Dans cette thèse nous avons eu pour but d’étudier la réactivité des complexes à bas degré d’oxydation du fer stabilisés par des ligands phosphines vis-à-vis des substrats insaturés. Cet objectif s’inscrit dans une démarche plus large d’accès à des systèmes catalytiques au fer capables de transformer de manière sélective l’éthylène, par la réaction d’oligomérisation, vers des alpha-oléfines linéaires courtes (butène-1, héxène-1, octène-1), ce qui n’a jamais été rapporté dans la littérature. Pour se faire, le passage par le mécanisme métallacyclique de transformation de l’éthylène est la voie privilégiée. Cependant, les propriétés électroniques et géométriques de ligand requises pour suivre un tel mécanisme, et en particulier son étape clé de couplage oxydant de deux molécules d’éthylène sur le centre métallique, ne sont pas clairement identifiées. Nous rapportons ici dans un premier temps la synthèse d’une bibliothèque de complexes de fer(II) et fer(III) à base de ligands phosphines présentant des propriétés électroniques et géométriques variées. Ces nouveaux complexes sont opportunément testés en tant que catalyseurs, d’une part pour la réaction d’oligomérisation de l’éthylène; mais également en tant qu’espèces réduites in situ en association avec des diènes (isoprène, butadiène) conduisant à leur polymérisation. Afin de nous rapprocher davantage de notre objectif d’accès aux espèces à bas degré d’oxydation du fer, l’emploi d’une voie de réduction en une étape et en conditions douces est rapportée; conduisant à l’isolement et la caractérisation de neuf complexes phosphorés de fer(0) à 18 et à 16 électrons. Bien qu’a priori inactifs vis-à-vis de l’éthylène ou des oléfines plus longues, nous montrons la capacité de ces complexes à promouvoir des réactions de couplage oxydant de substrats insaturés (alcynes) le couplage catalytique de l’éthylène et du butadiène et l’activation de divers composés tels que les silanes ou les halogénures d’alkyles, posant ainsi un premier jalon vers leur optimisation et application en tant que catalyseurs d’autres réactions, et potentiellement dans l’avenir, pour la transformation de l’éthylène. / In this thesis our aim was to study the reactivity of phosphine-based low-valent iron complexes towards unsaturated substrates. This goal is part of a wider approach of access to an iron catalytic system able to transform ethylene in a selective manner, by the reaction of oligomerization, towards short linear alpha-olefins (1-butene, 1-hexene, 1-octene), which is unreported in the literature. To achieve this, going through the metallacyclic mechanism of ethylene transformation is the most likely way. However, the electronic and geometrical features of the ligand required to follow this mechanism, and in particular the key step of the oxidative coupling of two molecules of ethylene to the metal center, are ill-defined. We thus report here in a first part the synthesis of a library of P-based iron(II) and iron(III) complexes bearing varied electronic and geometrical features. These novel complexes are opportunistically screened as catalysts for ethylene oligomerization on one hand, and as in situ reduced species in association with dienes (isoprene, butadiene) leading to the polymerization of the latter substrates, on the other hand. In order to get closer to our goal of access to low-valent iron complexes, the use of a one-pot reduction methodology under mild conditions is reported, leading to the isolation and characterization of nine 18- and 16-electron iron(0) complexes. Even though they do not show reactivity towards ethylene or longer olefins, we demonstrate the ability of these complexes to promote reactions involving the oxidative coupling elementary step of unsaturated substrates (alkynes), the catalytic coupling of ethylene and butadiene and the activation of various compounds such as silanes and organic halides, representing a first milestone towards their optimization and application as catalysts for other reactions, including potentially in the near future, for ethylene transformation

