Quantum dot-dye hybrid systems for energy transfer applications

International Nuclear Information System (INIS)

Ren, Ting

2010-01-01

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

Quantum dot-dye hybrid systems for energy transfer applications

Energy Technology Data Exchange (ETDEWEB)

Ren, Ting

2010-07-01

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

Efficacy of Slimming Cream Containing 3.5% Water-Soluble Caffeine and Xanthenes for the Treatment of Cellulite: Clinical Study and Literature Review

Science.gov (United States)

Byun, Sang-Young; Kwon, Soon-Hyo; Heo, Su-Hak; Shim, Jae-Seong; Du, Mi-Hee

2015-01-01

Background Cellulite is a 'cottage cheese-like' cutaneous change caused by subcutaneous fat bulging into the dermis that usually leads to cosmetic problems. Slimming cream containing 3.5% water-soluble caffeine and xanthenes exhibits a lipolytic effect with penetration into the dermis. Objective To evaluate the efficacy and safety of slimming cream for the treatment of cellulite. Methods Fifteen subjects with cellulite applied slimming cream to the thighs and inner side of the upper arms twice daily for 6 weeks. Efficacy was assessed using a standard visual scale, changes in the circumferences of the thighs and upper arms, and patient satisfaction by a questionnaire at baseline, week 3, and week 6. Safety was assessed by inquiring about adverse events through questionnaires. Results The standard visual scale score improved significantly by 0.49 points (19.8%) at week 6. Thigh and upper-arm circumferences decreased by 0.7 cm (1.7%) and 0.8 cm (2.3%), respectively, at week 6. Slight itching and transient flushing were commonly reported, but no serious adverse event occurred. Conclusion The slimming cream tested appears to be effective for the treatment of cellulitis without serious adverse effects. However, additional large clinical trials are required to confirm the efficacy and safety of slimming cream for the treatment of cellulitis. PMID:26082579

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-11-15

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

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

International Nuclear Information System (INIS)

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

2010-01-01

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

Hair cosmetics: dyes.

Science.gov (United States)

Guerra-Tapia, A; Gonzalez-Guerra, E

2014-11-01

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

Efficiency-limiting processes in cyclopentadithiophene-bridged donor-acceptor-type dyes for solid-state dye-sensitized solar cells

KAUST Repository

Hinkel, Felix

2018-01-26

The charge generation and recombination processes in three novel push-pull photosensitizers for dye-sensitized solar cells (DSSCs) are studied by ps–μs transient absorption (TA) and quasi-steady-state photoinduced absorption (PIA) spectroscopy. The three cyclopentadithiophene-based photosensitizer dye molecules exhibit comparably low power conversion efficiencies ranging from 0.8% to 1.7% in solid-state DSSCs. We find that the photocurrents increase in the presence of Li-salt additives. Both TA and PIA measurements observe long-lived dye cations created by electron injection from the dyes’ excited state for two dyes from the series. However, the third dye shows significantly lower performance as a consequence of the less efficient electron injection even after the addition of Li-salts and faster electron-hole recombination on the ns-μs time scale. In essence, the prerequisites for this class of donor-π bridge-acceptor photosensitizers to reach higher charge generation efficiencies are a combination of strong dipole moments and fine tuning of the electronic landscape at the titania-dye interface by Li-salt addition.

Efficiency-limiting processes in cyclopentadithiophene-bridged donor-acceptor-type dyes for solid-state dye-sensitized solar cells

KAUST Repository

Hinkel, Felix; Kim, Yoojin M.; Zagraniarsky, Yulian; Schlü tter, Florian; Andrienko, Denis; Mü llen, Klaus; Laquai, Fré dé ric

2018-01-01

The charge generation and recombination processes in three novel push-pull photosensitizers for dye-sensitized solar cells (DSSCs) are studied by ps–μs transient absorption (TA) and quasi-steady-state photoinduced absorption (PIA) spectroscopy. The three cyclopentadithiophene-based photosensitizer dye molecules exhibit comparably low power conversion efficiencies ranging from 0.8% to 1.7% in solid-state DSSCs. We find that the photocurrents increase in the presence of Li-salt additives. Both TA and PIA measurements observe long-lived dye cations created by electron injection from the dyes’ excited state for two dyes from the series. However, the third dye shows significantly lower performance as a consequence of the less efficient electron injection even after the addition of Li-salts and faster electron-hole recombination on the ns-μs time scale. In essence, the prerequisites for this class of donor-π bridge-acceptor photosensitizers to reach higher charge generation efficiencies are a combination of strong dipole moments and fine tuning of the electronic landscape at the titania-dye interface by Li-salt addition.

Chromed Leather Dyeing Peculiarities when Deliming with Peracetic Acid

Directory of Open Access Journals (Sweden)

Kęstutis BELEŠKA

2013-05-01

Full Text Available The research was aimed to investigate the influence of deliming with peracetic acid on leather dyeing kinetics. Hydrophobic C.I. Acid Red 213 and hydrophilic C.I. Acid Red 423 dyes were used. Sorption of dye depends on hydrophobicity/hydrophility of dye and dyeing temperature. Equilibrium of process is reached faster using hydrophobic C.I. Acid Red 213 at 45 ºC. However, both control and experimental leather fibres adsorb more hydrophilic dye C.I. Acid Red 423 and this fact does not depend on temperature. The diffusion coefficient of dye C.I. Acid Red 423 calculated according to Weisz model is higher when dyeing conventional leather. The change of deliming method has influence on chromed leather dyeing but this influence is not significant. The adsorption ability of control leather fibres at 30 ºC and 45 ºC is higher using both dyes as compared to the dyeing the experimental one. The increase of dyeing temperature increases the adsorption ability independently on the sort of leather fibres. Such dependence of the adsorption ability on the temperature shows that hydrophobic action and van der Waals forces prevail between dye and fibres during dyeing process. The Gibbs energy changes show that adsorption of both dyes by leather fibres independently on their sort is a spontaneous process. The affinity of both dyes to conventional leather fibres is higher comparing with experimental one. The change of enthalpy is positive in all cases, and it means that the driving force of the dyeing is the change of entropy.DOI: http://dx.doi.org/10.5755/j01.ms.19.2.4431

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

Directory of Open Access Journals (Sweden)

Chih-Ping Yen

2016-08-01

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

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

KAUST Repository

Al-Sehemi, Abdullah G.

2012-07-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-08-15

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

Kinetics of low temperature polyester dyeing with high molecular weight disperse dyes by solvent microemulsion and agrosourced auxiliaries

OpenAIRE

Radei, Shahram; Carrión-Fité, Francisco Javier; Ardanuy Raso, Mònica; Canal Arias, José Ma

2018-01-01

This work focused on the evaluation of the kinetics of dyeing polyester fabrics with high molecular weight disperse dyes, at low temperature by solvent microemulsion. This study also compared the effect of two non-toxic agro-sourced auxiliaries (o-vanillin and coumarin) using a non-toxic organic solvent. A dyeing bath consisting of a micro-emulsion system involving a small proportion of n-butyl acetate was used, and the kinetics of dyeing were analysed at four temperatures (83, 90, 95 and 100...

for aqueous dye lasers

Indian Academy of Sciences (India)

2014-02-12

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

Hair Dye and Hair Relaxers

Science.gov (United States)

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-09-01

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

Photoanode of Dye-Sensitized Solar Cells Based on a ZnO/TiO2 Composite Film

Directory of Open Access Journals (Sweden)

Lu-Ting Yan

2012-01-01

Full Text Available A photoanode of dye-sensitized solar cells based on a ZnO/TiO2 composite film was fabricated on a transparent conductive glass substrate using different techniques including electrophoretic deposition, screen printing, and colloidal spray coating. The ZnOs used in the composite film were ZnO tetrapods prepared via thermal evaporation and ZnO nanorods obtained via hydrothermal growth. The structural and morphological characterizations of the thin composite films were carried out using scanning electron microscope (SEM. The best power conversion was 1.87%, which corresponds to the laminated TiO2/ZnO/TiO2 structure prepared via screen printing.

Bleaching and diffusion dynamics in optofluidic dye lasers

DEFF Research Database (Denmark)

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

2007-01-01

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

Rhodanine dyes for dye-sensitized solar cells : spectroscopy, energy levels and photovoltaic performance.

Science.gov (United States)

Marinado, Tannia; Hagberg, Daniel P; Hedlund, Maria; Edvinsson, Tomas; Johansson, Erik M J; Boschloo, Gerrit; Rensmo, Håkan; Brinck, Tore; Sun, Licheng; Hagfeldt, Anders

2009-01-07

Three new sensitizers for photoelectrochemical solar cells were synthesized consisting of a triphenylamine donor, a rhodanine-3-acetic acid acceptor and a polyene connection. The conjugation length was systematically increased, which resulted in two effects: first, it led to a red-shift of the optical absorption of the dyes, resulting in an improved spectral overlap with the solar spectrum. Secondly, the oxidation potential decreased systematically. The excited state levels were, however, calculated to be nearly stationary. The experimental trends were in excellent agreement with density functional theory (DFT) computations. The photovoltaic performance of this set of dyes as sensitizers in mesoporous TiO2 solar cells was investigated using electrolytes containing the iodide/triiodide redox couple. The dye with the best absorption characteristics showed the poorest solar cell efficiency, due to losses by recombination of electrons in TiO2 with triiodide. Addition of 4-tert butylpyridine to the electrolyte led to a strongly reduced photocurrent for all dyes due to a reduced electron injection efficiency, caused by a 0.15 V negative shift of the TiO2 conduction band potential.

DYEING SILK FABRICS WITH STINK BEAN POD (PARKIA SPECIOSA HASSK. NATURAL DYE IN THE COLOR FASTNESS AND UV PROTECTION

Directory of Open Access Journals (Sweden)

M. MASAE

2017-07-01

Full Text Available This paper describes natural dye extracted from stink bean pod (Parkia speciosa Hassk. which was dyed on the silk fabric. The mordants as aluminum potassium sulfate, iron chloride, sodium hydroxide and mud were used to dye fabric using three different dyeing methods: pre-mordanting, meta-mordanting and post-mordanting. The color fastness to washing, water, perspiration, light and crocking of the dyed samples was determined according to AATCC test methods. In this study the UV-protection properties on silk fabrics were investigated. The chemical functional groups of the dyes were characterized by Fourier transform infrared spectroscopy (FTIR. The results revealed that the dyeing silk fabrics with stink beans pod were fair to good fastness to washing and crocking and very poor to poor light fastness with the exception of samples mordanted with iron chloride. The water and perspiration fastness ratings were fair to good. Silk fabrics mordanted with iron chloride and dyed with stink bean usually showed good UV-protection levels even if undyed. These extracts gave polyphenolic, betalain dye and chlorophyll content. Therefore, it was suggested that stink bean pod has the potential in producing functional dyes that could be imparted into the silk dyeing natural colorant system.

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

Science.gov (United States)

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

2018-03-01

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

Time dependent – density functional theory characterization of organic dyes for dye-sensitized solar cells

KAUST Repository

Hilal, Rifaat; Aziz, Saadullah G.; Osman, Osman I.; Bredas, Jean-Luc

2017-01-01

We aim at providing better insight into the parameters that govern the intramolecular charge transfer (ICT) and photo-injection processes in dyes for dye-sensitised solar cells (DSSC). Density functional theory (DFT) and time-dependent DFT (TD

Dye-sensitized photopolymerization of N,N ...

Indian Academy of Sciences (India)

Unknown

and a primary radical derived from the reducing agent. This radical initiates the vinyl polymerization. (scheme 1). In scheme 1, D is the dye, 1D the first excited singlet state, 3D the triplet state, DH. • the semi- quinone dye, DH2 the leuco dye, RH the reducing agent and R. • the initiating radical. Similar schemes. 1D → 3D,.

Use of the ultrasonic cavitation in wool dyeing process: Effect of the dye-bath temperature.

Science.gov (United States)

Actis Grande, G; Giansetti, M; Pezzin, A; Rovero, G; Sicardi, S

2017-03-01

The present work aims to study the effect of the liquid temperature on the performance of ultrasounds (US) in a dyeing process. The approach was both theoretical and experimental. In the theoretical part the simplified model of a single bubble implosion is used to demonstrate that the "maximum implosion pressure" calculated with the well known Rayleigh-Plesset equation for a single bubble can be correlated with the cavitation intensity experimentally measured with an Ultrasonic Energy Meter (by PPB Megasonics). In particular the model was used to study the influence of the fluid temperature on the cavitation intensity. The "relative" theoretical data calculated from the implosion pressure were satisfactorily correlated with the experimental ones and evidence a zone, between 50 and 60°C, were the cavitation intensity is almost constant and still sufficiently high. Hence an experimental part of wool dyeing was carried out both to validate the previous results and to verify the dyeing quality at low temperatures (40-70°C) in presence of US. A prototype dyeing equipment able to treat textile samples with US system of 600W power, was used. The dyeing performances in the presence and absence of US were verified by measuring ΔE (colour variation), R e,% (reflectance percentage), K/S (colour strength) and colour fastness. The US tests performed in the temperature range of 40-70°C were compared with the conventional wool dyeing at 98°C. The obtained results show that a temperature close to 60°C should be chosen as the recommended US dyeing condition, being a compromise between the cavitation intensity and the kinetics which rules the dyestuff diffusion within the fibres. Copyright © 2016 Elsevier B.V. All rights reserved.

Fabrication of Monolithic Dye-Sensitized Solar Cell Using Ionic Liquid Electrolyte

Directory of Open Access Journals (Sweden)

Seigo Ito

2012-01-01

Full Text Available To improve the durability of dye-sensitized solar cells (DSCs, monolithic DSCs with ionic liquid electrolyte were studied. Deposited by screen printing, a carbon layer was successfully fabricated that did not crack or peel when annealing was employed beforehand. Optimized electrodes exhibited photovoltaic characteristics of 0.608 V open-circuit voltage, 6.90 cm−2 mA short-circuit current, and 0.491 fill factor, yielding 2.06% power conversion efficiency. The monolithic DSC using ionic liquid electrolyte was thermally durable and operated stably for 1000 h at 80°C.

Uniform silica nanoparticles encapsulating two-photon absorbing fluorescent dye

International Nuclear Information System (INIS)

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

2009-01-01

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

Supramolecular hair dyes: a new application of cocrystallization

DEFF Research Database (Denmark)

Delori, Amit; Urquhart, Andrew; Oswald, Iain D. H.

2016-01-01

The manuscript presents the first report of hair dyes of various colors formed by cocrystallization. Unlike the most popular oxidative hair dye (OHD) products, these dyes are NH3 free and do not require H2O2 as a color developer. The importance of these new hair dyes products is further enhanced...

Ultrasound-assisted dyeing of cellulose acetate.

Science.gov (United States)

Udrescu, C; Ferrero, F; Periolatto, M

2014-07-01

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

Photoelectric characterization of fabricated dye-sensitized solar cell using dye extracted from red Siahkooti fruit as natural sensitizer

Science.gov (United States)

Mozaffari, Sayed Ahmad; Saeidi, Mahsa; Rahmanian, Reza

2015-05-01

Natural dye extracted from Siahkooti fruit with/without purification by solid phase extraction (SPE) technique was used in the fabrication of DSSC as natural sensitizer. The UV-Vis absorption spectroscopy and Fourier transform infrared (FTIR) were employed to indicate the presence of anthocyanins in the fruit of red Siahkooti. The photoelectrochemical performance and the efficiency of assembled DSSC using Siahkooti fruit dye extract were evaluated and efficiency enhancement was obtained by a preliminary purification of extracted dye. The efficiency and fill factor of the DSSC using purified Siahkooti fruit dye were 0.32% and 0.73%, respectively. The results successfully showed that the DSSC, using Siahkooti fruit extract as a dye sensitizer, is useful for the preparation of environmentally friendly, low-cost, renewable and clean sources of energy.

Degradation of azo dyes by environmental microorganisms and helminths

Energy Technology Data Exchange (ETDEWEB)

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

1993-11-01

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

Optimization of Physiochemical Parameters during Bioremediation of Synthetic Dye by Marasmius cladophyllus UMAS MS8 Using Statistical Approach

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Fatin Nur Sufinas Shuib

2016-01-01

Full Text Available In many industrial areas such as in food, pharmaceutical, cosmetic, printing, and textile, the use of synthetic dyes has been integral with products such as azo dye, anthrax, and dyestuffs. As such, these industries produce a lot of waste by-products that could contaminate the environment. Bioremediation, therefore, has become an important emerging technology due to its cost-sustainable, effective, natural approach to cleaning up contaminated groundwater and soil via the use of microorganisms. The use of microorganisms in bioremediation requires the optimisation of parameters used in cultivating the organism. Thus the aim of the work was to assess the degradation of Remazol Brilliant Blue R (RBBR dye on soil using Plackett-Burman design by the basidiomycete, M. cladophyllus UMAS MS8. Biodegradation analyses were carried out on a soil spiked with RBBR and supplemented with rice husk as the fungus growth enhancer. A two-level Plackett-Burman design was used to screen the medium components for the effects on the decolourization of RBBR. For the analysis, eleven variables were selected and from these four parameters, dye concentration, yeast extract concentration, inoculum size, and incubation time, were found to be most effective to degrade RBBR with up to 91% RBBR removal in soil after 15 days.

Dye removal from textile wastewater using bioadsorbent

International Nuclear Information System (INIS)

Gardazi, S.M.H.

2014-01-01

Textile industries throughout the world produce huge quantities of dyes and pigments annually. Effluents from textile industries are dye wastewater, and disposal of these wastes to freshwater bodies causes damage to the environment. Among the treatment technologies, adsorption is an attractive and viable option, provided that the sorbent is inexpensive and readily available for use. In this study, a typical basic dye, methylene blue, in wastewater was treated using Melia azedarach sawdust. The effects of contact time, adsorbent amount and particle size were investigated on the removal efficiency of adsorbent for methylene blue. Complete removal of the dye were attained at higher adsorbent dose of 3 g/L with 50 mg/L initial dye concentration. The maximum adsorption was at 240 minutes, whereas more than 90% removal with 105 meu m particle size of 1 g/L adsorbent for same initial dye concentration. The experimental data best fits with 2 Langmuir adsorption isotherm (R= 0.991). (author)

Hairy root induction and phytoremediation of textile dye, Reactive green 19A-HE4BD, in a halophyte, Sesuvium portulacastrum (L. L.

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Vinayak H. Lokhande

2015-12-01

Full Text Available In this study, we report phytoremediation of textile dyes using hairy roots derived through Agrobacterium rhizogenes (NCIM 5140 infection of in vitro leaf and stem explants of a halophyte Sesuvium portulacastrum (L. L. Leaf explants showed higher frequency of hairy root induction (70% than stem explants (30%, and maximum number of roots (leaf 42.3 ± 2.4 and stem 50.3 ± 1.7. Transformed nature of hairy roots was ascertained by amplifying 970 bp region of T-DNA of Ri plasmid. Hairy roots were screened for phytoremediation of various textile dyes and results showed that HRs were able to degrade Reactive green 19A HE4BD upto 98% within 5 days of incubation. Spectrophotometric analysis showed decrease in dye concentration while HPLC and FTIR analysis confirmed its degradation. Seed germination assay demonstrated non-toxic nature of the extracted metabolites. This is the first report on induction of hairy root culture in Sesuvium portulacastrum and phytoremediation of textile dyes.

A dye-decolorizing peroxidase from Bacillus subtilis exhibiting substrate-dependent optimum temperature for dyes and β-ether lignin dimer

Science.gov (United States)

Min, Kyoungseon; Gong, Gyeongtaek; Woo, Han Min; Kim, Yunje; Um, Youngsoon

2015-01-01

In the biorefinery using lignocellulosic biomass as feedstock, pretreatment to breakdown or loosen lignin is important step and various approaches have been conducted. For biological pretreatment, we screened Bacillus subtilis KCTC2023 as a potential lignin-degrading bacterium based on veratryl alcohol (VA) oxidation test and the putative heme-containing dye-decolorizing peroxidase was found in the genome of B. subtilis KCTC2023. The peroxidase from B. subtilis KCTC2023 (BsDyP) was capable of oxidizing various substrates and atypically exhibits substrate-dependent optimum temperature: 30°C for dyes (Reactive Blue19 and Reactive Black5) and 50°C for high redox potential substrates (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid [ABTS], VA, and veratryl glycerol-β-guaiacyl ether [VGE]) over +1.0 V vs. normal hydrogen electrode. At 50°C, optimum temperature for high redox potential substrates, BsDyP not only showed the highest VA oxidation activity (0.13 Umg−1) among the previously reported bacterial peroxidases but also successfully achieved VGE decomposition by cleaving Cα-Cβ bond in the absence of any oxidative mediator with a specific activity of 0.086 Umg−1 and a conversion rate of 53.5%. Based on our results, BsDyP was identified as the first bacterial peroxidase capable of oxidizing high redox potential lignin-related model compounds, especially VGE, revealing a previously unknown versatility of lignin degrading biocatalyst in nature. PMID:25650125

Significance of hair-dye base-induced sensory irritation.

Science.gov (United States)

Fujita, F; Azuma, T; Tajiri, M; Okamoto, H; Sano, M; Tominaga, M

2010-06-01

Oxidation hair-dyes, which are the principal hair-dyes, sometimes induce painful sensory irritation of the scalp caused by the combination of highly reactive substances, such as hydrogen peroxide and alkali agents. Although many cases of severe facial and scalp dermatitis have been reported following the use of hair-dyes, sensory irritation caused by contact of the hair-dye with the skin has not been reported clearly. In this study, we used a self-assessment questionnaire to measure the sensory irritation in various regions of the body caused by two model hair-dye bases that contained different amounts of alkali agents without dyes. Moreover, the occipital region was found as an alternative region of the scalp to test for sensory irritation of the hair-dye bases. We used this region to evaluate the relationship of sensitivity with skin properties, such as trans-epidermal water loss (TEWL), stratum corneum water content, sebum amount, surface temperature, current perception threshold (CPT), catalase activities in tape-stripped skin and sensory irritation score with the model hair-dye bases. The hair-dye sensitive group showed higher TEWL, a lower sebum amount, a lower surface temperature and higher catalase activity than the insensitive group, and was similar to that of damaged skin. These results suggest that sensory irritation caused by hair-dye could occur easily on the damaged dry scalp, as that caused by skin cosmetics reported previously.

Kinetics of Low Temperature Polyester Dyeing with High Molecular Weight Disperse Dyes by Solvent Microemulsion and AgroSourced Auxiliaries

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Shahram Radei

2018-02-01

Full Text Available This work focused on the evaluation of the kinetics of dyeing polyester fabrics with high molecular weight disperse dyes, at low temperature by solvent microemulsion. This study also compared the effect of two non-toxic agro-sourced auxiliaries (o-vanillin and coumarin using a non-toxic organic solvent. A dyeing bath consisting of a micro-emulsion system involving a small proportion of n-butyl acetate was used, and the kinetics of dyeing were analysed at four temperatures (83, 90, 95 and 100 °C. Moreover, the dyeing rate constants, correlation coefficient and activation energies were proposed for this system. It was found that o-vanillin yielded higher dye absorption levels than coumarin, leading to exhaustions of 88% and 87% for Disperse Red 167 and Disperse Blue 79, respectively. K/S values of dyed polyester were also found to be higher for dye baths containing o-vanillin with respect to the ones with coumarin. In terms of hot pressing fastness and wash fastness, generally no adverse influence on fastness properties was reported, while o-vanillin showed slightly better results compared to coumarin.

