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<p>Adhesives  are  found  in  almost  every  aspect  of  the  modern  world.  They  are  found  in plywood used in buildings, electronics, shoes, plumbing and in almost every facet of your daily life. Nature also has an abundance of these adhesives that are used fora multitude of applications. Some  animals, like  the  blue  mussel, use  their  adhesive  for  protection  against  ocean  waves  and predators  while other animals, such  as  the  spider, use  it  to  trap  prey. Investigation  of  theses adhesives has led to the identification of several different proteins that allow for these animals to make  their  adhesive.  Some  of  them  are  composed of rare  amino  acids that  while  other  animals use  a combination  of  inorganic  and  organic  components.  Understanding  of  these  unique adhesives  can be  a  boon  for designof future  adhesives  that  do  not  have  the disadvantagesof current day commercialized glues.</p> <p>Increasing interest  in  the  restoration  of  natural  oyster  reefs  and  the  cement  that  holds them  together  has  resulted  in  the  identification  of  the  Shelk2  protein  that  is  found  both  in  the mantle  of  the  oyster’s  shell  as  well  as  the  cement  that  holds  the  reefs  together. Gaining  an understanding  of  how  this  protein  functions  and  its  part  in  the  oyster  reef  could  be  quite beneficial  for  projects  investing  in  reef  restorations  as  well  as  underwater  adhesion.  Gathering protein  from  the  animal  for  experimentation  and  characterization  can  be  labor  intensive  and extremely challenging. Luckily, cloning technology has become a useful tool for the expression of large quantities of proteins that can be difficult or impossible to gather from the native animal. Using <em>E. coli</em>, it  is  possible  to design  and express  this protein  in  hopes  of  gaining  a  better understanding of its impact on oyster settlement and adhesion.</p> <p>Sustainability is a major downside to current day adhesives that current technologies have not  been  able  to  solve. Most adhesives  that  are  on  the  market  today  are  primarily  derived  from petroleum. Current  research  has  begun  investigating  alternatives  to  the  large   epoxy   and formaldehyde  adhesive  market,  but  the  barrier  of  entry  is  hard  to  overcome.  To  replace  these glues  the  new  material  must  be  affordable,  non-petroleum  derived,  and  available  on  a  massive scale.  These  requirements  are  hard  to  meet  for  many  materials  and  due  to  that  the  current  bio-adhesive are generally very low strength.</p> <p>The work presented here will detail the characterization, and expression of some of these natural  adhesives that  have  been  found  in  the  Eastern  oyster. Another  aspect of  this  work includes the synthesis of a new bio-based adhesive system. Utilizing biomimetic chemistry along with  sustainably  sourced  materials  a  new  adhesive  has  been  formulated that  has  comparable adhesive strength to current day commercial adhesives.</p>

The effects of climate change have made the need to develop sustainable production practices for biofuels and other chemicals imminent. The development of the green economy has also led to many industries voluntarily improving the sustainability of the products they produce. The microbial production of fatty acid-derived chemicals allows for the opportunity to reduce petroleum-based chemicals in the marketplace. However, for microbial produced chemicals to be industrially competitive, significant work is needed to improve the production capacity of industrial strains. There are a number of bottlenecks and challenges related to the production of various fatty acid derivatives that need to be addressed. One of these key challenges relates to the source of the fermentation feedstock. While sources such as corn or sugar cane are currently common, these feedstocks compete with food supply and require nutrient-rich soils. The use of lignocellulosic feedstocks is preferred to combat this issue, however these feedstocks present their own unique challenges. Pretreatment is required to release fermentable sugars, and this process also results in various fermentation inhibitors released into the solution. A better understanding of how engineered strains utilize these fermentable sugars as well as improving resistance to the inhibitors will help to improve the chemical production capacity of these chemical products. This work will focus on describing key bottlenecks related to fatty acid-derived products, while also evaluating proposed solutions to these bottlenecks. / Master of Science

