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Genetic divergence among Brazilian turmeric germplasm using morpho-agronomical descriptors; Divergência genética entre acessos brasileiros de cúrcuma utilizando descritores morfo-agronômicos

SIGRIST, Mário Sérgio; PINHEIRO, José Baldin; AZEVEDO FILHO, Joaquim Adelino de; ZUCCHI, Maria Imaculada
Fonte: Crop Breeding and Applied Biotechnology Publicador: Crop Breeding and Applied Biotechnology
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.1%
Turmeric (Curcuma longa L.) is a vegetatively-propagated crop which is used as a natural dye in the food industry and also presents many biological active compounds. Turmeric conventional breeding is difficult and often limited to germplasm selection. The aim of this study was to evaluate the genetic divergence among turmeric accessions available in Brazil using seven morpho-agronomical descriptors. Overall genetic divergence was low, although some divergent genotypes were identified. Four main groups of genotypes were identified and could be further used in breeding programs. Canonical variable analysis suggested that some descriptors were more important to discriminate accessions and also that one of the descriptors could be discarded. The results provided useful insights for better management of the germplasm collection, optimizing conservational and breeding efforts.; A cúrcuma (Curcuma longa L.) é uma planta propagada vegetativamente que, além de ser utilizada como corante natural pela indústria alimentícia, apresenta diversos compostos biologicamente ativos. O melhoramento convencional da cultura é difícil, sendo usualmente limitado à seleção de germoplasma. O presente estudo avaliou a divergência genética entre os acessos de cúrcuma disponíveis no Brasil...

Em busca da sustentabilidade: células solares sensibilizadas por extratos naturais; Toward sustainability: solar cells sensitized by natural extracts

PATROCÍNIO, Antonio Otávio T.; MURAKAMI IHA, Neyde Y.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
46.16%
The present work reports the use of anthocyanins extracted from mulberry (Morus Alba L.), raspberry (Rubus Idaeus L.) and blueberry (Vaccinium myrtillus L.) as sensitizers in dye-sensitized solar cells. The conversion efficiency of these devices is dependent on the extracts employed and can be rationalized in terms of their composition and spectral properties. Solar cells sensitized by the mulberry extract showed the highest efficiency among the fruits investigated. Moreover, a 16 cm² active area solar cell with the mulberry extract has presented fair good efficiency of conversion for natural dye-based solar cells, besides stability over twenty weeks, showing perspectives for developing these low cost devices with a commercial viability.

Genetic diversity of turmeric germplasm (Curcuma longa; Zingiberaceae) identified by microsatellite markers

SIGRIST, M. S.; PINHEIRO, J. B.; AZEVEDO FILHO, J. A.; ZUCCHI, M. I.
Fonte: FUNPEC-EDITORA Publicador: FUNPEC-EDITORA
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.01%
Turmeric (Curcuma longa) is a triploid, vegetatively propagated crop introduced early during the colonization of Brazil. Turmeric rhizomes are ground into a powder used as a natural dye in the food industry, although recent research suggests a greater potential for the development of drugs and cosmetics. In Brazil, little is known about the genetic variability available for crop improvement. We examined the genetic diversity among turmeric accessions from a Brazilian germplasm collection comprising 39 accessions collected from the States of Goias, Mato Grosso do Sul, Minas Gerais, Sao Paulo, and Para. For comparison, 18 additional genotypes were analyzed, including samples from India and Puerto Rico. Total DNA was extracted from lyophilized leaf tissue and genetic analysis was performed using 17 microsatellite markers (single-sequence repeats). Shannon-Weiner indexes ranged from 0.017 (Minas Gerais) to 0.316 (Sao Paulo). Analyses of molecular variance (AMOVA) demonstrated major differences between countries (63.4%) and that most of the genetic diversity in Brazil is found within states (75.3%). Genotypes from Sao Paulo State were the most divergent and potentially useful for crop improvement. Structure analysis indicated two main groups of accessions. These results can help target future collecting efforts for introduction of new materials needed to develop more productive and better adapted cultivars.; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)[07/02895-4]

