Дисертації з теми "Deep eutectic solvent electrolyte"

Cette thèse a pour but de caractériser le fonctionnement de supercondensateurs asymétriques composés de dioxyde de manganèse de structure birnessite et de carbone activé dans différents électrolytes. Les électrolytes aqueux neutres à base de sels inorganiques montrent les meilleures performances électrochimiques. La nature et la structure des cations et des anions du sel semblent impacter les performances électrochimiques et la stabilité de la structure du matériau d’oxyde de manganèse. Lors de cyclage en milieu aqueux avec de large de fenêtre de tension de fonctionnement appliquée, un mécanisme de dégradation du dispositif a été avancé tenant compte de la nature des anions ou des cations des sels utilisés. Quelques voies de modification du matériau MnO2, afin d’améliorer ces performances électrochimiques, ont été étudiés. Des électrolytes non aqueux originaux ont été également caractérisés et plus particulièrement, les solvants « Deep Eutectic » à base de N-méthylacétamide et de sels de Lithium. Ces derniers semblent prometteurs comme électrolytes pour des applications en température sur carbone activé ou matériaux d’insertion tels que le ferrophosphate de lithium. Cependant ils semblent non adaptés aux oxydes de manganèse, mais donnent de bons résultats en cyclage avec le carbone activé
The aim of this thesis was to investigate the performances of asymmetric supercapacitors based on manganese dioxide (birnessite) and activated carbon electrode materials using various electrolytes. From this work, it appears that neutral aqueous electrolytes containing inorganic salts have the best electrochemical performances. Furthermore, the nature and the structure of both ions (cations and anions) in solution seem to impact strongly the electrochemical performances of the supercapacitors, as well as, the MnO2’s structure stability and affinity. In the case of aqueous-based electrolyte, a device degradation mechanism has been proposed as a function of salt ions structure and nature to further understand the supercapacitor’s life-cycling when a large potential window is applied. Some novel synthesis ways and/or modifications were investigated to further improve the electrochemical properties of MnO2 material. Additionaly, original non-aqueous electrolytes has been also formulated and then characterized, particularly the ‘Deep Eutectic’ Solvents, based on the N-methylacetamide mixed with a lithium salt. However, these electrolytes don’t have a good affinity with manganese oxide-based materials. Interestingly, these Deep Eutectic Solvents show good cycling results with activated carbon. In fact, these electrolytes seem to be promising for high temperature energy storage applications, especially using activated carbon or insertion electrode material like the lithium ferrophosphate

Le captage et la réduction électrochimique du CO2 (CCU) est une solution pour décarboniser le secteur industriel. Cette technologie valorise la source de carbone peu chère en molécules carbonées à forte valeur ajoutée. Des nombreuses méthodes de valorisation du CO2 existent pour limiter la libération de ce gaz à effet de serre dans l’atmosphère. Pendant cette thèse, nous proposons le captage du CO2 complété par la conversion électrochimique en différentes molécules carbonées dans une cellule électrochimique. L’électroconversion de dioxyde de carbone est une méthode prometteuse grâce à des conditions réactionnelles douces en température et pression et la possibilité d’alimenter la cellule électrochimique avec de l’électricité produite par des énergies renouvelables. Ce procédé nécessite le développement de solvants de captage qui peuvent également jouer le rôle d’électrolyte pendant la réduction électrochimique du CO2. En même temps, le choix d’un matériau catalytique est indispensable pour la conversion sélective du CO2 en molécule(s) d’intérêt. Le choix du solvant de captage est souvent basé sur la capacité d’absorption du CO2, les stabilités chimique et électrochimique, les enjeux environnementaux et le coût. Les solvants eutectiques profonds (DESs) apparaissent comme des candidats très intéressants puisqu’ils répondent aux différents critères de sélection. Dans ce travail de thèse, nous focalisons sur le développement de ces nouveaux solvants émergents pour le captage et l’électroconversion du CO2 avec des catalyseurs à base de palladium. Le palladium est d’ailleurs connu pour être un électrocatalyseur effectif pour la transformation sélective du dioxyde de carbone en molécules type C1 tel que le monoxyde de carbone.Pendant cette thèse, nous avons synthétisé et testé électrochimiquement des nombreux DESs et des catalyseurs à base de palladium en vue de permettre la compréhension des mécanismes réactionnels de la réduction du CO2 en molécule de type C1. Les différentes techniques de caractérisation ont permis d’étudier les structures des matériaux catalytiques (morphologie et tailles des particules) et des solvants eutectiques profonds, d’analyser les produits et les intermédiaires réactionnels ainsi que de comprendre les verrous du système utilisé. Dans sa globalité, le projet a permis de faire un pas vers la séquestration et la valorisation du dioxyde de carbone par la méthode électrochimique pour décarboniser le secteur industriel et empêcher ainsi le dérèglement climatique
Carbon dioxide capture and utilization (CCU) is a way to decarbonize industrial sector. This technology provides a valorization of cheap carbon feedstock by its transformation to carbonaceous value-added chemicals. Multiple CO2 capture and utilization techniques exist to prevent the release of the greenhouse gas to the atmosphere. Here, we propose an integrated process of CO2 capture sequenced by electroconversion to C-based products in electrochemical cell. Electrochemical CO2 conversion is a promising method due to mild reaction conditions and possibility to power the reaction with electricity produced by renewable energy sources. This process necessitates the development of solvents capable to capture CO2 and to play a role of electrolyte during electrochemical reduction reaction. At the same time, efficient catalytic materials are vital for selective CO2 conversion to targeted product(s). The choice of capture solvent is usually based on CO2 capture ability, chemical and electrochemical stabilities, environmental issue and cost. Economically affordable deep eutectic solvent (DES) electrolytes seem to be promising candidates for CO2 capture and electroreduction because of good thermal and electrochemical stabilities, competitive CO2 uptake and large electrochemical windows. In this work, we focused on the development of novel deep eutectic solvent electrolytes for CO2 electroreduction with Pd-based electrocatalysts. Palladium proved its efficiency for selective conversion of carbon dioxide to C1 molecules such as carbon monoxide.During the thesis, we synthesized and electrochemically tested multiple DESs and Pd-based electrocatalysts with different morphologies and particle sizes to get more insights into reaction mechanism of CO2 electroreduction to C1 molecules. The implementation of different characterization techniques helped to study catalytic materials and DESs structures, to analyze gaseous and liquid reaction intermediates and products, and to understand main challenges of the studied system. Overall, this study is a one step forward the application of CO2ER (carbon dioxide electrochemical reduction) for valorisation of carbon dioxide and climate change mitigation

Salt forms homogeneous solutions with water; most studies to date have assumed that deep eutectic solvents (DES) and water form similar homogeneous systems. Several studies have used quantum mechanical and molecular dynamic simulations to prove that this is indeed the case. Study of physical properties of ionic liquid-water/ systems have revealed some anomalous observations without considering the fact that there may be micro- or nano-heterogeneities with in these systems. The key aim of this project is to demonstrate the heterogeneity of DES-water mixtures by careful measurement of physical properties such as viscosity, conductivity, surface tension and density. The first stage of the study involved the investigation of the above physical properties for pure DESs and DESs mixed with different amounts water to investigate if these were homogeneous or heterogeneous in nature. Analysis of these data showed some characteristics of heterogeneity, the extent of which depends on the number of hydrogen bond donors in the pure DES. Dynamic light scattering was used to determine the extent of the heterogeneity in the three DESs under investigation, namely Ethaline, Glyceline and Reline. Pulsed Field Gradient NMR (PFG-NMR) and electrochemical techniques have been used to study diffusion coefficients in DES-water mixtures. The results of PFG-NMR showed that the behaviour of DES-water mixtures was non-Stokesian, hence DES-water mixtures have water-dominant and some ion-dominant domains. Electrochemical studies also showed the same trends due to the electroactive species partitioning between the different phases. It is thought that Reline-water mixtures are more heterogeneous than the corresponding Ethaline and Glyceline systems. Electroplating in DES-water mixtures has previously been shown to improve the quality of deposited films. The electrodeposition of copper from Ethaline was studied as a function of water content. It was found that water affected the speciation of copper in solution.

Ionic liquids and deep eutectic solvents are areas of great interest to non-aqueous reaction systems. They can be fine-tuned for an array of properties and are often less harmful than other, organic, solvents. This research focused specifically on self-assembly in ionic liquids and deep eutectic solvents with an eye to understand self-assembly processes. Not only does this work offer industrial applications, for isolated reaction systems and batteries, it also provides an interesting insight into the possibility of non-aqueous life-forms. If compartmentalisation can occur without water, then perhaps so too can the other requirements of life. Ionic liquid nanostructure significantly affected phospholipid self-assembly with more nanostructure resulting in more curved micellar phases, rather than the lamellar phases observed in water and less structured ILs. This held true for both zwitterionic lipids and ionic surfactants, demonstrated by microscopy, small angle neutron and x-ray scattering. Phospholipids formed swellable lamellar phases in all fourteen of the deep eutectic solvents tested. Examination of lipid transition temperatures by polarising optical microscopy demonstrated that the components of the solvent could influence lipid behaviour and stability, solvents with long alkyl components acted as cosurfactants. Tethered lipid membranes and electrical impedance spectroscopy demonstrated that membranes could exist, and form, in a pure IL environment (ethanolammonium formate). This is the first time such a technique has been used to study membranes in an IL and offers unparalleled opportunities for further research. Furthermore, this technique was used to demonstrate the continued function of a membrane transporter, valinomycin, in ethanolammonium formate. Valinomycin continued to transport potassium with an extremely high selectivity over sodium. These results show that compartmentalisation, and even protein function, can continue even in the absence of water.

Electronically conducting polymers based on functionalised thiophenes and pyrroles have continued to stimulate academic interest as well as starting to be employed in practical applications and uses. This thesis describes studies of the electronic properties of mixed thiophene-pyrrole polymers (based on custom synthesised mixed monomer precursors) and polymers electrodeposited from commercially available monomers, pyrrole and 3,4-ethylenedioxythiophene, in respect to energy storage applications including batteries and ion selective membranes. In such applications the movement of ion and solvent through the polymer film during oxidation and reduction cycles is critical to application and function, e.g. charging rate, metal ion permeability or adhesion stability. Recently the unexpected behaviour of polypyrrole in choline chloride based ionic liquids has been described. These liquids are especially attractive because of their unique solubility profiles, high stability, low volatility and low toxicity. This thesis describes the electrochemical characterisation, DC capacitance behaviour and ion/solvent transport properties of conducting polymers using a range of electrochemical methodologies in combination with acoustic impedance electrochemical quartz crystal microbalance techniques (EQCM) and X-Ray Photo-electron Spectroscopy (XPS). The behaviour of several mixed thiophene-pyrrole films, polypyrrole and poly 3,4-ethylenedioxythiophene in different electrolyte media; deep eutectic solvents (DESs), conventional organic solvents and aqueous media are contrasted in this thesis. PEDOT and one of the mixed thiophene-pyrrole polymers (poly 2-(thiophene-2-yl)-1H pyrrole) gave the highest DC capacitances of the polymers investigated, with high values observed in both choline chloride based (Type III) and zinc based (Type IV) DESs. The ion dynamics of the polymers p-doping in the DESs, observed to fit gravimetric data recorded, was able to show a marked difference in the ion transfers between DES types and a conventional organic solvent, acetonitrile. Both polymers in acetonitrile and the zinc based DES (ZnCl2 / EG) satisfied the electro-neutrality condition through dominance of anion transfers. Whereas, polymers in the choline chloride based DES (Ethaline) satisfied the electro-neutrality condition through dominance of choline cation transfers (in the opposite direction to anion transfers). This research involved work towards the development of a new class of rechargeable batteries based on a Zinc-Polymer system incorporating a novel, inexpensive, environmentally sustainable solvent. This work is necessitated by the problems associated with petrol and diesel powered vehicles and the limitations of batteries available for electric vehicles.

