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1
Hélot, Frédérique. "Les pigments minéraux". Paris 5, 1998. http://www.theses.fr/1998PA05P046.
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2
Lawani, Leonard Olu. "Characterization of the Pigment-Protein and Pigment-ester of Xanthomonas Campestris Pv. Juglandis". Thesis, North Texas State University, 1987. https://digital.library.unt.edu/ark:/67531/metadc798279/.
Testo completoAbstract (sommario):
The objectives of this project were to develop a high performance liquid chromatographic method for separating the pigment esters mixture, to determine the locations of the pigment moiety in the isolated esters using pholosiphases, and to characterize the pigment-protein complex and determine its distribution in other bacteria. Saponification of the two pigment esters 1 and 2 with aqueous KOH yielded two free pigments on TLC plates developed by two solvent systems. The fasters moving of these two free pigments co-chromatographed with the one free pigment produced from each pigment ester by phospholipase A2 treatment. This suggests that the pigment molecule is a methoxy derivative of xanthomonadin and is esterified to the 2-position of the glycerol moiety of each pigment ester. No free pigment was released from phospholipases C and D treatment of the two pigment esters, indicating that pigment is not esterified to the sorbitol or phosphate moiety of pigment esters 1 or 2.
3
Majmudar, R. N. "Lake pigments". Thesis(Ph.D.), University of Bombay, 2018. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/3679.
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4
Beauquier, Myriam. "Classification et description chimique des pigments des champignons". Paris 5, 1999. http://www.theses.fr/1999PA05P026.
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5
Beltrán, Suito Rodrigo. "Surprisingly green: copper and its pigments". Revista de Química, 2013. http://repositorio.pucp.edu.pe/index/handle/123456789/99887.
Testo completoAbstract (sommario):
El premio Ig Nobel de Química 2012 fue otorgado al ingeniero sueco Johan Petterson por explicar que el cobre era el responsable de teñir el cabello de verde a los habitantes de una pequeña población sueca. En la naturaleza existen numerosos compuestos verdes de cobre, que se usan como pigmentos, y está presente también en las hemocianinas, enzimas sanguíneas de algunos artrópodos y moluscos.The 2012 Ig Nobel Prize in Chemistry was awarded to Johan Petterson, a Swedish engineer who discovered that copper was responsible for turning hair green in a little Swedish town. Many green copper compounds used as pigments are present in nature and there are also the hemocyanins, copper-containing proteins found in the blood of some arthropods and mollusks.
6
Engel, Eva. "Tattoo pigments in skin : determination and quantitative extraction of red tattoo pigments". kostenfrei, 2007. http://www.opus-bayern.de/uni-regensburg/volltexte/2008/850/.
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7
Kirk, Christopher J. "Pigments for the 21st century". Thesis, Loughborough University, 2008. https://dspace.lboro.ac.uk/2134/12528.
Testo completoAbstract (sommario):
Materials with potential for high temperature inorganic pigment applications (e.g. ceramics) have been synthesised using solid state methods and characterised using powder X-ray and neutron diffraction, magic angle spinning NMR, Mossbauer spectroscopy, UVNis spectroscopy and colour measurement techniques. A number of compounds containing tin (H) and niobium (V) have been modified and doped with various constituents to tailor and widen the colour properties of the bright yellow parent phases. The dark yellow (L*(91.28), a*(13.74), b*(54.76)) tin niobium oxide pyrochlores have been re-characterised using neutron diffraction techniques. These materials exhibit both cation and anion disorder caused by a stereoactive lone pair on the tin (H) metal centres. Solid state NMR and Mossbauer studies have shown the presence of tin (IV) on a symmetric site within the primary phase of the pure oxide pyrochlore and methods have been investigated to minimise the tin (H) disproportion method from where the tin (IV) is derived.
8
Pegg, N. A. "Synthesis of natural fungal pigments". Thesis, University of Nottingham, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380151.
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9
Boyce, Geraldine. "Electron crystallography of organic pigments". Thesis, University of Glasgow, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340747.
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10
Ammora, Ayham Awad. "Novel polymer-based luminescent pigments". Thesis, University of Cambridge, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621865.
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11
Goodall, Rosemary Anne. "Spectroscopic studies of Maya pigments". Thesis, Queensland University of Technology, 2007. https://eprints.qut.edu.au/16958/1/Rosemary_Goodall_Thesis.pdf.
Testo completoAbstract (sommario):
The Maya of Central America developed a complex society: among their many achievements they developed a writing system, complex calendar and were prolific builders. The buildings of their large urban centres, such as Copan in Honduras, were decorated with painted stucco, moulded masks, carving and elaborate murals, using a range of coloured pigments. In this study the paints used on the buildings of Copan and some ceramic sherds have been investigated, non-destructively, using micro-Raman spectroscopy, micro-ATR infrared spectroscopy, environmental scanning electron microscopy with energy dispersive X-ray analysis (ESEM-EDX) and FTIR-ATR imaging spectroscopy. The paint samples come from four buildings and one tomb covering three time periods in the four hundred year history of Copan. The main pigment used in the red paint on these samples was identified as haematite, and the stucco as a mixture of calcite particles dispersed throughout a calcite-based lime wash stucco. The composition and physical nature of the stucco changed through time, indicating a refining of production techniques over this period. A range of minor mineral components have been identified in each of the samples including rutile, quartz, clay and carbon. The presence and proportion of these and other minerals differed in each sample, leading to unique mineral signatures for the paint from each time period.
Green and grey paints have also been identified on one of the buildings, the Rosalila Temple. The green pigment was identified as a celadonite-based green earth, and the grey pigment as a mixture of carbon and muscovite. The combination of carbon and mica to create a reflective paint is a novel finding in Maya archaeology. The high spatial resolution of the micro-FTIR-ATR spectral imaging system has been used to resolve individual particles in tomb wall paint and to identify their mineralogy from their spectra. This system has been used in combination with micro-Raman spectroscopy and ESEM-EDX mapping to characterize the paint, which was found to be a mixture of haematite and silicate particles, with minor amounts of calcite, carbon and magnetite particles, in a sub-micron haematite and calcite matrix. The blending of a high percentage of silicate particles into the haematite pigment is unique the tomb sample. The stucco in this tomb wall paint has finely ground carbon dispersed throughout the top layer providing a dark base for the paint layer. Changing paint mixtures and stucco composition were found to correlate with changes in paint processing techniques and building construction methods over the four hundred years of site occupation.
12
Goodall, Rosemary Anne. "Spectroscopic studies of Maya pigments". Queensland University of Technology, 2007. http://eprints.qut.edu.au/16958/.
Testo completoAbstract (sommario):
The Maya of Central America developed a complex society: among their many achievements they developed a writing system, complex calendar and were prolific builders. The buildings of their large urban centres, such as Copan in Honduras, were decorated with painted stucco, moulded masks, carving and elaborate murals, using a range of coloured pigments. In this study the paints used on the buildings of Copan and some ceramic sherds have been investigated, non-destructively, using micro-Raman spectroscopy, micro-ATR infrared spectroscopy, environmental scanning electron microscopy with energy dispersive X-ray analysis (ESEM-EDX) and FTIR-ATR imaging spectroscopy. The paint samples come from four buildings and one tomb covering three time periods in the four hundred year history of Copan. The main pigment used in the red paint on these samples was identified as haematite, and the stucco as a mixture of calcite particles dispersed throughout a calcite-based lime wash stucco. The composition and physical nature of the stucco changed through time, indicating a refining of production techniques over this period. A range of minor mineral components have been identified in each of the samples including rutile, quartz, clay and carbon. The presence and proportion of these and other minerals differed in each sample, leading to unique mineral signatures for the paint from each time period.
