Master of Science / Department of Apparel, Textiles, and Interior Design / Sherry J. Haar / The recent green movement has created strong interest in sustainable practices in the apparel and textile industry. Accordingly, natural dye usage has increased in popularity over the recent years, as well as alternative fiber sources such as bamboo. Because of the inherently poorer fastness properties of natural dyes compared to synthetic dyes, additional research on natural dyes and mordant agents is necessary to obtain the best colorfastness results. Many salts, called mordants, are used to help affix natural dyes to fabrics, called mordants, but the most common is potassium aluminum sulfate. However, it has been suggested that aluminum acetate can be a substitute, if not a better mordant than potassium aluminum sulfate for cellulose fibers. This study compared the colorfastness of these two mordants in three different amounts including 5%, 10%, and 20% per weight of fiber (WOF). Three natural dye extracts (madder, weld, and coreopsis), were used to dye seven test fabrics, including a bamboo rayon jersey, two bamboo rayon woven fabrics, a cotton interlock knit, two woven cottons, and a bamboo rayon and cotton blend interlock knit. Lightfastness and colorfastness to laundering tests were conducted, and Gray Scale ratings were analyzed using ANOVA statistical analysis. This analysis showed significant four-way interaction between all variables. Results supported aluminum acetate as a more colorfast mordant for cellulose fibers. This research was supported in part by Agricultural Research Experiment Station at the Kansas State University.

Octahedral, six co-ordinate ruthenium complexes containing acid substituted polypyridyl ligands have proved particularly successful as dyes for Dye-Sensitised Solar Cells (DSSCs); thus there have been hundreds, if not thousands of these types of complexes synthesised and studied. Ruthenium dyes are now incorporated into commercial DSSCs; yet there is limited understanding of the interactions between the dye and the liquid I-/I3- electrolyte, which can both facilitate and hinder the generation of current and voltage within the cell. Monodentate –NCS ligands incorporated into ruthenium dyes appear to interact strongly with I- and I2 within the electrolyte. The analogous –NCO containing dye has therefore been synthesised to study the effect of the chalcogen atom on these interactions. Substituting –NCS for -NCO resulted in a significant change in the spectroscopic and electronic properties of the molecular dye, with destabilisation of the HOMO of the dye causing a red shift in dye absorption. Possibly due to this change in properties, the nature of the chalcogen atom was shown to have a significant impact on the performance of the dye in a DSSC. The effect of the nature of substituents on ancillary ligands of Ru(H2-dcbpy)(4,4`-Y2- bpy)(NCS)2 dyes on recombination across the TiO2 – electrolyte interface within the cell has been proven significant due to changes in the strength of binding of I2 to the substituent groups. However, few substituent groups have been investigated; therefore a series of halogenated dyes, where Y = Cl, Br, were synthesised. The effect of the nature of the halogen on dye recombination was significant, although the trends observed were not consistent with the reported data for iodine binding. Similar trends were observed for the analogous series, Ru(H2-dcbpy)(5,5’-Y2- bpy)(NCS)2 where Y = F, Cl, Br. By comparison of this series of dyes with the 4,4` dyes, it was discovered that the position of the substituent had a significant effect on the rate of recombination within the solar cell, as well as the electrochemical and spectroscopic properties of the dyes themselves. Such isomeric effects have not been previously reported. In the synthesis of these dyes, and in attempting the synthesis of five other ruthenium dyes, many barriers to efficient dye synthesis were discovered. Therefore, an investigation into the synthesis of ruthenium dyes has been conducted. By analysis of the breakdown products formed a number of avoidable side reactions, including decarboxylation and ruthenium catalysed nucleophilic substitution of the bpy ligands, were shown to occur. Problems associated with the high lability of the ruthenium centre at high temperatures have also been explored, and the use of UV/vis monitoring to aid optimisation of the reaction conditions was implemented. Thus, the development of two novel synthetic procedures allowed the synthesis of the dyes investigated during the course of this thesis.

