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1
Goetz, Charity. "Textile dyes techniques and their effects on the environment with a recommendation for dyers concerning the Green effect /." Lynchburg, Va. : Liberty University, 2008. http://digitalcommons.liberty.edu.
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Feldman, Roger A. "Recruitment, training and knowledge transfer in the London Dyers’ Company, 1649-1826." Thesis, London School of Economics and Political Science (University of London), 2005. http://etheses.lse.ac.uk/243/.
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This thesis studies the role of a craft guild as a training organisation. The study looks at the London Dyers’ Company binding and joining records over 150 years, available from the mid seventeenth century to the early nineteenth century. The study initially deals with transmission of knowledge from master to apprentice, a single generation. It then looks at factors associated with chains of transmission over several generations, taking advantage of available occupational specialization data. The Dyers’ Company records of membership are estimated to be at least 94 percent complete from 1710-1792, and probably similarly complete in the earlier period 1660-1710. In 1750, 93 percent and in 1792 81 percent of dyers in livery companies were members of the Dyers’ Company. In those same years, 34 percent in the livery of the Dyers’ Company were not practicing dyers. Chapters 2 and 3 describe the dynamics of the Dyers’ Company from binding and joining information. The apprentice binding data includes information about families of apprentices, their places of residence, their father’s occupation, along with what premia were paid when they were bound. Information is presented about time as a journeyman, about how many apprentices an individual master bound in a lifetime, and about women apprentices and women who bound apprentices. Scattered information about specialized dyeing occupations allowed categorisation of chains of transmission by occupation. One specialty, calico printing, potentially the most innovative of any in the dyeing trade, was not fully represented in the Dyers’ Company records. Sixty one percent of all chains were no more than three generations long. Chains involving silk dyers were more often longer than those involving dyers with no stated specialty. Long chains might either be evidence of technological conservatism, a more technically difficult craft, greater use of innovation, or increased economic activity.
3
Fuller, Ann T. "An Autecological Study of Dyers Woad (Isatis tinctoria L.) on Utah Rangeland." DigitalCommons@USU, 1985. https://digitalcommons.usu.edu/etd/6395.
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Northern Utah rangelands have become infested with dyers woad (Isatis tinctoria L.) and control is needed. Mechanical and chemical control on rangelands produce undesirable effects. A possible alternative is biological control, but information is not available on plant response to this control method. This autecological study and simulation of control methods examined dyers woad phenology, seed endurance and response to simulated grazing, hand rogueing and plowing. The phenology study documented dyers woad growth patterns from May 1982 to November 1983. During the first year, 65 percent of the seedlings died while the remaining 35 percent grew rosette leaves. During the following growing season, 50 percent of the remaining population flowered and died. The other 50 percent continued to grow rosette leaves. The seed endurance study showed seed viability remaining high and relatively stable, but germination decreased during the ten month study period. Methods used indicate future germination and viability studies should more closely simulate field conditions. The simulation of control methods involved clipping dyers woad once at three different heights to simulate grazing, hand rogueing and plowing on three different dates that correspond with the phenological stages of initial rosette growth, pre-bolting, and post-bolting. Simulated grazing stimulated plant survival and growth. Simulated plowing and hand rogueing reduced plant survival. Treatment at all three levels after initial rosette growth depressed flowering for one year. Treatment to simulate plowing and hand rogueing during initial rosette growth depressed flowering compared to the untreated controls. Treatment early in the growing season did not significantly affect plants receiving simulated grazing. Seed production was depressed by simulated plowing but was promoted by simulated hand rogueing when compared to untreated controls. The ability of plants to survive and/or flower after treatment could not be predicted from this study because a one time clipping of dyers woad did not produce significant population decreases. A more severe treatment in the form of more clippings per season is suggested for future study.
4
Farah, Kassim O. "Autecological and Grazing Control Studies of Dyers Woad (Isatis tinctoria L.) on Northern Utah Rangelands." DigitalCommons@USU, 1987. https://digitalcommons.usu.edu/etd/6448.
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Dyers woad (Isatis tinctoria L.) is a noxious weed on northern Utah rangelands. Chemical and mechanical means of control are unsuitable for rangelands. A potential alternative, biological control, is difficult due to a lack of basic ecological information. To remedy this, some aspects of the population biology and autecolgy of dyers woad were studied. The feasibility of controlling dyers woad by early spring grazing was also investigated via clipping experiments. A population study followed the survivorship of experimentally established populations over two years. Fall germinating individuals (1984) overwintered as rosettes twice and all survivors reproduced successfully. Spring germinating individuals (1985) overwintered as rosettes only once and 87% seeded the subsequent spring. Thus, on a good condition {high seral) foothill rangeland, dyers woad behaved predominantly as a biennial. Peak mortality in both fall and spring populations coincided with summer drought. The population size of dyers woad was constricted at two stages: (i) germination and establishment, and (ii) young rosette. The risk of mortality mortality in young rosettes was 77%. Dyers woad should be targeted for biological control at this vulnerable stage of growth. The seed dispersal pattern of dyers woad was best described by a negative exponential model of the type logy= a+ bx; (r = .78, a= 1.92, and b = -0.02). Ninety-five percent of a11 fruits were deposited within 54cm of mother plants. The root system of dyers woad was predominantly a taproot with some lateral sin the upper 30cm of the soil. There was little difference between mapped taproot and total mapped root lengths of rosette and mature plants. Significant mortality and reduction in reproductive performance occurred only by clipping, on or after 23 May 1984, at 60% or 90% intensity. Clipping twice, at either intensity, before 23 May had no effect on dyers woad. Sheep utilization of dyers woad ceased after mid-May, and had no significant effect on its mortality, percent flowering, and fruit production. Sheep grazing on dyers woad did not occur when much impact on mortality or seed production could be expected. The stocking re qui red to restrict dyers woad will result in range deterioration. More host-specific biological control agents should be tried.
5
Spencer, Richard. "The Joint Dyers' Movement : labour and industrial relations in the Lancashire and Yorkshire textile finishing industries 1918-1936." Thesis, Manchester Metropolitan University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251288.
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Owoeye, Omotato Idowu Oke. "Textiles texts and symbols : women dyers and symbols in the Indigo textile dyeing production process in Osogbo Nigeria." Thesis, University of Pretoria, 2017. http://hdl.handle.net/2263/62653.
