Includes errata attached to first leaf. / Includes bibliographical references. / vi, 158 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The complexation of a range of monovalent and divalent metal ions by the bibracchial lariat ethers has been investigated. Also investigates the complexation of metal ions and the anionic azo dye Brilliant Yellow by the diazacrown linked cyclodextrin dimers. / Thesis (Ph.D.)--University of Adelaide, Dept. of Chemistry, 2000

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 79-88). Also available via the Internet.

Thesis (Ph. D.)--University of Hong Kong, 1999. / Includes bibliographical references.

Programa de Pós-Graduação em Engenharia Ambiental. PROÁGUA, Pró-Reitoria de Pesquisa e Pós Graduação, Universidade Federal de Ouro Preto / Submitted by Oliveira Flávia (flavia@sisbin.ufop.br) on 2016-01-15T18:28:49Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) DISSERTAÇÃO_AplicaçãoLeveduraResidual.pdf: 2703105 bytes, checksum: e4447da72880a7841aa456cc83b77118 (MD5) / Approved for entry into archive by Oliveira Flávia (flavia@sisbin.ufop.br) on 2016-01-18T16:11:17Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) DISSERTAÇÃO_AplicaçãoLeveduraResidual.pdf: 2703105 bytes, checksum: e4447da72880a7841aa456cc83b77118 (MD5) / Made available in DSpace on 2016-01-18T16:11:17Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) DISSERTAÇÃO_AplicaçãoLeveduraResidual.pdf: 2703105 bytes, checksum: e4447da72880a7841aa456cc83b77118 (MD5) Previous issue date: 2015 / O principal objetivo desse trabalho foi investigar o uso de levedura residual proveniente de indústria fermentativa como fonte de mediador redox (riboflavina) para a degradação redutiva de um azo corante modelo (Amarelo Gold Remazol) em reatores (batelada) em escala de bancada. Para tanto, o projeto avaliou três diferentes metodologias para a lise celular da levedura residual, visando obter a maior quantidade de riboflavina liberada no produto da lise celular, de uma forma eficiente e economicamente viável. A otimização dos processos de lise da levedura residual estudados (liquidificação, sonicação e NaCl) foi realizada pela aplicação de metodologia de superfície resposta (MSR) tendo a concentração de riboflavina como variável resposta. Para os ensaios de remoção de cor feitos com os lisados de levedura residual (LLR) e um extrato de levedura comercial (Himedia®) os frascos reatores foram operados (25ºC; 150 rpm) por 48 horas, na presença e na ausência de uma fonte de mediador redox utilizando uma solução de azo corante modelo (50 mg L-1). Os principais resultados deste trabalho podem ser sistematizados como a seguir: i) O método de lise celular que resultou em uma maior liberação de riboflavina ( 92μg g-1) foi a lise osmótica por adição de NaCl – aproximadamente o dobro do encontrado no extrato de levedura comercial; ii) A eficiência de remoção de cor utilizando o LLR obtido a partir da lise osmótica foi de 86%, eficiência 28 % maior do que a obtida na condição experimental sem a adição de fonte de MR; iii) O uso de derivados da lise celular de levedura mostrou-se capaz de acelerar a cinética de degradação de cor do sistema, obtendo valores de k em 0,85 e 0,81, para os ensaios Residual e Comercial, respectivamente, ajustando à pseudo-segunda ordem cinética; iv) Além de fornecer MR ao sistema, o uso de LLR mostrou ser uma boa fonte de carbono e energia e compostos carreadores de elétrons (NADH); v) Os dados cinéticos mostraram que há uma competição pelo uso dos elétrons equivalentes, entre a remoção de cor a produção de metano, bem como o acúmulo de AGVs nas horas iniciais. Dessa forma, a análise integrada dos resultados gerados por esta pesquisa contribui de forma relevante para o avanço do conhecimento nas áreas de degradação anaeróbia de azo corantes e uso de mediadores redox para acelerar a cinética de remoção de cor, bem como fornece uma fonte sustentável de de LLR que pode ser utilizado em reatores de grande escala. __________________________________________________________________________ / ABSTRACT: The main goal purpose of this work was to investigate the use of residual yeast derived from fermentation industries as source of redox mediator (riboflavin) to the reductive degradation of a model azoic dye (Remazol Gold Yellow) in batch reactors in a bench scale. Therefore, this project analyzed three different methodologies to cell lysis from residual yeast, in order to attain the highest amount riboflavin released in the cell lysis product, in an efficient and economic procedure. The optimization of the process of the cell lysis from residual yeast was carried out by the response surface methodology (RSM). The cell lysis methods analyzes were the mechanical one by liquefaction, the sonication and chemical (NaCl), intending a release of a higher concentration of riboflavin (Vitamin B2). During the color-removing trials done with residual yeast lysate (LLR) from residual yeast and a commercial yeast extract (Himedia®), the flasks were operated (25ºC; 150 rpm) for 48 hours, in the presence or absence of a source redox mediator using a model azoic dye (50 mg L-1). The main results from this research are as folows: i) The chemical lysis method by NaCl addition has shown the highest release of riboflavin ( 92μg g-1) – approximately the double found commercial yeast extract; ii) The effectiveness of the color removal with the extract from chemical lysis was 86% with was 26% higher than that observed in the absence of redox mediators; iii) The use of yeast lysates accelerated the kinetics of color removal, with followed the pseudo second order model with k values of 0,87 and 0,81; iv) Besides providing redox mediators to system, the use of residual yeast lysate has shown to be a good source of carbon and energy and electron carries (NADH). v) Kinetic data showed that there is a competition for the use of equivalent electrons between the color removal and the methane production, as well as accumulation of VFAs in the initial hours. Thus, the integrated analysis of the results generated by this research contributes significantly to the advancement of knowledge in the areas of anaerobic degradation of azo dyes and use of redox mediators to accelerate color removal kinetics and provides a sustainable source LLR that may be used in large-scale reactors.

