-(4-methoxphenyl)oxazole, and a solvent into a laser dye cavity; screening the dye solution from ultraviolet light with an optical filter; flushing the dye solution with an inert gas; and optically pumping the dye solution with a flashlamp to produce laser emission.

  14. Technetium chemistry

    SciTech Connect

    Burns, C.; Bryan, J.; Cotton, F.; Ott, K.; Kubas, G.; Haefner, S.; Barrera, J.; Hall, K.; Burrell, A.

    1996-04-01

    Technetium chemistry is a young and developing field. Despite the limited knowledge of its chemistry, technetium is the workhorse for nuclear medicine. Technetium is also a significant environmental concern because it is formed as a byproduct of nuclear weapons production and fission-power generators. Development of new technetium radio-pharmaceuticals and effective environmental control depends strongly upon knowledge of basic technetium chemistry. The authors performed research into the basic coordination and organometallic chemistry of technetium and used this knowledge to address nuclear medicine and environmental applications. This is the final report of a three-year Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL).

  15. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1972

    1972-01-01

    Twelve new chemistry expermiments are described. Broad areas covered include atomic structure, solubility, gaseous diffusion, endothermic reactions, alcohols, equilibrium, atomic volumes, and some improvised apparatus. (PS)

  16. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1981

    1981-01-01

    Outlines laboratory procedures, demonstrations, teaching suggestions, and content information related to chemistry. Topics include polarizing power; calorimetry and momentum; microcomputers in school chemistry; a constant-volume dispenser for liquids, floating magnets, and crystal lattices; preparation of chromium; and solvent polarity and…

  17. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1972

    1972-01-01

    Short articles describing the construction of a self-testing device for learning ionic formulae, problems with standard'' experiments in crystallizing sulfur, preparative details for a cold-setting adhesive and vermillion dye, and providing data related to the industrial manufacture of sulphuric acid. (AL)

  18. Johann Peter Griess FRS (1829–88): Victorian brewer and synthetic dye chemist

    PubMed Central

    Yates, Edwin; Yates, Andrew

    2016-01-01

    The German organic chemist Johann Peter Griess (1829–88), who first developed the diazotization of aryl amines (the key reaction in the synthesis of the azo dyes), and a major figure in the formation of the modern dye industry, worked for more than a quarter of a century at the brewery of Samuel Allsopp and Sons in Burton upon Trent, which, owing to the presence of several notable figures and an increase in the scientific approach to brewing, became a significant centre of scientific enquiry in the 1870s and 1880s. Unlike the other Burton brewing chemists, Griess paralleled his work at the brewery with significant contributions to the chemistry of synthetic dyes, managing to keep the two activities separate—to the extent that some of his inventions in dye chemistry were filed as patents on behalf of the German dye company BASF, without the involvement of Allsopp's. This seemingly unlikely situation can be explained partly by the very different attitudes to patent protection in Britain and in Germany combined with an apparent indifference to the significant business opportunity that the presence of a leading dye chemist presented to Allsopp's. Although his work for the brewery remained largely proprietary, Griess's discoveries in dye chemistry were exploited by the German dye industry, which quickly outpaced its British counterpart. One less well-known connection between brewing and synthetic dyes, and one that may further explain Allsopp's attitude, is the use of synthetic dyes in identifying microorganisms—the perennial preoccupation of brewers seeking to maintain yield and quality. Developments of Griess's original work continue to be applied to many areas of science and technology.

  19. Circumstellar chemistry

    NASA Technical Reports Server (NTRS)

    Glassgold, Alfred E.; Huggins, Patrick J.

    1987-01-01

    The study of the outer envelopes of cool evolved stars has become an active area of research. The physical properties of CS envelopes are presented. Observations of many wavelengths bands are relevant. A summary of observations and a discussion of theoretical considerations concerning the chemistry are summarized. Recent theoretical considerations show that the thermal equilibrium model is of limited use for understanding the chemistry of the outer CS envelopes. The theoretical modeling of the chemistry of CS envelopes provides a quantitive test of chemical concepts which have a broader interest than the envelopes themselves.

  20. Hair Dye and Hair Relaxers

    MedlinePlus

    ... 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 ...

  1. Water soluble laser dyes

    DOEpatents

    Hammond, Peter R.; Feeman, James F.; Field, George F.

    1998-01-01

    Novel water soluble dyes of the formula I are provided ##STR1## wherein R.sup.1 and R.sup.4 are alkyl of 1 to 4 carbon atoms or hydrogen; or R.sup.1 -R.sup.2 or R.sup.2 -R.sup.4 form part of aliphatic heterocyclic rings; R.sup.2 is hydrogen or joined with R.sup.1 or R.sup.4 as described above; R.sup.3 is --(CH.sub.2).sub.m --SO.sub.3.sup.-, where m is 1 to 6; X is N, CH or ##STR2## where Y is 2 --SO.sub.3.sup.- ; Z is 3, 4, 5 or 6 --SO.sub.3.sup.-. The novel dyes are particularly useful as the active media in water solution dye lasers.

  2. Hair cosmetics: dyes.

    PubMed

    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.

  3. Water soluble laser dyes

    DOEpatents

    Hammond, P.R.; Feeman, J.F.; Field, G.F.

    1998-08-11

    Novel water soluble dyes of the formula 1 are provided by the formula described in the paper wherein R{sup 1} and R{sup 4} are alkyl of 1 to 4 carbon atoms or hydrogen; or R{sup 1}--R{sup 2} or R{sup 2}--R{sup 4} form part of aliphatic heterocyclic rings; R{sup 2} is hydrogen or joined with R{sup 1} or R{sup 4} as described above; R{sup 3} is --(CH{sub 2}){sub m}--SO{sub 3}{sup {minus}}, where m is 1 to 6; X is N, CH or formula 2 given in paper where Y is 2 --SO{sub 3}{sup {minus}} ; Z is 3, 4, 5 or 6 --SO{sub 3}{sup {minus}}. The novel dyes are particularly useful as the active media in water solution dye lasers.

  4. Laser dye technology

    SciTech Connect

    Hammond, P R

    1999-09-01

    The author has worked with laser dyes for a number of years. A first interest was in the Navy blue-green program where a flashlamp pumped dye laser was used as an underwater communication and detection device. It made use of the optical window of sea-water--blue for deep ocean, green for coastal water. A major activity however has been with the Atomic Vapor Laser Isotope Separation Program (AVLIS) at the Lawrence Livermore National Laboratory. The aim here has been enriching isotopes for the nuclear fuel cycle. The tunability of the dye laser is utilized to selectively excite one isotope in uranium vapor, and this isotope is collected electrostatically as shown in Figure 1. The interests in the AVLIS program have been in the near ultra-violet, violet, red and deep-red.

  5. Catalytic Chemistry.

    ERIC Educational Resources Information Center

    Borer, Londa; And Others

    1996-01-01

    Describes an approach for making chemistry relevant to everyday life. Involves the study of kinetics using the decomposition of hydrogen peroxide by vegetable juices. Allows students to design and carry out experiments and then draw conclusions from their results. (JRH)

  6. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1980

    1980-01-01

    Describes equipment, activities, and experiments useful in chemistry instruction, including among others, a rapid method to determine available chlorine in bleach, simple flame testing apparatus, and a simple apparatus demonstrating the technique of flash photolysis. (SK)

  7. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1973

    1973-01-01

    Several ideas are proposed for chemistry teachers to try in their classrooms. Subjects included are polymerization of acrylate, polymerization of styrene, conductivity, pollution, preparation of chlorine, redox equations, chemiluminescence, and molecular sieves. (PS)

  8. Nuclear Chemistry.

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1979

    1979-01-01

    Provides a brief review of the latest developments in nuclear chemistry. Nuclear research today is directed toward increased activity in radiopharmaceuticals and formation of new isotopes by high-energy, heavy-ion collisions. (Author/BB)

  9. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1981

    1981-01-01

    Describes 13 activities, experiments and demonstrations, including the preparation of iron (III) chloride, simple alpha-helix model, investigating camping gas, redox reactions of some organic compounds, a liquid crystal thermometer, and the oxidation number concept in organic chemistry. (JN)

  10. Photoredox Catalysis in Organic Chemistry

    PubMed Central

    2016-01-01

    In recent years, photoredox catalysis has come to the forefront in organic chemistry as a powerful strategy for the activation of small molecules. In a general sense, these approaches rely on the ability of metal complexes and organic dyes to convert visible light into chemical energy by engaging in single-electron transfer with organic substrates, thereby generating reactive intermediates. In this Perspective, we highlight the unique ability of photoredox catalysis to expedite the development of completely new reaction mechanisms, with particular emphasis placed on multicatalytic strategies that enable the construction of challenging carbon–carbon and carbon–heteroatom bonds. PMID:27477076

  11. Stratospheric chemistry

    SciTech Connect

    Brune, W.H. )

    1991-01-01

    Advances in stratospheric chemistry made by investigators in the United States from 1987 to 1990 are reviewed. Subject areas under consideration include photochemistry of the polar stratosphere, photochemistry of the global stratosphere, and assessments of inadvertent modification of the stratosphere by anthropogenic activity. Particular attention is given to early observations and theories, gas phase chemistry, Antarctic observations, Arctic observations, odd-oxygen, odd-hydrogen, odd-nitrogen, halogens, aerosols, modeling of stratospheric ozone, and reactive nitrogen effects.

  12. Dye filled security seal

    DOEpatents

    Wilson, Dennis C. W.

    1982-04-27

    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.

  13. Current developments in optical data storage with organic dyes.

    PubMed

    Mustroph, Heinz; Stollenwerk, Manfred; Bressau, Volker

    2006-03-20

    The main motivation for the development of digital data storage has been the improvement in play-back quality and the increase in storage capacity. In 1982 Philips and Sony introduced the first technically and economically successful system based on this-the compact disc (CD) and a compatible player. A very broad diversity of optical data recording formats are available today, and a difference is drawn between prerecorded, recordable, and rewritable media. This Review gives an overview of the systems used, the main features of production, and then concentrates on the properties of the organic dyes that are used in recordable systems. Dyestuffs chemistry has gained the reputation of having become a mature field of activity. Is this prejudice or a justified swan song for dyestuffs chemistry? When applications in optical data storage are considered, it is evident that even today progresses such as CD-R and DVD/R would not be feasible without functional dyes.

  14. Alzheimer's Dye Test?

    ERIC Educational Resources Information Center

    Science Teacher, 2005

    2005-01-01

    Massachusetts Institute of Technology (MIT) scientists have developed a new dye that could offer noninvasive early diagnosis of Alzheimer's disease, a discovery that could aid in monitoring the progression of the disease and in studying the efficacy of new treatments to stop it. The work is published in Angewandte Chemie. Today, doctors can only…

  15. Photochemistry of coumarin laser dyes

    SciTech Connect

    von Trebra, R.J.

    1984-01-01

    Coumarin laser dyes are widely used in dye lasers for the generation of tunable laser light in the blue-green spectral region. As in the case with most laser dyes, coumarin dyes undergo photochemical reactions that interfere with simulated emission and result in loss of laser power output. This thesis describes the photochemistry of coumarin laser dyes under both anaerobic and aerobic conditions and some attempts to extend the useful lifetime of several dyes in dye lasers. Irradiation of Coumarin 311, 7-dimethylamino-4-methyl-coumarin (15), in oxygen-free ethanol solution results in the inefficient dye destruction. Products formed absorb light at the lasing wavelength of the dye, interfere with stimulated emission, and decrease the power output of the dye laser. Addition of the sulfur free radical chain transfer agents ethanethiol and ethyl disulfide retard the rate of formation of photoproducts absorbing at the lasing wavelengths. Deuterium incorporation, from the irradiation of Coumarin 311 in the presence of ethanethiol-S-d and ethyl disulfide, indicates that photoproducts most likely result from the reactions of free radicals which are generated in a bimolecular reaction between excited Coumarin 311 and ground state Coumarin 311. Ethanethiol and ethyl disulfide are shown to decrease the rate of power loss from a Coumarin 1 (3) dye laser. The naturally occurring amino acid cysteine acts similarly.

  16. FY 1980 Report on Dye Laser Materials

    DTIC Science & Technology

    1981-02-01

    by block number) Dye Lasers Laser Dyes Tunable Lasers Photodegradation Rhodamine Dyes 20. ABSTRACT (Continue n resld* it necesiry and Identify by block...limited usefulness as a portable military device because of the photodegradation of the dye solution. Although there have been state-of-the-art reviews...on laser dyes , 1𔃼 the photodegradation of laser dyes ,3 and dye lasers, 4- 6 only authors from, or funded by, military organizations have given strict

  17. Reuse of reactive dyes for dyeing of jute fabric.

    PubMed

    Chattopadhyay, S N; Pan, N C; Day, A

    2006-01-01

    The aim of the work was to find out suitable method of dyeing so that costly reactive dye can be reused without draining them. The bleached jute fabric was dyed with four different class of reactive dyes namely, cold brand, hot brand, vinyl sulphone and high exhaustion (HE) brand. It is found that the two-step two-bath method of reactive dyeing, where exhaustion and fixation step is separated, is most ideal for reuse of dye bath. Separate original samples produced K/S value same as that of original sample and the K/S value of separate reuse sample varied from 50% to 80% of the original sample depending on the class of dye. In case of same bath method, colour yield of original reuse samples varies from only 10% to maximum 30% of the original samples depending on the class of dyes. Reuse of reactive dyes following separate bath method is particularly suitable for higher depth of shade (4% and above). This process not only utilises costly reactive dyes to the maximum extent but it also produces low water pollution as the effluent contain minimum amount of dye. So the process is economic and eco-friendly as well.

  18. Flow chemistry meets advanced functional materials.

    PubMed

    Myers, Rebecca M; Fitzpatrick, Daniel E; Turner, Richard M; Ley, Steven V

    2014-09-22

    Flow chemistry and continuous processing techniques are beginning to have a profound impact on the production of functional materials ranging from quantum dots, nanoparticles and metal organic frameworks to polymers and dyes. These techniques provide robust procedures which not only enable accurate control of the product material's properties but they are also ideally suited to conducting experiments on scale. The modular nature of flow and continuous processing equipment rapidly facilitates reaction optimisation and variation in function of the products.

  19. Polymer Chemistry

    NASA Technical Reports Server (NTRS)

    Williams, Martha; Roberson, Luke; Caraccio, Anne

    2010-01-01

    This viewgraph presentation describes new technologies in polymer and material chemistry that benefits NASA programs and missions. The topics include: 1) What are Polymers?; 2) History of Polymer Chemistry; 3) Composites/Materials Development at KSC; 4) Why Wiring; 5) Next Generation Wiring Materials; 6) Wire System Materials and Integration; 7) Self-Healing Wire Repair; 8) Smart Wiring Summary; 9) Fire and Polymers; 10) Aerogel Technology; 11) Aerogel Composites; 12) Aerogels for Oil Remediation; 13) KSC's Solution; 14) Chemochromic Hydrogen Sensors; 15) STS-130 and 131 Operations; 16) HyperPigment; 17) Antimicrobial Materials; 18) Conductive Inks Formulations for Multiple Applications; and 19) Testing and Processing Equipment.

  20. Chemistry Experiments

    NASA Technical Reports Server (NTRS)

    Brasseur, Guy; Remsberg, Ellis; Purcell, Patrick; Bhatt, Praful; Sage, Karen H.; Brown, Donald E.; Scott, Courtney J.; Ko, Malcolm K. W.; Tie, Xue-Xi; Huang, Theresa

    1999-01-01

    The purpose of the chemistry component of the model comparison is to assess to what extent differences in the formulation of chemical processes explain the variance between model results. Observed concentrations of chemical compounds are used to estimate to what degree the various models represent realistic situations. For readability, the materials for the chemistry experiment are reported in three separate sections. This section discussed the data used to evaluate the models in their simulation of the source gases and the Nitrogen compounds (NO(y)) and Chlorine compounds (Cl(y)) species.

  1. Efficiency enhancement of dye-sensitized solar cells (DSSC) by addition of synthetic dye into natural dye (anthocyanin)

    NASA Astrophysics Data System (ADS)

    Pratiwi, D. D.; Nurosyid, F.; Supriyanto, A.; Suryana, R.

    2017-02-01

    This article reported combination of anthocyanin and synthetic dyes in dye-sensitized solar cells (DSSC) applications. This study aims was to improve the performance of DSSC by addition of synthetic dye into anthocyanin dye. Anthocyanin dye was extracted from red cabbage and synthetic dye was obtained from N719. We prepared anthocyanin and synthetic dyes at 2 different volume, anthocyanin dye at volume of 10 ml and combination dyes with anthocyanin and synthetic dyes at volume of 8 mL : 2 mL. The DSSCs were designed into sandwich structure on the fluorine-doped tin oxide (FTO) substrates using TiO2 electrode, carbon electrode, anthocyanin and synthetic dyes, and redox electrolyte. The absorption wavelength of anthocyanin dye of red cabbage was 450 nm – 580 nm, the combination of anthocyanin and synthetic dyes can increase the absorbance peak only. The IPCE characteristic with anthocyanin dye of red cabbage and combination dyes resulted quantum efficiency of 0.081% and 0.092% at wavelength maximum about 430 nm. The DSSC by anthocyanin dye of red cabbage achieved a conversion efficiency of 0.024%, while the DSSC by combination dyes achieved a conversion efficiency of 0.054%, combination dyes by addition synthetic dye into anthocyanin dye enhanced the conversion efficiency up to 125%.

  2. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1980

    1980-01-01

    Presents 12 chemistry notes for British secondary school teachers. Some of these notes are: (1) a simple device for testing pH-meters; (2) portable fume cupboard safety screen; and (3) Mass spectroscopy-analysis of a mass peak. (HM)

  3. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1976

    1976-01-01

    Describes several chemistry projects, including solubility, formula for magnesium oxide, dissociation of dinitrogen tetroxide, use of 1-chloro-2, 4-dinitrobenzene, migration of ions, heats of neutralizations, use of pocket calculators, sonic cleaning, oxidation states of manganese, and cell potentials. Includes an extract from Chemical Age on…

  4. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1972

    1972-01-01

    Short articles on the alkylation of aniline, the preparation and properties of perbromate, using scrap copper in chemistry instruction, a safe method of burning hydrogen, and the use of an ion-charge model as an alternative to the mole concept in secondary school instruction. (AL)

  5. Confectionary Chemistry.

    ERIC Educational Resources Information Center

    Levine, Elise Hilf

    1996-01-01

    Presents activities and demonstrations that enable teachers to use various types of confections as tactile experiences to spark chemistry students' interest and generate enthusiasm for learning. Presents uses of candy in teaching about atomic structure, spontaneous nuclear decay, chemical formulas, fractoluminescence, the effect of a molecular…

  6. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1972

    1972-01-01

    Short articles on the kinetics of the hydrogen peroxide-iodide ion reaction, simulation of fluidization catalysis, the use of Newman projection diagrams to represent steric relationships in organic chemistry, the use of synthetic substrates for proteolytic enzyme reactions, and two simple clock reactions"--hydrolysis of halogenoalkanes and…

  7. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1983

    1983-01-01

    Presents chemistry experiments, laboratory procedures, demonstrations, teaching suggestions, and classroom materials/activities. These include: game for teaching ionic formulas; method for balancing equations; description of useful redox series; computer programs (with listings) for water electrolysis simulation and for determining chemical…

  8. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1983

    1983-01-01

    Presents chemistry experiments, laboratory procedures, demonstrations, and classroom materials/activities. These include: experiments on colloids, processing of uranium ore, action of heat on carbonates; color test for phenols and aromatic amines; solvent properties of non-electrolytes; stereoscopic applications/methods; a valency balance;…

  9. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1982

    1982-01-01

    Presents procedures, experiments, demonstrations, teaching suggestions, and information on a variety of chemistry topics including, for example, inert gases, light-induced reactions, calculators, identification of substituted acetophenones, the elements, analysis of copper minerals, extraction of metallic strontium, equilibrium, halogens, and…

  10. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1978

    1978-01-01

    Describes some laboratory apparatus, chemistry experiments and demonstrations, such as a Kofler block melting point apparatus, chromatographic investigation of the phosphoric acid, x-ray diffraction, the fountain experiment, endothermic sherbet, the measurement of viscosity, ionization energies and electronic configurations. (GA)

  11. Azaquinolone dye lasers

    DOEpatents

    Hammond, Peter R.; Atkins, Ronald L.; Henry, Ronald A.; Fletcher, Aaron N.

    1978-01-01

    A dye laser comprising a laser dye solution of a compound having the general structure: ##STR1## wherein at least one of the 5, 6 and 8 ring positions is occupied by a nitrogen atom in lieu of the corresponding CR group and X is OH, alkoxy, or amino including amino substituted by at least one of the following: alkyl, aryl, acyl, aracyl, a group which taken together with the nitrogen atom of the amino group forms a heterocyclic ring, or part of one or two 5 or 6 membered aliphatic heterocyclic rings attached to ring A at positions 6 or 8 or both depending on where the N in ring A is located. R.sub.1, R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.8 are hydrogen or other groups as defined below. The compounds lase in the blue to near ultraviolet region.

  12. Azacoumarin dye lasers

    DOEpatents

    Hammond, Peter R.; Atkins, Ronald L.; Henry, Ronald A.; Fletcher, Aaron N.

    1978-01-01

    A dye laser comprising a laser dye solution of a compound having the general structure: ##STR1## wherein at least one of the 5, 6 and 8 ring positions is occupied by a nitrogen atom in lieu of the corresponding CR group and X is OH, alkoxy, or amino including amino substituted by at least one of the following: alkyl, aryl, acyl, aracyl, a group which taken together with the nitrogen atom of the amino group forms a heterocyclic ring, or part of one or two 5 or 6 membered aliphatic heterocyclic rings attached to ring A at positions 6 or 8 or both depending on where the N in ring A is located. R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.8 are hydrogen or other groups as defined below. The compounds lase in the blue-green to near ultraviolet region.

  13. Fiberized fluorescent dye microtubes

    NASA Astrophysics Data System (ADS)

    Vladev, Veselin; Eftimov, Tinko

    2013-03-01

    In the present work we study the effect of the length of fluorescent dye-filled micro-capillaries on the fluorescence spectra. Two types of micro-capillaries have been studied: a 100 μm inner diameter fused silica capillary with a transparent coating and one of the holes of a fiber optic glass ferrule with 125 μm inner diameter. The tubes were filled with solutions of Rhodamine 6G dissolved in ethanol and then in glycerin. Experimental data show that the maximum fluorescence and the largest spectral widths are observed for a sample length of about 0.25 mm for the used concentration. This results show that miniature tunable fiberized dye lasers can be developed using available standard micro-and fibre-optic components.

  14. Microscale Chemistry and Green Chemistry: Complementary Pedagogies

    NASA Astrophysics Data System (ADS)

    Singh, Mono M.; Szafran, Zvi; Pike, R. M.

    1999-12-01

    This paper describes the complementary nature of microscale chemistry and green chemistry. Green chemistry emphasizes the concepts of atom economy, source reduction, pathway modification, solvent substitution, and pollution prevention as means of improving the environmental impact of industrial chemistry. Microscale chemistry serves as a tool for incorporating green chemistry ideas across the curriculum in educational institutions. Examples are drawn from microscale laboratory experiments to illustrate the pedagogic connection between the two areas.

  15. Photodissociation Dye Laser

    DTIC Science & Technology

    1975-04-01

    Chemical Properties of Free Radicals 5 C. Criteria for the Selection of Photodissociation Dye Laser Molecules 6 III. EXPERIMENTAL EFFORT AND...nanoseconds. In radicl systems, however, there is evidence both theoretical and experimental, that the first doublet-doublet electronic tra-jitions are...Properties, of Free Radicals Recombination is only one of many possible reaction paths that can occur in a radical system. Because they are characterized

  16. Cold Pad-Batch dyeing method for cotton fabric dyeing with reactive dyes using ultrasonic energy.

    PubMed

    Khatri, Zeeshan; Memon, Muhammad Hanif; Khatri, Awais; Tanwari, Anwaruddin

    2011-11-01

    Reactive dyes are vastly used in dyeing and printing of cotton fibre. These dyes have a distinctive reactive nature due to active groups which form covalent bonds with -OH groups of cotton through substitution and/or addition mechanism. Among many methods used for dyeing cotton with reactive dyes, the Cold Pad Batch (CPB) method is relatively more environment friendly due to high dye fixation and non requirement of thermal energy. The dyed fabric production rate is low due to requirement of at least twelve hours batching time for dye fixation. The proposed CPB method for dyeing cotton involves ultrasonic energy resulting into a one third decrease in batching time. The dyeing of cotton fibre was carried out with CI reactive red 195 and CI reactive black 5 by conventional and ultrasonic (US) method. The study showed that the use of ultrasonic energy not only shortens the batching time but the alkalis concentrations can considerably be reduced. In this case, the colour strength (K/S) and dye fixation (%F) also enhances without any adverse effect on colour fastness of the dyed fabric. The appearance of dyed fibre surface using scanning electron microscope (SEM) showed relative straightening of fibre convolutions and significant swelling of the fibre upon ultrasonic application. The total colour difference values ΔE (CMC) for the proposed method, were found within close proximity to the conventionally dyed sample.

  17. Dye-coated europium monosulfide

    SciTech Connect

    Kar, Srotoswini; Dollahon, Norman R.; Stoll, Sarah L.

    2011-05-15

    Nanoparticles of EuS were synthesized using europium dithiocarbamate complexes. The resulting nanoparticles were coated with the dye, 1-pyrene carboxylic acid and the resulting material was characterized using X-ray powder diffraction, TEM, and UV-visible spectroscopy. Fluorescence spectroscopy was used to determine the relative energy of the conduction band edge to the excited state energy of the dye. -- Graphical abstract: Dye sensitized magnetic semiconductor materials were prepared by synthesizing EuS nanoparticles using single source precursors and coating with the dye, 1-pyrene carboxylic acid. Display Omitted highlights: > Synthesized EuS nanoparticles, 11{+-}2.4 nm characterized using XRD, TEM, and UV-vis. spect. > Grafted a dye to the surface and characterized the product using XRD, FTIR, UV-vis., and TEM. > Studied the photophysical properties using fluorescence spectroscopy. > Determined the relative dye excited state to the conduction band of the semiconductor.

  18. A survey of extraction solvents in the forensic analysis of textile dyes.

    PubMed

    Groves, Ethan; Palenik, Christopher S; Palenik, Skip

    2016-11-01

    The characterization and identification of dyes in fibers can be used to provide investigative leads and strengthen associations between known and questioned items of evidence. The isolation of a dye from its matrix (e.g., a textile fiber) permits detailed characterization, comparison and, in some cases, identification using methods such as thin layer chromatography in conjunction with infrared and Raman spectroscopy. A survey of dye extraction publications reveals that pyridine:water (4:3) is among the most commonly cited extraction solvent across a range of fiber and dye chemistries. Here, the efficacy of this solvent system has been evaluated for the extraction of dyes from 172 commercially prevalent North American textile dyes. The evaluated population represents seven dye application classes, 18 chemical classes, and spans nine types of commercial textile fibers. The results of this survey indicate that ∼82% of the dyestuffs studied are extractable using this solvent system. The results presented here summarize the extraction efficacy by class and fiber type and illustrate that this solvent system is applicable to a wider variety of classes and fibers than previously indicated in the literature. While there is no universal solvent for fiber extraction, these results demonstrate that pyridine:water represents an excellent first step for extracting unknown dyes from questioned fibers in forensic casework.

  19. Automated pressure scanning of tunable dye lasers

    NASA Astrophysics Data System (ADS)

    Gottscho, R. A.

    1985-04-01

    A method for the remote control of tunable laser frequency tuning is proposed in the framework of real-time monitoring of the chemistry and physics of plasma, combustion, and chemical vapor deposition reactions. The technique presented involves indirect frequency tuning and stabilization by direct control of the laser cavity pressure. The long-term drift in power, resulting from the grating and etalon misalignment is suggested to be correctable by using a second feedback circuit which would optimize laser power by finely tuning the etalon or grating. Experimental results obtained with a dye laser of Hansch type are included; a maximum variation in LIF signal of + or - 7 percent, which corresponds to a frequency drift of + or - 0.005/cm, over a 30-min interval was achieved. A block diagram of the feedback loop and the LIF apparatus are included.

  20. Homogeneous plate based antibody internalization assay using pH sensor fluorescent dye.

    PubMed

    Nath, Nidhi; Godat, Becky; Zimprich, Chad; Dwight, Stephen J; Corona, Cesear; McDougall, Mark; Urh, Marjeta

    2016-04-01

    Receptor-mediated antibody internalization is a key mechanism underlying several anti-cancer antibody therapeutics. Delivering highly toxic drugs to cancer cells, as in the case of antibody drug conjugates (ADCs), efficient removal of surface receptors from cancer cells and changing the pharmacokinetics profile of the antibody drugs are some of key ways that internalization impacts the therapeutic efficacy of the antibodies. Over the years, several techniques have been used to study antibody internalization including radiolabels, fluorescent microscopy, flow cytometry and cellular toxicity assays. While these methods allow analysis of internalization, they have limitations including a multistep process and limited throughput and are generally endpoint assays. Here, we present a new homogeneous method that enables time and concentration dependent measurements of antibody internalization. The method uses a new hydrophilic and bright pH sensor dye (pHAb dye), which is not fluorescent at neutral pH but becomes highly fluorescent at acidic pH. For receptor mediated antibody internalization studies, antibodies against receptors are conjugated with the pHAb dye and incubated with the cells expressing the receptors. Upon binding to the receptor, the dyes conjugated to the antibody are not fluorescent because of the neutral pH of the media, but upon internalization and trafficking into endosomal and lysosomal vesicles the pH drops and dyes become fluorescent. The enabling attributes of the pHAb dyes are the hydrophilic nature to minimize antibody aggregation and bright fluorescence at acidic pH which allows development of simple plate based assays using a fluorescent reader. Using two different therapeutic antibodies--Trastuzumab (anti-HER2) and Cetuximab (anti-EGFR)--we show labeling with pHAb dye using amine and thiol chemistries and impact of chemistry and dye to antibody ration on internalization. We finally present two new approaches using the pHAb dye, which will be

  1. Polynitrogen Chemistry

    DTIC Science & Technology

    2013-09-24

    4N3, while As(C6H5)4N3 presents a borderline case.23 Theoretical Calculations High-level theoretical studies of nitrogen, oxygen, selenium and...Dixon, D. A.; Christe, K. O., "Thermochemical Properties of Selenium Fluorides, Oxides, and Oxofluorides," Inorganic Chemistry, p. 2472, vol. 51, (2012...34Thermochemical Properties of Selenium Fluorides, Oxides, and Oxofluorides," Inorg. Chem., p. 2472, vol. 51, (2012). 26. K. S. Thanthiriwatte, M. Vasiliu

  2. Computational chemistry

    NASA Technical Reports Server (NTRS)

    Arnold, J. O.

    1987-01-01

    With the advent of supercomputers, modern computational chemistry algorithms and codes, a powerful tool was created to help fill NASA's continuing need for information on the properties of matter in hostile or unusual environments. Computational resources provided under the National Aerodynamics Simulator (NAS) program were a cornerstone for recent advancements in this field. Properties of gases, materials, and their interactions can be determined from solutions of the governing equations. In the case of gases, for example, radiative transition probabilites per particle, bond-dissociation energies, and rates of simple chemical reactions can be determined computationally as reliably as from experiment. The data are proving to be quite valuable in providing inputs to real-gas flow simulation codes used to compute aerothermodynamic loads on NASA's aeroassist orbital transfer vehicles and a host of problems related to the National Aerospace Plane Program. Although more approximate, similar solutions can be obtained for ensembles of atoms simulating small particles of materials with and without the presence of gases. Computational chemistry has application in studying catalysis, properties of polymers, all of interest to various NASA missions, including those previously mentioned. In addition to discussing these applications of computational chemistry within NASA, the governing equations and the need for supercomputers for their solution is outlined.

  3. Overhead Projector Spectrum of Polymethine Dye: A Physical Chemistry Demonstration.

    ERIC Educational Resources Information Center

    Solomon, Sally; Hur, Chinhyu

    1995-01-01

    Encourages the incorporation into lecture of live experiments that can be predicted or interpreted with abstract models. A demonstration is described where the position of the predominant peak of 1,1'-diethyl-4,4'-cyanine iodide is measured in class using an overhead projector spectrometer, then predicted using the model of a particle in a…

  4. Dye sensitized solar cells.

    PubMed

    Wei, Di

    2010-03-16

    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 TiO(2), ZnO electrodes, ionic liquid electrolytes, carbon nanotubes, graphene and solid state DSSC have all been included and discussed.

  5. Dye Sensitized Solar Cells

    PubMed Central

    Wei, Di

    2010-01-01

    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. PMID:20480003

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

    PubMed

    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

  7. Synthesis of Triarylmethane and Xanthene Dyes Using Electrophilic Aromatic Substitution Reactions

    ERIC Educational Resources Information Center

    McCullagh, James V.; Daggett, Kelly A.

    2007-01-01

    The synthesis of dyes has long been a popular topic in organic chemistry laboratory experiments because it allows students to see first hand that reactions learned in class can be used to make compounds with useful applications. In this experiment electrophilic aromatic substitution reactions are used to synthesize several triarylmethane and…

  8. Parallel Combinatorial Synthesis of Azo Dyes: A Combinatorial Experiment Suitable for Undergraduate Laboratories

    ERIC Educational Resources Information Center

    Gung, Benjamin W.; Taylor, Richard T.

    2004-01-01

    An experiment in the parallel synthesis of azo dyes that demonstrates the concepts of structure-activity relationships and chemical diversity with vivid colors is described. It is seen that this experiment is suitable for the second-semester organic chemistry laboratory and also for the one-semester organic laboratory.

  9. New Analytical Method for the Determination of Detergent Concentration in Water by Fabric Dyeing

    ERIC Educational Resources Information Center

    Seng, Set; Kita, Masakazu; Sugihara, Reiko

    2007-01-01

    The use of harmful organic solvents in classrooms has become a critical issue of concern in the field of chemistry education. This article describes a classroom activity at a high school in which an acrylic fabric was used as the extraction medium in the analysis of the detergent concentration in water instead of organic solvents. Dyes were used…

  10. Photocatalytic Destruction of an Organic Dye Using TiO2 and Solar Energy.

    ERIC Educational Resources Information Center

    Giglio, Kimberly D.; And Others

    1995-01-01

    Describes a general chemistry experiment that is carried out in sunlight to illustrate the ability of TiO2 to act as a photocatalyst by mineralizing an organic dye into carbon dioxide. Details about the construction of the reactor system used to perform this experiment are included. (DDR)

  11. Dye laser traveling wave amplifier

    NASA Technical Reports Server (NTRS)

    Davidson, F.

    1983-01-01

    A flash lamp pumped dye laser suitable for use as an amplifier stage was developed. The desired output laser pulses are of nanosecond duration, tunable in center frequency, and of good optical quality. Its usefulness as a laser oscillator is emphasized, because it constitutes a compact, relatively efficient source of tunable dye laser light.

  12. Effects of Dye Structure in Dye Sensitized Solar Cells

    NASA Astrophysics Data System (ADS)

    Hoskins, Anna R.

    Dye sensitized solar cells (DSSCs) are photovoltaic devices that may compete with standard silicon solar cells due to their ease of construction and lower cost [32]. Ruthenium dye structures, such as N3 (Ru -- (4,4' -- dicarboxylic acid -- 2,2' -- bipyridine)2(NCS)2), have shown promise for collection efficiencies near silicon photovoltaic levels [20, 33]. DSSCs have not achieved the reproducibility and maximum efficiency of silicon solar cells [33, 34]. Altering ligands on the dye molecules may affect the energies of light that are absorbed by the DSSC. Photovoltaic testing, including current versus voltage tests, of DSSCs with both narrow band monochromated light sources and broadband (AM1.5 solar simulator) allows comparison between maximum efficiency, short-circuit current, open circuit voltage, and spectral response (SR) for the dye molecules. By studying how the efficiency and power output change with different dye structures, the nature of how to increase efficiency of the DSSC can be addressed. Conjugation length of the ligands in ruthenium dye molecules can be shown, through square-well and Huckel theory calculations, to have a role in changing the HOMO-LUMO gap of the molecules and the absorption of specific wavelengths of light by the DSSC. The efficiency, max power, short circuit current, open circuit voltage, and SR were all measured for the DSSCs at wavelengths from 350 nm to 690 nm using a monochromated light source. Measurements taken at 20 nm steps reveal trends in the photon acceptance for dye molecules that can be linked to the conjugation length of the ligands in the dye through the SR. The change in the SR centroid and UV-VIS measurements indicate a trend toward increasing optimal wavelength with increasing conjugation length in the dye molecules; however these trends are not as pronounced as theoretical calculations for the dyes. This difference in wavelength shift occurs due to the theoretical calculations accounting for only the ligands

  13. Antimicrobial dyes and mechanosensitive channels.

    PubMed

    Boulos, Ramiz A

    2013-08-01

    The search for new and effective antimicrobial agents has never been as important; however, since the discovery of antibiotics, exploring the antimicrobial activity of dyes has been forgotten. Antimicrobial dyes are an untapped resource and have the ability to potentially combat the spread of drug-resistant bacteria either alone or as antimicrobial adjuvants. The mechanosensitive ion channel of large conductance (MscL) is highly conserved and ubiquitous in bacterial species. There is evidence to suggest that at least one triphenylmethane dye acts through the highly conserved MscL channel and combining the two approaches of exploring the mechanism of action of other triphenylmethane dyes or antimicrobial dyes in general and the novel MscL target provides a new opportunity for further exploration.

  14. Fluorometric procedures for dye tracing

    USGS Publications Warehouse

    Wilson, James F.

    1968-01-01

    This manual describes the current fluorometric procedures used by the U.S. Geological Survey in dye tracer studies such as time of travel, dispersion, reaeration, and dilution-type discharge measurements. The advantages of dye tracing are (1) low detection and measurement limits and (2) simplicity and accuracy in measuring dye tracer concentrations using fluorometric techniques. The manual contains necessary background information about fluorescence, dyes, and fluorometers and a description of fluorometric operation and calibration procedures as a guide for laboratory and field use. The background information should be useful to anyone wishing to experiment with dyes, fluorometer components, or procedures different from those described. In addition, a brief section on aerial photography is included because of its possible use to supplement ground-level fluorometry.

  15. Fluorometric procedures for dye tracing

    USGS Publications Warehouse

    Wilson, James E.; Cobb, E.D.; Kilpatrick, F.A.

    1984-01-01

    This manual describes the current fluorometric procedures used by the U.S. Geological Survey in dye tracer studies such as time of travel, dispersion, reaeration, and dilution-type discharge measurements. The outstanding characteristics of dye tracing are: (1) the low detection and measurement limits, and (2) the simplicity and accuracy of measuring dye tracer concentrations using fluorometric techniques. The manual contains necessary background information about fluorescence, dyes, and fluorometers and a description of fluorometric operation and calibration procedures as a general guide for laboratory and field use. The background information should be useful to anyone wishing to experiment with dyes, fluorometer components, or procedures different from those described. In addition, a brief section is included on aerial photography because of its possible use to supplement ground-level fluorometry. (USGS)

  16. Fluorometric procedures for dye tracing

    USGS Publications Warehouse

    Wilson, James F.; Cobb, Ernest D.; Kilpatrick, F.A.