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Despite the emergence of narrative and humanistic anthropological perspectives on thriving indigenous textile technologies, indigo dyed textile products are often read as homogenous products, devoid of Yoruba women-dyers' symbolic narratives. This ethnographic research on indigo textile dyeing in Osogbo examines the relationship between textile production and ritual by focusing on how indigenous peoples are stimulated to create what they make and the textile makers' unit of expression. A key argument throughout the thesis is that the dyeing act is a ritual performance by women dyers in Osogbo a re-enacted symbolic performance of the formation and evolution of human sociality and the socialization of human beings. It is also a symbolic representation of motherhood (parenthood when it comes to the societal level) a process of inscribing the kadara (destiny) of a child and the development of iwa (character) and ewa (beauty) to be an omoluabi (good and cultured child) in Yoruba ontology. The thesis also explores alkaline water production processes as part of the indigenous indigo textile dyeing processes and the use of adire textile for communication in Osogbo the notions of colour and colour symbolism and the use of texts, proverbs and images on dyed textiles as communicative tools specifically to show the transformatory nature of rituals in indigo textile dyeing.Thesis (DPhil)--University of Pretoria, 2017.
Anthropology and Archaeology
DPhil
Unrestricted
7
Farooq, Salma. "The determination of dyers' perceived components of colour difference (depth, brightness and hue) between two similar colours from their spectral reflectance values." Thesis, Heriot-Watt University, 2011. http://hdl.handle.net/10399/2443.
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An algorithm, called the WSF algorithm, was developed which could predict the dyers‟ attributes of colour difference (depth, ΔD, brightness, ΔB, and hue, ΔH*) from the reflectance values of a pair of dyeings, enabling the dyer to take full advantage of colorimetric analysis. The algorithm was based on extensive experimental work to map surfaces of constant visual depth throughout the colour space and the thesis describes the methodology and the necessary calculations to determine the ΔD, ΔB and ΔH values of a pair of dyed samples. This algorithm was compared to other existing algorithms (the DBH and the Sato models) using two data sets with 49 dyed pairs for data set 1 and 117 dyed pairs for data set 2 respectively. The correlation of the values of ΔD, ΔB and ΔH determined using the WSF algorithm with the DBH and the Sato models showed an excellent relationship between these three algorithms for both the data sets. Qualitative comparison of the visual assessments of data set 2 with the WSF algorithm was encouraging but the quantitative comparison of the visual assessment for data set 1 was disappointing. The pre-requisite of the WSF algorithm is the six equi-depth surfaces which have been defined numerically in the CIELAB colour space and previously reported as WSI depth surfaces. The first stage of this algorithm was to generate, using the WSI algorithm, the equi-depth line in the L* C* plane that passes through the L* C* coordinates of the standard. The K/S values of the batch were then iterated, until its depth became equal to that of the standard. At this point, the precise location of the batch on the equi-depth surface might be different from that of the standard. The linear distances between the batch and the standard, gave the differences in depth and brightness between the standard and the batch. A new approach was investigated for the hue correction of dyed pairs, where the hue of the batch was different from that of the standard. Real data of highest possible chroma values from Munsell colour atlas were used to create maximum chroma boundaries which were found necessary for the hue correction of the batch. It was noted that the DBH and the Sato models also incorporated hue correction of the batch. The WSF algorithm described in Chapter 4 contained an iterative stage which created an additional complexity in programming. Therefore an alternative version of the WSF algorithm was developed, called the linear WSF model, which avoided the need for iteration and yielded the same results. This linear WSF algorithm strongly correlated with the WSF (iterative) model and also to other empirical models as well.
8
Williamson, Patricia Catherine. "Squaraine dyes." Thesis, Cranfield University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323902.
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Burton, S. J. "Biomimetic anthraquinone dyes." Thesis, University of Cambridge, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383771.
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Leontyev, Alexey E. "Carbazole-Fluorenone Dyes." Bowling Green State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1245273099.
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Xue, Yulin. "Some new reactive dyes." Thesis, University of Kent, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333964.
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Bello, K. A. "Near-infrared absorbing dyes." Thesis, University of Leeds, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375504.
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13
Vohra, A. A. "Nickel chelates as dyes." Thesis, University of Manchester, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.601469.
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The chelates of seven commercial disperse dyes with nickel, copper and chromium have been formed in cotton and in nylon 6 fabrics. Exhaustion dyeing was satisfactory on nylon 6 and subsequent treatment in the metal salt solution at optimum pH was followed by steaming. The cotton was pretreated with a urea/melamine precondensate with glyoxal formaldehyde, and a polyethylene glycol. Dye was introduced by vapor-transfer from coated paper. Chelation was achieved in a final step. The hue and brightness, fastness to Light, washing and perspiration were assessed for the dyed fabrics. The nickel complexes were in general found to be slightly better than the chromium and copper complexes. Photodegeration of the fibres was reduced by the presence of the nickel complexes. Average stabilisation of nylon 6 was found to be 43% and that of cotton 23%. It may be possible to use selected nickel chelates as dyes that stabilise photodegradabLe fibres. The amount of nickel reacting with the dyed cotton fabric was determined by employing atomic absorption spectroscopy.
14
Beydilli, Mumtaz Inan. "Reductive biotransformation and decolorization of reactive azo dyes." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/21451.
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Matthews, Rosalyn D. "Transformation and decolorization of reactive phthalocyanine." Diss., Available online, Georgia Institute of Technology, 2004:, 2003. http://etd.gatech.edu/theses/available/etd-04062004-164728/unrestricted/matthews%5Frosalyn%5Fd%5F200312%5Fphd.pdf.
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Thesis (Ph. D.)--School of Civil and Environmental Engineering, Georgia Institute of Technology, 2004. Directed by Spyros G. Pavlostathis.Vita. Includes bibliographical references (leaves 381-393).
16
Haleem, Asad Bilal. "Crosslinking nucleophilic dyes on cotton." Thesis, University of Leeds, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250890.
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Velykodna, V. V. "Dissociative state of polymethine dyes." Thesis, Сумський державний університет, 2014. http://essuir.sumdu.edu.ua/handle/123456789/34957.
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Relaxation of molecules can occur not only through the direct transitions to S1 and T1 state, but also through such channels. Polymethine dyes and its derivatives are attractive for their interesting optical and photoelectric properties. They are used as very efficient spectral sensitizers and laser dyes.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/34957
18
Corns, Stephen Nigel. "Novel near-infrared absorbing dyes." Thesis, University of Leeds, 1990. http://etheses.whiterose.ac.uk/981/.