Development of the plastic solid-dye cell for tunable solid-state dye lasers and study on its optical properties

Energy Technology Data Exchange (ETDEWEB)

Ko, Do Kyeong; Lee, Jong Min; Cha, Byung Heon; Yi, Jong Hoon; Lee, Kang Soo; Kim, Sung Ho; Lim, Gwon

2000-01-01

We have fabricated solid-state dyes with Copolex NK-55, which is the base element of plastic lens, and PMMA. We have measured the longevity of solid-state dyes doped in both polymers and found that PMMA has better properties than Coploex NK-55. We have realized the tuning range of 560-620 nm by doping rhodamine 6Gand rhodamin B in the manufactured solid-state dye laser oscillators. In the standing-wave cavity we achieved the slop efficiency of 10.8 percent and in the grazing incidence cavity, 1.2 percent. We have constructed a very compact grazing- incidence cavity which is only 6 cm long and the linewidth of the laser was less than 1.5 GHz with 3-ns pulse duration. And we have fabricated disk-type solid-state dye cell and installed it in the cavity in which the dye cell can be translated and rotated with the help of the two steeping motors. By this we could constantly changed the illuminated area of the dye cell and , therefore, were able to achieve long time operation and to use almost the entire region of the solid-state dye cell. (author)

Development of the plastic solid-dye cell for tunable solid-state dye lasers and study on its optical properties

International Nuclear Information System (INIS)

Ko, Do Kyeong; Lee, Jong Min; Cha, Byung Heon; Yi, Jong Hoon; Lee, Kang Soo; Kim, Sung Ho; Lim, Gwon

2000-01-01

We have fabricated solid-state dyes with Copolex NK-55, which is the base element of plastic lens, and PMMA. We have measured the longevity of solid-state dyes doped in both polymers and found that PMMA has better properties than Coploex NK-55. We have realized the tuning range of 560-620 nm by doping rhodamine 6G and rhodamin B in the manufactured solid-state dye laser oscillators. In the standing-wave cavity we achieved the slop efficiency of 10.8 percent and in the grazing incidence cavity, 1.2 percent. We have constructed a very compact grazing- incidence cavity which is only 6 cm long and the linewidth of the laser was less than 1.5 GHz with 3-ns pulse duration. And we have fabricated disk-type solid-state dye cell and installed it in the cavity in which the dye cell can be translated and rotated with the help of the two steeping motors. By this we could constantly changed the illuminated area of the dye cell and , therefore, were able to achieve long time operation and to use almost the entire region of the solid-state dye cell. (author)

Kinetics of Low Temperature Polyester Dyeing with High Molecular Weight Disperse Dyes by Solvent Microemulsion and AgroSourced Auxiliaries

OpenAIRE

Shahram Radei; F. Javier Carrión-Fité; Mònica Ardanuy; José María Canal

2018-01-01

This work focused on the evaluation of the kinetics of dyeing polyester fabrics with high molecular weight disperse dyes, at low temperature by solvent microemulsion. This study also compared the effect of two non-toxic agro-sourced auxiliaries (o-vanillin and coumarin) using a non-toxic organic solvent. A dyeing bath consisting of a micro-emulsion system involving a small proportion of n-butyl acetate was used, and the kinetics of dyeing were analysed at four temperatures (83, 90, 95 and 100...

Treatment of dye house effluents

International Nuclear Information System (INIS)

Waheed, S.; Ashraf, C.M.

1999-01-01

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

Performance of dye sensitized solar cells (DSSC) using Syngonium Podophyllum Schott as natural dye and counter electrode

Science.gov (United States)

Oktariza, Lingga Ghufira; Yuliarto, Brian; Suyatman

2018-05-01

The extraction of chlorophyll pigment of Syngonium podophyllum Schott leaves which is used as natural dyes in this DSSC devices. The use of dye from nature with its simple production process is very effective to reduce DSSC production cost. Besides being used as a natural dye, chlorophyll can also be used as an alternative counter electrode. Chlorophyll that is used as a counter electrode has been through chemical activation and carbonization processes. The characterization were done using Uv-Vis, Cyclic Voltametry and DSSC device under solar simulator. Characterization of chlorophyll absorbance using UV-Vis has resulted in typical absorbance peak at visible light wavelength of 447 nm and 666 nm. The Tauc equation analysis of the Uv-Vis characterization showed 1.91 eV energy gap of chlorophyll. Chlorophyll carbonized dye is used as an alternative to Pt counter electrode. Carbonized chlorophyll dye resulted in lower conversion efficiency of 0.308% with HSE electrolyte.

Effect of sintering temperatures and screen printing types on TiO2 layers in DSSC applications

Science.gov (United States)

Supriyanto, Agus; Furqoni, Lutfi; Nurosyid, Fahru; Hidayat, Jojo; Suryana, Risa

2016-03-01

Dye-Sensitized Solar Cell (DSSC) is a candidate solar cell, which has a big potential in the future due to its eco-friendly material. This research is conducted to study the effect of sintering temperature and the type of screen-printing toward the characteristics of TiO2 layer as a working electrode in DSSC. TiO2 layers were fabricated using a screen-printing method with a mesh size of T-49, T-55, and T-61. TiO2 layers were sintered at temperatures of 600°C and 650°C for 60 min. DSSC structure was composed of TiO2 as semiconductors, ruthenium complex as dyes, and carbon as counter electrodes. The morphology of TiO2 layer was observed by using Nikon E2 Digital Camera Microscopy. The efficiencies of DSSC were calculated from the I-V curves. The highest efficiency is 0.015% at TiO2 layer fabricated with screen type T-61 and at a sintering temperature of 650°C.

Effect of sintering temperatures and screen printing types on TiO_2 layers in DSSC applications

International Nuclear Information System (INIS)

Supriyanto, Agus; Furqoni, Lutfi; Nurosyid, Fahru; Suryana, Risa; Hidayat, Jojo

2016-01-01

Dye-Sensitized Solar Cell (DSSC) is a candidate solar cell, which has a big potential in the future due to its eco-friendly material. This research is conducted to study the effect of sintering temperature and the type of screen-printing toward the characteristics of TiO_2 layer as a working electrode in DSSC. TiO_2 layers were fabricated using a screen-printing method with a mesh size of T-49, T-55, and T-61. TiO_2 layers were sintered at temperatures of 600°C and 650°C for 60 min. DSSC structure was composed of TiO_2 as semiconductors, ruthenium complex as dyes, and carbon as counter electrodes. The morphology of TiO_2 layer was observed by using Nikon E2 Digital Camera Microscopy. The efficiencies of DSSC were calculated from the I-V curves. The highest efficiency is 0.015% at TiO_2 layer fabricated with screen type T-61 and at a sintering temperature of 650°C.

Removal of reactive dyes from aqueous solutions by a non-conventional and low cost agricultural waste: adsorption on ash of Aloe Vera plant

Directory of Open Access Journals (Sweden)

Mohammad Malakootian

2014-08-01

Full Text Available Dyes are an important class of pollutants and disposal of them in precious water resources must be avoided. Among various methods adsorption occupies a prominent place in dye removal. The aim of this study is to evaluate adsorption of dye Reactive Red 198 and Blue 19 (RR-198 & RB-19 (on to Aloe Vera plant ash from aqueous solutions. In this research Aloe Vera ash was prepared at laboratory conditions and then after shredding, screened by ASTM standard sieve with 60 -200 mesh sizes and the effects of pH (3-12, adsorbent dose (0.1-1 g/L, contact time (10-60 min, initial dye concentration (10-160 mg/L and temperature were investigated in the experiment. In different samples Dye concentration was measured by spectrophotometer at 592 nm and 520 nm wavelength for RR198 and RB19 respectively. Also the Langmuir and Freundlich adsorption isotherms were determined in order to describe the relations between the colored solutions and the adsorbent. The results of this study showed that acidic conditions were more conducive to enhance the hydrolysis rate than basic ones as the decomposition was optimum at pH 3. The adsorption rate of RR-198 and RB-19 dyes was increased by increasing of initial dye concentration, increasing of adsorbent dose in 0.1 to 0.4 mg/L. Dye solution was decolorized in a relatively short time (20 min. The efficiencies for RR-198 and RB- 19 reactive dyes were 82.68% and 90.42% respectively. The maximum adsorption capacity (qmax has been found to be 80.152 mg/g for RR-198 reactive dye and 88.452 mg/g for Blue 19 reactive dye. Adsorption isotherms were examined by Freundlich and Langmuir isotherm that finally showed the Freundlich multilayer isotherm has better accordance with dates. The results indicate that Aloe Vera ash plant as a natural and inexpensive adsorbent is a suitable adsorbent for the adsorption of textile dyes.

COMPARATIVE STUDY OF TWO DYEING METHODS USING REACTIVE DYE

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HINOJOSA Belén

2016-05-01

Full Text Available Environment preservation is a common worry not only for people but for companies as well. Industry is more and more concern about the necessity of developing new and more respectful processes. Dye is one of the most important processes in the textile industry but it is also considered as no too safe regarding environment issues. This process uses large amounts of water and generates big volumes of wastewater. Following this issue, new regulations and laws emerge to control the waste generated. This leads to the companies and increased costs in terms of wastewater treatments and high water consumption. In this research we compare two systems on garment finishing application, the conventional bath process and the new Ecofinish system that is able to save water and product. To compare these processes, we carried out a reactive dyeing using both systems in order to determine the quality differences in the final product. For this purpose, the samples have been tested to washing and rubbing fastness, according to UNE EN ISO 105 C10 and UNE- EN ISO 105 X12 standards, respectively. This study confirms that this system achieves water savings and reduces the wastewater produced, getting a good dyeing. This process can be considered as an alternative to the conventional one.

Forster resonance energy transfer in the system of human serum albumin-xanthene dyes

Science.gov (United States)

Kochubey, V. I.; Pravdin, A. B.; Melnikov, A. G.; Konstantinova, I.; Alonova, I. V.

2016-04-01

The processes of interaction of fluorescent probes: eosin and erythrosine with human serum albumin (HSA) were studied by the methods of absorption and fluorescence spectroscopy. Extinction coefficients of probes were determined. Critical transfer radius and the energy transfer efficiency were defined by fluorescence quenching of HSA. Analysis of the excitation spectra of HSA revealed that the energy transfer process is carried out mainly between tryptophanyl and probes.

Modelling of polyester fabric dyeing in the presence of ultrasonic waves

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Kodrić Marija

2017-01-01

Full Text Available In this paper, modelling of dyeing, i.e. adsorptive behaviour of disperse dyes on polyester fibres (dyeing, under the influence of ultrasound has been considered with the aim of getting the data about mechanisms of binding the dyes and defining the conditions of dyeing process of this synthetic fibres along with additional energy source without the use of carriers, compounds that increase permeability of the fibres and help dyeing. Dyeing - adsorption is conducted under different conditions, and the concentration of dyes, mass of the substrate, recipes and time of dyeing were being varied. It has been established that ultrasound allows dyeing without carriers and the efficiency of dyeing depends on the time of contact, initial concentration of the dye and the amount of absorbent - material. There is the continuity of growth of the amount of bound dye to the mass of the absorbent. Characteristic graphs, obtained from Langmuir isotherm, have confirmed that this model ensures precise description of polyester dyeing by disperse dye. Kinetic of dyeing has been remarkably interpreted by pseudo second-order in regards to the high functionality.

Quirks of dye nomenclature. 1. Evans blue.

Science.gov (United States)

Cooksey, C J

2014-02-01

The history, origin, identity, chemistry and use of Evans blue dye are described along with the first application to staining by Herbert McLean Evans in 1914. In the 1930s, the dye was marketed under the name, Evans blue dye, which was profoundly more acceptable than the ponderous chemical name.

Chromed Leather Dyeing Peculiarities when Deliming with Peracetic Acid

OpenAIRE

Kęstutis BELEŠKA; Virgilijus VALEIKA; Justa ŠIRVAITYTĖ; Violeta VALEIKIENĖ

2013-01-01

The research was aimed to investigate the influence of deliming with peracetic acid on leather dyeing kinetics. Hydrophobic C.I. Acid Red 213 and hydrophilic C.I. Acid Red 423 dyes were used. Sorption of dye depends on hydrophobicity/hydrophility of dye and dyeing temperature. Equilibrium of process is reached faster using hydrophobic C.I. Acid Red 213 at 45 ºC. However, both control and experimental leather fibres adsorb more hydrophilic dye C.I. Acid Red 423 and this fact does not depend on...

Isolasi Dye Organik Alam dan Karakterisasinya Sebagai Sensitizer

Directory of Open Access Journals (Sweden)

Nurussaniah Nurussaniah

2018-03-01

Full Text Available Tujuan penelitian ini adalah untuk mengetahui cara mengisolasi dan karakteristik dye organik alam sebagai sensitizer. Penelitian ini dilakukan melalui beberapa tahap yaitu persiapan, isolasi dye organik alam, karakterisasi sifat optik, analisis dan menyimpulkan. Isolasi dye organic alam dilakukan untuk memperoleh sari dari bahan-bahan alam. Penelitian ini menggunakan bahan alam yaitu jagung (Zea mays dan labu kuning (Cucurbita moschata. Karakterisasi optik dye organik alam dalam penelitian ini dilihat dari spektrum absorbansi yang diukur menggunakan Spektrophotometer Uv-Vis. Spektrum absorbansi dye diukur dalam kuvet optik, pada panjang gelombang 350-800 . Hasil penelitian menunjukkan bahwa isolasi dye organik alam diperoleh melalui metode ekstraksi, yaitu suatu metode untuk memperoleh sari dari bahan-bahan alam. Proses ekstraksi dilakukan dengan melarutkan biji jagung (Zea mays dan daging buah labu kuning (Cucurbita moschata dalam pelarut etanol dengan konsentrasi 1:5. Karaktistik optik jagung (Zea mays dan labu kuning (Cucurbita moschata  menunjukkan panjang gelombang yaitu berada pada cahaya tampak dengan rentang panjang gelombang 350 – 500 nm.  Dengan demikian  dye  beta-karoten yang berasal dari jagung (Zea mays dan labu kuning (Cucurbita moschata dapat dimanfaatkan sebagai sensitizer dalam prototipe Dye Sensitized Solar Cell (DSSC.

Radiation induced degradation of dyes-An overview

International Nuclear Information System (INIS)

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

2009-01-01

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

Photochemistry of triarylmethane dyes bound to proteins

Science.gov (United States)

Indig, Guilherme L.

1996-04-01

Triarylmethanes represent a class of cationic dyes whose potential as photosensitizers for use in photodynamic therapy of neoplastic diseases has never been comprehensively evaluated. Here, the laser-induced photodecomposition of three triarylmethane dyes, crystal violet, ethyl violet, and malachite green, non-covalently bound to bovine serum albumin (a model biological target) was investigated. Upon laser excitation at 532 nm, the bleaching of the corresponding dye-protein molecular complexes follows spectroscopic patterns that suggest the formation of reduced forms of the dyes as major reaction photoproducts. That implies that an electron or hydrogen atom transfer from the protein to the dye's moiety within the guest-host complex is the first step of the photobleaching process. Since the availability of dissolved molecular oxygen was not identified as a limiting factor for the phototransformations to occur, these dyes can be seen as potential phototherapeutic agents for use in hypoxic areas of tumors. These triarylmethane dyes strongly absorb at relatively long wavelengths (absorption maximum around 600 nm; (epsilon) max approximately equals 105 M-1 cm-1), and only minor changes in their absorption characteristics are observed upon binding to the protein. However the binding event leads to a remarkable increase in their fluorescence quantum yield and photoreactivity.

PHYSICO-CHEMICAL STUDIES OF DISAZO DYES DERIVED ...

African Journals Online (AJOL)

DJFLEX

with disazo disperse dyes on synthetic polymer-fibres. (Venkataraman, 1974; Otutu et al., 2008). In this present study, the physico-chemical studies of disazo dyes derived from p-aminophenol recently prepared by our research group is described. We also described the kinetics of the dyes on nylon 6 fibre. In another study.

Mechanism of improved maintenance of 2,3-diphosphoglycerate in stored blood by the xanthone compound 2-(2-hydroxyethoxy)-6-(1-H-tetrazole-5-yl)xanthen-9-one (BW A440C).

Science.gov (United States)

Beutler, E; Forman, L; West, C; Gelbart, T

1988-03-15

The effect of the xanthone derivative 2-(2-hydroxyethoxy)-6-(1-H-tetrazole-5-yl)xanthen-9-one (BW A440C) on red cells was studied. When added to stored red cells at a concentration of 6 mM, greatly improved preservation of 2,3-diphosphoglycerate (2,3-DPG) was observed. There was no effect on internal pH of the erythrocyte. At a concentration 0.500 mM, many red cell enzyme activities were inhibited completely. At a 0.500 mM concentration, however, inhibition of pyruvate kinase and diphosphoglycerate phosphatase was most striking. Inhibition of either of these enzymes could result in elevation of 2,3-DPG levels. BW A440C in concentrations which elevated 2,3-DPG levels in humans caused a decrease in 2,3-DPG levels in rabbits and markedly impaired the viability of 21-day stored rabbit erythrocytes.

Design of new metal-free dyes for dye-sensitized solar cells: A first-principles study

Energy Technology Data Exchange (ETDEWEB)

Gu, Xiong; Zhou, Le; Li, Yawei [Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871 (China); Sun, Qiang, E-mail: sunqiang@pku.edu.cn [Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871 (China); Center for Applied Physics and Technology, Peking University, Beijing 100871 (China); Jena, Puru [Department of Physics, Virginia Commonwealth University, Richmond, VA 23284 (United States)

2012-08-06

Five new metal-free dyes with acceptor–π–donor (A–π–D) structure are studied using first-principles calculation based on density functional theory. Benzothiadiazole (BTD) and triphenylamine (TPA) were chosen, respectively, as an acceptor and a donor with 4-(dicyanomethylene)-2-methyl-6-(4-dimethylamino-styryl)-4H-pyran (DCM) as a π linker. The linker was further modified by -CH=CH- resulting in a red-shift with improved absorption spectra caused by the smaller energy gap and the increased orbital hybridization. The designed dyes are found to exhibit wide absorption spectra, high molar extinction coefficients, desirable orbital distributions, and good energy levels alignment, and hence can have potential applications in dye-sensitized solar cells. -- Highlights: ► New metal-free dyes with A–π–D architecture. ► With wide absorption spectra and high molar extinction coefficients. ► With desirable orbital distribution and good energy levels alignment.

Theoretical Study of Ultrafast Electron Injection into a Dye/TiO2 System in Dye-Sensitized Solar Cells

Science.gov (United States)

Lin, Chundan; Xia, Qide; Li, Kuan; Li, Juan; Yang, Zhenqing

2018-06-01

The ultrafast injection of excited electrons in dye/TiO2 system plays a critical role, which determines the device's efficiency in large part. In this work, we studied the geometrical structures and electronic properties of a dye/TiO2 composite system for dye-sensitized solar cells (DSSCs) by using density functional theory, and we analyzed the mechanism of ultrafast electron injection with emphasis on the power conversion efficiency. The results show that the dye SPL103/TiO2 (101) surface is more stable than dye SPL101. The electron injection driving force of SPL103/TiO2 (101) is 3.55 times that of SPL101, indicating that SPL103/TiO2 (101) has a strong ability to transfer electrons. SPL103 and SPL101/TiO2 (101) both have fast electron transfer processes, and especially the electron injection time of SPL103/TiO2 (101) is only 1.875 fs. The results of this work are expected to provide a new understanding of the mechanism of electron injection in dyes/TiO2 systems for use in highly effective DSSCs.

Ultrasound assisted enhancement in natural dye extraction from beetroot for industrial applications and natural dyeing of leather.

Science.gov (United States)

Sivakumar, Venkatasubramanian; Anna, J Lakshmi; Vijayeeswarri, J; Swaminathan, G

2009-08-01

There is a growing demand for eco-friendly/non-toxic colorants, specifically for health sensitive applications such as coloration of food and dyeing of child textile/leather garments. Recently, dyes derived from natural sources for these applications have emerged as an important alternative to potentially harmful synthetic dyes and pose need for suitable effective extraction methodologies. The present paper focus on the influence of process parameters for ultrasound assisted leaching of coloring matter from plant materials. In the present work, extraction of natural dye from beetroot using ultrasound has been studied and compared with static/magnetic stirring as a control process at 45 degrees C. The influence of process parameters on the extraction efficiency such as ultrasonic output power, time, pulse mode, effect of solvent system and amount of beetroot has been studied. The use of ultrasound is found to have significant improvement in the extraction efficiency of colorant obtained from beetroot. Based on the experiments it has been found that a mixture of 1:1 ethanol-water with 80W ultrasonic power for 3h contact time provided better yield and extraction efficiency. Pulse mode operation may be useful in reducing electrical energy consumption in the extraction process. The effect of the amount of beetroot used in relation to extraction efficiency has also been studied. Two-stage extraction has been studied and found to be beneficial for improving the yield for higher amounts of beetroot. Significant 8% enhancement in % yield of colorant has been achieved with ultrasound, 80W as compared to MS process both using 1:1 ethanol-water. The coloring ability of extracted beet dye has been tested on substrates such as leather and paper and found to be suitable for dyeing. Ultrasound is also found to be beneficial in natural dyeing of leather with improved rate of exhaustion. Both the dyed substrates have better color values for ultrasonic beet extract as inferred from

Treatment of dyeing drainage by radiation

International Nuclear Information System (INIS)

Shimokawa, Toshinari; Sawai, Takeshi

1985-01-01

Decolorization of artificial dyeing drainage and sewage by radiation treatment. Artifical dyeing drainage was prepared from water, polyvinyl alcohol, starch, urea and several kinds of inorganic salts, and artificial sewage, from water, peptone, broth, urea and several kinds of inorganic salts. The above mentioned sample liquors of artificial dyeing drainage and sewage were exposed to γ-radiation of 5 kCi of 60 Co source by aerating through a ball filter. Absorption spectra, total organic carbon (TOC) and chemical oxygen demand (COD) were determined after irradiation to evaluate radiation treatment effect. With the experimental data obtained, it was clarified that absorbance, COD and TOC was decreased with the increase of absorbed dose. Decoloring was made effectively and about 95 % of bleaching ratio was obtained at 5 kGy of radiation. COD was decreased also by irradiation rather slower decreasing rate than that of decolorization, and TOC decrease was very slow at the initial stage of radiation but 40 % of TOC was decomposed by 10 kGy radiation. Dye of chemically stable structure was found more resistant to radiation decolorization. Decomposition efficiency was found less for dyes in the artificial sewage but secondary treated sewage showed no adverse effect. With the obtained understandings, a tentative scheme was planned for the radiation decolorization of dyeing drainage after aeration treatment. (Takagi, S.)

Investigation of adsorption of Rhodamine B onto a natural adsorbent Argemone mexicana.