Orientador: Silvania Lanfredi / Banca: Patrícia Alexandra Antunes / Banca: Sérgio Antônio Marques de Lima / Resumo: Este trabalho teve como objetivo a preparação, a caracterização estrutural e análise do potencial fotocatalítico de nanopartículas do tipo core@shell de ZnO@Cr, ZnO@Ni e dos compósitos de C/Zn@Cr e C/ZnO@Ni, combinando nanopartículas e carbono amorfo. As nanopartículas core@shell foram sintetizadas pelo método Pechini Modificado e os compósitos, contendo carbono amorfo, pelo método de Pirólise Parcial. Os materiais sintetizados foram caracterizados por análise termogravimétrica (TG), microscopia eletrônica de varredura (MEV) e microscopia eletrônica de transmissão (MET), difração de raios X (DRX), espectroscopia de absorção no infravermelho (I.V.), espectroscopia no ultravioleta-visível (UV-VIS) e medidas de condutividade térmica. As caracterizações estruturais mostraram a formação de um sistema do tipo core@shell, onde o recobrimento é essencialmente amorfo. Uma pequena fração de solução sólida foi identificada na interface núcleo/revestimento, bem como uma redução nos valores de energia de band gap, em função dos recobrimentos. Para os compósitos, as caracterizações estruturais mostraram a manutenção das nanopartículas core@shell em meio a uma matriz de carbono com estrutura do tipo turbostrática. A análise do potencial fotocatalítico mostrou que, os recobrimentos com Cr e Ni e a matriz de carbono, de modo geral, atuaram positivamente sobre a fotoatividade do ZnO. Foram obtidas taxas de descoloração entre 64 e 98%, sendo o melhor resultado obtido para a descoloração do corante basic blue 41 na presença das nanopartículas ZnO@Ni. Em todos os experimentos, a reação de descoloração dos corantes, seguiu uma cinética do tipo primeira ordem / Abstract: This work aimed the preparation, structural characterization and analysis of photocatalytic potential of ZnO@Cr and ZnO@Ni core@shell type nanoparticles and of C/Zn@Cr and C/ZnO@Ni composites, combining the nanoparticles and amorphous carbon. The core@shell nanoparticles were synthesized by the Pechini Modified method and the composites, containing amorphous carbon, were synthesized by the Partial Pyrolysis method. The synthesized materials were characterized by thermogravimetric (TG), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), X-ray diffraction (XRD), infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV-Vis) and thermal conductivity measurements. The structural characterization showed the formation of a core@shell type system where the coating is essentially amorphous. A small fraction of solid solution was identified in the interface core/coating, as well as a reduction in the band gap energy values as a function of the coatings. For the composites, structural characterizations showed the maintenance of the core@shell nanoparticles amid a carbon matrix with turbostratic type structure. The analysis of the photocatalytic potential showed that the coatings with Cr and Ni and carbon matrix acted positively on the photoactivity of ZnO. Discoloration rates between 64 and 98% were obtained. The best result was acquired for the discoloration of the basic blue 41 dye in presence of ZnO@Ni nanoparticles. In all experiments, the reaction of discoloration of dyes followed a kinetic of the first order type / Mestre