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New near-infrared absorbing donor-acceptor chromophores have been investigated by varying the electron donating and accepting strength of the two halves of the molecule within wide limits. The dihydroperimidine, perimidine, Michler's ethylene and 1-decyl-2(1H)- methyl-benz[c, d]indolium iodide residues were examined as donor residues, and these were coupled to 4-nitrobenzenediazonium chloride to give monoazo dyes. The λmax values of these gave a qualitative indication of relative electron donor strengths, and the 1-ethyl-2-methylperimidine azo dyes proved to be the most bathochromic, being blue in colour. The dyes were amongst the most bathochromic monoazo dyes yet prepared containing the 4-nitrophenylazo residue. The N-alkyl-3-cyano-6-hydroxy-4-methyl-2-pyridone system was investigated as a potentially powerful electron acceptor system, and the 5-formyl and 5-nitroso derivatives were condensed with Michler's ethylene and 1-decyl-2(1H)-methyl-benz[c, d]indolium iodide to give new donor-acceptor dyes. The aza dyes prepared from the nitroso compounds proved to be the most bathochromic in accord with PMO theory and many were near-infrared absorbing. A series of near-infrared absorbing squarylium dyes with narrow, intense absorption bands at about 800nm were obtained by reacting squaric acid with 2,2-disubstituted dihydroperimidines. The first dyes of this type possessed poor organic solvent solubilities but, through modification of the 2,2-substituents of the dihydroperimidines it was possible to obtain squarylium dyes with good organic solvent solubility, this being a much sought after property of infrared dyes. Other squarylium dyes were obtained by the reaction of squaric acid with 1-ethyl-2-methylperimidine, Michler's ethylene and 1-decyl-2(1H)-methyl-benz[c, djindolium iodide. The latter two dyes absorbed in the infrared region at 809 and 900nm respectively in toluene. A modified procedure for the synthesis of croconic acid was developed, which enables the acid to be obtained in the anhydrous form readily. Reaction of croconic acid with 3-hydroxy-N, N-dialkylanilines afforded highly bathochromic dyes (λ max ca. 830nm). Reaction with 1- decyl-2(1H)-methyl benz[c, d]indolium iodide gave a croconium dye that absorbed beyond 1000nm. The reaction of 8-hydroxyjulolidine with croconic acid was particularly interesting as it occurred readily at room temperature. Thus it was possible to undertake a kinetic study of mechanistic aspects of the condensation reaction between croconic acid and arylamines. The results indicated that the optimum reaction conditions involved using a low proportion of an alcohol in a nonpolar aprotic solvent in the presence of a weak acid catalyst. Dyes were also obtained from the reaction of various electrophilic chlorine-substituted compounds with electron-donor aromatic residues, thus giving new donor-acceptor dyes, several of which were nearinfrared absorbing with low molecular masses and good organic solvent solubilities. The dyes were, however, strongly coloured due to their broad absorption bands which extended well into the visible region. The thermal and photochemical stabilities of representative examples of all the infrared dye classes prepared in this work have been examined, using standard procedures.
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Carswell, Stewart. "Microanalysis of dyes from textiles." Thesis, Queensland University of Technology, 1991. https://eprints.qut.edu.au/35972/1/35972_Carswell_1991.pdf.
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The discrimination and/or matching of dye extracts is an important aspect of forensic investigations involving textile samples. The aim of this work was to study the use of Fourier transform infrared spectrometry and diffuse reflectance to obtain IR spectra of dye samples, and the subsequent analysis of these spectra using library searching and principle component analysis.
The work in this thesis has demonstrated the development of a simple method for obtaining DRIFT spectra of dye samples. Library searching and principle component analysis were used to distinguish between many types of dye samples, including extracts that were not distinguished using TLC.
20
Ip, Wui Man. "Enhanced biodegradation and adsorption for treating dye-containing effluents /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?BIEN%202009%20IP.
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Ferraro, Luca. "Physisorption of perylene dyes on graphite." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/13851/.
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This thesis work was carried out at CNR of Bologna. CNR- ISOF (Institute of Organic Synthesis and Photoreactivity) in the group of Dr. Vincenzo Palermo. The aim of this thesis was to perform a comparative and quantitative study on the interaction of three different PDI (perylene diimide) dyes with graphene (G) sheets in solution, using a phenomena called “dye’s capturing”. The only difference between the PDI dyes tested was the terminal atom in the side groups. In particular, we used a perylene core with side ethyl-phenyl group exposing in the para position a hydrogen (PDI-H), fluorine (PDI-F), or chlorine atom (PDI-Cl). Although the relative simplicity of the process and the measurement itself, the preparation of a reliable experimental setup is not trivial and several issues had to be taken into account.
The main challenges to be overcame were related to the effective stability and reliability of the chemical systems, such as dyes, solution and graphite during the entire exposure time. For this reasons the work addressed the following issues: 1)Studying the interaction of small organic molecules and graphite flakes, using commercial products. 2)Finding the best conditions for the dye capturing process (concentration, stabilization of the solution, solvent etc.).3)Understanding of the “dye’s capturing” phenomena by UV-VIS and fluorescence techniques.
4)Stabilizing a relationship between the chemical structure of PDI-X (with side chains symmetrically terminated with a different atom) and the interaction with graphite, taking into account adsorption speed, packing, etc. 5)After testing the samples, the reported results were used to: 1) Determinate the best suitable molecule for the dye capturing process, and optimize a hypothetical industrial process by calculating the surface area for each molecule.
6)Morphology and structural characterizations with different technique like: AFM, SEM, EDX, XRD, fluorescence microscopy, TGA/DSC, IR.
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Knutson, Kristina Parks. "Enzymatic Biobleaching of Recalcitrant Paper Dyes." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/7959.
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Modern manufacturing processes assume efficient utilization and recycling of
natural resources whenever possible. Over the past decade paper recycling has progressed
from 33.5% in 1990 to just above 48% in 2002.1 Indeed, for certain select grades,
(newspaper and old corrugated containers) greater than 70% is currently being recycled.