Science.gov (United States)

Khamparia, Shraddha; Jaspal, Dipika

2016-12-01

The present study aims at exploring the potential of the seeds of a tropical weed, Argemone mexicana (AM), for the removal of a toxic xanthene textile dye, Rhodamine B (RHB), from waste water. Impact of pH, adsorbent dosage, particle size, contact time and dye concentration have been assessed during adsorption. The weed has been well characterized by several latest techniques thereby providing an indepth information of the mechanism during adsorption. About 80% removal has been attained with 0.06 g of adsorbent over the studied system. Thermodynamic and kinetic studies, followed by second order kinetic model, directed towards the endothermic nature of adsorption. The results obtained from batch experiments were modelled using Langmuir and Freundlich isotherm and were analysed on the basis of R 2 and six error functions for selection of appropriate model. Langmuir isotherm was found to be best fitted to the experimental data with high values of R 2 and lower values of error functions. Adsorption study revealed the affinity of AM seeds for the dye ions present in waste water, introducing a novel adsorbent in field of waste water treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Study of the Eosin-Y/PAMAM interactions in alkaline aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Arbeloa, Ernesto M., E-mail: earbeloa@exa.unrc.edu.ar [Universidad Nacional de Río Cuarto, Río Cuarto, 5800 Córdoba (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina); Previtali, Carlos M. [Universidad Nacional de Río Cuarto, Río Cuarto, 5800 Córdoba (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina); Bertolotti, Sonia G., E-mail: sbertolotti@exa.unrc.edu.ar [Universidad Nacional de Río Cuarto, Río Cuarto, 5800 Córdoba (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina)

2016-04-15

The interactions between the xanthene dye Eosin-Y (Eos) and amino-terminated PAMAM dendrimers of low generations (G0–G3) were studied in alkaline water solution. The effect of concentration and generation of the dendrimer on the photophysics of Eos was evaluated by means of absorption and fluorescence spectroscopies. The observed spectral changes were ascribed to the association dye/dendrimer. From these data, the Eos/PAMAM binding constants (K{sub bind}) were determined, which strongly increased with the size of the dendrimer. Stationary fluorescence anisotropy and time-resolved single photon counting were also used to characterize the association process. The restriction in the rotational diffusion of the Eos increased as a function of the concentration and generation of PAMAM, as determined by anisotropy measurements. Biexponential fluorescence decays were obtained in the presence of G3, and the respective lifetimes were ascribed to free and bound Eos species. These results correlate with K{sub bind} values and suggest the formation of host/guest system with larger dendrimers. Therefore, this environmentally-friendly dye/dendrimer system would be appropriate for potential applications in fields such as drugs delivery and photopolymerization.

Study of the Eosin-Y/PAMAM interactions in alkaline aqueous solution

International Nuclear Information System (INIS)

Arbeloa, Ernesto M.; Previtali, Carlos M.; Bertolotti, Sonia G.

2016-01-01

The interactions between the xanthene dye Eosin-Y (Eos) and amino-terminated PAMAM dendrimers of low generations (G0–G3) were studied in alkaline water solution. The effect of concentration and generation of the dendrimer on the photophysics of Eos was evaluated by means of absorption and fluorescence spectroscopies. The observed spectral changes were ascribed to the association dye/dendrimer. From these data, the Eos/PAMAM binding constants (K bind ) were determined, which strongly increased with the size of the dendrimer. Stationary fluorescence anisotropy and time-resolved single photon counting were also used to characterize the association process. The restriction in the rotational diffusion of the Eos increased as a function of the concentration and generation of PAMAM, as determined by anisotropy measurements. Biexponential fluorescence decays were obtained in the presence of G3, and the respective lifetimes were ascribed to free and bound Eos species. These results correlate with K bind values and suggest the formation of host/guest system with larger dendrimers. Therefore, this environmentally-friendly dye/dendrimer system would be appropriate for potential applications in fields such as drugs delivery and photopolymerization.

Phytoremediation in education: textile dye teaching experiments.

Science.gov (United States)

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.

Insights into the Mechanism of a Covalently Linked Organic Dye-Cobaloxime Catalyst System for Dye-Sensitized Solar Fuel Devices.

Science.gov (United States)

Pati, Palas Baran; Zhang, Lei; Philippe, Bertrand; Fernández-Terán, Ricardo; Ahmadi, Sareh; Tian, Lei; Rensmo, Håkan; Hammarström, Leif; Tian, Haining

2017-06-09

A covalently linked organic dye-cobaloxime catalyst system based on mesoporous NiO is synthesized by a facile click reaction for mechanistic studies and application in a dye-sensitized solar fuel device. The system is systematically investigated by photoelectrochemical measurements, density functional theory, time-resolved fluorescence, transient absorption spectroscopy, and photoelectron spectroscopy. The results show that irradiation of the dye-catalyst on NiO leads to ultrafast hole injection into NiO from the excited dye, followed by a fast electron transfer process to reduce the catalyst. Moreover, the dye adopts different structures with different excited state energies, and excitation energy transfer occurs between neighboring molecules on the semiconductor surface. The photoelectrochemical experiments also show hydrogen production by this system. The axial chloride ligands of the catalyst are released during photocatalysis to create the active sites for proton reduction. A working mechanism of the dye-catalyst system on the photocathode is proposed on the basis of this study. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Effect of sintering temperatures and screen printing types on TiO{sub 2} layers in DSSC applications

Energy Technology Data Exchange (ETDEWEB)

Supriyanto, Agus; Furqoni, Lutfi; Nurosyid, Fahru, E-mail: nurosyid@yahoo.com; Suryana, Risa [Department of Physics, Faculty of Mathematics and Natural Sciences, Sebel as Maret University Jl. Ir. Sutami 36A Kentingan Surakarta 57126 (Indonesia); Hidayat, Jojo [Research Center for Electronics and Telecommunication, Indonesian Institute of Sciences (PPET-LIPI) Kampus LIPI Gd. 20 Jl. Sangkuriang Bandung (Indonesia)

2016-03-29

Dye-Sensitized Solar Cell (DSSC) is a candidate solar cell, which has a big potential in the future due to its eco-friendly material. This research is conducted to study the effect of sintering temperature and the type of screen-printing toward the characteristics of TiO{sub 2} layer as a working electrode in DSSC. TiO{sub 2} layers were fabricated using a screen-printing method with a mesh size of T-49, T-55, and T-61. TiO{sub 2} layers were sintered at temperatures of 600°C and 650°C for 60 min. DSSC structure was composed of TiO{sub 2} as semiconductors, ruthenium complex as dyes, and carbon as counter electrodes. The morphology of TiO{sub 2} layer was observed by using Nikon E2 Digital Camera Microscopy. The efficiencies of DSSC were calculated from the I-V curves. The highest efficiency is 0.015% at TiO{sub 2} layer fabricated with screen type T-61 and at a sintering temperature of 650°C.

A Study of Mixed Vegetable Dyes with Different Extraction Concentrations for Use as a Sensitizer for Dye-Sensitized Solar Cells

Directory of Open Access Journals (Sweden)

Kun-Ching Cho

2014-01-01

Full Text Available Two vegetable dyes are used for the study: chlorophyll dye from sweet potato leaf extract and anthocyanin dye from extracts of blueberry, purple cabbage, and grape. The chlorophyll and anthocyanin dyes are blended in a cocktail in equal proportions, by volume. This study determines the effect of different extraction concentrations and different vegetable dyes on the photoelectric conversion efficiency of dye-sensitized solar cells. In order to make the electrode for the experiments, P25 TiO2 powder was coated on the ITO conducting surface, using a medical blade, to form a thin film with a thickness of around 35 μm. The experimental results show that the cocktail dye blended using extracts of sweet potato leaf and blueberries, in the volumetric proportion 1 : 1, at a weight concentration of 40%, using an extraction temperature of 50°C and an extraction heating time of 10 min produces the greatest photoelectric conversion efficiency (η of up to 1.57%, an open-circuit voltage (VOC of 0.61 V, and a short-circuit current density (JSC of 4.75 mA/cm2.

Polymerization of novel methacrylated anthraquinone dyes

Directory of Open Access Journals (Sweden)

Christian Dollendorf

2013-02-01

Full Text Available A new series of polymerizable methacrylated anthraquinone dyes has been synthesized by nucleophilic aromatic substitution reactions and subsequent methacrylation. Thereby, green 5,8-bis(4-(2-methacryloxyethylphenylamino-1,4-dihydroxyanthraquinone (2, blue 1,4-bis(4-((2-methacryloxyethyloxyphenylaminoanthraquinone (6 and red 1-((2-methacryloxy-1,1-dimethylethylaminoanthraquinone (12, as well as 1-((1,3-dimethacryloxy-2-methylpropan-2-ylaminoanthraquinone (15 were obtained. By mixing of these brilliant dyes in different ratios and concentrations, a broad color spectrum can be generated. After methacrylation, the monomeric dyes can be covalently emplaced into several copolymers. Due to two polymerizable functionalities, they can act as cross-linking agents. Thus, diffusion out of the polymer can be avoided, which increases the physiological compatibility and makes the dyes promising compounds for medical applications, such as iris implants.

Daylight-driven photocatalytic degradation of ionic dyes with negatively surface-charged In{sub 2}S{sub 3} nanoflowers: dye charge-dependent roles of reactive species

Energy Technology Data Exchange (ETDEWEB)

Ge, Suxiang [Xuchang University, Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, Institute of Surface Micro and Nano Materials, and School of Chemistry and Chemical Engineering (China); Cai, Lejuan, E-mail: 494169965@qq.com [Central China Normal University, Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry (China); Li, Dapeng, E-mail: lidapengabc@126.com; Fa, Wenjun; Zhang, Yange; Zheng, Zhi [Xuchang University, Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, Institute of Surface Micro and Nano Materials, and School of Chemistry and Chemical Engineering (China)

2015-12-15

Even though dye degradation is a successful application of semiconductor photocatalysis, the roles of reactive species in dye degradation have not received adequate attention. In this study, we systematically investigated the degradation of two cationic dyes (rhodamine B and methylene blue) and two anionic dyes (methyl orange and orange G) over negatively surface-charged In{sub 2}S{sub 3} nanoflowers synthesized at 80 °C under indoor daylight lamp irradiation. It is notable to find In{sub 2}S{sub 3} nanoflowers were more stable in anionic dyes degradation compared to that in cationic dyes removal. The active species trapping experiments indicated photogenerated electrons were mainly responsible for cationic dyes degradation, but holes were more important in anionic dyes degradation. A surface-charge-dependent role of reactive species in ionic dye degradation was proposed for revealing such interesting phenomenon. This study would provide a new insight for preparing highly efficient daylight-driven photocatalyst for ionic dyes degradation.

Efficiency enhancement in dye-sensitized solar cells by in situ passivation of the sensitized nanoporous electrode with Li2CO3

International Nuclear Information System (INIS)

Zhang Jingbo; Zaban, Arie

2008-01-01

This work entails a method to improve the performance of dye-sensitized nanocrystalline TiO 2 solar cells by adding surface passivating elements to the electrolyte. The presence of either CO 2 , Li 2 CO 3 or K 2 CO 3 in electrolyte increases both the photocurrent and the photovoltage, resulting in higher overall conversion efficiency of these solar cells. The additives are used to form a passivation layer of lithium carbonate on the dye free surface of the TiO 2 nanoparticles and the conductive substrate. This layer suppresses the rate of the main recombination reaction between the photoinjected electrons and the oxidized ions in the electrolyte solution. While blocking part of the recombination, the lithium carbonate layer allows motion of the Li + ions towards the TiO 2 surface for charge screening. Consequently using this simple treatment, the conversion efficiency of dye-sensitized solar cell most improved by 17.2% (from 6.4% to 7.5%)

Environmental impact analysis of batik natural dyes using life cycle assessment

Science.gov (United States)

Rinawati, Dyah Ika; Sari, Diana Puspita; Purwanggono, Bambang; Hermawan, Andy Tri

2017-11-01

The use of natural dyes for batik dyeing is fewer than synthetic dyes because of its limitations in the application such complexity in manufacture and usage. For ease of use, natural dyes need to be processed into instant products. Extract of natural dyes are generally produced in liquid form that are less practical in long-term use. Dye powder obtained by drying the liquid extract using spray dryer. Production process of liquid natural dye is simpler and require less energy but need more energy for transporting. It is important to know which type of natural dyes should be produced based on their environmental impact. This research aim to compare environmental impact between liquid and powder natural dyes and also to find relative contribution of different stage in life cycle to total environmental impact. The appropriate method to analyze and compare the environmental impacts of powder and liquid natural dyes is Life Cycle Assessment (LCA). The "cradle to grave" approach used to assess environmental impact of powder and liquid natural dyes of Jalawe rind throughout production process of natural dyes, distribution and use of natural dyes for coloring batik. Results of this research show that powder natural dyes has lower environmental impacts than liquid natural dyes. It was found that distribution, mordanting and packaging of liquid dyes have big contribution to environmental impact.

Dye sensitized photovoltaic cells: Attaching conjugated polymers to zwitterionic ruthenium dyes

DEFF Research Database (Denmark)

Krebs, Frederik C; Biancardo, M.

2006-01-01

The synthesis of a zwitterionic ruthenium dye that binds to anatase surfaces and has a built-in functionality that allows for the attachment of a conjugated polymer chain is presented. The system was found to adsorb on the surface of anatase anchored by the ruthenium dye. Two types of devices were...... prepared: standard photoelectrochemical (PEC) solar cells and polymer solar cells. The PEC solar cells employed a sandwich geometry between TiO2 nanoporous photoanodes and Pt counter electrodes using LiI/I-2 in CH3CN as an electrolyte. The polymer solar cells employed planar anatase electrodes...

Knowledge, attitude, and practice of dyeing and printing workers

Directory of Open Access Journals (Sweden)

Paramasivam Parimalam

2010-01-01

Full Text Available Background: Millions of workers are occupationally exposed to dyes in the world, but little is known about their knowledge and attitudes toward the effects of dye on their health. Objectives: The aim of this study was to assess the fabric dyers′ and fabric printers′ knowledge, attitude, and practice toward the health hazard of dyes. Materials and Methods: The present study was taken up in the Madurai district which is situated in the Southern Tamil Nadu, India. One hundred and forty-two workers employed in small-scale dyeing and printing units participated in a face-to-face confidential interview . Results: The mean age of fabric dyers and fabric printers was 42 years (΁10.7. When enquired about whether dyes affect body organ(s, all the workers agreed that dye(s will affect skin, but they were not aware that dyes could affect other parts of the body. All the workers believed that safe methods of handling of dyes and disposal of contaminated packaging used for dyes need to be considered. It was found that 34% of the workers were using personal protective equipment (PPE such as rubber hand gloves during work. Conclusion: The workers had knowledge regarding the occupational hazards, and their attitudinal approach toward the betterment of the work environment is positive.

Study of the Leacril Dyeing Process by a Cationic Dye from an Emulsion System.

Science.gov (United States)

Chibowski, E.; Ortega, A. Ontiveros; Espinosa-Jiménez, M.; Perea-Carpio, R.; Holysz, L.

2001-03-15

Adsorption studies of a cationic dye, Rhodamine B, from an emulsion phase on Leacril fabric at different temperatures were conducted. The emulsion phase consisted of n-hexadecane emulsified by isopropyl alcohol (1 M) and stabilized by tannic acid. In the alcohol solution Rhodamine B was dissolved. The kinetics of its adsorption and desorption is discussed. The changes in Leacril surface free energy components in the dyeing process were also determined. The adsorption data show that the presence of an emulsion increases the dye adsorption at room temperature (293 K) and at 313 K, while at 333 K it is smaller than that from Rhodamine solution alone. However, Rhodamine desorbs more when adsorbed from the solution. Surface free energy components differ for the Leacril samples dyed at different temperatures, and the most hydrophobic surface was obtained for the samples dyed at 333 K, where the electron-donor component is the lowest one. In general, the work of water spreading is close to zero, except for the above sample for which it is relatively highly negative. Possible mechanisms of the dye adsorption are discussed. Copyright 2001 Academic Press.

Immobilized laccase mediated dye decolorization and transformation pathway of azo dye acid red 27.

Science.gov (United States)

Chhabra, Meenu; Mishra, Saroj; Sreekrishnan, Trichur Ramaswamy

2015-01-01

Laccases have good potential as bioremediating agents and can be used continuously in the immobilized form like many other enzymes. In the present study, laccase from Cyathus bulleri was immobilized by entrapment in Poly Vinyl Alcohol (PVA) beads cross-linked with either nitrate or boric acid. Immobilized laccase was used for dye decolorization in both batch and continuous mode employing a packed bed column. The products of degradation of dye Acid Red 27 were identified by LC MS/MS analysis. The method led to very effective (90%) laccase immobilization and also imparted significant stability to the enzyme (more than 70% after 5 months of storage at 4°C). In batch decolorization, 90-95% decolorization was achieved of the simulated dye effluent for up to 10-20 cycles. Continuous decolorization in a packed bed bioreactor led to nearly 90% decolorization for up to 5 days. The immobilized laccase was also effective in decolorization and degradation of Acid Red 27 in the presence of a mediator. Four products of degradation were identified by LC-MS/MS analysis. The immobilized laccase in PVA-nitrate was concluded to be an effective agent in treatment of textile dye effluents.

High-throughput measurement of polymer film thickness using optical dyes

Science.gov (United States)

Grunlan, Jaime C.; Mehrabi, Ali R.; Ly, Tien

2005-01-01

Optical dyes were added to polymer solutions in an effort to create a technique for high-throughput screening of dry polymer film thickness. Arrays of polystyrene films, cast from a toluene solution, containing methyl red or solvent green were used to demonstrate the feasibility of this technique. Measurements of the peak visible absorbance of each film were converted to thickness using the Beer-Lambert relationship. These absorbance-based thickness calculations agreed within 10% of thickness measured using a micrometer for polystyrene films that were 10-50 µm. At these thicknesses it is believed that the absorbance values are actually more accurate. At least for this solvent-based system, thickness was shown to be accurately measured in a high-throughput manner that could potentially be applied to other equivalent systems. Similar water-based films made with poly(sodium 4-styrenesulfonate) dyed with malachite green oxalate or congo red did not show the same level of agreement with the micrometer measurements. Extensive phase separation between polymer and dye resulted in inflated absorbance values and calculated thickness that was often more than 25% greater than that measured with the micrometer. Only at thicknesses below 15 µm could reasonable accuracy be achieved for the water-based films.

The molecular ordering phenomenon in dye-doped nematic liquid crystals

International Nuclear Information System (INIS)

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

2011-01-01

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

The molecular ordering phenomenon in dye-doped nematic liquid crystals

Energy Technology Data Exchange (ETDEWEB)

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

2011-03-15

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

Tunability of optofluidic distributed feedback dye lasers

DEFF Research Database (Denmark)

Gersborg-Hansen, Morten; Kristensen, Anders

2007-01-01

We investigate the tunability of optofluidic distributed feedback (DFB) dye lasers. The lasers rely on light-confinement in a nano-structured polymer film where an array of nanofluidic channels constitutes a third order Bragg grating DFB laser resonator with a central phase-shift. The lasers...... are operated by filling the DFB laser resonator with a dye solution by capillary action and optical pumping with a frequency doubled Nd: YAG laser. The low reflection order of the DFB laser resonator yields low out-of-plane scattering losses as well as a large free spectral range (FSR), and low threshold...... fluences down to similar to 7 mu J/mm2 are observed. The large FSR facilitates wavelength tuning over the full gain spectrum of the chosen laser dye and we demonstrate 45 nm tunability using a single laser dye by changing the grating period and dye solution refractive index. The lasers are straight...

Degradation of textile dyes by cyanobacteria.

Science.gov (United States)

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. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

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

Directory of Open Access Journals (Sweden)

Mohamed F. Abdel-Megeed

2013-01-01

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

Determination of 20 synthetic dyes in chili powders and syrup-preserved fruits by liquid chromatography/tandem mass spectrometry

Directory of Open Access Journals (Sweden)

Chia-Fen Tsai

2015-09-01

Full Text Available A liquid chromatography/tandem mass spectrometry (LC-MS/MS method is developed to simultaneously determine 20 synthetic dyes (New Coccine, Indigo Carmine, Erythrosine, Tartrazine, Sunset Yellow FCF, Fast Green FCF, Brilliant Blue FCF, Allura Red AC, Amaranth, Dimethyl Yellow, Fast Garnet GBC, Para Red, Sudan I, Sudan II, Sudan III, Sudan IV, Sudan Orange G, Sudan Red 7B, Sudan Red B, and Sudan Red G in food samples. This method offers high sensitivity and selectivity through the selection of two fragment ion transitions under multiple reaction monitoring mode to satisfy the requirements of both quantitation and qualitation. Using LC-MS/MS, the newly developed extraction protocol used in this study is rapid and simple and does not require the use of solid-phase extraction cartridges. The linearities and recoveries of the method are observed at the concentration range of 0.10–200 μg/kg and more than 90% for all dyes, respectively. The method has been successfully applied to screen 18 commercial chili powders and six commercial syrup-preserved fruits purchased from retail establishments in Taipei City. The results show that three legal food dyes, Tartrazine, and/or Sunset Yellow FCF, and/or New Coccine, are present in some syrup-preserved fruits. Amaranth, an illegal food dye in certain countries but declared illegal in Taiwan, is found in an imported syrup-preserved fruit.

Studies on Synthesis and Dyeing Preformance of Acid Dyes Based on 4,7-Dihydroxy-1,10-Phenanthroline-2,9-Dione

Directory of Open Access Journals (Sweden)

B. V. Patel

2008-01-01

Full Text Available Some new azo acid dyes were prepared by coupling various diazotized acid components such as anthranilic acid, sulphanilic acid, laurent acid, peri acid, tobias acid, H-acid, J-acid, gamma acid, sulphotobias acid, 4-aminotoluiene-3-sulphonic acid, 5-sulpho- anthranilic acid, 2-naphthylamine-3,6,8-trisulphonic acid, bronner acid, metanilic acid and cleve acid with 4,7-dihydroxy-1,10-phenanthroline-2,9-dione. The dyes were characterized by elemental, IR and TLC analyses. Their dyeing performance as acid dyes has been assessed on viscose rayon, wool and cotton fibres.

Quirks of dye nomenclature. 5. Rhodamines.

Science.gov (United States)

Cooksey, C J

2016-01-01

Rhodamines were first produced in the late 19(th) century, when they constituted a new class of synthetic dyes. These compounds since have been used to color many things including cosmetics, inks, textiles, and in some countries, food products. Certain rhodamine dyes also have been used to stain biological specimens and currently are widely used as fluorescent probes for mitochondria in living cells. The early history and current biological applications are sketched briefly and an account of the ambiguities, complications and confusions concerning dye identification and nomenclature are discussed.

Studies on the use of power ultrasound in leather dyeing.

Science.gov (United States)

Sivakumar, Venkatasubramanian; Rao, Paruchuri Gangadhar

2003-03-01

Uses of power ultrasound for acceleration/performing the chemical as well as physical processes are gaining importance. In conventional leather processing, the diffusion of chemicals through the pores of the skin/hide is achieved by the mechanical agitation caused by the paddle or drumming action. In this work, the use of power ultrasound in the dyeing of leather has been studied with the aim to improve the exhaustion of dye for a given processing time, to reduce the dyeing time and to improve the quality of dyed leather. The effect of power ultrasound in the dyeing of full chrome cow crust leather in a stationary condition is compared with dyeing in the absence of ultrasound as a control experiment both in a stationary as well as conventional drumming condition. An ultrasonic cleaner (150 W and 33 kHz) was used for the experiments. Actual power dissipated into the system was calculated from the calorimetric measurement. Experiments were carried out with variation in type of dye, amount of dye offer, temperature and time. The results show that there is a significant improvement in the percentage exhaustion of dye due to the presence of ultrasound, when compared to dyeing in absence of ultrasound. Experiments on equilibrium dye uptake carried out with or without ultrasound suggest that ultrasound help to improve the kinetics of leather dyeing. The results indicate that leathers dyed in presence of ultrasound have higher colour values, better dye penetration and fastness properties compared to control leathers. The physical testing results show that strength properties of the dyed leathers are not affected due to the application of ultrasound under the given process conditions. Apparent diffusion coefficient during the initial stage of dyeing process, both in presence and in absence of ultrasound was calculated. The values show that ultrasound helps in improving the apparent diffusion coefficient more for the difficult dyeing conditions such as in the case of metal

Removal of rhodamine B (a basic dye) and thoron (an acidic dye) from dilute aqueous solutions and wastewater simulants by ion flotation.