Efficient and low cost devices for solar energy conversion: Efficiency and stability of some natural-dye-sensitized solar cells

PATROCINIO, A. O. T.; MIZOGUCHI, S. K.; PATERNO, L. G.; GARCIA, C. G.; IHA, N. Y. Murakami
Fonte: ELSEVIER SCIENCE SA Publicador: ELSEVIER SCIENCE SA
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.35%
Dye-sensitized solar cells, named by us Dye-Cells, are one of the most promising devices for solar energy conversion due to their reduced production cost and low environmental impact, especially those sensitized by natural dyes. The efficiency and stability of devices based on natural sensitizers such as mulberry (Morus alba Lam), blueberry (Vaccinium myrtillus Lam), and jaboticaba`s skin (Mirtus cauliflora Mart) were investigated. Dye-Cells prepared with aqueous mulberry extract presented the highest P(max) value (1.6 mW cm(-2)) with J(sc) = 6.14 mA cm(-2) and V(oc) = 0.49 V, Photoelectrochemical parameters of 16 cm(2) active area devices sensitized by mulberry dye were constant for 14 weeks of continuous evaluation. Moreover, the cell remained stable even after 36 weeks with a fairly good efficiency. Therefore, mulberry dye opens up a perspective of commercial feasibility for inexpensive and environmentally friendly Dye-Cells. (C) 2009 Elsevier B.V. All rights reserved.; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); FAPESP; CNPq; Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); CAPES; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo do potencial de uso do resíduo efluente gerado da destilação do óleo de folhas de eucalipto (Corymbia citriodora (Hook) Pryor e Johnson 1976), como corante natural para o tingimento têxtil de algodão; Study of the potential of using waste effluent from the distillation of the leaf oil of eucalyptus (Corymbia citriodora (Hook) Pryor and Johnson 1976), as a natural dyestuff for dyeing cotton fabrics

Rossi, Ticiane
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 23/02/2010 PT
Relevância na Pesquisa
46.36%
Atualmente, os corantes naturais vêm ganhando maior interesse da sociedade, fazendo crescer um novo nicho de mercado, que valoriza produtos obtidos de matériasprimas naturais, devido aos menores danos causados à saúde humana e ao meio ambiente. Uma fonte potencial para obtenção de corantes encontra-se na operação industrial da obtenção de óleo essencial de folhas de eucalipto. Trata-se de um resíduo líquido gerado na etapa de destilação das folhas, mediante o emprego de vapor d´água. Um grande volume de extrato é gerado e descartado como efluente do processo. O Brasil é um dos principais produtores mundiais de óleo de folhas de eucalipto, sobretudo de Corymbia citriodora (ex Eucalyptus citriodora), havendo, desse modo, importante potencial de exploração do efluente gerado na destilação das folhas como matéria-prima. Contando com o apoio de uma empresa do setor de produção desse óleo, pretendeu-se avaliar o potencial desse extrato como corante natural, visando o tingimento de tecidos de algodão. Para caracterização do resíduo efluente e do corante natural dele obtido, foram realizadas avaliações físicas e químicas, tais como: teor de sólidos, pH, densidade, teor de taninos condensados e medição de cor mediante análises espectrofotométricas. Na avaliação do potencial do resíduo efluente como corante natural...