    1986-01-01

    This manual describes the current fluorometric procedures used by the U.S. Geological Survey in dye tracer studies such as time of travel, dispersion, reaeration, and dilution-type discharge measurements. The advantages of dye tracing are (1) low detection and measurement limits and (2) simplicity and accuracy in measuring dye tracer concentrations using fluorometric techniques. The manual contains necessary background information about fluorescence, dyes, and fluorometers and a description of fluorometric operation and calibration procedures as a guide for laboratory and field use. The background information should be useful to anyone wishing to experiment with dyes, fluorometer components, or procedures different from those described. In addition, a brief section on aerial photography is included because of its possible use to supplement ground-level fluorometry.

  17. Diode pumped tunable dye laser

    NASA Astrophysics Data System (ADS)

    Burdukova, O.; Gorbunkov, M.; Petukhov, V.; Semenov, M.

    2017-03-01

    A wavelength-tunable dye laser pumped by blue laser diodes (λ =445 nm) in a 200 ns pulsed mode has been developed. We used a 3-mirror cavity with transverse excitation and total internal reflection of laser beam in the active element. Tuning curves for 8 dyes in benzyl alcohol were measured in the range of 506-700 nm. Four dyes have their tuning range more than 60 nm, which is comparable to the tuning ranges of other dye lasers pumped by more expensive sources. The output energy obtained at the generation maximum of both DCM and coumarin 540A dyes was approximately 130 nJ while the pump energy was 2400 nJ.

  18. (Pesticide chemistry)

    SciTech Connect

    Barnthouse, L.W.

    1990-09-04

    This report summarizes a trip by L. W. Barnthouse of the Environmental Sciences Division (ESD), Oak Ridge National Laboratory (ORNL), to Hamburg, Federal Republic of Germany (FRG), where he participated in the 7th International Congress of Pesticide Chemistry. He chaired a workshop on experimental systems for determining effects of pesticides on nontarget organisms and gave an oral presentation at a symposium on pesticide risk assessment. Before returning to the United States, Dr. Barnthouse visited the Netherlands Institute for Sea Research in Texel, the Netherlands.

  19. Arylamine organic dyes for dye-sensitized solar cells.

    PubMed

    Liang, Mao; Chen, Jun

    2013-04-21

    Arylamine organic dyes with donor (D), π-bridge (π) and acceptor (A) moieties for dye-sensitized solar cells (DSCs) have received great attention in the last decade because of their high molar absorption coefficient, low cost and structural variety. In the early stages, the efficiency of DSCs with arylamine organic dyes with D-π-A character was far behind that of DSCs with ruthenium(II) complexes partly due to the lack of information about the relationship between the chemical structures and the photovoltaic performance. However, exciting progress has been recently made, and power conversion efficiencies over 10% were obtained for DSCs with arylamine organic dyes. It is thus that the recent research and development in the field of arylamine organic dyes employing an iodide/triiodide redox couple or polypyridyl cobalt redox shuttles as the electrolytes for either DSCs or solid-state DSCs has been summarized. The cell performance of the arylamine organic dyes are compared, providing a comprehensive overview of arylamine organic dyes, demonstrating the advantages/disadvantages of each class, and pointing out the field that needs to reinforce the research direction in the further application of DSCs.

  20. Adsorption of dyes using different types of clay: a review

    NASA Astrophysics Data System (ADS)

    Adeyemo, Aderonke Ajibola; Adeoye, Idowu Olatunbosun; Bello, Olugbenga Solomon

    2015-09-01

    Increasing amount of dyes in the ecosystem particularly in wastewater has propelled the search for more efficient low-cost adsorbents. The effective use of the sorption properties (high surface area and surface chemistry, lack of toxicity and potential for ion exchange) of different clays as adsorbents for the removal of different type of dyes (basic, acidic, reactive) from water and wastewater as potential alternatives to activated carbons has recently received widespread attention because of the environmental-friendly nature of clay materials. Insights into the efficiencies of raw and modified/activated clay adsorbents and ways of improving their efficiencies to obtain better results are discussed. Acid-modified clay resulted in higher rate of dye adsorption and an increased surface area and porosity (49.05 mm2 and 53.4 %). Base-modified clay has lower adsorption capacities, while ZnCl2-modified clay had the least rate of adsorption with a surface area of 44.3 mm2 and porosity of 43.4 %. This review also explores the grey areas of the adsorption properties of the raw clays and the improved performance of activated/modified clay materials with particular reference to the effects of pH, temperature, initial dye concentration and adsorbent dosage on the adsorption capacities of the clays. Various challenges encountered in using clay materials are highlighted and a number of future prospects for the adsorbents are proposed.

  1. Quantitative comparison of long-wavelength Alexa Fluor dyes to Cy dyes: fluorescence of the dyes and their bioconjugates.

    PubMed

    Berlier, Judith E; Rothe, Anca; Buller, Gayle; Bradford, Jolene; Gray, Diane R; Filanoski, Brian J; Telford, William G; Yue, Stephen; Liu, Jixiang; Cheung, Ching-Ying; Chang, Wesley; Hirsch, James D; Beechem, Joseph M; Haugland, Rosaria P; Haugland, Richard P

    2003-12-01

    Amine-reactive N-hydroxysuccinimidyl esters of Alexa Fluor fluorescent dyes with principal absorption maxima at about 555 nm, 633 nm, 647 nm, 660 nm, 680 nm, 700 nm, and 750 nm were conjugated to antibodies and other selected proteins. These conjugates were compared with spectrally similar protein conjugates of the Cy3, Cy5, Cy5.5, Cy7, DY-630, DY-635, DY-680, and Atto 565 dyes. As N-hydroxysuccinimidyl ester dyes, the Alexa Fluor 555 dye was similar to the Cy3 dye, and the Alexa Fluor 647 dye was similar to the Cy5 dye with respect to absorption maxima, emission maxima, Stokes shifts, and extinction coefficients. However, both Alexa Fluor dyes were significantly more resistant to photobleaching than were their Cy dye counterparts. Absorption spectra of protein conjugates prepared from these dyes showed prominent blue-shifted shoulder peaks for conjugates of the Cy dyes but only minor shoulder peaks for conjugates of the Alexa Fluor dyes. The anomalous peaks, previously observed for protein conjugates of the Cy5 dye, are presumably due to the formation of dye aggregates. Absorption of light by the dye aggregates does not result in fluorescence, thereby diminishing the fluorescence of the conjugates. The Alexa Fluor 555 and the Alexa Fluor 647 dyes in protein conjugates exhibited significantly less of this self-quenching, and therefore the protein conjugates of Alexa Fluor dyes were significantly more fluorescent than those of the Cy dyes, especially at high degrees of labeling. The results from our flow cytometry, immunocytochemistry, and immunohistochemistry experiments demonstrate that protein-conjugated, long-wavelength Alexa Fluor dyes have advantages compared to the Cy dyes and other long-wavelength dyes in typical fluorescence-based cell labeling applications.

  2. Dye-sensitized solar cells

    DOEpatents

    Skotheim, T.A.

    1980-03-04

    A low-cost dye-sensitized Schottky barrier solar cell is comprised of a substrate of semiconductor with an ohmic contact on one face, a sensitizing dye adsorbed onto the opposite face of the semiconductor, a transparent thin-film layer of a reducing agent over the dye, and a thin-film layer of metal over the reducing agent. The ohmic contact and metal layer constitute electrodes for connection to an external circuit and one or the other or both are made transparent to permit light to penetrate to the dye and be absorbed therein for generating electric current. The semiconductor material chosen to be the substrate is one having a wide bandgap and which therefore is transparent; the dye selected is one having a ground state within the bandgap of the semiconductor to generate carriers in the semiconductor, and a first excited state above the conduction band edge of the semiconductor to readily conduct electrons from the dye to the semiconductor; the reducing agent selected is one having a ground state above the ground state of the sensitizer to provide a plentiful source of electrons to the dye during current generation and thereby enhance the generation; and the metal for the thin-film layer of metal is selected to have a Fermi level in the vicinity of or above the ground state of the reducing agent to thereby amply supply electrons to the reducing agent. 3 figs.

  3. Dye-sensitized solar cells

    DOEpatents

    Skotheim, Terje A. [Berkeley, CA

    1980-03-04

    A low-cost dye-sensitized Schottky barrier solar cell comprised of a substrate of semiconductor with an ohmic contact on one face, a sensitizing dye adsorbed onto the opposite face of the semiconductor, a transparent thin-film layer of a reducing agent over the dye, and a thin-film layer of metal over the reducing agent. The ohmic contact and metal layer constitute electrodes for connection to an external circuit and one or the other or both are made transparent to permit light to penetrate to the dye and be absorbed therein for generating electric current. The semiconductor material chosen to be the substrate is one having a wide bandgap and which therefore is transparent; the dye selected is one having a ground state within the bandgap of the semiconductor to generate carriers in the semiconductor, and a first excited state above the conduction band edge of the semiconductor to readily conduct electrons from the dye to the semiconductor; the reducing agent selected is one having a ground state above the ground state of the sensitizer to provide a plentiful source of electrons to the dye during current generation and thereby enhance the generation; and the metal for the thin-film layer of metal is selected to have a Fermi level in the vicinity of or above the ground state of the reducing agent to thereby amply supply electrons to the reducing agent.

  4. Never say dye

    PubMed Central

    2012-01-01

    Recent years have seen a remarkable increase in the number of publications dealing with the application of epifluorescence microscopy in cell biology. This can be widely attributed to the development of state-of-the-art image processing programs, as well as the development of new reagents/probes, which allow the labeling of most cell structures, organelles and metabolites with high specificity. However, the use of a specific fluorescent dye, 3,3′-dihexyloxacarbocyanine iodide (DiOC6), has been recently revisited and several new application potentials have emerged. The goal of this mini-review is to provide an up-to-date overview of the multiple roles of this multifaceted probe. PMID:22476459

  5. Why Teach Environmental Chemistry?

    ERIC Educational Resources Information Center

    Gardner, Marjorie H.

    1974-01-01

    Discusses the importance of teaching environmental chemistry in secondary school science classes, and outlines five examples of environmental chemistry problems that focus on major concepts of chemistry and have critical implications for human survival and well-being. (JR)

  6. Science Update: Inorganic Chemistry

    ERIC Educational Resources Information Center

    Rawls, Rebecca

    1978-01-01

    This first in a series of articles describing the state of the art of various branches of chemistry reviews inorganic chemistry, including bioinorganic, photochemistry, organometallic, and solid state chemistries. (SL)

  7. Hair dye poisoning and rhabdomyolysis.

    PubMed

    Bokutz, Munira; Nasir, Nosheen; Mahmood, Faisal; Sajid, Sara

    2015-04-01

    Hair dye ingestion is a rare cause of toxicity in Pakistan. We are presenting the case report of a 55 year old male who presented with accidental hair dye ingestion and developed laryngeal oedema requiring emergent tracheostomy. He had also developed aspiration pneumonitis and chemical oesophagitis. However, the most alarming manifestation was rhabdomyolysis. Hair dye toxicity can be fatal if not recognized early. There is no antidote available. Rhabdomyolysis is a complication and needs to be managed aggressively in order to prevent long term morbidity.

  8. Bichromophoric Dyes for Wavelength Shifting of Dye-Protein Fluoromodules

    PubMed Central

    Pham, Ha H.; Szent-Gyorgyi, Christopher; Brotherton, Wendy L.; Schmidt, Brigitte F.; Zanotti, Kimberly J.; Waggoner, Alan S.

    2015-01-01

    Dye-protein fluoromodules consist of fluorogenic dyes and single chain antibody fragments that form brightly fluorescent noncovalent complexes. This report describes two new bichromophoric dyes that extend the range of wavelengths of excitation or emission of existing fluoromodules. In one case, a fluorogenic thiazole orange (TO) was attached to an energy acceptor dye, Cy5. Upon binding to a protein that recognizes TO, red emission due to efficient energy transfer from TO to Cy5 replaces the green emission observed for monochromophoric TO bound to the same protein. Separately, TO was attached to a coumarin that serves as an energy donor. The same green emission is observed for coumarin-TO and TO bound to a protein, but efficient energy transfer allows violet excitation of coumarin-TO, versus longer wavelength, blue excitation of monochromophoric TO. Both bichromophores exhibit low nanomolar KD values for their respective proteins, >95% energy transfer efficiency and high fluorescence quantum yields. PMID:25679477

  9. Combustion chemistry

    SciTech Connect

    Brown, N.J.

    1993-12-01

    This research is concerned with the development and use of sensitivity analysis tools to probe the response of dependent variables to model input variables. Sensitivity analysis is important at all levels of combustion modeling. This group`s research continues to be focused on elucidating the interrelationship between features in the underlying potential energy surface (obtained from ab initio quantum chemistry calculations) and their responses in the quantum dynamics, e.g., reactive transition probabilities, cross sections, and thermal rate coefficients. The goals of this research are: (i) to provide feedback information to quantum chemists in their potential surface refinement efforts, and (ii) to gain a better understanding of how various regions in the potential influence the dynamics. These investigations are carried out with the methodology of quantum functional sensitivity analysis (QFSA).

  10. Science Update: Inorganic Chemistry.

    ERIC Educational Resources Information Center

    Rawls, Rebecca

    1981-01-01

    Describes areas of inorganic chemistry which have changed dramatically in the past year or two, including photochemistry, electrochemistry, organometallic complexes, inorganic reaction theory, and solid state chemistry. (DS)

  11. Enzymatic biotransformation of synthetic dyes.

    PubMed

    Rodríguez-Couto, S

    2009-11-01

    Environmental pollution by discharge of dye-containing effluents represents a serious ecological concern in many countries. Public demands for colour-free discharges to receiving waters have made decolouration of a variety of industrial wastewater a top priority. The current existing techniques for dye removal have several drawbacks such as high cost, low efficiency, use of large amounts of chemicals and formation of toxic sub-products. This has impelled the search for alternative methods such as those based on oxidative enzymes. This approach is believed to be a promising technology since it is cost-effective, environmentally friendly and does not produce sludge. Enzymatic transformation of synthetic dyes can be described as the conversion of dye molecules by enzymes into simpler and generally colourless molecules. Detailed characterisation of the metabolites produced during enzymatic transformation of synthetic dyes as well as ecotoxicity studies is of great importance to assess the effectiveness of the biodegradation process. However, most reports on the biotreatment of dyes mainly deal with decolouration and there are few reports on the reduction in toxicity or on the identification of the biodegradation products. This implies a limitation to assess their true technical potential.

  12. Dye removal by immobilised fungi.

    PubMed

    Rodríguez Couto, Susana

    2009-01-01

    Dyes are widely used within the food, pharmaceutical, cosmetic, printing, textile and leather industries. This has resulted in the discharge of highly coloured effluents that affect water transparency and gas solubility in water bodies. Furthermore, they pose a problem because of their carcinogenicity and toxicity. Therefore, removal of such dyes before discharging them into natural water streams is essential. For this, appropriate treatment technologies are required. The treatment of recalcitrant and toxic dyes with traditional technologies is not always effective or may not be environmentally friendly. This has impelled the search for alternative technologies such as biodegradation with fungi. In particular, ligninolytic fungi and their non-specific oxidative enzymes have been reported to be responsible for the decolouration of different synthetic dyes. Thus, the use of such fungi is becoming a promising alternative to replace or complement the current technologies for dye removal. Processes using immobilised growing cells seem to be more promising than those with free cells, since the immobilisation allows using the microbial cells repeatedly and continuously. This paper reviews the application of fungal immobilisation to dye removal.

  13. Effect of silver and palladium on dye-removal characteristics of anatase-titania nanotubes.

    PubMed

    Harsha, N; Ranya, R; Shukla, S; Biju, S; Reddy, M L P; Warrier, K G K

    2011-03-01

    Anatase-titania nanotubes have been synthesized via hydrothermal and surface-modified by depositing silver and palladium via ultraviolet-reduction method. The pure and surface-modified anatase-titania nanotubes have been characterized using the transmission electron microscope, selected-area electron diffraction, X-ray diffraction, diffuse reflectance, photoluminescence, and Fourier transform infrared spectroscope to reveal their average size, structure, and surface-chemistry. The nanotubes have been utilized for the dye-removal application involving the surface-adsorption mechanism under the dark-condition and photocatalytic degradation mechanism under the ultraviolet-radiation exposure. The variation in the dye-concentration during the dye-adsorption and photocatalysis processes has been determined using the ultraviolet-visible absorption spectrophotometer with methylene blue as a model catalytic dye-agent. It has been shown that silver-deposited anatase-titania nanotubes are more effective in enhancing the kinetics of the dye-removal via surface-adsorption and photocatalytic degradation mechanisms relative to the palladium-deposited anatase-titania nanotubes, which has been attributed to the differences in the surface-chemistry of anatase-titania nanotubes induced by the respective metal-deposition.

  14. Using Chemistry and Color To Analyze Household Products: A 10-12 Hour Laboratory Project at the General Chemistry Level

    NASA Astrophysics Data System (ADS)

    Bosma, Wayne B.

    1998-02-01

    A general chemistry experiment is described in which the students use UV/Visible spectrometry as an analytical tool, for both compound identification and pH measurement. In the first portion of the experiment, the students compare spectra to determine which FD and C dyes are contained in household products. They furthermore use chromatography to separate the dyes in grape Kool-Aid, and analyze the products with the spectrometer. In the second portion of the experiment, the students use Beer's Law to determine the pH of solutions containing an acid/base indicator. The experiments are visually stimulating and provide a solid introduction to spectroscopy and perceived color.

  15. Trace Chemistry

    NASA Technical Reports Server (NTRS)

    Radhakrishnan, Krishnan; Whitefield, Philip

    1999-01-01

    The goals of the trace chemistry group were to identify the processes relevant to aerosol and aerosol precursor formation occurring within aircraft gas turbine engines; that is, within the combustor, turbine, and nozzle. The topics of discussion focused on whether the chemistry of aerosol formation is homogeneous or heterogeneous; what species are important for aerosol and aerosol precursor formation; what modeling/theoretical activities to pursue; what experiments to carry out that both support modeling activities and elucidate fundamental processes; and the role of particulates in aerosol and aerosol precursor formation. The consensus of the group was that attention should be focused on SO2, SO3, and aerosols. Of immediate concern is the measurement of the concentration of the species SO3, SO2, H2SO4 OH, HO2, H2O2, O, NO, NO2, HONO, HNO3, CO, and CO2 and particulates in various engines, both those currently in use and those in development. The recommendation was that concentration measurements should be made at both the combustor exit and the engine exit. At each location the above species were classified into one of four categories of decreasing importance, Priority I through IV, as follows: Combustor exit: Priority I species - SO3:SO2 ratio, SO3, SO2, and particulates; Priority II species: OH and O; Priority III species - NO and NO2; and Priority IV species - CO and CO2. For the Engine exit: Priority I species - SO3:SO2 ratio, SO3, SO2,H2SO4, and particulates; Priority II species: OH,HO2, H2O2, and O; Priority III species - NO, NO2, HONO, and HNO3; and Priority IV species - CO and CO2. Table I summarizes the anticipated concentration range of each of these species. For particulate matter, the quantities of interest are the number density, size distribution, and composition. In order to provide data for validating multidimensional reacting flow models, it would be desirable to make 2-D, time-resolved measurements of the concentrations of the above species and

  16. Dye laser amplifier including a dye cell contained within a support vessel

    DOEpatents

    Davin, James

    1992-01-01

    A large (high flow rate) dye laser amplifier in which a continous replenished supply of dye is excited by a first light beam, specifically a copper vapor laser beam, in order to amplify the intensity of a second different light beam, specifically a dye beam, passing through the dye is disclosed herein. This amplifier includes a dye cell defining a dye chamber through which a continuous stream of dye is caused to pass at a flow rate of greater than 30 gallons/minute at a static pressure greater than 150 pounds/square inch and a specifically designed support vessel for containing the dye cell.

  17. Dye laser amplifier including a dye cell contained within a support vessel

    DOEpatents

    Davin, J.

    1992-12-01

    A large (high flow rate) dye laser amplifier in which a continuous replenished supply of dye is excited by a first light beam, specifically a copper vapor laser beam, in order to amplify the intensity of a second different light beam, specifically a dye beam, passing through the dye is disclosed herein. This amplifier includes a dye cell defining a dye chamber through which a continuous stream of dye is caused to pass at a flow rate of greater than 30 gallons/minute at a static pressure greater than 150 pounds/square inch and a specifically designed support vessel for containing the dye cell. 6 figs.

  18. Azo Dyes and Their Interfacial Activity: Implications for Multiphase Flow Experiments

    SciTech Connect

    Tuck, D.M.

    1999-04-21

    Interfacial effects play an important role in governing multiphase fluid behavior in porous media (Neustadter 1984; Tuck et al. 1988). For instance, several dimensionless numbers have been developed to express important force ratios applicable to multiphase flow in porous media (Morrow and Songkran 1981; Chatzis and Morrow 1984; Wardlaw 1988; Pennell et al. 1996; Dawson and Roberts 1997). These force ratios emphasize the importance of interfacial properties. Our objectives are to provide chemical information regarding the dyes commonly used in multiphase flow visualization studies and to show the surface chemistry effects of the most commonly used dye, Sudan IV, in the tetrachloroethylene (PCE)-water-glass system

  19. Computational Chemistry Approach to Interpret the Crystal Violet Adsorption on Golbasi Lignite Activated Carbon

    NASA Astrophysics Data System (ADS)

    Depci, Tolga; Sarikaya, Musa; Prisbrey, Keith A.; Yucel, Aysegul

    2016-10-01

    In this paper, adsorption mechanism of Crystal Violet (CV) dye from the aqueous solution on the activated carbon prepared from Golbasi lignite was explained and interpreted by a computational chemistry approach and experimental studies. Molecular dynamic simulations and Ab initio frontier orbital analysis indicated relatively high energy and electron transfer processes during adsorption, and molecular dynamics simulations showed CV dye molecules moving around on the activated carbon surface after adsorption, facilitating penetration into cracks and pores. The experimental results supported to molecular dynamic simulation and showed that the monolayer coverage occurred on the activated carbon surface and each CV dye ion had equal sorption activation energy.

  20. Discovery of Black Dye Crystal Structure Polymorphs: Implications for Dye Conformational Variation in Dye-Sensitized Solar Cells.

    PubMed

    Cole, Jacqueline M; Low, Kian Sing; Gong, Yun

    2015-12-23

    We present the discovery of a new crystal structure polymorph (1) and pseudopolymorph (2) of the Black Dye, one of the world's leading dyes for dye-sensitized solar cells, DSSCs (10.4% device performance efficiency). This reveals that Black Dye molecules can adopt multiple low-energy conformers. This is significant since it challenges existing models of the Black Dye···TiO2 adsorption process that renders a DSSC working electrode; these have assumed a single molecular conformation that refers to the previously reported Black Dye crystal structure (3). The marked structural differences observed between 1, 2, and 3 make the need for modeling multiple conformations more acute. Additionally, the ordered form of the Black Dye (1) provides a more appropriate depiction of its anionic structure, especially regarding its anchoring group and NCS bonding descriptions. The tendency toward NCS ligand isomerism, evidenced via the disordered form 2, has consequences for electron injection and electron recombination in Black Dye embedded DSSC devices. Dyes 2 and 3 differ primarily by the absence or presence of a solvent of crystallization, respectively; solvent environment effects on the dye are thereby elucidated. This discovery of multiple Black Dye conformers from diffraction, with atomic-level definition, complements recently reported nanoscopic evidence for multiple dye conformations existing at a dye···TiO2 interface, for a chemically similar DSSC dye; those results emanated from imaging and spectroscopy, but were unresolved at the submolecular level. Taken together, these findings lead to the general notion that multiple dye conformations should be explicitly considered when modeling dye···TiO2 interfaces in DSSCs, at least for ruthenium-based dye complexes.

  1. Simultaneous dyeing and antibacterial finishing for cotton cellulose using a new reactive dye.

    PubMed

    Farouk, R; Gaffer, H E

    2013-08-14

    Simultaneous dyeing and antibacterial finishing for cotton fabric using a new antibacterial reactive dye having a modified chemical structure to the commercial reactive dye CI Reactive Red 198 were studied. This modification was carried out by replacing metanilic acid in the commercial dye with 4-amino-N-(4,6-dimethylpyrimidin-2-yl)benzenesulfonamide (sulfadimidine). Optimum exhaustion and fixation values were achieved at 60 g/l sodium sulphate and 20 g/l sodium carbonate for both dyes. The modified dye exhibited higher substantivity, exhaustion and fixation efficiency compared to the commercial dye. Antibacterial activities of the dyed samples at different concentrations of both dyes were studied against gram positive (Staphylococcus aureus) and gram negative (Escherichia coli) bacteria. The cotton dyed with the modified dye shows higher antibacterial efficacy compared to the dyed cotton fabric using the commercial dye, especially on gram negative (E. coli) bacteria. All the reactive dyeings also exhibited high fastness properties.

  2. Kent and Riegel's Handbook of industrial chemistry and biotechnology. 11th ed.

    SciTech Connect

    Kent, James A.

    2007-07-01

    This handbook provides extensive information on plastics, rubber, adhesives, textile fibers, pharmaceutical chemistry, synthetic organic chemicals, soaps and detergents, as well as various other major classes of industrial chemistry. There is detailed coverage of coal utilization technology, dyes and dye intermediates, chlor-alkali and heavy chemicals, paints and pigments, chemical explosives, propellants, petroleum and petrochemicals, natural gas, industrial gases, synthetic nitrogen products, fats and oils, sulfur and sulfuric acid, phosphorous and phosphates, wood products, and sweeteners. The chapter on coal is entitled: coal technology for power, liquid fuels and chemicals. 100 ills.

  3. Inclusion chemistry in periodic mesoporous hosts

    SciTech Connect

    Moller, K.; Bein, T.

    1998-10-01

    This review provides an overview of different aspects of inclusion chemistry in ordered mesoporous host materials such as MCM-41 or MCM-48 (Mobil codes). A rich field of inclusion chemistry has been explored in this context, including sorption, ion exchange, inhibition followed by reduction, grafting of reactive metal alkoxides, halides, etc., grafting of silane coupling agents (sometimes followed by subsequent reactions), grafting of reactive metal complexes, and polymerization in the channels. Finally, co-condensation of reactive species during the mesopore synthesis is a method to incorporate functionality into the walls of the channel system. Important applications of these modified and functionalized systems are heterogeneous catalysis and photocatalysis involving bulky grated catalysts and/or the conversion of large substrates. Other potential applications include ion exchange and separations, removal of heavy metals, chromatography, stabilization of quantum wires, stabilization of dyes, and polymer composites.

  4. Identification of natural red and purple dyes on textiles by Fiber-optics Reflectance Spectroscopy.

    PubMed

    Maynez-Rojas, M A; Casanova-González, E; Ruvalcaba-Sil, J L

    2017-05-05

    Understanding dye chemistry and dye processes is an important issue for studies of cultural heritage collections and science conservation. Fiber Optics Reflectance Spectroscopy (FORS) is a powerful technique, which allows preliminary dye identification, causing no damage or mechanical stress on the artworks subjected to analysis. Some information related to specific light scattering and absorption can be obtained in the UV-visible and infrared range (300-1400nm) and it is possible to discriminate the kind of support fiber in the near infrared region (1000-2500nm). The main spectral features of natural dye fibers samples, such as reflection maxima, inflection points and reflection minima, can be used in the differentiation of various red natural dyes. In this work, a set of dyed references were manufactured following Mexican recipes with red dyes (cochineal and brazilwood) in order to determine the characteristic FORS spectral features of fresh and aged dyed fibers for their identification in historical pieces. Based on these results, twenty-nine indigenous textiles belonging to the National Commission for the Development of Indigenous People of Mexico were studied. Cochineal and brazilwood were successfully identified by FORS in several pieces, as well as the mixture of cochineal and indigo for purple color.

  5. Dyes as tracers for vadose zone hydrology

    NASA Astrophysics Data System (ADS)

    Flury, Markus; Wai, Nu Nu

    2003-03-01

    Dyes are important tracers to investigate subsurface water movement. For more than a century, dye tracers have provided clues about the hydrological cycle as well as flow and transport processes in the subsurface. Groundwater contamination often originates in the vadose zone. Agrochemicals applied to the soil surface, toxic compounds accidentally spilled by human activities, and contaminants released from waste repositories leach through the vadose zone and can ultimately pollute groundwater resources. Dyes are an important tool to assess flow pathways of such contaminants. This review compiles information on dyes used as hydrological tracers, with particular emphasis on vadose zone hydrology. We summarize briefly different human-applied tracers, including nondye tracers. We then provide a historical sketch of the use of dyes as tracers and describe newer developments in visualization and quantification of tracer experiments. Relevant chemical properties of dyes used as tracers are discussed and illustrated with dye intermediates and selected dye tracers. The types of dyes used as tracers in subsurface hydrology are summarized, and recommendations are made regarding the use of dye tracers. The review concludes with a toxicological assessment of dyes used as hydrological tracers. Many different dyes have been proposed as tracers for water movement in the subsurface. All of these compounds, however, are to some degree retarded by the subsurface medium. Nevertheless, dyes are useful tracers to visualize flow pathways.

  6. Laser dye toxicity, hazards, and recommended controls

    SciTech Connect

    Mosovsky, J.A.

    1983-05-06

    Laser dyes are complex fluorescent organic compounds which, when in solution with organic solvents, form a lasing medium. The wavelength of a dye laser's output beam can vary with different dyes, concentrations, and solvents, giving it a tunable feature capable of emitting ultraviolet, visible, or infrared radiation. Toxicity information on the approximately 100 commercially available laser dyes is very scarce. Limited animal experimentation has been performed with only a few dyes. This paper summarizes what is known about laser dye toxicity, and offers recommendations for controlling dye hazards. The laser dyes investigated have been categorized according to their central chemical structures. These include the xanthenes (rhodamines and fluoresceins), polymethines (cyanines and carbocyanines), coumarins, and stilbenes. A few other miscellaneous dyes that do not fall into one of these categories have also been investigated. Prepared laser dye solutions usually contain very small quantities of dye--typical dye concentrations are 10/sup -2/ to 10/sup -5/ molar. For this reason, the solvent in which the dye is dissolved plays an important role when defining potential hazards. Practically all the solvents used are flammable and toxic by inhalation and skin absorption, and therefore must be controlled properly.

  7. Chemistry Rocks: Redox Chemistry as a Geologic Tool.

    ERIC Educational Resources Information Center

    Burns, Mary Sue

    2001-01-01

    Applies chemistry to earth science, uses rocks in chemistry laboratories, and teaches about transition metal chemistry, oxidation states, and oxidation-reduction reactions from firsthand experiences. (YDS)

  8. An enhanced mangiferaindica for dye sensitized solar cell application

    NASA Astrophysics Data System (ADS)

    Uno, U. E.; Emetere, M. E.; Fadipe, L. A.; Oluranti, Jonathan

    2016-02-01

    Titanium dioxide (T1O2) is preferred to Zinc oxide as mesoporous oxide layer because it raised the efficiency of DSSCs from 1% to 7%. The chemistry of the process however seem rigorous to allow the light induced electron injection from the adsorbed dye into the nanocrystallites i.e. which renders the TiO2 conductive. The DSSC fabricated consist of 2.25 cm2 active area of titanium dioxide coated on FTO glass (fluorine tin oxide) immersed in ethanol solution of natural dye extracted as an anode (electrode) and counter electrode. These two electrodes were coupled together and the space between them was filled with the Iodolyte AN-50 as solid electrolyte or redox mediator. The photo electrochemical parameters of the dye extracted (Mango fruit Peel) from the results obtained are short circuit current (Isc)= 1.22×10-2, current density (Jsc)=4.07×10-2, open circuit voltage (voc) =0.53V, fill factor (FF) of 0.16 and the overall conversion efficiency (Eff) =0.345%.

  9. An enhanced mangiferaindica for dye sensitized solar cell application

    SciTech Connect

    Uno, U. E.; Emetere, M. E.; Fadipe, L. A.; Oluranti, Jonathan

    2016-02-01

    Titanium dioxide (T1O2) is preferred to Zinc oxide as mesoporous oxide layer because it raised the efficiency of DSSCs from 1% to 7%. The chemistry of the process however seem rigorous to allow the light induced electron injection from the adsorbed dye into the nanocrystallites i.e. which renders the TiO{sub 2} conductive. The DSSC fabricated consist of 2.25 cm{sup 2} active area of titanium dioxide coated on FTO glass (fluorine tin oxide) immersed in ethanol solution of natural dye extracted as an anode (electrode) and counter electrode. These two electrodes were coupled together and the space between them was filled with the Iodolyte AN-50 as solid electrolyte or redox mediator. The photo electrochemical parameters of the dye extracted (Mango fruit Peel) from the results obtained are short circuit current (Isc)= 1.22×10{sup −2}, current density (Jsc)=4.07×10{sup −2}, open circuit voltage (voc) =0.53V, fill factor (FF) of 0.16 and the overall conversion efficiency (Eff) =0.345%.

  10. Single mode pulsed dye laser oscillator

    DOEpatents

    Hackel, Richard P.

    1992-01-01

    A single mode pulsed dye laser oscillator is disclosed. The dye laser oscillator provides for improved power efficiency by reducing the physical dimensions of the overall laser cavity, which improves frequency selection capability.

  11. Single mode pulsed dye laser oscillator

    DOEpatents

    Hackel, R.P.

    1992-11-24

    A single mode pulsed dye laser oscillator is disclosed. The dye laser oscillator provides for improved power efficiency by reducing the physical dimensions of the overall laser cavity, which improves frequency selection capability. 6 figs.

  12. Triarylmethane Dyes for Artificial Repellent Cotton Fibers.

    PubMed

    Montagut, Ana Maria; Gálvez, Erik; Shafir, Alexandr; Sebastián, Rosa María; Vallribera, Adelina

    2017-03-17

    Families of new hydrophobic and/or oleophobic triarylmethane dyes possessing long hydrocarbon or polyfluorinated chains have been prepared. When covalently grafted on to cotton fabric, these dyes give rise to a new type of colored superhydrophobic fibers.

  13. Dye Sensitized Tandem Photovoltaic Cells

    SciTech Connect

    Barber, Greg D.

    2009-12-21

    This work provided a new way to look at photoelectrochemical cells and their performance. Although thought of as low efficiency, a the internal efficiency of a 9% global efficiency dye sensitized solar cell is approximately equal to an 18% efficient silicon cell when each is compared to their useful spectral range. Other work undertaken with this contract also reported the first growth oriented titania and perovskite columns on a transparent conducting oxide. Other work has shown than significant performance enhancement in the performance of dye sensitized solar cells can be obtained through the use of coupling inverse opal photonic crystals to the nanocrystalline dye sensitized solar cell. Lastly, a quick efficient method was developed to bond titanium foils to transparent conducting oxide substrates for anodization.

  14. Feasibility of solar-pumped dye lasers

    NASA Technical Reports Server (NTRS)

    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.

  15. Dye laser amplifier including a low turbulence, stagnation-free dye flow configuration

    DOEpatents

    Davin, J.

    1992-12-01

    A large (high flow rate) dye laser amplifier in which a continuous replenished supply of dye is excited by a first light beam, specifically a copper vapor laser beam, in order to amplify the intensity of a second different light beam, specifically a dye beam, passing through the dye is disclosed herein. This amplifier includes a dye cell defining a dye chamber through which a continuous stream of dye is caused to pass at a flow rate of for example 30 gallons/minute, a specifically designed support vessel for containing the dye cell and a screen device for insuring that the dye stream passes into the dye cell in a substantially turbulent free, stagnation-free manner. 9 figs.

  16. Dye laser amplifier including a low turbulence, stagnation-free dye flow configuration

    DOEpatents

    Davin, James

    1992-01-01

    A large (high flow rate) dye laser amplifier in which a continuous replenished supply of dye is excited by a first light beam, specifically a copper vapor laser beam, in order to amplify the intensity of a second different light beam, specifically a dye beam, passing through the dye is disclosed herein. This amplifier includes a dye cell defining a dye chamber through which a continuous stream of dye is caused to pass at a flow rate of for example 30 gallons/minute, a specifically designed support vessel for containing the dye cell and a screen device for insuring that the dye stream passes into the dye cell in a substantially turbulent free, stagnation-free manner.

  17. Characteristics of nanostructure dye-sensitized solar cells using food dyes

    NASA Astrophysics Data System (ADS)

    Hosseinnezhad, M.; Rouhani, S.

    2016-01-01

    Dye-sensitized solar cells (DSSCs) were prepared using various food dyes. Food dyes are economically superior to organometallic dyes since they are nontoxic and inexpensive. The spectrophotometric evaluation of chosen food dyes in solution and on a TiO2 substrate show that the dyes form J-aggregation on the photoelectrode substrate. Oxidation of potential measurements for used food dyes ensured an energetically permissible and thermodynamically favorable charge transfer throughout the continuous cycle of a photo-electric conversion. The performance of dye-sensitized solar cells based on food dyes was studied. The results illustrate that the dye containing carboxylic acid and sulfonic acid as the acceptor group gave the maximum conversion efficiency 4.20%.

  18. Characteristics of nanostructure dye-sensitized solar cells using food dyes

    NASA Astrophysics Data System (ADS)

    Hosseinnezhad, M.; Rouhani, S.

    2016-01-01

    Dye-sensitized solar cells (DSSCs) were prepared using various food dyes. Food dyes are economically superior to organometallic dyes since they are nontoxic and inexpensive. The spectrophotometric evaluation of chosen food dyes in solution and on a TO2 substrate show that the dyes form J-aggregation on the photoelectrode substrate. Oxidation of potential measurements for used food dyes ensured an energetically permissible and thermodynamically favorable charge transfer throughout the continuous cycle of a photo-electric conversion. The performance of dye-sensitized solar cells based on food dyes was studied. The results illustrate that the dye containing carboxylic acid and sulfonic acid as the acceptor group gave the maximum conversion efficiency 4.20%.

  19. Constitutional dynamic chemistry: bridge from supramolecular chemistry to adaptive chemistry.

    PubMed

    Lehn, Jean-Marie

    2012-01-01

    Supramolecular chemistry aims at implementing highly complex chemical systems from molecular components held together by non-covalent intermolecular forces and effecting molecular recognition, catalysis and transport processes. A further step consists in the investigation of chemical systems undergoing self-organization, i.e. systems capable of spontaneously generating well-defined functional supramolecular architectures by self-assembly from their components, thus behaving as programmed chemical systems. Supramolecular chemistry is intrinsically a dynamic chemistry in view of the lability of the interactions connecting the molecular components of a supramolecular entity and the resulting ability of supramolecular species to exchange their constituents. The same holds for molecular chemistry when the molecular entity contains covalent bonds that may form and break reversibility, so as to allow a continuous change in constitution by reorganization and exchange of building blocks. These features define a Constitutional Dynamic Chemistry (CDC) on both the molecular and supramolecular levels.CDC introduces a paradigm shift with respect to constitutionally static chemistry. The latter relies on design for the generation of a target entity, whereas CDC takes advantage of dynamic diversity to allow variation and selection. The implementation of selection in chemistry introduces a fundamental change in outlook. Whereas self-organization by design strives to achieve full control over the output molecular or supramolecular entity by explicit programming, self-organization with selection operates on dynamic constitutional diversity in response to either internal or external factors to achieve adaptation.The merging of the features: -information and programmability, -dynamics and reversibility, -constitution and structural diversity, points to the emergence of adaptive and evolutive chemistry, towards a chemistry of complex matter.