Orientador: Marcelo Alexandre Prado / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-20T15:27:48Z (GMT). No. of bitstreams: 1 Beltramin_GabrielleDiasRosa_M.pdf: 5469686 bytes, checksum: 507fcd03670f5e77f40d07836a855261 (MD5) Previous issue date: 2012 / Resumo: O emprego de aditivos químicos em alimentos é um assunto que tem gerado bastante controvérsiaentre consumidores, indústrias, pesquisadores e governo. Exemplo são os corantes artificiais, aditivos bastante utilizados pela indústria de alimentos na coloração de seus produtos. Sem valor nutricional, seu uso é justificado apenas por questões alimentares. Em comparação com os corantes naturais, apresentam maior uniformidade, estabilidade e poder tintorial. Apesar das vantagens, evidências toxicológicas são consideravelmente maiores para os corantes artificiais e, apesar da alta estabilidade podem ter essa característica prejudicada por efeito de fatores físicoquímicos, como luz, temperatura e conservantes presentes na composição de alimentos e bebidas. Tendo em vista as características climáticas no Brasil e, levando em consideração sua enorme extensão, é de interesse analisar a estabilidade de corantes artificiais comumente utilizados em alimentos e bebidas comercializadas no país, uma vez que, a instabilidade desses corantes pode afetar a qualidade do produto, bem como causar riscos a saúde. Estudos comprovaram a influência de açúcares, ácidos ascórbico, sórbico, cítrico e benzóico na estabilidade de alguns corantes azo, porém, ácido cítrico em presença de ácido ascórbico ainda não foi abordado de forma minuciosa. Assim, o presente trabalho teve como objetivo estudar a estabilidade dos corantes tartrazina, amarelo crepúsculo e amaranto frente aos efeitos de luz, temperatura e presença dos ácidos ascórbico e cítrico, utilizando a técnica de espectrofotometria UV-visível. A estabilidade dos corantes também foi analisada em misturas de corantes para verificar a existência ou não de sinergia. Resultados demonstraram maior estabilidade dos corantes tartrazina e amarelo crepúsculo, independente das condições de estocagem. O amaranto apresentou alta instabilidade, principalmente em condições de alta temperatura e luz solar. Essas condições, de modo geral, provocaram maior instabilidade para os três corantes, que por outro lado, mantiveram-se estáveis em condição de escuro e baixa temperatura. A presença de ácido cítrico e ácido ascórbico provocou maior instabilidade dos corantes em todas as condições físicas testadas, exceto para a condição de escuro e alta temperatura, o qual apresentou estabilidade semelhanto ao grupo com presença apenas de ácido ascórbico. A análise de soluções com mistura de corantes garantiu, principalmente, maior estabilidade ao amaranto tanto na presença do amarelo crepúsculo quanto da tartrazina. Análises com bebidas coloridas artificialmente confirmaram o efeito da luz solar na diminuição da estabilidade dos corantes e da temperatura baixa na estabilidade desses compostos / Abstract: The adding of chemical additives in foods and beverages is a controversial issue between consumers, industries, researchers and government. Examples are artificial dyes, so used by food industries to color foodstuffs. With no nutritional value, use is only justified by alimentary habit. In comparison to natural dyes, they present higher uniformity, stability and coloring power. In spite of these advantages, toxicological evidences for artificial dyes are even higher than for natural ones and stability can be affected by physical-chemical factors, like for example, light, temperature and presence of preservative compounds in foods and beverages. Given the climatic characteristics in Brazil and taking into account its enormous extent, it is interesting to analyze the stability of artificial dyes commonly used in foods and beverages traded in the country, since the instability of these dyes can affect product quality as well as causing health risks. Researches have already proved sugar, ascorbic, sorbic, citric and benzoic acids influence on the stability of some azo dyes, though there are no information about citric and ascorbic acids influence together on the stability of tartrazine, sunset yellow and amaranth, neither when they are mixed with another artificial dye. Therefore, the aim of this study was to check the stability of tartrazine, sunset yellow and amaranth by the effects of light, temperature and presence of ascorbic and citric acid, using the technique of UV-visible spectrophotometry. Dyes¿ stability was also analyzed at dye mixtures to verify the existence of synergy. Results showed greater stability of tartrazine and sunset yellow, regardless of storage conditions. Amaranth was highly unstable, especially under conditions of high temperature and sunlight. These conditions generally caused greater instability for the three azo dyes. On the other hand, their color remained stable at dark and low temperature condition. The presence of citric and ascorbic acid caused greater instability of the dyes in all physical tested conditions, except for dark and high temperature condition, which presented the same stability of the group with only ascorbic acid. Analysis of dye mixture solutions ensured, especially, greater stability to amaranth in the presence of either sunset yellow or tartrazine. Analysis with artificially colored beverages confirmed the effect of sunlight in dyes¿ stability decrease and low temperature in the stability of these compounds / Mestrado / Ciência de Alimentos / Mestre em Ciência de Alimentos