Science.gov (United States)

Shakir, Kamal; Elkafrawy, Ahmed Faouzy; Ghoneimy, Hussein Fouad; Elrab Beheir, Shokry Gad; Refaat, Mamdoh

2010-03-01

The present work deals with removal, by ion flotation, of two dyes: a basic dye (rhodamine B (RB)) and an acidic one (thoron (TH)) from dilute aqueous solutions and simulated wastewaters. These dyes are widely used for analytical and biological staining purposes. Besides, RB is commonly used in dyeing of various industrial products. Therefore, wastewaters emanating from chemical and radiochemical laboratories, and biomedical and biological research laboratories may be contaminated with RB and TH. Ion flotation of these dyes has been investigated over a wide range of pH using the anionic surfactant, sodium lauryl sulfate (NaLS) and the cationic surfactant, cetyltrimethylammonium bromide (CTAB) as collectors. Successful removals could be achieved for RB and TH with the anionic collector, NaLS, and the cationic collector, CTAB, respectively. In addition to the effects of pH and type of collector on the efficiency of removal of each dye, the effects of collector and dye concentrations, frother dosage, ionic strength, bubbling time period and presence of foreign salts were investigated and the optimal removal conditions have been established. Removals exceeding 99.5 % and 99.9% could be achieved for RB and TH, respectively. The results obtained are discussed with respect to dissociation of dye, type of collector, ionic strength and sign and magnitude of charge of added foreign ions. Kinetics of flotation were also studied. Further studies demonstrate that under optimum conditions the developed flotation processes can be applied for the treatment of dye-contaminated wastewaters simulated to those generated at dyeing industries and radiochemical laboratories. Copyright 2009 Elsevier Ltd. All rights reserved.

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

International Nuclear Information System (INIS)

Fadadu, Kishan B.; Soni, Saurabh S.

2013-01-01

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

Degradation of Synthetic Dyes by Laccases – A Mini-Review

Directory of Open Access Journals (Sweden)

Legerská Barbora

2016-06-01

Full Text Available Laccases provide a promising future as a tool to be used in the field of biodegradation of synthetic dyes with different chemical structures. These enzymes are able to oxidize a wide range of phenolic substrates without the presence of additional co-factors. Laccases have been confirmed for their potential of synthetic dye degradation from wastewater and degradation products of these enzymatic reactions become less toxic than selected dyes. This study discusses the potential of laccase enzymes as agents for laccase-catalyzed degradation in terms of biodegradation efficiency of synthetic dyes, specifically: azo dyes, triphenylmethane, indigo and anthraquinone dyes. Review also summarizes the laccase-catalyzed degradation mechanisms of the selected synthetic dyes, as well as the degradation products and the toxicity of the dyes and their degradation products.

Unconsumed precursors and couplers after formation of oxidative hair dyes

DEFF Research Database (Denmark)

Rastogi, Suresh Chandra; Søsted, Heidi; Johansen, Jeanne Duus

2006-01-01

Contact allergy to hair dye ingredients, especially precursors and couplers, is a well-known entity among consumers having hair colouring done at home or at a hairdresser. The aim of the present investigation was to estimate consumer exposure to some selected precursors (p-phenylenediamine, toluene......-2,5-diamine) and couplers (3-aminophenol, 4-aminophenol, resorcinol) of oxidative hair dyes during and after hair dyeing. Concentrations of unconsumed precursors and couplers in 8 hair dye formulations for non-professional use were investigated, under the conditions reflecting hair dyeing. Oxidative...... hair dye formation in the absence of hair was investigated using 6 products, and 2 products were used for experimental hair dyeing. In both presence and absence of hair, significant amounts of unconsumed precursors and couplers remained in the hair dye formulations after final colour development. Thus...

Photoactive dye-enhanced tissue ablation for endoscopic laser prostatectomy.

Science.gov (United States)

Ahn, Minwoo; Hau, Nguyen Trung; Van Phuc, Nguyen; Oh, Junghwan; Kang, Hyun Wook

2014-11-01

Laser light has been widely used as a surgical tool to treat benign prostate hyperplasia (BPH) over 20 years. Recently, application of high laser power up to 200 W was often reported to swiftly remove a large amount of prostatic tissue. The purpose of this study was to validate the feasibility of photoactive dye injection to enhance light absorption and eventually to facilitate tissue vaporization with low laser power. Chicken breast tissue was selected as a target tissue due to minimal optical absorption at the visible wavelength. Four biocompatible photoactive dyes, including amaranth (AR), black dye (BD), hemoglobin powder (HP), and endoscopic marker (EM), were selected and tested in vitro with a customized 532 nm laser system with radiant exposure ranging from 0.9 to 3.9 J/cm(2) . Light absorbance and ablation threshold were measured with UV-Vis spectrometer and Probit analysis, respectively, and compared to feature the function of the injected dyes. Ablation performance with dye-injection was evaluated in light of radiant exposure, dye concentration, and number of injection. Higher light absorption by injected dyes led to lower ablation threshold as well as more efficient tissue removal in the order of AR, BD, HP, and EM. Regardless of the injected dyes, ablation efficiency principally increased with radiant exposure, dye concentration, and number of injection. Among the dyes, AR created the highest ablation rate of 44.2 ± 0.2 µm/pulse due to higher absorbance and lower ablation threshold. High aspect ratios up to 7.1 ± 0.4 entailed saturation behavior in the tissue ablation injected with AR and BD, possibly resulting from plume shielding and increased scattering due to coagulation. Preliminary tests on canine prostate with a hydraulic injection system demonstrated that 80 W with dye injection yielded comparable ablation efficiency to 120 W with no injection, indicating 33% reduced laser power with almost equivalent performance. Due to

Basic dye decomposition kinetics in a photocatalytic slurry reactor

International Nuclear Information System (INIS)

Wu, C.-H.; Chang, H.-W.; Chern, J.-M.

2006-01-01

Wastewater effluent from textile plants using various dyes is one of the major water pollutants to the environment. Traditional chemical, physical and biological processes for treating textile dye wastewaters have disadvantages such as high cost, energy waste and generating secondary pollution during the treatment process. The photocatalytic process using TiO 2 semiconductor particles under UV light illumination has been shown to be potentially advantageous and applicable in the treatment of wastewater pollutants. In this study, the dye decomposition kinetics by nano-size TiO 2 suspension at natural solution pH was experimentally studied by varying the agitation speed (50-200 rpm), TiO 2 suspension concentration (0.25-1.71 g/L), initial dye concentration (10-50 ppm), temperature (10-50 deg. C), and UV power intensity (0-96 W). The experimental results show the agitation speed, varying from 50 to 200 rpm, has a slight influence on the dye decomposition rate and the pH history; the dye decomposition rate increases with the TiO 2 suspension concentration up to 0.98 g/L, then decrease with increasing TiO 2 suspension concentration; the initial dye decomposition rate increases with the initial dye concentration up to a certain value depending upon the temperature, then decreases with increasing initial dye concentration; the dye decomposition rate increases with the UV power intensity up to 64 W to reach a plateau. Kinetic models have been developed to fit the experimental kinetic data well

Antibacterial Dyeing of Wool with Natural Cationic Dye Using Metal Mordants

Directory of Open Access Journals (Sweden)

Aminoddin HAJI

2012-09-01

Full Text Available In this study, Berberine colorant extracted from berberis vulgaris root was applied on wool fiber using alum (aluminum potassium sulfate, copper sulfate and potassium dichromate as mordant. The effect of treatment variables such as amount of mordant, time and temperature on the color strength of dyed fibers was examined. The fastness properties of dyed wool against washing, light and wet rubbing were evaluated. the use of metal mordants increased the color strength of the dyed goods. Increase in dyeing time and temperature caused deeper shades. All mordants, increased the rub fastness and wash fastness of dyed samples, but the light fastness was increased except in case of alum. Berberine is a cationic dye and because of it's quaternary ammonium structure can act as an antibacterial agent. So, dyed samples were tested for antibacterial activity using AATCC test method 100-2004. The dyed wool represented a high level of antibacterial activity. The extract of the berberis vulgaris can be considered as a natural dye of acceptable fastness properties together with excellent antibacterial activity for woolen textiles.DOI: http://dx.doi.org/10.5755/j01.ms.18.3.2437

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

Science.gov (United States)

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

2013-01-14

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

Low-threshold conical microcavity dye lasers

DEFF Research Database (Denmark)

Grossmann, Tobias; Schleede, Simone; Hauser, Mario

2010-01-01

element simulations confirm that lasing occurs in whispering gallery modes which corresponds well to the measured multimode laser-emission. The effect of dye concentration on lasing threshold and lasing wavelength is investigated and can be explained using a standard dye laser model....

Pulse radiolysis of ethanolic solutions of rhodamine dyes

International Nuclear Information System (INIS)

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

1983-01-01

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

Enhancement of power conversion efficiency of dye-sensitized solar cells by co-sensitization of Phloxine B and Bromophenol blue dyes on ZnO photoanode

Energy Technology Data Exchange (ETDEWEB)

Kushwaha, Suman; Bahadur, Lal, E-mail: lbahadur@bhu.ac.in

2015-05-15

A single dye usually absorbs light only in a limited range of solar spectrum. In order to widen the absorption range, a combination of dyes, namely, Phloxine B and Bromophenol blue have been used as sensitizers in ZnO based dye sensitized solar cell (DSSC). It has been found that the DSSC sensitized by mixed dyes exhibited better photovoltaic performance than those observed with the DSSCs using test dyes individually. It has been ascribed to the enhanced absorption of light particularly in higher energy region (λ=400–550 nm) when both dyes were used together as was evident from the absorption spectra of dyes adsorbed onto ZnO electrode. The DSSC using ZnO electrode sensitized by mixed dyes provided J{sub SC}=5.6 mA cm{sup −2}, V{sub OC}=0.606 V, FF=0.53 and maximum energy conversion efficiency (η) of 1.35% on illuminating the cell with visible light of 150 mW cm{sup −2} intensity. - Highlights: • Phloxine B and Bromophenol blue have been used as sensitizers in ZnO based DSSC. • DSSC sensitized by mixed dyes exhibited better photovoltaic performance than those observed with the DSSCs using test dyes individually. • Enhanced absorption of light particularly in higher energy region (λ=400–550 nm) have been observed when both dyes were used together. • The DSSC using ZnO electrode sensitized by mixed dyes provided J{sub sc}=5.6 mA cm{sup −2}, V{sub oc}=0.606 V, FF=0.53. • Efficiency of 1.35% is achieved at visible light intensity of 150 mW cm{sup −2}.

Dye filled security seal

International Nuclear Information System (INIS)

Wilson, D.C.

1982-01-01

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

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

Science.gov (United States)

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

2009-04-01

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

Photoactive dye enhanced tissue ablation for endoscopic laser prostatectomy

Science.gov (United States)

Ahn, Minwoo; Nguyen, Trung Hau; Nguyen, Van Phuc; Oh, Junghwan; Kang, Hyun Wook

2015-02-01

Laser light has been widely used as a surgical tool to treat benign prostate hyperplasia with high laser power. The purpose of this study was to validate the feasibility of photoactive dye injection to enhance light absorption and eventually to facilitate tissue ablation with low laser power. The experiment was implemented on chicken breast due to minimal optical absorption Amaranth (AR), black dye (BD), hemoglobin powder (HP), and endoscopic marker (EM), were selected and tested in vitro with a customized 532-nm laser system with radiant exposure ranging from 0.9 to 3.9 J/cm2. Light absorbance and ablation threshold were measured with UV-VIS spectrometer and Probit analysis, respectively, and compared to feature the function of the injected dyes. Ablation performance with dye-injection was evaluated in light of radiant exposure, dye concentration, and number of injection. Higher light absorption by injected dyes led to lower ablation threshold as well as more efficient tissue removal in the order of AR, BD, HP, and EM. Regardless of the injected dyes, ablation efficiency principally increased with input parameter. Among the dyes, AR created the highest ablation rate of 44.2+/-0.2 μm/pulse due to higher absorbance and lower ablation threshold. Preliminary tests on canine prostate with a hydraulic injection system demonstrated that 80 W with dye injection yielded comparable ablation efficiency to 120 W with no injection, indicating 33 % reduced laser power with almost equivalent performance. In-depth comprehension on photoactive dye-enhanced tissue ablation can help accomplish efficient and safe laser treatment for BPH with low power application.

Design and construction of liquid lasers using organic dyes

International Nuclear Information System (INIS)

Hariri, Akbar.

1984-01-01

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

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

KAUST Repository

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

2010-01-01

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

The effect of dendrimer on cotton dyeability with direct dyes

Directory of Open Access Journals (Sweden)

Khakzar Bafrooei F.

2014-01-01

Full Text Available Pretreatment of cotton fabric with poly(propylene imine dendrimer enhanced its colour strength using C.I. Direct Red 81 and C.I. Direct Blue 78. Application of this dendrimer and the direct dye simultaneously on cotton fabric by the exhaust and the continuous dyeing method were studied; slight improvements in the dyeing results were obtained. Pretreatment of the cotton fabric with dendrimer in an emulsion form using the pad-dry method followed by continuous dyeing markedly increased the colour strength. In addition, level dyeing was obtained, and no negative effects on the fastness properties of the dyes used were observed.

Photophysical properties of pyronin dyes in reverse micelles of AOT

Energy Technology Data Exchange (ETDEWEB)

Bayraktutan, Tuğba; Meral, Kadem; Onganer, Yavuz, E-mail: yonganer@atauni.edu.tr

2014-01-15

The photophysical properties of pyronin B (PyB) and pyronin Y (PyY) in reverse micelles formed with water/sodium bis (2-ethyl-1-hexyl) sulfosuccinate (AOT)/n-heptane were investigated by UV–vis absorption, steady-state and time-resolved fluorescence spectroscopy techniques. This study was carried out a wide range of reverse micelle sizes, with hydrodynamic radii ranging from 1.85 to 9.38 nm. Significant photophysical parameters as band shifts, fluorescence quantum yields and fluorescence lifetimes were determined to understand how photophysical and spectroscopic features of the dye compounds were affected by the variation of reverse micelle sizes. In this regard, control of reverse micelle size by changing W{sub 0}, the molar ratio of water to surfactant, allowed tuning the photophysical properties of the dyes in organic solvent via reverse micelle. Non-fluorescent H-aggregates of pyronin dyes were observed for the smaller reverse micelles whereas an increase in the reverse micelle size induced an increment in the amount of dye monomers instead of dye aggregates. Thus, the fluorescence intensities of the dyes were improved by increasing W{sub 0} due to the predomination of the fluorescent dye monomers. As a result, the fluorescence quantum yields also increased. The fluorescence lifetimes of the dyes in the reverse micelles were determined by the time-resolved fluorescence decay studies. Evaluation of the fluorescence lifetimes calculated for pyronin dyes in the reverse micelles showed that the size of reverse micelle affected the fluorescence lifetimes of pyronin dyes. -- Highlights: • The photophysical properties of pyronin dyes were examined by spectroscopic techniques. • Optical properties of the dyes were tuned by changing of W{sub 0} values. • The fluorescence lifetime and quantum yield values of the dyes in reverse micelles were discussed.

Power ultrasound-assisted cleaner leather dyeing technique: influence of process parameters.

Science.gov (United States)

Sivakumar, Venkatasubramanian; Rao, Paruchuri Gangadhar

2004-03-01

The application of power ultrasound to leather processing has a significant role in the concept of "clean technology" for leather production. The effect of power ultrasound in leather dyeing has been compared with dyeing in the absence of ultrasound and conventional drumming. The power ultrasound source used in these experiments was ultrasonic cleaner (150 W and 33 kHz). The effect of various process parameters such as amount of dye offer, temperature, and type of dye has been experimentally found out. The effect of presonication of dye solution as well as leather has been studied. Experiments at ultrasonic bath temperature were carried out to find out the combined thermal as well as stirring effects of ultrasound. Dyeing in the presence of ultrasound affords about 37.5 (1.8 times) difference as increase in % dye exhaustion or about 50% decrease in the time required for dyeing compared to dyeing in the absence of ultrasound for 4% acid red dye. About 29 (1.55 times) increase in % dye exhaustion or 30% reduction in time required for dyeing was observed using ultrasound at stationary condition compared with conventional dynamic drumming conditions. The effect of ultrasound at constant temperature conditions with a control experiment has also been studied. The dye exhaustion increases as the temperature increases (30-60 degrees C) and better results are observed at higher temperature due to the use of ultrasound. Presonication of dye solution or crust leather prior to the dyeing process has no significant improvement in dye exhaustion, suggesting ultrasound effect is realized when it is applied during the dyeing process. The results indicate that 1697 and 1416 ppm of dye can be reduced in the spent liquor due to the use of ultrasound for acid red (for 100 min) and acid black (for 3 h) dyes, respectively, thereby reducing the pollution load in the effluent stream. The color yield of the leather as inferred from the reflectance measurement indicates that dye offer can

Hair dye poisoning and the developing world

Directory of Open Access Journals (Sweden)

Sampathkumar Krishnaswamy

2009-01-01

Full Text Available Hair dye poisoning has been emerging as one of the important causes of intentional self harm in the developing world. Hair dyes contain paraphenylene-diamine and a host of other chemicals that can cause rhabdomyolysis, laryngeal edema, severe metabolic acidosis and acute renal failure. Intervention at the right time has been shown to improve the outcome. In this article, we review the various manifestations, clinical features and treatment modalities for hair dye poisoning.

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

African Journals Online (AJOL)

STORAGESEVER

2010-02-01

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

Chemical composition of felt-tip pen inks.

Science.gov (United States)

Germinario, Giulia; Garrappa, Silvia; D'Ambrosio, Valeria; van der Werf, Inez Dorothé; Sabbatini, Luigia

2018-01-01

Felt-tip pens are frequently used for the realization of sketches, drawings, architectural projects, and other technical designs. The formulations of these inks are usually rather complex and may be associated to those of modern paint materials where, next to the binding medium and pigments/dyes, solvents, fillers, emulsifiers, antioxidants, plasticizers, light stabilizers, biocides, and so on are commonly added. Felt-tip pen inks are extremely sensitive to degradation and especially exposure to light may cause chromatic changes and fading. In this study, we report on the complete chemical characterization of modern felt-tip pen inks that are commercially available and commonly used for the realization of artworks. Three brands of felt-tip pens (Faber-Castell, Edding, and Stabilo) were investigated with complementary analytical techniques such as thin-layer chromatography (TLC), VIS-reflectance spectroscopy, μ-Raman spectroscopy, surface-enhanced Raman spectroscopy (SERS), pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), GC-MS, and Fourier transform infrared (FTIR) spectroscopy. The use of TLC proved to be very powerful in the study of complex mixtures of synthetic dyes. First derivatives of the reflectance spectra acquired on the TLC spots were useful in the preliminary identification of the dye, followed by Raman spectroscopy and SERS, which allowed for the unambiguous determination of the chemical composition of the pigments (phthalocyanines, dioxazines, and azo pigments) and dyes (azo dyes, triarylmethanes, xanthenes). FTIR spectroscopy was used especially for the detection of additives, as well as for confirming the nature of solvents and dyes/pigments. Finally, (Py-)GC-MS data provided information on the binders (styrene-acrylic resins, plant gums), solvents, and additives, as well as on pigments and dyes.

Optical and Photovoltaic Properties of Thieno[3,2-b]thiophene-Based Push-Pull Organic Dyes with Different Anchoring Groups for Dye-Sensitized Solar Cells.

Science.gov (United States)

Fernandes, Sara S M; Castro, M Cidália R; Pereira, Ana Isabel; Mendes, Adélio; Serpa, Carlos; Pina, João; Justino, Licínia L G; Burrows, Hugh D; Raposo, M Manuela M

2017-12-31

The effect of anchoring groups on the optical and electrochemical properties of triphenylamine-thienothiophenes, and on the photovoltaic performance of DSSCs photosensitized with the prepared dyes, was studied using newly synthesized compounds with cyanoacetic acid or rhodanine-3-acetic acid groups. Precursor aldehydes were synthesized through Suzuki cross-coupling, whereas Knoevenagel condensation of these with 2-cyanoacetic acid or rhodanine-3-acetic acid afforded the final push-pull dyes. A comprehensive photophysical study was performed in solution and in the solid state. The femtosecond time-resolved transient absorption spectra for the synthesized dyes were obtained following photoexcitation in solution and for the dyes adsorbed to TiO 2 mesoporous films. Information on conformation, electronic structure, and electron distribution was obtained by density functional theory (DFT) and time-dependent DFT calculations. Triphenylamine-thienothiophene functionalized with a cyanoacetic acid anchoring group displayed the highest conversion efficiency (3.68%) as the dye sensitizer in nanocrystalline TiO 2 solar cells. Coadsorption studies were performed for this dye with the ruthenium-based N719 dye, and they showed dye power conversion efficiencies enhanced by 20-64%. The best cell performance obtained with the coadsorbed N719 and cyanoacetic dye showed an efficiency of 6.05%.

Optical and Photovoltaic Properties of Thieno[3,2-b]thiophene-Based Push–Pull Organic Dyes with Different Anchoring Groups for Dye-Sensitized Solar Cells

Science.gov (United States)

2017-01-01

The effect of anchoring groups on the optical and electrochemical properties of triphenylamine-thienothiophenes, and on the photovoltaic performance of DSSCs photosensitized with the prepared dyes, was studied using newly synthesized compounds with cyanoacetic acid or rhodanine-3-acetic acid groups. Precursor aldehydes were synthesized through Suzuki cross-coupling, whereas Knoevenagel condensation of these with 2-cyanoacetic acid or rhodanine-3-acetic acid afforded the final push–pull dyes. A comprehensive photophysical study was performed in solution and in the solid state. The femtosecond time-resolved transient absorption spectra for the synthesized dyes were obtained following photoexcitation in solution and for the dyes adsorbed to TiO2 mesoporous films. Information on conformation, electronic structure, and electron distribution was obtained by density functional theory (DFT) and time-dependent DFT calculations. Triphenylamine–thienothiophene functionalized with a cyanoacetic acid anchoring group displayed the highest conversion efficiency (3.68%) as the dye sensitizer in nanocrystalline TiO2 solar cells. Coadsorption studies were performed for this dye with the ruthenium-based N719 dye, and they showed dye power conversion efficiencies enhanced by 20–64%. The best cell performance obtained with the coadsorbed N719 and cyanoacetic dye showed an efficiency of 6.05%. PMID:29302638

Excimer Pumped Pulsed Tunable Dye Laser

Science.gov (United States)

Littman, Michael G.