This research work prepared a choline chloride/ascorbic acid natural deep eutectic solvent (CHCL/AA NADES) to enhance the solubility and stability of antioxidants extracts from the fruit wastes of Mangifera pajang. CHCL/AA NADES enhanced the solubility of antioxidant extracts by 11% as compared to water. Moreover, CHCL/AA NADES stabilized the antioxidant extracts under high temperature and pH by extending its half-life duration, determined by first-order kinetic model and a new proposed multi-term degradation model.

Fabrication of current generation integrated circuits involves the creation of multilevel copper/low-k dielectric structures during the back end of line processing. This is done by plasma etching of low-k dielectric layers to form vias and trenches, and this process typically leaves behind polymer-like post etch residues (PER) containing copper oxides, copper fluorides and fluoro carbons, on underlying copper and sidewalls of low-k dielectrics. Effective removal of PER is crucial for achieving good adhesion and low contact resistance in the interconnect structure, and this is accomplished using wet cleaning and rinsing steps. Currently, the removal of PER is carried out using semi-aqueous fluoride based formulations. To reduce the environmental burden and meet the semiconductor industry's environmental health and safety requirements, there is a desire to completely eliminate solvents in the cleaning formulations and explore the use of organic solvent-free formulations.The main objective of this work is to investigate the selective removal of PER over copper and low-k (Coral and Black Diamond®) dielectrics using all-aqueous dilute HF (DHF) solutions and choline chloride (CC) - urea (U) based deep eutectic solvent (DES) system. Initial investigations were performed on plasma oxidized copper films. Copper oxide and copper fluoride based PER films representative of etch products were prepared by ashing g-line and deep UV photoresist films coated on copper in CF4/O2 plasma. PER removal process was characterized using scanning electron microscopy and X-ray photoelectron spectroscopy and verified using electrochemical impedance spectroscopy measurements.A PER removal rate of ~60 Å/min was obtained using a 0.2 vol% HF (pH 2.8). Deaeration of DHF solutions improved the selectivity of PER over Cu mainly due to reduced Cu removal rate. A PER/Cu selectivity of ~20:1 was observed in a 0.05 vol% deaerated HF (pH 3). DES systems containing 2:1 U/CC removed PER at a rate of ~10 and ~20 Å/min at 40 and 70oC respectively. A mixture of 10-90 vol% de-ionized water (W) with 2:1 U/CC in the temperature range of 20 to 40oC also effectively removed PER. Importantly, etch rate of copper and low-k dielectric in DES formulations were lower than that in conventional DHF cleaning solutions.

Interconnection layers fabricated during back end of line processing in semiconductor manufacturing involve dry etching of a low-k material and deposition of copper and metal barriers to create copper/dielectric stacks. After plasma etching steps used to form the trenches and vias in the dielectric, post etch residues (PER) that consist of organic polymer, metal oxides and fluorides, form on top of copper and low-k dielectric sidewalls. Currently, most semiconductor companies use semi aqueous fluoride (SAF) based formulations containing organic solvent(s) for PER removal. Unfortunately, these formulations adversely impact the environmental health and safety (EHS) requirements of the semiconductor industry. Environmentally friendly "green" formulations, free of organic solvents, are preferred as alternatives to remove PER. In this work, a novel low temperature molten salt system, referred as deep eutectic solvent (DES) has been explored as a back end of line cleaning (BEOL) formulation. Specifically, the DES system comprised of two benign chemicals, malonic acid (MA) and choline chloride (CC), is a liquid at room temperature. In certain cases, the formulation was modified by the addition of glacial acetic acid (HAc). Using these formulations, selective removal of three types of PER generated by timed CF₄/O₂ etching of DUV PR films on Cu was achieved. Type I PER was mostly organic in character (fluorocarbon polymer type) and had a measured thickness of 160 nm. Type II PER was much thinner (25 nm) and consisted of a mixture of organic and inorganic compounds (copper fluorides). Further etching generated 17 nm thick Type III PER composed of copper fluorides and oxides. Experiments were also conducted on patterned structures. Cleaning was performed by immersing samples in a temperature controlled (30 or 40° C) double jacketed vessel for a time between 1 and 5 minutes. Effectiveness of cleaning was characterized using SEM, XPS and single frequency impedance measurements. Type II and III residues, which contained copper compounds were removed in CC/MA DES within five minutes through dissolution and subsequent complexation of copper by malonic acid. Removal of Type I PER required the addition of glacial acetic acid to the DES formulation. Single frequency impedance measurement appears to be a good in situ method to follow the removal of the residues. High water solubility of the components of the system in conjunction with their environmental friendly nature, make the DES an attractive alternative to SAF.

Les mescles de baix punt de fusió o mescles eutèctiques denominades DES per les sigles en anglès (Deep Eutectic Solvents), són bàsicament preparades a partir de compostos acceptors de ponts de hidrogen, els anomenats HBA, (en general una sal d'amoni quaternària), i donadors de ponts d'hidrogen (HBD) com són alcohols, àcids, amines i carbohidrats; que formen sistemes que contenen una àmplia varietat d'espècies catiòniques i / o aniòniques regides per interaccions de pont d'hidrogen que presenten una baixa energia d'enllaç, causant dels baixos punts de fusió que aquestes presenten. Aquesta és una de les característiques importants a l'hora d'emprar els diferents tipus de DES, pel que fa a el tipus de reacció i / o procés sintètic; per exemple, aquests dissolvents eutèctics han estat àmpliament utilitzats i estudiats en processos d'extracció de biomassa, síntesi de polímers, catàlisi, electroquímica, síntesi de nano partícules, entre d'altres. En el present treball, es presenta la preparació de nous solvents eutèctics de base biològica a partir de glicerol (Gly), el qual va ser obtingut mitjançant la hidròlisi de greixos animals no comestibles i després emprat per sintetitzar l'alcohol 3- cloro-1,2-propanodiol, que és el precursor del compost racèmic: clorur de rac-2,3-dihidroxipropiltrietilamonio: [Et3N+CH2CH(OH)CH2OH]Cl- (DPTAC). Dit compost es va sintetitzar emprant el 3- cloro-1,2-propanodiol, trietilamina i metanol. El compost (DPTAC), que inicialment va ser obtingut en forma de barreja racèmica, va ser transformat en un compost enantiomèricament enriquit mitjançant un procés d'acetilació quimioenzimàtica i d'acetilació directa emprant acetat d’isopropilè, per tal de separar la mescla racèmica. De la mateixa manera, es va obtenir el clorur de S - (-) 2,3-dihidroxipropiltrietilamoni, partint de l'alcohol precursor òpticament pur (2a). Totes aquestes sals van ser acetilades directament amb anhídrid acètic. Tots ells van ser emprats com HBA per preparar diferents mescles eutèctiques (DES). Així, es van emprar tres compostos de base biològica: glicerol (Gly), àcid làctic (LA) i urea com HBD per formar cadascuna de les mescles. Finalment, l'etilenglicol (7) va ser també utilitzat per formar un DES concret. És important destacar que el disseny d'aquests dissolvents es va dur a terme utilitzant l'estratègia de "disseny modular" en què cada DES conté un HBA de diferent naturalesa i propietats. Inicialment, es presenta l'estudi de les propietats físiques (viscositat, densitat, relació estequiomètrica, entre d'altres) de cada DES. Posteriorment, s'estudia la seva funció com a dissolvents en diferents processos químics. Els DES preparats van ser utilitzats com a dissolvents en el procés de fraccionament i extracció de material ligno-cel·lulòsic en diferents mostres de biomassa de fusta dura, com són la sansa, i la poda de branques (de tipus llenyós) d'arbres fruiters. Els resultats van mostrar que es pot extreure lignina tipus Klasson i es recuperen fraccions riques en holocel·lulosa utilitzant cada un dels DES. Els DES preparats van ser també utilitzats per estudiar la seva influència sobre la formació dels adductes endo:exo, en reaccions típiques de ciclació [4π + 2π] tipus Diels-Alder, entre el ciclopentadiè i acrilat d'etil o acrilat de butil. D'altra banda, amb base en els requeriments del procés, van ser seleccionats els DES adequats per ser utilitzats com a mitjans de reacció en la reacció d'obtenció d'alcohols quirals secundaris mitjançant la reducció de cetones pro-quirals en presència de NaBH4. La riquesa enantiomèrica dels alcohols produïts es va estudiar emprant un reactiu de derivatització quiral (reactiu de Mosher). D'aquesta manera es va estudiar la configuració absoluta de l'alcohol: 1-feniletanol (12) (obtingut com a producte de la reacció anterior). A més, van ser realitzats assajos preliminars per valorar la possibilitat de reciclar els DES obtinguts. Per a això, els DES inicials, preparats entre el compost racèmic (DPTAC) amb els quatre compostos HBD van ser fraccionats, fent ús d'una resina de bescanvi catiònic fort, per tal de comprovar que la facilitat amb què aquests són separables; a més de ser reusables i reciclables. Condicions que ha de complir un solvent perquè pugui ser considerat dins de la categoria "Green Solvents"; tenint en compte que els materials de partida per a la formació de les mescles eutèctiques gairebé són íntegrament compostos de base biològica. Tots els compostos precursors i els DES preparats van ser caracteritzades per FT-IR i tècniques d'espectroscòpia de 1H i 13C RMN; el compost racèmic va ser analitzat mitjançant espectrometria de masses; la proporció entre els adductes formats en les reaccions de Diels-Alder, va ser estudiada utilitzant cromatografia de gasos GC-FID (230 ° C i 270 ° C). L'activitat òptica i l'angle de rotació específica van ser mesurats en els compostos enantiomèricament enriquits i òpticament purs. Finalment, la separació de cada DES, realitzada mitjançant columnes de bescanvi catiònic, va ser seguida per FT-IR i 1H RMN.
Las mezclas de bajo punto de fusión o mezclas eutécticas denominadas DES por sus siglas en inglés (Deep Eutectic Solvents), son básicamente mezclas preparadas a partir de compuestos aceptores de puentes de hidrógeno llamados HBA, (generalmente sales de amonio cuaternarias) y donantes de puentes de hidrógeno de diferente naturaleza (HBD), por ejemplo, alcoholes, ácidos, aminas y carbohidratos; que forman sistemas que contienen una amplia variedad de especies catiónicas y/o aniónicas regidas por interacciones, principalmente de puentes de hidrógeno, que presentan una baja energía de enlace que causan los bajos puntos de fusión que estas presentan. Precisamente, esta es una de las características importantes a la hora de emplear los diferentes tipos de DES, dependiendo del tipo de reacción y/o proceso sintético. Por ejemplo, estos disolventes eutécticos han sido ampliamente utilizados y estudiados en procesos de extracción de biomasa, síntesis de polímeros, catálisis, electroquímica, síntesis de nanopartículas, entre otros. En el presente trabajo se presenta la preparación de diferentes novedosos disolventes eutécticos de base biológica, a partir de glicerol (Gly). Este glicerol fue obtenido mediante la hidrólisis y trans-esterificación de grasas animales no comestibles, y luego empleado para sintetizar el alcohol 3-cloro-1,2-propanodiol, que es el precursor del compuesto racémico de interés: el cloruro de rac-2,3-dihidroxipropiltrietilamonio: [Et3N+CH2CH(OH)CH2OH]Cl-, [C9H22N+O2]Cl- o (DPTAC). Dicho compuesto se sintetizó empleando el cloroalcohol obtenido, trietilamina y metanol. El compuesto (DPTAC) que inicialmente fue obtenido en forma de mezcla racémica, fue transformado en un compuesto enantiomericamente enriquecido mediante un proceso de acetilación quimioenzimática y de acetilación directa empleando acetato de isopropileno, con el fin enriquecer enantiomericamente este compuesto racémico. Además, se obtuvo el cloruro de S-(-)-2,3-dihidroxipropiltrietilamonio (S)-(-)-(DPTAC), partiendo del alcohol precursor ópticamente puro. Estas sales fueron acetiladas directamente con anhídrido acético y empleadas como componente HBA, en presencia de tres compuestos de base biológica: glicerol (Gly), ácido láctico (LA) y urea que actuaron como compuesto HBD en la formación de cada una de las mezclas eutécticas (DES). Además, el etilenglicol (EG) fue también utilizado para formar otro DES concreto. Es importante tener en cuenta que, el diseño de estos disolventes se realizó empleando la estrategia de “diseño modular” para que cada DES contenga un HBA de naturaleza y propiedades diferentes. En este trabajo es presentado el estudio de las propiedades físicas (viscosidad, densidad, relación estequiométrica, entre otras) de cada DES. Posteriormente, se estudió su empleo como disolventes en diferentes procesos químicos; donde, los DES preparados fueron utilizados como disolventes en el proceso de fraccionamiento y extracción de material ligno-celulósico en diferentes muestras de biomasa de madera dura como son: el orujo de oliva, y la poda de ramas (de tipo leñoso) de árboles frutales. Los resultados mostraron la obtención de lignina tipo Klasson y de fracciones ricas en holocelulosa utilizando cada uno de los DES. Asimismo, los DES preparados fueron utilizados para estudiar su influencia sobre la formación de los aductos endo:exo, en reacciones típicas de ciclación [4π+2π] tipo Diels-Alder, entre el ciclopentadieno con acrilato de etilo y acrilato de butilo. Por otra parte, con base en los requerimientos del proceso, fueron seleccionados los DES adecuados para ser utilizados como medios de reacción, en la obtención de alcoholes quirales secundarios mediante la reducción de cetonas pro-quirales en presencia de NaBH4. La riqueza enantiomérica de los alcoholes producidos se estudió empleando un reactivo de derivatización quiral (reactivo de Mosher). De esta manera se estudió la configuración absoluta del alcohol: 1-feniletanol (12) (obtenido como producto de la reacción anterior).
Low melting mixtures or Deep eutectic mixtures called DES (Deep Eutectic Solvents) are prepared from hydrogen bond acceptors called HBA, (usually a quaternary ammonium salt), and different hydrogen bond donors (HBD) for example alcohols, acid amines, and carbohydrates; form systems that contain a wide variety of cationic and/or anionic species governed by hydrogen bonding interactions that present low binding energy, causing their low melting points. This is one of the important characteristics when using the different types of DES, in terms of the type of reaction and/or synthetic process; for example, these eutectic solvents have been widely used and studied in biomass extraction processes, polymer synthesis, catalysis, electrochemistry, nanoparticle synthesis, among others. This work presents the preparation of several novel bio-based eutectic solvents from glycerol (Gly), which was obtained by hydrolysis and trans-esterification of inedible animal fats and then used to synthesize alcohol 3-chloro-1,2-propanediol, which is the precursor of the racemic compound: rac-2,3-dihydroxypropyltriethylammonium chloride: [Et3N+CH2CH(OH)CH2OH]Cl- (DPTAC). This compound was synthesized using the mentioned chloro-alcohol, triethylamine, and methanol. Compound (DPTAC) that was initially obtained as a racemic mixture, was transformed into an enantiomerically enriched compound employing chemoenzymatic acetylation and direct acetylation process using isopropylene acetate to separate the racemic mixture. Similarly, S-(-)-2,3-dihydroxypropyltriethylammonium chloride was obtained starting from the optically pure precursor alcohol. All these salts were acetylated directly with acetic anhydride. All of them were used as HBA to prepare different eutectic mixtures (DES). Thus, three bio-based compounds were used: glycerol (Gly), lactic acid (LA), and urea as HBD to form each of the mixtures. Finally, ethylene glycol (7) was also used to form a specific DES. It is important to note that the design of these solvents was carried out using the strategy of "modular design" in which each DES contains an HBA of different nature and properties. Initially, the study of the physical properties (viscosity, density, stoichiometric ratio, among others) of each DES is presented. Subsequently, their use as solvents in different chemical processes is also studied, the DES prepared were used as solvents in the process of fractionation and extraction of lignocellulosic material in different samples of hardwood biomass, such as olive pomace, and pruning of branches (woody type) of fruit trees. Results showed the obtaining of Klasson-type lignin and fractions rich in holocellulose using each of the DES. DES prepared were used to study their influence on the formation of endo: exo adducts, in a typical [4π + 2π] Diels-Alder type cyclization reactions, between cyclopentadiene with ethyl acrylate and butyl acrylate. On the other hand, based on the process requirements, suitable DES were selected to be used as reaction media to obtain chiral secondary alcohols by reducing pro-chiral ketones in the presence of NaBH4. The enantiomeric richness of the alcohols produced was studied using a chiral derivatization reagent (Mosher's reagent). In this way, the absolute configuration of the alcohol was studied: 1-phenylethanol (12) (obtained as a product of the previous reaction). In addition, preliminary tests were carried out to assess the possibility of recycling the DES obtained. For this reason, the initial DES prepared between the racemic compound (DPTAC) with the four HBD compounds were fractionated using a strong cation exchange resin to verify the ease with which they are separable; besides, being reusable and recyclable. Conditions that a solvent must meet to be considered within the “Green Solvents” category. Taking into account that the starting materials for the formation of eutectic mixtures are almost entirely bio-based compounds. All the precursor compounds and DES prepared were characterized by FT-IR and 1H and 13C NMR spectroscopy techniques; the racemic compound was analyzed by mass spectrometry; the proportion between the adducts formed in the Diels – Alder reactions was studied using GC-FID gas chromatography (230 ° C and 270 ° C); Optical activity and specific angle of rotation were measured on enantiomerically enriched and optically pure compounds. Finally, the separation of each DES, carried out using cation exchange columns and followed by FT-IR and 1H RMN.