published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

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Orientador: Raquel Fernandes Pupo Nogueira / Banca: Ian Castro Gamboa / Banca: Antonio Eduardo da Hora Machado / Resumo: Os processos convencionais de tratamento de efluentes não são capazes de remover corantes e seus produtos de degradação química e/ou biológica com eficiência e esses resíduos atingem os corpos d'água promovendo danos ao ecossistema aquático e posteriormente aos seres humanos. Neste contexto, o desenvolvimento de novos processos de tratamento de efluentes que contêm corantes é de fundamental importância. Neste trabalho estudou-se a degradação dos corantes Acid Orange 7 (AO7), Food Yellow 3 (FY3) e Food Red 17 (FR17) pelo processo foto-Fenton sob luz negra bem como solar. A influência do tartarato (TAR) e do citrato (CIT) como agentes complexantes de ferro, bem como a degradação em pH 5,0 também foram estudadas. Inicialmente verificou-se que a degradação de todos os corantes (50 mg L-1) pelo processo foto-Fenton utilizando 3,0 mmol L-1 de peróxido de hidrogênio, 0,2 mmol L-1 de nitrato férrico em pH 2,5 foi a condição que resultou em alta porcentagem de mineralização. Verificou-se que o corante AO7 é degradado em menor velocidade quando comparado aos outros dois corantes devido à maior densidade eletrônica nas estruturas dos corantes FY3 e FR17, proveniente principalmente da presença dos grupos sulfônicos. A adição de TAR e CIT melhorou significativamente o processo de degradação devido ao maior rendimento quântico em relação à fotorredução do ferro, sendo que o processo na presença de TAR apresentou ligeira vantagem em relação ao CIT. A presença dos ligantes também promoveu deslocamento batocrômico na banda de absorção das espécies de ferro (III). Entretanto isso não foi suficiente para aumentar a velocidade inicial de degradação sob luz solar em relação ao processo usando luz negra quando comparados em função da dose de energia. A degradação dos corantes foi possível em... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The conventional processes of wastewater treatment are unable to remove dyes and their chemical and/or biological degradation products efficiently and these effluents reach the surface waters promoting damage to aquatic ecosystem and subsequently to humans. In this context, the development of new processes for wastewater treatment that contains dyes is required. In this work the degradation of dyes Acid Orange 7 (AO7), Food Yellow 3 (FY3) and Food Red 17 (FR17) was studied using photo-Fenton process under black light or sunlight irradiation. The influence of tartrate (TAR) and citrate (CIT) as complexing agents of iron, as well as the degradation at pH 5.0 were also studied. Initially it was found that the degradation of all dyes (50 mg L-1) by photo-Fenton process using 3.0 mmol L-1 hydrogen peroxide, 0.2 mmol L-1 ferric nitrate at pH 2.5 was the condition that resulted in high percentage of mineralization. It was found that the dye AO7 degrades at a lower rate compared to the other two dyes due to a higher electron density in the structures of dyes FY3 and FR17, mainly from the presence of sulfonic groups. A significantly improvement on dyes degradation was observed when TAR and CIT were added due to the higher quantum yield of iron (III) photoreduction compared to aquocomplexes. The process in the presence of TAR had a slight advantage in relation to the CIT. The presence of ligands also promoted bathochromic shift in the absorption band of the species of iron (III), however it was not sufficient to increase the initial rate of degradation under sunlight in relation to process using black light when compared in function of the energy dose. The degradation of the dyes at pH 5.0 was possible only in the presence of ligands, with a similar rate when compared to the process at pH 2.5 without them. The dyes have also been... (Complete abstract click electronic access below) / Mestre