In contrast, mixed office waste and colored directory papers are often underutilized. A
major difficulty in recycling these grades of paper is the problems associated with
decolorizing the dyes present in the paper.2 Of the commonly used paper dyes, the
stilbene dye Direct Yellow 113 and methine dye Basazol 46L are notorious4 for poor
bleachability with the commonly used chemical bleaching agents including chlorine
dioxide, oxygen, hydrogen peroxide and sodium dithionite.
The ability of white-rot fungi to decolorize colored effluents containing textile
dyes is currently the subject of intensive research efforts. The secreted enzymes involved
in dye decolorization include manganese peroxidase, lignin peroxidase and laccase.
Laccase, a lignolytic enzyme, has also been studied for many years for the biobleaching
of wood pulps. The ability of laccase to delignify pulp is greatly enhanced by the addition
of small molecule mediators such as 2-2´ azinobis (3-ethylbenzthiazoline-6-sulfonate)
(ABTS) and 1-hydroxybenzotriazole (HBT).
This research project focused on applying laccase combined with a mediator to
decolorize C.I. Direct Yellow 11 and Basazol 46L. Three mediators were tested: ABTS,
HBT and violuric acid. Laccase/ABTS was most effective with 60% of the color being
removed. The level of color removal was maintained at 60% even when ABTS
concentration was lowered from 5 mM to 0.01 mM. When laccase/1 mM ABTS was
applied to Direct Yellow 11 in solution, the majority of color loss occurred within 60
minutes.
The ability of soybean (SBP) and horseradish (HRP) peroxidases and laccase to
decolorize Direct Yellow 11 and Basazol 46L in solution was also examined. The results
demonstrated that these two recalcitrant dyes could be effectively decolorized by
enzymatic treatments by horseradish peroxidase, soybean peroxidase, and laccase with
ABTS as mediator. SBP is effective from pH 4.5 to 8.5. The stilbene dye Direct Yellow
11 responded to both SBP and laccase/ABTS. For the methine dye Basazol 46L, SBP was
a more effective treatment than HRP or laccase/ABTS. Basazol 46L responded quickly to
SBP treatment with 74% reduction in signal intensity within 5 minutes.
To evaluate the effectiveness of laccase/ABTS treatment, pulp dyed with Direct
Yellow 11 and three commercial colored pulps were subjected to seven different
bleaching treatments. These treatments consisted of 1)laccase/ABTS; 2)laccase/ABTS
followed by alkaline extraction; 3)laccase/ABTS followed by bleaching with sodium
dithionite; 4)oxygen bleaching; 5)oxygen bleaching followed by dithionite treatment;
6)alkaline hydrogen peroxide bleaching; and 7)alkaline peroxide bleaching followed by
dithionite treatment. The best results were obtained by including reductive bleaching with
sodium dithionite. For Direct Yellow 11 dyed pulp, laccase/ABTS followed by dithionite
yield comparable reduction in color to oxygen or peroxide followed by dithionite.
23
Unsworth, Christine. "The chemistry of some triphenylmethane dyes." Thesis, University of Central Lancashire, 1991. http://clok.uclan.ac.uk/19774/.
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A comprehensive series of Pyrrole Green dyes containing substituents in the 2-, 3- and 4-positions of the phenyl ring have been synthesised from the relevant carbinols. The steric and electronic effects of the substituents on the visible absorption spectra of the dyes have been examined and linear correlations between A max and appropriate Hammett substituent constants have been established. The rates of hydrolysis of the 4-diethylamino substituted analogue of Pyrrole Green and some 4 1 ,4 11 -bis(N-ethyl-N- 2,2, 2-trifluoroethyl)aminotriphenylmethyl dyes have been studied under a range of different reaction conditions. A stopped-flow technique was used for the study of the fast reactions involved with these dyes. The results from the spectral investigation and the kinetic work indicate that the Pyrrole Green dye series is relatively unstable compared to other related dyes and the reasons for this behaviour are discussed. Pyrrole, pyrrolidine and diethylamino groups have been incorporated into the 2-, 3- and 4-positions of the phenyl ring of Brilliant Green. Spectral characteristics and kinetic data have been examined for the dyes and relevant substituent constants interpolated. The results are discussed in relation to the steric and electronic effects of the heterocyclic moieties. The rate data obtained for each dye studied have been used to derive thermodynamic activation parameters and to test the applicability of an isokinetic relationship in the systems. A novel reaction pathway for the synthesis of pyrroloindoles from 2-pyrrol-l-yl substituted dyes is advanced.
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Jansen, Lisinka M. G. "Photochemistry and photophysics of azo dyes." Thesis, Loughborough University, 1997. https://dspace.lboro.ac.uk/2134/28271.
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The photodegradation of azo dyes in solution and on cotton has been investigated. This is a major problem, because of the widespread use of this class of dyes to dye cotton. The photochemical pathways leading to photo degradation and the properties of the excited states and photophysical deactivation processes were studied. Many of the commercially used azo dyes are 1-aryl-2-naphthols with one or more azo groups which undergo azo-hydrazone tautomerism.
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Kolla, Suresh Babu. "Novel photochromic dyes for security marking." Thesis, University of Leeds, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.493300.
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An elegant synthesis of hitherto inaccessible naphthopyrans bearing one or more strongly electron withdrawing sulfone functions was accomplished. Key to the success of this approach was the development of the deactivating sulfone unit through the oxidation of a thioether moiety post to the Claisen propargyl ether rearrangement to form the naphthopyran.
26
Sjöqvist, Jonas. "Light interactions in flexible conjugated dyes." Doctoral thesis, Linköpings universitet, Beräkningsfysik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-109011.