Non-edible plant biomass (lignocellulose) is a valuable precursor for liquid biofuels, through the processes of pretreatment and saccharification followed by fermentation into products such as ethanol or butanol. However, it is difficult to gain access to the fermentable sugars in lignocellulose, and this problem is principally associated with limited enzyme accessibility. Hence, biomass pretreatments that destroy native cell wall structure and allows enzyme access are required for effective biomass conversion techniques. This research studied two novel pretreatment methods on two wood species: 1) a deep eutectic solvent (DES) that, under heat, swells lignocellulose and partially solubilizes cell wall materials by causing breakage of lignin-carbohydrate linkages and depolymerization of the biomass components, and 2) a chelator-mediated Fenton reaction (CMF) that chemically modifies the nanostructure of the cell wall through a non-enzymatic cell wall deconstruction. After pretreatment, utilizing analytical techniques such as nuclear magnetic spectroscopy, wide angle x-ray scattering, and gel permeation chromatography, samples were analyzed for chemical and structural changes in the solubilized and residual materials. After single stage DES (choline-chloride-glycerol) and two stage, CMF followed by DES pretreatments, lignin/carbohydrate fractions were recovered, leaving a cellulose-rich fraction with reduced lignin and hemicellulose content as determined by compositional analysis. Lignin and heteropolysaccharide removal by DES was quantified and the aromatic-rich solubilized biopolymer fragments were analyzed as water insoluble high molecular weight fractions and water-ethanol soluble low molecular weight compounds. After pretreatment for the hardwood sample, enzyme digestibility reached a saccharification yield of 78% (a 13-fold increase) for the two stage (DES/CMF) pretreated biomass even with the presence of some lignin and xylan remained on the pretreated fiber; only a 9-fold increase was observed after the other sequence of CMF followed by DES treatment. Single stage CMF treatment or single stage DES pretreatment improved 5-fold glucose yield compared to the untreated sample for the hardwood sample. The enhancement of enzymatic saccharification for softwood was less than that of hardwoods with only 4-fold increase for the sequence CMF followed by DES treatment. The other sequence of treatments reached up to 2.5-fold improvement. A similar result was determined for the single stage CMF treatment while the single stage DES treatment reached only 1.4-fold increase compared to the untreated softwood. Hence, all these pretreatments presented different degrees of biopolymer removal from the cell wall and subsequent digestibility levels; synergistic effects were observed for hardwood particularly in the sequence DES followed by CMF treatment while softwoods remained relatively recalcitrant. Overall, these studies revealed insight into two novel methods to enhance lignocellulosic digestibility of biomass adding to the methodology to deconstruct cell walls for fermentable sugars.
Ph. D.
Wood is a valuable material that can be used to produce liquid biofuels. Wood main components are biopolymers cellulose, hemicellulose and lignin that form a complex structure. Nature has locked up cellulose in a protective assembly that needs to be destroyed to gain access to cellulose, convert it to glucose and then ferment it to bioalcohol. This process is principally associated with limited enzyme accessibility. Therefore, biomass pretreatments that deconstruct native cell wall structure and allow enzyme access are required for effective biomass conversion techniques. This research studied two novel pretreatment methods on two wood species: 1) a deep eutectic solvent called glyceline that, under heat, swells wood and partially solubilizes cell wall materials by causing breakage of bonds and converting it into smaller molecules (monomers and oligomers), and 2) a chelator-mediated Fenton system (CMF) that chemically modifies the structure of the cell wall. Pretreatments were tested individually and in sequence in sweetgum and southern yellow pine. After pretreatments, utilizing analytical techniques, fractions were investigated for chemical and structural changes in the solubilized and residual materials. Treated wood samples were exposed to enzymatic conversion. A maximum 78% of glucose yield was obtained for the glyceline followed by CMF pretreated wood. For yellow pine only a 24% of glucose yield was obtained for the CMF followed by glyceline treatment. All these pretreatments presented different degrees of biopolymer removal from the cell wall and subsequent enzyme conversion levels. Overall, these studies revealed insight into two novel methods to enhance wood conversion adding to the methodology to deconstruct cell walls for fermentable sugars.

Conventional studies of ionomers have focused on ionomers bearing monovalent carboxylate or sulfonate pendant ions. There are relatively fewer studies on ionomers containing multivalent pendant ions, such as divalent phosphonate. In this dissertation, poly(ethylene terephthalate) (PET) and polystyrene ionomers with divalent phosphonate pendant ions have been synthesized, and the influence of divalent phosphonate pendant ions on the structure-morphology-property relationship has been compared to the ionomers with monovalent sulfonate pendant ions. The phosphonate groups generated a stronger physically crosslinked network in phosphonated ionomers as compared to sulfonated analogues. Higher plateau modulus, longer relaxation time, and significantly higher zero-shear viscosity were noted for phosphonated ionomers by a dynamic melt rheology study. Compared to the ionic aggregates generated from sulfonate groups, larger ionic aggregates with associated phosphonate groups have been observed. Furthermore, phosphonated ionomers displayed significantly higher glass transition temperatures than sulfonated ionomers. Ionomers have proven to be attractive, interfacially active compatibilizers for a number of polymer blend systems because of specific interactions that may develop between the ionic groups and complementary functional groups on other polar polymers within the blends. The successful compatibilization of polyester/polyamide blends (prepared by solution mixing and melt blending methods) using phosphonated PET ionomers as a minor-component compatibilizer has been demonstrated. The phase-separated polyamide domain dimension decreased with increasing mol % phosphonated monomers and this decrease was attributed to the specific interactions between the ionic phosphonate groups on the polyester ionomer and the amide linkages of polyamide. More importantly, the divalent phosphonate pendant ions are more effective at compatibilizing polyester/polyamide blends in comparison to the monovalent sulfonate pendant ions. Phosphonated PET ionomer-compatibilized polyester/polyamide blends required 6 times fewer ionic monomers to achieve domain dimension < 1 μm as compared to sulfonated PET-containing blends. Deep eutectic solvents (DES) have been reported to be the next generation solvents due to the superior biocompatibility, biodegradability, and sustainability as compared to ionic liquids. Two types of deep eutectic solvents, choline chloride : malic acid (ChCl:MA) and L-arginine : levulinic acid (Arg:LA), have been demonstrated as effective plasticizers for poly(vinyl alcohol) (PVOH) films. The plasticization effects on the properties of PVOH films were evidenced by lower crystallizability and improved film ductility. In addition, ChCl:MA deep eutectic solvent was more effective in plasticizing PVOH as compared to propylene glycol, one of the most widely studied alcohol-type plasticizers. From an applied perspective, DES-plasticized PVOH film is a promising candidate in the packaging market of heath-related products.
Doctor of Philosophy