  20. Reactive Fluorescent Dyes For Urethane Coatings

    NASA Technical Reports Server (NTRS)

    Willis, Paul B.; Cuddihy, Edward F.

    1991-01-01

    Molecules of fluorescent dyes chemically bound in urethane conformal-coating materials to enable nondestructive detection of flaws in coats through inspection under ultraviolet light, according to proposal. Dye-bonding technique prevents outgassing of dyes, making coating materials suitable for use where flaw-free coats must be assured in instrumentation or other applications in which contamination by outgassing must be minimized.

  1. USSR Report, Chemistry.

    DTIC Science & Technology

    2007-11-02

    This chemistry Report from the USSR contains articles mainly on Adsorption, Analytical Chemistry, Biochemistry, Catalysis, Chemical Industry, Coal ... Gasification , Electrochemistry, Fertilizers, Food Technology, Inorganic Compounds, Nitrogen Compounds and Organometallic Compounds.

  2. Chemistry for Potters.

    ERIC Educational Resources Information Center

    Denio, Allen A.

    1980-01-01

    Relates pottery making to chemistry by providing chemical information about clay, its origin, composition, properties, and changes that occur during firing; also describes glaze compositions, examples of redox chemistry, salt glazing, crystalline glazes, and problems in toxicity. (CS)

  3. Organometallic Chemistry of Molybdenum.

    ERIC Educational Resources Information Center

    Lucas, C. Robert; Walsh, Kelly A.

    1987-01-01

    Suggests ways to avoid some of the problems students have learning the principles of organometallic chemistry. Provides a description of an experiment used in a third-year college chemistry laboratory on molybdenum. (TW)

  4. Special Report: Brain Chemistry.

    ERIC Educational Resources Information Center

    Krassner, Michael B.

    1983-01-01

    Chemical actions in the brain result in cognitive, emotional, neuroendocrine, neuromuscular, and/or neurocirculatory effects. Developments in understanding brain chemistry are discussed, considering among others, neurotransmitter chemistry, neuropeptides, drugs and the brain, antidepressants, and actions of minor tranquilizers. (JN)

  5. Environmental chemistry: Volume A

    SciTech Connect

    Yen, T.F.

    1999-08-01

    This is an extensive introduction to environmental chemistry for engineering and chemical professionals. The contents of Volume A include a brief review of basic chemistry prior to coverage of litho, atmo, hydro, pedo, and biospheres.

  6. School Chemistry vs. Chemistry in Research: An Exploratory Experiment.

    ERIC Educational Resources Information Center

    Habraken, Clarisse L.; Buijs, Wim; Borkent, Hens; Ligeon, Willy; Wender, Harry; Meijer, Marijn

    2001-01-01

    Reports on a study exploring why students are not studying chemistry. Three groups of graduating high school students and their chemistry teachers stayed at a research institute working on molecular modeling and wrote essays on school chemistry versus chemistry in research. Concludes that school chemistry does not convey today's chemistry in…

  7. Chemistry on Stamps.

    ERIC Educational Resources Information Center

    Schreck, James O.

    1986-01-01

    Suggests how postage stamps can be incorporated into chemistry teaching. Categories considered include emergence of chemistry as a science, metric system, atoms (and molecules and ions), stoichiometry, energy relationships in chemical systems, chemical bonding, nuclear chemistry, biochemistry, geochemistry, matter (gases, liquids, and solids),…

  8. Green Chemistry and Education.

    ERIC Educational Resources Information Center

    Hjeresen, Dennis L.; Schutt, David L.; Boese, Janet M.

    2000-01-01

    Many students today are profoundly interested in the sustainability of their world. Introduces Green Chemistry and its principles with teaching materials. Green Chemistry is the use of chemistry for pollution prevention and the design of chemical products and processes that are environmentally benign. (ASK)

  9. Teaching School Chemistry.

    ERIC Educational Resources Information Center

    Waddington, D. J., Ed.

    This eight-chapter book is intended for use by chemistry teachers, curriculum developers, teacher educators, and other key personnel working in the field of chemical education. The chapters are: (1) "The Changing Face of Chemistry" (J. A. Campbell); (2) "Curriculum Innovation in School Chemistry" (R. B. Ingel and A. M.…

  10. Chemistry and Art.

    ERIC Educational Resources Information Center

    Berry, Martyn

    1999-01-01

    Describes a Chemistry and Art project developed for secondary students and teachers sponsored by the National Gallery and The Royal Society of Chemistry in the United Kingdom. Discusses aspects of the techniques used in creating five paintings as well as the chemistry involved in their making, deterioration, conservation, and restoration.…

  11. Chemistry as General Education

    ERIC Educational Resources Information Center

    Tro, Nivaldo J.

    2004-01-01

    The efficacy of different science and chemistry courses for science-major and non-major students, and the question of chemistry's contribution to general education are evaluated. Chemistry and science curriculum are too profession- and consumer-oriented, and to overcome this problem, it is advised that all disciplines must incorporate the major…

  12. Mechanisms in Photographic Chemistry

    ERIC Educational Resources Information Center

    Sahyun, M. R. V.

    1974-01-01

    Reviews current research interests in photographic chemistry, involving two proposed models for spectral sensitization of crystal defects and impurities in the photolysis reactivity and the mechanisms of development and complexation. Establishment of photographic chemistry in a chemistry curriculum is recommended. (CC)

  13. Chemistry as General Education

    NASA Astrophysics Data System (ADS)

    Tro, Nivaldo J.

    2004-01-01

    Science courses are common in most general education requirements. This paper addresses the role of chemistry classes in meeting these requirements. Chemistry professors have for many years questioned the appropriateness of the standard introductory chemistry course as general education, resulting in the growing popularity of specialized non-majors courses. I suggest that current non-major chemistry courses cover too much consumer chemistry and ignore some of the big contributions of chemistry to human knowledge. Majors chemistry courses, while they prepare students for majoring in science, do not address these issues either. Consequently, chemistry courses are often an ineffective and unpopular way to meet general education science requirements. Part of the reason for this dilemma is the lack of chemists who address the contributions of chemistry to human knowledge in general. I propose that faculty at liberal arts colleges engage in this important task and that non-majors chemistry textbooks incorporate questions and issues that relate chemistry to a broader view of human knowledge. If these things happen, perhaps chemistry courses will become more effective as general education.

  14. Characteristics of a Broadband Dye Laser Using Pyrromethene and Rhodamine Dyes

    NASA Technical Reports Server (NTRS)

    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.

  15. Improving optical absorptivity of natural dyes for fabrication of efficient dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Hemmatzadeh, Reza; Mohammadi, Ahmad

    2013-11-01

    Efficient and cheap dye-sensitized solar cells (DSSCs) were fabricated using natural dyes from Pastinaca sativa and Beta vulgaris. Natural dyes are environmentally and economically superior to ruthenium-based dyes because they are nontoxic and cheap. However, the conversion efficiency of dye-sensitized solar cells based on natural dyes is low. One way to improve the DSSC performance is to enhance the absorptivity of extracted dyes. We investigated the influence of various factors in the extraction process, such as utilization of different extraction approaches, the acidity of extraction solvent, and different compounds of solvents on the optical absorption spectra. It was found that we could considerably enhance the optical absorptivity of dye and consequently the performance of DSSC by choosing a proper mixture of ethanol and water for extracting solvent and also the acidity of dye solution.

  16. Dyeing of Jute with Reactive Dyes: Optimisation of the Process Variables and Assessment of Colourfastness Characteristics

    NASA Astrophysics Data System (ADS)

    Samanta, A. K.; Chakraborty, Sharmistha; Guha Roy, T. K.

    2012-08-01

    This paper deals with the studies on the effect of dye concentration, electrolyte (common salt) concentration, dyeing time, dyeing temperature, soda ash concentration, pH of the dye solution and material to liquor ratio (MLR) on colour strength and other colour parameters after being dyed of jute fabrics with reactive dyes, namely, Turquoise blue, Lemon Yellow, Red CN colours. The dye absorption increases with increase in electrolyte (common salt) concentration, dyeing time, dyeing temperature, soda ash concentration, pH and decreases with increase of MLR. Colour fastness to wash, light and rubbing for the dyed samples has been studied and reported. It is observed that reactive dye gives overall good colour fastness to both washing and rubbing. But the light fastness has been found to be moderate only, due to the UV-light initiated fading of jute fibre itself change of the colour substrate, ie, undyed material. This colour fastness has been significantly resolved by post treatment with 1 % benzotriazole.

  17. Principles of Environmental Chemistry

    NASA Astrophysics Data System (ADS)

    Hathaway, Ruth A.

    2007-07-01

    Roy M. Harrison, Editor RSC Publishing; ISBN 0854043713; × + 363 pp.; 2006; $69.95 Environmental chemistry is an interdisciplinary science that includes chemistry of the air, water, and soil. Although it may be confused with green chemistry, which deals with potential pollution reduction, environmental chemistry is the scientific study of the chemical and biochemical principles that occur in nature. Therefore, it is the study of the sources, reactions, transport, effects, and fates of chemical species in the air, water, and soil environments, and the effect of human activity on them. Environmental chemistry not only explores each of these environments, but also closely examines the interfaces and boundaries where the environments intersect.

  18. The Implementation of a Service-Learning Component in an Organic Chemistry Laboratory Course

    ERIC Educational Resources Information Center

    Glover, Sarah R.; Sewry, Joyce D.; Bromley, Candice L.; Davies-Coleman, Michael T.; Hlengwa, Amanda

    2013-01-01

    avenues for the implementation of service-learning into their curricula. A second-year undergraduate organic chemistry laboratory experiment, in which the undergraduate students make azo dyes, can provide a vehicle for a service-learning module in which university undergraduate…

  19. Use of Microcomputers in the Undergraduate Chemistry Laboratory: An Absorption Spectrum Experiment.

    ERIC Educational Resources Information Center

    Terry, Ronald J.; And Others

    1989-01-01

    Describes a computer program designed to enable undergraduate students to apply computer skills for data acquisition and processing in experimental chemistry. An example is given that examines the absorption spectra of conjugated molecules such as carbocyanine dyes, and the free electron model is explained. (six references) (LRW)

  20. A Guided Inquiry Liquid/Liquid Extractions Laboratory for Introductory Organic Chemistry

    ERIC Educational Resources Information Center

    Raydo, Margaret L.; Church, Megan S.; Taylor, Zane W.; Taylor, Christopher E.; Danowitz, Amy M.

    2015-01-01

    A guided inquiry laboratory experiment for teaching liquid/liquid extractions to first semester undergraduate organic chemistry students is described. This laboratory is particularly useful for introductory students as the analytes that are separated are highly colored dye molecules. This allows students to track into which phase each analyte…

  1. Photostability of luminescent dyes in solid-state dye lasers

    NASA Astrophysics Data System (ADS)

    Weiss, Aryeh M.; Yariv, Eli; Reisfeld, Renata

    2003-10-01

    Fluorescence photobleaching was measured in dye-impregnated sol-gel/polymer composite glasses. These fluorescent glasses were used as the gain medium in a transverse-pumped solid-state dye laser. In this configuration, the fluorescent glass was excited by a pulsed Nd:YAG laser (about 6 mJ/pulse) either while placed in an optical cavity (i.e., functioning as a pulsed laser) or with the optical cavity blocked, so that lasing did not occur. The decay of the fluorescence signal versus cumulative excitation energy was recorded. We found that the rate of photobleaching decreased when the glass was lasing, as compared to the case where the optical cavity was blocked. This paper presents these results, and suggests a simple kinetic model that may explain this phenomenon.

  2. Artificial evolution of coumarin dyes for dye sensitized solar cells.

    PubMed

    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.

  3. Batchwise dyeing of bamboo cellulose fabric with reactive dye using ultrasonic energy.

    PubMed

    Larik, Safdar Ali; Khatri, Awais; Ali, Shamshad; Kim, Seong Hun

    2015-05-01

    Bamboo is a regenerated cellulose fiber usually dyed with reactive dyes. This paper presents results of the batchwise dyeing of bamboo fabric with reactive dyes by ultrasonic (US) and conventional (CN) dyeing methods. The study was focused at comparing the two methods for dyeing results, chemicals, temperature and time, and effluent quality. Two widely used dyes, CI Reactive Black 5 (bis-sulphatoethylsulphone) and CI Reactive Red 147 (difluorochloropyrimidine) were used in the study. The US dyeing method produced around 5-6% higher color yield (K/S) in comparison to the CN dyeing method. A significant savings in terms of fixation temperature (10°C) and time (15 min), and amounts of salt (10 g/L) and alkali (0.5-1% on mass of fiber) was realized. Moreover, the dyeing effluent showed considerable reductions in the total dissolved solids content (minimum around 29%) and in the chemical oxygen demand (minimum around 13%) for the US dyebath in comparison to the CN dyebath. The analysis of colorfastness tests demonstrated similar results by US and CN dyeing methods. A microscopic examination on the field emission scanning electron microscope revealed that the US energy did not alter the surface morphology of the bamboo fibers. It was concluded that the US dyeing of bamboo fabric produces better dyeing results and is a more economical and environmentally sustainable method as compared to CN dyeing method.

  4. Development of new near-infrared and leuco-dye optical systems for forensic and crime fighting applications

    NASA Astrophysics Data System (ADS)

    Patonay, Gabor; Strekowski, Lucjan; Salon, Jozef; Medou-Ovono, Martial; Krutak, James J.; Leggitt, Jeffrey; Seubert, Heather; Craig, Rhonda

    2004-12-01

    New chemistry for leuco fluorescin and leuco rhodamine for latent bloodstain and fingerprint detection has been developed in our laboratories. The use of these leuco dyes results in excellent contrast for several hours. The FBI's Evidence Response Team and DNA I unit collaborated with Georgia State University to validate the new fluorescin chemistry for use in the field. In addition, several new NIR dyes have been developed in our laboratories that can be used to detect different chemical residues, e.g., pepper spray, latent fingerprint, latent blood, metal ions, or other trace evidence during crime scene investigations. Proof of principle experiments showed that NIR dyes reacting with such residues can be activated with appropriately filtered semiconductor lasers and LEDs to emit NIR fluorescence that can be observed using optimally filtered night vision intensifiers or pocket scopes, digital cameras, CCD and CMOS cameras, or other NIR detection systems. The main advantage of NIR detection is that the color of the background has very little influence on detection and that there are very few materials that would interfere by exhibiting NIR fluorescence. The use of pocket scopes permits sensitive and convenient detection. Once the residues are located, digital images of the fluorescence can be recorded and samples obtained for further analyses. NIR dyes do not interfere with subsequent follow-up or confirmation methods such as DNA or LC/MS analysis. Near-infrared absorbing dyes will be summarized along with detection mechanisms.

  5. NIR Dyes for Bioimaging Applications

    PubMed Central

    Escobedo, Jorge O.; Rusin, Oleksandr; Lim, Soojin

    2009-01-01

    Summary of recent advances Fluorescent dyes based on small organic molecules that function in the near infra red (NIR) region are of great current interest in chemical biology. They allow for imaging with minimal autofluorescence from biological samples, reduced light scattering and high tissue penetration. Herein, examples of ongoing NIR fluorophore design strategies as well as their properties and anticipated applications relevant to the bioimaging are presented. PMID:19926332

  6. Fate of Colored Smoke Dyes

    DTIC Science & Technology

    1992-01-01

    2,4- dinitrophenylhydrazine (DNP), hydroxylamine (NHOH) and sodium bisulfite (NaHSOO). These chemicals are expected to react with carbonyl moieties in...hydroxylamine and bisulfite . ................. ...................... .132 8-12 Etfect of carbonyl blocking groups on the sorption of 4-methoxyaniline in an EPA...their possible toxicity and carcinogenicity. This concern is heightened by the fact that many dyes formerly were made from known carcinogens such as

  7. Genotoxicity of Dyes Present in Colored Smoke Munitions.

    DTIC Science & Technology

    1986-07-07

    sister chromatid exchanges, and chromosome aberration induction in mammalian cells. The dyes evaluated in the report include Solvent Red 24, Solvent...Chromatid Exchanges from Dyes ... .............. .... 255 Chromosome Aberrations from Dyes .... ................ .... 26 RESULTS...77 Mammalian Cell Mutagenicity of Dyes .... ............... .... 79 Sister Chromatid Exchanges from Dyes .............. 91 Chromosome

  8. In defence of 'dye therapy'.

    PubMed

    Wainwright, Mark

    2014-07-01

    Worldwide, healthcare is facing enormous problems with the continuing rise of drug-resistant infectious diseases. In view of the scarcity of new antimicrobial agents and the withdrawal of many pharmaceutical houses from the fray, alternative approaches are required. One of these is photoantimicrobial chemotherapy, which is highly effective across the range of microbial pathogens and does not suffer from resistance. However, there is a lack of uptake of this approach by healthcare providers and the pharmaceutical industry alike. It is seldom recalled that, unlike anticancer photodynamic therapy, the development of photoantimicrobial agents has evolved from the antiseptic 'dye therapy' in common use until the widespread introduction of the penicillin class in the mid-1940s. Cationic biological dyes such as methylene blue, crystal violet and acriflavine were effective in local wound therapy and today provide a sound basis for light-activated antimicrobial therapeutics. It is proposed that such 'safe' dyes are introduced as locally administered photoantimicrobials, especially in order to conserve valuable conventional antibacterial drugs.

  9. Dye laser traveling wave amplifier

    NASA Technical Reports Server (NTRS)

    Davidson, F.; Hohman, J.

    1985-01-01

    Injection locking was applied to a cavity-dumped coaxial flashlamp pumped dye laser in an effort to obtain nanosecond duration pulses which have both high energy and narrow-linewidth. In the absence of an injected laser pulse, the cavity-dumped dye laser was capable of generating high energy (approx. 60mJ) nanosecond duration output pulses. These pulses, however, had a fixed center wavelength and were extremely broadband (approx. 6nm FWHM). Experimental investigations were performed to determine if the spectral properties of these outputs could be improved through the use of injection-locking techniques. A parametric study to determine the specific conditions under which the laser could be injection-locked was also carried out. Significant linewidth reduction to 0.0015nm) of the outputs was obtained through injection-locking but only at wavelengths near the peak lasing wavelength of the dye. It was found, however; that by inserting weakly dispersive tuning elements in the laser cavity, these narrow-linewidth outputs could be obtained over a wide (24nm) tuning range. Since the tuning elements had low insertion losses, the tunability of the output was obtained without sacrificing output pulse energy.

  10. Dye Photodestruction in a Solid-State Dye Laser with a Polymeric Gain Medium

    NASA Astrophysics Data System (ADS)

    Popov, Sergei

    1998-09-01

    The process of dye photodestruction in a solid-state dye laser is studied, and implemented is a polymeric gain medium doped with a strongly concentrated dye. The behavior of the conversion efficiency in the polymeric gain medium pumped with different laser-pulse repetition rates and the process of dye photobleaching are analyzed. The contribution of the heating of the host material into the dye molecules deactivation is discussed. The negative effect of high dye concentration on the dye stability under a high pump repetition rate is reported and analyzed for the first time to my knowledge. A comparison of the present results with recently published data demonstrates the major role of photodestruction, rather than direct thermodestruction, in the dye stability of the solid-state gain medium. The role of additives with low molecular weights in the polymeric matrix, for increasing the stability of the gain material, is discussed.

  11. Dye photodestruction in a solid-state dye laser with a polymeric gain medium.

    PubMed

    Popov, S

    1998-09-20

    The process of dye photodestruction in a solid-state dye laser is studied, and implemented is a polymeric gain medium doped with a strongly concentrated dye. The behavior of the conversion efficiency in the polymeric gain medium pumped with different laser-pulse repetition rates and the process of dye photobleaching are analyzed. The contribution of the heating of the host material into the dye molecules' deactivation is discussed. The negative effect of high dye concentration on the dye stability under a high pump repetition rate is reported and analyzed for the first time to my knowledge. A comparison of the present results with recently published data demonstrates the major role of photodestruction, rather than direct thermodestruction, in the dye stability of the solid-state gain medium. The role of additives with low molecular weights in the polymeric matrix, for increasing the stability of the gain material, is discussed.

  12. Stability and efficiency of dye-sensitized solar cells based on papaya-leaf dye.

    PubMed

    Suyitno, Suyitno; Saputra, Trisma Jaya; Supriyanto, Agus; Arifin, Zainal

    2015-09-05

    The present article reports on the enhancement of the performance and stability of natural dye-based dye-sensitized solar cells (DSSCs). Natural dyes extracted from papaya leaves (PL) were investigated as sensitizers in TiO2-based DSSCs and evaluated in comparison with N719 dye. The acidity of the papaya-leaf extract dyes was tuned by adding benzoic acid. The TiO2 film-coated fluorine-doped tin oxide glass substrates were prepared using the doctor-blade method, followed by sintering at 450 °C. The counter electrode was coated by chemically deposited catalytic platinum. The working electrodes were immersed in N719 dye and papaya dye solutions with concentrations of 8 g/100 mL. The absorbance spectra of the dyes were obtained by ultra-violet-visible spectroscopy. The energy levels of the dyes were measured by the method of cyclic voltammetry. In addition, Fourier transform infrared spectroscopy was used to determine the characteristic functionalities of the dye molecules. The DSSC based on the N719 dye displayed a highest efficiency of 0.87% whereas those based on papaya-leaf dye achieved 0.28% at pH 3.5. The observed improved efficiency of the latter was attributed to the increased current density value. Furthermore, the DSSCs based on papaya-leaf dye with pH 3.5-4 exhibited better stability than those based on N719 dye. However, further studies are required to improve the current density and stability of natural dye-based DSSCs, including the investigation of alternative dye extraction routes, such as isolating the pure chlorophyll from papaya leaves and stabilizing it.

  13. Stability and efficiency of dye-sensitized solar cells based on papaya-leaf dye

    NASA Astrophysics Data System (ADS)

    Suyitno, Suyitno; Saputra, Trisma Jaya; Supriyanto, Agus; Arifin, Zainal

    2015-09-01

    The present article reports on the enhancement of the performance and stability of natural dye-based dye-sensitized solar cells (DSSCs). Natural dyes extracted from papaya leaves (PL) were investigated as sensitizers in TiO2-based DSSCs and evaluated in comparison with N719 dye. The acidity of the papaya-leaf extract dyes was tuned by adding benzoic acid. The TiO2 film-coated fluorine-doped tin oxide glass substrates were prepared using the doctor-blade method, followed by sintering at 450 °C. The counter electrode was coated by chemically deposited catalytic platinum. The working electrodes were immersed in N719 dye and papaya dye solutions with concentrations of 8 g/100 mL. The absorbance spectra of the dyes were obtained by ultra-violet-visible spectroscopy. The energy levels of the dyes were measured by the method of cyclic voltammetry. In addition, Fourier transform infrared spectroscopy was used to determine the characteristic functionalities of the dye molecules. The DSSC based on the N719 dye displayed a highest efficiency of 0.87% whereas those based on papaya-leaf dye achieved 0.28% at pH 3.5. The observed improved efficiency of the latter was attributed to the increased current density value. Furthermore, the DSSCs based on papaya-leaf dye with pH 3.5-4 exhibited better stability than those based on N719 dye. However, further studies are required to improve the current density and stability of natural dye-based DSSCs, including the investigation of alternative dye extraction routes, such as isolating the pure chlorophyll from papaya leaves and stabilizing it.

  14. Solvent Effects on Emission Yield and Lifetime for Coumarin Laser Dyes. Requirements for a Rotatory Decay Mechanism.

    DTIC Science & Technology

    1983-10-31

    AD-A136 358 SOLVENT EFFECTS ON EMISSION YIELD AND LIFETIME FOR i/i COUMRRIN LASER DYES RE.-(U) BOSTON UNIV MR DEPT OF CHEMISTRY 6 JONES ET AL. 31 OCT...Subti) S. TYPE OF REPORT A PERIOD COVERED Solvent Effects on Emission Yield and Lifetime Technical, 1/1/82-10/31/82 00 for Coumarin Laser Dyes...Requirements for a = PERFORMING On. REPORT WUMENR Rotatory Decay Mechanism 7. AUTNOR(qI I. CONTRACT OR GRANT MUMSE1’.) G. Jones, II, W. R. Jackson, and C

  15. Accurate simulation of optical properties in dyes.

    PubMed

    Jacquemin, Denis; Perpète, Eric A; Ciofini, Ilaria; Adamo, Carlo

    2009-02-17

    Since Antiquity, humans have produced and commercialized dyes. To this day, extraction of natural dyes often requires lengthy and costly procedures. In the 19th century, global markets and new industrial products drove a significant effort to synthesize artificial dyes, characterized by low production costs, huge quantities, and new optical properties (colors). Dyes that encompass classes of molecules absorbing in the UV-visible part of the electromagnetic spectrum now have a wider range of applications, including coloring (textiles, food, paintings), energy production (photovoltaic cells, OLEDs), or pharmaceuticals (diagnostics, drugs). Parallel to the growth in dye applications, researchers have increased their efforts to design and synthesize new dyes to customize absorption and emission properties. In particular, dyes containing one or more metallic centers allow for the construction of fairly sophisticated systems capable of selectively reacting to light of a given wavelength and behaving as molecular devices (photochemical molecular devices, PMDs).Theoretical tools able to predict and interpret the excited-state properties of organic and inorganic dyes allow for an efficient screening of photochemical centers. In this Account, we report recent developments defining a quantitative ab initio protocol (based on time-dependent density functional theory) for modeling dye spectral properties. In particular, we discuss the importance of several parameters, such as the methods used for electronic structure calculations, solvent effects, and statistical treatments. In addition, we illustrate the performance of such simulation tools through case studies. We also comment on current weak points of these methods and ways to improve them.

  16. Solvent-free fluidic organic dye lasers.

    PubMed

    Choi, Eun Young; Mager, Loic; Cham, Tran Thi; Dorkenoo, Kokou D; Fort, Alain; Wu, Jeong Weon; Barsella, Alberto; Ribierre, Jean-Charles

    2013-05-06

    We report on the demonstration of liquid organic dye lasers based on 9-(2-ethylhexyl)carbazole (EHCz), so-called liquid carbazole, doped with green- and red-emitting laser dyes. Both waveguide and Fabry-Perot type microcavity fluidic organic dye lasers were prepared by capillary action under solvent-free conditions. Cascade Förster-type energy transfer processes from liquid carbazole to laser dyes were employed to achieve color-variable amplified spontaneous emission and lasing. Overall, this study provides the first step towards the development of solvent-free fluidic organic semiconducting lasers and demonstrates a new kind of optoelectronic applications for liquid organic semiconductors.

  17. Green Chemistry Pedagogy

    NASA Astrophysics Data System (ADS)

    Kolopajlo, Larry

    2017-02-01

    This chapter attempts to show how the practice of chemistry teaching and learning is enriched by the incorporation of green chemistry (GC) into lectures and labs. To support this viewpoint, evidence from a wide range of published papers serve as a cogent argument that GC attracts and engages both science and nonscience students, enhances chemistry content knowledge, and improves the image of the field, while preparing the world for a sustainable future. Published pedagogy associated with green and sustainable chemistry is critically reviewed and discussed.

  18. Connecting Algebra and Chemistry.

    ERIC Educational Resources Information Center

    O'Connor, Sean

    2003-01-01

    Correlates high school chemistry curriculum with high school algebra curriculum and makes the case for an integrated approach to mathematics and science instruction. Focuses on process integration. (DDR)

  19. USSR Report, Chemistry.

    DTIC Science & Technology

    2007-11-02

    Industry, Coal Gasification , Electrochemistry, Inorganic Compounds, Nitrogen Compounds, Organophosphorus Compounds, Petroleum Processing Technology, Pharmacology and Toxicology, Polymers and Polymerization and, Radiation Chemistry.

  20. Science Update: Analytical Chemistry.

    ERIC Educational Resources Information Center

    Worthy, Ward

    1980-01-01

    Briefly discusses new instrumentation in the field of analytical chemistry. Advances in liquid chromatography, photoacoustic spectroscopy, the use of lasers, and mass spectrometry are also discussed. (CS)

  1. Photostability of low cost dye-sensitized solar cells based on natural and synthetic dyes.

    PubMed

    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 100mWcm(-2), reveals highly stable DSSCs.

  2. Preliminary investigation of the effects of dye concentration on the output of a multiwavelength dye laser

    NASA Technical Reports Server (NTRS)

    Clark, I. O.; Burney, L. G.

    1974-01-01

    The effects of dye concentration on the output wavelength and energy of a multiwavelength dye laser were investigated. The dyes tested were Coumarin 2 in methyl alcohol and Rhodomine 6G, Acridine Red, and 7-diethylamino-4-methyl Coumarin (7DA 4MC) in ethyl alcohol.

  3. Photostability of low cost dye-sensitized solar cells based on natural and synthetic dyes

    NASA Astrophysics Data System (ADS)

    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.

  4. Hydrogen peroxide sensor using laser grade dye Rhodamine B

    NASA Astrophysics Data System (ADS)

    Pattanaik, Amitansu; Sahare, P. D.; Nanda, Maitreyee

    2007-11-01

    Many chemical sensors based on fluorescence spectroscopy have been reported in applications, ranging from biomedical and environmental monitoring to industrial process control. In these diverse applications, the analyte can be probed directly, by measuring its intrinsic absorption, or by incorporating some transduction mechanism such as reagent chemistry to enhance sensitivity and selectivity. Hydrogen Peroxide is a colorless liquid. It is a common oxidizing and bleaching agent. It plays an important role in High Power Laser such as Chemical Oxygen Iodine Laser (COIL). As it is on the Hazardous substance list and on the special health hazard substance list, detection of Hydrogen Peroxide is of great importance. In the present study the detection of hydrogen Peroxide is by fluorescence quenching of laser grade dye Rhodamine B. Estimation of rate constant of the bimolecular quenching reaction is made.

  5. Estimation of Fluorescent Dye Amount in Tracer Dye Test

    NASA Astrophysics Data System (ADS)

    Pekkan, Emrah; Balkan, Erman; Balkan, Emir

    2015-04-01

    Karstic groundwater is more influenced by human than the groundwater that disperse in pores. On the other hand karstic groundwater resources, in addition to providing agricultural needs, livestock breeding, drinking and domestic water in most of the months of the year, they also supply drinking water to the wild life at high altitudes. Therefore sustainability and hydrogeological investigation of karstic resources is critical. Tracing techniques are widely used in hydrologic and hydrogeologic studies to determine water storage, flow rate, direction and protection area of groundwater resources. Karanfil Mountain (2800 m), located in Adana, Turkey, is one of the karstic recharge areas of the natural springs spread around its periphery. During explorations of the caves of Karanfil mountain, a 600 m deep cave was found by the Turkish and Polish cavers. At the bottom of the cave there is an underground river with a flow rate of approximately 0.5 m3/s during August 2014. The main spring is located 8 km far from the cave's entrance and its mean flow rate changes between 3.4 m3/s and 0.21 m3/s in March and September respectively according to a flowrate observation station of Directorate of Water Works of Turkey. As such frequent storms, snowmelt and normal seasonal variations in rainfall have a significant and rapid effect on the volume of this main spring resource. The objective of our research is to determine and estimate dye amount before its application on the field inspired from the previously literature on the subject. This estimation is intended to provide a preliminary application of a tracer test of a karstic system. In this study dye injection, inlet point will be an underground river located inside the cave and the observation station will be the spring that is approximately 8 km far from the cave entrance. On the other hand there is 600 meter elevation difference between cave entrance and outlet spring. In this test Rodamin-WT will be used as tracer and the

  6. Dye lasers. Citations from the NTIS data base

    NASA Astrophysics Data System (ADS)

    Cavagnaro, D. M.

    1980-08-01

    Studies on dye laser theory, design, components, optical systems, and frequency range are presented in approximately 96 citations. Abstracts on lasing dyes, pumping, tuning, excitation, molecular structure, and modulation are included. Studies on dye laser use in spectroscopy are covered.

  7. Parallel Tandems of Dye Sensitized Solar Cells with CNT Collector

    NASA Astrophysics Data System (ADS)

    Velten, Josef; Yuan, Chao-Chen; Zakhidov, Anvar

    2009-03-01

    In this presentation, we demonstrate the fabrication of monolithic parallel tandem dye sensitized solar cells using a semitransparent layer of carbon nanotubes. Each DSC sub-cell has titania photoelectrode with two different dyes: N 719 and N 749, which absorb light in different parts of solar spectrum. This layer of carbon nanotubes laminated on highly porous polymeric Millipore filter acts as both the collector of charge carrier and as the catalyst of the I/I3^- redox reaction that completes the function of the cell, overall allowing easier fabrication for tandem solar cell devices, with a potential for creating flexible devices in the future. The parallel tandem shows the total photocurrent which is nearly the sum of two Isc currents of constituent cells, and total Voc, which is average of two Voc, while conventional in-series DSC tandems show the lowest Voc and slightly increased Isc[1]. Thus the higher efficiency can be achieved in parallel DSC tandems, and we discuss the physical reasons for this effect. [1] Yanagida, et.al. J. of Photochemistry and Photobiology A: Chemistry Volume 164, Issues 1-3, 1 June 2004, Pages 33-39

  8. Incorporating multiple energy relay dyes in liquid dye-sensitized solar cells.

    PubMed

    Yum, Jun-Ho; Hardin, Brian E; Hoke, Eric T; Baranoff, Etienne; Zakeeruddin, Shaik M; Nazeeruddin, Mohammad K; Torres, Tomas; McGehee, Michael D; Grätzel, Michael

    2011-02-25

    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.

  9. Metal oxide-encapsulated dye-sensitized photoanodes for dye-sensitized solar cells

    SciTech Connect

    Hupp, Joseph T.; Son, Ho-Jin

    2016-01-12

    Dye-sensitized semiconducting metal oxide films for photoanodes, photoanodes incorporating the films and DSCs incorporating the photoanodes are provided. Also provided are methods for making the dye sensitized semiconducting metal oxide films. The methods of making the films are based on the deposition of an encapsulating layer of a semiconducting metal oxide around the molecular anchoring groups of photosensitizing dye molecules adsorbed to a porous film of the semiconducting metal oxide. The encapsulating layer of semiconducting metal oxide is formed in such a way that it is not coated over the chromophores of the adsorbed dye molecules and, therefore, allows the dye molecules to remain electrochemically addressable.

  10. Bioorganic and bioinorganic chemistry.

    PubMed

    Constable, Edwin C; Housecroft, Catherine E; Creus, Marc; Gademann, Karl; Giese, Bernd; Ward, Thomas R; Woggon, Wolf D; Chougnet, Antoinette

    2010-01-01

    The interdisciplinary projects in bioinorganic and bioorganic chemistry of the Department of Chemistry, University of Basel led to the preparation of new systems that mimic biologically important processes and to the discovery of compounds from natural sources which are very promising with respect to medical applications. The advances in these areas are reported here.

  11. Coupled Phenomena in Chemistry.

    ERIC Educational Resources Information Center

    Matsubara, Akira; Nomura, Kazuo

    1979-01-01

    Various phenomena in chemistry and biology can be understood through Gibbs energy utilization. Some common phenomena in chemistry are explained including neutralization, hydrolysis, oxidation and reaction, simultaneous dissociation equilibrium of two weak acids, and common ion effect on solubility. (Author/SA)

  12. Chemistry and Philosophy

    ERIC Educational Resources Information Center

    Theobald, D. W.

    1970-01-01

    In the second article of a series, the author discusses some of the interactions between chemistry and philosophy. Evaluates chemistry's role within the scientific enterprise. Traces the rise and fall of the logical atom and argues for a new way of looking at science as an educational instrument. (RR)

  13. Chemistry from Issues.

    ERIC Educational Resources Information Center

    Harding, Jan; Donaldson, Jim

    1986-01-01

    Describes the "Chemistry from Issues" project at Chelsea College. Provides the background information, rationale, and overall structure of a proposed course about the importance of chemistry to common culture. Outlines one module about the British steel industry that has been taught at King's College. (TW)

  14. Infrared Lasers in Chemistry.

    ERIC Educational Resources Information Center

    John, Phillip

    1982-01-01

    Selected infrared laser chemistry topics are discussed including carbon dioxide lasers, infrared quanta and molecules, laser-induced chemistry, structural isomerization (laser purification, sensitized reactions, and dielectric breakdown), and fundamental principles of laser isotope separation, focusing on uranium isotope separation. (JN)

  15. Chemistry in Microfluidic Channels

    ERIC Educational Resources Information Center

    Chia, Matthew C.; Sweeney, Christina M.; Odom, Teri W.

    2011-01-01

    General chemistry introduces principles such as acid-base chemistry, mixing, and precipitation that are usually demonstrated in bulk solutions. In this laboratory experiment, we describe how chemical reactions can be performed in a microfluidic channel to show advanced concepts such as laminar fluid flow and controlled precipitation. Three sets of…

  16. Pre-Tech Chemistry.

    ERIC Educational Resources Information Center

    Florida Junior Coll., Jacksonville.

    This course guide is designed to aid chemistry instructors in teaching the skills and knowledge needed by those students planning to take junior college chemistry and is composed of 11 terminal performance objectives, with intermediate performance objectives and sample criterion measures. Suggestions for related laboratory activities are also…

  17. Brushing Up on Chemistry.

    ERIC Educational Resources Information Center

    Trantow, Ashley

    2002-01-01

    Presents an activity designed for use during National Chemistry Week 2002 with the theme "Chemistry Keeps Us Clean". Allows students to discover more about a cleaning product they use everyday. Students make their own toothpaste and compare its properties with those of commercial toothpaste. (MM)

  18. Movies in Chemistry Education

    ERIC Educational Resources Information Center

    Pekdag, Bulent; Le Marechal, Jean-Francois

    2010-01-01

    This article reviews numerous studies on chemistry movies. Movies, or moving pictures, are important elements of multimedia and signify a privileged or motivating means of presenting knowledge. Studies on chemistry movies show that the first movie productions in this field were devoted to university lectures or documentaries. Shorter movies were…

  19. Chemistry of Moth Repellents

    ERIC Educational Resources Information Center

    Pinto, Gabriel

    2005-01-01

    An effective way to teach chemistry is to examine the substances used in daily life from a pedagogical viewpoint, from the overlap of science, technology, and society (STS). A study aims to engage students in the topic of moth repellents and to encourage them to investigate the chemistry in this familiar product using a set of questions.

  20. Mathematics and Chemistry

    ERIC Educational Resources Information Center

    Henson, R.; Stumbles, A.