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In this thesis methodological developments have been made for the description of flexible conjugated dyes in room temperature spectrum calculations. The methods in question target increased accuracy and efficiency by combining classical molecular dynamics (MD) simulations with time-dependent response theory spectrum calculations. For absorption and fluorescence spectroscopies a form of conformational averaging is used, where the final spectrum is obtained as an average of spectra calculated for geometries extracted from ground and excited state MD simulations. For infrared and Raman spectroscopies averaged spectra are calculated based on individual spectra, obtained for zero-temperature optimized molecular structures, weighted by conformational statistics from MD trajectories. Statistics for structural properties are also used in both cases to gain additional information about the systems, allowing more efficient utilization of computational resources. As it is essential that the molecular mechanics description of the system is highly accurate for methods of this nature to be effective, high quality force field parameters have been derived, describing the molecules of interest in either the MM3 or CHARMM force fields. These methods have been employed in the study of three systems. The first is a platinum(II) actylide chromophore used in optical power limiting materials, for which a ultraviolet/visible absorption spectrum has been calculated. The second is a family of molecular probes called luminescent conjugated oligothiophenes, used to detect and characterize amyloid proteins, for which both absorption and fluorescence spectra have been calculated. Finally, infrared and Raman spectra have been calculated for a group of branched oligothiophenes used in organic solar cells. In addition, solvation effects have been studied for conjugated poly\-eletrolytes in water, resulting in the development of two solvation models suitable for this class of molecules. The first uses a quantum meachanics/molecular mechanics (QM/MM) description, in which the solute mole\-cule is described using accurate quantum mechanical methods while the surrounding water molecules are described using point charges and polarizable point dipoles. The second discards the water entirely and removes the ionic groups of the solute. The QM/MM model provides highly accurate results while the cut-down model gives results of slightly lower quality but at a much reduced computational cost. Finally, a study of protein-dye interactions has been performed, with the goal of explaining changes in the luminescence properties of the LCO chromophores when in the presence of amyloid proteins. Results were less than conclusive.
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Birkett, Helen Elizabeth. "NMR studies of water-soluble dyes." Thesis, Durham University, 2000. http://etheses.dur.ac.uk/4286/.
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Solution- and solid-state Nuclear Magnetic Resonance Spectroscopy (NMR) have been used to investigate a series of substituted, triazinylamino azo dyes. Proton, (^13)C and (^15)N solution-state spectra have been assigned using a variety of techniques and the chemical shifts are discussed. Site-exchange effects have been observed in (^1)H and (^13)C spectra for many of the dyes studied but most prominently for compound 13.The exchange effects were investigated at different temperatures below ambient, for a CD(_3)OD solution of compound 13. The bandshapes were fitted for three-site exchange and the relevant rate constants extracted. The exchange has been attributed to internal rotation of the substituents about the triazine ring. Activation parameters have been calculated: for exchange between one pair of sites H(^#) = 76 ± 8 kJ mol(^-1) and ɅS(^#) = 52 ± 27 J mol(^-1) K-(^-1) and for a second pair, H(^#) = 76 ± 4 kJ mol(^-1), S(^#) = 55 + 15 J mol(^-1) K(^-1). Direct exchange between the remaining pair of sites is negligible. Exchange involving a fourth site affects the spectra at somewhat lower temperatures, which assists in a partial assignment of the observed peaks to the rotamers. The rotations that are causing the effects observable in the NMR spectra are identified, with the help of molecular modelling investigations. Three out of the four possible energy barriers are found to be a combination of rotation and nitrogen inversion. Exploration of the energy surface shows that nitrogen inversion with rotation actually reduces the rotational energy barrier, compared to the planar rotation. The relative barrier heights can be rationalised, although their exact values are not consistent with those measured using NMR. Solid-state (^13)C spectra have also been recorded but are broad, making detailed assignment difficult. The broadness is found to be mainly due to the amorphous nature of the samples. The resolution is not vastly improved on increasing the spectrometer field and the powder X-ray diffraction exhibits only broad reflections.
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Kennerley, Vanessa M. "The microbial decolourisation of textile dyes." Thesis, Nottingham Trent University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314330.
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Nabi, Asfia. "Modified reactive dyes for cellulosic fibres." Thesis, University of Leeds, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.400880.
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Kunanandam, Suren. "Spectroscopy and photochemistry of arylazonaphtol dyes." Thesis, University of York, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.423732.
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Bennett, Philip Mark. "Two-photon dyes for biological application." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:b8cb9ce4-35eb-433c-86fc-b5df53a2e566.
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Two photon absorption (TPA) is the near simultaneous absorption of two photons of light to achieve an electronically excited state. It has led to huge advances in microscopy and microfabrication due to its quadratic dependence on the local light intensity. This thesis describes the design, synthesis and application of dyes with strong TPA properties, and as such is divided into three chapters. The first introduces the theory and measurement of TPA as well as structure-property relationships known to maximise the efficiency of TPA. The subsequent chapters present explorations of the application of these dyes in biological applications; namely two-photon uncaging and two-photon photodynamic therapy. A recurring theme in my research is the discussion and evaluation of strategies for improving the compatibility of organic macromolecules with biological systems. Uncaging is the use of photolysis to achieve a rapid increase in the local concentration of a physiologically active species via a photoremovable protecting groups. Photoremovable protecting groups are covalently attached to the physiologically active species, thus rendering it inactive. At the desired time and location, a light dose releases the molecule in its active form. There are many compounds known to uncage following photoexcitation, but there are few examples of caging groups which exhibit both strong two-photon absorption properties and highly efficient uncaging. Chapter 2 discusses the rational design of such groups through the development of a new mechanism for uncaging, in which a photoinduced electron transfer (PeT) between a two-photon-excited electron donor and an electron acceptor/release group drives the uncaging event. Photodynamic therapy (PDT) is a treatment for neoplastic disorders such as cancer in which localised cell death is induced through photoexcitation of a sensitiser. Following light absorption, the photosensitiser enters a relatively long-lived excited state which reacts with cellular oxygen to produce its highly cytotoxic singlet form. The main challenges of the field are to achieve deep penetration of light into tissue and to reduce coincident damage to unaffected tissue by light scattering during irradiation. In 2008, the Anderson group reported the development of PDT photosensitisers with highly efficient two-photon absorption as well as high singlet oxygen quantum yields. Chapter 3 discusses strategies for improving the pharmacokinetics and defining the sub-cellular localisation of these photosensitisers.
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Maskery, James Samuel. "Intramolecular hydrogen bonding in polyhydroxynaphthoquinone dyes." Thesis, Bangor University, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.664530.