Les nanocolloïdes magnétiques sont des dispersions de nanostructures magnétiques dans un liquide porteur. Par la combinaison des propriétés du liquide et des particules magnétiques, ces dispersions peuvent être confinées, déplacées, déformées et contrôlées par l'application d'un champ magnétique externe et ont ainsi de nombreuses applications en nanosciences et les nanotechnologies. Nous avons étudié la dispersion de nanoparticules magnétiques (NPM) dans les solvants eutectiques profonds (DES). Ces solvants, constitués d'un mélange entre un sel d'ammonium (ici le chlorure de choline (Ch) et un donneur de liaison H (ici, l'ethyleneglycol (EG) ou l'urée (U)) ont des propriétés proches des liquides ioniques tout en étant biodégradables. L'un des verrous concernant ces dispersions est la nature des forces impliquées dans la stabilité colloïdale. En effet, on ne peut plus expliquer la stabilité des dispersions dans ces milieux par le modèle DLVO, classiquement utilisé dans l'eau, du fait de leur force ionique élevée. Nous avons dans en premier temps caractérisé soigneusement deux DES (ChEH (1:3) et ChU (1:2) en mol) du point de vue de la densité et viscosité pour des températures entre 20 et 45°C. Ceci nous a permis de montrer la forte association de ces liquides. Un protocole de dispersion de nanoparticules de maghémite (Fe2O3) ou de ferrite mixte (CoxZn1-xFe2O4) est ensuite proposé, et les dispersions sont étudiées par diffusion de rayonnement (lumière et SAXS). Il s'est avéré que les particules les plus petites étaient les mieux dispersées. Enfin, un test de synthèse de NPM dans des solutions d'argile a permis d'obtenir une polydispersité plus faible en sortie de synthèse
Magnetic nanocolloids are dispersions of magnetic nanostructures in a carrier fluid. Thanks to the original properties of both the liquid and the magnetic particles, these dispersions can be confined, moved, deformed and controlled by applying an external magnetic field. Such dispersions thus have many applications in nanoscience and nanotechnologies.We studied the dispersion of magnetic nanoparticles in deep eutectic solvents (DES). These solvents (DES), obtained by mixing a quaternary ammonium salt (e.g., choline chloride Ch) and a hydrogen bond donor (e.g., ethyleneglycol EG or Urea U) have properties similar to ionic liquids, and are also biodegradable. One of the questions about these dispersions is the nature of the forces implied in colloidal stability, since the DLVO model classically used in water cannot be invoked here due to the very high ionic strength of the solvent.In a first step, we have carefully characterized two DES ((ChEG (1:3) and ChU (1:2) in mol), measuring the density and viscosity for temperatures between 20 and 45°C. We could thus show the high association in these liquids.A protocol to disperse nanoparticles of maghemite (Fe2O3) or mixed ferrite (CoxZn1-xFe2O4) is then proposed, and the obtained dispersions are studied by dynamic light scattering and SAXS. The size polydispersity was reduced by size sorting, and it reveals that the smallest particles are the most easy to disperse in the DES.Last, a synthesis of NMP in clay dispersion was tested and showed promising results with a reduced size polydispersity

The objective of this PhD study was to apply organocatalytic synthetic methods for the regio- and stereoselective synthesis of highly functionalized compounds. We exploited different organocatalytic activation modes to peculiar substrates we identified as suitable building blocks for versatile products in enantiomerically enriched form. In particular the developed projects relied on stereoselective amino- and hydrogen bonding organocatalysis, employing beta-nitroacrylates, beta-trifluoromethylated nitroalkenes and 2,2,2-trifluoroethyl 2-[(1,3-dithian)-2-yl]-ethanthioate in combination with various reaction partners, thus finding entries to valuable intermediates suitable for further subsequent transformations. The first Chapter of this thesis aim to give a general overview on those fields of organocatalysis related to the research topics studied in this PhD program, the second Chapter offers a literature background of the employed substrates. Following five Chapters (3-7) and Appendix report the discussion on the obtained results. According to our opinion, this PhD study offers solid examples of robustness, versatility and effectiveness of stereoselective organocatalytic strategies, which have been applied to interesting starting materials and in innovative reaction media, thus giving a reliable contribution to expand the boundaries of this field.

Le développement de diverses applications utilisant l’hydrogène en tant que vecteur énergétique ouvre des voies prometteuses pour l'avenir. L’hydrogène peut être produit de différentes manières, l’une d’entre elles est l’électrolyse de l’eau et plus particulièrement sa réduction qui conduit à la production d’hydrogène (connue sous le nom de Hydrogen Evolution Reaction, HER). Cette technique nécessite l’emploi d’électrocatalyseurs performants. À l'heure actuelle, les catalyseurs à base d'alliages ou de composés de métaux nobles se distinguent par leur rendement électrocatalytique exceptionnel dans le cadre de la production d'hydrogène. Cependant, leur coût élevé et leurs réserves limitées compliquent leur utilisation à grande échelle dans l'industrie. C'est pourquoi il est impératif de concevoir et de développer de nouveaux matériaux permettant de produire de l'hydrogène économiques et respectueux de l'environnement. Ces dernières années, de nouveaux matériaux, notamment les alliages à base de métaux de transition tels que le nickel (Ni) et le cobalt (Co), ont été proposés et ont démontré d'excellentes propriétés catalytiques. Cependant, réduire davantage les coûts de préparation tout en améliorant les performances catalytiques et en respectant l'environnement s'avère être un défi de taille. C'est pourquoi, dans cette étude, nous mettrons l'accent sur la préparation d'alliages par électrodépôt, une méthode économique, et nous explorerons les effets de la composition élémentaire, de la structure de phase et de la morphologie de surface sur les performances électrocatalytiques. Au cours du processus d'électrodéposition, nous employons des électrolytes non conventionnels, communément désignés sous l'appellation de liquides ioniques. Comparativement aux solutions aqueuses, ces liquides ioniques présentent une teneur en eau considérablement moindre. Cette particularité sert à réduire la formation d'oxydes de métaux de transition. Par ailleurs, les liquides ioniques se caractérisent par une fenêtre électrochimique élargie, ce qui élargit notre éventail d'options en termes d'éléments d'alliage. Cette diversification nous autorise à scruter l'influence de divers éléments sur les performances de l'évolution de l'hydrogène, offrant ainsi des perspectives précieuses. De plus, la surface spécifique de l'électrocatalyseur joue un rôle central dans l'incidence sur les performances de la génération d'hydrogène. Une méthode connue sous l'appellation de désalliage est employée pour éliminer sélectivement une fraction des éléments d'alliage, ce qui conduit à la formation d'une structure nanoporeuse. Cette modification accroît davantage la surface spécifique du matériau. Nous avons mené avec succès l'électrodépôt d'alliages à base de Ni/Co dans des liquides ioniques ou des solvants eutectiques profonds (DES) en vue de préparer des électrocatalyseurs, puis nous les avons soumis à un traitement de surface par désalliage, fournissant ainsi de nouvelles informations sur le développement de matériaux pour la production d'hydrogène
The use of fossil energy, one of the main contributors to carbon emissions and a major source of pollution, has become a hot topic of discussion in recent years. Predicted energy shortages and the resulting environmental challenges are forcing mankind to look for alternatives to fossil fuels. Hydrogen is attracting increasing attention as a clean energy source, with high energy density and minimal emissions. It represents a promising, low-carbon energy carrier ready to supplant fossil fuels, particularly in the demanding industrial and transport sectors, where decarbonization is particular difficult to implement. According to existing literature, there are three main methods for producing hydrogen: hydrogen production from (i) fossil fuels, (ii) gasification, and (iii) water splitting. Water electrolysis under renewable resource conditions can practically eliminate carbon emissions, which is a significant difference compared to hydrogen production from fossil fuels (66 gCO2 e/MJ) or gasification (55 gCO2 e/MJ). Clearly, hydrogen production by electrolysis under ideal conditions has the distinct advantage of being environmentally friendly, with a low carbon footprint. Furthermore, water electrolysis offers many advantages, including the production of high-purity hydrogen, the simultaneous production of oxygen as a by-product, and simple installation. Although the hydrogen evolution reaction (HER) by water electrolysis provides numerous advantages for hydrogen production applications, its industrial adoption remains relatively limited, especially behind the production of hydrogen from fossil fuels. One of the main obstacles to its widespread use is the choice of electrocatalytic materials. Precious metals have exceptional electrocatalytic properties; however, their high cost and limited abundance on earth limit their practical application in all industries. Consequently, the search for cost-effective alternatives involving transition metals and the improvement of electrocatalyst performance through alloying and adjustments of surface morphology has emerged as important and dynamic lines of research. A wide range of techniques have been explored for synthesizing transition metal alloys used in electrocatalytic HER. Among these methods, electrodeposition stands out for its streamlined process, ease of implementation, and precise control, making it a versatile choice for large-scale applications. However, the hydrolysis of water during electrodeposition poses a problem. This can be effectively resolved by employing ionic liquids (ILs) as electrolytes, which are becoming increasingly popular due to their wide electrochemical window, high ionic conductivity, and user-friendly characteristics arising from their non-volatile and non-flammable nature. Surprisingly, research on the electrodeposition of alloys in ionic liquids remains relatively scarce. Consequently, combining the electrodeposition of alloy electrocatalysts with ionic liquids represents an attractive avenue to explore. In this work, we address the following questions: (1) Is it possible to prepare transition metal-based alloys by electrodeposition in ionic liquids? (2) What kinds of alloys can be prepared by electrodeposition in ionic liquids? (3) What is the impact of other elements (Co, Zn, Cu) on the HER properties of alloys? (4) How can the HER properties of alloys be enhanced by surface modification (dealloying)?