1988-06-01

It has been recently shown and reported for the first time at this meeting, that Excimer pumping of a single-mode, short-cavity, grazing-incidence, longitudinally-pumped pulsed dye laser is feasible. In this paper the key concepts upon which this latest development is based are presented and are in a somewhat unusual form. This manuscript describes five specific dye laser examples. The five examples represent a progression from the simplest type of dye laser to the single-mode version mentioned above. The examples thus serve as a tutorial introduction to potential users of dye lasers. The article is organized into five sections or STEPS, each of which describes a different pulsed dye laser. Since the subtle points about dye lasers are best appreciated only after one actually attempts to build a working model, a PROCEDURES category is included in which details about the construction of the particular form of laser are given. As one reads through this category, think of it as looking over the shoulder of the laser builder. The NOTES category which follows is a brief but essential discussion explaining why various components and procedures are used, as well as how laser performance specifications are obtained. This subsection can he viewed as a discussion with the laser builder concerning the reasons for specific actions and choices made in the assembly of the example laser. The last category contains COMMENTS which provide additional related information pertaining to the example laser that goes beyond the earlier annotated discussion. If you like, these are the narrator's comments. At the end of the article, after the five sequential forms of the laser have been presented, there is a brief summation.

Azo dye decolorization assisted by chemical and biogenic sulfide

Energy Technology Data Exchange (ETDEWEB)

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

2013-04-15

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

Dyeing of γ-irradiated cotton with natural flavonoid dye extracted from irradiated onion shells (Allium cepa) powder

Science.gov (United States)

Rehman, Fazal-ur; Adeel, Shahid; Shahid, Muhammad; Bhatti, Ijaz Ahmad; Nasir, Faiza; Akhtar, Nasim; Ahmad, Zulfiqar

2013-11-01

Powder of Onion shells as a source of natural flavonoid dye (Quercetin) and cotton fabrics were exposed to absorbed doses of 2, 4, 6, 8 and 10 kGy using Cs-137 gamma irradiator. Irradiated and un-irradiated dye powder was used for extraction of quercetin as well as antibacterial, hemolytic and antioxidant activities were also determined to observe the effect of radiation. Furthermore, color strength and colourfastness of irradiated fabrics were improved by using pre and post-mordants such as alum and iron. It is found that 4 kGy is the optimal absorbed dose for extraction of natural quercetin extracted from onion shells while maximum color strength and acceptable fastness properties are obtained on dyeing of irradiated fabric at 60 °C keeping M:L of 1:30 using 10% alum as pre-mordant and 6% alum as post-mordant. Gamma irradiation has not only improved the color strength of the dye using irradiated cotton but also that of colourfastness properties.

Enhanced Photovoltaic Performances of Dye-Sensitized Solar Cells by Co-Sensitization of Benzothiadiazole and Squaraine-Based Dyes.

Science.gov (United States)

Islam, Ashraful; Akhtaruzzaman, Md; Chowdhury, Towhid H; Qin, Chuanjiang; Han, Liyuan; Bedja, Idriss M; Stalder, Romain; Schanze, Kirk S; Reynolds, John R

2016-02-01

Dye-sensitized solar cells (DSSCs) based on a donor-acceptor-donor oligothienylene dye containing benzothiadiazole (T4BTD-A) were cosensitized with dyes containing cis-configured squaraine rings (HSQ3 and HSQ4). The cosensitized dyes showed incident monochromatic photon-to-current conversion efficiency (IPCE) greater than 70% in the 300-850 nm wavelength region. The individual overall conversion efficiencies of the sensitizers T4BTD-A, HSQ3, and HSQ4 were 6.4%, 4.8%, and 5.8%, respectively. Improved power conversion efficiencies of 7.0% and 7.7% were observed when T4BTD-A was cosensitized with HSQ3 and HSQ4, respectively, thanks to a significant increase in current density (JSC) for the cosensitized DSSCs. Intensity-modulated photovoltage spectroscopy results showed a longer lifetime for cosensitized T4BTD-A+HSQ3 and T4BTD-A+HSQ4 compared to that of HSQ3 and HSQ4, respectively.

Revealing the influence of Cyano in Anchoring Groups of Organic Dyes on Adsorption Stability and Photovoltaic Properties for Dye-Sensitized Solar Cells.

Science.gov (United States)

Chen, Wei-Chieh; Nachimuthu, Santhanamoorthi; Jiang, Jyh-Chiang

2017-07-10

Determining an ideal adsorption configuration for a dye on the semiconductor surface is an important task in improving the overall efficiency of dye-sensitized solar cells. Here, we present a detailed investigation of different adsorption configurations of designed model dyes on TiO 2 anatase (101) surface using first principles methods. Particularly, we aimed to investigate the influence of cyano group in the anchoring part of dye on its adsorption stability and the overall photovoltaic properties such as open circuit voltage, electron injection ability to the surface. Our results indicate that the inclusion of cyano group increases the stability of adsorption only when it adsorbs via CN with the surface and it decreases the photovoltaic properties when it does not involve in binding. In addition, we also considered full dyes based on the results of model dyes and investigated the different strength of acceptor abilities on stability and electron injection ability. Among the various adsorption configurations considered here, the bidentate bridging mode (A3) is more appropriate one which has higher electron injection ability, larger V OC value and more importantly it has higher dye loading on the surface.

Physicochemical aspects of the liposome-wool interaction in wool dyeing.

Science.gov (United States)

Martí, Meritxell; Barsukov, Leonid I; Fonollosa, Jordi; Parra, José Luis; Sukhanov, Stanislav V; Coderch, Luisa

2004-04-13

Despite the promising application of liposomes in wool dyeing, little is known about the mechanism of liposome interactions with the wool fiber and dyestuffs. The kinetics of wool dyeing by two dyes, Acid Green 27 (hydrophobic) and Acid Green 25 (hydrophilic), were compared in three experimental protocols: (1) without liposomes, (2) in the presence of phosphatidylcholine (PC) liposomes, and (3) with wool previously treated with PC liposomes. Physicochemical interactions of liposomes with wool fibers were studied under experimental dyeing conditions with particular interest in the liposome affinity to the fiber surface and changes in the lipid composition of the wool fibers. The results obtained indicate that the presence of liposomes favors the retention of these two dyes in the dyeing bath, this effect being more pronounced in case of the hydrophobic dye. Furthermore, the liposome treatment is accompanied by substantial absorption of PC by wool fibers with simultaneous partial solubilization of their polar lipids (more evident at higher temperatures). This may result in structural modification of the cell membrane complex of wool fibers, which could account for a high level of the dye exhaustion observed at the end of the liposome dyeing process.

Adsorption Properties of Lac Dyes on Wool, Silk, and Nylon

Directory of Open Access Journals (Sweden)

Bo Wei

2013-01-01

Full Text Available There has been growing interest in the dyeing of textiles with natural dyes. The research about the adsorption properties of natural dyes can help to understand their adsorption mechanism and to control their dyeing process. This study is concerned with the kinetics and isotherms of adsorption of lac dyes on wool, silk, and nylon fibers. It was found that the adsorption kinetics of lac dyes on the three fibers followed the pseudosecond-order kinetic model, and the adsorption rate of lac dyes was the fastest for silk and the slowest for wool. The activation energies for the adsorption process on wool, silk, and nylon were found to be 107.15, 87.85, and 45.31 kJ/mol, respectively. The adsorption of lac dyes on the three fibers followed the Langmuir mechanism, indicating that the electrostatic interactions between lac dyes and those fibers occurred. The saturation values for lac adsorption on the three fibers decreased in the order of wool > silk > nylon; the Langmuir affinity constant of lac adsorption on nylon was much higher than those on wool and silk.

Incorporation of Kojic Acid-Azo Dyes on TiO2 Thin Films for Dye Sensitized Solar Cells Applications

Directory of Open Access Journals (Sweden)

Carolynne Zie Wei Sie

2017-01-01

Full Text Available Sensitization of heavy metal free organic dyes onto TiO2 thin films has gained much attention in dye sensitized solar cells (DSSCs. A series of new kojic acid based organic dyes KA1–4 were synthesized via nucleophilic substitution of azobenzene bearing different vinyl chains A1–4 with kojyl chloride 4. Azo dyes KA1–4 were characterized for photophysical properties employing absorption spectrometry and photovoltaic characteristic in TiO2 thin film. The presence of vinyl chain in A1–4 improved the photovoltaic performance from 0.20 to 0.60%. The introduction of kojic acid obtained from sago waste further increases the efficiency to 0.82–1.54%. Based on photovoltaic performance, KA4 achieved the highest solar to electrical energy conversion efficiency (η = 1.54% in the series.

Microstructure characterization of onion (A.cepa) peels and thin films for dye sensitized solar cells

Science.gov (United States)

Abodunrin, T.; Boyo, A.; Usikalu, M.; Obafemi, L.; Oladapo, O.; Kotsedi, L.; Yenus, Z.; Maaza, M.

2017-03-01

A.cepa peels are obtained from mature onion bulbs. Because of the continuous need for energy, alternative avenues for producing energy are gaining importance. The motivation for this work is based on an urgent need to source energy from readily available waste materials like domestic onion peels. Dye sensitized solar cells (DSSCs) fabricated via doctor blade method and high temperature sintering from waste (onion peels) are investigated for their ability to convert solar to electrical energy. The charge carriers were revealed under phytochemical screening. Functional groups of compounds present in A.cepa peel were analyzed with Fourier transform in infrared (FTIR). The influence of different electrolyte sensitizer is observed on the DSSCs under standard air mass conditions of 1.5 AM. The microstructure properties of these A.cepa DSSCs were explored using scanning electron microscope with energy dispersive spectroscopy (SEM/EDS), x-ray diffraction and Fluorecence spectroscopy (XRF). The interfacial boundary between A.cepa dye, TiO2 framework of TiO2 and indium doped tin oxide (ITO) reveals several prominent anatase and rutile peaks. Photoelectric results, revealed dye-sensitized solar cells with a maximum power output of 126 W and incident photon to conversion energy (IPCE) of 0.13%.This work has established that A.cepa peels can be used as a source of micro-energy generation.

Immobilized laccase mediated dye decolorization and transformation pathway of azo dye acid red 27

OpenAIRE

Chhabra, Meenu; Mishra, Saroj; Sreekrishnan, Trichur Ramaswamy

2015-01-01

Background Laccases have good potential as bioremediating agents and can be used continuously in the immobilized form like many other enzymes. Methods In the present study, laccase from Cyathus bulleri was immobilized by entrapment in Poly Vinyl Alcohol (PVA) beads cross-linked with either nitrate or boric acid. Immobilized laccase was used for dye decolorization in both batch and continuous mode employing a packed bed column. The products of degradation of dye Acid Red 27 were identified by ...

Hypersensitivity to contrast media and dyes.

Science.gov (United States)

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. Copyright © 2014 Elsevier Inc. All rights reserved.

Dye-sensitized solar cells using natural dye as light-harvesting materials extracted from Acanthus sennii chiovenda flower and Euphorbia cotinifolia leaf

Directory of Open Access Journals (Sweden)

Wuletaw Andargie Ayalew

2016-12-01

Full Text Available Natural dyes are environmentally and economically superior to ruthenium-based dyes because they are nontoxic and cheap. In this study, dye-sensitized solar cells (DSSCs were fabricated using natural dyes light harvesting materials. The natural dyes were extracted from Acanthus sennii chiovenda flower and Euphorbia cotinifolia leaf. In the as-prepared DSSC, a quasi-solid state electrolyte was sandwiched between the working electrode (photoanode and counter electrode (PEDOT-coated FTO glass. The photoelectrochemical performance of the as-prepared quasi-solid state DSSCs showed open-circuit voltages (VOC varied from 0.475 to 0.507 V, the short-circuit current densities (JSC ranged from 0.352 to 0.642 mA cm−2 and the fill factors (FF varied from 47 to 60% at 100 mWcm−2 light intensity. The dye extracted from A. sennii chiovenda flower, using acidified ethanol (in 1% HCl as extracting solvent, exhibited best conversion efficiency with a maximum open-circuit voltage (VOC of 0.507 V, short-circuit current density (JSC of 0.491 mA cm−2, fill factor (FF of 0.60 and an overall conversion efficiency (η of 0.15%. On the other hand, the maximum power conversion efficiency of the dye extracted from E. cotinifolia leaf was 0.136%. This is the first study that reports the fabrication of DSSC using natural dye sensitizers extracted from these plants in the presence of quasi-solid state electrolyte and PEDOT as a counter electrode.

Spectral-optical characteristics of anthocyanin-containing natural dye staff

International Nuclear Information System (INIS)

Astanov, S.; Sharipov, M.Z.; Dalmuradova, N.N.

2007-01-01

Spectral-optical characteristics of anthocyanin-containing natural dye staff received from fruit ficus carica are determined. The chromatographic separating of dyeing pigment obtained is performed. The data obtained can be used as passport characteristics of the new food dye staff. (authors)

A Novel Preparation Method of Two Polymer Dyes with Low Cytotoxicity

Directory of Open Access Journals (Sweden)

Dongjun Lv

2017-02-01

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

[1]Benzothieno[3,2-b]benzothiophene-Based Organic Dyes for Dye-Sensitized Solar Cells.

Science.gov (United States)

Capodilupo, Agostina L; Fabiano, Eduardo; De Marco, Luisa; Ciccarella, Giuseppe; Gigli, Giuseppe; Martinelli, Carmela; Cardone, Antonio

2016-04-15

Three new metal-free organic dyes with the [1]benzothieno[3,2-b]benzothiophene (BTBT) π-bridge, having the structure donor-π-acceptor (D-π-A) and labeled as 19, 20 and 21, have been designed and synthesized for application in dye-sensitized solar cells (DSSC). Once the design of the π-acceptor block was fixed, containing the BTBT as the π-bridge and the cyanoacrylic group as the electron acceptor and anchoring unit, we selected three donor units with different electron-donor capacity, in order to assemble new chromophores with high molar extinction coefficients (ε), whose absorption features well reflect the good performance of the final DSSC devices. Starting with the 19 dye, which shows a molar extinction coefficient ε of over 14,000 M(-1) cm(-1) and takes into account the absorption maximun at the longer wavelength, the substitution of the BFT donor unit with the BFA yields a great enhancement of absorptivity (molar extinction coefficient ε > 42,000 M(-1) cm(-1)), until reaching the higher value (ε > 69,000 M(-1) cm(-1)) with the BFPhz donor unit. The good general photovoltaic performances obtained with the three dyes highlight the suitable properties of electron-transport of the BTBT as the π-bridge in organic chromophore for DSSC, making this very cheap and easy to synthesize molecule particularly attractive for efficient and low-cost photovoltaic devices.

Vibrational spectroscopy of photosensitizer dyes for organic solar cells

Energy Technology Data Exchange (ETDEWEB)

Perez Leon, C.

2005-11-18

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

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

Science.gov (United States)

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

2014-11-01

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

Plasma surface functionalization and dyeing kinetics of Pan-Pmma copolymers

OpenAIRE

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

2013-01-01

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

Panchromatic Response in Solid-State Dye-Sensitized Solar Cells Containing Phosphorescent Energy Relay Dyes

KAUST Repository

Yum, Jun-Ho

2009-11-23

Running relay: Incorporating an energyrelay dye (ERD) into the hole transporter of a dye-sensitized solar cell increased power-conversion efficiency by 29% by extending light harvesting into the blue region. In the operating mechanism (see picture), absorption of red photons by the sensitizer transfers an electron into TiO2 and a hole into the electrolyte. Blue photons absorbed by the ERD are transferred by FRET to the sensitizer. Chemical Equitation Presentation © 2009 Wiley-VCH Verlag GmbH & Co. KGaA.

Solvent effect on indocyanine dyes: A computational approach

International Nuclear Information System (INIS)

Bertolino, Chiara A.; Ferrari, Anna M.; Barolo, Claudia; Viscardi, Guido; Caputo, Giuseppe; Coluccia, Salvatore

2006-01-01

The solvatochromic behaviour of a series of indocyanine dyes (Dyes I-VIII) was investigated by quantum chemical calculations. The effect of the polymethine chain length and of the indolenine structure has been satisfactorily reproduced by semiempirical Pariser-Parr-Pople (PPP) calculations. The solvatochromism of 3,3,3',3'-tetramethyl-N,N'-diethylindocarbocyanine iodide (Dye I) has been deeply investigated within the ab initio time-dependent density functional theory (TD-DFT) approach. Dye I undergoes non-polar solvation and a linear correlation has been individuated between absorption shifts and refractive index. Computed absorption λ max and oscillator strengths obtained by TD-DFT are in good agreement with the experimental data

Photocatalytic Removal of Azo Dye and Anthraquinone DyeUsing TiO2 Immobilised on Ceramic Tiles

Directory of Open Access Journals (Sweden)

P. N. Palanisamy

2011-01-01

Full Text Available The photocatalytic activity of TiO2 immobilized on different supports; cement and ceramic tile, was studied to decolorize two commercial dyes. The catalyst was immobilised by two different techniques, namely, slurry method on ceramic tile and powder scattering on cement. The degradation of the dyes was carried out using UV and solar irradiation. The comparative efficiency of the catalyst immobilised on two different supports was determined. The photodegradation process was monitored by UV-Vis spectrophotometer. The catalyst immobilised on ceramic tile was found to be better than the catalyst immobilised on cement. Experimental results showed that both illumination and the catalyst were necessary for the degradation of the dyes and UV irradiation is more efficient compared to solar irradiation.

Interplay between transparency and efficiency in dye sensitized solar cells.

Science.gov (United States)

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.

Threshold pump power of a solar-pumped dye laser

Science.gov (United States)

Lee, Ja H.; Kim, Kyung C.; Kim, Kyong H.

1988-01-01

Threshold solar power for dye laser pumping has been determined by measuring the gain of a rhodamine 6G dye laser amplifier at various solar-simulated irradiances on an amplifier cell. The measured threshold was 20,000 solar constants (2.7 kW/sq cm) for the dye volume of 2 x 5 x 40 cu mm and the optimum dye concentration of 0.001 M. The threshold is about one-third of that achievable with a high-intensity solar concentrator.

Management of Industrial Dye Wastes Through Adsorption By Functionalized Graft Copolymers

International Nuclear Information System (INIS)

El-Nagger Abdel-Wahab, M.; Hegazy El-Sayed, A.; Aly Hussein, A.; Zahran Abdel-Hamid, H.

1999-01-01

The sorption of Methyl Green (basic dye) by different grafted polymers with individual acrylonitrile (AN) and its binary comonomer mixture with N-vinylpyrrolidone (NVP) has been investigated. It was found that at approximately equal levels of graft yield of AN, poly(tetrafluoroethylene-hexafluoropropylene)(FEP) showed the highest dye sorption of the basic dye while the grafted low density polyethylene (LDPE) displayed the lowest dye sorption. On the other hand, the different grafted polymers with AN/NVP binary monomers which having an approximately equal total graft yield (TGY) showed a dye sorption for the same basic dye according to the order: HDPE>FEP> LDPE>PP. Nevertheless, it was found that the dye sorption values by the grafted polymers with AN/NVP mixtures are much higher than those by the grafted polymers with individual AN monomer. The dye ability of HDPE grafted with individual AN and the comonomer mixture AN/NVP towards basic and disperse dyes was utilized to investigate the synergism during radiation grafting of the comonomer mixture. Results showed that such graft materials are promising in practical use for the treatment of industrial dye wastes from textile factories

Investigation of the dye concentration influence on the lasing wavelength and threshold for a micro-fluidic dye laser

DEFF Research Database (Denmark)

Helbo, Bjarne; Kragh, Søren; Kjeldsen, B.G.

2003-01-01

We investigate a micro-fluidic dye laser, which can be integrated with polymer-based lab-on-a-chip microsystems without further processing steps. A simple rate-equation model is used to predict the lasing threshold. The laser device is characterised using the laser dye Rhodamine 6G dissolved...... in ethanol, and the influence of dye concentration on the lasing wavelength and threshold is investigated. The experiments confirm the predictions of the rate-equation model, that lasing can be achieved in the 10 mum long laser cavity with moderate concentrations of Rhodamine 6G in ethanol, starting from 5 x...

Computer control of pulsed tunable dye lasers

International Nuclear Information System (INIS)

Thattey, S.S.; Dongare, A.S.; Suri, B.M.; Nair, L.G.

1992-01-01

Pulsed tunable dye lasers are being used extensively for spectroscopic and photo-chemical experiments, and a system for acquisition and spectral analysis of a volume of data generated will be quite useful. The development of a system for wavelength tuning and control of tunable dye lasers and an acquisition system for spectral data generated in experiments with these lasers are described. With this system, it is possible to control the tuning of three lasers, and acquire data in four channels, simultaneously. It is possible to arrive at the desired dye laser wavelength with a reproducibility of ± 0.012 cm -1 , which is within the absorption width (atomic interaction) caused by pulsed dye lasers of linewidth 0.08 cm -1 . The spectroscopic data generated can be analyzed for spectral identification within absolute accuracy ± 0.012 cm -1 . (author). 6 refs., 11 figs

Simulations of longitudinally pumped dye laser amplifier

International Nuclear Information System (INIS)

Takehisa, Kiwamu; Takemori, Satoshi

1995-01-01

Simulations of a copper laser pumped dye laser amplifier and new designs of the longitudinally pumped dye laser amplifier are presented. The simulations take the consideration of the amplified spontaneous emission (ASE). The new designs utilize a center-hole reflector instead of a dichroic mirror. The simulation results indicate that the poor spatial overlap between the pump beam and the dye beam in the transverse pumping not only reduces the laser output power, but also generates ASE strongly. The results also indicate that the longitudinal pumping is as efficient as the transverse pumping. (author)

Effect of Isotopic Substitution on Elementary Processes in Dye-Sensitized Solar Cells: Deuterated Amino-Phenyl Acid Dyes on TiO2

Directory of Open Access Journals (Sweden)

Sergei Manzhos

2013-03-01

Full Text Available We present the first computational study of the effects of isotopic substitution on the operation of dye-sensitized solar cells. Ab initio molecular dynamics is used to study the effect of deuteration on light absorption, dye adsorption dynamics, the averaged over vibrations driving force to injection (∆Gi and regeneration (∆Gr, as well as on promotion of electron back-donation in dyes NK1 (2E,4E-2-cyano-5-(4-dimethylaminophenylpenta-2,4-dienoic acid and NK7 (2E,4E-2-cyano-5-(4-diphenylaminophenylpenta-2,4-dienoic acid adsorbed in monodentate molecular and bidentate bridging dissociative configurations on the anatase (101 surface of TiO2. Deuteration causes a red shift of the absorption spectrum of the dye/TiO2 complex by about 5% (dozens of nm, which can noticeably affect the overlap with the solar spectrum in real cells. The dynamics effect on the driving force to injection and recombination (the difference between the averaged <∆Gi,r> and ∆Gi,requil at the equilibrium configuration is strong, yet there is surprisingly little isotopic effect: the average driving force to injection <∆Gi> and to regeneration <∆Gr> changes by only about 10 meV upon deuteration. The nuclear dynamics enhance recombination to the dye ground state due to the approach of the electron-donating group to TiO2, yet this effect is similar for deuterated and non-deuterated dyes. We conclude that the nuclear dynamics of the C-H(D bonds, mostly affected by deuteration, might not be important for the operation of photoelectrochemical cells based on organic dyes. As the expectation value of the ground state energy is higher than its optimum geometry value (by up to 0.1 eV in the present case, nuclear motions will affect dye regeneration by recently proposed redox shuttle-dye combinations operating at low driving forces.