Green and grey paints have also been identified on one of the buildings, the Rosalila Temple. The green pigment was identified as a celadonite-based green earth, and the grey pigment as a mixture of carbon and muscovite. The combination of carbon and mica to create a reflective paint is a novel finding in Maya archaeology. The high spatial resolution of the micro-FTIR-ATR spectral imaging system has been used to resolve individual particles in tomb wall paint and to identify their mineralogy from their spectra. This system has been used in combination with micro-Raman spectroscopy and ESEM-EDX mapping to characterize the paint, which was found to be a mixture of haematite and silicate particles, with minor amounts of calcite, carbon and magnetite particles, in a sub-micron haematite and calcite matrix. The blending of a high percentage of silicate particles into the haematite pigment is unique the tomb sample. The stucco in this tomb wall paint has finely ground carbon dispersed throughout the top layer providing a dark base for the paint layer. Changing paint mixtures and stucco composition were found to correlate with changes in paint processing techniques and building construction methods over the four hundred years of site occupation.
13
Verger, Louisiane. "Les oxydes de chrome dans les pigments et les décors de porcelaine". Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066546/document.
Testo completoAbstract (sommario):
Les oxydes de chrome permettent d’obtenir une large variété de couleurs, conduisant à leur utilisation répandue dans les arts céramiques. À la manufacture de Sèvres, leurs propriétés colorantes ont été explorées dès la découverte du chrome à la fin du 18ème siècle. Les travaux initiés par Brongniart ont conduit à une série de 76 pigments pour porcelaine composés d’oxydes de chrome, régulièrement synthétisés au laboratoire de la manufacture. Nous avons mené une étude exhaustive de ces pigments, permettant une classification basée sur leur analyse minéralogique et mettant en évidence le rôle du Cr3+ dans ces pigments, avec l’absence de Cr6+. Le mélange de ces pigments avec un composant incolore est appliqué sur la porcelaine, et porté à haute température afin d’obtenir un émail, c’est-à-dire une couche décorative partiellement vitreuse à la surface de la porcelaine. Les pigments composés de chrome se retrouvent dans les décors verts, roses, bleu-vert, marron et noirs. Après avoir caractérisé la spéciation et l’environnement du chrome dans l’ensemble de ces pigments, cette thèse s’est concentrée sur un pigment particulier, majoritairement composé de gahnite au chrome ZnAl2O4:Cr3+. Ce type de pigment a été identifié dans une série d’œuvres produites par la manufacture, entre la fin du 19ème et le début du 20ème siècle, correspondant à la période de l’art nouveau. La solution solide complète ZnAl2-xCrxO4 a été étudiée afin de préciser l’environnement structural du chrome, montrant l’importance des seconds voisins Cr dans les variations de couleur. Au cours de la cuisson de l’émail, un mécanisme de dissolution progressive des grains de pigments a été mis en évidence, résultant de l’interaction avec le composant incolore en cours de vitrification. Notre travail montre la faible solubilité du Cr dans le verre et sa spéciation préférentielle dans les cristaux, entrainant parfois des changements de phases ou des modifications de composition le long de solutions solides lors du traitement thermique à haute température. Ces modifications ont permis de mieux comprendre l’origine de la couleur dans les décors de porcelaine ainsi que les mécanismes de formation des émauxChromium oxides are widely used in the ceramic industry because they are characterized by a large variety of colors. At the French porcelain manufacture of Sèvres, their coloring properties have been explored since the discovery of chromium at the end of the 18th century. The researches initiated by Brongniart lead to a group of 76 pigments for porcelain composed of chromium oxides, regularly synthesized at the laboratory of the manufacture. An exhaustive study was done on these pigments, which enables to propose a classification based on their mineralogical analysis and highlights the role of Cr3+ in the color of the pigments, without Cr6+. The mixture of one or two pigments and an uncolored frit is applied on the porcelain, and fired at high temperature to obtain a glaze, i.e. a partly glassy decorative layer on the top of the porcelain. Pigments composed of chromium are used to obtain green, pink, greenish-blue, brown and black glazes. This thesis focuses on a particular pigment, mainly composed of gahnite doped with chromium ZnAl2O4:Cr3+. This kind of pigment was identified in a collection of artefacts produced by the manufacture between the end of the 19th century and the beginning of the 20th century. This period corresponds to the artistic movement Art Nouveau. The solid solution ZnAl2-xCrxO4 was studied to get the structural environment of Cr, showing the role of the second neighbor Cr in the color variation. During firing of the glaze, a mechanism of gradual dissolution of the initial grains of pigments was determined, resulting of reactions with the uncolored frit. Our work shows the low solubility of Cr in glass and its preferential speciation in crystals, leading to crystalline phase changes or modifications of composition along solid solutions during the thermal treatment at high temperature. These modifications enable to understand the origin of color in porcelain glazes and the mechanism of glaze formation
14
Verger, Louisiane. "Les oxydes de chrome dans les pigments et les décors de porcelaine". Electronic Thesis or Diss., Paris 6, 2015. http://www.theses.fr/2015PA066546.
Testo completoAbstract (sommario):
Les oxydes de chrome permettent d’obtenir une large variété de couleurs, conduisant à leur utilisation répandue dans les arts céramiques. À la manufacture de Sèvres, leurs propriétés colorantes ont été explorées dès la découverte du chrome à la fin du 18ème siècle. Les travaux initiés par Brongniart ont conduit à une série de 76 pigments pour porcelaine composés d’oxydes de chrome, régulièrement synthétisés au laboratoire de la manufacture. Nous avons mené une étude exhaustive de ces pigments, permettant une classification basée sur leur analyse minéralogique et mettant en évidence le rôle du Cr3+ dans ces pigments, avec l’absence de Cr6+. Le mélange de ces pigments avec un composant incolore est appliqué sur la porcelaine, et porté à haute température afin d’obtenir un émail, c’est-à-dire une couche décorative partiellement vitreuse à la surface de la porcelaine. Les pigments composés de chrome se retrouvent dans les décors verts, roses, bleu-vert, marron et noirs. Après avoir caractérisé la spéciation et l’environnement du chrome dans l’ensemble de ces pigments, cette thèse s’est concentrée sur un pigment particulier, majoritairement composé de gahnite au chrome ZnAl2O4:Cr3+. Ce type de pigment a été identifié dans une série d’œuvres produites par la manufacture, entre la fin du 19ème et le début du 20ème siècle, correspondant à la période de l’art nouveau. La solution solide complète ZnAl2-xCrxO4 a été étudiée afin de préciser l’environnement structural du chrome, montrant l’importance des seconds voisins Cr dans les variations de couleur. Au cours de la cuisson de l’émail, un mécanisme de dissolution progressive des grains de pigments a été mis en évidence, résultant de l’interaction avec le composant incolore en cours de vitrification. Notre travail montre la faible solubilité du Cr dans le verre et sa spéciation préférentielle dans les cristaux, entrainant parfois des changements de phases ou des modifications de composition le long de solutions solides lors du traitement thermique à haute température. Ces modifications ont permis de mieux comprendre l’origine de la couleur dans les décors de porcelaine ainsi que les mécanismes de formation des émauxChromium oxides are widely used in the ceramic industry because they are characterized by a large variety of colors. At the French porcelain manufacture of Sèvres, their coloring properties have been explored since the discovery of chromium at the end of the 18th century. The researches initiated by Brongniart lead to a group of 76 pigments for porcelain composed of chromium oxides, regularly synthesized at the laboratory of the manufacture. An exhaustive study was done on these pigments, which enables to propose a classification based on their mineralogical analysis and highlights the role of Cr3+ in the color of the pigments, without Cr6+. The mixture of one or two pigments and an uncolored frit is applied on the porcelain, and fired at high temperature to obtain a glaze, i.e. a partly glassy decorative layer on the top of the porcelain. Pigments composed of chromium are used to obtain green, pink, greenish-blue, brown and black glazes. This thesis focuses on a particular pigment, mainly composed of gahnite doped with chromium ZnAl2O4:Cr3+. This kind of pigment was identified in a collection of artefacts produced by the manufacture between the end of the 19th century and the beginning of the 20th century. This period corresponds to the artistic movement Art Nouveau. The solid solution ZnAl2-xCrxO4 was studied to get the structural environment of Cr, showing the role of the second neighbor Cr in the color variation. During firing of the glaze, a mechanism of gradual dissolution of the initial grains of pigments was determined, resulting of reactions with the uncolored frit. Our work shows the low solubility of Cr in glass and its preferential speciation in crystals, leading to crystalline phase changes or modifications of composition along solid solutions during the thermal treatment at high temperature. These modifications enable to understand the origin of color in porcelain glazes and the mechanism of glaze formation
15
SANTOS, João Antonio Belmino dos. "Análise comparativa entre técnicas de processamentos para extração de pigmentos nas sementes de urucum". Universidade Federal de Campina Grande, 2007. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/1809.