Doutoramento em Ciência e Engenharia de Materiais
O método de síntese de nanoparticulas 1-D assistido por um modelo tornou-se um tópico em voga na química após o desenvolvimento de filmes anódicos com poros bem ordenados. Contudo, a maioria dos trabalhos nesta área tem sido feita utilizando filmes porosos destacados devido à presença de uma barreira no fundo dos poros. No entanto, esta estratégia segue demasiados passos, o que aumenta o seu custo, torna mais difícil a execução e impõe várias limitações. Consequentemente, existe a necessidade de uma técnica que permita o enchimento (electrofilling) dos tubos sem remover a camada barreira – esta tese representa o nosso contributo para esse trabalho. Utilizámos uma técnica mais simples que permite a electrodeposição e “electrofilling” de nanoestruturas directamente nos modelos sobre o substrato metálico, utilizando solventes eutécticos profundos à base de cloreto de colina como electrólito. Relativamente à água, os solventes eutécticos profundos demonstram superior estabilidade térmica e uma janela electroquímica mais alargada, o que aumenta o número de materais secundários depositados. Como materiais a investigar foram escolhidos titânia e alumina dada a sua capacidade para formar estruturas porosas altamente ordenadas, propriedades eletroquímicas distintas e uso generalizado em síntese assistida por padrão. O estudo aqui apresentado encontra-se dividido em duas etapas. Primeiramente, a influência da camada barreira foi investigada em sistemas modelo através da utilização de filmes barreira densos na superfície dos elétrodos. Para os filmes de alumina e titânia, identificaram-se vários parâmetros que afectam a electrodeposição, dos quais se destacam a influência da voltagem de anodização, a espessura da camada de barreira, a dupla camada eléctrica e o perfil de corrente. Durante esta etapa detectaram-se efeitos nefastos, como a formação de uma densa camada orgânica na superfície do eléctrodo, que foram ultrapassados aumentando a temperatura ou alternando o potencial aplicado. A segunda etapa consistiu em passar de elétrodos planos (primeira etapa) para modelos porosos (segunda etapa). Foi realizado, com sucesso, o preenchimento dos poros de alumina e dos poros de titânia. Parâmetros como o perfil de corrente, temperatura de solução, entre outras, foram ajustadas para melhorar o fator de preenchimento e a homogeneidade do preenchimento. Foi desenvolvido um processo de preenchimento de moldes de alumina anódica em duas etapas, nucleação AC (1º passo) e preenchimento galvanostático (2º passo). Foram utilizadas três condições diferentes de modelos de titânia anódica porosa no “electrofilling”. O primeiro é sem modificação e demonstrou que a electroredução do zinco ocorre de forma aleatória ao longo de todo o comprimento do poro, o que leva ao fecho do poro e a um enchimento não homogéneo. A segunda modificação, cristalização total por têmpera, permite a preparação de estruturas coaxiais devido à deposição uniforme de zinco nas paredes dos poros. A última modificação foi a cristalização selectiva do fundo do poro. Foi descoberto que uma anodização adicional em eletrólitos não agressivos leva à cristalização da parte barreira dos tubos (fundo) e, consequentemente, a maior condutividade na parte inferior do que nas paredes. Este efeito permite um enchimento ascendente dos modelos porosos de titânia. As estratégias aqui apresentadas alargam a gama de possibilidades para a aplicação de modelos porosos anódicos na electrodeposição de diferentes nanoestruturas.
The template assisted method of 1-D nanoparticles synthesis has become a hot topic in Chemistry after the development of high-ordered porous anodic films. Most studies in this field have focused on the use of detached porous films due to the presence of the barrier layer on the pore bottom. However, this strategy follows a great number of steps, which raises its cost while decreasing convenience of operation and imposing several limitations. Consequently, there is a need for a technique which allows electrofilling of tubes without removing the barrier layer – this thesis represents our contribution to that enterprise. We have devised a simpler technique which allows electrodeposition of nanostructures directly in the templates on metallic substrate, using choline chloride based deep eutectic solvents (DES) as electrolyte. Compared to water, DES have improved thermal stability and a wider electrochemical window, dramatically increasing the number of possible secondary materials deposited. Titania and alumina were chosen as materials under study due to their known capacity to form highly-ordered porous structures, different electrochemical profiles and widespread use in template assisted synthesis. The present work is divided in two parts. First, the influence of the barrier layer has been investigated by using dense barrier films on the electrode surface as a model system. For both alumina and titania films, several parameters affecting the electrodeposition of zinc have been identified, notably the influence of the anodization voltage, barrier layer thickness, electrical double layer and current profile. During this stage, some negative effects have been detected, such as a dense organic layer formation on electrode surface, a hurdle which has been overcome by either increasing the temperature or applying the alternating potential. The second stage consisted in transferring the method from the flat electrodes (the first stage) to the porous templates. The successful filling of both porous alumina and porous titania, has been achieved. Parameters such as current profile, solution temperature, among others, have been tuned to improve the fill factor and homogeneity of the filling. A two-step porous anodic alumina template filling with AC nucleation (1st step) and galvanostatic filling (2nd step) has been developed. Three different types of porous anodic titania templates have been used for electrofilling. The first one was used as-prepared, showing that zinc electroreduction occurs in random places along all pore length, resulting in pore sealing and non-homogeneous filling. The second modification, full crystallization by annealing, allows the preparation of coaxial structures due to uniform zinc deposition on the pore walls. The last modification is selective bottom crystallization. It has been found that additional anodization in unaggressive electrolytes leads to crystallization of the barrier (bottom) part of the tubes and, thus, to higher conductivity of the bottom part than that of the walls. This effect allows a bottom-up filling of the titania porous template. The strategies presented here widen the range of possibilities for the application of porous anodic templates in the electrodeposition of different nanostructures.

Ce travail porte sur l'étude de la capacité d'absorption du CO2 par différents types d'amines dissoutes en milieux aqueux et non aqueux. Ce dernier est constitué d'un mélange de chlorure de choline et d'éthylène glycol dans une proportion molaire respectivement de 1 pour 2. Ce solvant, communément appelé "Ethaline", appartient à la catégorie dite des « Solvants à Eutectique Profond » ainsi désignés car leur composition eutectique permet d'obtenir des mélanges généralement liquides à température ambiante. Pour ce faire un appareil d'équilibre liquide-vapeur avec analyse en ligne de la phase vapeur par GC a été réalisé et son fonctionnement validé. Les isothermes d'absorption du CO2 ainsi que la volatilité (composition de la phase vapeur) des mélanges étudiés, avec et sans CO2, ont été déterminées à différentes températures et pour différentes compositions en amines. Le domaine de pression exploré est particulièrement large : du Pascal à 800 kPa. L'étude a montré que la substitution de l'eau par "l'Ethaline" conduit à une capacité d'absorption du CO2 presque identique à celle de la MEA et DEA en solution aqueuse. Par contre dans le cas de la MDEA on observe une capacité d'absorption plus faible en milieu « Ethaline » qu'en milieu aqueux. Les isothermes d'absorption du CO2 des trois classes d'amines en milieu aqueux et non aqueux ont été corrélés par les modèles semi empiriques de (Gabrielsen et al., 2005) initialement établis par ces auteurs pour les solutions aqueuses (un modèle pour les amines primaires et secondaires conduisant à la formation de carbamates en présence de CO2, un modèle pour les amines tertiaires donnant des sels d'ammonium avec le CO2). Nous avons montré que ces deux modèles représentent avec succès les isothermes d'absorption en milieu non aqueux. Les constantes d'équilibre et les enthalpies de réaction qui s'en déduisent montrent que ces dernières sont plus faibles (en valeur absolue) pour la MEA et TMDEA en solution éthaline qu'en solution aqueuse. Dans le cas de la MDEA la nature du solvant n'a qu'une influence minime sur l'enthalpie de réaction. Les valeurs expérimentales des volatilités des amines dans les différents mélanges Amine- CO2 en milieu aqueux ont été corrélées par différents modèles semi-empiriques. Trois modèles thermodynamiques de coefficients d'activité ; le modèle de Wilson, NRTL et UNIQUAC ont été utilisés afin de restituer les données expérimentales de l'équilibre liquide-vapeur des systèmes aqueux d'amines (sans CO2). Une représentation satisfaisante des résultats expérimentaux par les trois modèles a été obtenue
This work focuses on the study of the absorption capacity of CO2 by different types of dissolved amines in aqueous and non-aqueous media. The latter consists of a mixture of choline chloride and ethylene glycol in a molar proportion of 1 to 2 respectively. This solvent, commonly called "Ethaline", belongs to the category called "Deep Eutectic Solvents" so designated because their eutectic composition makes it possible to obtain mixtures that are generally liquid at room temperature. With this aim, a liquid-vapor equilibrium apparatus with on-line analysis of the vapor phase by GC was performed and its operation validated. The CO2 absorption isotherms and the volatility (composition of the vapor phase) of the studied mixtures, with and without CO2, were determined at different temperatures and for different amine compositions. The explored pressure range is particularly large: from 1 Pa to 800 kPa. The study showed that the substitution of water by "Ethaline" leads to a CO2 absorption capacity almost identical to that of MEA and DEA in aqueous solution. On the other hand, in the case of MDEA, a lower absorption capacity is observed in Ethaline than in aqueous medium. In the hypothesis of a use of the DES+amine solvent for CO2 capture in post-combustion process, a decrease of the vapor pressure of the solvent (comparing to that of water+amine) has an advantage because of the low solvent loss due to vaporization in the absorber. The second advantage is most likely a lower effect of equipment corrosion, the third positive point is a lower enthalpy of absorption of MEA and MDEA in (1 ChCl : 2 EG) comparing to aqueous medium, resulting in a possible saving of energy in the regenerator of almost 40%. The disadvantage of the use of amines in "Ethaline" solution is the high viscosity of this solvent which decreases the kinetics of material transfer and reaction with CO2. The CO2 absorption isotherms and the experimental values of the amine volatilities in the different Amine-H2O-CO2 mixtures were well correlated by different semi-empirical models. Three thermodynamic models based on the activity coefficients; the Wilson model, NRTL and UNIQUAC were used to restitute experimental data for the liquid-vapor equilibrium of aqueous amine systems (without CO2). A satisfactory representation of the experimental results by the three models was obtained

Abstract Nanocellulose is a renewable, biodegradable, and easily available material that is considered as an attractive resource for many different value-added applications in the emerging bio-based economy. Its outstanding properties, such as strength, lightness, transparency, and good thermal insulation, have inspired research and product development around nanocellulose. The potential of nanocellulose to replace synthetic chemicals made from non-renewable sources, for example, is considered to be very promising. Chemical functionalization, that is, the modification of the cellulosic surface properties, is seen to be beneficial in applications such as those in which higher hydrophobicity is needed. In this thesis, the ability of cellulose nanoparticles to stabilize oil droplets in oil-in-water emulsions was studied. The aim of the study was to explore the possibility of developing a new type of "green" oil spill chemical from cellulose. Therefore, the cellulose was chemically modified in an aquatic environment with a sequential periodate oxidation and chlorite oxidation followed by reductive amination reaction, which increased the hydrophobicity of the produced nanocellulose. In addition, the use of deep-eutectic solvents in the preparation of modified (succinylated and carboxylated) and non-modified cellulose nanoparticles was studied. Chemical (kraft) pulp, dissolving pulp, and semi-chemical fine fibers were used as raw materials in this research. The results demonstrated that chemically modified cellulose nanoparticles work well as stabilizers for oil-water emulsions resulting in small, stable oil droplets and impeding creaming, which is a typical phenomenon for particle stabilized emulsions. The modification of cellulose nanoparticles improved their ability to partition at the oil-water interface, which enabled efficient and irreversible adsorption. It was found that because of their small size, the cellulose nanocrystals can be compressed more tightly onto the surface of the oil droplet, while longer and more flexible cellulose nanofibrils formed a web structure between the oil droplets. All cellulose nanoparticle-stabilized emulsions were stable against droplet coalescence, and even at low temperatures, they retained their droplet size and stability. Salinity, on the other hand, improved stability when CNCs from chemical pulp were used, but it negatively affected stability when nanocrystals from semichemical pulp were used
Tiivistelmä Uusiutuva, biohajoava ja helposti saatavilla oleva nanoselluloosa on merkittävä tulevaisuuden raaka-aine useissa erilaisissa käyttökohteissa. Sen ylivertaiset ominaisuudet, kuten lujuus, keveys, läpinäkyvyys ja lämmöneristävyys ovat olleet innoittamassa nanoselluloosan tutkimusta ja tuotekehitystä. Nanoselluloosan mahdollisuuksia ja käyttöä eri sovelluksissa korvaamaan esimerkiksi uusiutumattomista luonnonvaroista valmistettuja kemikaaleja, pidetään erittäin lupaavina. Kemiallisesta funktionalisoinnista eli selluloosan pintaominaisuuksien muokkauksesta nähdään olevan hyötyä, kun tavoitellaan nanoselluloosan toiminnallisuutta esimerkiksi hydrofobista luonnetta vaativissa sovelluksissa pinta-aktiivisen aineen tavoin. Tässä työssä tutkittiin erityisesti nanoselluloosapartikkeleiden kykyä stabiloida öljypisaroita dieselöljy-vesiemulsioissa. Tutkimuksen päämääränä oli selvittää mahdollisuutta kehittää uudentyyppistä, ”vihreää” öljyntorjuntakemikaalia selluloosasta. Tämän vuoksi selluloosaa muokattiin kemiallisesti vesiympäristössä yhdistetyllä hapetus- ja aminointikäsittelyllä, mikä lisäsi valmistetun nanoselluloosan hydrofobisuutta. Toisena käsittelyvaihtoehtona tutkittiin syväeutektisten liuottimien käyttöä sekä muokattujen (sukkinyloidut ja karboksyloidut) että muokkaamattomien nanoselluloosapartikkeleiden valmistuksessa. Raaka-aineina työssä käytettiin kemiallista sellumassaa, liukosellua sekä puolikemiallista hienokuitua. Työn tuloksena voidaan todeta, että nanoselluloosasta valmistetut kemiallisesti muokatut (funktionalisoidut) nanopartikkelit toimivat hyvin öljy-vesiemulsiossa estäen emulsion öljypisaroiden yhteensulautumista. Nanopartikkelit stabiloivat emulsiossa olevan öljyn hyvin pieniksi pisaroiksi hidastaen kermottumista eli emulsion yleistä faasierottumista. Nanoselluloosan funktionalisointi paransi sen kykyä hakeutua öljy-vesi rajapintaan, mahdollistaen tehokkaan ja palautumattoman adsorption. Havaittiin, että pienen kokonsa vuoksi selluloosananokiteet pystyivät pakkautumaan tiiviimmin öljyn pinnalle, kun taas selluloosananokuidut, jotka ovat pidempiä, muodostivat verkkomaisen rakenteen myös öljypisaroiden väliin. Suolan lisäys vaikutti emulsion stabiilisuuteen vaihtelevasti eri näytteiden välillä, kun taas kylmät olosuhteet poikkeuksetta paransivat stabiilisuutta