Resíduo líquido do tratamento com vapor da madeira de Eucalyptus grandis Hill ex. Maiden, aplicado como corante têxtil natural; Liquid waste from steaming of Eucalyptus grandis Hill ex. Maiden wood as a natural dye source for textile fibers

Rossi, Ticiane
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 12/02/2014 PT
Relevância na Pesquisa
56.32%
Aspectos ligados à saúde humana e ao meio ambiente têm ampliado o interesse da sociedade pelo uso de corantes naturais. Nesse contexto, inclui-se o retorno ao uso de corantes provenientes de matérias-primas de base florestal. Uma fonte potencial encontra-se na operação industrial de tratamento da madeira de Eucalyptus grandis por vapor. Usualmente, o resíduo líquido gerado ao final do processo é descartado, porém, por possuir cor, seu potencial como um corante natural para fibras têxteis foi aqui investigado. Especificamente, o resíduo foi aplicado em tecidos de algodão, lã e nylon, considerando-se o processo de tingimento por esgotamento. Foram estudados os efeitos da concentração do corante, forma de aplicação, in natura e em pó, tempo, temperatura, pH do banho de tingimento, e adição de sais metálicos no tingimento. Foi avaliada a solidez da cor dos tecidos tingidos quanto à luz, lavagem doméstica e fricção. O estudo contemplou as avaliação das características físico-química do resíduo, nos quesitos pH, cor, cromatografia de camada delgada e teores de sólidos totais e taninos condensados. Os resultados indicaram o resíduo líquido apresentando cor marrom, pH ácido, teor médio de sólidos totais e taninos condensados...

Obtenção de corante natural a partir de caroço de abacate (persea americana)

Holbach, Juliana Maciel
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Trabalho de Conclusão de Curso Formato: application/pdf
POR
Relevância na Pesquisa
46.16%
Com a crescente busca por alimentos mais saudáveis, naturais e com aparência agradável, a obtenção e uso de corantes naturais tornam-se importantes no mercado atual. Além da função de corante, existem interesses nas propriedades medicinais e seus efeitos na saúde humana. No grupo de corantes naturais, os carotenoides são os principais pigmentos naturais responsáveis pelas colorações amarela, laranja ou vermelha de muitos alimentos. Seus efeitos benéficos estão associados às suas propriedades antioxidantes e antidegenerativas. Uma fonte de carotenoides é o abacate (Persea americana), que contém esses pigmentos em sua casca, polpa e caroço. No processamento do fruto, o caroço é descartado, mas contém carotenoides. Logo, o caroço de abacate tem potencial para servir de matéria-prima para a extração de corante natural. Este trabalho teve por objetivo realizar extração de carotenoides a partir do caroço de abacate utilizando etanol como solvente. Os ensaios foram determinados por meio de um Planejamento Experimental Completo (2³) para avaliar os efeitos do volume de solvente (mL), número de extrações e tempo de extração (minutos). Foram obtidos extratos com concentração de carotenoides totais entre 9...

Determination of the phthalocyanine textile dye, reactive turquoise blue, by electrochemical techniques

Osugi, Marly E.; Carneiro, Patrícia A.; Zanoni, Maria Valnice Boldrin
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Conferência ou Objeto de Conferência Formato: 660-665
ENG
Relevância na Pesquisa
36.23%
Turquoise blue 15 (AT15) is a reactive dye widely used in the textile industry to color natural fibers. The presence of these dyes in effluent and industrial wastewater is of considerable interest due ecotoxicological and environmental problems. The electrochemical reduction of this dye has been investigated in aqueous solution using cyclic voltammetry, controlled potential electrolysis and cathodic stripping voltammetry. Optimum conditions for dye discoloration by controlled potential electrolysis use an alkaline medium. Using cathodic stripping voltammetry a linear calibration graph was obtained from 5.00×10-8 mol L-1 to 1.00×10 -6 mol L-1 of AT15 at pH 4.0, using accumulation times of 180 and 240 s and an accumulation potential of 0.0 V. The proposed method was applied in direct determination of the dye in tap water and in textile industry effluent.