Orientador: Raquel Fernandes Pupo Nogueira / Banca: Maria Valnice Boldrin Zanoni / Banca: Fabio Kummrow / Resumo:A indústria têxtil produz efluentes altamente coloridos, com composição complexa e de difícil degradação por processos biológicos devido à utilização de compostos sintéticos, que apresentam grande estabilidade. Diante disso é necessário o desenvolvimento de metodologias de tratamento eficientes que sejam capazes de remover esses compostos evitando a contaminação dos corpos receptores de água. O presente trabalho estudou a degradação do corante Disperse Red 1(DR1), na sua forma comercialmente disponibilizada, por processo foto-Fenton. Para avaliar a eficiência de degradação e monitorar a formação de sub-produtos foram empregadas as técnicas cromatografia líquida de alta eficiência e a espectrometria de massas. A mineralização das amostras foi monitorada pela determinação de carbono orgânico total. As concentrações adotadas para os experimentos de degradação foram Fe(NO3)3 0,2 mmol L-1, H2O2 5,0 mmol L-1 e corante 20 mg L-1. Inicialmente o pH foi ajustado para 2,5 e as degradações foram realizadas por 90 minutos. Com essas condições foi possível mineralizar 65% do conteúdo de carbono orgânico, degradar mais de 99% do corante e remover a absorção na região característica do corante já com 30 minutos de experimento. Os testes de toxicidade aguda com organismo Daphnia similis mostraram que com 10 minutos de tratamento há um aumento da toxicidade que depois é reduzida, atingindo valores não tóxicos após 45 minutos de experimento. A espectrometria de massas permitiu identificar quatro produtos de degradação, que continham o grupo azo em sua estrutura. A máxima concentração dos intermediários ocorreu com 10 minutos, podendo esses serem responsáveis pela maior toxicidade observada nesse tempo de tratamento. Os resultados desse trabalho mostram que corantes têxteis, como o DR1, podem ser degradados por processo foto-Fenton com completa remoção da toxicidade para o microcrustáceo Daphnia simillis... / Abstract:The textile industry produces highly colored effluents with complex composition and difficult degradation by biological processes due to the use of synthetic compounds of e high stability. Therefore it is necessary to develop efficient methods of treatment that be able to remove these compounds avoiding contamination of the receiving bodies of water. The present work studied the degradation of the dye Disperse Red 1 (DR1), in its commercially available form by photo-Fenton process. In order to evaluate the efficiency and monitor the formation of degradation products high performance liquid chromatography and mass spectrometry were used. The mineralization of samples was monitored by total organic carbon analysis . The concentration adopted for the degradation experiments was 0.2 mmol L-1 Fe(NO3)3 , 5.0 mmol L-1 H2O2 and 20 mg L-1 dye. Initially the pH was adjusted to 2.5 and the degradations were performed for 90 minutes. Under these conditions it was possible to mineralize 65% of the organic carbon content, degrade more than 99% of the dye and remove characteristic absorption after 30 minute experiment. The acute toxicity tests with the organism Daphnia similis showed that toxicity increased after 10 minutes of treatment, which was then reduced, no toxic values after 45 minutes of experiment. Mass spectrometry allowed to identify four degradation products, which contained the azo group in its structure. The maximum concentration of intermediates occurred after 10 minutes, which may be responsible for higher toxicity observed after this time of treatment. The results of this study showed that textile dyes, such as DR1 can be degraded by photo-Fenton process with complete removal of toxicity to Daphnia simillis microcrustacean and the ecotoxicological monitoring is essential for determining when the degradation process can be stopped. / Mestre