<p dir="ltr">Reported herein is a brief summary regarding the previous syntheses of borane-amines, newly developed protocols to synthesize borane-amines, and the material and synthetic applications utilizing borane-amines. Methods to generate borane-amines typically relied on a metathesis-dehydrogenation reaction between ammonium salts and metal borohydrides in organic solvent, typically hazardous tetrahydrofuran (THF). However, due to the poor solubility of inorganic salts in organic solvent, stirring of the reaction mixture becomes difficult and, in turn, scalability is made challenging. We report two new methods to generate borane-amines that both rely on the hydroboration of sodium borohydride and a carbonyl activator, followed by the S_N2-type reaction with the amine to form the requisite borane-amine. The activator for our procedures are either 1) gaseous carbon dioxide or 2) water/ethyl acetate system. The CO₂ mediated protocol was applied to a variety of 1°-, 2°-, 3°-, and heteroaromatic amines as well as phosphines to form the corresponding borane adducts (73-99%). Water was also found to be a green, compatible activator. Interestingly, we had swapped environmentally and health hazardous THF with ethyl acetate (EtOAc) and found the reaction had still proceeded with competitive conversion of amines to the borane-amines (72-97%). The robustness of this reaction was demonstrated with a 1.1 mol scale synthesis of borane pyridine with 87% yield. With increased accessibility of borane-amines established, we sought to investigate their potential applications, including testing their hypergolic properties. Additionally, we utilized borane-ammonia for a sequential reduction/Friedel-Crafts alkylation of benzyl carbonyls. Traditionally an alkyl halide, the scope of the electrophilic aromatic substitution reaction has widened to include alcohols and carbonyls as potential Friedel-Crafts reactants. Few reports exist for the arylation of aldehydes and ketones, while no precedence exists for the arylation of carboxylic acids and esters. Our group previously reported that TiCl₄ is capable of eliminating oxygen from benzyl alcohols, forming a carbocation intermediate. Theoretically, the carbocation formed from TiCl₄ and benzyl alcohols would be vulnerable from attacks from other nucleophiles, including pi bonds from arenes. This was indeed proven to be the case when benzyl alcohol was reacted in 1 equiv. TiCl₄with benzene as the solvent and diphenylmethane was obtained as the sole product. By including borane-ammonia as a hydride source, various aryl carbonyls and aryl carbinols were also reduced to the corresponding alcohol <i>in situ</i>, enabling these substrates to participate in Friedel-Crafts alkylation.</p>

<p dir="ltr">Aromatic phosphonates and phosphine oxides are highly desirable synthetic targets used in pharmaceuticals, natural products, agrichemicals, catalysis, and materials science. While a variety of aromatic precursors have been used to access these motifs, aryl halides remain one of the most desirable coupling partners owing to their low cost, commercial availability, and regioselective reactivity. Traditional phosphonation often requires the use of harsh reductants in the presence of liquid ammonia, which are caustic and pose incredible environmental concerns. Milder, transition metal-catalyzed approaches have been developed, but can be limited by air sensitivity, cost, low reaction selectivity, and low functional group compatibility. Photoredox catalysis has been significantly advanced in the past decade in the pursuit of greener, more sustainable avenues to facilitate desirable reaction transformations under mild conditions. These methods most commonly use a dual catalytic strategy in which a metal is paired with an organocatalyst. While these approaches enable facile phosphonation of a variety of aromatic precursors, the metals and organocatalysts used are often expensive and toxic. Indeed, there remains unexplored chemical space for transition metal-free photoredox-catalyzed aryl C-P bond formations. Herein, we present a series of transition metal-free, photoredox-catalyzed approaches to the phosphonation of aryl halides. The approaches and mechanistic works will be discussed in the following order: </p><p dir="ltr">First, the discovery that 10<i>H</i>-phenothiazine (PTZ) enables the transition metal-free phosphonation of aryl halides using trialkyl phosphites will be presented. PTZ serves as a photocatalyst capable of reducing the aryl halide to access aryl radicals, which readily couple with phosphite esters. This transformation exhibits broad functional group tolerance in good to excellent yields. Then, photoredox catalysis by PTZ enables the formation of unsymmetrical aromatic phosphine oxides using triphenylphosphine (PPh₃) and aryl halides. This is the first work in which PPh₃ has been used as the starting material, and the reaction proceeds via the alkaline hydrolysis of quaternary phosphonium salts. The final work exhibits novel photocatalytic activity of <i>N</i>-heterocyclic carbenes (NHC) to activate aryl halides, form aryl radicals, and enable phosphonation. This method displays broad functional group tolerance under mild conditions and highlights its untapped synthetic utility as a photocatalyst.</p>