REDISCOVERING THE ARRAIOLOS TAPESTRIES - ANALYSIS OF NATURAL DYES AND FIBERS IN HISTORICAL SAMPLES

Manhita, Ana; Vargas, Helena; Ribeiro, Isabel; Seruya, Isabel; Ferreira, Teresa; Mirão, José; Candeias, António; Costa, Cristina
Fonte: Universidade de Évora Publicador: Universidade de Évora
Tipo: Aula Formato: 63767 bytes; application/pdf
ENG
Relevância na Pesquisa
36.34%
Arraiolos tapestries are probably one of the richest artistic Portuguese expressions in terms of textile heritage. It is difficult to date the beginning of the production of rugs in Arraiolos, but they were already produced in the late 1600’s as they are listed in the inventories of Portuguese aristocratic households in the beginning of the 18th century. This study is integrated in project “REMATAR- Rediscovering the Materials of Arraiolos Tapestries” (PTDC/HAH/64045/2006) which intends to obtain systematized information on the composition, structure and degradation processes of these tapestries, and to use this data to improve conservation methodologies. The gathered data on natural dyes and mordants used in tapestries dated from different periods will hopefully allow the establishment of a time scale of materials usage. The tapestries studied belong to the Museu Nacional de Arte Antiga (MNAA) which the most complete and representative Arraiolos collection. Wool, linen and hemp were the most important fibres used in the making of Arraiolos tapestries. The richness of colours displayed by some of the Arraiolos tapestries denotes the likely use of a wide variety of dyes. However, only a few dye sources used worldwide to dye wool are described in the few bibliographic reports on Arraiolos making. Dye identification is usually done by extraction of the dyed fibre followed by high performance liquid chromatography with diode array detection (LC-DAD) and coupled with mass spectrometry (LC-MS) analysis of the extract. Scanning electronic microscopy (SEM)...

Extracting natural dyes from wool—an evaluation of extraction methods

Manhita, Ana; Ferreira, Teresa; Candeias, António; Barrocas Dias, Cristina
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
46.24%
The efficiency of eight different procedures used for the extraction of natural dyes was evaluated using contemporary wool samples dyed with cochineal, madder, woad, weld, brazilwood and logwood. Comparison was made based on the LC-DAD peak areas of the natural dye’s main components which had been extracted from the wool samples. Among the tested methods, an extraction procedure with Na2EDTA in water/DMF (1:1, v/v) proved to be the most suitable for the extraction of the studied dyes, which presented a wide range of chemical structures. The identification of the natural dyes used in the making of an eighteenth century Arraiolos carpet was possible using the Na2EDTA/DMF extraction of the wool embroidery samples and an LC-DAD-MS methodology. The effectiveness of the Na2EDTA/DMF extraction method was particularly observed in the extraction of weld dye components. Nine flavone derivatives previously identified in weld extracts could be identified in a single historical sample, confirming the use of this natural dye in the making of Arraiolos carpets. Indigo and brazilwood were also identified in the samples, and despite the fact that these natural dyes were referred in the historical recipes of Arraiolos dyeing, it is the first time that the use of brazilwood is confirmed. Mordant analysis by ICP-MS identified the widespread use of alum in the dyeing process...

Identification of Onion Dye Chromophores in the Dye Bath and Dyed Wool by HPLC-DAD: An Educational Approach

Barrocas Dias, Cristina; Miranda, Marco; Manhita, Ana; Candeias, António; Ferreira, Teresa; Teixeira, Dora
Fonte: Journal of Chemical Education Publicador: Journal of Chemical Education
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.28%
Onion skins (Allium cepa L.) and hydrated potassium aluminum sulfate were used to dye wool samples. The main chromophores associated with this natural dye source, quercetin and quercetin-4′-O-glucoside, were identified in the dye bath and in wool extracts by high-pressure liquid chromatography (HPLC)equipped with a diode array detector (DAD) with the help of standards. Two procedures were used to extract dye molecules from dyed wool prior to HPLC-DAD qualitative analysis and the analytical methodology used was discussed in terms of the analysis of historical textile pieces dyed with natural sources.