Integrated and sequential anaerobic/aerobic biodegradation of azo dyes

NARCIS (Netherlands)

Tan, N.G.C.

2001-01-01

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

Photo- and chemocatalytic oxidation of dyes in water.

Science.gov (United States)

Du, Wei-Ning; Chen, Shyi-Tien

2018-01-15

Three commonly used dyes, Acid Red-114 (AR-114), Reactive Black-5 (RB-5), and Disperse Black EX-SF (DB-EX-SF), were treated in a pH-neutral liquid with ultraviolet (UV) light by two reactive methods: photocatalysis with titanium dioxide (TiO 2 ), and/or chemocatalysis with hydrogen peroxide (H 2 O 2 ) as the oxidant and various ferrous-based electron mediators as catalysts. Important factors for dye oxidation were determined through bifactorial experiments. The optimum combinations and doses of the three key reagents, namely TiO 2 , H 2 O 2 , and EDTA-Fe, were also determined. The degradation kinetics of the studied dyes at their optimum doses reveal that the oxidation reactions are pseudo-first-order in nature, and that certain dyes are selectively degraded more by one method than the other. The overall results suggest that co-treatment using more than one oxidative method is beneficial for the treatment of wastewater from dyeing processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Degradation of environment pollutant dyes using phytosynthesized metal nanocatalysts

Science.gov (United States)

MeenaKumari, M.; Philip, Daizy

2015-01-01

We present for the first time biogenic reduction and stabilization of gold and silver ions at room temperature using fruit juice of Punica granatum. The formation, morphology and crystalline structure of the synthesized nanoparticles are determined using UV-Visible, XRD and TEM. An attempt to reveal the partial role of phenolic hydroxyls in the reduction of Au3+ and Ag+ is done through FTIR analysis. The synthesized nanoparticles are used as potential catalysts in the degradation of a cationic phenothiazine dye, an anionic mono azo dye and a cationic fluorescent dye. The calculated values of percentage removal of dyes and the rate constants from pseudo first order kinetic data fit give a comparative study on degradation of organic dyes in presence of prepared gold and silver nanoparticles.

Green grasses as light harvesters in dye sensitized solar cells

Science.gov (United States)

Shanmugam, Vinoth; Manoharan, Subbaiah; Sharafali, A.; Anandan, Sambandam; Murugan, Ramaswamy

2015-01-01

Chlorophylls, the major pigments presented in plants are responsible for the process of photosynthesis. The working principle of dye sensitized solar cell (DSSC) is analogous to natural photosynthesis in light-harvesting and charge separation. In a similar way, natural dyes extracted from three types of grasses viz. Hierochloe Odorata (HO), Torulinium Odoratum (TO) and Dactyloctenium Aegyptium (DA) were used as light harvesters in dye sensitized solar cells (DSSCs). The UV-Vis absorption spectroscopy, Fourier transform infrared (FT-IR), and liquid chromatography-mass spectrometry (LC-MS) were used to characterize the dyes. The electron transport mechanism and internal resistance of the DSSCs were investigated by the electrochemical impedance spectroscopy (EIS). The performance of the cells fabricated with the grass extract shows comparable efficiencies with the reported natural dyes. Among the three types of grasses, the DSSC fabricated with the dye extracted from Hierochloe Odorata (HO) exhibited the maximum efficiency. LC-MS investigations indicated that the dominant pigment present in HO dye was pheophytin a (Pheo a).

A dye center laser pumped by emission from copper vapor and dye lasers

Energy Technology Data Exchange (ETDEWEB)

Loktyushin, A A; Chernyshev, A I; Soldatov, A N; Sukhanov, V B; Troitskiy, V O

1983-01-01

LiF:F2+ lasing is reported for the case of pumping by total emission with frequencies of 570.6 and 578.2 nanometers or by a single yellow copper vapor laser line and emission from an oxazene-17 dye laser excited by emission from a Cu laser. Lasing with a mean power level of 23 milliwatts with a maximum at 911 nanometers is obtained. The maximum efficiency was 3.4 percent with pumping of the dye centers by emission from the yellow Cu laser line. The lasing characteristics of the laser for all the types of pumping used are given.

Resonance Raman and UV-visible spectroscopy of black dyes on textiles.

Science.gov (United States)

Abbott, Laurence C; Batchelor, Stephen N; Smith, John R Lindsay; Moore, John N

2010-10-10

Resonance Raman and UV-visible diffuse reflectance spectra were recorded from samples of cotton, viscose, polyester, nylon, and acrylic textile swatches dyed black with one of seven single dyes, a mixture of two dyes, or one of seven mixtures of three dyes. The samples generally gave characteristic Raman spectra of the dyes, demonstrating that the technique is applicable for the forensic analysis of dyed black textiles. Survey studies of the widely used dye Reactive Black 5 show that essentially the same Raman spectrum is obtained on bulk sampling from the dye in solution, on viscose, on cotton at different uptakes, and on microscope sampling from the dye in cotton threads and single fibres. The effects of laser irradiation on the Raman bands and emission backgrounds from textile samples with and without dye are also reported. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Graft polymerization using radiation-induced peroxides and application to textile dyeing

Energy Technology Data Exchange (ETDEWEB)

Enomoto, Ichiro, E-mail: enomoto.ichiro@iri-tokyo.j [Tokyo Metropolitan Industrial Technology Research Institute, KFC Bldg., 12F, 1-6-1, Yokoami, Sumida-ku, Tokyo 130-0015 (Japan); School of Engineering, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Katsumura, Yosuke [School of Engineering, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Advanced Science Research Center, Japan Atomic Energy Agency, 2-4 Shirakata Shirane, Tokai-mura, Ibaraki 319-1195 (Japan); Kudo, Hisaaki [School of Engineering, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Soeda, Shin [Tokyo Metropolitan Industrial Technology Research Institute, KFC Bldg., 12F, 1-6-1, Yokoami, Sumida-ku, Tokyo 130-0015 (Japan)

2011-02-15

To improve the dyeing affinity of ultra high molecular weight polyethylene (UHMWPE) fiber, surface treatment by radiation-induced graft polymerization was performed. Methyl methacrylate (MMA), acrylic acid (AA) and styrene (St) were used as the monomers. The grafting yields as a function of storage time after irradiation were examined. Although the grafting yield of St after the sulfonation processing was quite low compared with those of MMA and AA, it was successfully dyed to a dark color with a cationic dye. Some acid dyes can dye the grafted fiber with AA. The acid dye is distributed to the amorphous domains of the AA grafted fiber. The dyeing concentration depended on the grafting yield, and the higher the grafting yield the darker the dye color.

Graft polymerization using radiation-induced peroxides and application to textile dyeing

International Nuclear Information System (INIS)

Enomoto, Ichiro; Katsumura, Yosuke; Kudo, Hisaaki; Soeda, Shin

2011-01-01

To improve the dyeing affinity of ultra high molecular weight polyethylene (UHMWPE) fiber, surface treatment by radiation-induced graft polymerization was performed. Methyl methacrylate (MMA), acrylic acid (AA) and styrene (St) were used as the monomers. The grafting yields as a function of storage time after irradiation were examined. Although the grafting yield of St after the sulfonation processing was quite low compared with those of MMA and AA, it was successfully dyed to a dark color with a cationic dye. Some acid dyes can dye the grafted fiber with AA. The acid dye is distributed to the amorphous domains of the AA grafted fiber. The dyeing concentration depended on the grafting yield, and the higher the grafting yield the darker the dye color.

The Versatile SALSAC Approach to Heteroleptic Copper(I Dye Assembly in Dye-Sensitized Solar Cells

Directory of Open Access Journals (Sweden)

Frederik J. Malzner

2018-05-01

Full Text Available Surface-bound heteroleptic copper(I dyes [Cu(Lanchor(Lancillary]+ are assembled using the “surfaces-as-ligands, surfaces as complexes” (SALSAC approach by three different procedures. The anchoring and ancillary ligands chosen are ((6,6′-dimethyl-[2,2′-bipyridine]-4,4′-diyl-bis(4,1-phenylenebis(phosphonic acid (3 and 4,4′-bis(4-iodophenyl-6,6′-diphenyl-2,2′-bipyridine (4, respectively. In the first SALSAC procedure, the FTO/TiO2 electrode is functionalized with 3 in the first dye bath, and then undergoes ligand exchange with the homoleptic complex [Cu(42][PF6] to give surface-bound [Cu(3(4]+. In the second method, the FTO/TiO2 electrode functionalized with 3 is immersed in a solution containing a 1:1 mixture of [Cu(MeCN4][PF6] and 4 to give surface-anchored [Cu(3(4]+. In the third procedure, the anchor 3, copper(I ion and ancillary ligand 4 are introduced in a sequential manner. The performances of the DSSCs show a dependence on the dye assembly procedure. The sequential method leads to the best-performing DSSCs with the highest values of JSC (7.85 and 7.73 mA cm−2 for fully masked cells and overall efficiencies (η = 2.81 and 2.71%, representing 41.1 and 39.6% relative to an N719 reference DSSC. Use of the 1:1 mixture of [Cu(MeCN4][PF6] and 4 yields DSSCs with higher VOC values but lower JSC values compared to those assembled using the sequential approach; values of η are 2.27 and 2.29% versus 6.84% for the N719 reference DSSC. The ligand exchange procedure leads to DSSCs that perform relatively poorly. The investigation demonstrates the versatile and powerful nature of SALSAC in preparing dyes for copper-based DSSCs, allowing the photoconversion efficiency of dye to be optimized for a given dye. The SALSAC strategy provides alternative hierarchical strategies where the isolation of the homoleptic [Cu(Lancillary2]+ is difficult or time-consuming; stepwise strategies are more atom-economic than ligand exchange involving the

Self-Assembly of ZnO-Nanorods and Its Performance in Quasi Solid Dye Sensitized Solar Cells

Science.gov (United States)

Aprilia, A.; Erdienzy, A.; Bahtiar, A.; Safriani, L.; Syakir, N.; Risdiana; Saragi, T.; Hidayat, S.; Fitrilawati; Hidayat, R.; Siregar, R. E.

2017-07-01

Zinc oxide (ZnO) nanorods (NRs) were successfully prepared by self-assembly methods using zinc nitrate hexahydrate and hexamethylenetetramine as raw materials. ZnO-NRs were grown on FTO/ZnO seed layer and to enhance dye adsorption it was continued by deposition of titania (TiO2) paste by screen printing method. Deposition time of ZnO-NRs were varied, for 120, 150 and 180 minutes and subsequently stacked with one layer of TiO2 mesoporous. The resulting heterojunction layers of FTO/ZnO-Nrs/TiO2 was then applied as a photoanode in quasi-solid dye sensitized solar cell (QS- DSSC) with polymer gel electrolyte (PGE) as a hole conductor. UV-Vis spectrometer was used to investigate the changes of dye adsorption in photoanode with/without inserting titania mesoporous. Characterizations of scanning electron microscopy (SEM) and X-ray diffraction was carried out and the results shows that increasing the deposition time produces a smaller average grain size, diameter and denser layer of ZnO-nanorods. From current-voltage measurement, higher efficiency (η = 2.53%) was obtained for 120 min ZnO nanorods with short circuit current density (Jsc ) of 2.84 mA/cm2 and open circuit voltage (Voc) of 0.7 V. The combination of TiO2 and ZnO-NRs shows a better performance in solar cells characteristics due to increases of dye adsorption on photoanode and high photogenerated electron transport rate. This work emphasizes an optimum condition of ZnO-NRs in combination with TiO2 mesoporous as an alternative photoanode in QS-DSSC.

Cnidarian-derived filamentous fungi from Brazil: isolation, characterisation and RBBR decolourisation screening.

Science.gov (United States)

Da Silva, M; Passarini, M R Z; Bonugli, R C; Sette, L D

2008-12-01

Marine-derived fungi represent a valuable source of structurally novel and biologically active metabolites of industrial interest. They also have drawn attention for their capacity to degrade several pollutants, including textile dyes, organochlorides and polycyclic aromatic hydrocarbons (PAHs), among others. The fungal tolerance to higher concentrations of salt might be considered an advantage for bioremediation processes in the marine environment. Therefore, filamentous fungi were isolated from cnidarians (scleractinian coral and zoanthids) collected from the north coast of São Paulo State, Brazil. A total of 144 filamentous fungi were morphologically and molecularly characterised. Among them there were several species of Penicillium and Aspergillus, in addition to Cladosporium spp., Eutypella sp., Fusarium spp., Khuskia sp., Mucor sp., Peacilomyces sp., Phoma sp. and Trichoderma spp. These fungi were tested regarding their decolourisation activity for Remazol Brilliant Blue R (RBBR), a textile dye used as an initial screening for PAH-degrading fungi. The most efficient fungi for RBBR decolourisation after 12 days were Penicillium citrinum CBMAI 853 (100%), Aspergillus sulphureus CBMAI 849 (95%), Cladosporium cladosporioides CBMAI 857 (93%) and Trichoderma sp. CBMAI 852 (89%). Besides its efficiency for dye decolourisation within liquid media, C. cladosporioides CBMAI 857 also decolourised dye on solid media, forming a decolourisation halo. Further research on the biotechnological potential, including studies on PAH metabolism, of these selected fungi are in progress.

Comparison of multiple DNA dyes for real-time PCR: effects of dye concentration and sequence composition on DNA amplification and melting temperature

DEFF Research Database (Denmark)

Guðnason, Haukur; Dufva, Hans Martin; Bang, Dang Duong

2007-01-01

investigate 15 different intercalating DNA dyes for their inhibitory effects on PCR, effects on DNA melting temperature and possible preferential binding to GC-rich sequences. Our results demonstrated that in contrast to the results of SYBR Green I, two intercalating dyes SYTO-13 and SYTO-82 do not inhibit......The importance of real-time polymerase chain reaction (PCR) has increased steadily in clinical applications over the last decade. Many applications utilize SYBR Green I dye to follow the accumulation of amplicons in real time. SYBR Green I has, however, a number of limitations that include...... the inhibition of PCR, preferential binding to GC-rich sequences and effects on melting curve analysis. Although a few alternative dyes without some of these limitations have been recently proposed, no large-scale investigation into the properties of intercalating dyes has been performed. In this study, we...

Effects of Introducing Methoxy Groups into the Ancillary Ligands in Bis(diimine Copper(I Dyes for Dye-Sensitized Solar Cells

Directory of Open Access Journals (Sweden)

Annika Büttner

2018-04-01

Full Text Available A systematic investigation of four heteroleptic bis(diimine copper(I dyes in n-type Dye-Sensitized Solar Cells (DSSCs is presented. The dyes are assembled using a stepwise, on-surface assembly. The dyes contain a phosphonic acid-functionalized 2,2′-bipyridine (bpy anchoring domain (5 and ancillary bpy ligands that bear peripheral phenyl (1, 4-methoxyphenyl (2, 3,5-dimethoxyphenyl (3, or 3,4,5-trimethoxyphenyl (4 substituents. In masked DSSCs, the best overall photoconversion efficiency was obtained with the dye [Cu(5(4]+ (1.96% versus 5.79% for N719. Values of JSC for both [Cu(5(2]+ (in which the 4-MeO group is electron releasing and [Cu(5(4]+ (which combines electron-releasing and electron-withdrawing effects of the 4- and 3,5-substituents and are enhanced with respect to [Cu(5(1]+. DSSCs with [Cu(5(3]+ show the lowest JSC. Solid-state absorption spectra and external quantum efficiency spectra reveal that [Cu(5(4]+ benefits from an extended spectral range at higher energies. Values of VOC are in the order [Cu(5(4]+ > [Cu(5(1]+ > [Cu(5(2]+ > [Cu(5(3]+. Density functional theory calculations suggest that methoxyphenyl character in MOs within the HOMO manifold in [Cu(5(2]+ and [Cu(5(4]+ may contribute to the enhanced performances of these dyes with respect to [Cu(5(1]+.

Radiation resistance of organic azo dyes in aqueous solutions

International Nuclear Information System (INIS)

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

1987-01-01

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

Dye-sensitized solar cells based on purple corn sensitizers

Science.gov (United States)

Phinjaturus, Kawin; Maiaugree, Wasan; Suriharn, Bhalang; Pimanpaeng, Samuk; Amornkitbamrung, Vittaya; Swatsitang, Ekaphan

2016-09-01

Natural dye extracted from husk, cob and silk of purple corn, were used for the first time as photosensitizers in dye sensitized solar cells (DSSCs). The dye sensitized solar cells fabrication process has been optimized in terms of solvent extraction. The resulting maximal efficiency of 1.06% was obtained from purple corn husk extracted by acetone. The ultraviolet-visible (UV-vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS) and incident photon-to-current efficiency (IPCE) were employed to characterize the natural dye and the DSSCs.

Bio-degradation of synthetic textile dyes by thermophilic lignolytic fungal isolates

Directory of Open Access Journals (Sweden)

Nidhi Sahni

2014-10-01

Full Text Available Synthetic dyes are extensively used in different industries like textile dyeing, paper, printing, color, photography, pharmaceutics and cosmetics. These are generally toxic and carcinogenic in nature. If not treated, they will remain in nature for a long period of time as they are recalcitrant. Among these, azo dyes represent the largest and most versatile class of synthetic dyes. Approximately 10-15% of the dyes are released into the environment during manufacture and usage. Various methods are used for dye removal viz. physical, chemical, electrochemical and biological. Advantage of chemical, electrochemical and biological methods over physical involves the complete destruction of the dye, but chemical and electrochemical methods are found to be expensive and have operational problems. So the biological method is preferred over other methods for degradation/decolorization of dyes. In the present study, thermophilic lignolytic fungal culture was isolated from compost/soil/digested slurry/plant debris, were subjected for acclimatization to Remazol Brilliant Blue (RBB at 0.05% concentration, in the malt extract broth (MEB. The most promising fungal isolates were used for further dye degradation studies. The results suggest that the isolates T10, T14 and T17 as a useful tool for degradation of reactive dyes.

Product Diversification of Turmeric (Curcuma Domestica Val) for TextileDyes

International Nuclear Information System (INIS)

Kuntari-Sasas; Syafril-Nurdiansyah

2000-01-01

In order to increase the use of natural source and variation of naturalpigment for textile dyes, research activity has been carried out in productdiversification of turmeric for textile dyes however its fixation ability tocotton fibre in this dyes does not have strong fixation ability to cottonfibre in order to improve its colour fastness it was necessary to do aftertreatment with mordant. Up to present time, it has been well known thatturmeric was used as raw material for medicine and cosmetic. Considering thatturmeric contains of carbonyl as chromophore in natural pigment. it has highpossibility to serve it as textile dyes. In this study, turmeric wasextracted with water and used its yields for dyeing cotton fabrics. Theextraction was carried out by using water as medium with ratio of 1 : 4 byboiling until reaching the medium ratio of 1 : 2. The extracted turmeric wasre-extracted again with fresh water in the same condition as the previousextraction and repeating the process up to several times until no more dyeswill be extracted out. The mixture of the extracted dyes were then put intoevaporation to obtain dry pigment and was grinned to obtain powder dyes.Color measurement by means of spectrophotometry was subjected to the dyespowder from known various concentrations to obtain the linear calibrationcurve between dyes concentrations and absorbance. The linear equationobtained from this experiment was : Y = 0.0075 + 0.0435 X. From this equationit was calculated that the dyes yields from the whole turmeric extraction was2.6805 %, and from 3 times repeating extraction was 2.2648 % or 84.49 % fromthe whole extracted dyes. Dyeing experiment for cotton fabrics were carriedout at 60 o C for various times of dyeing (30 minutes to 120 minutes). Thedyed fabrics were then mordanted or after treatment with respected potassiumbichromate, aluminum potassium sulphate (Tawas), and diazonium salt (Red SaltB). The dyed fabrics and the mordanted ones were tested for color fastness

Plasma surface functionalization and dyeing kinetics of Pan-Pmma copolymers

Science.gov (United States)

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

2013-10-01

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

Experimental Researches Regarding the Ecological Dyeing with Natural Extracts

Directory of Open Access Journals (Sweden)

Budeanu Ramona

2014-12-01

Full Text Available The concept of ‘environmental awareness’ has recently had a major impact on the textile industry and on the fashion world as well. In this context, the use of natural fibres and the development of natural dyeing processes gradually became important goals of the textile industry. Of all natural textile fibres, hemp is considered to be one of the strongest and most durable. A wide range of natural extracts have been used for natural textile coloration and dyeing. Dyes deriving from natural sources have emerged as an important alternative to synthetic dyes. Ecofriendly, nontoxic, sustainable and renewable natural dyes and pigments have been used for colouring the food substrate, leather, wood, natural fibres and fabrics from the dawn of human history. The purpose of the research is to obtain ecologically coloured fabrics for textiles by using a method of dyeing that relies on natural ingredients extracted from red beet, onion leaves and black tea. The experiments are conducted on three different types of hemp fabrics. This paper presents the results of the studies regarding the dyeing process of hemp fabrics with natural extracts, the colours of the dyed samples inspected with reflectance spectra and the CIE L*a*b* colour space measurements.

Use of grape seed and its natural polyphenol extracts as a natural organic coagulant for removal of cationic dyes.

Science.gov (United States)

Jeon, Jong-Rok; Kim, Eun-Ju; Kim, Young-Mo; Murugesan, Kumarasamy; Kim, Jae-Hwan; Chang, Yoon-Seok

2009-11-01

Natural organic coagulants (NOCs) such as chitosan and Moringa oleifera seeds have been extensively characterized for potential application in water treatment as an alternative to metal-based coagulants. However, the action of both chitosan and M. oleifera seeds is mainly restricted to anionic organic pollutants because of their cationic functional groups affording poor cationic pollutant coagulation by electrostatic repulsion. In this study, we employed ethanolic grape seed extract (GSE) and grape seed-derived polyphenols such as tannic acid and catechin in an effort to find novel NOCs showing stable anionic forms for removal of cationic organic pollutants. The target substances tested were malachite green (MG) and crystal violet (CV), both mutagenic cationic dyes. Polyphenol treatment induced fast decolorization followed by gradual floc formation concomitant with red or blue shifts in maximum absorbance wavelengths of the cationic dyes. Liquid chromatography analysis of flocs formed by polyphenols directly showed that initial supramolecular complexes attributed mainly to electrostatic attraction between polyphenol hydroxyphenyl groups and cationic dyes further progressed into stronger aggregates, leading to precipitation of dye-polyphenol complexes. Consistent with the results obtained using catechin and tannic acid, use of GSE also resulted in effective decolorization and coagulation of soluble MG and CV in aqueous solutions. Screening of several organic GSE components for NOC activity strongly suggested that natural polyphenols are the main organic ingredients causing MG and CV removal via gradual floc formation. The treatment by natural polyphenols and GSE decreased toxicity of MG- or CV-contaminated water.

Mycoremediation of congo red dye by filamentous fungi

OpenAIRE

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

2011-01-01

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

DEGRADATION OF TEXTILE DYES BY WHITE ROT BASIDIOMYCETES

OpenAIRE

B.P. PARMAR, P.N. MERVANA B.R.M. VYAS*

2014-01-01

ABSTRACT: Dyes released by the textile industries pose a threat to environmental quality. Ligninolytic white-rot basidiomycetes can effectively degrade colored effluents and conventional dyes. White-rot fungi produce various isoforms of extracellular oxidases including laccase, Mn peroxidase and lignin peroxidase (LiP), which are involved in the degradation of lignin in their natural lignocellulosic substrates.  The textile industry, by far the most avid user of synthetic dyes, is in need...