Un nouveau procédé d'extraction des huiles essentielles a été développé, mis au point et optimisé nommé «Vapo-diffusion Assistée par Micro-ondes (MSDf)». Le procédé MSDf à été appliqué à l'extraction des huiles essentielles des peaux d'oranges et de fleurs de lavande. Ce procédé est basé sur la combinaison d'une technique d'extraction classique : l'hydro-diffusion et le chauffage micro-ondes comme technologie d'intensification. Une deuxième nouvelle approche pour l'extraction des huiles essentielles à partir de matrices aromatiques sèches et sans ajout de vapeur ni d'eau nommé «Diffusion à sec générée par micro-ondes (MDG)». Le procédé MDG à été appliqué à l'extraction des huiles essentielles des graines de carvi. Le MSDf et le MDG apparaissent comme des procédures «douces» permettant un gain de temps et d'énergie considérable et la diminution des rejets de CO2 dans l'atmosphère / Microwave steam diffusion (MSDf) was developed as a cleaner and new process design and operation for isolation of essentials oils and was compared to conventional steam diffusion (SDf). This green process has been applied and tested using two aromatic matrixes: fresh orange peels and dry lavender flowers. This process is based on the combination of a traditional technique of extraction: hydro-diffusion and the microwave irradiation energy. Without adding any steam or water, we proposed also a novel and green approach for extraction of secondary metabolites from dried plant materials. This “steam and water free” approach based on a simple principle involves the application of microwave irradiation and earth gravity to extract the essential oil from dried caraway seeds. MSDf and MDG were better than SDf in terms of energy saving, cleanliness and reduced waste water

Cette thèse porte sur la mise en œuvre de procédés innovants d'extraction de composés naturels bioactifs de plantes. Nous avons considéré ici l'extraction d'un composé anti-oxydant, l'acide rosmarinique, à partir du végétal mélisse (Melissa officinalis L.), qui contient également d'autres composés d'intérêt (citral et caryophyllène). Différentes techniques d'extraction-purification, soit à haute pression (extraction au CO2 supercritique) ou à pression atmosphérique (extraction Soxhlet, extraction batch, nanofiltration etc.) ont été envisagées. L'objectif de ce travail a été d'étudier expérimentalement l'influence des paramètres opératoires (débit, composition et concentration du solvant, taille des particules, pression et température) sur la cinétique des processus afin de sélectionner les meilleures conditions pour chaque opération. Les résultats expérimentaux ont été ensuite comparés avec plusieurs modèles mathématiques décrivant les phénomènes de transfert de masse et l'écoulement au travers du milieu poreux constitué par la matière végétale broyée. Cette démarche, à partir de la détermination des paramètres physiques du modèle, a fourni les éléments pour une extrapolation potentielle à l'échelle industrielle. Du point de vue du procédé complet d'extraction-purification, l'originalité du travail a été de proposer plusieurs scénarii d'enchainement d'opérations, couplant en synergie des opérations conventionnelles à pression atmosphériques (macération, nano-filtration etc.) et des opérations de traitement au CO2 supercritique avec co-solvant. / This thesis deals with the extraction of natural bioactive compounds from plants (case study with Lemon Balm (Melissa officinalis L.)) by using different separation techniques at high (supercritical extraction) and atmospheric pressure (Soxhlet extraction, batch extraction, nanofiltration etc.). The influence of main operational parameters (solvent composition and flow rate, particle size of the raw material, pressure, temperature) on the process kinetics is studied experimentally with the aim to determine appropriate operational conditions for better extraction. The experimental results are confronted to a number of mathematical models in order to estimate the applicability of different theoretical concepts to the particular process and to select and apply appropriate models for determination of important parameters, characterizing the mass transfer process and necessary for scale-up and design purposes. Coupling between different separation methods is also considered and a number of integrated process schemes are proposed resulting in better yield of the targeted compounds.