Testo completoAbstract (sommario):
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O urucuzeiro (Bixa orellana L) é um arbusto que predomina nas regiões da América Tropical em particular no Brasil, que detém a maior produção mundial. Os pigmentos das sementes do urucum são mais consumidos como pigmento natural e são constituídos basicamente de bixina, com cerca de 80 %, e a norbixina, em menor concentração. O corante obtido através da semente de urucum apresenta-se, para uso industrial, nas formas líquida, pasta ou em pó; entretanto, para a sua industrialização, é imprescindível o conhecimento tecnológico que permita a obtenção de corantes a baixo custo e com qualidade aceitável, tornando o produto capaz de competir no mercado internacional. A otimização de um processo de extração é de fundamental importância e visa não só aumentar o rendimento, mas também, minimizar a contaminação com subprodutos de decomposição. O desenvolvimento de tecnologia que conduza não apenas extração do pigmento bruto, mas principalmente que leve à obtenção de bixina de elevada pureza, conjugada à sua estabilização, é de fundamental importância para agregar valor ao produto. Portanto o objetivo deste trabalho foi realizar uma análise comparativa entre técnicas de processamentos para extração de pigmentos nas sementes de urucum, sendo conduzidos dois tipos de extração de bixina das sementes de urucum: extração lipossolúvel e extração hidrossolúvel. Na extração lipossolúvel, o solvente utilizado foi óleo vegetal comercial e na extração hidrossolúvel, o solvente utilizado foi hidróxido de sódio. Nos sistemas de extração estudados conclui-se que é possível produzir corante de semente de urucum tanto pelo método lipossolúvel como também pelo método hidrossolúvel e que a estabilidade dos pigmentos é afetada em função da concentração de hidróxido de sódio e também em função das temperaturas de armazenamento.
The annatto tree (Bixa orellana L), is a tree with predominance in Tropical America regions particularly in Brazil, which has the biggest world production. The annatto seeds pigments are most used as natural pigment basically and are basically composed of bixin, with level around 80%, and norbixin, in a lower concentration. The pigment obtained through the annatto seeds is applied on the industry as a liquid, paste or powder; however, for its industrialization, technological knowledge which allows the gain of pigments with low cost and with an acceptable quality is indispensable and this technology turns the product capable to compete in the international market. The extraction process optimization is of fundamental importance and seeks not only increase the productivity but also minimize the contamination with the by-products of decomposition. The technological development that leads not only the extraction of gross pigment, but mainly induces the bixin high purity gain, conjugated with its stabilization, is of fundamental importance to add value to the product. Therefore, the objective of this work was to accomplish a comparative analysis between technical of processes in the extraction of pigments from the annatto seeds. It was driven two ways of extraction of annatto pigments seeds: oil soluble extraction and water soluble. In the oil soluble extraction, the solvent used was the commercial vegetal oil and on the water soluble extraction, the solvent used was sodium hydroxide. In the studied extraction systems it is ended that is possible to produce annatto seed pigment with the oil soluble method as well as the water soluble method and that the stability of pigments is affect in function the concentration of hydroxide sodium and also in function of the temperature of storage.
16
Li, Dapeng. "Coloration of textiles with nanoparticle pigments /". For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2004. http://uclibs.org/PID/11984.
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17
Powell, Christopher. "The polyphenolic pigments of black tea". Thesis, University of Surrey, 1994. http://epubs.surrey.ac.uk/843227/.
Testo completoAbstract (sommario):
The polyphenolic pigments of black tea include the theaflavins (TF), the flavonol glycosides (FG) and a group of uncharacterised brown pigments referred to as thearubigins (TR). The TR are shown to be a complex, heterogeneous group of compounds, the majority of which are unresolvable by reverse phase HPLC. Fractionation procedures have been modified, developed, combined and applied to black tea liquor, to improve the separation of black tea components and to allow fractions of less complexity be obtained. A degree of resolution has been achieved for TR fractions, unresolvable with reverse phase HPLC, using size exclusion HPLC. Calibration of the column suggested there may be little material above 2,000 daltons associated with the TR. Two heterogeneous TR fractions have been subjected to Porter's autoxidative assay for proanthocyanidins. The resulting solutions were analysed by reverse phase HPLC and shown to contain proanthocyanidins (9.4 and 16.1 %) and galloyl ester (7.1 and 7.4 %), some 73 and 84 % remains uncharacterised. A novel group of yellow pigments has been isolated for which the name theacitrins (TC) has been proposed. Data are presented that suggest the TC are possibly derived from the TF by oxidative opening of the dihydroxybenzene ring associated with the benztropolone structure. The contribution of the phenolic pigments to tea cream was investigated using reversed phase HPLC and found to be ? 86 % TR, 12 % TF and 2 % FG. Evidence is also presented for a synergistic interaction between TF and TR during cream formation. A method has been developed, using caffeine precipitation, for the isolation of TR material that is free from TF and FG Tea pigments have been stored in aqueous solutions to evaluate their potential for use as commercial colourants. The TF and TC were found to possess poor stability. The FG exhibited greater stability but possess low tinctoral power and poor water solubility. Many of the stability trials exhibited a darkening of colour associated with an increase in unresolvable TR material. Storage of an aqueous solution of a TF enriched fraction at 37 °C resulted in the production of unresolvable (TR-like) material. This material was found to possess molecular weights in excess of 2,000, indicating polymerisation. Evidence is presented to suggest the involvement of galloyl groups in the formation of non-hydrolysable bonds within this polymeric material.
18
O'Brien, Duncan L. J. "Preparation of environmentally-friendly inorganic pigments". Thesis, Loughborough University, 2005. https://dspace.lboro.ac.uk/2134/9591.
Testo completoAbstract (sommario):
A series of compounds that have potential as environmentally-friendly inorganic pigments have been prepared using solid-state methods. The materials have been characterised using a variety of techniques including powder X-ray diffraction, colour measurements, EDX, Mössbauer spectroscopy and solid state NMR. Materials based on the industrial pigment, ultramarine blue, have been investigated using a variety of methods to determine the source of the favoured red-hue. Industrial materials of different shades as well as laboratory synthesised and ion-exchanged ultramarine materials have been analysed for colour, impurities using bromine insoluble method and structure by Rietveld analysis. ICP analysis has been shown to have limited success in determining the AI:Si ratio for ultramarine materials. The role of small levels of potassium in the formation of red-shade blue and the introduction of impurities by the use of feldspar in the industrial formulation has been confirmed. The investigation of a green pigment based on CuO-B203 mixtures has been investigated by varying the ratios of the two components. In the copper-rich region, the materials produced have similar colour properties to the industrial green standard, chrome oxide. The blue boron-rich materials have relatively poor pigment properties and the colour weakens dramatically on grinding and mixing with diluents such as titanium oxide. The poor acid and water stability of the products suggest that the use of these materials as pigments would be limited. A solid solution in the CoO-A1203-GeO2 spinel system has been investigated. As the germanium level increases, the firing temperature required to produce a pure phase decreases. The samples range in colour from blue at the aluminium-rich end through purple to pink at the germanium-rich end. The use of mineralisers appears to have a favourable effect on the colour of the materials. Rietveld refinement of the materials suggests that the series shows disordering of the cations over both tetrahedral and octahedral sites and that the materials become cobalt deficient as the aluminium level increases. Doping, annealing and mineralisation of the SnO-Nb2O5 series using cation (V, Ca, Ta) and anion (Cl, S) doping has produced two different phases with very different properties. The foordite structure, SnNb2O6 is a very stable stoichiometric yellow phase that shows good temperature and gaseous environment resistance. The pyrochlore phase, SnII2x_N, b2y.S n7yO7_7h, owever is very susceptible to changes in atmosphere and readily undergoes substitution at both anion and cation sites to produce phases that vary in colour from yellow through to red. The product phases have mixed divalent and tetravalent tin across two different sites. Substitution of some of the oxygen with sulfur (to a limit of 0.3 per unit cell) leads to a reddening of the sample and stabilisation of the divalent tin within the structure. Mössbauer analysis indicates the presence of both divalent and tetravalent tin in the compound where the level of tin (IV) decreases on substitution of sulfur. Thermal treatment of both tin samples facilitates a reversible temperature dependent change in the colour of the samples from yellow/orange through to bright red. Temperature dependent XRD analysis has shown that the colour change does not result from a change in the structure.