Effect of Tannic Acid on the zeta Potential, Sorption, and Surface Free Energy in the Process of Dyeing of Leacril with a Cationic Dye.

Science.gov (United States)

Espinosa-Jiménez; Giménez-Martín; Ontiveros-Ortega

1998-11-01

The behavior of the surface free energy in the process of dyeing Leacril pretreated with tannic acid and subsequently dyeing with the cationic dye Rhodamine B has been studied. Also the electrokinetic behavior of these systems has been analyzed by studying the zeta potential, which has been obtained by means of the streaming potential technique. Values more significative of the zeta potential of these systems have been obtained using the three models of capillaries existing in the literature. The qualitative behavior of the zeta potential is the same for the three models of capillaries tested in this paper. These models are those of Goring and Mason, Biefer and Mason, and Chang and Robertson. The zeta potential of the systems analyzed is negative in the range of concentration of the dye in the liquid phase from 10(-6) to ca. 10(-4) M of dye. In the range of low concentrations (from 10(-6) to ca. 10(-5) M of dye) the zeta potential of the system untreated Leacril/Rhodamine B increases in absolute value due to increasing hydrophobic attractions between both the hydrophobic chains of the dye and the Leacril fibers in aqueous media. In the system Leacril treated with tannic acid/Rhodamine B, this increase is also due to the presence of hydrogen bonding between the phenolic hydroxyl groups of the tannic acid and the sulfonate and sulfate end groups of Leacril fibers. For concentrations of dye between 10(-5) and 10(-4) M of dye in solution, the zeta potential decreases in absolute value due to the electrostatic attractions between the groups negatively charged in the fiber and the cation of the dye. The zeta potential changes its sign at the highest concentrations of dye used in this work. The adsorption of Rhodamine B onto both untreated Leacril and Leacril treated with tannic acid is favored by the increasing temperature of adsorption. The behavior of the components of the surface free energy obtained by the thin-layer wicking technique led us to consider that the

Radiation degradation and hemolytic toxicity evaluation of mono azo reactive dyes

International Nuclear Information System (INIS)

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

2017-01-01

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

Removal of dyes using immobilized titanium dioxide illuminated by fluorescent lamps

International Nuclear Information System (INIS)

Zainal, Zulkarnain; Hui, Lee Kong; Hussein, Mohd Zobir; Taufiq-Yap, Yun Hin; Abdullah, Abdul Halim; Ramli, Irmawati

2005-01-01

The photodegradation of various dyes in aqueous solution was studied. Experiments were carried out using glass coated titanium dioxide thin film as photocatalyst. Photodegradation processes of methylene blue (MB), methyl orange (MO), indigo carmine (IC), chicago sky blue 6B (CSB), and mixed dye (MD, mixture of the four mentioned single dye) were reported. As each photodegradation system is pH dependent, the photodegradation experiment was carried out in each dye photodegradation reactive pH range at ∼28 deg C. The dyes removal efficiency was studied and compared using UV-vis spectrophotometer analysis. The total removal of each dye was: methylene blue (90.3%), methyl orange (98.5%), indigo carmine (92.4%), chicago sky blue 6B (60.3%), and mixed dyes (70.1%), respectively. The characteristic of the photocatalyst was investigated using X-ray diffractometer (XRD). The amount of each dye intermediate produced in the photodegradation process was also determined with the help of total organic carbon (TOC) analysis

Extraction and Characterization of Natural Dye from Green Walnut Shells and Its Use in Dyeing Polyamide: Focus on Antibacterial Properties

Directory of Open Access Journals (Sweden)

Mohammad Mirjalili

2013-01-01

Full Text Available Extraction of dyes from walnut using Soxhlet apparatus has been studied. The color components extracted and isolated from walnut shells were characterized by column chromatography, thin layer chromatography (TLC, nuclear magnetic resonance (NMR, mass spectroscopy (MS, and infrared (IR techniques. Natural dye extract obtained from the walnut was used in dyeing polyamide fabrics with different mordants. The dyed fabrics were evaluated for antibacterial activity against pathogenic strains of Gram-positive (Staphylococcus aureus and Gram-negative (Escherichia coli bacteria. As such, the relationship between antibacterial activity and dye concentration is investigated. Durability of antibacterial activity to laundering is also discussed. Results indicate that the polyamide dyed with walnut displayed excellent antibacterial activity in the presence of ferric sulfate, cupric sulfate, and potassium aluminum sulfate and exhibited good and durable fastness properties.

A highly flexible polymerization technique to prepare fluorescent nanospheres for trace ammonia detection

International Nuclear Information System (INIS)

Waich, K.; Sandholzer, M.; Mayr, T.; Slugovc, C.; Klimant, I.

2010-01-01

The preparation of pH-sensitive nanospheres by emulsion polymerization for the detection of trace levels of ammonia is described. A fluorescent, polymerizable xanthene dye was copolymerized with styrene, crosslinkers and further copolymers aimed at enhancing the sensitivity to obtain materials for sensing of ammonia. A half-seeded technique was used to obtain stable emulsions of the monomers which were cured to obtain nanospheres with covalently attached active components. The nanospheres were embedded in a silicon matrix and the sensor films obtained were investigated regarding their response to ammonia at concentrations between 25 and 1,000 ppb. Sensors containing polystyrene nanospheres crosslinked with divinylbenzene showed the best performance in ammonia measurements exhibiting detection limits (LODs) of less than 25 ppb ammonia.

Effects of gamma irradiation on the degradation of dyes

International Nuclear Information System (INIS)

Piccinini, N.; Ferrero, F.

1975-01-01

To investigate the degradation kinetics of aqueous solutions of dyes of several classes, we studied the effects of gamma irradiation versus the dose (up to 80 krad), the dye concentration, the pH and the oxygen content of these solutions. To study the influence of some of the above-mentioned parameters, anthraquinonic dyes have been irradiated in a wide range of doses (up to 5 Mrad). Furthermore these dyes were acted upon in order to investigate the complex reactions of molecular alteration through chromatographic separations and spectrophotometric analyses. Experimental results agreed with a first order kinetics for dye concentrations lower than 0.04 g/1, and with a zero order one for higher concentrations. The pH was found to have a different influence according to the type of dye; for example we found that the degradation efficiency for anthraquinonic dyes has higher values for basic ranges. The dissolved oxygen supports the degradation in comparison with de-aerated solutions, though its influence varies according to the dye type and the pH. The oxygen action is particularly evident with high doses; in fact, tests on anthraquinonic dyes with doses up to 5 Mrad showed a marked decrease in the kinetic constants caused by the oxygen disappearance. Radiochemical degradation yields (Gd), never greater than a few units, show that the radical reactions responsible for the decolorization effect, are limited to a few transfer sequences. COD decrease, on the other hand, confirms the presence of oxidation phenomena which correspond to computed radiochemical yields (Gsub(ox)) markedly higher than those spectrophotometrically measured; such a difference is enhanced in the case of irradiation with aeration of solutions. The theoretical considerations are also described that were developed for outlining a general scheme involving the experimental results of both the kinetics and the radiochemical yield. (author)

Decolorization of reactive dyes under batch anaerobic condition by ...

African Journals Online (AJOL)

However, decolorization was lower for the dye of RB 49 than other two dyes in all concentrations despite 72 h incubation period by mixed anaerobic culture. All of the three dyes correlated with 1st order reaction kinetic with respect to decolorization kinetics. The results of the study demonstrated that high decolorization was ...

Biosorption and biodegradation of a sulfur dye in high-strength dyeing wastewater by Acidithiobacillus thiooxidans.

Science.gov (United States)

Nguyen, Thai Anh; Fu, Chun-Chieh; Juang, Ruey-Shin

2016-11-01

The ability of the bacterial strain Acidithiobacillus thiooxidans to remove sulfur blue 15 (SB15) dye from water samples was examined. This bacterium could not only oxidize sulfur compounds to sulfuric acid but also promote the attachment of the cells to the surface of sulfidic particles, therefore serving as an efficient biosorbent. The biosorption isotherms were better described by the Langmuir equation than by the Freundlich or Dubinin-Radushkevich equation. Also, the biosorption process followed the pseudo-second-order kinetics. At pH 8.3 and SB15 concentrations up to 2000 mg L(-1) in the biomass/mineral salt solution, the dye removal and decolorization were 87.5% and 91.4%, respectively, following the biosorption process. Biodegradation was proposed as a subsequent process for the remaining dye (250-350 mg L(-1)). A central composite design was used to analyze independent variables in the response surface methodology study. Under the optimal conditions (i.e., initial dye concentration of 300 mg L(-1), initial biomass concentration of 1.0 g L(-1), initial pH of 11.7, and yeast extract dose of 60 mg L(-1)), up to 50% of SB15 was removed after 4 days of biodegradation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Physical and chemical investigations on natural dyes

Science.gov (United States)

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.

Extracting natural dyes from wool--an evaluation of extraction methods.

Science.gov (United States)

Manhita, Ana; Ferreira, Teresa; Candeias, António; Dias, Cristina Barrocas

2011-05-01

The efficiency of eight different procedures used for the extraction of natural dyes was evaluated using contemporary wool samples dyed with cochineal, madder, woad, weld, brazilwood and logwood. Comparison was made based on the LC-DAD peak areas of the natural dye's main components which had been extracted from the wool samples. Among the tested methods, an extraction procedure with Na(2)EDTA in water/DMF (1:1, v/v) proved to be the most suitable for the extraction of the studied dyes, which presented a wide range of chemical structures. The identification of the natural dyes used in the making of an eighteenth century Arraiolos carpet was possible using the Na(2)EDTA/DMF extraction of the wool embroidery samples and an LC-DAD-MS methodology. The effectiveness of the Na(2)EDTA/DMF extraction method was particularly observed in the extraction of weld dye components. Nine flavone derivatives previously identified in weld extracts could be identified in a single historical sample, confirming the use of this natural dye in the making of Arraiolos carpets. Indigo and brazilwood were also identified in the samples, and despite the fact that these natural dyes were referred in the historical recipes of Arraiolos dyeing, it is the first time that the use of brazilwood is confirmed. Mordant analysis by ICP-MS identified the widespread use of alum in the dyeing process, but in some samples with darker hues, high amounts of iron were found instead.

Application of dye analysis in forensic fibre and textile examination: Case examples.

Science.gov (United States)

Schotman, Tom G; Xu, Xiaoma; Rodewijk, Nicole; van der Weerd, Jaap

2017-09-01

Seven cases and a quality assurance test are presented. In these cases, fibres or textiles submitted for investigation were analysed by HPLC-DAD-MS to identify the dyes present. The cases presented illustrate that it is possible to identify textile dyes in fibre traces recovered for forensic analysis. The results show that a mixture of dyes is present in all textiles investigated, except one sample that was taken from a manufacturer dye shade card. It is concluded that dye analyses improves the evidential value of forensic fibre examinations, as it becomes possible to distinguish textiles that are different in dye chemistry, but have a similar colour. In addition dye analysis makes the examination more robust, as it becomes possible to attribute colour differences between samples to identical dyes (mixed in different ratios) or to chemically different dyes. Copyright © 2017 Elsevier B.V. All rights reserved.

Green grasses as light harvesters in dye sensitized solar cells.

Science.gov (United States)

Shanmugam, Vinoth; Manoharan, Subbaiah; Sharafali, A; Anandan, Sambandam; Murugan, Ramaswamy

2015-01-25

Chlorophylls, the major pigments presented in plants are responsible for the process of photosynthesis. The working principle of dye sensitized solar cell (DSSC) is analogous to natural photosynthesis in light-harvesting and charge separation. In a similar way, natural dyes extracted from three types of grasses viz. Hierochloe Odorata (HO), Torulinium Odoratum (TO) and Dactyloctenium Aegyptium (DA) were used as light harvesters in dye sensitized solar cells (DSSCs). The UV-Vis absorption spectroscopy, Fourier transform infrared (FT-IR), and liquid chromatography-mass spectrometry (LC-MS) were used to characterize the dyes. The electron transport mechanism and internal resistance of the DSSCs were investigated by the electrochemical impedance spectroscopy (EIS). The performance of the cells fabricated with the grass extract shows comparable efficiencies with the reported natural dyes. Among the three types of grasses, the DSSC fabricated with the dye extracted from Hierochloe Odorata (HO) exhibited the maximum efficiency. LC-MS investigations indicated that the dominant pigment present in HO dye was pheophytin a (Pheo a). Copyright © 2014 Elsevier B.V. All rights reserved.

Performance of dye-sensitized solar cells with various carbon nanotube counter electrodes

International Nuclear Information System (INIS)

Zhang, D.; Li, X.; Chen, S.; Sun, Z.; Huang, S.; Yin, X.J.

2011-01-01

Double-wall carbon nanotubes (DWCNTs), single-wall carbon nanotubes (SWCNTs), and multi-wall carbon nanotubes (MWCNTs) were investigated as an alternative for platinum in counter-electrodes for dye-sensitized solar cells. The counter-electrodes were prepared on fluorine-doped tin oxide glass substrates by the screen printing technique from pastes of carbon nanotubes and organic binder. The solar cells were assembled from carbon nanotubes counter-electrodes and screen printed anodes made from titanium dioxide. The cells produced with DWCNTs, SWCNTs or MWCNTs have overall conversion efficiencies of 8.0%, 7.6% and 7.1%, respectively. Electrochemical impedance spectroscopy measurements revealed that DWCNTs displayed the highest catalytic activity for the reduction of tri-iodide ions. The large surface area and superior chemical stability of the DWCNTs facilitated the electron-transfer kinetics at the interface between counter-electrode and electrolyte and yielded the lowest transfer resistance, thereby improving the photovoltaic activity. A short-term stability test at moderate conditions confirmed the robustness of solar cells based on the use of DWCNTs, SWCNTs or MWCNTs. (author)

Intermolecular energy transfer in binary systems of dye polymers

Science.gov (United States)

Liu, Lin-I.; Barashkov, Nikolay N.; Palsule, Chintamani P.; Gangopadhyay, Shubhra; Borst, Walter L.

2000-10-01

We present results and physical interpretations for the energy transfer mechanisms in two-component dye polymer systems. The data consist of fluorescence emission spectra and decays. Two dyes were embedded in an epoxypolymer base, and only they participated in the energy transfer. Following pulsed laser excitation of the donor dye, energy transfer took place to the accept dye. The possible transfer paths considered here were nonradiative and radiative transfer. The latter involves two steps, emission and absorption of a photon, and therefore is relatively slow, while nonradiative transfer is a fast single step resulting from direct Coulomb interactions. A predominantly nonradiative transfer is desirable for applications, for instance in wavelength shifters in high energy particle detection. We studied the concentration effects of the dyes on the energy transfer and obtained the relative quantum efficiencies of various wavelength shifters from the fluorescence emission spectra. For low acceptor concentrations, radiative transfer was found to dominate, while nonradiative transfer became dominant at increasing dye concentrations. The fluorescence decays were analyzed with a sum-of-exponentials method and with Förster kinetics. The sum of exponential model yielded mean decay times of the dye polymers useful for a general classification. The decay times decreased as desired with increasing acceptor concentration. The samples, in which nonradiative energy transfer dominated, were analyzed with Förster kinetics. As a result, the natural decay times of the donor and acceptor dyes and the critical radii for nonradiative energy transfer were obtained from a global best fit.

Photoanode Thickness Optimization and Impedance Spectroscopic Analysis of Dye-Sensitized Solar Cells based on a Carbazole-Containing Ruthenium Dye

Science.gov (United States)

Choi, Jongwan; Kim, Felix Sunjoo

2018-03-01

We studied the influence of photoanode thickness on the photovoltaic characteristics and impedance responses of the dye-sensitized solar cells based on a ruthenium dye containing a hexyloxyl-substituted carbazole unit (Ru-HCz). As the thickness of photoanode increases from 4.2 μm to 14.8 μm, the dye-loading amount and the efficiency increase. The device with thicker photoanode shows a decrease in the efficiency due to the higher probability of recombination of electron-hole pairs before charge extraction. We also analyzed the electron-transfer and recombination characteristics as a function of photoanode thickness through detailed electrochemical impedance spectroscopy analysis.

DYE-SENSITIZED PHOTOPOLYMERIZATION OF METHYL METHACRYLATE INITIATED BY COUMARIN DYE/IODONIUM SALT SYSTEM

Institute of Scientific and Technical Information of China (English)

Fang Gao; Yong-yuan Yang

1999-01-01

The photosensitive initiating system composed of 7-diethylamino-3-(2'-benzimidazolyl)coumarin dye (DEDC) and diphenyliodonium hexafluorophosphate (DIHP) which act as the sensitizer and the initiator respectively, can be used to initiate the polymerization of methyl methacrylate (MMA). The results showed that when exposed to visible light, coumarin dye/iodonium salt undergoes quick electron transfer from DEDC to DIHP and free radicals are produced. The visible light photoinduced reaction between DEDC and DIHP is mainly through the excited singlet state of DEDC and thus it is a little sensitive to O2. The influence of concentration of DEDC, DIHP and MMA on the rate of photopolymerization of MMA was also investigated.

Formation of double-layered TiO2 structures with selectively-positioned molecular dyes for efficient flexible dye-sensitized solar cells

International Nuclear Information System (INIS)

Kim, Eun Yi; Yu, Sora; Moon, Jeong Hoon; Yoo, Seon Mi; Kim, Chulhee; Kim, Hwan Kyu; Lee, Wan In

2013-01-01

Graphical abstract: A novel flexible tandem dye-sensitized solar cell, selectively loading different dyes in discrete layers, was successfully formed on a plastic substrate by transferring the high-temperature-processed N719/TiO 2 over an organic dye-adsorbed TiO 2 film by a typical compression process at room temperature. -- Highlights: • A novel flexible dye-sensitized solar cell, selectively loading two different dyes in discrete layers, was successfully formed on a plastic substrate. • η of the flexible tandem cell obtained by transferring the high-temperature-processed TiO 2 layer was enhanced from 2.91% to 6.86%. • Interface control between two TiO 2 layers is crucial for the efficient transport of photo-injected electrons from the top to bottom TiO 2 layer. -- Abstract: To fabricate flexible dye-sensitized solar cells (DSCs) utilizing full solar spectrum, the double-layered TiO 2 films, selectively loading two different dyes in discrete layers, were formed on a plastic substrate by transferring the high-temperature-processed N719/TiO 2 over an organic dye (TA-St-CA)-sensitized TiO 2 film by a typical compression process at room temperature. It was found that interface control between two TiO 2 layers is crucial for the efficient transport of photo-injected electrons from the N719/TiO 2 to the TA-St-CA/TiO 2 layer. Electron impedance spectra (EIS) and transient photoelectron spectroscopic analyses exhibited that introduction of a thin interfacial TiO 2 layer between the two TiO 2 layers remarkably decreased the resistance at the interface, while increasing the electron diffusion constant (D e ) by ∼10 times. As a result, the photovoltaic conversion efficiency (η) of the flexible tandem DSC was 6.64%, whereas that of the flexible cell derived from the single TA-St-CA/TiO 2 layer was only 2.98%. Another organic dye (HC-acid), absorbing a short wavelength region of solar spectrum, was also applied to fabricate flexible tandem DSC. The η of the cell

Dye characteristics of Zingiber officinale var rubrum, Cinnamomum zaylanicum, Curcuma longa L., Oryza sativa L. Indica in dye sensitized solar cell (DSSC)

Science.gov (United States)

Cari; Mahfudli Fadli, U.; Bayu Prasada, A.; Supriyanto, A.

2017-01-01

The aims of the research to were know performance of DSSC using the dye of Zingiber, Cinnamomum, Curcuma, and Oryza as a photosensitizer with a variation of dye deposition area with spin coating techniques. The structure of the samples as a sandwich consisting of the working electrode (TiO2), dye, electrodes of platinum (Pt) and the electrolyte sandwiched between two electrodes. Test absorbance dye using UV-Visible Spectrophotometer Lambda 25, using a two-point conductivity test probes El Kahfi 100 and characterization test IV using a Keithley 2602A. For Zingiber results showed that absorbance at 243 nm and 279 nm, photoconductivity of 0.29 Ω-1m-1 and the efficiency is 0.015% on 0.5 cm2. Cinnamomum results showed that absorbance at 253 nm and 403 nm, photoconductivity of 0.11 Ω-1m-1 and the efficiency is 0.002% on 3 cm2. Curcuma results showed that absorbance at 243 nm and 422 nm, photoconductivity of 0.177 Ω-1m-1 and the efficiency is 0.072% on 3 cm2. Oryza results showed that absorbance at 240 nm and 423 nm, photoconductivity of 0.21 Ω-1m-1 and the efficiency is 0.04% on 2.25 cm2. Best absorbance value was obtained from Oryza dye; the highest photoconductivity was obtained from Zingiber dye, and the highest efficiency was obtained from Curcuma dye.

Dye characteristics of Zingiber officinale var rubrum, Cinnamomum zaylanicum, Curcuma longa L., Oryza sativa L. Indica in dye sensitized solar cell (DSSC)

International Nuclear Information System (INIS)

Cari; Fadli, U. Mahfudli; Prasada, A. Bayu; Supriyanto, A.

2017-01-01

The aims of the research to were know performance of DSSC using the dye of Zingiber , Cinnamomum , Curcuma , and Oryza as a photosensitizer with a variation of dye deposition area with spin coating techniques. The structure of the samples as a sandwich consisting of the working electrode (TiO 2 ), dye, electrodes of platinum (Pt) and the electrolyte sandwiched between two electrodes. Test absorbance dye using UV-Visible Spectrophotometer Lambda 25, using a two-point conductivity test probes El Kahfi 100 and characterization test IV using a Keithley 2602A. For Zingiber results showed that absorbance at 243 nm and 279 nm, photoconductivity of 0.29 Ω -1 m -1 and the efficiency is 0.015% on 0.5 cm 2 . Cinnamomum results showed that absorbance at 253 nm and 403 nm, photoconductivity of 0.11 Ω -1 m -1 and the efficiency is 0.002% on 3 cm 2 . Curcuma results showed that absorbance at 243 nm and 422 nm, photoconductivity of 0.177 Ω -1 m -1 and the efficiency is 0.072% on 3 cm 2 . Oryza results showed that absorbance at 240 nm and 423 nm, photoconductivity of 0.21 Ω -1 m -1 and the efficiency is 0.04% on 2.25 cm 2 . Best absorbance value was obtained from Oryza dye; the highest photoconductivity was obtained from Zingiber dye, and the highest efficiency was obtained from Curcuma dye. (paper)

Removal of some basic dyes by poly (Vinyl Alcohol/ acrylic acid)Hydrogel

International Nuclear Information System (INIS)

Hegazy, S.A.; Abdel-AAl, S.E.; Abdel-Rehim, H.A.; Khalifa, N.A.; El-Hosseiny, E.M.