Ce mémoire porte sur la synthèse de matériaux composites nanostructurés à base de polyoxométallates pour la conversion de l’énergie et des applications à des problèmes environnementaux. Pour atteindre ces objectifs, de nombreux composés nouveaux de cette famille d’oxydes moléculaires ont été synthétisés puis ont été associés à différentes matrices éco-compatibles dans le respect des principaux critères de la Chimie Verte. Les principales techniques d’étude sont l’électrochimie, la photochimie et la spectroscopie UV-visible. Dans le domaine de l’énergie, les catalyseurs obtenus se sont révélés très efficaces dans des réactions très importantes mais difficiles à réaliser, comme la production de l’hydrogène, la réduction de l’oxygène et l’oxydation de l’eau. De même, parmi les applications aux problèmes de dépollution, ces nanomatériaux ont montré une forte activité électrocatalytique et photocatalytique pour la réduction des oxydes d’azote, des bromates et la photodégradation d’un colorant textile toxique, l’Acide Orange 7. Les performances de ces nouveaux catalyseurs sont comparables à celles des meilleurs systèmes connus. / This thesis focuses on the synthesis of nanostructured composite materials based on polyoxometalates for energy conversion and applications to environmental problems. To achieve these goals, many new compounds of this family of molecular oxides were synthesized and were associated with different nature friendly matrices, in agreement with the main criteria of Green Chemistry. In the field of energy, the new catalysts have proved very effective in important but difficult to achieve reactions, such as producing hydrogen, oxygen reduction or water oxidation. Similarly, among applications to pollution problems, these nanomaterials have shown a strong electrocatalytic and photocatalytic activity for the reduction of nitrogen oxides, bromate and for the photodegradation of a toxic textile dye, Acid Orange 7. The performances of these new catalysts are comparable to those of the best known systems.

Dióxido de carbono supercrítico (scCO2) é um solvente pouco eficiente para substâncias polares em geral. Uma maneira interessante de superar esta limitação e explorar todo o seu potencial como solvente verde, possível substituto para os solventes orgânicos voláteis comuns, é a introdução de tensoativos específicos para scCO2 no sistema. No presente trabalho, foram sintetizadas três novas séries de tensoativos oxigenados para scCO2. As moléculas possuem cabeças CO2-fóbicas mono e poli-hidroxiladas, em sua maioria à base de açúcares, e três tipos de cadeias CO2-fílicas, duas delas perfluoradas (-C7F15 e -C9F19) e uma peracetilada (derivada do ácido D-glucônico). Foram investigadas as suas solubilidades e comportamentos de fase em CO2 e em sistemas ternários (água-CO2-tensoativo), bem como a atividade na interface CO2-água. Todos eles dispersaram água em scCO2 com [água] / [tensoativo] (W) igual a 10, exibindo pressões de névoa comparáveis àquelas do sistema \"a seco\". Adicionalmente, os tensoativos reduziram a tensão interfacial CO2-água. O efeito das cabeças CO2-fóbicas e cadeias CO2-fílicas nessa redução pôde ser analisado separadamente. Os resultados dos experimentos de tensão interfacial dinâmica sugerem que tanto a difusão das moléculas da fase contínua para a subinterface, quanto a sua inserção e migração na interface contribuem para o decaimento das tensões interfaciais. / Supercritical carbon dioxide (scCO2) is a poor solvent for polar substances in general. An interesting way to overcome this limitation and fulfill its potential as a green solvent, a possible substitute for common volatile organic solvents, is the introduction of scCO2-suitable surfactants in the system. In the present work, three series of novel oxygenated surfactants for scCO2 were synthesized. The amphiphiles contain mono and poly-hydroxylated CO2-phobic heads, most of them sugar-based, as well as three types of CO2-philic tails, two of them perfluorinated (-C7F15 and -C9F19) and one peracetylated (D-gluconic acid derivative). Their solubilities and phase behaviors in CO2 and in ternary systems (water-CO2-surfactant), as well as their activities at the CO2-water interface, were investigated. All of them dispersed water in scCO2- with water-to-surfactant ratio (W) of 10, exhibiting cloud pressures comparable to those of \"dry\" systems. Also, the surfactants reduced the CO2-water interfacial tension. The effect of both the CO2-phobic heads and the CO2-philic tails could be analyzed separately. Dynamic interfacial tension results suggest that both diffusion from bulk CO2 to subinterface and insertion and migration of molecules within the interface contribute to the time-dependent decay of the interfacial tensions.