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京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第21963号 / 工博第4618号 / 新制||工||1720(附属図書館) / 京都大学大学院工学研究科高分子化学専攻 / (主査)教授 山子 茂, 教授 辻井 敬亘, 教授 大内 誠 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

<p>Predmet izučavanja ove disertacije je ispitivanje mogućnosti primene homogenog, heterogenog i Fentonsličnog procesa u tretmanu obojenih otpadnih voda grafičke industrije.&nbsp; Kao Fenton katalizatori kori&scaron;ćeni su sintetisani gvožđe(III)-molibdat i nano nula valentno gvožđe, kao i komercijalni gvožđe(II)-sulfat. Istraživanja&nbsp; su sprovedena u četiri faze. U prvoj fazi&nbsp; je izvr&scaron;ena sinteza&nbsp; i karakterizacija&nbsp; Fenton&nbsp; katalizatora, pri čemu su ustanovljene njihove osnovne morfolo&scaron;ke karakteristike. Nano nula valentno gvožđe je sintetisano iz ekstrakta&nbsp; li&scaron;ća hrasta, dok je&nbsp; gvožđe(III)-molibdat sintetisan putem tzv. vlažnog hemijskog postupka. U drugoj fazi je&nbsp; izvr&scaron;ena optimizacija Fenton procesa u tretmanu sintetičkih rastvora grafičkih&nbsp; boja primenom nove statističke&nbsp; metode,&nbsp;<em> definitive screening design</em>.&nbsp; U&nbsp; cilju postizanja&nbsp; maksimalnog stepena obezbojavanja i mineralizacije tretiranog uzorka&nbsp; ispitan&nbsp; je&nbsp; uticaj&nbsp; sledećih&nbsp; procesnih parametara: inicijalne koncentracije boje, koncentracije gvožđa, pH vrednosti i koncentracije vodonik-peroksida. Nakon ustanovljenih optimalnih uslova i izvr&scaron;ene verifikacije predloženog optimuma, sproveden je tretman realnog efluenta.&nbsp; Stepen mineralizacije&nbsp; tretiranog&nbsp; efluenta&nbsp; ustanovljen&nbsp; je&nbsp; na&nbsp; osnovu&nbsp; vrednosti&nbsp; sadržaja&nbsp; ukupnog&nbsp; organskog&nbsp; ugljenika&nbsp; i&nbsp; hemijske&nbsp; potro&scaron;nje kiseonika.&nbsp; U cilju razumevanja mehanizma degradacije grafičkih boja u Fenton procesu, kao i identifikacije prirode&nbsp; degradacionih&nbsp; produkata,&nbsp; izvr&scaron;ena&nbsp; je&nbsp; kvalitativna&nbsp; gasno-hromatografska/maseno&nbsp; spektrometrijska analiza. Kinetika obezbojavanja realnog&nbsp; efluenta&nbsp; najbolje&nbsp; je opisana primenom&nbsp; Behnajady&nbsp; -&nbsp; Modirshahla&nbsp; -Ghanbary&nbsp; modela,&nbsp; koji&nbsp; defini&scaron;e&nbsp; inicijanu&nbsp; brzinu&nbsp; i&nbsp; oksidacioni&nbsp; kapacitet&nbsp; posmatranog&nbsp; procesa.&nbsp; Rezultati&nbsp; su ukazali&nbsp; na&nbsp; moguću&nbsp; primenu&nbsp; Fenton&nbsp; procesa&nbsp; u&nbsp; tretmanu&nbsp; CMYK&nbsp; boja&nbsp; usled&nbsp; postizanja&nbsp; visokih&nbsp; efikasnosti obezbojavanja i mineralizacije tretiranih efluenata. Nedostatak primenjene metode se ogleda u činjenici da je većina&nbsp; uzoraka&nbsp; okarakterisana&nbsp; kao&nbsp; visoko&nbsp; toksična,&nbsp; a&nbsp; ujedno&nbsp; i&nbsp; izrazito&nbsp; kisela,&nbsp; budući&nbsp; da&nbsp; je&nbsp; ustanovljena optimalna&nbsp; pH&nbsp; vrednost&nbsp; Fenton&nbsp; tretmana&nbsp; 2&nbsp; -&nbsp; 3.&nbsp; Stoga&nbsp; je&nbsp; u&nbsp; okviru&nbsp; treće&nbsp; faze&nbsp; istraživanja&nbsp; primenjen&nbsp; dodatni tretman&nbsp; realnog&nbsp; efluenta,&nbsp; adsorpcija&nbsp; na&nbsp; aktivnom&nbsp; uglju&nbsp; sintetisanom&nbsp; iz&nbsp; ko&scaron;tica&nbsp; divlje&nbsp; &scaron;ljive.