En 2030, la chimie du végétal occupera 30% de la chimie totale en France. Les bioressources offrent l’opportunité de substituer les produits issus de la pétrochimie. Avec un taux de pénétration stable de 25-30% selon les prévisions de l’ADEME, les biotensioactifs constituent une voie de valorisation des produits issus de l’agriculture. Les sources lipophiles et hydrophiles nécessaires à l’obtention de ces composés amphiphiles peuvent être totalement naturelles. Ainsi, la graine de chia de la variété Oruro® a été utilisée comme source de la partie hydrophile représentée par le mucilage. Le mucilage surfacique de la graine de cette variété domestiquée en France est constitué de polysaccharides, de protéines et de minéraux. Il peut être extrait de façon efficace par cavitation ultrasonore en milieux aqueux. La composition et les propriétés du mucilage sont liées au temps d’extraction. Ce mucilage constitue une source hydrophile pour l’obtention d’esters amphiphiles. La source lipophile choisie est l’amande de Irvingia gabonensis issue d’une variété riche en beurre laurique haut myristique (51%) et laurique (38%). Les triglycérides de ce beurre sont constitués par des mélanges en acides gras saturés. Ce sont de bons candidats pour l’alimentation, la nutrition et aussi l’industrie et la production de biotensioactifs technofonctionnels. Le travail vise donc la valorisation simultanée du mucilage et de l’huile de I. gabonensis par la synthèse de biotensioactifs. Deux voies de synthèse pour l’obtention des esters amphiphiles ont été explorées. La première voie a impliqué la mise en œuvre de la réaction de transestérification entre le glucose et le laurate de méthyle en milieu eutectique profond DES Chlorure de choline/glucose. La deuxième voie fait appel à la catalyse acide en milieu organisé par la mise en œuvre de la réaction d’estérification du glucose ou du mucilage avec les acides gras laurique C12:0, et myristique C14:0 en présence de l’acide dodécylbenzène sulfonique (ADBS). Les études des réactions d’estérification ont préalablement été réalisées à partir du glucose puis transposées au mucilage. L’utilisation de l’ADBS doté d’un double rôle en tant que catalyseur de Brönsted et tensioactif favorise la mise en contact des réactifs, catalyse la réaction la réaction d’estérification entre les hydroxyles du glucose ou des polysaccharides et les groupes carboxyliques des acides gras laurique C12:0 et myristique C14:0 et par conséquent permet l’obtention des esters de glucose de degré de substitution DS=1-2. Les propriétés tensioactives et émulsionnantes sont comparables de ces esters de glucose sont comparables à celles d’un ester commercial Olivem 1000, un mélange d’olivate de sorbitan et d’olivate de cétéaryl. La réaction entre le mucilage de chia Oruro® et le mélange d’acides gras de I. gabonensis en présence de l’ADBS a permis une modification structurale profonde du biopolymère. Sa lipophilisation est obtenue par la double monoacylation des sites hydroxyles du mucilage par le mélange d’acides gras laurique C12:0 et myristique C14:0. La viscosité intrinsèque du mucilage acylé est très faible (6,34 dL/g) par rapport à celle du mucilage brut (36,18 dL/g) utilisé en tant que réactif de départ. Il en découle un changement profond de propriétés techno-fonctionnelles du mucilage acylé
In 2030, vegetal-based chemistry will occupy 30% of total chemistry in France. Bioresources offer the opportunity to substitute products from petrochemicals. With a stable penetration rate of 25- 30% according to ADEME forecasts, biosurfactants are a way of adding value to agricultural products. The lipophilic and hydrophilic sources needed to obtain these amphiphilic compounds can be completely natural. Thus, the chia seed of the Oruro® variety has been used as a source of the hydrophilic part represented by the mucilage. The surface mucilage of the seed of this variety domesticated in France is made up of polysaccharides, proteins and minerals. It can be extracted effectively by ultrasonic cavitation in aqueous media. The composition and properties of the mucilage are related to the extraction time. This mucilage constitutes a hydrophilic source for obtaining amphiphilic esters. The lipophilic source chosen is the Irvingia gabonensis almond from a variety rich in high myristic (51%) and lauric (38%) butter. The triglycerides of this butter are made up of mixtures of saturated fatty acids. They are good candidates for food, nutrition and also industry and production of technofunctional biosurfactants. The work is therefore aimed at the simultaneous valorization of the mucilage and oil of I. gabonensis by the synthesis of biosurfactants. Two synthesis routes for obtaining amphiphilic esters have been explored. The first pathway involved the implementation of the transesterification reaction between glucose and methyl laurate in a deep eutectic medium DES Choline chloride/glucose. The second pathway involved acid catalysis in an organized medium by the implementation of the esterification reaction of glucose or mucilage with lauric C12:0 and myristic C14:0 fatty acids in the presence of dodecylbenzene sulfonic acid (DBSA). The studies of the esterification reactions were previously carried out using glucose and then transferred to mucilage. The use of DBSA with a dual role as a Brönsted catalyst and surfactant promotes the contact of the reagents, catalyzes the esterification reaction between the hydroxyl groups of glucose or polysaccharides and the carboxylic groups of the C12:0 lauric and C14:0 myristic fatty acids and therefore allows the glucose esters of degree of substitution DS=1-2 to be obtained. The surfaceactive and emulsifying properties of these glucose esters are comparable to those of a commercial Olivem 1000 ester, a mixture of sorbitan olivate and cetearyl olivate. The reaction between chia Oruro® mucilage and the fatty acid mixture of I. gabonensis in the presence of ADBS resulted in a profound structural modification of the biopolymer. Its lipophilization is obtained by the double monoacylation of the hydroxyl sites of the mucilage by the mixture of lauric C12:0 and myristic C14:0 fatty acids. The intrinsic viscosity of the acylated mucilage is very low (6.34 dL/g) compared to that of the crude mucilage (36.18 dL/g) used as starting reagent. This results in a profound change in the techno-functional properties of the acylated mucilage

Les solvants eutectiques profonds (DES) forment une nouvelle famille de solvants qui a émergé ces dernières années. Les DES sont de plus en plus étudiés de par leur faible coût, leur faible toxicité et leurs propriétés qui devraient leur permettre de remplacer des solvants toxiques utilisés dans de nombreux domaines de la chimie. Lors de ma thèse, un premier travail a permis d’établir les diagrammes de phases solide-liquide de trois DES partiellement biosourcés. Par la suite, une comparaison entre ces DES et des mélanges idéaux a permis d’établir que ces systèmes peuvent être considérés comme solvants eutectiques « profonds ». Au cours de mes travaux, un premier solvant aqueux possédant une température de solution critique inférieure a été mis en évidence et l’origine de cette propriété remarquable a été élucidée. Au-delà des travaux sur la compréhension des DES, ces solvants ont été testés pour deux applications : le captage du dioxyde de carbone et l’extraction liquide-liquide de colorants
Deep Eutectics Solvents (DES) is a new class of solvent which has emerged during the last decades. DES have been increasingly studied because of their low cost and low toxicity. Because of these properties, DES could potentially replace toxic solvents used in large area of chemistry. To reach this goal, a broader knowledge of these new systems has to be acquired. Therefore, in the first work of this thesis, solid-liquid phase diagrams of three partially renewable DES have been established. The comparison of these diagrams to an ideal mixing model is showing a negative deviation that allows to considered them as “deep” eutectics solvents. Following this work on the binary mixture, water was added to these DES. A first aqueous - DES mixture with a lower critical solution temperature (LSCT) has been highlighted and the origin of this remarkable property has been elucidated. To complete the initial work aiming to get a deeper understanding of these new DES, these solvents have also been tested for two applications: carbon dioxide capture and liquid-liquid extractions of dyes

碩士
國立中央大學
化學工程與材料工程學系
103
In this research, we study the electrochemical properties of new Deep eutectic solvent (DES) from the view of their possible application as non-aqueous electrolytes in sodium-ion batteries. The new DES electrolytes are formulated by mixing ethylene glycol, sodium salts and additives (Choline acetate, ChOAc and 1-Ethyl-3-methylimidazolium tetrafluoroborate, [C2mim][BF4]) at room temperature. The potential window of different electrolytes is studied by linear sweep voltammetry (LSV) and cyclic voltammetry (CV) measurements. The new DES electrolytes containing ChOAc and [C2mim][BF4] are found to be electrochemically stable up to 4.1 V and 4.2 V (potential window). The ionic conductivity and viscosity of the new DES electrolytes are found exhibit ranging from 2.3 mS/cm to 11.3 mS/cm at 26 ℃and 16 cp to 77 cp at 25 ℃, respectively. Compared to conventional organic electrolyte (1 M NaClO4 in EC-DEC (1:1 v/v)), the new DES electrolytes show better thermal stability (~100 ℃) and non-flammability. In addition, different electrolytes used in Na-ion battery system (with Na0.44MnO2 and NaTi2(PO4)3 as a positive and negative electrode, respectively) are tested at room temperature. It was found that the new DES electrolytes show better capacity retention than traditional organic electrolyte (1 M NaClO4 in EC-DEC (1:1 v/v)) after 100 charge-discharge cycles. Based on its excellent electrochemical properties and cycling performances, the ethylene glycol based new DES can be considered as promising electrolytes for high-safety applications in sodium-ion battery.

博士
國立清華大學
化學工程學系
98
Carbon dioxide capture and sequestration is becoming an important means for reducing anthropogenic carbon dioxide emission and global warming. One of the most developed technologies for carbon dioxide capture from post-combustion flue gas is the absorption/stripping process utilizing aqueous alkanolamine solutions. However, this process is still energy intensive. This work explores the feasibility of reducing energy consumption using alternative solvents and process configurations. Firstly, we measured the solubilities of carbon dioxide in the deep eutectic solvent, Reline with different water contents. Water can act as an anti-solvent to strip carbon dioxide from Reline. However, a concentration swing process based on anti-solvent effect is non-competitive due to the low carbon dioxide capacity in Reline. The carbon dioxide loadings in the amino acid salt, [Choline][Pro], with different water contents were measured. High water content results in the formation of bicarbonate ion and increase carbon dioxide loadings. Water acts as a co-solvent rather than anti-solvent. A thermal energy free stripping process was proposed by using ion exchange resin. Chloride form resin was used to convert saturated [Choline][Pro] solution to choline chloride and L-proline, driving out dissolved carbon dioxide. Hydroxide form resin was used to regenerate [Choline][Pro] from the mixture of choline chloride and L-proline. Finally, a simplified method to evaluate the energy consumption of different carbon dioxide absorbents was developed. It was found that [Choline][Pro] in PEG200 solution is the energy-efficient alternative absorbent because of its high capacity and negligible solvent vaporization loss. However, high viscosity of the solution becomes the bottleneck of its application. Based on results of this study, two directions for developing new solvent systems and processes are proposed. One way is to dissolve innovative amino acid salts in non-viscous solvent of low volatility. Alternatively, the thermal energy free stripping process can be applied to aqueous solutions of amino acid salts.

碩士
中原大學
生物環境工程研究所
102
Efficient separation technologies are required for the removal of carbon dioxide from natural gas streams. Membrane-based natural gas separation has emerged as one of the fastest growing technologies, due to the compactness, higher energy efficiency and economic advantages which can be reaped. In this study, Polyimide membranes which are mostly used in the separation of gases are blended with a new kind of solvent: Deep Eutectic Solvents or simply DES. The three types of DES are used are choline chloride based mixed with three different hydrogen bond donors: Lactic acid, N-methylurea and Urea. The blending of the DESs to Polyimide gave out high permeability performance. The Gas Separation performance for all the membranes involving CO2/CH4 showed low performance while for CO2/N2 surpassed the performance of some studies. Among the three types of DES used the solvent Choline Chloride/Lactic acid exhibited the highest performance for both Gas Separation applications. The values are 10.5 for CO2/CH4 selectivity and 60.5 for CO2/N2. The separation results for CO2/CH4 may be due to the viscosity of the DESs. DES/blended Polyimide membranes fabricated are novel and have the potential of a low-cost and environmental friendly application for gas separation.