Orientador: Maria Valnice Boldrin Zanoni / Banca: Raquel Fernandes Pupo Nogueira / Banca: Marcos Roberto de Vasconcelos Lanza / Banca: Germano Tremiliosi Filho / Banca: Carlos Alberto Martinez Huitle / Resumo: O presente trabalho tem por objetivo explorar o uso de sistemas fotoeletroquímicos baseados em semicondutores bicomponentes nanoestruturados de Ti/TiO2/WO3 preparados por moldes de poliestireno (templates) e Si/TiO2/Pt preparado por junção metalica. A sintese desses materiais foi realizada por anodização e deposição eletroquímica e a presença do TiO2 na fase anatasio e WO3 monoclínico foi confirmada por difração de raios-X e EDS. Analises de espectroscopia de reflectancia difusa (DRS) mostraram que o material bicomponente possui absorção na região do visível pela observação do red shift. A caracterização eletroquímica foi realizada por medidas de voltametria linear sob irradiação UV e visível por diferentes lâmpadas: de vapor de mercúrio de alta pressão de 125 W e xenônio de 150 W com filtros que isolam a contribuição UV e visível. Maior fotocorrente foi obtida pela irradiação com a lâmpada de Hg de 11,0 mA cm-2 enquanto que na presença da lâmpada de Xe os valores obtidos foram de cerca de 0,4 mA cm-2. Posteriormente, os eletrodos de TiO2/WO3 foram aplicados na oxidação fotoeletrocatalítica do corante têxtil preto reativo 5 (RB5) e concomitante geração de hidrogênio em um reator de dois compartimentos. Seu desempenho foi comparado ao dos eletrodos de Ti/TiO2 e W/WO3. As melhores condições experimentais levaram a 100% de descoloração do corante para os eletrodos de Ti/TiO2, W/WO3 e Ti/TiO2/WO3 sob iluminação pela lâmpada de vapor de Hg, mineralização de 73, 80 e 85% e a produção de hidrogênio também revelou rendimentos estimados satisfatórios de 43, 34 e 46%, respectivamente. A natureza do gás H2 foi confirmada por cromatografia gasosa (CG-TCD). Completa remoção do corante RB5 também foi obtida para o fotoanodo de Si/TiO2/Pt e eficiencia estimada da geração de H2 foi de 30% com valores de fotocorrente da ordem de 0,5 mA cm-2 sob irradiação pela lâmpada de vapor de Hg nas melhores... / Abstract: The present project meets the challenge of exploring the use of photoelectrochemical devices based on Ti/TiO2/WO3 bicomponent nanostructured semiconductors prepared by templates and Si/TiO2/Pt prepared by microgrid heterojunction. The synthesis was performed by anodization and electrochemical deposition and the presence of anatese TiO2 and monoclinic WO3 was confirmed by X ray and EDS analysis. Difuse reflectance spectroscopy (DRS) analysis indicated Ti/TiO2/WO3 extension of optical absorption spectrum into the visible light region (red shift). Electrochemical characterisation was performed by linear sweep voltammetry under UV and visible light irradiation by two different lamp sources: 125 W high pressure mercury lamp and 150 W xenon lamp coupled to filters which isolte UV and visible light contribuition. Enhanced photocurrent response was obtained under high pressure mercury lamp 11,0 mA cm-2 and under xenon lamp irradiation the observed values are close to 0,4 mA cm-2. The Ti/TiO2/WO3 were used as photoanodes on the Reactive Black 5 (RB5) photoelectrochemical oxidation and simultaneous hydrogen generation in a two compartment PEC reactor. The photoanode's performance was compared to the pure Ti/TiO2 nanotubes and W/WO3 nanoporous electrodes. The best experimental conditions leaded to 100% dye discoloration in the presence of TiO2, WO3 e TiO2/WO3 under mercury lamp irradiation, 73, 80 and 85% mineralization and satisfactory hydrogen generation estimated efficiencies of 43, 34 and 46%, respectively. Hydrogen generation was confirmed by gas chromatography analysis (CG/TCD). Complete dye degradation was obtained under UV and visible light irradiation of Si/TiO2/Pt photanodes and 30% of estimated hydrogen generation efficiency and 0,5 mA cm-2 photocurrent response under mercury lamp irradiation under the best experimental conditions. Dye removal and by-products generation were confirmed by LC-MS/MS by the detection of m/z 137, 280, 210, 297... / Doutor