&nbsp; Adsorpcioni tretman&nbsp; je rezultovao smanjenjem&nbsp; toksičnosti&nbsp; kod&nbsp; svih tretiranih uzoraka, koji&nbsp; se&nbsp; karakteri&scaron;u&nbsp; kao nisko do umereno toksični, te je sa tog aspekta moguće njihovo bezbedno ispu&scaron;tanje u recipijent. Ujedno je ustanovljena i povećana mineralizacija uzoraka, kao posledica degradacije jedinjenja koja su inicijalno doprinela povećanoj toksičnosti. U četvrtoj fazi rada primenjena je metoda ocenjivanja životnog ciklusa sinteze Fenton katalizatora. Rezultati LCA su utvrdili da sinteza heterogenog Fenton katalizatora, gvožđe(III)-molibdata, ostvaruje najveće opterećenje&nbsp; životne&nbsp; sredine,&nbsp; dok&nbsp; bi&nbsp; se&nbsp; proces&nbsp; sinteze&nbsp; nano&nbsp; nula&nbsp; valentnog&nbsp; gvožđa&nbsp; mogao&nbsp; unaprediti modifikovanjem ekstrakcione faze uz kori&scaron;ćenje alternativnih materijala i obnovljivih izvora energije. Značaj&nbsp; predstavljenih rezultata se ogleda u činjenici da su uzorci obojenih otpadnih voda grafičke industrije prvi put podvrgnuti Fenton tretmanu koji je rezultovao visokim stepenom efikasnosti.</p> / <p>The subject of this thesis is&nbsp; exploring the possibility of homogeneous, heterogeneous and Fenton-like process application in the treatment of dye wastewater in printing industry. Synthesized iron(III)-molybdate and nano zero valent iron, as well as commercial iron(II)-sulfate were used as a Fenton catalyst. The research was carried out in four&nbsp; phases.&nbsp; In&nbsp; the&nbsp; first&nbsp; phase,&nbsp; the&nbsp; catalyst&nbsp; synthesis&nbsp; and&nbsp; their&nbsp; characterization&nbsp; were&nbsp; performed,&nbsp; whereby&nbsp; the morphological characteristics were established. Nano zero valent iron was synthesized from&nbsp; oak leaf extract&nbsp; and iron(III)-molybdate was synthesized by wet chemical process. In the second phase, the optimization of Fenton process was performed within the treatment of synthetic printing dye solution using a new statistical method, a definitive screening design. In order to achieve maximum decolorization and mineralization of the treated sample, the influence of&nbsp; following&nbsp; process parameters was conducted: initial dye concentration, iron concentration, pH value&nbsp; and hydrogen peroxide concentration.&nbsp; The treatment of printing effluent was performed&nbsp; after&nbsp; establishing optimal&nbsp; conditions&nbsp; and&nbsp; verifying&nbsp; the&nbsp; proposed&nbsp; optimum&nbsp; values.&nbsp; Mineralization&nbsp; degree&nbsp; of&nbsp; treated&nbsp; effluent&nbsp; was determined based on the results of total organic carbon and chemical oxygen demand. In order to understand the dye&nbsp; degradation&nbsp; mechanism&nbsp; in&nbsp; Fenton&nbsp; process,&nbsp; as&nbsp; well&nbsp; as&nbsp; to&nbsp; identify&nbsp; degradation&nbsp; products,&nbsp; a&nbsp; qualitative&nbsp; gaschromatographic/mass spectrometric analysis was carried out. The&nbsp; kinetic studies of the printing effluent were best described by using the Behnajady- Modirshahla-Ghanbary model, which defines the initial speed and oxidation capacity of the process. The results indicated the possible application of the Fenton process in the treatment of CMYK dyes due to the high decolorization and mineralization efficiency of treated effluent. Disadvantage of the applied method is reflected in the fact that most of the samples are characterized as highly toxic and,&nbsp; at the same time, extremely acidic since the optimum pH value of Fenton treatment is 2 - 3. Therefore, in the third phase of the study, adsorption process on functionalized biochar prepared from wild plum kernels was applied on real printing effluent.&nbsp; Adsorption&nbsp; treatment&nbsp; resulted&nbsp; in&nbsp; toxicity&nbsp; reduction&nbsp; in&nbsp; all&nbsp; treated&nbsp; samples,&nbsp; characterized&nbsp; as&nbsp; low&nbsp; to moderately toxic. Therefore, from this aspect, treated effluent can be safely released into the recipient. At the same time, increased mineralization of the samples was established as a result of the compounds degradation that initially contributed to high toxicity. In the fourth phase, a life cycle assessment method of Fenton catalyst was applied. The results of the LCA indicated that the synthesis of the heterogeneous Fenton catalyst, iron(III) molybdate, achieved the highest environmental burden, while the synthesis of nano zero valent iron could be improved by modifying the extraction phase using alternative materials and renewable energy sources.&nbsp; The significance of the obtained results is high decolorization efficiency achieved by Fenton treatment of printing dye wastewater,&nbsp; which was used for the first time.</p>