    1977-01-01

    The relationship between mathematics and chemistry has been changing rapidly in recent years. Some chemistry teachers have experienced difficulties in their teaching with the introduction of modern mathematics in the schools. Some suggestions for reinforcing the concepts and language of modern mathematics are put forth. (Author/MA)

  1. Organic Chemistry Made Easy.

    ERIC Educational Resources Information Center

    Bradt, Steve

    1998-01-01

    Student-led workshops are helping undergraduate students learn from each other as they tackle organic chemistry. Each week, small groups brainstorm tough problems in sessions guided by upper-class students who have taken and passed the course. Debating and discussing chemistry problems with peers engages students with the material and boosts…

  2. Undergraduate Chemistry Laboratory

    ERIC Educational Resources Information Center

    Bretz, Stacey Lowery; Fay, Michael; Bruck, Laura B.; Towns, Marcy H.

    2013-01-01

    Forty chemistry faculty from American Chemical Society-approved departments were interviewed to determine their goals for undergraduate chemistry laboratory. Faculty were stratified by type of institution, departmental success with regard to National Science Foundation funding for laboratory reform, and level of laboratory course. Interview…

  3. Biosynthetic inorganic chemistry.

    PubMed

    Lu, Yi

    2006-08-25

    Inorganic chemistry and biology can benefit greatly from each other. Although synthetic and physical inorganic chemistry have been greatly successful in clarifying the role of metal ions in biological systems, the time may now be right to utilize biological systems to advance coordination chemistry. One such example is the use of small, stable, easy-to-make, and well-characterized proteins as ligands to synthesize novel inorganic compounds. This biosynthetic inorganic chemistry is possible thanks to a number of developments in biology. This review summarizes the progress in the synthesis of close models of complex metalloproteins, followed by a description of recent advances in using the approach for making novel compounds that are unprecedented in either inorganic chemistry or biology. The focus is mainly on synthetic "tricks" learned from biology, as well as novel structures and insights obtained. The advantages and disadvantages of this biosynthetic approach are discussed.

  4. Characteristics of dye Rhoeo spathacea in dye sensitizer solar cell (DSSC)

    NASA Astrophysics Data System (ADS)

    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.

  5. Effects of pH of Dyes on Characteristics of Dye-Sensitized Solar Cells

    NASA Astrophysics Data System (ADS)

    Furukawa, Shoji; Iino, Hiroshi; Kukita, Koudai; Kaminosono, Kaoru

    Dye-sensitized solar cells were fabricated using natural dyes and synthesized dyes in which rear metal was not contained. Effects of pH of dyes on the characteristics of the dye-sensitized solar cells were also examined. As a result, it was found that the conversion efficiency of the dye-sensitized solar cell fabricated using red-cabbage dye with a pH of 2.5 was 0.10 point larger than that of the solar cell fabricated using red-cabbage dye with a pH of 4.0. It was also found that the conversion efficiency of the solar cell fabricated using red-perilla dye with a pH of 3.1 was 0.10 point larger than that of the solar cell fabricated using red-perilla dye with a pH of 5.8. The results are discussed on the bases of the molecular structure of mainly contained dye and the optical absorption spectra.

  6. Clickable degradable aliphatic polyesters via copolymerization with alkyne epoxy esters: synthesis and postfunctionalization with organic dyes.

    PubMed

    Teske, Nele S; Voigt, Julia; Shastri, V Prasad

    2014-07-23

    Degradable aliphatic polyesters are the cornerstones of nanoparticle (NP)-based therapeutics. In this paradigm, covalent modification of the NP with cell-targeting motifs and dyes can aid in guiding the NP to its destination and gaining visual confirmation. Therefore, strategies to impart chemistries along the polymer backbone that are amenable to easy modification, such as 1,3-dipolar cycloaddition of an azide to an alkyne (the "click reaction"), could be significant. Here we present a simple and efficient way to introduce alkyne groups at high density in aliphatic polyesters without compromising their crystallinity via the copolymerization of cyclic lactones with propargyl 3-methylpentenoate oxide (PMPO). Copolymers of lactic acid and ε-caprolactone with PMPO were synthesized with up to 9 mol % alkyne content, and accessibility of the alkyne groups to the click reaction was demonstrated using several dyes commonly employed in fluorescence microscopy and imaging (Cy3, ATTO-740, and coumarin 343). In order to establish the suitability of these copolymers as nanocarriers, copolymers were formulated into NPs, and cytocompatibility, cellular uptake, and visualization studies undertaken in HeLa cells. Dye-modified NPs exhibited no quenching, remained stable in solution for at least 10 days, showed no cytotoxicity, and were readily taken up by HeLa cells. Furthermore, in addition to enabling the incorporation of multiple fluorophores within the same NP through blending of individual dye-modified copolymers, dye-modified polyesters offer advantages over physical entrapment of dye, including improved signal to noise ratio and localization of the fluorescence signal within cells, and possess the necessary prerequisites for drug delivery and imaging.

  7. Dyeing behaviour of gamma irradiated cotton fabric using Lawson dye extracted from henna leaves (Lawsonia inermis)

    NASA Astrophysics Data System (ADS)

    Rehman, Fazal-ur; Adeel, Shahid; Qaiser, Summia; Ahmad Bhatti, Ijaz; Shahid, Muhammad; Zuber, Mohammad

    2012-11-01

    Dyeing behavior of gamma irradiated cotton fabric using Lawson dye extracted from henna leaves has been investigated. Cotton and dye powder are irradiated to different absorbed doses of 2, 4, 6, 8 and 10 kGy using Cs-137 gamma irradiator. The dyeing parameters such as dyeing time, electrolyte (salt) concentration and mordant concentrations using copper and iron as mordants are optimized. Dyeing is performed using un-irradiated and irradiated cotton with dye solutions and their color strength values are evaluated in CIE Lab system using Spectraflash -SF650. Methods suggested by International Standard Organization (ISO) have been employed to investigate the colourfastness properties such as colourfastness to light, washing and rubbing of irradiated dyed fabric. It is found that gamma ray treatment of cotton dyed with extracts of henna leaves has significantly improved the color strength as well as enhanced the rating of fastness properties.

  8. High excitation transfer efficiency from energy relay dyes in dye-sensitized solar cells.

    PubMed

    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

    2010-08-11

    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 (ETE) of 96% inside TT1-covered, mesostructured TiO(2) 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.

  9. Adsorption of dyes on Sahara desert sand.

    PubMed

    Varlikli, Canan; Bekiari, Vlasoula; Kus, Mahmut; Boduroglu, Numan; Oner, Ilker; Lianos, Panagiotis; Lyberatos, Gerasimos; Icli, Siddik

    2009-10-15

    Sahara desert sand (SaDeS) was employed as a mineral sorbent for retaining organic dyes from aqueous solutions. Natural sand has demonstrated a strong affinity for organic dyes but significantly lost its adsorption capacity when it was washed with water. Therefore, characterization of both natural and water washed sand was performed by XRD, BET, SEM and FTIR techniques. It was found that water-soluble kyanite, which is detected in natural sand, is the dominant factor affecting adsorbance of cationic dyes. The sand adsorbs over 75% of cationic dyes but less than 21% for anionic ones. Among the dyes studied, Methylene Blue (MB) demonstrated the strongest affinity for Sahara desert sand (Q(e)=11.98 mg/g, for initial dye solution concentration 3.5 x 10(-5)mol/L). The effects of initial dye concentration, the amount of the adsorbent, the temperature and the pH of the solution on adsorption capacity were tested by using Methylene Blue as model dye. Pseudo-first-order, pseudo-second-order and intraparticle diffusion models were applied. It was concluded that adsorption of Methylene Blue on Sahara desert sand followed pseudo-second order kinetics. Gibbs free energy, enthalpy change and entropy change were calculated and found -6411 J/mol, -30360 J/mol and -76.58 J/mol K, respectively. These values indicate that the adsorption is an exothermic process and has a spontaneous nature at low temperatures.

  10. Art in Chemistry; Chemistry in Art.

    ERIC Educational Resources Information Center

    Greenberg, Barbara R.; Patterson, Dianne

    High school teachers are often challenged to motivate students who have little or no interest in a subject and are bored with traditional instruction. This unique book is designed to help educators make chemistry classes more interesting and links art curriculum to practical applications, integrating the two subjects through scores of hands-on…

  11. Korean Kimchi Chemistry: A Multicultural Chemistry Connection

    ERIC Educational Resources Information Center

    Murfin, Brian

    2009-01-01

    Connecting science with different cultures is one way to interest students in science, to relate science to their lives, and at the same time to broaden their horizons in a variety of ways. In the lesson described here, students make kimchi, a delicious and popular Korean dish that can be used to explore many important chemistry concepts,…

  12. EVOLVING FROM GREEN CHEMISTRY TO SUSTAINABLE CHEMISTRY

    EPA Science Inventory

    The twelve principles of green chemistry provide a foundation and pathway which allows researchers to incorporate greenness into existing reactions or when developing new technologies. Research from our laboratory has adopted many of these principles and utlizes them as a major c...

  13. Environmental chemistry. 5th edition

    SciTech Connect

    Manahan, S.E. . Dept. of Chemistry)

    1991-01-01

    This book is organized around several major sections: aquatic Chemistry, atmospheric chemistry, the geosphere and hazardous wastes, toxicological chemistry, and resources and energy. Specific topics discussed in the book include a general introduction to environment chemistry, basic principles of aquatic chemistry, water pollution and water treatment, the essential role of microorganisms in aquatic chemical phenomena, atmospheric chemistry, a discussion of major threats to the global atmosphere (particularly greenhouse gases and ozone-depleting chemicals), the geosphere and hazardous substances, soil chemistry, and the nature and sources of hazardous wastes. The environmental chemistry of hazardous wastes, their treatment, minimization, and recycling, and the effects of these hazardous substances in also presented.

  14. Effectiveness of photosensitive dye during uptake and redistribution

    NASA Astrophysics Data System (ADS)

    He, Xiao-Yan; Jacques, Steven L.; Gofstein, Gary

    1992-06-01

    The location of photosensitive dye within a cell will affect the efficacy of photodynamic therapy (PDT). This report demonstrates that during the first 3 hours of dye (Photofrin porfimer) uptake from a liquid medium, the dye is diffusely distributed within the cell. After 24 hours of dye uptake, the dye is localized in specific sites within the cell. Fluorescence spectroscopy demonstrated that the 3-hour dye's emission peak near 635 nm was slightly blue shifted for the localized 24-hour dye. This paper demonstrates that the diffuse dye (at 3 hours) is more effective for PDT than the localized dye (at 24 hours). The amount of diffuse dye within the cell that is required to achieve an LD50 (50% lethal dose) is 1.5-fold to 4.5- fold less than the amount of localized dye required, using the same light exposure. The range of 1.5 - 4.5-fold refers to the results for four cell lines.

  15. Molecular engineering of simple phenothiazine-based dyes to modulate dye aggregation, charge recombination, and dye regeneration in highly efficient dye-sensitized solar cells.

    PubMed

    Hua, Yong; Chang, Shuai; He, Jian; Zhang, Caishun; Zhao, Jianzhang; Chen, Tao; Wong, Wai-Yeung; Wong, Wai-Kwok; Zhu, Xunjin

    2014-05-19

    A series of simple phenothiazine-based dyes, namely, TP, EP, TTP, ETP, and EEP have been developed, in which the thiophene (T), ethylenedioxythiophene (E), their dimers, and mixtures are present to modulate dye aggregation, charge recombination, and dye regeneration for highly efficient dye-sensitized solar cell (DSSC) applications. Devices sensitized by the dyes TP and TTP display high power conversion efficiencies (PCEs) of 8.07 (Jsc = 15.2 mA cm(-2), Voc =0.783 V, fill factor (FF) = 0.679) and 7.87 % (Jsc = 16.1 mA cm(-2), Voc = 0.717 V, FF = 0.681), respectively; these were measured under simulated AM 1.5 sunlight in conjunction with the I(-)/I3(-) redox couple. By replacing the T group with the E unit, EP-based DSSCs had a slightly lower PCE of 7.98 % with a higher short-circuit photocurrent (Jsc) of 16.7 mA cm(-2). The dye ETP, with a mixture of E and T, had an even lower PCE of 5.62 %. Specifically, the cell based on the dye EEP, with a dimer of E, had inferior Jsc and Voc values and corresponded to the lowest PCE of 2.24 %. The results indicate that the photovoltaic performance can be finely modulated through structural engineering of the dyes. The selection of T analogues as donors can not only modulate light absorption and energy levels, but also have an impact on dye aggregation and interfacial charge recombination of electrons at the interface of titania, electrolytes, and/or oxidized dye molecules; this was demonstrated through DFT calculations, electrochemical impedance analysis, and transient photovoltage studies.

  16. Moderator Chemistry Program

    SciTech Connect

    Dewitt, L.V.; Gibbs, A.; Lambert, D.P.; Bohrer, S.R.; Fanning, R.L.; Houston, M.W.; Stinson, S.L.; Deible, R.W.; Abdel-Khalik, S.I.

    1990-11-01

    Over the past fifteen months, the Systems Chemistry Group of the Reactor Engineering Department has undertaken a comprehensive study of the Department`s moderator chemistry program at Savannah River Site (SRS). An internal review was developed to formalize and document this program. Objectives were as outlined in a mission statement and action plan. In addition to the mission statement and action plan, nine separate task reports have been issued during the course of this study. Each of these task reports is included in this document as a chapter. This document is an organized compilation of the individual reports issued by the Systems Chemistry Group in assessment of SRS moderator chemistry to determine if there were significant gaps in the program as ft existed in October, 1989. While these reviews found no significant gaps in that mode of operation, or any items that adversely affected safety, items were identified that could be improved. Many of the items have already been dear with or are in the process of completion under this Moderator Chemistry Program and other Reactor Restart programs. A complete list of the items of improvement found under this assessment is found in Chapter 9, along with a proposed time table for correcting remaining items that can be improved for the chemistry program of SRS reactors. An additional external review of the moderator chemistry processes, recommendations, and responses to/from the Reactor Corrosion Mitigation Committee is included as Appendix to this compilation.

  17. Moderator Chemistry Program

    SciTech Connect

    Dewitt, L.V.; Gibbs, A.; Lambert, D.P.; Bohrer, S.R.; Fanning, R.L.; Houston, M.W.; Stinson, S.L.; Deible, R.W.; Abdel-Khalik, S.I.

    1990-11-01

    Over the past fifteen months, the Systems Chemistry Group of the Reactor Engineering Department has undertaken a comprehensive study of the Department's moderator chemistry program at Savannah River Site (SRS). An internal review was developed to formalize and document this program. Objectives were as outlined in a mission statement and action plan. In addition to the mission statement and action plan, nine separate task reports have been issued during the course of this study. Each of these task reports is included in this document as a chapter. This document is an organized compilation of the individual reports issued by the Systems Chemistry Group in assessment of SRS moderator chemistry to determine if there were significant gaps in the program as ft existed in October, 1989. While these reviews found no significant gaps in that mode of operation, or any items that adversely affected safety, items were identified that could be improved. Many of the items have already been dear with or are in the process of completion under this Moderator Chemistry Program and other Reactor Restart programs. A complete list of the items of improvement found under this assessment is found in Chapter 9, along with a proposed time table for correcting remaining items that can be improved for the chemistry program of SRS reactors. An additional external review of the moderator chemistry processes, recommendations, and responses to/from the Reactor Corrosion Mitigation Committee is included as Appendix to this compilation.

  18. The potential application of activated carbon from sewage sludge to organic dyes removal.

    PubMed

    Graham, N; Chen, X G; Jayaseelan, S

    2001-01-01

    The objective of this research work was to study the potential application of activated carbon from sewage sludge to organic dye removal. Methylene blue and crystal violet were the two dyes investigated in the present study. Three activated carbons were produced from the exclusive sewage sludge (referred to as DS), the sludge with the additive of coconut husk (DC) and sludge with the additive of peanut shell (DP) respectively. They were characterized by their surface area and porosity and their surface chemistry structure. Adsorption studies were performed by the batch technique to obtain kinetic and equilibrium data. The results show that the three sludge-derived activated carbons had a developed porosity and marked content of surface functional groups. They exhibited a rapid three-stage adsorption process for both methylene blue and crystal violet. Their adsorption capacities for the two dyes were high, the carbon DP performed best in the adsorption whereas the carbon DC performed worst. It is therefore concluded that the activated carbons made from sewage sludge and its mixtures are promising for dye removal from aqueous streams.

  19. Covalently deposited dyes: a new chromogen paradigm that facilitates analysis of multiple biomarkers in situ.

    PubMed

    Day, William A; Lefever, Mark R; Ochs, Robert L; Pedata, Anne; Behman, Lauren J; Ashworth-Sharpe, Julia; Johnson, Donald D; May, Eric J; Grille, James G; Roberts, Esteban A; Kosmeder, Jerry W; Morrison, Larry E

    2017-01-01

    Multiplexed analysis of multiple biomarkers in a tissue sample requires use of reporter dyes with specific spectral properties that enable discrimination of signals. Conventional chromogens with broad absorbance spectra, widely used in immunohistochemistry (IHC), offer limited utility for multiplexed detection. Many dyes with narrow absorbance spectra, eg rhodamines, fluoresceins, and cyanines, potentially useful for multiplexed detection are well-characterized; however, generation of a chromogenic reagent useful for IHC analysis has not been demonstrated. Studies reported herein demonstrate utility of tyramine-chemistry for synthesis of a wide variety of new chromogenic dye conjugates useful for multiplexed in situ analysis using conventional light microscopes. The dyes, useful individually or in blends to generate new colors, provide signal sensitivity and dynamic range similar to conventional DAB chromogen, while enabling analysis of co-localized biomarkers. It is anticipated that this new paradigm will enable generation of a wide variety of new chromogens, useful for both research and clinical biomarker analysis that will benefit clinicians and patients.

  20. Computational quantum chemistry website

    SciTech Connect

    1997-08-22

    This report contains the contents of a web page related to research on the development of quantum chemistry methods for computational thermochemistry and the application of quantum chemistry methods to problems in material chemistry and chemical sciences. Research programs highlighted include: Gaussian-2 theory; Density functional theory; Molecular sieve materials; Diamond thin-film growth from buckyball precursors; Electronic structure calculations on lithium polymer electrolytes; Long-distance electronic coupling in donor/acceptor molecules; and Computational studies of NOx reactions in radioactive waste storage.

  1. Fluorine in medicinal chemistry.

    PubMed

    Swallow, Steven

    2015-01-01

    Since its first use in the steroid field in the late 1950s, the use of fluorine in medicinal chemistry has become commonplace, with the small electronegative fluorine atom being a key part of the medicinal chemist's repertoire of substitutions used to modulate all aspects of molecular properties including potency, physical chemistry and pharmacokinetics. This review will highlight the special nature of fluorine, drawing from a survey of marketed fluorinated pharmaceuticals and the medicinal chemistry literature, to illustrate key concepts exploited by medicinal chemists in their attempts to optimize drug molecules. Some of the potential pitfalls in the use of fluorine will also be highlighted.

  2. Frontiers in analytical chemistry

    SciTech Connect

    Amato, I.

    1988-12-15

    Doing more with less was the modus operandi of R. Buckminster Fuller, the late science genius, and inventor of such things as the geodesic dome. In late September, chemists described their own version of this maxim--learning more chemistry from less material and in less time--in a symposium titled Frontiers in Analytical Chemistry at the 196th National Meeting of the American Chemical Society in Los Angeles. Symposium organizer Allen J. Bard of the University of Texas at Austin assembled six speakers, himself among them, to survey pretty widely different areas of analytical chemistry.

  3. Chemistry in Novae

    NASA Astrophysics Data System (ADS)

    Rawlings, J. M. C.; Williams, D. A.

    It is shown that the 5 μm excess, which is attributed to CO in the ejecta of novae, can be modelled chemically. The principle problems involved in the modelling are: (1) the high ejecta temperature (≡104K), (2) the extremely high UV flux, and (3) the marginal self-shielding capability of H2. The authors find that the condition of H2 self-shielding alone is sufficient to allow rapid chemistry to proceed. Time-dependent chemistry calculations indicate that the chemistry is steered by the physics of the system.

  4. Photophysical and electrochemical properties, and molecular structures of organic dyes for dye-sensitized solar cells.

    PubMed

    Ooyama, Yousuke; Harima, Yutaka

    2012-12-21

    Dye-sensitized solar cells (DSSCs) based on organic dyes adsorbed on oxide semiconductor electrodes, such as TiO(2), ZnO, or NiO, which have emerged as a new generation of sustainable photovoltaic devices, have attracted much attention from chemists, physicists, and engineers because of enormous scientific interest in not only their construction and operational principles, but also in their high incident-solar-light-to-electricity conversion efficiency and low cost of production. To develop high-performance DSSCs, it is important to create efficient organic dye sensitizers, which should be optimized for the photophysical and electrochemical properties of the dyes themselves, with molecular structures that provide good light-harvesting features, good electron communication between the dye and semiconductor electrode and between the dye and electrolyte, and to control the molecular orientation and arrangement of the dyes on a semiconductor surface. The aim of this Review is not to make a list of a number of organic dye sensitizers developed so far, but to provide a new direction in the epoch-making molecular design of organic dyes for high photovoltaic performance and long-term stability of DSSCs, based on the accumulated knowledge of their photophysical and electrochemical properties, and molecular structures of the organic dye sensitizers developed so far.

  5. Alexa dyes, a series of new fluorescent dyes that yield exceptionally bright, photostable conjugates.

    PubMed

    Panchuk-Voloshina, N; Haugland, R P; Bishop-Stewart, J; Bhalgat, M K; Millard, P J; Mao, F; Leung, W Y; Haugland, R P

    1999-09-01

    Alexa 350, Alexa 430, Alexa 488, Alexa 532, Alexa 546, Alexa 568, and Alexa 594 dyes are a new series of fluorescent dyes with emission/excitation spectra similar to those of AMCA, Lucifer Yellow, fluorescein, rhodamine 6G, tetramethylrhodamine or Cy3, lissamine rhodamine B, and Texas Red, respectively (the numbers in the Alexa names indicate the approximate excitation wavelength maximum in nm). All Alexa dyes and their conjugates are more fluorescent and more photostable than their commonly used spectral analogues listed above. In addition, Alexa dyes are insensitive to pH in the 4-10 range. We evaluated Alexa dyes compared with conventional dyes in applications using various conjugates, including those of goat anti-mouse IgG (GAM), streptavidin, wheat germ agglutinin (WGA), and concanavalin A (ConA). Conjugates of Alexa 546 are at least twofold more fluorescent than Cy3 conjugates. Proteins labeled with the Alexa 568 or Alexa 594 dyes are several-fold brighter than the same proteins labeled with lissamine rhodamine B or Texas Red dyes, respectively. Alexa dye derivatives of phalloidin stain F-actin with high specificity. Hydrazide forms of the Alexa dyes are very bright, formaldehyde-fixable polar tracers. Conjugates of the Alexa 430 (ex 430 nm/em 520 nm) and Alexa 532 (ex 530 nm/em 548 nm) fluorochromes are spectrally unique fluorescent probes, with relatively high quantum yields in their excitation and emission wavelength ranges.

  6. Ultrasound-assisted dyeing of cellulose acetate.

    PubMed

    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.

  7. Dye-sensitized Schottky barrier solar cells

    DOEpatents

    Skotheim, Terje A.

    1978-01-01

    A low-cost dye-sensitized Schottky barrier solar cell comprised of a substrate of semiconductor with an ohmic contact on one face, a sensitizing dye adsorbed onto the opposite face of the semiconductor, a transparent thin-film layer of a reducing agent over the dye, and a thin-film layer of metal over the reducing agent. The ohmic contact and metal layer constitute electrodes for connection to an external circuit and one or the other or both are made transparent to permit light to penetrate to the dye and be absorbed therein for generating electric current. The semiconductor material chosen to be the substrate is one having a wide bandgap and which therefore is transparent; the dye selected is one having a ground state within the bandgap of the semiconductor to generate carriers in the semiconductor, and a first excited state above the conduction band edge of the semiconductor to readily conduct electrons from the dye to the semiconductor; the reducing agent selected is one having a ground state above the ground state of the sensitizer to provide a plentiful source of electrons to the dye during current generation and thereby enhance the generation; and the metal for the thin-film layer of metal is selected to have a Fermi level in the vicinity of or above the ground state of the reducing agent to thereby amply supply electrons to the reducing agent.

  8. Molecularly imprinted polymers for some reactive dyes.

    PubMed

    Okutucu, Burcu; Akkaya, Alper; Pazarlioglu, Nurdan Kasikara

    2010-01-01

    Depending upon their structure, azo- and anthraquinonic dyes are the two major classes and together represent 90% of all organic colorants. Adsorption of dye molecules onto a sorbent can be an effective, low-cost method of color removal. Most of the techniques used for removal of dyes are of high production cost, and the regeneration also makes them uneconomical. There is much interest in the development of cheaper and effective newer materials for use as adsorbents. Molecular imprinting is a new kind of materials that can be alternative adsorbents. In this study, molecularly imprinted polymers of three textile dyes (Cibacron Orange P-4R, Cibacron Red P-4B, Cibacron Black PSG) were prepared. Methacrylic acid was used as a monomer for red and orange dyes and acrylamide was used for black dye. Methanol:acetonitrile was used as a porogen. The selective recognition ability of the molecularly imprinted polymers was studied by an equilibrium-adsorption batch method. The adsorption data are for Cibacron Black PSG 65% and nonimprinted polymer (NIP) 25%; Cibacron Red P-4B 72% and NIP 18%; and Cibacron Orange P-4R 45% and NIP 10%, respectively. Dye-imprinted polymers were used as a solid-phase extraction material for selective adsorption from wastewater of textile factory.

  9. Nano-TiO2 for dye-sensitized solar cells.

    PubMed

    Baraton, Marie-Isabelle

    2012-01-01

    Photovoltaics are amongst the most popular renewable energy sources and low-cost solar cell technologies are making progress to the market. Research on dye-sensitized solar cells (DSSCs) usually based on nanocrystalline TiO2 has been extensively pursued, and the number of papers and patents published in this area has grown exponentially over the last ten years. Research efforts have largely focused on the optimization of the dye, but recently the TiO2 nanocrystalline electrode itself has attracted more attention. It has been shown that particle size and shape, crystallinity, surface morphology and chemistry of the TiO2 material are key parameters to be controlled for optimized performance of the solar cell. This article will review the most recent research activities on nanostructured TiO2 for improvement of the DSSC performance.

  10. Water Chemistry: Seeking Information

    ERIC Educational Resources Information Center

    Delfino, Joseph J.

    1977-01-01

    A survey of the available literature in water chemistry is presented. Materials surveyed include: texts, reference books, bibliographic resources, journals, American Chemical Society publications, proceedings, unpublished articles, and reports. (BT)

  11. Uncertainty in chemistry.

    PubMed

    Menger, Fredric M

    2010-09-01

    It might come as a disappointment to some chemists, but just as there are uncertainties in physics and mathematics, there are some chemistry questions we may never know the answer to either, suggests Fredric M. Menger.

  12. Frontiers in Chemistry.

    ERIC Educational Resources Information Center

    Joyce, Robert M., Ed.

    1980-01-01

    This article describes recent progress in chemical synthesis which depends on comparable advances in other areas of chemistry. Analysis and theories of chemical structure and reactions are determinants in progress in chemical synthesis and are described also. (Author/SA)

  13. Chemistry and Detective Fiction.

    ERIC Educational Resources Information Center

    Labianca, Dominick A.; Reeves, William J.

    1981-01-01

    Describes an interdisciplinary program consisting of two courses. The first course deals with the chemistry of drugs and poisons; the second course focuses on fictional works in which these drugs and poisons are central to the plots. (SK)

  14. Environmental Bioinorganic Chemistry

    ERIC Educational Resources Information Center

    Ochiai, Ei-Ichiro

    1974-01-01

    Discusses some important aspects of bioinorganic chemistry, including interactions of organisms with metallic and nonmetallic elements and compounds. Indicates that many environmental problems are created by human exploitation of nature and technologies if studied from a bioinorganic chemical viewpoint. (CC)

  15. Chemistry for Kids.

    ERIC Educational Resources Information Center

    Sato, Sanae; Majoros, Bela

    1988-01-01

    Reports two methods for interesting children in chemistry. Describes a method for producing large soap bubbles and films for study. Examines the use of simple stories to explain common chemical concepts with example given. Lists titles of available stories. (ML)

  16. Magnetism in Chemistry

    ERIC Educational Resources Information Center

    Brookes, R. W.; McFadyen, W. D.

    1975-01-01

    Discusses the technical aspects of paramagnetism and an electrostatic model called Crystal Field Theory (CFT), very often used in the case of transition metal compounds. Suggests that this discussion be included as an option for college chemistry courses. (MLH)

  17. Chemistry for Nonscientists

    ERIC Educational Resources Information Center

    Weil, Thomas A.; And Others

    1974-01-01

    Discusses the case of DDT which can be introduced to nonscience students in a chemistry course, including the development of DDT, problems associated with its adverse effects, and curtailment of its use in our environments. (CC)

  18. Chemistry with a Peel.

    ERIC Educational Resources Information Center

    Borer, Londa; Larsen, Eric

    1997-01-01

    Presents experiments that introduce natural product chemistry into high school classrooms. In the laboratory activities, students isolate and analyze the oil in orange peels. Students also perform a steam distillation and learn about terpenes. (DDR)

  19. Supplemental instruction in chemistry

    NASA Astrophysics Data System (ADS)

    Lundeberg, Mary A.

    This study was designed to measure some effects of supplemental instruction in chemistry. Supplemental instruction is a peer-led cooperative learning program that encourages students to develop conceptual understanding by articulating both understandings and misconceptions in a think-aloud fashion. Supplemental instruction was offered three hours weekly outside of class and lab time for students in four classes of General Organic and Biological Chemistry. Over a two-year period 108 students volunteered to participate in this program; 45 students did not participate. As measured by final grades in chemistry and responses to a questionnaire, supplemental instruction was effective in increasing students' achievement in chemistry. Further research is needed to determine the in-depth effects of supplemental instruction on students' learning, problem solving, and self-esteem.

  20. Indicators: Soil Chemistry

    EPA Pesticide Factsheets

    The chemical makeup of the soil can provide information on wetland condition, wetland water quality and services being provided by the wetland ecosystem. Analyzing soil chemistry reveals if the soil is contaminated with a toxic chemical or heavy metal.

  1. General Chemistry for Engineers.

    ERIC Educational Resources Information Center

    Kybett, B. D.

    1982-01-01

    Discusses the relationship between molecular structure, intermolecular forces, and tensile strengths of a polymer and suggests that this is a logical way to introduce polymers into a general chemistry course. (Author/JN)

  2. Microfluidics in inorganic chemistry.

    PubMed

    Abou-Hassan, Ali; Sandre, Olivier; Cabuil, Valérie

    2010-08-23

    The application of microfluidics in chemistry has gained significant importance in the recent years. Miniaturized chemistry platforms provide controlled fluid transport, rapid chemical reactions, and cost-saving advantages over conventional reactors. The advantages of microfluidics have been clearly established in the field of analytical and bioanalytical sciences and in the field of organic synthesis. It is less true in the field of inorganic chemistry and materials science; however in inorganic chemistry it has mostly been used for the separation and selective extraction of metal ions. Microfluidics has been used in materials science mainly for the improvement of nanoparticle synthesis, namely metal, metal oxide, and semiconductor nanoparticles. Microfluidic devices can also be used for the formulation of more advanced and sophisticated inorganic materials or hybrids.

  3. Impact of surface chemistry

    PubMed Central

    Somorjai, Gabor A.; Li, Yimin

    2011-01-01

    The applications of molecular surface chemistry in heterogeneous catalyst technology, semiconductor-based technology, medical technology, anticorrosion and lubricant technology, and nanotechnology are highlighted in this perspective. The evolution of surface chemistry at the molecular level is reviewed, and the key roles of surface instrumentation developments for in situ studies of the gas–solid, liquid–solid, and solid–solid interfaces under reaction conditions are emphasized. PMID:20880833

  4. EPA Environmental Chemistry Laboratory

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The Environmental Protection Agency's (EPA) Chemistry Laboratory (ECL) is a national program laboratory specializing in residue chemistry analysis under the jurisdiction of the EPA's Office of Pesticide Programs in Washington, D.C. At Stennis Space Center, the laboratory's work supports many federal anti-pollution laws. The laboratory analyzes environmental and human samples to determine the presence and amount of agricultural chemicals and related substances. Pictured, ECL chemists analyze environmental and human samples for the presence of pesticides and other pollutants.

  5. Impact of surface chemistry.

    PubMed

    Somorjai, Gabor A; Li, Yimin

    2011-01-18

    The applications of molecular surface chemistry in heterogeneous catalyst technology, semiconductor-based technology, medical technology, anticorrosion and lubricant technology, and nanotechnology are highlighted in this perspective. The evolution of surface chemistry at the molecular level is reviewed, and the key roles of surface instrumentation developments for in situ studies of the gas-solid, liquid-solid, and solid-solid interfaces under reaction conditions are emphasized.

  6. Properties of nucleic acid staining dyes used in gel electrophoresis.

    PubMed

    Haines, Alicia M; Tobe, Shanan S; Kobus, Hilton J; Linacre, Adrian

    2015-03-01

    Nucleic acid staining dyes are used for detecting nucleic acids in electrophoresis gels. Historically, the most common dye used for gel staining is ethidium bromide, however due to its toxicity and mutagenicity other dyes that are safer to the user and the environment are preferred. This Short Communication details the properties of dyes now available and their sensitivity for detection of DNA and their ability to permeate the cell membrane. It was found that GelRed™ was the most sensitive and safest dye to use with UV light excitation, and both GelGreen™ and Diamond™ Nucleic Acid Dye were sensitive and the safer dyes using blue light excitation.

  7. Improved Charge-Transfer Fluorescent Dyes

    NASA Technical Reports Server (NTRS)

    Meador, Michael

    2005-01-01

    Improved charge-transfer fluorescent dyes have been developed for use as molecular probes. These dyes are based on benzofuran nuclei with attached phenyl groups substituted with, variously, electron donors, electron acceptors, or combinations of donors and acceptors. Optionally, these dyes could be incorporated as parts of polymer backbones or as pendant groups or attached to certain surfaces via self-assembly-based methods. These dyes exhibit high fluorescence quantum yields -- ranging from 0.2 to 0.98, depending upon solvents and chemical structures. The wavelengths, quantum yields, intensities, and lifetimes of the fluorescence emitted by these dyes vary with (and, hence, can be used as indicators of) the polarities of solvents in which they are dissolved: In solvents of increasing polarity, fluorescence spectra shift to longer wavelengths, fluorescence quantum yields decrease, and fluorescence lifetimes increase. The wavelengths, quantum yields, intensities, and lifetimes are also expected to be sensitive to viscosities and/or glass-transition temperatures. Some chemical species -- especially amines, amino acids, and metal ions -- quench the fluorescence of these dyes, with consequent reductions in intensities, quantum yields, and lifetimes. As a result, the dyes can be used to detect these species. Another useful characteristic of these dyes is a capability for both two-photon and one-photon absorption. Typically, these dyes absorb single photons in the ultraviolet region of the spectrum (wavelengths < 400 nm) and emit photons in the long-wavelength ultraviolet, visible, and, when dissolved in some solvents, near-infrared regions. In addition, these dyes can be excited by two-photon absorption at near-infrared wavelengths (600 to 800 nm) to produce fluorescence spectra identical to those obtained in response to excitation by single photons at half the corresponding wavelengths (300 to 400 nm). While many prior fluorescent dyes exhibit high quantum yields

  8. Biscoumarins: New laser dyes in Coumarin series

    SciTech Connect

    Padhye, M.R.; Varadarajan, T.S.; Deshpande, A.V.

    1984-06-01

    With a view to extend the tunability range using new derivatives in the coumarin series of dyes, a novel series have been synthesized, viz. the biscoumarins where two coumarin nuclei are coupled. These are studied for their lasing characteristics, optical spectra and quantum efficiencies. Laser spectra of these dyes in various solvents are also studied. Tunability range of these dyes have been found to cover blue green region of the spectrum and though there is shift to longer wavelength as compared to monocoumarins, extending the tunability range, it is not as much as would be normally expected with extended conjugation involving two coumarin nuclei.

  9. Hypersensitivity to contrast media and dyes.

    PubMed

    Brockow, Knut; Sánchez-Borges, Mario

    2014-08-01

    This article updates current knowledge on hypersensitivity reactions to diagnostic contrast media and dyes. After application of a single iodinated radiocontrast medium (RCM), gadolinium-based contrast medium, fluorescein, or a blue dye, a hypersensitivity reaction is not a common finding; however, because of the high and still increasing frequency of those procedures, patients who have experienced severe reactions are nevertheless frequently encountered in allergy departments. Evidence on allergologic testing and management is best for iodinated RCM, limited for blue dyes, and insufficient for fluorescein. Skin tests can be helpful in the diagnosis of patients with hypersensitivity reactions to these compounds.

  10. Holograms with corn honey and erioglaucine dye

    NASA Astrophysics Data System (ADS)

    Grande-Grande, A.; Mejias-Brizuela, N. Y.; Olivares-Pérez, A.; Paez-Trujillo, G.; Fuentes-Tapia, I.

    2008-02-01

    We present a comparative analysis between the diffraction gratings efficiencies recorded on films corn honey and corn honey whit ereoglaucine dye (Blue ® No. 1). For recording the diffraction gratings in the films using the technique of lithography pattern obtained by computer and exposure of the samples to ultraviolet radiation. Although the main reason of the addition of dye to the honey was the one of increasing its diffraction efficiency, the experimental results demonstrated that the gratings recorded in honey had bigger diffraction efficiency than those recorded in honey with dye.

  11. Novel aminobenzanthrone dyes for amyloid fibril detection

    NASA Astrophysics Data System (ADS)

    Vus, Kateryna; Trusova, Valeriya; Gorbenko, Galyna; Kirilova, Elena; Kirilov, Georgiy; Kalnina, Inta; Kinnunen, Paavo

    2012-04-01

    A series of novel fluorescent aminobenzanthrone dyes have been tested for their ability to identify and characterize the oligomeric and fibrillar aggregates of lysozyme. The parameters of the dye binding to native, oligomeric and fibrillar protein have been calculated from the results of fluorimetric titration. Furthermore, several additional quantities reflecting the preference of the probe to either pre-fibrillar or fibrillar protein aggregates, have been evaluated. Based on the comparative analysis of the recovered parameters, AM4 was recommended for selective detection of protein pre-fibrillar assemblies, while the dyes AM1, AM2, AM3 were selected as the most prospective amyloid tracers.

  12. Squaraine dyes for dye-sensitized solar cells: recent advances and future challenges.

    PubMed

    Qin, Chuanjiang; Wong, Wai-Yeung; Han, Liyuan

    2013-08-01

    In the past few years, squaraine dyes have received increasing attention as a sensitizer for application in dye-sensitized solar cells. This class of dyes not only leaves open a good opportunity to afford conventional high performance dyes but also holds great promise for applications in transparent solar cells due to its low absorption intensity in the eye-sensitive region. This review provides a summary of the developments on squaraine dyes in the field of dye-sensitized solar cells and the opportunities used to improve their overall energy conversion efficiency. In particular, the main factors responsible for the low values of open-circuit voltage, short-circuit photocurrent and fill factor are discussed in detail. Future directions in research and development of near-infrared (NIR) organic materials and their applications are proposed from a personal perspective.