Previous work in our group has been directed towards the synthesis of crown-ethers for use in the selective complexation of metal ions and as chiral ligands for use in asymmetric catalysis. The development of a modular approach to macrocycle assembly has enabled the synthesis of a library of pyridine-based macrocycles possessing multiple donor sites where chirality was readily introduced from simple amino acids.The nucleophilic ring opening of aziridines 181, 193 or 194, allowed the highly selective synthesis of thioether-based spacers and macrocycles. Extension of this basic approach to the synthesis of seleno-crown ethers was also investigated. The use of chiral-pool starting materials derived from D- or L-alanine, provided access to optically pure macrocycles. The use of the Sharpless-Huisgen 'click' reactions allowed the attachment of a carbohydrate residue directly to a macrocycle via a triazole unit. We hope to attach a macrocycle, carbohydrate residue and azo dye together, to be able to examine further diseases such as Alzheimer's. We have so far succeeded in attaching a macrocycle and sugar to a central scaffold by performing a one-pot double 'click' reaction. The distance between the points of attachment of the chromophore to the macrocycle metal binding site is probably, in this first generation sensor, too great to enable a metal-macrocycle binding event to be reported.

Decolorization of Azo dyes in synthetic wastewater composition which is similar to real textile wastewater was carried out by microbial process. Experiments were performed in two continuous systems. Experiments were performed under anaerobic conditions in order to break the nitrogen bond of the azo group (-N=N-). A synthetic dye solution which contained 200 mg/L Reactive Black 5, 200 mg/L Procion Red MX-5B and 1 g/L yeast extract was prepared. In this study, living microorganisms were used to degrade the dyes in wastewater. Rice husks which contain bacteria and fungi were used in the reactors of continuous systems. The parameters tested on continuous system were wastewater composition, the number of reactors, the amount of yeast extract in wastewater composition, the wastewater flowrate, washing the system with wood chips solution, addition of yeast extract solution.  Results have shown that increasing the number of reactors, the retention time, the amount of yeast extract and washing the system with wood chips solution had positive effects for degradation of the dyes from wastewater. When the flowrate was increased the retention time has decreased so degradation of dyes has decreased but although the flowrate increased twice, % degradation hasn’t decreased as the same ratio. Therefore this result showed that this process can be worked for faster flowrates. Microbial process is a promising technology which might be used to treat wastewater containing azo dyes with good performance.

京都大学 / 0048 / 新制・課程博士 / 博士(エネルギー科学) / 甲第22794号 / エネ博第408号 / 新制||エネ||78(附属図書館) / 京都大学大学院エネルギー科学研究科エネルギー社会・環境科学専攻 / (主査)教授 石原 慶一, 准教授 奥村 英之, 教授 佐川 尚 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM

This dissertation describes the synthesis of novel, small molecule building blocks and the phenomena that are revealed when they are studied in unusual environments. Chapter 1 is divided into two sections, serving as introductions for chapters 2-3 and 4-5 respectively. The first section introduces the scanning tunneling microscope break junction (STM-BJ) as a new environment for reaction chemistry. Chapter 2 describes a truly single molecule reaction in which azobenzenes are formed in the STM-BJ one molecule at a time. Chapter 3 describes an electrostatically driven Ullmann coupling reaction of biphenyl iodides in the STM-BJ. In contrast to the reaction described in chapter 2, this reaction occurs throughout the solution in the presence of an electric field that surrounds the nanoelectrodes. The second half of chapter 1 provides a primer on the photoisomerization of azobenzenes, a class of small molecule dyes whose unique photochromic profile and switchable properties have been exploited across a wide range of fields. Chapter 4 introduces azobenzenes as photoswitchable ligands on superatomic clusters. Chapter 5 details the phenomenon and mechanism of white light driven rolling of Cu(I) isocyanoazobenzene crystals. Finally, chapter 6 is a self-contained research project. It details an organocatalytic O₂-coupled oxidation platform that capitalizes on the capacity of hydrazines to undergo rapid autoxidation to diazenes.