Les adduits cuivre-oxygène dans les métallo-enzymes ont été proposés comme étant responsables de l'activation de liaisons C-H, processus qui ont un intérêt pour des applications industrielles potentielles. La première partie de ce travail est consacrée à une présentation de différentes mono-oxygénases à cuivre et de leurs complexes modèles. Récemment, des intermédiaires réactionnels ont émergé et parmi ceux-ci, des espèces de valence mixte CuIICuIII ont été proposées comme étant des espèces réactives clés pour l'activation de liaisons C-H fortes.Dans ce travail, à partir de ligands binucléants basés sur un espaceur 1,8-naphtyridine, la stabilisation et les caractérisations spectroscopiques de ce type d’intermédiaires à haut degré d’oxydation sont explorées. La préparation d’espèces Cu2:O2 à partir de l'activation du dioxygène par les complexes CuI2 est discutée. Deux complexes µ-ɳ2:ɳ2-peroxo-CuII2 ont été préparés à -80°C et caractérisés par différentes méthodes spectroscopiques associées à des calculs par la théorie de la fonctionnelle de la densité (DFT). A partir de nouveaux ligands dissymétriques possédant une fonction amide, nos tentatives pour contrôler la préparation des complexes binucléaires associés sont également présentées. Puis, les caractérisations des espèces à valence mixte CuIICuIII obtenues par mono-oxydation électronique des complexes CuII2 sont décrites (voltammétrie cyclique, résonance paramagnétique électronique, UV-visible, proche infrarouge et DFT).Enfin, ce travail est complété par l’étude de la réactivité des espèces CuIICuIII, pour lesquelles la littérature est presque inexistante. Lorsque des ligands stériquement encombrés sont utilisés dans les espèces à valence mixte, des oxydations intramoléculaires sont observées, alors que l’espèce CuIICuIII possédant un ligand moins encombré oxyde le toluène. Il est à noter que l'ajout d'une base rend le système catalytique. / Copper-oxygen adducts in enzymes have been proposed to be responsible for the activation of C-H bonds, a process that has industrial applications. The first part of this thesis is therefore dedicated to a discussion on various copper oxygenases and their model complexes. Recently, key reactive intermediates have emerged and among them mixed valent CuIICuIII species have been proposed to be responsible for strong C-H bond activation.In this work the stabilisation and spectroscopic characterisation of high valent intermediates using dinucleating ligands based on a 1,8-naphthyridine spacer are explored. The generation of Cu2:O2 species from the activation of O2 by CuI2 complexes is discussed. Two µ-ɳ2:ɳ2-peroxo-CuII2 complexes have been prepared at -80°C and characterised by spectroscopy and density functional theory (DFT). Our attempts at generating dinuclear systems using new dissymmetric ligands with an amide function are also discussed. Finally the successful characterisation of mixed valent CuIICuIII species by mono-electronic oxidation of CuII2 complexes is described (cyclic voltammetry, electron paramagnetic resonance, UV-visible, near infrared and DFT).The last part focusses on probing the reactivity of CuIICuIII species, for which the literature is almost inexistent. When sterically congested ligands are used to support the mixed valent system, intramolecular aliphatic C-H oxidation was observed, whether as the CuIICuIII species supported by a less bulky ligand was able to oxidise toluene. Interestingly the addition of a base made the system catalytic.