碩士
國立成功大學
化學系
104
Deep eutectic solvent choline chloride-urea (DES　ChCl/Urea) was used as the electrolyte to study the voltammetric behavior of Pb(II), Te(IV), and their mixtures. Te(IV) was introduced into the DES by the addition of TeCl4. Interertingly, when the PbSO4, PbO2, and PbO were dissolved in the ChCl/Urea, they exhibits the almost identical electrochemical behavior, indicating Pb(II) is formed in the DES regardless of what Pb compound is introduced. The experimental results indicated the the reduction of Pb(II) to Pb is an irreverisible process and controlled by diffusion at temperature varying from 333 to 363 K. The value of diffusion coefficient are about 10-8 cm2/s order, and the activation energy of PbSO4 and PbO2 for diffusion is determined to be 33.7 and 34.1 kJ/mol, respectively. The nucleation mechanism of Pb was determined to be three-dimensional instantaneous nucleation under diffusion control. The electrodeposition of Pb was achieved under constant potential or current at copper foil substrate. The electrodeposition of PbTe alloy was achieved under constant potential and in various molar ratio of [Pb(II)/Te(IV)] electrolytes at nickel foil. The morphology of PbTe alloy deposits significantly depends on applied potential and the molar ratio of [Pb(II)/Te(IV)] in electrolytes. The XRD and EDS analysis confirmed that the electrodeposits were consisted of high-pure Pb metal and the stoichiometric PbTe alloy.

博士
國立清華大學
化學工程學系
99
In this article, we demonstrate a new, facile and green antisolvent process to prepare nanostructure ZnO. The deep eutectic solvent (DES) is a new class green solvent that is negligible vapor pressure, high polar and biocompatible. UCC is one of DES that shows high solubility of many metal oxides that can be used as solvent in this approach. The antisolvent should be miscible with the DES UCC and non-solvent for the solute. By controlling the nucleation and growth, various morphologies of ZnO can be made by this method. At low ZnO concentration in UCC, ZnO twin-cone and rods can be prepared with morphology and size controls by injection rate and the ethanol content in antisolvent. The ethanol in the antisolvent can reduce the growth rate of ZnO and also lower the product dimensions. If the injection rate of ZnO-containing DES was reduced, the supply of Zn source became limited and the crystal growth became 1D dominated and grows on the preferred direction. It turns the product structure from twin-cones to nanorods. Mesocrystal ZnO is a mesoporous material fabricated from nanocrystals (NCs) with ordered orientation superstructure. Thus the material possesses high surface area and good crystallinity as single crystal. We use a biological buffer Tris as an oriented agent in antisolvent. ZnO NCs were made in antisolvent then Tris can increase the concentration of hydroxyl group in antisolvent. The hydroxyl group can attach on the oxygen vacancies on the polar O-terminated surface then increased the polarity of the ZnO NCs and then be attached together with the same orientation to form a mesocrystal ZnO. The increasing amount of Tris can make a larger size, better crystallinity and smaller surface area mesocrystal ZnO. The crystallinity is the more important factor rather than surface area. Thus a mesocrystal ZnO prepared in high Tris concentration shows better photocatalytic reactivity. At high ZnO dissolved concentration and low injection rate, the ZnO-ZCH nanosheet can be made by this antisolvent approach. After the annealing, single crystal mesoporous ZnO nanosheet can be parpared. The sheet is thin with a thickness of 10 nm and many pores with size of 5-60 nm can be found on the nanosheets. The ZnO nanosheet is single crystal and high surface area (~90 m2/g) with the exposed plane of (11-20). It can be used as photocatalyst for degradation of methylene blue (MB) in aqueous solution. The single crystal mesocrystal ZnO nanosheet shows performance as good as TiO2 P25.

Hierarchical systems that integrate nano- and macroscale structural elements can offer enhanced stability over traditional immobilization methods. Microparticles were synthesized using interfacial assembly of lipase with (CLMP-N) and without (CLMP) nanoparticles into a crosslinked polymeric core, to determine the impact of the highly ordered system on lipase stability in extreme environments. Kinetic analysis revealed the macrostructure significantly increases the turnover rate (kcat) following immobilization. The macrostructure also stabilized lipase at neutral and basic pH values, while the nanoparticles influenced stability under acidic pH conditions. A greener solvent, choline chloride and urea, was applied to produce sugar ester surfactants. Microparticles exhibited decreases in the turnover rate (kcat) and catalytic efficiency (kcat/Km) following exposure, but retained over 60% and 20% activity after exposure at 50 ºC and 60 ºC, respectively. CLMP and CLMP-N outperformed the commercially available lipase per unit protein in the production of sugar esters. The utilization of greener solvent systems with hierarchical immobilized enzyme systems has the potential to improve processing efficiency and sustainability for the production of value-added agricultural products.

碩士
中原大學
化學工程研究所
101
The equilibrium solubilities of CO2 in the deep eutectic solvent (DES) systems [Reline (1 mole choline chloride + 2 moles urea) + H2O] and [Reline + monoethanolamine (MEA) + H2O] were measured at temperatures (40 to 80)ºC and pressures (1 to 1000) kPa using a vapor recirculation equilibrium cell. The investigated DES systems include binary mixtures of (50, 60, and 70) wt% Reline + H2O, and ternary mixtures of (50, 60, and 70) wt% Reline + (15, 10, and 5) wt% MEA + H2O. The solubility of CO2 (in terms of CO2 loading) was correlated with CO2 partial pressure, temperature, and solute (DES/amine) concentration using a modified form of the KentEisenberg model. Results showed that the experimental data were satisfactorily represented by the applied model with acceptable absolute average deviations (AAD) of 11.5% and 14.7% for the binary and ternary systems, respectively. Hence, it can be concluded that the measurements and correlations presented in this work can be used in the design of processes, which would utilize aqueous Reline and/or aqueous Reline + MEA as CO2 absorbents.

碩士
國立臺灣科技大學
化學工程系
103
Electrodeposition of metals such as Zn, Co, and Ni has been shown possible in a wide range of ionic liquids. A deep eutectic solvent (DES) is new generation of ionic liquid, which can replace the traditional ionic liquid (IL) and act as both a solvent and an electrolyte. Commonly, DESs based on ChCl–urea and ChCl–ethylene glycol have been used for the deposition process. In this thesis, the study was about searching the ChCl based DESs to be used as suitable electrolyte towards the electrodeposition. The electrochemical characterization of metals to be electrodeposited was carried out using cyclic voltammetry at 70 oC. The results showed that the reaction of metal(II) to metal(0) was irreversible. The diffusion coefficients of metals were in the range of 1–2.5 x 10-7 cm2/s at 70 oC. Initially, 5 different DESs were tested as the electrolyte and the best electrolyte was chosen for the optimization process on the system. Electrodeposition of metals was studied at different cathodic potentials, metal salt concentrations, and working temperatures in order to optimized the plating process. The metal deposits were characterized using scanning electron microscope (SEM), energy disperse X-ray spectroscopy (EDX), and X-ray diffraction (XRD). The results of metal deposits showed that the process proceeds smoothly in DES from ChCl–glycerol at a lower temperature (40 oC). EDS and XRD analysis confirmed that high-purity metallic deposits were obtained.

碩士
中原大學
化學工程研究所
105
In this study, a mixture of 2-methylethanolamine (MMEA) solution with deep eutectic solvent (DES) of choline chloride (ChCl) and ethylene glycol (EG) was used as an absorbent to capture carbon dioxide from gas stream in a rotating paced bed. The effect of rotating speed, gas flow rate, concentration of alkanolamine and the ratio of DES and water in the absorbent on carbon dioxide removal efficiency (E%), mass transfer coefficient (KGa) was investigated. Additionally, the regeneration energy of absorbent was estimated by Aspen Plus and theoretical method. Experimental results showed that CO2 removal efficiency increased with increasing concentration of alkanolamine and rotating speed ranging between 600 and 1800 rpm, but decreased with increasing gas flow rate. Moreover, adding 30wt% DES in 60wt% MMEA solution could effectively enhance CO2 removal efficiency. Calculated results showed that specific regeneration energy of Aspen Plus and theoretical method is approximate. Specific regeneration energy decreased with increasing concentration of alkanolamine and DES. In this study, an optimum composition of absorbent of 60wt% MMEA/30wt% DES/10wt% H2O was obtained. The removal efficiency and KGa of the proposed absorbent were 93.36 % and 10.5 1/s at gas flow rate of 50 L/min, liquid flow rate of 0.1 L/min, temperature of 50°C and rotating speed of 2400 rpm. Compared with 30wt% MEA solution, the removal efficiency and KGa of the proposed absorbent were increased from 68% to 93.36% and 3.51 to 10.5 1/s while the regeneration energy can be reduced from 3.57 GJ/ton CO2 to 2.09 GJ/ton CO2. This result shows that MMEA solution mixed with DES has a great potential for CO2 capture process in a RPB.

碩士
國立清華大學
化學工程學系
95
Preparation of long, straight nanopore structures using the anodization process is relatively simple, low cost, and easy to mass-produce as compared to other processes. In addition, application properties of the nanopore structures such as size and uniformity can be easily adjusted by varying relevant operating parameters. The most popular and well-known application of the anodization process is the preparation of aluminum oxide membranes. For the past five years, researchers began to study the preparation of titanium dioxide nanotubes through Ti anodization. Titanium dioxide nanotubes have excellent photocatlytic and self-cleaning properties. They can be applied to water degradation processes because of their excellent electrocatalytic property. Such property allows them to be used in methanol oxidation process. Titanium dioxide nanotubes can also be used in a wide range of areas such as dye-sensitized solar cell and hydrogen sensing. Experimental results obtained from this research include the following. (1) Nanoporous structures with pore size of 20~30nm were successfully prepared with addition of a deep eutectic solvent (DES), and the growth rate of the titianium dioxide nanotubes can be as high as 9.79μm/min. Pore size of the nanostructure prepared can be increased from 50nm to 80~100nm by combining DES and glycerol as the solvent system. (2) Non-tubular nanostructures were successfully prepared through control of the composition of the electrolyte and reaction mechanism. Electrolyte composed mainly of succinic acid was used to prepare nanorod arrays with heights of 20~100nm. (3) Reaction mechanisms and applications of the titanium nanotubes prepared were studied. Comparison was made for titanium dioxide nanotubes of two different lengths, 50 and 100nm. (4) A modified nanotube growth mechanism was proposed to explain the high growth rate achieved in this work made possible by addition of the DES. (5) Field emission characteristics of the titania nanotubes of 20-30 nm with various heat treatment were studied. The turn-on field was 1.5V/μm (defined at current density of 1μA/cm2) when the vacuum gap was 300μm. The current density reached 1 mA/cm2 at the applied field of 2.2V/μm. (6) The relationship between the field enhancement factor (β) and vacuum gap was studied. The resulting absolute field enhancement factor, β0, was determined for the titanium dioxide nanotube arrays to be 11,111, which is larger than that of the carbon nanotubes grown on silicaon wafers.