Photoelectrochemical solar cell using extract of Eugenia jambolana Lam as a natural sensitizer

Garcia,Christian G.; Polo,André S.; Iha,Neyde Y. Murakami
Fonte: Academia Brasileira de Ciências Publicador: Academia Brasileira de Ciências
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2003 EN
Relevância na Pesquisa
56.27%
The extract of Jambolão (java plum), Eugenia jambolana Lam, was used as a natural sensitizer of a wide band-gap semiconductor (TiO2) in photoelectrochemical solar cells. The natural dye, adsorbed onto the semiconductor surface, absorbs visible light and promotes electron transfer across the dye/semiconductor interface. Photogenerated current and voltage as high as 2.3 mA and 711 mV, respectively, were obtained and effective conversion of visible light into electricity was achieved. The use of a natural product as the semiconductor sensitizer enables a faster and simpler production of cheaper and environmentally friendly solar cells.

Genetic divergence among Brazilian turmeric germplasm using morpho-agronomical descriptors

Sigrist,Mário Sérgio; Pinheiro,José Baldin; Azevedo Filho,Joaquim Adelino de; Zucchi,Maria Imaculada
Fonte: Crop Breeding and Applied Biotechnology Publicador: Crop Breeding and Applied Biotechnology
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2011 EN
Relevância na Pesquisa
46.01%
Turmeric (Curcuma longa L.) is a vegetatively-propagated crop which is used as a natural dye in the food industry and also presents many biological active compounds. Turmeric conventional breeding is difficult and often limited to germplasm selection. The aim of this study was to evaluate the genetic divergence among turmeric accessions available in Brazil using seven morpho-agronomical descriptors. Overall genetic divergence was low, although some divergent genotypes were identified. Four main groups of genotypes were identified and could be further used in breeding programs. Canonical variable analysis suggested that some descriptors were more important to discriminate accessions and also that one of the descriptors could be discarded. The results provided useful insights for better management of the germplasm collection, optimizing conservational and breeding efforts.

Flour and anthocyanin extracts of jaboticaba skins used as a natural dye in yogurt

Fonte: Association of Food Scientists and Technologists of India (AFSTI) Publicador: Association of Food Scientists and Technologists of India (AFSTI)
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
56.11%
This study used the flour and anthocyanin extracts from jaboticaba skins as a dye in yogurt. Jaboticaba skins were lyophilised and ground. Yogurt that was made in the conventional fashion was treated with the addition of flour from jaboticaba skins in the concentrations of 0.1%, 0.5%, 1.0%, 1.5% and 2.0% or with the anthocyanin extract in the concentrations of 0.5%, 1.0%, 1.5%, 2.0% and 2.5%, with and without tannic acid; the yogurt samples were stored for 45 days. In general, the results of the acceptance test of the yogurt samples ranged between like slightly and like moderately. The highest scores received by the anthocyanin extract (like slightly) were obtained for the concentrations of 0.5–1.5%. The colour retention for all yogurt samples was above 70%. The average half-life was greater than 2500 h, considered high. We conclude that the use of jaboticaba skins as additives to yogurt can be an alternative to add value to jaboticaba.

Empleo de películas de TiO2 modificadas con un colorante natural para el tratamiento de aguas residuales de laboratorio

Fernández, Jorge Andres
Fonte: Pontifícia Universidade Javeriana Publicador: Pontifícia Universidade Javeriana
Formato: PDF
Relevância na Pesquisa
36.27%
La primera etapa del presente estudio contempló la elaboración de películas delgadas de TiO2 por medio de la técnica de sedimentación simple. Determinando que la zona de inestabilidad alrededor del punto isoeléctrico del TiO2 (USP) se encontraba entre 5,0 y 7,0. Se seleccionaron valores de pH extremos (1,6 y 9,0) para disminuir la velocidad de sedimentación (14 mmh-1 y 18 mmh-1) y se planteó un experimento con el cual se establecieron las variables (pH, Na4P2O7, uso de ultrasonido y radiación microondas) para la preparación de las películas. El procedimiento diseñado incluyó someter al material a 4 ciclos de sedimentación, la preparación de una suspensión de TiO2 al 0,05 % m/v a pH 9,0, la adición de Na4P2O7 (0,01M) y el uso de radiación microondas durante 20 min. La caracterización microscópica y espectroscópica permitió establecer que las películas obtenidas presentan tamaños de grano predominantes de 83 nm con un recubrimiento uniforme del sustrato. De igual manera, se determinó que el gap (energía de banda) del material es de 3,2 eV. La espectroscopia vibracional reveló señales correspondientes a la fase anatasa del TiO2. Las películas de TiO2 fueron empleadas en la degradación fotocatalítica del agua residual de laboratorio usando luz UV de 254 nm...