Orientador: Jonas Contiero / Resumo: A contaminação ambiental causada por compostos orgânicos é um importante problema que afeta solos e água superficiais. Para reduzir ou remover esses poluentes, os locais contaminados são geralmente tratados com métodos físicos e químicos. No entanto, a maioria dessas técnicas de remediação é custosa e geralmente leva à remoção incompleta e à produção de resíduos secundários. A nanotecnologia consiste na produção e aplicação de estruturas extremamente pequenas, cujas dimensões estão na faixa de 1 a 100 nm, neste cenário a nanopartícula de ferro zero valente representa uma nova geração de tecnologias de remediação ambiental. É não tóxica, abundante, barata, fácil de produzir, e seu processo de produção é simples. No entanto, a fim de diminuir a tendência de agregação, a nanopartícula de ferro zero é frequentemente revestida com surfactantes. A maioria dos surfactantes é quimicamente sintetizado a partir de fontes petroquímicas, eles são persistentes ou parcialmente biodegradáveis, enquanto oferecem baixos riscos à saúde humana, esses compostos podem prejudicar plantas e animais. Para diminuir o uso de métodos químicos, a síntese e estabilização verde de nanomateriais metálicos apresentam-se como uma opção menos perigosa ao meio ambiente. Os biossurfactantes podem potencialmente substituir qualquer surfactante sintético, eles são compostos extracelulares produzidos por microrganismos, como bactérias, e cultivados em diferentes fontes de carbono, podendo ser substratoshidrofílico... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Environmental contamination caused by organic compounds is the most important challenge that affects a huge number of soils and water surfaces. To reduce or remove these pollutants, contaminated sites are usually treated using physical and chemical methods. However, most of these remediation techniques are expensive and commonly lead to incomplete removal and to the production of secondary wastes. Nanotechnology is the production and application of extremely small structures, whose dimensions are in the range of 1 to 100 nm and Nanoscale zero-valent iron represents a new generation of environmental remediation technologies, is non-toxic, abundant, cheap, easy to produce, and its reduction process requires little maintenance. Nonetheless, in order to diminish the tendency of aggregation, nanoscale zero-valent iron is often coated with surfactants. Most surfactants are chemically synthesized from petrochemical sources, they are slowly or partially biodegradable, while offer low harm to humans, such compounds can influence plants and animals. To decrease the use of chemical methods green synthesis and stabilization of metallic nanomaterials viable option. Biosurfactants can potentially replace virtually any synthetic they are extracellular compounds produced by microbes such as by bacteria and grown on different carbon sources containing hydrophobic/hydrophilic substrates. The biosurfactants have a wide variety of chemical structures and surface properties and among them is the ... (Complete abstract click electronic access below) / Doutor

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In the past 30 years zero-valent iron (ZVI) has become an increasingly popular reducing agent technology for remediating environmental contaminants prone to chemical degradation. Azo dyes and chlorinated organic compounds (COCs) are two classes of such contaminants, both of which include toxic compounds with known carcinogenic potential. ZVI has been successfully applied to the surfaces of permeable reactive barriers, as well as grown into nanoscale particles (nZVI) and applied in-situ to chemically reduce these contaminants into more environmentally benign compounds. However, the reactivity of ZVI and nZVI in these technologies is limited by their finite supply of electrons for facilitating chemical reduction, and the tendency of nZVI particles to homo-aggregate in solution and form colloids with reduced surface area to volume ratio, and thus reduced reactivity. The goal of this project was to combine reactive nanoparticle and membrane technologies to create an electro-catalytic permeable reactive barrier that overcomes the weaknesses of nZVI for the enhanced electrochemical filtration of azo dyes in solution. Specifically, nZVI was successfully grown and