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Intra- and inter-molecular hydrogen bonding greatly affects both physical and chemical properties for a wide variety of important molecules. This study focuses on intramolecular hydrogen bonding in polyhydroxy-1 ,4-naphthoquinones. The little known "bond counting rule", dictates that the global minimum will be comprised of a maximum number of highly stabilizing interactions. Hydrogen bonding was chosen for this work as the energy of the bond is typically 20-40 kJ mol-1, which is larger than computational error, allowing statistically significant energy differences between conformers to be determined. A series of interactions between neighbouring hydroxyl groups and each other, and between hydroxyl groups and neighbouring carbonyl groups were postulated. Quantification of the interaction energies was accomplished using a training set of several hundred unique isomers, allowing a quantitative bond counting rule to be developed. Harmonic vibrational spectroscopic and QTAIM analyses were performed for key interactions to aid in their characterisation as baseline, stabilising or destabilising. The effect of molecular conformation upon the wavelength and absorbance of electronic absorption spectra were also probed, highlighting the need to obtain low-energy conformations. Potential energy hypersurface (PES) for single and pairs of C-O bond rotation(s) not only indicate the presence of stationary points corresponding to maxima, minima and transition structures, but also any rotational barriers and reaction pathways for rotamer interconversion. To aid PES visualization, a set of custom Python-based tools were designed and constructed allowing creation of both graphic and haptic Web3D virtual models for teaching purposes. Increased topological perception and object manipulation were obtained using 3-D rapid prototyped models.
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Reeve, James Edward. "Functional dyes as tools for neurophysiology." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:8d8e7fa1-0f1d-4ff5-9f90-6915b15c1ad4.
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The aim of the project described in this thesis is to synthesise new functional molecules which interact with light for neurophysiological applications. In particular, I describe a family of amphiphilic porphyrins with large first hyperpolarisabilities which are used as SHG contrast agents and voltage-sensitive probes. In addition I detail a methodological microscopy tool and a novel caged form of a neuronal ion-channel antagonist. Chapter 1 introduces the key concepts underlying the use of dyes as SHG contrast agents. In particular it focuses on aspects of molecular design, covering both the amphiphilicity and nolinearity required by the target molecule. It covers quantification of the nonlinear properties of SHG stains, then surveys a number of examples which showcase the flexibility of SHG imaging as a biomedical technique. Chapter 2 describes a family of amphiphilic porphyrins with large first hyperpolarisabilities. Working from the structure-property relationships identified in Chapter 1, we fully characterise these dyes and demonstrate that they can be used in SHG imaging. We demonstrate that these molecules may also be tuned by complexation of a metal ion which can modulate their photophysical and solubility behaviour. Chapter 3 provides a description of how to determine the orientational distribution of dipolar dyes in a membrane by multiphoton microscopy. We measure the signal intensity of the dye in a model membrane system then find distributional moments which lead to the distribution itself. Chapter 4 explores whether off-axis contributions to the first hyperpolarisability tensor can significantly augment the dominant on-axis contribution from the main dipolar charge-transfer band. We synthesise and characterise a series of cis-donor cis-acceptor porphyrin compounds and explore their biophysical characteristics. Chapter 5 is the culmination of this project and after discussing method development, goes on to show how we measure the voltage sensitivity of an amphiphilic porphyrin SHG dye. We compare the archetypal porphyrin dye chromophore with three commercially available styryl dyes and demonstrate that our dye has greater sensitivity and a more rapid response. Chapter 6 describes a side project, the use of a photolabile cage to protect MK801, a neuronal ion-channel antagonist. By developing a water soluble photolabile cage using molecular design techniques, we are able to release MK801 in neurons with precise spatiotemporal control, allowing us to pinpoint the locus of two key neurophysiological processes.
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Worrall, David Robert. "Laser photolysis of photographic image dyes." Thesis, Loughborough University, 1992. https://dspace.lboro.ac.uk/2134/25247.
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Studies have been carried out investigating the photochemical and photophysical properties of pyrazolotriazole azomethine dyes. Such compounds can be used as magenta images in the subtractive colour photographic process. This work has been carried out both in dilute fluid solution and in high concentration, high viscosity systems designed to mimic the photographic product. Picosecond pump-probe laser flash photolysis studies have provided the first observation of photoinduced transient absorption changes attributable to the excited states of this class of dyes, and have allowed assignment of the excited singlet state lifetime as being in the range 1 to 3ps at room temperature, with little dependence upon solvent properties or the pattern of substituents on the dye skeleton. Using picosecond laser flash photolysis it has also been possible to observe evolution of the population along the ground state potential surface to the two isomeric forms, the rate of this process showing some solvent dependence. Nanosecond and picosecond laser flash photolysis studies have been used to investigate the process of syn-anti and anti-syn isomerisation about the azomethine linkage. The syn-anti photoisomerisation occurs on picosecond timescales, the anti isomer so produced relaxing thermally back to the syn form on timescales ranging from microseconds to milliseconds. The rate constant for this process is a complex function of solvent properties as well as being dependent upon steric factors within the molecule, and the reasons for this are discussed. Triplet energy sensitisation studies have demonstrated that a pathway exists for this isomerisation process via the triplet manifold, and has allowed determination of minimum isomerisation quantum yields from the triplet state. Such studies have also allowed estimation of limits for the molar decadic absorption coefficients of the anti isomer. The photographic product dyes have been demonstrated to be efficient quenchers of singlet molecular oxygen, the quenching mechanism being predominantly physical in nature. The quantum yields of singlet oxygen production are too small to be measured using time resolved techniques. These factors are used to explain in part the resistance of such compounds to oxidative photodegradation. Steady state irradiation of azomethine dyes in systems designed to simulate the photographic product by a high intensity source of known spectral profile has allowed determination of the quantum yields of photodegradation, which in combination with the results obtained in fluid solution provide a basis for explaining the behaviour of image dyes in the photographic product environment.
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Sjöqvist, Jonas. "Luminescence properties of flexible conjugated dyes." Licentiate thesis, Linköpings universitet, Beräkningsfysik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-75191.
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In this licentiate thesis the luminescence properties of two flexible conjugated dyes have been studied. The first, Pt1, is a platinum(II) acetylide chromophore used in optical power limiting materials. The second is a set of optical probes known as luminescent conjugated oligothiophenes (LCOs), which are used to detect and characterize the protein structures associated with amyloid diseases such as Alzheimer’s disease. MM3 and CHARMM force field parameters have been derived for the Pt1 chromophore and LCOs, respectively, based on potential energy surface references calculated at the density functional theory (DFT)/B3LYP level of theory. The parameters have been used to perform room temperature molecular dynamics simulations of the chromophores in solvent, where tetrahydrofuran was used for Pt1 and water for the LCOs. Conformationally averaged absorption spectra were obtained, based on response theory calculations at the time-dependent DFT(TDDFT)/CAM-B3LYP level of theory for a selection of structures from the simulations. For one of the LCOs, p-HTAA, force field parameters were also created describing the dominant first excited state, based on TDDFT/B3LYP reference potential energy surfaces. These were used for molecular dynamics simulations of the chromophore in the excited state, allowing the creation of an emission spectrum. A theoretically obtained Stokes shift of 112 nm could be computed based on the absorption and emission spectra, which is in good agreement with the experimental value of 124 nm. In addition, a quantum mechanics/molecular mechanics study of the effects of solvation on the absorption properties of the p-HTAA chromophore in water has been conducted, resulting in two models for including these effects in the averaged spectra. The first includes explicit water molecules in the form of point charges and polarizable dipole moments, and results in an absorption wavelength that is blueshifted by 2 nm from a high quality reference calculation. The second model involves the complete removal of the solvent as well as the ionic groups of the chromophore. The resulting absorption wavelength is blueshifted by an additional 4 nm as compared to the first model, but requires only one fifth of the computational resources.