A dye sensitized solar cell using natural counter electrode and natural dye derived from mangosteen peel waste

Maiaugree, Wasan; Lowpa, Seksan; Towannang, Madsakorn; Rutphonsan, Phikun; Tangtrakarn, Apishok; Pimanpang, Samuk; Maiaugree, Prapen; Ratchapolthavisin, Nattawat; Sang-aroon, Wichien; Jarernboon, Wirat; Amornkitbamrung, Vittaya
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
Publicado em 13/10/2015 EN
Relevância na Pesquisa
36.29%
Mangosteen peel is an inedible portion of a fruit. We are interested in using these residues as components of a dye sensitized solar cell (DSSC). Carbonized mangosteen peel was used with mangosteen peel dye as a natural counter electrode and a natural photosensitizer, respectively. A distinctive mesoporous honeycomb-like carbon structure with a rough nanoscale surface was found in carbonized mangosteen peels. The efficiency of a dye sensitized solar cell using carbonized mangosteen peel was compared to that of DSSCs with Pt and PEDOT-PSS counter electrodes. The highest solar conversion efficiency (2.63%) was obtained when using carbonized mangosteen peel and an organic disulfide/thiolate (T2/T−) electrolyte.

Light harvesting in solar cells using natural pigments from red fruits adsorbed to mesoporous TiO2

Pinto, Ana Lúcia Moreira
Fonte: Universidade Nova de Lisboa Publicador: Universidade Nova de Lisboa
Tipo: Dissertação de Mestrado
Publicado em /11/2015 ENG
Relevância na Pesquisa
36.34%
Nature has developed strategies to present us with a wide variety of colours, from the green of leaves to the bright colours seen in flowers. Anthocyanins are between these natural pigments that are responsible for the great diversity of colours seen in flowers and fruits. Anthocyanins have been used to sensitize titanium dioxide (TiO2) in Dye-Sensitized Solar Cells (DSSCs). DSSCs have become one of the most popular research topic in photovoltaic cells due to their low production costs when compared to other alternatives. DSSCs are inspired in what happens in nature during photosynthesis. A primary charge separation is achieved by means of a photoexcited dye capable of performing the electron injection into the conduction band of a wide band-gap semiconductor, usually TiO2. With this work we aimed to synthesize a novel mesoporous TiO2 structure as the semiconductor in order to increase the dye loading. We used natural occurring dyes such as anthocyanins and their synthetic flavylium relatives, as an alternative to the widely used metal complexes of Ru(II) which are expensive and are environmentally unsafe. This offers not only the chance to use safer dyes for DSSCs, but also to take profit of waste biological products, such as wine and olive oil production residues that are heavily loaded with anthocyanin dyes. We also performed a photodegradation study using TiO2 as the catalyst to degrade dye contaminants...