  13. Dye ingredients and energy conversion efficiency at natural dye sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Özbay Karakuş, Mücella; Koca, İrfan; Er, Orhan; Çetin, Hidayet

    2017-04-01

    In this work, natural dyes extracted from the same genus but different species flowers were used as sensitizer in Dye Sensitized Solar Cell (DSSC). To clearly show dye ingredients effect on electrical characteristics, the same genus flowers were selected. The dye ingredients were analyzed by Gas Chromatography Mass Spectrometer (GC-MS). The dyes were modified by a procedure that includes refluxing in acetone. All results indicate a relationship between gallic acid quantity in dyes and solar cell efficiency. To gain further insight, the solar cell parameters were obtained by using the single-diode and double-diode models and they were compared to each other. It was observed that the applied process causes a decrease in series resistance. How the modification process and gallic acid affect energy conversion efficiency were argued in detail in the frame of results that were obtained from solar cell models.

  14. Treatment of azo dye-containing synthetic textile dye effluent using sulfidogenic anaerobic baffled reactor.

    PubMed

    Ozdemir, Sebnem; Cirik, Kevser; Akman, Dilek; Sahinkaya, Erkan; Cinar, Ozer

    2013-10-01

    This study aims at investigating azo dye reduction performance of a sulfidogenic anaerobic baffled reactor (ABR) for around 400 days. ABR was operated at 30 °C in a temperature-controlled room and hydraulic retention time (HRT) was kept constant at 2 days. The robustness of ABR was assessed under varying azo dye loadings and COD/sulfate ratios. Additionally, oxygen was supplied (1-2 L air/m(3)reactor min) to the last compartment to investigate the removal of azo dye breakdown products. ABR performed well in terms of COD, sulfate and azo dye removals throughout the reactor operation. Maximum azo dye, COD and sulfate removals were 98%, 98% and 93%, respectively, at COD/sulfate ratio of 0.8. Aeration created different redox conditions in last compartment, which enhanced the removal of COD and breakdown products. The adverse effects of aeration on azo dye reduction were eliminated thanks to the compartmentalized structure of the ABR.

  15. Decolourisation of Red 5 MB dye by microbes isolated from textile dye effluent.

    PubMed

    Subashini, P; Hiranmaiyadav, R; Premalatha, M S

    2010-07-01

    One of the major environmental problems is the presence of dye materials in textile wastewater, which need to be removed before releasing into the environment. Some dyes are toxic and carcinogenic in nature. The discharge of the textile effluent into rivers and lakes leads to higher BOD causing threat to aquatic life. Development of efficient dye degradation requires suitable strain and its use under favorable condition to realize the degradation potential. In this study, three microorganisms were isolated from the Red 5 MB dye containing textile wastewater. They were identified and tested for the dye decolourisation provided with different sugars as carbon source. The percentage of dye decolorized by Bacillus subtilis, Aspergillus flavus and Aspergillus fumigatus were found to be about 40%, 75% and 53.8% respectively.

  16. Natural Dye Extracted from Vitex negundo as a Potential Alternative to Synthetic Dyes for Dyeing of Silk

    NASA Astrophysics Data System (ADS)

    Narayana Swamy, Venkataramanappa; Gowda, Kurikempanadoddi Ninge; Sudhakar, Rajagopal

    2016-04-01

    Since the last decade, the application of natural dyes on textile material has been gaining popularity all over the world, possibly because of the increasing awareness of issues concerning the environment, ecology and pollution control. The present paper investigates extraction of natural dye from leaves of the plant Vitex negundo, which is an abundant, cheap, and readily available agricultural by-product. Water extracts from V. negundo was used to dye silk fabrics. Optimum extraction conditions included pH 9, duration 120 min, and temperature 90 °C. Optimum dyeing conditions included dyeing pH 5 and duration of 60 min. Potash alum, tannic and tartaric acid were used as mordants, all of which are benign to human health and the environment. Color strength and color coordinates in terms of L*, a*, b*, C, and h were examined. A range of shades were obtained when fabrics were dyed with different mordants and mordanting techniques. The extracted dye was tested for some of the eco-parameters using atomic absorption spectrophotometry and GC/MS. The test results were compared with set standards to determine the eco-friendliness of natural dye. Their concentrations were found to be lower than the stipulated limits. Dyed samples were tested for antimicrobial activity against gram-positive and gram-negative bacteria. The dyed silk fabrics showed acceptable fastness properties and were also found to possess antibacterial activity. It can be concluded that the abundantly available agricultural by-product V. negundo has great potential to be effectively utilized as a natural dye for silk.

  17. Photochemistry and photophysics of laser dyes. Final report, 1 November 1978-31 October 1982

    SciTech Connect

    Jones, G. II

    1983-10-31

    Results of a study of photophysical properties and mechanisms of photodegradation of coumarin dyes are summarized. Discussion includes effects of polar media on dye emission yield and lifetime, solubilization of dyes in water with surfactants, products of dye photodegradation, electron transfer properties of coumarin dyes, mechanisms of dye photodecomposition, and recommendations of restorative procedures for dye media.

  18. Efficient synthesis of triarylamine-based dyes for p-type dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Wild, Martin; Griebel, Jan; Hajduk, Anna; Friedrich, Dirk; Stark, Annegret; Abel, Bernd; Siefermann, Katrin R.

    2016-05-01

    The class of triarylamine-based dyes has proven great potential as efficient light absorbers in inverse (p-type) dye sensitized solar cells (DSSCs). However, detailed investigation and further improvement of p-type DSSCs is strongly hindered by the fact that available synthesis routes of triarylamine-based dyes are inefficient and particularly demanding with regard to time and costs. Here, we report on an efficient synthesis strategy for triarylamine-based dyes for p-type DSSCs. A protocol for the synthesis of the dye-precursor (4-(bis(4-bromophenyl)amino)benzoic acid) is presented along with its X-ray crystal structure. The dye precursor is obtained from the commercially available 4(diphenylamino)benzaldehyde in a yield of 87% and serves as a starting point for the synthesis of various triarylamine-based dyes. Starting from the precursor we further describe a synthesis protocol for the dye 4-{bis[4‧-(2,2-dicyanovinyl)-[1,1‧-biphenyl]-4-yl]amino}benzoic acid (also known as dye P4) in a yield of 74%. All synthesis steps are characterized by high yields and high purities without the need for laborious purification steps and thus fulfill essential requirements for scale-up.

  19. Efficient synthesis of triarylamine-based dyes for p-type dye-sensitized solar cells

    PubMed Central

    Wild, Martin; Griebel, Jan; Hajduk, Anna; Friedrich, Dirk; Stark, Annegret; Abel, Bernd; Siefermann, Katrin R.

    2016-01-01

    The class of triarylamine-based dyes has proven great potential as efficient light absorbers in inverse (p-type) dye sensitized solar cells (DSSCs). However, detailed investigation and further improvement of p-type DSSCs is strongly hindered by the fact that available synthesis routes of triarylamine-based dyes are inefficient and particularly demanding with regard to time and costs. Here, we report on an efficient synthesis strategy for triarylamine-based dyes for p-type DSSCs. A protocol for the synthesis of the dye-precursor (4-(bis(4-bromophenyl)amino)benzoic acid) is presented along with its X-ray crystal structure. The dye precursor is obtained from the commercially available 4(diphenylamino)benzaldehyde in a yield of 87% and serves as a starting point for the synthesis of various triarylamine-based dyes. Starting from the precursor we further describe a synthesis protocol for the dye 4-{bis[4′-(2,2-dicyanovinyl)-[1,1′-biphenyl]-4-yl]amino}benzoic acid (also known as dye P4) in a yield of 74%. All synthesis steps are characterized by high yields and high purities without the need for laborious purification steps and thus fulfill essential requirements for scale-up. PMID:27196877

  20. Bioremediation of dyes by fungi isolated from contaminated dye effluent sites for bio-usability

    PubMed Central

    Rani, Babita; Kumar, Vivek; Singh, Jagvijay; Bisht, Sandeep; Teotia, Priyanku; Sharma, Shivesh; Kela, Ritu

    2014-01-01

    Biodegradation and detoxification of dyes, Malachite green, Nigrosin and Basic fuchsin have been carried out using two fungal isolates Aspergillus niger, and Phanerochaete chrysosporium, isolated from dye effluent soil. Three methods were selected for biodegradation, viz. agar overlay and liquid media methods; stationary and shaking conditions at 25 °C. Aspergillus niger recorded maximum decolorization of the dye Basic fuchsin (81.85%) followed by Nigrosin (77.47%), Malachite green (72.77%) and dye mixture (33.08%) under shaking condition. Whereas, P. chrysosporium recorded decolorization to the maximum with the Nigrosin (90.15%) followed by Basic fuchsin (89.8%), Malachite green (83.25%) and mixture (78.4%). The selected fungal strains performed better under shaking conditions compared to stationary method; moreover the inoculation of fungus also brought the pH of the dye solutions to neutral from acidic. Seed germination bioassay study exhibited that when inoculated dye solutions were used, seed showed germination while uninoculated dyes inhibited germination even after four days of observation. Similarly, microbial growth was also inhibited by uninoculated dyes. The excellent performance of A. niger and P. chrysporium in the biodegradation of textile dyes of different chemical structures suggests and reinforces the potential of these fungi for environmental decontamination. PMID:25477943

  1. Dyeing regions of oxidative hair dyes in human hair investigated by nanoscale secondary ion mass spectrometry.

    PubMed

    Kojima, Toru; Yamada, Hiromi; Yamamoto, Toshihiko; Matsushita, Yasuyuki; Fukushima, Kazuhiko

    2013-06-01

    To develop more effective oxidative hair coloring products, it is important to understand the localization of colored chromophores, which are formed from oxidative dyes, in the fine structure of hair. However, the dyeing regions of oxidative hair dyes in the fine structure of hair have not been extensively examined. In this study, we investigated the distribution and localization of colored chromophores formed by an oxidative hair coloring product in the fine structure of human hair by using a stable isotope-labeled oxidative dye with nanoscale secondary ion mass spectrometry (NanoSIMS). First, formation of the colored chromophore from a deuterium-labeled oxidative dye was examined by visible spectra similarly to a study of its formation using nonlabeled oxidative dye. Furthermore, the formation of binuclear indo dye containing deuterium in its chemical structure was confirmed using time-of-flight secondary ion mass spectrometry (TOF-SIMS) analysis. As a result of the NanoSIMS image on a cross-sectional dyed hair, although deuterium ions were detected in whole hair cross-section, quite a few of them were detected at particulate regions. These particulate regions of the dyed black hair in which deuterium ions were intensely detected were identified as melanin granules, by comparing the dyeing behaviors of black and white hair. NanoSIMS analysis revealed that melanin granules of black human hair are important dyeing regions in oxidative hair coloring.

  2. Bioremediation of dyes by fungi isolated from contaminated dye effluent sites for bio-usability.

    PubMed

    Rani, Babita; Kumar, Vivek; Singh, Jagvijay; Bisht, Sandeep; Teotia, Priyanku; Sharma, Shivesh; Kela, Ritu

    2014-01-01

    Biodegradation and detoxification of dyes, Malachite green, Nigrosin and Basic fuchsin have been carried out using two fungal isolates Aspergillus niger, and Phanerochaete chrysosporium, isolated from dye effluent soil. Three methods were selected for biodegradation, viz. agar overlay and liquid media methods; stationary and shaking conditions at 25 °C. Aspergillus niger recorded maximum decolorization of the dye Basic fuchsin (81.85%) followed by Nigrosin (77.47%), Malachite green (72.77%) and dye mixture (33.08%) under shaking condition. Whereas, P. chrysosporium recorded decolorization to the maximum with the Nigrosin (90.15%) followed by Basic fuchsin (89.8%), Malachite green (83.25%) and mixture (78.4%). The selected fungal strains performed better under shaking conditions compared to stationary method; moreover the inoculation of fungus also brought the pH of the dye solutions to neutral from acidic. Seed germination bioassay study exhibited that when inoculated dye solutions were used, seed showed germination while uninoculated dyes inhibited germination even after four days of observation. Similarly, microbial growth was also inhibited by uninoculated dyes. The excellent performance of A. niger and P. chrysporium in the biodegradation of textile dyes of different chemical structures suggests and reinforces the potential of these fungi for environmental decontamination.

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

    NASA Astrophysics Data System (ADS)

    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.

  4. Energy and hole transfer between dyes attached to titania in cosensitized dye-sensitized solar cells.

    PubMed

    Hardin, Brian E; Sellinger, Alan; Moehl, Thomas; Humphry-Baker, Robin; Moser, Jacques-E; Wang, Peng; Zakeeruddin, Shaik M; Grätzel, Michael; McGehee, Michael D

    2011-07-13

    Cosensitization of broadly absorbing ruthenium metal complex dyes with highly absorptive near-infrared (NIR) organic dyes is a clear pathway to increase near-infrared light harvesting in liquid-based dye-sensitized solar cells (DSCs). In cosensitized DSCs, dyes are intimately mixed, and intermolecular charge and energy transfer processes play an important role in device performance. Here, we demonstrate that an organic NIR dye incapable of hole regeneration is able to produce photocurrent via intermolecular energy transfer with an average excitation transfer efficiency of over 25% when cosensitized with a metal complex sensitizing dye (SD). We also show that intermolecular hole transfer from the SD to NIR dye is a competitive process with dye regeneration, reducing the internal quantum efficiency and the electron lifetime of the DSC. This work demonstrates the general feasibility of using energy transfer to boost light harvesting from 700 to 800 nm and also highlights a key challenge for developing highly efficient cosensitized dye-sensitized solar cells.

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

    PubMed

    Hoke, Eric T; Hardin, Brian E; McGehee, Michael D

    2010-02-15

    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.

  6. Solid state dye laser for medical applications

    NASA Astrophysics Data System (ADS)

    Aldag, Henry R.

    1994-06-01

    The development of solid state dye lasers could lead to a major breakthrough in the cost and compactness of a medical device. Advantages include: elimination of the flow system for the gain medium; ease with which to implement wavelength agility or the replacement of a degraded rod or sheet; and toxicity and flammability become a non-issue. Dye lasers have played a role in cardiology, dermatology, and urology. Of these cardiology is of interest to Palomar. The Palomar Model 3010 flashlamp-pumped dye laser medical device was used during phase 1 FDA clinical trials to break-up blood clots that cause heart attacks, a process known as coronary laser thrombolysis. It is the objective of this research and development effort to produce solid matrix lasers that will replace liquid dye lasers in these medical specialties.

  7. Chromosome characterization using single fluorescent dye

    DOEpatents

    Crissman, Harry A.; Hirons, Gregory T.

    1995-01-01

    Chromosomes are characterized by fluorescent emissions from a single fluorescent dye that is excited over two different wavelengths. A mixture containing chromosomes is stained with a single dye selected from the group consisting of TOTO and YOYO and the stained chromosomes are placed in a flow cytometer. The fluorescent dye is excited sequentially by a first light having a wavelength in the ultraviolet range to excite the TOTO or YOYO to fluoresce at a first intensity and by a second light having a wavelength effective to excite the TOTO or YOYO dye to fluoresce at a second intensity. Specific chromosomes may be identified and sorted by intensity relationships between the first and second fluorescence emissions.

  8. Ballistic labeling with fluorescent dyes and indicators.

    PubMed

    Morgan, Joshua L; Wong, Rachel O L

    2008-04-01

    Neuronal cell labeling is fundamental to investigations of the nervous system. Labeling of cells in live or fixed tissue with dyes or ion indicators using ballistic approaches has recently been developed for the study of neuronal architecture and function. In this approach, dye-coated particles are propelled into cells by a pulse of pressurized helium. This unit provides step-by-step protocols for coating tungsten particles with fluorescent or indicator dyes and for delivering these particles into cells and tissue. The major advantage of the ballistic method of dye delivery is that large populations of neurons can be rapidly labeled within a piece of live or fixed tissue. Advantages and limitations of the approach are discussed and technical advice is provided.

  9. Thermal treatment of dyes from military munitions

    SciTech Connect

    1996-09-01

    Los Alamos National Laboratory has developed thermal treatment equipment to treat Navy smoke and dye compounds. Navy smokes were burned in the Los Alamos Controlled Air Incinerator (CAI) in the early 1980s. These test results were used in the development of a portable system consisting of a Thermal Treatment Unit (TTU), feed preparation and pumping skid, utility skid, and control trailer. This equipment was started up at Navy facilities at China Lake, CA where several destruction removal efficiency tests were completed in 1993 burning smoke compositions. The equipment was set up at the Nevada Test Site (NTS) in 1996 where tests were completed burning green Navy spotting dyes. Operating and test results from the NTS efforts resulted in clearer understanding of equipment deficiencies, dye characteristics and composition, and secondary wastes generated. Future tests, scheduled for July, 1996 will demonstrate higher bum rates, better pH measurement and control, and stack emission test results for other colored dyes.

  10. Phytoremediation in education: textile dye teaching experiments.

    PubMed

    Ibbini, Jwan H; Davis, Lawrence C; Erickson, Larry E

    2009-07-01

    Phytoremediation, the use of plants to clean up contaminated soil and water, has a wide range of applications and advantages, and can be extended to scientific education. Phytoremediation of textile dyes can be used as a scientific experiment or demonstration in teaching laboratories of middle school, high school and college students. In the experiments that we developed, students were involved in a hands-on activity where they were able to learn about phytoremediation concepts. Experiments were set up with 20-40 mg L(-1) dye solutions of different colors. Students can be involved in the set up process and may be involved in the experimental design. In its simplest forms, they use two-week-old sunflower seedlings and place them into a test tube of known volume of dye solution. Color change and/or dye disappearance can be monitored by visual comparison or with a spectrophotometer. Intensity and extent of the lab work depends on student's educational level, and time constraints. Among the many dyes tested, Evan's Blue proved to be the most readily decolorized azo dye. Results could be observed within 1-2 hours. From our experience, dye phytoremediation experiments are suitable and easy to understand by both college and middle school students. These experiments help visual learners, as students compare the color of the dye solution before and after the plant application. In general, simple phytoremediation experiments of this kind can be introduced in many classes including biology, biochemistry and ecological engineering. This paper presents success stories of teaching phytoremediation to middle school and college students.

  11. Corrosion Inhibitors as Penetrant Dyes for Radiography

    NASA Technical Reports Server (NTRS)

    Novak, Howard L.; Hall, Phillip B.

    2003-01-01

    Liquid/vapor-phase corrosion inhibitors (LVCIs) have been found to be additionally useful as penetrant dyes for neutron radiography (and perhaps also x-radiography). Enhancement of radiographic contrasts by use of LVCIs can reveal cracks, corrosion, and other defects that may be undetectable by ultrasonic inspection, that are hidden from direct optical inspection, and/or that are difficult or impossible to detect in radiographs made without dyes.

  12. Incoherently pumped continuous wave dye laser

    NASA Astrophysics Data System (ADS)

    Thiel, E.; Zander, C.; Drexhage, K. H.

    1987-05-01

    Continuous wave operation of a dye laser, pumped by an incoherent light source, is reported. A jet of a water-based solution of Rhodamine 6G is used as the laser medium in a spherical cavity with high reflectivity mirrors. Two high pressure arcs generated by electrical discharge between tungsten electrodes serve as pump source. They produce a power density of 0.5-10 kW/cm 2 in the jet causing the dye to lase at 615 nm.

  13. Near-infrared dyes and upconverting phosphors as biomolecule labels and probes

    NASA Astrophysics Data System (ADS)

    Patonay, Gabor; Strekowski, Lucjan; Nguyen, Diem-Ngoc; Seok, Kim Jun

    2007-02-01

    Near-Infrared (NIR) absorbing chromophores have been used in analytical and bioanalytical chemistry extensively, including for determination of properties of biomolecules, DNA sequencing, immunoassays, capillary electrophoresis (CE) separations, etc. The major analytical advantages of these dyes are low background interference and high molar absorptivities. NIR dyes have additional advantages due to their sensitivity to microenvironmental changes. Spectral changes induced by the microenvironment are not desirable if the labels are used as a simple reporting group, e.g., during a biorecognition reaction. For these applications upconverting phosphors seem to be a better choice. There are several difficulties in utilizing upconverting phosphors as reporting labels. These are: large physical size, no reactive groups and insolubility in aqueous systems. This presentation will discuss how these difficulties can be overcome for bioanalytical and forensic applications. During these studies we also have investigated how to reduce physical size of the phosphor by simple grinding without losing activity and how to attach reactive moiety to the phosphor to covalently bind to the biomolecule of interest. It has to be emphasized that the described approach is not suitable for medical applications and the results of this research are not applicable in medical applications. For bioanalytical and forensic applications upconverting phosphors used as reporting labels have several advantages. They are excited with lasers that are red shifted respective to phosphorescence, resulting in no light scatter issues during detection. Also some phosphors are excited using eye safe lasers. In addition energy transfer to NIR dyes is possible, allowing detection schemes using donor-acceptor pairs. Data is presented to illustrate the feasibility of this phenomenon. If microenvironmental sensitivity is required, then specially designed NIR dyes can be used as acceptor labels. Several novel dyes

  14. Degradation of textile dyes by cyanobacteria.

    PubMed

    Dellamatrice, Priscila Maria; Silva-Stenico, Maria Estela; Moraes, Luiz Alberto Beraldo de; Fiore, Marli Fátima; Monteiro, Regina Teresa Rosim

    Dyes are recalcitrant compounds that resist conventional biological treatments. The degradation of three textile dyes (Indigo, RBBR and Sulphur Black), and the dye-containing liquid effluent and solid waste from the Municipal Treatment Station, Americana, São Paulo, Brazil, by the cyanobacteria Anabaena flos-aquae UTCC64, Phormidium autumnale UTEX1580 and Synechococcus sp. PCC7942 was evaluated. The dye degradation efficiency of the cyanobacteria was compared with anaerobic and anaerobic-aerobic systems in terms of discolouration and toxicity evaluations. The discoloration was evaluated by absorption spectroscopy. Toxicity was measured using the organisms Hydra attenuata, the alga Selenastrum capricornutum and lettuce seeds. The three cyanobacteria showed the potential to remediate textile effluent by removing the colour and reducing the toxicity. However, the growth of cyanobacteria on sludge was slow and discoloration was not efficient. The cyanobacteria P. autumnale UTEX1580 was the only strain that completely degraded the indigo dye. An evaluation of the mutagenicity potential was performed by use of the micronucleus assay using Allium sp. No mutagenicity was observed after the treatment. Two metabolites were produced during the degradation, anthranilic acid and isatin, but toxicity did not increase after the treatment. The cyanobacteria showed the ability to degrade the dyes present in a textile effluent; therefore, they can be used in a tertiary treatment of effluents with recalcitrant compounds.

  15. Technetium Chemistry in HLW

    SciTech Connect

    Hess, Nancy J.; Felmy, Andrew R.; Rosso, Kevin M.; Xia Yuanxian

    2005-06-06

    Tc contamination is found within the DOE complex at those sites whose mission involved extraction of plutonium from irradiated uranium fuel or isotopic enrichment of uranium. At the Hanford Site, chemical separations and extraction processes generated large amounts of high level and transuranic wastes that are currently stored in underground tanks. The waste from these extraction processes is currently stored in underground High Level Waste (HLW) tanks. However, the chemistry of the HLW in any given tank is greatly complicated by repeated efforts to reduce volume and recover isotopes. These processes ultimately resulted in mixing of waste streams from different processes. As a result, the chemistry and the fate of Tc in HLW tanks are not well understood. This lack of understanding has been made evident in the failed efforts to leach Tc from sludge and to remove Tc from supernatants prior to immobilization. Although recent interest in Tc chemistry has shifted from pretreatment chemistry to waste residuals, both needs are served by a fundamental understanding of Tc chemistry.

  16. Optical properties of natural dyes on the dye-sensitized solar cells (DSSC) performance

    NASA Astrophysics Data System (ADS)

    Pratiwi, D. D.; Nurosyid, F.; Supriyanto, A.; Suryana, R.

    2016-11-01

    This study reported several natural dyes for application in dye-sensitized solar cells (DSSC). This study aims was to determine the effect of optical absorption properties of natural dyes on efficiency of DSSC. The sandwich structure of DSSC consist of TiO2 as working electrode, carbon layer as counter electrode, natural dyes as photosensitizer, and electrolyte as electron transfer media. The natural dyes used in this experiment were extracted from dragon fruit anthocyanin, mangosteen peels anthocyanin, and red cabbage anthocyanin. The absorbance of dyes solutions and the adsorption of the dye on the surface of TiO2 were characterized using UV-Vis spectrophotometer, the quantum efficiency versus wavelength was characterized using incident photon-to-current efficiency (IPCE) measurement system, and the efficiency of DSSC was calculated using I-V meter. UV-Vis characteristic curves showed that wavelength absorption of anthocyanin dye of red cabbage was 450 - 580 nm, anthocyanin of mangosteen peels was 400 - 480 nm, and anthocyanin of dragon fruit was 400 - 650 nm. Absorption spectra of the dye adsorption on the surface of TiO2 which was resulted in the highest absorbance of red cabbage anthocyanin. IPCE characteristic curves with anthocyanin dye of red cabbage, mangosteen peels anthocyanin, and dragon fruit anthocyanin resulted quantum efficiency of 0.058%; 0.047%; and 0.043%, respectively at wavelength maximum about 430 nm. I-V characteristic curves with anthocyanin dye of red cabbage, mangosteen peels anthocyanin, and dragon fruit anthocyanin resulted efficiency of 0.054%; 0.042%; and 0.024%, respectively.

  17. Reaction chemistry of cerium

    SciTech Connect

    1997-01-01

    It is truly ironic that a synthetic organic chemist likely has far greater knowledge of the reaction chemistry of cerium(IV) than an inorganic colleague. Cerium(IV) reagents have long since been employed as oxidants in effecting a wide variety of organic transformations. Conversely, prior to the late 1980s, the number of well characterized cerium(IV) complexes did not extend past a handful of known species. Though in many other areas, interest in the molecular chemistry of the 4f-elements has undergone an explosive growth over the last twenty years, the chemistry of cerium(IV) has for the most part been overlooked. This report describes reactions of cerium complexes and structure.

  18. Uranium triamidoamine chemistry.

    PubMed

    Gardner, Benedict M; Liddle, Stephen T

    2015-07-07

    Triamidoamine (Tren) complexes of the p- and d-block elements have been well-studied, and they display a diverse array of chemistry of academic, industrial and biological significance. Such in-depth investigations are not as widespread for Tren complexes of uranium, despite the general drive to better understand the chemical behaviour of uranium by virtue of its fundamental position within the nuclear sector. However, the chemistry of Tren-uranium complexes is characterised by the ability to stabilise otherwise reactive, multiply bonded main group donor atom ligands, construct uranium-metal bonds, promote small molecule activation, and support single molecule magnetism, all of which exploit the steric, electronic, thermodynamic and kinetic features of the Tren ligand system. This Feature Article presents a current account of the chemistry of Tren-uranium complexes.

  19. Dye laser amplifier including a specifically designed diffuser assembly

    DOEpatents

    Davin, James; Johnston, James P.

    1992-01-01

    A large (high flow rate) dye laser amplifier in which a continuous replened supply of dye is excited by a first light beam, specifically a copper vapor laser beam, in order to amplify the intensity of a second different light beam, specifically a dye beam, passing through the dye is disclosed herein. This amplifier includes a dye cell defining a dye chamber through which a continuous stream of dye is caused to pass at a relatively high flow rate and a specifically designed diffuser assembly for slowing down the flow of dye while, at the same time, assuring that as the dye stream flows through the diffuser assembly it does so in a stable manner.

  20. JPRS Report, Science & Technology, USSR: Chemistry

    DTIC Science & Technology

    2007-11-02

    This report contains foreign media information from the USSR concerning analytical chemistry, electrochemistry, environmental chemistry, inorganic compounds, organophosphorous compounds, polymers (rubber) and radiation chemistry.

  1. Enzymatic decolorization of spent textile dyeing baths composed by mixtures of synthetic dyes and additives.

    PubMed

    Ciullini, Ilaria; Gullotto, Antonella; Tilli, Silvia; Sannia, Giovanni; Basosi, Riccardo; Scozzafava, Andrea; Briganti, Fabrizio

    2012-10-01

    The effects of different components of real dyeing bath formulations, such as the equalizing and fixing additives-acids, salts, and surfactants-on the decolorization catalyzed by Funalia trogii enzymatic extracts, were investigated to understand their influence on the recalcitrance to biodegradation of this type of wastewater. The decolorization of selected dyes and dye mixtures after tissue dyeing was performed in the presence/absence of auxiliary compounds. All spent dyeing baths were enzymatically decolorized to different extents, by the addition of extracts containing laccase only or laccase plus cellobiose dehydrogenase. Whereas surfactant auxiliaries, in some instances, inhibit the decolorization of spent dyeing baths, in several occurrences the acid/salt additives favor the enzymatic process. In general, the complete spent dyeing formulations are better degraded than those containing the dyes only. The comparison of extracellular extracts obtained from spent straws from the commercial growth of Pleurotus sp. mushrooms with those from F. trogii reveals similar decolorization extents thus allowing to further reduce the costs of bioremediation.

  2. Study of the release of a microencapsulated acid dye in polyamide dyeing using mixed cationic liposomes.

    PubMed

    de Sousa, Isabel S C; Castanheira, Elisabete M S; Rocha Gomes, Jaime I N; Real Oliveira, M Elisabete C D

    2011-06-01

    The main objective of this work was to increase the retarding effect of the acid dye Telon(®) Blue RR (C.I. Acid Blue 62; DyStar, Frankfurt, Germany) release on polyamide fibres dyeing by encapsulation of the dye in liposomes as an alternative to synthetic auxiliaries, in order to reduce effluent pollution. The retarding effect achieved with the use of mixed cationic liposomes of dioctadecyldimethylammonium bromide (DODAB)/soybean lecithin (containing a 10% molar fraction of DODAB) was better in comparison with either pure soybean lecithin liposomes or synthetic auxiliaries. The retarding effect of liposomes on the dye release was analysed through changes in the absorption and fluorescence spectra of the acid dye at different conditions. The effect of temperature (in the range of 25 °C - 70 °C) on the spectroscopic behaviour of the dye in the absence and in presence of polyamide was also studied, in order to simulate the dyeing conditions. Exhaustion curves obtained in dyeing experiments showed that, below 45 °C, the retarding effect of the mixed liposomes (lecithin/DODAB (9:1)) was similar to that of the auxiliaries, but better than the one of pure lecithin liposomes. At higher temperatures (above 45 °C), the system lecithin/DODAB presents a better performance, achieving a higher final exhaustion level when compared with the commercial leveling agent without losing the smoothing effect of lecithin.

  3. Dye screening and signal-to-noise ratio for retrogradely transported voltage-sensitive dyes.

    PubMed

    Tsau, Y; Wenner, P; O'Donovan, M J; Cohen, L B; Loew, L M; Wuskell, J P

    1996-12-28

    Using a novel method for retrogradely labeling specific neuronal populations, we tested different styryl dyes in attempt to find dyes whose staining would be specific, rapid, and lead to large activity dependent signals. The dyes were injected into the ventral roots of the isolated chick spinal cord from embryos at days E9-E12. The voltage-sensitive dye signals were recorded from synaptically activated motoneurons using a 464 element photodiode array. The best labeling and optical signals were obtained using the relatively hydrophobic dyes di-8-ANEPPQ and di-12-ANEPEQ. Over the 24 h period we examined, these dyes bound specifically to the cells with axons in the ventral roots. The dyes responded with an increase in fluorescence of 1-3% (delta F/F) in response to synaptic depolarization of the motoneurons. The signal-to-noise ratio obtained in a single trial from a detector that received light from a 14 x 14 microns2 area of the motoneuron population was about 10:1. Nonetheless, signals on neighboring diodes were similar, suggesting that we were not detecting the activity of individual neurons. Retrograde labeling and optical recording with voltage-sensitive dyes provides a means for monitoring the activity of identified neurons in situations where microelectrode recordings are not feasible.

  4. Chemistry in cometary comae

    NASA Technical Reports Server (NTRS)

    Irvine, W. M.; Dickens, J. E.; Lovell, A. J.; Schloerb, F. P.; Senay, M.; Bergin, E. A.; Jewitt, D.; Matthews, H. E.

    1998-01-01

    Significant gas-phase chemistry occurs in the comae of bright comets, as is demonstrated here for the case of Comet Hale-Bopp. The abundance ratio of the two isomers, hydrogen cyanide and hydrogen isocyanide, is shown to vary with heliocentric distance in a way that is consistent with production of HNC by ion-molecule chemistry initiated by the photoionization of water. Likewise, the first maps of emission from HCO+ show an abundance and an extended distribution that are consistent with the same chemical model.

  5. Chemistry of Transactinides

    NASA Astrophysics Data System (ADS)

    Kratz, J. V.

    In this chapter, the chemical properties of the man-made transactinide elements rutherfordium, Rf (element 104), dubnium, Db (element 105), seaborgium, Sg (element 106), bohrium, Bh (element 107), hassium, Hs (element 108), and copernicium, Cn (element 112) are reviewed, and prospects for chemical characterizations of even heavier elements are discussed. The experimental methods to perform rapid chemical separations on the time scale of seconds are presented and comments are given on the special situation with the transactinides where chemistry has to be studied with single atoms. It follows a description of theoretical predictions and selected experimental results on the chemistry of elements 104 through 108, and element 112.

  6. Chemistry WebBook

    National Institute of Standards and Technology Data Gateway

    SRD 69 NIST Chemistry WebBook (Web, free access)   The NIST Chemistry WebBook contains: Thermochemical data for over 7000 organic and small inorganic compounds; thermochemistry data for over 8000 reactions; IR spectra for over 16,000 compounds; mass spectra for over 33,000 compounds; UV/Vis spectra for over 1600 compounds; electronic and vibrational spectra for over 5000 compounds; constants of diatomic molecules(spectroscopic data) for over 600 compounds; ion energetics data for over 16,000 compounds; thermophysical property data for 74 fluids.

  7. Chemistry of atmospheres.

    NASA Astrophysics Data System (ADS)

    Wayne, R. P.

    Atmospheric chemistry has been the focus of much research activity in recent years. Like its predecessor, this new edition lays down the principles of atmospheric chemistry and provides the necessary background for more detailed study. New developments are covered, including the startling discovery of the "Antarctic ozone hole", and the increasingly rapid changes in the composition of the Earth's atmosphere, apparently a result of man's activities. Information gathered by the Voyager 2 and other space missions, which have provided a new understanding of the atmospheres of planets other than our own, is also discussed.

  8. Fiber optics interface for a dye laser oscillator and method

    DOEpatents

    Johnson, S.A.; Seppala, L.G.

    1984-06-13

    A dye laser oscillator in which one light beam is used to pump a continuous stream of dye within a cooperating dye chamber for producing a second, different beam is generally disclosed herein along with a specific arrangement including an optical fiber and a fiber optics interface for directing the pumping beam into the dye chamber. The specific fiber optics interface illustrated includes three cooperating lenses which together image one particular dimension of the pumping beam into the dye chamber from the output end of the optical fiber in order to insure that the dye chamber is properly illuminated by the pumping beam.

  9. Fiber optics interface for a dye laser oscillator and method

    DOEpatents

    Johnson, Steve A.; Seppala, Lynn G.

    1986-01-01

    A dye laser oscillator in which one light beam is used to pump a continuous tream of dye within a cooperating dye chamber for producing a second, different beam is generally disclosed herein along with a specific arrangement including an optical fiber and a fiber optics interface for directing the pumping beam into the dye chamber. The specific fiber optics interface illustrated includes three cooperating lenses which together image one particular dimension of the pumping beam into the dye chamber from the output end of the optical fiber in order to insure that the dye chamber is properly illuminated by the pumping beam.

  10. Organic Chemistry Self Instructional Package 1: Review of General Chemistry.

    ERIC Educational Resources Information Center

    Zdravkovich, V.

    This booklet is one of a series of 17 developed at Prince George's Community College, Largo, Maryland. It provides an individualized, self-paced undergraduate organic chemistry instruction module designed to augment any course in organic chemistry but particularly those taught using the text "Organic Chemistry" by Morrison and Boyd. The…

  11. Connected Chemistry--Incorporating Interactive Simulations into the Chemistry Classroom.

    ERIC Educational Resources Information Center

    Stieff, Mike; Wilensky, Uri

    2003-01-01

    Describes a novel modeling and simulation package and assesses its impact on students' understanding of chemistry. Connected Chemistry was implemented inside the NetLogo modeling environment. Using Connected Chemistry, students employed problem -solving techniques characterized by stronger attempts at conceptual understanding and logical…

  12. Chemistry: Experiments, Demonstrations and Other Activities Suggested for Chemistry.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

    This publication is a handbook used in conjunction with the course of study in chemistry developed through the New York State Education Department and The University of the State of New York. It contains experiments, demonstrations, and other activities for a chemistry course. Areas covered include the science of chemistry, the atomic structure of…

  13. Is Chemistry Attractive for Pupils? Czech Pupils' Perception of Chemistry

    ERIC Educational Resources Information Center

    Kubiatko, Milan

    2015-01-01

    Chemistry is an important subject due to understanding the composition and structure of the things around us. The main aim of the study was to find out the perception of chemistry by lower secondary school pupils. The partial aims were to find out the influence of gender, year of study and favorite subject on the perception of chemistry. The…

  14. Turkish Prospective Chemistry Teachers' Beliefs about Chemistry Teaching

    ERIC Educational Resources Information Center

    Boz, Yezdan; Uzuntiryaki, Esen

    2006-01-01

    In order to study the beliefs of Turkish prospective chemistry teachers about teaching chemistry, semi-structured interviews were conducted with 12 prospective teachers. Analysis of the interviews revealed that most of the prospective teachers held intermediate (transition between constructivist and traditional) beliefs about chemistry teaching.…

  15. Emphasizing Mineral Chemistry in an Analytical Chemistry Unit.

    ERIC Educational Resources Information Center

    Dunn, Jeffrey G.; And Others

    1995-01-01

    Describes an analytical chemistry unit in the second year of the chemistry degree course at Curtin University that was designed to reflect the numerous employment opportunities for chemistry graduates in the mineral processing industries and private analytical laboratories. Presents the lecture syllabus, the laboratory course description, and…

  16. Top Down Chemistry Versus Bottom up Chemistry

    NASA Astrophysics Data System (ADS)

    Oka, Takeshi; Witt, Adolf N.