19
Rooke, Joanne Claire. "Oxynitride systems as potential inorganic pigments". Thesis, University of Southampton, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.494463.
Testo completoAbstract (sommario):
Inorganic oxynitride materials, with potential applications as pigments, have been synthesised and characterised in terms of their crystal structure, band gap energies and physical properties using powder X-ray and powder neutron diffraction (PXD,PND), solid state UV-Visible spectroscopy, L*a*b* colour measurements, scanning electron microscopy (SEM), energy dispersive analysis of X-rays and thermal analysis. Oxynitride perovskites, AII,IIIBV(O,N)3, where A is a group 2 or lanthanide metal and B an early transition metal have been synthesised by the direct ammonolysis of stoichiometric metal oxides and carbonates at high temperatures, typically 850°C, with the inclusion of group 1 and 2 metal halide salts acting as mineralisers. Powder X-ray diffraction studies show the synthesised perovskites to have primarily an orthorhombic distortion, crystallising in the space group Pnma, similar to CaTaO2N. Exceptions include compounds crystallising in a rhombohedral system, Ca0.77Eu0.23TaO1.77N1.23 or in a monoclinic system, LaTaON2. PXD profiles have highlighted the presence of a competing pyrochlore phase, which becomes more prevalent as the radius of the divalent and trivalent cations decreases such that perovskite phases for smaller lanthanides do not form. Neutron diffraction studies show that the oxygen to nitrogen ratio in the orthorhombic perovskite is Ca0.5Nd0.5TaO1.5N1.5 and there is a slight ordering of O/N over the two anionic sites. In the octahedra forming the framework, the axial positions have greater nitrogen occupancy, whereas the equatorial positions favour oxygen. In contrast to this, the group 2 substitutions onto the lanthanide position in LaTaON2 yielding A(1-x)LaxTaO(2-x)N(1+x), have shown a random distribution of oxygen and nitrogen over both positions. UV-Visible spectroscopy of these oxynitrides reveal broad reflectance bands and a steep absorption edge, which is directly related to the and gap energy of the compound. By varying the doping levels on the B site with transition elements other than Ta such as Nb, Ti, W and Zr, the colour of the compound can be seen to visibly alter. Solution methods, such as co-precipitation techniques, have been employed to deposit oxide precursors onto mica flakes, which are then fired under flowing ammonia to target thin films of oxynitride pigment on mica to produce interference effects. SEM has shown the presence of two separate morphologies, mica and pigment, thus resulting in unsuccessful depositions. Although the pearlescent nature of mica remains after heat treatment with ammonia, solution methods do not yield the same intense colours seen by the solid state route. This necessitates the use of halide salts to target pigments with high quality hues but this destroys the pearlescent effects seen in mica.
20
Duckett, Gordon Richard. "Electron microscope studies of organic pigments". Thesis, University of Glasgow, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305588.
Testo completo
21
Hughes, Eric M. "Synthesis and characterisation of inorganic pigments". Thesis, University of Southampton, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313210.
Testo completo
22
Booth, Douglas Geoffrey. "Synthesis and struture of ultramarine pigments". Thesis, University of Southampton, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250047.
Testo completo
23
Hope, Andrew J. "Rod visual pigments of teleost fish". Thesis, University of Bristol, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.319236.
Testo completo
24
Ronot, Anais. "New methodologies for covalently modifying pigments". Thesis, University of Edinburgh, 2006. http://hdl.handle.net/1842/14317.
Testo completoAbstract (sommario):
Pigments are widely used materials in inkjet inks and their surface properties are an important factor in their performance. The aim of this project was to devise methodologies for covalently modifying the surfaces of pigments in order to modulate their properties. This was achieved by activating the surface of pigments with either gamma or plasma irradiation and then covalently grafting polymers onto their surfaces. The four pigments used were: Pigment red 122, Pigment blue 15:3, Pigment yellow 155 and Carbon black, which are already used in Kodak inks. It was demonstrated that dispersability in water or DMF could be greatly improved by grafting polymers onto pigments. After dispersion tests over two weeks, poly(N,N-dimethylacrylamide) was found to be the best polymer to graft onto pigments in order to improve pigment dispersability in water, while polystyrene allowed dispersion of pigments in DMF. Further modifications were attempted by copolymerisation, cross-liking and esterification reactions. The optimised pigments were analysed using filtration, UV/Vis measurement, contact angle and SEM to determine their particle sizes and properties. They were used in basic ink formations, printed onto paper and tested against light and ozone fading.
25
Potts, Graham David. "The crystal chemistry of organic pigments". Thesis, University of Cambridge, 1993. https://www.repository.cam.ac.uk/handle/1810/272647.
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26
Hartnell, Regan David. "The synthesis of novel porphyrinoid pigments". Thesis, Queensland University of Technology, 2000. https://eprints.qut.edu.au/37043/6/37043_Digitised%20Thesis.pdf.
Testo completo
27
Clabaux, Emmanuelle Céline Magali. "Réactivité d'amines et synthèses hétérocycliques appliquées à la synthèse de pigments organiques". Lille 1, 2003. https://pepite-depot.univ-lille.fr/RESTREINT/Th_Num/2003/50376-2003-359.pdf.
Testo completoAbstract (sommario):
La synthèse de pigments organiques, toujours insolubles dans les milieux réactionnels, doit aussi être complétées par la mise en forme des particules pour obtenir l'effet de coloration escompté. Nous avons abordé dans l'optique de développer les méthodes de préparation de produits très insolubles, la synthèse de trois types de pigments d'intérêts industriels actuels: les pigments azoi͏̈ques, les pigments pérylènes, les pigments d'isoindolinone. L'ensemble des difficultés pour la préparation de ces produits se concentrent autour de la réactivité des amines qui interviennent dans leur constitution chimique et de la faible solubilité des réactifs et produits. Le travail permet donc d'obtenir de nouveaux produits qui pourraient potentiellement trouver leur application en tant que pigments organiques, ou d'intermédiaires utilisables pour leur préparation. Il apporte également des éclairages mécanistiques sur la réactivité des amines aromatiques peu réactives et sur les voies de synthèses envisageables pour la préparation de ce type de produits.
28
Lin, Ying-Chuan. "Production, Location, and Binding of Violacein in Janthinobacterium". Thesis, University of North Texas, 1988. https://digital.library.unt.edu/ark:/67531/metadc798326/.
Testo completoAbstract (sommario):
Violacein is a purple pigment typically produced by species of Chromobacterium and Janthinobacterium. A soil isolate, identified as as Janthinobacterium, was studied. Maximal pigmentation ocurred at 25°C under aerobic conditions in the Keeble and Cross medium.
29
Kahya, Sevinc Sevim. "Synthesis And Characterization Of Fluorescent Zinc Phthalocyanine Pigments And Its Combination Pigment With Mica Titania Pig Ment". Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12615041/index.pdf.
Testo completoAbstract (sommario):
In the present work, zinc phthalocyanine and tetra nitro substituted zinc phthalocyanine were sytnhesized by using phthalic anhydride and nitro phthalic acid precursor respectively under microwave irradiation. Molecular structures of these pigments were confirmed by FT-IR and UV-visible spectroscopy analyses. Furthermore, these pigments were deposited on mica-titania pigment substrate in dimethyl formamide solvent to obtain the combination pigment. FT-IR analysis was conducted to analyze the deposition of pigments onto the mica-titania surfaces. Fluorescence spectroscopy analysis was performed to observe zinc phthalocyanine, tetra nitro zinc phthalocyanine pigments, and their combination pigment with mica- titania pigments. The surface morphologies of zinc phthalocyanines on the mica titania pigments were investigated by scanning electron microscopy. Optimum deposition temperature and deposition time were determined by v depositing varying amounts of zinc phthalocyanines. The paint samples of these combination pigments were prepared by alkyd based paint formulation. L*a*b* values of the paint samples were determined by color measuring spectrophotometry. The optimum deposition temperature was determined as 120 oC and the optimum deposition time was determined as half an hour and effective deposition was obtained at 120 °C. It is observed that, with the increasing amount of ZnPc, the interaction between ZnPc particles increases and they desorp the surface of mica-titania pigment. The best result was obtained with 0.08 g ZnPc at 120 oC.