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Bu, Lulu. "Synthesis of NIR Dyes and Nanoparticles for in vivo Bioimaging and Dicyanovinyl Dyes for Primary Amine Detection." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEN086.
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L’imagerie de fluorescence et l'imagerie photo-acoustique (PA) sont deux outils puissants pour la visualisation des tissus et organes biologiques de manière non invasive. Toutefois, ces technologies sont actuellement limitées par le manque d'agents de contraste efficaces. Utiliser des longueurs d’onde de domaine du proche infrarouge (NIR, 650-900 nm), dont l'absorption et la diffusion dans les organismes est relativement faible, permet une imagerie in vivo plus profonde, induit moins d’auto-fluorescence et apporte un bon rapport signal/bruit. Par conséquent, la conception et la synthèse de nouveaux colorants organiques NIR efficaces revêt une importance fondamentale pour l’imagerie de fluorescence ou photo-acoustique. L'encapsulation de colorants organiques dans des nanoparticules dispersibles dans l'eau présente un grand potentiel en imagerie bio-optique, offrant les avantages d'une haute luminosité, d'une bonne photo-stabilité, d'une excellente biocompatibilité et d'une capacité potentielle de ciblage, etc. Notre objectif principal dans cette thèse est de synthétiser de nouvelles molécules organiques pouvant servir d’agents de contraste pour l'imagerie in vivo par fluorescence ou PAFluorescence and photoacoustic (PA) imaging are both powerful tools for visualization of biological tissues and organs in non-invasive ways. However, these technologies are limited by the lack of efficient contrast agents. NIR light (650-900 nm) with relatively low absorption and scattering in organisms allows for deeper in vivo imaging, lower auto-fluorescence as well as a good signal to noise ratio. Hence, design and synthesis of efficient NIR organic dyes are of great significance for fluorescence or PA bio-imaging. Meanwhile, encapsulation of organic dyes in nanoparticles dispersible in water present great potential in bio-optical imaging, offering the advantages of high brightness, good photo-stability, excellent biocompatibility and potential targeting ability, etc. Our main goal in this thesis is to synthesize novel organic contrast agents for in vivo fluorescence or PA imaging
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Mcclure, Kathryn Raeburn. "Development of new extraction methods for analysis of natural and synthetic organic colourants from historical and artistic matrices." Master's thesis, Universidade de Évora, 2020. http://hdl.handle.net/10174/29168.
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Abstract:
In this thesis, an innovative approach for the extraction and clean-up of natural and synthetic
textile dyes based on a recently developed ammonia extraction protocol and a novel
Dispersive Liquid-Liquid Microextraction (DLLME) is presented. The thesis builds upon recent
research highlighting the benefits of the ammonia-based extraction protocol for efficient
extraction and preservation of the glycosyl moieties present in some types of natural dyes.
This state-of-the-art extraction technique requires the use of a clean-up step to purify and preconcentrate the dye molecules for analysis. This clean-up step has never before been
investigated or developed, and current methods rely upon traditional Liquid-Liquid Extractions
(LLE), which are not well suited to the very small quantities of materials available for the
analysis of artefacts of cultural heritage. The novel DLLME protocol presented by this thesis
was developed in order to improve the recovery of natural dyes for analysis, and is also the
first clean-up protocol to be developed for the analysis of synthetic textile dyes from cultural
heritage matrices. Whilst a clean-up system has never before been applied to synthetic dyes
within cultural heritage, pre-concentration and pre-treatment protocols are frequently reported
for analysis of the same type of dyes used in food colourants. For this reason, this research
adapts a DLLME method from the analysis of edible products, and combines this with the
state-of-the-art ammonia extraction method reported in literature. DLLME protocols for both
natural and synthetic dyes were developed and optimised first on known analytical standards,
considered representative of the possible structures of natural dyes and synthetic azoic acid
dyes respectively. The extraction recoveries of a variety of disperser and extraction solvents
were analysed using HPLC coupled with targeted mass spectrometry. The optimised
conditions were then coupled with the ammonia based extraction to ensure coherence of the
methods. The results showed significant improvements in the recovery of natural dye analytes
compared to current methods, as well as increased precision and efficiency. For synthetic
dyes, results showed adequate recovery of analytes and allowed the ammonia-based
extraction method to be applied successfully for the first time. After optimisation, the protocol
for synthetic dyes was applied successfully to 15 samples (11 fibres, 4 powders) of suspected
azo dyes from the Azienda Coloranti Nazionali e Affini (ACNA) synthetic dye collection housed
at Sapienza University of Rome’s Museum of Chemistry. The novel protocol was performed
after preliminary Raman screening to obtain some introductory information about the unknown
samples in the collection. After application of the novel protocol, the samples were identified
through untargeted analysis by HPLC-HRMS.
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Bisht, R. "NIR active squaraine dyes for dye-sensitized solar cells: modulating aggregation, orientation and electronic properties of the dyes." Thesis(Ph.D.), CSIR-National Chemical Laboratory, 2018. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/4349.
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Squaraine dyes are a subclass of polymethine dyes, which owing to its low band gap and strong absorption (ε >105 M−1 cm−1) in the far-red and NIR region have found application in dye-sensitized solar cells. While the squaraine dyes have excellent absorption in the far-red region, the exciton quenching by aggregation limits its overall performance in dye-sensitized solar cells. The aggregates form when the dipoles of the molecules interact with each other due to pi-pi interaction. When a molecule absorbs light and reaches excited state, the photoexcited electron in the LUMO state hops between the neighboring molecules instead of injecting electron in the metal oxide semiconductor. Thus aggregation may hamper the efficiency of DSSC by quenching the exciton which leads to low electron injection on TiO2. Thus it is desirable to have such a design for dyes which can help in controlling aggregation and promote charge injection efficiency in squaraine dyes. It is also beneficial to shift the absorption of squaraine dyes further towards NIR to utilize maximum available photons. It can be achieved by extension of conjugation which can be done either towards the anchoring end or the non-anchoring end.