    2016-06-01

    The idea of interstellar top down chemistry (TDC), in which molecules are produced from decomposition of larger molecules and dust in contrast to ordinary bottom up chemistry (BUC) in which molecules are produced synthetically from smaller molecules and atoms in the ISM, has been proposed in the chemistry of PAH and carbon chain molecules both for diffusea,c and dense cloudsb,d. A simple and natural idea, it must have occurred to many people and has been in the air for sometime. The validity of this hypothesis is apparent for diffuse clouds in view of the observed low abundance of small molecules and its rapid decrease with molecular size on the one hand and the high column densities of large carbon molecules demonstrated by the many intense diffuse interstellar bands (DIBs) on the other. Recent identification of C60^+ as the carrier of 5 near infrared DIBs with a high column density of 2×1013 cm-2 by Maier and others confirms the TDC. This means that the large molecules and dust produced in the high density high temperature environment of circumstellar envelopes are sufficiently stable to survive decompositions due to stellar UV radiaiton, cosmic rays, C-shocks etc. for a long time (≥ 10^7 year) of their migration to diffuse clouds and seems to disagree with the consensus in the field of interstellar grains. The stability of molecules and aggregates in the diffuse interstellar medium will be discussed. Duley, W. W. 2006, Faraday Discuss. 133, 415 Zhen,J., Castellanos, P., Paardekooper, D. M., Linnartz, H., Tielens, A. G. G. M. 2014, ApJL, 797, L30 Huang, J., Oka, T. 2015, Mol. Phys. 113, 2159 Guzmán, V. V., Pety, J., Goicoechea, J. R., Gerin, M., Roueff, E., Gratier, P., Öberg, K. I. 2015, ApJL, 800, L33 L. Ziurys has sent us many papers beginning Ziurys, L. M. 2006, PNAS 103, 12274 indicating she had long been a proponent of the idea. Campbell, E. K., Holz, M., Maier, J. P., Gerlich, D., Walker, G. A. H., Bohlender, D, 2016, ApJ, in press Draine, B. T. 2003

  17. USSR Report, Chemistry, No. 98

    DTIC Science & Technology

    2007-11-02

    The report contains information on USSR Chemistry in generally in civil technology with particular attention to biochemistry, Catalysts, Coal ... gasification , combustion, Fertilizers, petroleum processing technology. The report also covers important issues related to polymerization, wood chemistry and Elastomer production.

  18. The Art of Teaching Chemistry.

    ERIC Educational Resources Information Center

    Lloyd, Baird W., Ed.

    1994-01-01

    Contains descriptions of 11 college chemistry education programs that were awarded grants by the Pfizer Foundation because they make the introductory chemistry experience more positive and engaging for students, especially women and minorities. (LZ)

  19. The Lighter Side of Chemistry.

    ERIC Educational Resources Information Center

    Lamb, William G.

    1984-01-01

    Discusses the rationale for using photochemistry to merge descriptive chemistry and molecular orbital theory in first-year chemistry courses. Includes procedures and safety information for various activities, demonstrations, and experiments involving photochemical reactions. (DH)

  20. Polymer Chemistry in High School.

    ERIC Educational Resources Information Center

    Stucki, Roger

    1984-01-01

    Discusses why polymer chemistry should be added to the general chemistry curriculum and what topics are appropriate (listing traditional with related polymer topics). Also discusses when and how these topics should be taught. (JN)

  1. The Mystery of Consumer Chemistry.

    ERIC Educational Resources Information Center

    Anderson, Carol P.

    1988-01-01

    Compares processes used to investigate issues in consumer chemistry to the solving of a puzzle in a mystery story. Suggests using similar methods to teach problem solving in consumer chemistry classes. Describes how such a process might progress. (CW)

  2. The Birthday of Organic Chemistry.

    ERIC Educational Resources Information Center

    Benfey, Otto Theodor; Kaufman, George B.

    1979-01-01

    Describes how the synthesis of urea, 150 years ago, was a major factor in breaking the artificial barrier that existed between organic and inorganic chemistry, and this contributed to the rapid growth of organic chemistry. (GA)

  3. Special Report: Chemistry of Comets.

    ERIC Educational Resources Information Center

    A'Hearn, Michael F.

    1984-01-01

    Discusses the chemistry of comets. How comets provide clues to the birth of the solar system, photolytic reactions on comets involving water, chemical modeling, nuclear chemistry, and research findings are among the areas considered. (JN)

  4. Engendering Long-Term Air and Light Stability of a TiO2-Supported Porphyrinic Dye via Atomic Layer Deposition.

    PubMed

    Hoffeditz, William L; Son, Ho-Jin; Pellin, Michael J; Farha, Omar K; Hupp, Joseph T

    2016-12-21

    Organic and porphyrin-based chromophores are prevalent in liquid-junction photovoltaic and photocatalytic solar-cell chemistry; however, their long-term air and light instability may limit their practicality in real world technologies. Here, we describe the protection of a zinc porphyrin dye, adsorbed on nanoparticulate TiO2, from air and light degradation by a protective coating of alumina grown with a previously developed post-treatment atomic layer deposition (ALD) technique. The protective Al2O3 ALD layer is deposited using dimethylaluminum isopropoxide as an Al source; in contrast to the ubiquitous ALD precursor trimethylaluminum, dimethylaluminum isopropoxide does not degrade the zinc porphyrin dye, as confirmed by UV-vis measurements. The growth of this protective ALD layer around the dye can be monitored by an in-reactor quartz crystal microbalance (QCM). Furthermore, greater than 80% of porphyrin light absorption is retained over ∼1 month of exposure to air and light when the protective coating is present, whereas almost complete loss of porphyrin absorption is observed in less than 2 days in the absence of the ALD protective layer. Applying the Al2O3 post-treatment technique to the TiO2-adsorbed dye allows the dye to remain in electronic contact with both the semiconductor surface and a surrounding electrolyte solution, the combination of which makes this technique promising for numerous other electrochemical photovoltaic and photocatalytic applications, especially those involving the dye-sensitized evolution of oxygen.

  5. Chemistry in a Nutshell.

    ERIC Educational Resources Information Center

    Rupnow, John; And Others

    1995-01-01

    Presents an activity that involves making peanut butter in the laboratory as a way to teach students the chemistry concepts of emulsification, solubility, and formulation. Enables students to realize that they can actually create or modify the physical and sensory characteristics of peanut butter and taste the differences in their work. (JRH)

  6. Chemistry Between The Stars.

    ERIC Educational Resources Information Center

    Gammon, Richard H.

    This booklet is part of an American Astronomical Society curriculum project designed to provide teaching materials to teachers of secondary school chemistry, physics, and earth science. The following topics are covered: the physical conditions in interstellar space in comparison with those of the earth, particularly in regard to gas density,…

  7. General Chemistry, 1970 Edition.

    ERIC Educational Resources Information Center

    Dunham, Orson W.; Franke, Douglas C.

    This publication is a syllabus for a senior high school chemistry course designed for the average ability, nonscience major. The content of the syllabus is divided into three basic core areas: Area I: Similarities and Dissimilarities of Matter (9 weeks); Area II: Preparation and Separation of Substances (10 weeks); Area III: Structure and…

  8. The Chemistry of Health.

    ERIC Educational Resources Information Center

    National Inst. of General Medical Sciences (NIH), Bethesda, MD.

    This booklet, geared toward an advanced high school or early college-level audience, describes how basic chemistry and biochemistry research can spur a better understanding of human health. It reveals how networks of chemical reactions keep our bodies running smoothly. Some of the tools and technologies used to explore these reactions are…

  9. Chemistry "en Miniature"

    NASA Astrophysics Data System (ADS)

    Roesky, Herbert W.

    1997-04-01

    By using the video camera projector system we are improving the techniques which are employed in various schools. This is an important reason for employing "Chemistry en Miniature", as this method provides a new means of demonstrating chemical experiments in a lecture hall.

  10. Bringing chemistry to life

    PubMed Central

    Boyce, Michael; Bertozzi, Carolyn R

    2011-01-01

    Bioorthogonal chemistry allows a wide variety of biomolecules to be specifically labeled and probed in living cells and whole organisms. Here we discuss the history of bioorthogonal reactions and some of the most interesting and important advances in the field. PMID:21799498

  11. Chemistry Is Fun.

    ERIC Educational Resources Information Center

    Yaniv, D; And Others

    1982-01-01

    Encouraging scientific thinking through open-ended experiments, allowing students access to common chemical instrumentation, and introduction to laboratory techniques are goals of a high school science laboratory program. Course content (general, inorganic, and organic chemistry), limitations, and course evaluation are discussed. (Author/JN)

  12. Epoxying Isoprene Chemistry

    EPA Science Inventory

    It seems that every few months we read about another missing aspect of atmospheric chemistry: missing products, missing reactivity, missing sources, missing understanding. Thus, it is with some relief that we read in this issue the paper of Paulot et al. The paper provides more...

  13. Green chemistry metrics

    EPA Science Inventory

    Synthetic chemists have always had an objective to achieve reliable and high-yielding routes to the syntheses of targeted molecules. The importance of minimal waste generation has emphasized the use of green chemistry principles and sustainable development. These directions lead ...

  14. Chemistry in the Troposphere.

    ERIC Educational Resources Information Center

    Chameides, William L.; Davis, Douglas D.

    1982-01-01

    Topics addressed in this review of chemistry in the troposphere (layer of atmosphere extending from earth's surface to altitude of 10-16km) include: solar radiation/winds; earth/atmosphere interface; kinetic studies of atmospheric reactions; tropospheric free-radical photochemistry; instruments for nitric oxide detection; sampling…

  15. Chemistry Curricula. Course Suggestions.

    ERIC Educational Resources Information Center

    American Chemical Society, Washington, DC.

    Listings of suggested topics aimed at helping university and college faculties plan courses in the main areas of the chemistry curricula are provided. The suggestions were originally offered as appendices to the American Chemical Society's (ACS) Committee on Professional Training's 1983 guidelines for ACS-approved schools. The course data included…

  16. The Lens of Chemistry

    ERIC Educational Resources Information Center

    Thalos, Mariam

    2013-01-01

    Chemistry possesses a distinctive theoretical lens--a distinctive set of theoretical concerns regarding the dynamics and transformations of a perplexing variety of organic and nonorganic substances--to which it must be faithful. Even if it is true that chemical facts bear a special (reductive) relationship to physical facts, nonetheless it will…

  17. Chemistry by Computer.

    ERIC Educational Resources Information Center

    Garmon, Linda

    1981-01-01

    Describes the features of various computer chemistry programs. Utilization of computer graphics, color, digital imaging, and other innovations are discussed in programs including those which aid in the identification of unknowns, predict whether chemical reactions are feasible, and predict the biological activity of xenobiotic compounds. (CS)

  18. Computational chemistry at Janssen

    NASA Astrophysics Data System (ADS)

    van Vlijmen, Herman; Desjarlais, Renee L.; Mirzadegan, Tara

    2016-12-01

    Computer-aided drug discovery activities at Janssen are carried out by scientists in the Computational Chemistry group of the Discovery Sciences organization. This perspective gives an overview of the organizational and operational structure, the science, internal and external collaborations, and the impact of the group on Drug Discovery at Janssen.

  19. The Chemistry of Health

    ERIC Educational Resources Information Center

    Davis, Alison

    2009-01-01

    Do people realize that chemistry plays a key role in helping solve some of the most serious problems facing the world today? Chemists want to find the building blocks of the chemical universe--the molecules that form materials, living cells and whole organisms. Many chemists are medical explorers looking for new ways to maintain and improve…

  20. Chemistry Cook-Off

    ERIC Educational Resources Information Center

    McCormick, Cynthia

    2012-01-01

    For this activity, high school chemistry students compete in a cooking contest. They must determine the chemical and physical changes that occur in the food they prepare, present their recipe as a step-by-step procedure similar to a lab procedure, identify chemicals in the food, and present all measurements in both metric and English units. The…

  1. Computational chemistry at Janssen.

    PubMed

    van Vlijmen, Herman; Desjarlais, Renee L; Mirzadegan, Tara

    2016-12-19

    Computer-aided drug discovery activities at Janssen are carried out by scientists in the Computational Chemistry group of the Discovery Sciences organization. This perspective gives an overview of the organizational and operational structure, the science, internal and external collaborations, and the impact of the group on Drug Discovery at Janssen.

  2. Using Computers in Chemistry.

    ERIC Educational Resources Information Center

    Pankuch, Brian

    1985-01-01

    Describes the use of two interactive computer programs in a college chemistry course. The first is a commercially-available simulation program (for Apple microcomputers with game paddles) which demonstrates gas laws. The second is a teacher-developed molecular bonding simulation program. (JN)

  3. Chemistry of Meridiani Outcrops

    NASA Technical Reports Server (NTRS)

    Clark, B. C.; Squyres, S. W.; Ming, D. W.; Morris, R. V.; Yen, A.; Gellert, R.; Knoll, A.H.; Arvidson, R. E.

    2006-01-01

    The chemistry and mineralogy of the sulfate-rich sandstone outcrops at Meridiani Planum, Mars, have been inferred from data obtained by the Opportunity rover of the MER mission and reported in recent publications [1-6]. Here, we provide an update on more recent samples and results derived from this extensive data set.

  4. Chemistry and Heritage

    NASA Astrophysics Data System (ADS)

    Vittoria Barbarulo, Maria

    2014-05-01

    Chemistry is the central science, as it touches every aspect of the society we live in and it is intertwined with many aspects of our culture; in particular, the strong link between Chemistry and Archaeology and Art History is being explored, offering a penetrating insight into an area of growing interest from an educational point of view. A series of vital and vibrant examples (i.e., ancient bronzes composition, colour changes due to natural pigment decomposition, marble degradation) has been proposed, on one hand, to improve student understanding of the relationship between cultural and scientific issues arising from the examination, the conservation, and the maintenance of cultural Heritage, on the other, to illustrate the role of the underlying Chemistry. In some case studies, a survey of the most relevant atmospheric factors, which are involved in the deterioration mechanisms, has also been presented to the students. First-hand laboratory experiences have been providing an invaluable means of discovering the full and varied world of Chemistry. Furthermore, the promotion of an interdisciplinary investigation of a famous painting or fresco, involving the study of its nature and significance, the definition of its historical context, any related literature, the chemical knowledge of the materials used, may be an excellent occasion to experiment the Content and Language Integrated Learning (CLIL). The aim of this approach is to convey the important message that everyone has the responsibility to care for and preserve Heritage for the benefit of present and future generations.

  5. The Pimlico Chemistry Trail.

    ERIC Educational Resources Information Center

    Borrows, Peter

    1984-01-01

    Describes a chemistry "trail" (similar to a nature trail) which focuses on chemical phenomena in the environment. The trail includes 20 stops in and around a local school. Types of phenomena examined include building materials, air pollution, corrosion of metals, swimming pools, and others. Additional activities are also suggested. (DH)

  6. Analytical Chemistry Laboratory

    NASA Technical Reports Server (NTRS)

    Anderson, Mark

    2013-01-01

    The Analytical Chemistry and Material Development Group maintains a capability in chemical analysis, materials R&D failure analysis and contamination control. The uniquely qualified staff and facility support the needs of flight projects, science instrument development and various technical tasks, as well as Cal Tech.

  7. Evaluating Environmental Chemistry Textbooks.

    ERIC Educational Resources Information Center

    Hites, Ronald A.

    2001-01-01

    A director of the Indiana University Center for Environmental Science Research reviews textbooks on environmental chemistry. Highlights clear writing, intellectual depth, presence of problem sets covering both the qualitative and quantitative aspects of the material, and full coverage of the topics of concern. Discusses the director's own approach…

  8. General Chemistry Multimedia Problems

    NASA Astrophysics Data System (ADS)

    Whisnant, David M.

    2000-10-01

    Literature Cited

    1. Moore, J. W.; Jacobsen, J. J. Chemistry Comes Alive!, J. Chem. Educ. Software 2000, SP 18 2nd ed., SP 21 2nd ed., SP 23; SP 25; and additional video in press.
    2. Summerlin, L. R.; Borgford, C. F.; Ealy, J. B. Chemical Demonstrations, Volume 2; ACS: Washington, DC, 1987.

    3. Water Chemistry Laboratory Manual.

      ERIC Educational Resources Information Center

      Jenkins, David; And Others

      This manual of laboratory experiments in water chemistry serves a dual function of illustrating fundamental chemical principles of dilute aqueous systems and of providing the student with some familiarity with the chemical measurements commonly used in water and wastewater analysis. Experiments are grouped in categories on the basis of similar…

    4. Getting Reactions to Chemistry.

      ERIC Educational Resources Information Center

      Smith, Walter S.

      1983-01-01

      "COMETS on Careers" describes science-related careers, introduces activities illustrating a science concept being studied, and encourages use of professional persons as activity leaders. Several COMETS chemistry activities are described. These activities, which can be performed in school or at home, focus on colloids, acid/base…

    5. News: Green Chemistry & Technology

      EPA Science Inventory

      A series of 21 articles focused on different features of green chemistry in a recent issue of Chemical Reviews. Topics extended over a wide range to include the design of sustainable synthetic processes to biocatalysis. A selection of perspectives follows as part of this colu

    6. Chemistry: Curriculum Guide.

      ERIC Educational Resources Information Center

      Harlandale Independent School District, San Antonio, TX. Career Education Center.

      The guide is arranged in vertical columns relating the chemistry curriculum concepts to curriculum performance objectives, career concepts and career performance objectives, suggested teaching methods, and resource materials. Occupational information for 40 different occupations includes job duties, educational requirements, salary range, and…

    7. Microscale Gas Chemistry

      ERIC Educational Resources Information Center

      Mattson, Bruce; Anderson, Michael P.

      2011-01-01

      The development of syringes having free movement while remaining gas-tight enabled methods in chemistry to be changed. Successfully containing and measuring volumes of gas without the need to trap them using liquids made it possible to work with smaller quantities. The invention of the LuerLok syringe cap also allowed the gas to be stored for a…

    8. USSR Report, Chemistry

      DTIC Science & Technology

      2007-11-02

      obtained from copyright owner» JPRS-UCH-85-009 24 July 19 85 USSR REPORT CHEMISTRY CONTENTS ADSORPTION Adsorption Thermoluminescence of Oxides of...541.183 ADSORPTION THERMOLUMINESCENCE OF OXIDES OF MAGNESIUM AND CALCIUM IN OXYGEN Moscow KHIMICHESKAYA FIZIKA in Russian Vol 4, No 3, Mar 85

    9. Greener and Sustainable Chemistry

      EPA Science Inventory

      The special issue on Greener and Sustainable Chemistry highlights various strategies that can be adopted to address the pollution preventive measures promoting the use of energy efficient reactions that utilize benign and bio-renewable raw materials in a relatively safer reaction...

    10. Chemistry between the stars

      NASA Technical Reports Server (NTRS)

      Gammon, R. H.

      1976-01-01

      A unit is presented for the secondary school teacher of physics, chemistry, astronomy, or earth sciences. Included are a list of reference materials, teaching aids, and projects. Discussion questions and a glossary are also provided. Concepts developed are: the nature of interstellar space, spectroscopy, molecular signals from space and interstellar molecules and other areas of astronomy.

    11. Get Cooking with Chemistry!

      ERIC Educational Resources Information Center

      American Chemical Society, Washington, DC.

      This book presents science activities investigating the chemical changes and reactions with powders that are used in baking. Activities include: (1) Mystery Powders; (2) Find the Fizz: Discover the Secret of Baking Powder; and (3) A Feast for Yeast and Cheese: Behold the Power of Chemistry. (YDS)

    12. The Language of Chemistry.

      ERIC Educational Resources Information Center

      Bretz, Stacey Lowery; Meinwald, Jerrold

      2002-01-01

      Describes a new curriculum called The Language of Chemistry designed to illustrate how problems of biological and/or medical importance can be understood on a molecular basis and to show that the logic, knowledge, and language needed are easily accessible. Among the case studies in the curriculum are the giant peacock moth, bacterial chemotaxis,…

    13. Online Organic Chemistry

      ERIC Educational Resources Information Center

      Janowicz, Philip A.

      2010-01-01

      This is a comprehensive study of the many facets of an entirely online organic chemistry course. Online homework with structure-drawing capabilities was found to be more effective than written homework. Online lecture was found to be just as effective as in-person lecture, and students prefer an online lecture format with shorter Webcasts. Online…

    14. Polyhedra in (inorganic) chemistry.

      PubMed

      Alvarez, Santiago

      2005-07-07

      A systematic description of polyhedra with varying degrees of regularity is illustrated with examples of chemical structures, mostly from different fields of Inorganic Chemistry. Also the geometrical relationships between different polyhedra are highlighted and their application to the analysis of complex structures is discussed.

  1. Spectral Studies of UV and Solar Photocatalytic Degradation of AZO Dye and Textile Dye Effluents Using Green Synthesized Silver Nanoparticles

    PubMed Central

    Mariselvam, R.; Ranjitsingh, A. J. A.; Mosae Selvakumar, P.; Alarfaj, Abdullah A.; Munusamy, Murugan A.

    2016-01-01

    The photocatalytic degradation of the chemical dye AZO and dye effluents in different time duration has been investigated using biologically synthesized silver nanoparticles. Dye industry effluents and AZO dye undergo degradation to form harmless intermediate and colourless products following irradiation by UV and solar light in the presence of green synthesized silver nanoparticles. The degree of degradation was tested under the experimental conditions such as PH, temperature, and absorbance of the dye in UV and solar light was measured. The degradation was higher in the UV light source than in the solar light source. Green synthesized silver nanoparticles in the UV light source were found to expedite the dye degradation process. PMID:27382364

  2. Spectral Studies of UV and Solar Photocatalytic Degradation of AZO Dye and Textile Dye Effluents Using Green Synthesized Silver Nanoparticles.

    PubMed

    Mariselvam, R; Ranjitsingh, A J A; Mosae Selvakumar, P; Alarfaj, Abdullah A; Munusamy, Murugan A

    2016-01-01

    The photocatalytic degradation of the chemical dye AZO and dye effluents in different time duration has been investigated using biologically synthesized silver nanoparticles. Dye industry effluents and AZO dye undergo degradation to form harmless intermediate and colourless products following irradiation by UV and solar light in the presence of green synthesized silver nanoparticles. The degree of degradation was tested under the experimental conditions such as P(H), temperature, and absorbance of the dye in UV and solar light was measured. The degradation was higher in the UV light source than in the solar light source. Green synthesized silver nanoparticles in the UV light source were found to expedite the dye degradation process.

  3. Physical and chemical investigations on natural dyes

    NASA Astrophysics Data System (ADS)

    Acquaviva, S.; D'Anna, E.; de Giorgi, M. L.; Della Patria, A.; Baraldi, P.

    2010-09-01

    Natural dyes have been used extensively in the past for many purposes, such us to colour fibers and to produce inks, watercolours and paints, but their use declined rapidly after the discovery of synthetic colours. Nowadays we witness a renewed interest, as natural dyes are neither toxic nor polluting. In this work, physical and chemical properties of four selected dyes, namely red (Madder), yellow (Weld and Turmeric) and blue (Woad) colours, produced by means of traditional techniques at the Museo dei Colori Naturali (Lamoli, Italy), have been investigated. The chromatic properties have been studied through the reflectance spectroscopy, a non-invasive technique for the characterisation of chromaticity. Reflection spectra both from powders and egg-yolk tempera models have been acquired to provide the typical features of the dyes in the UV-vis spectral range. Moreover, to assess the feasibility of laser cleaning procedures, tempera layers were investigated after irradiation with an excimer laser. Micro Raman spectroscopy, Scanning Electron Microscopy and Energy Dispersive X-Ray analyses have complemented the survey, returning compositional and morphological information as well. Efforts have been made to give scientific feedback to the production processes and to support the research activity in the restoration of the artworks where these dyes were employed.

  4. REVIEW: Laser media based on polymethine dyes

    NASA Astrophysics Data System (ADS)

    Ishchenko, Aleksandr A.

    1994-06-01

    An account is given of the results of investigations of the use of polymethine (cyanine) dyes as passive Q switches and active media for lasers operating in the visible and nearinfrared range. Characteristic features of the electronic structure of cyanines, which govern their switching and lasing properties, are considered. An analysis is made of the relationship of these properties with isomerisation processes, as well as with vibronic and intermolecular interactions in solutions of polymethine dyes. The spectral, luminescence, and nonlinear optical characteristics of polymer laser media based on polymethine dyes are considered as a function of their structure and the nature of the matrix containing them. Different approaches to the modification of the molecular structure of cyanines, with the aim of achieving efficient lasing characterised by a large 'red' shift, are discussed. Criteria for the selection of the optimal polymethine dyes and solvents are formulated, including the choice of polymer matrices, for when these dyes are used in passive switches and active media of lasers.

  5. An Advanced Chemistry Laboratory Program.

    ERIC Educational Resources Information Center

    Wise, John H.

    The Advanced Chemistry Laboratory Program is a project designed to devise experiments to coordinate the use of instruments in the laboratory programs of physical chemistry, instrumental analysis, and inorganic chemistry at the advanced undergraduate level. It is intended that such experiments would incorporate an introduction to the instrument…

  6. Six Pillars of Organic Chemistry

    ERIC Educational Resources Information Center

    Mullins, Joseph J.

    2008-01-01

    This article describes an approach to teaching organic chemistry, which is to have students build their knowledge of organic chemistry upon a strong foundation of the fundamental concepts of the subject. Specifically, the article focuses upon a core set of concepts that I call "the six pillars of organic chemistry": electronegativity, polar…

  7. Chemistry 200, 300 Interim Guide.

    ERIC Educational Resources Information Center

    Manitoba Dept. of Education, Winnipeg.

    This guide, developed for the chemistry 200, 300 program in Manitoba, is designed to articulate with previous science courses, provide concepts, processes, and skills which will enable students to continue in chemistry-related areas, and relate chemistry to practical applications in everyday life. It includes a program overview (with program goals…

  8. Pad ultrasonic batch dyeing of causticized lyocell fabric with reactive dyes.

    PubMed

    Babar, Aijaz Ahmed; Peerzada, Mazhar Hussain; Jhatial, Abdul Khalique; Bughio, Noor-Ul-Ain

    2017-01-01

    Conventionally, cellulosic fabric dyed with reactive dyes requires significant amount of salt. However, the dyeing of a solvent spun regenerated cellulosic fiber is a critical process. This paper presents the dyeing results of lyocell fabrics dyed with conventional pad batch (CPB) and pad ultrasonic batch (PUB) processes. The dyeing of lyocell fabrics was carried out with two commercial dyes namely Drimarine Blue CL-BR and Ramazol Blue RGB. Dyeing parameters including concentration of sodium hydroxide, sodium carbonate and dwell time were compared for the two processes. The outcomes show that PUB dyed samples offered reasonably higher color yield and dye fixation than CPB dyed samples. A remarkable reduction of 12h in batching time, 18ml/l in NaOH and 05g/l in Na2CO3 quantity was observed for PUB processed samples producing similar results compared to CPB process, making PUB a more economical, productive and an environment friendly process. Color fastness examination witnessed identical results for both PUB and CPB methods. No significant change in surface morphology of PUB processed samples was observed through scanning electron microscope (SEM) analysis.

  9. Fluorescence enhancement of dye-doped liquid crystal by dye-induced alignment effect

    NASA Astrophysics Data System (ADS)

    Shim, Taekyu; Kim, Sunghyun; Kim, Doseok; Oh-e, Masahito

    2011-09-01

    We investigated fluorescence from hemicyanine dye molecules in a liquid crystal (4,4'-n-pentylcyanobiphenyl) (5CB) medium at different temperatures. The fluorescence decay lifetime decreased monotonically irrespective of the thermodynamic phases of the host medium as the temperature was increased. This behavior is due to an intramolecular motion of the dye promoted with the decrease in the viscosity of the medium facilitating a nonradiative decay of the excited dye molecules. By contrast, fluorescence intensity from the dyes in the nematic phase was about 3 times stronger than that in the crystalline or isotropic phase. This fluorescence enhancement in the nematic phase was found to be due to an anisotropic alignment of the dye molecules following the anisotropic alignment of the host liquid crystal medium along the pump-beam polarization direction. This light-induced liquid crystal molecular alignment was markedly enhanced by the guest dyes preferentially excited along the pump-beam polarization direction. The orientational order parameter of the dyes in the liquid-crystalline phase deduced from fluorescence anisotropy measurement was similar to the known order parameter of the liquid crystalline 5CB.

  10. π-Spacer effect in dithiafulvenyl-π-phenothiazine dyes for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaofeng; Gou, Faliang; Zhao, Dongning; Shi, Jian; Gao, Hong; Zhu, Zhenping; Jing, Huanwang

    2016-08-01

    New dithiafulvenyl-π-phenothiazine dyes have been devised and prepared for dye-sensitized solar cells. Various π-spacers have been successfully introduced into the skeleton of dithiafulvenyl and phenothiazine unit to generate novel D-π-D-A dyes (DPP-1 ∼ 4). All dyes have been characterized with NMR, HRMS, UV-vis and fluorescence spectra, and taken into cyclic voltammetry measurements. The devices of new dyes have been determined by photoelectrochemical experiments (IV, IPCE and EIS), in which, solar cell of DPP-4 with biphenyl ring π-spacer enhances obviously its photoelectric conversion efficiency to 7.66% reaching 94% of N719-based standard cell and displays good long-term stability with quasi-solid-state electrolyte. Density functional theory (DFT) calculations of new dyes provide further insight into the molecular geometries and the impacts of the torsion angles on their photovoltaic performance. Large dihedral angles in DPP dyes induce good charge separation for efficient unidirectional flow of electron from donor to acceptor.

  11. CYP450 Enzymes Effect Oxygen-Dependent Reduction of Azide-Based Fluorogenic Dyes

    PubMed Central

    2016-01-01

    Azide-containing compounds have broad utility in organic synthesis and chemical biology. Their use as powerful tools for the labeling of biological systems in vitro has enabled insights into complex cellular functions. To date, fluorogenic azide-containing compounds have primarily been employed in the context of click chemistry and as sensitive functionalities for hydrogen sulfide detection. Here, we report an alternative use of this functionality: as fluorogenic probes for the detection of depleted oxygen levels (hypoxia). Oxygen is imperative to all life forms, and probes that enable quantification of oxygen tension are of high utility in many areas of biology. Here we demonstrate the ability of an azide-based dye to image hypoxia in a range of human cancer cell lines. We have found that cytochrome P450 enzymes are able to reduce these probes in an oxygen-dependent manner, while hydrogen sulfide does not play an important role in their reduction. These data indicate that the azide group is a new bioreductive functionality that can be employed in prodrugs and dyes. We have uncovered a novel mechanism for the cellular reduction of azides, which has implications for the use of click chemistry in hypoxia. PMID:28149949

  12. Natural dye extract of lawsonia inermis seed as photo sensitizer for titanium dioxide based dye sensitized solar cells.

    PubMed

    Ananth, S; Vivek, P; Arumanayagam, T; Murugakoothan, P

    2014-07-15

    Natural dye extract of lawsonia inermis seed were used as photo sensitizer to fabricate titanium dioxide nanoparticles based dye sensitized solar cells. Pure titanium dioxide (TiO2) nanoparticles in anatase phase were synthesized by sol-gel technique and pre dye treated TiO2 nanoparticles were synthesized using modified sol-gel technique by mixing lawsone pigment rich natural dye during the synthesis itself. This pre dye treatment with natural dye has yielded colored TiO2 nanoparticles with uniform adsorption of natural dye, reduced agglomeration, less dye aggregation and improved morphology. The pure and pre dye treated TiO2 nanoparticles were subjected to structural, optical, spectral and morphological studies. Dye sensitized solar cells (DSSC) fabricated using the pre dye treated and pure TiO2 nanoparticles sensitized by natural dye extract of lawsonia inermis seed showed a promising solar light to electron conversion efficiency of 1.47% and 1% respectively. The pre dye treated TiO2 based DSSC showed an improved efficiency of 47% when compared to that of conventional DSSC.

  13. Interaction of Sensitizing Dyes with Nanostructured TiO2 Film in Dye-Sensitized Solar Cells Using Terahertz Spectroscopy

    PubMed Central

    Ghann, William; Rahman, Aunik; Rahman, Anis; Uddin, Jamal

    2016-01-01

    The objective of this investigation was to shed light on the nature of interaction of different organic dyes and an inorganic dye, Ruthenium (II) polypyridine complex, with TiO2 nanoparticles. TiO2 is commonly deployed as an efficient energy transfer electrode in dye sensitized solar cells. The efficiency of dye sensitized solar cells is a function of the interaction of a dye with the electrode material such as TiO2. To the best of our knowledge the present study is the first effort in the determination of terahertz absorbance signals, investigation of real-time dye permeation kinetics, and the surface profiling and 3D imaging of dye sensitized TiO2 films. Herein, we report that the terahertz spectra of the natural dye sensitized TiO2 films were distinctively different from that of the inorganic dye with prominent absorption of natural dyes occurring at approximately the same wavelength. It was observed that the permeation of the natural dyes were more uniform through the layers of the mesoporous TiO2 compared to the inorganic dye. Finally, defects and flaws on TiO2 film were easily recognized via surface profiling and 3D imaging of the films. The findings thus offer a new approach in characterization of dye sensitized solar cells. PMID:27443236

  14. 1. Pamorana of Daniel F. Waters Germantown Dye Works site ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Pamorana of Daniel F. Waters Germantown Dye Works site (with the former Hinckley Knitting Mills in the foreground) from Germantown Avenue looking east. - Daniel F. Waters Germantown Dye Works, 37-55 East Wister Street, Philadelphia, Philadelphia County, PA

  15. Continuous-wave organic dye lasers and methods

    DOEpatents

    Shapira, Ofer; Chua, Song-Liang; Zhen, Bo; Lee, Jeongwon; Soljacic, Marin

    2014-09-16

    An organic dye laser produces a continuous-wave (cw) output without any moving parts (e.g., without using flowing dye streams or spinning discs of solid-state dye media to prevent photobleaching) and with a pump beam that is stationary with respect to the organic dye medium. The laser's resonant cavity, organic dye medium, and pump beam are configured to excite a lasing transition over a time scale longer than the associated decay lifetimes in the organic dye medium without photobleaching the organic dye medium. Because the organic dye medium does not photobleach when operating in this manner, it may be pumped continuously so as to emit a cw output beam. In some examples, operation in this manner lowers the lasing threshold (e.g., to only a few Watts per square centimeter), thereby facilitating electrical pumping for cw operation.

  16. The Ideal Solvent for Paper Chromatography of Food Dyes.

    ERIC Educational Resources Information Center

    Markow, Peter G.

    1988-01-01

    Uses paper chromatography with food dyes to provide a simple and inexpensive basis for teaching chromatography. Provides experimental methodology and tabled results. Includes a solvent system comparison (Rf) for seven dyes and twenty-two solvents. (MVL)

  17. Quirks of dye nomenclature. 6. Malachite green.

    PubMed

    Cooksey, C J

    2016-08-01

    Malachite green was discovered independently by two researchers in Germany in the 19(th) century and found immediate employment as a dye and a pigment. Subsequently, other uses, such as staining biological specimens, emerged. A much later application was the control of fungal and protozoan infections in fish, for which the dye remains popular, although illegal in many countries owing to a variety of toxicity problems. In solution, malachite green can exist as five different species depending on the pH. The location of the positive charge of the colored cation on a carbon atom or a nitrogen atom is still debated. The original names of this dye, and their origins, are briefly surveyed.

  18. Contact dermatitis to hair dye: an update.

    PubMed

    Handa, Sanjeev; Mahajan, Rahul; De, Dipankar

    2012-01-01

    Exposure to hair dyes has long been known as a significant risk factor for development of allergic contact dermatitis among the exposed population as these lead to severe eczema of face and upper trunk in the consumer and hand eczema in hair-dressers. Currently, para-phenylenediamine (PPD) is the main ingredient used in permanent hair color products in the market and is the most important allergen. Prevalence of PPD sensitization is high in patients with contact dermatitis across all continents, with hair dye use being the commonest cause. In order to decrease the burden of disease, use of alternative natural dyeing agents among consumers and use of barrier neoprene gloves among hairdressers should be encouraged apart from stringent legislation to reduce the amount of PPD reaching the consumer.

  19. Effectiveness of dye sensitised solar cell under low light condition using wide band dye

    SciTech Connect

    Sahmer, Ahmad Zahrin Mohamed, Norani Muti Zaine, Siti Nur Azella

    2015-07-22

    Dye sensistised solar cell (DSC) based on nanocrystalline TiO{sub 2} has the potential to be used in indoor consumer power application. In realizing this, the DSC must be optimized to generate power under low lighting condition and under wider visible light range. The use of wide band dye N749 which has a wider spectrum sensitivity increases the photon conversion to electron between the visible light spectrums of 390nm to 700nm. This paper reports the study on the effectiveness of the dye solar cell with N749 dye under low light condition in generating usable power which can be used for indoor consumer application. The DSC was fabricated using fluorine doped tin oxide (FTO) glass with screen printing method and the deposited TiO{sub 2} film was sintered at 500°C. The TiO{sub 2} coated FTO glass was then soaked in the N749 dye, assembled into test cell, and tested under the standard test condition at irradiance of 1000 W/m{sup 2} with AM1.5 solar soaker. The use of the 43T mesh for the dual pass screen printing TiO{sub 2} paste gives a uniform TiO{sub 2} film layer of 16 µm. The low light condition was simulated using 1/3 filtered irradiance with the solar soaker. The fabricated DSC test cell with the N749 dye was found to have a higher efficiency of 6.491% under low light condition compared to the N719 dye. Under the standard test condition at 1 sun the N749 test cell efficiency is 4.55%. The increases in efficiency is attributed to the wider spectral capture of photon of the DSC with N749 dye. Furthermore, the use of N749 dye is more effective under low light condition as the V{sub OC} decrement is less significant compared to the latter.

  20. Towards "Bildung"-Oriented Chemistry Education

    ERIC Educational Resources Information Center

    Sjöström, Jesper

    2013-01-01

    This paper concerns "Bildung"-oriented chemistry education, based on a reflective and critical discourse of chemistry. It is contrasted with the dominant type of chemistry education, based on the mainstream discourse of chemistry. "Bildung"-oriented chemistry education includes not only content knowledge in chemistry, but also…

  1. Oxidative degradation of azo dyes using tourmaline.

    PubMed

    Wang, Cuiping; Zhang, Yanwei; Yu, Li; Zhang, Zhiyuan; Sun, Hongwen

    2013-09-15

    This study aimed to investigate the catalyzed degradation ability of tourmaline on the dyes methylene blue (MB), rhodamine B (RhB), and congo red (CR) at different pH values. Interestingly, tourmaline strongly adsorbed anionic dyes, but it did not adsorb cationic dyes. When H₂O₂ was introduced into the tourmaline-dye systems, the degradation percentage for CR catalysis by tourmaline was lower than the percentage of adsorption, whereas the opposite was true for MB and RhB systems. Notably, the catalyzed degradation decreased from 100% to 45% for MB, 100% to 15% for RhB and 100% to 25% for CR as the pH increased from 3.0 to 10.0, respectively, which was much greater than the degradation obtained for previously reported materials at pH values ranging from 4.0 to 10.0. Tourmaline catalytically degraded the dyes over a broad range of pH values, which was attributed to tourmaline automatically adjusting the pH of the dye solutions to approximately 5.5 from an initial range of 4.2-10.0. An electron paramagnetic resonance spin trapping technique observed peroxyl (ROO·) and alkoxy (RO·) or alkyl (R·) radicals originated from the attack of ·OH radicals and O₂(·-) radicals, indicating that these radicals were involved in the catalyzed degradation of MB. Importantly, four intermediate products of MB at m/z 383, 316, 203 and 181 were observed by LC/MS.