30
Leitinho, Janaina Lopes. "Estabilidade tÃrmica de tintas epoxÃdicas em presenÃa de pigmentos anticorrosivos". Universidade Federal do CearÃ, 2005. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=1433.
Testo completoAbstract (sommario):
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel SuperiorOs primers sÃo tintas primÃrias que funcionam como fundo anticorrosivo quando aplicados sobre metais. As suas propriedades anticorrosivas devem-se os pigmentos usados na sua composiÃÃo, sendo os mais comuns o zarcÃo, o cromato de zinco, o Ãxido de ferro e o pà de zinco. As tintas à base de resina epoxÃdica sÃo bastanteutilizadas como primers, pois apÃs a cura estas tornam-se impermeÃveis e, quandosÃo associadas a pigmentos com propriedades anticorrosivas, aumentam a resistÃnciado substrato à corrosÃo. PelÃculas secas de tintas-primers formuladas com resinaepoxÃdica DGEBA (Ãter Diglicidil de Bisfenol A), reticuladas com umapoliaminoamida (Versamid 125), e com dois pigmentos anticorrosivos, um tÃxico (cromato de zinco) e outro nÃo-tÃxico (sÃlica trocadora de cÃlcio) foram estudadas atravÃs das tÃcnicas de termogravimetria (TG), infravermelho (FTIR) e microscopia eletrÃnica de varredura (MEV). AtravÃs de TG foram determinados parÃmetros cinÃticos, como a Energia de ativaÃÃo, tanto pelo mÃtodo de Ozawa-Wall-Flynn, quanto de Kissinger. Verificou-se que o mecanismo de degradaÃÃo das tintas epoxidÃcas à alterado na presenÃa dos pigmentos. A estabilidade termo-oxidativa do primer com cromato de zinco, baseada nos valores de IPDT, à menor do que a do primer com o pigmento silica cÃlcio. A imersÃo dos primers em Ãcido clorÃdrico, nas concentraÃÃes de 10-5 atà 6,0M, reduz a estabilidade tÃrmica, sendo o mais afetado aquele contendo cromato de zinco. Neste ocorre a formaÃÃo de poros, detectados pela MEV. O uso do pigmento anticorrosivo sÃlica cÃlcio apresenta, alÃm da vantagem da nÃo toxidade, maior estabilidade termo-oxidativa e maior resistÃncia a ambientes Ãcidos do que o pigmento cromato de zinco.
The primers are primary anticorrosive dyes, with anticorrosive property due to the presence of appropriate pigment. The most common used anticorrosive pigments are zarcÃo, zinc chromate, iron oxide and zinc powder. Paints based on epoxy resin are very used as primers, because their impermeability and, when associated with anticorrosive pigments, the increase in the resistance against corrosion. Films of paint-primers formulated with DGEBA epoxy resin (Diglycidyl Ether of Bisphenol A), crosslinked with polyaminoamida (Versamid 125) , and with two anticorrosive pigments, zinc chromate (toxic) and calcium silicate (not toxic), were studied by thermogravimetric analysis (TG), infrared spectroscopy (FTIR) and scanning electronic microscopy (SEM). Kinetic parameters, such as activation energy, were calculated by TG, using Ozawa-Wall-Flynn and Kissinger methods. Change in the mechanism of epoxy paint degradation was observed in the presence of the two pigments. Primer with calcium silicate was more thermally stable than that with zinc chromate, based on IPDT values. The immersion of primers films in hydrochloric acid in the concentrations range from 10-5 to 6,0 M led to a decrease in the thermal stability. The most affected primer was that with zinc chromate, in which porous was detected by SEM after the immersion in acid solution. The primer with calcium silicate has the advantage of being more thermally stable and more resistant to acid attack, in addition to its more important ecological property, the non toxicity.
31
Gu, Wei. "Surface Modification of Pigments and its Role in Offset Ink Setting". Fogler Library, University of Maine, 2006. http://www.library.umaine.edu/theses/pdf/GuW2006.pdf.
Testo completo
32
Ghannam, Leïla. "Pigments hybrides inorganique/organique colorés à base de mica". Pau, 2006. http://www.theses.fr/2006PAUU3011.
Testo completoAbstract (sommario):
"L’objectif principal de ce travail est la synthèse des pigments inorganique/organique à base de mica ayant des effets visuels. Ces pigments se différencient soit par leur couleur, soit par la présence d’effets d’irisation par interférence de la lumière. Nous avons développé deux méthodes de synthèse: - la première consiste au couplage des procédés de Nitroxide Mediated Polymerization et greffage à partir de la surface du mica. Par cette méthode le succès essentiel de cette étude a été l'obtention d'une large gamme de couleurs à partir de particules de mica grâce à l’incorporation dans la partie organique d’un colorant sensible à son environnement. La couleur de ces pigments dépend de la densité d’adsorption des chaînes polymères, de la quantité incorporée dans les chaînes et surtout de la conformation des chaînes à la surface du mica. En complément de cette gamme de pigments, nous avons réussi, grâce à la NMP à synthétiser un nouveau type de pigments en multicouches en formant des copolymères à blocs à la surface du mica. L’observation à l’oeil nu des ces pigments a montré une variété de couleurs et des brillances plus ou moins exacerbées. - alors que cette première voie est liée à la formation de couches de polymères d'indice de réfraction différents à la surface des particules, la deuxième voie explorée est basée sur la structuration "bidimensionnelle" de films de polymère. Des effets visuels d’irisation ont pu être obtenus grâce à l’auto-organisation de polymères et copolymères préparés par NMP en une structure en nid d’abeille à la surface des feuillets de mica. La caractérisation physico-chimique et colorimétrique des différents pigments montre que ces deux méthodes de synthèse nous ont permises d’atteindre tous les objectifs que nous nous étions fixés, c'est-à-dire l’obtention des pigments à effets visuels particuliers. Cette approche représente donc un outil efficace pour la synthèse des pigments et permettrait d’assurer un avenir industriel à ce type de procédé. "The principal aim of this study is the synthesis of inorganic/organic pigments based on mica that have special visual effects. These pigments differ either by their colour or by the presence of iridescent visual effects due to light interference. We have developed here two synthesis methods: - The first consists of coupling controlled radical polymerization and grafting process from mica surface. The main achievement of this method is the generation of a variety of coloured products thanks to the incorporation of pH-depending modified dyes into organic parts. The colour of these pigments depends on the polymer chains adsorption density, the incorporated dye quantity into these chains and on the chains conformation on mica surface in particular. Moreover, for these pigments kind, we have, synthesized a new multilayered pigment by modified dye, and styrene copolymerization by activation of polybutylacrylate end chains previously adsorbed from mica thanks to Nitroxide Mediated Polymerization. The naked eye observation of these pigments shows colour varieties and certain gloss levels. - While this first way is related to the formation of polymer layers with different refraction index on mica surface, the second way of pigment synthesis is based on the polymer films 2D organization. Visual iridescent effects were reached by selfassembly of polymers or copolymers prepared by NMP on honeycomb structure on sheet mica surfaces. The physicochemical and colorimetric characterization of different pigments synthesized show that these two methods have allowed us to attain our objectives: that means to obtain pigments with special visual effects from mica surface. These approaches represent an efficient tool to synthesize pigments and can be of great interest for pigment industries destined to many applications such as cosmetics, plastics, automobiles, etc
33
Poon, Kelvin Weng Chun. "In situ chemical analysis of tattooing inks and pigments : modern organic and traditional pigments in ancient mummified remains". University of Western Australia. Centre for Forensic Science, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0257.