碩士
國立臺灣科技大學
化學工程系
106
Efficient and durable water electrolysis is a key technology for sustainable clean energy production. In order to have an efficient electricity- gas conversion, materials that require low overpotential to make water splitting possible must be used. Materials for the cathodic reaction that provides good energetic efficiency have already been synthesized. However, the sluggish kinetics in the anode reaction is still a limiting to make water splitting economical viable. Iridium and ruthenium oxides are the benchmark materials for anodes in water splitting. Nevertheless, the high cost and scarcity of this materials increase the industrial cost of the process. The fabrication of economical materials with high activity is crucial to achieve the viability of water electrolysis. From earth abundant elements, materials composed by nickel and iron are the ones that present the best prospect as anodes for water splitting, and being possible to outperformed the benchmark Ir and Ru oxides catalyst. Deep eutectic solvents (DES) are a new family of ionic liquids. In the last decades, they have become attractive because they are considering a green solvent. DES possess a wide potential window, which make possible the electrodeposition of many metals without hydrogen evolution in the cathode. Various metals with decorative and specific purposes have already electrodeposited from them. In the present work, First, a suitable potential for electrodeposition of Ni and Fe alloys in ethaline DES solution was determined by cyclic voltammetry and confirmed with electrochemical impedance spectroscopy. Then, the electrodeposition of the Ni, Fe and Ni-Fe alloys was carried out at conditions that allows to obtain a well attached to the substrate and uniform films. The metal composition of the alloys electrodeposited is found to be directly proportional to the metal concentration in the ethaline solution.The as-deposited films then were characterized by SEM. Ni and Fe samples present nodular and grain-crystal morphology respectively. Ni films present a face cubic center crystallinity, iron film esasly oxidize into magnetite crystalline structure and Ni-Fe alloys presents a crystalline phase of Ni Fe. The films were tested as electrocatalyst for oxygen evolution reaction in alkaline media. It has been found that the alloy with Ni:Fe 3:1 metal ratio presents the lowest overpotential of the analyzed alloys, with a overpotential value of 316 mV at 10 mA∙cm-2 and a Tafel slope value of 62 mV∙dec-1 and durability on a 0.1 M NaOH electrolyte. XPS shows after OER a change valence state from Ni metal to Ni+2 due to oxidation of the surface, while Fe is present in Fe+3 before and after OER.

碩士
中原大學
化學工程研究所
99
This study presented experimental data on vapor pressures of carbon dioxide absorbents at temperatures from (303.15 to 343.15) K. The CO2 absorbents used were deep eutectic solvents (DESs) + water systems at concentrations (20, 40, 60 and 80 wt%); 30 wt% alkanolamine + water systems; and mixed alkanolamines + water systems at 30 wt% total amine concentration. The DESs considered were choline chloride + urea (Reline), choline chloride + malonic acid (Maline), choline chloride + glycerol (Glyceline) and choline chloride + ethylene glycol (Ethaline) while the alkanolamines were monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), methyldiethanolamine (MDEA), 2-amino-2-methyl-1-propanol (AMP) and piperazine (PZ). In addition, the viscosities of mixed-solvent desiccant systems (glycol + water + MgCl2) were measured in the same temperature range and at (4.0, 9.0 and 16.0 wt%) MgCl2 + 40 wt% glycol (diethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol) concentrations. Vapor pressures and viscosities were reported as functions of temperature and composition. The temperature and composition were correlated with the vapor pressure data using the Antoine equation and with the viscosity using a modified Vogel-Tamman-Fulcher equation. The applied correlations were found to yield satisfactory results.

This thesis describes in the form of a commentary on own original publications research on the problems of cannabinoids, ie. phytocannabinoids and some synthetic cannabinoids, their pharmacokinetics and effects. The work consists of four thematic areas: the pharmacokinetics of delta-9- tetrahydrocannabinol (THC) and cannabidiol (CBD) in rats, depending on the route of administration; THC concentration time profile in humans (after inhalation) and implications for transport safety; the pharmacokinetic profile of synthetic cannabinoids in rats; extraction and determination of phytocannabinoids in plant material. The first part of the thesis was to determine pharmacokinetic profiles of THC, CBD and combination thereof (1:1 weight ratio) in rats with respect to administration common in humans, i.e. inhalation, oral and subcutaneous administration. THC, its metabolites (11-hydroxy-tetrahydrocannabinol, 11-OH-THC; 11-nor-delta-9- carboxytetrahydrocannabinol, THCOOH) and CBD concentrations in serum and brains of animals were monitored at the 24 hours experimental interval during the study. Except for inhalation administration, co-administration of CBD inhibited THC metabolism (after both oral and subcutaneous), resulting in an increase in THC concentrations in both serum and brain of the rats relative to...

In questo lavoro di ricerca di Dottorato sono state sviluppate piattaforme sensoristiche, basate su elettrodi SPE modificati con nanomateriali, per permetterere una rapida, facile ed economica individuazione delle frodi legate alla produzione e al commercio dell'olio extravergine di oliva. Il risultato della ricerca è stata la creaziobne di due piattaforme in grado rispettivamente di catalogare oli extravergine di oliva a seconda della cultivar della pianta di origine e di quantificare il contenuto di antiossidanti polari in campioni incogniti di olii vegetali, permettendo di discriminare oli di oliva da oli di altri semi.
In this PhD research work, sensor platforms have been developed, based on SPE electrodes modified with nanomaterials, to allow rapid, easy and economic identification of frauds linked to the production and trade of extra virgin olive oil. The result of the research was the creation of two platforms able respectively to catalog extra virgin olive oils according to the cultivar of the plant of origin and to quantify the content of polar antioxidants in unknown samples of vegetable oils, allowing to discriminate olive oils from oils of other seeds.

Il commercio equo e solidale (CEeS) è una forma di commercio, nata per contrastare il commercio convenzionale, volta alla promozione e alla salvaguardia del benessere dei lavoratori e dell’ambiente. Il CEeS inizialmente nacque per la vendita di prodotti dell’artigianato dei Paesi in Via di Sviluppo (PVS) e successivamente aprì le porte anche alla commercializzazione dei prodotti agro-alimentari di questi Paesi. Tra i prodotti alimentari che sono maggiormente venduti dal CEeS troviamo principalmente gli alimenti e le bevande nervine (cioccolato, tè e caffè), caratterizzate tutte non solo dalla medesima zona pedoclimatica di coltivazione, ma anche da un profilo chimico-nutrizionale simile. Pertanto, nel presente studio è stata effettuata l’analisi dei composti bioattivi (ammine biogene, acidi grassi liberi essenziali e polifenoli), ossia molecole presenti generalmente in piccole concentrazioni negli alimenti che hanno effetti benefici per la salute del consumatore, in campioni di cioccolato fondente, tè verde e nero e caffè macinato e infuso a marchio Fairtrade e non. Questi composti sono stati presi in considerazione per valutare sia la qualità degli alimenti e delle bevande nervine, ma anche per valutare l’influenza delle tecniche di trasformazione e conservazione dell’alimento. Nello studio sono state prese in considerazione otto ammine biogene (serotonina, β-feniletilammina, cadaverina, putrescina, tiramina, istamina, spermina e spermidina) e sei acidi grassi (a. linolenico, a. miristico, a. linoleico, a. palmitico, a. oleico e a. stearico) analizzati mediante cromatografia liquida ad alte prestazioni (HPLC) con rivelatore UV-Vis e Fluorimetrico. Inoltre, è stato valutato il contenuto di polifenoli totali (TPC), il contenuto di flavonoidi totali (TFC) e l’attività antiradicalica (saggi ABTS e DPPH), mediante saggi spettrofotometrici in tutte le matrici alimentari considerate. Inoltre, sui campioni di cioccolato è stata valutata la possibilità di utilizzare, al posto dei solventi organici convenzionali (metanolo, acqua e soluzioni di metanolo/acqua) adoperati nell’estrazione dei polifenoli, solventi green di nuova generazione: i Deep Eutectic Solvent (DES). Questi solventi sono costituiti da una coppia di molecole donatori di legami idrogeno (Hydrogen Bond Donar; HBD) e accettori di legame idrogeno (Hydrogen Bond Acceptor; HBA). Nello studio sono state prese in considerazione differenti HBD (Betaina e Clorin Clorina) e HBA (Fruttosio e Trietilenglicole) a diversi rapporti molari e percentuali di idratazione (10, 20 e 30 %). Per valutare la resa di estrazione dei differenti solventi convenzionali e DES sono stati effettuati sugli estratti i saggi spettrofotometrici per la valutazione del contenuto totale di polifenoli e flavonoidi e l’attività antiradicalica (saggi ABTS e DPPH). Inoltre, per valutare l’effettiva sostenibilità delle metodiche green prese in esame, rispetto ai solventi organici convenzionali per l’estrazione dei polifenoli da campioni di cioccolato, è stata applicata la metodologia del Life Cycle Assessment. L’applicazione di strumenti chemiometrici come l’analisi delle componenti principali (Principal Component Analysis, PCA) e la Cluster Analysis (CA) sul profilo di ammine biogene, di acidi grassi liberei e sui risultati dei saggi spettrofotometrici (TPC, TFC, ABTS e DPPH) ha consentito di evidenziare raggruppamenti all’interno dei campioni esaminati secondo la tipologia di campione e secondo la presenza o meno del marchio Fairtrade. Pertanto, questo studio rappresenta un punto di partenza per valutare la qualità degli alimenti e delle bevande nervine mediante l’analisi dei composti bioattivi in esso presenti. Inoltre, lo studio ha consentito di sviluppare e ottimizzare nuove procedure di estrazione dei composti fenolici da alimenti e bevande nervine mediante metodiche green, che possono essere applicate in sostituzione dei solventi organici convenzionali che sono meno sostenibili a livello ambientale ed economico.
Fair trade (FT) is a form of trade, created to counter conventional trade, aimed at promoting and safeguarding the welfare of workers and the environment. FT initially originated for the sale of handicraft products from Developing Countries (DCs) and later opened its doors to the marketing of agri-food products from these Countries as well. Among the food products that are mostly sold by FT are mainly psychoactive foods and beverages (chocolate, tea and coffee), all of which are characterized not only by the same soil and climate zone of cultivation, but also by a similar chemical-nutritional profile. Therefore, in the present study, the analysis of bioactive compounds (biogenic amines, essential free fatty acids, and polyphenols), i.e., molecules generally present in small concentrations in foods that have beneficial effects on consumer health, in Fairtrade and non-Fairtrade samples of dark chocolate, green and black tea, and ground and infused coffee was conducted. These compounds were considered to assess both the quality of psychoactive food and beverages, but also to evaluate the influence of food processing and conservation techniques. Eight biogenic amines (serotonin, β-phenylethylamine, cadaverine, putrescine, tyramine, histamine, spermine, and spermidine) and six fatty acids (a. linolenic, a. myristic, a. linoleic, a. palmitic, a. oleic, and a. stearic) analyzed by high-performance liquid chromatography (HPLC) with UV-Vis and Fluorimetric detector were considered in the study. In addition, total polyphenol content (TPC), total flavonoid content (TFC) and antiradical activity (ABTS and DPPH assays) were evaluated by spectrophotometric assays in all food matrices considered. In addition, the possibility of using, instead of conventional organic solvents (methanol, water, and methanol/water solutions) used in polyphenol extraction, new generation green solvents: the Deep Eutectic Solvents (DES) was evaluated on the chocolate samples. These solvents consist of a pair of hydrogen bond donor (Hydrogen Bond Donar; HBD) and hydrogen bond acceptor (Hydrogen Bond Acceptor; HBA) molecules. Different HBDs (Betaine and Chlorin Chlorine) and HBAs (Fructose and Triethylene Glycol) at different molar ratios and hydration rates (10, 20 and 30 percent) were considered in the study. Spectrophotometric assays for evaluation of total polyphenol and flavonoid content and antiradical activity (ABTS and DPPH assays) were performed on the extracts to evaluate the extraction yield of different conventional solvents and DES. In addition, the Life Cycle Assessment methodology was applied to assess the real sustainability of the green methods examined, compared to conventional organic solvents for the extraction of polyphenols from chocolate samples. The application of chemometric tools such as Principal component analysis (PCA) and Cluster Analysis (CA) on the profile of biogenic amines, free fatty acids, and the results of spectrophotometric assays (TPC, TFC, ABTS and DPPH) allowed us to highlight groupings within the examined samples according to the type of sample and to the presence or absence of the Fairtrade label. Therefore, this study provides a starting point for assessing the quality of nerve foods and beverages by analysing the bioactive compounds in it. In addition, the study made it possible to develop and optimize new procedures for the extraction of phenolic compounds from psycoactive foods and beverages using green methods, which can be applied to replace conventional organic solvents that are less environmentally and economically sustainable.