2000-01-01

A study has made on the preparation and properties of poly (vinyl alcohol/ acrylic acid) hydrogel for the purpose of removal of cationic dyes from aqueous solutions. The effect of dose and monomer concentration on the uptake property of the hydrogel toward dye was studied. The uptake of basic methylene blue-9 dye with PVA/AAc was studied by the batch adsorption technique. The effect of pH on the dye uptake was demonstrated to find out that the suitable pH for maximum uptake occurred at pH 5. It was observed that as the concentration of dye is increased the dye uptake decreased. Furthermore, the uptake of dye by hydrogels increased as the temperature was elevated. The recovery of dye adsorbed is possible by treating the hydrogel with 5% HCl. The results obtained suggested this hydrogel possessed good removal properties towards basic methylene blue-9 dye, and this suggests that such hydrogels could be acceptable for practical uses

Application of natural dyes in textile industry and the treatment of dye solutions using electrolytic techniques

OpenAIRE

Abouamer, Karima Massaud

2008-01-01

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 25/02/2008. Anodic oxidation of a commercial dye, methylene blue (MB), from aqueous solutions using an electrochemical cell is reported. Data are provided on the effects of eight different types of supporting electrolytes, concentration of electrolytes, initial dye concentration, current and electrolytic time on the percentage removal of methylene blue. Anodic oxidation was found to be effect...

First principles DFT study of dye-sensitized CdS quantum dots

Energy Technology Data Exchange (ETDEWEB)

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

2014-04-24

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

Screening action potentials: The power of light

Directory of Open Access Journals (Sweden)

Lars eKaestner

2011-07-01

Full Text Available Action potentials reflect the concerted activity of all electrogenic constituents in the plasma membrane during the excitation of a cell. Therefore, the action potential is an integrated readout and a promising parameter to detect electrophysiological failures or modifications thereof in diagnosis as well as in drug screens. Cellular action potentials can be recorded by optical approaches. To fulfill the pre-requirements to scale up for e.g. pharmacological screens the following preparatory work has to be provided: (i model cells under investigation need to represent target cells in the best possible manner; (ii optical sensors that can be either small molecule dyes or genetically encoded potential probes need to provide a reliable readout with minimal interaction with the naive behavior of the cells and (iii devices need to be capable to stimulate the cells, read out the signals with the appropriate speed as well as provide the capacity for a sufficient throughput. Here we discuss several scenarios for all three categories in the field of cardiac physiology and pharmacology and provide a perspective to use the power of light in screening cardiac action potentials.

Contact dermatitis in tie and dye industry workers

Energy Technology Data Exchange (ETDEWEB)

Mathur, N K; Mathur, A; Banerjee, K

1985-01-01

A survey of the Tie and Dye industry of Jodhpur City in India was made to investigate occupational dermatoses. 49 (16.6%) of 250 workers had incapacitating dermatitis. Skin lesions were seen mostly over the dorsa of the hands and fingers. 26 patients were patch tested with various dyes and chemicals; 14 were positive. Fast Red RC salt was the most potent sensitizer. Other dyes showing positive reactions were Orange GC salt, Bordeaux GP salt, Blue B salt, Red B base and naphthol.

Immune responses to hair dyes containing toluene-2,5-diamine

DEFF Research Database (Denmark)

Schmidt, J D; Johansen, J D; Nielsen, M M

2014-01-01

BACKGROUND: Toluene-2,5-diamine (PTD) is the most frequently used dye in oxidative hair dyes on the Scandinavian market. However, little is known about immune responses to PTD-containing oxidative hair dyes. OBJECTIVES: To study immune responses induced by PTD-containing hair dyes in mice. METHODS......: Immune responses against two different permanent hair dye products containing 1·60% (w/w) and 0·48% (w/w) PTD within the colour gel, and various concentrations of pure PTD were studied. The local inflammatory response was measured by ear swelling and cell infiltration, and T- and B-cell infiltration...... and proliferation was determined in the draining lymph nodes. RESULTS: Concentration-dependent immune responses were seen to PTD both in the skin and draining lymph nodes. The hair dye containing 1·60% PTD induced strong local inflammation and caused T- and B-cell infiltration and proliferation as well...

Ranking of hair dye substances according to predicted sensitization potency

DEFF Research Database (Denmark)

Søsted, H; Basketter, D A; Estrada, E

2004-01-01

Allergic contact dermatitis following the use of hair dyes is well known. Many chemicals are used in hair dyes and it is unlikely that all cases of hair dye allergy can be diagnosed by means of patch testing with p-phenylenediamine (PPD). The objectives of this study are to identify all hair dye...... in order to help select a number of chemically diverse hair dye substances that could be used in subsequent clinical work. Various information sources, including the Inventory of Cosmetics Ingredients, new regulations on cosmetics, data on total use and ChemId (the Chemical Search Input website provided...... by the National Library of Medicine), were used in order to identify the names and structures of the hair dyes. A QSAR model, developed with the help of experimental local lymph node assay data and topological sub-structural molecular descriptors (TOPS-MODE), was used in order to predict the likely sensitization...

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

KAUST Repository

Voïtchovsky, Kislon

2015-05-27

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

Dye sensitized solar cells. How do they work?

International Nuclear Information System (INIS)

Laurie M, Peter

2008-01-01

Dye sensitized solar cells (DSC), also known as Gratzel cells, harvest sunlight using a dye adsorbed onto the high surface area of a porous nanocrystalline titanium dioxide film. Photoexcitation of the dye results in the injection of electrons into the conduction band of the oxide. The dye is regenerated in its original state by donation of electrons from iodide ions presenting an electrolyte that permeates the porous oxide film. The regeneration cycle is completed at a platinum coated cathode at which tri-iodide ions are reduced to iodide ions. DSC has achieved solar conversion efficiencies of over 10% in the laboratory, with best module efficiencies of around 8%. This lecture will describe the fabrication of the basic DSC and discuss the basic Physics and Chemistry of the cell. (Full text)

Synthesis, Characterization, and Antimicrobial Activity of a Novel Trisazo Dye from 3-Amino-4H-thieno[3,4-c][1]benzopyran-4-one

Science.gov (United States)

Tsemeugne, Joseph; Rohand, Taoufik; Ngongang, Arnaud Djintchui; Sondengam, Beibam Luc

2018-01-01

A new trisazo dye has been synthesized by coupling the diazonium ion of 3-amino-4H thieno[3,4-c][1]benzopyran-4-one with 2-tert-butyl-4-methoxyphenol. The newly prepared trisazo dye was characterized by its physical, elemental, and spectroscopic data. 2D-NMR (COSY, HSQC, and HMBC) techniques were used to secure the structural assignments. The new trisazo dye (compound 7) along with precursors 3, 4, and 6 was screened by microdilution susceptibility assay for antibacterial and antifungal activities towards eight bacterial strains and three yeasts selected on the basis of their relevance as human pathogens. The results showed that compound 7 (MIC = 2–128 μg/mL) was the most active as compared with its precursors. The most resistant microorganisms were V. cholerae NB2 and V. cholerae SG24, whereas the most sensitive microorganism was C. neoformans. The overall results of this study indicated that compound 7 had the greatest potential value against both yeasts and multidrug-resistant bacteria, so further investigation is warranted. PMID:29484208

Synthesis, Characterization, and Antimicrobial Activity of a Novel Trisazo Dye from 3-Amino-4H-thieno[3,4-c][1]benzopyran-4-one

Directory of Open Access Journals (Sweden)

Joseph Tsemeugne

2018-01-01

Full Text Available A new trisazo dye has been synthesized by coupling the diazonium ion of 3-amino-4H thieno[3,4-c][1]benzopyran-4-one with 2-tert-butyl-4-methoxyphenol. The newly prepared trisazo dye was characterized by its physical, elemental, and spectroscopic data. 2D-NMR (COSY, HSQC, and HMBC techniques were used to secure the structural assignments. The new trisazo dye (compound 7 along with precursors 3, 4, and 6 was screened by microdilution susceptibility assay for antibacterial and antifungal activities towards eight bacterial strains and three yeasts selected on the basis of their relevance as human pathogens. The results showed that compound 7 (MIC = 2–128 μg/mL was the most active as compared with its precursors. The most resistant microorganisms were V. cholerae NB2 and V. cholerae SG24, whereas the most sensitive microorganism was C. neoformans. The overall results of this study indicated that compound 7 had the greatest potential value against both yeasts and multidrug-resistant bacteria, so further investigation is warranted.

Investigation of the lasing of dyes under copper vapor laser irradiation

Energy Technology Data Exchange (ETDEWEB)

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

1980-10-01

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

Specific interactions within micelle microenvironment in different charged dye/surfa

Directory of Open Access Journals (Sweden)

Adina Roxana Petcu

2016-01-01

Full Text Available The interactions of two ionic dyes, Crystal Violet and Methyl Orange, with different charged surfactants and also with a nonionic surfactant were investigated using surface tension measurements and visible spectroscopy in pre-micellar and post-micellar regions. It was found that for the water dominant phase systems the dye was localized between the polar heads, at the exterior of the direct micelle shells for all the systems. For the oil dominant phase systems, in case of the same charged dye/surfactant couples, the dye was localized in the micelle shell between the hydrocarbon chain of the surfactant nearby the hydrophilic head groups while for nonionic surfactant and oppositely charged dye/surfactant, localization of dye was between the oxyethylenic head groups towards the interior of the micelle core. Mixed aggregates of the dye and surfactant (below the critical micellar concentration of cationic surfactant, dye-surfactant ion pair and surfactant-micelles were present. The values of equilibrium constants (for TX-114/MO and TX-114/CV systems were 0.97 and 0.98, respectively, partition coefficients between the micellar and bulk water phases and standard free energy (for the nonionic systems were −12.59 kJ/mol for MO and −10.97 kJ/mol for CV were calculated for all the studied systems. The partition processes were exothermic and occurred spontaneously.

Using Eggshell in Acid Orange 2 Dye Removal from Aqueous Solution

Directory of Open Access Journals (Sweden)

Ahmad Reza Yari

2015-05-01

Full Text Available Background and purpose: Generated dye wastewater by the textile industry is usually toxic, non-biodegradable and resistant in the environment. Eggshell is one of the inexpensive material and for the reason the vesicular structures can be used as a proper adsorbent for pollutants removal. The aim of this study is to investigate the efficiency of eggshell for removal of acid orange 2 dye from aqueous solution. Materials and Methods: In the experimental study was determined the efficacy of variant variables such as contact time (15, 30, 60, 90 and 120 min, pH (3, 7 and 11, adsorbent dose (10, 25, 50 and 75 g/L, and initial dye concentration (25, 50 and 100 mg/L. The concentration of dye by spectrophotometer ultraviolet/visible in the wavelength 483 nm was examined. Results: The results showed that with increasing contact time and adsorbent dose, the dye removal efficiency was increased, but with increasing pH and initial dye concentration the removal efficiency was decreased. The maximum of removal efficiency of acid orange 2 dye got in the optimum pH: 3, contact time: 90 min, adsorbent dose: 50 g/L and initial dye concentration: 25 mg/L. Adsorption of acid orange 2 dye (R2 = 0.87 follow the Freundlich isotherm. Conclusion: Eggshells can be used as an inexpensive and effective adsorbent for the removal of acid orange 2 dye.

Photophysical and laser characteristics of pyrromethene 567 dye ...

Indian Academy of Sciences (India)

Narrow-band laser performance of alcohol solutions of pyrromethene 567 ... curves of each dye solution were obtained by scanning the wavelength of the dye ... solutions, using ethanol and methanol solvents, are summarized in table 1.

Tunable lasers in isotope separation, a colorful view of a dye chemist

International Nuclear Information System (INIS)

Hammond, P.R.

1976-01-01

Some of the problems to be encountered in the large-scale use of dye lasers in an isotope separation plant are discussed. Why should dye lasers be employed. How can dye conversion efficiency be optimized. How can dye photochemical decomposition and hence running costs be minimized and how serious is this effect anyway. What are toxicity problems with the dye. These and similar issues are examined

Modified dynamical equation for dye doped nematic liquid crystals

Energy Technology Data Exchange (ETDEWEB)

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

2010-04-15

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

Assessment of the dye-sensitized solar cell

Energy Technology Data Exchange (ETDEWEB)

McConnell, R. D. [Center for Basic Sciences, National Renewable Energy Laboratory, MIS 3211, 1617 Cole Boulevard, Golden, CO 80401 (United States)

2002-09-01

The field of solar electricity, or photovoltaics (PV), is rich in that there are many materials and concepts for converting sunlight into electricity. The technologies accepted as conventional are those well along in the process of commercialization. The dye-sensitized solar cell, developed in the 1990s, is a nonconventional solar electric technology that has attracted much attention, perhaps a result of its record cell efficiency above 10%. This paper reviews the technology, discusses new research results and approaches presented at a recent symposium of many of the world's important dye solar cell researchers, and presents an assessment of the dye-sensitized solar cell in a comparison with current conventional solar electric technologies. It concludes the dye solar cell has potential for becoming a cost-effective means for producing electricity, capable of competing with available solar electric technologies and, eventually, with today's conventional power technologies. But it is a relatively new technology and faces many hurdles on the path to commercialization. Because of its potential, this assessment recommends further funding for research and development (RandD) of the dye-sensitized solar cell technology on the basis of the promising technical characteristics of the technology, a strong US and worldwide research base, positive industry interest, and today's relatively small funding allocation for its RandD. (Author)

Efficient dye-sensitized solar cells from mesoporous zinc oxide nanostructures sensitized by N719 dye

Science.gov (United States)

Kumara, G. R. A.; Deshapriya, U.; Ranasinghe, C. S. K.; Jayaweera, E. N.; Rajapakse, R. M. G.

2018-03-01

Dye-sensitized solar cells (DSCs) have attracted a great deal of attention due to their low-cost and high power conversion efficiencies. They usually utilize an interconnected nanoparticle layer of TiO2 as the electron transport medium. From the fundamental point of view, faster mobility of electrons in ZnO is expected to contribute to better performance in DSCs than TiO2, though the actual practical situation is quite the opposite. In this research, we addressed this problem by first applying a dense layer of ZnO on FTO followed by a mesoporous layer of interconnected ZnO nanoparticle layer, both were prepared by spray pyrolysis technique. The best cell shows a power conversion efficiency of 5.2% when the mesoporous layer thickness is 14 μm and the concentration of the N719 dye in dye coating solution is 0.3 mM, while a cell without a dense layer shows 4.2% under identical conditions. The surface concentration of dye adsorbed in the cell with a dense layer and that without a dense layer are 5.00 × 10‑7 and 3.34 × 10‑7 mol/cm2, respectively. The cell with the dense layer has an electron lifetime of 54.81 ms whereas that without the dense layer is 11.08 ms. As such, the presence of the dense layer improves DSC characteristics of ZnO-based DSCs.

Decolorization of dyes by recombinase CotA from Escherichia coli ...

African Journals Online (AJOL)

The CotA laccase could efficiently decolorize anthraquinone and azo dyes in 24 h. The decolourization capacity of this recombinant laccase suggested that it could be a useful biocatalyst for the treatment of dye-containing effluents. Key words: Recombinant CotA laccase, Escherichia coli, purification, dye decolorization.

Fabrication of Microcapsules for Dye-Doped Polymer-Dispersed Liquid Crystal-Based Smart Windows.

Science.gov (United States)

Kim, Mingyun; Park, Kyun Joo; Seok, Seunghwan; Ok, Jong Min; Jung, Hee-Tae; Choe, Jaehoon; Kim, Do Hyun

2015-08-19

A dye-doped polymer-dispersed liquid crystal (PDLC) is an attractive material for application in smart windows. Smart windows using a PDLC can be operated simply and have a high contrast ratio compared to those of other devices that employed photochromic or thermochromic material. However, in conventional dye-doped PDLC methods, dye contamination can cause problems and has a limited degree of commercialization of electric smart windows. Here, we report on an approach to resolve dye-related problems by encapsulating the dye in monodispersed capsules. By encapsulation, a fabricated dye-doped PDLC had a contrast ratio of >120 at 600 nm. This fabrication method of encapsulating the dye in a core-shell structured microcapsule in a dye-doped PDLC device provides a practical platform for dye-doped PDLC-based smart windows.

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

Science.gov (United States)

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

2018-05-17

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

Microfluidic Dye Lasers

DEFF Research Database (Denmark)

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

2006-01-01

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

Configuration of organic dye excimers in nanoporous SiO2 matrices

International Nuclear Information System (INIS)

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

2016-01-01

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

Nine cases of bladder cancer occurring in occupational dye users

OpenAIRE

村瀬, 達良; 高士, 宗久; 青田, 泰博; 下地, 敏雄; 三宅, 弘治; 三矢, 英輔

1985-01-01

Workers in the dye manufacturing industry have a high risk of urinary bladder cancer. There may also be a high relative risk of bladder cancer in occupational dye users. Nine occupational dye users were found to have bladder cancer. The period of engaging with dye work ranged from 5 to 40 years. Seven patients had bladder cancer and the other 2 patients had lesions both in the bladder and in the renal pelvis. Histopathology of all cases was transitional cell carcinoma. Three cases were classi...

Biophotovoltaics: Natural pigments in dye-sensitized solar cells

International Nuclear Information System (INIS)

Hug, Hubert; Bader, Michael; Mair, Peter; Glatzel, Thilo

2014-01-01

Highlights: • Natural pigments are photosensitizers in dye-sensitized solar cells (DSSCs). • Efficiency is still lower compared to synthetic pigments. • The use of natural pigments such as carotenoids and polyphenols is cheap. • General advantages of DSSCs are flexibility, color and transparency. • Usage under diffuse light and therefore, indoor applications are possible. - Abstract: Dye-sensitized solar cells (DSSCs) which are also called Graetzel cells are a novel type of solar cells. Their advantages are mainly low cost production, low energy payback time, flexibility, performance also at diffuse light and multicolor options. DSSCs become more and more interesting since a huge variety of dyes including also natural dyes can be used as light harvesting elements which provide the charge carriers. A wide band gap semiconductor like TiO 2 is used for charge separation and transport. Such a DSSC contains similarities to the photosynthetic apparatus. Therefore, we summarize current available knowledge on natural dyes that have been used in DSSCs which should provide reasonable light harvesting efficiency, sustainability, low cost and easy waste management. Promising natural compounds are carotenoids, polyphenols and chlorophylls

Dye shift: a neglected source of genotyping error in molecular ecology.

Science.gov (United States)

Sutton, Jolene T; Robertson, Bruce C; Jamieson, Ian G

2011-05-01

Molecular ecologists must be vigilant in detecting and accounting for genotyping error, yet potential errors stemming from dye-induced mobility shift (dye shift) may be frequently neglected and largely unknown to researchers who employ 3-primer systems with automated genotyping. When left uncorrected, dye shift can lead to mis-scoring alleles and even to falsely calling new alleles if different dyes are used to genotype the same locus in subsequent reactions. When we used four different fluorophore labels from a standard dye set to genotype the same set of loci, differences in the resulting size estimates for a single allele ranged from 2.07 bp to 3.68 bp. The strongest effects were associated with the fluorophore PET, and relative degree of dye shift was inversely related to locus size. We found little evidence in the literature that dye shift is regularly accounted for in 3-primer studies, despite knowledge of this phenomenon existing for over a decade. However, we did find some references to erroneous standard correction factors for the same set of dyes that we tested. We thus reiterate the need for strict quality control when attempting to reduce possible sources of genotyping error, and in cases where different dyes are applied to a single locus, perhaps mistakenly, we strongly discourage researchers from assuming generic correction patterns. © 2011 Blackwell Publishing Ltd.

Severe allergic hair dye reactions in 8 children

DEFF Research Database (Denmark)

Sosted, Heidi; Johansen, Jeanne Duus; Andersen, Klaus Ejner

2006-01-01

Serious adverse skin reactions to permanent hair dyes and temporary black tattoos have been reported. As temporary tattoos have become fashionable among adolescents, the risk profile for p-phenylenediamine (PPD) sensitization of the population has changed simultaneously with an increasing use...... of hair dyes in this age group. This investigation reports PPD sensitization in children with regard to cause of sensitization, clinical presentation and consequences. Clinical history and patch test results for consecutive children below 16 years of age with suspected hair dye allergic reactions...... and positive patch tests to PPD were collected over 2 years in 2 Danish dermatology clinics. 8 children aged 12-15 years were collected, and they all reacted to several hair dye ingredients. 5 of the patients were hospitalized, 1 in the intensive care unit. 6 of the patients gave a history of prior reaction...

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

Directory of Open Access Journals (Sweden)

M. I. Mohammed

2014-01-01

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

THE DYEING PROCESS OF KNITTED FABRICS AT DIFFERENT TEMPERATURES USING ULTRASOUND

Directory of Open Access Journals (Sweden)

MITIC Jelena

2014-05-01

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

Evaluation of concordance between labelling and content of 52 hair dye products: overview of the market of oxidative hair dye.

Science.gov (United States)

Antelmi, Annarita; Bruze, Magnus; Zimerson, Erik; Engfeldt, Malin; Young, Ewa; Persson, Lena; Foti, Caterina; Sörensen, Östen; Svedman, Cecilia

2017-04-01

Hair dyes contain strong allergens and are widely available. Correct labelling is a necessity in order to provide information about the contents. To compare the labelling and content of hair dyes. In total, 52 hair dyes, from 11 different countries, were bought over the counter. High-pressure liquid chromatography was used for the analysis of p-phenylenediamine (PPD), toluene-2,5-diamine (2,5-TDA), and three oxidation products of PPD. There was good agreement between labelling and content, although seven of the 52 products (13.5%) studied were incorrectly labelled. There were differences in the geographical use of PPD and 2,5-TDA; 2,5-TDA was more common in European products, while PPD was more common in products purchased outside Europe and was present in higher concentrations. All dyes purchased in Europe contained PPD and 2,5-TDA at levels within the limits defined by European legislation, however, levels were higher in some products purchased outside Europe. Only a small group of hair dyes sold in Europe were mislabelled. Further improvement in labelling, by providing the concentration of chemicals, may facilitate products to be purchased both locally and within the global market, when travelling or on the internet.

Biotreatment of anthraquinone dye Drimarene Blue K 2 RL | Siddiqui ...

African Journals Online (AJOL)

Drimarene Blue (Db) K2RL is a reactive anthraquinone dye, used extensively in textile industry, due to poor adsorbability to textile fiber; it has a higher exhaustion rate in wastewater. The dye is toxic, carcinogenic, mutagenic and resistant to degradation. Decolorization of this dye was studied in two different systems.

Column studies for biosorption of dyes from aqueous solutions on ...

African Journals Online (AJOL)

Biosorption is becoming a promising alternative to replace or supplement the present dye removal processes from dye wastewaters. Based on the results of batch studies on biosorption of the dyes on powdered fungal biomass, Aspergillus niger, an immobilised fungal biomass was used in column studies for removal of four ...

Quirks of dye nomenclature. 6. Malachite green.

Science.gov (United States)

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.

A comparative study of polymer-dye interaction

Directory of Open Access Journals (Sweden)

Nandini R.

2009-08-01

Full Text Available The interaction between an anionic dye Methyl Orange and two poly cations namely, Poly (N-vinyl-4-methylpyridiniumiodide, (PC1 & Poly (vinylbenzyltriphenylphosphoniumchloride, (PC2 has been investigated by spectrophotometric method. The polymers are observed to induce metachromasy in the dye as evidenced from the considerable blue shift in the absorption maximum of the dye. The interaction constant and thermodynamic parameters of interaction have been determined by absorbance measurements at the metachromatic band. The effect of additives such as ionic salts, alcohols, urea and polyelectrolytes on the reversal of metachromasy has been studied and used to determine the stability of the metachromatic complex and to understand the nature of binding.

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

Science.gov (United States)

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

2010-12-07