Testo completoAbstract (sommario):
At various points in human history, tattooing has been ubiquitous on almost every continent on Earth, used for reasons of aestheticism, religious beliefs or for social purposes. To study the art of tattooing with respect to a particular culture, one must always be critical to any references to the practice (written, pictorial or artefactual) due to issues of translation and misinterpretation. Complete verification may only come with the discovery of actual tattooed human remains. In combination with artefactual and anthropological evidence, these remains not only provide physical proof of the practice in a culture's ancestry but also possess the ability to link various other forms of physical evidence, which on their own would remain speculative. By its very nature, tattooing may only exist while the bearer is alive. Once the owner dies, the skin, along with the tattoo, decomposes (under normal decomposition conditions) and is lost forever. However, tattoos may survive if the dermal layers of the skin are preserved, either by natural or artificial means. The processes of mummification in various civilisations have provided us with a rare opportunity to study the art and processes of tattooing in antiquity. Existing tattooed mummified remains have been found in: Egypt; Siberia; Eastern Central Asia; Greenland; Alaska and St. Lawrence Islands; Central Andes (Peru and Chile); Philippines; New Zealand and Italy. Existing literature regarding the analysis of tattooing inks and pigments once deposited into the skin is very limited. Comparatively, the industrial organic pigments used to colour the majority of modern tattooing inks sold today have not been officially approved by any regulating body and as such, manufacturers are not required to disclose the chemical ingredients of their products. Chemical identification of these tattoo pigments post-procedure will aid medical practitioners in the event of complications or for the purposes of tattoo removal. Forensically, tattoos are often one of the distinguishing features used in the identification of victims of crime or accidents. Experiments were carried out using an animal model (Sus scrofa) for the tattooing. Given the theoretically large but ultimately limited range of substances available to both ancient and modern tattooists, the premise of the experiment involved surveying the literature regarding possible tattooing pigments and either obtaining or reproducing a careful selection of these in the laboratory. These pigments were then tattooed onto the ii animal model and after allowing for the essential healing period, the tattooed areas were excised, with those tattooed with traditional pigments subjected to various simulated mummification environments.
34
Bagdzevičienė, Jurga. "Investigation and Description of Ancient Pigments in Paintings and Archaeological Glass Finds". Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2012. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2012~D_20120629_152636-81665.
Testo completoAbstract (sommario):
In this dissertation, the results of detailed investigation of the seven unique art objects are presented. The presented results show that complex apllying of the instrumental analytical methods of OM, FTIR, SEM/EDX, XRD, μXRD and µRS is accurate and efficient way to identify composition of works of art and archaeological finds of glass, pigments or describe their technology. IR spectroscopy has been successfully applied to determine pigments and some pigment mixtures in painting‘s ground, paint layers, and destruction products in archaeological glass. The SEM/EDX analysis successfully can be used in determining the main elements of the paint samples at different cross-section points perform a qualitative analysis of the pigments (cinnabar, lead white, chalk, smalt et. al. ), in some cases, to discuss the features of the production of pigments. The SEM/EDX provided a possibility to examine three archaeological glass beads. According to the elemental composition, microstructure, and the specific features in different areas of the glass was defined nature of the destruction of glass. XRD and μXRD analysis successfully can be used in determining the crystalline phases in the paint and archaeological glass samples. Identify following pigments and their mixtures: calcite CaCO3, carbon, lead tin yellow type I Pb2SnO4, lead tin yellow type II PbSn03, hydrocerussite 2PbCO3 ∙ Pb (OH)2, cerussite PbCO3, Egyptian blue CaCuSi4O10, gypsum CaSO4 ∙ 2H2O, anhydrite CaSO4, huntite Mg3Ca(CO3)4... [to full text]Septynių unikalių, didelę istorinę ir meninę vertę turinčių objektų – trijų XVII ir XVIII a. paveikslų, Senovės Egipto sarkofago bei trijų archeologinių stiklo karolių iš Kernavės-Kriveikiškių kapinyno – tyrimams sėkmingai pritaikyti OM, FTIR, SEM/EDX, XRD, μXRD ir µRS analizės metodai. Konstatuota, kad taikant kompleksinius tyrimus galima tiksliai ir efektyviai identifikuoti kūrinių medžiagas, charakterizuoti jų sandarą, apibūdinti technologijas. IR spektroskopija sėkmingai panaudota identifikuojant tapybos grunto ir dažų sluoksnių neorganinius tapybos pigmentus ir jų mišinius bei stiklo korozijos produktus. Parodyta, kad IR spektroskopija gali būti sėkmingai panaudota identifikuojant istorines restauravimo medžiagas. SEM/EDX analizės metodu nustatyta tapybos elementinė sudėtis, identifikuoti cinoberio, švino baltojo, kreidos, smaltos, suriko ir kt. pigmentai. SEM/EDX analizės metodu ištirti trys archeologiniai stiklo karoliai. Pagal elementinės sudėties skirtumus ir specifinius mikrostruktūros bruožus nustatytas stiklo destrukcijos pobūdis. XRD ir μXRD analizės metodais sėkmingai identifikuoti šie pigmentai ir/ar jų mišiniai: kalcitas CaCO3, anglis, I tipo Pb–Sn geltonasis Pb2SnO4, II tipo Pb–Sn geltonasis PbSn03, hidrocerusitas 2PbCO3∙Pb(OH)2, cerusitas PbCO3, Egipto mėlynasis CaCuSi4O10, gipsas CaSO4∙2H2O, anhidritas CaSO4, huntitas Mg3Ca(CO3)4, dolomitas CaMg(CO3)2. Pirmą kartą μRS metodu identifikuotas II tipo švino alavo geltonasis pigmentas, archeologiniam stiklui... [toliau žr. visą tekstą]
35
Gatelytė, Aurelija. "Synthesis and characterization of novel black pigments". Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2012. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2012~D_20120402_093928-15742.
Testo completoAbstract (sommario):
For this doctoral dissertation there were synthesized and observed the black pigments which are important in both – in art and industry. It was the first time when using the sol-gel method in our laboratory were synthesized YFeO3, Y3Fe5O12, CoFe2O4, NiFe2O4, ZnFe2O4 nanocompounds, which latter were fitted for the black pigmentation of the ceramic glazes.Buvo sudaryti modeliniai juodieji pigmentai iš C suodžių ir K2CO3, Ca3(PO4)2, CaCO3 bei Mg3(PO4)2.Vandeniniu zolių-gelių metodu buvo susintetinti įvairūs metalų vienfaziai nanoferatai YFeO3, Y3Fe5O12, CoFe2O4, NiFe2O4, ZnFe2O4, kurie pirmą kartą panaudoti juodaisiais keraminiais pigmentais.
36
James, Ashley L. "Characterisation of II-VI based semiconducting pigments". Thesis, Lancaster University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.480855.
Testo completo
37
Badcock, Tracey Dianne. "Disazoacetoacetanilide pigments : crystallographic colouristic and application properties". Thesis, Edinburgh Napier University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261159.
Testo completo
38
Howard, Helen Catherine. "The pigments of English medieval wall painting". Thesis, Courtauld Institute of Art (University of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369503.
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39
Stott, Colin Mark. "Synthesis and photoconduction properties of haloanthanthrone pigments". Thesis, Open University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.255409.
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40
Keely, Brendan J. "Early diagenesis of chlorophyll and chlorin pigments". Thesis, University of Bristol, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329905.
Testo completo
41
Alattas, Noor Abdulrahman S. "Polysaccharide-mediated formation of pigments from serotonin". Thesis, Tennessee State University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10119066.