Através do uso de reagentes ambientalmente corretos, foram desenvolvidos métodos mais simples que os tradicionais para obtenção de diversos tipos de nanopartículas de magnetita (MagNP) funcionalizadas. Em todos os casos foi confirmado um comportamento superparamagnético consistente com a presença de monodomínios magnéticos de Fe3O4, com diâmetros médios de partícula inferiores a 100 nm, além de histerese nula acima de 280 K, Tb=90K em H=500 Oe e magnetização de saturação em torno de 90 emu g-1. Os métodos de síntese das MagNP foram conduzidos em solventes derivados do biodiesel de soja/mamona, em substituição ao insumos importados, permitindo uma redução significativa nos custos de produção desse tipo de nanomaterial, e viabilizando sua produção em larga escala. Os nanomateriais foram voltados inicialmente para captura, separação e reciclagem de insumos e produtos químicos, incluindo poluentes, catalisadores e enzimas, utilizando ímãs externos. Os procedimentos desenvolvidos proporcionaram uma alternativa verde para os processos convencionais que fazem uso extensivo de solventes, geram muito descarte, e utilizam processos com alta demanda de energia, como centrifugação, extração por solventes e filtração sob altas pressões. As MagNP foram especialmente projetadas para serem dispersas em diversos meios polares e apolares, de acordo com o tipo de funcionalização química na superfície, utilizando principalmente moléculas orgânicas anfifílicas capazes de se ligar na superfície do Fe3O4 por meio de grupos polares, e com matrizes carbonáceas por meio de interações hidrofóbicas. Dessa forma foram gerados novos nanomateriais superparamagnéticos incorporando diversos tipos de matrizes que foram testadas para a remoção de óleo e de compostos orgânicos responsáveis por odores e cores indesejadas em efluentes industriais, bem como para a captura, transporte, recuperação, análise de espécies metálicas ou orgânicas. Foram testadas janelas ópticas e displays nos quais a intensidade de luz transmitida ou refletida pode ser modulada com ímãs externos. O projeto, financiado pela PETROBRÁS contemplou ainda outras aplicações sigilosas, que foram omitidas desta tese. Seu andamento abriu uma importante janela em prol da sustentabilidade, levando ao início do desenvolvimento no Laboratório, da nanomagneto-hidrometalurgia verde para obtenção e reciclagem de metais estratégicos, e de trabalhos de despoluição magnética de ambientes contaminados. / New routes for low cost production of functionalized magnetic nanoparticles (MagNP) have been pursued in this Thesis, by employing environmentally compatible chemicals and resources. The nanomaterials exhibited typical superparamagnetic behavior consistent with the presence of magnetic monodomains, revealing no hysteresis above 280 K, Tb = 90 K at H = 500 Oe, and saturation magnetization as high as 90 emu g-1. The synthetic procedures were carried out using biocompatible solvents derived from biodiesel of soybean and Brazilian mamona seeds, leading to substantial reduction of cost for large-scale production. The superparamagnetic nanoparticles were initially designed for capturing, transporting and recycling chemicals or drugs, including pollutants, catalysts and enzymes, using external magnets. They provide a green alternative strategy for conventional processes that make extensive use of solvents, generate too much waste, and proceeds through highly energetic demanding steps such as centrifugation, solvent extraction and high-pressure filtration. In our work, the MagNPs were appropriately modified for working in polar and non-polar media, employing for instance, amphiphilic species for interacting with Fe3O4 using the available polar groups, and also with carbon surfaces by means of hydrophobic interactions. Accordingly, new superparamagnetic nanomaterials incorporating several types of materials carbon based. It was observed that the carbon materials containing 15 to 20% of magnetic nanoparticles could be completely removed from the media with the use of a magnet. In this way, the functionalized superparamagnetic nanoparticles proved useful for the removal of oil spills and of organic pollutants from industrial processing water, as well as for the capture, removal and recovery of metallic elements and organic species from the effluents. In addition, as a proof of concept, smart windows and displays were elaborated based on the modulation of the transmitted or reflected light by the external magnet. This work was sponsored by PETROBRÁS, and also covered missing, non-authorized aspects involved in two patent applications. Finally, an important consequence to be mentioned is the contribution of this project for launching new chemical routes towards sustainability, such as the development in this Laboratory, of green, magnetic nano-hydrometalurgy for processing and recycling strategic metals, and of the magnetic remediation of polluted environments using the functionalized nanomaterials.