  2. Dye-sensitized composite semiconductor nanostructures

    NASA Astrophysics Data System (ADS)

    Tennakone, K.; Bandaranayake, P. K. M.; Jayaweera, P. V. V.; Konno, A.; Kumara, G. R. R. A.

    2002-04-01

    Understanding of the charge transport and recombination mechanisms of dye-sensitized solar cells based on semiconductor nanostructures is essential for the improvement of their performance. A great deal of information on these systems have been obtained from studies on a single material (mostly TiO 2 and to a lesser extent ZnO and SnO 2). We have conducted extensive measurements on composite dye-sensitized nanosturctures and found that the composite systems possess unusual properties. Dye-sensitized photoelectrochemical cells made from nanocrystalline films of some materials (e.g., SnO 2) yield comparatively small open-circuit voltages and energy and quantum conversion efficiencies, despite excellent dye-semiconductor interaction. However, on deposition of ultra-thin shells of insulators or high band gap semiconductors on the crystallites, a dramatic increase in the above parameters is observed. Outer shells were found to have insignificant or in most cases a negative effect on TiO 2 films. We explain the above findings on the basis of vast differences in the leakage rates of trapped electrons in different materials which is sensitive to the effective electron mass. Electrons injected to the conduction band in dye-sensitization enter into shallow traps from which they get thermally reemitted to the conduction band. The building up of the electron quasi-fermi level and transport depends on this process. The spread of the hydrogenic wave function of a trapped electron increases inverse exponentially with the effective mass so that the electron leakage and their recombination with acceptors ‘outside’ become severe when the crystallite size is comparable to the Bohr radius of the trapped electron. Such recombinations are effectively suppressed by deposition of thin films on the crystallites. Excited dye molecules anchored to the outer shell injects electrons to the conduction band via tunneling.

  3. Observations and modeling of a tidal inlet dye tracer plume

    NASA Astrophysics Data System (ADS)

    Feddersen, Falk; Olabarrieta, Maitane; Guza, R. T.; Winters, D.; Raubenheimer, Britt; Elgar, Steve

    2016-10-01

    A 9 km long tracer plume was created by continuously releasing Rhodamine WT dye for 2.2 h during ebb tide within the southern edge of the main tidal channel at New River Inlet, NC on 7 May 2012, with highly obliquely incident waves and alongshore winds. Over 6 h from release, COAWST (coupled ROMS and SWAN, including wave, wind, and tidal forcing) modeled dye compares well with (aerial hyperspectral and in situ) observed dye concentration. Dye first was transported rapidly seaward along the main channel and partially advected across the ebb-tidal shoal until reaching the offshore edge of the shoal. Dye did not eject offshore in an ebb-tidal jet because the obliquely incident breaking waves retarded the inlet-mouth ebb-tidal flow and forced currents along the ebb shoal. The dye plume largely was confined to <4 m depth. Dye was then transported downcoast in the narrow (few 100 m wide) surfzone of the beach bordering the inlet at 0.3 m s-1 driven by wave breaking. Over 6 h, the dye plume is not significantly affected by buoyancy. Observed dye mass balances close indicating all released dye is accounted for. Modeled and observed dye behaviors are qualitatively similar. The model simulates well the evolution of the dye center of mass, lateral spreading, surface area, and maximum concentration, as well as regional ("inlet" and "ocean") dye mass balances. This indicates that the model represents well the dynamics of the ebb-tidal dye plume. Details of the dye transport pathways across the ebb shoal are modeled poorly perhaps owing to low-resolution and smoothed model bathymetry. Wave forcing effects have a large impact on the dye transport.

  4. Dermatotoxicologic clinical solutions: hair dying in hair dye allergic patients?

    PubMed

    Edwards, Ashley; Coman, Garrett; Blickenstaff, Nicholas; Maibach, Howard

    2015-03-01

    This article describes how to identify allergic contact dermatitis resulting from hair dye, and outlines interventions and prevention principles for those who wish to continue dyeing their hair despite being allergic. Hair dye chemicals thought to be the most frequent sensitizers are discussed with instructions for health care providers on how to counsel patients about techniques to minimize exposure to allergenic substances. This framework should allow many patients to continue dyeing their hair without experiencing adverse side effects.

  5. Antimicrobial and Dyeing Properties of Reactive Dyes with Thiazolidinon-4-one Nucleus

    PubMed Central

    Reda, Gebremedihin; Gashaw, Tsegaye; Babu, Neelaiah; Upadhyay, Raj Kumar

    2014-01-01

    Four imines, the condensation products of 2,4-dioxo-4-phenylbutanal with four primary amines, were condensed with mercapto acetic acid to obtain thiazolidinon-4-ones which on subsequent condensation with vanillin and isatin separately yielded eight thiazolidin-4-one derivatives. The chemical structures of the synthesized compounds were elucidated by elemental analysis, molecular weight determination, IR and 1H and 13C NMR spectral measurements. Antibacterial and antifungal properties were studied in vitro against two bacteria and two fungi. The dyeing potential of synthesized reactive dyes was investigated with regard to silk, wool, cotton, and polyester fabrics under hot and cold dyeing conditions. PMID:24955258

  6. RISK ASSESSMENT FOR THE DYE AND PIGMENT ...

    EPA Pesticide Factsheets

    This risk assessment calculates the maximum loadings of constituents found in dyes and pigment industries waste streams which can be disposed in different types of waste management units without causing health benchmarks to be exceeded at plausible receptor locations. The assessment focuses on potential risks from volatilization and leaching to groundwater of constituents disposed in surface impoundments and landfills with either clay liners or composite liners. This product will be used by EPA decision makers to assist in determining whether certain waste streams generated by the dyes and pigments industries should be designated as hazardous.

  7. Pyrylium-based dye and charge tagging in proteomics.

    PubMed

    Bayer, Malte; König, Simone

    2016-11-01

    The pyrylium group is a selective reagent for ε-amino groups in proteins. In particular, for fluorescence labeling, a number of advantages over traditional N-hydroxysuccinimidyl ester chemistry were recognized such as the rapid prestaining procedure. Here, we have investigated the labeling reaction for the fluorogenic pyrylium dye Py-1 using liquid chromatography coupled to MS with the aim of determining its specificity and possible side products. Peptides containing no, one, and two lysine residue and a choice of no or one cysteine residue were labeled with Py-1 at yields > 30%. Gas phase fragmentation proved both labeling of lysine residues as well as that of the N-terminus also in peptides that contained a lysine residue. Evidence for cysteine labeling was not found, but several other products were detected such as the results of rearrangements with adjacent acidic amino acids. Apart from the use as a fluorogenic label, Py-1 recommends itself for N-terminal charge tagging as alternative to the commonly used quaternary ammonium salts. Predominantly a- and b-type ion series were observed for N-terminally labeled peptides. Further applications include chromophore tagging since the labeled product is not only fluorescent but also colored red.

  8. 40 CFR 721.5917 - Phenyl azo dye (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Phenyl azo dye (generic). 721.5917... Substances § 721.5917 Phenyl azo dye (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a phenyl azo dye (PMN P-02-17) is subject...

  9. 21 CFR 864.1850 - Dye and chemical solution stains.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Dye and chemical solution stains. 864.1850 Section... (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Biological Stains § 864.1850 Dye and chemical solution stains. (a) Identification. Dye and chemical solution stains for medical purposes are mixtures...

  10. 40 CFR 721.2527 - Substituted diphenylazo dye (generic name).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Substituted diphenylazo dye (generic... Specific Chemical Substances § 721.2527 Substituted diphenylazo dye (generic name). (a) Chemical substance... substituted diphenylazo dye (PMN P-95-514) is subject to reporting under this section for the significant...

  11. 40 CFR 721.5917 - Phenyl azo dye (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phenyl azo dye (generic). 721.5917... Substances § 721.5917 Phenyl azo dye (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a phenyl azo dye (PMN P-02-17) is subject...

  12. 40 CFR 721.2527 - Substituted diphenylazo dye (generic name).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted diphenylazo dye (generic... Specific Chemical Substances § 721.2527 Substituted diphenylazo dye (generic name). (a) Chemical substance... substituted diphenylazo dye (PMN P-95-514) is subject to reporting under this section for the significant...

  13. 21 CFR 864.1850 - Dye and chemical solution stains.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Dye and chemical solution stains. 864.1850 Section... (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Biological Stains § 864.1850 Dye and chemical solution stains. (a) Identification. Dye and chemical solution stains for medical purposes are mixtures...

  14. 40 CFR 721.9717 - Azo monochloro triazine reactive dye.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Azo monochloro triazine reactive dye... Substances § 721.9717 Azo monochloro triazine reactive dye. (a) Chemical substance and significant new uses... reactive dye (PMN P-96-238) is subject to reporting under this section for the significant new...

  15. 40 CFR 721.5917 - Phenyl azo dye (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Phenyl azo dye (generic). 721.5917... Substances § 721.5917 Phenyl azo dye (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a phenyl azo dye (PMN P-02-17) is subject...

  16. 21 CFR 864.1850 - Dye and chemical solution stains.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Dye and chemical solution stains. 864.1850 Section... (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Biological Stains § 864.1850 Dye and chemical solution stains. (a) Identification. Dye and chemical solution stains for medical purposes are mixtures...

  17. 40 CFR 721.5917 - Phenyl azo dye (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phenyl azo dye (generic). 721.5917... Substances § 721.5917 Phenyl azo dye (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a phenyl azo dye (PMN P-02-17) is subject...

  18. 40 CFR 721.5915 - Polysubstituted phenylazopolysubstitutedphenyl dye.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... phenylazopolysubstitutedphenyl dye. 721.5915 Section 721.5915 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.5915 Polysubstituted phenylazopolysubstitutedphenyl dye. (a) Chemical... as a polysubstituted phenylazopolysubstitutedphenyl dye (PMN P-93-658) is subject to reporting...

  19. 40 CFR 721.5917 - Phenyl azo dye (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Phenyl azo dye (generic). 721.5917... Substances § 721.5917 Phenyl azo dye (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a phenyl azo dye (PMN P-02-17) is subject...

  20. 40 CFR 721.9717 - Azo monochloro triazine reactive dye.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Azo monochloro triazine reactive dye... Substances § 721.9717 Azo monochloro triazine reactive dye. (a) Chemical substance and significant new uses... reactive dye (PMN P-96-238) is subject to reporting under this section for the significant new...

  1. 40 CFR 721.9717 - Azo monochloro triazine reactive dye.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Azo monochloro triazine reactive dye... Substances § 721.9717 Azo monochloro triazine reactive dye. (a) Chemical substance and significant new uses... reactive dye (PMN P-96-238) is subject to reporting under this section for the significant new...

  2. 40 CFR 721.2527 - Substituted diphenylazo dye (generic name).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Substituted diphenylazo dye (generic... Specific Chemical Substances § 721.2527 Substituted diphenylazo dye (generic name). (a) Chemical substance... substituted diphenylazo dye (PMN P-95-514) is subject to reporting under this section for the significant...

  3. 40 CFR 721.9717 - Azo monochloro triazine reactive dye.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Azo monochloro triazine reactive dye... Substances § 721.9717 Azo monochloro triazine reactive dye. (a) Chemical substance and significant new uses... reactive dye (PMN P-96-238) is subject to reporting under this section for the significant new...

  4. 40 CFR 721.5915 - Polysubstituted phenylazopolysubstitutedphenyl dye.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... phenylazopolysubstitutedphenyl dye. 721.5915 Section 721.5915 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.5915 Polysubstituted phenylazopolysubstitutedphenyl dye. (a) Chemical... as a polysubstituted phenylazopolysubstitutedphenyl dye (PMN P-93-658) is subject to reporting...

  5. 40 CFR 721.9717 - Azo monochloro triazine reactive dye.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Azo monochloro triazine reactive dye... Substances § 721.9717 Azo monochloro triazine reactive dye. (a) Chemical substance and significant new uses... reactive dye (PMN P-96-238) is subject to reporting under this section for the significant new...

  6. 40 CFR 721.5915 - Polysubstituted phenylazopolysubstitutedphenyl dye.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... phenylazopolysubstitutedphenyl dye. 721.5915 Section 721.5915 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.5915 Polysubstituted phenylazopolysubstitutedphenyl dye. (a) Chemical... as a polysubstituted phenylazopolysubstitutedphenyl dye (PMN P-93-658) is subject to reporting...

  7. 40 CFR 721.5915 - Polysubstituted phenylazopolysubstitutedphenyl dye.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... phenylazopolysubstitutedphenyl dye. 721.5915 Section 721.5915 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.5915 Polysubstituted phenylazopolysubstitutedphenyl dye. (a) Chemical... as a polysubstituted phenylazopolysubstitutedphenyl dye (PMN P-93-658) is subject to reporting...

  8. 40 CFR 721.2527 - Substituted diphenylazo dye (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Substituted diphenylazo dye (generic... Specific Chemical Substances § 721.2527 Substituted diphenylazo dye (generic name). (a) Chemical substance... substituted diphenylazo dye (PMN P-95-514) is subject to reporting under this section for the significant...

  9. 40 CFR 721.5915 - Polysubstituted phenylazopolysubstitutedphenyl dye.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... phenylazopolysubstitutedphenyl dye. 721.5915 Section 721.5915 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.5915 Polysubstituted phenylazopolysubstitutedphenyl dye. (a) Chemical... as a polysubstituted phenylazopolysubstitutedphenyl dye (PMN P-93-658) is subject to reporting...

  10. 21 CFR 864.1850 - Dye and chemical solution stains.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... solution stains. (a) Identification. Dye and chemical solution stains for medical purposes are mixtures of synthetic or natural dyes or nondye chemicals in solutions used in staining cells and tissues for diagnostic... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dye and chemical solution stains. 864.1850...

  11. 21 CFR 864.1850 - Dye and chemical solution stains.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... solution stains. (a) Identification. Dye and chemical solution stains for medical purposes are mixtures of synthetic or natural dyes or nondye chemicals in solutions used in staining cells and tissues for diagnostic... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Dye and chemical solution stains. 864.1850...

  12. An investigation of dye reduction by food-borne bacteria.

    PubMed

    Learoyd, S A; Kroll, R G; Thurston, C F

    1992-06-01

    The rates of reduction of seven redox dyes by 13 bacterial strains were measured and found to vary greatly between different bacterium/dye combinations. Phenazine ethosulphate and toluidine blue were the most rapidly reduced dyes by the majority of bacteria and resorufin and 2-hydroxy-1,4-naphthoquinone were reduced slowly, if at all. There was also considerable variation in the rates of reduction with any single dye/organism combination. Glucose stimulated the rates of endogenous dye reduction in about half of the organisms. For Bacillus cereus, Pseudomonas fluorescens and Escherichia coli, dye reduction was stimulated by a range of exogenous substrates but lactose, the primary available carbon and energy source in milk, had little effect. In Lactococcus lactis, dye reduction was stimulated by sugars but not by organic acids. Oxygen successfully competed with dye reduction in organisms containing respiratory chains, but with membrane fractions, dye reduction was more rapid than oxygen consumption. All the organisms showed little cytosolic dye reduction, except L. lactis which showed substantial rates of reduction of some dyes by this fraction. With the membrane fraction of E. coli and Ps. fluorescens, cyanide inhibited NADH and succinate-dependent dye reduction, Antimycin A inhibited lactate and succinate and rotenone had no significant effect, but inhibition was not always observed with membrane from both organisms.

  13. Dye lasers. Citations from the NTIS data base

    NASA Astrophysics Data System (ADS)

    Cavagnaro, D. M.

    1980-08-01

    This bibliography covers studies on dye laser theory, design, components, optical systems, and frequency range. Abstracts on lasing dyes, pumping, tuning, excitation, molecular structure, and modulation are included. Studies on dye laser use in spectroscopy are covered. This updated bibliography contains 217 citations, none of which are new entries to the previous edition.

  14. Aqueous chemistry of iodine

    SciTech Connect

    Toth, L.M.; Pannell, K.D.; Kirkland, O.L.

    1984-01-01

    The chemistry of iodine has been examined in aqueous solutions of pH 6 to 10 containing 2500 ppM boron as H/sub 3/BO/sub 3/ at temperatures up to 150/sup 0/C using absorption spectrophotometry to identify and monitor the iodine species present. Kinetic rate constants for the disproportionation of the HOI intermediate, 3HOI= IO/sub 3//sup -/ + 2I/sup -/ + 3H/sup +/, have been measured as a function of pH even though no direct spectral evidence for HOI itself has been observed. An HOI partition coefficient >10/sup 4/ has been estimated; results of ionic strength tests are consistent with HOI being present as an uncharged triatomic species in solution. Redox and radiation effects on the aqueous iodine chemistry have also been described. 11 refs., 2 figs., 3 tabs.

  15. Quo vadis, analytical chemistry?

    PubMed

    Valcárcel, Miguel

    2016-01-01

    This paper presents an open, personal, fresh approach to the future of Analytical Chemistry in the context of the deep changes Science and Technology are anticipated to experience. Its main aim is to challenge young analytical chemists because the future of our scientific discipline is in their hands. A description of not completely accurate overall conceptions of our discipline, both past and present, to be avoided is followed by a flexible, integral definition of Analytical Chemistry and its cornerstones (viz., aims and objectives, quality trade-offs, the third basic analytical reference, the information hierarchy, social responsibility, independent research, transfer of knowledge and technology, interfaces to other scientific-technical disciplines, and well-oriented education). Obsolete paradigms, and more accurate general and specific that can be expected to provide the framework for our discipline in the coming years are described. Finally, the three possible responses of analytical chemists to the proposed changes in our discipline are discussed.

  16. Medicinal chemistry for 2020

    PubMed Central

    Satyanarayanajois, Seetharama D; Hill, Ronald A

    2011-01-01

    Rapid advances in our collective understanding of biomolecular structure and, in concert, of biochemical systems, coupled with developments in computational methods, have massively impacted the field of medicinal chemistry over the past two decades, with even greater changes appearing on the horizon. In this perspective, we endeavor to profile some of the most prominent determinants of change and speculate as to further evolution that may consequently occur during the next decade. The five main angles to be addressed are: protein–protein interactions; peptides and peptidomimetics; molecular diversity and pharmacological space; molecular pharmacodynamics (significance, potential and challenges); and early-stage clinical efficacy and safety. We then consider, in light of these, the future of medicinal chemistry and the educational preparation that will be required for future medicinal chemists. PMID:22004084

  17. Evolution of hydroformylation chemistry

    SciTech Connect

    Slaugh, L.H.

    1995-12-01

    A new generation of hydroformylation catalysts was discovered in 1960 at Shell Development Company which dramatically altered the chemistry of producing industrially important alcohols from synthesis gas (CO/H{sub 2}) and olefins. These new homogeneous catalysts were obtained via the use of auxiliary tertiary phosphine ligands with the conventional OXO cobalt carbonyl catalyst. This is believed to have been the first historical example illustrating the utility of phosphine ligands to modify the catalytic properties of homogenous catalysts. In contradistinction to the conventional OXO reaction, highly linear alcohols were obtained in a single-step operation with ease of catalyst recycle. Based on this discovery, an industrial process was developed to produce large volume, environmentally friendly detergent alcohols. The chemistry of this process and a comparison with other hydroformylation catalyst systems will be made. Recent results obtained with phosphine-modified cobalt catalysts for the hydroformylation of substrates other than olefins will be presented.

  18. Chemistry of silybin.

    PubMed

    Biedermann, D; Vavříková, E; Cvak, L; Křen, V

    2014-09-01

    Silybin, a secondary metabolite isolated from the seeds of the blessed milk thistle (Silybum marianum) was discovered as the first member of a new family of natural compounds called flavonolignans in 1959. Over the years it has received the research attention of many organic chemists. This research has resulted in a number of semisynthetic derivatives prepared in an effort to modulate and better target the biological activities of silybin or to improve its physical properties, such as its solubility. A fundamental breakthrough in silybin chemistry was the determination of the absolute configurations of silybin A and silybin B, and the development of methods for their separation. This review covers articles dealing with silybin chemistry and also summarizes all the derivatives prepared.

  19. Turbine Chemistry Modeling

    NASA Technical Reports Server (NTRS)

    Liu, Nan-Suey; Wey, Thomas

    2001-01-01

    Many of the engine exhaust species resulting in significant environmental impact exist in trace amounts. Recent research, e.g., conducted at MIT-AM, has pointed to the intra-engine environment as a possible site for important trace chemistry activity. In addition, the key processes affecting the trace species activity occurring downstream in the air passages of the turbine and exhaust nozzle are not well understood. Most recently, an effort has been initiated at NASA Glenn Research Center under the UEET Program to evaluate and further develop CFD-based technology for modeling and simulation of intra-engine trace chemical changes relevant to atmospheric effects of pollutant emissions from aircraft engines. This presentation will describe the current effort conducted at Glenn; some preliminary results relevant to the trace species chemistry in a turbine passage will also be presented to indicate the progress to date.

  20. Heterogeneous atmospheric chemistry

    NASA Technical Reports Server (NTRS)

    Schryer, D. R.

    1982-01-01

    The present conference on heterogeneous atmospheric chemistry considers such topics concerning clusters, particles and microparticles as common problems in nucleation and growth, chemical kinetics, and catalysis, chemical reactions with aerosols, electron beam studies of natural and anthropogenic microparticles, and structural studies employing molecular beam techniques, as well as such gas-solid interaction topics as photoassisted reactions, catalyzed photolysis, and heterogeneous catalysis. Also discussed are sulfur dioxide absorption, oxidation, and oxidation inhibition in falling drops, sulfur dioxide/water equilibria, the evidence for heterogeneous catalysis in the atmosphere, the importance of heterogeneous processes to tropospheric chemistry, soot-catalyzed atmospheric reactions, and the concentrations and mechanisms of formation of sulfate in the atmospheric boundary layer.

  1. [Gaubius and medical chemistry].

    PubMed

    van Gijn, Jan; Gijselhart, Joost P

    2011-01-01

    Hieronymus David Gaub (1705-1780) was the son of a protestant cloth merchant in Heidelberg. Disliking a pietistic boarding school in Halle, Germany, he came to stay with a paternal uncle who was a physician in Amsterdam. Hieronymus studied medicine in Harderwijk and in Leiden, under the guidance of Herman Boerhaave (1668-1738). In 1731 he was appointed reader (and in 1734 professor) in chemistry at the Leiden medical faculty. After Boerhaave's death he also taught medicine, but without access to hospital beds. Gaubius correctly envisaged that chemistry would become an important discipline in medicine, but was limited by the technical constraints of his time. In his textbook of general pathology (1758) he attributed disease to disturbances of not only fluids, but also solid parts, although symptoms remained the basis of his classification. The book would remain influential for several decades, until the advent of pathological anatomy.

  2. Nuclear analytical chemistry

    SciTech Connect

    Brune, D.; Forkman, B.; Persson, B.

    1984-01-01

    This book covers the general theories and techniques of nuclear chemical analysis, directed at applications in analytical chemistry, nuclear medicine, radiophysics, agriculture, environmental sciences, geological exploration, industrial process control, etc. The main principles of nuclear physics and nuclear detection on which the analysis is based are briefly outlined. An attempt is made to emphasise the fundamentals of activation analysis, detection and activation methods, as well as their applications. The book provides guidance in analytical chemistry, agriculture, environmental and biomedical sciences, etc. The contents include: the nuclear periodic system; nuclear decay; nuclear reactions; nuclear radiation sources; interaction of radiation with matter; principles of radiation detectors; nuclear electronics; statistical methods and spectral analysis; methods of radiation detection; neutron activation analysis; charged particle activation analysis; photon activation analysis; sample preparation and chemical separation; nuclear chemical analysis in biological and medical research; the use of nuclear chemical analysis in the field of criminology; nuclear chemical analysis in environmental sciences, geology and mineral exploration; and radiation protection.

  3. Carbohydrates in Supramolecular Chemistry.

    PubMed

    Delbianco, Martina; Bharate, Priya; Varela-Aramburu, Silvia; Seeberger, Peter H

    2016-02-24

    Carbohydrates are involved in a variety of biological processes. The ability of sugars to form a large number of hydrogen bonds has made them important components for supramolecular chemistry. We discuss recent advances in the use of carbohydrates in supramolecular chemistry and reveal that carbohydrates are useful building blocks for the stabilization of complex architectures. Systems are presented according to the scaffold that supports the glyco-conjugate: organic macrocycles, dendrimers, nanomaterials, and polymers are considered. Glyco-conjugates can form host-guest complexes, and can self-assemble by using carbohydrate-carbohydrate interactions and other weak interactions such as π-π interactions. Finally, complex supramolecular architectures based on carbohydrate-protein interactions are discussed.

  4. Chemistry of superheavy elements.

    PubMed

    Schädel, Matthias

    2006-01-09

    The number of chemical elements has increased considerably in the last few decades. Most excitingly, these heaviest, man-made elements at the far-end of the Periodic Table are located in the area of the long-awaited superheavy elements. While physical techniques currently play a leading role in these discoveries, the chemistry of superheavy elements is now beginning to be developed. Advanced and very sensitive techniques allow the chemical properties of these elusive elements to be probed. Often, less than ten short-lived atoms, chemically separated one-atom-at-a-time, provide crucial information on basic chemical properties. These results place the architecture of the far-end of the Periodic Table on the test bench and probe the increasingly strong relativistic effects that influence the chemical properties there. This review is focused mainly on the experimental work on superheavy element chemistry. It contains a short contribution on relativistic theory, and some important historical and nuclear aspects.

  5. Organic Chemistry in Space

    NASA Technical Reports Server (NTRS)

    Charnley, Steven

    2009-01-01

    Astronomical observations, theoretical modeling, laboratory simulation and analysis of extraterrestrial material have enhanced our knowledge of the inventory of organic matter in the interstellar medium (ISM) and on small bodies such as comets and asteroids (Ehrenfreund & Charnley 2000). Comets, asteroids and their fragments, meteorites and interplanetary dust particles (IDPs), contributed significant amounts of extraterrestrial organic matter to the young Earth. This material degraded and reacted in a terrestrial prebiotic chemistry to form organic structures that may have served as building blocks for life on the early Earth. In this talk I will summarize our current understanding of the organic composition and chemistry of interstellar clouds. Molecules of astrobiological relevance include the building blocks of our genetic material: nucleic acids, composed of subunits such as N-heterocycles (purines and pyrimidines), sugars and amino acids. Signatures indicative of inheritance of pristine and modified interstellar material in comets and meteorites will also be discussed.

  6. Wet chemistry instrument prototype

    NASA Technical Reports Server (NTRS)

    1974-01-01

    A wet chemistry instrument prototype for detecting amino acids in planetary soil samples was developed. The importance of amino acids and their condensation products to the development of life forms is explained. The characteristics of the instrument and the tests which were conducted to determine the materials compatibility are described. Diagrams are provided to show the construction of the instrument. Data obtained from the performance tests are reported.

  7. Analytical Chemistry in Russia.

    PubMed

    Zolotov, Yuri

    2016-09-06

    Research in Russian analytical chemistry (AC) is carried out on a significant scale, and the analytical service solves practical tasks of geological survey, environmental protection, medicine, industry, agriculture, etc. The education system trains highly skilled professionals in AC. The development and especially manufacturing of analytical instruments should be improved; in spite of this, there are several good domestic instruments and other satisfy some requirements. Russian AC has rather good historical roots.

  8. USSR Report, Chemistry

    DTIC Science & Technology

    1987-03-17

    EKSPERIMENTALNAYA KHIMIYA, No 4, Jul-Aug 86) 5 Synthesis and Catalytic Properties of Cesite (0. A. Mulina, N. F. Meged, et al.; ZHURNAL FIZICHESKOY...Plenum of Central Committee of Chemical and Petrochemical Workers’ Trade Union (Yu. I. Vlasov; KAUCHUK I REZINA; No 10, Oct 86) 27 Synthesis and...al.; ZHURNAL NEORGANICHESKOY KHIMII, No 9, Sep 86) 34 Synthesis and Physical Chemistry Study of LiCrTeO^ (0. V. Sorokina, I. G. Chaban, et al

  9. Green chemistry: development trajectory

    NASA Astrophysics Data System (ADS)

    Moiseev, I. I.

    2013-07-01

    Examples of applications of green chemistry methods in heavy organic synthesis are analyzed. Compounds, which can be produced by the processing of the biomass, and the criteria for the selection of the most promising products are summarized. The current status of the ethanol production and processing is considered. The possibilities of the use of high fatty acid triglycerides, glycerol, succinic acid, and isoprene are briefly discussed. The bibliography includes 67 references.

  10. General chemistry students' understanding of the chemistry underlying climate science

    NASA Astrophysics Data System (ADS)

    Versprille, Ashley N.

    The purpose of this study is to investigate first-semester general chemistry students' understanding of the chemistry underlying climate change. The first part of this study involves the collection of qualitative data from twenty-four first-semester general chemistry students from a large Midwestern research institution. The semi-structured interview protocol was developed based on alternative conceptions identified in the research literature and the essential principles of climate change outlined in the U.S. Climate Change Science Program (CCSP) document which pertain to chemistry (CCSP, 2003). The analysis and findings from the interviews indicate conceptual difficulties for students, both with basic climate literacy and underlying chemistry concepts. Students seem to confuse the greenhouse effect, global warming, and the ozone layer, and in terms of chemistry concepts, they lack a particulate level understanding of greenhouse gases and their interaction with electromagnetic radiation, causing them to not fully conceptualize the greenhouse effect and climate change. Based on the findings from these interviews, a Chemistry of Climate Science Diagnostic Instrument (CCSI) was developed for use in courses that teach chemistry with a rich context such as climate science. The CCSI is designed for professors who want to teach general chemistry, while also addressing core climate literacy principles. It will help professors examine their students' prior knowledge and alternative conceptions of the chemistry concepts associated with climate science, which could then inform their teaching and instruction.

  11. Advanced Chemistry Basins Model

    SciTech Connect

    William Goddard; Mario Blanco; Lawrence Cathles; Paul Manhardt; Peter Meulbroek; Yongchun Tang

    2002-11-10

    The DOE-funded Advanced Chemistry Basin model project is intended to develop a public domain, user-friendly basin modeling software under PC or low end workstation environment that predicts hydrocarbon generation, expulsion, migration and chemistry. The main features of the software are that it will: (1) afford users the most flexible way to choose or enter kinetic parameters for different maturity indicators; (2) afford users the most flexible way to choose or enter compositional kinetic parameters to predict hydrocarbon composition (e.g., gas/oil ratio (GOR), wax content, API gravity, etc.) at different kerogen maturities; (3) calculate the chemistry, fluxes and physical properties of all hydrocarbon phases (gas, liquid and solid) along the primary and secondary migration pathways of the basin and predict the location and intensity of phase fractionation, mixing, gas washing, etc.; and (4) predict the location and intensity of de-asphaltene processes. The project has be operative for 36 months, and is on schedule for a successful completion at the end of FY 2003.

  12. Covalent Chemistry beyond Molecules.

    PubMed

    Jiang, Juncong; Zhao, Yingbo; Yaghi, Omar M

    2016-03-16

    Linking molecular building units by covalent bonds to make crystalline extended structures has given rise to metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), thus bringing the precision and versatility of covalent chemistry beyond discrete molecules to extended structures. The key advance in this regard has been the development of strategies to overcome the "crystallization problem", which is usually encountered when attempting to link molecular building units into covalent solids. Currently, numerous MOFs and COFs are made as crystalline materials in which the large size of the constituent units provides for open frameworks. The molecular units thus reticulated become part of a new environment where they have (a) lower degrees of freedom because they are fixed into position within the framework; (b) well-defined spatial arrangements where their properties are influenced by the intricacies of the pores; and (c) ordered patterns onto which functional groups can be covalently attached to produce chemical complexity. The notion of covalent chemistry beyond molecules is further strengthened by the fact that covalent reactions can be carried out on such frameworks, with full retention of their crystallinity and porosity. MOFs are exemplars of how this chemistry has led to porosity with designed metrics and functionality, chemically-rich sequences of information within their frameworks, and well-defined mesoscopic constructs in which nanoMOFs enclose inorganic nanocrystals and give them new levels of spatial definition, stability, and functionality.

  13. Chemistry of sex attraction.

    PubMed Central

    Roelofs, W L

    1995-01-01

    The chemical communication system used to attract mates involves not only the overt chemical signals but also indirectly a great deal of chemistry in the emitter and receiver. As an example, in emitting female moths, this includes enzymes (and cofactors, mRNA, genes) of the pheromone biosynthetic pathways, hormones (and genes) involved in controlling pheromone production, receptors and second messengers for the hormones, and host plant cues that control release of the hormone. In receiving male moths, this includes the chemistry of pheromone transportation in antennal olfactory hairs (binding proteins and sensillar esterases) and the chemistry of signal transduction, which includes specific dendritic pheromone receptors and a rapid inositol triphosphate second messenger signal. A fluctuating plume structure is an integral part of the signal since the antennal receptors need intermittent stimulation to sustain upwind flight. Input from the hundreds of thousands of sensory cells is processed and integrated with other modalities in the central nervous system, but many unknown factors modulate the information before it is fed to motor neurons for behavioral responses. An unknown brain control center for pheromone perception is discussed relative to data from behavioral-threshold studies showing modulation by biogenic amines, such as octopamine and serotonin, from genetic studies on pheromone discrimination, and from behavioral and electrophysiological studies with behavioral antagonists. Images Fig. 1 PMID:7816846

  14. Chemistry and cosmology.

    PubMed

    Black, John H

    2006-01-01

    The simplest elements, hydrogen and helium, offer a remarkably rich chemistry, which has controlled crucial features of the early evolution of the universe. Theoretical models of the origin of structure (stars, galaxies, clusters of galaxies, etc.) now incorporate this chemistry in some detail. In addition to the origin of structure, cosmologists are concerned with observational tests of competing world models. Primordial chemistry may give rise to some of the earliest departures from thermodynamic equilibrium in the universe. These effects may be observable as broad-band spectroscopic distortions of the cosmic background radiation, which otherwise exhibits a nearly perfect blackbody spectrum. The chemical history of the expanding universe is followed through a detailed calculation of the evolution of the abundances of H, H+, H-, H2, H2+, H3+, and other minor species. It is shown that continuous absorption by the small concentration of H- can produce a distortion in the cosmic background spectrum with a maximum at a frequency near nu/c = 9 cm-1 (wavelength 1.1 mm). The predicted effect lies only a factor of 5 below current limits. Its detection would provide an important test of our understanding of the recombination epoch of the universe.

  15. Measurement of atmospheric OH by titration of near-IR fluorescent dyes

    NASA Technical Reports Server (NTRS)

    Betterton, Eric A.; Gast, Karl

    1994-01-01

    Recent research has shown that certain polymethine dyes can be detected at ultratrace levels (greater than or equal to 6x10(exp -14) M) in solution by fluorimetry. These detection limits are possible because of the inherent sensitivity of fluorescence techniques, because the dyes fluoresce in the near infrared region where background interference is negligible, and because powerful infrared diode lasers are now available to improve the signal to noise ratio. Other work has shown that the hydroxyl radical destroys the ability of polymethine dyes to fluoresce. These observations form the basis for a new hydroxyl radical detector that is essentially a fluorometric titrator. Theoretically, the detector should show an acceptable sensitivity and response time. Assuming that the atmospheric HO concentration is about 10(exp -11) moles m(exp -3) (i.e. 10(exp 6) molecules cm(exp -3)), then 10 L of air 'titrated' with 20 mL of 10(exp -11) M dye solution (an easily detected concentration) should result in a drop in the fluorescent signal of 50 percent - a readily detectable change. At a flow rate of 3 L min(exp -1) the sampling time would be 3 minutes. The biggest potential problem is selectivity: other oxidants may also cause the fluorescence signal to be lost. The chemistry of polymethine dyes has not been studied in detail and so no quantitative data are available. However, a survey of the literature suggests that in general HO should react up to six orders of magnitude faster than HO2 and other radicals such as RO2 and RO. It should also react much more rapidly than H2O2 and O3. Thus it may be possible to discriminate kinetically against potential interfering substances. It was shown in the laboratory that 10(exp -4) M H2O2 has little effect on the absorption spectrum of the dye IR125 over a period of hours but that the band at 780 nm is slowly lost in water over a period of days even under argon in the dark. By contrast, DMSO solutions of IR125 are stable.

  16. A model for recombination in Type II dye-sensitized solar cells: Catechol-thiophene dyes

    NASA Astrophysics Data System (ADS)

    Manzhos, Sergei; Segawa, Hiroshi; Yamashita, Koichi

    2011-03-01

    Recombination in dye-sensitized solar cells with direct injection is cast as internal conversion in the dye-Ti(OH) 2 complex. For catechol-thiophene dyes with 1, 2, or 3 thiophene units, the complex reproduces the previously observed dye-to-semiconductor bands. We compare the decomposition of the internal conversion rate by vibrational mode and predict a trend in recombination with the extension of conjugation, which offers an explanation for the trend in DSSC efficiency. We employ a simple model for the vibrational factors and show that they are only important in the presence of vibrational modes with ℏω⩽kT and strong electronic factors, as is the case here.

  17. Dye-sensitized solar cells with natural dyes extracted from plant seeds

    NASA Astrophysics Data System (ADS)

    El-Ghamri, Hatem S.; El-Agez, Taher M.; Taya, Sofyan A.; Abdel-Latif, Monzir S.; Batniji, Amal Y.

    2014-12-01

    The application of natural dyes extracted from plant seeds in the fabrication of dye-sensitized solar cells (DSSCs) has been explored. Ten dyes were extracted from different plant seeds and used as sensitizers for DSSCs. The dyes were characterized using UV-Vis spectrophotometry. DSSCs were prepared using TiO2 and ZnO nanostructured mesoporous films. The highest conversion efficiency of 0.875 % was obtained with an allium cepa (onion) extract-sensitized TiO2 solar cell. The process of TiO2-film sintering was studied and it was found that the sintering procedure significantly affects the response of the cell. The short circuit current of the DSSC was found to be considerably enhanced when the TiO2 semiconducting layer was sintered gradually.

  18. Near-infrared thermochromic diazapentalene dyes.

    PubMed

    Qian, Gang; Wang, Zhi Yuan

    2012-03-22

    A series of 2,5-diazapentalene containing dyes with tunable energy gaps are visible and near-infrared halochromic towards various acids and their protonated counterparts represent a new class of thermochromic materials with the near-infrared absorption being switched on at room temperature and off above 50 °C.