Testo completoAbstract (sommario):
As a continuation of the research on the pigment formation from catecholamines, we studied the polysaccharide-mediated oxidation of serotonin and other 5-hydroxy indoles into pigmented substances. As for catecholamines, we observed that many polysaccharides promote the oxidation of such compounds, particularly in the presence of Cu (II). The same polysaccharides, e.g., carrageenan or fucoidan, which strongly promoted the oxidation of catecholamines, strongly promoted the oxidation of serotonin, leading to the formation of darkly colored pigments. The reactions were evaluated using RP-HPLC and size exclusion chromatography (SEC) as the main analytical techniques. SEC proved particularly informative as these analyses allowed us to monitor (1) the decline in the substrate, (2) the formation of low-molecular mass oxidation products, (3) the formation of polysaccharide-associated pigments, and (4) the formation of potential pigment-based nanoparticles. We observed that increased amounts of polysaccharide or Cu (II) increased the amount of pigment generated. However, other cations like Co(II), Ni(II), Mn(II), or Fe(II) had no or very little effect on the reactivity. Apart from serotonin, 5-hydroxy indole could serve as a substrate to generate polysaccharide-associated pigments. However, reactions with the related substrate, 5-hydroxy indole-3-acetic acid yielded a low molecular mass chromophore, but not any polysaccharide-associated pigments. Large-scale reactions were set up in an attempt to isolate and characterize any pigments that were generated. The reaction mixtures could readily be dialyzed and lyophilized to obtain polysaccharide-associated pigments. Pigments were evaluated using UV-Vis spectroscopy, SEC analysis, FT_IR spectroscopy, and atomic absorption spectroscopy to evaluate the amount of Cu remaining in the materials.
42
Kent, Jeremy. "The visual pigments of deep-sea crustaceans". Thesis, University of Bristol, 1997. http://hdl.handle.net/1983/c15eaa2a-756c-43dc-bf73-c30c09e5d5f2.
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43
Barrell, K. J. "The Langmuir-Blodgett films of conjugated pigments". Thesis, University of the West of England, Bristol, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234286.
Testo completo
44
Dejoie, Catherine. "Structure et propriétés de pigments hybrides archéomimétiques". Phd thesis, Grenoble 1, 2009. http://www.theses.fr/2009GRE10169.
Testo completoAbstract (sommario):
Par l'association d'une molécule organique colorée avec une matrice inorganique incolore, les composés hybrides sont une solution appropriée pour l'obtention de pigments stables. Ces composés sont en effet capables de résister au temps et aux conditions du milieu les environnant : la stabilité de la couleur est assurée après fixation ou encapsulation de la molécule organique à la surface d'un minéral ou dans une matrice microporeuse. Dans ce travail, nous étudions la diffusion et le processus de physisorption de l'indigo à l'intérieur des cavités et canaux d'alumino-silicates ordonnés tels que les zéolithes. Nous obtenons un complexe hybride, dont la couleur et la stabilité se rapprochent de celles du pigment Bleu Maya archéologique. Le processus physico-chimique à l'origine de la stabilité remarquable du Bleu Maya est encore très controversé. L'élaboration et l'étude du composé archéomimétique ouvre alors de nouvelles perspectives sur la compréhension des caractéristiques spectroscopiques et structurales du Bleu Maya. Les composés analogues sont caractérisés en combinant spectroscopies optiques et vibrationnelles, diffraction des rayons X sur poudre et monocristaux, et diffusion quasi-élastique des neutrons. Nous montrons que l'indigo diffuse sous la forme de monomères dans le réseau de canaux de certaines zéolithes, et se localise en stabilisant le minéral dans un état métastable. Ce travail sur les pigments hybrides anciens et leurs analogues modernes est le premier exemple sur la façon dont les matériaux anciens peuvent être une source d'inspiration dans la conception de matériaux fonctionnels modernesThe search for stable dyes, resisting heat and moisture in particular, places several organic-inorganic hybrids as particularly appropriate and environmentally friendly solutions: the colour can be durably fixed by trapping or encapsulating the organic dye on a mineral or in a clay matrix. Here we examine the diffusion and the fixing process of indigo molecules inside the cages and channels of appropriate alumino-silicates such as zeolites. We succeed in producing a stable composite, whose colour and stability resemble those of the historical Maya Blue pigment. Yet the physical and chemical processes which govern the exceptional stability of Maya Blue still are an object of controversy. Therefore the present study revisits the structural and spectroscopic features of Maya Blue using the indigo-zeolite archaeomimetic complex as a model case. Our new zeolitic analogues are characterized by combining optical and vibrational spectroscopies, quasi-elastic neutron scattering, and synchrotron X-ray powder/single crystal diffraction. We show that indigo diffuses as monomers through the channel network of some specific zeolites and sits at particular crystallographic positions while the matrix is maintained in a metastable state. The present study of ancient and modern hybrid pigments is the first example on how ancient materials may inspire the design of functional materials and shed new light on particular physical properties of historical pigments
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Dejoie, Catherine. "Structure et propriétés de pigments hybrides archéomimétiques". Phd thesis, Université Joseph Fourier (Grenoble), 2009. http://tel.archives-ouvertes.fr/tel-00443569.
Testo completoAbstract (sommario):
Par l'association d'une molécule organique colorée avec une matrice inorganique incolore, les composés hybrides sont une solution appropriée pour l'obtention de pigments stables. Ces composés sont en effet capables de résister au temps et aux conditions du milieu les environnant : la stabilité de la couleur est assurée après fixation ou encapsulation de la molécule organique à la surface d'un minéral ou dans une matrice microporeuse. Dans ce travail, nous étudions la diffusion et le processus de physisorption de l'indigo à l'intérieur des cavités et canaux d'alumino-silicates ordonnés tels que les zéolithes. Nous obtenons un complexe hybride, dont la couleur et la stabilité se rapprochent de celles du pigment Bleu Maya archéologique. Le processus physico-chimique à l'origine de la stabilité remarquable du Bleu Maya est encore très controversé. L'élaboration et l'étude du composé archéomimétique ouvre alors de nouvelles perspectives sur la compréhension des caractéristiques spectroscopiques et structurales du Bleu Maya. Les composés analogues sont caractérisés en combinant spectroscopies optiques et vibrationnelles, diffraction des rayons X sur poudre et monocristaux, et diffusion quasi-élastique des neutrons. Nous montrons que l'indigo diffuse sous la forme de monomères dans le réseau de canaux de certaines zéolithes, et se localise en stabilisant le minéral dans un état métastable. Ce travail sur les pigments hybrides anciens et leurs analogues modernes est le premier exemple sur la façon dont les matériaux anciens peuvent être une source d'inspiration dans la conception de matériaux fonctionnels modernes.
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Seeley, Gordon John. "Development and application of new methods for investigating pyrolysis products from selected pigments and pigmented polymer systems". Thesis, University of Glasgow, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321504.
Testo completo
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Aguero, Natasha Fioretto. "Estudo de processos de degradação de pigmentos de coloração azul e amarela". Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-21062017-204330/.
Testo completoAbstract (sommario):
Em arqueometria e nas ciências aplicadas, metodologias físicas e químicas são de grande utilidade para estudar diferentes materiais e objetos do patrimônio cultural como pinturas de cavalete, murais, cerâmicas, metais, etc. No caso particular de pinturas, tais análises podem auxiliar na compreensão do processo criativo, dos materiais utilizados pelo artista e do estado de conservação desta obra. No contexto deste último item, podem ser caracterizados sinais de degradação, como a alteração de cores. Dentro do objetivo de compreender a degradação de alguns pigmentos por exposição luminosa, estudaram-se os pigmentos amarelo de cádmio (CdS), amarelo de cromo (PbCrO4), azul de cobalto (CoAl2O4) e cerúleo (Co2SnO4), sendo estes dois últimos também misturados ao branco de zinco (ZnO). Tais estudos foram realizados através de três ensaios com amostras padrões preparadas com estes pigmentos: fotodegradação induzida na linha TGM (Toroidal Grating Monochromator) do Laboratório Nacional de Luz Síncrotron; exposição à luz ultravioleta no simulador solar SOL-UV; e exposição às radiações ultravioleta, visível e infravermelha em uma câmara projetada neste mestrado. Os resultados apontaram para indicativos de alteração em todas as amostras, em especial mudanças no espectro de reflectância na região do visível. Por fim, analisaram-se amostras de tintas obtidas de obras do pintor Candido Portinari que possuíam indícios de alteração cromática. A partir destes fragmentos, construíram-se modelos estratigráficos dos materiais utilizados pelo artista nestas pinturas.In archeometry and applied sciences, physical and chemical methodologies are very useful for studying different materials and objects of cultural heritage such as easel paintings, murals, ceramics, metals, etc. In the particular case of paintings, such analyses can help in understanding the creative process, the materials used by the artist and the conservation status of this work. In the context of this latter item, signs of degradation, such as color change, can be characterized. In order to understand the degradation of some pigments by light exposure, the cadmium yellow (CdS), chrome yellow (PbCrO4), cobalt blue (CoAl2O4) and cerulean blue (Co2SnO4) pigments were studied, the latter two being also mixed with zinc white pigment (ZnO). Such studies were carried out through three experiments prepared with these pigments: photodegradation induced in the TGM (Toroidal Grating Monochromator) line of the National Laboratory of Synchrotron Light; exposure to ultraviolet light in the SOL-UV solar simulator; and exposure to ultraviolet, visible and infrared radiation in a chamber designed in this master\'s degree. The results pointed out changes in all samples, especially in their reflectance spectrum in the visible region. Finally, samples obtained from works by the painter Candido Portinari that had signs of chromatic alteration were analyzed. Based on these fragments, stratigraphic models of the materials used by the artist in these paintings could be constructed.