Hence, we designed and synthesized squaraines based dye for DSSC with focus on modulating electronic and steric properties of dyes to enhance absorption in NIR region and avoid aggregation on TiO2 surface respectively. To achieve this, we used moieties like benzodithiophene (BDT), fused fluorenylindolenine and fused indenoquinalidne to enhance absorption and also several in-plane and out-of-the plane alkyl chains were integrated to control aggregation.AcSIR
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Millan, Michael John. "The attachment of dyes to amino acids /." Title page, contents and abstract only, 1996. http://web4.library.adelaide.edu.au/theses/09PH/09phm6448.pdf.
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Patel, Dinesh G. "Organic dyes for photoswitching and photovoltaic applications /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/8537.
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Gragg, Jamie Loretta. "Synthesis of Near-Infrared Heptamethine Cyanine Dyes." Digital Archive @ GSU, 2010. http://digitalarchive.gsu.edu/chemistry_theses/28.
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Carbocyanine dyes are organic compounds containing chains of conjugated methine groups with electron-donating and electron-withdrawing substituents at the terminal heterocycles of the general formula [R1-(CH)n-R2]+X-. The synthetic methodology and optical properties of carbocyanines will be discussed. This thesis consists of two parts: (A) synthesis and optical properties of novel carbocyanine dyes substituted with various amines and the synthesis of unsymmetrical carbocyanine dyes containing monofunctional groups for bioconjugation. (B) synthesis of heptamethine carbocyanine dyes to be used for image-guided surgery. In part A, the synthesis of carbocyanine dyes functionalized with various amines and studies of their optical properties with respect to absorbance, fluorescence, quantum yield and extinction coefficient will be presented. These property studies will aid in designing efficient dyes for future biomedical applications. Part A will also include a one pot synthesis of unsymmetrical carbocyanine dyes functionalized with mono carboxylic acid chains, useful for biomolecule (i.e. proteins, amino acids, etc.) conjugation. Part B will describe the synthesis of novel carbocyanine dyes to be used for cancer image-guided surgery. Cancers are thus far incurable diseases, i.e. there are no drugs currently available to cure cancer; however, by designing a dye to visualize tumor cells will greatly increase the efficiency of cancer removal and hopefully increase the survival rate of cancer patients. The dyes reported in this thesis are superior to commercially available dyes used to visualize and identify various tumors invisible to the naked eye of surgeons with regards to biodistribution and clearance through kidney filtration.
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Gilmore, Laurie Ann. "Chlorination of synthetic dyes and synthetic brighteners." Thesis, Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/20794.
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Lam, Suk Yee. "Gain grating techniques in solid state dyes." Thesis, Imperial College London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.420431.
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Berry, R. J. "Photophysics and photochemistry of indoaniline photographic dyes." Thesis, Swansea University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.636085.
Full textAbstract:
The photophysics and photochemistry of indoaniline dyes have been investigated. Absorption and fluorescence characteristics have been studied at room and liquid nitrogen temperatures. Extinction coefficients for the dyes at room temperature were found to be between 2 - 3 x 104 mol-1 dm3 cm-1 increasing to 5 - 6 x 104 mol-1 dm3 cm-1 at 77K. Fluorescence quantum yields of ~ 4 x 10-5 have been found at room temperature, but these increase by at least a factor of one hundred at 77 K. The first excited triplet state energies have been obtained using flash photolysis energy transfer methods and values of 87 to 94 kJ mol-1 determined. Nanosecond flash photolysis gives rate constants for singlet oxygen quenching by the dyes which are close to the diffusion controlled limit. Flash excitation of benzophenone has been used to photo-reduce the dyes. The reduced forms have extinction coefficients around half the value of the parent dye, and maxima to the red of the dyes. NMR and UV/vis spectrophotometry have been used to investigate the effect of acid on the dyes. This was found to be a simple protonation reaction for which pKa values of between 2.8 and 4.4 have been determined. Using the nuclear Overhauser Effect it has been found that all of the dyes studied exist in the anti configuration in their ground state. The rate of alkaline hydrolysis of the dyes has been investigated using UV/vis spectrophotometry and HPLC. The reaction is composed of two consecutive reactions. LC-MS has identified the products of the first reaction as replacement of amide groups by simple amines. The photodegradation after intense visible light irradiation was investigated and product patterns obtained using HPLC. Identification of some of the products has been possible using LC-MS. Under nitrogen the main product is the reduced form of the dye, whereas, under oxygen, products which involve the dealkylation of the tertiary amine group dominate.
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Thorley, Karl John. "Carbocation Near-IR Dyes for Nonlinear Optics." Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.515003.
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Al-Gamdy, Ahmad H. "Adsorptive stripping voltammetric determination of reactive dyes." Thesis, Loughborough University, 2000. https://dspace.lboro.ac.uk/2134/15294.
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The present study was mainly devoted to evaluate the applicability of differential pulse adsorptive stripping voltammetry (DPAdSV) for the determination of ultra-trace concentration levels of a range of reactive dyes. The studied reactive dyes were found to adsorb effectively onto the hanging mercury drop electrode (HMDE). This applied electroanalytical method was primarily based on the nonelectrolytic accumulation (adsorption) of the analyte of interest (reactive dye), followed by a cathodic reduction scan measurement. Consequently, the adsorptive stripping voltammograms of the analysed reactive dyes exhibited several useful electrochemical signals, corresponding to the cathodic reduction of the anthraquinone, azo and halo-striazine groups.
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Thomas, David Alan. "Merocyanine dyes via carbene additions to naphthopyrans." Thesis, University of Leeds, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.396930.
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Murray, S. G. "Solution and polymer photochemistry of azo dyes." Thesis, University of Leeds, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.371437.
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Blaiberg, Joel Stacy. "Photodegradation and photostabilisation of rhodamine laser dyes." Thesis, University of Leeds, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.419955.
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Swatton, Stewart Nathan Ridgley. "Dynamic excited state properties of organic dyes." Thesis, University of Exeter, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244422.
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