  19. Fluorescent indicator dyes for calcium ions

    NASA Technical Reports Server (NTRS)

    Tsien, Roger Y. (Inventor); Grynkiewicz, Grzegorz (Inventor)

    1986-01-01

    The present invention discloses a new class of highly fluorescent indicator dyes that are specific for calcium ions. The new fluorescent indicator dyes combine a stilbene-type fluorophore with a tetracarboxylate parent Ca.sup.2+ chelating compound having the octacoordinate pattern of liganding groups characteristic of EGTA and BAPTA. Preferred forms contain extra heterocyclic bridges to reinforce the ethylenic bond of the stilbene and to reduce hydrophobicity. Compared to their widely used predecessor, quin2, the new dyes offer up to thirty-fold brighter fluorescence, major changes in wavelength (not just intensity) upon Ca.sup.2+ binding, slightly lower affinities for Ca.sup.2+, slightly longer wavelengths of excitation, and considerably improved selectivity for Ca.sup.2+ over other divalent cations. These properties, particularly the wavelength sensitivity to Ca.sup.2+, make the dyes useful indicators for many intracellular applications, especially in single cells, adherent cell layers, or bulk tissues. The present invention also discloses an improved method for synthesizing alpha-acyloxyalkyl bromides wherein the bromides so synthesized are free of contaminating bis(1-bromoalkyl)ether. The improved method is exemplified herein in the synthesis of acetoxymethyl bromide, a compound useful in preparing the acetoxymethyl esters disclosed herein as novel Ca.sup.2+ specific fluorescent indicators.

  20. Development of New Laser Protective Dyes

    DTIC Science & Technology

    1993-07-31

    Squaric Acid 40 mg 1065 0.84 Squaric Acid 10 mg 1065 0.84 + Endgroup 40 mg B-3 Dyes to Cover the 700-800 nm Reion ( Alexandrite ) In order to determine...together, they cover the tuning range of the Alexandrite laser (700 to 800 nm), which is finding increased use in both military and commercial

  1. Removal of triphenylmethane dyes by bacterial consortium.

    PubMed

    Cheriaa, Jihane; Khaireddine, Monia; Rouabhia, Mahmoud; Bakhrouf, Amina

    2012-01-01

    A new consortium of four bacterial isolates (Agrobacterium radiobacter; Bacillus spp.; Sphingomonas paucimobilis, and Aeromonas hydrophila)-(CM-4) was used to degrade and to decolorize triphenylmethane dyes. All bacteria were isolated from activated sludge extracted from a wastewater treatment station of a dyeing industry plant. Individual bacterial isolates exhibited a remarkable color-removal capability against crystal violet (50 mg/L) and malachite green (50 mg/L) dyes within 24 h. Interestingly, the microbial consortium CM-4 shows a high decolorizing percentage for crystal violet and malachite green, respectively, 91% and 99% within 2 h. The rate of chemical oxygen demand (COD) removal increases after 24 h, reaching 61.5% and 84.2% for crystal violet and malachite green, respectively. UV-Visible absorption spectra, FTIR analysis and the inspection of bacterial cells growth indicated that color removal by the CM-4 was due to biodegradation. Evaluation of mutagenicity by using Salmonella typhimurium test strains, TA98 and TA100 studies revealed that the degradation of crystal violet and malachite green by CM-4 did not lead to mutagenic products. Altogether, these results demonstrated the usefulness of the bacterial consortium in the treatment of the textile dyes.

  2. Removal of Triphenylmethane Dyes by Bacterial Consortium

    PubMed Central

    Cheriaa, Jihane; Khaireddine, Monia; Rouabhia, Mahmoud; Bakhrouf, Amina

    2012-01-01

    A new consortium of four bacterial isolates (Agrobacterium radiobacter; Bacillus spp.; Sphingomonas paucimobilis, and Aeromonas hydrophila)-(CM-4) was used to degrade and to decolorize triphenylmethane dyes. All bacteria were isolated from activated sludge extracted from a wastewater treatment station of a dyeing industry plant. Individual bacterial isolates exhibited a remarkable color-removal capability against crystal violet (50 mg/L) and malachite green (50 mg/L) dyes within 24 h. Interestingly, the microbial consortium CM-4 shows a high decolorizing percentage for crystal violet and malachite green, respectively, 91% and 99% within 2 h. The rate of chemical oxygen demand (COD) removal increases after 24 h, reaching 61.5% and 84.2% for crystal violet and malachite green, respectively. UV-Visible absorption spectra, FTIR analysis and the inspection of bacterial cells growth indicated that color removal by the CM-4 was due to biodegradation. Evaluation of mutagenicity by using Salmonella typhimurium test strains, TA98 and TA100 studies revealed that the degradation of crystal violet and malachite green by CM-4 did not lead to mutagenic products. Altogether, these results demonstrated the usefulness of the bacterial consortium in the treatment of the textile dyes. PMID:22623907

  3. Spotlight on medicinal chemistry education.

    PubMed

    Pitman, Simone; Xu, Yao-Zhong; Taylor, Peter; Turner, Nicholas; Coaker, Hannah; Crews, Kasumi

    2014-05-01

    The field of medicinal chemistry is constantly evolving and it is important for medicinal chemists to develop the skills and knowledge required to succeed and contribute to the advancement of the field. Future Medicinal Chemistry spoke with Simone Pitman (SP), Yao-Zhong Xu (YX), Peter Taylor (PT) and Nick Turner (NT) from The Open University (OU), which offers an MSc in Medicinal Chemistry. In the interview, they discuss the MSc course content, online teaching, the future of medicinal chemistry education and The OU's work towards promoting widening participation. SP is a Qualifications Manager in the Science Faculty at The OU. She joined The OU in 1993 and since 1998 has been involved in the Postgraduate Medicinal Chemistry provision at The OU. YX is a Senior Lecturer in Bioorganic Chemistry at The OU. He has been with The OU from 2001, teaching undergraduate courses of all years and chairing the master's course on medicinal chemistry. PT is a Professor of Organic Chemistry at The OU and has been involved with the production and presentation of The OU courses in Science and across the university for over 30 years, including medicinal chemistry modules at postgraduate level. NT is a Lecturer in Analytical Science at The OU since 2009 and has been involved in the production of analytical sciences courses, as well as contributing to the presentation of a number of science courses including medicinal chemistry.

  4. Method of dye removal for the textile industry

    DOEpatents

    Stone, Mark L.

    2000-01-01

    The invention comprises a method of processing a waste stream containing dyes, such as a dye bath used in the textile industry. The invention comprises using an inorganic-based polymer, such as polyphosphazene, to separate dyes and/or other chemicals from the waste stream. Membranes comprising polyphosphazene have the chemical and thermal stability to survive the harsh, high temperature environment of dye waste streams, and have been shown to completely separate dyes from the waste stream. Several polyphosplhazene membranes having a variety of organic substituent have been shown effective in removing color from waste streams.

  5. Spectroscopic investigations of a novel tricyanofuran dye for nonlinear optics.

    PubMed

    Han, Likun; Jiang, Yadong; Li, Wei; Li, Yuanxun; Hao, Peng

    2008-11-01

    A novel tricyanofuran dye was synthesized and the dye-in-polymer films were fabricated by spin-coating process. The spectroscopic properties of the dye in the solutions and polymer films were investigated by the absorption spectra and fluorescence emission spectra. It is found that the absorption and fluorescence maxima are largely red-shifted along with the increase of the solvent polarity. And the low values of fluorescence quantum yield in higher polarity solvents suggest the presence of twisted intramolecular charge transfer states of the dye. Moreover, the second order polarizability value of the novel dye was estimated based on the quantum-mechanical two-level model.

  6. Ionic Liquid Electrolytes for Flexible Dye-Sensitized Solar Cells

    DTIC Science & Technology

    2014-09-01

    2 The dye usually consists of a metal complex such as a ruthenium bipyridine, excited by a metal- to-ligand charge transfer, or an organic compound...for baseline characterization of DSSC test modules. Both the N719 ruthenium dye and D149 indoline-based organic dye were purchased from Sigma...placed directly in the co-sensitizer dye bath. The dye solutions prepared previously consist of 0.3-mM solutions of the N719 ruthenium and the D149

  7. Organic dyes based on fluorene and its derivatives

    NASA Astrophysics Data System (ADS)

    Kurdyukova, I. V.; Ishchenko, Aleksandr A.

    2012-03-01

    Data on various types of organic dyes based on fluorene and its derivatives, including polymethine, styryl, triphenylmethane, spiran, merocyanine, porphyrin and polymeric dyes, as well as azo dyes and donor-acceptor polyenes, are described systematically. The key methods for their synthesis are considered. The properties of the dyes are analyzed and summarized. The principles of development of modern functional materials based on these dyes are outlined. The use of these materials in advanced fields of science and technology such as photovoltaics, electroluminescence, nonlinear optics, holography, sensing photodynamic therapy are considered. The bibliography includes 476 references.

  8. Method of dye removal for the textile industry

    SciTech Connect

    Stone, M.L.

    2000-07-25

    The invention comprises a method of processing a waste stream containing dyes, such as a dye bath used in the textile industry. The invention uses an inorganic-based polymer, such as polyphosphazene, to separate dyes and/or other chemicals from the waste stream. Membranes comprising polyphosphazene have the chemical and thermal stability to survive the harsh, high temperature environment of dye waste streams, and have been shown to completely separate dyes from the waste stream. Several polyphosplhazene membranes having a variety of organic substituent have been shown effective in removing color from waste streams.

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

    NASA Astrophysics Data System (ADS)

    Mohankumar, V.; Pandian, Muthu Senthil; Ramasamy, P.

    2016-05-01

    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 TiO2 and their HOMOs are under the reduction potential energy of the electrolytes (I-/I3-) which can facilitate electron transfer from the excited dye to TiO2 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.

  10. Dye-sensitized solar cells with improved performance using cone-calix[4]arene based dyes.

    PubMed

    Tan, Li-Lin; Liu, Jun-Min; Li, Shao-Yong; Xiao, Li-Min; Kuang, Dai-Bin; Su, Cheng-Yong

    2015-01-01

    Three cone-calix[4]arene-based sensitizers (Calix-1-Calix-3) with multiple donor-π-acceptor (D-π-A) moieties are designed, synthesized, and applied in dye-sensitized solar cells (DSSCs). Their photophysical and electrochemical properties are characterized by measuring UV/Vis absorption and emission spectra, cyclic voltammetry, and density functional theory (DFT) calculations. Calix-3 has excellent thermo- and photostability, as illustrated by thermogravimetric analysis (TGA) and dye-aging tests, respectively. Importantly, a DSSC using the Calix-3 dye displays a conversion efficiency of 5.48 % in under standard AM 1.5 Global solar illumination conditions, much better than corresponding DSSCs that use the rod-shaped dye M-3 with a single D-π-A chain (3.56 %). The dyes offer advantages in terms of higher molar extinction coefficients, longer electron lifetimes, better stability, and stronger binding ability to TiO2 film. This is the first example of calixarene-based sensitizers for efficient dye-sensitized solar cells.

  11. Efficient organic dye-sensitized solar cells: molecular engineering of donor-acceptor-acceptor cationic dyes.

    PubMed

    Cheng, Ming; Yang, Xichuan; Zhao, Jianghua; Chen, Cheng; Tan, Qin; Zhang, Fuguo; Sun, Licheng

    2013-12-01

    Three metal-free donor-acceptor-acceptor sensitizers with ionized pyridine and a reference dye were synthesized, and a detailed investigation of the relationship between the dye structure and the photophysical and photoelectrochemical properties and the performance of dye-sensitized solar cells (DSSCs) is described. The ionization of pyridine results in a red shift of the absorption spectrum in comparison to that of the reference dye. This is mainly attributable to the ionization of pyridine increasing the electron-withdrawing ability of the total acceptor part. Incorporation of the strong electron-withdrawing units of pyridinium and cyano acrylic acid gives rise to optimized energy levels, resulting in a large response range of wavelengths. When attached to TiO2 film, the conduction band of TiO2 is negatively shifted to a different extent depending on the dye. This is attributed to the electron recombination rate between the TiO2 film and the electrolyte being efficiently suppressed by the introduction of long alkyl chains and thiophene units. DSSCs assembled using these dyes show efficiencies as high as 8.8 %.

  12. Decolorization and biodegradation of reactive dyes and dye wastewater by a developed bacterial consortium.

    PubMed

    Saratale, R G; Saratale, G D; Chang, J S; Govindwar, S P

    2010-11-01

    A bacterial consortium (consortium GR) consisting of Proteus vulgaris NCIM-2027 and Micrococcus glutamicus NCIM-2168 could rapidly decolorize and degrade commonly-used sulfonated reactive dye Green HE4BD and many other reactive dyes. Consortium GR shows markedly higher decolorization activity than that of the individual strains. The preferable physicochemical parameters were identified to achieve higher dye degradation and decolorization efficiency. The supplementation of cheap co-substrates (e.g., extracts of agricultural wastes) could enhance the decolorization performance of consortium GR. Extent of mineralization was determined with TOC and COD measurements, showing nearly complete mineralization of Green HE4BD by consortium GR (up to 90% TOC and COD reduction) within 24 h. Oxidoreductive enzymes seemed to be involved in fast decolorization/degradation process with the evidence of enzymes induction in the bacterial consortium. Phytotoxicity and microbial toxicity studies confirm that the biodegraded products of Green HE4BD by consortium GR are non-toxic. Consortium GR also shows significant biodegradation and decolorization activities for mixture of reactive dyes as well as the effluent from actual dye manufacturing industry. This confers the possibility of applying consortium GR for the treatment of industrial wastewaters containing dye pollutants.

  13. More Chemistry with Light! More Light in Chemistry!

    PubMed

    Bach, Thorsten

    2015-09-21

    "…︁ Why is chemistry overlooked when talking about light? Is the photon a physical particle per se? Are all important light-induced processes biological? Maybe the role of light for chemistry and the role of chemistry for light may be far less important than a few eccentric scientists would like to believe. From the perspective of a synthetically oriented photochemist, however, the facts are different …︁" Read more in the Editorial by Thorsten Bach.

  14. Leon Marchlewski: one of the precursors of clinical chemistry.

    PubMed

    Ostrowski, Janusz; Muszytowski, Marek; Rutkowski, Bolesław

    2011-01-01

    Dynamic progress in the basic sciences such as clinical chemistry exerted a great influence on the development of clinical science in medicine in the 19th century. We should rate Prof. Leon Marchlewski among the group of prominent foreign and Polish scientists working in that period. Marchlewski was born in 1869 in Wloclawek, Poland. He began his chemical studies in Warsaw and then continued at the Zurich Technical University. After having graduated, he began working in the famous Edward Schunk's laboratory in Kersal near Manchester in England. At that time he achieved recognition for his research on the chemical affinity of dyes of the animal and plant world. Later he cooperated in this field with another great scholar Marceli Nencki. In 1900 he returned to Poland, and in 1906 he took charge of the Department of Medical Chemistry at Jagiellonian University. He was nominated for the Nobel Prize twice in 1913 and 1914 for his numerous achievements in the field of clinical chemistry. He took many positions at Jagiellonian University in Krakow, including dean and rector. In 1930-1935 he was a senator of the Republic of Poland. He died in 1946 in Krakow.

  15. Dye-sensitized solar cells consisting of dye-bilayer structure stained with two dyes for harvesting light of wide range of wavelength

    NASA Astrophysics Data System (ADS)

    Inakazu, Fumi; Noma, Yusuke; Ogomi, Yuhei; Hayase, Shuzi

    2008-09-01

    Dye-sensitized solar cells (DSCs) containing dye-bilayer structure of black dye and NK3705 (3-carboxymethyl-5-[3-(4-sulfobutyl)-2(3H)-bezothiazolylidene]-2-thioxo-4-thiazolidinone, sodium salt) in one TiO2 layer (2-TiO-BD-NK) are reported. The 2-TiO-BD-NK structure was fabricated by staining one TiO2 layer with these two dyes, step by step, under a pressurized CO2 condition. The dye-bilayer structure was observed by using a confocal laser scanning microscope. The short circuit current (Jsc) and the incident photon to current efficiency of the cell (DSC-2-TiO-BD-NK) was almost the sum of those of DSC stained with black dye only (DSC-1-TiO-BD) and DSC stained with NK3705 only (DSC-1-TiO-NK).

  16. Raman Spectroscopic Investigation of Dyes in Spices

    NASA Astrophysics Data System (ADS)

    Uhlemann, Ute; Ramoji, Anuradha; Rösch, Petra; Da Costa Filho, Paulo Augusto; Robert, Fabien; Popp, Jürgen

    2010-08-01

    In this study, a number of synthetic colorants for spices have been investigated by means of Raman spectroscopy, resonance Raman spectroscopy, and surface enhanced (resonance) Raman spectroscopy (SER(S)). The aim of the study was the determination of limits of detection for each dye separately and in binary mixtures of dyes in spiked samples of the spices. Most of the investigated dyes have been azo dyes, some being water-soluble, the other being fat-soluble. Investigating the composition of food preparations is an ongoing and important branch of analytical sciences. On one hand, new ingredients have to be analyzed with regard to their contents, on the other hand, raw materials that have been tampered have to be eliminated from food production processes. In the last decades, the various Raman spectroscopic methods have proven to be successful in many areas of life and materials sciences. The ability of Raman spectroscopy to distinguish even structural very similar analytes by means of their vibrational fingerprint will also be important in this study. Nevertheless, Raman scattering is a very weak process that is oftentimes overlaid by matrix interferences or fluorescence. In order to achieve limits of detection in the nanomolar range, the signal intensity has to be increased. According to the well-known equations, there are several ways of achieving this increase: •increasing sample concentration •increasing laser power •decreasing the laser wavelength •using electronic resonance •increasing the local electromagnetic field In this study, nearly all of the above-mentioned principles were applied. In a first step, all dyes were investigated in solution at different concentrations to determine a limit of detection. In the second step, spiked spice samples have been extracted with a variety of solvents and process parameters tested. To lower the limit of detection even further, SERS spectroscopy has been used as well in as out of electronic resonance.

  17. Dye-sensitized PS-b-P2VP-templated nickel oxide films for photoelectrochemical applications

    PubMed Central

    Massin, Julien; Bräutigam, Maximilian; Kaeffer, Nicolas; Queyriaux, Nicolas; Field, Martin J.; Schacher, Felix H.; Popp, Jürgen; Chavarot-Kerlidou, Murielle; Dietzek, Benjamin; Artero, Vincent

    2015-01-01

    Moving from homogeneous water-splitting photocatalytic systems to photoelectrochemical devices requires the preparation and evaluation of novel p-type transparent conductive photoelectrode substrates. We report here on the sensitization of polystyrene-block-poly-(2-vinylpyridine) (PS-b-P2VP) diblock copolymer-templated NiO films with an organic push–pull dye. The potential of these new templated NiO film preparations for photoelectrochemical applications is compared with NiO material templated by F108 triblock copolymers. We conclude that NiO films are promising materials for the construction of dye-sensitized photocathodes to be inserted into photoelectrochemical (PEC) cells. However, a combined effort at the interface between materials science and molecular chemistry, ideally funded within a Global Artificial Photosynthesis Project, is still needed to improve the overall performance of the photoelectrodes and progress towards economically viable PEC devices. PMID:26052420

  18. The role of transition metal ions chemistry on multiphase chemistry

    NASA Astrophysics Data System (ADS)

    Deguillaume, L.; Leriche, M.; Monod, A.; Chaumerliac, N.

    2003-04-01

    A modelling study of the role of transition metal ions chemistry on cloud chemistry is presented. First, new developments of the Model of Multiphase Cloud Chemistry (M2C2) are described: the transition metal ions reactivity and variable photolysis in the aqueous phase. Secondly, three summertime scenarios describing urban, remote and marine conditions are simulated. First, comparisons between results from M2C2 and from CAPRAM2.3 models for the same scenarios (Herrmann et al., 2000) show a good agreement between the two models with respect to their different chemical mechanisms. Secondly, chemical regimes in cloud are analysed to understand the role of transition metal ions chemistry on cloud chemistry. This study focuses on HOx chemistry, which afterwards influences the sulphur and the VOCs chemistry in droplets. The ratio of Fe(II)/Fe(III) exhibits a diurnal variation with values in agreement with the few measurements of Fe speciation available. In the polluted case, sensitivity tests with and without TMI chemistry, show an enhancement of OH concentration in the aqueous phase when TMI chemistry is considered. This implies a more important oxidation of VOCs in droplets, which produces the HO2 radical, the hydrogen peroxide precursor. In fact, the HO2 radical is mainly converted into hydrogen peroxide by reactions between HO2/O2- radicals with Fe(II). This production of hydrogen peroxide leads to a rapid conversion of S(IV) into S(VI) at the beginning of the simulation.

  19. Novel water soluble NIR dyes: does charge matter?

    NASA Astrophysics Data System (ADS)

    Patonay, Gabor; Henary, Maged; Beckford, Garfield; Daube, Alison

    2012-03-01

    Near-Infrared (NIR) dyes are used as reporters, probes or markers in the biological and medical field. NIR dyes can be useful for investigating and characterizing biomolecular interactions or imaging which is possible because biological mammalian tissue has a low absorption window in the NIR region. Biomolecules such as proteins are known to bind to NIR dyes. Upon binding NIR dyes often exhibit spectral changes that can be used for characterizing the binding event. Serum albumins may be responsible for in vivo transport of NIR dyes. Studying this binding event can be useful when correlated to in vivo behavior of the NIR dye. The studies presented here use spectroscopic methods to investigate how NIR dyes that may be used in imaging, biological or bioanalytical applications bind to proteins, such as serum albumins. Our research group systematically synthesized several NIR dyes that have varying hydrophobicity, chromophore size and charge. During these investigations we developed novel NIR cyanine fluorophores having varying aqueous solubility and a variety of net charges. The binding properties of the carbocyanines change when charged or hydrophobic moieties are systematically varied. One of the properties we put a special emphasis on is what we call residual hydrophobicity of the NIR dye molecule which is defined as the unmasked (by the charged moieties) hydrophobicity of the molecule. Residual hydrophobicity may be responsible for binding the otherwise highly water soluble NIR dye to hydrophobic pockets of biomolecules. High residual hydrophobicity of a highly water soluble dye can be disadvantageous during biological, medical or similar applications.

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

    SciTech Connect

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

    2009-04-15

    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.

  1. Interplay between transparency and efficiency in dye sensitized solar cells.

    PubMed

    Tagliaferro, Roberto; Colonna, Daniele; Brown, Thomas M; Reale, Andrea; Di Carlo, Aldo

    2013-02-11

    In this paper we analyze the interplay between transparency and efficiency in dye sensitized solar cells by varying fabrication parameters such as the thickness of the nano-crystalline TiO(2) layer, the dye loading and the dye type. Both transparency and efficiency show a saturation trend when plotted versus dye loading. By introducing the transparency-efficiency plot, we show that the relation between transparency and efficiency is linear and is almost independent on the TiO(2) thickness for a certain thickness range. On the contrary, the relation between transparency and efficiency depends strongly on the type of the dye. Moreover, we show that co-sensitization techniques can be effectively used to access regions of the transparency-efficiency space that are forbidden for single dye sensitization. The relation found between transparency and efficiency (T&E) can be the general guide for optimization of Dye Solar Cells in building integration applications.

  2. Novel method for evaluation of natural dyes in DSSC

    SciTech Connect

    Lakshmi, M.; Kavitha, S.; Paul, Mercyleena

    2014-10-15

    Dye sensitized Solar Cell (DSSC) is presently centered on Ruthenium based dyes. Recent research is diverted to explore the potential of natural dyes in replacing the conventional dyes. In this work we have chosen few natural dyes, which when coated on TiO{sub 2} leads to increase in absorption capacity of TiO{sub 2}. Co-relation of absorption and electrochemical properties of natural dyes gives a scientific insight of the probable performance of a dye, even without fabricating a cell. We have tried to compare this predictions based on HOMO-LUMO energy levels with the real cell performance. Measurements of cell parameters suggest that there is scope for further research in this area.

  3. Halogen Bonding Promotes Higher Dye-Sensitized Solar Cell Photovoltages.

    PubMed

    Simon, Sarah J C; Parlane, Fraser G L; Swords, Wesley B; Kellett, Cameron W; Du, Chuan; Lam, Brian; Dean, Rebecca K; Hu, Ke; Meyer, Gerald J; Berlinguette, Curtis P

    2016-08-24

    We report here an enhancement in photovoltage for dye-sensitized solar cells (DSSCs) where halogen-bonding interactions exist between a nucleophilic electrolyte species (I(-)) and a photo-oxidized dye immobilized on a TiO2 surface. The triarylamine-based dyes under investigation showed larger rate constants for dye regeneration (kreg) by the nucleophilic electrolyte species when heavier halogen substituents were positioned on the dye. The open-circuit voltages (VOC) tracked these kreg values. This analysis of a homologous series of dyes that differ only in the identity of two halogen substituents provides compelling evidence that the DSSC photovoltage is sensitive to kreg. This study also provides the first direct evidence that halogen-bonding interactions between the dye and the electrolyte can bolster DSSC performance.

  4. Tropospheric Halogen Chemistry

    NASA Astrophysics Data System (ADS)

    von Glasow, R.; Crutzen, P. J.

    2003-12-01

    Halogens are very reactive chemicals that are known to play an important role in anthropogenic stratospheric ozone depletion chemistry, first recognized by Molina and Rowland (1974). However, they also affect the chemistry of the troposphere. They are of special interest because they are involved in many reaction cycles that can affect the oxidation power of the atmosphere indirectly by influencing the main oxidants O3 and its photolysis product OH and directly, e.g., by reactions of the Cl radical with hydrocarbons (e.g., CH4).Already by the middle of the nineteenth century, Marchand (1852) reported the presence of bromine and iodine in rain and other natural waters. He also mentions the benefits of iodine in drinking water through the prevention of goitres and cretinism. In a prophetic monograph "Air and Rain: The Beginnings of a Chemical Climatology," Smith (1872) describes measurements of chloride in rain water, which he states to originate partly from the oceans by a process that he compares with the bursting of "soap bubbles" which produces "small vehicles" that transfer small spray droplets of seawater to the air. From deviations of the sulfate-to-chloride ratio in coastal rain compared to seawater, Smith concluded that chemical processes occur once the particles are airborne.For almost a century thereafter, however, atmospheric halogens received little attention. One exception was the work by Cauer (1939), who reported that iodine pollution has been significant in Western and Central Europe due to the inefficient burning of seaweed, causing mean gas phase atmospheric concentrations as high as or greater than 0.5 μg m-3. In his classical textbook Air Chemistry and Radioactivity, Junge (1963) devoted less than three pages to halogen gas phase chemistry, discussing chlorine and iodine. As reviewed by Eriksson (1959a, b), the main atmospheric source of halogens is sea salt, derived from the bursting of bubbles of air which are produced by ocean waves and other

  5. Green Chemistry: Progress and Barriers

    NASA Astrophysics Data System (ADS)

    Green, Sarah A.

    2016-10-01

    Green chemistry can advance both the health of the environment and the primary objectives of the chemical enterprise: to understand the behavior of chemical substances and to use that knowledge to make useful substances. We expect chemical research and manufacturing to be done in a manner that preserves the health and safety of workers; green chemistry extends that expectation to encompass the health and safety of the planet. While green chemistry may currently be treated as an independent branch of research, it should, like safety, eventually become integral to all chemistry activities. While enormous progress has been made in shifting from "brown" to green chemistry, much more effort is needed to effect a sustainable economy. Implementation of new, greener paradigms in chemistry is slow because of lack of knowledge, ends-justify-the-means thinking, systems inertia, and lack of financial or policy incentives.

  6. Mars aqueous chemistry experiment

    NASA Technical Reports Server (NTRS)

    Clark, Benton C.; Mason, Larry W.

    1993-01-01

    The Mars Aqueous Chemistry Experiment (MACE) is designed to conduct a variety of measurements on regolith samples, encompassing mineral phase analyses, chemical interactions with H2O, and physical properties determinations. From these data, much can be learned or inferred regarding the past weathering environment, the contemporaneous soil micro-environments, and the general chemical and physical state of the Martian regolith. By analyzing both soil and duricrust samples, the nature of the latter may become more apparent. Sites may be characterized for comparative purposes and criteria could be set for selection of high priority materials on future sample return missions. Progress for the first year MACE PIDDP is reported in two major areas of effort: (1) fluids handling concepts, definition, and breadboard fabrication and (2) aqueous chemistry ion sensing technology and test facility integration. A fluids handling breadboard was designed, fabricated, and tested at Mars ambient pressure. The breadboard allows fluid manipulation scenarios to be tested under the reduced pressure conditions expected in the Martian atmosphere in order to validate valve operations, orchestrate analysis sequences, investigate sealing integrity, and to demonstrate efficacy of the fluid handling concept. Additional fluid manipulation concepts have also been developed based on updated MESUR spacecraft definition. The Mars Aqueous Chemistry Experiment Ion Selective Electrode (ISE) facility was designed as a test bed to develop a multifunction interface for measurements of chemical ion concentrations in aqueous solution. The interface allows acquisition of real time data concerning the kinetics and heats of salt dissolution, and transient response to calibration and solubility events. An array of ion selective electrodes has been interfaced and preliminary calibration studies performed.

  7. Chemistry and Science Fiction

    NASA Astrophysics Data System (ADS)

    Stocker, Jack H.

    1998-11-01

    This lively collection looks at science as filtered through literature, film, and television. It discusses classic works in science fiction and provides an in-depth look at the chemistry depicted in popular culture, particularly in Start Trek , Star Wars , and Doctor Who . It includes an examination by Nebula Award winner Connie Willis of how science fiction authors use science, and reprints two tongue-in-cheek short stories by Isaac Asimov. The book also includes suggestions for using science fiction as an educational resource.

  8. Extended Wordsearches in Chemistry

    NASA Astrophysics Data System (ADS)

    Cotton, Simon

    1998-04-01

    Students can be encouraged to develop their factual knowledge by use of puzzles. One strategy described here is the extended wordsearch, where the wordsearch element generates a number of words or phrases from which the answers to a series of questions are selected. The wordsearch can be generated with the aid of computer programs, though in order to make them suitable for students with dyslexia or other learning difficulties, a simpler form is more appropriate. These problems can be employed in a variety of contexts, for example, as topic tests and classroom end-of-lesson fillers. An example is provided in the area of calcium chemistry. Sources of suitable software are listed.

  9. Phoenix's Wet Chemistry Lab

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This is an illustration of soil analysis on NASA's Phoenix Mars Lander's Wet Chemistry Lab (WCL) on board the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) instrument. By dissolving small amounts of soil in water, WCL will attempt to determine the pH, the abundance of minerals such as magnesium and sodium cations or chloride, bromide and sulfate anions, as well as the conductivity and redox potential.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  10. Phoenix's Wet Chemistry Lab

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This is an illustration of the analytical procedure of NASA's Phoenix Mars Lander's Wet Chemistry Lab (WCL) on board the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) instrument. By dissolving small amounts of soil in water, WCL can determine the pH, the abundance of minerals such as magnesium and sodium cations or chloride, bromide and sulfate anions, as well as the conductivity and redox potential.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  11. Solvents and sustainable chemistry

    PubMed Central

    Welton, Tom

    2015-01-01

    Solvents are widely recognized to be of great environmental concern. The reduction of their use is one of the most important aims of green chemistry. In addition to this, the appropriate selection of solvent for a process can greatly improve the sustainability of a chemical production process. There has also been extensive research into the application of so-called green solvents, such as ionic liquids and supercritical fluids. However, most examples of solvent technologies that give improved sustainability come from the application of well-established solvents. It is also apparent that the successful implementation of environmentally sustainable processes must be accompanied by improvements in commercial performance. PMID:26730217

  12. Sustainable chemistry metrics.

    PubMed

    Calvo-Flores, Francisco García

    2009-01-01

    Green chemistry has developed mathematical parameters to describe the sustainability of chemical reactions and processes, in order to quantify their environmental impact. These parameters are related to mass and energy magnitudes, and enable analyses and numerical diagnoses of chemical reactions. The environmental impact factor (E factor), atom economy, and reaction mass efficiency have been the most influential metrics, and they are interconnected by mathematical equations. The ecodesign concept must also be considered for complex industrial syntheses, as a part of the sustainability of manufacturing processes. The aim of this Concept article is to identify the main parameters for evaluating undesirable environmental consequences.

  13. USSR Report, Chemistry

    DTIC Science & Technology

    2007-11-02

    showing predominance of the P phase. Figures 1 ; references 4 (Western). [345-12172] UDC 541.71.28 CATALYTIC CONVERSION OF 1,1- DIMETHYLHYDRAZINE ON... dimethylhydrazine (I) on applied iridium catalyst Ir/Al20., (30% by wt.) was reported recently by the authors in reference 1 . Though the catalyst was...365006 JPRS-UCH-85-0 1 3 2 2 October 1985 USSR Report CHEMISTRY MBTmiraoirimSSff-jf DäfflMböäaa OBJira«««ä A9980729 070 FBIS JW1C

  14. Screening π-conjugated bridges of organic dyes for dye-sensitized solar cells with panchromatic visible light harvesting

    NASA Astrophysics Data System (ADS)

    Yang, Zhenqing; Liu, Chunmeng; Shao, Changjin; Zeng, Xiaofei; Cao, Dapeng

    2016-07-01

    Developing highly efficient organic dyes with panchromatic visible light harvesting for dye-sensitized solar cells (DSSCs) is still one of the most important scientific challenges. Here, we design a series of phenothiazine derivative organic dyes with donor-π-acceptor (D-π-A) structure using density functional theory (DFT) and time-dependent DFT (TDDFT) based on experimentally synthesized typical SH-6 organic dyes. Results indicate that the newly designed BUCT13 - BUCT30 dyes show smaller HOMO-LUMO energy gaps, higher molar extinction coefficients and obvious redshifts compared to the SH-6 dye, and the maximum absorption peaks of eight dyes are greater than 650 nm among the newly designed dyes. In particular, BUCT27 exhibits a 234 nm redshift and the maximum molar extinction coefficient with an increment of about 80% compared to the SH-6 dye. BUCT19 exhibits not only a 269 nm redshift and higher molar extinction coefficient with an increment of about 50% compared to the SH-6 dye, but the extremely broad absorption spectrum covering the entire visible range up to the near-IR region of 1200 nm. It is expected that this work can provide a new strategy and guidance for the investigation of these dye-sensitized devices.

  15. Data mining with molecular design rules identifies new class of dyes for dye-sensitised solar cells.

    PubMed

    Cole, Jacqueline M; Low, Kian Sing; Ozoe, Hiroaki; Stathi, Panagiota; Kitamura, Chitoshi; Kurata, Hiroyuki; Rudolf, Petra; Kawase, Takeshi

    2014-12-28

    A major deficit in suitable dyes is stifling progress in the dye-sensitised solar cell (DSC) industry. Materials discovery strategies have afforded numerous new dyes; yet, corresponding solution-based DSC device performance has little improved upon 11% efficiency, achieved using the N719 dye over two decades ago. Research on these dyes has nevertheless revealed relationships between the molecular structure of dyes and their associated DSC efficiency. Here, such structure-property relationships have been codified in the form of molecular dye design rules, which have been judiciously sequenced in an algorithm to enable large-scale data mining of dye structures with optimal DSC performance. This affords, for the first time, a DSC-specific dye-discovery strategy that predicts new classes of dyes from surveying a representative set of chemical space. A lead material from these predictions is experimentally validated, showing DSC efficiency that is comparable to many well-known organic dyes. This demonstrates the power of this approach.

  16. Investigation of dye functional group on the photocatalytic degradation of dyes by nano-TiO2.

    PubMed

    Vinu, R; Akki, Spurti U; Madras, Giridhar

    2010-04-15

    The photocatalytic degradation of five anionic, eight cationic and three solvent dyes using combustion-synthesized nano-TiO(2) (CS TiO(2)) and commercial Degussa P-25 TiO(2) (DP-25) were evaluated to determine the effect of the functional group in the dye. The degradation of the dyes was quantified using the initial rate of decolorization and mineralization. The decolorization of the anionic dyes with CS TiO(2) followed the order: indigo carmine > eosin Y > amido black 10B > alizarin cyanine green > orange G. The decolorization of the cationic dyes with DP-25 followed the order: malachite green > pyronin Y > rhodamine 6G > azure B > nile blue sulfate > auramine O approximately = acriflavine approximately = safranin O. CS TiO(2) showed higher rates of decolorization and mineralization for all the anionic dyes compared to DP-25, while DP-25 was better in terms of decolorization for most of the cationic dyes. The solvent dyes exhibited adsorption dependent decolorization. The order of decolorization and mineralization of the anionic and cationic dyes (a) with CS TiO(2) and DP-25 was different and correlated with the surface properties of these catalysts (b) were rationalized with the molecular structure of the dye and the degradation pathway of the dye.

  17. Effect of electron withdrawing unit for dye-sensitized solar cell based on D-A-π-A organic dyes

    SciTech Connect

    Kwon, Dong Yuel; Chang, Dong Min; Kim, Young Sik

    2014-10-15

    Highlights: • To gain the red-shifted absorption spectra, withdrawing unit was substituted in dye. • By the introduction of additional withdrawing unit, LUMOs level of dye are decreased. • Decreasing LUMOs level of dye caused the red-shifted absorption spectra of dye. • Novel acceptor, DCRD, showed better photovoltaic properties than cyanoacetic acid. - Abstract: In this work, two novel D-A-π-A dye sensitizers with triarylamine as an electron donor, isoindigo and cyano group as electron withdrawing units and cyanoacetic acid and 2-(1,1-dicyanomethylene) rhodanine as an electron acceptor for an anchoring group (TICC, TICR) were designed and investigated with the ID6 dye as the reference. The difference in HOMO and LUMO levels were compared according to the presence or absence of isoindigo in ID6 (TC and ID6). To gain insight into the factors responsible for photovoltaic performance, we used density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations. Owing to different LUMO levels for each acceptor, the absorption band and molar extinction coefficient of each dye was different. Among the dyes, TICR showed more red-shifted and broader absorption spectra than other dyes and had a higher molar extinction coefficient than the reference. It is expected that TICR would show better photovoltaic properties than the other dyes, including the reference dye.

  18. USSR Report, Chemistry, No. 103

    DTIC Science & Technology

    1983-06-21

    The reports contains a variety of abstracts on research and development of USSR Chemistry with particular attention to coal gasification , fertilizers, organophosphorus compound synthesis, and polymerization.

  19. Green chemistry: principles and practice.

    PubMed

    Anastas, Paul; Eghbali, Nicolas

    2010-01-01

    Green Chemistry is a relatively new emerging field that strives to work at the molecular level to achieve sustainability. The field has received widespread interest in the past decade due to its ability to harness chemical innovation to meet environmental and economic goals simultaneously. Green Chemistry has a framework of a cohesive set of Twelve Principles, which have been systematically surveyed in this critical review. This article covers the concepts of design and the scientific philosophy of Green Chemistry with a set of illustrative examples. Future trends in Green Chemistry are discussed with the challenge of using the Principles as a cohesive design system (93 references).

  20. Inorganic Chemistry by Gary Wulfsberg

    NASA Astrophysics Data System (ADS)

    Ackermann, Martin N.

    2000-11-01

    Inorganic Chemistry is an interesting new option for teachers of advanced inorganic courses and offers the possibility of serving an introductory course as well. Since PDIC first appeared, more authors have adopted the approach of developing descriptive inorganic chemistry around common principles instead of a group-by-group treatment, which makes this text less of a departure from the traditional than PDIC was. Still, Wulfsberg offers an original and engaging perspective on inorganic chemistry. Even if this text is not adopted for a course, it deserves a place on the shelf of every teacher of inorganic chemistry, where it will be a valuable resource.