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Jonynaitė, Dalia. "Investigation of Historical Analogues and Sol-Gel Preparation of Novel Inorganic Cobalt-Based Pigments". Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110222_154516-45308.
Testo completoAbstract (sommario):
X-ray diffraction analysis (XRD), infrared (IR) spectroscopy and scanning electron microscopy have been used for the characterization of cobalt-based pigments (Kremer Pigmente) and their lead-based glazes.It was also demonstrated that XRD analysis could be successfully used for the identification of cobalt pigments cobalt violet brilliant light CoNH4PO4•H2O, cobalt blue light, cerulean blue, cobalt green bluish CoO·ZnO in their glazes. However, only non-oxide cobalt pigments cobalt yellow [K3(Co(NO2)6]•3H2O, cobalt violet brilliant light and cobalt violet dark Co3(PO4)2 could be determined in their glazes using IR spectroscopy. The similarity of all SEM images of cobalt-based glazes let us to conclude, that the main morphological features of glazes are not dependent on the nature of cobalt pigment. The single phase cobalt violet light brilliant pigment has been synthesized using a simple co-precipitation approach. The characteristics of the obtained product were compared with those of a commercial sample purchased from Kremer Pigmente. For the first time to our knowledge, it was demonstrated that the characteristic Si-O absorption band at 812 cm-1 could be successfully used as indicator in the evaluation of molar ratio of CoO and SiO2 in their mixture. The novel method for the determination of SiO2 in physical mixtures of CoO ir SiO2 (in the range 9,1-50 %) or blue cobalt smalt pigment (CoO×nSiO2) (in the range 20-50 %) by FTIR spectroscopy is suggested. New cobalt-based... [to full text]Atlikta istorinių kobalto pigmentų analogų Rentgeno spindulių difrakcinė analizė parodė, kad metodas efektyvus, nustatant kobalto šviesiai violetinį CoNH4PO4•H2O, kobalto mėlynąjį šviesų, ceruleumą ir kobalto žalsvai mėlyną CoO·ZnO, jų švino glazūrose, bet netinka aureolino [K3(Co(NO2)6]•3H2O, kobalto tamsiai violetinio Co3(PO4)2, kobalto mėlynojo tamsus, kobalto melsvai žalio ir smaltos CoO•nSiO2 nustatymui. IR spektroskopiniai tyrimai parodė, kad šis metodas efektyvus, kokybiškai nustatant neoksidinius kobalto pigmentus aureoliną, kobalto šviesiai violetinį, kobalto tamsiai violetinį jų švino glazūrose. Paprastu nusodinimo metodu susintetintas kobalto pigmentas violetinis šviesusis CoNH4PO4, pasižymintis analogiškomis fizikinėmis savybėmis, kaip ir komercinis Kremer Pigmente pigmentas. Sukurtas naujas, patogus ir pakankamai tikslus IR spektroskopinis SiO2 kiekio CoO ir SiO2 mišiniuose (ribose tarp 9,1-50 mol%) ir kobalto pigmente smaltoje CoO×nSiO2 (ribose tarp 20 iki 50 mol%) nustatymo metodas. Zolių-gelių metodu susintetinti ir visapusiškai ištirti nauji kobalto pigmentai: špinelio struktūros kobalto aliuminatas CoAl2O4 ir chromatas CoCr2O4 bei kobalto, aliuminio ir neodimio oksidų mišiniai (CoAl1,75Nd0,25O4, CoAl1,5Nd0,5O4, CoAlNdO4), pasižymintys spalvinėmis keraminių pigmentų savybėmis. Pirmą kartą zolių-gelių metodu susintetinti ir visapusiškai ištirti nauji kobalto pigmentai: vienfazis perovskito struktūros neodimio kobaltatas NdCoO3, mišrūs perovskitiniai neodimio... [toliau žr. visą tekstą]
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Dainenka, Kęstutis. "Didėjančių temperatūrų ir drėgmės deficito poveikis sėjamųjų žirnių (Pisum sativum L.) biometriniams ir biocheminiams rodikliams". Master's thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20100609_134643-24051.
Testo completoAbstract (sommario):
Tiriant didėjančių temperatūrų ir drėgmės deficito poveikį sėjamųjų žirnių biometriniams ir biocheminiams rodikliams, bandymai atlikti LSDI Augalų fiziologijos laboratorijos fitotroniniame komplekse 2009 metais. Tirta didėjančių temperatūrų ir drėgmės deficito įtaka sėjamųjų žirnių (Pusum sativum L.) 'Gloriosa' antžeminės dalies augimui, žaliųjų bei sausųjų medžiagų kaupimuisi antžeminėje dalyje, asimiliaciniam lapų plotui ir fotosintetinių pigmentų kiekiui. Atlikus tyrimus nustatyta, kad, didėjant temperatūrai ir mažėjant substrato drėgmei chlorofilų a ir b bei karoteno kiekis sėjamųjų žirnių daiguose, didėja. Iš tyrimų duomenų matyti, kad didžiausias sausųjų medžiagų kiekis buvo daiguose, kurie augo normalaus drėgnio (40 - 45%) substrate, aukštesnėje - 25/18 °C temperatūroje. Sėjamųjų žirnių didžiausias daigų lapų plotas buvo prie žemesnės temperatūros ir normalaus substrato drėgnio (40 - 45%). Aukščiausi daigai buvo normalaus drėgnio (40 - 45%) substrate ir prie - 25/18 °C temperatūros. Tyrimai parodė, kad kompleksinis drėgnio ir aukštos temperatūros poveikis skatina žirnių daigų augimą. Taip pat iš duomenų matosi, kad normalus (40 - 45%) substrato drėgnis ir aukštesnė - 25/18 °C temperatūra skatina asimiliacinį žirnių daigų lapų plotą.A study of rising temperatures and water deficit effects on pea biometric and biochemical characteristics was conducted at LSDI. It was accomplished at Plant Physiology Laboratory fitotronical complex in 2009. The research was made on the influence of rising temperatures and water deficit on pea (Pisum sativum L.) 'Glorioso' canopy growth, green and dry matter accumulation in terrestrial, assimilated leaf area and photosynthetic pigment content. The investigation showed that with increasing temperature and decreasing the substrate moisture of chlorophylls a and b and carotene content of pea shoots have been rising. The survey data shows that the highest dry material concentrations was of the shoots, which grew at normal humidity (40 - 45%) substrate and higher temperature - 25/18 ° C. The highest pea shoots leaf area was lower at normal temperature and substrate moisture (40 - 45%). Tallest plants were normal humidity (40 - 45%) and the substrate - 25/18 ° C temperature. Studies have shown that a complex of high humidity and temperature on pea plants promote growth. Also the data shows that normal (40 - 45%) substrate moisture content and higher - 25/18 ° C temperature promotes assimilation of pea sprouts leaves area.
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Ahmadiani, Neda. "RED CABBAGE ANTHOCYANINS: HORTICULTURAL AND CHEMICAL FACTORS AFFECTING COLOR CHARACTERISTICS OF CRUDE EXTRACTS, SELECT PIGMENT MIXTURES, AND ISOLATED PIGMENTS". The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1437655932.
Testo completo