stabilized in a network of functionalized carbon nanotubes (CNTs) and deposited into an electrically conductive thin film on the surface of a polymeric microfiltration support membrane. Under a cathodic applied voltage, this thin film facilitated the direct reduction of the methyl orange (MO) azo dye in solution, and regenerated nZVI reactivity for enhanced electro-catalytic operation. The electro-catalytic performance of these nZVI-CNT membrane surface composites to remove MO was validated, modelled, and optimized in a batch system, as well as tested in a dead-end continuous flow cell system. In the batch experiments, systems with nZVI and a -2 V applied potential demonstrated synergistic enhancement of MO removal, which indicated the regeneration of nZVI reactivity and allowed for the complete removal of 0.25 mM MO batches within 2-3 hours. Partial least squares regression (PLSR) modelling was used to determine the impact of each experimental parameter in the batch system and provided the means for an optimization leading to maximized MO removal. Finally, tests in a continuous system yielded rates of MO removal 1.6 times greater than those of the batch system in a single pass, and demonstrated ~87% molar removal of MO at fluxes of approximately 422 lmh. The work herein lays the foundation for a promising technology that, if further developed, could be applied to remediate azo dyes and COCs in textile industry effluents and groundwater sites respectively. / Thesis / Master of Applied Science (MASc)

Utilizing biomass such as lignin, bamboo, soybean, corn stalk, rice husk, etc., as a carbon source to produce graphene-based nanomaterials has been reported recently. However, the potential of using such nanomaterials for engineering and environmental applications has not been realized. This dissertation investigates the use of graphene-based nanomaterials synthesized from using biomass as a carbon source for water remediation and cement-based composites’ (CBCs) property enhancement. The first chapter introduces graphene and graphene-based nanomaterials, as well as the synthesis and application of graphene-based nanomaterials for removing heavy metals in an aqueous solution and for property enhancement in CBCs. The experimental investigation on the pyrolytic synthesis of graphene-encapsulated iron nanoparticles from biochar (BC) as the carbon source (BC-G@Fe0) was covered in the second chapter. Two synthetic routes for producing BC-G@Fe0, i.e., impregnation-carbonization (route-I) and pyrolysis-impregnation-carbonization (route-II) processes, were investigated experimentally using different characterization techniques and heavy metal removal methods. The third chapter reports the experimental performances of the heavy metal removal of Pb2+, Cu2+, and Ag+ from an aqueous solution using BC-G@Fe0. The effectivenesses of various adsorption benchmarks, such as pH, kinetics, and isotherms were assessed. Additionally, the removal efficiency of BC-G@Fe0 was evaluated. BC-G@Fe0 sample made from route II, in particular, FeCl2-impregnated-BC with 15% wt% iron loading carbonized at 1000 ℃ for 1h showed promising Pb2+, Cu2+, and Ag+ removal capacities of 0.30, 1.58, and 1.91 mmol/g, respectively. The fourth chapter experimentally investigated the reinforcement effect of commercially sourced, industrial graphene nanoplates (IG) on the mechanical properties of CBCs. This investigation was based on a hypothesis that the uniform dispersion of IG would significantly enhance the compressive strength of CBC. The main outcome of this research was that, while the wet dispersion mixing process of IG into CBC did not consistently yield significant increases in the composite compressive strength, but the newly proposed dry dispersion process demonstrated significant increases (22%) in the composite compressive strength. Chapter Five investigated the synthesis of lignin-based graphene nanoplatelets (LG) and their application in CBC reinforcement. The main findings were that LG did not show impressive increases compared to IG, even when dry dispersion was introduced. This was attributed to LG's lack of effective surface area compared to IG. Finally, a general conclusion and outlook for the future of research into biomass-based graphene nanomaterials were discussed in chapter six.

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