Study of a natural dye solubilisation in o/w microemulsions and its dyeing behaviour

Paul, Roshan; Solans, Conxita; Erra Serrabasa, Pilar
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 22195 bytes; application/pdf
ENG
Relevância na Pesquisa
66.37%
7 pages, 7 figures, 1 table.-- Available online Dec 15, 2004.; The manufacture of synthetic dyes involves many non eco-friendly chemical procedures. For this reason, the application of natural dyes in textile dyeing is being explored worldwide. The dye exhaustion, fixation and levelness of dyeing depends on several factors such as the properties of fibres, the molecular structure of dyes, and the medium of the dyebath. The solubilisation of insoluble natural dyes in colloidal systems like microemulsions and its influence on dye exhaustion and fixation are becoming important in this connection. In the present investigation, the phase behaviour of water/non-ionic surfactant/polar oil system was studied and the microemulsion regions were identified. A water insoluble natural dye, C.I. Natural Orange 2, was then solubilised in selected microemulsions and its ability to dye wool was studied. The mechanism involved in the dye migration from the oil-swollen micelles to the fibre surface was also investigated.; The authors wish to acknowledge the financial assistance from Ministerio de Ciencia y Tecnología (PP Q 2002-04514-C03-03 and MAT 2002-02613), as well as the grant from Generalitat de Catalunya, DURSI (Grant 2001 SGR-00357).; Peer reviewed

The quest for quercitron: revealing the story of a forgotten dye

Hansen, Heather
Fonte: University of Delaware Publicador: University of Delaware
Tipo: Tese de Doutorado
Relevância na Pesquisa
36.28%
Linda Eaton; Quercitron is a natural dye derived from the inner yellow bark of the black oak tree. Significant because it is one of only two natural dyes with a known discoverer, quercitron receives merely a passing mention in sources of dyeing and printing history, textile design, economic history, and scientific texts. Edward Bancroft discovered quercitron in 1771, received a British patent controlling the distribution of the dye for a period of fourteen years in 1775, and had the patent extended for an additional fourteen-year term in 1785. He introduced the dye to printers in his 1794 manual Experimental Researches Concerning the Philosophy of Permanent Colours. When his patent expired in 1799, quercitron was in high demand among calico printers and the "drab style" prints produced by the dye dominated the textile markets. Generally this is the extent of the quercitron story. This study fills the gaps in the literature by examining the reaction to quercitron from Bancroft???s contemporaries and comparing the dye to other yellow sources. It investigates processes of production, printing, and distribution of quercitron and explores the relationships and networks of people involved in these processes. Finally this study challenges the notion that natural dyes disappear after the invention of synthetic dyes beginning in 1856. It illustrates quercitron???s evolution and longevity in the dyeing and printing industry.; M.A.; Winterthur Program in American Material Culture

Multiwalled carbon nanotube-titania nanocomposites: Understanding nano-structural parameters and functionality in dye-sensitized solar cells

Mombeshora,Edwin T.; Simoyi,Reuben; Nyamori,Vincent O.; Ndungu,Patrick G.
Fonte: South African Journal of Chemistry Publicador: South African Journal of Chemistry
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2015 EN
Relevância na Pesquisa
46%
Nanocomposites consisting of multiwalled carbon nanotubes and titania were synthesized by two methods, namely, sol-gel and chemical vapour deposition (CVD) methods. The work takes advantage of the bridging ability of nanotechnology between macromolecules and the solid state process in engineering alternative nanomaterials for various applications including solar cell fabrication. Physical and chemical characterization of the mesoporous nanocomposites from the two synthetic methods were investigated using Raman spectroscopy, thermogravimetric analysis, Fourier transformation infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, surface characterization and X-ray diffraction analysis. Physicochemical properties in the nanocomposites such as thermal stability, pore volume, crystallinity and surface area were observed to be a subject of MWCNT: titania ratios and synthetic methods. From the CVD synthetic method, observed attributes include more uniform and smoother coating; better crystallinity and larger pore width than sol-gel method. On the other hand, nanocomposites from sol-gel synthetic method had larger surface areas, were more defective and less thermally stable than those from CVD. Nanocomposites by the CVD method performed 39.2 % more efficient than those from sol-gel in light-harvesting experiments. The study shows that the nanocomposites synthesized were more effective than titania alone when the cheaper natural dye...